간내 담석과 동반된 간내 담도암에서의 p53과 Ki-ras의 발현

김명환,이성구,서동완,이승규,남승우,박능화,민영일,김연석,심기남,공경엽 대한소화기학회 1997 대한소화기학회지 Vol.30 No.5

Background/Aims: Hepatolithiasis or primary intrahepatic stones may be accompanied later by intrahepatic cholangiocarcinoma. This cancerous lesion is frequently associated with atypical hyperplastic epithelium that was suspected of being precancerous. To investigate the Ki-ras or p53 mutation may play a role in carcinogenesis, and to determine whether atypical hyperplastic epithelium may be precancerous, this study was performed in intrahepatic cholangiocarcinomas associated with hepatolithiasis. Methods: We examined 12 patients with intrahepatic cholangiocarcinomas associated with hepatolithiasis. Ki-ras point mutations were assessed by direct DNA sequencing. Expressions of p53 protein were immunohistochemically assessed. The overexpression of p53 and point mutation of Ki-ras were examined in normal, hyperplastic, atypical hyperplastic, and can- cerous tissues separately. Results: The expressions of p53 protein were detected in 4 (33%) of 12 cholangiocarcinomas and Ki-ras point mutations at codon 12 were found in 2 (17%) of 12 cholangiocarcinomas. In those two carcinoma cases which contained the mutant sequence of Ki-ras, the same point mutation from wild type GGT (glycine) to GAT (aspartic acid) was. found in the associated atypical hyperplastic epithelium. However, none of the normal and hyperplastic epithelium harbored Ki-ras or p53 mutations. Conclusions: The overexpression of p53 may play a part in the carcinogenesis of some intrahepatic cholangiocarcinomas associated with hepatolithiasis, whereas the role of Ki-ras mutations in those cases is dubious. However, Ki-ras point mutation at codon 12 may be responsible for either cancer or atypical hyperplastic epithelium associated with hepatolithiasis in certain cases, suggesting atypical hyperplastic epithelium may give rise to carcinoma.

Ki-1 임파종 1 예

김용진,김경재,박재복,이지현,안기성,강민모,최석문,황기석 대한내과학회 1993 대한내과학회지 Vol.45 No.4

A 60-year-old man was admitted to our hospital complaining of fever with chillness and anarexia for 12 weeks. Physical examination revealed supraclavicular lymphadenopathy and left inguinal lymphadenopathy. Abdominal CT scan showed the evidence of maked lymphadenopathy on retraperitoneal, external iliac, obturator, left inguinal, and celiac lymph nodes. A pathologic diagnosis of Ki-1(+) lymphoma was made by the biopsed supraclavicular lymph node because the node consisted of large cells with pleomorphic nuclei, scanty cytoplasm, large basophilic nucleoli, atypical vacuoli and large cells were positive for leukocyte common antigen, Ber-H2, marker, and B-cell marker.

요관압 상승시 신혈류량 조절에 prostaglandin이 미치는 효과

민영기,양훈모,김종규,이석호 순천향의학연구소 2001 Journal of Soonchunhyang Medical Science Vol.7 No.1

