Effects of epigallocatechin gallate on CoCl_(2)-induced apoptosis in PC12 cells

Yang, Kyu-Ho,Mo, Hyun-Chul,Choi, Nam-Ki,Kim, Seon-Mi,Kim,Won-Jae 大韓小兒齒科學會 2006 大韓小兒齒科學會誌 Vol.33 No.1

Neuronal apoptotic events, consequently resulting in neuronal cell death, are occurred in hypoxic/ischemic condition. This cell death has been shown to be accompanied with the production of reactive oxygen species (ROS), which can attack cellular components such as nucleic acids, proteins and phospholipid. However, the underlying mechanisms of apoptosis induced in hypoxic/ischemic condition and its treatment methods are unsettled. Cobalt chloride (CoCl_(2)) has been known to mimic hypoxic condition including the production of ROS. Epigallocatechin gallate (EGCG). a green tea polyphenol, has diverse pharmacologial activities in cell growth and death. This study was aimed to investigate the apoptotic mechanism by CoCl_(2) and effects of EGCG on CoCl_(2)-induced apoptosis in PC12 cells. Administration of CoCl_(2) decreased cell survival in dose- and time-dependent manners and induced genomic DNA fragmentation. Treatment with 100 µM EGCG for 30 min before PC12 cells were exposed to 150 µM CoCl_(2), being resulted in the cell viability and DNA fragmentation being rescued. CoCl_(2) caused morphologic changes such as cell swelling and condensed nuclei, whereas EGCG attenuated morphologic changes by CoCl_(2). EGCG suppressed the apoptotic peak and a loss of Δψ_(m) induced by CoCl_(2). CoCl_(2) decreased Bcl-2 expression but Bax expression was not changed in CoCl_(2)-treated cells. EGCG attenuated the Bcl-2 underexpression by CoCl_(2). CoCl_(2) augumented the cytochrome c release from mitochondria into cytoplasm and increased caspase-8, -9 and caspase-3 activity, a marker of the apoptotic executing stage. EGCG ameliorated the incruement in caspase-8, -9 and -3 activity, and cytochrome c release by CoCl_(2). NAC (N-acetyl-cysteine), a scavenger of ROS, attenuated CoCl_(2)-induced apoptosis in consistent with those of EGCG. These results suggest, that CoCl_(2) induces apoptotic cell death through both mitochondria- and death receptor-dependent pathway and EGCG has neuroprotective effects against CoCl_(2)-induced apoptosis in PC12 cells. 신경세포자멸사는 저산소 및 허혈환경에서 일어나며 이러한 세포죽은 reactive oxidant species (ROS) 생성을 동반함이 알려져있다. 그러나, 저산소 및 허혈환경에서 일어나는 세포자멸사의 기전 및 그 치료방법은 아직 정립되어 있지 않다. CoCl_(2)는 ROS를 생성하는 등 저산소환경과 유사한 조건을 초래하는 것으로 알려져 있다. Epigallocatechin gallate (EGCG)는 녹차의 polyphenol 성분으로서 세포성장과 죽음에 다양한 약리학적 효과를 나타냄이 알려져 있다. 본 연구는 PC12 세포에서 CoCl_(2)에 의한 세포자멸사기전을 밝히고 이에 미치는 EGCG의 효과를 조사하는데 목적이 있다. Cell viability는 MTT 측정으로 조사되었고, DNA fragmentation은 DNA laddering으로 조사되었다. Bcl-2와 Bax발현 정도는 RT-PCR로, caspase-3와 -9의 활성은 spectrophotometer, caspase-8의 활성은 flow cytometry에 의해 측정되었다. 미토콘드리아에서 세포질로 분비된 cytochrome c는 western blot으로, 분해된 DNA 양과 미토콘드리아 세포막전위 (Δψ_(m))는 FACScan으로 조사되었다. CoCl_(2)투여로 PC12 세포수는 용량 및 시간 의존형태로 감소하였고, genomic DNA fragmentation이 발생하였다. CoCl_(2)투여로 야기된 cell viability의 감소와 DNA fragmentation은 EGCG 전처치에 의해 억제되었다. CoCl_(2)은 세포용적팽창과 condensed nuclei 같은 형태적 변화를 일으켰으며, apoptotic peak, Δψ_(m)감소 및 cytochrome c 유리를 야기하였다. EGCG는 CoCl_(2)에 의한 세포형태변화, apoptotic peak, Δψ_(m)소실 및 cytochrome c 유리를 억제시켰다. CoCl_(2)는 Bcl-2 발현을 감소시켰지만, Bax 발현에는 영향을 미치지 않았다. EGCG는 CoCl_(2)에 의해 야기된 Bcl-2 발현 감소를 억제시켰다. CoCl_(2)는 caspase-3, -8, 그리고 -9의 활성을 증가시켰으며, EGCG는 CoCl_(2)에 의한 세포자멸사를 억제시켰다. 본 실험결과는 PC12 세포에서 CoCl_(2)가 미토콘드리아 의존 및 death receptor의존 기전으로 세포자멸사를 일으키며, EGCG는 세포자멸사기전을 억세지킴으로 신경보호기능을 가짐을 시사하였다.

