[Some Aspects of Medical Activities to Overcome Consequences of Chernobyl Accident].

The results of the long term work of the Russian Scientific Centre of Roentgenology and Radiology on me- dical investigation of the participants in the liquidation of the consequences of Chernobyl power plant acci- dent have been summarized. It has been stated that circulatory system and tumor diseases occupy the leading position in the disease rate among the affected liquidators. The important role of cytogenetic investigation was pointed out. It allows us not only to determine the efficient impact on the human body but also to evaluate the effective dose of radiation, the information about which allows us to predict the development of distant post-irradiation pathology. The results of cytogenetic investigations testify to the interrelation between the level of chromosomal abnormalities and cardiovascular diseases and confirm the clinical data on the non- neoplastic.pathology among the liquidators of the accident.

[Genotype dependence of cytogenetic and epidemiological characteristics in the liquidators of the accident at the ChNPP].

The dependence of the level of unstable chromosome aberrations and nononcological diseases on the genotype in 57 liquidators of the ChNPP accident was studied. Candidate genes presumably affecting radiosensitivity were highly polymorphic loci of xenobiotic detoxication genes (glutathione-S-transferases GSTM1, GSTT1, GSTP1) and the 5,10-methylenetetrahydrofolate reductase gene (MTHFR) involved in DNA methylation and synthesis. An increased frequency (0.014 +/- 0.001 per cell) of unstable chromosome aberrations, including radiation-specific dicentrics and centric rings (0.0015 +/- 0.0002 per cell), has been found to be preserved in the group of liquidators examined in 2006-2007. No associations of polymorphism for each of the studied genes with cytogenetic parameters were revealed. Increased frequencies of chromosome aberrations were recorded in homozygous carriers of a deletion at the GSTM1 locus in combination with homozygosity for minor alleles at the MTHFR and GSTP1 loci (p = 0.00002 and p = 0.0233, respectively). The number of homozygous carriers of the minor allele GSTP1 was increased among patients with chronic obstructive pulmonary disease and in liquidators with acute circulation disturbances (p = 0.014 and p = 0.04, respectively). Double homozygotes for GSTM1 and GSTT1 deletions were significantly more frequent among subjects with benign tumors (cysts, polyps, p = 0.015) and with benign thyroid tumors (p = 0.017). This genotype has proved to be protective for patients with severe cardiovascular diseases (acute circulation disturbances, p = 0.027).

Evolution of bioinorganic motifs in P450-containing systems.

The choice of bioinorganic motifs by Nature results in a spectacular variety of active-site structures even within the same protein family. Here, we use the concept of the bioinorganic motif to discuss the function and evolution of P450-containing and other related systems. Apart from P450, these systems include a FAD flavoprotein or domain, a FMN domain, ferredoxins and cytochrome b(5). Analysis of available complete genomes can shed light on what an ancestral P450-containing system could be.