[The peculiarities of polymorphism of XPD and XRCC1 repair genes in cells of Down and Ehlers-Danlo syndrome patients characterized by increased radiosensitivity].

Codon 312 and 751 polymorphisms ofXPD gene and codon 399 polymorphism of XRCC1 gene of peripheral blood lymphocytes in patients with Down syndrome (DS) (46 individuals), Ehlers-Danlo syndrome (EDS) (47 individuals) and in a group of healthy donors (control) (40 individuals) have been studied. Frequency of XPD genotype (G312G) coding for the most effectively functioning form of XPD protein was lower in patients with DS (26%) than in a group of healthy donors (42.5%) (p = 0.035), whereas no significant differences with the control were revealed for this codon in patients with EDS. No patients with XPD genotype (C751C) (p = 0.036) were revealed in a group of EDS patients, while this genotype was found in 16% of a group of healthy donors and in 17% of patients with DS. The trend of XRCC1 genotype frequency reduction (A399A) (p = 0.085) in EDS patients (3.9%) compared with the group of healthy donors (13.5%) and DS patients (13.3%) has been obtained. These data show that polymorphisms of the excision repair genes under study are accompanied by an elevated individual radio sensitivity in patients with DS. Genes investigated (their polymorphic variants) did not participate in the mechanisms for radio sensitive phenotype formation in EDS patients.

[Investigation of detoxification polymorphisms genes, methylenetetrahydrofolate-reductase (MTHFR) and P53 in the radiosensitive human cells].

The genes of detoxication, MTHFR and p53 were studied in Down' and Ehlers-Danlos syndrome cells. The frequency GSTM1(0/0) genotype in Down syndrome patients was in 1.5 times higher than in control cells (p < 0.069). Opposite the frequency GSTM1(0/0) genotype in Ehlers-Danlos syndrome was 23.3% 2 times lower than in control cells (p < 0.034). This indication was in 2 times lower in women cells than in men cells and in 3 times lower than in control cells (p < 0.026). The mutations of p53 gene (7th exon) were detected in 4 from 11 Down patients (36.7%; in 2 cases af women and men), in Ehlers-Danlos patients--in 5 cases and only in men (29.4% among all the observed patients). The observations 24 healthy donors weren't revealed any mutations (p < 0.013-0.001). The hypothesis about the connection between gene polymorphisms which take a part in genome stability and radiosensitivity in Down and Ehlers-Danlos patients was developed.

[Antimutagenes' protection action in human repair-defected cells].

The action of natural (garlick extract, retinol) and of synthetic (crown-compound) antimutagenes in lymphotytes with gamma-radiation-induced inhibition of DNA-damages repair in cases of Elers-Danlos, syndrom, progeria and gomocystinurea was studied. Antimutagen cells defence from mutagenes was shown at all cases except one: progeria cells treated by retinol. Thus the repair-deficient cells resistance against mutagenes could be increased by antimutagenes.

[Genetic polymorphism of glutathione-S-transferases and inhibition of DNA repair].

A complex investigation of different cell defence systems, such as: DNA repair, antioxidant system (SOD), xenobiotic detoxification system (glutathione-S-transferases M1 and T1), radioadaptive response (RAR) in lymphocytes of patients with hereditary disease of connective tissue (Elers-Danlose syndrome) was carried out. The frequency of genotype GSTM1 (0/0) in children with Elers-Danlose syndrome (23%) is lower as compared to the control group (44%). The lymphocytes of children with Elers-Danlose syndrome were characterized by reduced ability to repair gamma-induced damage of DNA. At given size of the samples of examined children no correlative relationships between GST-status of organism and the condition of other cell defence systems were revealed. The data obtained demonstrate the individual peculiarities of the defence systems in repair-deficient cells of the examined children.

[DNA repair and antioxidant defence in the repair-deficient human cells (Marfan's syndrome) after gamma-irradiation].

