大鼠实验性变态反应性脑脊髓炎中一氧化氮的变化

目的　观察外周和中枢一氧化氮 (NO)在大鼠实验性变态反应性脑脊髓炎 (EAE)中的动态变化 ,探讨EAE大鼠发病的相关生物学机制。方法　 采用免疫组化法和硝酸还原酶法 ,观察豚鼠全脊髓匀浆诱导的Wistar大鼠EAE的过程中 ,脊髓内表达iNOS胶质细胞与外周NO代谢物NO 2 和NO 3的变化。 结果　 对照组脊髓内未发现表达iNOS阳性细胞 ,表达iNOS的CNS胶质细胞可能是小胶质细胞 ,而且它的变化与EAE大鼠的病情一致 ,评分 2分和 3分EAE大鼠脊髓表达iNOS的小胶质细胞比评分 1分大鼠明显增多 (P <0 .0 1) ,恢复期EAE大鼠表达iNOS的小胶质细胞明显减少 (P <0 .0 1)。EAE大鼠外周血清NO值随症状程度加重而升高 ,但在EAE恢复期时仍保持较高水平。未发病大鼠血清NO值明显增高 ,与对照组之间具有显著性差异 (P <0 .0 1)。 结论　 小胶质细胞产生的NO可能在急性期EAE大鼠的发病中起重要作用     

实验性变态反应性脑脊髓炎大鼠星形胶质细胞的变化

目的观察实验性变态反应性脑脊髓炎(EAE)大鼠脊髓中星形胶质细胞的变化,探讨EAE大鼠的发病相关生物学机制。方法采用免疫组化法,对豚鼠全脊髓匀浆诱导的Wistar大鼠EAE的过程中,脊髓内星形胶质细胞变化情况进行研究。结果EAE大鼠症状高峰期时星形胶质细胞开始激活,恢复期时激活达到高峰,而且活化的星形胶质细胞未见表达主要组织相容性抗原(MHC)。结论活化的星形胶质细胞可能与EAE大鼠的恢复有关。     

实验性自身免疫性脑脊髓炎小鼠脑内主要组织相容性复合体Ⅱ类抗原和分化群3ε的变化

目的观察实验性自身免疫性脑脊髓炎(EAE)小鼠脑内主要组织相容性复合体Ⅱ类抗原(MHC-Ⅱ)和分化群3ε(CD3ε)的变化。方法 25只C57BL/6小鼠随机分为EAE组(n=13)和正常对照组(n=12)。应用髓鞘少突胶质细胞糖蛋白35-55抗原诱导小鼠EAE模型。观察记录小鼠行为学变化;采用常规及髓鞘染色方法观察脊髓损伤和炎症细胞浸润程度;荧光定量PCR检测脑MHC-Ⅱ和CD3εmRNA的表达。结果 EAE组小鼠发病后EAE症状评分逐渐增加;脊髓炎症细胞浸润明显;髓鞘脱失较多;脑组织MHC-Ⅱ和CD3εmRNA表达显著高于正常对照组(均P<0.01),并与EAE症状评分呈正相关。结论 EAE小鼠脑内MHC-Ⅱ及CD3εmRNA表达水平增高与其病情严重程度一致。     

趋化因子MCP-1、MIP-1α在EAE小鼠脊髓中的表达

目的:研究单核细胞趋化蛋白(MCP)-1和巨噬细胞炎性蛋白(MIP)-1α与实验性自身免疫性脑脊髓炎(EAE)发病的关系。方法:用髓鞘少突胶质细胞糖蛋白_(35-55)多肽加福氏完全佐剂皮下注射免疫C57BL/6小鼠建立EAE模型,用免疫组织化学方法观察EAE小鼠发病后第0天(初期)、第7天(高峰期)及第30天(恢复期)脊髓中MCP-1、MIP-1α的表达的变化,并通过免疫组化染色标记星形胶质细胞及小胶质细胞,判断MCP-1、MIP-1α的细胞来源。结果: MCP-1、MIP-1α在EAE小鼠发病初期脊髓中有少量表达,发病高峰期表达增高,而恢复期无表达,MCP-1主要由星形胶质细胞产生,MIP-1α主要由小胶质细胞产生;对照组小鼠脊髓中则没有MCP-1、MIP-1α表达。结论:趋化因子MCP-1、MIP-1α在EAE小鼠CNS不同胶质细胞中表达,是EAE发病早期募集免疫反应细胞向CNS浸润的重要致炎性因子。     

