• Biomedical Science Letters
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• v.13 no.3
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• pp.231-237
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• 2007

Subway environments such as crowd, passenger's gab, or subway-generated mechanical noise may become a potential stressor. The present study was sought to determine whether subway noise with or without mental activity affects cerebral hemodynamics and sympathetic system. Fifty-four healthy volunteers were divided group I which underwent subway noise (n=24) and group II which underwent a combined mental activity (mental arithmetic) with subway noise (n=30). Sympathetic factors such as heart rate (HR), blood pressure (BP) and heart rate-systolic pressure product (RPP), and mean blood flow velocity in the middle cerebral artery (MCAV) were measured before (baseline), during and after the noise-exposure. Systolic and diastolic blood pressure, HR and RPP significantly increased in group II (P<0.05) but not in group I during the noise-exposure. Peak-MCAV, diastolic-MCAV and mean-MCAV in the both groups were elevated during the noise-exposure (P<0.05) and the increased ratios in group II were greater than those in group I. These results suggest that a combined mental activity with subway noise may be a stressor which affects cerebral hemodynamics and sympathetic system.

• Annals of Clinical Neurophysiology
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• v.1 no.1
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• pp.64-69
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• 1999

Background : Syncope was defined as transient loss of consciousness and postural tone. The mechanisms of changes in cerebral hemodynamics during syncope have not been fully evaluated. Transcranial Doppler Ultrasonography can continuously monitor the changes in cerebral hemodynamics during head-up tilt (HUT). TCD could reveal the different patterns of changes in cerebral hemodynamics during syncope. Syncope without hypotension or bradycardia could be detected by TCD. We investigated the changes in cerebral blood flow velocity during HUT using TCD in 33 patients with a history of recurrent syncope or presyncope of unknown origin. Methods & Results : The positive responses were defined as presyncope or syncope with hypotension, bradycardia, or both. During HUT without isoproterenol infusion, there were a $86{\pm}23%$ drop in DV and a $41{\pm}34%$ drop in SV in 5 patients with positive reponses, and mean changes in those were less than 10% in patients with negative reponses (p=.00, p=.00). During HUT with isoproterenol infusion, TCD showed a $80{\pm}18%$ drop in diastolic velocity in 14 patients with positive reponses, and a $47{\pm}10%$ drop in that in patients with negative reponses (p=.00), however the change in systolic velocity did not differ. TCD showed three patterns during positive responses; loss of all flow, loss of end diastolic flow, and a decrease in diastolic velocity. Loss of consciousness occurred in the patients with loss of all flow or end-diastolic flow during positive reponses. Conclusions : TCD shows different patterns of changes in cerebral hemodynamics during HUT. TCD can be used to investigate the pathophysiology of neurocardiogenic syncope.

• Biomedical Science Letters
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• v.11 no.3
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• pp.397-405
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• 2005

Noise may cause damage of the auditory system, hypertension, and cardiovascular disease. However, we haven't the data enough to be available for understanding various effects of noise on the human body. The current study was prospectively designed to investigate the changes of the cardiac factors and cerebral hemodynamics following a transient exposure to noise in young people. 80 subjects (mean aged $23.45\pm2.40$ years) participated in this experiment and were exposed to excavator-noise with 90 decibels for 15 minutes using ear-phone. Cardiac factors such as heart rate (HR), blood pressure (BP) and heart rate-systolic pressure product (RPP), and cerebral hemodynamics such as mean blood flow velocities (Vm), pulsatility indexes (PI), resistance indexes (RI) and mean blood flow velocities at breathing-hold (Vh) in the middle (MCA), anterior (ACA) and posterior cerebral arteries (PCA) were measured before (baseline) and during the noise-exposure. Although there were individual differences in above mentioned parameters, HR, systolic and diastolic BP, RPP, MCA-Vm, MCA-PI, MCA-RI, ACA-Vm, ACA-PI, ACA-RI, PCA-Vm, PCA-PI, and PCA-RI during the noise-exposure decreased compared with the baselines (P<0.05 or P<0.01), The findings of the present study suggest that a transient exposure to excavator-noise at rest causes changes in the cardiac factors and cerebral hemodynamics with individual differences. Further studies need to be carried out for clarifying the effects of longer exposure and combined mental activity with noise exposure.

