Proteoglycans: Road Signs for Neurite Outgrowth

Proteoglycans in the central nervous system play integral roles as ＂traffic signals＂ for the direction of neurite outgrowth. This attribute of proteoglycans is a major factor in regeneration of the injured central nervous system. In this review, the structures of proteoglycans and the evidence suggesting their involvement in the response following spinal cord injury are presented. The review further describes the methods routinely used to determine the effect proteoglycans have on neurite outgrowth. The effects of proteoglycans on neurite outgrowth are not completely understood as there is disagreement on what component of the molecule is interacting with growing neurites and this ambiguity is chronicled in an historical context. Finally, the most recent findings suggesting possible receptors, interactions, and sulfation patterns that may be important in eliciting the effect of proteoglycans on neurite outgrowth are discussed. A greater understanding of the proteoglycan-neurite interaction is necessary for successfully promoting regeneration in the iniured central nervous system.     

Strategies for myelin regeneration: lessons learned from development

Myelin regeneration is indispensably important for patients suffering from several central nervous system （CNS） disorders such as multiple sclerosis （MS） and spinal cord injury （SCI）, because it is not only essential for restoring neurophysiology, but also protects denuded axons for secondary degeneration. Understanding the cellular and molecular mechanisms underlying remyelination is critical for the development of remyelination-specific therapeutic approaches. As remyelination shares certain common mechanisms with developmental myelination, knowledge from study of developmental myelination contributes greatly to emerging myelin regeneration therapies, best evidenced as the recently developed human anti-Nogo receptor interacting protein-1 （LINGO-1） monoclonal antibodies to treat MS patients in clinical trials.     

缺血预处理对兔脊髓缺血损伤后的保护作用及其机制

目的:探讨缺血预处理对兔脊髓缺血损伤的保护作用及机制。方法:24只雄性新西兰大白兔随机数字表法分3组(每组8只):即缺血组(IC组)、缺血预处理组(IPC组)及假手术组(S组)。IC组夹闭兔腹主动脉肾下段20min,制作兔脊髓缺血模型;IPC组预先使脊髓缺血6min,再灌注30min后再次阻闭兔腹主动脉肾下段20min;S组除不夹闭腹主动脉外,其余处理同IC组。再灌注后8,12,24和48h分别对动物神经功能评分;再灌注后48h,测定血浆血栓素B2(TXB2,TXA2的稳定代谢产物)的含量及6-酮前列素(6-keto-PGF1α,PGI2的稳定代谢产物)的含量,然后处死动物取脊髓,测定脊髓组织中TXB2及6-keto-PGF1α的含量。结果:IPC组神经功能评分各时间点均明显高于IC组。与IC组相比,IPC组血浆和脊髓中TXB2含量明显减少,分别为(108±20)mg/L,(733±64)ng/g(P<0.05,F=27.93,132.887),而IPC组血浆和脊髓中6-keto-PGF1α含量明显增多,分别为(75±14)mg/L,(502±37)ng/g(P<0.05,F=13.185,64.141)。IPC组血浆和脊髓中TXB2/6-keto-PGF1α分别为(1.45±0.17),(1.47±0.19),明显低于IC组(P<0.05,F=20.83,29.447)。结论:缺血预处理对脊髓缺血损伤有显著的保护作用,保护机制与缺血预处理改善脊髓缺血损伤后TXA2-PGI2平衡失调有关。     

Semen retrieval by penile vibratory stimulation in men with spinal cord injury.

Traumatic spinal cord injury resulting from car accidents, falls, violence or sport-related activities is a common occurrence throughout the world. Spinal cord injuries occur most often to young men in their parenting years. Among the medical challenges facing many of these men is the inability to ejaculate via sexual intercourse. To achieve biological fatherhood, their semen may be retrieved by methods of assisted ejaculation. This paper discusses the use of penile vibratory stimulation in men with spinal cord injury, and includes the topics: patient selection and management; proper placement and timing of stimulation; appropriate use of low-amplitude, high-amplitude or dual vibrators; and factors influencing ejaculatory success rate. Also summarized are recent data on semen quality in men with spinal cord injury. When performed properly, penile vibratory stimulation is a safe and easy method of obtaining semen from anejaculatory men with spinal cord injury. Semen quality is better when obtained by penile vibratory stimulation compared with electroejaculation, an alternative method of semen retrieval. For these reasons, and because of the low investment of time and money, it is recommended that penile vibratory stimulation be used as the first line of treatment for anejaculation in men with spinal cord injury.     

多疣壁虎血管活性肠肽基因的克隆及表达

目的:克隆多疣壁虎血管活性肠肽(VIP)的cDNA全长序列,研究VIP在正常壁虎各组织中的表达及断尾损伤后脊髓再生过程中的表达变化。方法:通过对多疣壁虎断尾损伤cDNA文库克隆测序获得VIP基因序列。通过Northern blot验证VIP转录本的大小,通过原位杂交检测VIP mRNA在正常壁虎脊髓中的分布。制备壁虎断尾损伤模型,通过采用Real time-PCR和原位杂交的方法检测VIP mRNA在壁虎损伤模型断端近侧脊髓中的表达变化。结果:VIP mRNA全长1933 bp,编码156个氨基酸的前原蛋白。编码的成熟肽与其他物种的同源性约为82.1%。RT-PCR和Northern blot显示VIP在正常壁虎组织中广泛表达,且通过Northern blot发现正常壁虎体内只一个转录本,大小约1.9kb。原位杂交结果显示VIP阳性信号主要分布于脊髓灰质中,白质中仅有少量表达。Real-time PCR和原位杂交结果表明断尾损伤后的近端脊髓组织中VIP表达呈动态变化。结论:获得壁虎VIP全长mRNA序列的基本特征及其多组织表达图谱。VIP在壁虎的脊髓中主要分布于灰质中,壁虎在断尾损伤后近端脊髓VIP的表达呈动态变化。     

