• Journal of Korean Physical Therapy Science
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• v.6 no.4
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• pp.153-165
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• 1999

The transcranial Doppler(TCD) is a technique for measuring blood flow velocity of intracranial and extarcranial arteries. This examination based on Doppler effect which was first formulated in 1842 by the Austrian physicist Christian Doppler. In 1982, Rune Aaslid first maked 2MHz pulsed probe and recording intracranial vessels with transcranially. There are six criteria utilized in gaining positive identification of the intracranial vessels. The six criteria are as follows l)acoustical windows 2)depth of sample volume 3)direction of flow 4)spatial relationship of ACA and MCA bifurcation 5)mean velocity and 6)response common carotid artery compression and/or oscillation test. The affected factors for TCD examination are angle of insonation, posture of subject, age, gender, hematocrit, metabolic factors, and cardiac output. Clinical application of TCD are detection of stenosis, occlusion, emboli, thrombsis in intracranial and extracranial arteries and evaluation of cerebral arterovenous malformation, collateral capacity in the circle of Willis, ischemia cerebrovascular disease, stroke patient and vertebrobasilar system.

• Korean Journal of Plant Resources
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• v.35 no.6
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• pp.713-719
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• 2022

Platycodon grandiflorum and Glycyrrhiza uralensis contain several bioactive compounds, such as saponin, oleanolic acid, and flavone. P. grandiflorum and G. uralensis have traditionally been used to treat disorders related to blood pressure, diabetes, and counteracting poison, and they have antinociceptive and antiinflammatory properties. However, the validity of complex saponin's vasodilatory effect has not been scientifically investigated. Therefore, this study explores the vasodilatory effect of complex saponin extracted from P. grandiflorum and G. uralensis mixture extract on rabbit carotid arteries. To this end, arterial rings with intact or damaged endothelium were used in an organ bath experiment and contracted by endothelin. Complex saponins, the major active constituents of P. grandiflorum and G. uralensis mixture extract, exhibited a moderate vasodilatory effect on the rabbit's basilar arteries. Therefore, treatment with complex saponin extracted from P. grandiflorum and G. uralensis mixture extract may selectively accelerate cerebral blood flow through basilar arterial dilation. Overall, the findings suggest that the extracted complex saponins can serve as vasodilator sources.

• Investigative Magnetic Resonance Imaging
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• v.21 no.2
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• pp.82-90
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• 2017

Purpose: This study investigated the MRI, MR angiography (MRA) and MR perfusion findings of seizure-related cerebral cortical lesions during the periictal period. Materials and Methods: From a retrospective review of the institutional database between 2011 and 2014, a total of 21 patients were included in this study. Two radiologists assessed periictal MRI, including MRA and MR perfusion, in patients with seizure-related cortical lesions. The parameters examined include: location of cortical abnormality, multiplicity of the affected cortical region, cerebral vascular dilatation, perfusion abnormality and other parenchymal lesions. Results: All patients showed T2 hyperintense cerebral cortical lesions with accompanying diffusion restriction, either unilateral (18/21, 85.7%) or bilateral (3/21, 14.3%). Of the 21 patients enrolled, 10 (47.6%) had concurrent T2 hyperintense thalamic lesions, and 10 (47.6%) showed hippocampal involvement. Of the 17 patients (81%) who underwent MRA, 13 (76.5%) showed vascular dilatation with increased flow signal in the cerebral arteries of the affected cortical regions. On MR perfusion, all 5 patients showed cortical hyperperfusion, corresponding to the region of cortical abnormalities. Conclusion: Seizure-related cerebral cortical lesions are characterized by T2 and diffusion hyperintensities, with corresponding cerebral hyperperfusion and vascular dilatation. These findings can be helpful for making an accurate diagnosis in patients with seizure.

