칼슘이 결장뉴 K-경축에 미치는 영향

조성일,엄대용,이상돈,Cho, Sung-Il,Uhm, Dae-Yong,Rhee, Sang-Don 대한생리학회 1982 대한생리학회지 Vol.16 No.1

The in vitro experiments for isometric contraction were done to investigate the different action mechanism of calcium ion on phasic and tonic components of K-contracture in guinea pig's taenia coli. The results were as follows: 1) The degrees of K-contracture were increased gradually from 4 mM to 15, 20, 40 & 100 mM of$[K^+]_0$. The maximal developed tension in tonic component was observed in 100 mM of $[K^+]_0$. 2) The phasic components were not so affected by 2, 4, 8 & 16 mM of $[Ca^{++}]_0$ in 100 mM K-contracture, but the tonic components were gradually increased in a dose-responsive manner. 3) The K-contracture was not influenced by norepinephrine, 1 mg/l, but was completely abolished by verapamil, 2 mg/l. 4) The phasic component was little affected by verapamil, 0.01 mg/l, 0.1 mg/l, and 1 mg/l, but the tonic component was completely disappeared at the concentration of verapamil 1 mg/l. The above results suggest that $[Ca^{++}]_0.$ primarily affected the tonic component than the phasic component of K-contracture in guinea pig's taenia coli.

학생반응으로 살펴본 문제바탕학습 교육과정의 질적 평가

김주희(Ju-Hui Kim),김지영(Ji Young Kim),손희정(Hee Jung Son),최윤호(Yoon-Ho Choi),홍경표(Kyung-Pyo Hong),안병헌(Byung-Heon Ahn),엄대용(Dae-Yong Uhm),진영은(Young Eun Chin),서정돈(Jung-Don Seo) 한국의학교육학회 2004 Korean journal of medical education Vol.16 No.2

Purpose: Recently established in 1997, Sungkyunkwan University School of Medicine was the first medical school in Korea to adopt problem-based learning (PBL) as a core curriculum from the very beginning. The purpose of this study was to evaluate the PBL curriculum from the viewpoint of the medical students. Methods: This study used a qualitative approach to understand students perceptions of the positive aspects of PBL. A total of 22 second-year medical students at Sungkynkwan medical school were surveyed. Student perceptions were obtained from questionnaire and face-to-face interviews. The interview was designed to evoke more personal and in-depth responses. Results: Students perceptions of the effects of PBL were found to be very favorable. Most students showed positive responses on the issues of more active learning attitude, self-directed learning, motivation to study, improved problem solving, and integrated learning. Conclusion: The results of this study demonstrated that the students had a good understanding of PBL and experienced its positive aspects of PBL approach. It might be concluded that PBL was successfully implemented into the curriculum and specific and expected effects of PBL accomplished.

모틸린에 의한 사람 위 평활근의 수축 기전에 관한 연구

심상군(Sang Goon Shim),이종철(Jong Chul Rhee),이풍렬(Poong Lyul Rhee),최규완(Kyoo Wan Choi),전성국(Sung Kook Jeon),강동묵(Tong Mook Kang),엄대용(Dae Yong Uhm),이종석(Jong Seok Lee),성인경(In Kyung Sung),김현서(Hyun Seo Kim) 대한소화기학회 2002 대한소화기학회지 Vol.39 No.1

