S100 protein as a marker of central nerves injury

为了评估脑损伤的严重程度，本研究对300例法医尸检病例的大脑皮质S100蛋白的免疫组织化学分布及其与血清S100B蛋白水平的关系进行了研究。在死后48h内，血清S100B蛋白水平在锁骨下静脉高于右心和髂外静脉，在左心静脉最低，在死后48h内没有显著影响。急性颅脑损伤死亡和颈部受压窒息(勒死和上吊)患者的血清水平明显较高。在颅脑损伤患者中，血清S100水平与脑损伤的严重程度和存活时间有关；超急性和急性颅脑损伤死亡患者的血清S100水平明显高于存活时间较长的患者。星形胶质细胞中S100的阳性表达与死因有关，在因勒死、上吊和溺水而引起的急性死亡中显著降低，而在因损伤引起的死亡中则略低。在迟发性脑损伤死亡和火灾死亡中，神经元和髓鞘中S100的阳性表达较多，与脑损伤中星形胶质细胞的阳性表达呈负相关。在急性死亡病例中，星形胶质细胞S100阳性表达与血清S100B水平呈负相关，提示联合分析脑内S100阳性表达和血清S100B水平可能有助于脑损伤、缺氧和/或缺血性脑损伤死亡的调查。

To evaluate the severity of cerebral damage, this study investigated the immunohistochemical distribution of S100 protein in cerebral cortex in forensic autopsy cases (n=300) with regard to the cause of death and relationship to serum S100B protein levels.The serum S100B level was usually higher in the subclavian vein than in the right heart and external iliac vein, and lowest in the left, heart blood, showing no significant postmortem influence within 48 h postmortem. The serum level was markedly higher for acute deaths from head injury and asphyxiation due to neck compression (strangulation and hanging). For head injury cases, the serum level was dependent on the severity of the brain injury and survival ; it was significantly higher for the cases of peracute and acute deaths due to head injury than for longer survival cases.S100 immunopositivity was mainly observed in the gliacytes, in part, in the neurons and myelin. S100 positivity in the astrocytes was dependent on the cause of death, and was significantly lower in acute deaths due to strangulation/hanging and drowning, and mildly low in those due to injuries. S100 positivity in neurons and myelins was frequently observed in delayed head injury deaths and fire fatalities, showing an inverse relationship with the positivity in astrocytes in head injury cases. For cases of acute death, there was an inverse relationship between S100 positivity in the astrocytes and the serum S100B level.The above observations suggest that combined analyses of S100 positivity in the brain and serum S100B levels may be useful for investigation death due to head injury, hypoxic and/or ischemic cerebral damage.