• Biomolecules & Therapeutics
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• v.7 no.3
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• pp.234-241
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• 1999

The present study assessed the cerebroprotective effect of platelet-activating factor(PAF) antagonists in transient cerebral ischemia of rats. Right middle cerebral artery (MCA) of Sprague-Dawley rats was occluded for 2 hours using an intraluminal filament technique, and was reperfused for 6 hours following cerebral ischemia. The infarct area of seven coronal brain slices was measured morphometrically following stain ing in the 2% 2,3,5-triphenyltetrazolium chloride solution. The changes in regional cerebral blood flow (rCBF) and pial arteriolar diameter were measured by laser-Doppler flowmetry and by a videomicroscopy, respectively. The infarct size was significantly reduced by PAF antagonists, BN 52021 and CV-6209, which were administered i.p. 10 min before MCA occlusion. Pretreatment with PAF antagonists significantly restored the changes in pial arterial diameter as well as those in rCBF during the period of cerebral ischemia-reperfusion. PAF antagonists significantly inhibited the inducible nitric oxide synthase activity in the pial arteries ipsilateral to ischemia. These results suggest that PAF antagonists exert a cerebroprotective effect against ischemic brain damage through an improvement of postocclusive cerebral blood flow.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.5
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• pp.1404-1409
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• 2004

Cheonmabanhwa-Tang(CBT) has been used in the Oriental Medicine for many centuries as a therapeutic agent for dizziness due to Poong-Dam. This Study was designed to investigate the mechanism of Prescription on cerebral hemodynamics [regional cerebral blood flow(rCBF) and pial arterial diameter(PAD)J in cerebral ischemia rats, The results in cerebral ischemic rats were as follows: Both rCBF and PAD were significantly and stably increased by CBT (10 ㎎/㎏, i.p.) during the period of cerebral reperfusion, which contrasted with the findings of rapid and marked increase in control group. Pretreatment with indomethacin(1 ㎎/㎏, i.p.), an inhibitor of cyclooxygenase significantly but unstably increased the CBT-induced increases in PAD as well as rCBF during the period of cerebral reperfusion. Pretreatment with methylene blue(10 (.1.㎍/㎏, i.p.), an inhibitor of guanylate cyclase significantly but unstably increased the CBT-induced increases in PAD as well as rCBF during 150 minutes of cerebral reperfusion, but decreased stably the CBT-induced increases in rCBF and PAD after 180 minutes of cerebral reperfusion. In conclusion, the present authors thought that CBT caused effect on cerebral hemodynamics via mediation of cyclooxygenase.

• Journal of Physiology & Pathology in Korean Medicine
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• v.27 no.2
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• pp.173-182
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• 2013

This Study was designed to investigate the effects of Sibjeondaebo-tang (SDT) and Gamy-Sibjeondaebo-tang (GST, Sibjeondaebo-tang adding Cervi Pantotrichum Cornu) on the improvement in regional cerebral blood flow (rCBF) and mean arterial blood pressure (MABP) in normal rats, and in the rats with cerebral ischemia induced by middle cerebral artery occlusion, and further to determine the mechanisms. And, It was to investigate the effects of the SDT and GST with the change of histologic examination through the BDNF in the hippocampus CA1. In changes of cerebral hemodynamics, SDT and GST significantly increased rCBF in a dose-dependent manner but decreased MABP in normal rats. In mechanism of cerebral hemodynamics, Increase of GST-induced rCBF was significantly inhibited by pretreatment with methylene blue (0.01 mg/kg, i.p.), an inhibitor of guanylate cyclase, and Decrease of GST-induced MABP was significantly increased by pretreatment with methylene. These results suggested that the action of GST was mediated by guantlate cyclase pathway. In cerebral ischemics, the rCBF was stably improved by SDT (10 mg/kg, i.p.) significantly and stably increased by GST (10 mg/kg, i.p.) during the period of cerebral reperfusion, which contrast with the findings of rapid and marked increase in Control group. These results suggested that GST had anti-ischemic action in cerebral ischemic state. In histological examination through TTC stain, Sample A group and Sample B group decreased discoloration in the cortical part at $28^{th}$ day after MCAO induction. In immunohistochemistric response of BDNF, Sample A group and Sample B group increased respondent effect at $28^{th}$ day after MCAO induction. These results suggest that GST can Increase rCBF in normal state, as well as improve the stability of rCBF in cerebral ischemic state. Furthermore, methylene blue inhibitor study suggested the mechanism of blood flow enhancement by GST may be mediated by guanylate cyclase pathway.

• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.1
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• pp.64-70
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• 2003

Jaeumgenby-tang(JGT) have been used in oriental medicine for many centuries as a therapeutic agent of vertigo caused by deficiency of qi(氣) and blood(血). Effect of Aurantii Fructus(AF) take off the phlegm by promoting the circulation of qi, Gastrodae Rhizoma(GR) has effects treating for headache, vertigo by calming the liver and suppressing hyperactivity of the liver-yang(陽). And, I designed to investigate whether injection of JGT adding AFㆍGR extract(JGTAG) affects cytotoxicity in vitro, cerebral hemodynamics [regional cerebral blood flow(rCBF), pial arterial diameter(PAD), mean arterial blood pressure(MABP)] in normal and cerebral ischemia rats by MCA occlusion method. The changes of rCBF and MABP were determinated by laser-doppler flowmetry(LDF), and the change of PAD was determinated by video microscope and width analyzer. The results were as follows in normal rats; JGTAG was not cytotoxicity in brain cells. And JGTAG was significantly increased rCBF, PAD and MABP. This results suggest that JGTAG increased significantly rCBF by dilating PAD. And the results were as follows in cerebral ischemic rats; The changes of rCBF and PAD were increased stably by treatment with JGTAG(10mg/kg, i.v.) during the period of cerebral reperfusion, and pretreatment with propranolol and indomethacin were increased JGT AG induced increase of rCBF and PAD during the period of cerebral reperfusion. We suggest that JGTAG has an anti-ischemic effect through the improvement of cerebral hemodynamics.

