Wallerian Degeneration: A Major Component of Early Axonal Pathology in Multiple Sclerosis

Axonal loss is a major component of the pathology of multiple sclerosis (MS) and the morphological basis of permanent clinical disability. It occurs in demyelinating plaques but also in the so‐called normal‐appearing white matter (NAWM). However, the contribution of Wallerian degeneration to axonal pathology is not known. Here, we analyzed the extent of Wallerian degeneration and axonal pathology in periplaque white matter (PPWM) and lesions in early multiple sclerosis biopsy tissue from 63 MS patients. Wallerian degeneration was visualized using an antibody against the neuropeptide Y receptor Y1 (NPY‐Y1R). The number of SMI‐32‐positive axons with non‐phosphorylated neurofilaments was significantly higher in both PPWM and plaques compared to control white matter. APP‐positive, acutely damaged axons were found in significantly higher numbers in plaques compared to PPWM. Strikingly, the number of NPY‐Y1R‐positive axons undergoing Wallerian degeneration was significantly higher in PPWM and plaques than in control WM. NPY‐Y1R‐positive axons in PPWM were strongly correlated to those in the lesions. Our results show that Wallerian degeneration is a major component of axonal pathology in the periplaque white matter in early MS. It may contribute to radiological changes observed in early MS and most likely plays a major role in the development of disability.     

Cognitive Impairment in Multiple Sclerosis: Clinical,Radiologic and Pathologic Insights

Cognitive impairment is a common and debilitating feature of multiple sclerosis (MS) that has only recent gained considerable attention. Clinical neuropsychological studies have made apparent the multifaceted nature of cognitive troubles often encountered in MS and continue to broaden our understanding of its complexity. Radiographic studies have started to decipher the neuroanatomic substrate of MS‐related cognitive impairment and have shed light onto its pathogenesis. Where radiographic studies have been limited by inadequate resolution or non‐specificity, pathological studies have come to the fore. This review aims to provide an overview of the nature of cognitive impairment typically seen in MS and to explore the literature on imaging and pathological studies relevant to its evolution. In particular, the relative contributions of gray (ie, cerebral cortex, hippocampus, thalamus and basal ganglia) and white matter to MS‐related cognitive impairment will be discussed and the importance of interconnectivity between structures highlighted. The pressing need for longitudinal studies combining standardized neuropsychometric, paraclinical and radiographic outcomes obtained during life with post‐mortem tissue analysis after death is presented.     

Purkinje Cell Pathology and Loss in Multiple Sclerosis Cerebellum

Cerebellar ataxia commonly occurs in multiple sclerosis, particularly in chronic progressive disease. Previous reports have highlighted both white matter and grey matter pathological changes within the cerebellum; and demyelination and inflammatory cell infiltrates appear commonly. As Purkinje cell axons are the sole output of the cerebellar cortex, understanding pathologic processes within these cells is crucial to develop strategies to prevent their loss and thus reduce ataxia. We studied pathologic changes occurring within Purkinje cells of the cerebellum. Using immunohistochemic techniques, we found changes in neurofilament phosphorylation states within Purkinje cells, including loss of dephosphorylated neurofilament and increased phosphorylated and hyperphosphorylated neurofilament. We also found Purkinje axonal spheroids and Purkinje cell loss, both of which occurred predominantly within areas of leucocortical demyelination within the cerebellar cortex. These changes have important implications for the study of cerebellar involvement in multiple sclerosis and may help design therapies to reduce the burden of ataxia in the condition.     

大鼠脊髓损伤及继发损伤时脊髓诱发电位与运动诱发电位的变化

本文采用改良Ａｌｌｅｎ’ｓ法，分别以５０ｇ／ｃｍ和１００ｇ／ｃｍ打击大鼠Ｔ１３～Ｌ１脊髓，造成不同程度的脊髓损伤，分别观察伤后２４小时内的ＳｐＥＰ和ＣＭＥＰ的变化，以了解不同程度损伤对ＳｐＥＰ和ＣＭＥＰ的影响及ＳｐＥＰ、ＣＭＥＰ的变化与脊髓继发性损伤发展过程的关系。结果表明：①两种不同程度的脊髓损伤均可造成大鼠脊髓ＳｐＥＰ，ＣＭＥＰ的明显变化，尤以ＳｐＥＰ变化明显。损伤越重，电位改变越明显．②在脊髓损伤后１～２４小时内，伤后１０分钟ＳｐＥＰ，ＣＭＥＰ波幅却有明显降低，４～８小时进一步降低。两次降低有明显差异。ＳｐＥＰ峰潜伏时延长，以４～８小时显著。表明原发损伤后在受损部位存在继发性损伤，提示阻止继发损伤的时间应早于伤后４小时，并尽可能提前。     

