电刺激预处理对大鼠颅脑创伤后认知功能的影响

目的探讨非创伤性（电刺激）动员外周血内皮祖细胞对大鼠颅脑创伤后认知功能的影响及其可能机制。方法于电刺激后24h对成年雄性Wistar大鼠施行液压打击术,制备颅脑创伤模型,流式细胞术测量创伤后外周血内皮祖细胞数量;免疫组织化学染色观察患侧海马区血管性血友病因子表达阳性（vwF）微血管密度;Morris水迷宫实验评价大鼠伤后认知功能恢复程度。结果与单纯打击组比较,创伤后3h和6h电刺激预处理组大鼠外周血内皮祖细胞数量显著升高（均P=0．000）,之后逐渐降至正常水平;与其他各组相比,伤后第1天电刺激预处理组大鼠海马区vWF微血管密度即开始增加,至第7天达高峰平台期（P=0．000）;与单纯打击组相比,Morris水迷宫实验训练第3天时电刺激预处理组大鼠逃避潜伏期开始缩短,随着训练时间的延长,组间差异明显增加且具有统计学意义（P=0．016）。结论电刺激预处理可促进颅脑创伤后认知功能的恢复。其潜在的机制可能与创伤前动员机体外周血内皮祖细胞,使得伤后更多的内皮祖细胞归巢到损伤区域,有助于伤后血管新生和神经功能的恢复。     

创伤性与非创伤性应激对大鼠内皮祖细胞的影响

目的 观察大鼠在创伤性和非创伤性应激状态下外周血内皮祖细胞数目的 变化,探讨可能影响其变化的相关因素.方法 36只健康雄性Wistar大鼠,随机接受颅脑创伤、电休克和冷水游泳刺激,分别于应激前(0 h)及应激后3 h、6 h、24 h、48 h、72 h和7 d采集内眦球后静脉从血,分离单个核细胞,CD34和CD133双荧光标记内皮祖细胞,流式细胞术计数内皮祖细胞数目.结果 颅脑创伤组大鼠外周血内皮祖细胞数目于伤后3 h即明显减少(P=0.000);随后迅速增加,至6 h达峰值水平(P=0.005);至24 h降至正常值范围(P=0.728).而非创伤性应激(电休克和冷水游泳)后3 h,大鼠外周血内皮祖细胞数目即开始增加(P=0.000,0.019);至24 h达峰值水平(P=0.000,0.004);随后逐渐减少,至72 h恢复至正常值范围(P=0.999,0.055).对照组大鼠各观察时间点外周血内皮祖细胞数目变化,差异无统计学意义(均P>0.05).结论 应激反应可以促进骨髓内皮祖细胞的动员,创伤性应激后内皮祖细胞数目先减少后增加的特征与非创伤性应激明显不同,其短暂性减少可能与组织损伤修复导致的内皮祖细胞消耗有关.     

重组人红细胞生成素改善小鼠颅脑创伤后认知功能的机制探讨

研究背景颅脑创伤后的炎症反应可导致继发性脑损伤,引起神经元凋亡和神经功能缺损。重组人红细胞生成素(rhEPO)具有神经保护作用,我们采用液压打击动物模型,观察经rhEPO治疗后脑组织中性粒细胞变化和神经元凋亡情况,以探讨该药对颅脑创伤后神经功能保护的潜在作用机制。方法采用液压打击模型模拟颅脑创伤,分别于创伤后第1、3和7天观察不同处理组小鼠海马区髓过氧化物酶阳性中性粒细胞和Caspase-3阳性神经元表达变化;并于创伤后第7~11天进行Morris水迷宫实验,记录小鼠逃避潜伏期。结果与假手术组相比,伤后第1天小鼠海马区髓过氧化物酶阳性中性粒细胞数目即开始增加(均P=0.000),并于第3天达峰值水平(均P=0.000),至第7天时减少(均P=0.000);Caspase-3阳性神经元数目于伤后第1天开始逐渐增多(均P=0.000),至第7天达峰值水平(均P=0.000)。与生理盐水组相比,rhEPO组小鼠伤后第1~7天海马区髓过氧化物酶阳性中性粒细胞和Caspase-3阳性神经元数目呈逐渐减少趋势,不同观察时间点差异具有统计学意义(均P=0.000)。与生理盐水组相比,rhEPO组小鼠于Morris水迷宫实验训练第3天逃避潜伏期开始缩短(P=0.013),随着训练时间的延长,组间差异具有统计学意义(P=0.011,0.000)。结论液压打击后给予rhEPO可促进小鼠颅脑创伤后认知功能的恢复。其可能机制与抑制创伤后局部炎症反应、减少神经元凋亡、促进神经功能恢复有关。     

