FK506이 T 림프구 사멸에서 활성산소 생성에 미치는 영향

이호균(Ho Kyun Lee),정상영(Sang Young Chung),최수진나(Soo Jin Na Choi) 대한외과학회 2009 Annals of Surgical Treatment and Research(ASRT) Vol.77 No.5

Purpose: Tacrolimus (FK506) has been widely used as an immunosuppressant in organ transplanted recipients to suppress organ rejection phenomenon. We investigated the role of oxidative stress and heme oxygense-1 by FK506 on human Jurkat T cells. Methods: The cells viability was examined by DAPI stain, enzyme activity of caspase family proteins, and western blotting for Baks, PUMA, iNOS, HO-1. Cells were cultured in the absence or presence of CoPPIX or ZnPPIX and the fluorescence intensity was analyzed using a flow cytometry. Results: Treatment with FK506 increased the generation of reactive oxygen species (ROS), including hydrogen peroxide and superoxide anion, and NO in Jurkat cells in a dose-dependent manner. Immunohistochemistry and Western blot analysis data revealed the hemoxygenase-1 (HO-1) was induced by the addition of FK506 in Jurkat cells. Induction of CoPP, HO-1 inducer, resulted in decreased intracellular H₂O₂ and NO concentrations. Instead ZnPP, an HO-1 competitive inhibitor did it reversely. In addition, ZnPP regulates iNOS protein synthesis by inhibition of HO-1. Conclusion: Increase of HO-1 expression would induce to decrease the intracellular H₂O₂ and NO concentrations. Also, HO-1 would regulate iNOS protein synthesis. Consequently, we can expect the regulation of HO-1 expression with concomitants use of FK506 to suppress organ rejection phenomenon by enhancing apoptosis.

Heme oxygenase-1 induced by desoxo-narchinol-A attenuated the severity of acute pancreatitis via blockade of neutrophil infiltration

Bae, Gi-Sang,Kim, Dong-Goo,Jo, Il-Joo,Choi, Sun-Bok,Kim, Myoung-Jin,Shin, Joon Yeon,Kim, Dong-Uk,Song, Ho-Joon,Joo, Myungsoo,Park, Sung-Joo ELSEVIER 2019 INTERNATIONAL IMMUNOPHARMACOLOGY Vol.69 No.-

<P><B>Abstract</B></P> <P>Heme oxygenase-1 (HO-1) has an anti-inflammatory action in acute pancreatitis (AP). However, its mechanism of action and natural compounds/drugs to induce HO-1 in pancreas are not well understood. In this study, we investigated the regulatory mechanisms of HO-1 during AP using desoxo-narchinol-A (DN), the natural compound inducing HO-1 in the pancreas. Female C57/BL6 Mice were intraperitoneally injected with supramaximal concentrations of cerulein (50 μg/kg) hourly for 6 h to induce AP. DMSO or DN was administered intraperitoneally, then mice were sacrificed 6 h after the final cerulein injection. Administration of DN increased pancreatic HO-1 expression through activation of activating protein-1, mediated by mitogen-activated protein kinases. Furthermore, DN treatment reduced the pancreatic weight-to-body weight ratio as well as production of digestive enzymes and pro-inflammatory cytokines. Inhibition of HO-1 by tin protoporphyrin IX abolished the protective effects of DN on pancreatic damage. Additionally, DN treatment inhibited neutrophil infiltration into the pancreas via regulation of chemokine (C-X-C motif) ligand 2 (CXCL2) by HO-1. Our results suggest that DN is an effective inducer of HO-1 in the pancreas, and that HO-1 regulates neutrophil infiltration in AP via CXCL2 inhibition.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Desoxo-narchinol-A (DN) is a natural compound of HO-1 inducer in pancreas. </LI> <LI> Mechanism of DN-induced HO-1 is mediated by MAPK/Activator Protein-1/HO-1 signaling. </LI> <LI> DN-induced HO-1 blocks neutrophil infiltration into pancreas via inhibition of CXCL2. </LI> <LI> DN inhibits cerulein-induced acute pancreatitis (AP) and AP-associated lung injury. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Rheology of Decamethylceclopentasiloxane (cyclomethicone) W/O Emulsion System

Choi, Min-Hyung,Jeong, So-Ra,Nam, Sang-In,Shim, Sang-Eun,Chang, Yoon-Ho The Polymer Society of Korea 2009 Macromolecular Research Vol.17 No.12

