[Genomic imprinting: a case of inherited hematocrit, radiosensitivity, and antioxidant status in human being, as well as weight of newborn mammals].

Epigenetic hypothesis of dynamic genomic parental imprinting, explaining the mechanisms of formation and inheritance of quantitative characters in multicellular organisms, is proposed. Method for analyzing the compliance of quantitative characters of organisms with the hypothesis of dynamic genomic parental imprinting is developed. Examples of human characters and characters of other mammals inherited in accordance with the proposed model are given. It is concluded that the hypothesis can be used for studying ontogeny and explaining the mechanisms of inheritance of the morphoses providing the stability and evolution of species. Possible ways of further experimental verification of the hypothesis and areas of its practical application are discussed.

Genetic markers in coronary artery disease in a Russian population.

The association of genetic markers at the apolipoprotein B gene (APOB) (XbaI, MspI, and EcoRI polymorphisms) and the lipoprotein lipase gene (LPL) (PvuII polymorphism) with coronary artery disease (CAD) and with variation in plasma lipid levels (total cholesterol, high-density lipoprotein cholesterol, and total triglycerides) was studied in 94 male patients with CAD diagnosed by angiography and in 122 unrelated men of Russian descent free of clinical signs of CAD. The frequent allele (M+) of the APOB MspI RFLP was seen more frequently in CAD patients than in control subjects (0.963 vs. 0.898, p < 0.025). No significant differences in allele frequencies were observed for the APOB XbaI and EcoRI polymorphisms or for the LPL PvuII polymorphism. In patients, carriers of the rare allele (E-) of the EcoRI RFLP had higher mean triglyceride levels than homozygotes for E+ (p < 0.05). No significant differences in lipid variables were determined for the other three polymorphisms studied. Analysis of intragenotype variances and the multivariate measure of mean values of lipid concentrations showed that genetic variability within the APOB locus may contribute to a certain extent to the level and variability of serum lipid levels in this Russian population.

[Polymorphism of noncoding regions of the mitochondrial genome in the indigenous population of Southeastern Tuva Republic]. / Polimorfizm nekodiruiushchikh oblastei mitokhondrial'nogo genoma u korennogo naseleniia iugo-vostoka Tuvy.

Deletion-insertion polymorphism of the V region and restriction polymorphism of D-loop for seven restriction enzymes--AspS9I (Cfr3I isoschizomere), BamHI, Bme18I (AvaII), EcoRV, HaeIII, KpnI, and Kzo9I (Sau3AI)--in mitochondrial DNA (mt DNA) were studied in the indigenous population of southeastern Tuva Republic. The results were compared with the data on Russians, Mongols, Buryats, and Altaians. Tuvinians significantly differed from Mongols in the frequency of the 9-bp deletion of the V region (1.89 and 8.07%, respectively). Additionally, significant differences between Tuvinians and samples of Mongols and Russians were obtained for frequencies of the AspS9I, HaeIII, and KpnI restriction sites. A comparison of the polymorphism of mitochondrial genome in individuals of different sexes and ages was performed in the studied sample.

[Fluorometric analysis of the formation and repair of DNA breaks in irradiated cells]. / Fluorimetricheskii analiz poiavleniia i reparatsii razryvov v DNK obluchennykh kletok.

A study was made of the dependence of the fluorescence of ethidium bromide upon NaOH concentration after staining of single- and double-strand DNA fragments. The possibility of the fluorometric estimation of the share of double-stranded DNA in cell lysates was demonstrated. The method of fluorometry was used to study the dose dependence of a change in the share of double-stranded DNA in the irradiated thymocytes and Ehrlich ascites carcinoma cells which permitted to determine the appearance and repair of DNA breaks in these cells.

[Factors which determine the oxygen status of ascites tumors]. / Faktory, opredeliaiushchie kislorodnyi status astsitnykh opukholei.

A study was made of the oxygen status of cells of an Ehrlich ascites tumor at different stages of its development. Radiosensitivity of the tumor cells was determined with a reference to the yield of micronuclei. It was shown that the major role in the ascites tumor oxygenation is played by its volume rather than cellularity.

[Toxic and radiosensitizing effect of reduced nitroimidazoles on E. coli B/r cells]. / Toksicheskoe i radiosensibiliziruiushchee deistvie vosstanovlennykh nitroimidazolov na kletki E. coli B/r.

The spectrophotometric method was used to study the rate of chemical reduction of misonidazole and metronidazole by NH4Cl and Zn in the atmosphere of argon and oxygen. Reduction of drugs increased their toxicity for hypoxic and oxygenated E. coli B/r. The reduced metronidazole is a more effective radiosensitizer of hypoxic E. coli B/r than the original compound.