• 한국동물학회지
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• 제18권1호
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• pp.41-49
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• 1975

DNA 回復合成과 染色體交換과의 聯關性을 추구하기 위해 감마線을 照射한 BHK-21 과KB 細胞의 DNA 回復合成의 線量反應과 時期를 調査하였다. 감마 線에 의한 DNA 回復合成率은 5kR까지 照射線量에 比例하나 그후 50kR 까지는 變化가 없었다. DNA 回復合成의 初期 線量反應은 細胞에 따라 다르나 照射후 1$\\sim$2時間까지 지속하였다. 감마 線에 의한 染色體交換은 細胞에 따라 다른 感受性을 보였고 DNA 回復合成과의 聯關性을 보여주지 않았다.

• 한국동물학회지
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• 제20권1호
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• pp.41-48
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• 1977

Bleomycin에 의해 유발된 DNA 회복합성은 저농도 처리군에서는 농도의 증가에 따라 증가하며 $5\\mu$g/ml 군에서 조사한 전세포의 15%가 회복합성을 하여 최고율을 보인다. 고농도 처리군에서 DNA 회복합성율이 감소하며 처리 시간을 연장해도 그율은 변화가 없다. BUdR이나 IUdR을 전처리한군에서는 DNA회복합성을 증가시키는 것으로 판명됐으며 또한 고동도 처리군에서는 정상적인 DNA 합성을 억제한다. 시간 변화에 따른 실험에서는 처리한 bleomycin을 제거한후 24시간까지 DNA 회복합성이 계속됐다. 이들 결과는 bleomycin이 excision repair를 유발하는 효과적인 화학물질이 아니며, bleomycin에 의해 유발되는 DNA의 손상은 DNA 나선 절단뿐만 아니라 다른 형태의 DNA 손상도 유발함을 추측할수 있다.

• BMB Reports
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• 제32권2호
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• pp.196-202
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• 1999

The existence of the Ras-independent signal transduction pathway of insulin leading to DNA synthesis was investigated in Rat-1 fibroblasts overexpressing human insulin receptor (HIRc-B) using the single-cell microinjection technique. Microinjection of a dominant-negative mutant $Ras^{N17}$ protein into quiescent HIRc-B cells inhibited the DNA synthesis stimulated by insulin. Microinjection of oncogenic H-$Ras^{V12}$ protein ($H-Ras^{V12}$) (0.1 mg/ml) induced DNA synthesis by 35%, whereas that of control-injected IgG was induced by 20%. When the marginal amount of oncogenic H-$Ras^{V12}$ protein was coinjected with a dominant-negative mutant of the H-Ras protein ($Ras^{N17}$), DNA synthesis was 35% and 74% in the absence and presence of insulin, respectively. This full recovery of DNA synthesis by insulin suggests the existence of the Ras-independent pathway. The same recovery was observed in the cells coinjected with either H-$Ras^{V12}$ plus H-$Ras^{N17}$ plus SH2 domain of the p85 subunit of PI3-kinase ($p85^{SH2-N}$) or H-$Ras^{V12}$ plus H-$Ras^{N17}$ plus interfering anti-Shc antibody. When co-injected with a dominant-negative H-$Ras^{N17}$, the DNA synthesis induced by the Ras-independent pathway was blocked. These results indicate that the Ras-independent pathway of insulin leading to DNA synthesis exists, bypassing the p85 of PI3-kinase and Shc protein, and requires Rac1 protein.

• Journal of Plant Biology
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• 제36권1호
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• pp.19-27
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• 1993

Effects of polyamines on DNA synthesis were studied in synchronized culture of Nicotiana tabacum L. When DFMO and DFMA, inhibitors of ornithine decarboxylase and arginine decarboxylase, respectively were initially applied to the cells, the polyamine contents were rapidly dropped and [methyl-3H] thymidine incorporation into DNA was markedly reduced during the early stage of culture period. Inhibition of DNA synthesis, however, was partially reversed when these inhibitors were applied simultaneously with putrescine. In addition, exogenous administration of putrescine also increased the DNA synthesis during the all over the culture period. In vitro activity of DNA polymerase from Nicotiana tabacum L. was promoted by increasing concentrations of polyamines in the reaction mixture. Maximal activity was shown at 5 mM putrscine, 0.5 mM spermidine and spermine, respectively. Lack of Mg2+ ion in the reaction buffer resulted in an inhibition of the enzyme activity by about 30%. The inhibition could not be completely reversed by application of polyamines at optimal concentrations. These results suggest that polyamines promote the DNA synthesis in vivo and in vitro by stabilizing the DNA-helix upon binding to negatively charged groups on DNA or increasing the activity of DNA polymerase in Nicotiana tabacum L.

• 한국환경성돌연변이발암원학회지
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• 제9권1호
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• pp.23-32
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• 1989

Chinese hamster ovary (CHO)-K1 cells echibited a differential sensitivity in the process of DNA repair synthesis induced by ethyl methanesulfonate (EMS) or bleomycin (BLM) in relation to cell cycle. Two assays were employed in this study: alkaline elution and unscheduled DNA synthesis. The post-treat-ment with aphidicolin (APC), an inhibitor of DNA polymerase alpha, inhibited DNA repair synthesis induced by EMS in G2 phase, while APC did not show any effect on BLM-induced DNA repair synthesis in all phases. On the other hands, the 2', 3'-dideoxythymidine (ddTTP), an inhibitor of DNA polymerase beta, inhibited DNA repair synthesis induced by EMS or BLM in both of G1 and G2 phases. These results suggested that the involvement of DNA polymerase alpha and beta in DNA repair was dependent on cell stage or used chemical agent.