• Journal of Korean Neurosurgical Society
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• v.39 no.1
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• pp.46-51
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• 2006

Objective : An Intracranial aneurysm is an important acquired cerebrovascular disease that can cause a catastrophic subarachnoid hemorrhage. Atherosclerosis is one of possible mechanism, but its contribution to aneurysm formation is unclear. Human apolipoprotein E[apoE] is best known for its arterial protection from atherosclerosis. In this study we observe apoE expression in experimental cerebral aneurysms of rats to elucidate the role of apoE in the process of cerebral aneurysm formation. Methods : Twenty-four male 7-week-old Sprague-Dawley strain rats received a cerebral aneurysm induction procedure. One month[12] and three months[12] after the operation, the rats were killed, their cerebral arteries were dissected, and the regions of the bifurcation of the right anterior cerebral artery-olfactory artery [ACA-OA] bifurcations were examined histologically and immunohistochemically. Results : In the 1 month group [n=12], the ACA-OA bifurcation showed no aneurysmal change in 7 rats and early aneurysmal change in 5 rats. In the 3 months group (n=12), the bifurcation showed no aneurysmal change in 2 rats and an advanced aneurysm in 10 rats. ApoE expression were in 3 specimen in early aneurysmal change, but not in advanced aneurysms. Conclusion : ApoE expression in early aneurysmal wall suggests a possible role for apoE in early events leading to aneurysm formation. Further studios are necessary to elucidate the exact role of apoE in the pathophysiology of cerebral aneurysm.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.2
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• pp.538-543
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• 2004

Objective : This study investigated a neuroprotective effect of Puerariae Radix on cerebral ischemia. Method : The global cerebral ischemia was induced by bilateral common carotid arteries occlusion under hypotension (40mmHg) in Sprague-Dawley rats. After the treatment of Puerariae Radix extract, changes of c-Fos and c-Jun expressions, immediate early genes expressed by cerebral ischemia, in the hippocampus were observed immunohistochemically. Result: The results obtained are as follows; The significant increases of c-Fos and c-Jun expressions were observed in the hippocampus of the ischemic damaged rat brains. Then Puerariae Radix treatment demonstrated significant decreases of c-Fos and c-Jun expressions in CA1 region and dentate gyrus as compared with control group. On the upregulated c-Fos expression induced by cerebral ischemia, Puerariae Radix treatment demonstrated significant decreases of c-Fos expressions in CA1 region (P<0.01) and dentate gyrus (P<0.05) as compared to the control group, but there were not a significant changes in CA2 and CA3 regions of the hippocampus. On the upregulated c-Jun expression induced by cerebral ischemia, Puerariae Radix treatment demonstrated significant decrease of c-Jun expression in CA1 region (P<0.05) as compared to the control group, but there were not a significant changes in CA2, CA3, and dentate gyrus of the hippocampus. Conclusion : These results suggested that Puerariae Radix reveals the neuroprotective effect through the reduction of immediate early genes, c-Fos and c-Jun, induced by cerebral ischemia.

• The Journal of Internal Korean Medicine
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• v.20 no.1
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• pp.222-231
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• 1999

Uwhangchungsimwon(UC) has been used in the treatment of a wide variety of conditions including stroke, hypertension, arteriosclerosis, autonomic imbalance, mental instablity, etc in Korean traditional hospitals, In particular it is often initialy chosen for emergency care of acute stroke. The aim of this study was to evaluate the effect of UC on cerebral hemodynamics. Using transcranial Doppler ultrasound, we studied changes of mean flow velocity and pulsatility index(PI) of middle cerebral arteries (MCAs) from 11 health young volunteers who were administrated with 1 pill UC and 11 health controls who were not. We obtained hypercapnia with breath-holding and evaluated cerebrovascular reactivity with breath-holding index(BHI). Systolic blood pressure, diastolic blood pressure, and heart rate were measured using ambulatory blood pressure monitoring(ABPM). In UC administration group, the evaluation was performed during basal condition. and repeated at 20, 40, and 60 min after administration. In controls, the evaluation was performed at corresponding time intervals. Mean flow velocity in middle cerebral artery, systolic blood pressure, diastolic blood pressure, and heart rate did not change during the observation period and were not different between these two groups. However, administration of UC was associated with decreases in PI by $3.6{\sim}12.4%$ in BHI by $17.9{\sim}24.8%$ compared with pre-administration period. Decreases in PI and BHI with UC were significantly different compared with control group (p<0.05). These results indicate that UC decreases PI and BHI in cerebral artery, which is due to a dilation of cerebral resistance vessels.

