• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.6
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• pp.1967-1974
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• 1991

When the functional electrical stimulation is employed to recover mobility to the plegic, it is very important to understand functions of the selected muscles. I have investigated how a muscle acts to accelerate the body segments, since the body segements are connected by joints so that contraction of a muscle not only rotates the segments to which it is attached but also causes other segments to rotate by creation a reaction force at every joint, which is called the inertial coupling. I found that a single-joint muscle always acts to accelerate the spanned joint in the same direction as the joint torque produced by the muscle. However, a double-joint muscle can act to accelerate the spanned joint in the opposite direction to the joint torque produced by the muscle depending on (1) the body position, (2) the body-segmental parameters, and (3) the type of the movement. Investigating the condition number of the inertia matrix of the body-segmental model gave us some insights into how controllable the body-segmental system is for different values of the factors mentioned above. The results suggested that the upright position is the most undesirable position to independently control the three segments(trunk, thigh and shank) and that the controllability is the most sensitive to variation of the shank length and the trunk mass, which implies that accuracy is required particularly when we estimate these two body-segmental parameters before the paralyzed muscles are innervated by using electrical stimulation.

• The Korean Journal of Pharmacology
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• v.12 no.2 s.20
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• pp.13-19
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• 1976

A fluid extract of Zizyphi Semen was employed in this experiment. The cardiac effects of Zizyphi Semen were examined on isolated rabbits atria and heart in situ of anesthetized cats and rabbits. The adrenergic blocking activity and refractory period of cardiac muscle were measured after administration of this drug. In rabbits and cats the antiarrhythmic action of Zizyphi Semen on atrial and ventricular arrhythmias produced by epinephrine or ouabain was examined. The results were following: 1. Zizyphi Semen produced a decrease in rate and contractile amplitude of the isolated rabbit atria and had a week blocking effect on epinephrine acceleration of atrial movement. 2. Zizyphi Semen effectively abolished the spontaneous arrhythmia occurring in the isolated rabbit atria ana the atrial arrhythmia induced by ouabain. 3. Zizyphi Semen produced a marked prolongation of the refractory period in isolated atrial muscle of rabbit. 4. Zizyphi Semen prevented the induction of ventricular arrhythmia arising from excessive dose of epinephrine in anesthetized rabbits and cats. 5. With regard to the ventricular arrhythmia induced by a continuous infusion of ouabain, Zizyphi Semen exerted suppressive effect and produced a marked prolongation of cardiac arrest time in anesthetized rabbits and cats. From the above results, it may be concluded that Zizyphi Semen is effective against atrial and ventricular arrhythmias. The antiarrhythmic effect of this drug may be the result of direct myocardial depressive and partially adrenergic beta receptor blocking activities including prolongation of the refractory period of cardiac muscle.

• The Korean Journal of Physiology and Pharmacology
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• v.7 no.2
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• pp.103-109
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• 2003

The cellular mechanisms that contribute to the acceleration of atherosclerosis in diabetes are poorly understood. Therefore, the potential mechanisms involved in the diabetes-dependent increase in vascular smooth muscle cell (VSMC) proliferation was investigated. Using primary culture of VSMC from streptozotocin-induced diabetic rat aorta, cell proliferation assay showed two-fold increase in cell number accompanied with enhanced superoxide generation compared to normal VSMC, 2 days after plating. Both the increased superoxide production and cell proliferation in diabetic VSMC were significantly attenuated by not only tiron (1 mM), a superoxide scavenger, but also by diphenyleneiodonium (DPI; $10{\mu}M$), an NAD(P)H oxidase inhibitor. NAD(P)H oxidase activity in diabetic VSMC was significantly higher than that in control cell, accompanied with increased mRNA expression of p22phox, a membrane subunit of oxidase. Furthermore, inhibition of p22phox expression by transfection of antisense p22phox oligonucleotides into diabetic VSMC resulted in a decrease in superoxide production, which was accompanied by a significant inhibition of cell proliferation. Based on these results, it is suggested that diabetes-associated increase in NAD(P)H oxidase activity via enhanced expression of p22phox contributes to augmented VSMC proliferation in diabetic rats.

