• Title/Summary/Keyword: IkB

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Background $K^+$ channel currents in WEHI-231 cells, immature B lymphocytes

  • Nam, Joo-Hyun;Woo, Ji-Eun;Kim, Tae-Jin;Uhm, Dae-Yong;Kim, Sung-Joon
    • Proceedings of the Korean Biophysical Society Conference
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    • 2003.06a
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    • pp.39-39
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    • 2003
  • In our previous study, WEHI-231, an immature B cell line, showed intractable increase in [C $a^{2+}$]$_{c}$ after the B-cell receptor (BCR) ligation and treatment with 2-aminoethoxydiphenylborate (2-APB), which was never observed in Bal-17, a mature B cell line (Nam et al., 2003, FEBS Lett). In this study, a whole cell voltage clamp study revealed a specific expression of a novel type of $K^{+}$ current, namely voltage-independent background-type $K^{+}$ channels (IK-bg), in WEHI-231 cells. IK-bg was dramatically increase by the application of 2-APB (50 $\square$M), which induced severe hyperpolarization of WEHI-231 from -45 ㎷ to -90 ㎷, When dialyzed with $Mg^{2+}$ and ATP-free pipette solution, a spontaneous development of IK-bg and membrane hyperpolarization were observed. IK-bg was insensitive to classical $K^{+}$ channel blockers (TEA, glibenclamide, $Ba^{2+}$(1 mM)), whereas blocked by quinine and quinidine in a voltage-dependent manner ($IC_{50}$/=6~9 $\square$M at +60㎷). Phorbol myrstate, a PKC activator, decreased the amplitude of IK-bg. Extracellular acidification (pH 6.5) slightly inhibited IK-bg. Arachidonic acid, riluzole, or hyposmotic stress could not affect the IK-bg after the full development by the intracellular dialysis with Mg-ATP-free solution. In a cell-attached mode of single channel recording from WEHI231, we found two types of voltage-independent $K^{+}$ channels with unitary conductance of 300 pS and 120 pS, respectively. Both channels showed very short mean open times and their open probabilities were increase by the application of 2-APB. In Bal-17 cells, no such $K^{+}$ current was observed in 50 cells tested. In summary, WEHI-231 immature B cells express background $K^{+}$ channels. The pharmacological properties and the large unitary conductance suggest that novel types of two-pore domain $K^{+}$ channels (2-P-K channels) might be expressed in WEHI-231, which may provide an intriguing targets of signal transduction in the immature B lymphocytes.e B lymphocytes.

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A Benefit-Cost Analysis on the DSM Programs Part II (DSM 프로그램의 비용효과 분석 II)

  • Park, Jong-Bae;Kim, Jin-Ho;Hwang, Sung-Wook;Kim, Bal-Ho
    • Proceedings of the KIEE Conference
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    • 2000.11a
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    • pp.190-192
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    • 2000
  • This paper presents an approach to B/C analysis amenable to evaluate the impact of DSM programs especially on the strategic conservation programs and the load management programs. The proposed approach embedding the existing B/C analyses is applicable to the new electricity market. Case studies show the B/C ratio and the avoided cost due to the impact of DSM programs.

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A Study on the Power System Simulator Technologies for the Domestic Development (전력계통 시뮬레이터의 기술현황과 국내개발의 방법론 고찰)

  • Kim, J.H.;Lee, B.Y.;Shim, K.B.;Shin, J.R.;Lee, H.J.;Kwon, T.W.;Yoon, Y.B.;Lee, C.H.
    • Proceedings of the KIEE Conference
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    • 1993.07a
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    • pp.529-533
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    • 1993
  • Recently, the analysis of power systems is transfering from analytical techniques to simulation because it is difficult to analyze accurately the phenomena occured in complicated and huge power systems. Digital computers are used popularly to analyze the phenomena of power systems. But real-time simulators were used due to the limitation of digital computer - real time analysis, non-linearity and so on - and rapid development of digital technologies. In this paper, we discuss the advanced foreign power system simulators and the conceptual designs for the KEPCO power system simulator have been drawn for the domestic development.

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Load Modeling based on the System Identification (시스템 식별법에 의한 부하모델링)

  • Shim, K.B.;Lee, B.Y.;Kim, J.H.;Lee, H.S.;Choo, J.B.;Lee, S.J.;Chun, Y.S.
    • Proceedings of the KIEE Conference
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    • 1993.07a
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    • pp.148-151
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    • 1993
  • Load models for the analysis and simulation of power system are often introduced when the more accurate result is required. This work presents a single expressed load model as T-equivalent circuit of induction motor, for the composite characteristics of various loads. The parameters of the proposed load model are identified based on the system identification method as Recursive Least Square identification method. Case study results show the accuracy of proposed load model, and compared with some field measurements.