A highly dispersed W/O emulsion of silicone oil (cyclomethicone)/water system was prepared with a nonionic surfactant. The surface and interfacial tension between the oil and water were characterized in terms of the droplet size distribution and viscosity change of the emulsion. When the dispersed phase concentration was relatively high, the viscosity of the emulsion was rapidly increased and the droplet size of the emulsion was decreased. The rheological behavior of the emulsion system showed non-Newtonian and shear thinning phenomena depending upon the content of the dispersed phase. The droplet size of the emulsion was decreased with increasing surfactant content and water concentration. The relative viscosity of the emulsion was better predicted with the Choi-Schowalter model than with the Taylor model. The value of the complex modulus increased with increasing surfactant concentration. The linear viscoelastic region was expanded with a dispersed phase concentration. According to the change in the viscosity, the behavior was classified into three distinct regions: [I] linear viscoelastic, [II] partially viscoelastic, and [III] viscous. The creep/recovery behaviors in each region were characterized.

<i>Toxoplasma gondii</i> protects against H₂O₂‐induced apoptosis in ARPE‐19 cells through the transcriptional regulation of apoptotic elements and downregulation of the p38 MAPK pathway

Choi, Si‐,Hwan,Park, Sung Jun,Cha, Guang‐,Ho,Quan, Juan Hua,Chang, Nam‐,Sik,Ahn, Myoung‐,Hee,Shin, Dae‐,Whan,Lee, Young‐,Ha Blackwell Publishing Ltd 2011 Acta ophthalmologica Vol.89 No.4

<P><B>Abstract.</B></P><P><B>Purpose: </B> Toxoplasmosis, which is caused by the protozoan parasite <I>Toxoplasma gondii</I>, can lead to severe visual impairment. <I>T.?gondii</I> inhibits or delays programmed cell death caused by various apoptotic triggers; however, the mechanisms involved in the <I>T</I>.?<I>gondii</I>‐induced suppression of apoptosis in retinal cells have not been analysed in detail.</P><P><B>Methods: </B> We investigated the role of <I>T</I>.<I>?gondii</I> infection in H<SUB>2</SUB>O<SUB>2</SUB>‐induced apoptosis in human retinal pigment epithelial cells (ARPE‐19) by monitoring the activities of apoptosis‐regulating molecules and mitogen‐activated protein kinases (MAPKs), including p38 MAPK. We also examined the gene downstream from p38 MAPK.</P><P><B>Results: </B> <I>T.?gondii</I> infection significantly inhibited the cellular toxicity of H<SUB>2</SUB>O<SUB>2</SUB> (500 μ<SMALL>m</SMALL>) and increased cell viability in a multiplicity of infection (MOI)‐dependent manner by reducing DNA fragmentation and reactive oxygen species (ROS) generation in ARPE‐19 cells. Western blot analysis also showed that <I>T</I>.?<I>gondii</I> infection prevented the host cell expression of pro‐apoptotic factors, such as Bad and Bax, and the activation of caspase‐3. Infection with <I>T</I>.?<I>gondii</I> increased the expression of the anti‐apoptotic factor Bcl‐2 in ARPE‐19 cells under oxidative stress. In accordance with these findings, <I>Toxoplasma</I> infection was protective enough to suppress the phosphorylation of p38 MAPK following H<SUB>2</SUB>O<SUB>2</SUB> treatment. Exposure to H<SUB>2</SUB>O<SUB>2</SUB> increased the expression of heme oxygenase‐1 (HO‐1) in ARPE‐19 cells, and its expression was significantly inhibited in H<SUB>2</SUB>O<SUB>2</SUB>‐treated infected cells.</P><P><B>Conclusion: </B> The protective function of <I>T</I>.?<I>gondii</I> infection against ROS‐induced apoptosis results from changes in the expression of apoptotic molecules and the downregulation of stress‐induced intracellular signalling.</P>

Fatigue Crack Growth Behavior in Ultrafine Grained Low Carbon Steel

Ho,Kyung Kim,Myung-Il Choi,Chin-Sung Chung Dong-Hyuk Shin 대한기계학회 2002 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.16 No.10