Higher ureteral pressure than in normal condition causes increase in renal blood flow (RBF) and partial impairment of the autoregulation of RBF. Higher ureteral pressure increased renal prostaglandin production, it is not clear whether or not it is also responsible for partial impairment of the autoregulation of RBF. Therefore, we investigated the role which prostaglandin play in the autoregulation of RBF, studying the interaction between ureteral pressure and RBF autoregulation may reveal the role of prostaglandin in tubuloglomerular feedback. For the purpose of this experiment, six anesthetized mongrel dogs were prepared for the measurements of RBF, mean systemic and renal arterial pressure (RAP) and the manipulation of ureteral pressure to 0 cmH20, 20 cmH20 and 40 cmH20. The autoregulation curves were determined during both control and elevation of the ureteral pressure, before and after the pretreatment with indomethacin, a cyclooxygenase inhibitor. The desired ureteral pressure was achieved by vertically elevating the water-filled reservoir connected to the ureteral catheter to 20 cm and 40 cm above the kidney level. In response to the elevation of the ureteral pressure, RBF increased from 167±11 ml/min to 185±8 ml/min, 204±11 ml/min respectively and the renal arterial pressure and the systemic arterial pressure didn't change significantly. During 0 mmHg of ureteral presure threshold pressure of RBF autoregulation was 59±3 mmHg. On the other hand, during 20 cmH20, 40 cmH20 of ureteral pressure, the autoregulation curves shifted upward and rightward from control, threshold pressure is elevated by 74±3 mmHg. The pretreatment of the dogs with indomethacin failed to affect the lower limit of RBF autoregulation during both control (63±5 mmHg) and the elevated ureteral pressure (77±5 mmHg). Since RBF failed to increase in response to the elevated ureteral pressure, RBF autoregulation curves obtained during the elevated ureteral pressure shifted only rightward from indomethacin control. The results indicate that the increased intrarenal level of prostaglandin by increased ureteral pressure or prostaglandin-induced vasodilation does not appear to bear any relation to the reduction in the autoregulatore capacity during elevated ureteral pressure. It seems that the partial impairment of the autoregulation during acute ureteral obstruction is due to the consumption of tubuloglomerular feedback mechanism at 0 mmHg of ureteral pressure and that prostaglandin is neither mediator nor effector of tubuloglomerular feedback mechanism.

enalapril의 혈압하강효과에 대한 renomedullary depressor system의 역할

민영기,양훈모,김종규,이석호 순천향의학연구소;Soonchunhyang Medical Research Institute 2000 Journal of Soonchunhyang Medical Science Vol.6 No.1

It has long been recognised that renin-angiotensin system(RAS) takes part in blood pressure control. It was previously known that the physiological effects of the renomedullary depressor mechanism are in virtually all aspects the very opposite of those of RAS. Muirhead proposed that there was a negative-feedback interaction between two systems, RAS and renomedullary antihypertensive depressor system, and they balance each other. If true, as the suppression of angiotensin Ⅱ(ANG Ⅱ)by angiotensin converting enzyme(ACE) inhibitor activates the renomedullary antihypertensive function, we can assume the blood pressure lowering effects of ACE inhibitor due to an increased secretion of medullary depressor substance. After rats with intact and chemically destroyed renal medulla received either saline or the ACE inhibitor, mean arterial pressure(MAP) was clearly decreased after ACE inhibitor administration in controls with intact medulla, but MAP in rats with chemically destroyed renal medullar was not changed. According to these results, we can come to a conclusion that renomedullary depressor substance plays an important role to normal blood pressure control.

유전율 및 도전율을 고려한 765kV 송전선하의 전계에 의한 인체내부 유도 전류밀도 해석

민석원,송기현 순천향대학교 부설 산업기술연구소 2004 순천향 산업기술연구소논문집 Vol.10 No.1

This paper analysed the induced current density by electric field of human body under the 765 kV transmission line considering permittivity and conductivity. As permittivity of human body is very high as 10^6 at 60Hz, special numerical computation technique in Surface Charge Method(SCM) for composite media with extremely different propertis is applied to reduce calculation error of induced current density and electric field inside the human body. Calculation results show that the average of the induced current density human body is about 3mA/m^2, which is less than ICNIRP criterion(10mA/m^2)

가전기기 발생 극저주파 자계 고조파특성 해석

민석원,송기현 순천향대학교 부설 산업기술연구소 2004 순천향 산업기술연구소논문집 Vol.10 No.1

With biological effects by ELF(Extremely Low Frequency) magnetic field generated from power system, the transient magnetic field from electric appliances is a major issue presently. Because the transient magnetic field induces higher current than the power frequency field inside living bodies, transient magnetic field exposure has been much focused. In this paper, it is shown that transient magnetic field from electric home appliances can be characterized as magnetic dipole moment. In this method, the dipole moment vector is assumed by allowing an uncertainty of 6 dB in the estimated field. A parameter M that represents biological interaction was applied also. The proposed method was applied to 6 type of appliances(Mixer, Microwave oven, PC, etc.) and their equivalent magnetic dipole moment and harmonic components were estimated. As the results, the useful data for quantifying magnetic field distribution around electric appliances were obtained.

