적출 유두근에서 근육길이에 따른 계단현상 및 칼슘 수축력의 변화

김기환,엄융의,남기용,Kim, Ki-Whan,Earm, Yung-E,Nam, Kee-Yong 대한생리학회 1980 대한생리학회지 Vol.14 No.2

The effects of various inotropic interventions on the shape of the steady state length tension relation and the length-dependent activation process in cardiac muscle were studied. The influence of inotropic interventions upon the action potential was also observed. The range of varying muscle length was from the optimal length$(l_{max})$, where the active tension production is maximal, to 0.85 $l_{max}$. Changes in stimulus frequency or in external bathing Ca concentration constituted the inotropic interventions in this experiment. The papillary muscles were isolated from the rabbit right ventricles and perfused with $HCO-_3\;-buffered$ normal Tyrode solution which was aerated with $3%\;CO_2-97%\;O_2$ mixed gas and kept at $35^{\circ}C$. Resting Passive tension at $l_{max}$ was approximately 30% of the total tension and appeared from the muscle length of 0.90 $l_{max}$. The effect of stimulus frequency on the steady state level of developed tension was: As the stimulus frequency was increased from 0.1 to 0.5 Hz, there was little change in developed tension. As the frequency was increased further, to a value of about 3 Hz, tension increased steeply. Further increase of the frequency to 5 Hz had little additional effect on the developed tension. The length-tension curves for isometric peak tension became more steeper with the degree of potentiation by inotropic interventions. The relative steepness of the normalized length-tension curves where tension production was expressed as a percentage of maximal tension developed at $l_{max}$, varied inversely with the level of inotropic state and these curves were not superimposable one another. Thus at the stimulus frequency of 2 Hz or at the external Ca concentration of 8 mM, the relative decline in the developed tension for a given change in muscle length was considerably less than the decline observed at the frequency of 0.5 Hz or at the concentration of 2 mM Ca. Action potential duration was prolonged significantly as the frequency increased from 0.2 to 2 Hz, and this change in action potential duration was not observable on the changes in muscle length. There was a tendency of the hyperpolarization of membrane potential when the muscle length was shortened from $l_{max}$ to 0.95 $l_{max}$. These results support the hypothesis that there is a length-dependence of the activation process.

임파유통에 영향을 주는 인자에 관한 실험적 연구

김기환,엄융의,Kim, Ki-Whan,Earm, Yung-E 대한생리학회 1975 대한생리학회지 Vol.9 No.1

Various factors influencing the lymph flow from thoracic duct were investigated in an attempt to evaluate their contributing degree and the mechanisms. Sixteen mongrel dogs weighing between 10 and 16 kg were anesthetized and polyethylene catheters were inserted into the thoracic duct and femoral veins. Arterial blood pressure, heart rate, central venous pressure, lymph pressure and lymph flow were measured under various conditions. Electrical stimulation of left sciatic nerve, stepwise increase of central venous pressure, manual application of rhythmical depressions onto abdomen, injection of hypertonic saline solution and histamine infusion were employed. Measurement of cental venous pressure was performed through the recording catheter inserted into abdominal inferior vena cava. Changes in central venous pressure were made by an air-ballooning catheter located higher than the tip of the recording catheter in the inferior vena cava. Lymph flow from thoracic duct was measured directly with a graduated centrifuge tube allowing the lymph to flow freely outward through the inserted cannula. The average side pressure of thoracic lymph was $1.1\;cmH_2O$ and lymph flow was 0.40 ml/min or 1.9 ml/kg-hr. Hemodynamic parameters including lymph flow were measure immediately before and after (or during) applying a condition. Stimulation of left sciatic nerve with a square wave (5/sec, 2 msec, 10V) caused the lymph flow to increase 1.4 times. The pattern of lymph flow from thoracic duct was not continuous throughout the respiratory cycle, but was continuous only during Inspiration. Slow and deep respiration appeared to increase the lymph flow than a rapid and shallow respiration. Relationship between central venous pressure and the lymph flow revealed a relatively direct proportionality; Regression equation was Lymph Flow (ml/kg-hr)=0.09 CVP$(cmH_2O)$+0.55, r=0.67. Manual depressions onto the abdomen in accordance with the respiratory cycle caused the lymph flow to increase most remarkably, e.g,. 5.5 times. The application of manual depressions showed a fluctuation of central venous pressure superimposed on the respiratory fluctuation. Hypertonic saline solution (2% NaCl) administered Intravenously by the amount of 10 m1/kg increased the lymph flow 4.6 times. The injection also increased arterial blood pressure, especially systolic Pressure, and the central venous pressure. Slow intravenous infusion of histamine with a rate of 14-32 ${\mu}g/min$ resulted in a remarkable increase in the lymph flow (4.7 times), in spite of much decrease in the blood pressure and a slight decrease in the central venous pressure.

