• 제목/요약/키워드: E4

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Curcumin Induces Downregulation of E2F4 Expression and Apoptotic Cell Death in H CT116 Human Colon Cancer Cells; Involvement of Reactive Oxygen Species

  • Kim, Kyung-Chan;Lee, Chu-Hee
    • The Korean Journal of Physiology and Pharmacology
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    • 제14권6호
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    • pp.391-397
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    • 2010
  • E2F transcription factors and their target genes have been known to play an important role in cell growth control. We found that curcumin, a polyphenolic phytochemical isolated from the plant Curcuma longa, markedly suppressed E2F4 expression in HCT116 colon cancer cells. Hydrogen peroxide was also found to decrease E2F4 protein level, indicating the involvement of reactive oxygen species (ROS) in curucmin-induced downregulation of E2F4 expression. Involvement of ROS in E2F4 downregulation in response to curcumin was confirmed by the result that pretreatment of cells with N-acetylcystein (NAC) before exposure of curcumin almost completely blocked the reduction of E2F4 expression at the protein as well as mRNA level. Anti-proliferative effect of curcumin was also suppressed by NAC which is consistent to previous reports showing curcumin-superoxide production and induction of poly (ADP-ribose) polymerase (PARP) cleavage as well as apoptosis. Expression of several genes, cyclin A, p21, and p27, which has been shown to be regulated in E2F4-dependent manner and involved in the cell cycle progression was also affected by curcumin. Moreover, decreased (cyclin A) and increased (p21 and p27) expression of these E2F4 downstream genes by curcumin was restored by pretreatment of cells with NAC and E2F4 overexpression which is induced by doxycycline. In addition, E2F4 overexpression was observed to partially ameliorate curcumin-induced growth inhibition by cell viability assay. Taken together, we found curcumin-induced ROS down-regulation of E2F4 expression and modulation of E2F4 target genes which finally lead to the apoptotic cell death in HCT116 colon cancer cells, suggesting that E2F4 appears to be a novel determinant of curcumin-induced cytotoxicity.

배구경기 세터 토스 동작의 운동학적 비교분석 (Kinematic Variables Comparison of Setter Toss Motion on Volleyball According to Toss Types)

  • 정남주;김재필
    • 한국운동역학회지
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    • 제25권1호
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    • pp.57-64
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    • 2015
  • Purpose : The purpose of this study was to analyze setter toss motion kinematically according to toss types. Method : Dependent variables were elapsed time, vertical displacement of the body center, the projected speed of the ball, and differences of the joint angle to the target for four setters positioning. Result : There was no significant difference in the time but the ball contact time was shorter when the toss distance of P3 was longer. There was significant difference in the vertical displacement of COM (p<.05). The vertical displacement of COM showed that the vertical movement gradually decreased when the quick distance was longer. The vertical displacement of COM was difference (p<.05), also there was difference of the ball speed (p<.001) at the Release point(E4). There was significant difference in the knee joint angle at a certain moment among the Release(E4) and Landing point(E5)(p<.05). The hip joint was significant difference among the Apex(E2), Ball Touch(E3), Release(E4), and the Landing point(E5) on the surface(E2, E3, E4 p<.05; E5 p<.005). The shoulder angle was significant difference among the Ball Touch(E3), Release(E4) and the Landing point(E5) on the surface(E3, E4 p<.05; E5 p<.001). The elbow was significant difference in the Apex(E2) (p<.05). The wrist was significant difference in the Release(E4) (p<.05). Conclusion : If we find the clue to expect the direction of the setter's ball, we have to fine the clues in the Apex(E2) that hip join and elbow, Ball Touch(E3) that hip joint and shoulder joint, Release(E4) that wrist, elbow, hip joint, and knee joint.

HepG2 세포에서 Ethanol, Glycerol, 4-Methylpyrazole 및 Isoniazid에 의한 Human CYP2E1 활성변화 (Differential Role of Ethanol, Glycerol, 4-Methylpyrazole and Isoniazid on Human CYP2E1 Activity in Intact HepG2 Cells)

  • 최달웅
    • Toxicological Research
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    • 제19권3호
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    • pp.235-240
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    • 2003
  • The modification of CYP2E1 activity is of considerable interest because of its role in the metabolic activation of a variety of toxic chemicals. In the present studies, the time-course of changes in human CYP2E1 activities was determined after treatment with ethanol, glycerol, 4-methylpyrazole or isoniazid using intact HepG2 cells transfected by human CYP2E1. Hydroxylation of chlorzoxazone was chosen for the measurement of CYP2E1 activity. CYP2E1 protein levels were increased upon cultivation of cells in the presence of ethanol, glycerol, 4-methylpyrazole or isoniazid for 24 hr. After 24 hr cultivation, ethanol or glycerol increased CYP2E1 activities, whereas 4-methylpyrazole or isoniazid inhibited. This different effect of the chemical inducers on CYP2E1 activi-ties persisted to subsequent 24 hr. Competitive inhibition study suggested that 4-methylpyrazole or isoniazid has stronger binding affinity to CYP2E1 than ethanol or glycerol. These results demonstrate that different binding affinity of the chemical inducers to the active site of CYP2E1 plays important role in determining real CYP2E1 activity in intact cells after treatment with the chemical inducers. Present study would be helpful in precise understanding of human CYP2E1-mediated toxicity.

