UNDERSTANDING VIBRATION INJURY

长期目标是了解振动综合征的细胞和分子机制，以便确定预防伤害的对策，促进电动工具的安全使用。介绍了一种新的振动损伤动物模型，利用大鼠的尾巴，研究了短期和长期振动对特定组织的主要影响。一般的假设是，振动损伤是神经和血管联合损伤的结果。具体假设如下：1.振动损伤始于大段有髓神经纤维的雪旺细胞和细胞骨架的破坏，导致全身感觉和骨骼肌功能下降。最初，与疼痛和血管运动调节相关的细小神经纤维是不存在的。2.振动刺激动脉血管痉挛。这会导致平滑肌细胞肥大、增殖和内膜基质重组，最终导致慢性血管闭塞和缺血。3.振动损伤扰乱了大神经元的轴浆运输。这会阻止神经元和末端器官之间的营养相互作用，从而加剧损伤。对振动反应最早的细胞类型的检测将通过细胞类型特异性标记的免疫染色、即刻早期基因蛋白(磷酸化的c-jun)的表达和通过溴脱氧尿苷掺入的增殖来完成。电子显微镜被用来解决原发超微结构损伤。我将通过测量尾部皮肤温度、血流量、对伤害性刺激和触摸刺激的反射撤退、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.比较神经、动脉和骨骼肌组织对损伤的组织特异性敏感性。这些研究将进一步加深对振动病的病理生理学的理解，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.