키넥트 센서를 이용한 고령자 대상의 선자세 균형능력 평가

양승태(Seung-Tae Yang),강동원(Dong-Won Kang),서정우(Jeong-Woo Seo),김대혁(Dae-Hyeok Kim),김태호(Tae-Ho Kim),최진승(Jin-Seung Choi),탁계래(Gye-Rae Tack) 대한전기학회 2017 전기학회논문지 Vol.66 No.2

Portable low-cost Kinect sensor was used to analyze standing balance ability of the elderly. Eighty subjects who can walk alone and have a normal cognitive level participated in this experiment. Based on Berg Balance scale (BBS) test with 52 points, subjects were divided into Healthy older (HO: 46 persons, BBS: 53.80 ± 1.19) and Impaired older (IO: 34 persons, BBS: 49.06 ± 2.03) group. Each subject performed 30 seconds four different standing balance tests (EO: Eyes Open, EC: Eyes Close, EOf: Eyes Open on foam, ECf: Eyes Close on foam). Five variables (Mean distance, Range of distance, Root mean square, Mean velocity, 95% ellipse area) were calculated from the hip joint center movement of Kinect sensor. Results showed that there were significant differences between groups for four different standing tests. Calculated variables from kinect sensor showed significant correlation with BBS score. Especially, mediolateral mean distance, mediolateral root mean square, mediolateral range of distance and 95% ellipse area showed discriminative ability for all tests. Mean values of variables of IO were higher than those of HO, which means the decreased balance ability in IO compared with HO. Therefore, it was possible to estimate simple balance assessment of the elderly using portable low-cost Kinect sensor.

수소손상 검출과 평가기술

원순호,현양기,이종오,조경식,이재도 한국비파괴검사학회 2002 한국비파괴검사학회지 Vol.22 No.1

산업현장에서 수소는 설비를 손상시킬 수 있는 주원인 중의 하나이며, 종종 설비를 파괴시키는 사고를 발생시킨다. 수소손상에 의한 결정립계의 공동 또는 미세균열은 강재의 파괴인성과 강도를 떨어뜨리는 원인이 되고, 따라서 과거 제한적인 방법으로 수소손상을 평가하기 위한 시도가 수행되었다. 본 연구에서는 초음파를 적용하여 수소손상을 검출하고 평가하기 위한 연구를 수행하였다. 미세조직시험에 의해 확인된 시험편을 이용하여 초음파의 속도와 감쇠계수를 구한 결과, 수소손상에 의해서 초음파 속도는 감소하고 감쇠는 현저하게 증가하는 것으로 나타났다. 이러한 결과를 바탕으로 수소손상을 검출하기 위한 신뢰성 있는 평가법을 제시하였다. The presence of hydrogen in industrial plants is a source of damage. Hydrogen attack is one such form of degradation and often causing large tube ruptures that necessitate an immediate shutdown. Hydrogen attack may reduce the fracture toughness as well as the strength of steels. This reduction is caused partially by the presence of cavities and microcracks at the grain boundaries. In the past several techniques have been used with limited results. This paper describes the application of an ultrasonic velocity and attenuation in hydrogen damage. Ultrasonic tests showed a decrease in wave velocity and an increase in attenuation. Such results demonstrate the potential for ultrasonic nondestructive testing to quantify damage. Based on this study, reliable recommendation is suggested to detect hydrogen attack.

