Basal lamina at the site of spinal cord transection in the rat: An ultrastructural study

This electron microscopic study confirms that basal lamina (BL) begins to cap the cut end of the spinal cord 15 days after spinal cord transection. BL is first seen immediately adjacent to reactive glial cells but only when there is collagen in the nearby interstitial space. This finding suggests that collagen may provide a trigger to initiate the production of BL by reactive glia. We found no direct evidence that BL in this injury area impeded the outgrowth of regenerating neurites.     

自制脊髓打击器致大鼠脊髓损伤的组织形态学演变特征

目的:通过大鼠脊髓组织H-E染色和电镜观察,以评价自制撞击型脊髓打击器的应用价值。方法:采用自制脊髓打击器分别从2、3 cm和4 cm高度将10 g撞击头自由下落对脊髓进行撞击,以制备大鼠脊髓损伤模型,于制模术后3、7、14 d及28 d随机选取各组大鼠样品,对其脊髓组织进行H-E染色及电镜观察。结果:假手术组各观察时间点脊髓组织结构均完整;2 cm高度打击组脊髓损伤后至第7天组织坏死明显,14 d后受损组织部分修复;3 cm和4 cm高度打击组随时间延长受损脊髓组织坏死加重。电镜观察3个打击组随时间延长,髓鞘板层均表现为逐渐松解,轴突逐渐消失,尤以3 cm和4 cm高度打击组的损害更为严重。结论:本研究采用的自制脊髓打击器具有随打击高度的不同而出现不同程度组织损伤的演变特征,是一种较为理想的脊髓损伤制模装置。     

脊髓压迫性损伤大鼠海马和脊髓内BDNF的表达变化

目的探讨脑源性神经营养因子(BDNF)在脊髓压迫性损伤后的表达变化及作用。方法用自行设计的方法制作脊髓压迫模型,免疫荧光检测BDNF在星形胶质细胞、神经元和上下行轴突的表达;WB检测BDNF在大鼠海马及脊髓的表达。结果随着时间延长,受损部位的BDNF+-GFAP荧光强度逐渐增强;BDNF+-Tuj1荧光强度逐渐减弱;受损部位相邻上下段的BDNF+-NF200比受损部位的明显增强。海马和脊髓受损中心相邻的上、下段的BDNF蛋白表达在损伤后1d达到峰值,然后逐渐下降(P0.05);而脊髓受损中心的BDNF蛋白表达逐渐下降(P0.05)。结论脊髓损伤后,BDNF的表达下调,随伤后时间呈一定规律变化,是引起受损部位神经元表达下降的原因之一。     

脊髓全横断大鼠模型的构建

背景：脊髓全横断模型在造模时常难以保证神经纤维的完全离断。 目的：构建大鼠脊髓全横断损伤模型。 方法：将大鼠随机分为模型组和假手术组。模型组构建脊髓T10节段全横断模型;假手术组动物仅打开椎管与硬脊膜而后缝合,但不损伤脊髓。建模后1,3,5,7 d分别进行BBB评分以评估后肢运动功能,检测其体感诱发电位和运动诱发电位来评估神经传导通路的完整性,并行形态学观察来评估脊髓肉眼观病理形态。 结果与结论：与假手术组相比,模型组大鼠在建模后1,3,5,7 d时,其BBB评分降低(P < 0.01),未检测出体感和运动诱发电位。形态学观察结果显示模型组大鼠脊髓完全横断,而假手术组脊髓形态完整。结果提示实验成功构建了大鼠脊髓全横断模型。     

Increased oxidative-related mechanisms in the spinal cord injury in old rats

In the present study, we evaluated the effect of age, in a model of spinal cord injury that was induced by the application of vascular clips to the dura via a four-level T5-T8 laminectomy. Spinal cord injury in old rats resulted in severe trauma characterized by edema and neutrophil infiltration. Immunohistochemical examination demonstrated an increase in immunoreactivity for nitrotyrosine. In contrast, the degree of: (a) spinal cord inflammation and tissue injury (histological score), (b) nitrotyrosine, (c) PARS, and (d) neutrophils infiltration was markedly reduced in spinal cord tissue obtained from young rats. We have also demonstrated that ageing significantly worsened the recovery of limb function and caused an increase in mortality rate when compared with young rats.     

