[Hygienic evaluation of hydrolytic lignin waste, by using alternative test models].

Chemical analysis showed that lignin samples contained phenols, phenanthrene, and methanol. The highest total content of organic compounds was noted in the lignin samples taken directly at a manufacturing plant. Phenols prevailed in the upper layers of stored lignin samples and methanol predominated in the lower ones. Studies on Tetrahymena pyriformis infusoria indicated that the fresh lignin samples are most toxic. A number of the samples exerted pronounced cytotoxic and genotoxic effects when the mollusks Limneae stagnalis and murine embryonic fibroblasts were examined.

[Estimation of potential mutagenic activity of 24-epibrassinolide]. / Otsenka potentsial'noi mutagennoi aktivnosti 24-épibrassinolida.

Genotoxic effect of synthetic phytohormone analogue of steroid origin epibrassinolide was studied in in vitro- and in vivo-tests. Epibrassinolide did not display mutagenic properties in Ames' test (S. typhimurium, TA100) and DNA damaging activity test (DNA of phage lambda). The rise in the level of polichromatophilous erythrocytes with micronuclei was observed in the micronuclear test at intraperitoneal epibrassinolide injection at the dose of 500 mg/kg that seems to be associated with disturbance of cell membrane permeability.

The level of aberrant cells in various tissues of bank vole depending on doses and radionuclide balance in organism.

A regression analysis shows the direct linear relation between 137Cs accumulation in rodents and the level of aberrant cells. For 90Sr this trend was negative. The dose relationship was the same with 137Cs. The trends were negative 1 month later after feeding of animals with clean food. Correspondingly the dose relationship was also negative. The levels of cells with apoptosis features were different in animals from the control and the radiocontaminated sites. The analysis has revealed the correlation between the 90Sr content in animal body and the number of alveolar macrophages containing micronuclei. The relationship was revealed between the 137Cs content in the animal body and the number of intestinal epithelial cells with micronuclei.

[Chromosome aberrations in different tissues of the murine rodents and amphibians from radionuclide-contaminated regions of Belarus]. / Khromosomnye aberratsii v razlichnykh tkaniakh myshevidnykh gryzunov i amfibii iz zagriaznennykh radionuklidami raionov Belarusi.

Cytogenetic investigations of amphibian and rodent populations from the contaminated by radionuclides regions of Belarus was conducted. A significant increase in the levels of cytogenetic anomalies in bone marrow cells and intestinal epithelium of amphibians and rodents, the levels of alveolar macrophages of rodents, and micronuclei in peripheral blood erythrocytes of amphibians was revealed. Presence of chromosome type aberrations indicates that radiation as a mutagenic factor was involved. No strict relationship between the levels of contamination of the area and levels of cytogenetic anomalies was found.

[The genetic monitoring of populations of brown frogs inhabiting radionuclide-contaminated regions of the Republic of Byelarus]. / Geneticheskii monitoring populiatsii burykh liagushek, obitaiushchikh v zagriaznennykh radionuklidami raionakh Respubliki Belarus'.

Genetic monitoring of brown frog populations inhabiting radiocontaminated areas of Belarus (contamination range: 177-2331 kBq/m2 for 137Cs; 3.7-284 kBq/m2 for 90Sr) has shown that the frequency of aberrant metaphases in bone marrow cells of animals from the contaminated areas is 3 to 10 times as much as that of the control, aberration load of cells being also higher. The aberration spectrum differs from a spontaneous one. There is no strict dependence of the yield of cytogenetic damages on the contamination.

[Polymorphism for supernumerary chromosomes in populations of Rana temporaria L]. / Polimorfizm po dobavochnym khromosomam v populiatsiiakh Rana temporaria L.

Occurrence of B-chromosomes in four populations of Rana temporaria L. in Minsk, its suburb and Berezinskii biosphere reserve has been studied. The percentage of individuals with B-chromosomes and the average number of B-chromosomes per genome are shown to multiply increase in the population inhabiting for 40 years in the region polluted with waste products. The results obtained are discussed from the standpoint of the action of mechanism for the accumulation of additional chromosomes due to environmental pollution.