大剂量伽玛刀照射后脑组织一氧化氮合酶亚型表达改变及其与急性脑水肿的关系

目的探讨大剂量伽玛刀(γ刀)照射后脑组织一氧化氮合酶(NOS)亚型表达改变及其与急性脑水肿的关系。方法200Gy量γ刀照射正常大鼠脑,采用光镜、电镜、免疫组化及原位杂交技术研究照射后急性脑水肿的发生发展及脑组织NOS亚型表达变化。结果①照射后30min出现急性脑水肿病理改变,照射后2h出现明显血管源性脑水肿,照射后6h出现明显细胞性脑水肿,照射后3d急性脑水肿达高峰。②脑组织NOS亚型表达在照射后30min开始增高,内皮型一氧化氮合酶(eNOS)及诱导型一氧化氮合酶(iNOS)表达分别于照射后2h及6h显著增高,神经元型一氧化氮合酶(nNOS)表达亦增高,但nNOS阳性表达细胞数量较少。3种NOS亚型表达增高持续时间长,伴行于脑水肿的急性发展阶段。结论大剂量γ刀照射后脑组织NOS亚型表达增高与急性脑水肿的发生发展有关。     

大鼠颅脑损伤后一氧化氮合酶和内皮素的变化及依达拉奉对其的影响

目的观察大鼠颅脑损伤后脑组织中一氧化氮合酶（NOS）和内皮素（ET）含量的变化及依达拉奉对其的影响，并探讨其作用机制。方法将45只SD大鼠随机分为3组，其中正常组5只，麻醉后只行开颅手术，不作头颅打击；治疗组和对照组各20只，采用骨窗形成后硬膜外打击法造成鼠脑挫裂伤模型，治疗组致伤后即刻腹腔内注射5mg／kg依达拉奉，对照组则即刻腹腔内注射等量生理盐水。正常组在伤后1h，对照组和治疗组大鼠分别在伤后1h、6h、12h、24h断头取脑，对大鼠脑外伤后脑组织中NOS和ET含量进行检测。结果（1）治疗组和对照组大鼠脑皮质中的NOS活性在伤后1h较正常组显著升高（P〈0．01），6h开始下降，12～24h降至基础水平。治疗组在伤后1h、6hNOS活性较对照组显著降低（均P〈0.05）。（2）治疗组和对照组大鼠脑皮质中的ET在伤后1-24h较正常组显著升高（P〈0．01）。治疗组在伤后1～24hET较对照组显著降低（ P〈0．05）。结论颅脑损伤后受损脑组织中NOS和ET升高，依达拉奉可通过抑制损伤后NOS和ET起到保护创伤神经元的作用。     

颅脑创伤后脑红蛋白表达变化的实验研究

目的 研究弥漫性颅脑创伤后大鼠脑组织中脑红蛋白的表达变化情况,探究脑红蛋白与颅脑创伤的关系.方法 选择Marmarou自由落体打击装置复制颅脑创伤模型,分别采用实时定量PCR技术及免疫组化技术检测伤后不同时间脑组织中脑红蛋白的核酸、蛋白表达情况,并对所得数据进行统计学分析.结果 (1)核酸表达:在伤后0.5 h,脑组织中脑红蛋白核酸表达出现首个高峰,此后逐渐下降,至6 h恢复至正常水平;伤后12 h再次升高,于伤后48 h达高峰,此后下降,至伤后120 h仍高于正常水平;(2)蛋白表达:致伤区皮层神经元脑红蛋白表达分别于伤后2 h、72 h呈现出两次高峰表达.结论 弥漫性颅脑创伤后脑组织中脑红蛋白表达呈"双峰",提示脑红蛋白可能与创伤后神经元保护相关.     