脑损伤大鼠内皮祖细胞与早期血管新生的关系

目的 探讨创伤性脑损伤大鼠外周血中内皮祖细胞的变化及创伤区早期动态血管新生情况.方法 成年雄性Wistar 大鼠70只随机分为创伤组及假手术组,每组各35只,两组于伤前及伤后3、6、24、48、72、168 h随机取7只大鼠外周血,用流式细胞仪测外周血中内皮祖细胞数量.同时于伤前及伤后1、4、7、14 d各随机取5～7只大鼠取脑, 行血管内皮标志物CD31免疫组化染色观察创伤区血管的新生情况. 结果脑创伤大鼠外周血中的内皮祖细胞表现于3 h先降低(P<0.01),在6 h升高达峰(P<0.05),后逐渐降低达基础水平.创伤区周围CD31~+细胞与对照组相比于1d开始增多(P<0.01),于7 d左右达到平台高峰;外周血中内皮祖细胞的数量变化与创伤区周围血管的数量变化存在明显的相关性.同时微血管呈逐渐增多的趋势.结论 脑创伤后外周血中的内皮祖细胞明显增加,归巢到创伤区,参与了创伤区血管的新生和损伤组织的修复.     

Adult neurogenesis for repairing cognitive function after deferent graded traumatic hippocampus injury

摘要 研究背景： 内源性神经细胞再生存在于成年哺乳动物脑内,海马是其中的一个典型区域。外伤性颅脑损伤后,该部位的神经前体细胞可能通过细胞增殖反应和突触重建修复神经功能。 目的： 检测不同程度海马创伤后空间学习和记忆能力的修复情况以及神经前体细胞的再生状态,评价内源性神经细胞再生对于脑创伤修复的意义。 实验设计,工作时间和环境： 随机对照实验。2009年2月到2009年10月于天津医科大学总医院神经损伤变异与修复重点实验室完成。 材料： 小鼠抗BrdU一抗,山羊抗小鼠二抗IgG-cy2,小鼠抗NeuN一抗,山羊抗小鼠二抗IgG-cy3用来进行免疫组化荧光染色,通过Morris水迷宫检测脑创伤后认知功能的情况。 方法： 按照完全随机化原则,成年Wistar大鼠45只随机分为轻型组(n=15)、重型组(n=15)和对照组(n=15),前两组分别给予不同程度的液压打击致海马损伤,对照组不给予创伤。使用生物标记物BrdU和NeuN对脑组织进行免疫组化荧光染色。 主要指标的测量： 在伤后8—12天、29—33天和57—61天3个时间点对大鼠进行Morris水迷宫检测以评价认知功能的修复情况,在伤后第7天和第61天对脑组织进行免疫组化荧光染色观察新生细胞的状态。 结果： 在伤后8—12天和29—33天,轻型组和重型组较对照组表现出明显的认知功能障碍(P＜0.01);在伤后57—61天,轻型组和对照组认知功能无明显差异(P=0.627),重型组依然存在认知功能障碍(P＜0.01)。伤后7天,打击组较对照组表现出明显增强的细胞增殖（BrdU+细胞）(P＜0.01);伤后61天,轻型组的新生神经细胞（BrdU+/NeuN+细胞）明显高于重型组和对照组(P＜0.01);在存活细胞中,对照组较打击组有更高比例的细胞分化为成熟神经细胞(P＜0.01)。 结论： 颅脑创伤对于成年海马的神经前体细胞增殖可能是一个促进因素,但是,严重的颅脑创伤并没有伴随着更多的神经细胞再生。内源性神经细胞再生能够在一定程度上修复神经功能障碍,对于严重的颅脑创伤,细胞再生的微环境遭到破坏,不能修复创伤从而残留神经功能障碍,需要外部治疗的干预。     

