Biomedical subjects
Publications and source records attributed to N V Titenko.
The Gc, Hp, and Tf polymorphisms were studied in the population of South Yemen. The gene frequencies were in agreement with those of other populations in the Middle East. There was an indication of local variations due to ethnic heterogeneity, e.g. a relatively high frequency of TfD in 1 of the 5 subpopulations studied.
Transferrin (TF) subtypes were studied in 7 different populations from the Soviet Union (Buryats, Russians, Koreans, Kirghizes and Pamirians) and in 3 different populations from Mongolia. The frequency of the C2 gene varied between 10.4% in Pamirians and 27.4% in Koreans and was generally higher in populations of Mongoloid origin. The frequency of the C3 gene was found to be very low (nonpolymorphic) in the Mongoloid groups, but it was also low (1.5%) in Russians. Rare B and D variants were found in 7 populations. The highest D frequencies were found in the Mongoloid populations.
Polymerase chain reaction polymorphisms have been used to study European, Chinese, Russian and Buryat populations at the HLA-DQ alpha and IL6 loci. DNA from individuals in these populations was specifically amplified at these loci, and analyzed either with allele-specific oligonucleotides for HLA-DQ alpha or directly on agarose gels for IL6. Allelic frequencies were calculated for each of the loci in each population. Comparisons between the population frequencies show that the Russian population is more closely related to Europeans, and that the Buryat population is more closely related to Chinese. This finding is in agreement with conclusions based on the phenotypic frequencies of classical blood-group and other protein markers in these populations.
The article contains data on a cytogenetic monitoring of workers engaged in asbestos production, depending on duration of professional service and degrees of dust contamination of the air. The results of the cytogenetic analysis of the peripheral blood lymphocytes in 31 workers revealed the average rate of aberrant cells 1.78% in workers with professional service below 1.5 years, 2.43%--with more than 10 years of service, 2.72%--in the control group (the personnel not engaged in the production). The differences were statistically negligible.
Polymorphism of blood groups ABO, MN, Rh and serum proteins Hp, Tf, Gc, C3 was studied in Buryat populations of Zabaikalie, Pribaikalie, Olkhon island. No indication of significant heterogeneity was observed. Gene frequencies varied in different systems within the ranges: ABO (p-0.142-0.183; q-0.205-0.324; r-0.567-0.630); MN (m-0.531-0.624), Rh(d) (0-0.214), Hp (Hp 1-0.268-0.339), C3 (C3F-0.023-0.090), Tf (TfC-0.971-1.0), Gc (Gc1-0.728-0.840). Genetic distances between main Buryat groups were estimated.
The distribution of transferrin (Tf) suballeles have been studied in Russians and Buriats, in connection with sex-age characters. No directional change in Tf suballele frequencies was obtained for age cohorts of Buriats. The tendency for decrease in the Tf allele frequency was noted in oldest age groups of Russians. The differences between Russians and Buriats were conditioned by differences between female subgroups, with respect to transferrins solely. The frequencies of relatively rare Tf alleles (C3, B, D) were higher in female subgroups, as compared with males.
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Serum samples from seventeen Caucasoids and Mongoloid populations of the USSR were tested for transferrin (Tf) subtypes. According to Tf patterns, the Caucasoids groups had high TfC1 frequency, whereas Mongoloids are characterized by increased frequency of TfC2 suballele. The following gene frequencies were observed: TfC1 - 0.8515, TfC2 - 0.1166, TfC3 - 0.0129, TfD - 0.0129, TfB - 0.0065 for Russians of Yegoryevsk town; TfC1 - 0.8663, TfC2 - 0.0930, TfC3 - 0.0233 for West-Pamirian populations of Khuf, those being for Pastkhuf 0.8476, 0.1159 and 0.0244, respectively. Mongoloid populations demonstrate following frequencies of five genes described (in the order shown above): 0.7870, 0.1620, 0.0232, 0.0139 for Kirghizes of East Pamir; 0.7963, 0.1805, 0.0050, 0.0182 for Buriats of Suduntui; 0.7647, 0.1985, 0.0074, 0.0221, 0.0037 and 0.0037 (gene TfDX) for Buriats of Sakhiurta, the frequencies of these genes being 0.7647, 0.1985, 0.0074, 0.021, 0.0037 and 0.0037 for Aginsky national district, Chita Region. The total sample of Buriats of Gakhan cluster (Ust-Ordyn national district) and Olkhon island of Irkutsk Region demonstrates following frequencies of genes (in the same order): 0.7876, 0.1962, 0.0012, 0.0057, 0.0082 and 0.7679 and 0.2321, respectively. In addition, a rare anodal variant designated tentatively TfC12Like was found among Pamir populations. The results obtained are compared with those reported for world populations.
