排序方式: 共有34条查询结果,搜索用时 390 毫秒
1.
The results obtained show the possibility of polyamine (spermine and spermidine) utilization to stabilize the nuclear chromatin and to protect it against nuclease degradation in the course of isolation of liver cell nuclei. Besides, the inhibition of the unscheduled DNA synthesis induced by nuclease incision and by gamma- or UV-radiation was demonstrated in the presence of polyamines. 相似文献
2.
A study was made of the effect of poly(ADP-ribosylation) of proteins on the formation and repair of single-strand DNA breaks in gamma-irradiated (50 Gy) permeable Zajdela ascites hepatoma cells permeabilized by the treatment with 0.05% triton X-100. Incubation of gamma-irradiated permeable cells in conditions promoting DNA synthesis and providing ADP-ribosylation (in the presence of 1 mM NAD) did not cause any substantial changes in the formation of single-strand DNA breaks and did not influence their repair. 相似文献
3.
The micronucleus frequency in bone marrow erythrocytes from the F1 progeny of male mice exposed to chronic low-dose -irradiation was determined. Male BALB/c mice were irradiated with 10, 25 and 50 cGy at dose rates of 1, 5, and 15 cGy/day and mated with unirradiated females on day 15 after irradiation. The obtained offspring had an elevated micronucleus frequency in bone marrow erythrocytes at the age of 2 months. This suggests the transmission of genome instability from damaged germ-line cells of irradiated male parents to somatic cells of the progeny. 相似文献
4.
I. Yu. Strelkova S. A. Abdullaev G. P. Snigireva V. G. Bezlepkin A. I. Gaziev 《Biochemistry (Moscow) Supplemental Series B: Biomedical Chemistry》2011,5(1):88-93
Quantitative and qualitative changes in circulating extracellular DNA (ec-DNA) of blood plasma are considered as markers for
diagnosis and prognosis of tumor pathology. We have investigated the content of mutant copies of the circulating mitochondrial
DNA (ec-mtDNA) in blood plasma in 8 patients with lung cancer before and after radiotherapy as well as in healthy young and
elderly donors. It was found that in plasma of healthy elderly donors the proportion of ec-mtDNA with mutations (in the total
circulating DNA) is much higher than in young donors. Before radiotherapy the proportion of ec-mtDNA with mutations was higher
in plasma of lung cancer patients (aged 70–76 years) than that of healthy elderly donors. After radiotherapy of lung cancer
patients a twofold increase in the proportion of ec-mtDNA with mutations was observed in total circulating plasma DNA. This
may be attributed to release of mutant DNA copies from dying tumor cells and also from normal cells injured by the radiation
treatment. 相似文献
5.
Malakhova L Bezlepkin VG Antipova V Ushakova T Fomenko L Sirota N Gaziev AI 《Cellular & molecular biology letters》2005,10(4):721-732
Changes in the number of mitochondrial DNA (mtDNA) copies in the brain and spleen tissues of gamma-irradiated (3 Gy) mice were studied by comparative analysis of the long-extension PCR products of mtDNA (15.9 kb) and a fragment of the cluster nuclear beta-globin gene (8.7 kb) amplified simultaneously in one and the same test-tube within total DNA. The analysis showed that, compared to the nuclear beta-globin gene, an increase in mtDNA copy number (polyploidization) took place in the brain and spleen cells of mice exposed to gamma-radiation. This data led to the suggestion that the major mechanism for maintenance of the mitochondrial genome, which is constantly damaged by endogenous ROS and easily affected by ionizing radiation or other exogenous factors, is the induction of synthesis of new mtDNA copies on intact or little affected mtDNA templates because the repair systems in the mitochondria function at a low level of efficiency. 相似文献
6.
7.