氯美噻唑对大鼠脑出血周边组织一氧化氮含量、一氧化氮合酶活性及细胞凋亡的干预作用

目的 研究氯美噻唑对大鼠脑出血周边组织一氧化氮(NO)含量、一氧化氮合酶(NOS)活性及细胞凋亡的影响.方法 Wistar大鼠112只,随机分为脑出血组和脑出血+氯美噻唑(CMZ)组,两组各分为(出血前和出血后4h、6h、12h、24h、72h、7d)7个时间点.利用化学方法测定大鼠脑出血周边组织NO含量、NOS活性;利用原位末端标记法测定出血周边组织中神经细胞的凋亡情况.结果 大鼠脑出血周边组织NO含量、诱导型一氧化氮合酶(iNOS)、一氧化氮合酶(NOS)4h开始升高(P<0.05),24h到7d显著升高(P<0.01),大约72h左右NO、iNOS、NOS达峰值.大鼠脑出血周边组织6h出现凋亡细胞,12h上升显著(P<0.01),3d凋亡细胞达峰值,与NO、iNOS、NOS峰值对应,7d时仍存在较多凋亡细胞.氯美噻唑干预后,NO含量、iNOS和NOS活性及凋亡细胞数量与脑出血组对应时间点比较显著下降(P<0.01).结论 大鼠脑出血周边组织NO含量增高,iNOS、NOS活性增强,脑出血周边组织神经细胞存在长时间凋亡,NO、iNOS可以促进其凋亡;氯美噻唑干预后NO含量降低,iNOS、NOS活性下降,减少大鼠脑出血周边组织神经细胞凋亡.     

甲基强的松龙对大鼠颅脑损伤后一氧化氮合成酶活性的影响

目的观察甲基强的松龙对大鼠颅脑损伤后血、脑组织中NOS含量的影响,并探讨其作用机制。方法将45只SD大鼠随机分为3组:实验组(20只)、对照组(20只)、正常组(5只),均采用骨窗形成后硬膜外打击法造成鼠脑挫裂伤。正常组麻醉后,只行开颅手术,不作头颅打击,治疗组大鼠致伤后即刻腹腔内注射30mg/kg甲基强的松龙,对照组则注射30mg/kg生理盐水。对照组和治疗组大鼠分别在伤后1h、6h、12h、24h断头取脑,对大鼠脑外伤后脑组织中一氧化碳合成酶(NOS)含量进行检测。结果大鼠脑皮质中的NOS活性在伤后1h较正常组显著性升高(P <0.01),6h开始下降,12～24h降至基础水平。甲基强的松龙治疗组在伤后1h(P <0.01)、6h(P <0.05)NOS活性较损伤组显著性降低。结论颅脑损伤后,受损脑组织中NOS活性升高,甲基强的松龙可通过抑制损伤后NOS活性起到保护创伤神经元的作用。     

针刺对急性脑挫裂伤大鼠脑组织内p-CREB表达的影响

目的探讨针刺对急性脑挫裂伤大鼠磷酸化的环磷酸腺苷反应元件结合蛋白(p-CREB)表达的影响。方法 48只雄性SD大鼠随机分为针刺治疗组、模型对照组、正常对照组,每组16只。模型对照组仅制备急性脑挫裂伤模型,针刺治疗组在建立模型后行针刺治疗,正常对照组不致伤。损伤后48 h、6 d取损伤或对应局部脑组织,采用免疫组化法观察p-CREB的表达变化,并进行统计学分析。结果伤后48 h、6 d,模型对照组损伤脑组织中p-CREB的表达较正常对照组升高(均P<0.05),针刺治疗组损伤脑组织中p-CREB表达较模型对照组显著升高(均P<0.05)。伤后6 d针刺治疗组p-CREB表达较伤后48 h降低(P<0.05)。结论针刺治疗对大鼠颅脑损伤后p-CREB的表达具有明显的促进作用,并呈一定规律性,提示p-CREB与颅脑损伤后脑组织的修复相关。     

L-NIL在大鼠创伤性脑损伤中的应用研究

目的探讨选择性诱导型一氧化氮合酶(iNOS)抑制剂L-N6-亚氨乙基-赖氨酸(L-NIL)在大鼠创伤性脑损伤(TBI)模型中对大鼠伤后学习记忆功能、海马神经元的影响.方法 24只SD大鼠随机分为假创伤性脑损伤组、创伤性脑损伤组、非选择性一氧化氮合酶(NOS)抑制剂N-硝基-L-精氨酸(L-NNA)组、选择性诱导型一氧化氮合酶抑制剂L-NIL组.其中L-NNA组、L-NIL组分别于伤后即刻、24 h、48 h经腹腔注射L-NNA或L-NIL.进行避暗回避试验以评价伤后各组大鼠的学习记忆功能恢复情况.伤后第7 d处死大鼠取脑,采用Nissl染色及神经元抗核抗体(NeuN)免疫组化染色观察测量伤侧海马CA2区锥体细胞层面积.结果①L-NIL组避暗回避试验结果显著好于创伤性脑损伤组(P<0.05).②L-NIL组海马CA2区锥体细胞层面积与创伤性脑损伤组比较显著增加(P<0.05).③L-NIL组避暗回避试验结果及海马CA2区锥体细胞层面积值均优于L-NNA组.结论适当地应用选择性iNOS抑制剂L-NIL可促进大鼠脑损伤后学习记忆功能的恢复,保护海马神经元,其效果优于非选择性NOS抑制剂.     

