• Title/Summary/Keyword: inhibitory mechanism

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The Experience of Open Reduction and Internal Fixation of Mandible Fracture by Acupuncture Method (Acupuncture를 이용한 하악골 골절수술경험 -증례 보고-)

  • Khil, Hong-Mo;Kwak, Ho-Sung;Ro, Shik
    • The Korean Journal of Pain
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    • v.9 no.1
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    • pp.195-199
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    • 1996
  • Based on points of neuroendocrine physiology, stimulus developed at the acupuncture site can pass to the pituitary gland through somatosensory and activated descending inhibitory mechanism which originated in raphe magnus of midbrain. For the operation of mandible fracture, acupuncture anesthesia was performed at 6 points of both forearm and both feet by method taking point on distant segment. Acupuncture anesthesia deals with central analgesic mechanism and the theory of diffuse noxious inhibitory control.

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Inhibitory Effect of Anaphylaxis by WK101 and Mechanism of Action (WK101에 의한 아나필락시의 억제효과와 작용기전)

  • 이영미;김형룡
    • YAKHAK HOEJI
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    • v.39 no.6
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    • pp.616-621
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    • 1995
  • The effect of WK101 on compound 48/80-induced anaphylaxis was studied in rat. WK101 was found to exhibit a inhibitory activity on the compound 48/80-induced anaphylaxis. WK101 also inhibited the serum histamine release induced in anaphylaxis by compound 48/80. The effect of WK101 on the histamine release from rat peritoneal mast cells was studied. WK101 ($10^{3}-1mg/ml$) inhibited the histamine release induced by compound 48/80($5{\;}\mu\textrm{g}/ml$) in rat peritoneal mast cells. To clarify the mechanism of these inhibitons, we investigated the effects of WK101 on cAMP and intracellular calcium content of rat peritoneal mast cell. The content of cAMP in mast cells, when WK101 was added, was increased transiently, and was significantly increased more 53 fold at 10 sec than that of basal cells. Moreover, WK101 inhibited intracellular calcium release induced by compoound 48/80. This results suggest that WK101 may be useful for the prevention and treatment of allergy-related disease.

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Inhibitory Mechanism of a New Antitumor Agent DA125 on DNA Replication (새로운 항암제 DA-125의 유전자 복제 억제 기작)

  • 이상광;김도진;오유택;이상득;우은란;신차균
    • YAKHAK HOEJI
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    • v.43 no.5
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    • pp.623-628
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    • 1999
  • DA-125, a new antitumor agent, was compared with adriamycin, a known DNA intercalator, in terms of inhibitory mechanism of DNA replication by using replicating simian virus 40 (SV40) genome in vivo. In analyzing the SV40 DNA replication intermediates present in cells treated with DA-125, it was not observed to accumulate B-dimers of SV40 DNA which are prominent in adriamycin-treated cells. However, treatment with DA-125 induced dose-dependent formation of DNA-topoisomerase complex which is characteristic of topoisomerase poisons. In addition, DA-125 showed more efficient in inhibiting SV40 DNA replication than adriamycin. Therefore, on the basis of this observation, we suggest that DA-125, a derivative of adriamycin, inhibits DNA replication by blocking topoisomerase activity as a toposomerase poison although adriamycin blocks topoisomerase activity as a DNA intercalator.

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Inhibition Mechanism of $\alpha$-D-Glucosidase Inhibitor from Streptomyces sp (Streptomyces속 균주가 생성하는 $\alpha$-D-Glucosidase 저해물질의 작용상)

  • 도재호;주현규
    • Microbiology and Biotechnology Letters
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    • v.18 no.1
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    • pp.39-43
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    • 1990
  • The inhibitor had the inhibitory activities against hydrolysis of PNPG, sucrose and ONPG by $\alpha$-Dglucosidase, $\alpha$ - and $\beta$ -galactosidase, but it did not inhibit amylases and other carbohydrases. Kinetic studies exhibited that the inhibitory substance non-competitively inhibited the enzyme reaction with a Ki value of 118 $\mu$g/m$\ell$, and enzyme-inhibitor complex was formed slowly.

