实验性大鼠脑损伤后脑组织中肿瘤坏死因子α基因表达的变化

目的：观察闭合性脑损伤后脑组织肿瘤坏死因子αmRNA表达变化，探讨对脑组织的影响。方法：实验于2004—09／2005—03在郑州大学基础医学院人体解剖学教研室神经分子生物学实验室进行，选择SD大鼠72只，随机分为实验组66只和对照组6只，实验组采用Marmarou法制备闭合性颅脑损伤模型，对照组不做任何处理。实验组又分为脑损伤后30min，1，3，9，12h和1，2，3，4，5，6d 11个时间点，每个时间点6只。应用反转录多聚酶链反应检测脑损伤后不同时间点脑组织中肿瘤坏死因子αmRNA表达。结果：72只大鼠全部进入结果分析：对照组未见肿瘤坏死因子α表达。实验组损伤后30min及1h组与对照组无明显差别，9h-5d明显增加，12h-3d达到高峰，6d后开始下降。结论：大鼠闭合性脑损伤后脑组织肿瘤坏死因子dmRNA表达水平增加，是加重继发性脑损伤的重要囡素．     

益赛普对脑外伤后核转录因子-κB、肿瘤坏死因子-α的表达及脑水肿的影响

目的 观察注射用重组人Ⅱ型肿瘤坏死因子受体-抗体融合蛋白(rhTNFB:Fc,益赛普)对创伤性脑损伤后脑组织核转录因子-κB(NF-KB)和肿瘤坏死因子-α(TNF-α)的表达及对脑水肿的影响.方法 采用Feeney自由落体撞击法建立脑损伤模型,益赛普组大鼠于脑损伤模型建立后30 min腹腔注射益赛普3.0 mg/kg,对照组及创伤组大鼠注射生理盐水.采用放射免疫法检测大鼠脑组织匀浆TNF-α的蛋白表达,免疫组织化学法检测脑组织NF-κB的阳性细胞表达,用干湿重法测定大鼠脑组织含水量;并应用电镜技术进行脑组织病理形态学观察.结果 与对照组比较,大鼠脑损伤后脑组织NF-κB和TNF-α的表达及脑组织含水量均明显升高(P<0.05或P<0.01);与创伤组比较,益赛普治疗组大鼠NF-κB、TNF-α表达及脑组织含水量均显著降低(P<0.05,P<0.01).在电镜下观察,益赛普组大鼠脑组织损伤明显较创伤组大鼠轻.结论 大鼠急性脑损伤后脑组织NF-κB及TNF-α表达增加,并与脑水肿程度相平行;急性脑损伤后应用益赛普治疗可以抑制脑组织NF-κB和TNF-α的表达,减轻脑水肿.     

胶质细胞源性神经营养因子及其受体在大鼠创伤性脑损伤后皮层中的表达

目的探讨大鼠闭合性创伤性脑损伤后不同时间胶质细胞源性神经营养因子（GDNF）及其受体GFRα-1、Ret在大脑皮层的表达。方法制备Marmarou＇s大鼠落体打击损伤模型，将大鼠随机分为正常对照组、手术对照组及损伤后1h组、2h组、4h组、8h组、12h组、24h组、48h组、72h组和5d组。制备组织芯片，采用免疫组化法检测大脑皮层GDNF、GFRα-1、Ret的表达。结果正常组、手术对照组皮层中可见GDNF及其受体低水平表达，损伤后2h，皮层中GDNF的表达达到高峰，大量表达可持续至伤后5d，GFRα-1和Ret的表达在损伤后4h时达到高峰，于伤后24h降至正常。结论大鼠闭合性创伤性脑损伤后皮层中GDNF及其受体在早期即明显表达，两者在脑损伤后表达的时序性变化特点基本一致，共同参与创伤性脑创伤的病理生理过程。     