咪唑克生对实验性自身免疫性脑脊髓炎大鼠小胶质细胞激活和白介素17、肿瘤坏死因子α表达的影响

目的观察咪唑克生对实验性自身免疫性脑脊髓炎(EAE)大鼠脑组织中小胶质细胞、白介素17(IL-17)、肿瘤坏死因子α(TNF-α)表达的影响。方法 SD大鼠30只随机分成3组:EAE-咪唑克生组(免疫当日开始给予咪唑克生2 mg·kg~(-1),腹腔注射,连续14 d)、EAE-生理盐水组(给予相同剂量生理盐水)和空白对照组。用豚鼠全脊髓匀浆免疫诱导制作EAE大鼠模型。每天观察评估各组大鼠神经功能变化;苏木精-伊红染色观察病理学改变;免疫组化法检测小胶质细胞(Iba1阳性)的激活与表达水平;酶联免疫吸附试验(ELISA)法检测发病高峰期(免疫后15 d)脑组织中IL-17,TNF-α表达水平。结果与EAE-生理盐水组比较,EAE-咪唑克生组(1)日均神经功能评分降低(P0.05),最大临床症状评分显著降低(P0.01);(2)苏木精-伊红染色:中枢炎症细胞浸润减少(P0.05);(3)免疫组化:Iba1阳性细胞表达减少(P0.05);而EAE-生理盐水组大鼠腰髓内Iba1阳性细胞表达较空白对照组明显升高(P0.01);(4)ELISA:炎性细胞因子IL-17和TNF-α表达明显降低(P0.01)。结论咪唑克生能够减缓大鼠EAE病情,其机制可能与抑制中枢神经系统小胶质细胞激活,下调中枢神经系统炎症因子IL-17和TNF-α的表达,扰乱中枢神经系统内炎症因子的平衡有关。     

小胶质细胞活化在实验性自身免疫性脑脊髓炎中的作用机制

目的探讨小胶质细胞活化在实验性自身免疫性脑脊髓炎(EAE)发病机制中的作用。方法利用同种脑脊髓匀浆诱导EAE模型。采用免疫组化法、免疫组织荧光染色观察小胶质细胞对EAE不同病期炎性脱髓鞘病灶的反应,采用免疫组化法、ELISA法观察脑组织及外周血肿瘤坏死因子α(TNF-α)的表达。结果EAE发病前小胶质细胞即开始激活并持续至高峰期,形态学上表现为从正常的细小分枝状逐渐演变为高度分枝状、阿米巴状。免疫组化染色显示TNF-α阳性细胞多为小胶质细胞。EAE大鼠发病前脑组织中小胶质细胞、TNF-α阳性细胞数及外周血TNF-α水平已升高并持续至高峰期。结论小胶质细胞活化伴随EAE发病的整个过程。活化后的小胶质细胞可能通过合成和释放多种炎症介导物及细胞因子如TNF-α,进一步扩大炎症反应,进而促使髓鞘病变。     

