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.

皮膚自家移植후의 形態學的 變化에 관한 硏究

梁原模,李永浩,申台均,朴景蘭,金源式 충남대학교 의과대학 지역사회의학연구소 1989 충남의대잡지 Vol.16 No.2

The skin of abdominal wall homografted t the back of rats and observed the morphological changes of grafted tissues and mother tissues on the 1 day, 1 week & 2 weeks after operation. For light microscopic observation, the tissues were fixed within 10% neutral buffered formalin solution and stained with routine hematoxylin & eosin and alcian blue-safranin. The results were as follows; 1. The grafted abdominal skin were degenerated markedly on 1 day after operation but some cells near hair follicle remained alive. 2. In the grafted skin, the epidermis was formed newly at the upper part of muscle layer on 1 weeks after operation. 3. The epidermis of grafted skin was thicker than mother skin on 2 weeks after operation, and there were many small cells having long nucleus arranged vertically to the basal lamina. 4. Few mast cells were found in the lower portion of muscle layer on 1 day after graft operation, but the mast cells which contain heparin mainly increased in number gradually from 1 weeks to 2 weeks after operation.

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).

TiO₂에 담지된 금속 산화물 촉매상에서 TCE 산화분해반응

양원호,김문현 한국환경과학회 2006 한국환경과학회지 Vol.15 No.3

복합하중상태에 있는 복합재료 원통형 쉘의 거동

양원호,조명래,여경수 기계기술연구소 1999 성균관대학교 논문집 기계기술편 Vol.1 No.1

The advent of laminate composite materials opened the way for efficient shell structures. Cylindrical shells are already widely used in indstrial applications. And their buckling behaviour is a vital safety consideration. The objective of this paper is to analyse buckling behavior of laminated composite cylindrical shells subjected to combination of axial compression and torsion by finite element analysis. The influence of load type, fiber orientation angle, and stacking sequence on the buckling behaviour is discussed.

박실지에서 계절적으로 조사한 식물성 플랑크톤상과 환경변이에 관한 연구

양운진,이호원 慶南大學校 附設 基礎科學硏究所 1997 硏究論文集 Vol.11 No.-

박실지 자연호소에서 1996년 8, 11월 및 1997년 3월과 5월등 4회에 걸쳐 식물성 프랑크톤 군집을 조사하였다. 본 조사 결과 5강 45속 95종 10변종으로 총 106분류군이 출현하였으며, 8월이 31분류군. 11월이 30분류군 그리고 3월이 41분류군 그리고 5월이 38분류군으로 월별 종조성은 큰 차이가 없었다. 그리고 이들의 각 강별 구성을 살펴보면 규조강이 49.1%, 유글레나강이 15.1%, 녹조강이 24.5%, 남조강이 6.6%로 황갈조류강이 4.7%의 순으로 유글레강의 구성비가 높고 녹조강의 구성비가 낮은것이 특징이다. 현존량은 11월이 1.94개체/㎖, 3월이 2,046개체/㎖, 8월이 2,850개체/㎖로 5월에는 3,542개체/㎖로 나타났으며, 그리고 8월에는 Microcystis aeruginosa (2.090), 11월에는 Fragilaria corotenesis(1.584) 그리고 3월에는 Dinobryon divergens (1.306)가 5월에는 Scenedesmus ecornis (1.700)가 우점하였다. Species composition and dynamic of the phytoplankton community were studied in the Pacsil Swamp. August 1996 to May 1997. 106 taxa of 5 classes.45 genera. 95 species. and 10 varieties were observed. The composition of species was as follows: Bacillariophyceae is 49.1% Euglenophyceae is 15.1% Chlorophyceae is 24.5%. Cyanophyceae is 6.6%. Chrysophyceae is 4.7% and so on. The standing crops of phytoplankton varied from 1.941 cells/㎖ to 3.542 cells/㎖. The dominent species were Microcystis aeruginosa in the August 1996. Fragilaria corotenesis in November 1996. and Dinobryon divergens in March 1997. and Scenedesmus ecornis in May 1997.

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.

수동식 시료채취기를 이용한 사무실 직장인의 이산화질소 노출평가 및 예측 : 한국의 서울과 호주의 브리스베인 비교 연구 Comparative Study of Seoul in Korea and Brisbane in Australia

양원호,손부순,김종오 한국환경과학회 2002 한국환경과학회지 Vol.11 No.3

Indoor and outdoor nitrogen dioxide (NO_2) concentrations were measured and compared with measurements of personal exposures of 95 persons in Seoul, Korea and 57 persons in Brisbane, Australia, respectively. This activity diary was used to determine the impact on NO_2 exposure assessment and microenvironmental model to estimate the personal NO_2 exposure. Most people both Seoul and Brisbane spent their times more than 90% of indoor and more than 50% in home, respectively. Personal NO_2 exposures were significantly associated with indoor NO_2 levels with Person coefficient of 0.70 (p<0.01) and outdoor NO_2 levels with Person coefficient of 0.66 (p<0.01) in Seoul and of 0.51 (p<0.01) and of 0.33 (p<0.05) in Brisbane, respectively. Using microenvironmental model by time weighted average model, personal NO_2 exposures were estimated with NO_2 measurements in indoor home indoor office and outdoor home. Estimated NO_2 measurements were significantly correlated with measured personal Exposures (r = 0.69, p<0.001) in Seoul and in Brisbane (r = 0.66, p<0.001), respectively. Difference between measured and estimated NO_2 exposures by multiple regression analysis was explained that NO_2 levels in near workplace and other outdoors in Seoul (p = 0.023), and in transportation in Brisbane (p = 0.019) affected the personal NO_2 exposures.

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.