大鼠轻型颅脑损伤后神经胶质病理改变与血清GFAP水平

目的研究轻型颅脑损伤的病理变化和胶质纤维酸性蛋白(GFAP)的表达。方法收集32只成年大鼠,随机分为假手术组(n=8)、伤后1 d组(n=8)、伤后3 d组(n=8)和伤后7 d组(n=8)。损伤组采用液压冲击设备建立大鼠轻型闭合性颅脑损伤模型,假手术组仅切开头皮并钻孔。免疫组化方法检测脑组织中星形细胞特异性标志物GFAP的表达,Fluoro-Jade B(FJ-B)免疫荧光检测脑组织中神经元急性损伤程度,ELISA法测定尾静脉的血清GFAP水平,观察损伤后脑组织神经元和星形细胞改变,并分析血清GFAP水平和神经元损伤程度间的关系。结果与假手术组比较,伤后1、3、7 d邻近顶叶皮质GFAP阳性染色的星形细胞数量减少(P0.05);伤后1、3、7 d可见星形细胞肿胀增生。伤后1 d皮质FJ-B阳性染色神经元轻度增加,伤后3、7 d明显增加(P0.05)。伤后1 d血清GFAP水平较假手术组明显增加(P0.05),伤后3、7 d回落至正常水平;伤后1 d血清GFAP水平与伤后7 d皮质区损伤神经元计数呈正相关(r=0.8095,P0.05)。结论轻型颅脑损伤后急性期发生星形细胞破坏伴胶质反应及血清标志物GFAP增加,亚急性期发生神经元变性损伤。急性期血清GFAP水平可以预测中枢神经元损伤程度。     

缺氧预处理对颅脑损伤周围皮质神经血管单元的影响

目的观察缺氧预处理对颅脑损伤周围皮质神经血管单元(NVU)的影响。方法 108只SD雄性大鼠随机分为对照组(n=6)、缺氧预处理组(HPC组n=6)、颅脑损伤组(TBI组n=48)、缺氧预处理+颅脑损伤组(HPCT组n=48)。免疫组化技术检测神经元核抗原(Neu N)、胶质纤维酸性蛋白(GFAP),Ig G法测定血-脑屏障通透性变化情况。结果 TBI组和HPCT组的GFAP在伤后3 h~14 d、Ig G在伤后1 h~14 d均增加,而Neu N在两组表达分别在伤后3 h~14 d、6 h~14 d减少(均P0.05)。HPCT组Neu N在伤后3 h~7 d均多于TBI组,GFAP在伤后6 h~1 d多于TBI组而伤后7 d少于TBI组,Ig G在伤后1 h~14 d少于TBI组(P0.05)。结论缺氧预处理在一定时间窗内保护神经元,调整星形胶质细胞活化,降低血-脑屏障通透性,减轻随后颅脑损伤对周围皮质NVU的损伤。     

红藻氨酸致痫大鼠海马Fos和GFAP的共同表达

目的 研究红藻氨酸（kainic acid,KA)诱导大鼠癫痫发作后海马（hippocampus,HI)内神经元和星形胶质细胞的时空效应性反应变化。方法 大鼠侧脑室内注射KA，用抗即刻早期基因Fos蛋白和抗胶质原纤维酸性蛋白（GFAP）的双重免疫荧光组织化学方法结合激光共聚焦显微镜技术，显示痫性发作后HI同一部位内反应性神经元与星形胶质细胞的分布。结果 KA诱导大鼠癫痫发作，HI内的Fos阳性神经元和GFAP阳性星形胶质细胞明显增多。两分布范围基本一致，且癫痫诱发30min后GFAP开始增多，1h达高峰；1h后Fos阳性产物开始增多；2h达高峰；部分Fos阳性神经元周围有GFAP免疫反应产物包绕，显示反应性神经元（Fos阳性）与反应性星形胶质细胞（GFAP阳性）之间关系密切。结论 HI内的神经元和星形胶质细胞与癫痫发作直接相关且存在相互关系。可能共同参与癫痫的发生及其调节。     