풍소음 저감용 특수 다중도체 방식의 3차원 전계해석

민석원,송기현,김용준 순천향대학교 부설 산업기술연구소 2000 순천향 산업기술연구소논문집 Vol.6 No.2

This paper investigates characteristics of spiral charge for charge simulation method to calculate electric fields of special conductor bundles with spiral rods in 765 kV transmission line. We finds the arranging spiral charge in central position of spiral rod give less potential calculation error than lower position of spiral rod. When a spiral rod is simulated as spiral charge, we also knows two spiral charge with four integral interval can simulate spiral rod best.

인공 생명 기법을 이용한 로봇 군 지능 구현

민석기,강훈 중앙대학교 생산공학연구소 1998 생산공학연구소 논문집 Vol.7 No.1

본 논문의 목적은, 인공 생명의 원리에 따라 간단한 지역적 규칙으로부터 복잡한 전역적 지능을 형성하는 복수의 자율 이동 로봇의 창발적 행동을 유도하도록 하는 데 있다. 여기서, 강화 신호를 가진 신경 회로망의 학습 구조를 제안하여 이동 로봇이 집단을 이루어 이동할 때 주변의 정보를 센서로 인지하여 움직이는 방향과 속력이 결정되도록 하였다. 시뮬레이션 결과로써, 동적 환경에서 장애물 및 개체간의 충돌을 방지할 뿐 만 아니라 이동 로봇들이 여러 가지 형태를 유지하며 이동하도록 하는 신경 회로망의 최적 하중값을 실시간으로 구하였다. The objective of this paper is, based upon the principles of artificial life, to induce emergent behaviors of multiple autonomous mobile robots which form from simple local rules to complex global intelligence. Here, we propose an architecture of neural network learning with reinforcement signals which perceives the neighborhood information and decides the direction and the velocity of movement as mobile robots navigates in a group. As results of the simulations, the optimum weights are obtained in real time, which not only prevent from the collisions between agents and obstacles in the dynamic environment, but also have the mobile robots move and keep in various patterns.

강소성 가공한 Al에서 Sc과 Zr의 석출 거동

민복기,김형욱,강석봉 대한금속재료학회 2003 대한금속·재료학회지 Vol.41 No.11

The elements of Sc and Zr were added to pure Al for improving thermal stability and refining grain size. Sc was presented on boundaries and Zr dominantly on matrix in as cast state. After homogenization treatment, Sc was dissolved mostly but Zr retained in matrix; though the two elements were presented on the same location in Al-Sc-Zr alloy. Semi-coherent Al₃Sc in Sc added alloy was precipitated during severe plastic deformation, and shown (001)_(matrix)//(001)_(Al₃Sc) orientation relationship with matrix. Al₃Zr in as cast Zr added alloy was shown the orientation relationship (011)_(matrix)//(100)_(Al₃Zr), and partially retained and dissolved with increasing deformation. In the Al-Sc-Zr alloy, retained Al₃Zr had the role of nucleation site for Al-Sc precipitates so that Al₃Zr mainly coexist with Al-Sc precipitates.

Al₃Sc 나노 석출물이 ARB 가공한 Al-0.2 wt% Sc 합금의 고경각립계 형성에 미치는 영향

민복기,김형욱,강석봉 대한금속재료학회 2004 대한금속·재료학회지 Vol.42 No.12

The cold rolled Al-0.2 wt% Sc alloy sheets were pre- heat treated: (1) as solution treated at 630℃ for 1 hour and (2) as artificial aged at 300℃ for 5 hours, and the following accumulative roll bonding was conducted up to the 8 cycles at ambient temperature. The interconnecting boundary spacing of the aged alloys was narrow and maintained constantly at each ARB cycle. While, the spacing of solution treated alloy was relatively broad and decreased rapidly with increasing ARB cycles. The fraction of high angle boundaries in both alloys increased gradually with increasing equivalent strain, however the age-ARB alloys showed relatively higher fraction of HAGBs than the solution treat-ARB alloys at the same strain levels. And the former shows faster development of lamellar structure than the later. These variations are attributed to the fact that the nano-scale, semi-coherent A13Sc hinders the migration of dislocation. However, those precipitates cannot apply pinning effect sufficiently during static recrystallization above 350℃ because the driving pressure for recrystallization overcomes the Zener pinning pressure. (Received September 30, 2004)