• Journal of Korean Neurosurgical Society
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• v.37 no.3
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• pp.207-212
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• 2005

Objective: Classically, single photon emission tomography is known to be the reference standard for evaluating the hemodynamic status of patients with moyamoya disease. Recently, T2-weighted perfusion magnetic resonance(MR) imaging has been found to be effective in estimating cerebral hemodynamics in moyamoya disease. We aim to assess the utility of perfusion-weighted MR imaging for evaluating hemodynamic status of moyamoya disease. Methods: The subjects were fourteen moyamoya patients(mean age: 7.21 yrs) who were admitted at our hospital between Sep. 2001 to Sep 2003. Four normal children were used for control group. Perfusion MR imaging was performed before any treatment by using a T2-weighted contrast material-enhanced technique. Relative cerebral blood volume(rCBV) and time to peak enhancement(TTP) maps were calculated. Relative ratios of rCBV and TTP in the anterior cerebral artery(ACA), middle cerebral artery(MCA) and basal ganglia were measured and compared with those of the posterior cerebral artery(PCA) in each cerebral hemispheres. Using this data, we analysed the hemodynamic aspect of pediatric moyamoya disease patients in regarding to the age, Suzuki stage, signal change in FLAIR MR imaging, and hemispheres inducing symptoms. Results: The mean rCBV ratio of ACA, MCA did not differ between normal children and moyamoya patients. However the significant TTP delay was observed at ACA, MCA territories (mean = 2.3071 sec, 1.2089 see, respectively, p < 0.0001). As the Suzuki stage of patients is advanced, rCBV ratio is decreased and TTP differences increased. Conclusion: Perfusion MR can be applied for evaluating preoperative cerebral hemodynamic status of moyamoya patients. Furthermore, perfusion MR imaging can be used for determine which hemisphere should be treated, first.

• Biomedical Science Letters
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• v.14 no.4
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• pp.219-223
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• 2008

The present study was designed to clarify whether scuba diving at 5 meters of seawater influences cerebral hemodynamics, hematological and biochemical variables. Twenty healthy young men well trained scuba diving participated in this study. The blood flow velocity in the right and left middle cerebral arteries (L-MCAV and R-MCAV), blood pressure (BP), heart rate (HR), CBC and differential count, prothrombin time (PT), activated partial thromboplastin time (aPTT), biochemical variables, D-dimer and interleukin-8 (IL-8) levels were determined before, immediately after scuba diving for 30 min, and after 30 min of rest (Pre-scuba, Scuba and R-30m, respectively). L-MCAV and R-MCAV tended to increase, but the only significant increase was in L-MCAV in Scuba. SBP and HR significantly declined in R-30m compared with those of Pre-scuba and the Scuba. IL-8 levels were elevated in Scuba and R-30m compared with that of Pre-scuba. In Scuba and R-30m, hematological variables except PT and biochemical parameters excluding glucose and lactic acid did not significantly changed in comparison with those of Pre-scuba. PT level at Scuba and glucose level at R-30m significantly declined in Scuba, while lactate level at R-30m increased compared with each in Pre-scuba. However, PT level at Scuba was within a normal range. These results suggest that scuba diving at 5 m of seawater for 30 min has no adverse effects, is safe and useful for improving health. However, further study must be performed to clarify the mechanism of elevated IL-8 level following scuba diving.

• Journal of computational fluids engineering
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• v.16 no.2
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• pp.81-87
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• 2011

The importance of shear thinning non-Newtonian blood rheology on the hemodynamic characteristics of idealized cerebral saccular aneurysms were investigated by carrying out CFD simulations assuming two different non-Newtonian rheology models (Carreau and Ballyk models). To explore effects of vessel curvature, a straight and a curved vessel geometry were considered. The wall shear stress(WSS), relative residence time(RRT) and velocity distribution were compared at the different phases of cardiac cycle. As expected, blood entered the aneurysm at the distal neck and created large vortex in both aneurysms, but with higher momentum on the curved vessel. Hemodynamic characteristics such as WSS, and RRT exhibited only minor effects by choice of different rheological models although Ballyk model produced relatively higher effects. We conclude that the assumption of Newtonian fluid is reasonable for studies aimed at quantifying the hemodynamic characteristics, in particular, WSS-based parameters, considering the current accuracy level of medical image of cerebral aneurysm.

