人脑挫伤后神经丝蛋白NF200表达的变化

目的研究人脑挫伤后NF200在脑组织中神经元及轴索中表达的变化。方法88例闭合性脑挫伤标本,按损伤时间分为0.5h、1h、3h、24h、3d、7d、14d和30d共8个实验组,另以6例非脑挫伤的脑作为对照组,应用NF200免疫组织化学染色,结合图像分析技术,观察伤后不同时间NF200的变化。结果脑挫伤后0.5h和1h组,挫伤灶内及边缘NF200免疫组化染色几乎阴性;随时间的延长,挫伤灶内残存神经元及其周围神经元NF200染色逐渐增强,甚至发生核内转移;挫伤灶周围轴索在伤后出现波浪状扭曲、肿胀和断裂,最早在24h组出现收缩球(retractionball,RB),7d组轴索病变最明显,可见大量RB。图像分析发现伤后0.5h组和1h组,脑挫伤部位NF200阳性细胞的平均光密度(AOD)下降,其后逐渐升高,在14d组或30d组达高峰。结论脑损伤后NF200变化有一定规律性,并可用于诊断轴索损伤(AI),免疫组织化学结合结合图像分析技术在推断脑损伤时间上的有一定参考价值。

Changes of NF200 expression following human brain contusion

Objective To study NF200 expression in neurons and axons following brain contusion in human.Methods 88 cases of brain contusions of the closed head injury were divided into 8 experimental groups according to posttraumatic interval(PTI),namely 0.5h,1h,3h,24h,3d,7d,14d and 30d groups.And 6 brains of non head injury were chosen as control group.NF200 immunohistochemistry method and image analysis technique(IAT) were used for examing the changes of NF200 in neurons and axons.Results The loss of immunoreactivity of NF200 was observed in most neurons in the core of the brain contusion in 0.5h and 1h groups. The NF200 immunoreactivity was increased gradually after contusion in the neurons localized in the boundary zone and a few neurons localized in the core of the brain.NF200 appeared in the nucleus in some neurons.Axonal damages including swollen,waved and rupture were found.The retraction balls(RB) were detectable in the 24h group firstly.The axonal damage was the most serious in the 7d group and many RBs were observed.AOD of NF200 positive cells of 0.5h and 1h groups were decreased in contusion by IAT.Then increased gradually in dependance on PTI and reached the peak in 14d or 30d groups.Conclusion There were some characters of NF200 expression following human brain contusion.And NF200 could be used for detection of axonal injury(AI).Immunohistochemistry combining with IAT could be used for a reference to estimate PTI of brain contusion.