Background/Aims: Motilin is an intestinal peptide that stimulates the contraction of gut smooth muscle. A discrepancy exists between the in vivo (neurally mediated) and in vitro (direct action on a smooth muscle receptor) mechanisms of motilin action in many species. We investigated in vitro mechanisms of motilin action on human gastric smooth muscle. Methods: Antral cirular muscle strips of the surgical tissue obtained during gastrectomy, were used to measure contractile force and electrical activity. Dispersed muscle cells were used to measure L-type Ca2+ current and electrical activity. Results: Motilin of 1-100nM contracted smooth muscle in a concentration-dependent manner. Motilin-induced contractions were unaffected by tetrodotoxin or atropine treatment. Nifedipine or Ca2+-free bath solution blocked motilin (10nM)-induced contractions. Low concentration of motilin (1nM) resulted in an increase in acetylcholine (0.1~100M)-induced contractions. By patch clamp recording technique, motilin (1 or 10nM) did not modify the L-type Ca2+ current, but motilin-induced membrane depolarization was detected. Erythromycin also contracted smooth muscle with membrane depolarization but verapamil inhibited the contraction. Conclusions: These results suggest that motilin contracts smooth muscle through a direct action on smooth muscle receptor and Ca2+ influx through the L-type Ca2+ channel, which is due to membrane depolarization, also mediates motilin-induced contractions. (Korean J Gastroenterol 2002;39:4-12)

혈액투석이 좌심실 기능에 미치는 영향

김열자 ( Yul Ja Kim ),김인호 ( In Ho Kim ),표희정 ( Heui Jung Pyo ),이홍순 ( Hong Soon Lee ),김미자 ( Mi Ja Kim ),노태영 ( Tae Yung Nho ),이학중 ( Hack Choong Lee ),윤동헌 ( Dong Hun Yoon ),엄대용 ( Dae Yong Uhm ) 대한내과학회 1985 대한내과학회지 Vol.29 No.4

심근세포의 전기생리학

엄대용 중앙대부설한국의과학연구소 1980 한국의과학 Vol.12 No.4

집 토끼 유두근의 전기적 및 기계적 특성에 미치는 고장성 서당 용액의 효과

엄대용 중앙대학교 의과대학 의과학연구소 1978 中央醫大誌 Vol.3 No.1

The isometric contraction with its first derivatives and action potential of papillary muscles from right ventricles of rabbits were studied in media of bicarbonate buffered solutions that had the tonicities of 1.2, 1.4, 1.6 times that of the control. The results were as follows: 1. Intracellular negativity of resting membrane potential significantly increased in 1.4T, 1.6T from 78.5±6.2 mV to 83.3±4.7 and 89.8±6.0±mV respectively and the duration of action potential decreased, 233±32.1 in the control to 210.7±17.9 and 204.0±18.0 msec in 1.4T and 1.6T. 2. Isometric contraction showed a little change with a tendency to increase in 1.2T and then gradually decrease to 86.6±4.5% and 42.2±9.2% of the control in 1.4T, 1.6T. 3. +dT/dt decreased remarkably to 74.7±3.8%, 35.9±6.0% of the control in 1.4T, 1.6T and -dT/dt also decreased to 70.5±6.8%, 29.014.6% of the control. The above results suggested that the hypertonic solution on myocardium showed multiple effects simultaneously, an inhibition to the contractile element, alteration in intracellularly available calcium level and intracellular dehydration.

Okadaic acid에 의한 칼슘-작동성 포타슘 통로의 조절

엄대용,구현남,이무열,방효원 중앙대학교 의과대학 의과학연구소 1995 中央醫大誌 Vol.20 No.3

High conductance Ca-activated K(maxi-K) channels were studied in inside-out patches with smooth muscle cells isolated from rabbit gastric antrum. These channels showed a single channel conductance of about 260 pS in symmetrical concentration of K (140mM) on both sides of the patch. The current-voltage relationship of the single channel was linear from +80 to -80mM of pipette voltage. When the cytoplasmic calcium concentration was changed from pCa 9 to 6, open probability of the channel started to increase and reached to a quasi-saturation. Mg and ATP respectively increased the channel activity in dose-dependent manner. Okadaic acid(100nM) increased the channel activity only in the presense of MgㆍATP. Therefore it could be concluded that maxi-K channel itself or an endogenous protein kinase activity which was firmly associated with the channel, was modulated by okadaic acid-sensitive phosphatase.

