| Project/Area Number |
01870062
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| Research Category |
Grant-in-Aid for Developmental Scientific Research (B).
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| Allocation Type | Single-year Grants |
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| Research Field |
Cerebral neurosurgery
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| Research Institution | Tokyo Medical and Dental University |
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Principal Investigator |
HIRAKAWA Kimiyoshi Tokyo Medical and Dental University, School of Medicine, Professor, 医学部, 教授 (00010166)
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| Co-Investigator(Kenkyū-buntansha) |
AOYAGI Masaru Tokyo Medical and Dental University, School of Medicine, Instructor, 医学部, 講師 (40134704)
OHNO Kikuo Tokyo Medical and Dental University, School of Medicine, Instructor, 医学部, 講師 (50014238)
TSUYUMU Matsutaira Tokyo Medical and Dental University, School of Medicine, Instructor, 医学部, 講師 (50014345)
KATO Daisuke MITI, Electrotechnical Laboratory, Chief researcher, 光技術部, 主任 研究官
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| Project Period (FY) |
1989 – 1990
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| Project Status |
Completed (Fiscal Year 1990)
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| Budget Amount *help |
¥11,400,000 (Direct Cost: ¥11,400,000)
Fiscal Year 1990: ¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1989: ¥9,400,000 (Direct Cost: ¥9,400,000)
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| Keywords | Photoradiation / Brain tumor / Argon laser / In vitro study / Rat C_6 glioma model / brain tumor / argon laser |
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| Research Abstract |
We studied on the effect of photoradiation therapy (PRT) using the argon laser tuned to 514.5 nm in the in vitro model, the rat C_6 glioma model and clinical cases.
In the in vitro study, mechanisms of cell damage by PRT and the selective effect of PRT on tumor cells were investigated. It is suggested that the initial damage after PRT may occur to the cytoplasm, from observations of intracellular uptake of HpD and the effect of PRT on living cells, and from the findings obtained by transmission electronmicroscope. Although tumor cells were more sensitive to PRT than other functional cells, Cell damage of tumor appeared not to be highly selective to PRT. This study also supports the hypothesis that vascular damage of tumors is attributable to a specific reaction of tumor vessels to PRT, since normal endothelial cells are less sensitive to PRT than tumor cells.
From the study of the rat C_6 glioma model, it was concluded that the initial effects of PRT on tumors include both tumor cell damage and tumor vessel damage. Argon laser tuned to 514.5 nm at doses of 287 joules/cm^2 and 15 mg of HpD per kg produced tumor destruction ranging from 3 to 5mm in depth.
The clinical study suggested that PRT may produce necrosis of tumor cells, vascular congestions, and edematous change in the irradiated areas without significant elevation of local temperature. It seems, however, difficult to evaluate the effect of PRT and to draw conclusions concerning the efficacy of PRT, because the number of patients in this study is too small.
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