N. A. Gulyaeva S. A. Abdullaev L. V. Malakhova V. N. Antipova V. G. Bezlepkin A. I. Gaziev 《Russian Journal of Genetics》2009,45(7):833-839
Changes in the number of mutant copies of mitochondrial DNA (mtDNA) were studied in the brain and spleen tissues of mice after their X-irradiation at a dose of 5 Gy. For this purpose, heteroduplexes obtained via hybridization of the products of PCR amplification of mtDNA (ND3 gene and two D-loop regions) from irradiated and control mice were digested with the CelI nuclease capable of specific mismatch cleavage. Heteroduplexes obtained via hybridization of the products of PCR amplification of mtDNA from irrradiated and control mice were digested by the CelI nuclease to a greater degree than heteroduplexes of the PCR products of mtDNA of mice from the control group. This suggests the presence of mutations in mtDNA regions in irradiated mice. Digestion by the CelI nuclease of heteroduplexes obtained via hybridization of the PCR products of mtDNA (ND3 gene and D-loop regions) on day 8 after irradiation is essentially more efficient than digestion of heteroduplexes obtained via hybridization of the PCR products of mtDNA isolated from mouse tissues on days 14 and 28 of the postradiation period. These results indicate a reduction in the number of mtDNA copies with mutations in tissues of irradiated mice by day 28 of the postradiation period. The reduction in the level of mutant mtDNA copies by this term is especially significant in the spleen. The total number of mtDNA copies in the mouse brain and spleen tissues estimated by real-time PCR, relative to the nuclear β-actin gene, is also decreased by 30–50% as compared to the control on days 8 to 28 after irradiation. The results of the study suggest that mutant mtDNA copies are eliminated from tissues of irradiated animals in the postradiation period. This elimination can be regarded either as a result of selective degradation of mitochondria carrying mutant DNA copies or as a result of cell death being continued in tissues of irradiated animals. 相似文献
8.
Large mtDNA deletions in mouse brain and spleen cells, induced by X-radiation at doses of 2 and 5 Gy were studied within four weeks after the exposure of animals to X-rays. Variations in the content of extracellular (deletion) mtDNA were examined in the blood plasma of mice irradiated with 5 Gy in the same postirradiation times. Ionizing radiation was shown to effectively induce large mtDNA deletions at the doses chosen. The level of deletion mtDNA was dependent on dose and postirradiation time. 相似文献
9.
In experiments with NIH3T3 mouse fibroblast the authors showed a dose-dependent (gamma- or UV-radiation) increase in the immortalized fibroblast transformation by purified DNA preparations from Ehrlich ascites tumour cells. The transformant yield was the highest when the transfection started within the first few minutes after irradiation, when radiation lesions occurred in the genome and the system of enzymic DNA repair was activated. The proteolytic activity inhibition by treating the exposed cells with phenylmethanesultonyl fluorine reduced the radiation-induced transformation. 相似文献
10.
Fomenko LA Lomaeva MG Bezlepkin VG Gaziev AI 《Radiatsionnaia biologiia, radioecologiia / Rossi?skaia akademiia nauk》2006,46(4):431-435
The F1-progeny of BALB/c male mice chronically exposed to low-dose gamma-radiation (0.1; 0.25 and 0.5 Gy; dose rate 0.01 Gy/day) as well as the F1-progeny of females exposed to acute X-radiation (0.5; 1.0 and 2.0 Gy; dose rate 0.1 Gy/min) shown the significant elevated micronuclei frequencies in bone marrow erythrocytes, as compared to the F1-progeny of unirradiated males and females. The increase in the micronuclei frequency in the F1-progeny was determined by the dose of irradiation of parents. The values of elevated micronuclei frequency in the F1-progeny of chronically irradiated males and acutely irradiated females for a dose of 0.5 Gy were comparable. The micronuclei frequencies in the F1-progeny of irradiated females and males for this dose were in 1.5 and in 1.6 times higher than ones in the F1-progeny of unirradiated mice correspondingly. The results suggest the possibility of transfer of genome instability from irradiated parents to the somatic cells of the F1-progeny via non-lethally damaged germ cells of parents. 相似文献