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.

8년간(1992~1999) 산업안전보건연구원에 의뢰된 직업병 심의 사례 분석

강성규,김규상,김양호,최정근,안연순,진영우,최병순,양정선,김은아,채창호,최용휴,김대성,박정선,정호근 대한산업의학회 2000 대한직업환경의학회지 Vol.12 No.2

Objectives : Pneumoconisis and noise-induced hearing loss (NIHL) have been reported as main occupational diseases by the Special Health Examination. The Industrial Accident Compensation Insurance has reported various work-related diseases, however, these two diseases occupied almost a half of compensated cases. Therefore, it was not well known about the status of occupational diseases other than pneumoconiosis, NIHL, and cardio-cerebrovascular accident (CVA). This study was conducted to analyze claimed cases as an occupational disease, that was requested to the Korea Industrial Safety and Health Agency (KOSHA). Methods : The local office of the Korea Labor Welfare Corporation (KLWC) has asked the KOSHA for confirmation of claimed cases as an occupational disease. We analyzed 379 cases requested from KLWC, the Ministry of Labor, employers, unions and occupational health agencies from 1992 to 1999. Results : Male was 80.7 % of the requested cases. Their mean age was 42 years old and 75.5 % of them were more than 35 years old. The requested cases were increased rapidly from 25 cases in 1992 to 108 cases in 1999 and the accept rate was 50.7 %. The majority of requested cases were respiratory diseases(22.4%), cancers(18.5%), Neuropsychiatric problems(14.5%), and musculoskeletal problems(13.5%). The accept rate was high in reproductive, respiratory, musculoskeletal and digestive disorders and low in neuropsychiatric, renal and otologic problems and occupational cancers. 73.6% of them were caused by chemical agents, especially 28.5 % were by organic solvents. 67% of them were clinically confirmed at university hospitals. A half of the cases were from KyongIn area, even the request came from the whole country. Conclusions : A claim was common in workers whose age was over 35 years old and exposure history was over 10 years. The respiratory diseases and neuropsychiatric disorders were still main problems in occupational health and occupational cancers was increasing even though its accept rate was not high yet.

청신경종의 크기에 따른 어지러움의 양상 및 전정기능 검사의 특징

정원호,홍성화,조양선,김성민,장병찬,최재연,이승진 대한이비인후과학회 2000 대한이비인후과학회지 두경부외과학 Vol.43 No.1

환경문제에 대한 언론의 역할과 커뮤니케이션이론

최양호 朝鮮大學校 社會科學硏究所 2000 社會科學硏究 Vol.21 No.1

언론과 프라이버시 침해 : Time, Inc. v. Hill 사건을 중심으로 Time, Inc. v. Hill

최양호 朝鮮大學校 社會科學硏究所 1998 社會科學硏究 Vol.19 No.-

앞으로의 정보사회에서의 구성원들은 농경사회, 산업사회의 구성원들보다도 알게 모르게 프라이버시를 침해당하는 사례가 많을 것이다. 예를 들어 전자주민카드에 개인의 신상뿐만 아니라 경제적 활동, 정치적 활동에 관한 모든 세세한 정보가 기록된다고 가정하면, 정부, 기업, 종교단체 등 기타 여러 조직으로부터 원형감옥에 갇힌 사람처럼 의도적이든지 비의도적이든지 간에 프라이버시를 상실한 채 감시를 지속적으로 당하게 될 것이다. 이처럼 중요한 개인의 프라이버시문제에 대해 우리나라에서는 체계적인 법리연구가 되지 않고 있는 현실이다. 미국에서는 국민들의 알 권리를 충족시키는 언론의 자유와 개인의 '홀로 있을 수 있는 권리' 사이에 빚어질 수 있는 마찰을 최소화하기 위해서 연방 대법원 판사들과 법리학자, 언론학자 등이 많은 논의 및 연구를 해왔다. 이 연구에서는 최초로 개인의 프라이버시 권리와 언론 자유에 관한 상충되는 영역을 검증한 Time, Inc. v Hill사건에서 제기된 쟁점들을 중심으로 미국 헌법과 관련되는 쟁점들에 관해서 논의하고자 한다.

Sequential Source Localization Using Signal Subspace Components

최양호 동양대학교 산업기술연구소 2000 東洋大學校 産業技術硏究所 論文集 Vol.2 No.1

A new sequential estimation method is proposed which exploits only the signal subspace components of steering vectors. When the sources are uncorrelated with each other its asymptotic root mean square error (RMSE) performance is theoretically better than that of the previous method which considers both the signal subspace and noise subspace components of steering vectors.

사출 조건이 사출품의 기계적 성질에 미치는 영향

최양호,이용성 한국공작기계학회 1997 한국생산제조학회지 Vol.6 No.1

In producing moldings by using an injection mold, several variables such as the metal mold status and the condition of injection molding should be selected properly in order to obtain good quality of moldings. In this study, focussed are the mechanical properties of injection moldings, since many researches on injection have been focussed mainly on the molding quality, injection pressure, and bulk temperature but the properties of injection moldings have not been studied extensively. The mechanical properties of present injection moldings can be improved simply by changing the molding material and the injection condition without changind the metal mold. To have the final products meet the specified molding quality and mechanical properties at the same time, the bulk temperature of injection, pressure variation, volumetric shrinkage, stress, and cooling should be analized by CAE(computer aided engineering) after injection mold design. In this paper the effects of dischare condition on mechanical properties of injection moldings are studied by testing the moldings which are injected by varying injection conditions.

매스미디어 연구에서 실증주의와 비판주의에 관한 비교분석

최양호 朝鮮大學校 社會科學硏究所 1999 社會科學硏究 Vol.20 No.1

이 연구의 주요 목적은 매스미디어 연구에서 주요 연구 접근방법 및 패러다임이라고 할 수 있는 실증주의(positivism)와 비판주의이론(critical theory)에서 논의되고 있는 쟁점들을 역사철학적 방법으로 비교 고찰하는 것이다. 또한, 미디어 연구에서 두 접근방법의 차이점과 유사점은 무엇이고, 두 접근방법의 통합은 실재적으로 가능할 것인가? 이 연구질문에 대해 이 논문은 융화모형(convergence model)을 제안하고 있다. 즉, 실증주의학파와 비판주의 학파가 서로 강조하고 있는 일정 부분을 수용하도록 요구되고 있다. 특히, 비판주의 학파 중에서 채택될 수 있는 영역을 보면 매스미디어 구조 맥락, 커뮤니케이션 과정의 윤리적 측면, 그리고 문화적, 이데올로기등 다양한 접근 방법 수용등 실증주의와 융화될 수 있는 공통분모가 있다. 하지만, 두 학파의 대화를 통한 융화라기 보다는 일방적으로 경험주의학파가 비판주의를 접수했다는 비난도 받을 수 있기 때문에 대화를 통한 미디어연구 융화모형 개발이 절실히 필요할 것이다.

Gradient Guided 탐색을 이용한 고속 CDMA 다중사용자 검출

최양호 江原大學校 産業技術硏究所 2004 産業技術硏究 Vol.24 No.B

We present a fast algorithm for CDMA (code division multiple access) multiuser detection using the gradient guided search. The fast algorithm calculates the maximum likelihood (ML) metric so efficiently that it needs only O(K) additions in the presence of K users once some initialization is completed. The computational advantages of the fast algorithm over the conventional method are more noticeable as more iterations are required to obtain a suboptimal solution as in the initialization with matched filters.