颈内动脉粥样硬化性脑梗死患者外周血内皮祖细胞的变化趋势

目的 观察急性颈内动脉粥样硬化性脑梗死患者外周血内皮祖细胞数目的 变化趋势.方法 分别于发病24 h,以及第4、7、14 和21 天时提取30 例成年急性脑梗死患者外周血单个核细胞,流式细胞术检测CD34和CD133表达水平,计数内皮祖细胞数目.结果 不同处理组患者各观察时间点外周血内皮祖细胞数目比较,差异均有统计学意义(P = 0.000).脑梗死后24 h,脑梗死组和颈动脉硬化组患者外周血内皮祖细胞数目均低于对照组(P = 0.000);脑梗死后第7 天,外周血内皮祖细胞数目减少至最低水平(P = 0.001),至第21 天外周血内皮祖细胞数目接近颈动脉硬化组水平(P = 0.901),但仍低于正常值范围(P = 0.000).内皮祖细胞数目的 变化与血小板计数之间不具有相关性(R2 = 0.852,P = 0.895).结论 颈内动脉系统粥样硬化所致脑梗死患者外周血内皮祖细胞数目低于正常值范围,且于急性期可能存在骨髓动员抑制,同时需要消耗大量内皮祖细胞以进行损伤内皮的修复,使得患者在急性期出现短暂性内皮祖细胞数目减少.     

创伤性脑损伤后大鼠海马区糖皮质激素受体mRNA的表达

目的研究创伤性脑损伤(TBI)后大鼠海马区糖皮质激素受体(GR)mRNA表达的变化及其对大鼠认知功能的影响。方法建立大鼠头颅侧向旋转加速脑创伤模型,应用逆转录酶-聚合酶链式反应(RT-PCR)和Morris水迷宫检测伤后大鼠海马区GR mRNA的表达与学习记忆功能的关系。结果伤后4～7 d大鼠海马区GR持续低表达;Morris水迷宫检测伤后大鼠出现认知功能障碍。结论 TBI大鼠海马区GR mRNA的降低影响大鼠认知功能。     

颅脑损伤后不同剂量糖皮质激素应用对大鼠继发性脑损伤和死亡率的影响

目的 探讨颅脑损伤后早期应用不同剂量糖皮质激素对大鼠继发性脑损伤和死亡率的影响. 方法 将成年雄性Wistar大鼠220只按随机数字表法分为正常组、地塞米松正常给药组、甲基强的松龙正常给药组、创伤对照组、小剂量地塞米松组、中剂量地塞米松组、大剂量地塞米松组、小剂量甲基强的松龙组、中剂量甲基强的松龙组和大剂量甲基强的松龙组(后7组统称损伤组),每组各22只.损伤组通过液压打击方法制备成颅脑损伤模型且分别给予生理盐水或不同剂量不同类型糖皮质激素处理,并于伤后24 h进行改良神经功能缺损评分.采用TUNEL法于伤后24h、48h、7d和14d时检测各组大鼠损伤侧海马组织的细胞凋亡情况.观察伤后14d内各组大鼠的死亡率,并通过尸检和常规HE染色观察死亡大鼠脑组织、垂体、心脏和肺脏的变化. 结果 损伤组间伤后24h神经功能缺损评分比较差异无统计学意义(P＞0.05).损伤组大鼠海马组织中凋亡细胞于伤后24h开始出现,48 h达到高峰,7～14d内降至正常,其中大剂量地塞米松组和大剂量甲基强的松龙组凋亡细胞数在伤后48 h时均明显高于创伤对照组,差异均有统计学意义(P=0.000,P=0.002).大剂量地塞米松组和大剂量甲基强的松龙组的大鼠死亡率也均明显高于创伤对照组,差异均有统计学意义(P=0.012,P=0.038).尸检发现大剂量地塞米松组和大剂量甲基强的松龙组的死亡大鼠均有不同程度的间质性肺炎及垂体淤血. 结论 颅脑损伤可以导致海马神经细胞凋亡,而伤后早期应用大剂量糖皮质激素可进一步加重其凋亡,同时增加死亡率,其原因可能为间质性肺炎和垂体淤血的发生.     

