| Project/Area Number |
11558110
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 展開研究 |
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| Research Field |
Biomedical engineering/Biological material science
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| Research Institution | Kagawa University |
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Principal Investigator |
SENDA Shoichi Kagawa University, Medical Hospital, Professor, 医学部附属病院, 教授 (30145049)
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| Co-Investigator(Kenkyū-buntansha) |
MIZEUSHIGE Katsufumi Kagawa University, FACULTY OF MEDICINE, Associate Professor, 医学部, 助教授 (90166009)
KOSAKA Hiroaki Kagawa University, FACULTY OF MEDICINE, Professor, 医学部, 教授 (60158897)
MAETA Hajime Kagawa University, FACULTY OF MEDICINE, Professor, 医学部, 教授 (00075508)
OMORI Koji Kagawa University, Medical Hospital, Assistant Professor, 医学部附属病院, 講師 (00263913)
阪本 整司 香川医科大学, 医学部・附属病院, 講師 (60253267)
松尾 裕英 香川医科大学, 医学部, 教授 (90028514)
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| Project Period (FY) |
1999 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥13,400,000 (Direct Cost: ¥13,400,000)
Fiscal Year 2001: ¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 2000: ¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 1999: ¥8,300,000 (Direct Cost: ¥8,300,000)
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| Keywords | Doppler ultrasound / Pulse wave velocity / Cross correlation / Propagation velocity / Atheroscrerosis / Vasodilation / 脈波速度 / 局所脈波速度 |
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| Research Abstract |
We propose a new method for local -measurement of the propagation velocity of a pulse wave for the quantitative evaluation of severity of atherosclerosis. This method uses a complex cross correlation of Doppler signals and, theoretically, has the potential for precise estimation of the propagation time of a pulse wave of less than 1 millisecond. Doppler signals shifted by blood flow are detected at two adjacent locations on the artery using the simultaneous two-gate pulsed Doppler method, stored in a computer, and then analyzed by cross correlation. Time delay at maximum correlation output gives propagation time of the pulse wave. The pulse wave velocity is calculated as the ratio between the distance separating the two transducers and the time delay. In an experimental study using a pulsatile. flow circuit model, regardless of sampling distance and flow velocity profile, there was little fluctuation in calculated pulse wave velocity. Practical velocity resolution. of this method was e
… More
stimated to be less than 2 m/sec, which is sufficient accuracy for measurement of local pulse wave velocity (LPWV) over a 2 cm distance. In a study in vivo of healthy volunteer, LPWV was faster in the femoral artery (6.4±0.8 m/sec) than in the carotid artery (4.8±0.5 m/sec) and abdominal aorta (4.0±0.5 m/sec).
A new ultrasound system measuring LPWV has been developed, which can detect LPWV at 2 close points. The system is used to assess :1.LPWV foot-to-foot along abdominal aorta of normal and hypercholesterolemic rabbits. 2.Vascular responses to acetylcholine in conditions of inhibition of NO synthesis by L-NAME and augmentation of NO synthesis by L-NAME and L-arginine Results : (1)LPWV increases from proximal to distal along abdominal aorta of normal and hypercholesterolemic rabbits. In corresponding region, LPWV in hypercholesterolemic rabbits is higher than in normal ones, despite different sample distances. (2)L-NAME inhibits vascular relaxation to acetylcholine (Ach), Concurrent administration of L-arginine and L-NAME restores relaxation to Ach in normal rabbits, L-NAME attenuates relaxation to acetylcholine (Ach), L-arginine along with L-NAME slightly reverses relaxation to acetylcholine in hypercholesterolemic rabbits. (3)Plasma cyclic GMP is unchanged in situations of L-NAME alone or L-arginine plus L-NAME in normal and hypercholesterolemic rabbits. Conclusion : The new system is non-invasive and easy to be operated and can detect LPWV alterations, so it is worth being used to assess local vascular alteration Less
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