尼莫地平对大鼠脊髓损伤的作用研究

目的:研究尼莫地平(nimodipine)对大鼠脊髓损伤后继发性损害的保护作用。方法:成年SpragueDawley雄性大鼠24只,体重180～220 g,采用NYU脊髓撞击伤仪制成脊髓损伤模型后,随机分成尼莫地平(n=12)和生理盐水组(n=12)。两组大鼠受伤后1 h内分别经腹腔给予尼莫地平(1.0 mg/kg)或等量盐水治疗,3次/d,共1周。于受伤后1周和2周进行BBB评分和足迹实验对大鼠双后肢运动功能进行评估。受伤后2周,对损伤部位脊髓组织丙二醛(MDA)含量及脊髓过氧化物酶(MPO)活性进行检测;同时进行免疫组织化学检查确定损伤星形胶质瘢痕和所形成的坏死空洞,利用ED1观察活性小胶质细胞和巨噬细胞。结果:与生理盐水组比较,通过旷场试验(BBB评分)和足迹实验,脊髓损伤后大鼠尼莫地平组1周和2周运动功能明显改善(P<0.01)。与盐水组比较,伤后2周,尼莫地平组大鼠脊髓组织中MDA水平(nmol/g,25.6±9.7 vs 68.5±16.7)和MPO活性(U/g,252.2±63.9 vs 382.8±108.2)均明显降低(P<0.01);尼莫地平组空洞面积(mm2,4.45±1.28 vs 6.16±2.65)和ED1抗体免疫组化染色阳性面积(mm2,1.87±0.42 vs 2.86±1.01)也明显减少(P<0.01)。结论:尼莫地平可以减轻大鼠脊髓损伤后自由基的氧化损伤作用,减小空洞面积和炎症细胞浸润,具有促进脊髓损伤后的修复作用。     

BMSC修复大鼠脊髓损伤的效果的实验研究

目的 研究骨髓间质干细胞(Bone marrow stromal cells,BMSCs)用于修复大鼠脊髓损伤(spinal cord injury,SCI)的效果. 方法 30只成年SD大鼠按改良Tuszynsl法建立大鼠脊髓完全横断伤模型,损伤水平位于T9,损伤24 h后随机分为对照组、实验组,实验组经尾静脉注射BMSCs,对照组经静脉注射PBS.利用BBB(Basso-Beattie-Bresnahan)评分法进行后肢运动功能评价,并进行斜板实验. 结果 实验组运动功能改善,实验组与对照组的BBB评分比较差异有统计学意义(P<0.05),实验组的神经功能恢复较快.其中实验组大鼠在注射BMSCs 后35 d时后肢能支撑身体站立行走.斜板实验结果2组相比有显著性差异(P<0.05). 结论 骨髓间质干细胞移植组大鼠脊髓功能恢复优于对照组,说明骨髓间质干细胞用于修复大鼠SCI作用显著.     

骨髓间质干细胞修复大鼠脊髓损伤的效果的实验研究

目的研究骨髓间质干细胞（Bone marrow stromal cells，BMSCs）用于修复大鼠脊髓损伤（spinal cord injury，SCI）的效果。方法30只成年SD大鼠按改良Tuszynsl法建立大鼠脊髓完全横断伤模型，损伤水平位于T9，损伤24h后随机分为对照组、实验组，实验组经尾静脉注射BMSCs，对照组经静脉注射PBS。利用BBB（Basso-Beetle-Bresnahan）评分法进行后肢运动功能评价，并进行斜板实验。结果实验组运动功能改善，实验组与对照组的BBB评分比较差异有统计学意义（P〈0．05），实验组的神经功能恢复较快。其中实验组大鼠在注射BMSCs后35d时后肢能支撑身体站立行走。斜板实验结果2组相比有显著性差异（P〈0．05）。结论骨髓间质干细胞移植组大鼠脊髓功能恢复优于对照组，说明骨髓间质干细胞用于修复大鼠SCI作用显著。     