• Korean Journal of Clinical Laboratory Science
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• v.36 no.1
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• pp.43-48
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• 2004

Cerebral vasoreactivity is an index of autoregulation of cerebral perfusion, and can be measured using functional images such as Xe CT, SPECT and PET in reponse to hypercapneic stimulus. In order to measure cerebral $CO_2$ vasoreactivity in routine TCD study conveniently and reliably, we devised a method of rebreathing into closed volume of reservoir bag as a hypercapneic stimulus, and applied it to 44 healthy volunteers. As a hypercapneic stimulus, we applied fitting mask connected with closed reservoir bag for about 90 seconds, and mean blood flow velocity(MBFV) and pulsatility index(PI) were evaluated at proximal middle cerebral arteries(MCA) of 50-55 mm depth, before and after the hypercapneic stimulus. Age affected the MFV and PI value showed significant and the MFV was 56.45(SD=9.75)cm/sec, while PI was 0.406(SD=0.089). As age increases the flow velocity decreased significantly whereas PI value increased(P<0.05). The vasoreactvity significantly decreased with age(P<0.05). The decrease of cerebral blood flow quantity and cerebral blood flow velocity is not only because of increase of diameter of cerebrovascular resulting from aging, but the resistance increase of small blood vessel resulting from the increase of PI & RI value is regarded. We suppose that the rebreathing method is a reliable and convenient technique as a hypercapneic stimulus in determining cerebral $CO_2$ vasoreactivity. The rebreathing method could be non-invasive and useful methods in estimation of the cerebrovascular reactivity and could be applied to the basal and follow-up evaluation of the cerebrovascular reserve of the ischemic stroke patients.

• The Korean Journal of Physiology and Pharmacology
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• v.2 no.6
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• pp.695-703
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• 1998

$[K^+]_o$ can be increased under a variety of conditions including subarachnoid hemorrhage. The increase of $[K^+]_o$ in the range of $5{\sim}15$ mM may affect tensions of blood vessels and can change their sensitivity to various vasoactive substances. Therefore, it was examined in the present study whether the sensitivity of cerebral arteries to vasoactive substances can be changed with the moderate increase of $[K^+]_o$, using Mulvany-type myograph and $[Ca^{2+}]_c$ measurement. The contractions of basilar artery and branch of middle cerebral artery induced by histamine were not increased with the elevation of $[K^+]_o$ from 6 mM to 9 mM or 12 mM. On the contrary, the contractions induced by serotonin were significantly increased with the elevation of $[K^+]_o$. The contractions were also significantly increased by the treatment with nitro-L-arginine $(10^{-4}$ M for 20 minutes). In the nitro-L-arginine treated arteries, the contractions induced by serotonin were significantly increased with the elevation of $[K^+]_o$ from 6 mM to 12 mM. $K^+-induced$ relaxation was evoked with the stepwise increment of extracellular $K^+$ from 0 or 2 mM to 12 mM by 2 mM in basilar arterial rings, which were contracted by histamine. But $[K^+]_o$ elevation from 4 or 6 mM to 12 mM by the stepwise increment evoked no significant relaxation. Basal tension of basilar artery was increased with $[K^+]_o$ elevation from 6 mM to 12 mM by 2 mM steps or by the treatment with ouabain and the increase of basal tension was blocked by verapamil. The cytosolic free $Ca^{2+}$ level was not increased by the single treatment with serotonin or with the elevation of $[K^+]_o$ from 4 mM to 8 or 12 mM. In contrast to the single treatment, the $Ca^{2+}$ level was increased by the combined treatment with serotonin and the elevation of $[K^+]_o$. The increase of free $Ca^{2+}$ concentration was blocked by the treatment with verapamil. These data suggest that the sensitivity of cerebral artery to serotonin is increased with the moderate increase of $[K^+]_o$ and the increased sensitivity to serotonin is due to the increased $[Ca^{2+}]_i$ induced by extracellular $Ca^{2+}$ influx.