퍼지추론을 이용한 전문가시스템에 관한 연구

梁豪原,裵相賢 조선대학교 기초과학연구소 1994 自然科學硏究 Vol.17 No.1

The aim of this paper is a study on the fuzzy reasoning for the process of natural language in Expert system. When the man want to deal indefinite data in Expert system, it's no matter whether he is an expert or not, he may make use of an existing way which is based on probability. But, in this way, the indefinite data cannot be reflected in inputting it consequently it cannot express the indefinite thought of man. So, I tried to operate Expert system in Fuzzy theory which is similar to Man's thinking procedure. In this paper, the fuzzy reasoning is realized for processing the natural language in interface expert system with user on the ground of the fuzzy theory.

Sophora flavescens의 뿌리에서 유래한 Cholinesterase 저해 화합물

장원희, 트란홍광, 김장훈, 양서영, 김영호 충남대학교 약학대학 의약품개발연구소 2021 藥學論文集 Vol.36 No.-

Searching for cholinesterase inhibitory compounds from natural products is important to de- velop therapeutic agents for Alzheimer’s disease. Our previous research on the chemical components of Sophora flavescens roots resulted in the isolation of twelve flavonoids, kushenol E (1), maackiain (2), 8-prenylkaemperol (3), 8-prenylnaringenin (4), kushenol L (5), kushenol A (6), kushenol C (7), kushenol B (8), sophoraflavanone G (9), kushenol H (10), isoxanthohumol (11) and kurarinone (12) and their structures were elucidated by spectroscopic methods. Inhibitory effect of cholinesterase were tested using the Ellman's method. Most flavonoid compounds showed good inhibitory activities on cholinesterases. Kushenol E (1) and sophoraflavanone G (9) showed good inhibitory activities on acetylcholinesterase with IC50 values of 3.75 and 4.14 μM and butyrylcholinesterase with IC50 values of 2.00 and 0.75 μM, respectively. In addition, a kinetic analysis revealed that kushenol E (1) was non-competitive inhibitor with Ki value of 0.77 μM on acetylcholinesterase and 0.16 μM on butyrylcholinesterase, whereas sophoraflavanone G (9) was mixed type inhibitior with Ki value of 9.42 μM on acetylcholinesterase and 0.81 μM on butyrylcholinesterase. These findings suggest that flavonoid compounds from S. flavescens roots are potential cholinesterase inhibitors.

軸의 Keyway 附近에서의 應力集中現狀에 관한 硏究

양원호,이정하 成均館大學校 科學技術硏究所 1990 論文集 Vol.41 No.2

The fatigue strength is decreased by stress concentration in the curvature part of a keyway. Thus, the stress concentration phenomena near the kewway of a shaft have been treated as an important issue. The objective of this thesis is to analyze stress concentration phenomena numerically by means of 3-Dimensional Finite Element Method and to examine fracture form near the keyway of a shaft by a torsional fatigue testing. Stress concentration phenomena have been studied for various width, depth, and sled radius of the sled runner type key way of the shaft which is subjected to torsional moment. Torsional fatigue tests were carried out using PMMA bar specimen to examine the initiation and the form of fracture. The following results were obtained. 1.. The maximum principal stress was appeared near the end corner portion of a sled part and the direction of the maximum principal stress was 45 degree with the axis of the shaft. 2. As the depth of the keyway is being increased, the stress concentration coefficient for the maximum principal stress which appeared sled part is increased. And as the width of the keyway or the radius of the sled is being increased, stress concentration coefficient is decreased. 3. The fracture of a low ductile shaft occurs at the point where the distortion energy density is greatest and the direction of fracture is 45 degree with the axis of the shaft by means of principal stresses. The fracture of a high ductile shaft occurs, however, in the dirction of 90 degree with the axis of the shaft by means of the maximum shear stress at the parallel portion of the keyway.

에멀젼 연료의 성능평가에 관한 연구

양원호,이동원,김홍석,박윤범,현명택 제주대학교 공과대학 첨단기술연구소 2005 尖端技術硏究所論文集 Vol.16 No.2

Emulsified fuel (mixed fuels with a small quantity of water) is suggested as a way of simultaneously diminishing NO_(x) and particulate matter. It is, therefore, an eco-friendly fuel and economical energy source. In this research, a comparative analysis between diesel fuel and emulsified fuel on their characteristics and the performance was done.

