췌장암에서 Cyclooxygenase - 2 발현의 역할

김은경,이용욱,이규택,최규완,박동일,백승운,이준행,이종균,고광철,이풍렬,이종철,김재준,김완선,공구 대한소화기학회 2001 대한소화기학회지 Vol.38 No.3

Background/Aims: Accumulating evidence suggests that the use of NSAID may reduce the incidence of colorectal cancer. The likely mechanisms of these effects by NSAID is cyclooxygenase-2 (COX-2)-related inhibition of tumor proliferation and induction of apoptosis. The aim of our study was to examine possible roles and clinical significance of COX-2 expression in pancreatic cancer. Methods: Seventy-two pancreatic adenocarcinoma tissue specimens were obtained from surgical resection. After the immunohistochemical staining of the specimens, we examined proliferation activity (assayed by Ki-67 expression), apoptosis (by TUNEL stain), and microvessel density (by CD34 expression). We also investigated the relationship between the immunohistochemical expression of COX-2 and various clinicopathological characteristics. Results: The COX-2 positive rate in pancreatic epithelial cells was 41.7%. Proliferation index (PI) was significant higher in COX-2 positive specimens comparing to negative specimen (p=0.015) and the increase in intensity of COX-2 expression correlated with increasing PI (p=0.036). Apoptotic index (AI) was significantly higher in positivee COX-2 expression than in negative expression (p=0.044), but there was no significant difference in AI/PI between the COX-2 positive and negative specimens (p=0.44). The expression of COX-2 protein did not correlate with microvessel density, sex, age, differentiation, tumor size, stage, metastasis or patients survival. Conclusions: The expression of COX-2 enzyme in pancreatic cancer contributes to tumor proliferation, but is not related to apoptosis, angiogenesis or clinical characteristics. Further study is needed to examine the clinical usefulness of NSAID and COX-2 selective inhibitors.

간세포암과 주위 조직에서의 Transforming Growth Factor-beta 1과 그 수용체의 발현

최규완,백승운,최문석,김소정,이준혁,고광철,이풍렬,이종철,박상종,안병훈,김재준 대한소화기학회 2001 대한소화기학회지 Vol.37 No.4

Background/Aims: Transforming growth factor-beta 1 (TGF-β1) is a potent inhibitor of hepatocyte proliferation and its receptor is known to be involved in the carcinogenesis. This study was designed to compare the expression levels of the TGF-β1 and its receptor in neoplastic cells and its surrounding tissue and to assess their role in hepatic carcinogenesis. Methods: We measured the levels of TGF-β1 mRNA and TGF-β1 receptor II mRNA by semiquantitive RT-PCR for the tumor and its surrounding tissue of 30 patients with hepatocellular carcinoma (HCC). We analyzed the relationship between the expression of TGF-β1 mRNA, TGF-β1 receptor II mRNA and clinicopathological characteristics of HCC. Results: The expression of TGF-β1 mRNA showed no difference between HCC and its surrounding tissue, but the expression of TGF-β1 receptor II mRNA was lower in HCC than in its surrounding tissue (2.47±1.08 vs 3.53±1.50, p=0.00). There was no difference in the expression level of TGF-β1 mRNA and TGF-β1 receptor II mRNAo the clinicopathological characteristics of HCC. However, the ratio of TGF-β1 receptor II mRNA in HCC to that in surrounding tissue was more decreased in HCC with portal vein invasion (0.49±0.22 vs 0.77±0.21, p=0.01). Conclusions: Our data suggest that the loss of TGF-β1 receptor II may play an important role in carcinogenesis and tumor progression of HCC.

광섬유 센서를 이용한 절연유의 방전신호 및 감쇄특성 측정

김태영,김상준,남진호,서광석,이수묵 고려대학교 공학기술연구소 1999 공학논문집 Vol.37 No.1

This paper presents the preliminary results on the application of optical fiber sensor(OFS) for the measurements of discharging signal and degradation in insulation oil such as transformer and silicone oil. An OFS system using a Mach-Zehnder interferometry technique was built to detect attenuation of acoustic signal produced by discharging. Simultaneous measurements were made of electrical signal and OFS signal from discharge. It was found that the arcing signal produced by needle-sphere electrode system could be detected by OFS installed in an oil bath. With increasing OFS distance from an arcing spot, the attenuation of acoustic signal became greater. From the results of sound attenuation for various insulation oils, the linear relationship was observed between the attenuation signal and viscosity in log scale. Details of these results are discussed.

