CHRONIC HEAT EFFECTS ON TISSUE AND BLOOD INTERFACES

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 总人工心脏(TAHS)和许多心脏辅助设备。 这项研究的目的是调查 对组织和血液表面相互作用的慢性加热。 阐明设备/组织和组织的热响应机制 血液/体表界面将允许建立 这些设备的热设计标准。我们之前的工作是 表明肺和肌肉可以适应长期的高温，只要 温度低于临界值。在组织有了 经调整，热流耗散上限为0.08W/cm2 肺和肌肉分别为0.06 W/cm2和0.06 W/cm2 表面温度为43摄氏度。形态测量学和 免疫组织化学分析表明发生了 显著的血管生成和耐热性的发展 加热过的纸巾。下一步是确定 在组织和细胞水平上的适应。此外， 因为大多数Tahs和心脏辅助设备会将热量散失到 血液通过泵表面，热对血液的影响- 必须研究表面相互作用。这样做的具体目的是 建议方案如下：(L)调查影响 热对血液和组织耐热性发展的影响 修复细胞。体外试验将被用来鉴定热能 正规函数的极限及其热容差的刻画 发生在细胞中的。(2)阐明 组织能适应长期的加热。体内研究将被用于 获取组织温度和时间的空间和时间变化 将这些与相应的细胞变化联系起来 在加热的组织中。(3)研究高温对环境的影响 使用体外和体内的急慢性血液-表面相互作用 活体研究。体外培养的数学模型，例如 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，以及 预测未评估条件下的响应 试验性的。

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.