谷氨酸受体拮抗剂MK801对肢体缺血再灌注致脑损伤大鼠脑组织中一氧化氮的影响

目的:观察肢体缺血再灌注所致脑损伤大鼠脑组织中一氧化氮的变化,分析一氧化氮在损伤中的作用及MK801对其的影响。方法:实验于2003-09/2004-12在华北煤炭医学院解剖教研室和实验中心完成。①40只Wistar大鼠随机分成5组,每组8只:对照组、再灌4h组(缺血4h再灌4h)、再灌12h组(缺血4h再灌12h)、再灌24h组(缺血4h再灌24h),MK801干预组(缺血4h再灌24h MK801)。②复制大鼠肢体缺血再灌损伤模型,MK801干预组在再灌注前5min立刻皮下注射MK801(0.5mg/kg)。③分别测定各组大鼠脑组织中一氧化氮、丙二醛含量、免疫组化观察各组脑组织诱导型一氧化氮合酶表达变化、并用Western-blot检测诱导型一氧化氮合酶蛋白表达。结果:40只大鼠均进入结果分析。①MK801干预组与再灌24h组比较,丙二醛含量降低了45.8%,一氧化氮含量降低了12.8%。②免疫组化结果显示随再灌时间的延长,大鼠脑组织诱导型一氧化氮合酶表达呈逐渐上升趋势,再灌24h达高峰。阳性信号主要分布海马区,中脑红核区等部位的神经元细胞,对照组仅见少量表达,而MK801干预后诱导型一氧化氮合酶表达明显降低,同时减轻脑组织水肿及神经元受损。与Western-blot检测诱导型一氧化氮合酶蛋白表达结果一致。结论:MK801减少脑组织一氧化氮、丙二醛含量,降低诱导型一氧化氮合酶表达,说明MK801可减轻肢体缺血再灌注所致脑损伤,可能与一氧化氮含量及诱导型一氧化氮合酶表达在肢体缺血再灌注所致脑损伤中降低有关。     

白细胞介素1和诱导型一氧化氮合酶在兔肢体缺血再灌注后关节软骨中的表达

目的:观察肢体缺血再灌注损伤后兔膝关节软骨中诱导型一氧化氮合酶和白细胞介素1的表达规律并探讨其相关性。方法:实验于2005-01/06在泰山医学院形态学实验室完成。①实验分组:健康新西兰兔35只,随机分为缺血再灌注2h,4h,8h,24h,3d,7d,14d组,每组5只。②实验方法:手术显露右后肢股动静脉,用血管夹完全阻断血运4h后恢复血运,建立兔右后肢原位缺血再灌注模型。分别于再灌注2h、4h、8h、24h、3d、7d、14d空气栓塞处死动物,切取免股骨髁软骨1.0cm×0.5cm大小制备切片。③实验评估:用免疫组化和免疫荧光法观察关节软骨内诱导型一氧化氮合酶、白细胞介素1的表达情况。结果:①肢体缺血再灌注2h后白细胞介素1在兔膝关节软骨内即有明显增高,8h达高峰,24h开始减少,3d后明显下降。②肢体缺血再灌注2h后开始出现诱导型一氧化氮合酶酶阳性细胞,其荧光强度在8h达高峰,在24h开始减少,3d后明显下降。③诱导型一氧化氮合酶阳性颗粒分布区与白细胞介素1阳性细胞分布区域一致,主要集中在同源细胞族和增殖区。④肢体缺血再灌注损伤后关节软骨内白细胞介素1与诱导型一氧化氮合酶的表达高度正相关(r=0.867,P=0.011)。结论:肢体缺血再灌注损伤后白细胞介素1和诱导型一氧化氮合酶在关节软骨内大量表达,呈时间依从性变化;诱导型一氧化氮合酶和白细胞介素1在肢体缺血再灌注后关节软骨损伤中起到重要作用。     