氢盐水对脑创伤后大鼠认知功能的保护作用

目的 观察氢生理盐水对脑外伤后大鼠认知功能的改善作用,并初步探讨其可能机制.方法 应用液压打击损伤装置建立大鼠中度颅脑损伤模型,实验动物随机分为对照组、损伤+生理盐水组、损伤+含氢生理盐水组,采用Morris水迷宫法测定大鼠的认知功能表现;利用分光光度比色法、酶联免疫吸附法和Western blot等方法,分别检测受损同侧海马组织中丙二醛(MDA)、脑源性神经生长因子(BDNF)和突触蛋白Ⅰ的水平,并采用方差分析方法进行统计学分析.结果 Morris 水迷宫法显示腹腔注射含氢的生理盐水能够明显地提高大鼠的认知功能;在对受伤同侧大鼠的海马组织进行测定中,显示损伤后大鼠海马组织中MDA水平的升高及BDNF和突触蛋白Ⅰ水平的下降,而腹腔内注射含氢生理盐水能够明显改善受伤大鼠的认知功能,并能够降低MDA水平,提高BDNF和突触蛋白Ⅰ.结论 腹腔内注射含氢生理盐水能够通过抑制氧化损伤,改善颅脑损伤后动物的认知功能,而BDNF及其效应蛋白突触蛋白Ⅰ可能与其认知功能改善有关.     

慢性脑缺血海马CA1区微血管LRP-1的表达及其对认知功能的影响

目的探讨慢性脑缺血大鼠海马CA1区微血管LRP—1表达与认知功能改变的相关性。方法应用双侧颈动脉结扎的方法制作SD大鼠慢性缺血模型;Morris水迷宫对大鼠的认知功能进行测试;免疫组化技术测定海马CA1区微血管LRP-1,Ⅷ因子相关抗原及GFAP的表达;放免技术对脑脊液Aβ蛋白的浓度进行测定。采用 MIAS图像分析系统对免疫组化结果进行平均光密度测定及微血管计数。结果术后1个月手术组大鼠认知功能已明显下降,寻找平台所需游走的距离较假手术显著延长。术后6个月手术组大鼠海马CA1区微血管LRP-1的表达较假手术组大鼠显著降低;GFAP的表达显著增强;但VIII因子相关抗原的表达及微血管计数两组之间无显著差异。微血管LRP-1表达与水迷宫成绩呈负相关。手术组大鼠脑脊液Aβ蛋白含量较假手术组显著下降。结论慢性缺血过程中,大鼠认知功能下降与海马CA1区微血管LRP-1的表达下降有显著相关性。     

Therapeutic effects of environmental enrichment on cognitive function and tissue integrity following severe traumatic brain injury in rats

Postinjury environmental enrichment (EE) has been shown to alter functional and anatomical outcomes in a number of injury paradigms, including traumatic brain injury (TBI). The question of whether EE alters functional outcome following TBI in a model which produces overt histopathological consequences has not been addressed. We investigated this question using the severe, parasagittal fluid percussion injury (FPI) model. Rats (n = 7 per group, enriched and standard for behavior; n = 15 per group for histology) underwent severe (2.2-2.6 atm) FPI, with sham-operated rats (n = 7 per group, enriched and standard for behavior; n = 6 enriched, n = 3 standard for histology) serving as controls. Animals were allowed to recover for 11 days either in standard single housing or together (injured and sham) in an enriched environment consisting of a 92 x 61 x 77-cm ferret cage filled with various stimulatory objects. Consistent with earlier reports, injured animals recovering in the enriched environment showed significantly (P < 0.05) shorter latencies to find the platform in a Morris Water Maze task versus injured/standard animals on day 12 post-TBI. However, both injured groups showed significant deficits versus sham groups (P < 0.05). There were no differences between the sham/enriched and sham/standard groups. No significant group differences in swim speed were observed. At 14 days post-TBI, enriched animals had approximately twofold smaller lesion areas in regions of the cerebral cortex posterior to the injury epicenter (-4.5, -5.8, -6.8 mm relative to bregma; P < 0.05) compared to injured/standard animals. In addition, overall lesion volume for the entire injured cortical hemisphere was significantly smaller in animals recovering in the enriched environment. These results indicate that noninvasive environmental stimulation is beneficial in attenuating cognitive deficits and preserving tissue integrity in a TBI model which causes cerebral contusion and cell death.     