• The Journal of Korean Medicine
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• v.26 no.3 s.63
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• pp.188-203
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• 2005

Objectives : This study was designed to investigate the effects of Jayun-tang extract (JYT) on the change of cerebral hemodynamics [regional cerebral blood flow (rCBF), pial arterial diameter (PAD) and mean arterial blood pressure (MABP)] in normal and cerebral ischemic rats, na to determine the mechanisms of action of JYT. Methods : We investigated whether JYT inhibits lactate dehydrogenase activity in neuronal cells and cytokines production in serum of cerebral ischemic rats. Results : 1. JYT significantly increased rCBF and PAD in a dose-dependent manner, but MABP was not changed by injecting JYT. These results suggested JYT significantly increased rCBF by dilating PAD. 2. The JYT-induced increase in rCBF was significantly inhibited from pretreatment with indomethacin (1mg/kg, i.p.), an inhibitor of cyclooxygenase and methylene blue $(10{\mu}g/kg, i.p.)$, an inhibitor of guanylate cyclase. 3. The JYT-induced dilation in PAD was significantly inhibited from pretreatment with indomethacin, but was increased by pretreatment with methylene blue. 4 The JYT-induced increase in MABP was reduced by pretreatment with indomethacin and methylene blue. 5. JYT significantly inhibited lactate dehydrogenase activity in neuronal cells. These results suggest that JYT prevented the neuronal death. 6. Both rCBF and PAD were significantly and stably increased by JYT $(10{\mu}g/kg,\;i.p.)$ during the Period or cerebral reperfusion, which contrasted with the findings of rapid and marked increase in the control group. 7. In cytokine production in the serum drawn from femoral artery 1hr after middle cerebral artery occlusion, the sample group showed significantly decreased production of $IL-1\beta$ and $TNF-\alpha$ as well as increased production of IL-10 and $TGF-\beta$ compared with rho control group. 8. In cytokine production in the serum drawn from femoral artery 1hr after reperfusion, the sample group showed significantly decreased production of $IL-1\beta$ and $TNF-\alpha$ as well as significantly increased production of IL-10 and $TGF-\beta$ compared with the control group. Conclusions : JYT mediated by cyclooxygenase had an inhibitive effect on brain damage by inhibiting lactate dehydrogenase activity, $IL-1\beta$ and $TNF-\alpha$ production, and by accelerating IL-10 and $TGF-\beta$ production. The author feels that JYT had anti-ischemic effects through the improvement of cerebral hemodynamics and inhibitive effects on brain damage.

• Herbal Formula Science
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• v.7 no.1
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• pp.121-130
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• 1999

Oriental medicine prescription has been used for the treatment of various clinical symptoms associated with cerebral apoplexy. However, single herb drug does not used cerebral apoplexy and there mechanisms of action have not been defined, and it is not yet known what effects they have on the hemodynamics of cerebral circulation. The study was aimed to investigate the effect batryticatus bombycis(BB) on the vascular systems including changes in blood pressure (BP), and regional cerebral blood flow (rCBF) and of male Sprague-Dawely rats. The changes in rCBF were determinated by laser-Doppler flowmetry. 1. Blood pressure was not affected by BB in rats. 2. rCBF was increased by BB in a dose-dependent manner. 3. Pretreatment with methylene blue(1mg/kg), and propranolol(1mg/kg) did not inhibited BB induced increased in rCBF. 4. Pretreatment with propranolol(1mg/kg) was increased by BB in a dose-dependent manner in blood perssure. 5. Pretreatment with ODQ($10{\mu}g/kg$) and L-NNA(1mg/kg) were inhibited BB induced increased in rCBF. 6. Pretreatment with L-NNA(1mg/kg) was increased rCBF in a dose-dependent manner. These results suggest that BB causes a diverse response of blood pressure and regional cerebral blood flow(rCBF). The increased in rCBF is also mediated by nitric oxide synthease and guanylate cyclase.

