Anti-apoptotic Activity of Heme Oxygenase-1 Up-regulated by Etoposide in Human Retinal Pigment Epithelial Cells

이상권,송주동,김강미,김종민,이상률,유영현,박영철,Lee, Sang-Kwon,Song, Ju-Dong,Kim, Kang-Mi,Kim, Jong-Min,Lee, Sang-Yull,Yoo, Young-Hyun,Park, Young-Chul Korean Society of Life Science 2007 생명과학회지 Vol.17 No.9

The topoisomerase II inhibitor etoposide causes an accumulation of DNA double strand breaks within the nuclei of cells. In this study, we investigated the effect of etoposide on the cell growth and apoptosis of human RPE cells. Etoposide evoked a significant inhibition of cell growth, and also induced DNA fragmentation in ARPE-19 cells. In addition, etoposide significantly up-regulated the expression of heme oxygenase-1 (HO-1), which is a stress-responsive protein and is known to play a protective role against the oxidative injury. And, etoposide-induced HO-1 expression was affected by the ROS scavenger N-acetyl cysteine. We also used oligonucleotides interfering with HO-1 mRNA (siRNA) for the inhibition of HO-1 expression. Interestingly, knock-down of the HO-1 gene significantly increased the level of DNA fragmentation in etoposide-treated ARPE-19 cells. In conclusion, these results suggest that up-regulated HO-1 plays as an anti-apoptotic factor in the process of apoptosis of ARPE-19 cells stimulated by etoposide. Totopoisomerase II 저해제인 etoposide는 핵안에 DNA double strand breaks를 일으키므로써 세포의 DNA에 손상을 초래한다. 본 연구에서는 인간 망막색소상피세포인 ARPE-19 세포에서의 세포성장 및 아폽토시스에서 etoposide의 역할을 살펴보았다. Etoposide는 세포의 성장을 크게 감소시켰으며 TUNEL에서 아폽토시스를 나타내는 DNA fragmentation의 증가를 유도하였다. 게다가, etoposide는 산화적 손상에 대해 세포나 조직을 보호하는 역할을 하는 것으로 알려진 세포내 항산화효소인 heme oxygenase-1 (HO-1)의 발현을 크게 증가시켰다. Etoposide에 의한 HO-1 발현증가는 항산화물질 NAC에 의해 억제되었는데, 이는 etoposide에 의한 세포내 ROS의 증가가 HO-1 발현에 중요한 역할을 한다는 것을 의미한다. 또한 HO-1 발현을 억제하기 위하여 HO-1 siRNA 방법을 사용하였다. 흥미롭게도, HO-1 유전자의 knock-down은 etoposide에 의해 유도되는 DNA fragmentation의 정도를 증가시켰다. 이들 결과를 종합해볼 때, etoposide에 의해 자극되어진 ARPE-19 세포에서 발현증가된 HO-1은 etoposide에 의한 아폽토시스 유발과정에서 세포를 보호하는 항아폽토시스의 기능을 한다는 것을 시사한다.

소아 백혈병에서 중추신경계 예방 치료에 따른 백질뇌병증:자기공명영상 소견

이상권,김태헌,김용주,강덕식,Lee, Sang-Gwon,Kim, Tae-Heon,Kim, Yong-Ju,Gang, Deok-Sik 대한영상의학회 2001 대한영상의학회지 Vol.45 No.4

