Budget Amount *help |
¥2,300,000 (Direct Cost: ¥2,300,000)
Fiscal Year 1987: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1986: ¥1,600,000 (Direct Cost: ¥1,600,000)
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Research Abstract |
Biomaterials which are used in artificial organs, plasmapheresis and catheters could increase the concentrations of bioactive substances in plasma by contact with blood. Although many authors have been referred to the issues, investigations about the pathophysiological effects of these phenomena are very few. The purpose of this study is not only to evaluate the changes of bioactive substances, but also to elucidate the effects of them on the functions of blood cells and clinical findings of patients. 1. Changes in plasma bioactive substances. Activated fractions of complement, prostaglandins, thromboxanes and leucotrienes are increased by the contact with biomaterials. The magnitude of these increases differs with the type of membrane materials and also therapeutic modes. In general, celllulosic materials are associated with more increase as compared to synthetic materials. 2. Effects on blood cells. Changes in leucocyte count, superoxide generation of neutrophiles, complement-recepto
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rs and subsets of lymphocyte were observed associated with complement activation. Changes in platelet count and platelet-releasing factors were also observed, but independent to the complement activation, indicating the direct effects if blood-membrane contact. 3. Clinical evaluations. The effects of complement activation on clinical findings of hemodialysis patients were evaluated by the double blind, crossover protocol with complement-activating and non-activating membranes. The 3 month observations on 28 patients revealed that the incidence or severity of dialysis-assoiated syndrome, decrease of arterial oxygen pressure or changes of <bet>_2 -microglobulin were not different between two groups. Conclusion: The blood-biomaterial contact could affect plasma bioactive substances. The magnitude and pattern of the changes differ with the type of materials and therapeutic modes. The effects on the physiological functions of patients were investigated, and the short-term effects on blood cells were confirmed. However, the effects of complement activation on clinical findings could not be demonstrated in either short-term or long-term observation. Less
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