• Journal of Physiology & Pathology in Korean Medicine
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• v.23 no.1
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• pp.50-56
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• 2009

The present study was designed to investigate the effects of Phamacopuncture therapy using Cervi Pantotrichum Cornu (PC) at BL23 BL52 on the regional cerebral blood flow (rCBF) and mean arterial blood pressure (MABP) in normal rats, then the related mechanisms were also investigated. In addition, the present author also investigated the effects of phamacopuncture therapy at BL23.BL52 on the rCBF in cerebral ischemic rats. The results in normal rats were as follows; PC (3 mg/kg and 5 mg/kg) at BL23 BL52 significantly increased rCBF but decreased MABP. This result suggests that PC at BL23 BL52 significantly increased rCBF by dilating pial arterial diameter. Increase of PC (5 mg/kg)-induced rCBF was significantly inhibited by pretreatment with indomethacin (1 mg/kg, i.p.), an inhibitor of cyclooxygenase and methylene blue ($10{\mu}g/kg$, i.p.), an inhibitor of guanylate cyclase. Decrease of PC (5 mg/kg)-induced MABP was significantly increased by pretreatment with methylene blue but was decreased by pretreatment with indomethacin. These results suggested that the action of PC (5 mg/kg) was mediated by guanylate cyclase. The results in cerebral ischemic rats were as follows ; The rCBF was significantly and stably increased by PC (5 mg/kg) during the period of cerebral reperfusion, which contrasted with the findings of rapid and marked increase in Control group. In conclusion, these results suggest that phamacopuncture therapy using Carthami flos at BL23 BL52 can increase rCBF in normal state, and improve stability of rCBF in ischemic state. In addition, the present author also suggest that related mechanisms are involved in guanylate cyclase pathway.

• Journal of Physiology & Pathology in Korean Medicine
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• v.16 no.6
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• pp.1127-1133
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• 2002

Cheonghunhwadam-tang(CHT) have been used in oriental medicine for many centuries as a therapeutic agent of vertigo by wind, fire and phlegm. CHTGR was CHT adding Gastrodae Rhizoma. The effects of CHTGR on the regional cerebral blood flow(rCBF) and mean arterial blood pressure(MABP) is not known. A comparative Study of action-mechanism of CHT and CHTGR on the cerebral hemodynamics is not known too. Therefore, purpose of this Study was to investigate effects of CHT and CHTGR on the rCBF and MABP, compare action-mechanism of CHT and CHTGR on the rCBF and MABP. The changes of rCBF and BP was determinated by Laser-Doppler Flowmetry(LDF). The results were as follows ; CHT extract was increased rCBF in a dose-dependent, but was not changed MABP compared with CHT non-treated group. CHTGR extract was decreased rCBF and MABP compared with CHTGR non-treated group in a dose-dependent. Action of CHT is not related with adrenergic β-receptor, cyclooxygenase and guanylate cyclase, but action of CHTGR is related with guanylate cyclase.

• Journal of Mechanical Science and Technology
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• v.19 no.spc1
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• pp.343-349
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• 2005

There are many things in common between hemodynamics in arterial systems and multibody dynamics in mechanical systems. Hemodynamics is concerned with the forces generated by the heart and the resulting motion of blood through the multi-branched vascular system. The conventional hemodynamics model has been intended to show the general behavior of the body arterial system with the frequency domain based linear model. The need for detailed models to analyze the local part like coronary arterial tree and cerebral arterial tree has been required recently. Non-linear analysis techniques are well-developed in multibody dynamics. In this paper, the studies of hemodynamics are summarized from the view of multibody dynamics. Computational algorithms of arterial tree analysis is derived, and proved by experiments on animals. The flow and pressure of each branch are calculated from the measured flow data at the ascending aorta. The simulated results of the carotid artery and the iliac artery show in good accordance with the measured results.