力竭运动后24 h模型大鼠肾脏结构和炎症因子对黑加仑提取物干预的反应

背景：急性运动后肾脏组织易出现运动性肾缺血再灌注现象,自由基生成增加,发生炎症反应,导致肾功能异常。目的：观察黑加仑提取物对力竭运动后24 h大鼠肾脏结构、肿瘤坏死因子α和核因子κB表达的影响。方法：30只雄性Wistar健康大鼠随机分为3组,每组10只,黑加仑提取物组给予0.44 g/kg黑加仑提取物灌胃,安静对照组、力竭运动后24 h组灌服同等体积的蒸馏水,连续灌胃6周。力竭运动后24 h组和黑加仑提取物组于末次灌胃后进行无负重游泳运动直至力竭疲劳,于24 h后取材,电镜和光镜观察肾脏组织形态和超微结构变化,免疫组化法检测肿瘤坏死因子α蛋白和核因子κB蛋白表达,RT-PCR检测肿瘤坏死因子α mRNA和核因子κB mRNA的表达。结果与结论：与安静对照组比较,力竭运动后24 h组中肾脏核因子κB蛋白和肿瘤坏死因子α蛋白高表达,核因子κB mRNA和肿瘤坏死因子α mRNA表达水平极显著增加（P 〈0.01）;与力竭运动后24 h组比较,黑加仑提取物组中肾脏核因子κB蛋白和肿瘤坏死因子α蛋白低表达,核因子κB mRNA表达水平显著性降低（P 〈0.05）;肿瘤坏死因子α mRNA表达水平极显著性下降（P〈0.01）。力竭运动后24 h组大鼠肾脏发生明显的形态变化和超微结构损伤,黑加仑提取物组大鼠肾脏结构趋于正常。结果表明黑加仑提取物可修复力竭运动后24 h肾脏组织结构,减少炎症因子的表达,防止肾脏发生炎症性损伤。     

心肺复苏大鼠脑红蛋白缺氧诱导因子-1α的表达变化

目的 研究大鼠心肺复苏后不同时间点脑红蛋白(neuroglobin,Ngb)、缺氧诱导因子-1α(HIF-1α)在mRNA水平表达中的变化规律,探讨Ngb在心脏骤停后脑缺血缺氧损伤病理变化中的作用机制及其诱导表达途径.方法 SD雄性大鼠40只随机分为五组(n=8):假手术组及复苏后1 h、6 h、12 h、24 h组.窒息法致大鼠心脏骤停后予以心肺复苏,复苏后不同时间点处死大鼠,应用RT-PCR法观察脑组织Ngb mRNA、HIF-1α mRNA表达情况.结果 复苏组脑组织Ngb mRNA表达高于假手术组(P<0.05),并于损伤后12 h达高峰;与假手术组比较,复苏组脑组织HIF-1α mRNA表达增加(P<0.05),且于复苏后1 h、6 h、12 h、24 h呈持续上升趋势.结论 大鼠心脏骤停后早期脑组织Ngb mRNA、HIF-1α mRNA表达增加,且呈时相性改变.     

亚低温对急性脊髓损伤后肿瘤坏死因子-α表达及运动功能恢复的影响

目的 观察大鼠脊髓损伤(SCI)后亚低温对肿瘤坏死因子-α (TNF-α)mRNA表达及运动功能恢复的影响,探讨其可能的作用机制.方法 72只SD大鼠随机分为对照组(n=24)、常温组(n=24)和亚低温组(n=24),每组再分为六个亚组,每亚组4只,参照改良Allen法建立大鼠脊髓(T9)中度损伤模型,亚低温组给予亚低温治疗5 h,而对照组不做亚低温处理.分别于损伤后6 h、12 h、24 h、72 h、1周和4周,利用 Tarlov评分检测亚低温对大鼠SCI后运动功能恢复的影响;然后将大鼠处死,利用半定量 RT-PCR方法观察损伤段脊髓组织中TNF-α mRNA表达的变化.结果 亚低温组TNF-α mRNA表达SCI后6~72 h明显少于常温组(P<0.05),而运动功能评分每个时间点都明显高于常温组(P<0.05).结论 亚低温可明显抑制SCI后TNF-α的表达,具有良好的恢复运动功能的作用.     

