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.

A. 高校 科學 (生物·地球科學) 및 數學科 探究學習의 評價模型 定立과 評價紙 開發

李相協,權炳奎,林在圭,孫文求,吳岱燮,楊洪準,梁承榮,姜用熙,林成圭,金正遠,金吉民,兪正在 경북대학교 과학교육연구소 1982 科學敎育硏究誌 Vol.6 No.-

Currently the evaluation of high school science and mathematics learning has been too much knowledge-centered without concerning the inquiring ability or scientific attitude. This study, therefore, was made for the purpose of establishing of evaluation model for high school science (biology and earth science) and mathematics learning and its evaluation items. In this paper, the research was done about three fields, biology, earth science and mathematics. 1. For the biology, the evaluation methods of inquiry learning were studied with the foreign references, and proper evaluation items were suggested. 2. For the earth science, after analizing 5 kinds of earth science textbook of current using in high school, essential 19 items were selected. 5 of them were tested in test group and control group, then, the results were analized. 3. For the mathematice, the teaching elements of「Set」and「Flow chart」in mathematics (Ⅰ) were selected and structured. Detailed teaching objects were established and evaluation items were introduced.

의류제품 구매에 있어서 유통채널갈등과 가격단서 지각

양원정;서민정;박재옥;이규혜 한양대학교 2006 韓國 生活 科學 硏究 Vol.26 No.2

Differentiated On Off line channel strategies are getting more attention due to conflicts between Off line channel and active E commerce. Choosing an appropriate channel strategy can prevent apparel products from clashing in market and manage each channel more efficiently. In fashion industry, product prices are flexible because of the short product life cycle and different distribution channels. It is essential to understand consumers’ apparel price cue perception when purchasing apparel in both On line and Off line. The objectives of this study was to examine the effects of apparel price cues on perceived savings and purchase intention in On line versus Off line retail channel. 303 quetionnaires from internet experienced women were used for the data analysis. Statistical analyses employed in this study were descriptive statistics, reliabilities conjoint analysis and regression. Overall, the perceived importance of apparel price cues were different between On line and Off line channels and each apparel price cue affected perceived savings and purchase intention differently according to distribution channels. Therefore, by considering characteristics of apparel price cue in On line versus Off line channels, differentiated channel strategies should be imposed to implement more effective marketing strategies.

데페록사민 전처치가 토끼 심근경색 크기의 감소에 미치는 효과

양관모,오동렬,박승현,박규남,이원재,김형국,황두영,최승필,채장성 대한응급의학회 1998 대한응급의학회지 Vol.9 No.4

Background: Reperfusion of ischemic myocardium has been postulated to result in a specific oxygen radical mediated tissue injury. Iron may liberate during ischemia and we hypothesized that administration of the iron chelator, deferoxamine during ischemia would result in improved recovery after postischemic reperfusion. Purpose: To test whether iron-catalyzed processes contribute to myocardial necrosis during ischemia and reperfusion, deferoxamine was administered to block iron catalyzed hydroxyl radical formation in rabbits. Methods: Eleven rabbits were divided into two groups : control group (n=5) and deferoxamine pretreatment group (n=6). The left circumflex coronay artery was ligated for 30 minutes and reperfused for 180 minutes. Area at risk (AR) was measured by non-stained area with methylene blue injection into left atrium after left circumflex coronary artery ligation. Infarct size was measured by weighing after triphenyltetrazolium chloride staining. Heart rate was measured using electrocardiographic recording and systemic blood pressure was monitored by pressure transducer connected to the catheter in the left ventricle. Results: 1. There was no significant difference of heart rate and blood pressure in deferoxamine pretreatment group compared with control group. 2. There was significant decrease of serum iron concentration after continuous infusion of deferoxamine compared with serum iron concentration before ligation of coronary artery(P<0.05). 3. There was no significant difference of area at risk between control and deferoxamine pretreatment group. 4. Area at necrosis to area at risk was significantly reduced in deferoxamine pretreatment group compared with control group(P<0.05). The results suggest that deferoxamine infusion prior to coronary artery occlusion has a significant benefit in reducing infarct size in this model.

