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H Kikuchi

Publications and source records attributed to H Kikuchi.

At least 703 records · Page 39Linked to original sources
PubMed1988

[Problems in the embolization therapy of spinal arteriovenous malformation].

Six cases with spinal arteriovenous malformation refractory to repetitive embolization therapy were reported. In these, de novo feeding arteries appeared after the emboli obliterated the proximal portion of the blood feeding system. Though the malformation disappeared after the embolization therapy in the angiograms of the original feeding arteries, the lesion was visualized in the follow-up angiogram from different segmental arteries via various collaterals. Through angiographic evaluation and magnetic resonance imaging were necessary to point out the "false angiographic disappearance" of the spinal arteriovenous malformation after the embolization therapy.

Adolescent↗
PubMed1988

[A case of chondroblastoma with intracranial extension].

A case of chondroblastoma with intracranial extension from middle cranial base is reported here. Chondroblastomas usually arise from the epiphysis of long bone. Intracranial chondroblastomas are very rare and only 14 cases have been reported. Histological feature of this tumor is to have numerous multinucleated giant cells resembling the giant-cell tumor. But this case has the typical features of chondroblastoma in the histological, immunohistochemical, and electron microscopical studies.

Adult↗
PubMed1988

[Effects of bifemelane on the free fatty acid levels during ischemia].

Using the four-vessel extracranial one staged occlusion model of adult Wistar rats, we analyzed quantitatively released free fatty acids during ischemia. Also have we analyzed the effect of bifemelane to reduce free fatty acid accumulation after the onset of ischemia. Bifemelane (15 mg/kg, 30 mg/kg) and saline as control were intraperitoneally administered to adult Wistar rat prior to 30 minutes of experimentally induced ischemia. The results obtained were analyzed by one or two way analysis of variance (ANOVA). Physiological variables (systemic arterial pressure, PaO2, PaCO2, pH) did not change significantly in all four experimental groups. Total free fatty acid levels (sum of 5 fatty acid) increased significantly after ischemia (30 minutes). Higher dose (30 mg/kg) of bifemelane administration significantly reduced total free fatty acid accumulation, though lower dose (15 mg/kg) did have no effect. Bifemelane (30 mg/kg) reduced significant accumulation in the amount of saturated and monounsaturated fatty acid (palmitic acid [16:0], stearic acid [18:0] and oleic acid [18:1]). Arachidonic (20:4) and docosahexaenoic (22:6) acid failed to show any effective reduction by bifemelane pre-treatment of lower nor higher dose. Bifemelane is supposed to have many pharmacological effects such as increase in cerebral blood flow, augmentation of glucose uptake, monoamine metabolism, cerebral vasodilatation and platelet antiaggregation. Free fatty acid accumulation is effectively suppressed by the higher dose of bifemelane administration. Although the exact mechanism are not clearly identified by the result obtained in this experiment, selective inhibition of accumulation in saturated and monounsaturated fatty acids by bifemelane pretreatment may be obtained by the improvement of energy metabolism, which may help to reacylation of fatty acid into phospholipid.

Animals↗
PubMed1988

[Experimental hemodynamic study on carotid ligation combined with EC-IC bypass for giant aneurysm].

Although carotid ligation or balloon occlusion has been an accepted method for the inaccessible ICA aneurysm, there have been several reports of growth or rupture of the aneurysm, and cerebral embolism originating from the site of arterial occlusion or from the aneurysm. The hemodynamic changes after operation are suspected to play some role in these events. It is, therefore, very important to predict what will happen after operation in individual patients. However, it is usually difficult because multiple factors are related in a complex fashion in a living body. One of the effective means is to simulate these hemodynamic conditions by a hydraulic vascular model. We have already reported the hemodynamic changes resulting from EC-IC bypass for MCA stenosis. In this research, a glass-model aneurysm of 2.5 cm in diameter is placed at the ICA bifurcation of the model to evaluate hemodynamics after therapeutic carotid occlusion with or without EC-IC bypass. Dye was injected into the aneurysm and intensity change of the light transmitted there was measured by a photocell. Half-life of the dye was calculated from thus obtained clearance curve and was regarded as an index of intraaneurysmal stagnation, while embolus formation in an aneurysm is considered to be due to the stagnation there. The results obtained are: 1. Half-life of the dye increases significantly after carotid ligation even if collateral flow through the anterior communicating artery (A-com) or EC-IC bypass equals the ICA flow before ligation. 2. The higher collateral flow through A-com results in the more normograde flow in M1 portion, which shortens the half-life.(ABSTRACT TRUNCATED AT 250 WORDS)

Carotid Arteries↗
PubMed1988

[Experimental simulation study on EC-IC bypass--Part 1: Optimum conditions for bypass on the basis of hydraulic and theoretical models with autoregulation mechanism].

