CHRONIC HEAT EFFECTS ON TISSUE AND BLOOD INTERFACES

散热及其对组织和血液界面的影响是 与发展和增加使用有关的共同问题 全人工心脏（TAH）和许多心脏辅助设备。 本研究的目的是调查 对组织和血液表面相互作用的慢性加热。 阐明器械/组织的热反应机制， 血液/表面界面将允许建立 这些器件的热设计标准。我们之前的工作 表明肺和肌肉可以适应慢性热， 温度低于临界值。在组织 调整后，热通量耗散的上限为0.08 W/cm 2 对于肺和0.06 W/cm 2肌肉对应于最大值 地表温度43摄氏度。形态学和 免疫组织化学分析表明， 显著的血管生成和耐热性的发展， 加热的纸巾下一步是确定 适应在组织和细胞水平。此外，委员会认为， 因为大多数TAH和心脏辅助设备将热量耗散到 通过泵表面的血液，热对血液的影响- 必须研究表面相互作用。具体目标是 建议方案如下：（1）调查的影响， 热对血液和组织耐热性的发展 修复细胞。体外试验将用于识别热 正常功能的限值，并表征耐热性 发生在细胞中。(2)为了阐明 组织适应慢性加热。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 在整个加热的组织中。(3)To研究高温对 急性和慢性血液表面相互作用，使用离体和体内 体内研究，分别。体外实验的数学模型 体内和体内系统将被开发，以帮助设计 实验，解释数据，阐明机制， 在未评估的条件下预测响应 实验性的

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.