신장이식에 대한 마취경험

김종래,박광원,문영삼,정인석,손영은 대한마취과학회 1982 Korean Journal of Anesthesiology Vol.15 No.1

활동성 크론병에서 초기 스테로이드 치료 반응에 따른 임상적, 생화학적, 병리학적 인자들에 관한 연구

김영호,장재권,김지은,최규완,박동일,도재혁,백승운,고광철,이풍렬,이종철,현재근,안병훈,김재준,류민규 대한소화기내시경학회 2001 Clinical Endoscopy Vol.22 No.6

Background/Aims: The predictory factors of the response to initial steroid therapy in active Crohn's disease has been controversial in numerous literature reviews. We evaluated any predictory faetor of the response to initial steroid therapy in active Crohn`s disease patients, Methods: The medical records of 32 patients with active Crohn`s disease who clinically responded to oral steroid therapy were retrospectively reviewed. The steroid responsive group was defined as the one showing maintenance of response for more than one month from steroid withdrawal and the steroid dependent group as the one showing relapse or exacerbation during steroid tapering or within 30 days from steroid withdrawal. The clinical, biochemical, and pathologic factors were evaluated. Results: There were 22 male and 10 female patients. The mean age was 28.9 years. The number of steroid responsive and dependent group was 22 (68.8%) and 10 (31.2%), respectively. There were no significant differences between these two groups in age, sex, time to diagnosis, perianal lesion, extent of disease, extraintestinal manifestations, presence of granuloma, presenting features, hemoglobin, ESR, and CRP, except serum albumin level. Conclusions: Serum albumin level was significantly lower in steroid dependent group than steroid responsive group, reflecting severe inflammation in steroid dependent group.

역류성 식도염 환자에서 Helicobacter pylori 치료 1 년 후 증상과 내시경적 변화

김영호,손희정,최규완,박동일,백승운,이준행,고광철,이풍렬,이종철,임윤정,김재준 대한소화기내시경학회 2001 Clinical Endoscopy Vol.24 No.1

Glutaraldehyde 와 자동 세척기를 이용한 내시경 소독방법의 임상에서의 유용성

김영호,손희정,윤성원,최규완,이남용,백승운,이준행,고광철,이풍렬,이종철,송재훈,안병훈,김재준,최원혁,홍일철 대한소화기내시경학회 2001 Clinical Endoscopy Vol.22 No.6

Background/Aims: Safety of endoscopic procedures has been a major issue over the last 10 years. Most endoscopy units use 2% glutaraldehyde and automated endoscope reprocessors (AERs) for disinfecting gastrointestinal endoscopes. We attempted an in-use evaluation of the current reprocessing procedures. Methods: Thirty flexible endoscopes were randomly collected just after upper endoscopic examinations and were disinfected using 2% glutaraldehyde in an AER. Cultures were taken from biopsy channels (S-l), tip of the insertion tubes (S-2), umbilical cords (S-3), and angulation knobs (S-4). Results: In 63,3% (19/30) of endoscopes, there was no microbial contamination after disinfection procedures. The culture positive rates of S-l, S-2, S-3, and S-4 samples were 20,0%, 0.0%, 3.3%, and 20.0%, respectively. Microorganisms of 13 species were identified, but there was no pathogen related with reported infectious complications after endoscopic procedures. Conclusions: Current disinfection procedure using 2% glutaraldehyde and an AER appears to be very effective in decontaminating patient-used endoscopes. Low level microbial contamination of endoscopes after conventional reprocessing methods may not impose great risk on patients.

고에너지 전자빔투사방법을 사용한 TiB2/Ti 표면합금화 재료의 제조 연구

구양모,이성학,어광준,김낙준,오준철 대한금속재료학회(대한금속학회) 1998 대한금속·재료학회지 Vol.36 No.12

The present study is concerned with the fabrication and the microstructural analysis of a TiB₂/Ti surfacealloyed material fabricated by high-energy electron beam irradiation. The mixture of TiB₂ powders and flux was deposited on a Ti-10V-2Fe-3Al alloy substrate, and then electron beam was irradiated on these mixture using an electron beam accelerator. The melted region of about 1.5 ㎜ thickness was homogeneously formed without pores or cracks, and was composed of primary and eutectic TiB borides in the β phase matrix. The formation of these TiB borides greatly improved hardness, especially high-temperature hardness up to 450℃. These findings suggested that the surface-alloying method using high-energy electron beam irradiation was economical and useful to the development of new advanced materials with improved high-temperature properties.