There have been several reports about unexpected occlusive change of stenotic lesion in the internal carotid artery (ICA) or middle cerebral artery (MCA) following bypass surgery, rupture or formation of an aneurysm after carotid ligation and ICA EC-IC bypass for the treatment of inaccessible ICA aneurysm. These suggest that operation for one vessel causes hemodynamic changes in others, not only near the operation site but in remote sites. Although complete hemodynamic analysis in the brain and quantitative speculation of the possible effect of a cerebrovascular operation are essential to prevent these complications, these measures are usually very difficult to carry out because multiple factors are related mutually in complex fashion in a living body. One effective means to simulate these changes would be the use of a vascular model. A hydraulic model of unilateral ICA stenosis (resistance of stenosis: R) with EC-IC bypass (resistance of bypass: Rby) has been manufactured with silicone and glass tubes. Peripheral vascular resistance (Rp) is adjusted to obtain an arterial flow of 180 ml/min at poststenotic pressures of 60, 70, 80, 90, and 100 mmHg. To simulate the autoregulation mechanism, appropriate Rp is selected for each combination of R and Rby so as to make, as far as possible, a hemispheric flow (sum of stenosis flow and bypass flow) of 180 ml/min. The Rp with the lowest value (60/180 mmHg/ml/min) is to be chosen in flow conditions of lower than 180 ml/min, where autoregulation is no longer functioning. Twelve kinds of stenosis segments with an inner diameter from 0.37 to 2.59 mm are prepared and used in the models.(ABSTRACT TRUNCATED AT 250 WORDS)

Cerebral Revascularization↗
PubMed1988

[Cerebral circulation and oxygen metabolism in children's "moyamoya" diseases].

Regional (r) CBF, rOEF, rCMRO2, rCBV in five cases of "moyamoya" disease in children were studied with PET scan, using 15O steady-state methods. All cases showed ischemic symptoms such as TIA, RIND and minor stroke. Intervals from the latest ictus to PET ranged from 3 days to 3 years 6 months. Control data were obtained through PET studies in 8 normal volunteers. Physiological parameters described above, in cerebral gray matter, white matter and basal ganglia were calculated and were carefully compared with normal control. Apparently low density area in X-ray CT were excluded from this analysis. Although rCBF showed a little bit higher value in all gray, white and basal ganglia, it was not statistically significant. rCBV of "moyamoya" disease significantly increased in gray, white and basal ganglia. The calculated value of CBF/CBV is considered to be an index of perfusion pressure and is the reversed value of transit time. This value was significantly decreased in "moyamoya" disease in every three region. Under the normal autoregulation, further decrease of perfusion pressure initiate increase of rOER and also decrease of rCBF. In spite of reduction of CBF/CBV, rOER was not significantly increased in every three region. Hence the cerebral circulation in children's "moyamoya" disease of ischemic type appears to be characterized by the mild decrease of perfusion pressure, dilated resistant vessels and prolonged circulation time.

Adolescent↗
PubMed1988

[A case of tentorial cavernous angioma].

A case of tentorial cavernous angioma is reported. A 61-year-old woman was admitted because of left auditory disturbance and left hemifacial spasm. CT scan and angiography, MRI revealed a dumb-bell typed tumor extended above and below the left tentorium cerebelli. Under the preoperative diagnosis of tentorial meningioma, a craniotomy was performed and the tumor was removed totally with minimal bleeding by left subtemporal approach. The tumor was well capsulated and spongy, attached to the tentorium cerebelli. Histologically, the tumor had many various vascular cavities with the wall lined with a single layer of endothelial cell, had neither glial cell nor meningeal cells. Some of cavities were thrombosed. Pathological diagnosis was a cavernous angioma. We discussed the characters of this rare tumor with a review of 4 cases.

Cerebellar Neoplasms↗
PubMed1988

[An experimental study on SRCA (subrenal capsule assay)--comparison of the test between normal and nude mice].