비가역성 실혈성 쇽에서 본 가토심근, 혈장의 전해질 및 혈당량 변화

김기환,남기용,Kim, Ki-Whan,Nam, Kee-Yong 대한생리학회 1968 대한생리학회지 Vol.2 No.1

Twenty white rabbits anesthetized with nembutal (30 mg/kg) were employed in this experiment. Five of them served as controls; the remaining rabbits as experimental group were subjected to irreversible hemorrhagic shock. Shock was induced by bleeding the animals until mean blood pressure decreased to a level of 50-40 mmHg. This level of pressure was maintained for 3-4 hours, after which the drawn blood was reinfused. The reinfusion of blood caused the elevation of arterial pressure almost the control level for some minutes, after which a gradual and progressive decline of blood pressure became evident. This decline was thought to be the result from irreversible hemorrhagic shock. When mean blood pressure declined to less than 50 mmHg, chest was opened and samples of arterial blood and left ventricular muscle were taken. Left ventricular muscle and blood plasma were analyzed for potassium, sodium, chloride and water content. Blood glucose concentration was determined by Somogyi-Nelson's method. Extracellular and intracellular myocardial water and electrolyte content were calculated on the basis that electrolytes are distributed between plasma water and interstitial water according to Gibbs-Donnan equilibrium. In this calculation extracellular water was substituted for Na space. The findings obtained were as follows: 1. The concentration of blood glucose was 87mg% in the controls and it rose to 222 mg% in shock (P<0.01). 2. Plasma potassium elevated significantly from 3.3 mEq/l in controls to 8.0 mEq/l in shock (P<0.01), while small decreases in sodium (151-146 mEq/l) and chloride (102-96 mEq/l) were observed (P<0.3, P<0.1), 3. The changes of blood water content (83.1-84.3%) and cardiac water content (77.5-78.3 gm/100gm WT) were observed. 4. In control animals myocardial potassium levels which averaged 30.2 mEq/100 gmDT rose significantly to 40.3 mEq/100 gmDT in shock (P<0.01), while moderate decreases in sodium(16.3-14.3 mEq/100 gmDT) were observed in shock. 5. The calculated transmembrane resting potential of left ventricular muscle of control animals averaged 95 mV, while rabbits in shock averaged 77 mV. (P <0.01). The findings of this experiment do not correspond with the conclusions that myocardial depression seems to be the cause of irreversible hemorrhagic shock, because the excitability of heart muscle is elevated. From the point of view that the lowered transmembrane resting potential, the cause of death in terminal stage of irreversible hemorrhagic shock may be ventricular fibrillation. It can't be said, however, that the lowered transmembrane resting potential is responsible for the transition from reversible to irreversible hemorrhagic shock. The marked increase in blood glucose suggested that glycogenolysis in the liver is favorably active in shock.

학령인구 감소에 따른 지역별 대입지원자 감소에 대한 예측연구

김기환,이창호,최보승,Kim, Ki Whan,Lee, Chang Ho,Choi, Boseung 한국데이터정보과학회 2015 한국데이터정보과학회지 Vol.26 No.6

