Genotoxicity of single-walled carbon nanotubes: in vitro study on human embryonic fibroblast cells.

The effects of single-walled carbon nanotubes on the levels of DNA aberrations, chromosome and genome disorders were studied on human embryonic fibroblasts, their karyotype was analyzed by the spectral karyotyping method. The level of DNA aberrations increased after 3-h exposure to the nanotubes. No appreciable increase in the incidence of aberrant metaphases, micronuclei, and chromosome 1, 6, 8, 11, X, and Y aneuploidy after 24- and 48-h incubation with the nanotubes were detected.

Chromosome variability of human multipotent mesenchymal stromal cells.

We elaborated a method of preparing cytogenetic preparations of cultured multipotent mesenchymal stromal cells from the adipose tissue. It was found that karyotypic changes (monosomy, translocations) appear in some samples during culturing. Clones with changed karyotype were detected in 11-14-passage cultures from 2 of 7 individuals. The percent of aberrant cells in cultures from different individuals varied from 1.5 to 5.95 per 100 cells, which attested to karyotype instability. These data substantiate the need for cytogenetic control of cells before their transplantation into donor organism and further investigation of chromosome variability in stem cells.

Phytoadaptogen correction of clinical and immunobiological parameters in patients with benign prostatic hyperplasia.

Correction of hormonal, immune, interferon, and antioxidant status and genetic abnormalities with a complex phytoadaptogen leads to positive clinical effects in elderly patients with benign prostatic hyperplasia.

Effects of vitamin supply on spontaneous and chemically induced mutagenesis in human cells.

Chromosome aberrations in donor peripheral blood lymphocyte culture were evaluated before, 14 and 30 days after treatment with a vitamin/mineral complex. Treatment with the complex had no effect on spontaneous level of aberrant cells. The number of chromosome aberrations induced by dioxidine or cadmium chloride in vitro at the G2 stage decreased on days 14 and 30 of treatment with the complex.

[Periodic variations of spontaneous chromosome aberration rate in human blood lymphocytes ]. / Vremennye kolebaniia spontannogo urovnia khromosomnykh aberratsii v kul'ture limfotsitov perifericheskoi krovi cheloveka.

Spontaneous chromosome aberration rate in human blood lymphocytes was studied using the data collected during 30 years. Seasonal variation was found. An absolute maximum of chromosome aberration rate was observed in winter and a local maximum, in summer. In spring and autumn, this value decreased. There was a statistically significant trend towards higher frequencies of aberrant metaphases during the period studied. A periodic pattern of changes in the chromosome aberration frequency was found. The data fitted a sinusoid with a period of 4.5 years.

[The database for analysis of quantitative characteristics of chromosome aberration frequencies in the culture of human peripheral blood lymphocytes]. / Baza dannykh dlia analiza kolichestvennykh kharakteristik chastoty khromosomnykh aberratsii v kul'ture limfotsitov perifericheskoi krovi cheloveka.

The data on spontaneous chromosome aberration rates in cultures of human peripheral blood lymphocytes obtained in the past 30 years have been collected to form a database. The database contains the results of analysis of more than 330,000 metaphases in lymphocytes from more than 1200 subjects. The frequency of aberrant metaphases in the control group has been estimated at 0.0213 +/- 0.00085. No differences between sexes have been found with respect to either the total chromosome aberration rate or the rates of individual aberration types. The total chromosome aberration rate did not depend on age; however, it has been found that the number of fragments increased and the number of exchanges decreased with age. Smoking has been found to increase the frequency of chromosome aberrations in individuals with occupational hazards, but not in those who are not occupationally exposed to radiation or chemicals. Alcohol consumption increased the frequency of paired fragments, whereas the frequencies of other aberrations did not differ from the control values.

[Dioxins and medical-genetic indices of health of residents of the town of Chapayevsk]. / Dioksiny i mediko-geneticheskie pokazateli zdorov'ia naseleniia goroda Chapaevska.