• Annals of Clinical Neurophysiology
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• v.1 no.1
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• pp.39-46
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• 1999

Transcranial doppler ultrasonography (TCD) is a new, non-invasive and easily applicable method to evaluate cerebral hemodynamics. Last 10 years, its use in Korea has been dramatically expanded, but the qualification of TCD laboratory has yet to be settled. Since duplex sonography is seldom used in Korea, we have to depend totally on TCD to evaluate cerebral hemodynamic changes. Thus, all of the available data from every detectabler cerebral arteries has to be obtained for accurate interpretation of TCD measurements. Moreover, flow direction and wave form should be concerned in addition to the flow velocity. In this article, I present technique to measure the anterior, meddle and posterior cerebral arteries, the internal carotid artery siphon and at cervical level, and the vertebral and the basilar artery, and normal values for these measurements which is essential for the adequate interpretation.

• Journal of Acupuncture Research
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• v.19 no.5
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• pp.92-111
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• 2002

Objective : Carthami Flos has been used as a herb to promote blood circulation to remove blood stasis in oriental medicine for many centuries, and Amun(GV15) has been used as a meridian point to treat apoplexy etc. To investigate treatment of cerevral vascular disease(CVA) by promoting blood circulation and removing blood stasis(活血化瘀法), we observed the experimental effects and mechanism of auqa-acupunture of Carthami Flos(ACF) injected into GV15 on cerevral hemodynamics and cardiovascular system of rats. Method : Aqua-acupuncture of Carthami Flos(ACF) was injected into GV15, and then we investigated experimental effects and mechanism of ACF on the cerebral hemodynamics[regional cerebral blood flow(rCBF), pial arterial diameter(PAD), meal arterial blood pressure(MABP)] and cardiovascular system[cardiac muscle contractile force(CMF), heart rate(HR)I by pretreatment with methylene blue(MTB) and indomethacin(IDN). The changes in rCBF, MABP, CMF and HR were tested by Laser Doppler Flowmetry(LDF), and the changes in PAD was determinated by video microscopy methods and video analyzer. Results :The results were as follows in normal rats ; The changes of rCBF and PAD were significantly increased by ACF($120{\mu}{\ell}/kg$) in a injected time-dependent manner, but MABP was not changed by ACF. The changes of cardiovascular system were increased by ACF in a injected time-dependent manner. And pretreatment with MTB was significantly inhibited ACE induced increase of rCBF and PAD, and was decreased ACF induced increase of HR. And pretreatment with IDN was increased ACF induced MABP and CMF. And the results were as follows in cerebral ischemic rats ; The changes of rCBF was increased stabilizly by treatment with ACF($120{\mu}{\ell}/kg$) in during the period of cerebral reperfusion, but pretreatment with MTB was increased ACF induced increase of rCBF during the period of cerebral reperfusion. The results were as follows in normal rats ; The changes of rCBF and PAD were significantly increased by ACF($120{\mu}{\ell}/kg$) in a injected time-dependent manner, but MABP was not changed by ACF. The changes of cardiovascular system were increased by ACF in a injected time-dependent manner. And pretreatment with MTB was significantly inhibited ACF induced increase of rCBF and PAD, and was decreased ACF induced increase of HR. And pretreatment with IDN was increased ACF induced MABP and CMF. And the results were as follows in cerebral ischemic rats ; The changes of rCBF was increased stabilizly by treatment with ACF($120{\mu}{\ell}/kg$) in during the period of cerebral reperfusion, but pretreatment with MTB was increased ACF induced increase of rCBF during the period of cerebral reperfusion Conclusions : In conclusion, ACF causes a diverse response of rCBF, PAD an HR, and action of ACF is mediated by cyclic GMP. I suggested that ACF has an anti-ischemic effect through the improvement of crebral hemodynamics in a transient cerebral ischemia.