Ultrafine grained (UFG) low carbon (0.15 wt.% C) steel produced by equal channel angular pressing (ECAP) was tested for investigating the effect of load ratio on the fatigue crack growth rate. Fatigue crack growth resistance and threshold of UFG steel were lower than that of as-received coarse grained steel. It was attributed to the less tortuous crack path. The UFG steel exhibited slightly higher crack growth rates and a lower △K_th with an increase of R ratio. The R ratio effect on crack growth rates and △K_th was basically indistinguishable at lower load ratio (R>0.3), compared to other alloys, which indicates that contribution of the crack closure vanishes. The crack growth rate curve for UFG steel exhibited a longer linear extension to the lower growth rate regime than that for the coarse grained as-received steel.<br/>

경부고속철도건설사업 성과평가

송성태(Sung Tae Song),최문규(Moon Kyu Choi),박상구(Sang Gu Park),장호환(Ho Hwan Jang),차효정(Hyo Jung Cha) 한국철도학회 2012 한국철도학회 학술발표대회논문집 Vol.2012 No.5

1992년 첫 삽을 뜨면서 시작한 경부고속철도건설사업이 2004년 4월, 1단계 개통을 한데 이어 지난 2010년 11월 완전 개통하였다. 경부고속철도 개통으로 경부축 지역의 2시간대 서비스 제공을 통한 국토의 균형발전 촉진 및 여가·관광사업 활성화, 기술발전, 환경비용 및 에너지 절감 등 긍정적인 효과를 이룬 반면, 잦은 기본계획 변경으로 인한 사업비 및 사업기간의 증가, 현실과 맞지 않은 설치기준으로 인한 과잉설계 문제 등 부정적 효과도 초래했다. 본 연구를 통해 사업추진 단계별 주요 이슈에 대해 객관적인 시각으로 문제점을 분석하고 시사점을 도출함으로써, 현재 추진하고 있는 호남고속철도와 수도권고속철도 사업에서는 시행착오를 줄이고 사업을 효율적으로 추진하는데 활용하고자 한다. Launched in 1992, the Gyeung-Bu High Speed Railway (HSR) was fully opened in November 2010 following the partial opening of the first phase in April 2004. Since the opening it has made tremendous achievements, including but not limited to, technical innovation, balanced regional development, growth of leisure and tourism industries, and savings of environmental costs and energy. On the other hand, it has brought negative effects such as increase in project time and cost by frequent changes of the basic plan and over-design based on unrealistic criteria. In this study we will analyze major issues that occurred at each stage of the Gyeong-Bu HSR project and draw implications. Thus, this study will enhance to efficiently implement the Ho-Nam and Seoul Metropolitan HSR project through minimizing possible trials and errors.

정밀 Positioning를 이용한 망막세포 치료 및 담석 제거

최상훈(Sang-hoon Choi),김진수(Jin-녀 Kim),이호(Ho Lee) 한국레이저가공학회 2008 한국레이저가공학회 학술대회 논문집 Vol.2008 No.-

Among many medical application of lasers, the pulsed laser induced surgery is one of the most popular fields. In the current study, we demonstrated the laser-induced selective cell targeting using the precision positioning stage. Furthermore, we compared laser induced ablation of human urinary calculi using two different lasers (Ho:YAG : 2.9㎛, Er:YAG : 2.1㎛).

고연령 연금계좌 가입자 세액공제 확대에 따른 수익비 효과 분석

성주호(Sung, Joo-Ho),이동화(Lee, Dong-Hwa),최은미(Choi, Eun-Mi) 한국경영교육학회 2020 경영교육연구 Vol.35 No.5