电针对脑缺血再灌注损伤大鼠海马诱导型一氧化氦合酶mRNA表达的影响

背景：诱导型一氧化氮合酶mRNA在脑缺血再灌注脑损伤中具有减轻血脑屏障的破坏，保护血管内皮和脑组织的作用。目的：观察电针水沟、内关、足三里对脑缺血再灌注大鼠海马诱导型一氧化氮合酶mRNA表达的影响。设计：随机对照实验。单位：上海中医药大学、上海市针灸经络研究所及复旦大学华山医院。方法：实验于2003-12／2004—12在上海中医药大学实验动物中心、上海市针灸经络研究所针灸免疫学实验室和复旦大学华山医院完成。40只SD大鼠随机分为4组：正常组、假手术组、模型组和电针治疗组，每组10只。用双肾双夹法复制易卒中型肾血管性高血压模型，在此基础上，运用栓线法制备大鼠局灶性脑缺血再灌注模型；假手术组除不插入栓线外，其余步骤同模型组；电针治疗组取水沟（唇裂鼻尖下1mm正中处，向上斜刺1mm）、双侧内关（前肢内侧，离腕关节约3mm处的尺桡骨缝间，直刺1mm）、双侧足三里（膝关节下侧，在腓骨小头下约5mm处，直刺7mm）水沟穴与右耳根部皮肤、内关与足三里接G6805电针治疗仪，连续波，频率120次／min，强度1mA，留针30min。缺血后即时治疗1次，再灌注后每12h治疗1次。所有动物于再灌注后24h断头处死，取出脑组织，分离海马，应用荧光定量逆转录聚合酶链反位技术观察电针对实验性脑缺血再灌注大鼠海马诱导型一氧化氮合酶mRNA表达的影响。主要观察指标：大鼠海马诱导型一氧化氮合酶mRNA的表达。结果：40只SD大鼠均进入结果分析。大鼠海马诱导型一氧化氮合酶mRNA的表达：①模型组明显高于电针治疗组{[（4．85&;#177;1．29）&;#215;1000，（3．19&;#177;1．38）&;#215;1000]拷贝，（t=2．77，P〈0．05））；②模型组明显高于假手术组{[（4．85&;#177;1．29）&;#215;1000，（4．93&;#177;2．17）&;#215;10]拷贝，（t=97．38，P〈0．01））；③模型组显著高于正常组{[（4．85&;#177;1．29）&;#215;1000，（3．13&;#177;1．68）&;#215;10]拷贝。（t=11．81，P〈0．01）}。结论：电针可以显著抑制脑缺血再灌注后大鼠海马诱导型一氧化氮合酶mRNA表达，从而减少一氧化氮的产生，有助于减轻脑缺血再灌注损伤。     

血红素加氧酶1与诱导型一氧化氮合酶在肠缺血再灌注损伤大鼠肾组织中的表达

目的：探讨血红素加氧酶1与诱导型一氧化氮合酶在肠缺血再灌注致肾损伤中的表达及其作用。 方法：实验于2005—06／11在武汉大学人民医院麻醉学研究室完成。选择健康雄性Wistar大鼠66只，建立钳闭大鼠肠系膜上动脉缺血再灌注模型，随机数字表法分为正常组（6只）．假手术（0min，2，6，18，24h）组．各时相点6只，缺血再灌注（0min，2，6，18，24h）组，各时相点6只。应用免疫组织化学方法和图像分析系统检测肾组织中血红素加氧酶1和诱导型一氧化氮合酶的表达和分布，观察各组血清肌酐、尿素氮含量变化，同时光镜观察肾组织病理形态学改变。 结果：纳入大鼠66只，均进入结果分析。①缺血再灌注2h组血红素加氧酶1的表达（A）与假手术组相比明显增加（0．221&;#177;0．028，0．009&;#177;0．023，P〈0．05），缺血再灌注18h达到高峰（0．326&;#177;0．030）。②缺血再灌注0min组诱导型一氧化氮合酶的表达（A）比假手术组明显增加（0．172&;#177;0．024，0．075&;#177;0．036，P〈0．05）；缺血再灌注6h达到高峰（0．278&;#177;0．014）。③缺血再灌注后血清肌酐、尿素氮较正常组明显增加（P〈0．05或P〈0．01），且诱导型一氧化氮合酶表达的变化与血清肌酐、尿素氮之间呈正相关（r=0．612，0．728，P〈0．01）。④病理学检查显示肠缺血再灌注后肾组织明显损伤。 结论：肠缺血再灌注损伤时，血红素加氧酶1和诱导型一氧化氮合酶参与了远隔脏器-肾损伤／抗损伤机制。     