20년 이상 유지된 낮은 합계출산율은 학령인구 감소로 이어져 고등학교 졸업자 수가 급격히 감소하는 상황에 직면하게 되었고, 교육부는 2014년 1월 향 후 10년간 약 16만 명에 해당하는 대학 입학정원을 강제로 감축하는 대학 구조개혁 추진 계획을 발표였다. 대학의 정원감축은 피할 수 없는 문제이지만, 대학 구조개혁 추진계획의 주된 근거로 교육부가 제시한 것은 통계청의 18세 전국 장래 추계인구와 2014년 전국단위 대학정원의 비교자료뿐이다. 대학정원의 감축이 학생, 대학, 지역경제까지 큰 파장을 미치는 것임을 고려할 때, 교육부의 근거가 세밀하지 못한 것에 아쉬움이 따를 수밖에 없다. 따라서 본 연구에서는 고3 수험생, 재수생을 포함하는 대학수학능력시험 응시자를 16개 시도 별로 2032년까지 전망하고 지역별 특성을 비교하였다. 16개 시도 별 현재의 대학정원이 2032년까지 계속된다는 가정 아래서 16개 시도 별 대학수학능력시험 응시자 전망결과를 이용하여 지역별 대학 충원율을 산출을 시도하였으나, 수험생의 지역 간 이동을 반영할 수 없어 현실적인 전망결과를 산출하지 못하였다. 이 문제의 해결을 위하여 본 연구에서는 2014학년도 대학배치표 상의 학과순위가 계속 유지된다는 가정에서 전체 일반대학 7,277개 학과 순위를 추정하고, 이 학과들의 정원을 전체 대학 정원에서 차감해 가는 방법으로 지역별 대학 충원율을 2032년까지 산출하였다. 16개 시도 별로 산출된 대학 충원율은 전국단위로 보았을 때보다 지역별 특성과 문제점을 좀 더 확연하게 보여주었다. The Ministry of Education of Korea announced the university structural reform plans which reduces 160,000 of the university entrance quota during 10 years from January 2014. Because the reduction plans of entrance quota influence regional economy as well as students and universities, naive evidence of the Ministry of Education of Korea is disappointed. In this research, we forecast the total number of the university entrance exam candidate by 2032 including not only third grade high school students but also repeaters according to the 16 metropolises and provinces in Korea. We also forecast the regional university recruiting rate using the forecasts of the total number of the university entrance exam candidates. However, we can not make more realistic results because we can not apply the inter-regional movement of students to the forecast. In order to handle this limitation, we first estimated the rank of the whole 7,277 departments of all universities in Korea and assigned the quotas according to the estimated rank for each departments and then we calculated the local university recruiting rate. The estimated the university recruiting rates of 16 metropolises and provinces can provide more noticeable results of characteristics and problems than that of nationwide.

혈관 및 장관 평활근의 K-경축 발생기전

김기환,황상익,남기용,Kim, Ki-Whan,Hwang, Sang-Ik,Nam, Kee-Yong 대한생리학회 1979 대한생리학회지 Vol.13 No.1

The activation mechanism of K-induced contracture was studied in renal vascular muscle which does not generate an action potential readily and in taenia coli which generates a spike potential spontaneously. Helical strips of arterial muscle from rabbit renal arteries and longitudinal strips of taenia coli from guinea-pig's colons, respectively, were prepared. All experiments were performed in Tris-buffered Tyrode solution which was aerated with 100% $O_2$ and kept $35^{\circ}C$. Renal arterial muscles developed the contracture rapidly, which was composed of a small phasic and a large tonic components, when exposed to a 40 mM K-Tyrode solution. In the absence of external $Ca^{++}$, however, no K-contracture appeared. The contracture induced by K-depolarization was abolished by the treatment with verapamil, which is known to be a selective $Ca^{++}-blocker$ through potential-sensitive $Ca^{++}-channel$. K-contracture of taenia coli showed the contracture composed of a large phasic and a small tonic components. In the $Ca^{++}-free$ Tyrode solution, only the tonic component was abolished and almost no change in the phasic component was observed. The amplitude of tonic component was dependent on the external $Ca^{++}$; The tonic component increased dose-dependently by a stepwise increase of the external $Ca^{++}$, and this component decreased in parallel with the increase of verapamil in the external medium. The results of this experiment suggest that K-contracture of rabbit renal artery is the direct result of the influx of the external $Ca^{++}$, while that of taenia coli is the result of both $Ca^{++}$ influx and the release of sequestered $Ca^{++}$.