侧脑室注射甘珀酸后豚鼠EAE模型脑白质内胶质细胞形态学改变

目的 观察豚鼠实验性自身免疫性脑脊髓炎(experimental autoimmune encephalomyelitis,EAE)模型侧脑室注射缝隙连接(gap junction, GJ)阻滞剂甘珀酸后,脑白质内免疫损伤发生发展变化以及脑内星形胶质细胞和小胶质细胞表达变化.方法 将豚鼠随机分为实验组和对照组,每组6只.实验组豚鼠经侧脑室注射甘珀酸,对照组以同样方式注射等量生理盐水,然后于豚鼠足底注射髓鞘碱性蛋白制作EAE动物模型.观察两组豚鼠EAE发病率,并采用免疫组化法观察豚鼠脑白质星形胶质细胞标志物胶质纤维酸性蛋白(glial fibrillary acidic protein, GFAP)和小胶质细胞标志物OX42的表达变化.结果 与对照组(平均EAE症状评分3.00分)相比较,实验组动物EAE发病率减少且症状(平均EAE症状评分0.67分)明显减轻(P<0.01);对照组与实验组EAE脑白质内均可见反应性GFAP(GFAP-like,GFAP-Li)星形胶质细胞表达, GFAP-Li标志物计数对照组为(504.00±55.88)个,实验组为(497.00±49.69)个,两组间比较无统计学差异(P>0.05);对照组与实验组EAE鼠脑白质内均可见反应性OX42(OX42-like,OX42-Li)小胶质细胞表达,实验组OX42-Li标志物计数[(120.00±10.64)个]较对照组[(242.00±35.35)个]明显减少(P<0.01).结论 GJ阻滞剂甘珀酸可明显减少EAE的发生率并明显减轻EAE发病的临床症状,其机制可能与其阻断GJ后继而降低小胶质细胞OX42的表达有关,表明GJ阻断剂可能成为多发性硬化防治的新途径.     

黑质小胶质细胞主要组织相容性复合物Ⅱ的表达与帕金森病发生和进展的关系

近年来诸多证据显示,中枢神经统的免疫异常和炎症反应参与了黑质多巴胺能神经元的变性坏死。小胶质细胞的激活是脑内炎症反应的主要标志,小胶质细胞主要组织相容性复合物Ⅱ(MHCⅡ)的表达是小胶质细胞活化的标志。尽管人脑中的小胶质细胞并不持续表达MHCⅡ类分子,但随着年老以及在中枢神经系统出现病变的情况下(包括神经变性),它们的表达确是明显上调的。研究发现,在PD病人和PD动物模型的中脑黑质均可发现大量MHCⅡ阳性的小胶质细胞,MHCⅡ类分子在小胶质细胞将外源性抗原呈递给CD4+Th细胞的过程中起重要作用。在6-羟多巴胺(6-OHDA)、脂多糖(LPS)大鼠模型的观察发现,促红细胞生成素、地塞米松等能明显降低MHCⅡ的表达和小胶质细胞的活化,从而减轻动物模型的临床症状。鉴于MHCⅡ抗原启动的免疫反应在PD的发病过程中有促进慢性神经变性进展的作用,因此,抑制小胶质细胞活性和MHCⅡ表达对控制PD进展可能有重要的治疗上的意义。     

实验性自身免疫性脑脊髓炎小鼠脊髓中细胞色素C和凋亡诱导因子表达的变化

目的观察实验性自身免疫性脑脊髓炎(EAE)小鼠脊髓中细胞色素C(CytC)和凋亡诱导因子(AIF)表达的变化。方法 C57BL/6小鼠12只随机分为EAE组和正常对照组。使用髓鞘少突胶质细胞糖蛋白和完全弗氏佐剂混合抗原乳剂免疫C57BL/6小鼠制作EAE模型。每天2次记录各组小鼠体重和神经功能评分的变化。采用苏木精-伊红染色、髓鞘LFB染色、免疫组化染色,检测发病高峰期(免疫后第19天)小鼠脊髓的病理变化、髓鞘脱失程度、CytC和AIF的变化。结果与正常对照组比较,EAE组神经功能评分增加(P<0.01)、炎症细胞浸润增加(P<0.01)、脱髓鞘程度严重(P<0.01)、CytC和AIF表达均增加(P<0.01),而且与EAE的病情变化指标(最高症状评分、病理评分)均呈正相关关系。结论 EAE小鼠发病高峰期脊髓中CytC和AIF表达增加,提示EAE小鼠的病情变化与中枢神经系统的线粒体损伤有关。     