Response characteristics of spinal cord dorsal horn neurons in chronic allodynic rats after spinal cord injury

The physiological mechanisms of chronic pain in patients with spinal cord injury (SCI) are poorly understood. In the present study, we explored response characteristics of dorsal horn neurons of spinally injured rats exhibiting chronic pain (pain-like response to innocuous mechanical and cold stimulation). Several abnormalities were found in the distribution and response characteristics of dorsal horn neurons in chronic allodynic rats. First, 17% of the recorded neurons (vs. 0% in control animals) had no receptive field. Most of these units were located at or close to the lesioned spinal segment, and they discharged spontaneously at high frequencies. Allodynic rats also showed a significant decrease in the proportion of low-threshold (LT) neurons and an increase in the proportion of wide dynamic range (WDR) neurons. The rate of spontaneous activity of high-threshold (HT) neurons was significantly higher in allodynic compared with control rats. Moreover, HT neurons in allodynic animals showed increased neuronal responses to mechanical stimulation. WDR neurons responded with higher discharge rates to innocuous von Frey hair stimulation in allodynic compared with control rats. The percentage of WDR and HT neurons showing afterdischarges to noxious pinch was also significantly increased in the allodynic rats. The proportion of WDR and HT neurons responding to innocuous cold stimulation respectively increased from 53 and 25% in control rats to 91 and 75% in allodynic animals. These results suggest that the chronic pain-like behaviors in spinally injured rats may be generated and maintained by abnormalities in dorsal horn neurons.     

大鼠颈椎骨折错位致脊髓损伤模型的继发性损伤研究

目的　建立大鼠颈椎骨折错位致脊髓继发性损伤模型。 方法　20只成年SD大鼠,随机分为实验组(n=11)和对照组(n=6),3只处死取颈椎测量C4/5水平椎管和椎体矢状径。实验组利用颈椎骨折错位脊髓损伤装置在C4/5之间快速（200 mm/s）错位1.65 mm,造成颈椎骨折错位和颈脊髓损伤,采用自制器械固定颈椎。对照组除未行错位外与实验组相同。术后进行行为学（前肢运动和梳理试验）评价8周,和病理学检查。 结果 实验组行为学评分各个观察时间点均较对照组低。脊髓HE染色切片见实验组脊髓萎缩,灰质破坏,空洞,对照组未见明显异常。实验组损伤中心残留面积（2.79±0.98）mm2,明显小于对照组（6.36±0.08）mm2（P=0.034）。 结论　成功建立了大鼠颈椎骨折错位脊髓继发性损伤模型,大鼠C4/5骨折错位1.65 mm导致明显的脊髓组织损伤和运动功能障碍。     