16Hz次声作用对大鼠海马TRPV4、GFAP和fos蛋白表达的影响

目的研究16Hz，90dB和130dB次声作用后，大鼠海马瞬时感受电位香草酸家族4（TRPV4）通道蛋白、胶质纤维酸性蛋白（GFAP）和fos蛋白的表达情况。方法16Hz，90dB和130dB次声作用于大鼠，2h／d，作用7d后采用免疫组织化学染色方法，观察大鼠海马中TRPV4蛋白、GFAP和fos蛋白表达的情况。结果16Hz，130dB次声作用7d后，与对照组相比较大鼠海马中显著表达TRPV4阳性神经元，GFAP阳性星形胶质细胞和fos阳性神经元（P〈0．05），三者分布一致，关系密切；90dB组大鼠的上述三种蛋白表达均较130dB组弱（P〈0．05）。结论16Hz，90dB和130dB次声作用可以引起大鼠海马TRPV4阳性细胞表达增多，且能够激活神经元和星形胶质细胞。     

创伤性脑损伤急性期高血糖对脑GLUT-3表达的影响

目的探讨大鼠创伤性脑损伤后高血糖对神经元的损害作用及其可能机制。方法成年雄性SD大鼠180只,随机分成正常对照组,创伤性脑损伤(traumatic brain injury,TBI)组,胰岛素治疗组,每组伤侧及健侧皮层设立自身对照。分别测定每组伤前及伤后各时间点血糖值,逆转录-聚合酶链反应(RT-PCR)测定伤后伤侧及健侧皮层葡萄糖转运蛋白3(glucose transporter 3,GLUT-3)基因表达,Western-blot法测定伤后伤侧及健侧皮层GLUT-3蛋白表达,免疫荧光法测定伤后各组伤侧及健侧皮层单个神经元神经特异性烯醇化酶(neuronspecificenolase,NSE)表达量和NSE阳性染色细胞数。结果正常对照组各时间点血糖值,GLUT-3表达量,单个神经元NSE表达量及NSE阳性细胞数均未见明显变化(P均0.05);TBI组动物伤后血糖升高,伤侧皮层GLUT-3表达增加,单个神经元NSE表达量增加而NSE阳性染色细胞数明显减少(P均0.05);胰岛素治疗组伤后血糖变化不明显(P0.05),伤后12、24、48、72 h GLUT-3表达量,单个神经元NSE表达量及NSE阳性染色细胞数均明显多于TBI组(P均0.05)。各组健侧皮层GLUT-3和单个神经元NSE表达量,NSE阳性染色细胞数均未见明显变化(P均0.05)。结论 TBI后高血糖可加重神经元损伤,其机制可能与TBI后高血糖减少伤后神经元GLUT-3的表达,增加伤后神经元葡萄糖代谢障碍有关。     

缺血预处理后海马CA1区反应性星形胶质细胞增生与迟发性神经元缺血耐受性的关系

目的 探讨缺血预处理后海马CA1区反应性星形胶质细胞增生与迟发性神经元缺血耐受性的关系。方法 实验动物被随机分为手术组、缺血组、预缺血组、预缺血后再缺血组。阴断沙土鼠双侧颈总动脉造成前脑缺血模型。采用细胞特异性抗原胶质纤维酸性蛋白（GFAP）免疫组化法标记星形胶质细胞。结果 预缺血后1－7天,海马CA1区GFAP阳性的星形胶质细胞数轻度增加,至28天时增生非常显著（P＜0．01）。预缺血后1－7天再缺血,海马CA1区存活正常神经元数逐渐下降,预缺血后28天再缺血又显著增加（P＜0．01）。结论 缺血预处理后,神经元可出现迟发性缺血耐受,反应性星形胶质细胞增生可能起了重要作用。     

