甘珀酸对癫痫大鼠前脑connexin-32和GFAP表达研究

目的研究大鼠在脑室埋管注射甘珀酸(CBX)预处理后戊四氮导致癫痫发作时前脑内胶质纤维酸性蛋白(GFAP)和连接蛋白-32(Cx32)表达及其相互关系. 方法动物分为生理盐水(NS)对照组(NS组)、CBX预处理对照组(CBX组)、戊四氮(PTZ)致痫组(PTZ组)、CBX预处理后再PTZ致痫组(CBX PTZ组),应用免疫荧光组织化学双重标记显示GFAP和Cx32在前脑的表达及其相互关系.结果 CBX PTZ组的大鼠癫痫发作的行为表现比PTZ组显著加重,星形胶质细胞GFAP的表达也比PTZ组明显升高,值得注意的是CBX组的星形胶质细胞GFAP的表达比NS组明显升高.Cx32在PTZ引起的癫痫大鼠的大脑皮层、海马和杏仁核内是增加的,而CBX预处理后的癫痫模型中Cx32却降低了.在Cx32与GFAP双标的切片上发现,Cx32与GFAP阳性的星形胶质细胞非常接近,在CBX预处理后的癫痫模型中GFAP阳性的星形胶质细胞显著增加的同时Cx32却明显降低. 结论在整体动物CBX预处理可以导致癫痫发作增强,这可能与星形胶质细胞增生及其Cx32表达降低有关.     

柚皮苷对脑缺血再灌注损伤的保护作用

目的研究柚皮苷(Naringin,NRG)对大鼠局灶性脑缺血再灌注损伤的保护作用及星形胶质细胞是否参与其中。方法柚皮苷连续灌胃7 d后进行大脑中动脉栓塞(middle cerebral artery occlusion,MCAO),缺血2 h后拔出线栓进行再灌注。24 h后TUNEL染色观察凋亡细胞数量,苏木精-伊红(hematoxyli-eosin,HE)染色观察形态学改变,免疫荧光染色分别检测星形胶质细胞标记物胶质纤维酸性蛋白(glial fibrillary acidic protein,GFAP)和缝隙连接蛋白43(connexin43,Cx43)。结果同模型组相比,柚皮苷预干预后凋亡细胞数量显著减少(P0.05),细胞损伤明显减轻。免疫染色显示柚皮苷可以减轻星形胶质细胞的激活程度,同时Cx43的表达也有所降低(P0.05)。结论柚皮苷预干预可有效减轻脑缺血再灌注损伤,该保护作用同降低星形胶质细胞Cx43表达密切相关。     

脑白质低灌注损伤后星形胶质细胞缝隙连接蛋白43的表达变化

目的研究慢性脑白质缺血后星形胶质细胞和缝隙连接蛋白Connexin43(Cx43)的变化。方法原代培养星形胶质细胞,建立体外慢性缺氧模型;双侧颈总动脉狭窄法,建立慢性低灌注脑白质损伤小鼠模型;免疫荧光共染观察星形胶质细胞活化与Cx43表达。Western蛋白定量分析髓鞘相关指标髓鞘相关糖蛋白MAG,星形胶质细胞标记物GFAP和Cx43的表达。结果与对照组相比,细胞慢性缺氧7d后,星形胶质细胞明显增生活化,伴随Cx43表达水平明显上调。Western blot发现,在慢性脑白质缺血过程中,MAG的表达逐渐降低,GFAP持续增高,Cx43表达明显上调。免疫荧光共标记可见,星形胶质细胞中Cx43表达上调,主要分布于胼胝体中央区。结论慢性脑白质缺血损伤过程伴随星形胶质细胞Cx43表达增加,Cx43可能成为临床治疗血管性认知障碍的新靶点。     

