• Korean Journal of Animal Reproduction
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• v.17 no.1
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• pp.49-56
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• 1993

Mouse mammary epithelial cells(NMuMG) were plated onto 24 well phates(100,000 cells/well), in DMEM supplemented with 10% fetal calf serum. After serum starvation for 24 hours, EGF)0~100ng/ml) was added simultaneously with IGF-I(10ng/ml), 1$\mu$M photoreactive cAMP(4,5-dimethoxy-2-nitrobenzyl adenosine-3',5' cyclic monophosphate, DMNB) or IGF-I plus DMNB. After 2 hours, the cells were expposed to UV light(300nm, 3 second pulse0 in order to activate DMNB which induces a rapid transient increase in intracellular cAMP upon UV irradiation. DNA synthesis was estimated as incorporation of 3H-thymidine into DNA(1 hour pulse with 1$\mu$Ci/ml, 18~19 hours after UV exposure). Without IGF-I or DMNB, EGF(10 or 100ng/ml) increased DNA synthesis from 8,362 dpm/well in control to 16,345 or 18,684 dpm/well with EGF(pooled SE=1,239 dpm/well, P<0.05). IGF-I or IGF-I plus DMNB alone increased DNA synthesis from 8,362 dpm/well in control to 17,307 or 20,427 dpm/well, respectively(P<0.05). Addition of IGF-I, DMNB or IGF-I plus DMNB into 0~100ng/ml EGF did not significantly change the shape of dose response curve of EGF alone. In other experiment, EGF or IGF-I plus DMNB into 10ng/ml EGF group exhibited interaction effect in DNAsynthesis [EGF(10ng/ml)=18,497; IGF-I＋EGF=22,837; DMNB＋EGF=20,658 ; IGF-I＋DMNB＋EGF=29,658, pooled SE=1,055, P<0.05]. These results indicate that simultaneous activation of EGF, IGF-I and intracellular cAMP interact in DNA synthesis of mouse mammary epithelial cells.

• Biomedical Science Letters
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• v.23 no.4
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• pp.372-379
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• 2017

This study was investigated to test whether paternal DNA that was destined for degradation was properly licensed by testing for the presence of mini-chromosome maintenance protein (MCM) 7 and origin recognition complex (ORC) 2 in the paternal pronuclei. ORC2 is one of the first licensing protein to come on and MCM7 is one of the last licensing protein to come on. Zygotes were prepared by injection of control and treated sperm injection (ICSI). To control for DNA breakage, epididymal spermatozoa were treated with DNase I to fragment the DNA, then injected into oocytes. The presence of MCM7 and ORC2 in the pronuclei of mouse zygotes was tested by immunohistochemistry, just before the onset of DNA synthesis, at 5 h after fertilization, and after DNA synthesis began, at 9 h post fertilization. We found that in all cases, both MCM7 and ORC2 were present in both pronuclei at 5 h after sperm injection, just before DNA synthesis began. This indicates that no matter how extensive the DNA damage, recruitment of licensing proteins to the origins of replication was not inhibited. Sperm DNA fragmentation does not prevent licensing of DNA replication origins. Furthermore, the embryo recognizes DNA that is damaged by nucleases. Our data indicate that the one-cell embryo does harbor a mechanism to prevent the replication of severely damaged DNA from spermatozoa, even though the embryos do not undergo classical apoptosis.

• Proceedings of the Korean Society of Toxicology Conference
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• 2001.10a
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• pp.9-9
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• 2001

Several micronutrients (vitamins and minerals) are required as co-factors in DNA synthesis, DNA repair, DNA methylation and apoptosis. Some notable examples include (a) folic acid and vitamin B12 required for maintenance methylation of DNA and the synthesis of dTTP from dUTP, thus prevent the misincorporation of uracil into DNA, a highly mutagenic and chromosome-breaking event, (b) niacin, is essential in the form of the coenzymes NAD and NADP which act as a substrate for polyADPribose polymerase (PARP), an enzyme thought to facilitate efficient DNA repair and telomere length regulation and (c) zinc, apart from its antioxidant role as a co-factor in Cu/Zn SOD, it is required in its stabilizing role of the DNA-binding domain of p53 (residues 102-292) and thus is essential for apoptotic response to DNA damage. (omitted)

• The Journal of Internal Korean Medicine
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• v.27 no.3
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• pp.653-663
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• 2006

Objective : Graves' disease, the most common cause of hyperthyroidism, is an autoimmune disorder associated with autoantibodies to the TSH receptor. The clinical features of Graves' disease are goiter and hypermetabolic symptoms induced by excessive hormones. Antithyroid drug therapy is the first-line treatment for Graves' disease in Korea, Japan and European countries. Yet in spite of a long period and high-dose of treatment, it is hard to achieve remission because of adverse effects, frequent recurrence and resistance to antithyroid drugs. Recently, it has been reported that the abnormal thyroid hormone and clinical symptoms of Graves' disease were reduced by Ahnjeonbaekho-tang (AJBHT). Methods : To investigate the effectiveness and action mechanism of AJBHT, we studied the influence of AJBHT on FRTL-5 thyroid cell proliferation, DNA synthesis and expression of T4, TSH, cAMP, Tg and TPO mRNA. Results : AJBHT significantly inhibited the FRTL-5 cell proliferation, DNA synthesis, T4 synthesis, cAMP production and the expression of Tg mRNA in comparison with control and MMI. Conclusions : These results suggest that AJBHT may inhibit the cell proliferation and DNA synthesis by regulating the cAMP, and suppress the T4 synthesis by modulating Tg mRNA expression and cAMP synthesis, and that it may be useful agent for treating the goiter and hormone abnormality of Graves' disease.

