人原发性脑干损伤后脑干nNOS和HIF-1的表达变化

目的观察原发性脑干损伤死亡者脑干内神经元型一氧化氮合酶（nNOS）、低氧诱导因子-1（HIF-1）的表达变化,为原发性脑干损伤致死的病理学诊断、法医病理学死因判断提供稳定、简便、可行的检测指标及方法。方法标本分为脑干损伤组和对照组,运用常规HE染色和免疫组化方法,观察神经元的形态学改变和脑干组织nNOS和HIF-1的表达变化水平。结果对照组脑干仅见少量nNOS阳性神经细胞;伤后1h死亡组可见阳性细胞增多,与对照组比较差异有统计学意义（P〈0.05）,且随时间增加阳性神经细胞数增多,表达强度增强,伤后24h达到高峰,随后表达减弱。对照组神经元偶见HIF-1α表达,伤后1h死亡组可见表达HIF-1α的神经细胞数增多,表达强度增强,差异有统计学意义（P〈0.05）;随着时间的增加,HIF-1α阳性表达的神经细胞增多,伤后48h达高峰,随后表达减弱。结论 nNOS、HIF-1α参与了原发性脑干损伤的过程,脑干损伤后nNOS、HIF-1α蛋白随损伤时间变化的规律为原发性脑干损伤的法医学鉴定提供了新的方法,可望应用于法医学实践。

Expression of nNOS and HIF-1 in human brain-stem neuron suffering from primary brain-stem injury

Objective To study the expression of nNOS and HIF-1 in the cases which were died of primary brain stem injury（PBSI）,and its forensic medicine significance and the clinical significance and offer a new evidence for the pathological diagnosis and forensic medicine appraisal of PBSI.Methods All the samples were divided into 2 groups：control group and experiment group.The morphological changes of the neurons were detected by HE and the expression of nNOS and HIF were determined by immunohistochemistry.Results In the control group,there was little nNOS positive cells in the reticular substance of medulla oblongata,while a large number of nNOS positive cells could be seen in the 1h dead group,and the number of positive cells were increased with the prolong of injury time and was peaked at 24 h.After 24 h,the number of positive cells decreased with the prolong of injury time.The expression of HIF-lα protein could be detected at 1h after injury,and increased with the prolong of injury time and peaked at 48 h.After 48 h,the number of positive cells was decreased with the prolong of injury time.Little expression was found in control group.Conclusion nNOS and HIF-1 play an important role in the primary brain-stem suffering from craniocerebral trauma.Expression of NOS and HIF-1 protein is correlated with post-traumatic intervals after primary brain stem injury in human,suggesting that the expression of NOS and HIF-1 may be served as the markers for timing of PBSI in forensic practice.