포도상구균의 약제 내성 및 β-lactamase의 생산에 관하여

양재윤,박상욱,이용진,조규봉,이연태 단국대학교 신소재기술연구소 1994 신소재 Vol.4 No.-

항균제의 오남용으로 내성균의 출혈빈도가 매우 높아져 임상가에서는 환자치료에 어려움이 적지 않다. 특히 많은 균종중에서 병원감염의 문제가 되고 있고 포도상구균에 대한 내성빈도는 환자치료에 중요하다고 판단된다. 따라서, 1992년 12월부터 1993년 2월 사이에 서울대 병원에 내원(來院)한 환자로부터 총 108주의 포도상구균을 분양 받아 항균제 내성검사를 실시하였고 황색포도상구균의 경우는 β-lactamase 생산유무 확인 및 methicillin에 대한 MIC 농도를 비교하였으며, methicillin에 대하여 각기 다른 MIC농도를 갖는 균종에 대한 substrate 분해능 검사를 실시하여 다음과 같은 결론을 얻었다 (1). 항균제 내성검사를 실시한 108주의 포도상구균은 penicillin에 가장 높은 내성을 나타냈다. 황색포도상 구균의 경우는 97%, 표피포도상 구균의 경우 100%, coagulase 음성포도상구균의 경우 95.7%로 나타났다 (2). vancomycin의 경우는 전 균주가 감수성을 나타냈다 (3). methicillin에 대한 내성율은 41.4%로 나타났다. 이 내성균주들은 10가지 검사 항생제중 최고 9가지에 대한 항균제 내성을 나타내어 다약제 내성임을 알 수 있었다 (4). β-lactamase 생산 실험에서는 58균주의 황색포도상 구균중 53주가 양성을 나타내어 91.4%의 결과를 얻었다. β-lactamase 생산균주와 methicillin에 대한 내성균주가 반드시 일치하지는 않았다 (5). Spectrophotometric assay에서는 내성이 높은 균주와 낮은 균주간에 β-lactamase에 의한 substrate 분해능이 서로 유사하게 나와 황색포도상 구균의 methicililin에 대한 내성 획득은 β-lactamase 뿐만이 아닌 penicillin binding protein(PBP)의 구조적 변화로 인한 내성획득도 시사함을 알 수 있다. One hundred and eight Staphylococcus aureus strains were isolated from patients of Seoul National University Hospital from December 1992 to Feburary 1993. All strains were tested for their sensitivities against antibiotics. β-lactamse producing test was also performed in order to know the relationship between the methicillin resistance and β-lactamase production. Its activity was determined by direct spectrophotometric method. Initial velocities of hydrolysis of the antibiotics were monitored at wavelength 323 nm which corresponded to maximal change in absorbance between the unhydrolyzed substrate and the hydrolyzed product. The results are summarized as follows: 1. In antibiotics sensitivity test of 108 isolated strains of Staphylococcus, they showed hightest resistance to penicillin but all of tested strains were susceptible to vancomycin. 2. 41.4% of them showed resistance to methicillin. 3. All methicillin resistant strains were found to be multi-drug resistant, from 3 to 9 antibiotics. 4. 91.4%(53 out of 58) produced β-lactamase, β-lactamase producing strains did not always coincide with the methicillin resistant strains. 5. β-lactamase activities were similar among staphylococus strains, irrespective of their methicillin resistance.

백서의 일과성 국소허혈-재괄류 모델에서 U-74389G와 MK-801이 뇌경색 크기에 미치는 효과

김재일,김종민,양대웅,이근호,윤병우,노재규,이상복 대한신경과학회 1999 대한신경과학회지 Vol.17 No.1

핵연료에서 핵분열 생성물의 방출 기구에 관한 연구

양재춘,이호연,정문규 충남대학교 기초과학연구소 1986 연구논문집 Vol.6 No.-

중성자와 우라늄의 핵 반응에 의해 생성된 핵분열 생성물의 물리적 특성을 이용하여 원자로 내의 핵연료 상태를 해석하는 새로운 모델을 도입하였다. 고체 핵연료 내에서 핵분열 생성물의 생성과 이것의 원자로 냉각재까지 방출되는 과정을 계산하는 방정식을 세웠다. 이 방정식으로 핵분열 생성물의 source term을 계산하고, 이것이 고체 핵연료 내에서 방출되어 gap과 핵연료 피복재를 통하여 원자로 냉각재까지 방출하는 양을 계산하였으며, 원자로 1차 냉각재에서의 tramp uranium양을 계산하였다. 이 방정식을 computer로 계산하기 위하여 전산화 하였다. 실험 자료로는 가압 수형 원자로 (Pressurized Water Reactor)인 고리 원자력 발전소 1호기의 제 3주기 동안에 핵연료의 상태를 감시하기 위해 1차 냉각재를 분석해서 얻은 핵분열 생성물의 방사능 강도를 이용하였다. 이 실험 자료와 위 방정식에서 계산한 방사능 강도를 비교하여 결함 핵연료 수와 tramp uranium 양을 구하였다. 이렇게 구한 결과와 고리 1호기의 제 3주기 말에 핵연료 재장진을 위해 수행한 sipping test 결과를 비교해 보았다. 그 결과 본 연구에서 도입한 모델이 잘 맞는 것을 알 수 있었다. We propose the new model which analyzes the nuclear fuel state of the reactor from the physical characteristics of nuclear fission products which are produced by reactions between neutron and uranium 235. The main feature of this model is to calculate the generation of fission products inside the solid nuclear fuel and the release mechanism of fission products into the reactor coolant. Using the computer we solved the equation of the model and put the experimental activity data of the fission products to determine the number of failed fuel rods and amount of tramp uranium. These data had been taken from the primary coolant of the Kori Nuclear Generating Station, Unit 1. This result of our calculation is in a fairly good agreement with the result of the sipping test during the refueling period for cycle 3 of the Kori Nuclear Generating Station, Unit 1. As a result of this research we conclude that our model for the release mechanism of unclear fission products in reactor fuel is well describing the actual processes.

