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.

흉선종 제거후에 발생한 재생 불량성 빈혈 : 증례보고

전원선,이상철,김현정,배상병,김찬규,이남수,박노진,이규택,박성규,홍대식,박희숙,원종호 순천향의학연구소 2007 Journal of Soonchunhyang Medical Science Vol.13 No.2

Thymoma is associated with myasthenia gravis, Pure red cell aplasia, and autoimmune diseases such as autoimmune hemolytic anemia, aplastic anemia, and hypogammaglobulinemia. It's association with aplastic anemia is rare and aplastic anemia appearing after surgical removal of thymoma is especially rare. The authors hereby report a case of aplastic anemia occuring in a patient who was diagnosed with thymoma and myasthenia gravis and had the tumor surgically removed. The patient was treated with anti-thymocyte globulin, cyclosporin, and prednisolone, and showed partial remission with hematologic improvements after 12 months.

한국 유치원에서의 통일교육: 유치원 교육과정 및 교재 분석

서규선,조경희 서원대학교 교육연구소 1995 敎育發展 Vol.1995 No.14

The first purpose of the study is to analysis the curriculum of our kindergarten Unification Education from the 1945 Liberation of Korea to now. The second purpose of the study is to analysis the texts used for unification Education in our Kindergartens. The results of this study are as follows. 1.The curriculum of Kindergarten Unification Education was developed later then that of primary or secondary school. Kindergarten curriculum of Unification Education has been dealt with only secondary by the authorities and others. 2.There were no texts in this area till 1970. It was 1984 that the first teaching materials of Unification Education for chilern was published. 3.Most of texts used for Unification Education in Kindergartens are not suitable to childern' intellectual and affective developing level. But things have changed greatly in recent years. 4.Man-cented illustrations of theaching materials used for Unification Education in Kindergartens are overwhelmingly lager in number then female-centered illustrations. This show that our society is man-centered one. 5.Cramming method is used mostly to teach the text of our Unification Education in Kindergarten

흰쥐 심장혈관계통에서 3β-hydroxysteroid dehydrogenase/△⁵-△⁴ isomerase의 분포에 관한 연구

오선희,오재민,백용아,박옥규,정연태 대한해부학회 1988 Anatomy & Cell Biology Vol.31 No.3

한국 성장기 아동의 Ⅲ급 부정교합 양상에 관한 두부방사선 계측학적 연구

양규호,김선희 大韓小兒齒科學會 1995 大韓小兒齒科學會誌 Vol.22 No.1

This study was performed to analyse the pattern of the Class Ⅲ malocclusion in Korean growing children. The cephlometric radiograms were taken from the growing children at 8 to 12 years old, then 11 items were statistically analysed. The results of this study were as follows : 1. As compared 11 items between Class Ⅲ malocclusion and normal occlusion, there was significant difference on SNA angle, Maxillary incisor to point A(mm), Maxillary incisor-NA line(angle), Maxillary incisor to NA line(mm), IMPA, Facial angle and Pog to Nasion Perpendicular(mm) between Class Ⅲ malocclusion and onrmal occlusion. 2. The most common Class Ⅲ malocclusion pattern was found that the normal maxilla and madible followed by normal maxilla and prognathic mendible. 3. In vertical component of Class Ⅲ malocclusion, subjects with long lower facial height were 54% of the total but with short lower facial height were 10%.