大鼠心肌缺血再灌注损伤与红花黄素的保护作用

目的：观察大鼠心肌缺血再灌注损伤模型心肌组织中超氧化物歧化酶、谷胱甘肽过氧化物酶、诱导型一氧化氮合酶、总一氧化氮合酶活性及一氧化氮，丙二醛含量的变化，探讨红花黄素对离体大鼠缺血再灌注心肌的保护作用。 方法：①实验于2004—06／2005—02在南阳医学高等专科学校药理学教研室完成。选用健康Wistar大鼠32只，随机分为4组，每组8只：正常对照组、模型组、红花黄素组、地奥心血康组。②采用Langendofff创建的离体心脏灌流法建立离体大鼠心肌缺血缺氧再灌注损伤模型。以持续平衡的充有体积分数0．95O2＋0．05CO2混合气体的KH液进行非循环逆行灌流。灌注数秒后心脏恢复跳动。稳定15min后停灌30min，再灌40min，给药组在停灌前10min以红花黄素（0．33g生药／mL）或地奥心血康灌注，直至再灌后40min。正常对照组离体心脏持续灌注K—H液90min。模型组离体心脏灌注．K—H液35min，全心缺血25min，再灌注30min。③心肌中超氧化物歧化酶、谷胱甘肽过氧化物酶、一氧化氮合酶活性变化、一氧化氮、丙二醛含量测定按南京建成生物工程研究所提供的相应试剂盒说明完成。④分别进行成组t检验和配对t检验。 结果：进入结果分析大鼠32只。①超氧化物歧化酶、谷胱甘肽过氧化物酶活力：模型组明显低于其他3组（P〈0．05～0.01）；丙二醛含量：模型组明显高于其他3组（P〈0．05～0．01）。②一氧化氮含量：模型组明显低于其他3组（P〈0．05～0．01）。③诱导型一氧化氮合酶活力：地奥心血康组明显高于模型组（P〈0．01）；总一氧化氮合酶活力：模型组明显高于对照组和红花黄素组（P〈0．01），明显低于地奥心血康组（P〈0．05）。 结论：红花黄素对离体大鼠缺血再灌损伤的心肌具有保护作用，此作用可能与抑制心肌脂质过氧化、增强抗氧化能力有关。     

脑缺血再灌注损伤大鼠脑组织nNOS的表达

【目的】通过对缺血再灌注早期脑组织神经型一氧化氮合酶（nNOS）表达情况的观察,探讨一氧化氮在脑缺血再灌注损伤早期发挥神经毒性作用时nNOS亚型的变化。【方法】采用线栓法制作大鼠脑缺血／再灌注（CI／R）模型,分别应用免疫组化及westernblot方法检测缺血脑组织nNOS蛋白表达情况。【结果】免疫组化及westernblot研究结果显示缺血区脑组织nNOS的表达在缺血到再灌注2h内始终呈上升趋势。【结论】CI／R大鼠模型缺血区脑组织的nNOS的表达在缺血再灌注早期持续升高,表明缺血脑组织nNOS的表达变化参与了缺血性脑损伤早期的病理过程。     

丹参酮ⅡA对鼠脑缺血再灌注损伤一氧化氮及一氧化氮合酶的影响

目的 探讨丹参酮ⅡA(Tan ⅡA)对脑缺血再灌注损伤大鼠脑组织及血清中一氧化氮(NO)含量、一氧化氮合酶(NOS)及诱导型一氧化氮合酶(iNOS)活性的影响.方法 40只Wistar大鼠随机分为假手术组、缺血再灌注组、Tan Ⅱ A低剂量治疗组和TanⅡA高剂量治疗组,线栓法建立局灶性脑缺血再灌注模型.Tan Ⅱ A高、低剂量治疗组于术前连续灌胃给予高、低剂量Tan Ⅱ A 3 d,每天1次.各组于脑缺血90 min再灌注24 h进行HE染色观察病理形态学变化,检测脑组织和血清中NO含量和NOS、iNOS活性.结果 Tan Ⅱ A高、低剂量治疗组脑组织缺血损伤病理学改变轻于缺血再灌注组,Tan ⅡA高剂量治疗组缺血改变轻于低剂量治疗组.与假手术组比较,缺血再灌注组脑组织和血清中NO含量和NOS、iNOS活性明显升高;与缺血再灌注组比较,Tan Ⅱ A高、低剂量治疗组脑组织和血清中NO含量和NOS、iNOS活性均降低,高、低剂量组之间有显著性差异(P《0.05).结论 Tan Ⅱ A可减轻神经元损伤程度,对缺血再灌注脑损伤具有保护作用,其机制可能与可降低NOS、iNOS活性,减少NO含量有关.     