• 한국동물학회지
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• 제18권3호
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• pp.131-140
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• 1975

HeLa $S_3$ 細胞를 재료로 DNA 回復合成에 미치는 Methyl methanesulfonate(MMS)와 thymidine 相似體(BUdR, IUdR)의 이중효과를 농도와 시간변화에 따라 $^3 H$-thymidine 처리에 의한 自記放射法으로 조사한 결과는 다음과 같다. 1. MMS를 단독 처리한 경우 標識細胞의 빈도는 MMS의 농도 증가에 따라 증가한다. 이는 DNA 回復合成을 한 細胞의 빈도가 증가한 결과로 細胞當 Grain 數의 증가현상과 일치한다. 시간변화에 따른 DNA 回復合成은 MMS와 $^3 H$-thymidine 처리후 2$\\sim$3시간에 최대증가율을 보인다. 2. BUdR 또는 IUdR의 단독처리후 DNA 回復合成을 일으키지 않는다. 그러나 MMS와 이중 처리할 경우 標識細胞, DNA 回復合成細胞, 그리고 細胞當 Grain 數는 MMS 단독 처리한 경우보다 훨씬 증가한다. 따라서 이 두 물질은 MMS에 의한 DNA 回復合成을 효과적으로 증가시키는 感受性物質로 작용함이 판명되었다.

• 대한한방내과학회지
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• 제26권2호
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• pp.398-408
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• 2005

Objective: Graves' disease encompasses hyperthyroidism and diffused goiter associated with auto-antibodies to the thyroid stimulating hormone(TSH) receptors. In clinical environment, treatments of Graves' disease have many side effects such as recurrence and hypothyroidism. We've studied the effects of Sipyukmiyukieum on DNA synthesis, cAMP synthesis, and MHC-class II expression of FRTL-5 thyroid cells were studied. Methods: DNA synthesis was investigated by using BrdU staining and cAMP synthesis by ELISA kit, and expression of $interferon-{\gamma}$ activated MHC class II by Flow cytometer. Results: After introduction of Sipyukmiyukieum, significant inhibition of DNA synthesis. cAMP synthesis, and expression of $interferon-{\gamma}$ activated MHC class II of FRTL-5 thyroid cells was observed. Conclusions: Judging from these results, Sipyukmiyukieum has potential as a potent herbal treatment for inhibiting the enlargement of goiter, synthesis of abnormal thyroidal hormones, and autoimmuine responses of Graves' disease.

• Journal of Ginseng Research
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• 제16권3호
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• pp.210-216
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• 1992

The effect of saponin extracted from Panax grneng CA Meyer on DNA repair and replicative DNA synthesis were examined in CHO-Kl cells cotreated with benzo(a)pyrene and rat liver S-15 fraction. The DNA strand breaks inititated by benzo(a)pyrene metabolites were measured by alkaline election technique. The addition of ginseng saponin to the culture media resulted in decrease of benzo(a)pyrene-induced DNA strand breaks, and restored the suppressed-semiconservative-DNA-synthesis by the carcinogen. DNA repair synthesis in the damaged cells was also elevated by the ginseng treatment when the repairing activites were measured for the (3H)-thymidine incorporation into the carcinogen damaged cellular DNk Comparative analysis of DNA-adduces of benzo(a)pyrene metabortes in microsomes suggested that ginseng saponin treatment in rats reduced the formation of electrophilic metabolites of benzo (a)-pyrene in the rat liver microsomes.

• 한국식품영양과학회지
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• 제18권4호
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• pp.444-448
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• 1989

세포증식에 관한 개체발생의 일주리듬을 검토하기 위하여 부화직후의 병아리 간장 DNA 합성 리듬 및 간 세포증식의 개체발생에 대해서 검토한 결과 포유류에 있어서 DNA 합성 리듬은 이유기 후기에 출현하는데 비하여 조류(병아리)에 있어서 DNA합성 리듬은 부화 12시간후 바로 출현하였고 간장의 DNA 합성 리듬은 사료섭취에 의해 리듬주기가 유지되었다. 한편 DNA 합성 활성은 절식에 의해 감소되었으며 DNA 합성의 리듬변화는 사료섭취에 의해서도 변화하였지만 빛의 조건에 의해서도 많은 영향을 받았다. 이러한 간 DNA 합성은 12시간 늦은 위상에서 유사분열도 동반하였다.

• 한국환경성돌연변이발암원학회지
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• 제11권2호
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• pp.107-117
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• 1991

The effect of 3-aminobenzamide (3AB), an inhibitor of poly (ADP-ribose) polymerase, on ethyl methanesulfonate (EMS)-or bleomycin (BLM)-induced DNA repair synthesis and chromosome aberrations was examined during the cell cycle of Chinese hamster ovary (CHO)-K$_1$ cells. The synchronized cells were obtained by using thymidine double block method and mitotic selection method. Three assays were employed in this study: unscheduled DNA synthesis, alkaline elution and chromosome aberrations. 3AB alone did not induce DNA repair and chromosome aberrations in all phases. The post-treatment with 3AB inhibited DNA repair synthesis induced by EMS or BLM in G$_2$ phase, whereas 3AB did not affect chromosome aberrations induced by EMS or BLM in all phases. These results suggest that 3AB aggravates the cell cycle disturbance which occur after DNA damage, and leads to an accumulation of cells at G$_2$ phase, and inhibits DNA repair synthesis, while the effect 3AB on chromosome aberrations may need reevaluated.