一氧化氮与多发性硬化

多发性硬化是中枢神经系统一种广泛脱髓鞘性自身免疫性疾病,其发病机制与免疫调节功能异常密切相关。一氧化氮具有重要的免疫调节作用,它与多发性硬化的发生、发展有着密切的关系。一氧化氮在多发性硬化的经典动物模型—实验性变态反应性脑脊髓炎的预防和治疗中发挥重要作用。因此,对一氧化氮的深入研究将为临床防治多发性硬化等自身免疫疾病提供有价值的新思路。     

多发性硬化症发病机理研究进展

多发性硬化（ＭＳ），重症肌无力（ＭＧ）是比较公认的神经系统自身免疫性疾病，格林巴利综合征（ＧＢＳ）也被认为与自身免疫有关，下面对多发性硬化的发病机理作一综述。ＭＳ是最常见的ＣＮＳ自身免疫性疾病，属慢性炎症性脱髓鞘性疾病，病理特征为白质有Ｔ细胞、巨噬细...     

Antigen-Specific Therapies in Multiple Sclerosis

During recent years, many new therapies for human autoimmune diseases such as multiple sclerosis (MS) have been considered based on promising in vitro data or animal experiments. A number of them have proceeded to early clinical testing. However, very few finally advanced to approval by the regulatory agencies and are currently available to patients. The main reasons for failure were either lack of efficacy in humans and/or unexpected and untolerable adverse events. Although previous attempts toward antigen-specific immunomodulation have often been disappointing, these difficulties have led to renewed interest in therapies that aim at reestablishing tolerance to autoantigens at the level of either T cell-mediated or antibody-mediated immune responses or both. Such antigen-specific immunotherapies offer the prospect of correcting pathological immune reactivity against autoantigens in a highly specific and effective manner and also achievement of this goal with relatively little side effects. Here we will review the various approaches that are currently being considered for antigen-specific immunotherapies in MS.     

Molecular Changes in White Matter Adjacent to an Active Demyelinating Lesion in Early Multiple Sclerosis

A stereotactic biopsy of a 17-year-old woman revealed an active inflammatory demyelinating lesion compatible with pattern III multiple sclerosis (MS) according to Lucchinetti et al . The biopsy included a white matter region distant from the active inflammatory demyelinating lesion with abnormal MRI signal, lacking histopathological signs of demyelination and/or oligodendrocyte apoptosis. Expression analysis of this area revealed a strong up-regulation of neuronal nitric oxide synthase (nNOS). Furthermore, detection of nitrotyrosine provided evidence for reactive nitrogen species (RNS)-mediated damage to oligodendrocytes. Concomitantly, genes involved in neuroprotection against oxidative stress such as heme oxygenase 1 were up-regulated. Even though a single case report, this study shows earliest molecular changes in white matter surrounding an actively demyelinating lesion during the first manifestation of MS, pointing toward a more widespread pathological process. Therapeutic targeting of the identified mechanisms of tissue injury might be crucial to prevent further lesion formation or secondary tissue damage.     

大鼠脊髓压迫损伤后COX-2基因和蛋白的表达

目的观察大鼠脊髓压迫损伤后COX-2mRNA和蛋白在脊髓组织内表达的时间特征,以及COX-2的空间分布特点。方法以压迫装置致脊髓损伤后,在伤后不同时间点(30min、3h、6h、24h、72h、1w)分别应用RT-PCR、Western blotting、免疫组化技术检测COX-2mRNA和蛋白表达和分布。结果RT-PCR和Western blotting显示,COX-2mRNA和蛋白伤后30min表达开始增加,于伤后6h达到峰值,伤后1w表达接近基础水平。免疫组化提示,COX-2蛋白在假手术组表达仅见于脊髓血管内皮细胞,伤后COX-2蛋白表达见于损伤区附近脊髓灰质内的神经元和血管内皮细胞,损伤中心部位COX-2免疫阳性细胞少见。结论脊髓压迫损伤早期可快速诱导COX-2基因的表达上调和蛋白的合成,伤后COX-2蛋白分布发生变化,主要位于脊髓神经元和血管内皮细胞。     

外加电场对实验性大鼠脊髓损伤作用的研究

目的:探讨脊髓损伤后外加电场(electric fields,EF)对脊髓血流量(spinal cord blod flow,SCBF)及神经功能的影响。方法:Wistar大鼠20只,随机分为对照组(CON组)和EF治疗组(EF组)。Allen's打击法50 gcm(5 g×10 m)致伤大鼠L1～L2段脊髓,给予EF治疗,于伤前、伤后即刻、1、3、6、24 h分别记录T12段脊髓血流量、脊髓感觉诱发电位。术后7、14天行联合行为评分(CBS)。结果:与盐水对照组比较,应用EF后,大鼠SCBF、SEP明显优于CON组(P<0.05)。结论:EF能有效改善损伤早期脊髓微循环,保护脊髓神经功能。     