大鼠脑缺血后海马CA1区胶质纤维酸性蛋白表达与迟发性神经元死亡的关系

目的观察大鼠大脑缺血再灌注后海马CA1区胶质纤维酸性蛋白(GFAP)的表达与迟发性神经元死亡的关系。方法采用大鼠大脑中动脉阻塞再灌注模型(MCAO),将大鼠随机分为MCAO后3d、7d、30d组及假手术组,应用免疫荧光与TUNEL染色法分别观察脑缺血再灌注后不同时间点缺血侧海马CA1区GFAP表达情况和迟发性神经元死亡(DND)的变化。结果(1)3d组海马DND阳性(DND 组)的MCAO大鼠、海马DND阴性(DND-组)的MCAO大鼠与假手术组大鼠比较,缺血侧海马CA1区GFAP染色的平均光密度无显著性差异(P>0.05),但GFAP阳性细胞的形态发生变化;(2)7d组大鼠缺血侧海马CA1区GFAP阳性细胞大量活化增殖,表现为胞体变大,突起增多;DND( )、DND(-)组海马CA1区GFAP染色的平均光密度较假手术组增高(P<0.01),且DND(-)组的GFAP平均光密度较DND( )组明显增高(P<0.01);(3)30d组大鼠缺血侧海马CA1区GFAP表达呈瘢痕样改变,DND( )、DND(-)组与假手术组比较其GFAP染色的平均光密度明显增高(P<0.05),且DND( )组的GFAP平均光密度较DND(-)组明显增高(P<0.05)。结论大鼠MCAO后星形胶质细胞反应性变化的差异可能与海马CA1区迟发性神经元死亡的发生有关。     

一氧化氮供体及前体对大鼠脑缺血再灌注损伤保护机制的探讨

目的 观察介入给药一氧化氮（NO）供体硝酸甘油（Nitroglycerine，NG）及前体L-精氨酸（L-Arginine，ARG）对大鼠脑缺血再灌注后海马区星形胶质细胞表达的胶质纤维酸性蛋白（GFAP）的影响，探讨NG及ARG的脑保护机制。方法 采用大鼠大脑中动脉阻塞（MCAO）法建立局灶性脑缺血模型。将大鼠随机分为假手术组、MCAO组、NG组和ARG组。MCAO组、NG组和ARG组于缺血2 h再灌注同时分别局部介入给予生理盐水、NG和ARG，于再灌注3 h或24 h时，荧光法检测血清NO含量。并在3 h或24 h时处死大鼠，病理分析脑梗死体积以及免疫组织化学法检测海马区GFAP表达情况。结果 缺血再灌注后3 h血清NO升高（P <0.01），治疗组较MCAO组明显（P <0.01），GFAP表达阳性细胞数增加，但治疗组较MCAO组减少（P <0.01），各组大鼠脑组织未出现肉眼可见梗死灶；缺血再灌注后24 h，血清NO治疗组较3 h降低，而MCAO组较3 h升高（P <0.05），GFAP表达阳性细胞数较3 h增加（P <0.01），治疗组较MCAO组减少（P <0.01），TTC染色显示脑梗死体积治疗组较MCAO组减小（P <0.05）。结论 脑缺血再灌注后海马区脑组织GFAP表达增强，通过局部介入给予NG、ARG增加NO合成，抑制GFAP高表达，减小脑梗死体积。提示NG、ARG抗脑缺血性损伤的保护机制可能与抑制星形胶质细胞过度表达有关。     

大鼠前脑缺血再灌注后GFAP、S-100表达的变化

目的 探讨胶质纤维酸性蛋白（GFAP）和S-100蛋白在大鼠前脑缺血再灌注后反应性星形胶质细胞的活化情况.方法 利用免疫组织化学方法检测前脑缺血再灌注模型的细胞活化情况.结果 脑缺血再灌注后第1d,顶叶皮层和海马可见少量GFAP阳性细胞表达 脑缺血再灌注第3d及第5d后GFAP阳性表达明显增加,并与对照组比较有统计学意义（P＜0.01）.S-100蛋白在脑缺血再灌注后第1d即有增加,并随着时间延长表达明显增强,各时间点与对照组有显著性差异（P＜0.01）.结论 脑缺血再灌注后GFAP、S-100蛋白表达增加,说明反应性星形胶质细胞的活化参与了脑缺血损伤后神经元的修复过程.     