$Cd_4GeSe_6$$Cd_4GeSe_6:Co^{2+}$ 단결정의 광전도도 특성 (Photoconductivity spectra of undoped and co-doped $Cd_4GeSe_6$ single crystals)

  • 김덕태
    • E2M - 전기 전자와 첨단 소재
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    • 제9권2호
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    • pp.152-158
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    • 1996
  • Optical absorption and photoconductivity spectra of undoped and Co-doped Cd$_{4}$GeSe$_{6}$ single crystals, grown by the chemical transport reaction using iodine as a transporting agent, were investigated. At 20K, the optical energy gaps of the single crystals are 1.934eV for Cd$_{4}$GeSe$_{6}$ and 1.815eV for Cd$_{4}$GeSe$_{6}$ :Co$^{2+}$. The photoconductivity spectra of these single crystals were closely investigated over the temperature range 20-290K. At 20K, the photoconductivity peaks were located at 1.797eV, 1.347eV for Cd$_{4}$GeSe$_{6}$ and 1.815eV, I,.57eV, 1.46eV and 1.38eV for Cd$_{4}$GeSe$_{6}$ :Co$^{2+}$, respectively.ely.

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배추흰나비(Pieris rapae L.)의 esterase에 관한 연구 II. 생화학적 특성 및 면역학적 연구 (Studies on Esterase of Pieris rapae L. II. Biochemical Properties and Immunological Studies)

  • 박철호;김학열;여성문
    • 한국동물학회지
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    • 제33권3호
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    • pp.337-345
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    • 1990
  • 배추흰나비로부터 정제된 3개의 esterase의 특성을 조사하였으며 면역학적 연구를 통해 E6의 생리적 역할을 추정하였다. 억제제의 연구결과, E2, E6, E11 모두 carboxylesterase임이 밝혀졌다. Km 값은 E2, E6 및 E11이 각각 6.89 X 10-$^4$M. 3.19 $\times$ l0-$^4$M, 3.69 X 10-$^4$M이었다. 분자량은 E2, E6 및 E11이 각각 42 KD, 81 KD, 174 KD이었고 등전점은 각각 pH 5.54, pH 5.89, pH 6.50이었다. 변태에 따른 E6의 농도는 5령 말기에서 가장 높았으며 특히 중장조직에서 높게 나타났다. 따라서 E6은 소화효소로 사료된다.

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지실(枳實)에 의한 면역(免疫)글로블린 E 생성(生成)의 억제효과(抑制效果) (Inhibitory Effect of Immunoglobulin E Production by Poncirus tripoliata)

  • 김형균;권용택
    • 대한한의학회지
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    • 제19권1호
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    • pp.419-429
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    • 1998
  • Poncirus trifoliata (L.) Raf (Rutaceae) fruits (PTFE) has been used for the treatment of allergic disease. IgE is normally one of the least abundant immunoglobulin (Ig) isotypes in the serum of both humans and several species of experimental animals: however a number of different stimuli can result in profound increases in IgE levels relative to other isotypes. In rodents, infection with many parasitic helminths can cause approximately 100-fold elevation in IgE within 2 wks. Immunization of mice with small amounts of protein antigens on alum also results in 10-fold to fold increase in total serum IgE, much of it specific for the immunizing antigen. In this experiment, I investigated the effect of an aqueous extract of Poncirus trifoliata (L.) Raf (Rutaceae) fruits (PTFE) on a in vivo and in vitro IgE production. PTFE dose-dependently inhibited the serum levels of IgE induced by antigens. The regulation of IgE synthesis is influenced by T cells and T cell derived factors. IL -4, a T cell-derived cytokine, has been shown to stimulate murine IgE synthesis both in vitro and in vivo. Current evidence suggests that IL-4 induces IgE synthesis in the mouse by stimulating H chain isotype switch. Lipopolysaccharide (LPS) plus IL-4 cause about l00-fold increase in IgE secretion by murine B cells. The effects of PTFE on the IL-4-dependent IgE response by mouse whole spleen cells were studied. Whole spleen cells were cultured for 7 days in the presence of LPS plus IL-4 and PTFE and the supernatants were assayed for IgE. IL-4 dependent IgE production of LPS-stimulated whole spleen cells was inhibited by PTFE. Moreover, in the present study using U266Bl human IgE-bearing B cells, I found that PTFE inhibited the production of IgE activated by LPS plus IL-4. These results indicate that PTFE have antiallergic activity by inhibition of IgE production from B cells.