Effects of atorvastatin in the regulation of circulating EPCs and angiogenesis in traumatic brain injury in rats

Circulating endothelial progenitor cells (EPCs) play an important role in angiogenesis and vasculogenesis. Statins administered promote functional improvement in rats, independent of their capability to lower cholesterol. Whether statin treatment regulates circulating EPCs after traumatic brain injury (TBI) has not been investigated. We hypothesized that atorvastatin increases circulating EPCs and promotes angiogenesis in TBI rats. Wistar rats (20 months old) were subjected to TBI and treated with or without atorvastatin (orally administered, 1mg/kg/day) starting 1h after TBI and then daily for 14 consecutive days. Long term potentiation (LTP) in the cornu ammonis1 of the hippocampus as well as the Modified Neurological Severity Score (mNSS) and the Morris Water Maze (MWM) functional tests were performed. Blood circulating EPCs were identified by flow cytometry. Rats were sacrificed 25 days after TBI. vWF and CD31 immunostaining was performed. We found that atorvastatin administration significantly induced angiogenesis and increased circulating EPC levels as well as improved functional recovery when compared with non-treatment TBI-control rats (P<0.05). The circulating EPC level is correlated with vascular density (r=0.878, P <0.05) and CD31 positive cell number in the injured brain (r=0.921, P <0.05). The results suggest that increasing circulating EPCs with atorvastatin treatment may contribute to the observed increase in angiogenesis and improved functional outcome after TBI.     

大鼠颅脑损伤后大脑中动脉形态结构的变化

目的探讨颅脑损伤后大鼠损伤侧和对侧大脑中动脉形态结构及管壁细胞Cx40、Cx43的改变。方法成年SD大鼠45只按随机数字表发随机分为正常组（9只）、假手术组（9只）及损伤组（27只）,损伤组又根据伤后时间分为伤后6 h、24 h、72 h三个亚组（每亚组9只）。利用液压冲击法建立大鼠颅脑损伤模型,通过显微镜和透射电镜观察损伤侧和对侧大脑中动脉形态学改变,免疫组化法检测管壁细胞Cx40、Cx43表达水平改变。结果颅脑损伤后,大鼠损伤侧大脑中动脉随时间进程出现不同程度的内皮细胞形态结构改变、内弹力膜皱缩、平滑肌细胞水肿变形,进而管腔出现不同程度的狭窄甚至闭塞;损伤对侧大脑中动脉也出现形态结构改变,但发生较晚,程度较轻。与对照组相比,损伤组大鼠损伤侧和对侧大脑中动脉血管壁细胞Cx40、Cx43表达均明显增加（P〈0.05）,伤后24 h达高峰。结论颅脑损伤后不仅损伤区域大血管受损,远隔区域大血管亦可见损伤性改变。     

大鼠颅脑创伤后肝细胞生长因子表达变化的实验研究

目的 探讨肝细胞生长因子(HGF)在颅脑创伤后的表达趋势,为颅脑创伤治疗中的HGF干预策略提供前期研究基础. 方法 96只wistar大鼠按随机数字表法分为实验组和假手术组,实验组为液压冲击中度颅脑创伤大鼠,并分为伤后2h、6h、12h、24 h、72h、168 h、336 h组,假手术组不致伤,每组再分为两个亚组.每亚组6只,一组行HE及免疫组化染色,观察伤后病理变化及HGF的表达部位和表达量,另外一组用RT-PCR的方法 观察创伤后HGF mRNA表达情况.结果 在创伤后的大鼠大脑皮层组织中,HGF在蛋白水平以及基因水平都出现表达增高的情况.创伤边缘区HGF阳性细胞数从伤后24 h开始增多,168 h达高峰,336 h有所下降,但仍高于伤前水平,差异有统计学意义(P<0.05).HGF mRNA表达量从创伤后72 h开始增加,168 h达高峰,与假手术组比较差异有统计学意义(P<0.05). 结论 HGF作为神经营养因子和血管生长因子,可能参与了颅脑创伤后神经元的保护和组织的修复、再生.     