盐酸小檗碱对颅脑创伤模型小鼠双侧丘脑继发性损伤的神经保护作用

目的探讨盐酸小檗碱对颅脑创伤(TBI)模型小鼠双侧丘脑继发性损伤(炎症反应、氧化损伤和神经元缺失)的神经保护作用。方法采用自由落体撞击法制备颅脑创伤模型,盐酸小檗碱组小鼠予以盐酸小檗碱50 mg/(kg·d)灌胃21 d,TBI组予等量生理盐水灌胃21 d,对照组不予自由落体撞击。免疫组织化学染色计数双侧丘脑诱导型一氧化氮合酶(i NOS)、环氧合酶-2(COX-2)、8-羟基脱氧鸟苷(8-OHd G)和神经元核抗原(Neu N)阳性神经元或胶质细胞数目,免疫荧光染色计数双侧丘脑胶质纤维酸性蛋白(GFAP)阳性星形胶质细胞和离子钙结合蛋白1(Iba1)阳性小胶质细胞数目。结果 3组小鼠颅脑创伤同侧丘脑i NOS(P=0.015)、COX-2(P=0.022)、8-OHd G(P=0.000)和Neu N(P=0.000)阳性神经元或胶质细胞数目以及GFAP阳性星形胶质细胞数目(P=0.024)和Iba1阳性小胶质细胞数目(P=0.000)差异均有统计学意义,其中,TBI组i NOS(P=0.005)、COX-2(P=0.011)和8-OHd G(P=0.000)阳性神经元或胶质细胞数目以及GFAP阳性星形胶质细胞数目(P=0.011)和Iba1阳性小胶质细胞数目(P=0.000)均高于对照组,而Neu N阳性神经元数目低于对照组(P=0.000);盐酸小檗碱组i NOS(P=0.031)、COX-2(P=0.024)和8-OHd G(P=0.008)阳性神经元或胶质细胞数目以及GFAP阳性星形胶质细胞数目(P=0.031)和Iba1阳性小胶质细胞数目(P=0.012)均低于TBI组,仅8-OHd G阳性神经元数目(P=0.014)和Iba1阳性小胶质细胞数目(P=0.024)仍高于对照组,而Neu N阳性神经元数目高于TBI组(P=0.016)、仍低于对照组(P=0.027)。3组小鼠颅脑创伤对侧丘脑仅COX-2(P=0.029)和8-OHd G(P=0.000)阳性神经元或胶质细胞数目差异有统计学意义,其中,TBI组COX-2(P=0.011)和8-OHd G(P=0.000)阳性神经元或胶质细胞数目高于对照组,盐酸小檗碱组COX-2(P=0.047)和8-OHd G(P=0.010)阳性神经元或胶质细胞数目低于TBI组,仅8-OHd G阳性神经元数目仍高于对照组(P=0.004)。结论颅脑创伤可以引起双侧丘脑继发性损伤,尤以同侧丘脑显著,对侧丘脑仅出现炎症反应和氧化损伤;盐酸小檗碱通过抑制颅脑创伤后双侧丘脑炎症反应和氧化损伤而发挥神经保护作用。     