[연구목적] 본 연구에서는 정부의 2019 세법개정안이 가입자들의 연금계좌 수익비에 미치는 영향을 살펴보고, 정책적인 시사점을 제공하였다. [연구방법] 본 연구는 연금 세제개편 흐름 및 이와 관련된 선행연구들을 충분히 검토하였으며 3가지의 제도 시나리오를 설정하여 수익비 분석을 진행하였다. 나아가 본 연구에서는 현실적인 분석을 수행하기 위하여 통계청의 마이크로 데이터를 활용하였으며, 이를 통해 연령 별 소득분위에 따른 보유 자산, 소비수준 등을 고려하여 분석을 진행하였다. [연구결과] 분석결과, 수익비 관점에서 저소득층이 연금계좌 추가납입에 따른 혜택을 가장 많이 받는 것으로 나타났으나 현실적으로 저소득층 고령자의 경우 추가납입을 위한 여유자금을 보유하고 있지 않아 추가납입이 제한되는 것으로 나타났다. 이에 따라 연금계좌 세액공제 확대에 따른 혜택은 고소득 고령자들에게 집중되는 것으로 나타났다. [연구의 시사점] 연금계좌의 추가납입을 제도적으로 유인하기 위하여 저소득층 세액공제 확대와 함께 보조금 매칭이나 고령자의 재고용 지원정책 등과 같이 현실적으로 저소득 고령자의 연금계좌 추가납입을 실현할 수 있는 방안이 모색될 필요가 있다. [Purpose] The purpose of this paper is to analyze the effect of expanding tax credit on contribution to private pension accounts for the elderly. [Methodology] For this purpose, we described prior literature review and summarized the details of the tax reform. Then, we conducted the money’s worth analysis in consideration of asset and consumption level according to the income quintile by age. [Findings] Our results shows that lower income people receive more benefits from additional payments to the private pension accounts from the perspective of money’s worth. In reality, however, additional payments are limited as they do not have any sufficient assets for additional payments. As a result, benefits from expanding tax credit on contribution amounts were concentrated on the elderly with high incomes. [Implications] Therefore, it would be necessary to seek ways to realistically realize additional payments to low-income senior citizens, such as introducing the marginal tax credit, matching subsidies and so on.

압축성 코드에서 예조건화 코드로의 이진

한상훈(Sang-Hoon Han),김명호(Myeong-Ho Kim),최정열(Jeong-Yeol Choi) 한국항공우주학회 2007 韓國航空宇宙學會誌 Vol.35 No.3

이차원 범프 유동에 대한 다양한 예조건화 행렬의 수렴 특성을 살펴 Choi와 Merkle의 예조건화 행렬을 선택하여, 압축성 및 예조건화 Roe의 Riemann 해법의 수치 소산항을 수학적으로 비교하였다. 이 결과 코드의 구조는 동일하게 유지한 채, 고유치의 작은 수정만으로 압축성 해법을 예조건화 해법으로 이전할 수 있는 방법을 알 수 있었다. 아울러 점성 유동 영역에서의 안정성 및 정확성을 향상시키기 위하여 von Neumann 안정 조건 및 점성 자코비안을 고려하였으며, 개발된 코드는 표준 검증 문제에 적용하여 검증을 수행하였다. Comprehensive mathematical comparison of numerical dissipation vector was made for a compressible and the preconditioned version Roe's Riemann solvers. Choi and Merkle type preconditioning method was selected from the investigation of the convergence characteristics of the various preconditioning methods for the flows over a two-dimensional bump. The investigation suggests a way of migration from a compressible code to a preconditioning code with a minor changes in Eigenvalues while maintaining the same code structure. Von Neumann stability condition and viscous Jacobian were considered additionally to improve the stability and accuracy for the viscous flow analysis. The developed code was validated through the applications to the standard validation problems.

Detection of benzalkonium chloride on glass surfaces using silver nanoparticles

Nguyễn Hoàng Ly,Phuong-Dong Nguyen,Sang Jun Son,이철민,Soonmin Jang,주상우,Kyungjoo Kim,Jiseon Choi,Ye-eun Joo,Jung Il Lee 대한화학회 2022 Bulletin of the Korean Chemical Society Vol.43 No.2

Raman reporter-based surface-enhanced Raman scattering (SERS) has been used to investigate the detection of one member of a class of the cationic surfactant quaternary ammonium compounds, alkyl dimethyl benzyl ammonium chloride, also known as benzalkonium chloride (BAC). For this study, SERS was performed using silver nanoparticles (AgNPs). Density functional theory (DFT) of BAC on Ag6 clusters was introduced to estimate binding at the level of the B3LYP/LANL2DZ basis sets. As the chain length increased from n = 8 to 18, the binding energies were expected to increase by 2.1 kcal/mol. Methylene blue (MB) Raman reporter molecules were subsequently treated on BAC thin-film-covered glass surfaces. Atomic force microscopy (AFM) images were used to determine the coverage of BAC on the glass, and field-emission electron microscope (FE-SEM) images revealed the surface morphologies of the SERS substrates. A standard calibration curve was prepared to quantify BAC within a concentration range of 0.0036805 to 36?805?ppm (r2?≥?0.99), according to the BAC-correlated SERS intensities of MB Raman peaks at ~1620?cm?1 adsorbed on AgNPs. A molecular dynamics (MD) simulation supported strong adsorption of BAC on glass surfaces.