SD大鼠脊髓损伤后微环境的模拟实验

BACKGROUND: We built Sprague-Dawley rat models with mild, moderate, and severe spinal cord injuries to accord with the spinal cord injury types for basic empirical study, and consequently to further understand the microenvironmental change in Sprague-Dawley rats with spinal cord injury, and to provide help for clinical treatment. OBJECTIVE: To observe the changes in nerve function, pathological manifestation and motor sensory evoked potential in Allen’s models and Sprague-Dawley rats with complete spinal cord transection at different time points after spinal cord injury by simulating the microenviroment in Sprague-Dawley rats. METHODS: A total of 125 healthy adult female Sprague-Dawley rats were selected and randomly divided into group sham operation group, 100 gcf hit potential group (20 g×5 cm), 200 gcf hit potential (20 g×10 cm), 300 gcf hit potential group (20 g×15 cm), and spinal cord complete transection group with 25 rats in each group. At 1, 5, 7, 14 and 28 days after model establishment, the degree of spinal cord injury was identified by the BBB scores of motion function, motor evoked potential, and pathological section. RESULTS AND CONCLUSION: (1) Totally 24 Sprague-Dawley rats died in the experiment. The death rate and the rate of complications were highest in the spinal cord complete transection group. The BBB score of each group was decreased. The BBB scores in every group increased as time went on. There were significant differences between each surgery group and the sham operation group at corresponding time points (P < 0.05).  No significant difference was found between the 300 gcf hit potential group and the spinal cord complete transection group at corresponding time points (P > 0.05). (2) In each surgery group, the infiltration of inflammatory cells and obvious swelling of neurons were visible at 1 day after injury. Neural cells reduced with time prolonged. At 28 days after injury, a large number of astrocytes proliferated, scar and spinal cord cavity formed. Above symptoms were worse in the 300 gcf hit potential group and spinal cord complete transection group than in the 100 gcf and 200 gcf hit potential groups. (3) Significant differences in amplitude and latency were detectable between each surgery group and the sham operation group (P < 0.05). No significant difference in amplitude and latency was detected between the 300 gcf hit potential group and the spinal cord complete transection group at corresponding time points (P > 0.05). Results confirmed that hit potential of 20 g×5 cm, 20 g×10 cm and 20 g×15 cm can simulate the microenvironment of Sprague-Dawley rats with mild, moderate and severe spinal cord injury. The rate of complication was lower in modified Allen’s model of different hit potentials than in models of spinal cord complete transection, and was more accorded with basic research.       

白藜芦醇对大鼠脊髓损伤后氧化与抗氧化过程的影响

目的探讨白藜芦醇﹙RES﹚对脊髓损伤﹙SCI﹚后髓过氧化物酶﹙MPO﹚和超氧化物歧化酶﹙SOD﹚活性的影响。方法 2008年2月~2010年8月在武汉大学人民医院动物实验中心将96只SD健康成年雄性大鼠随机分成4组,根据Allen’s法制成中度脊髓损伤模型,术后立即管饲白藜芦醇100mg/kg或甲基强的松龙﹙MPSS﹚100mg/kg;通过比色法观察脊髓损伤8小时、1天、3天及7天后白藜芦醇组脊髓MPO及SOD活性的变化,并与MPSS﹙甲基强的松龙﹚组进行疗效对比。结果在脊髓损伤后8小时、1天、3天及7天白藜芦醇组MPO及SOD活性与损伤组差异均有统计学意义,显示白藜芦醇对脊髓损伤具有明显神经细胞保护作用,而且白藜芦醇组与MPSS组间损伤后1天差异具有统计学意义﹙<0.05﹚。结论白藜芦醇在脊髓损伤后能够有效抑制MPO活性的升高幅度,并提高SOD活性,对损伤后脊髓起保护作用。     

减压对大鼠脊髓压迫性损伤后脱髓鞘病变和BDNF表达的影响

目的观察脑源性神经生长因子(BDNF)对脊髓压迫性损伤(CSCI)后有髓神经纤维脱髓鞘病变的影响,为阐明BDNF对神经纤维脱髓鞘病变修复提供实验基础。方法将大鼠均分成4组:正常组、假手术组、压迫组和减压组。用自行设计的压迫器制作大鼠脊髓压迫模型。压迫组作脊髓压迫12 h,减压组作脊髓压迫1 h,假手术组仅作脊髓显露,不作压迫。用锇酸染色观察CSCI后1、3和7 d有髓神经纤维变化情况;Western blot和免疫荧光双标检测BDNF和髓鞘碱性蛋白(MBP)的表达。结果压迫组和减压组都出现脱髓鞘病变,并随着时间的延长,髓鞘逐渐水肿、变性、MBP崩解。BDNF表达量在CSCI后随时间延长也逐渐降低(P0.05),但与压迫组相比较,减压组脱髓鞘病变较轻且MBP和BDNF降低幅度小而缓慢(P0.05)。结论 CSCI后尽早减压可减轻脱髓鞘的发生,且可能与BDNF的表达有关。     