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Anticancer Activity of Indeno[1,2-b]-Pyridinol Derivative as a New DNA Minor Groove Binding Catalytic Inhibitor of Topoisomerase IIα

  • Jeon, Kyung-Hwa;Shrestha, Aarajana;Jang, Hae Jin;Kim, Jeong-Ahn;Sheen, Naeun;Seo, Minjung;Lee, Eung-Seok;Kwon, Youngjoo
    • Biomolecules & Therapeutics
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    • v.29 no.5
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    • pp.562-570
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    • 2021
  • Topoisomerase IIα has been a representative anti-cancer target for decades thanks to its functional necessity in highly proliferative cancer cells. As type of topoisomerase IIα targeting drugs, topoisomerase II poisons are frequently in clinical usage. However, topoisomerase II poisons result in crucial consequences resulted from mechanistically induced DNA toxicity. For this reason, it is needed to develop catalytic inhibitors of topoisomerase IIα through the alternative mechanism of enzymatic regulation. As a catalytic inhibitor of topoisomerase IIα, AK-I-191 was previously reported for its enzyme inhibitory activity. In this study, we clarified the mechanism of AK-I-191 and conducted various types of spectroscopic and biological evaluations for deeper understanding of its mechanism of action. Conclusively, AK-I-191 represented potent topoisomerase IIα inhibitory activity through binding to minor groove of DNA double helix and showed synergistic effects with tamoxifen in antiproliferative activity.

p53-mediated Inhibitory Mechanism on HIV-1 Tat is Likely to be Associated with Tat-Phosphorylation (p53에 의한 HIV-1 Tat 활성억제와 인산화관련 가능성 연구)

  • Byune, Hee-Sun;Lee, Sang-Gu;Bae, Yong-Soo
    • The Journal of Korean Society of Virology
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    • v.28 no.1
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    • pp.39-52
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    • 1998
  • HIV-1 tat, a strong transactivator, is essential for the HIV-1 replication and AIDS progression. The Tat function is markedly inhibited by human anti-oncogene p53. This work was initiated to identify the p53-associated inhibitory mechanism on tat-mediated transactivation. Inhibitory function of p53 was confirmed by co-transfection of tat-expressing Jurkat cells with LTR-CAT plasmid, or H3T1 cells (LTR-CAT integrated HeLa cells) with different ratio of pSV-tat/pCDNA-p53 plasmids. Results from the direct protein-protein interaction between soluble p53 and tat, and yeast two-hybrid experiments showed that the co-suppression mechanism is unlikely to be due to the direct interaction. CAT activity was not affected by tat in Jurkat cells which were transfected with p53-promoter-CAT or p53-enhancer-CAT, suggesting that the tat-mediated p53 suppression is not directly associated with p53-promoter. Finally, we have tested protein kinase activity in p53-tranfected Jurkat cells, which might phosphorylate HIV-1 tat, resulting in inhibition of tat function. Some of our data lead us to assume that the p53-mediated tat inhibition is likely to be associated with p53-associated, signaling-mediated phosphorylation of tat, resulting in the dysfunction of tat. This study is now under investigation.

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Inhibitory mechanism of Korean Red Ginseng on GM-CSF expression in UVB-irradiated keratinocytes

  • Chung, Ira;Lee, Jieun;Park, Young Sun;Lim, Yeji;Chang, Do Hyeon;Park, Jongil;Hwang, Jae Sung
    • Journal of Ginseng Research
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    • v.39 no.4
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    • pp.322-330
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    • 2015
  • Background: UV-irradiated keratinocytes secrete various proinflammatory cytokines. UV-induced skin damage is mediated by growth factors and proinflammatory cytokines such as granulocyte macrophage colony stimulating factor (GM-CSF). In a previous study, we found that the saponin of Korean Red Ginseng (SKRG) decreased the expression of GM-CSF in UVB-irradiated SP-1 keratinocytes. In this study, we attempted to find the inhibitory mechanism of SKRG on UVB-induced GM-CSF expression in SP-1 keratinocytes. Methods: We investigated the inhibitory mechanism of SKRG and ginsenosides from Panax ginseng on UVB-induced GM-CSF expression in SP-1 keratinocytes. Results: Treatment with SKRG decreased the expression of GM-CSF mRNA and protein induced by irradiation of UVB in SP-1 keratinocytes. The phosphorylation of ERK was induced by UVB at 10 min, and decreased with SKRG treatment in SP-1 keratinocytes. In addition, treatment with SKRG inhibited the UVB-induced phosphorylation of epidermal growth factor receptor (EGFR), which is known to be an upstream signal of ERK. From these results, we found that the inhibition of GM-CSF expression by SKRG was derived from the decreased phosphorylation of EGFR. To identify the specific compound composing SKRG, we tested fifteen kinds of ginsenosides. Among these compounds, ginsenoside-Rh3 decreased the expression of GM-CSF protein and mRNA in SP-1 keratinocytes. Conclusion: Taken together, we found that treatment with SKRG decreased the phosphorylation of EGFR and ERK in UVB-irradiated SP-1 keratinocytes and subsequently inhibited the expression of GM-CSF. Furthermore, we identified ginsenoside-Rh3 as the active saponin in Korean Red Ginseng.

