Immune therapy with cultured microglia grafting into the injured spinal cord promoting the recovery of rat's hind limb motor function

Objective: To study the effect of activated microglia grafting on rats' hind limb motor function recovery after spinal cord injury.Methods: Microglia were separated from primary culture and subcultured for 3 generations. Lipopolysaccharide was added to the culture medium with the terminal concentrition of 10 μl/L for microglia activation 3 days before transplantation. Totally 80 adult Wistar rats were divided into transplantation group and control group, with 40 rats in each group. Spinal cord injury model of rats was set by hitting onto the spinal cord using a modified Allen impactor. With a 5 μl micro-syringe, the activated microglia suspension was injected into the injured area 7 days after the first operation. Basso, Beattie and Bresnahan (BBB) scoring for hind limb motor function was taken on the 1st, 7th, 14th, 21st, and 28th day after microglia transplantation, and 8 rats were sacrificed at each time point mentioned above, respectively. Frozen sections of the spinal cord were made for haematoxylin-eosin (HE) and Naoumenko-Feigin stainings. SPSS 11.0 software was used for statistical analysis.Results: BBB scores for hind limb motor function on the 14th, 21 st, and 28th day were significantly higher compared with the control group. Most liquefaction necrosis areas disappeared and only a few multicystic cavities surrounded by aggregated microglia remained in the transplantation group. Naoumenko-Feigin staining for microglia showed that the transplantation group had significantly more positive cells (P＜0.05).Conclusions: Grafting of activated microglia into the injured spinal cord can significantly promote the hind limb motor function recovery in rats with spinal cord injury and reduce the size of liquefaction necrosis area. The extent of lower limb motor function improvement has a positive correlation with the number of aggregated microglia.     

Functional recovery after human umbilical cord blood cells transplantation with brain-derived neutrophic factor into the spinal cord injured rat

Summary There have been many efforts to recover neuronal function from spinal cord injuries, but there are some limitations in the treatment of spinal cord injuries.The neural stem cell has been noted for its pluripotency to differentiate into various neural cell types. The human umbilical cord blood cells (HUCBs) are more pluripotent and genetically flexible than bone marrow neural stem cells. The HUCBs could be more frequently used for spinal cord injury treatment in the future.Moderate degree spinal cord injured rats were classified into 3 subgroups, group A: media was injected into the cord injury site, group B: HUCBs were transplanted into the cord injury site, and group C: HUCBs with BDNF (Brain-derived neutrophic factor) were transplanted into the cord injury site. We checked the BBB scores to evaluate the functional recovery in each group at 8 weeks after transplantation. We then, finally checked the neural cell differentiation with double immunofluorescence staining, and we also analyzed the axonal regeneration with retrograde labelling of brain stem neurons by using fluorogold. The HUCBs transplanted group improved, more than the control group at every week after transplantation, and also, the BDNF enabled an improvement of the BBB locomotion scores since the 1 week after its application (P<0.05). 8 weeks after transplantation, the HUCBs with BDNF transplanted group had more greatly improved BBB scores, than the other groups (P<0.001). The transplanted HUCBs were differentiated into various neural cells, which were confirmed by double immunoflorescence staining of BrdU and GFAP & MAP-2 staining. The HUCBs and BDNF each have individual positive effects on axonal regeneration. The HUCBs can differentiate into neural cells and induce motor function improvement in the cord injured rat models. Especially, the BDNF has effectiveness for neurological function improvement due to axonal regeneration in the early cord injury stage. Thus the HUCBs and BDNF have recovery effects of a moderate degree for cord injured rats.     

Serotonin-related enhancement of recovery of hind limb motor functions in spinal rats after grafting of embryonic raphe nuclei

Recently, we demonstrated improvements in hind limb locomotor-like movements following grafting of embryonic raphe nuclei cells into the spinal cord below the level of total transection in adult rats. The purpose of the present study was to clarify whether this improvement was due to newly established serotonergic innervation between the graft and the host. Two months after intraspinal grafting of the embryonic raphe nuclei, the spinalized rats, when put on a treadmill, could be induced to walk with regular alternating hind limb movements with the plantar contact with the ground during the stance phase, and ankle dorsiflexion during the swing phase of each step cycle. In the same situation the spinal rats, that did not receive the graft, were not able to initiate the dorsiflexion of the ankle joint during the swing phase and very often the dorsal surface of the foot was dragged along the ground. Intraperitoneal application of directly acting 5-HT2 antagonist Cyproheptadine (1 mg/kg) impaired reversibly the hind limb locomotor-like movements in grafted rats. This impairment lasted for 2-3 h. The same procedure in control rats did not markedly alter the hind limb locomotor-like movements. The effect of Cyproheptadine in grafted rats was reversed by i.p. injections of the 5-HT2 agonist Quipazine (0.5 mg/kg). These results show that the graft-induced restitution of hind limb locomotor abilities in adult spinal rats is brought about by the new serotonergic innervation of the host spinal cord circuitry from the grafted neurons and is mediated by 5-HT2 receptors.     