NOGO-A在创伤性脑损伤后大鼠脑组织含量表达及干预实验研究

目的研究创伤性脑损伤（TBI）后大鼠脑组织内NOGO-A分子含量及大鼠脑超微结构的改变以及二者与RHOA/ROCK信号传导通道的联系。 方法45只健康SD大鼠按照随机数字表法分为对照组、中度创伤组和干预组，每组15只。中度创伤组和干预组大鼠采用击锤、撞杆自由落体原理致伤，制作TBI大鼠模型，干预组大鼠创伤后立即给予静脉注射盐酸法舒地尔注射液。TBI后24 h处死各组大鼠，采用电子显微镜观察各组损伤区脑组织细胞超微结构的变化，采用免疫组化技术观察各组大鼠脑组织中NOGO-A蛋白的含量，并测定NOGO-A蛋白的灰度值。 结果TBI后24 h，中度创伤组及干预组大鼠脑组织损伤区出现病理性损伤，干预组程度较中度创伤组轻。3组大鼠脑组织内NOGO-A蛋白表达量比较，差异有统计学意义（F=176.085，P<0.05），中度创伤组的NOGO-A蛋白含量最高，干预组次之，对照组最低。 结论TBI后24 h大鼠脑内损伤区出现细胞核、线粒体损害及细胞水肿，NOGO-A含量增加。RHOA/ROCK信号通路被阻断后能够改善TBI大鼠脑组织损伤区细胞超微结构损害以及减少NOGO-A的含量。     

创伤性颅脑损伤后脑组织中TLR4表达的实验研究

目的 研究创伤性脑损伤(TBI)后损伤灶周围脑组织Toll样受体4(TLR4)的表达,探讨TLR4/NF-κB信号通路在TBI中的作用机制.方法 SD大鼠36只按随机数字表法分为对照组(n=12)、TBI后1d组(n=6)、TBI后3d组(n=12)和TBI后7d组(n=6),后3组采用Feeney自由落体撞击法制作TBI模型,对照组仅行右侧顶部开窗而无TBI.应用RT-PCR、凝胶电泳迁移率实验(EMSA)、ELISA分别检测4组大鼠挫伤脑组织TLR4 mRNA、NF-κB活性、TNF-α和IL-6浓度的变化;免疫组化染色检测对照组和TBI后3d组大鼠挫伤脑组织TLR4的表达.结果 与对照组比较,TBI后1d、3d、7d组TLR4 mRNA表达、NF-κB活性、TNF-α和IL-6浓度均增加,差异有统计学意义(P＜0.05);对照组脑组织TLR4表达较少,TBI后3d组创伤灶周围可见大量TLR4阳性细胞,主要表达在皮层胶质细胞、神经元中;NF-κB活性与TLR4 mRNA的表达呈正相关关系(r=0.786,P=-0.000).TNF-α、IL-6与TLR4的表达也呈正相关关系(r=0.517,P=0.010;r=0.503,P=0.012).结论 TBI可引起损伤区脑组织TLR4的表达和下游NF-κB、促炎症因子水平的增加,TLR4/NF-κB信号通路可能在脑组织的继发性损害中起重要作用.     

Intravenous multipotent adult progenitor cell therapy for traumatic brain injury: Preserving the blood brain barrier via an interaction with splenocytes

Recent investigation has shown an interaction between transplanted progenitor cells and resident splenocytes leading to the modulation of the immunologic response in neurological injury. We hypothesize that the intravenous injection of multipotent adult progenitor cells (MAPC) confers neurovascular protection after traumatic brain injury through an interaction with resident splenocytes, subsequently leading to preservation of the blood brain barrier.Four groups of rats underwent controlled cortical impact injury (3 groups) or sham injury (1 group). MAPC were injected via the tail vein at two doses (2 * 10⁶ MAPC/kg or 10 * 10⁶ MAPC/kg) 2 and 24 h after injury. Blood brain barrier permeability was assessed by measuring Evans blue dye extravasation (n = 6/group). Additionally, splenic mass was measured (n = 12/group) followed by splenocyte characterization (n = 9/group) including: cell cycle analysis (n = 6/group), apoptosis index (n = 6/group), cell proliferation (n = 6/group), and inflammatory cytokine measurements (n = 6/group). Vascular architecture was determined by immunohistochemistry (n = 3/group).Traumatic brain injury results in a decrease in splenic mass and increased blood brain barrier permeability. Intravenous infusion of MAPC preserved splenic mass and returned blood brain barrier permeability towards control sham injured levels. Splenocyte characterization indicated an increase in the number and proliferative rate of CD4+ T cells as well as an increase in IL-4 and IL-10 production in stimulated splenocytes isolated from the MAPC treatment groups. Immunohistochemistry demonstrated stabilization of the vascular architecture in the peri-lesion area.Traumatic brain injury causes a reduction in splenic mass that correlates with an increase in circulating immune cells leading to increased blood brain barrier permeability. The intravenous injection of MAPC preserves splenic mass and the integrity of the blood brain barrier. Furthermore, the co-localization of transplanted MAPC and resident CD4+ splenocytes is associated with a global increase in IL-4 and IL-10 production and stabilization of the cerebral microvasculature tight junction proteins.     