Session 1 : Korea-Japan Joint Session ; Regulation of Colonic Motility

김기환 ( Ki Whan Kim ) 대한소화관운동학회 2004 심포지움 Vol.10 No.1

아동학대의 세대간 전승을 단절시키는 생태학적 변인 연구

김기환(Ki Whan Kim) 연세대학교 사회복지연구소 1995 연세사회복지연구 Vol.2 No.-

본 연구는 아동 학대의 세대간 전승이론을 재검증하기 위해 아동시절의 경험과 현재의 생태학적 변인들간의 상호작용을 살펴보고, 이들 변인들이 아동학대의 세대간 전승에 미치는 고유한 영향 및 상대적 중요성을 살펴보았다. 이를 위해 아동기의 경험을 1) 부모로부터 직접 체벌을 받은 경험, 2) 부부간의 학대를 관찰한 경험, 3) 체벌과 부부간의 학대를 모두 경험한 경우, 4) 정상적인 아동시절을 보낸 경우(통제집단)의 네 집단으로 구분하였으며, 현재의 생태학적 변인들은 Kaufman과 Zigler의 상호교환적 모형이론을 이용하였다. 이의 이론적 모형을 토대로 본 연구는 미국의 Strauss와 Gelles에 의해서 행해진 1985년 가족 폭력에 관한 전국 재조사 (1985 National Family Violence Resurvey)의 6,002가구 중 본 연구의 목적에 맞는 3,360가구를 연구대상으로 하였다. 이를 통하여 본 연구는 아동학대가 부모로부터 학대받은 경험에 의해서 세대간 전승되기 보다는 현재의 가정환경 내에 있는 위험변인들 간의 상호작용에 의해 일어나는 가족 역기능의 결과임을 나타내었고, 아동기의 경험종류에 따른 아동학대의 다양한 특성들도 살펴보았다. 또한 아동학대를 유발시키는 고위험 (high-risk) 생태학적 변인들 간의 상대적 중요성을 밝히고 아동학대 연구에 있어서 구체적 역할모델과정과 생애발달적 관점의 중요성을 제시하였다. This study explores not only the unique impacts of violence experience as a teenager but also the relative importance of socioecological conditions on the cycle of physical violence toward children. By differentiating a parent’s teenage experience into four different categories (i.e., Never Experienced Any Violence, Only Witnessed Conjugal Violence, Only Physically Punished, and Experienced Both Types of Violence), this study reveals that each type of violence experience has a different impact on transmitting physical violence to the next generation and that the same type of the experience has a unique influence on physical punishment or child abuse. In addition to the effects of various teenage experience, this study identifies that current ecological conditions are relatively more important than the violence experience as a teen in the transmission of physical violence. Consequently, by distinguishing the unique ecological factors for physical punishment and child abuse, this study explains that child abuse is not the extreme continuum of physical punishment but the dysfunctional parent-child relationship with ecological systems. Also the present study identifies differences between child abuse and adolescent abuse in terms of life-span developmental perspective. Hence this study suggests that prevention and intervention strategies need to be different for physical punishment and child abuse as well as for child abuse and adolescent abuse.

청소년의 성행위에 대한 고찰

김기환(Ki Whan Kim) 한국아동복지학회 1999 한국아동복지학 Vol.- No.8

청소년의 성을 올바로 이해하기 위해서는 청소년의 성행위를 무조건 금기시하거나 혹은 비행행동으로만 낙인화하는 기존의 관점에서 벗어나, 이들의 성을 인간의 발달 단계와 사회문화적 환경과의 상호작용속에서 이해하는 인식의 전환이 필요하다. 이를 위해서는 ① 청소년기의 신체적·심리적·사회적 발달특성과 이러한 특성이 청소년의 성행위에 미치는 영향을 파악하고, ② 시대의 변화에 따른 청소년 성행위의 변천을 고찰하며, ③청소년의 성행위에 대한 사회적 규범과 가치의 변화 및 대처방안을 개발하는 것이 필요하다. 따라서 본 연구는 청소년의 성에 대한 기존의 실태조사를 바탕으로 하여 현대사회에 나타나고 있는 청소년의 성행위를 조명해 보고 청소년의 성을 이해하기 위한 새로운 인식의 전환을 제시하고자 한다. 구체적으로 청소년도 성적 행위의 주체자로서 인식되어 져야 하며, 이들의 성행위를 비행이나 일탈행위로만 낙인화할 것이 아니라 청소년의 발달과정상 필요한 과업으로 인식하여 이들에게 인권존중과 평등의 가치관을 교육시키는 것이 필요하며 자신의 성행위에 대하여 책임을 갖도록 교육하는 것이 필요하다. 나아가 기성세대의 양성차별적인 성역할이나 성의 상품화를 감소시키고, 청소년들을 위한 성교육나 원조 프로그램을 개발하는 총체적인 사회적 노력이 필요하다. In order to properly understand sexual activities of adolescents, it is important that sexual activity of adolescents be perceived in the contextual relationship between human developmental tasks and socio-cultural environment. Since the sexual activities are natural and necessary in every human developmental stages, adolescents should achieve these activities through healthy method. Despite this fact, we have not accepted sexual activities of adolescents because of traditional and male-oriented values. Rather, we have been labeling adolescents who have experienced sexual activities as delinquents. This negative perception toward adolescent s sexual activities needs to be changed because of high prevalence of sexual activities in adolescents. And sexual activities of adolescents are natural phenomena of adolescent s pshcyo-sexual development. The purposes of this study are to 1) discuss i) the influence of adolescent`s psycho-social characteristics on his/her sexual activity, ii) the prevalence of adolescent`s sexual activities today, and iii) the need for new perception toward sexual activities of adolescents and 2) suggest how the current perception of sexual activities of adolescents should be altered. This study suggests that an adolescent should be considered as a pro-active person who is able to make decision regarding sexual activities in his/her developmental process. Hence we should not label sexually active adolescents as delinquents but educate them to express their sexuality in healthy methods. The contents of education should include sexual equality between male and female, responsibility of sexual behaviors and respect for human being.

