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The adult mammalian central nervous system (CNS) lacks the capacity to support axonal regeneration. There is increasing evidence to suggest that astrocytes, the major glial population in the CNS, may possess both axon-growth promoting and axon-growth inhibitory properties and the latter may contribute to the poor regenerative capacity of the CNS. In order to examine the molecular differences between axon-growth permissive and axon-growth inhibitory astrocytes, a panel of astrocyte cell lines exhibiting a range of axon-growth promoting properties was generated and analysed. No clear correlation was found between the axon-growth promoting properties of these astrocyte cell lines with: (i) the expression of known neurite-outgrowth promoting molecules such as laminin, fibronectin andN-cadherin; (ii) the expression of known inhibitory molecules such tenascin and chondroitin sulphate proteoglycan; (iii) plasminogen activator and plasminogen activator inhibitor activity; and (iv) growth cone collapsing activity. EM studies on aggregates formed from astrocyte cell lines, however, revealed the presence of an abundance of extracellular matrix material associated with the more inhibitory astrocyte cell lines. When matrix deposited by astrocyte cell lines was assessed for axon-growth promoting activity, matrix from permissive lines was found to be a good substrate, whereas matrix from the inhibitory astrocyte lines was a poor substrate for neuritic growth. Our findings, taken together, suggest that the functional differences between the permissive and the inhibitory astrocyte cell lines reside largely with the ECM.  相似文献   
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A 16-year-old boy, the only affected member of the family, noticed early onset contracture of the elbows, and developed slowly progressive humeroperoneal weakness and atrophy, and bilateral equinus. The severe restriction of the forward flexion of the neck and thoracolumbar spine, resembled a rigid spine syndrome. An electrocardiogram showed atrioventricular conduction abnormalities. Muscle biopsy was consistent with mild myopathy. The overall conventional findings of a detailed electromyographic study in the limbs and erector trunci muscles, as well as the results of conduction velocity, automatic analysis of the voluntary pattern and single fiber electromyography studies were consistent with myopathy, although some atypical findings were found. The controversy about neurogenic and myopathic features in Emery-Dreifuss disease is discussed. The unspecific value of the flexion limitation of the spine, and the uncertain nosological position of the rigid spine syndrome are also commented.  相似文献   
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目的 探讨急性胰腺炎与血浆维生素C、维生素E和 β 胡萝卜素的关系。 方法 采用分光光度比色分析法检测 6 8例急性胰腺炎和 4 0例健康献血员血浆三种维生素含量。结果 急性胰腺炎组维生素C、维生素E、β 胡萝卜素含量较对照组显著降低 (P <0 .0 1) ,且随着禁食时间的延长呈逐渐降低趋势。 结论 急性胰腺炎时患者体内的氧化和抗氧化系统平衡失调 ,补充抗氧化维生素有助于病情的恢复。  相似文献   
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Japie  Du  Toit  张振安 《中国卫生产业》2005,(10):76-79
南非在建立和发展公平、高效、高质量的医疗保障体系的过程中,为公立医疗机构和私立医疗机构之间开展建设性的合作提供了相当大的空间。当决定是否应该在医疗体系中追求新的公私互动或公私合营机制之前,有必要对现有这种机制的功过是非、全民医疗体系的目标和已经取得的成绩进行认真评估。  相似文献   
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目的:探讨髋臼骨折合并同侧下肢骨折的创伤机制和治疗方法。方法:髋臼骨折并同侧下肢骨折14例,男9例,女5例;年龄18~65岁,平均35岁。髋臼骨折按Letournel分型,后壁伴后柱骨折11例,单纯后柱骨折3例,均行钢板内固定。伴同侧股骨转子间骨折3例,1例行起重机架外固定,2例行DHS固定;伴同侧股骨颈骨折3例,均行空心钉加压固定;伴同侧股骨干骨折6例,1例行钢板固定,余5例行带锁髓内钉固定;伴同侧胫骨平台骨折2例,行钢板内固定。结果:1例半年后死亡,余13例获得随访,随访时间18个月~5年,平均30个月。按照美国矫形外科研究院髋关节疗效评定标准,优9例,良3例,差1例。结论:髋臼骨折合并同侧下肢骨折受伤暴力大、机制复杂、合并创伤多、易漏诊,应早期明确诊断,合理内固定。  相似文献   
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BACKGROUND: Vitiligo is the most common pigmentary disorder with a global incidence from 0.1% to 2% in different geographical areas. Histopathology and histochemistry have shown the reduction of melanocytes in achromic patches, but microscopic changes of lesional and non-lesional skin are still not completely understood. Reflectance confocal microscopy (RCM), based on the different light reflectance index of cutaneous structures, allowed in vivo, en face microscopic evaluation of superficial skin layers with a resolution similar to skin histology. AIM: The purpose of this study was to evaluate RCM features of lesional and non-lesional skin of vitiligo patients. Moreover, re-pigmented areas were taken into consideration in order to evaluate melanocyte response to ultraviolet B (UVB) radiation. SUBJECTS AND METHODS: Sixteen patients of different phototypes affected by active non-segmental vitiligo and 10 controls were enrolled in the study. In vivo skin imaging was done using a commercially available RCM (Lucid, Vivascope 1500. Re-pigmented areas from 6 to 16 patients (after UVB narrow-band therapy) were also examined. RESULTS: Vitiligo lesions showed the disappearance of the bright rings normally seen at the dermo-epidermal junction. Moreover, non-lesional skin of vitiligo patients showed unexpected changes as the presence of half-rings or scalloped border-like features of the bright papillary rings. In re-pigmented areas after UVB narrow band therapy, the presence of activated, dendritic melanocytes was seen. CONCLUSIONS: Considering our results, and following further studies, RCM clinical applications could be used in the therapeutic monitoring and evaluation of the evolution of vitiligo.  相似文献   
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