• Journal of Physiology & Pathology in Korean Medicine
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• v.24 no.1
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• pp.143-151
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• 2010

In Vivo and In vitro antispasmodic effects of Jun-Si-Baek-Chul-San, a Traditional Korean Polyherbal Medicineconsisted of 7 types of herbs were observed in the present study. To clarify the effects of Jun-Si-Baek-Chul-San, on accelerating small intestinal movement induced by the stimulation of cholinergic neurotransmission, we evaluated the effects of Jun-Si-Baek-Chul-San on In vivo carbachol (an acetylcholinergic agent)-accelerated mice small intestinal transit and on In vitro contractions induced by low-frequency electrostimulation, KCl, histamine or acetylcholine using isolated guinea pig ileum. To induce the acceleration of mice small intestinal transit, Carbachol 1 mg/kg was once subcutaneously dosed 15min before last administration of the test drugs. In the present study, Jun-Si-Baek-Chul-San 500, 250 and 125 mg/kg or domperidone 20 mg/kg were orally pretreated on the carbachol-accelerated mice small intestinal transit once a day for 7 days and the small intestinal transit rateof activated charcoal powder were monitored. In vitro assays, Jun-Si-Baek-Chul-San1, 0.1, 0.01 and 0.001 mg/ml or domperidone $2{\times}10^{-5}M$ were treated 10min before ileal contraction was induced by filed stimulation, acetylcholine, KCl and histamine, and the % changes of contractions were observed compared to the treatment of inducer alone. In spontaneous contraction, the % changes of contractions were observed compared to treatment of vehicle alone at 10min after Jun-Si-Baek-Chul-San or domperidone treatment. The efficacy of Jun-Si-Baek-Chul-San was compared to those of domperidone. High concentration, 1 mg/ml of Jun-Si-Baek-Chul-San was found to decrease the spontaneous contraction of the isolated guinea-pig ileum. In addition, Jun-Si-Baek-Chul-San decrease contractions induced by electrostimulation, acetylcholine, histamine and KCl in the isolated guinea-pig ileum. In addition, Jun-Si-Baek-Chul-San effectively inhibited the accelerated small intestinal movement induced by carbachol stimulation of cholinergic neurotransmission in In vivo. Based on the results, although the exact molecular or action mechanism and which herbs or compound in Jun-Si-Baek-Chul-San are responsible for actions, it was concluded that Jun-Si-Baek-Chul-San normalization in the accelerated intestinal motility might be interfere with a variety of muscarinic, adrenergic and histaminic receptor activities or with the mobilization of calcium ions required for smooth muscle contraction non-specificly. Therefore, it is expected that Jun-Si-Baek-Chul-San will be promising as a prescription of clinical treatment of digestive tract disorders such as accelerated the motility of intestine, diarrhea or intestinal painful contractions.

• YAKHAK HOEJI
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• v.41 no.6
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• pp.802-816
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• 1997

In order to investigate the pharmacological properties of New Woohwangehungsimwon Pill (NWCH). Effects of Woohwangehungsimwon Pill (WCH) and NWCH were compared using various experimental models. In isolated rat aorta, NWCH and WCH showed the relaxation of blood vessels in maximum contractile response to phenylephrine ($10^{-6}$M) without regard to endothelium containing or denuded rings of the rat aorta. Furthermore, the presence of the inhibitors of NO synthase and guanylate cyclase did not affect significantly the relaxative effects of NWCH and WCH. NWCH and WCH inhibited the vascular contractions induced by acethylcholine, prostaglandin endoperoxide or peroxide in a dose-dependent manner. In conscious spontaneously hypertensive rats(SHRs), NWCH and WCH decreased significantly heart rate. These, at high doses, had a negative inotropic effect that was a decrease of LVDP and (-dp/dt)/(+dp/dt) in the isolated perfused rat hearts, and also decreased the contractile force and heart rate in the isolated rat right atria. In excised guinea-pig papillary muscle, these had no effects on parameters of action potential at low doses, whereas inhibited the cardiac, contractility at high doses. Furthermore, these had a significant inhibitory effects on heart acceleration in normotensive rats and SHRs. These results suggested that NWCH and WCH have weak cardiovascular effects, and that there is no significant differences between two preparations.