Session 1 : Korea-Japan Joint Session ; Regulation of Colonic Motility

김기환 ( Ki Whan Kim ) 대한소화기학회 2004 대한소화기학회 춘계학술대회 Vol.2004 No.-

위 평활근의 부위별 전압-장력 관계에 관한 연구

김기환(Kim, Ki-Whan),이상진(Lee, Sang-Jin),서석효(Suh, Suk-Hyo) 대한생리학회 1989 대한생리학회지 Vol.23 No.2

Mechanical contractions and electrical activities of the fundic longitudinal and antral circular muscle fibers were investigated in order to elucidate topical differences of gastric motility. K-induced contracture was produced by exposure of muscle strips to high K Tyrode solution. Membrane potential and mechanical contraction were simultaneously recorded by conventional glass microelectrode method and single sucrose-gap technique. All experiments were performed in tris-buffered Tyrode solution which was aerated with 100% O₂ and kept 35℃. The results obtained were as follows: 1) The resting membrane potential of circular muscle cells in the antral region was about 10 mV more negative than that in the fundic region. 2) The membrane potentials decreased almost linearly as the extracellular KCI concentration was increased both in antral circular muscle cells and in fundic longitudinal muscle cells. 3) The thresholdal K concentration of K-contracture was 15 mM (membrane potential, -48 mV) for the antral circular muscle strip and 20 mM for the fundic longitudinal muscle cells. 4) The ratio of membrane permeability coefficient for Na⁺ and K⁺, P_Na/P_K(α) was 0.065 for antral circular muscle cells and was 0.108 for fundic longitudinal muscle cells. 5) K-contracture of antral and fundic smooth muscle strips showed the contracture composed of phasic and tonic components. The amplitude of the phasic component increased sigmoidally in a dose-dependent manner, whereas that of the tonic component was maximal at a concentration of 40 mM KCI and at the concentrations above or below 40 mM KCI the amplitude was reduced. 6) The inverse relationship between the amplitude of tonic component and extracellular KCI concentration in the range of 40 to 150 mM KCI was more prominent in the antral circular muscle strip than in the fundic longitudinal muscle strip, where the amplitude of the tonic component decreased less steeply and was maintained higher at the same high K concentrations. 7) The tonic component was totally dependent on the external Ca²⁺ and completely abolished by verapamil, while tile phasic component was far less dependent on the external Ca²⁺ and partially suppressed by verapamil. From the above results, the following conclusions could be made. 1) The phasic component of K-contracture is produced both by intracellular Ca²⁺ mobilization and by Ca²⁺-influx from outside, while the tonic component is generated and maintained by the Ca²⁺-influx through the potential-dependent Ca²⁺ channel. 2) The mechanism of reducing the free Ca²⁺ concentration in the myoplasm seems to be more developed in the antral circular muscle than in the fundic longitudinal muscle. 3) The lower resting membrane potential of the fundic longitudinal muscle cell reflects a relatively high P_Na/P_K ratio of about 0.108.