목적:소아 백혈병에서 중추신경계 예방 치료에 따른 백질뇌병증의 자기공명영상 소견을 분석하고 진단과 추적에 있어 자기공명영상의 유용성에 대해 알아보고자 하였다. 대상과 방법:척수강내 methotrexate 투여나 두부 방사선 조사를 시행한 급성 백혈병 환아에서 신경정신학적 증상이 있었던 17명 중 자기공명영상에서 백질 병변이 발견된 8명의 초기 및 추적 자기공명영상 소견을 후향적으로 분석하였다.모든 예에서 초기 자기공명영상은 신경정신학적 증상 발현 후 1주일 이내에 시행하였다.추적 자기공명영상은 초기 검사 뒤 1개월에서 16개월 후에 시행하였으며,초기 및 추적 자기공명영상 소견을 비교하였다. 결과:초기 자기공명영상 소견은 단발성 또는 다발성 국소성 백질 병변을 보인 경우 (3/8),조영증강 없이 미만성 백질 병변을 보인 경우 (3/8),조영증강을 동반한 미만성 백질 병변을 보인 경우 (2/8)의 3가지 범주로 분류할 수 있었다.추적 자기공명영상에서는 모든 환아에서 국소성 또는 미만성 뇌 위축을 볼 수 있었다.단발성 또는 다발성 국소성 백질 병변을 보인 3예중 2예에서 백질 병변이 호전되었다.미만성 백질 병변을 보인 5예에서는 백질 병변의 범위는 큰 변화가 없었으나,조영증강을 동반한 미만성 백질 병변을 보인 2예에서는 조영증강의 감소를 볼 수 있었다. 결론:소아 백혈병에서 중추신경계 예방 치료에 따른 백질뇌병증의 자기공명영상 소견은 다양하나,척수강내 methotrexate 투여와 두부 방사선 조사 후 신경정신학적 증상 발현의 적절한임상 병력을 가진다면 특이적이다.자기공명영상은 소아 백혈병에서 중추신경계 예방 치료에따른 백질뇌병증의 진단과 추적에 유용한 검사 방법으로 생각된다. Purpose: To evaluate the MR imaging findings and the usefulness of MR imaging in the diagnosis and follow-up of leukoencephalopathy following CNS prophylaxis therapy in pediatric leukemia. Materials and Methods: We retrospectively evaluated the MR imaging findings of eight children with white matter abnormalities on MR out of seventeen acute leukemic patients with various neuropsychiatric symptoms who received intrathecal methotrexate administration, with or without cranial irradiation. In all cases, initial MR was performed within a week of the onset of neuropsychiatric symptoms. Follow-up MR was performed one to sixteen months after initial study, and the MR imaging findings were compared with the initial findings. Results: The initial MR imaging findings were classified into three categories: focal or multifocal white matter abnormalities (3/8), and diffuse white matter abnormalities without enhancement (3/8), and diffuse white matter abnormalities with enhancement (2/8). At follow-up MR, diffuse or focal atrophic changes were noted in all children. White matter abnormalities improved in two out of three patients with focal or multifocal white matter abnormalities. In five with diffuse white matter abnormalities, the extent of these showed no significant change, but contrast enhancement was markedly reduced in two children in whom diffuse white matter abnormalities with enhancement had been demonstrated. Conclusion: In pediatric leukemia, the MR imaging findings of leukoencephalopathy following CNS prophylaxis therapy are variable, but are specific with the clinical history of neuropsychiatric symptoms after intrathecal methotrexate administration, with or without cranial irradiation. The MR imaging is valuable in the diagnosis and follow-up of leukoencephalopathy following CNS prophylaxis therapy in pediatric leukemia.

연속 웨이블렛 변환의 확대된 위상 지도를 이용한 기어의 초기 퍼팅 결함 진단

이상권,심장선,Lee, Sang-Gwon,Sim, Jang-Seon 대한기계학회 2001 大韓機械學會論文集A Vol.25 No.11

Vibration transient generated by developing localized fault in gear can be used as indicators in gear fault detection. In this paper, we propose the zoomed phase map for a fault signal using continuous wavelet transfers to detect this vibration transient. Local fault induces the abrupt fluctuation of load exciting tooth and phase lag in the vibration signal measured on the gearbox. The relatively large fault like "tip breakage" easily can be detected by the clear fluctuation of exciting load. However, minor fault like "initial pitting"cannot be detected using the load fluctuation. To defect this kind of minor fault, the phase map for a fault signal is taken into account. The phase lag by minor fault is observed well in the zoomed phase map.

가스분석(4)

이상권,Lee, Sang-Gwon 한국설비기술협회 1992 설비 : 공조ㆍ냉동ㆍ위생 Vol.9 No.3

KDSM(KAIST Distributed Shared Memory) 시스템의 설계 및 구현

이상권,윤희철,이준원,맹승렬,Lee, Sang-Kwon,Yun, Hee-Chul,Lee, Joon-Won,Maeng, Seung-Ryoul 한국정보과학회 2002 정보과학회논문지 : 시스템 및 이론 Vol.29 No.5

본 논문에서는 KDSM(KAIST Distributed Shared Memory) 시스템의 설계 및 구현에 관해서 설명한다. KDSM은 Linux 2.2.13 상에서 실행되는 사용자 수준 라이브러리로 구현되었고, TCP/IP를 기반 통신 구조로 사용한다. KDSM은 페이지 기반 무효화 프로토콜(page-based invalidation protocol)과 다중 쓰기 프로토콜(multiple writer protocol)을 기반으로 하고, HLRC(Home-barred Lazy Release Consistency) 메모리 일관성 모델을 사용한다. KDSM의 성능을 측정하기 위해서 4개의 과학계산용 응용 프로그램을 실행하여 JIAJIA와 성능 비교를 하였다. 그 결과, 2개의 응용은 같은 결과를 냈고, 나머지 2개는 KDSM의 성능이 우수하였다. In this paper, we give a detailed description of KDSM(KAIST Distributed Shared Memory) system. KDSM is implemented as a user-level library running on Linux 2.2.13, and TCP/IP is used for communication. KDSM uses page-based invalidation protocol, multiple-writer protocol, and supports HLRC(Home-based Lazy Release Consistency) memory consistency model. To evaluate performance of KDSM, we executed 4 scientific applications and compared the result to JLAJLA. The results showed that performance of KDSM almost equal to JIAJIA for 2 applications and performance of KDSM is better than JIAJIA for 2 applications.