Early loss of astrocytes after experimental traumatic brain injury

Neuronal-glial interactions are important for normal brain function and contribute to the maintenance of the brain's extracellular environment. Damage to glial cells following traumatic brain injury (TBI) could therefore be an important contributing factor to brain dysfunction and neuronal injury. We examined the early fate of astrocytes and neurons after TBI in rats. A total of 27 rats were euthanized at 0.5, 1, 2, 4, or 24 h after moderate lateral fluid percussion TBI or after sham TBI. Ipsilateral and contralateral hippocampi were examined in coronal sections from -2.12 to -4.80 mm relative to bregma. Adjacent sections were processed with markers for either astrocytes or degenerating neurons. Astrocytes were visualized using glial fibrillary acidic protein (GFAP) or glutamine synthetase immunohistochemistry. Neuronal degeneration was visualized using Fluoro-Jade (FJ) histofluorescence. At 30 min, there was a significant loss of GFAP immunoreactivity in ipsilateral hippocampal CA3 with some loss of normal astrocyte morphology in the remaining cells. The number of normal staining astrocytes decreased progressively over time with extensive astrocyte loss at 24 h. At 4 h, lightly stained FJ-positive neurons were scattered in the ipsilateral CA3. The intensity and number of FJ-positive neurons progressively increased over time with moderate numbers of degenerating neurons in the ipsilateral hippocampal CA3 evident at 24 h. We conclude that astrocyte loss occurs in the hippocampus early after TBI. The data suggest that loss of supporting glial cell may contribute to subsequent neuronal degeneration.     

小容量复苏对脑外伤合并休克大鼠脑超微结构和vWF表达的影响

目的 观察小容量高晶体-高胶体渗透压混合液(HHS)复苏对脑外伤合并休克大鼠脑超微结构和Ⅷ因子相关抗原(vWF)表达的影响.方法 SD大鼠54只随机分为:(1)假手术组;(2)脑外伤+休克组;(3)HHS组;每组各18只.脑外伤+休克组和HHS组建立脑外伤合并急性失血性休克模型,随后在HHS组进行小容量HHS复苏.观察各组脑超微结构和vWF的表达.结果 电镜显示HHS对神经元、星形细胞和血脑屏障均有保护作用.脑外伤+休克组在损伤后4h和24h vWF的表达显著减少(P＜0.01),48h开始恢复,但显著低于假手术组和HHS组(P＜0.01);HHS组在损伤后4h,vWF的表达显著减少(P＜0.0l),24h开始恢复,至48h恢复正常.结论 小容量HHS复苏治疗脑外伤合并休克大鼠,可以抑制脑血管内皮损伤,促进微血管修复,减轻继发性脑损伤.     

Selective alterations in the cellular distribution of apolipoprotein E immunoreactivity following transient cerebral ischaemia in the rat

The aim of this study was to examine the cellular localization and alterations of apolipoprotein E (apoE) following a transient ischaemic insult using immunohistochemistry. Transient cerebral ischaemia was induced in Wistar rats by occlusion of both carotid arteries with hypotension followed by reperfusion for 4 h (n = 5), 24 h (n = 5) or 72 h (n = 6). In sham-operated animals (n=9), the carotids were not occluded. In this model, ischaemia for 15 min results in selective neuronal damage in the caudate nucleus and neocortex (24 h after reperfusion) and the hippocampal CA1 pyramidal cells (72 h after reperfusion) while there is minimal damage in other areas such as the CA3 hippocampal region. In sham animals, apoE immunoreactivity was confined to astrocytes and their processes. ApoE immunoreactivity was not altered at 4 h post-ischaemic reperfusion. At 24 h reperfusion, intense apoE staining of the cytoplasm of astrocytes and neuropil within the caudate and neocortex was observed and at 72 h reperfusion apoE stained neuronal cell bodies within these regions. Within the CA1 region at 24 h reperfusion, there was increased immunoreactivity of the cytoplasm of astrocytes and the neuropil was more intensely stained compared with sham animals. At 72 h reperfusion, intense apoE staining of pyramidal cell bodies and dendrites was consistently observed in the CA1 region of the hippocampus. In contrast, at 72 h reperfusion, apoE staining of astrocytic processes was dramatically reduced in the CA1 region although GFAP staining indicated their preservation. The results demonstrate that following an ischaemic insult apoE is localized to degenerating neurons and their processes. This may indicate an inherent protective response of cells to injury. Alternatively, the results are consistent with the hypothesis that apoE is synthesized and released by astrocytes and taken up by neurons following injury.     

Alterations in mammalian target of rapamycin signaling pathways after traumatic brain injury.

