The Baseline Level of Cytogenetic Damage in Lymphocytes and Buccal Epitheliocytes of Lung Cancer Patients

Russian Journal of Genetics - The results of the study of chromosomal aberrations and micronuclei in blood lymphocytes, as well as micronuclei in buccal epithelium cells of 50 untreated men with...     

Quantitative characteristics of the frequency of chromosomal aberrations in a group of residents of a large western Siberian industrial region

The results of a 15-year study of chromosome aberration frequency in cultured peripheral blood lymphocytes from subjects living in the Kuzbass industrial region are presented. The database for the analysis of the main parameters of chromosome aberrations contains data on 925 subjects, with the total number of cells examined being 92,900. It has been found that the total frequency of aberrant metaphases in the database is 3.73 +/- 0.1%, whereas this frequency for the sample of subjects from industrial areas of this region (the basic control group) is significantly lower (2.86 +/- 0.26%). It has been demonstrated that the sex and age of the subjects do not affect substantially the frequency of any type of chromosome aberrations. Tobacco smoking is associated with a slight increase in chromosome damage frequency; however, the difference between smokers and nonsmokers is insignificant even among subjects exposed to occupational hazards. The possible causes that have determined the increased basic and background chromosome aberration frequencies in the population of the Kemerovo oblast compared to these parameters for the European part of Russia and the CIS are discussed.     

The criterion of cell division synchronization for assessing the stressor exposure of a Salmonella typhi population

Criterion of the synchronization (CS) of cells division for S. typhi population is proposed. The criterion is based on the assumption of the normal distribution of cells with different generation time in the population after stressor (shock) action. CS is equal to the ratio of the dispersion of the generation time of cells in the population to the average generation time of the whole population and determined from the parameters of the mathematical model. The quantitative values of the parameters of the mathematical model were obtained by the minimization of error between the calculation and experimental data. CS was used for the evaluation and choice of the optimum stressor action in the synchronization of the division of S. typhi.     

Genomic dosages of active rRNA genes in coke-oven workers

Genomic dosage (copy number) of active ribosomal genes was evaluated using visual semi-quantitative method determining the sizes of Ag-NORs in acrocentric chromosomes after selective silver nitrate staining. A relationship between the length of service and the active ribosomal gene copy number was established: the highest numbers of active rRNA genes were observed in coke-oven workers with a length of service exceeding 20 years. An inverse relationship between the individual doses of active ribosomal genes and toxicogenetic susceptibility of the workers to the occupational factors was also revealed.     

Long-Term Monitoring of Cytogenetic Aberrations in Adolescents of a Large Industrial Town

Long-term cytogenetic monitoring was carried out in adolescents of the town of Kemerovo. In total, aberrant metaphase frequency increased from 1.53% in 1992 to 4.40% in 1996 in Kemerovo adolescents, being significantly higher than a control frequency from 1993 to 1996. In all samples, chromosome aberrations mostly included acentric fragments, while exchanges were rare. The highest number of aberrations per aberrant metaphase was 2 in Kemerovo adolescents and 1 in the control sample. The observed increase in total number of chromosome aberrations suggests that the mutagenic effect of chemical environmental pollutants on Kemerovo adolescents increased over the five years.     

Resource density regulates the foraging investment in higher termite species

1. Resource density can regulate the area that animals use. At low resource density, there is a conflict in terms of balance between costs of foraging and benefits acquired. The foraging of the higher termite Nasutitermes aff. coxipoensis consists of searching throughout trails and a building galleries phase. 2. In this study, a manipulative field experiment was used to test the hypothesis that colonies of N. aff. coxipoensis forage towards a more profitable balance between the establishment of trails and gallery construction at low resource density. 3. The experiment was conducted in north‐eastern Brazil. Seven experimental plots were established with a continuous increase in resource density (sugarcane baits). Entire colonies of N. aff. coxipoensis were transplanted from their original sites to the experimental plot, totalling 35 nests. The number, branches and total length of trails and galleries were quantified. 4. The results show that N. aff. coxipoensis optimises its foraging output, intensifying the establishment of trails at the cost of gallery construction when resource density is low. The number of trails, the number of trail branches and the total length of trails decreased with increasing resource density. Interestingly, at low resource density, the search effort was concentrated on forming longer and a greater number of trails, a small proportion of which were converted into galleries. The opposite relationship was observed at high resource density. 5. These results suggest an optimisation of search efforts during foraging depending on resource density, a mechanism that may help researchers to understand the use of space by higher termite species.     

Polymorphisms in glutathione S-transferase M1 and T1 (GSTM1 and GSTT1) in the indigenous and the nonresident population of the Kemerovo region

GSTM1 and GSTT1 gene polymorphisms were studied in Shorians, Teleuts, and Caucasians of the Kemerovo region. It has been shown that distribution of homozygous deletions in the examined groups is significantly heterogeneous. The frequency of deletion genotypes and combinations of deletion in these genes was lower in Shorians and, Teleuts than in Caucasians.