缺氧－复氧损伤对大鼠脊髓组织牛磺酸转运的影响

本工作在大鼠离体脊髓缺氧－复氧损伤模型上，观察了脊髓组织牛磺酸转运的特征，结果发现：缺氧４５ｍｉｎ后复氧孵育１５ｍｉｎ，脊髓组织出现明显的牛磺酸转运的障碍，表现为Ｖ＿（ｍａｘ）明显降低（为正常组的７１％，Ｐ＜０．０１），Ｋｍ值无明显改变，推测缺氧。复氧可能通过影响能量代谢而导致脊髓组织牛磺酸转运的障碍。     

Morphofunctional Changes in Spinal Cord Neurons After Epidural Lidocaine

Morphofunctional and histoenzymological changes in spinal cord neurons of mongrel dogs were studied after epidural administration of isobaric 2% lidocaine solution. Control animals received epidural 0.9% sodium chloride. The results obtained from these studies provide evidence for the absence of pathological structural-metabolic changes in nerve tissue after treatment with lidocaine. The occurrence of certain morphofunctional rearrangements in spinal cord neurons were typical of animals of both the experimental and control groups. The changes recorded varied within the limits of physiological variation and provided evidence predominantly of the functional response of these nerve tissue structures to epidural injections of both sodium chloride and lidocaine.     

Bioelectric Activity of Spinal Cord in Patients with Vertebrospinal Pathologies

A method for functional evaluation of spinal cord conducting systems in patients with vertebrospinal diseases is proposed. The method is based on the analysis of changes in electrospinoneurogram recorded with epidural electrodes below the injury during an attempt at voluntary activation of foot muscles. The degree of changes in electrospinoneurogram frequency during voluntary command addressed to motoneurons of the lumbar enlargement reflect the state of descending spinal systems.     

Arterial Blood Supply to the Spinal Cord in Animal Models of Spinal Cord Injury. A Review

Animal models are used to examine the results of experimental spinal cord injury. Alterations in spinal cord blood supply caused by complex spinal cord injuries contribute significantly to the diversity and severity of the spinal cord damage, particularly ischemic changes. However, the literature has not completely clarified our knowledge of anatomy of the complex three‐dimensional arterial system of the spinal cord in experimental animals, which can impede the translation of experimental results to human clinical applications. As the literary sources dealing with the spinal cord arterial blood supply in experimental animals are limited and scattered, the authors performed a review of the anatomy of the arterial blood supply to the spinal cord in several experimental animals, including pigs, dogs, cats, rabbits, guinea pigs, rats, and mice and created a coherent format discussing the interspecies differences. This provides researchers with a valuable tool for the selection of the most suitable animal model for their experiments in the study of spinal cord ischemia and provides clinicians with a basis for the appropriate translation of research work to their clinical applications. Anat Rec, 300:2091–2106, 2017. © 2017 Wiley Periodicals, Inc.     

New Minimally Invasive Model of Spinal Cord Ischemia in Rats

We developed a new minimally invasive model of spinal cord ischemia in rats: intravascular occlusion of the abdominal aorta and its branches. This model can be used on small laboratory animals and allows qualitatively and quantitatively evaluating the morphofunctional state of the nervous system during spinal cord ischemia by clinical manifestations and histological changes. Selective intravascular occlusion determines minimal invasiveness and adequacy of the proposed model to in vivo pathological processes. This model of spinal cord ischemia can be used in experimental pharmacology for evaluation of neuroprotective activity of various drugs and bioactive substances.     

功能性电刺激对脊髓损伤的修复作用

目的：回顾功能性电刺激（functional electrical stimulation, FES）对诱导瘫痪或麻痹的肌肉产生功能性或治疗性运动的作用．总结功能性电刺激修复脊髓损伤中应用进展。方法：应用计算机检索CNKI1990年11月至2009年11月有关组织工程修复脊髓损伤方面的文章,检索词”脊髓损伤,电刺激”,限定文献语言种类为中文。同时计算机检索Medline1999年11月至2009年11月有关功能性电刺激在修复脊髓损伤方面的文章,检索词”spinalcordinjury,electricalstimulation”,限定文献语言种类为English。对资料进行初审。选取功能性电刺激修复脊髓损伤方面的相关文献,查找全文,对文献分析,总结研究内容。结果：功能性电刺激通过一定频率电刺激诱导瘫痪或麻痹的肌肉产生功能性或治疗性运动,可以达到改善或恢复被刺激肌肉或肌群功能的目的。功能性电刺激技术可以恢复截瘫患者的部分运动功能。结论：功能性电刺激是现代康复工程领域具有应用前景的一项新的治疗性技术。功能性电刺激技术可以可以达到改善脊髓损伤患者被刺激肌肉或肌群功能,恢复截瘫患者的部分运动功能。     