電子商去來의 擴散과 價格構造, 企業戰略

崔善奎,李明豪,趙伯濟 서울大學校經濟硏究所 2001 經濟論集 Vol.40 No.4

이 글에서는 최근 전자상거래의 비중이 높아짐에 따라 경제학의 주요 연구대상인 가격구조, 시장의 효율성, 기업의 전략 측면에서는 어떤 이슈가 생성·연구되고 있는지 살펴보고 있다. 이 논문에서 다루고 있는 주요 내용은 다음과 같다. 소비자의 탐색비용이 낮아짐에 따라 전자상거래에서 팔리고 있는 제품의 전반적인 가격수준은 오프라인에 비해선 낮아지고 있다. 전자상거래가 소비자 수요의 가격탄력성에 미치는 영향은 양면적으로 보인다. 전자상거래의 가격구조에서 흥미로운 사실은 오프라인에 비해서 동일 제품에 대한 가격분산의 폭이 크다는 것이다. 전자상거래가 확산되면서 가격경쟁이 벌어질 경우 디지털 정보재화시장에서의 가격은 한계비용인 영에 근접하기 쉽다. 기업들은 가격경쟁을 회피하는 방안으로 여러 가지 차별화전략을 구사하게 되고, 새로운 중계기관이 생겨나고 있다. 또 기존의 예상과는 구매자-판매자 관계는 시장 지향적이라기 보다는 위계 지향적인 관계가 주류를 이루고 있는 것으로 나타난다. 인터넷의 등장과 전자상거래의 확산으로 기업전략 측면에서 제품의 효과적인 개인화 방법, 브랜드 관리기법, 인터넷 광고의 효과성, 전자상거래 하에서의 여러 혁신적인 가격차별전략(경매가격, 실시간 동적 가격차별), 기존의 유통채널과 온라인 유통채널 간의 갈등(channel conflict) 등의 문제가 나타나고 있다.

綠藻식물 청각 Codium fragile의 성분 연구

김인규,강선영 성균관대학교 기초과학연구소 1987 論文集 Vol.38 No.2

There has been a continuing interest in the sterols and steroids of marine organisms. The most exciting results of recent studies have been the characterization of a host of novel sterols, many with unique alkylation patterns in the side chain, but some with modified ring structures. The Korean Sea marine siphonous green alga Codium fragile was shown to contain 25-methylene sterols. The major sterol of Codium fragile was isolated and identified as (24 S)-24-ethylcholesta-5, 25-dien-3β-ol (clerostrol) by spectroscopic methods. Studies on the C-24 alkylation mechanisms in a Trebouxia sp. (Chlorococcales) have already shown by B. Wilkomirski and L.J. Goad that elaboration of the 24-methyl and 25-ethyl sterols proceed with the production of 25-methylene sterol intermediates. The 25-methylene sterols found in Codium fragile probably arise by a similar alkylation mechanism to that operating in the Trebouxia species.