방사선 측정 및 해석 연구 : 원자로 냉각수중의 방사능해석에 의한 결함핵연료봉의 평가 Assessment of Defected Fuel by Analysis of Reactor Coolant Activities

양재춘,오희필,전재식,이호연,오헌진,정문규,박해용 충남대학교 기초과학연구소 1987 연구논문집 Vol.7 No.-

중성자와 우라늄의 핵반응에 의해 생성된 핵분열생성물의 물리적 특성을 이용하여 원자로 내의 핵연료 상태를 해석하는 모델을 개선하였다. 이 모델에서는 고체 핵연료 내에서 특정핵종의 핵분열생성물의 생성과 이것이 원자로 냉각재까지 방출되는 과정을 계산하고 추적하여 방사능농도와 결함 핵연료봉의 수를 관계짓는 방정식의 계수들을 결정한다. 핵분열생성물의 거동은 이탈(knock out)과 이동(migration) 두 부분으로 나누어 해석하였으며 트램프 우라늄의 영향을 분리할 수 있도록 하였다. 실측자료로는 가압 경수형 원자로인 고리 원자력발전소 1호기의 1차 냉각재를 분석해서 얻은 I-131과 I-133의 방사능 강도를 이용하였다. 이 실험자료와 위 방정식에서 구한 방사능 강도로부터 구한 결함 핵연료의 수는 제3주기에서 9.34±1.13개 제6주기에서 0.294±0.092개로 나타났다. An improved mothod of assessing fuel status by analyzsis of the fission product in the reactor coolant system is proposed. The release mechanism of specific fission products is established for determination of the coefficients in the equations which relate the radioactivities with the amount of detected fuel. Knock-out and migration models are employed in the formulation of the release mechanism. The influence of the tramp uranium is quantified. Sample calculations were made for KNU 1 reactor system using the I-131 and I-133 concentrations in the primary coolant. The estimated number of defected fuel pins in the third and sixth cycles appeared to be 9.34±1.13 and 0.294±0.092, respectively.

Modified Twin Blocks에 의한 성장기 아동의 Ⅱ급 부정교합의 치료증례

박재홍,양규호 大韓小兒齒科學會 1994 大韓小兒齒科學會誌 Vol.21 No.2

The Twin Blocks technique was developed by Dr. William Clark of Scotland during the early 1980's. Twin Blocks are an uncomplicated system that incorporates the use of upper and lower bite blocks. These blocks reposition the mandible and redirect occlusal forces to achieve rapid correction of malocclusions. They are also comfortable and the patients wear them full-time-inducing eating time. Occlusal forces transmitted through the dentition provide a constant proprioceptive stimulus to influence the rate of growth and the trabecular structure of the supporting bone. The features of Twin Blocks mean easier and quicker treatment. The occlusal inclined plane is the fundamental functional mechanism of the natural dentition. Twin blocks are bite blocks that effectively modify the occlusal inclined plane to induce favorably directed occlusal forces by causing a functional mandibular displacement. Upper and lower bite blocks interlock at a 45˚ angle and are designed for full-time wear to take advantage of all functional forces applied to the dentition including the forces of mastication. The patients who were treated with modified Twin Blocks, and following results were observed : 1. Large overjet and deep overbite were corrected. 2. ClassⅡ molar relationship was changed into classⅠ. 3. Labial inclination of upper incisors was corrected by adjustment of labial bow of upper bite block. 4. The profiles of two patients were improved by anterior displacement of mandible.

갑상선기능저하증에 기인한 내인성 급사 1예 보고

이정규,전지현,김민정,이규재,김한겸,조현득,채양석 大韓法醫學會 1999 대한법의학회지 Vol.23 No.2

Although it is known that hypothyroidism can cause cardiac dysfunction, it is very hard to find a case report on sudden death due to hypothyroidism. There are only two reported cases on mediline; one is about a 15-year-old girl who died suddenly of Hashimoto's thyroiditis and the other is about a 31-year-old man who also died suddenly of hypothyroidism associated with chronic lymphocytic thyroiditis. Recently we found a young woman who unexpectedly died while she was sleeping. She was diagnosed as hypothyroidism when she went to hospital about a month before she died. At autopsy there were roughly four abnormal findings; Hashimoto's thyroiditis, mild chronic active hepatitis, diverticulosis and accessory spleen. Trace of chlorpheniramine was detected in gastric remains and blood alcohol level was 0.37 percent. To our knowledge, this is the first case reporting sudden and unexpected natural death associated with hypothyroidism in Korea.