Spinal upregulation of glutamate transporter GLT-1 by ceftriaxone: therapeutic efficacy in a range of experimental nervous system disorders

Glutamate neurotransmission is highly regulated, largely by glutamate transporters. In the spinal cord, the glutamate transporter GLT-1 is primarily responsible for glutamate clearance. Downregulation of GLT-1 can occur in activated astrocytes, and is associated with increased extracellular glutamate and neuroexcitation. Among other conditions, astrocyte activation occurs following repeated opioids and in models of chronic pain. If GLT-1 downregulation occurs in these states, GLT-1 could be a pharmacological target for improving opioid efficacy and controlling chronic pain. The present studies explored whether daily intrathecal treatment of rats with ceftriaxone, a β-lactam antibiotic that upregulates GLT-1 expression, could prevent development of hyperalgesia and allodynia following repeated morphine, reverse pain arising from central or peripheral neuropathy, and reduce glial activation in these models. Ceftriaxone pre-treatment attenuated the development of hyperalgesia and allodynia in response to repeated morphine, and prevented associated astrocyte activation. In a model of multiple sclerosis (experimental autoimmune encephalomyelitis; EAE), ceftriaxone reversed tactile allodynia and halted the progression of motor weakness and paralysis. Similarly, ceftriaxone reversed tactile allodynia induced by chronic constriction nerve injury (CCI). EAE and CCI each significantly reduced the expression of membrane-bound, dimerized GLT-1 protein in lumbar spinal cord, an effect normalized by ceftriaxone. Lastly, ceftriaxone normalized CCI- and EAE-induced astrocyte activation in lumbar spinal cord. Together, these data indicate that increasing spinal GLT-1 expression attenuates opioid-induced paradoxical pain, alleviates neuropathic pain, and suppresses associated glial activation. GLT-1 therefore may be a therapeutic target that could improve available treatment options for patients with chronic pain.     

人胎儿脊髓星形胶质细胞形态及分布

目的　观察星形胶质细胞在胎儿脊髓不同发育阶段形态和分布的变化。方法　在引产 19例胎儿脊髓 ,多克隆抗体GFAP ,应用SP免疫组织化学染色和图像分析。结果　星形胶质细胞在中央管、毛细血管周围密度大 ,染色深 ,环绕血管呈辐射状排列。 16W时已有少突起GFAP阳性细胞出现 ,胞体小 ,分布于脊髓白质的周边部 ,细长突起指向中央管方向 ;突起较短的细胞分布于脊髓前后正中沟两侧和中央管周围 ;灰质内阳性细胞主分布于背侧部的两侧 ,突起多而短 ,细胞核大。 2 4W时 ,多突起细胞增多 ,GFAP阳性细胞染色强度、细胞密度接近出生时水平。结论　人胎儿脊髓星形胶质细胞 16W时最多 ,2 4W时逐渐减少至出生时水平     

Therapeutic Effect of Curcumin and Methylprednisolone in the Rat Spinal Cord Injury

In addition to imperiling an individual's daily life, spinal cord injury (SCI), a catastrophic medical damage, can permanently impair an individual's body function. Methylprednisolone (MP), a medically accepted therapeutic drug for SCI, is highly controversial for the lack of consensus on its true therapeutic effect. In recent years, curcumin has served as a potential and novel therapeutic drug in SCI. Our study was intended to investigate the precise effect of MP and curcumin in SCI. We examined the function of MP and curcumin in a SCI model rat, both in vivo and in vitro, and found that there was a momentous improvement in Basso‐Beattie‐Bresnahan scores in the MP‐treated group when compared with Cur‐treated group within 14 days. Results obtained from the histological, immunohistochemistry and ultrastructural examinations evidenced the curative effect of MP was better than curcumin before Day 14. Nonetheless, there was a significant variation in the treatment effect between the MP‐treated and Cur‐treated groups after 14 days. The curcumin's effectiveness was more obvious than MP after 14 days following SCI. As such, we surmise that curcumin has a better therapeutic potential than MP with a prolong treatment time in the wake of SCI. Anat Rec, 301:686–696, 2018. © 2017 Wiley Periodicals, Inc.