DNA repair synthesis (RS) was investigated in lymphocytes of healty donors and repair-deficient cells (Marfan's syndrome), treated with inhibitor of superoxidedismutase (SOD)--TRIEN--after gamma-irradiation. Significant difference was revealed in cells of healthy donors and Marfan's syndrome: in cells of healthy donors TRIEN stimulated DNA RS whereas this effect didn't observed in Marfan's syndrome cells. So it is possible to suppose that SOD activity is different in normal and gamma-repair-deficient cells.

[Differentiation of activity of a superoxide dismutase inhibitor in human cells exposed to radiation, chemical mutagens and radioadaptive response]. / Differentsirovannaia aktivnost' ingibitora superoksiddismutazy v kletakh cheloveka pri vozdeistvii radiatsii, khimicheskikh mutagenov i pri radioadaptivnom otvete.

The superoxide dismutase (SOD) inhibitor, TRIEN, which enhanced the formation of gamma-induced DNA breaks in cells of healthy donors and patients with Marfan syndrome and Bloom syndrome (repair-defective hereditary diseases), had virtually no effect on the formation of radioadaptive response (RAR) in these systems. Similar results were obtained in studies on cell survival: TRIEN facilitated mortality in cells irradiated with gamma-rays but did not affect RAR formation. TRIEN also increased the deleterious effect of CdCl2, which indicates that SOD apparently plays a certain role in cell defence against this mutagen.

[Tripeptidyl peptidase 1 deficiency in neuronal ceroid lipofuscinosis. A novel mutation]. / Nedostatochnost' tripeptidil peptidazy 1 pri neironal'nom tseroidnom lipofuktsinoze. Novaia mutatsiia.

The data on biochemical and molecular-genetic diagnostics of a hereditary lisosomal storage disease, late infantile neuronal ceroid lipofuscinosis (CLN2) are presented. The disease is associated with a hereditary deficiency of pepstatin-unsensitive peptidase--tripeptidylpeptidase 1 (TPP1)--caused by mutations in the TPP1-coding gene CLN2. Among the 30 patients with clinical manifestations of CLN, six patients with a pronounced decrease in TPP1 activity were revealed; these data were interpreted as indicating the presence of CLN2 in these patients. The analysis of the isolated DNA indicated the availability of the most widespread mutation g3670 C > T(R208X) leading to the untimely termination of TPP1 synthesis. It was shown that in 5 patients this mutation is present in homozygous state and in one patient, in the heterozygous state. In this patient a hitherto unknown mutation, g3665G > A (R206H), was revealed. The pathogenetic significance of this mutation and the importance of molecular-genetic diagnosis of CLN are discussed with regard to medico-genetic consulting and prenatal diagnosis of this disease.

[A defense mechanism of human cells in the radioadaptive response and antimutagenic activity of interferon has common paths]. / [Mekhanizm zashity kletok cheloveka pri radioadaptivnom otvete i antimutagennoi aktivnosti interferona imeet obshchie puti.

The radioadaptive response was assessed by the chromosome aberration test in lymphocytes of humans with hereditary diseases of connective tissue, which were earlier characterized as repair-deficient: Marfan syndrome (SM), Elers-Danlos syndrome (E-D), and homocystinurea (HCU). The radioadaptive response was observed in cells of patients with Marfan syndrome and Elers-Danlos syndrome but not in cells of patients with homocystinurea. Parameters of cell protection against gamma-irradiation at radioadaptive response were similar to those obtained in cells pretreated with interferon. These data indicate, first, the possibility that repair pathways and the radioadaptive response are independent and second, that there are common pathways of protection upon radioadaptive response and the antimutagenic action of interferon.

[Independence of DNA repair after gamma irradiation and radioadaptive response in lymphocytes of patients with Bloom syndrome]. / Razobshchennost' protsessov reparatsii gamma-povrezhdenii DNK i radioadaptivnogo otveta v limfotsitakh patsientov s sindromom Bliuma.

