K - 통로개방제가 배양심근세포와 생쥐 체내의 Thallium - 201 역동학에 미치는 영향

이규보(Kyu Bo Lee),이재태(Jae Tae Lee),안병철(Byeong Cheol Ahn),김은지(Eun Ji Kim),손상균(Kang Kyun Sohn),하정희(Jeoung Hee Ha),김천기(Chun K . Kim) 대한핵의학회 1996 핵의학 분자영상 Vol.30 No.4

N/A Background: Potassium channel opener (K-opener) opens ATP-sensitive K+-channel located at membrane and induces potassium efflux from cytosol, resulting in intracellular hyperpolarization. Newly synthesized K-opener is currently examined for pharmacologic potency by means of rubidium release test from smooth muscle strip pre-incubated with Rb-86. Since in-vive behavior of thallium is similar to that of rubidium, we hypothesized that K-opener can alter T1-201 kinetics in vivo. Purpose: This study was prepared to investigate the effects of pinacidil (one of potent K-openers) on the T1-201 uptake and clearance in cultured myocyte, and in-vivo biodi- stribution in mice. Methods: Spontaneous contracting myocytes were prepared to imitate in-vivo condition from 20 hearts of 3-5 days old Sprague-Dawley rat and cultured for 3-5 days before use (5×105 cells/ml). Pinacidil was dissolved in 10% DMSO solution at a final concentration of 100nM or 10uM and was co-incubated with T1-201 in HBSS buffer for 20-min to evaluate its effect on cellular T1-uptake, or challenged to cell preparation pre-incubated with T1-201 for washout study. Two, 40 or 100μg of pinacidil was injected intravenously into ICR mice at 10 min after 5μCi T1-201 injection, and organ uptake and whole body retention rate were measured at different time points. Results: Co-incubation of pinacidil with T1-201 resulted in a decrease in T1-201 uptake into cultured myocyte by 1.6 to 2.5 times, depending on pinacidil concentration and activity of T1-201 used. Pinacidil enhanced T1-201 washout by 1.6-3.1 times from myocyte preparations pre-incubated with T1-201. Pinacidil treatment appears to be resulted in mild decreases in blood and liver activity in normal mice, in contrast, renal and cardiac uptake were mildly decreased in a dose dependent manner. Whole body retention ratios of T1-201 were lower at 24 hour after injection with 100μg of pinacidil than control. Conclusion: These results suggest that treatment with K-opener may affect the interpretation of T1-201myocardial images, due to decreasing thallium accumulation and enhancing washout from myocardium.

The Phase-Shift Method for the Langmuir Adsorption Isotherms of Electroadsorbed Hydrogens for the Cathodic H₂ Evolution Reactions at the Poly-Pt Electrode Interfaces

천장호,전상규,이재항,Chun, Jang H.,Jeon, Sang K.,Lee, Jae H. The Korean Electrochemical Society 2002 한국전기화학회지 Vol.5 No.3