차세대 레진 개발을 위한 광중합형 복합레진의 화학적 분해와 마모에 관한 연구

양규호,최은영,최남기,김선미 大韓小兒齒科學會 2005 大韓小兒齒科學會誌 Vol.32 No.3

전남대학교 치과대학 소아치과학교실 및 치의학 연구소 수복재료로 사용되는 복합레진은 치아의 저작기능과 심미성을 회복할 수 있는 물리적, 화학적 성질뿐만 아니라 생물학적 적합성과 구강내 환경변화에 대한 내구성을 가지고 있어야 한다. 유치에 사용하려고 할 때에도 마모저항성과 구강내 환경에서의 분해저항성은 고려해야할 중요한 물성이다. 실험에 사용된 복합레진은 최근에 시판되고 있는 Metafil CX(Sun Medical, Japan) Solitaire 2(Heraeus Kulzer, USA), Composan LCM(Promedica, Germany), DenFil(Vericom, Korea)이었다. 각 제품의 분해저항성과 마모도를 평가하고자 마모시험 후 마모된 면의 깊이를 측정하였고 화학적분해를 얻기 위해 0.1N NaOH에 보관 시 각 제품의 분해저항성을 무게손실, 표면하 분해층 깊이, 용출된 Si 농도를 기준으로 평가하였고 주사전자현미경과 공촛점 레이저 현미경으로 분해층을 관찰하여 다음과 같은 결과를 얻었다. 1. 무게 손실량은 0.74~7.94%까지 다양하였으며 Metafil에서 가장 높았다. 2. 분해층 깊이는 Metafil이 가장 깊었고 Solitare 2, Denfil, Composan LCM순이었고 Metafil은 다른제품과 유의한 차이를 보였다(p<0.05). 3. Si 용출량은 Metafil이 가장 많았으며 Metafil CX와 Composan LCM, DenFil, Solitaire 2사이에 유의한 차이를 보였다(P<0.05). 4. 주사전자현미경 관찰시 표면 양상 및 분해층 깊이를 관찰할 수 있었고 공촛점 레이저 현미경 관찰시 NaOH용액에 보관한 후 수복재의 기질과 충전제 사이의 결합의 파괴 양상을 관찰할 수 있었다. 5. 최대마모깊이는 DenFil에서 가장 낮았고, Metafil CX에서 가장 깊었으며 각 제품 간에는 유의한 차이를 보였다(p<0.05). 6. 각 제품의 Si 용출량과 분해층 깊이 사이 (r=0.491, p<0.05), 최대마모깊이와 비커스경도 간(r=-0.942, p<0.01)에 유의한 상관관계를 보였다. 이상의 결과 복합레진의 평가요소로서 마모도와 함께 가수분해도 고려되어야 할 것으로 사료된다. The aim of this study was to evaluate the resistance to degradation and to compare the wear resistance characteristics of four esthetic restorative materials in an alkaline solution(0.1N NaOH). The brands studied were MetafilCX(Sun medical, Japan) Solitaire 2(Heraeus Kulzer, USA), Composan LCM(Promedica, Germany), DenFil(Vericom, Korea). The results were as follows: 1. The mass loss of each brand was 0.74~7.94% and highest value in Metafil(7.94±0.39%). 2. The sequence of the degree of degradation layer depth was in descending order by Metafil, Solitaire 2, DenFil, Composan LCM. There were significant differences between Metafil and the others(p<0.05). 3. The sequence of the Si loss was in descending order by Metafil, Solitaire 2, Composan LCM, DenFil. There were significant differences among the materials(p<0.05). 4. On SEM, destruction of bonding between matrix and filler and on CLSM, the depth of degradation layer of specimen surface was observed. 5. The sequence of maximum wear depth was in descending order by Metafil, Solitaire 2, Composan LCM and DenFil. There were significant differences among the materials(p<0.05). 6. The correlation coefficient between Si loss and degradation layer depth (r=0.491, p<0.05) and Vicker's hardness number and maximum wear depth (r=-0.942, p<0.05) were relatively high. These results indicate that hydrolytic degradation and wear may consider as a evaluation factors of composite resins.

국제윤리 교육내용으로서의 현실주의

서규선 서원대학교 미래창조연구소 2004 과학과 문화 Vol.1 No.1

We investigate the meaning and significance of international ethics as well as the principle of selecting contents for international ethics education. And then we deal with realism as a part of international ethical thought. Also we review the realism which is recorded in the textbook for moral education. The international ethical education is world citizen education. The essence of international realism is its belief in the primacy of self-interest over moral principle. This can mean either that self-interest confer a positive right of some kind, as when the national interest is seen as a moral principle, or that morality is wholly inapplicable to international politics. There are five logic of realism in citizenship education. They are (1) two wrongs don't make a right, (2) slippery-slope, (3) lesser of two evils, (4) ends don't justify means, and (5) can imply ought to. Our moral education textbook does not deal with them because we think that such contents is not suitable in our moral education, this thought is wrong. The prescription which is not based on diagnosis is empty. Ethics and moral education emphasizes a prescription, but a prescription without description is meanless. We are not able to solve all international problems ethically. Realism is the starting point of International ethics. Realism must be more emphasized in our moral education curriculum and textbook. We are knowing well that the issue raised by realism is how that ethical good can be reconciled with the necessities of international politics and whether it remains plausible in the face of a world characterized by immoral necessities.

하악골에 발생한 심부성 치성섬유종의 치험 2예

김일규,김영렬,김종철,유선열 대한악안면성형외과학회 1986 대한악안면성형외과학회지 Vol.8 No.1