实验性自身免疫性脑脊髓炎脑内缝隙连接蛋白Cx43和Cx32的表达变化

目的 观察豚鼠实验性自身免疫性脑脊髓炎(EAE)模型脑内星形胶质细胞(AS)缝隙连接(GJ)蛋白Cx43与神经元缝隙连接蛋白Cx32表达变化及相互关系,以探讨胶质细胞和神经元表面缝隙连接与EAE模型损伤的关系.方法 采用免疫组化方法,显示EAE模型豚鼠脑内胶质细胞和神经元表面缝隙连接蛋白Cx43和Cx32的表达变化及分布规律.结果 EAE豚鼠模型建立成功后,脑内星形胶质细胞Cx43-Li细胞表达明显增加,呈斑点样或分枝样;神经元Cx32-Li细胞表达也增加,并存在一定时间相关性.结论 EAE豚鼠脑内Cx43和Cx32表达增加,提示EAE发生后星形胶质细胞与神经元间信息交流可能加强.     

甲基强的松龙对伽玛刀照射后胶质细胞Cx43和GFAP表达的影响

目的 研究甲基强的松龙（MP）对伽玛刀照射后胶质细胞缝隙连接蛋白43（Cx43）和胶质纤维酸蛋白（GFAP）表达的影响。方法体外培养原代星形胶质细胞,经伽玛刀照射（边缘剂量32Gy）并培养36h后随机分为1μg／ml、5μg／ml、10μg／ml、20μg／ml、30μg／ml、40μg/ml组及实验对照组,各组进一步随机分为48h、72h、96h、120h4个亚组。将各组胶质细胞与相应剂量MP共培养,于48、72、96、120h各时间点采用免疫组化方法检测GFAP及Cx43的表达。结果伽玛刀照射后,胶质细胞Cx43表达降低,GFAp表达增高。添加MP后,20μg／ml、30μg／ml组Cx43呈时间依赖性上调;GFAP表达虽呈时间依赖性上升,但其峰值低于实验对照组,峰值出现时间亦晚于实验对照组。结论MP可上凋伽玛刀照射后胶质细胞Cx43的表达,抑制GFAP表达的上升趋势。     

PCNA和GFAP在脑星形胶质细胞瘤中表达的双重染色研究

目的研究人脑星形胶质细胞瘤中增殖细胞核抗原（PCNA）和胶质纤维酸性蛋白（GFAP）的表达及其与肿瘤分级的关系。方法采用免疫组化双重染色法对41例人脑星形胶质细胞瘤进行PCNA和GFAP两重标记检测。结果脑星形胶质细胞瘤中PCNA与GFAP表达率均为100％，PCNA表达水平与肿瘤分级呈正相关（r=-0．627，P〈0．01），GFAP表达水平与肿瘤分级呈负相关（r=-0．568，P〈0．01）；Ⅰ-Ⅱ级与Ⅲ-Ⅳ级胶质瘤间PCNA和GFAP表达均有显著性差异（P〈0．05）；GFAP表达和PCNA表达水平呈负相关（r=-0．332，P〈0．05）。结论PCNA与GFAP的表达有一定的相关性。PCNA与GFAP的双重表达与脑星形胶质细胞瘤的增殖活性和恶性程度有关。     

伽玛刀照射后胶质细胞CX43和GFAP表达变化及意义

目的研究伽玛刀照射后胶质细胞缝隙连接蛋白43(Connexin43,Cx43)和胶质纤维酸蛋白(glial fibrillary acid protein,GFAP)表达的变化。方法体外培养原代星形胶质细胞(astrocytes,Ast)分为正常对照组和γ刀照射组,后者经γ刀照射(边缘剂量4～36Gy),培养72小时后检测GFAP,Cx43。结果4～12Gy组与正常对照组无显著差异,至16Gy组胶质细胞开始增生GFAP表达阳性细胞数大于正常对照组且呈剂量依赖性增高至32Gy组GFAP表达达最大值。Cx43表达在12Gy组即开始明显下降且Cx43表达呈计量依赖性减低,在24～32Gy降低尤为显著至32Gy组达最低值。结论原代培养Ast经伽玛刀照射后GFAP表达增高,同时Cx43表达减低。Cx43的异常低表达可能是胶质增生及放射损伤的重要原因。     