In response to traumatic brain injury (TBI), neurons initiate neuroplastic processes through the activation of intracellular signaling pathways. However, the molecular mechanisms underlying neuroplasticity after TBI are poorly understood. To study this, we utilized the fluid-percussion brain injury (FPI) model to investigate alterations in the mammalian target of rapamycin (mTOR) signaling pathways in response to TBI. Mammalian target of rapamycin stimulates mRNA translation through phosphorylation of eukaryotic initiation factor 4E binding protein-1 (4E-BP1), p70 ribosomal S6 kinase (p70S6K), and ribosomal protein S6 (rpS6). These pathways coordinate cell growth and neuroplasticity via dendritic protein synthesis. Rats received sham surgery or moderate parasagittal FPI on the right side of the parietal cortex, followed by 15 mins, 30 mins, 4 h, 24 h, or 72 h of recovery. Using Western blot analysis, we found that mTOR, p70S6K, rpS6, and 4E-BP1 phosphorylation levels were significantly increased in the ipsilateral parietal cortex and hippocampus from 30 mins to 24 h after TBI, whereas total protein levels were unchanged. Using confocal microscopy to localize these changes, we found that rpS6 phosphorylation was increased in the parietal cortex and all subregions of the hippocampus. In accordance with these results, eIF4E, a key, rate-limiting mRNA translation factor, was also phosphorylated by mitogen-activated protein kinase-interacting kinase 1 (Mnk1) 15 mins after TBI. Together, these results suggest that changes in mRNA translation may be one mechanism that neurons use to respond to trauma and may contribute to the neuroplastic changes observed after TBI.     

单侧液压脑损伤对大鼠双侧海马GFAP表达和CA1区突触传递的影响

目的研究单侧液压脑损伤(FPI)对大鼠双侧海马区胶质纤维酸性蛋白(GFAP)表达和CA1区突触传递的影响。方法建立大鼠单侧液压脑损伤模型,脑标本分为对照组(包括正常对照和假手术对照)、FPI损伤同侧组和FPI损伤对侧组。免疫组化法检测海马水平切片GFAP表达,对海马CA1区锥体神经元进行细胞内记录。结果FPI大鼠双侧海马齿状回门区和CA1区GFAP表达均比对照组明显增强。FPI损伤同侧组兴奋性输入-输出关系曲线的斜率比其他两组显著增大(P<0.05);FPI损伤同侧组和对侧组双脉冲易化(PPF)比值和抑制性突触后电位(IPSP)幅值均比对照组显著减小(P<0.05);FPI损伤同侧组和对侧组双脉冲抑制(PPD)比值均比对照组显著增大(P<0.05)。结论大鼠单侧液压脑损伤对双侧海马均可产生影响,导致双侧海马CA1区兴奋性突触传递增强,抑制性突触传递减弱。     

颅脑创伤模型小鼠海马水通道蛋白1表达及作用

研究背景颅脑创伤后继发性脑损伤包括脑组织缺血、缺氧和脑水肿,可进一步加重原发性损伤,影响预后。作为选择性易损区,海马对缺血和水肿尤为敏感,易出现不可逆性损伤。水通道蛋白1(AQP1)与脑水肿的发生关系密切,但迄今尚无颅脑创伤后海马AQP1表达变化及其相关作用的报道。本研究采用闭合性颅脑创伤小鼠模型对海马水肿过程进行观察,以探讨AQP1在相关病理生理学过程中的作用机制。方法采用改良自由落体法建立BALB/c系小鼠闭合性颅脑创伤模型,于创伤后不同观察时间点(1、6、24和72 h)进行神经功能缺损程度评价和脑组织含水量测定,并通过TUNEL法观察海马神经元凋亡率、免疫组织化学染色和Western blotting法检测AQP1表达变化。结果成功制备闭合性颅脑创伤小鼠模型,并经神经功能评价和脑组织含水量测定证实存在重型颅脑创伤和脑水肿。TUNEL检测显示,模型组小鼠伤后6 h海马神经元凋亡率即升高[(44.26±15.18)%对(8.61±8.25)%;t=-9.676,P=0.002],至72 h达峰值水平[(61.62±26.55)%对(10.17±6.08)%;t=-5.018,P=0.015];免疫组织化学染色和Western blotting法观察,模型组小鼠创伤后各观察时间点海马AQP1表达水平均高于假手术组(P0.05),以伤后24 h表达水平最高(0.69±0.32对0.15±0.07,t=-4.335,P=0.023;0.46±0.19对0.14±0.04,t=-4.113,P=0.004)。结论颅脑创伤后小鼠海马AQP1表达上调可能参与了脑水肿和迟发性神经元凋亡等病理生理学过程,AQP1可能成为继发性脑损伤机制研究的新靶点。     