不同方法移植胚胎脊髓促进成鼠损伤脊髓功能恢复的研究

目的：研究提供血运的胚胎脊髓移植对成鼠损伤脊髓功能恢复的作用。方法：将成年Ｗｉｓｔａｒ大鼠作为脊髓半切洞损伤模型,应用单纯胚髓组织、胚胎脊髓＋大网组织、胚社以半切洞损伤的脊髓中,手术后１、２、４、１２周进行联合行为发,感觉诱闰（ＳＥＰ）和运动诱发电位（ＭＥＰ）检查,并与一言堂３组为单纯损伤线比较。结果：联合行为评分,单纯移植级和胚胎脊髓＋大网膜组织移植组优于单纯损伤组,ＳＥＰ和ＭＥＰ潜峰时的恢复,     

Long-term assessment of hind limb motor function and neuronal injury following spinal cord ischemia in rats

Recent evidence suggests that brain injury caused by ischemia is a dynamic process characterized by ongoing neuronal loss for at least 14 days after ischemia. However, long-term outcome following spinal cord ischemia has not been extensively examined. Therefore, we investigated the changes of hind limb motor function and neuronal injury during a 14-day recovery period after spinal cord ischemia. Male Sprague-Dawley rats received spinal cord ischemia (n = 64) or sham operation (n = 21). Spinal cord ischemia was induced by inflation of a 2F Fogarty catheter placed into the thoracic aorta for 6, 8, or 10 minutes. The rats were killed 2, 7, or 14 days after reperfusion. Hind limb motor function was assessed with the 21-point Basso, Beattie, and Bresnahan (BBB) scale during the recovery period. The number of normal and necrotic neurons was counted in spinal cord sections stained with hematoxylin/eosin. Longer duration of spinal cord ischemia produced severer hind limb motor dysfunction at each time point. However, BBB scores gradually improved during the 14-day recovery period. Neurologic deterioration was not observed between 7 and 14 days after reperfusion. The number of necrotic neurons peaked 2 days after reperfusion and then decreased. A small number of necrotic neurons were still observed 7 and 14 days after reperfusion in some of the animals. These results indicate that, although hind limb motor function may gradually recover, neuronal loss can be ongoing for 14 days after spinal cord ischemia.     

甲基强的松龙对脊髓损伤后伤段脊髓线粒体功能的影响

目的：探讨脊髓损伤后伤段脊髓线粒体呼吸功能和线粒体内游离钙的变化和早期使用甲基强的松龙（MP）对其的影响。方法：54只SD大鼠，随机分组为假手术组（对照组）、脊髓损伤组（SCI组，采用Allen’s打击法造成大鼠脊髓损伤模型）和脊髓损伤后应用MP治疗组（MP组），每组又分为处理后6h、12h、24h三个时间相，每个时间相6只。在各时间相处死动物后提取伤段脊髓线粒体，测定线粒体呼吸Ⅲ态（R3）、呼吸Ⅳ态（R4）、呼吸控制率（RCR）、磷氧比（P／0）和线粒体内游离Ca^2＋浓度。结果：SCI组在伤后6h、12h和24hR3、RCR和P／0显著低于对照组，R4和线粒体内游离Ca^2＋浓度显著高于对照组。差异有显著性（P〈0．01）；伤后6h和12h MP组R3、RCR和P／0高于SCI组，R4和线粒体内游离Ca^2＋浓度低于SCI组，差异有显著性（P〈0．01）；MP组R3、R4和RCR在6h和12h时与对照组之间无显著性差异，24h时R3、RCR和P／0低于正常对照组，有显著性差异（P〈0．05）。结论：脊髓损伤后伤段脊髓线粒体呼吸功能和线粒体内游离Ca^2＋浓度明显受到影响，线粒体内膜通透性增加，线粒体氧化磷酸化的偶联程度明显受到抑制。早期使用甲基强的松龙可明显改善线粒体的呼吸功能，抑制Ca^2＋内流，保护伤段脊髓线粒体的稳定性。     

胶质细胞源性神经营养因子对大鼠脊髓损伤后运动功能的影响

目的:研究胶质细胞源性神经营养因子（GDNF）对大鼠脊髓损伤后后肢运动功能恢复的影响。方法:采用改良Nystr(?)m法后路压迫大鼠胸段脊髓造成损伤模型,经蛛网膜下腔置管局部连续给予NGF （10μg/d）或GDNF（10μg/d）1周,对照组给予生理盐水。伤后4周3组分别观测:①伤段脊髓残存组织面积;②采用斜板试验和运动功能评分观察大鼠后肢运动功能恢复情况。结果:大鼠脊髓损伤后4～14d,GDNF治疗组后肢运动功能评分明显高于NGF组和生理盐水对照组（P<0.05）。伤后28d GDNF组伤段残存脊髓组织面积大于对照组和NGF组（P<0.01）。结论:外源性GDNF能减少脊髓损伤后伤区的坏死、萎缩并促进大鼠后肢运动功能的早期恢复。     