The maxi-K channel opener BMS-204352 attenuates regional cerebral edema and neurologic motor impairment after experimental brain injury.

Large-conductance, calcium-activated potassium (maxi-K) channels regulate neurotransmitter release and neuronal excitability, and openers of these channels have been shown to be neuroprotective in models of cerebral ischemia. The authors evaluated the effects of postinjury systemic administration of the maxi-K channel opener, BMS-204352, on behavioral and histologic outcome after lateral fluid percussion (FP) traumatic brain injury (TBI) in the rat. Anesthetized Sprague-Dawley rats (n = 142) were subjected to moderate FP brain injury (n = 88) or surgery without injury (n = 54) and were randomized to receive a bolus of 0.1 mg/kg BMS-204352 (n = 26, injured; n = 18, sham), 0.03 mg/kg BMS-204352 (n = 25, injured; n = 18, sham), or 2% dimethyl sulfoxide (DMSO) in polyethylene glycol (vehicle, n = 27, injured; n = 18, sham) at 10 minutes postinjury. One group of rats was tested for memory retention (Morris water maze) at 42 hours postinjury, then killed for evaluation of regional cerebral edema. A second group of injured/sham rats was assessed for neurologic motor function from 48 hours to 2 weeks postinjury and cortical lesion area. Administration of 0.1 mg/kg BMS-204352 improved neurologic motor function at 1 and 2 weeks postinjury (P < 0.05) and reduced the extent of cerebral edema in the ipsilateral hippocampus, thalamus, and adjacent cortex (P < 0.05). Administration of 0.03 mg/kg BMS-204352 significantly reduced cerebral edema in the ipsilateral thalamus (P < 0.05). No effects on cognitive function or cortical tissue loss were observed with either dose. These results suggest that the novel maxi-K channel opener BMS-204352 may be selectively beneficial in the treatment of experimental TBI.     

基因转染人羊膜细胞对颅脑创伤大鼠海马的作用

目的 观察移植转染胶质源性神经营养因子(GDNF)基因人羊膜细胞(HACs)对创伤性脑损伤(TBI)大鼠海马神经元的影响.方法 采用改进Feeney法制作TBI致海马神经元损伤模型.TBI 24 h后于挫伤灶边缘移植,移植处距硬脑膜4 mm和2 mm深浅两点移植,共5μl含5×10~5个细胞.TBI+GDNF组移植转染GDNF基因HACs;TBI+eGFP组移植转染eGFP基因HACs;TBI+PBS组注射5μl PBS;假TBI组未行移植操作.移植后12 d Morris水迷宫检测结束后制片并行焦油紫染色,检测海马及移植针道靶点周围组织,取移植针道靶点周围组织行RT-PCR检测GDNFmRNA水平.结果 免疫荧光法检测转染GDNF基因HACs荧光显微镜下呈红色荧光.TBI+GDNF组大鼠学习记忆功能明显好于TBI+eGFP组和TBI+PBS组,TBI+eGFP组和TBI+PBS组大鼠损伤侧海马神经元显著缺失,胞体缩小,深染.TBI+GDNF组部分海马神经元缺失.RT-PCR检测TBI+GDNF组GDNFmRNA高水平表达.结论 移植转染GDNF基因HACs对TBI大鼠海马神经元有保护作用.