Gonadal hormones down-regulate reactive gliosis and astrocyte proliferation after a penetrating brain injury

Astrocytes are a target for gonadal steroids in the normal brain. The putative modulation by gonadal hormones of the astrocytic reaction to brain injury was assessed in this study. Male and female adult Wistar albino rats were gonadectomized and, one month later, their brains were lesioned by a longitudinal incision crossing the parietal cerebral cortex, the CA1 field of the dorsal hippocampus and the dentate gyrus. Males were injected either with testosterone (20 μg/rat) or vehicle immediately after surgery. Females were injected either with 17β estradiol (250 μg/rat), progesterone (500 μg/rat) or vehicle. Hormonal injections were repeated 24 and 48 h after brain injury. All animals received injections of 5′-bromodeoxyuridine (BrdU) to label proliferating cells. Histological sections from the brain of animals killed 72 h after surgery were used for the double immunohistochemical localization of BrdU and glial fibrillary acidic protein (GFAP). The number of GFAP-immunoreactive astrocytes and the number of double labelled astrocytes (GFAP+BrdU) were recorded as a function of the distance to the lesion site in the parietal cerebral cortex, the CA1 field of the hippocampus and the dentate gyrus. Testosterone, estradiol and progesterone treatments resulted in a significant decrease in the number of GFAP-immunolabelled reactive astrocytes in the vicinity of the wound. The number of double labelled cells and the labelling index (proportion of GFAP-immunoreactive astrocytes labelled with BrdU) varied according to the cerebral area, the distance to the wound and the sex of the animals, and were significantly decreased by gonadal steroids in all the areas examined. These results ndicate that gonadal hormones may decrease gliosis and astrocyte proliferation after a penetrating brain injury.     

SPECT及SOD检测在颅脑损伤患者中的应用

目的探讨超氧化物歧化酶（SOD）及单光子发射计算机体层摄影（SPECT）在评价颅脑损伤后病情和预后中的作用。方法选择符合要求的颅脑损伤患者60例，按照GCS评分标准分成轻型损伤组45例，中型损伤组8例和重型损伤组7例。20例健康员工为对照组。对人选的所有对象进行SPECT、CT扫描和SOD检测，其中颅脑损伤患者在伤后24h内和2周后进行SPECT和CT检查，伤后12h、24h、36h、48h、72h、1周、2周、1月和2-月抽取外周静脉血测定SOD含量。并对所有患者在伤后6月按GOS评价预后。结果入院初和伤后2周，对颅脑损伤患者SPECT检出阳性率要明显高于CT检出阳性率（P〈0．01），尤其对轻型损伤的患者更是如此．SPECT检出的颅脑损伤病灶数也比CT多。外周血SOD含量在伤后24h显著下降（P〈0．05），其中中型和重型损伤组SOD值下降最明显，直到1月后其值才恢复正常；伤后24h外周血SOD值与入院时GCS评分及伤后6月GOS评分呈正相关（P〈0.05）。结论颅脑损伤后早期进行SPECT和SOD的检测可以评价病情等级并可以对预后情况最出初步估计。     

Expression of Fas and Fas ligand after experimental traumatic brain injury in the rat.