实验性变态反应性脑脊髓炎发病初期血脑屏障的变化及基质金属蛋白酶的作用研究

目的:探讨多发性硬化的动物模型-实验性变态反应性脑脊髓炎(EAE)发病初期血脑屏障(BBB)的变化及基质金属蛋白酶(MMPs)的作用机制。方法:建立Wistar大鼠EAE动物模型,取发病初期未出现临床症状的EAE大鼠,取脊髓组织通过共聚焦显微镜观察伊文思兰在BBB中的通透性,并用免疫组化的方法测定免疫球蛋白(IgG)的沉积和基质金属蛋白酶(MMPs)的分布。探讨发病初期BBB的变化。结果:CM观察发现,未发病的EAE大鼠沿脊膜下有桔红色荧光分布,同样,EAE大鼠脊髓切片可见有IgG渗出,表现为神经纤维网和神经胶质细胞胞浆呈棕褐色染色,MMP9,-2在脊膜和血管内皮细胞内呈阳性表达,而对照组均呈阴性表达。结论:BBB在EAE发病初期已经受损,MMPs是BBB破坏的重要因素,有降解血管基底膜的作用,可促使炎细胞侵入中枢神经系统。     

Neuroimaging in epilepsy in tropics

Epilepsy is a major public health problem in many tropical countries. Also, some of the tropical diseases are major contributors to the higher prevalence of epilepsy in these countries. The etiologic factors responsible for epilepsy in these countries are quite different from those in the developed world. This article discusses the etiologic factors and neuroimaging of epilepsy in light of the conditions in these tropical countries.     

癫痫与抑郁关系的研究进展

抑郁是癫痫患者中常见的精神障碍,严重地影响了患者的生活质量。传统的观点认为癫痫患者因为存在着诸多社会学问题易出现抑郁倾向,癫痫和抑郁是单向的联系,但大量的研究已经证明癫痫和抑郁之间存在双向的联系,一种异常状态的存在可能易转化为另一种异常状态的发展。癫痫和抑郁存在着共同的发病机制。本文主要就癫痫和抑郁的双向联系以及抗抑郁药物在癫痫患者中的应用进行阐述。     

Sudanophilic lipid accumulation in astrocytes in periventricular leukomalacia in monkeys

Summary Sudanophilic lipid accumulation is a characteristic feature of periventricular leukomalacia (PVL) of infants. At least two types of lipid-containing cells have been identified, one being the macrophage, the other the pre-myelin glial cell. A third type of lipid-containing cell has been seen in two monkeys with spontaneous PVL. Electron microscopically this cell appears to be an astrocyte. This probably represents a reaction of the astrocyte to hypoxia and may be the equivalent of the hypertrophic astrocytes found in human infants.Supported in part by NIH grant HDO 8633 and the Regional Primate Research Center Grant RR-00166     

Increase in cathepsin D activity in rat brain in aging

Cathepsin D-like activity in homogenates of five brain areas of 3-month-old and 24-month-old Fischer 344 rats was measured. With hemoglobin as substrate at pH 3.2, more than 90% of the activity was inhibited by pepstatin. In each area studied, activity was more than twice as high in the old rat brain: 140-160% higher in the cortex, cerebellum, pons-medulla, and striatum and 90-100% higher in the hippocampus and spinal cord. The greatly increased metabolic capacity in the absence of an increase in protein turnover may have a role in age-related pathological degeneration in the brain.     

Characteristics of nociceptors in the periodontium--an in vitro study in rats

Recent studies have indicated that nociceptors can be classified into various types according to their physiological properties. These studies have clarified that the frequency distribution of various nociceptor types is different among body sites and animal species. In the present study, we investigated the physiological properties of rat's periodontal nociceptors in an in vitro jaw-nerve preparation. Responses were recorded from functional single filaments in the inferior alveolar nerve. To determine the nociceptor type, calibrated von Frey filaments, heat, and bradykinin (BK) stimuli were used. We found five subtypes of nociceptors in the periodontal ligaments of the lower incisor: Adelta-high threshold mechanonociceptors (Adelta-HTM, n=28), Adelta-mechanoheat nociceptors (Adelta-MH, n=6), Adelta-polymodal nociceptors (Adelta-POLY, n=26), C-high threshold mechanonociceptors (C-HTM, n=3) and C-polymodal nociceptors (C-POLY, n=4). Most nociceptors were Adelta-innervated, while only a small number of C-innervated nociceptors were found. The present results suggest that periodontal nociceptors transmit mainly fast pain, and may thus play a role in rapid detection of injure-related stimuli during mastication.     