大鼠急性脊髓损伤后NeuroD的时空表达

目的:探讨神经源性分化因子NeuroD在大鼠急性脊髓损伤过程中的表达及意义。方法:以改良Allen's法建立急性脊髓损伤(SCI)大鼠模型,以假手术组为对照,应用免疫组织化学、半定量RT-PCR、免疫印迹分别检测脊髓损伤后不同时间点NeuroD的表达变化。结果:NeuroD特异性表达于脊髓灰质,与对照组相比,急性脊髓损伤后3 d,NeuroD mRNA的相对表达量明显增加,5 d达到峰值,7 d后回落;Neurod的蛋白相对表达量则在急性脊髓损伤5 d后明显升高,持续至第7天,14 d明显回落。结论:急性脊髓损伤可上调NeuroD表达水平,提示NeuroD参与了急性脊髓损伤后的病理过程。     

SHH缓释的脊髓去细胞支架促进大鼠脊髓损伤修复

目的:研究可缓释音猬因子(sonic hedgehog,SHH)的脊髓去细胞支架(acellular spinal cord scaffolds,ASCSs)对大鼠脊髓损伤修复的效果。方法:(1)用物理和化学联合法制备ASCSs,并检测其效果。(2)使用京尼平(genipin,GP)作为交联剂,体外制备缓释SHH的ASCSs(ASCSs-GP-SHH),探究其缓释效果。(3)建立大鼠脊髓损伤(spinal cord injury,SCI)模型,随机分为四组(每组20只):单纯SCI组,ASCSs组,ASCSs-GP组(GP交联的ASCSs),ASCSs-GP-SHH组。术后每周记录BBB评分,评估功能恢复。术后12周取出损伤处脊髓组织,行免疫组化和Western Blot检测损伤处相关蛋白Nestin(巢蛋白),GAP43(生长相关蛋白),MBP(髓磷脂碱性蛋白),NF200(神经丝蛋白),GFAP(胶质纤维酸性蛋白)的表达。结果:(1)物理及化学联法制备ASCSs效果良好;(2)ASCSs-GP-SHH具有良好的缓释SHH的性能;(3)ASCS-GP-SHH组BBB评分从术后到12周较其他组高(P0.05);(4)免疫组化及HE染色结果显示:ASCS-GP-SHH组脊髓横断处有神经元再生。SCI组神经元凋亡明显,纤维瘢痕及空洞大,ASCS-GP组较ASCS组稍好,ASCS组较SCI组稍好;(5)Western Blot结果显示:ASCS-GP-SHH组Nestin,GAP43,MBP,NF200表达高于SCI、ASCS-GP、ASCS组(P0.05),而GFAP低于SCI、ASCS-GP、ASCS组(P0.05)。结论:物理和化学联合制备可以有效的制备ASCSs,ASCSs-GP-SHH缓释效果良好,对大鼠脊髓损伤的修复有明显的促进作用。     

Glutathione monoethyl ester improves functional recovery, enhances neuron survival, and stabilizes spinal cord blood flow after spinal cord injury in rats

