• 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.

• Advances in Traditional Medicine
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• v.2 no.2
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• pp.87-93
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• 2002

The present study was aimed to examine the role of endothelium in the relaxant effect of hawthorn fruit extract of Crataegus pinnatifida in four different types of rat arteries, posterior cerebral communicating artery, right descending coronary artery, common carotid artery, and aorta. In $9,11-dideoxy-11{\alpha}$, $9{\alpha}-epoxy-methanoprostaglandin$ $F_{2{\alpha}}$ (U46619)-preconstricted arterial rings except for aorta, the extract produced endothelium-independent relaxations with similar potency. This relaxation was unaffected by pretreatment with $100\;{\mu}M\;N^G-nitro-L-arginine$ methylester (L-NAME, the nitric oxide synthase inhibitor), $3\;{\mu}M$ 1H-[l,2,4]oxadiazolo$[4,2-{\alpha}]$quinoxalin-1-one (ODQ, the guanylate cyclase inhibitor), or $10\;{\mu}M$ indomethacin (the cyclooxygenase inhibitor). Putative $K^+$ channel blockers (charybdotoxin plus apamin or glibenclamide) did not affect the extract-induced relaxation in cerebral or coronary artery rings. In contrast, in rat aortic rings the extract produced significantly smaller relaxant response in endothelium-denuded rings than that in endothelium-intact rings. Pretreatment with L-NAME or ODQ abolished the extractinduced endothelium-dependent aortic relaxation, whilst indomethacin $(3\;{\mu}M)$ had no effect. The present results indicate that hawthorn fruit extract possesses a vasorelaxing effect in cerebral, coronary and carotid arteries and this effect is independent of the presence of a functional endothelium. However, the extract-induced endothelium-dependent relaxation in rat aorta was mediated through endothelial nitric oxide and cyclic GMP-dependent mechanisms, suggesting that active components in the extract may act on endothelium to stimulate release of nitric oxide in large conduit arteries of the rats.

• Journal of Veterinary Science
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• v.24 no.5
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• pp.65.1-65.9
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• 2023

Background: Bone subtraction computed tomography angiography (BSCTA) is a useful alternative technique for improving visualization of vessels surrounded by skull bone. However, no studies have compared computed tomography angiography (CTA) and BSCTA for improving the visibility of canine cerebral blood vessels. Objectives: To evaluate the potential benefit of BSCTA for better delineation of brain arteries of the circle of Willis (CoW) in dogs by comparing BSCTA with non-subtraction computed tomography angiography (NSCTA). Methods: Brain CTA was performed for nine healthy beagle dogs using a bolus tracking method with saline flushing. A total dose of 600 mgI/kg of contrast agent with an iodine content of 370 mgI/mL was injected at a rate of 4 ml/s. Bone removal was achieved automatically by subtracting non-enhanced computed tomography (CT) data from contrast CT data. Five main intracranial arteries of the CoW were analyzed and graded on a scale of five for qualitative evaluation. Results: Scores of basilar artery, middle cerebral artery, and rostral cerebral artery in the BSCTA group were significantly higher than those in the NSCTA group (p = 0.001, p = 0.020, and p < 0.0001, respectively). Scores of rostral cerebellar artery (RcA) and caudal cerebral artery (CCA) did not differ significantly between the two groups. However, scores of RcA and CCA in the BSCTA group were higher than those in the NSCTA group. Conclusions: BSCTA improved visualization of intracranial arteries of the CoW with close contact to bone. Thus, it should be recommended as a routine scan method in dogs suspected of having brain vessel disease.

• Journal of Korean Neurosurgical Society
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• v.42 no.4
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• pp.342-345
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• 2007

The azygos anterior cerebral artery, a rare anomaly in the circle of Willis in which only a single vessel supplies the medial aspects of both anterior cerebral hemispheres, is closely associated with saccular aneurysms. We present three cases of azygos anterior cerebral artery aneurysms among the 781 cerebral aneurysms surgically treated at our institution in an 11-year period. These three cases all involved elderly women who presented with subarachnoid hemorrhage. Conventional cerebral angiography and CT angiography revealed small saccular aneurysms at the distal ends of the azygos anterior cerebral arteries. These aneurysms were clipped successfully using a bifrontal interhemispheric approach. Hence, the pathogenesis of these particular aneurysms relating to hemodynamic change, associated anomalies, and surgical pitfalls is discussed with review of literature.

