[The mutagenic activity of coal tar].

Genotoxicity of tar samples collected at the Kemerovo and Altai by-product coke plants has been studied, the contribution of benz(a)pyrene (BP) into the total mutagenic activity of extracts being estimated. Both direct and indirect mutagenicity of the samples is determined in the Ames test. A direct mutagenic effect of coal tar may be attributed neither to the BP action nor to other polycyclic aromatic hydrocarbons.

[Study of sea water pollution by determining the mutagenic activity of sediments].

Extracts from bottom sediments sampled in the Bering Sea and in certain regions of the Pacific Ocean were studied. Benzene and acetone-hexane extracts were tested for mutagenicity by Ames' bacterial test-system using the TA 98 and TA 100 Salmonella typhimurium strains. Extract from 4 stations of the 10 studied ones produced significant increase in the number of revertants.

[Effect of the transfer of F1 plasmids of various lengths on Shigella sonnei virulence].

The influence of F' plasmids of different length, carrying the genetically characterized Escherichia coli K-12 chromosomal regions, on the virulence of S. sonnei has been studied. The study has revealed that in S.

[Dynamics of enterobacterial multiplication in a mouse model of intraperitoneal infection in the presence of iron cations as dependent on the availability and type of K antigens].

In this work the results of research on the influence of iron cations on the characteristics of the infectious process caused by different enterobacteria (Shigella sonnei, Shigella flexneri, Escherichia coli) are analyzed. In the experimental intraperitoneal infection of mice in the presence of saccharose and iron cations S. sonnei in phase I showed the decrease of 1g LD50 by 3-4 orders, while S.