| Project/Area Number |
11671333
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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 |
Thoracic surgery
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| Research Institution | OITA MEDICAL UNIVERSITY |
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Principal Investigator |
MIYAMOTO Shinji OITA MEDICAL UNIVERSITY, MEDICAL SCHOOL, ASSOCIATE PROFESSOR, 医学部, 助教授 (70253797)
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| Co-Investigator(Kenkyū-buntansha) |
ANAI Hirofumi OITA MEDICAL UNIVERSITY, MEDICAL SCHOOL, INSTRUCTOR, 医学部, 助手 (20291544)
SHIGEMITSU Osamu OITA MEDICAL UNIVERSITY, MEDICAL SCHOOL, ASSOCIATE PROFESSOR, 医学部, 助教授 (40215968)
HADAMA Tetsuo OITA MEDICAL UNIVERSITY, MEDICAL SCHOOL, PROFESSOR, 医学部, 教授 (00145377)
SAKO Hidenori OITA MEDICAL UNIVERSITY, MEDICAL SCHOOL, INSTRUCTOR, 医学部, 助手 (20315344)
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| Project Period (FY) |
1999 – 2000
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| Project Status |
Completed (Fiscal Year 2000)
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| Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 2000: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1999: ¥900,000 (Direct Cost: ¥900,000)
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| Keywords | platelet spontaneous aggregation / platelet microaggregation / profound hypothermia / 血小板微少凝集 / 超低体温体外循環 / ヘパリン |
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| Research Abstract |
Objective of this research is to study mechanism of bleeding tendency during profound hypothermia (PH) on thoracic aneurysm operation highlighting platelet injury. In vitro experiments, 60 minutes incubation at 4℃ caused no spontaneous aggregation in PRP (platelet rich plasma) without heparin, whereas spontaneous aggregation was observed when it was supplemented with heparin (4u/ml). PRP supplemented with heparin showed small amount of spontaneous aggregation at 10℃ not at 20℃ nor 30℃. In both moderate and PH cardiopulmonary bypass (CPB) cases, 3×10^<-6>mol/L of ADP (adenosine diphosphate) caused platelet micro aggregation (PMA) before heparin administration and 3.9×10^<-7> mol/L of ADP could cause PMA after systemic heparinazation. PH CPB reduced platelet activity (3×10^<-6> mol/L of ADP was not enough to cause micro aggregation) as time went more than moderate hypothermic CPB did. Although particles like spontaneous aggregation were observed 60 minutes after PH was established, it was hard to distinguish them from debris in plasma. In extracorporeal circuit model experiment with blood not containing any cells other than platelets, platelet aggregability was attenuated as time passed. After cooling platelets rapidly lost its activity. However, spontaneous aggregation was not observed even under PH condition. Therefore, bleeding tendency in operations is probably due to reduction of platelet aggregability not due to platelet consumption caused by PH.
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