Inhibitory Mechanism of Propranolol on the Effects of VIP in Peripheral Blood T-lymphocytes of Rat (흰쥐 말초혈액 T-림프구에서 Vasoactive Intestinal Polypeptide의 효과에 대한 Propranolol의 억제 기전)

  • Ahn, Young-Soo;Choo, Sung-Yee;Kang, Dong-Won;Lee, Sang-Hun
    • The Korean Journal of Pharmacology
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    • v.31 no.2
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    • pp.219-231
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    • 1995
  • Vasoactive intestinal polypeptide(VIP) and ${\beta}-adrenergic$ agonists have immunomodultory effects on the peripheral blood T-lymphocytes of rat through their own receptors. Both of them utilize the same signal transduction pathway. That is, the stimulatory guanine nucleotide binding protein(G protein) mediates the receptor-adenylyl cyclase coupling, producing intracellular increase of cyclic adenosine monophosphate(cAMP). In the previous experiment, propranolol, a ${\beta}-adrenergic$ receptor blocker, inhibited the VIP-induced protein phosphorylation in lymphocytes. However, propranolol could not block the effect induced by forskolin. Therefore, this study was designed to elucidate the mechanism of the inhibitory action of propranolol on the effects of VIP. Using peripheral blood lymphocytes of rats, the effect of propranolol on the receptor binding characteristics of VIP was observed. And the effects of propranolol were compared to the effects of timolol on the cAMP increase induced by isoproterenol, VIP or forskolin. The results obtained are as follows. 1) Receptor binding study showed no significant differences in the affinity or density of VIP receptor between the control and propranolol-pretreated groups. 2) VIP-induced increase of cAMP was inhibited by propranolol, but not by timolol. 3) Both propranolol and timolol suppressed the isoproterenol-induced cAMP increase. 4) Propranolol also inhibited the histamine-induced cAMP increase. 5) Propranolol did not inhibit the increase of cAMP stimulated by forskolin. 6) Lidocaine did not block the VIP-induced cAMP increase. These results show that the inhibitory mechanism of propranolol is not related to ${\beta}-adrenergic$ receptor or its membrane stabilizing effect, and it is suggested that propranolol can block the effects of VIP by inhibiting the intermediate step between the VIP receptor and adenylyl cyclase.

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The Experimental Stydy on the Anti-Allergic Rhinitis Effects of the Gamigyeji-tang (加味柱枝湯이 알레르기 비염에 미치는 영향에 관한 실험적 연구)

  • Sim Sung-yong;Kim Kyung-jun
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.17 no.1
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    • pp.45-54
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    • 2004
  • Major symptoms of allergic rhinitis are nasal obstructions, sneezing and watery rhinorrhea. Gamigyeji-tang has been used to treat for watery rhinorrhea, which is one of the symptoms of allergic rhinitis. This experimental study was done to rescarch effects of Gamigyeji-tang. We have studied effect of mice on OVA-induced Production of IL-4, IL-5, IFN-${\gamma}$ by Murine Splenocytes, and effect of OVA-induced total IgE and OVA-Specific IgE. The results were as follows ; 1. In IL-4 study, Gamigyeji-tang treated group was proved significant inhibitory effect(p〈0.005) 2. In IL-5 study, Gamigyeji-tang treated group was proved significant inhibitory effect.(p〈0.05) 3. In IFN-${\gamma}$ study, Gamigyeji-tang treated group was proved significant inhibitory effect(p〈0.000001) 4. In Total IgE, Gamigyeji-tang treated group didn't showed significant inhibitory effect. 5. In OVA-specific IgE, Gamigyeji-tang treated group didn't showed significant inhibitory effect. According to this result, Gamigyejj-tang was concluded to be effective on anti-allergic action. More studies are required to investigate the mechanism of inhibition by herbal medicine in allergic rhinitis model.

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