Apoptotic cell death plays an important role in the cascade of neuronal degeneration after traumatic brain injury (TBI), but the underlying mechanisms are not fully understood. However, increasing evidence suggests that expression of Fas and its ligand (FasL) could play a major role in mediating apoptotic cell death in acute and chronic neurologic disorders. To further investigate the temporal pattern of Fas and FasL expression after experimental TBI in the rat, male Sprague Dawley rats were subjected to unilateral cortical impact injury. The animals were killed and examined for Fas and FasL protein expression and for immunohistologic analysis at intervals from 15 minutes to 14 days after injury. Increased Fas and FasL immunoreactivity was seen in the cortex ipsilateral to the injury site from 15 minutes to 72 hours after the trauma, respectively. Immunohistologic investigation demonstrated a differential pattern of Fas and FasL expression in the cortex, respectively: increased Fas immunoreactivity was seen in cortical astrocytes and neurons from 15 minutes to 72 hours after the injury. In contrast, increased expression of FasL was seen in cortical neurons, astrocytes, and microglia from 15 minutes to 72 hours after impact injury. Concurrent double-labeling examinations using terminal deoxynucleotidyl transferase-mediated deoxyuridine-biotin nick end labeling identified Fas- and FasL-immunopositive cells with high frequency in the cortex ipsilateral to the injury site. In contrast, there was no evidence of Fas- and FasL-immunopositive cells in the hippocampus ipsilateral to the injury site up to 14 days after the trauma. Further, Fas and FasL immunoreactivity was absent in the contralateral cortex and hippocampus at all time points investigated. These results reveal induction of Fas and FasL expression in the cortex after TBI in the rat. Further, these data implicate an involvement of Fas and FasL in the pathophysiologic mechanism of apoptotic neurodegeneration after TBI. Last, these data suggest that strategies aimed to repress posttraumatic Fas- and FasL-induced apoptosis may open new perspectives for the treatment of TBI.     

创伤性脑损伤后大鼠脑组织CtyC与AIF的变化及其对神经细胞的影响

目的 探讨创伤性脑损伤后大鼠脑组织中细胞色素C(ctyC)与凋亡诱导因子(AIF)的变化及其对神经细胞的影响.方法 70只SD大鼠按随机数字表法分为假损伤组(n=10)和脑损伤组,脑损伤组按伤后1、6、24、48、72和168 h观察时间点分为6个亚组(n=10).用Feeny氏自由落体撞击法制作重型颅脑损伤模型.利用免疫荧光和共聚焦显微镜技术测定损伤后不同时间点CtyC和AIF的荧光表达强度.用免疫荧光双标记技术观察损伤后24 h时CtyC及AIF对神经细胞的影响.结果 (1)脑损伤后脑组织中CtyC变化:伤后1、6、24、48 h,皮层CtyC分别增高为1.89±0.03、2.69±0.07、2.99±0.06、3.05±0.05,海马CtyC分别增高为1.34±0.04、1.87±0.03、2.60±0.03、2.80±0.06,明显高于假损伤组,差异有统计学意义(P<0.05).72h皮层与海马CtyC分别降为1.94±0.05及1.12±0.04,亦明显高于假损伤组,差异有统计学意义(P<0.05).168 h皮层与海马CtyC与假损伤组比较差异无统计学意义(P>0.05).(2)脑损伤后脑组织中AIF变化:伤后1、6、24、48 h,皮层AIF分别增高为1.82±0.16、2.16±0.34、2.75±0.22、2.87±0.12,海马AIF分别增高为1.27±0.06、2.01±0.05、2.49±0.02、2.62±0.05,明显高于假损伤组,差异有统计学意义(P<0.05).72 h皮层与海马AIF分别降为1.35±0.09及1.32±0.05,亦明显高于假损伤组,差异有统计学意义(P<0.05).168 h皮层与海马AIF恢复正常水平,与假损伤组比较差异无统计学意义(P>0.05).(3)CtyC与AIF都能引起神经细胞凋亡.结论 创伤性脑损伤后CtyC和AIF可从线粒体释放,并起到凋亡因子的作用,诱导神经细胞发生凋亡.