상악 제1소구치에서 전부도재관의 finish line 형태에 따른 파절강도와 응력 분포에 관한 연구

이상권,동진근,Lee, Sang-Kwon,Dong, Jin-Keun 대한턱관절교합학회 2003 구강회복응용과학지 Vol.18 No.2

he purpose of this study was to compare the fracture resistance of the IPS Empress ceramic crown with 1.0mm width rounded shoulder, which is usually recommended in all ceramic crown, and 0.5mm width chamfer finish lines on the maxillary first premolar. 30 sound maxillary first premolars were selected and then storaged in 5% NaOCl and saline. 15 teeth were performed preparation for each group(1.0mm rounded shoulder, 0.5mm chamfer). After 30 stone dies were made for each group, the IPS Empress ceramic crowns were fabricated and cemented with resin cement(Bistite resin cement, Tokuyama Soda Co. LTD., Japan) on the natural teeth. The cemented crowns were mounted on the positioning jig and the universal testing machine(Zwick Z020, Zwick Co., Germany)was used to measure the fracture strength, with stress loading on the occlusal surface between buccal and lingual cusp. And also, three-dimensional finite element model was used to measure the stress distribution with two types of the finish lines(1.0mm rounded shoulder, 0.5mm chamfer) and two loading conditions(both buccal and lingual cusp inclination, lingual cusp inclination only). The result of the this study were as follows. In the fracture resistance experiment according to the finish line, the mean fracture strength of rounded shoulder(842N) showed higher value than that of the chamfer(590N) (p<0.05). In the three dimensional finite element analysis of all ceramic crown, metal die and natural teeth model did not show any differences in stress distribution between finish lines. Generally, when force was loaded on the occlusal inclination of buccal and lingual cusp, the stress was concentrated on the loading point and the central groove of occlusal surface. When force was loaded only on the occlusal inclination of lingual cusp, the stress was concentrated on the lingual finish line and loading point.

체험현장-도전만이 수출의 길 열 수 있다.

이상권,Lee, Sang-Gwon 한국전기산업진흥회 1998 電氣産業 Vol.9 No.1

위선암에서 Matrix Metalloproteinase-2, Cathepsin D 및 E-cadherin의 발현

이상권,박승철,김원우,김욱,이교영,전해명,김응국,고용복,Lee Sang Kuon,Park Seung Cheol,Kim Won Woo,Kim Wook,Lee Kyo Young,Jeon Hae Myung,Kim Eung Kook,Koh Yong Bok 대한위암학회 2002 대한위암학회지 Vol.2 No.3

Purpose: The prognosis of gastric cancer depends on the depth of invasion, lymph-node metastasis, invasion to adjacent tissues, and distant metastasis. Recently, it is known that tumor-associated proteases and adhesion molecules have been shown to play a relevant role in the process of progression and metastasis. The purpose of our study was to demonstrate the value of MMP-2 (matrix metalloproteinase), cathepsin D and E-cadherin as prognostic factors. Materials and Methods: In this study, formalin-fixed, paraffin-embedded tissue blocks from 69 patients with gastric cancer were immunohistochemically studied using antibodies to MMP-2, cathepsin D, and E-cadherin, and their expressions were analyzed according to the pathologic stage, lymph-node metastasis, histological differentiation, and patient survival. The medical records of these patients were retrospectively reviewed. Results: Increased expression of MMP-2 significantly correlated with advanced pathologic stage (P=0.026). Patients with lymph-node metastasis also had increased expression of MMP-2. Those patients with increased expression of MMP-2 showed a poorer survival; nevertheless, it was not statistically significant. Increased expression of cathepsin D significantly correlated with advanced pathologic stage (p=0.029). However, no correlation was observed between advanced pathologic stage and either lymph-node status or histological differentiation. Patients with increased expression of cathepsin D had a poorer survival, but that result was not statistically significant. No association was found between reduced expression of E-cadherin and pathologic stage, lymph-node status, or histological differentiation. Also, no correlation was found between the expression of E-cadherin and survival. In addition, when a combination of MMP-2 and cathepsin D expressions was analyzed, if both were negative, the survival seems to be longer, but it was not statistically significant. Conclusions: In patients with gastric cancer, expressions of MMP-2 and cathepsin D correlated with tumor stage; therefore, they may be considered as prognostic factors.

가스분석(2)

이상권,Lee, Sang-Gwon 한국설비기술협회 1991 설비 : 공조ㆍ냉동ㆍ위생 Vol.8 No.11

가스분석(3)

이상권,Lee, Sang-Gwon 한국설비기술협회 1992 설비 : 공조ㆍ냉동ㆍ위생 Vol.9 No.1