• 제목/요약/키워드: Response inhibition

검색결과 1,104건 처리시간 0.027초

당근(Daucus carota L.)배양세포의 DNase활성에 미치는 Polyamines의 영향 (The Effect of Polyamines on the DNase Activity in Cultured Carrot Cells)

  • 윤미정
    • Journal of Plant Biology
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    • 제29권4호
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    • pp.285-294
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    • 1986
  • The present study was attempted to investigate the effects of polyamines such as putrescine, spermidine and spermine on protein content and DNase activity in vivo and in vitro in carrot embryos. It was also investigated whether polyamines could replace role of cations required for DNase activity in vitro. The results obtained are as follows. Putrescine, spermidine and spermine increased protein content, although response to spermine reached plateau at the concentration of 0.1 mM. DNase activity was inhibited by polyamines, the inhibition being concentration-dependent and the highest att he concentration of 10 mM. The inhibition of DNase activity was the most prominent with spermine. Similar inhibitory effect to polyamines which was concentration-dependent was found in DNase activity but no change was shown on time-course in vitro. Putrescine and spermidine enhanced the DNase activity at low Mg2+ and Mn2+ concentrations, suggesting that the role of Mg2+ and Mn2+ for DNase activity could be, in part, replaced by these polyamines. These results, therefore, suggest that plyamines can modulate DNase activity through binding to DNA rather than direct effect on DNase activity.

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단삼추출물의 Src-family Kinase 억제에 의한 항앨러지 효과 (Salviae Radix Suppresses Mast Cell-mediated Allergic Response: Inhibition of Src-family Kinase)

  • 김영미
    • 약학회지
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    • 제52권5호
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    • pp.370-375
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    • 2008
  • In this study, the anti-allergic activity and mechanim of Salviae radix (SR) were investigated. The ethanol extract of SR showed significant inhibitory effect on degranulation from antigen-stimulated mast cells and it also inhibited the expression and secretion of TNF-${\alpha}$ and IL-4 in antigen-stimulated RBL-2H3 cells. In the mast cell-mediated local animal allergy model, it suppressed the passive cutaneous anaphylaxis in a dose-dependent manner. As its mechanism of action, SR inhibited the activating phosphorylation of Syk, a downstream signaling molecule of Src-family kinase, for the activation of mast cells. The results of the study indicate that the anti-allergic activity of SR is mediated by the inhibition of Src-family kinase in mast cells.

생체생장에 관한 세포생물학적 연구 당근 뿌리의 원형질체에서 D-glucose-6-phosphate cyclohydrolase 활성도에 미치는 polyamine과 $Ca^{2+}$의 영향 (Cell Biological Studies on Growth and Development Effect of polyamine and $Ca^{2+}$ on D-glucose-6-phosphate cyclohydrolase activity in carrot root protoplast)

  • 이순희
    • Journal of Plant Biology
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    • 제30권4호
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    • pp.249-255
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    • 1987
  • The effect of polyamine and Ca2+ on D-glucose-6-phosphate cyclohydrolase activity was studied in Daucus carota root. The enzyme activity was reduced in response to increase in concentration of Ca2+, not the Ca2+-calmodulin complex. The inhibition effect due to Ca2+ was reversed by polyamine, especially remarkable at low concentration of Ca2+. The effect of the Ca2+ on the enzyme seemed to compete with polyamine according to the Lineweaver-Burk plot. The enzyme activity from carrot root protoplast cultured in the prescence of verapamil was higher than that of the control. Such cumulative results suggest that the inhibition by the Ca2+ and enhancement or reversal by polyamine could regulate the biosynthesis of pectin and hemicellulose to some extent.

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Immunotherapy for Non-Small Cell Lung Cancer

  • Yoon, Sung Ho
    • Tuberculosis and Respiratory Diseases
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    • 제77권3호
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    • pp.111-115
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    • 2014
  • Lung cancer is the leading cause of cancer-related mortality worldwide, and more than 80% of cases are of non-small cell lung cancer. Although chemotherapy and molecularly targeted therapy may provide some benefit, there is a need for newer therapies for the treatment of patients with advanced NSCLC. Immunotherapy aims to augment the recognition of cancer as foreign, to stimulate immune responsiveness, and to relieve the inhibition of the immune response that allows tolerance to tumor survival and growth. Two immunotherapeutic approaches showing promise in NSCLC are immune checkpoint inhibition and cancer vaccination. Although currently immunotherapy does not have an established role in the treatment of NSCLC, these patients should be enrolled in formal clinical trials.

오존에 대한 식물 기공 반응고찰 (Stomatal Response by Ozone)

  • 이준상;김병우
    • The Korean Journal of Ecology
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    • 제20권2호
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    • pp.83-94
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    • 1997
  • Stomatal closing by ozone and water stress could reduce further ozone injury by inhibition of ozone influx to the tissue. Direct effect of ozone on stomata can be explained from two aspects which are a stimulation of stomatal closing and an inhibition of stomatal opening. An increase of $Ca^{2+}$ influx into cytoplasm by ozone could stimulate potassium efflux ion channel and inhibits inward potassium ion channels. By this mechanism ozone could induce stomatal closing. On the other hand, ozone could inhibit stomatal opening by affecting the activity of $H^{+}$ dependent ATPase of the membrane in guard cells. This would inhibit proton efflux which precede stomatal opening. It is also possible that ozone could reduce the activity of photosynthesis in guard cells which lead to affect the production of osmotically active sugars and energy. Indirect effect of ozone to stomata is through the effect of $CO_2$ elevation as a result of damage of the photozynthetic machinery. This indirect effect is slower than the direct effect.