• Archives of Pharmacal Research
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• v.22 no.1
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• pp.25-29
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• 1999

Psammaplin A, a natural bromotyrosine derivative from an associated form of two sponges (Poecillastra sp. and jaspis sp.) was found to possess the antimicrobial effect on the Gram-positive bacteria, especially on methicillin-resistant Staphylococcus aureus (MRSA). The minimal inhibitory concentration of psammaplin A against twenty one MRSAs ranged from 0.781 to 6.25 ${\mu}g/ml$, which that of ciprofloxacin was 0.391~3.125${\mu}g/ml$. Psammaplin A could not bind to penicillin binding protein, but inhibited the DNA synthesis and the DNA gyrase activity with the respective 50% (DNA synthesis) and 100% (DNA gyrase) inhibitory concentration 2.83 and 100 ${\mu}g/ml$. These results indicate that psammaplin A has a considerable antibacterial activity, although restricted to a somewhat narrow range of bacteria, probably by inhibiting DNA gyrase.

• BMB Reports
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• v.28 no.5
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• pp.464-470
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• 1995

Quinolone antibiotics are DNA gyrase inhibitors, but their bactericidal action seems to involve more than the inhibition of DNA gyrase activity. Hence, the potentially crucial factors among possible mechanisms of quinolone action; cleavable complex formation, inhibition of DNA synthesis, and induction of SOS response were investigated. These parameters were measured in an Escherichia coli strain exposed to quinolones in the logarithmic growth phase, and correlated with the bactericidal activity of quinolones. Cleavable complex formation proved to be the factor most related to bactericidal action. Inhibition of DNA synthesis was substantially correlated with bactericidal activity, but induction of SOS response was least correlated with bactericidal activity. Therefore, it was concluded that quinolones exert bactericidal action primarily through cleavable complex formation, and subsequent unknown cellular processes together with inhibition of DNA synthesis contribute to the bactericidal activity of quinolones.

• Journal of the Korean Society of Tobacco Science
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• v.15 no.2
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• pp.152-160
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• 1993

Using a flue- cured tobacco variety, KF 109, effect of growth regulators(fatty alcohol and C- MH) on the change of protein, DNA, and RNA were investigated. Generally, inhibition of DNA synthesis was observed soon after become notably reduced when checked on 14 days after the treatment. Fatty alcohol treatment appeared to alleviate the inhibition of DNA synthesis caused by the C - MH treatment. It was also observed that in the tips DNA content increased slightly at the early stage after the C - MH treatment but evident reduction of it was resulted from 7th day after the treatment. RNA content in cutters and tips was increased initially but variable transcription inhibitory activities - not so obvious as was observed in DNA synthesis - according to leaf positions were shown thereafter. Ripening of leaves probably due to senescence was advanced by the treatment of the growth regulators. DNA content in root was relatively higher in plants treated with the growth regulators while it was clearly decreased in stalk, However, RNA contents in tissue of stalk and root was not different with that of foliage. Increase of protein content in foliage as well as in stalk was evident 14 days after dual treatment of fatty alcohol and C - MH.

• Bulletin of the Korean Chemical Society
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• v.32 no.10
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• pp.3779-3782
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• 2011

• Journal of Life Science
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• v.17 no.9 s.89
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• pp.1232-1236
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• 2007

Growth and DNA synthesis inhibitory effects of extracts from root bark of Ulmus parvifolia on MG-63 human osteosarcoma cells, HT-29 human colon cancer cells and K-562 leukemia cancer cells were studied. The root bark extract of Ulmus parvifolia was extracted with methanol, hot water and juice. The methanol extract showed the highest inhibitory effect on growth of MG-63, HT-29 and K-562 cancer cells by >85%. The treatment of hot water and juice extracts from root bark of Ulmus parvifolia also inhibited growth of the above cancer cells with increasing concentration. DNA synthesis of MG-63 and HT-29 cancer cells was significantly inhibited by adding methanol, hot water and juice extracts from root bark of Ulmus parvifolia with increasing concentration, showing that the inhibitory effect of growth was more effective on HT-29 cancer cells. These results suggest that the methanol extract from root bark of Ulmus parvifolia may have specific active com-pounds on anticancer effect. The hot water extract also showed a strong inhibitory effect on growth of cancer cells, indicating that the active compounds may be stable to heat.

• Bulletin of the Korean Chemical Society
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• v.35 no.4
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• pp.1105-1109
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• 2014

While single strand DNAs have been widely used for the scaffold of brightly fluorescent silver nanoclusters (Ag NCs), double strand DNAs have not been as successful. Herein, we report a novel synthetic approach for bright Ag NCs using branched double strand DNAs as the scaffolds for synthesis. X-shaped DNA (X-DNA) and Y-shaped DNA (Y-DNA) effectively stabilized Ag NCs, and both X-DNA and Y-DNA resulted in brightly fluorescent Ag NCs. The concentration and molar ratio of silver and DNA were found important for the fluorescence efficiency. The brightest Ag NC with the photoluminescence quantum efficiency of 19.8% was obtained for the reaction condition of 10 ${\mu}M$ X-DNA, 70 ${\mu}M$ silver, and the reaction time of 48 h. The fluorescence lifetime was about 2 ns for the Ag NCs and was also slightly dependent on the synthetic condition. Addition of Cu ions at the Ag NC preparations resulted in the quenching of Ag NC fluorescence, which was different to the brightening cases of single strand DNA stabilized Ag NCs.