Two episodes of remote ischemia preconditioning improve motor and sensory function of hind limbs after spinal cord ischemic injury

Objectives: To investigate the effect of one and two remote ischemia preconditioning episodes (1-RIPC or 2-RIPC, respectively) on neuro-protection after spinal cord ischemic injury (SCI) in rats.Design: Experimental animal study.Setting: College of Medicine, King Khalid University, Abha, KSA.Interventions: Male rats (n = 10/group) were divided into control, sham, SCIRI, 1-RIPC + SCIRI, and 2-RIPC + SCIRI. SCI was induced by aortic ligation for 45 min and each RIPC episode was induced by 3 cycles of 10 min ischemia/10 min perfusion. The two preconditioning procedures were separated by 24 h.Outcome measures: after 48 h of RIPC procedure, Tarlov’s test, withdrawal from the painful stimulus and placing/stepping reflex (SPR) were used to evaluate the hind limbs neurological function. SC homogenates were used to measure various biochemical parameters.Results: Motor and sensory function of hind limbs were significantly improved and levels of MDA, AOPPs, PGE2, TNF-α, and IL-6, as well as the activity of SOD, was significantly decreased in SC tissue in either 1 or 2 episodes of RIPC intervention. Concomitantly, levels of total nitrate/nitrite and eNOS activity were significantly increased in both groups. Interestingly, except for activity of SOD, eNOS and levels of nitrate/nitrite, the improvements in all neurological biochemical endpoint were more profound in 2-RIPC + SCIRI compared with 1-RIPC + SCIRI.Conclusion: applying two preconditioning episodes of 3 cycles of 10 min ischemia/10 min perfusion, separated by 24 h, boost the neuro-protection effect of RIPC maneuver in rats after ischemic induced SCI in rats.     

Delayed transplantation of foetal cerebral tissue into injured spinal cord of adult rats

Summary Delayed transplantation of foetal cerebral tissue into injured spinal cord of adult rats was performed for the purpose of evaluating the usefulness of the procedure for reconstructing the spinal cord and providing motor recovery. Transplanted tissue showed a survival rate greater than 80% and integration with the host tissue. Nerve fibers of the host surrounded the transplanted tissue, penetrating it. Foetal cerebral neurons matured into recipient spinal cord, but they were not organized in layers. The experience obtained suggests that delayed transplantation of foetal cerebral tissue into contused spinal cord is useful in morphological spinal cord reconstruction. Nevertheless, at least during the first two months after transplantation, clinical assessment of motor recovery showed no differences between transplanted and nontransplanted rats.     

振荡电场对脊髓损伤大鼠运动功能恢复和轴突再生的影响

目的:探讨振荡电场对脊髓损伤大鼠运动功能恢复和轴突再生的影响。方法:改良Allen′s打击法建立90只SD大鼠脊髓损伤模型,随机分为实验组和对照组,两组均置入刺激电极。实验组施加振荡电场干预,对照组只置入振荡电场刺激器而不给予干预。电场强度600μV/mm,振荡周期为每15min极性交替变换,供电方式为感应式供电,工作方式为大鼠清醒状态下持续刺激至实验结束。建模成功后2周、6周、12周进行BBB评分、运动诱发电位评价脊髓神经传导情况(MEP潜伏期差和波幅差);HE染色行组织学观察,神经丝蛋白(NF200)、胶质纤维酸性蛋白(GFAP)免疫组化染色,观察轴突再生情况、行轴突计数、胶质瘢痕形成和星形胶质细胞突起夹角测量,两组间比较行t检验。结果:实验组和对照组比较,2周时,BBB评分、MEP波幅差和轴突计数无差异(P>0.05),但右下肢MEP潜伏期差缩短(P<0.05)。6周和12周时,BBB评分、MEP潜伏期差和波幅差、轴突计数和星形胶质细胞突起夹角测定两组间均有显著差异(P<0.05)。12周时HE染色观察两组可见损伤部位脊髓空洞及瘢痕形成;NF染色实验组可见较多神经纤维通过损伤区;GFAP染色发现两组间IOD值测定无显著差异。结论:振荡电场可以促进脊髓损伤大鼠的脊髓传导功能改善和后肢运动功能恢复,电场作用时间需达6周以上。大鼠后肢运动功能恢复可能与振荡电场促进轴突再生、诱导其定向生长,促进星形胶质细胞线性排列等有关。     