The evidence for independency of DNA repair and radioadaptive response (RAR) was obtained in cells of patients with Bloom syndrome. The cells of patients with Bloom syndrome (human autosomal recessive disorder) are characterized by chromosomal instability and increased risk of malignancy at an early age. Resynthesis of gamma-induced DNA breaks wasn't find in lymphocytes of 3 patients with Bloom syndrome while the level of RAR was the same as in the cells of healthy donors.

[Current problems in diagnosis and treatment of hereditary disturbances of growth and development in children]. / Sovremennye problemy diagnostiki i lecheniia nasledstvennykh naryshenii rosta and razvitiia u detei.

The authors' long-term experience in diagnosing and treating childhood hereditary growth and developmental disturbances, such as genetic diseases of connective tissue, amino acid metabolic disturbances, rickets-like diseases, mitochondrial abnormalities, Rett syndrome, and fragile X syndrome is presented. The findings suggest that multimodality treatment is highly effective in treating children with hereditary growth and developmental disturbances in genetic care.

[Radioadaptive response in lymphocytes of children living in territories polluted by radionuclides as a result of the accident at the Chernobyl power plant]. / Radioadaptivnyi otvet v limfotsitakh detei prozhivaiushchikh na territoriiakh, zagriaznennykh radionuklidami v rezultate avarii na Chernobyl'skoi AES.

The radioadaptive response and antimutagenic action of lymphoblastoid interferon in the human blood lymphocytes of the children from polluted after Chernobyl accident Bryansk region were studied. Cells pretreated with tritiated thymidine with 2 Gy of gamma-rays at 20 h of culture after PHA-stimulation on seven of the ten donors result in lack of radioadaptive response. On testing some of them (4 donors) no protective adaptive response was found, others (3 donors) pretreated with tritiated thymidine gave sensibilization. Significant decrease in interferon antimutagenic activity in lymphocytes with disturbed adaptive response was also found. It has been proposed that there is similarity or identity of mechanism of radioadaptive response and of non-repair component of interferons antimutagenic action.

[Radio-adaptive response in repair-defective cells from patients with homocystinuria]. / Radioadaptivnyi otvet v reparatsionno-defektnykh kletkakh bol'nykh gomotsistinuriei.

Two lines of fibroblasts isolated by skin biopsy from patients with homocystinuria were characterized as repair-defective cells. Preirradiation of these cells at low doses (0.1 Gy) and irradiation at high doses demonstrated their decreased ability to form radioadaptive response, in comparison with normal cells. Radioadaptive response did not differ from that of normal cells after chemical treatment with 4NQO and NG used as damaging agents. The method for detection of DNA breaks by means of hydroxyapatite column chromatography of cell lysates and the method of determining sister chromatid exchanges (SCE) were used.

[Dna repair activity in children exposed to small doses of ionizing radiation as a result of the accident at the Chernobyl nuclear power station]. / Reparativnaia aktivnost' DNK u detei, podverzhennykh vozdeistviiu malykh doz ioniziruiushchego izlycheniia v rezultate avarii na Chernobyl'skoi AES.

The repair activity of DNA was studied by variola vaccine virus reactivation and induced mutagenesis tests in the peripheral blood lymphocytes of children living in areas with an increased level of ionizing radiation due to breakdown at the Chernobyl' nuclear power station. A more profound repair disturbance was revealed in children living on strictly controlled territories and born after the disaster, compared to those born before it, and children living in areas where the radiation level does not exceed background values. The disturbances were characterized by increased induced mutagenesis and decreased reactivation of the variola vaccine virus. No changes in the degree of DNA repair synthesis were registered in any of the groups studied.

[The adaptive response in the lymphocytes of children from an area with an elevated background of ionizing radiation]. / Adaptivnyi otvet v limfotsitakh detei iz zony s povyshennym fonom ioniziruiushchei radiatsii.

The ability to form the adaptive response in lymphocytes of 23 children, exposed to small radiation doses as the result of Chernobyl accident was studied by hydroxylapatite chromatography of cell lysates. No correlation was found between the ability to form adaptive response and received radiation dose.