허혈성 대장염의 임상 양상과 예후 인자

이미숙,손희정,강태욱,최규완,박동일,백승운,이준행,고광철,이종철,임윤정,이풍렬,김갑철,김재준 대한소화기내시경학회 2001 Clinical Endoscopy Vol.22 No.2

Background/Aims: Colonic ischemia is recognized as the most common vascular disorder of the intestines in the elderly. The severity of the disease may vary considerably with the prevalent benign transient forms, being amenable to conservative treatments and the severe gangrenous forms, requiring surgery. Correct diagnosis is usually made after the ischemic episode is over and colonic ischemia is frequently misdiagnosed. The aim of this study is to identify the clinical patterns and prognostic factors of ischemic colitis. Methods: We found 60 patients with nonoccusive ischemia of the large intestine, We analyzed age, sex, symptoms, signs, associated disease, location, endoscopy, hematologic, histologic, radiologic finding and treatment, retrospectively. Results: The mean age was 60.2±6.3 years. The most common symtoms were abdominal pain or bloody diarrhea. The most common sign was diffuse abdominal tenderness. The most common hematologic findings were anemia and leukocytosis. Associated medical illnesses wer diabetes, rhematoid arthritis and cerebrovascular accident, et al. Both computed tomography (CT) and endoscopy were useful diagnostic tools. The most common involved site was sigmoid colon. 46 patients were treated conservatively and 14 patients were managed surgically. Conclusions: Male gender, those with rebound tenderness, severe anemia, right or total colon involvement as well as rheumatoid arthritis had a poor prognosis. Both CT and endoscopy were useful in predicting prognosis.

HDPE 폐비닐 개질 아스팔트 혼합물의 강도 및 공용 특성 연구

김광우 ( Kim Kwang Woo ),이기호 ( Lee Gi Ho ),권오선 ( Kwon Oh Sun ),조문진 ( Cho Mun Jin ) 한국농공학회 2004 한국농공학회 학술대회초록집 Vol.2004 No.-

본 연구는 폐비닐 펠렛을 도로포장재료로 재활용하여 자원절약 및 아스팔트 혼합물의 품질향상을 위한 연구이다. 이를 위하여 폐비닐의 첨가량별 배합설계를 수행하여 적정 폐비닐 첨가량과 최적 아스팔트 함량으로 편마암과 화강암 2가지 골재와 폐비닐인 RHDPE의 함량을 4가지로 혼합물을 제작하여 8종류의 개질 혼합물과 2종류의 무개질 혼합물을 제작하였다. 그리고 이 공시체에 대하여 마살안정도, 간접인장강도 및 Kim test와 반복주행시험 등 실내시험을 통하여 혼합물의 특성을 분석하였다. 폐비닐 첨가량은 RHDPE가 8%일 때 안정도와 간접인장강도 모두 가장 우수한 것으로 나타났고 취성도 나타나지 않았다. RHDPE를 첨가한 혼합물에 대하여 Kim test를 수행한 결과 DR과 DS 모두 높은 상관성을 보였다. 그리고 반복주행시험에서는 RHDPE를 첨가한 혼합물이 일반 혼합물보다 우수하였다. 향후 많은 실험을 통해 RHDPE의 우수성을 입증한다면 소성변형 저항성에 우수한 재료로 이용될 수 있을 것이다. This study is a fundamental research for recycled high-density polyethylene (RHDPE) in asphalt mixture for improving roadway pavement. Mix design was conducted by RHDPE content and optimum asphalt content (OAC) was determined for dense-graded surface course mixture. Marshall stability test, indirect tensile strength (ITS) test, wheel tracking test and Kim-test were carried out to measure the characteristics of RHDPE-added asphalt concretes. From the results of this study, RHDPE in asphalt mixture is possible. It could be considered that adding too much RHDPE in asphalt mixture is not proper. The optimum content of RHDPE was appeared to be 8%. In Kim-test, Statistical analysis were performed for each loading head and aggregate to find out correlation between SD values and each rut parameter. The analysis result showed that SD had very high coefficient of determination on the average with rut parameters.