葛根素对全脑缺血再灌流后脑组织诱导型一氧化氮合酶影响的实验观察

目的：观察葛根素对全脑缺血再灌注后脑组织诱导型一氧化氮合酶的影响。方法：将实验大鼠随机分为空白对照组、缺血再灌注盐水组及葛根素组,采用Pulsineli4血管阻塞法造成全脑缺血再灌注模型,用免疫组织化学免疫法行大鼠脑组织的iNOS测定。结果：随缺血再灌注时间的延长,盐水组iNOS逐渐降低,较空白对照组差异明显（P＜0．05）。且再灌流时间越长,此差异越显著（P＞0．01）;而葛根素组iNOS逐渐增高,缺血再灌流24h时,葛根素组畔国水组iNOS明显增高（P＜0．05）,接近空白对照组,结论：全脑缺血再灌流后,脑组织iNOS系统有明显损伤,葛根素可减轻这种损伤。     

诱导型一氧化氮合酶在关节软骨缺血再灌注损伤及软骨细胞凋亡中的作用

目的：观察兔膝关节软骨缺血再灌注损伤过程中诱导型一氧化氮合酶的表达规律及软骨细胞的凋亡情况，探讨诱导型一氧化氮合酶在关节软骨缺血再灌注损伤中的作用。方法：实验于2004-03／09在泰山医学院形态学研究室完成。①选择健康新西兰白兔45只，随机分为假手术组5只，暴露股动静脉但不阻断血运，术后4h取材；缺血组5只，缺血4h不恢复血运即取材；缺血再灌注组35只，阻断股动静脉4h后恢复血运，于缺血再灌注2，4，8，24h，3，7，14d取材，每时点各5只。②采用免疫荧光法测定软骨内诱导型一氧化氮合酶的表达阳性细胞，染色成功后用激光共聚焦显微镜观察并扫描记录。阳性细胞标记为红色荧光。③采用原位末端标记法测定凋亡软骨细胞数目，染色成功后在显微镜下观察并记数。细胞核中有棕黄色颗粒者为阳性细胞，即凋亡细胞。结果：纳入动物45只，均进入结果分析。①缺血再灌注组诱导型一氧化氮合酶阳性细胞数高于缺血组和假手术组f假手术组、缺血组、缺血再灌注2，4，8，24h，3，7，14d分别为0，（1．20&;#177;0．40），（22．20&;#177;1．30），（33．00&;#177;1．58），（40．00&;#177;1．58），（33．80&;#177;1．30），（18．20&;#177;1．48），（11．20&;#177;1．67），（3．00&;#177;1．00）个／mm^2，P〈0．01]。②缺血再灌注组软骨细胞凋亡数高于缺血组和假手术组[假手术组、缺血组、缺血再灌注2，4，8，24h，3，7，14d分别为[（0．50&;#177;0．40），（1．20&;#177;0．45），（7．80&;#177;1．30），（12．60&;#177;1．14），（16．60&;#177;1．12），（17.80&;#177;1．30），（15．20&;#177;0．87），（13．60&;#177;0．89），（4．40&;#177;1．67）个／mm^2，P〈0．011。③诱导型一氧化氮合酶的表达与软骨细胞凋亡数高度相关（r=0．716，P=0．046）。结论：诱导型一氧化氮合酶参与了软骨缺血再灌注损伤，并可能是触发软骨细胞凋亡的重要因素。     

脑缺血再灌注大鼠脑组织内皮型一氧化氮合酶表达的变化

【目的】通过对缺血再灌注早期脑组织的内皮型一氧化氮合酶（endothelial nitric oxide synthase,eNOS）表达情况的观察,探讨一氧化氯在脑缺血再灌注损伤早期发挥神经毒性作用时eNOS亚型的变化。【方法】采用线栓法制作大鼠脑缺血再灌注模型,免疫纽化及western blot方法检测缺血脑组织的eNOS蛋白表达变化。【结果】免疫组化及western blot结果显示缺血区脑组织血管内皮细胞内的eNOS表达在缺血1h内达高峰,缺血2h到再灌注2h内持续降低。【结论】大鼠脑缺血再灌注模型中血管内皮细胞eNOS出现变化,表明一氧化氮在缺血性脑损伤的病理过程的作用发挥与eNOS亚型的变化有关。     

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.