• Journal of Korean Neurosurgical Society
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• v.45 no.6
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• pp.394-396
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• 2009

Cerebral embolic infarction is the most common neurologic complication of cardiac myxoma (CM). Development of cerebral aneurysms in CM is very rare. We present a 64-year-old woman with acute cerebral infarction and multiple cerebral aneurysms complicated by CM. The aneurysms were multiple, fusiform-shaped, and located in distal branch of major cerebral arteries. The serum interleukin (IL)-6 was highly elevated, which was normalized after surgical resection of CM. There was no regression of aneurysms on follow-up neuroimaging. Multiple cerebral aneurysms in CM are rare condition. Highly elevated serum IL-6 may be associated with increased risk of cerebral aneurysmal formation.

• Journal of Korean Neurosurgical Society
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• v.39 no.6
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• pp.447-450
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• 2006

Cerebral amyloid angiopathy[CAA] is characterized by the deposition of amyloid ${\beta}-protein$ in the walls of small to medium-sized arteries of the leptomeninges and cerebral cortex. While often asymptomatic, CAA can develop into intracerebral hemorrhage facilitated by arterial hypertension. We report the case of a 52-year-old man with CAA and arterial hypertension who developed recurrent cerebral hemorrhages on three different occasions and in multiple non-overlapping loci over a period of nine years. Based on our findings, we recommend brain biopsies for all patients undergoing evacuation of multiple recurrence or atypical pattern intracerebral hemorrhages.

• Journal of Korean Neurosurgical Society
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• v.54 no.3
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• pp.239-242
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• 2013

Spontaneous bilateral cerebellar infarction in the territory of the superior cerebellar arteries is extremely rare. Occasionally there have been reports of bilateral cerebellar infarction due to vertebrobasilar atherosclerotic occlusion or stenosis, whereas no report of bilateral cerebellar infarction due to complicated hemodynamic changes. In this report, we present a patient with bilateral cerebral infarctions related to stenoses of bilateral internal carotid arteries, in whom vertebrobasilar system was supplied by multiple collaterals from both posterior communicating arteries and right external carotid artery. We performed stent-angioplasty of bilateral internal cerebral arterial stenosis, and then acute infarction developed on bilateral superior cerebellar artery territories. The authors assumed that the infarction occurred due to hemodynamic change between internal carotid artery and external carotid artery after stent-angioplasty for stenosis of right internal carotid artery.

• Journal of Chest Surgery
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• v.37 no.1
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• pp.88-91
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• 2004

Aortic regurgitation is not a rare complication of Takayasu's disease. Aortic regurgitation may aggravate cerebral ischemic syndrome like syncope in patients with stenotic or occlusive lesions in cerebral branches of aorta secondary to acute or progressive inflammation. In a 34-yrs-old male patient who complained of syncope and exertional dyspnea with occlusion of both carotid arteries and severe stenoses of both subclavian arteries, occlusion of right coronary artery, and aortic regurgitation, his symptom was improved with perioperative aggressive steroid therapy, stent insertion in both subclavian arteries, and aortic valve replacement.

• Annals of Clinical Neurophysiology
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• v.1 no.1
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• pp.55-59
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• 1999

Vasoconstriction of intracerebral arteries is the leading cause of delayed cerebral infarction and mortality following aneurysmal subarachnoid hemorrhage. Transcranial Doppler studies show and increase in the flow velocities of basal cerebral arteries, which usually start around day 4 following a subarachnoid hemorrhage, and peaking by days 7 to 14. Angiographic studies confirm the presence of at least some degree of MCA vasospasm when the flow velocities are higher than 100 cm/sec. Mean velocities in the 120 to 200 cm/sec range correspond to 25 to 50% luminal narrowing. MCA and ACA vsospasm is detected with around 90% specificity. Sensitivity is 80% and 50% respectively. A 200cm/sec threshold and rapid flow velocity increase exceeding 50 cm/sec on consecutive days, has been associated with subsequent infarction. Transcranial Doppler is also used to monitor the effects of endovascular treatment of vasospasm. Flow velocities decrease following successful angioplasty or papaverine infusion. Overall, transcranial Doppler studies are considered to have acceptable accuracy for the evaluation of vasospasm in aneurysmal subarachnoid hemorrhage, with limitations that have to be taken into consideration in the clinical setting.

• Anatomy and Cell Biology
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• v.56 no.4
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• pp.575-578
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• 2023

Anterior cerebral arteries are paired and supply the major portion of the medial surface of the brain. They are branches of the intracranial part of the internal carotid artery and form the anterior portion of the circle of Willis (CW) which is situated in the interpeduncular fossa. During routine dissection in the department of anatomy, All India Institute of Medical Sciences, Bibinagar, Hyderabad, a rare variation had been observed in the CW, azygos anterior cerebral artery associated with hypoplastic A1 fragment of the right anterior cerebral artery in a 63-year-old female cadaver. It is important to identify and study this kind of rare variation for surgeons, anatomists, and radiologists during dissection, surgical, radiological, and diagnostic interventions.