肿瘤坏死因子-α、白细胞介素-6在糖尿病大鼠骨骼肌中表达及与细胞凋亡关系研究

目的:探讨炎性细胞因子肿瘤坏死因子-α、白细胞介素-6在糖尿病大鼠骨骼肌中的表达及其与细胞凋亡的关系.方法:将16只Wistar大鼠随机分为实验组8只与对照组8只.实验组喂养8周高脂高糖饮食空腹12 h后腹腔内注射小剂量链脲佐菌素(30 mg/kg),对照组喂养标准饲料8周空腹12 h后腹腔内注射柠檬酸-柠檬酸钠缓冲液,每4周测体质量、血糖.第13周末处死大鼠,大鼠股四头肌,用免疫组织化学方法检测肿瘤坏死因子-α、白细胞介素-6及细胞凋亡蛋白bcl-2表达情况,并分析其相关性.结果:实验组大鼠骨骼肌中肿瘤坏死因子-α与白细胞介素-6表达水平高于对照组(P＜0.01),bcl-2表达低于对照组(P＜0.01),肿瘤坏死因子-α,白细胞介素-6与bcl-2表达呈负相关(r=-0.876,r=-0.823,P＜0.05).结论:糖尿病骨骼肌病变时炎症与凋亡同时发生,并可能共同导致胰岛素抵抗.     

川芎嗪对大鼠惊厥性脑损伤caspase-1 mRNA表达的影响

目的探讨幼年大鼠反复惊厥后caspase-1 mRNA的表达及川芎嗪对其表达的影响。方法162只20日龄健康Sprague-Dawley(SD)大鼠随机分为3组:对照组、惊厥组及川芎嗪干预组。通过三氟乙醚反复吸入(连续6次,1次/d)制作发育期大鼠惊厥动物模型。RT-PCR方法检测各组动物反复惊厥后6h、1d、3d、7d时点的脑组织caspase-1 mRNA的表达,同时观察脑含水量变化及对脑损伤进行神经病理半定量积分。结果川芎嗪干预组各时间点caspase-1 mRNA表达较惊厥组显著下调、脑含水量和脑损伤积分显著降低(P<0.01)。结论川芎嗪能有效减轻惊厥性脑水肿和神经元病理损伤,其机制可能与抑制caspase-1 mRNA的异常表达有关。     

恒河猴肝移植模型移植后急性排斥反应时肿瘤坏死因子α的变化

背景：肿瘤坏死因子α是一种炎性细胞因子,参与移植免疫反应并增加移植物抗原表达,并在其中发挥着重要作用。目的：分析恒河猴肝移植后肝组织中肿瘤坏死因子α的变化与急性排斥反应的关系。方法：采用改良血管袖套＋胆道支撑管＋动脉吻合法建立稳定的恒河猴肝移植模型,将其随机分为实验组（围手术期不给予免疫抑制治疗）和对照组（围手术期给予免疫抑制治疗）。分别在移植后6,12,24和72h4个时间点分别收集血清及肝脏组织,检测肝功指标变化,通过苏木精-伊红染色Banff评分评定其移植排斥反应情况,并最终应用免疫组织化学技术、蛋白印迹分析分别检测肿瘤坏死因子α的表达水平。结果与结论：实验组和对照组肿瘤坏死因子α的表达在移植后6h即开始增高,至12h时达到高峰,24-72h降低,并且实验组变化最明显。移植后6,12,24和72h4个时间点组实验组肿瘤坏死因子α蛋白表达明显高于对照组（P〈0.05）,此变化早于肝组织病理学及肝功能的改变。提示肝移植后肝组织肿瘤坏死因子α的表达水平变化,对肝移植后急性排斥反应的早期诊断具有重要意义。     

