| Project/Area Number |
02670626
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Cerebral neurosurgery
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| Research Institution | Kyoto Universiyt |
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Principal Investigator |
HASHIMOTO M. D. Nobuo Kyoto University, Faculty of Medicine, Instructor, 医学部, 講師 (40135570)
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| Project Period (FY) |
1990 – 1991
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| Project Status |
Completed (Fiscal Year 1991)
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| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1991: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1990: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Keywords | cerebral aneurysm / endothelium / rheology / growth factor / experimental cerebral aneurysm / 脈動脈瘤 / 実験的脈動脈瘤 / 実験的動脈瘤 / レオロジ- |
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| Research Abstract |
Cerebral arterial bifurcations in rats were treated to induce cerebral aneurysms experimentally, and flow patterns of latex particles introduced under a constant flow rate were analyzed with a 16-mm cine-camera and videocassette recorder. Small particles tended to accumulate at the region just distal to the apical intimal pad, where the initial aneurysmal changes are known to occur. In the bifurcation with shallow invaginations, a marked pressure gradient was present at the proximal end of the aneurysm orifice. A tendency for stagnation of small particles near the aneurysm wall was also observed. The wall shear stress was highest at the distal end of the aneurysmal orifice, which may be responsible for the development of these lesions.
In vivo flow visualization of cerebral arterial bifurcations was also done by introducing fluorescent particles intravenously under the fluorescence microscope. Flow studies in the cerebral arterial bifurcations with small aneurysms showed that there were spiral flows proximal and distal to the bifurcation. This indicateds turbulance of flow, which was caused by the change of geometry of the arterial bifurcation with the development of a small aneurysm. This vicious cycle may be responisible for the development of cerebral aneurysms.
To elucidate the mitogenicity of endothelial cells, which is related to the formation of aneurysms, the activities of growth factors were compared between those in normotensive and spontaneously hypertensive rats. The conditioned medium of cultured endothelial cells from aorta and cellular extract were analyzed with western blotting method. Endothelial cells of hypertensive rats secreted PDGF more than those of normotensive rats. Basic FGF-like activity was also seen in the extract of these cells.
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