• Korean Journal of Veterinary Research
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• v.41 no.3
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• pp.327-332
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• 2001

In recent years, experimental evidence have been suggested that melatonin has either contractive or relaxing effects on the vascular smooth muscle in vitro. But the effect of melatonin on the cardiovascular system in vivo had been emphasized about the hypotensive effect. In this work, we found not only hypotensive effect but also hypertensive effect of melatonin in rats and attempted to determine the mechanism of these effects elicited by melatonin. Regadless of concentration, melatonin(0.002~5 mg/kg) produced increase in mean blood pressure (MBP) in 36% (54/150 cases) and decrease in mean blood pressure in 64%(96/150 cases). As a whole melatonin caused an increase or a decrease in MBP without compensatory decrease or increase in heart rate. The melatonin-induced hypertension was abolished by the pretreatment of phenoxybenzamine, a ${\alpha}$-adrenoceptor antagoninst. The melatonin-induced hypotension was abolished by the pretreatment of propranolol, a ${\beta}$-adrenoceptor antagonist, ODQ, a NO-sensitive guanylate cyclase inhibitor, or nifedipine, a L-type $Ca^{2+}$ channel blocker, but not by bilateral cervical vagotomy. The results indicate that melatonin-induced hypertension may be related to ${\alpha}$-adrenoceptor stimulation and melatonin-indued hypotension may be related to ${\beta}$-adrenoceptor stimulation, inhibition of $Ca^{2+}$ channel and/or activation of guanylate cyclase.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2000.10a
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• pp.451-454
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• 2000

Invasive methode and Non-invasive methode are used in blood pressure measurement. The Invasive methode can Set the correct measured blood pressure but, it has patient feels uncomfortable. So most of cases use Non-invasive methode. The Oscillometric method is commonly apply to modem electric sphygmomanometer and using various algorithm. In this paper describe about a algorithm it control and to determinate the cuff pressure, and filtering that data for measure the blood pressure. The communicating with personal computer can pressure deflation is by Solenoid valve and it uses RS-232 system in packet communication. The main using algorithm for blood pressure measurements are maximum amplitude algorithm and oscillometric algorithm. MAA(maximum amplitude algorithm) has various measured oscillation it depend on patient's age, height, weight and arm circumference size. In this paper, 1 studied the various measured oscillation apply to characteristic ratio and can get the result of systolic blood pressure, diastolic blood pressure, mean blood pressure. It was not used same ratio to measuring oscillation. In the MAA(maximum amplitude algorithm), we hope for reduce the difference with the real blood pressure and the measured blood pressure, when it applied with various specific ratio.

• Journal of Acupuncture Research
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• v.19 no.1
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• pp.147-158
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• 2002

Objective : The aim of the present study is to investigate the effect of stimulation on different sites of the body on MBP(mean blood pressure) and HR(heart rate). Methods : Six healthy men have participated in this study. Before and after 10 min, exercise on a running machine of l0km/hr, acupressure, plain acupuncture and electroacupuncture(50Hz) stimulation was practiced on GV20, LI4, ST36, BL40 and non-acupoints on T4 and T10 respectively for 20 min. and in a control group without any treatment. The changes of MBP and HR after exercise have been observed for 20 min. at 5 minute intervals. Results : Compared with control, no significant difference was observed in research of the blood pressure measurement regardless of methods nor sites of stimulation. But there were trends of reduction in the heart rates in all experimental groups. Especially, in the group of acupressure on T10 before exercise, GV20, T10 after exercise and electroacupuncture on GV20, LI4, BL40 after exercise there was statistically significant decreases in heart rates. Conclusion : From the present experiment, it is concluded that somatic stimulation has effect on the heart rates but not on the blood pressures, and the presence of effective sites on the decreases of heart rates suggest that this effect may depend on sites of stimulation.

• The Journal of Korean Medicine
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• v.27 no.3 s.67
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• pp.38-50
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• 2006

Objectives: The aim of this study was to evaluate the effects of Korean ginseng (KG), Korean red ginseng (KRG) and fermented Korean red ginseng (FKRG) extracts on cerebral hemodynamics and to compare distinction of each extract. Methods: Ten healthy male volunteers $(26.0{\pm}1.8yrs)$ participated in the study according to double-blind and cross-over protocols. Each volunteer was blindly administered 500mg of KG, KRG, FKRG extract or placebo (Dextrin). Blinded researchers measured changes of hyperventilation-induced cerebrovascular reactivity (CVR), mean blood flow velocity (MBFV) of middle cerebral arteries (MCAs) and corrected blood flow velocity at $P_{ETCO2}=40mmHg$ (CV40) using transcranial Doppler ultrasound (DWL Co., Germany). Researchers also observed changes of mean blood pressure (MBP), pulse rate (PR) and expiratory $CO_2$ using S/5 Collector (Datex-Ohmeda Co., Finland). The evaluation was performed at basal condition, and repeated at 1, 2, 3, 4 and 5 hours after administration. Results: MBFV and CV40 in the KRG group tended to rise at I hour after administration, while those of the FKRG group tended to rise at 2 hours after administration. CVR increased significantly after 1 hour in the KRG group (p=0.009) and after 2 hours in the FKRG group (p=0.035), respectively. The KG group showed increasing tendency at 4 hours after administration. No group showed significant difference from the placebo in changes of MBP and PR. Conclusions: It is suggested that KG, KRG and FKRG extracts have effects of enhancing CVR and thus of increasing cerebral blood flow in human subjects.

• Neonatal Medicine
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• v.18 no.1
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• pp.124-129
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• 2011

Purpose: To evaluate the effect of oral sildenafil therapy in neonates with persistent pulmonary hypertension of the newborn (PPHN) Methods: We conducted a retrospective review of 32 neonates ${\geq}$35 weeks' gestation and fraction of inspired oxygen ($FiO_2$) 1.0 with PPHN. The first dose (0.5 mg/kg) of oral sildenafil was started and 1 mg/kg was given every 6 hour thereafter. Mean airway pressure (MAP), $FiO_2$, oxygenation index (OI), mean arterial blood pressure (MBP) were documented before and 6, 12, 24, and 48 hours after sildenafil. For adverse effects, gastrointestinal symptoms, brain ultrasound, funduscopy and auditory brainstem response results were evaluated. Results: The underlying diseases of PPHN (n=32) were meconium aspiration syndrome (n=9), respiratory distress syndrome (n=8), pneumonia (n=3), and idiopathic (n=12). Thirty-one neonates survived; 3 neonates were transferred for inhaled nitric oxide (iNO) and all of them survived. In 28 infants, $FiO_2$ and OI improved significantly by 6 hours and MAP improved significantly by 48 hours after initiation of sildenafil. There were no clinically significant adverse effects of sildenafil. Conclusion: Sildenafil may be an effective and safe agent for near-term and term neonates with PPHN, providing significant improvement in oxygenation, and thus may be especially useful in the treatment of PPHN in hospitals without iNO.