UNDERSTANDING VIBRATION INJURY

长期目标是了解振动综合征的细胞和分子机制，以确定预防伤害和促进更安全使用电动工具的对策。本文介绍了一种新的振动损伤动物模型--大鼠尾部振动损伤模型，用于研究短期和长期振动对特定组织的初步影响。一般的假设是振动损伤是神经和血管联合损伤的结果。具体假设有：1.振动损伤开始于雪旺细胞和大的有髓神经纤维的细胞骨架的破坏，其降低一般感觉和骨骼肌功能。与疼痛和血管调节相关的小神经纤维最初被保留。2.振动刺激动脉血管痉挛。这诱导平滑肌细胞的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而加剧损伤。通过细胞类型特异性标记物的免疫染色检测对振动响应的最早细胞类型，用于立即早期基因蛋白（磷酸化c-jun）表达和通过溴脱氧尿苷掺入用于增殖。采用电子显微镜来解决初级超微结构损伤。将通过测量尾部皮肤温度、血流量、对伤害性和触摸刺激的反射退缩、复合神经动作电位记录和神经元逆行标记来评估功能变化。4.将比较神经、动脉和骨骼肌组织对损伤频率（30、60和120 Hz）的组织特异性敏感性。这些研究将进一步了解振动疾病的病理生理学，并提供新的治疗策略的见解。

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.