• Journal of the Korean Society of Radiology
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• v.84 no.6
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• pp.1361-1366
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• 2023

The persistent primitive olfactory artery (PPOA) is a rare variant of the anterior cerebral artery, first reported in 1979. It reportedly has a high correlation with the development of aneurysms, owing to the hemodynamic stress induced by the structural characteristics of the hairpin turn. Herein, we present a rare case of PPOA type 4 with a fusiform aneurysm at the hairpin turn segment in a 46-year-old female with occasional headaches. Time-of-flight MR angiography and transfemoral cerebral angiography revealed an unusual branch arising from the left A1 segment, running anteromedially along the ipsilateral olfactory tract, and turning the hairpin posterior to the olfactory bulb. This branch continued into the left accessory middle cerebral artery, and a fusiform aneurysm was observed at the hairpin segment. No further treatment was performed, and follow-up imaging was recommended. Nevertheless, it is essential to recognize and diagnose these rare variations.

• Journal of Korean Neurosurgical Society
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• v.29 no.4
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• pp.451-460
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• 2000

Objective : This experiment is aimed at clarifying the characteristics of spasmodic basilar arteries in the rabbits of subarachnoid hemorrhage(SAH) with observation of vascular response to nitric oxide(NO) and endothelin-1. Material and Methods : Seventy-nine New Zealand white rabbits were divided into 4 groups : control(n=17), sham operation(n=13), postictal-2-day(n=25), and postictal-7-day group(n=24). Rabbits in the postictal-2-day group and postictal-7-day group underwent transfemoral vertebral angiography 2 days and 7 days after SAH respectively. A vascular ring of spasmodic basilar artery was harvested and suspended in organ chamber($37^{\circ}C$) to observe isometric tension changes in response to NO and endothelin-1 under both high(95% $O_2$/5% $CO_2$) and low(95% $N_2$/5% $CO_2$) $O_2$ tension. To investigate the vascular response to NO, acetylcholine from $10^{-7}M$ to $3{\times}10^{-4}M$ concentration was applied to basilar artery ring precontracted with histamine $10^{-6}-10^{-5}M$ in the organ chamber. The vascular response to endothelin-1 was observed by applying endothelin-1 from $10^{-11}M$ to $3{\times}10^{-8}M$ concentration into organ chamber. Results : Seven of 15 live rabbits which underwent angiography 2 days after SAH, were confirmed to develop vasospasm($64.3{\pm}11.2%$) whereas seven of 13 live rabbits which underwent angiography 7 days after SAH, were confirmed to develop vasospasm($64.9{\pm}10.9%$). In all groups, hypoxia significantly reduced the vascular relaxation of basilar arteries to NO. However, hypoxia made no influence on the vascular contraction of basilar arteries to endothelin-1 in all groups. In vascular relaxation of basilar arteries to NO under high $O_2$ tension between groups, the maximum relaxation of basilar arteries in the postictal-7-day group was significantly reduced compared to the postictal-2-day group. In vascular contraction of basilar arteries to endothelin-1 under high $O_2$ tension between groups, the maximum contraction of basilar arteries in the postictal-7-day group was significantly reduced compared to the postictal-2-day group. Conclusions : This experiment suggests that the characteristics of vascular response to NO and endothelin-1 in the spasmodic basilar arteries of rabbits observed 2 days after SAH is different from those observed 7 days after SAH.