In the framework of the ecogenetic research programme, the data are presented on the genetic polymorphism of the vitamin D-binding protein (Gc) in various USSR populations. Blood serum samples were studied, taken from the Russians of the town Yegorievsk, Moscow Region (p = 321) and 113 Russian patients with tuberculosis using the method of isoelectrofocusing. The information was obtained of the Gc frequencies in two population units of Buryats of Aginsky and Ost-Ordynsky Autonomous Districts of Chita and Irkutsk Regions, including the Olkhon island (on the lake Baikal), in totality, 593 individuals and 13 local groups. The position of the studied Russian and Buryat groups within the gene frequency co-ordinate space is well in line with the estimated area of their localization, with regard to the world distribution. Among the Buryat populations studied, there is distinct heterogeneity for which the factor Gc1F plays a leading role within the Gc system/responsible for 92% of all possible genetic variability. Gc factor frequencies in Buryats range within the following limits: 1F.-0.3864-0.6023, 1S-0.1895-0.4535, 2-0.1364-0.2581. For the Russians of Yegorievsk and the patients with tuberculosis of Moscow and Moscow Region following allele frequencies are established: 1-F0.1169, 1S-0.5476, 2-0.1364 and 1F-0.1106, 1S-0.5531, 2-0.3363, respectively, which indicates that no association exists between Gc variants and tuberculosis. The correlation of the Gc allele frequency distribution with the ratio of insulin-independent diabetes (type 2) world-wide indicates that expression of high frequency of diseases is accompanied with comparatively rare characteristic combination of frequencies of three Gc alleles.
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The preimplantation losses among the mouse embryos at the age of 3.5 days in different crosses consist of unfertilized eggs (2-6%) and abnormal embryos (2-25%). When crossing the BALB and CBA females with the BALB, CBA and C57BL males, a similar genotypic influence of both the mother and father on the frequency of abnormalities in the embryos was found which could be expressed by an inequality. C57BL greater than BALB greater than CBA. The embryos of the BALB AND CBA females differed by the mitotic index and the occurrence of embryos without mitoses. The hybrid BALB X C57BL embryos had reliably more cells than all other hybrids.
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Mutagenic character of formaldehyde in vivo was estimated by determining the level of chromosomal aberrations, sister chromatid exchanges and unscheduled DNA synthesis in human lymphocytes. It was found that in case of occupational exposure to formaldehyde the unscheduled DNA synthesis after thiophosphamide treatment in vitro was inhibited and spontaneous level of chromosomal aberrations increased. A negative correlation observed between the unscheduled DNA synthesis and sister chromatid exchanges indirectly confirmed a connection of these exchanges with the DNA repair. The comparison of the results obtained from evaluation of chromosomal aberrations, sister chromatid exchanges and unscheduled DNA synthesis permits suggesting that these methods estimate different sides of the mutagen interaction with a cell and should be considered as mutually complementary methods but not as interchangeable ones.
Studies of mice embryos of different genotypes revealed 4.1% of polyploids, 8.5% of aneuploids and 7.9% of embryos with structural chromosome aberrations. Embryos of lines BAIB and CBA were reliably different in micronuclei occurrence (9.8 and 4.6%). A relation is shown to exist between the presence of micronuclei and structural aberrations. Normalization of the embryo genotype at early stages of embryogeny might occur by means of elimination of cells with disturbances or due to the death of anomalous embryos in the period of implantation.
An unscheduled DNA synthesis in human nonreplicative lymphocytes is shown to follow cell exposure to thiophosphamide at a dose level of 1-10 microgram/ml. Incorporation of 3H-thymidine in the absence of the mutagen is probably due to spontaneous reparative processes. Significant variations are found of spontaneous and thio-phosphamide-induced levels of a reparative DNA synthesis in normal individuals.