CHRONIC HEAT EFFECTS ON TISSUE AND BLOOD INTERFACES

组织和血液界面的慢性热效应

• 批准号: 2028476
• 负责人: HIROAKI HARASAKI
• 金额: $ 31.14万
• 依托单位: CLEVELAND CLINIC FOUNDATION
• 依托单位国家: 美国
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-04-01 至 2000-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2028476
• 关键词: biomaterial interface interaction; blood; blood coagulation; body temperature regulation; clinical research; cow; fibroblasts; heart prosthesis; heat; heat injury; human subject; hyperthermia; immunocytochemistry; implant; lymphocyte; mathematical model; monocyte; neutrophil; perfusion; platelets; surface property; vascular endothelium; wound healing

Heat dissipation and its effects on tissue and blood interfaces are common problems associated with the development and increased use of total artificial hearts (TAHs) and many cardiac assist devices. The objective of this research is to investigate the effects of chronic heating on tissues and on blood-surface interactions. Elucidating the mechanisms of heat responses at device/tissue and blood/surface interfaces will allow for the establishment of thermal design criteria for these devices. Our previous work has shown that lung and muscle can adapt to chronic heat provided that the temperature is below a critical value. After the tissues have adapted, the upper limit for heat-flux dissipation is 0.08 W/cm2 for lung and 0.06 W/cm2 for muscle corresponding to a maximum surface temperature of 43 degree Centigrade. Morphometric and immunohistochemical analyses indicated the occurrence of significant angiogenesis and the development of thermo-tolerance in heated tissues. The next step is to determine the mechanisms of adaptation at both the tissue and cellular levels. Furthermore, because most TAHs and cardiac assist devices dissipate heat into the blood through the pump surface, the effects of heat on blood- surface interactions must be studied. The specific aims of this proposed program are as follows: (l) To investigate the effects of heat on blood and on the development of thermo-tolerance in tissue repair cells. In vitro tests will be used to identify the thermal limits for normal function and to characterize the thermo-tolerance occurring in cells. (2) To elucidate the mechanisms by which the tissue adapts to chronic heating. In vivo studies will be used to obtain the spatial and temporal changes in tissue temperature and to correlate these with-the corresponding cellular changes throughout the heated tissue. (3)To examine the effects of heat on acute and chronic blood-surface interactions using ex vivo and in vivo studies, respectively. Mathematical models of the in vitro, ex vivo, and in vivo systems will be developed to help design experiments, interpret the data, elucidate the mechanisms, and predict responses under conditions that are not evaluated experimentally.

散热及其对组织和血液界面的影响 与开发和增加使用相关的常见问题 全人工心脏 (TAH) 和许多心脏辅助装置。 本研究的目的是调查以下因素的影响 组织和血液表面相互作用的慢性加热。 阐明设备/组织的热响应机制和 血液/表面界面将允许建立 这些设备的热设计标准。我们之前的工作有 研究表明，肺和肌肉可以适应慢性高温，前提是 温度低于临界值。组织完成后 经过调整，热通量耗散上限为 0.08 W/cm2 对于肺和 0.06 W/cm2 对于肌肉对应于最大 表面温度43摄氏度。形态测量和 免疫组织化学分析表明发生 显着的血管生成和耐热性的发展 加热的组织。下一步是确定机制 组织和细胞水平上的适应。此外， 因为大多数 TAH 和心脏辅助装置都会将热量散发到 血液通过泵表面，热量对血液的影响- 必须研究表面相互作用。本次活动的具体目标 拟议的计划如下： (l) 调查以下措施的影响： 血液中的热量和组织耐热性的发展 修复细胞。体外测试将用于识别热 正常功能的限制和耐热性的表征 发生在细胞中。 (2) 阐明其机制 组织适应长期加热。体内研究将用于 获得组织温度的空间和时间变化 将这些与相应的细胞变化联系起来 整个受热组织。 (3) 考察热效应 使用离体和体内的急性和慢性血液表面相互作用 分别进行体内研究。体外的数学模型 将开发体内和体内系统来帮助设计 实验，解释数据，阐明机制，以及 预测未评估条件下的响应 实验性地。