UNDERSTANDING VIBRATION INJURY

长期目标是了解振动综合征的细胞和分子机制，以便确定预防损伤的对策，并促进更安全地使用电动工具。本文介绍了一种新的振动损伤动物模型，利用大鼠的尾巴来研究短期和长期振动对特定组织的主要影响。一般认为振动损伤是神经和血管的联合损伤。具体的假设有：1。振动损伤开始于雪旺细胞和大髓鞘神经纤维的细胞骨架的破坏，使全身感觉和骨骼肌功能退化。与疼痛和血管舒缩调节有关的小神经纤维最初不受影响。2. 振动刺激血管痉挛。这导致平滑肌细胞肥大和增生以及内膜基质重组，最终导致慢性血管闭塞和缺血。3. 振动损伤破坏大神经元的轴浆运输。这通过阻断神经元和终末器官之间的营养相互作用加剧了损伤。检测最早的细胞类型响应振动将完成免疫染色与细胞类型特异性标记，立即早期基因蛋白（磷酸化c-jun）表达和增殖通过溴脱氧尿苷掺入。采用电子显微镜分析原发性超微结构损伤。通过测量尾皮温度，血流量，对有毒和触觉刺激的反射消退，复合神经动作电位记录，以及神经元的逆行标记来评估功能变化。4. 比较神经、动脉和骨骼肌组织对损伤频率（30,60和120hz）的组织特异性敏感性。这些研究将进一步加深对振动病病理生理学的认识，并为新的治疗策略提供见解。

The long-term goal is to understand the cellular and molecular mechanisms of vibration syndrome in order to define countermeasures to prevent injury and promote the safer use of power tools. A new animal model of vibration injury, employing the rat's tail, is introduced for studying the primary effects of short- and long-term vibration on specific tissues. The general hypothesis is that vibration injury results from combined neural and vascular damage. Specific hypotheses are: 1. Vibration injury begins with disruption of the schwann cells and cytoskeleton of large myelinated nerve fibers which degrades general sensation and skeletal muscle function. Small nerve fibers, associated with pain and vasomotor regulation, are initially spared. 2. Vibration stimulates vasospasm of arteries. This induces hypertrophy and hyperplasia of smooth muscle cells and intimal matrix reorganization, which culminates in chronic vessel occlusion and ischemia. 3. Vibration damage disrupts axoplasmic transport in large neurons. This exacerbates injury by blocking trophic interactions between the neurons and end organs. Detection of the earliest cell types responding to vibration will be accomplished by immunostaining with cell type specific markers, for immediate early gene protein (phosphorylated c-jun) expression and for proliferation by bromodeoxyuridine incorporation. Electron microscopy is employed to resolve primary ultrastructural damage. Functional changes will be assessed my measurements of tail skin temperature, blood flow, reflex withdrawal to noxious and touch stimulation, compound nerve action potential recording, and retrograde labeling of neurons. 4. Tissue specific sensitivity to injury is frequency (30, 60 and 120 Hz) on nerve, artery and skeletal muscle tissues will be compared. These studies will further the understanding of the pathophysiology of vibration disease and provide insight into novel treatment strategies.