Secondary damage after spinal cord (SC) injury remains without a clinically effective drug treatment. To explore the neuroprotective effects of cell-permeable reduced glutathione monoethyl ester (GSHE), rats subjected to SC contusion using the New York University impactor were randomly assigned to receive intraperitoneally GSHE (total dose of 12 mg/kg), methylprednisolone sodium succinate (total dose of 120 mg/kg), or saline solution as vehicle. Motor function, assessed using the Basso-Beattie-Bresnahan scale for 8 weeks, was significantly better in GSHE (11.2+/-0.6, mean+/-S.E.M., n=8, at 8 weeks) than methylprednisolone (9.3+/-0.6) and vehicle (9.4+/-0.7) groups. The number of neurons in the red nuclei labeled with FluoroRuby placed caudally to the injury site was significantly higher in GSHE (158+/-9.3 mean+/-S.E.M., n=4) compared with methylprednisolone (53+/-14.7) and vehicle (46+/-16.4) groups. Differences in the amount of spared SC tissue at the epicenter and neighboring areas were not significant among experimental groups. In a second series of experiments, using similar treatment groups (n=6), regional changes in microvascular SC blood flow were evaluated for 100 min by laser-Doppler flowmetry after clip compression injury. SC blood flow fell in vehicle-treated rats 20% below baseline and increased significantly with methylprednisolone approximately 12% above baseline; changes were not greater than 5% in rats given GSHE. In conclusion, GSHE given to rats early after moderate SC contusion/compression improves functional outcome and red nuclei neuron survival significantly better than methylprednisolone and vehicle, and stabilizes SC blood flow. These results support further investigation of reduced glutathione supplementation after acute SC injury for future clinical application.     

嗅鞘细胞移植促进脊髓损伤模型大鼠修复损伤区组织的超微结构特征

文题释义： 嗅鞘细胞：是一种嗅神经的支持细胞,它起源于嗅基底膜,分布在嗅球,嗅神经和嗅中枢。位于中枢和外周神经系统过渡区,具有降解抑制再生分子、分泌不同神经营养因子、促进神经轴突和髓鞘的再生、改善脊髓损伤后的微环境等重要作用。 超微结构：通过透射电子显微镜观察脊髓损伤后损伤部位神经元的细胞膜、细胞器(高尔基复合体,尼氏体,内质网、核糖体、神经微丝、微管)、细胞核(核仁、核周体);髓鞘,轴突,突触,胶质瘢痕等亚细胞水平的变化。 背景：嗅鞘细胞移植治疗脊髓损伤是目前的研究热点,其研究主要探讨脊髓损伤后微环境的影响,嗅鞘细胞移植对脊髓损伤后脊髓超微结构的影响未见报道。 目的：观察脊髓损伤后损伤部位神经细胞、轴突、髓鞘、突触和胶质瘢痕的超微结构以及嗅鞘细胞移植对大鼠损伤脊髓的保护和神经修复再生的影响。 方法：实验方案经西安交通大学医学部生物医学伦理委员会批准(批准号2018-2048)。将成年健康雌性SD大鼠20只随机分成3组：空白组(4只)仅仅切除T₁₀全部椎板及T₉, T₁₁部分椎板,未对脊髓作其他处理;DF12组(8只)切断脊髓,注射DF12培养液;嗅鞘细胞移植组(8只)切断脊髓,进行嗅鞘细胞移植。于脊髓损伤后1,7,28,56 d,对各组大鼠麻醉后取出脊髓,透射电镜观察脊髓损伤区神经细胞超微结构的变化。 结果与结论：①与空白组比较,DF12组大鼠脊髓损伤区神经元胞体内细胞器明显减少,轴突、髓鞘和突触的超微结构发生明显的变化;嗅鞘细胞移植组损伤区的神经元胞体内细胞器明显增加,核仁明显,促进轴突、髓鞘和突触的再生,且胶质瘢痕明显较少;②嗅鞘细胞移植组大鼠星形胶质细胞和毛细血管周细胞的反应比较轻微;③结果说明,脊髓损伤后嗅鞘细胞移植可有效地保护脊髓损伤区的神经组织,促进轴突、髓鞘和突触的再生,抑制神经胶质和周围细胞的增生反应,从而使损伤后微环境有利于神经元、轴突和突触再生。ORCID: 0000-0001-6049-2551(王国毓) 中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程