阻滞弥漫性脑损伤ERK1/2信号通路对星形胶质细胞反应的作用

目的研究阻滞弥漫性脑损伤急性期ERKI／2信号通路过度激活对星形胶质细胞反应的影响。方法制作大鼠外伤性弥漫性脑损伤模型，打击损伤前30min自尾静脉注射U0126。Westemblot法检测损伤脑皮层pERKl／2表达水平，免疫组化染色法检测pERKl／2和GFAP在损伤脑组织中的表达。结果pERKl／2表达在损伤后迅速、显著升高，5min为表达高峰，其后下降，但直到损伤后72h都有高水平表达，至7d下降至基础水平。损伤后各个时间点，U0126组pERKl／2水平较DBI组明显降低（P〈0．05）。U0126组与DBI组比较，12～72h各时间点GFAP阳性细胞平均光密度值降低（P〈0.05）。结论弥漫性脑损伤诱导了强烈的ERKl／2信号通路激活和星形胶质细胞反应。U0126能够剂量依赖性抑制GFAP的表达，抑制急性期星形胶质细胞反应。     

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。     

高渗刺激后大鼠视上核星形胶质细胞和神经元的反应及其相互关系的光、电镜研究

目的探讨大鼠尾静脉注射高渗盐水(9％NaCl，5．5mL／kg)后，视上核(SON)内星形胶质细胞和神经元的可塑性反应及相互间的关系。方法用免疫组织化学和免疫电镜技术，观察刺激后15，45，90，180和360minSON内缝隙连接蛋白43(Cx43)和蛋白32(Cx32)的变化及超微结构。结果光镜下观察到Cx43阳性星形胶质细胞在15min出现，45min达到高峰；Cx32阳性神经元90min达到高峰。电镜下在SON内，观察到下列四种超微结构：(1)突触样结构(synapse like structure)，位于神经元的轴突末梢与Cx43阳性的星形胶质细胞突起之间；(2)三成分的突触复合体(tripartite synaptic structure)，由突触前膜、突触后膜和靠近此突触的星形胶质细胞突起共同组成；(3)同源性缝隙连接(gap junction，GJ)，位于星形胶质细胞突起之间，两侧均为Cx43；(4)“异源性缝隙连接样结构”(heterotypic gap junctions，HGJ)，是由Cx32阳性神经元和Cx43阳性星形胶质细胞突起组成的一种超微结构。结论高渗刺激后，SON内Cx43阳性星形胶质细胞和Cx32阳性神经元明显增加，前者出现和高峰的时间早于神经元；两者之间的HGJ数量明显增加，其他结构的数量变化不明显，因此两者可能是通过HGJ进行快速的信息交流。     

Sleep: big brain meets little brain

2001 Harcourt Publishers Ltd     

梗死灶切除治疗重型颅脑外伤合并大面积脑梗死

目的探讨重型颅脑外伤合并大面积脑梗死的最佳外科处理方式.方法对53例重型颅脑外伤病人行开颅血肿、挫伤脑组织清除术加去骨瓣减压术,其中31例未行梗死灶切除(第1组),22例行梗死灶切除(第2组).术后1个月、12个月评价两组的GOS,并行χ2检验.结果术后第1组死亡7例,植物生存5例,重残8例,轻残11例;第2组死亡1例,植物生存2例,重残9例,轻残10例.两组不良结果率(死亡 植物状态)有显著性差异,P＜0.05.结论对重型颅脑外伤合并大面积脑梗死的病人行挫伤脑组织和血肿加梗死灶切除,对降低病死率、提高有效生存率有明显作用.     