The paper presents the results of an integrated medical genetic survey carried out in the town of Chapayevsk. The survey included an estimation of the incidence of congenital malformations (CMF), congenital morphogenetic options (CMGO), evaluation of the frequency of chromosomal mutations of various types and micronuclei in human somatic cells. The incidence of CMF among newborn infants corresponds to that in Russia, but such forms of CMF as congenital hydrocephalus and agenesia and disgenesis of the kidney were more common in the town. The study ascertained that the average number of CMGO per child was on the increase. Cytogenetic findings unambiguously demonstrate that there was a spatial gradient within the town (from the plant to remote districts), higher rates of chromosomal aberrations. Further studies of the effects of dioxins on genetic health are required to assess the actual genetic risk due to its human contact.

[Unusually high level of chromosome variability in cultured human peripheral blood lymphocytes]. / Neobychaino vysokii uroven' khromosomnoi izmenchivosti v kul'ture limfotsitov perifericheskoi krovi cheloveka.

A cytogenetic examination carried out in the inhabitants of Seversk (Tomsk oblast) and workers of the Siberian chemical industrial complex (a complex of nuclear-chemical and fuel plants), living in the same town, revealed unusually high level of spontaneous chromosomal variability both in control and industrial groups (total irradiation doses 1.8 to 3.7 and 9.3 to 15.7 Gy, respectively). The frequencies of cells with chromosomal aberrations (estimated per 100 cells) in control and industrial groups were 4.69, 6.04, and 6.64, respectively, and the total number of aberrations constituted 6.93, 8.47 and 12.06, respectively. These frequencies were several times higher compared to the summarized literature data on the control levels. The high average aberration level was caused by the elevated proportion of chromatid-type aberrations and paired fragments. The reasons for this are unclear. The levels of radioactive background and chemical air pollution in the town were not increased.

[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 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.

[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.

[Comparison of the cytogenetic effects of cyclophosphamide on monkey lymphocytes in vivo and in vitro]. / Sravnenie tsitogeneticheskikh éffektov pri deistvii tsiklofosfamida na limfotsity obez'ian in vivo i in vitro.

The comparative in vivo and in vitro study of chromosomal aberrations and SCE induced by cyclophosphamide (CP) in macaca rhesus lymphocytes was performed. The dose of mutagenic exposure for quantitative estimation of effects was determined as a product of concentration of alkylating CP metabolites on the exposure time. The mutagenic effect caused by the same doses of CP (CP metabolites) appeared similar in vivo and in vitro. This suggests that the results obtained in adequate in vitro mutagen-testing experiments may be quantitatively extrapolated for the in vivo conditions.

Alterations in the baseline sister-chromatid exchange frequency in human lymphocyte culture following a number of cell divisions.

A significant decrease in the baseline of sister-chromatid exchanges (SCEs) was observed in cultured human lymphocytes, if 5-bromodeoxyuridine (BrdU) was added after 60 h of culture, and the cells were harvested at least 24-30 h after BrdU exposure. This decrease is supposed to occur if at least one cell division takes place before the addition of BrdU. For cytogenetic monitoring of mutagenic environmental factors, using human lymphocyte cultures, it is assumed that two time periods are sufficient for comparison.

[Decrease in the spontaneous frequency level of sister chromatid exchanges in cell division in culture]. / Snizhenie spontannogo urovnia chastot sestrinskikh khromatidnykh obmenov pri delenii kletok v kul'ture.

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.

[Dynamics of the frequencies of chemically induced sister chromatid exchanges in a series of cell generations]. / Dinamika chastot khimicheski indutsiorvannykh sestrinskikh khromatidnykh obmenov v riadu kletochnykh pokolenii.

The number of sister chromatid exchanges (SCE) in a culture of human lymphocytes and the established cultures of Chinese hamster cells has been studied after the exposure to thiophosphamide and dipin at different stages of the cell cycle. The most pronounced effect is observed under the action of the mutagens at the G1 of the first cycle, prior to harvest. The SCE level becomes lower with the increase of the interval between the exposure to the mutagen and the time of 5-BUdR introduction. The number of SCEs per cell drops to the control level when the duration of the first interval is equal to that of the cell cycle. The results obtained prove the mutagen-induced impairments causing SCE formation to be repaired practically 100%, provided that at least one cycle of DNA replication took place.