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Induction of Autophagy by Rosa acicularis Leaves Extracts in RAW264.7 Cells

  • Jeong Won Choi;Hyeok Jin Choi;Gwang Hyeon Ryu;Seung Woo Im;Jae Won Lee;Jin Boo Jeong
    • 한국자원식물학회:학술대회논문집
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    • 한국자원식물학회 2023년도 임시총회 및 춘계학술대회
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    • pp.45-45
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    • 2023
  • Autophagy contributes to enhancing the immune system (innate and adaptive immune system) against foreign pathogens. Autophagy of macrophages is used as a major indicator for developing vaccine adjuvants to increase the adaptive immune response. In this study, RAL increased the production of immunostimulatory mediators and phagocytotic activity in RAW264.7 cells. RAL increased p62/SQSTM1 expression. Inhibition of TLR4, JNK, and PI3K/AKT blocked RAL-mediated increase of p62/SQSTM1. RAL activated JNK and PI3K/AKT signaling. RAL-mediated activation of JNK and PI3K/AKT signaling was reversed by TLR4 inhibition. Taken together, it is believed that RAL-mediated autophagy may be dependent on activating via TLR4-dependent activation of JNK and PI3K/AKT signaling in macrophages.

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청금탕(淸金湯)의 효능(效能)에 관(關)한 실험적(實驗的) 연구(硏究) (Experimental Studies on the Effects of Chunggeumtang)

  • 김응식;이시형
    • 대한한방내과학회지
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    • 제18권2호
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    • pp.1-26
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    • 1997
  • Chunggeumtang has been used in Korea for many centuries as a treatment for respiratory disease. The effect of Chunggeumtang on tracheal smooth muscle is not konwn. The purpose of the present study is to determine the effect of Chunggeumtang on histamine and acetylcholine induced tracheal smooth muscle contraction in rats and guinea pigs. Guinea pig(500g, male) and Sprague Dawley rats (250g, male) were killed by $CO_2$ exposure and a segment (8-10mm) of the thoracic trachea from each rat and guinea pig was cut into equal swegments and mounted 'in pairs' in a tissue bath. Contractile force was measured with force diplacement transducers under 0.5g loading tension. The dose of histamine (His) and acetylcholine (Ach) which evoked 50% of maximal response ($ED_{50}$) was obtained from cumulative dose response curves for histamine and acetylcholine($10^{-7}{\sim}10^{-4}M$). Contractions evoked by His ($ED_{50}$) and Ach ($ED_{50}$) were inhibited significantly by Chunggeumtang. In guinea pig tracheal smooth muscle, the mean percent inhibition of acetylcholine induced contraction was $6.1%after\;30{\mu}l/ml$ Chunggeumtang, and 49.4% (p<0.01) after $100{\mu}l/ml$ Chunggeumtang. In rat tracheal smooth muscle, the mean percent inhibition of acetylcholine induced contraction was $6.7%\;after\;30{\mu}l/ml$ Chunggeumtang, and $54.2%\;(p<0.01)\;after\;100{\mu}l/ml$ Chunggeumtang. Also, in guinea pig tracheal smooth muscle, the mean percent inhibition of histamine induced contraction was $30.6%\;(p<0.05)\;after\;30{\mu}l/ml$ Chunggeumtang, and $53.0%\;(p<0.01)\;after\;100{\mu}l/ml$ Chunggeumtang. In rat tracheal smooth muscle, the mean percent inhibition of histamine induced contraction was $24.1%\;(p<0.05)\;after\;30{\mu}l/ml$ Chunggeumtang, and $55.3%\;(p<0.01)\;after\;100{\mu}l/ml$ Chunggeumtang. Propranolol and indomethacin($10^{-7}M$) slightly but significantly attenuated the inhibitory effects of Chunggeumtang. Following treatment with propranolol, the mean percent inhibition caused by $100{\mu}l/ml$ Chunggeumtang fell to 27.6% in guinea pig induced by acetylcholine contraction and by $100{\mu}l/ml$ Chunggeumtang fell to 28.7% (p<0.05) in rat induced by acetylcholine contraction and the mean percent inhibition caused by $100{\mu}l/ml$ Chunggeumtang fell to 16.2% in guinea pig induced by histamine contraction and by $100{\mu}l/ml$ Chunggeumtang fell to 28.7% (p<0.05) in rat induced by histamine contraction. Indomethacin, the mean percent inhibition caused by $100{\mu}l/ml$ Chunggeumtang fell to 20.0% in guinea pig induced by acetylcholine contraction and by $100{\mu}l/ml$ Chunggeumtang fell to 16.9% (p<0.05) in rat induced by acetylcholine contraction and the mean percent inhibition caused by $100{\mu}l/ml$ Chunggeumtang fell to 16.4% in guinea pig induced by histamine contraction and by $100{\mu}l/ml$ Chunggeumtang fell to 23.1% (p<0.05) in rat induced by histamine contraction. Methylene blue($10^{-7}M$) did not significantly alter the inhibitory effect of Chunggeumtang. Also, I could find the effects of Chunggeumtang and Chunggeumtanggamorphine on the tracheal smooth muscle in guinea pig and rat did not change significantly. These results indicate that Chunggeumtang can relax histamine and acetylcholine-induced contraction of guinea pig and rat tracheal smooth muscle, and that this inhibition involves sympathetic effects and the release of cyclooxygenase products.

