| Project/Area Number |
09670758
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Circulatory organs internal medicine
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| Research Institution | Jikei University School of Medicine |
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Principal Investigator |
FURUHATA Hiroshi Jikei Univ.Sch.of Med.Assosiate Prof., 医学部, 助教授 (70056985)
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| Co-Investigator(Kenkyū-buntansha) |
WATANABE Hisayuki Jikei Univ.Sch.of Med.Lecturer, 医学部, 講師 (80192441)
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| Project Period (FY) |
1997 – 1998
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| Project Status |
Completed (Fiscal Year 1998)
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| Budget Amount *help |
¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 1998: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 1997: ¥2,500,000 (Direct Cost: ¥2,500,000)
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| Keywords | thrombolysis / ultrasound / thrombolysis drug / thrombus / 血管再開通術 / 血栓 |
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| Research Abstract |
[Purpose] The early recanalization of the thrombosis at deeply-located arteries are very usefull for good prognoses of ischmic organs such as the acute myocardiac infarction, the ischemic stroke and so on. We developed a new thrombolytic method combined with thrombolysis drug and ultrasonic irradiation. Particularly we actualized an ultrasonic equipment capable for clinical uses. The safty of ultrasonic beam was examined in in-vitro experiments. Simultaneously the effectiveness was tested for old clots.
[Method] We made an ultrasonic irradiation equipment which could control the following factors ; power level 0-1W/cm^2, pulse waveform, intermittent time and frequuency (200, 300, 500, l000KHz). The intensity distribution of ultrasonic beam was simulated by a computer simulation software and was actually measured in the meet by a needle type thermister. As a thrombus in a deeply-located artery, we examined thrombolysis in ischemic animal models for the coronary thrombosis and old thrombosis in the brain by using urokimase and ultrasonic irradiation.
[Results] (l)The thermal spot showing more than 3ﾟC could not exist in the beam in meets inspite of that the computer simulation indicated high intensity spots. (2)The recanalization in accute myocardial infarction animal model were 32min. at the mean in our method using 200KHz. (3)Our combined method was effective to the old thrombus in 200 and 300KHz, even if the ultrasonic beam would be penetrated through the temporal bone.
[Conclusion] The combined thrombolytic method using ultrasound 0.25W/cm^2 at 200 or 300KHZ was quite useful for the early recanalization of thomboses in deeply-located arteries. Our fundamental experimental data suggested that this method would become a high potential approach to treat ischenic organs.
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