FTY720对EAE小鼠脑组织NO含量和iNOS表达影响的研究

目的探讨芬戈莫德(fingolimod,FTY720)对试验性自身免疫性脑脊髓炎(EAE)小鼠脑组织中一氧化氮(NO)含量和诱导型一氧化氮合酶(i NOS)表达的影响。方法 48只雌性C57BL/6小鼠随机平均分为3组,EAE组运用MOG35-55构建EAE小鼠模型;CFA组由生理盐水代替MOG35-55构建模型;FTY720干预组在EAE基础上给予FTY720腹腔注射,CFA组、EAE组给予生理盐水腹腔注射。HE染色和LBF染色观察炎症情况和脱髓鞘情况,ELLISA检测小鼠脑组织中的NO含量,RT-PCR检测的诱导型一氧化氮合酶(i NOS)mRNA表达。结果 FTY720组EAE小鼠较EAE组临床症状减轻,炎症程度和脱髓鞘程度减轻(P<0.05)。FTY720组小鼠脑组织NO含量较EAE组降低(P<0.05),i NOS mRNA表达量降低(P<0.05)。结论 FTY720能抑制EAE小鼠脑组织中i NOS mRNA表达,从而减少NO含量。     

重症肌无力患者IgG对大鼠脑内NOS不同时间表达的影响

目的观察重症肌无力(myasthenia gravis,MG)患者IgG(AchRab)对大鼠脑内一氧化氮合酶(NOS)表达的影响,探讨NOS在MG中造成中枢神经系统损害的机制.方法将AchRab IgG或健康人的IgG注入大鼠侧脑室,1次/d,连续4次.免疫组化方法观察不同时间点大鼠脑皮质、海马及杏仁核神经元型一氧化氮合酶(nNOS)和诱导型一氧化氮合酶(iNOS)的表达变化.结果侧脑室注射后1周实验组大鼠皮质、海马神经元nNOS表达量明显减少,后2周实验组皮质、海马神经元nNOS表达下降更为明显,同时杏仁核神经元nNOS表达量也减少;实验组及对照组脑内细胞均未见iNOS表达.结论AchRab侧脑室内注射可引起大鼠皮质、海马及杏仁核神经元nNOS表达量减少,且2周内这种减少效应随时间延长而增强,但未能诱导脑内细胞iNOS表达,提示AchRab尚可通过抑制大鼠中枢神经系统nNOS表达,降低脑内正常的一氧化氮浓度,减弱一氧化氮对脑组织的保护作用,增加神经元的易损性.     

Aβ1—40海马注射对大鼠脑内一氧化氮合酶表达的影响

目的探讨一氧化氮合酶(NOS)在β淀粉样蛋白(Aβ)神经毒性及阿尔茨海默病(AD)病理机制中的作用.方法应用免疫组化方法,观察大鼠海马齿状回Aβ1-40注射后神经元型一氧化氮合酶(nNOS)和诱导型一氧化氮合酶(iNOS)表达变化.结果正常大鼠海马齿状回区含nNOS神经元计数为8.96±0.35个/视野;生理盐水注射后局部含nNOS神经元无明显变化(8.97±0.29个/视野);Aβ1-40注射后,注射区周围含nNOS神经元数目显著减少(2.98±0.24个/视野).正常及生理盐水注射组脑内未见iNOS表达;Aβ1-40注射后2d、10d和30d,注射区持续出现大量含iNOS的胶质细胞(主要为星形胶质细胞),反应面积分别为0.905±0.082、0.962±0.161、0.935±0.125mm2.结论Aβ1-40海马注射可损伤局部含nNOS神经元及诱导胶质细胞iNOS表达,NOS在Aβ神经毒性和AD发病中有重要作用.     