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마우스에 있어서 에이코사펜타엔산이 면역반응(免疫反應)에 미치는 영향(影響)( I ) -I. 체액성(體液性) 면역(免疫)- (The Effect of Eicosapentaenoic Acid on the Immune Response in Mice(I) -I. Humoral-mediated immunity-)

  • 안영근;김정훈;이상근;김행순
    • 약학회지
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    • 제33권1호
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    • pp.20-29
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    • 1989
  • The humoral immune response of Eicosapentanoic acid(EPA) was investigated in mice. ICR male mice were divided into 8 groups and received intraperitoneal injection of EPA(5 mg, 10 mg, 20 mg/kg) for 4 weeks. Cyclophosphamide(5 mg/kg) was administered i.p. 2 days prior to secondary immunization. Humoral immune response was evaluated by antibody titer, hypersensitivity to SRBC (Arthus), plaque forming cell(PFC) and organ weight. The ontanined results were as followings: The increased rate of body weight, the ratio of liver weight, spleen weight to body weight were decreased by all EPA administration groups as compared to normal group. HA titer, HY titer and Arthus reaction were enhanced according to the increase of EPA doses as compared to normal group. PFC was significantly enhanced by EPA 10 mg administration group. These results suggest that EPA enhances humoral immune response to SRBC in mice, indicating that EPA may block a immunoglobulin synthesis inhibition of arachidonic acid.

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Loss of estrogen responsiveness under hypoxia occurs through hypoxia inducible factor-l induced proteasome-dependent down regulation of estrogen receptor

  • Cho, Jung-Yoon;Kim, Duk-Kyung;Lee, Young-Joo
    • 한국응용약물학회:학술대회논문집
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    • 한국응용약물학회 2003년도 Annual Meeting of KSAP : International Symposium on Pharmaceutical and Biomedical Sciences on Obesity
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    • pp.70-70
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    • 2003
  • Estrogen receptor is a ligand-activated transcription factor. Its action depends on the receptor, its ligand, and its coactivator proteins. As a consequence, the concentration of the receptor is a major component that governs the magnitude of the estrogen response. Despite the extensive knowledge on mechanism of estrogen receptor action, regulation of estrogen receptor itself is not very well understood. Estrogen receptor is known to be downregulated under hypoxia leading to inhibition of estrogen receptor mediated transcription activation. We have studied mechanism of loss of estrogen responsiveness under hypoxia. We found that Hif-l${\alpha}$, a major transcription factor regulating hypoxic response, inhibited transcription of estrogen response element driven luciferase gene by expression of HIF-l${\alpha}$/vp16 construct designed to contain transcription activity under normoxia. This loss of estrogen responsiveness appears to be the result of ER${\alpha}$ downregulation. ER${\alpha}$was downregulated at the levels of ligand-biding and protein within l2-24h, and the response was blocked by the proteasome inhibitor MG132, protein synthesis inhibitor cyclohexamide, and tyrosine kinase inhibitor Genistein. These results demonstrate that Hif-l${\alpha}$ downregulates ER${\alpha}$ by proteasome dependent pathway.

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Lower Antibody Response in Chickens Homozygous for the Mx Resistant Allele to Avian Influenza

  • Qu, L.J.;Li, X.Y.;Xu, G.Y.;Ning, Z.H.;Yang, N.
    • Asian-Australasian Journal of Animal Sciences
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    • 제22권4호
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    • pp.465-470
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    • 2009
  • The chicken Mx gene has been regarded as a candidate gene for resistance to avian influenza virus (AIV). In this study, three groups of chickens with homozygotes (AA, GG) and heterozygotes (AG) of the resistant (A) and susceptible alleles (G) to AIV of the Mx gene were constructed from a line of dwarf egg-type chickens. These chickens were not examined for their resistant activities to AIV because the differential resistance had only been detected in vitro. The birds of the three groups were vaccinated with inactivated H5N2 AIV vaccine and the level of hemagglutination inhibition (HI) antibody to AIV was detected. The association between disease resistant activity to AIV and antibody response to AIV vaccination in the three groups was analyzed. The chickens with homozygous resistant allele A showed the lowest antibody levels, whereas the heterozygous chickens (AG) presented the highest antibody level after the boosting vaccination, which indicates that the efficiency of artificial selection on the resistant allele of Mx gene will be compromised since the homozygotes of the allele presented the weakest antibody response to the corresponding vaccine.