Defects in Bioenergetic Coupling in Schizophrenia

Synaptic neurotransmission relies on maintenance of the synapse and meeting the energy demands of neurons. Defects in excitatory and inhibitory synapses have been implicated in schizophrenia, likely contributing to positive and negative symptoms as well as impaired cognition. Recently, accumulating evidence has suggested that bioenergetic systems, important in both synaptic function and cognition, are abnormal in psychiatric illnesses such as schizophrenia. Animal models of synaptic dysfunction demonstrated endophenotypes of schizophrenia as well as bioenergetic abnormalities. We report findings on the bioenergetic interplay of astrocytes and neurons and discuss how dysregulation of these pathways may contribute to the pathogenesis of schizophrenia, highlighting metabolic systems as important therapeutic targets.     

Progress in neuroprotection in Parkinson's disease

Slowing or aborting the progress of neurodegeneration in Parkinson's disease (PD) remains the most important unmet need of this disorder. There are several recent developments in trial design and also in drugs under investigation for possible neuroprotective effect. Emphasis has been placed on clinical as opposed to imaging end-points and these include change in a clinical rating scale, e.g. United Parkinson's disease Rating Scale (UPDRS), or time to additional therapy. The introduction of the delayed-start, or wash-in, trial design adds an additional dimension to drug evaluation for neuroprotection. Compounds that have been recently tested in clinical trial include the monoamine oxidase-B inhibitor rasagiline, the anti-apoptotic agents TCH346 and CEP1347, and the promitochondrial agent creatine. The dopamine agonists have been evaluated for a neuroprotective effect using imaging end-points. Perhaps the most important and simplest concept for neuroprotection has been the theory that early dopaminergic support for the degenerating dopaminergic system per se provides significant long-term clinical benefit for PD patients.     

Gender in Voice Perception in Autism

Deficits in the perception of social stimuli may contribute to the characteristic impairments in social interaction in high functioning autism (HFA). Although the cortical processing of voice is abnormal in HFA, it is unclear whether this gives rise to impairments in the perception of voice gender. About 20 children with HFA and 20 matched controls were presented with voice fragments that were parametrically morphed in gender. No differences were found in the perception of gender between the two groups of participants, but response times differed significantly. The results suggest that the perception of voice gender is not impaired in HFA, which is consistent with behavioral findings of an unimpaired voice-based identification of age and identity by individuals with autism. The differences in response times suggest that individuals with HFA use different perceptual approaches from those used by typically developing individuals.     

Increase in noradrenaline-synthesizing enzyme activity in medulla oblongata in Parkinson's disease

Summary Dopamine beta hydroxylase (DBH), the noradrenaline-synthesizing enzyme, and phenylethanolamine-N-methyltransferase (PNMT), the adrenaline-synthesizing enzyme, were assayed in 18 areas of brain stem in eight cases of parkinsonian syndromes and of four age- and postmortem delay-matched controls. Dissection was performed by the punch technique and enzyme activities assayed by radiometric methods. No significant change was found for PNMT activity. DBH activity was significantly increased in the A2-C2 area of the medulla oblongata (including the nucleus tractus solitarius) in the cases of Parkinson's disease.The A2-C2 area is known to be implicated in the control of blood pressure in rats. These findings are discussed in relation to orthostatic hypotension and the influence ofl-dopa therapy.Supported by grants from INSERM ATP 657897, ATP 8179113, CRL 79-1-356-6, DGRST (80 E 0882), FRMF, and Sandoz-France France