ELECTRIC INJURY--IMAGING OF THERMAL/NON-THERMAL ASPECTS

高能电伤仍然是职业伤害和残疾的主要原因。尽管如此，由于有关其病理生理学的悬而未决的问题，治疗方面的主要进展一直进展缓慢。我们在实验室的研究表明，组织损伤的生物物理机制比之前认为的更复杂，即可能涉及热机制和直接电机制，并且它们的相对贡献高度依赖于电流通过的时间。骨骼肌和神经细胞最容易受到细胞膜损伤(电穿孔和电构象蛋白变性)的直接电机制的影响。我们随后的报告表明，使用生物相容表面活性物质可以恢复被直接电机制损伤的组织的生存能力，而热损伤(烧伤)组织需要手术切除。本项目涉及的一个基本需求是确定组织损伤的热机制与电机制在职业性电创伤特征的一系列暴露中的相对贡献。这项拟议的项目将通过将组织分别暴露在与60赫兹电创伤相同的热应力和电应力中来实现这一点。第二个基本需求是开发一种用于电损伤诊断的成像方法。我们建议改进磁共振成像(MRI)分析序列，使其能够根据组织蛋白质变性的程度来区分热损伤和纯电损伤组织。这种诊断工具将具有巨大的临床价值，因为快速检测、识别和定位组织损伤将加速和指导临床处理。虽然这些方法对于最优的电击伤处理是必不可少的，但对于评估新的医疗疗法以及评估纯热(热和冷)损伤也具有实用的临床价值。

High-energy electrical trauma remains a major cause of occupational injury and disability. Nonetheless, major advances in therapy have been slow to develop because of the unresolved questions regarding its pathophysiology. We have shown in laboratory studies that the biophysical mechanisms of tissue injury are more complex than previously thought, that is, both thermal and direct electrical mechanisms are likely to be involved, and their relative contribution is highly dependent on the duration of electrical current passage. Skeletal muscle and nerve cells are the most vulnerable to direct electrical mechanisms of cellular membrane damage (electroporation and electroconformational protein denaturation). Our subsequent reports indicate that it may by possible to restore viability to tissues injured by direct electrical mechanisms using biocompatible surfactants, whereas thermally injured (burned) tissue requires surgical excision. One essential need addressed in this project is to determine the relative contribution of thermal versus electrical mechanisms of tissue injury over a range of exposures characteristic of occupational electrical trauma. The proposed project would accomplish this by separately exposing tissue to the equivalent thermal and electrical stresses involved in a 60 Hz electrical trauma. A second essential need is to develop an imaging method for electrical injury diagnosis. We propose to refine magnetic resonance imaging (MRI) analysis sequences, useable on common hospital MRI machines, which can distinguish heat-damaged from pure electrical-damaged tissue on the basis of extent of tissue protein denaturation. Such a diagnostic tool would be of tremendous clinical value because rapid detection, discrimination and localization of tissue injury would accelerate and guide clinical management. Although essential for optimal electrical injury management, these methods would also be of practical clinical value for assessment of new medical therapies as well as valuable for pure thermal (hot and cold) injury evaluation.