Measuring brain temperature while maintaining brain normothermia in patients with severe traumatic brain injury

The aim of this study was to evaluate the relationship between superficial temporal artery temperature (Tt), rectal temperature (Tr) and intracranial temperature (ICT) when attempting to keep the brain in a normothermic condition in patients with severe traumatic brain injury (TBI). We also compared the incidence of temperature gradient reversal in patients who survived (survivors) and patients who did not (non-survivors) and the difference in temperature gradient reversal between survivors and non-survivors. Tr is normally lower than and ICT and temperature gradient reversal, when Tr exceeds ICT, has been demonstrated to be an early sign of brain death. A total of 28 patients with severe TBI were enrolled retrospectively in our study between November 2008 and February 2010. Each patient’s Tt, Tr and ICT was recorded every hour for 4 days. Our results show that the frequency of brain hyperthermia in our participants (ICT > 38 °C) was 17.7%. Using a paired t-test and Bland-Altman plots, it was shown that a significant temperature difference existed between Tt, Tr and ICT (p < 0.001). The use of Spearman’s correlation method revealed that Tt, Tr and ICT were positively correlated (p < 0.001). Brain death occurred in five patients at a mean of 9.6 hours (range: 8-12 hours) after a temperature gradient reversal between Tt, Tr and ICT. Fisher’s exact test showed that there was a significant difference in the incidence of temperature gradient reversal between Tt, Tr and ICT in survivors and non-survivors (p < 0.001). We conclude that a significant temperature difference exists between Tt, Tr and ICT when maintaining brain normothermia. The daily practice of non-invasive Tt measurement may cause doctors to underestimate ICT; reversal of the ICT and Tt and/or Tr temperatures could be an early marker of a poor prognosis for patients with severe TBI.     

Repeat traumatic brain injury in the developing brain

The Center for Disease Control estimates that there are 1.7 million brain injuries in the US each year with 51% of these injuries occurring during periods of cerebral development. Among this population there is a growing population of individuals with repeat traumatic brain injury (RTBI). While the exact incidence is unknown, estimates range from 5.6 to 36% of the TBI population. This review summarizes the clinical problems/challenges and experimental research models that currently exist. It is intended to reveal the critical areas that need to be addressed so that age-relevant clinical management guidelines can be established to protect this population.     

Clinical cerebral microdialysis: brain metabolism and brain tissue oxygenation after acute brain injury.

While continuous monitoring of brain tissue oxygenation (P(ti)O2) is known as a practicable, safe and reliable monitoring technology supplementing traditional ICP-CPP-monitoring, the impact of cerebral microdialysis, now available bedside, is not proven extensively. Therefore our studies focused on the practicability, complications and clinical impact of microdialysis during long term monitoring after acute brain injury, especially the analysis of the correlation between changes of local brain oxygenation and metabolism. Advanced neuromonitoring including ICP-CPP-p(ti)O2 was performed in 20 patients suffering from acute brain injury. Analysis of the extracellular fluid metabolites (glucose, lactate, pyruvate, glutamate) were performed bedside hourly. No catheter associated complications, like infection and bleeding, occurred. However, longterm monitoring was limited in 5 out of 20 patients caused by obliteration of the microdialysis catheter after 3-4 days. In the individual patients partly a correlation between increased lactate levels as well as lactate pyruvate ratios and hypoxic brain tissue oxygenation could be found. Analysing the data sets of all patients only a low correlation was detected indicating physiological and increased lactate and lactate/pyruvate ratio during sufficient brain oxygenation. Additionally, concentrations of excitatory amino acid glutamate were found in normal and elevated range during periods of hypoxic oxygenation (P(ti)O2 < 10 mmHg) and intracranial hypertension. Our data strongly suggest partly evidence of correlation between hypoxic oxygenation and metabolic disturbances after brain injury. On the other hand brain metabolism is altered without changes of cerebral oxygenation. Further studies are indicated to improve our pathophysiological knowledge before microdialysis is routinely useful in neurointensive care.