음식점 비흡연 종업원의 간접흡연 노출량 지표로써 이산화질소 이용

양원호,고영림,한인규,이정민,정문식,정문호 대한위생학회 2000 대한환경위생공학회지 Vol.15 No.3

There, is increasing evidence suggesting that passive smoking increases the risk of lung cancer and other disease. though the potential health effects of exposure to environmental tobacco smoke (ETS) is a controversial subject. Since smoking in restaurant is prevalent in Korea. The concern on passive smoking exposure of non smoking service workers has been. requested. ETS exposure of non smoking service workers at restaurant was assessed because they have spent their times in restaurant indoors. The purpose of this study was feasibility of nitrogen dioxide(NO_(2))as exposure marker of ETS. The results of the study were as follows: 1. Average NO_(2), concentrations in indoor and outdoor at restaurants were 57.01ppb(±12.4) and 54.29ppb(±9.54), respectively. Comparing office-workers, service-workers at restaurants were exposured highly. 2. The personal NO_(2) measurement as exposure marker of ETS could cause The exposure error because NO_(2) can he generated by combustion appliances in indoor. 3. Service-workers spent their most time (86.6%) in indoor. Mean time spent at restaurant indoors and at home was 9.4 hours and 10.9 hours. respectively. 4. Personal NO_(2) levels correlated with indoor NO_(2) concentrations of restaurant (r=0.70) and of their home (r= 0.52) rather than of outdoor NO_(2) concentration of restaurant (r=0.35). The causes of personal NO_(2) exposure of non-smoking service-workers were considered as smoking of guests and combustion appliance indoors. 5. Personal NO_(2) exposures were estimated using Monte-Carlo simulation and time-weighted model. Estimated personal NO_(2) level was 47.2ppb (±8.3).

이모장치의 적응증에 관한 후향적 고찰

양원식,김병호 대한치과교정학회 1995 대한치과교정학회지 Vol.25 No.1

본 연구는 초진시의 골격형태로부터 이모장치에 대한 반응성을 예측하는 지표를 구하여 Ⅲ급부정교합환자의 조기 치료를 결정할 때 고려할 수 있는 기준을 마련하기 위해 시행하였다. 성장기의 골격성 Ⅲ급 부정교합아동 40명을 연구대상으로 하였으며, 이들을 영구치열완성 이후의 교합의 안정성과 최대성장기 이후의 안모의 개선도를 기준으로하여 양호반응군 25명과 불량반응군 15명으로 나누었다. 초진시 두 군 사이에 현저한 차이를 보이는 주요 골격계측항목을 선택하고, 판별분석을 시행하여 다음의 결과를 얻었다. 1. 치료전 Bjo¨rk sum, 전후안면고경비율, gonial angle, lower gonial angle, occlusal plane to SN, occlusal plane to AB plane angle 등의 항목에서 두 군 사이의 유의성이 인정되어 양호반응군이 불량반응군에 비해 치료전에 보다 수평적인 안모형태를 지니고 있었음을 알 수 있었다. 2. Bjo¨rk sum등 두군사이에 유의한 차이를 보인 각 항목들의 임계값과 판별력을 구하였다. 3. 판별에 기여도가 높은 세 항목 즉, Bjo¨rk sum, gonial angle 그리고 occlusal plane to AB plane angle을 이용한 판별식을 구하였으며, 이를 이용할 때 본 연구에 사용된 표본의 85%를 올바르게 판별할 수 있었다. The purpose of this study was to predict the respose to the chincap therapy from the initial cephalometric measurements and to obtain the indication of chincap therapy. 40 patients selected for this study were classified into two groups by the occlusal stability after completion of permanent dentition and the improvement of facial profile, after chincap therapy. One was good response group which consisted of 25 children and the other was poor response group with 15 patients. Various measurements of the craniofacial structure in the initial lateral cephalogram were calculated and analyzed by t-test and discriminant analysis. The results were as follows : 1. Good response group had more horizontal growth pattern in initial stage of treatment, and the contributing measurements were Bjo¨rk, anterior-posterior facial height ratio, gonial angle, lower gonial angle and occlusal plane to AB plane angle. 2. The critical points and predictive values of the influential skeletal measurements were calculated. 3. The discriminant function was obtained from three major influential measurements; Bjo¨rk sum, gonial angle and occlusal plane to AB plane angle, and this function could discreminate correctly in 85% of this samples.

만곡 근관에서 엔진 구동용 Ni-Ti File과 초음파 기구에 의한 근관셩형 능력의 비교

양규호,오원만,김현주 大韓齒科保存學會 1995 Restorative Dentistry & Endodontics Vol.20 No.2