신부전환자에 있어서의 혈청이온화된 칼슘의 측정

박한철,엄대용,이상돈 중앙대학교 의과대학 의과학연구소 1984 中央醫大誌 Vol.9 No.1

1. With glass microelectrode technique specific for calcium ion, measurements were made for serum ionized calcium. The calibration curve was linear for pCa(2-4) and the tests were reproducible. 2. For five persons each with normal health and with uremia, serum creatinine above 10㎎/㎗, ionized calcium, total calcium, total protein, albumin, and inorganic phosphate were measured in the sera. The results are as following: 1) There were significant differences in serum phosphate and ionized calcium levels between healthy group and uremic patients. The differences were not significant in total calcium, total protein, and albumin contents. 2) The values of ionized calcium, total calcium, total protein and albumin were scattered, but individually some with uremia had lower values. 3. Preliminary tests for ionized calcium assay gave the experience that the ways of collecting and storing samples would alter the data significantly. 4. It is, therefore, felt that further studies on simplification of the sample handing before the measurement of ionized calcium is desirable.

강축양 심근에서 칼슘저장고에 관한 실험적 연구

조성일,엄대용,이상돈 중앙대학교 의과대학 의과학연구소 1981 中央醫大誌 Vol.6 No.2

1. The sequestration of activated intracellular Ca^++ ions in isolated Rabbit's cardiac papillary muscle cells, primed with square waves in normal Tyrode solution, histamine-Tyrode (3μM/L) and lanthanum-Tyrode (50μM/L), was studied by contractile responses to various test pulse interval. 2. In normal Tyrode, the disappearance of activated intracellular Ca^++ ions occurred in two pattern, i.e., the initial one was the fast component in which the contractility decreased rapidly within 5 sec. of test pulse, interval and the next, slow component in which the contractility decreased rather slowly following fast component. 3. In histamine-Tyrode, the contractility increased to 110.3±6.0% as compared with that in normal Tyrode. The fast component of Ca^++ ion disappearance was prolonged up to 10 sec. and a significant increase in contractile responses to test pulse manifested during this component. The slow component, however, was similar to that in normal Tyrode. 4. In lanthanum-Tyrode, the contractility decreased to 65.2±6.7% as compared with that in normal Tyrode. The fast component of Ca^++ ion disappearance was complete within 3 sec. of test pulse intervals and the slow component similar to that in normal Tyrode followed. 5. The data appear to indicate that the initial, rapid disappearance of activated Ca^++ ions, the fast component, was the result of sequestration of intracellular Ca^++ ions influxed across cell membrane from outside, and the next, slow component represented the sequestration of Ca^++ ions freed from intracellular storage site.

토끼 동방결절의 부위에 따른 전기생리학적 특성의 차이에 관한 연구

김덕호,엄대용,이상돈 중앙대학교 의과대학 의과학연구소 1984 中央醫大誌 Vol.9 No.2

By a 3M KCI glass microelectrode, transmembrane potentials were recorded in the compact and transitional areas bounded by superior, inferior vena cava and left, right, atria. The results were as followings: 1. In 35℃, normal Tyrode solution, the beating frequency, maximum diastolic potential (M.D.P.) and overshoot potential (O.P.) in the compact and transitional areas were 180±17/min. and 210±19/min., -76±3.7㎷ and -73±2.4㎷, 15±2.9㎷ and 19±2.8㎷ respectively which showed the transitional area was faster, and showed more positive M.D.P., more positive O.P. 2. Adrenaline made the transitional area more sensitively the frequency faster, more steeper the pacemaker potential, more positive the overshoot potential. 3. Tetrototoxin (TTX) has been found to be more sensitive on the transitional area to be less steeper the slope of pacemaker potential and the frequency slower. 4. Blocking the calcium current by 2mM Mn^2+ made the compact area, more sensitively and sometimes irreversible to reduce the beating frequency, overshoot potential and M.D.P.