Denervation study of synapses of organ of corti of old world monkeys

Fine structural characteristics of synapses in the spiral organ of Corti were examined, with reference to differences between inner and outer haircell systems, and to location of neurons of origin of efferent axons. Surgical interruption of crossed olivocochlear bundle, of vestibular nerve, of facial nerve, and excision of superior cervical ganglia were used to determine the pathways of efferent axons. Interruption of the vestibular nerve near the brainstem results in degeneration of all efferent terminals on outer hair cells. Mid-line lesions at, and caudal to, the facial colliculus result in degeneration of about half of these efferent terminals. Efferent synaptic bulbs to the inner hair-cell system are small, of the order of one micron, and form type 2 junctions with afferent dendrites. They tend to have more large dense-core vesicles (about 80 nm) than the large efferent terminals of the outer hair-cell system, and appear to be the terminals of axons in the habenula perforata, which exhibit varicosities laden with large dense core vesicles. The varicosities are unaffected by excision of the superior cervical ganglia. So far as our material can reveal, it appears that the varicosities in the habenula perforata do not survive vestibular root interruption, nor do the efferent processes in the internal spiral bundle or at the base of inner hair cells. Most interestingly, the afferent processes of the inner hair-cell system, as identified for example by their relation to pre-synaptic bodies in the inner hair cells, are subject to a trans-synaptic reaction after severance of the vestibular root. They undergo a dramatic cytological transformation, characterized by increase of volume, engorgement with microtubules, microfilaments, microvesicles of various sizes, and clusters of lysosomes. Thus, both the efferent and afferent terminals of the inner hair-cell system show marked cytological differences from the corresponding terminals of the outer hair cell system.     

Mechanism of action of tubocurarine on nicotinic cholinoreceptors of neurons of the sympathetic ganglia of rats

Tubocurarine (Tc) effect on membrane currents elicited by acetylcholine (ACh) was studied in isolated superior cervical ganglion neurons of rat using patch-clamp method in the whole-cell recording mode. The "use-dependent" block of ACh current by Tc was revealed in the experiments with ACh applications, indicating that Tc blocked the channels opened by ACh. Mean lifetime of Tc-open channel complex, tau, was found to be 9.8 +/- 0.5 s (n = 7) at -50 mV and 20-24 degrees C. tau exponentially increased with membrane hyperpolarization (e-fold change in tau corresponded to the membrane potential shift by 61 mV). Inhibition of the ACh-induced current by Tc (3-30 microM/1) was completely abolished by membrane depolarization to the level of 80-100 mV. Inhibition of ACh-induced current was augmented at increased ACh doses. It is concluded that the open channel block produced by Tc is likely to be the only mechanism for Tc action on nicotinic acetylcholine receptors in superior cervical ganglion neurons of rat.     

The effect of age of onset of PD on risk of dementia

Background Dementia occurs in the majority of patients with Parkinson’s disease (PD). Late onset of PD has been reported to be associated with a higher risk for dementia. However, age at onset (AAO) and age at baseline assessment are often correlated. The aim of this study was to explore whether AAO of PD symptoms is a risk factor for dementia independent of the general effect of age. Methods Two community-based studies of PD in New York (n = 281) and Rogaland county, Norway (n = 227) and two population-based groups of healthy elderly from New York (n = 180) and Odense, Denmark (n = 2414) were followed prospectively for 3–4 years and assessed for dementia according to DSM-IIIR. All PD and control cases underwent neurological examination and were followed with neurological and neuropsychological assessments. We used Cox proportional hazards regression based on three different time scales to explore the effect of AAO of PD on risk of dementia, adjusting for age at baseline and other demographic and clinical variables. Findings In both PD groups and in the pooled analyses, there was a significant effect of age at baseline assessment on the time to develop dementia, but there was no effect of AAO independent of age itself. Consistent with these results, there was no increased relative effect of age on the time to develop dementia in PD cases compared with controls. Interpretation This study shows that it is the general effect of age, rather than AAO that is associated with incident dementia in subjects with PD. Received in revised form: 22 December 2005     

Limits of deinstitutionalization--perspectives of relatives of psychiatric patients

After a hopeful beginning, the social process of the reintegration of those with severe mental illness has come to a standstill. I am led to wonder whether "the community" really wants to live together with people suffering from severe mental illness, and if so, how closely? As long as the medical treatment of mental illness provided by the general practitioners is fundamentally deficient, as they are not able to prescribe the necessary interventions--such as out-patient psychiatric nursing, and service providers in the out-patient sector are content with offering increasingly intensive forms of care for the less seriously ill at the cost of the Social Welfare System--the reintegration of those with serious mental illness remains an illusion--which is mainly to the benefit of providers of residential care in homes and hostels.