外源性一氧化碳释放分子2对大鼠脊髓缺血再灌注损伤的保护作用研究

目的探讨外源性一氧化碳释放分子2(CORM2)对大鼠脊髓缺血再灌注损伤的保护作用与相关机制。方法将30只健康雄性Wistar大鼠分为实验组、对照组、空白组,每组各10只。实验组在造模前1h尾静脉注射外源性CORM2。实验组和对照组采用相同的方法造模。对照组造模后1h注射与实验组相同剂量的生理盐水。空白组仅完成开腹和关腹操作,并术后1h注射与实验组相同剂量的生理盐水。在术后不同时间进行神经行为学评分(Tarlov评分)、脊髓组织病理学检查和白细胞介素-6(IL-6)、肿瘤坏死因子-α(TNF-α)检测。结果再灌注后不同时间点,实验组Tarlov评分均高于对照组,但实验组和对照组Tarlov评分均低于空白组(P0.05)。缺血再灌注48h后,对照组脊髓组织标本可见损伤及坏死神经元,表现为细胞核固缩或溶解,细胞质中的尼氏体消失;空白组脊髓组织标本中可见正常神经元,表现为结构呈多角形,细胞质中可见尼氏体;实验组脊髓组织标本中的神经元坏死表现介于对照组和空白组之间。缺血再灌注48h,实验组与对照组IL-6、TNF-α表达水平均高于空白组,但实验组IL-6、TNF-α表达水平低于对照组(P0.05)。结论外源性CORM2可抑制炎性因子的表达,对大鼠脊髓缺血再灌注损伤具有一定的保护作用。     

Mediators of brain edema and secondary brain damage

Progress is our understanding of the roles of vasogenic and cytotoxic brain edema in secondary brain damage can be expected from studies of the ability of biochemical factors to open the blood-brain barrier, derange the microcirculation, and cause cell swelling and necrosis. Mediator compounds are considered to form or to become released in an area of primarily damaged brain (necrosis) and to enter the cerebral parenchyma through the broken blood-brain barrier from the intravascular space. Many biochemical factors must be considered. We suggested three criteria for determining the roles of mediators: a) they must inflict brain tissue damage, b) they must occur in pathologic concentrations or in compartments not normally present, and c) specific inhibition should attenuate secondary brain damage. These requirements are met by the kallikrein-kinin system and by glutamate. In the case of arachidonic acid and its many metabolites, the concept is difficult to test because fatty acids may be active only if not bound to proteins, and therapeutic inhibition might be difficult. A variety of mediators may enhance each other in a cascade manner by various initiating reactions that might be amenable for pharmacologic inhibition.     

Imaging brain development: the adolescent brain

The past 15 years have seen a rapid expansion in the number of studies using neuroimaging techniques to investigate maturational changes in the human brain. In this paper, I review MRI studies on structural changes in the developing brain, and fMRI studies on functional changes in the social brain during adolescence. Both MRI and fMRI studies point to adolescence as a period of continued neural development. In the final section, I discuss a number of areas of research that are just beginning and may be the subject of developmental neuroimaging in the next twenty years. Future studies might focus on complex questions including the development of functional connectivity; how gender and puberty influence adolescent brain development; the effects of genes, environment and culture on the adolescent brain; development of the atypical adolescent brain; and implications for policy of the study of the adolescent brain.     

Enhanced brain extraction improves the accuracy of brain atrophy estimation

BET (Brain Extraction Tool) is a widely used computer program to automatically separate brain from non-brain structures in MR images. This procedure is used in SIENAX and SIENA, which are robust approaches to quantifying brain volume (atrophy state) and volume change (atrophy rate), respectively. Occasionally, however, BET produces imperfect results (e.g., inclusion of non-brain structures). This is usually either ignored (if inaccuracies are small) or corrected by manual adjustment, with the disadvantages of user intervention. We describe here a new, automated option in BET. This is based on the original BET, but uses standard-space masking to remove tissue around the eyes, and further morphological operations and thresholding to refine eyeball removal and eliminate additional non-brain tissues. To assess whether the new BET procedure improves brain volume measurements, this was compared with the traditional and manual editing procedures in SIENA and SIENAX. Measures of atrophy rate and state were significantly higher with the traditional procedure than with the manual editing and new procedures. In contrast, both atrophy measures were almost identical and highly correlated when the manual editing and new procedures were used. The voxels excluded with these two procedures showed close overlap, as judged by the Dice overlap coefficient. We conclude that, in SIENA and SIENAX, the proposed BET procedure shows results matching those obtained after manual editing, thus more closely approximating the "true" brain volume. Multicentre studies monitoring brain atrophy in clinical trials may receive benefit by using this unbiased, fully automated procedure.     

