[Genetic structure and the load of hereditary diseases in five populations of Arkhangel'skaia region]. / Geneticheskaia struktura i gruz nasledstvennykh boleznei v piati populiatsiiakh Arkhangel'skoi oblasti.

A population and medical genetic investigation was performed in a number of raions in the Arkhangel' skaya oblast. Random inbreeding coefficients were 0.000358 and 0.000361 in the Vinogradovskii and Krasnoborskii raions. Malecot's local inbreeding coefficients were 0.000565 and 0.000472, respectively. The endogamy indices were 0.37 and 0.54, respectively. In the urban population, the loads of autosomal dominant, autosomal recessive, and X-linked pathology were 1.01 and 0.98 per 1000 individuals, and 0.29 per 1000 men; in the rural population, they were 1.22, 1.55, and 1.08, respectively. In the populations studied, the hereditary pathology spectrum is described.

[Interferon as a stimulator of DNA repair in patients with xeroderma pigmentosum]. / Interferon kak stimuliator reparatsii DNK u bol'nykh xeroderma pigmentosum.

Natural leucocyte interferon (IF) upon injection to two patients affected with Xeroderma pigmentosum for three weeks stimulated the inhibited DNA replication and Host reactivation at the level of healthy donors. Tigasol--the drug used traditionally for the treatment of diseases caused by Xeroderma pigmentosum proved less effective than IF.

[Structure and variability of hereditary disease in the Kirov Province]. / Struktura i raznoobrazie nasledstvennoi patologii v Kirovskoi oblasti.

The main purpose of this report is to present the nosological spectrum of hereditary diseases in 9 Districts of Kirov Province and to compare it with that studies earlier in other Russian populations. This comparison is undertaken in an attempt to define a "nucleus" of hereditary diseases in the Russian population studied. During this study 343 families with 546 affected were registered. The spectrum covered 55 different autosomal dominant, 14 autosomal recessive and 11 X-linked recessive hereditary disorders in the population under study. Some of these forms could be considered as common forms for the whole Russian population, because they were met in all Russian populations which were analysed. This conclusion is proved by the cluster analysis of genetic distances calculated on the basis of gene frequencies for autosomal recessive hereditary disorders.

[The effect of the environment on the repair of DNA damage in human lymphocytes]. / Vliianie okruzhaiushchei sredy na reparatsiiu povrezhdenii DNK limfotsitov cheloveka.

The dependence of UV-induced unscheduled DNA synthesis (UDS) in the unstimulated lymphocytes of human peripheral blood on the ionic strength (mu) of the culture medium has been shown. In the level of mu lower or higher than the physiological (mu ph) one, UDS significantly decreases. The effect of modification of mu due to the changes of ionic strength is absent in the lymphocytes of the classic form of xeroderma pigmentosum. The phenomenon may become useful in the development of a new test for revealing cells with a genetically or physiologically changed system of UV-induced DNA repair. The mechanisms of investigated phenomenon, particularly their dependence on the structure of chromatin, as well as the influence of ionic strength on binding of the repair enzymes with DNA are discussed.

[Prevalence of hereditary pathologies in residents of the Kirov Province]. / Otiagoshchennost' naseleniia kirovskoi oblasti nasledstvennoi patologiei.

Medical-genetic study was carried out in the population of Kirov Province (population size about 120.000). 203 families with 334 affected with hereditary disorders were registered. The correctness of pathology classification for the inheritance type was confirmed by segregational analysis. The load of hereditary diseases in the population was: 1.25 +/- 0.06 for autosomal dominant, 1.37 +/- 0.07 for autosomal recessive and 0.22 +/- 0.06 for X-linked recessive disorders. It is suggested that variability in the values of the load of autosomal recessive disorders is determined to the large extent by genetic structure of the population.

[The dependence of DNA repair induced by genetically hazardous exposures on the ionic strength of the medium containing the cells]. / Zavisimost' reparatsii DNK, indutsirovannoi geneticheski opasnymi vozdeistviiami, ot ionnoi sily sredy, v kotoroi nakhodiatsia kletki.

The dependence of UV-induced unscheduled DNA synthesis (UDS) in non-stimulated lymphocytes of human peripheral blood on the ionic strength (mu) of the culture medium has been shown. With the level of mu lower or higher than physiological (mu ph) the UDS significantly decreases. The effect of modification of mu due to changes in ionic strength is absent in the lymphocytes of patients with the classic form of xeroderma pigmentosum. This phenomenon may become useful for development of a new test revealing cells with genetically or physiologically changed system of UV-induced DNA repair. Mechanisms of investigated phenomenon, particularly their dependence on the chromatin structure, as well as the influence of ionic strength on binding the repair enzymes with DNA are discussed.

[Mechanisms of disruption of DNA in human cells. Mutagenesis of a virus in xeroderma pigmentosum cells as an indicator of a defect in DNA repair]. / Mekhanizmy narushenii reparatsii DNK v kletkakh cheloveka. Mutagenez virusa v kletkakh pigmentnoi kcerodermy kak pokazatel' defekta reparatsii DNK.

Lymphocytes of two patients with Xeroderma pigmentosum, their mothers and cell lines isolated from the third patient were examined. The reaction of vaccinia virus treated with mutagens, the index of virus-induced mutagenesis and DNA repair synthesis were the criteria of estimation of cell repair activity. Significant inhibition of DNA repair synthesis was detected in cells of all the patients observed (primary and established lines) in the experiments with UV-irradiation and 4-nitroquinoline-4-oxide. These indexes correlated with decreased virus reactivation and increased level of virus-induced mutagenesis. Inhibition of DNA repair synthesis was also revealed in lymphocytes of both mothers. These data claim a possibility of discovering heterozygotes, the carriers of mutant genes. The data on virus-induced mutagenesis serve as a simple test for detection of DNA repair disorders.