强啡肽A（1－17）致大鼠脊髓损伤

为研究脊髓损伤及继发性损伤的发病机理及其治疗方法，建立了蛛网膜下腔注射强啡肽Ａ（ＤｙｎＡ）致大鼠脊髓损伤动物模型。发现内源性ＤｙｎＡ（１－１７）的氨基端酪氨酸与竣基端的氨基酸残基在致脊髓损伤中都是重要的：Ｎ－甲基－Ｄ－天冬氨酸受体拮抗剂ＤＬ－２－氨基－５－胯酰戊酸（ＡＰＶ），犬尿氨酸及ＭＫ－８０１在对抗ＤｙｎＡ的损伤中均有一定的疗效。但ＡＰＶ和ＭＫ－８０１本身有一定毒性。而犬尿酸氨是一种内源性物质，主要作用于甘氨酸Ｂ变构调节位点，对整体生理功能影响较小。钙拮抗剂维拉帕米对抗强啡肽的致脊髓损伤作用迅速而完全。在所用剂量（５０ｎｍｏｌ）下无毒副作用。     

前路减压治疗陈旧性胸腰椎骨折伴截瘫12例

目的：探讨前路减压治疗陈旧性胸腰椎骨折伴截瘫的临床效果。方法：12例患者中7例单纯行前路减压+植骨,5例会并骨折脱位或严重后凸畸形行前路成压+Kaneda钉矫形内固定+植骨。结果：经6月～3年5个月随访,10例按Frankel分级有1～3级改善,平均改善1．6级,总有效率达83．3％。结论：对于脊髓前方有明显压迫物存在的陈旧性胸腰椎骨折伴截瘫患者,前路减压视野清晰,减压充分,神经损伤小,截瘫恢复率高。     

脊髓肿瘤的手术治疗

目的 探讨脊髓肿瘤的手术方法和技巧。方法 回顺性分析421例脊髓肿瘤(髓外264例，髓内157例)病人的手术入路、操作方法和手术疗效。结果 肿瘤全切除率88．6％(髓外91．7％，髓内83.4％)，神经功能保留率(改善 不变)91.0％(髓外96.6％，髓内81．5％)。结论 对不同部位和不同病理类型肿瘤的切除要遵循不同的方法。     

强啡肽A（1－17）致大鼠脊髓损伤

为研究脊髓损伤及继发性损伤的发病机理及其治疗方法，建立了蛛网膜下腔注射强啡肽Ａ（ＤｙｎＡ）致大鼠脊髓损伤动物模型。发现内源性ＤｙｎＡ（１－１７）的氨基端酪氨酸与竣基端的氨基酸残基在致脊髓损伤中都是重要的：Ｎ－甲基－Ｄ－天冬氨酸受体拮抗剂ＤＬ－２－氨基－５－胯酰戊酸（ＡＰＶ），犬尿氨酸及ＭＫ－８０１在对抗ＤｙｎＡ的损伤中均有一定的疗效。但ＡＰＶ和ＭＫ－８０１本身有一定毒性。而犬尿酸氨是一种内源性物质，主要作用于甘氨酸Ｂ变构调节位点，对整体生理功能影响较小。钙拮抗剂维拉帕米对抗强啡肽的致脊髓损伤作用迅速而完全。在所用剂量（５０ｎｍｏｌ）下无毒副作用。     

脊髓种植性髓母细胞瘤6例的联合化疗

目的 :探讨应用联合化疗方法治疗种植性脊髓髓母细胞瘤。方法 :髓母细胞瘤术后脊髓播散性复发的患者 ,用替尼泊苷 (VM 2 6 ,卫萌 ) 1 0 0mg m2 溶入 0 .9%氯化钠注射液 2 50ml静脉点滴 ,连用 3天 ,间隔 7天重复治疗 1次 ,共治疗 5次 ,为一个疗程。平阳霉素 (PYM) 4mg m2 溶入 0 .9%氯化钠注射液 2 50ml静脉点滴 ,每周 2次 ,共治疗 5次 ,为一个疗程。甲氨蝶呤 (MTX) 1 0mg溶入 0 .9%氯化钠注射液 5ml,地塞米松 3mg分别鞘内缓慢注射 ,每周 1次 ,共治疗 5次 ,为一个疗程。平均一个疗程治疗 1 .5个月。结果 :一个疗程结束后两周复查MRI,神经影像显示 :6例患者中 2例肿瘤全部消失 ,4例肿瘤缩小 >80 %。继续第 2个疗程的治疗 (方法相同 ) ,余 4例肿瘤全部消失 ,疗效显著。结论 :化疗对髓母细胞瘤是有明显的治疗效果 ,特别是对手术后复发及不宜行手术的患者更是一种重要的治疗手段