Six-day SRCA using normal mice developed by Bogden et al. is a promising in vivo chemosensitivity test. However, this method has a problem on the influence of the host reaction. We compared the tumor growth kinetics and host reaction between normal and nude mice. The tumor diameter increased until day 6 in normal and day 16 in nude mice, but the histological finding revealed many host reactive cells and few viable tumour cells on day 6 in normal mice, and well preserved tumour cells on day 16 in nude mice. These results were supported by flow cytometrical analysis. Autoradiogram using 3H-TdR showed a recovery of labeling index to the steady label by day 1. This index was similar between normal and nude mice. When antitumor activity of adriamycin, cisplatin or mitomycin C was compared with nude mice system, the order of effectiveness was the same as the system using nude mice implanted tumor cells subcutaneously and given the drugs intraperitoneally, but different in normal mice.

Adenocarcinoma↗
PubMed1988

[Experimental simulation study on hemodynamics in multiple cerebral arterial stenoses and EC-IC bypass].

In recent years, unilateral or bilateral multiple stenoses in the internal carotid artery have been increasing in number. Full understanding and complete analysis of these hemodynamics are, however, sometimes difficult because multiple factors such as number, size and location of the stenotic lesions, and capacity of collateral circulation differ with individual cases and are related mutually in complex fashions. One of the effective means to solve these problems is to study the hemodynamics and to simulate their changes after an expected operative procedure by the use of a hydraulic vascular model, where any factor can be managed independently. A vascular model of the internal carotid artery (ICA) has been manufactured with silicone and glass tubes in similar dimensions to averaged adults. Peripheral vascular resistance (Rp) is so adjusted as to obtain an arterial flow of 180 ml/min at an intraluminal pressure of 60 mmHg. Four kinds of stenosis segments, Ra (2.59 mm in diameter), Rb (1.94 mm), Rc (1.12 mm) and Rd (0.84 mm) are prepared and used in various models simulating unilateral multiple stenoses, unilateral solitary long stenosis and bilateral multiple stenosis. The results obtained are; 1. In case of two stenoses of different degree arranged in series, advanced one was found to have a dominant effect on flow reduction. This implies that only its removal can results in good augmentation of flow in unilateral multiple stenoses of the ICA. 2. In case of more than three stenoses of the some degree arranged in series, increase in flow can not be obtained until the last one is cleared.(ABSTRACT TRUNCATED AT 250 WORDS)

Brain Ischemia↗
PubMed1988

[Spontaneous hematomyelia properly diagnosed with magnetic resonance imaging].

A case of spontaneous hematomyelia with symptoms localized to the C 5-6 level is presented. Myelography and metrizamide CT scan failed to demonstrate the lesion, while magnetic resonance imaging clearly revealed a small intramedullary mass in the ventral portion of C 3-4. Subsequent intensity changes over four weeks indicated the lesion to be hematoma. The patient was successfully treated through an anterior approach.

Adult↗
PubMed1988

[Experimental simulation study on cerebral hemodynamics--Part 2: Bilateral severe internal carotid arterial stenosis and theoretical study].

Although cerebrovascular surgery, typically bypass procedure for example, is considered to change hemodynamics not only near the region but in remote sites, their quantitative speculation and evaluation are usually difficult because of mutually related multiple factors in a living body. One of the effective means is to stimulate expected operative procedures and resulting changes by use of a hydraulic vascular model. We have already reported the hemodynamics in bilateral moderate ICA stenosis and their changes after EC-IC bypass. In this research, vascular model of bilateral severe ICA stenosis has been manufactured with silicon and glass tubes. Peripheral vascular resistance (Rp) is so adjusted as to obtain an arterial flow of 180 ml/min at an intraluminal pressure of 60 mmHg. Four kinds of stenosis segments, Ra (2.59 mm in diameter), Rb (1.94 mm), Rc (1.12 mm) and Rd (0.84 mm) are prepared and used in the models. In addition, theoretical study was performed in an unilateral ICA stenosis to evaluate quantitatively and extensively the effects of stenosis and cut bypass flow on the ICA flow and bypass flow. The results obtained are as follows: 1. Under marked low flow conditions from 55% to 30% of normal value simulated in this study, collateral flow from the opposite ICA has reached the maximum and therefore its increase is no more expected against the advance of the stenosis. 2. Both increase of the hemispheric flow and decrease of the carotid flow were still observed after EC-IC bypass procedures.(ABSTRACT TRUNCATED AT 250 WORDS)

Carotid Artery Diseases↗