Effect of brain cooling on brain ischemia and damage markers after fluid percussion brain injury in rats

Although systemic cooling had recently been reported as effective in improving the neurological outcome after traumatic brain injury, several problems are associated with whole-body cooling. The present study was conducted to test the effectiveness of brain cooling without interference with the core temperature in rats after fluid percussion traumatic brain injury (TBI). Brain dialysates ischemia (e.g., glutamate and lactate-to-pyruvate ratio) and injury (e.g., glycerol) markers before and after TBI were measured in rats with mild brain cooling (33 degrees C) and in the sham control group. Brain cooling was accomplished by infusion of 5 mL cold saline via the external jugular vein under general anesthesia. The weight loss was determined by the difference between the first and third day of body weight after TBI. The maximum grip angle in an inclined plane was measured to determine motor performance, whereas the percentage of maximal possible effect was used to measure blockade of proprioception. The triphenyltetrazolium chloride staining procedures were used for cerebral infarction assay. As compared with those of the sham-operated controls, the animals with TBI had higher values of extracellular levels of glutamate, lactate-to-pyruvate ratio, and glycerol in brain and intracranial pressure, but lower values of cerebral perfusion pressure. Brain cooling adopted immediately after TBI significantly attenuated the TBI-induced increased cerebral ischemia and injury markers, intracranial hypertension, and cerebral hypoperfusion. In addition, the TBI-induced cerebral infarction, motor and proprioception deficits, and body weight loss evaluated 3 days after TBI were significantly attenuated by brain cooling. We successfully demonstrate that brain cooling causes attenuation of TBI in rats by reducing cerebral ischemia and injury resulting from intracranial hypertension and cerebral hypoperfusion. Because jugular venipuncture is an easy procedure frequently used in the emergency department, for preservation of brain function, jugular infusion of cold saline may be useful in resuscitation for trauma patients.     

重型颅脑损伤术后顽固性脑蕈的临床分析

目的 探讨重型颅脑损伤术后顽固性脑蕈的形成原因及有效治疗措施。方法 对32例病人进行回顾性分析，总结其形成原因、有效治疗措施。结果 脑水肿、脑积水、颅内感染是重型颅脑损伤术后形成顽固性脑蕈的主要原因，有效运用脱水药物和各种措施降低颅内压、预防感染、保证创口I期愈合是治疗顽固性脑蕈的有效措施。结论 针对不同情况采取相应措施治疗重型颅脑损伤术后顽固性脑蕈，取得较好疗效。     

脑胶质瘤中肿瘤干细胞的体外傲射敏感性

背景：目前放疗治疗脑胶质瘤效果不理想,可能因素有很多.目的：探讨脑胶质瘤中肿瘤干细胞的体外放射敏感性.方法：取脑胶质瘤细胞,接种于含生长因子的无血清培养基中培养,取细胞活力最强的位点扩增3-5代的肿瘤球细胞,给予不同X射线剂量照射,检测其细胞活力,以确定最适的放疗剂量.结果与结论：胶质瘤中不同部位的肿瘤细胞增殖活力有差异;8 Gy以上X射线剂量对脑肿瘤干细胞具有显著的杀伤作用.说明脑胶质瘤具有异质性,部位不同,脑肿瘤干细胞增殖活力不同;不同的放疗剂量对脑肿瘤干细胞有不同的影响.     

Human fetal brain imaging by magnetoencephalography: verification of fetal brain signals by comparison with fetal brain models

Fetal magnetoencephalogram (fMEG) is measured in the presence of a large interference from maternal and fetal magnetocardiograms (mMCG and fMCG). This cardiac interference can be successfully removed by orthogonal projection of the corresponding spatial vectors. However, orthogonal projection redistributes the fMEG signal among channels. Such redistribution can be readily accounted for in the forward solution, and the signal topography can also be corrected. To assure that the correction has been done properly, and also to verify that the measured signal originates from within the fetal head, we have modeled the observed fMEG by two extreme models where the fetal head is assumed to be either electrically transparent or isolated from the abdominal tissue. Based on the measured spontaneous, sharp wave, and flash-evoked fMEG signals, we have concluded that the model of the electrically isolated fetal head is more appropriate for fMEG analysis. We show with the help of this model that the redistribution due to projection was properly corrected, and also, that the measured fMEG is consistent with the known position of the fetal head. The modeling provides additional confidence that the measured signals indeed originate from within the fetal head.