[The formation of an adaptive response in children exposed to the effect of low doses of radiation as a result of the accident at the Chernobyl Atomic Electric Power Station]. / Formirovanie adaptivnogo otveta u detei, podvergshikhsia vliianiiu malykh doz radiatsii v rezul'tate avarii na ChAES.

The ability of lymphocytes to form an adaptive response in cells of the children which were exposed to small radiation doses during the Chernobyl accident was studied by hydroxyapatite chromatography of cell lysates. Ten children living in the area with high radiation level (Bryansk region) and seventeen children living in the area with natural radiation level (Bryansk region too) were examined. No difference in cell ability to form adaptive response was found in both children group.

[Automated genetic register and computer support for the physician's diagnostic decisions]. / Avtomatizirovannyi geneticheskii registr i komp'iuternaia podderzhka diagnosticheskikh reshenii vracha.

Computer-based genetical register "GENREG" allows to carry out a prophylactic medical examination for families with children, having hereditary diseases, multifactorial pathology and congenital developmental defects of various nature, and also epidemiological examination. Automated consultative system for pre-laboratory diagnosis of genetically determined diseases after the phenotypical manifestations "DIAGEN" allows to identify up to 1200 nosologic units; diagnostic value (or weight) of the signs according to physician's evaluation is taken into consideration. The system sorts out a narrow differential-and-diagnostic row and information about specific laboratory and functional changes for every selected diagnosis. Efficiency of the system is over 94% (after the next laboratory findings). The results of computer diagnosis and final physician's diagnosis, and also questionnaire of a child are stored in archives (files) of the "DIAGEN" system. Both of the systems are realized on PC/AT IBM-compatible computer.

[Automated information-diagnostic system for hereditary diseases in childhood]. / Avtomatizirovannaia informatsionno-diagnosticheskaia sistema po nasledstvennym zabolevaniiam v detskom vozraste.

This article describes computer-based information-and-diagnostic system dealing with child hereditary diseases which makes in possible to organize automated consultative service on a wide range of monogene and chromosome syndromes. The system is oriented for sorting out a narrow differential-and-diagnostic row from 1200 of genetically determined diseases at the stage of pre-laboratory child examination. The choice of diagnoses in the system is based on the analysis of the likeness of phenotypical manifestation of the syndromes described in literature with the case under analysis. The system envisages information exchange with a physician in a dialogue using the natural language. The system is based on IBM-370 computer and can be operated from remote video device in the data TV transmitting mode.

[Use of 4-methylumbelliferryl-alpha-L-iduronide and 4-trifluoromethylumbelliferryl-alpha-L-iduronide for detecting alpha-L-iduronidase deficiencies in human tissue and for rapid prenatal diagnosis of Hurler disease]. / Ispol'zovanie 4-metilumbelliferil-alpha-L-iduronida i 4-triftormetil- umbelliferil-alpha-L-iduronida dlia vyiavleniia nedostatochnosti alpha-L-iduronidazy v tkaniakh cheloveka i dlia bystroi prenatalnoi diagnostiki bolezni gurler.

Activity of alpha-L-iduronidase was studied in leukocytes of healthy persons, of patients with Hurler disease and of heterozygous carriers of the disease where 4-methylumbelliferyl-alpha-L-iduronide and 4-trifluoromethylumbelliferyl-alpha-L-iduronide were used as substrates. 4-Trifluoromethylumbelliferyl-alpha-L-iduronide proved to be also a specific substrate of alpha-L-iduronidase and enabled to detect the enzyme deficiency in patients with Hurler disease as well as a decrease of the enzymatic activity in heterozygous carriers of the disease. Using these two substrates prenatal diagnosis of Hurler disease was carried out in fetus which exhibited absence of the enzymatic activity in cell culture from amniotic fluid. The diagnosis was corroborated after analysis of alpha-L-iduronidase activity in liver and kidney tissues of the fetus. 4-Trifluoromethylumbelliferyl-alpha-L-iduronide was very effective in express detection of alpha-L-iduronidase deficiency immediately in tissue slices as well as in placenta which is of importance in prenatal diagnosis of Hurler disease.