순환전압전류 및 교류임피던스 기법을 이용하여 다결정 Pt/0.5M $H_2SO_4$ 및 0.5M LiOH수용액 계면에서 저전위 수소흡착(UPD H) 과 전위 수소흡착(OPD H)에 관한 Langmuir 흡착등온식 $({\theta}\;vs.\;E)$ 을 연구조사 하였다. 계면에서 치적중간주파수일 때 위상이동$(0^{\circ}{\leq}{-\phi}{\leq}90^{\circ})$ 거동은 표면피복율$(1{\geq}{\theta}{\geq}0)$ 거동에 정확하게 상응한다. 위상이 동 방법 즉 최적중간주파수일 때 위상이동 변화$({-\phi}\;vs.\;E)$는 계면에서 음극 $H_2$ 발생 반응에 관한 UPD H와 OPDH의 Langmuir흡착등온식을 결정할 수 있는 새로운 전기화학적 방법으로 사용할 수 있다 다결정 Pt/0.5M $H_2SO_4$ 수용액 계면에서 OPD H의 흡착평형상수(K)와 표준자유에너지$({\Delta}G_{ads})$는 각각 $2.1\times10^{-4}$와 21.0kJ/mol 이다. 다결정 Pt/0.5M LiOH 수용액 계면에서 K는 음전위(E)에 따라 2.7 (UPD H)에서 $6.2\times10^{-6}$ (OPD H) 또는 $6.2\times10^{-6}$(OPD H)에서 2.7 (UPD H)로 전이한다. 유사하게 ${\Delta}G_{ads}$는 E에 따라 -2.5kJ/mol (UPD H)에서 29.7kJ/mol (OPD H)또는 29.7kJ/mol (OPD H)에서 -2.5kJ/mol (UPD H)로 전이한다. K와 ${\Delta}G_{ads}$의 전이는 다결정 Pt전극 표면의 상이한 UPD H와 OPD H의 흡착부위에 기인한다. 다결정 Pt전극 계면에서 UPD H와 OPD H는 음극 $H_2$ 발생 반응에 따른 순차적 과정이 아니라, 수소 흡착부위 자체에 따른 독립적 과정이다. UPD H와 OPD H의 기준은 음극 $H_2$발생 반응과 전위가 아니라, 수소 흡착부위와 과정이다. 수용액에서 음극 $H_2$발생 반응에는 다결정 Pt선 전극이 단결정 Pt(100)원반 전극보다 더 효율적이고 유용하다 위상이동 방법은 열역학적 방법과 상충적이 아니라, 보완적이다. The Langmuir adsorption isotherms of the under-potentially deposited hydrogen (UPD H) and the over-potentially deposited hydrogen (OPD H) at the poly-Pt/0.5M $H_2SO_4$ and 0.5 M LiOH aqueous electrolyte interfaces have been studied using cyclic voltammetric and ac impedance techniques. The behavior of the phase shift $(0^{\circ}{\leq}{-\phi}{\leq}90^{\circ})$ for the optimum intermediate frequency corresponds well to that of the fractional surface coverage $(1{\geq}{\theta}{\geq}0)$ at the interfaces. The phase-shift method, i.e., the phase-shift profile $({-\phi}\;vs.\;E)$ for the optimum intermediate frequency, can be used as a new electrochemical method to determine the Langmuir adsorption isotherms $({\theta}\;vs.\;E)$ of the UPD H and the OPD H for the cathodic $H_2$ evolution reactions at the interfaces. At the poly-Pt/0.5M $H_2SO_4$ aqueous electrolyte interface, the equilibrium constant (K) and the standard free energy $({\Delta}G_{ads})$ of the OPD H are $2.1\times10^{-4}$ and 21.0kJ/mol, respectively. At the poly-Pt/0.5M LiOH aqueous electrolyte interface, K transits from 2.7(UPD H) to $6.2\times10^{-6}$ (OPD H) depending on the cathode potential (E) and vice versa. Similarly, ${\Delta}G_{ads}$ transits from -2.5kJ/mol (UPD H) to 29.7kJ/mol (OPD H) depending on I and vice versa. The transition of K and ${\Delta}G_{ads}$ is attributed to the two distinct adsorption sites of the UPD H and the OPD H on the poly-Pt surface. The UPD H and the OPD H on the poly-Pt surface are the independent processes depending on the H adsorption sites themselves rather than the sequential processes for the cathodic $H_2$ evolution reactions. The criterion of the UPD H and the OPD H is the H adsorption sites and processes rather than the $H_2$ evolution reactions and potentials. The poly-Pt wire electrode is more efficient and useful than the Pt(100) disc electrode for the cathodic $H_2$ evolution reactions in the aqueous electrolytes. The phase-shift method is well complementary to the thermodynamic method rather than conflicting.

대장 선종과 암의 동시성 병변에서 K-ras 유전자의 돌연변이 및 k-Ras, p16, Cyclin D1과 p53 단백질의 발현

오용열 ( Y. L. Oh ),전훈재 ( H. J. Chun ),박동규 ( D. K. Park ),박재홍 ( J. H. Park ),박철희 ( C. H. Park ),진윤태 ( Y. T. Jeen ),이홍식 ( H. S. Lee ),이상우 ( S. W. Lee ),엄순호 ( S. H. Um ),최재현 ( J. H. Choi ),김창덕 ( C. D. Kim 대한소화기학회 2002 대한소화기학회 춘계학술대회 Vol.2002 No.-

<Background> The colorectal adenoma-carcinoma sequence represents a well-known paradigm for the sequential development of cancer driven by the accumulation of genomic defects, Although the colorectal adenoma-carcinoma sequence is well established, the stu

Constant Correlation Factors between Temkin and Langmuir or Frumkin Adsorption Isotherms at Poly-Pt, Re, and Ni/Aqueous Electrolyte Interfaces

Chun Jang H.,Jeon Sang K.,Chun Jin Y. The Korean Electrochemical Society 2004 한국전기화학회지 Vol.7 No.4