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항진균 알릴아민 유도체의 합성과 생물학적 평가 (Synthesis and Biological Evaluation as a Potential Antifungal Allylamine Derivatives)

  • 정병호;정순영
    • 약학회지
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    • 제48권4호
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    • pp.254-260
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    • 2004
  • Structure-activity relationship studies of allylamine type of antimycotics were carried out to evaluate the effect of naphthyl and methyl portion of naftifine. Compounds with 2,4-difluorophenyl( 2a-5a), 2,5-difluorophenyl(2b-5b), 4-ethylphenyl(2c-5c), 2-hydroxyphenyl(2d-5d) and 2-methylnaphthyl(2e-5e) instead of naphthyl group with hydrogen(3a-3e), methyl(4a-4e), and ethyl(5a-5e) in the place of methyl in naftifine were synthesized and tested their in vitro anti-fungal activity against five different fungi. Eight compounds( 3a, 4a, 5a, 3d, 4d, 4d, 5d, 3e, and 4e) showed significant anti-fungal activity against T. mentagroPhytes. (E)-N-(3-Phenyl-2-propenyl)-2- hydroxy-benzenemethaneamine( 3d) displayed moderate antifungal activity against all five different fungi.

백강잠(Bombysis corpus)으로부터 유용물질 분리 (A useful material isolation from the Bombycis corpus (Beauveria bassiana) growing of the silkworm, Bombyx mori L.)

  • 정이연;남성희;홍인표;유승헌;권학철;이강노
    • 한국잠사곤충학회지
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    • 제45권1호
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    • pp.25-30
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    • 2003
  • 뇌신경세포주(PC12)에 백강잠의 분획물(조추출물)을 10 $\mu\textrm{g}$/ml 농도로 처리한 결과 헥산분획층과 부탄올분획층에서 뇌신경세포성장을 촉진하는 활성을 나타내어 헥산분획물로부터 화합물 4종(Fig.2: compound 1-4)과 부탄올분획물로부터 화합물 5종(Fig.2: compound 5-9)을 분리하여 각각의 화합물에 대하여도 검색한 결과 모두 뇌신경세포주(PC12)에 뇌신경세포 성장 촉진효과를 나타냈으며 특히 이들중 3종(4E, 6E, 2S, 3R)-2-N-Eicosanoy1-4,6-tetrade-casphingadienine,(4E, 6E, 2S, 3R)-2-N-Docosanoyl-4,6-tetradecasphingadienine, Urea)이 화합물은 NGF보다 우수한 활성을 나타냈다. 또한 헥산분획물로부터 분리한 4종의 스핑고신 유도체는 천연에서 처음 보고되는 물질이다. 이러한 결과로부터 백강잠 유래의 유효성분을 함유하는 추출물은 뇌졸중, 뇌허혈, 파킨슨, 노인성치매 및 헌팅턴질환을 포함하는 뇌질환 예방 및 치료를 위한 약학적 제제로 활용할 수 있을 것으로 기대된다.

2-pyran-4-ylidene-malononitrile을 기본으로 하는 작은 Band Gap을 가지는 공중합체의 합성 및 광전변환 특성 (Synthesis and Photovoltaic Properties of Low Band Gap π-conjugated Polymers Based on 2-pyran-4-ylidene-malononitrile Derivatives)

  • 유혜리;신웅;박정배;박상준;임준혁;김주현
    • 공업화학
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    • 제20권3호
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    • pp.273-278
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    • 2009
  • Heck coupling reaction을 이용해서 poly[2-(2,6-dimethylpyran-4-ylidene)malononitrile-alt-1,4-bis(dodecyloxy)-2,5-divinylbenzene] (PM-PPV), poly[2-{2,6-Bis-[2-(5-bromothiophen-2-yl)-vinyl]-pyran-4-ylidene}-malononitrile-alt-1,4-bis(dodecyloxy)-2,5-divinylbenzene] (PMT-PPV), poly[2-[2,6-Bis-(2-{4-[(4-bromophenyl)-phenylamino]-phenyl}-vinyl)-pyran-4-ylidene]-malononitrile-alt-1,4-bis(dodecyloxy)-2,5-divinylbenzene] (PMTPA-PPV)를 합성하였다. PM-PPV, PMT-PPV, PMTPA-PPV의 band gap은 각각 2.18 eV, 1.90 eV, 2.07 eV로 나타났다. LUMO 에너지 준위는 각각 3.65 eV, 3.54 eV, 3.62 eV로 나타났고 HOMO 에너지 준위는 각각 5.83 eV, 5.61 eV, 5.52 eV이고 소자를 제작하여 측정한 결과는 AM 1.5 G [1 sun condition ($100mA/cm^2$)]에서의 효율은 0.028%, 0.031%, 0.11%이고 open-circuit voltage (Voc)는 0.59 V~0.69 V로 나타났다.