• Journal of Korean Neurosurgical Society
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• v.66 no.4
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• pp.382-392
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• 2023

Objective : The use of indocyanine green videoangiography (ICG-VA) to assess blood flow in the brain during cerebrovascular surgery has been increasing. Clinical studies on ICG-VA have predominantly focused on qualitative analysis. However, quantitative analysis numerical modelling for time profiling enables a more accurate evaluation of blood flow kinetics. In this study, we established a multiple exponential modified Gaussian (multi-EMG) model for quantitative ICG-VA to understand accurately the status of cerebral hemodynamics. Methods : We obtained clinical data of cerebral blood flow acquired the quantitative analysis ICG-VA during cerebrovascular surgery. Varied asymmetric peak functions were compared to find the most matching function form with clinical data by using a nonlinear regression algorithm. To verify the result of the nonlinear regression, the mode function was applied to various types of data. Results : The proposed multi-EMG model is well fitted to the clinical data. Because the primary parameters-growth and decay rates, and peak center and heights-of the model are characteristics of model function, they provide accurate reference values for assessing cerebral hemodynamics in various conditions. In addition, the primary parameters can be estimated on the curves with partially missed data. The accuracy of the model estimation was verified by a repeated curve fitting method using manipulation of missing data. Conclusion : The multi-EMG model can possibly serve as a universal model for cerebral hemodynamics in a comparison with other asymmetric peak functions. According to the results, the model can be helpful for clinical research assessment of cerebrovascular hemodynamics in a clinical setting.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.4
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• pp.1083-1088
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• 2004

This Study was designed to investigate the mechanism of Prescription for Treatment Abundant Expectoration due to Deficiency of Qi(Yukgunja-Tang, YGT) on cerebral hemodynamics [regional cerebral blood f1ow(rCBF) and pial arterial diameter(PAD)] in cerebral ischemia rats. The results were as follows: Both rCBF and PAD were significantly and stably decreased by YGT (10㎎/㎏, i.p.) during the period of cerebral reperfusion, which contrasted with the findings of rapid and marked increase in Control group. Pretreatment with indomethacin(1㎎/㎏, i.p.), an inhibitor of cyclooxygenase and methylene blue(10㎍/㎏, i.p.), an inhibitor of guanylate cyclase significantly but unstably increased the YGT-induced increases in rCBF during the period of cerebral reperfusion. Pretreatment with indomethacin significantly and stably decreased the YGT-induced increases in PAD during the period of cerebral reperfusion, but pretreatment with methylene blue increased unstably the YGT-induced increases in PAD during the period of cerebral reperfusion. In conclusion, the present authors thought that mechanism of YGT on cerebral hemodynamics was connected with guanylate cyclase in cerebral ischemia rats.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.6
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• pp.1714-1721
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• 2004

This experimental study was designed to investigate the mechanism of Palmul-Tang(PMT) on the changes of cerebral hemodynamics in rats. The changes of cerebral hemodynamics in normal rats were as follows ; The PMT-induced increase in regional cerebral blood flow was significantly inhibited by pretreatment with indomethacin(1㎎/㎏, i.p.), an inhibitor of cyclooxygenase, and was inhibited by methylene blue(10㎍/㎏, i.p.), an inhibitor of guanylate cyclase. The PMT-induced dilation in pial arterial diameter was significantly inhibited by pretreatment with indomethacin and methylene blue. The PMT-induced increase in mean arterial blood pressure was significantly inhibited by pretreatment with indomethacin but was increased by methylene blue. This results were suggested that the mechanism of PMT was mediated by cyclooxygenase. The changes of cytokine production in cerebral ischemic rats were as follows ; In cytokine production of serum by drawing from femoral arterial blood after middle cerebral arterial occlusion 1hr, sample group was decreased IL-1β and TNF-α production compared with control group, IL-10 production of sample group was similar to that of control group, but sample group was significantly increased TGF-β production compared with control group. In cytokine production of serum by drawing from femoral arterial blood after reperfusion 1hr, sample group was significantly decreased IL-1β production compared with control group and decreased TNF-α production compared with control group. IL-10 production of sample group was similar to that of control group, but sample group was significantly increased TGF-β production compared with control group. In cytokine production of serum by drawing from femoral arterial blood after reperfusion 4 hrs, sample group was significantly decreased IL-1β production compared with control group, but IL-10 production of sample group was similar to that of control group. sample group was increased TNF-α and TGF-β production compared with control group. These results suggested that PMT had inhibitive effect on the brain damage by inhibiting IL-1β and TNF-α production, but by accelerating TGF-β production. The present author thought that PMT had an anti-ischemic effect through the improvement of cerebral hemodynamics and inhibitive effect on the brain damage.