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Sodium Salicylate Inhibits Expression of COX-2 Through Suppression of ERK and Subsequent $NF-{\kappa}B$ Activation in Rat Ventricular Cardiomyocytes

  • Kwon, Keun-Sang;Chae, Han-Jung
    • Archives of Pharmacal Research
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    • v.26 no.7
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    • pp.545-553
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    • 2003
  • The expression of cyclooxygenase-2 (COX-2) is a characteristic response to inflammation, which can be inhibited with sodium salicylate. IL-1$\beta$ and TNF-$\alpha$ can induce extracellular signal-regulated kinase (ERK), IKK, IkB degradation and NF-$\kappa$B activation. Salicylate inhibited the IL-1$\beta$ and TNF-$\alpha$-induced COX-2 expressions, regulated the activation of ERK, IKK and IkB degradation, and the subsequent activation of NF-$\kappa$B, in neonatal rat ventricular cardiomyocytes. The inhibition of the ERK pathway, with a selective inhibitor, PD098059, blocked the expressions of IL-1$\beta$ and TNF-$\alpha$-induced COX-2 and $PGE_2$ release. The antioxidant, N-acetyl-cysteine, also reduced the glutathione or catalase- attenuated COX-2 expressions in IL-1$\beta$ and TNF-$\alpha$-treated cells. This antioxidant also inhibited the activation of ERK and NF-$\kappa$B in neonatal rat cardiomyocytes. In addition, IL-1$\beta$ and TNF-$\alpha$-stimulated the release of reactive oxygen species (ROS) in the cardiomyocytes. However, salicylate had no inhibitory effect on the release of ROS in the DCFDA assay. The results showed that salicylate inhibited the activation of ERK and IKK, I$\kappa$B degradation and NF-$\kappa$B activation, independently of the release of ROS, which suggested that salicylate exerts its anti-inflammatory action through the inhibition of ERK, IKK, IkB and NF-$\kappa$B, and the resultant COX-2 expression pathway in neonatal rat ventricular cardiomyocytes.

The Effect of Cobrotoxin on $NF-{\kappa}B$ binding Activity in Raw264.7 cells

  • Yoo, Jae-Ryong;Song, Ho-Sueb
    • Journal of Acupuncture Research
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    • v.22 no.2
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    • pp.133-139
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    • 2005
  • Cobrotoxin, a venom of Vipera lebetina turanica, is a group of basic peptidescomposed of 233 amino acids with six disulfide bonds formed by twelve cysteins. NF-kB is activated by subsequent release of inhibitory IkB and translocation of p50. Since sulfhydryl group is present in kinase domain of p50 subunit of NF-kB, cobrotoxin could modify NF-kB activity by protein-protein interaction. We therefore examined effect of cobrotoxin on NF-kB activities in lipopolysaccharide (LPS) and sodium nitroprusside (SNP)-stimulated Raw 264.7 mouse macrophages. Cobrotoxin suppressed the LPS and SNP-induced release of IkB and p50 translocation resulted in inhibition of DNA binding activity of NF-kB. Inhibition of NF-kB resulted in reduction of the LPS and SNP-induced production of inflammatory mediators NO and PGE2 generation. The inhibitory effect of cobrotoxin on the NF-kB activity were blocked by addition of reducing agents dithiothreitol and glutathione. These results demonstrate that cobrotoxin inhibits activation of NF-kB, and suggest that pico to nanomolar range of cobrotoxin could inhibit the expression of genes in the NF-kB signal pathway.

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Design of 3dB Directional Coupler using NRD Guide at 60GHz (NRD 도파로를 이용한 60GHz대 3dB 방향성 결합기 설계)

  • Oh Dong-Chul;Lee Jeong-Hae
    • 한국정보통신설비학회:학술대회논문집
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    • 2003.08a
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    • pp.283-285
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    • 2003
  • 본 논문에서는 nonradiative dielectric(NRD) 도파로를 이용해 60GHz대에서의 $90^{\circ}$ 하이브리드 3dB 방향성 결합기를 설계하였다. 3dB 결합기의 설계 시 NRD 도파로의 기본 모드인 $LSM_{11}$ 모드를 여기 시키기 위한 변환기를 설계하였고 NRD 도파로의 특징인 밴딩에서의 모드 컨버젼 현상을 확인하고 이를 이용하여 $LSE_{11}$ 모드를 이용한 3dB 결합기를 설계하였다.

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Involvement of IKK/IkBα/NF-kB p65 Signaling into the Regulative Effect of Engeletin on MUC5AC Mucin Gene Expression in Human Airway Epithelial Cells

  • Hossain, Rajib;Kim, Kyung-il;Li, Xin;Lee, Hyun Jae;Lee, Choong Jae
    • Biomolecules & Therapeutics
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    • v.30 no.5
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    • pp.473-478
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    • 2022
  • In this study, we examined whether engeletin exerts an effect on the gene expression of MUC5AC mucin, in human pulmonary epithelial NCI-H292 cells. The cells were pretreated with engeletin for 30 min and stimulated with phorbol 12-myristate 13-acetate (PMA), for the following 24 h. The effect of engeletin on PMA-induced nuclear factor kappa B (NF-kB) signaling pathway was also investigated. Engeletin suppressed the mRNA expression and production of MUC5AC mucin, induced by PMA through the inhibition of degradation of inhibitory kappa Bα (IkBα) and NF-kB p65 nuclear translocation. These results suggest engeletin inhibits the gene expression of mucin through regulation of NF-kB signaling pathway, in human airway epithelial cells.

Electrical Characteristics of Langmuir-Blodgett Ultra Thin Films (Langmuir-Blodgett 초박막의 전기적 특성)

  • You, D.S.;Kang, H.;Choi, M.K.;Jeong, S.W.;Shon, B.C.;Kang, D.Y.
    • Proceedings of the KIEE Conference
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    • 1989.07a
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    • pp.374-376
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    • 1989
  • Ultra Tihn Film of 100 angstrom-order is fabricated by Langmuir-Blodgett technique. The conductivity of this this measured by the direction of either vertical or horizontal axis is results in a quite different value. Specific inductive capacity and effect of time variation of LB films are also considered.

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