The constant correlation factors between the Temkin and the Langmuir or the Frumkin adsorption isotherms of over-potentially deposited hydrogen (OPD H) for the cathodic H2 evolution reaction (HER) at poly-Pt and Re/0.5M $H_2SO_4$ and poly-Ni/0.05 M KOH aqueous electrolyte interfaces have been experimentally and consistently found using the phase-shift method. At intermediate values of the fractional surface coverage $(\theta),\;i.e.,\;02<{\theta}<0.8$, the Langmuir and Temkin adsorption isotherms of OPD H for the cathodic HER are correlated to each other even though the adsorption conditions or processes are different from each other. At the same range of $\theta$, correspondingly, the Frumkin and Temkin adsorption isotherms of OPD H for the cathodic HER are correlated to each other. The equilibrium constants $(K_o)$ for the Temkin adsorption isotherms $({\theta}\;vs.\; E)$ are consistently ca. 10 times greater than those (K, Ko) for the corresponding Langmuir or Frumkin adsorption isotherms ($({\theta}\;vs.\; E)$. The interaction parameters (g) for the Temkin adsorption isotherms $({\theta}\;vs.\; E)$ are consistently ra. 4.6 greater than those (g) for the corresponding Langmuir or Frumkin adsorption isotherms $({\theta}\;vs.\; E)$. These numbers (10 times and 4.6) can be taken as constant correlation factors between the corresponding adsolftion isotherms (Temkin, Langmuir, Frumkin) at the interfaces. The Temkin adsorption isotherm corresponding to the Langmuir or the Frumkin adsorption isotherm, and vice versa, can be effectively verified or confirmed using the constant correlation factors. Both the phase-shift methodand constant correlation factors are useful and effective for determining or confirming the suitable adsorption isotherms (Temkin, Langmuir, Frumkin) of intermediates for sequential reactions in electrochemical systems.

Expression of the IKr components KCNH2 (rERG) and KCNE2 (rMiRP1) during late rat heart development

K. R. J. Chun,M. Koenen,H. A. Katus,J. Zehelein 생화학분자생물학회 2004 Experimental and molecular medicine Vol.36 No.4

To understand molecular mechanisms that regulate formation and maintenance of cardiac IKr (rapidly activating component of the delayed rectifier K+ curent), we have investigated the spatiotemporal expresion patern of two rat po-tassium voltage-gated channels, namely sub-family H (eag-related), member2 (KCNH2) (alias name: rERG) and Isk-related family, member2 bryonic development by means of the in situ hybridization technique. KCNE2 is transcribed predominantly in atrial und ventricular myocar-dium at stages E14.5-E18.5dpc and only a minor signal emerged in the tongue at E16.5dpc. In contrast, KCNH2 transcripts appeared in a les confined patern with intense signals in atrial and ventricular myocardium, somites, spinal cord, bowel system, central nervous system and thymus at stages E14.5-E18.5dpc. Non-cardiac expresion even exceeds the intensity of the cardiac signal, indicating that KCNH2 contri-butes to K+ curents in non-cardiac tisue as well. Transcription of the rat β-subunit KCNE2 is present in all regions of the fetal myocardium and co-distributes perfectly with transcription of the pore forming α-subunit KCNH2. It seems likely that KCNH2 and KCNE2 are linked to form cardiac IKr channels, asociated to cardiogene-sis and cardiomyocyte excitability.

A study of shear correction factors on composite laminated orthotropic plates

전종균 성화대학교 1993 成和論叢 Vol.- No.3

A solution method has been described and illustrated for the analysis of the natural vibrations of arbitrarily laminated orthotropic plates. Three dimensional elasticity problem reduces to one dimensional problem by adopting modern finite element technique. Refined plate theory is the extension of Timoshenko beam theory to the plate. Comparing frequencies between Refined Plate Theory and Elasticity Theory solution composite correction factors come out at cutoff. For relatively stiff transverse normal modulus, the third lowest cutoff frequency is associated with thickness shear behavior. This information is especially useful in providing a basis for developing plate and shell structure composed of laminated materials which include transverse shear deformation.

PERFORMANCE ANALYSIS OF THE TURBULENCE MODELS FOR A TURBULENT FLOW IN A TRIANGULAR ROD BUNDLE

W. K. In,T. H. Chun,H. K. Myong 한국전산유체공학회 2005 한국전산유체공학회지 Vol.10 No.1

A computational fluid dynamics(CFD) analysis has been made for fully developed turbulent flow in a triangular bare rod bundle with a pitch to diameter ratio (P/D) of 1.123. The nonlinear turbulence models predicted the turbulence-driven secondary flow in the triangular subchannel. The nonlinear quadratic k- ε models by Speziale[1] and Myong-Kasagi[2] predicted turbulence structure in the rod bundle fairly well. The nonlinear quadratic and cubic k- ε models by Shih et al.[3] and Craft et al.[4] showed somewhat weaker anisotropic turbulence. The differential Reynolds stress model by Launder et al.[5] appeared to overpredict the turbulence anisotropy in the rod bundle.

Effects of Antagonistic Microorganisms, Bacillus spp., on Growth of Orchardgrass (Dactylis glomerata L.)

Choi, K. C 韓國酪農學會 1997 韓國酪農學會誌 Vol.19 No.1

CFD Simulation of Axial Turbulent Flow in a Triangular Rod Bundle

W. K. In,T. H. Chun,H. K. Myong,K. K0 한국전산유체공학회 2003 한국전산유체공학회 학술대회논문집 Vol.2003 No.10

Effects of Bacillus spp. and Pathogenic Fungi on Growth of Italian Ryegrass (Lolium multiflorum Lam.)

Choi, K. C 韓國酪農學會 1997 韓國酪農學會誌 Vol.19 No.1