骨髓间质干细胞与胚胎嗅鞘细胞联合移植治疗大鼠脊髓损伤的实验研究

目的：观察人骨髓间质干细胞（MSCs）与胚胎嗅鞘细胞（OECs）联合移植治疗大鼠脊髓损伤的效果，探讨共移植的OECs对MSCs分化的影响。方法：采用Allen’s法制作大鼠脊髓损伤模型．随机分为MSCs移植组（A组）、OECs移植组（B组）、MSCs与OECs联合移植组（C组）及PBS注射组（D组），术后1-5周采用BBB评分、经颅磁刺激运动诱发电位及组织学方法检查脊髓损伤修复情况。结果：术后2周起，A、B、C组BBB评分和诱发电位潜伏期与D组比较恢复明显，C组与A、B组相比亦有显著性差异（P〈0．05），术后5周时C组损伤区有较密的神经轴突分布，近端可见大量成束再生轴突；A、B组损伤区及近端再生轴突分布稀疏；D组损伤区及近端少见轴突。C组移植的MSCs中Nestin及NF表达阳性的比率较A组高（P〈0.05）。结论：联合移植OECs可促进MSCs向神经元方向转化，提高MSCs分化为神经元的比例；MSCs与OECs可以在脊髓损伤修复中发挥协同作用，联合细胞移植是提高脊髓损伤修复效果的可行方法。     

脊髓损伤后脑萎缩对运动功能恢复的影响

 目的 探讨脊髓损伤后脑部萎缩情况以及脑萎缩对患者运动功能恢复的影响。方法 回顾性分析2012年10月至2014年3月,25例接受脊柱内固定治疗的脊髓损伤患者完整随访资料,根据随访6个月后的运动功能恢复情况分为恢复较好组和恢复一般组,同时另选取25例年龄、性别相匹配的健康人作为对照组。恢复较好组10例,男6例,女4例;年龄24~55岁,平均（37.9±13.9）岁;入院时ASIA评级A级1例,B级4例,C级3例,D级2例;6个月后ASIA评级均有一个以上好转,其中A级0例,B级1例,C级3例,D级3例,E级3例;入院时ASIA运动评分为（71.9±16.3）分,6个月后为（85.5±1.5）分。恢复一般组15例,男8例,女7例;年龄24~55岁,平均（35.8±11.5）岁;入院时ASIA评级A级7例,B级3例,C级3例,D级2例）;6个月时ASIA评级未见明显改善;入院时ASIA运动评分为（71.9±16.3）分,6个月后为（85.5±1.5）分。对照组25名,男15名,女10名,年龄（36.5±9.3）岁。采用MRI扫描三组受试者脑部结构信息,运用CIVET软件及DtiStudio软件对比三组大脑灰质和白质萎缩的区域。运用Pearson相关性分析探讨脑皮层萎缩与患者运动功能恢复率之间的相关性。结果 与健康对照组相比,脊髓损伤恢复较好组和恢复一般组均存在双侧初级运动皮层的灰质萎缩,但恢复一般组的萎缩程度更广泛和严重,同时还出现右侧辅助运动区和运动前区的灰质萎缩。恢复较好组未见明显的脑内皮质脊髓束萎缩,而恢复一般组脑内皮质脊髓束初级运动皮层区域及内囊区域均出现白质萎缩。此外,脊髓损伤患者辅助运动区的灰质体积（r=0.75,P< 0.001）及初级运动皮层的白质体积（r=0.76,P< 0.001）与患者6个月后的运动恢复率存在正相关关系。结论 在脊髓损伤早期,运动感觉中枢即可出现明显的萎缩现象,同时这种萎缩对患者的运动功能恢复存在不利影响。     

芬苯达唑对大鼠脊髓损伤后免疫反应和运动功能恢复的影响

目的：观察芬苯达唑对脊髓损伤大鼠的CD45R阳性B细胞、IgG免疫反应以及运动功能恢复的影响。方法将75只成年雌性SD大鼠随机分为假手术组、模型对照组和芬苯达唑组,每组25例。假手术组、模型对照组术前4周给予常规啮齿动物饲料喂食（含18%蛋白质的饲料）,芬苯达唑组术前4周给予加入芬苯达唑的常规啮齿动物饲料喂食。用Allen法构建脊髓损伤模型,分别于术后第1、7、14、21、28天行Basso?Beatti?Bresnahan（BBB）运动功能评估,利用免疫组化检测损伤部位脊髓组织中IgG的表达水平,利用免疫荧光检测脊髓损伤部位CD45R阳性B细胞的信号水平。结果脊髓损伤后,模型对照组和芬苯达唑组的BBB评分均显著低于假手术组（均P＜0.05）,随着时间的延长,两组的BBB运动评分均逐渐有所恢复,但仍低于假手术组;脊髓损伤后第1天,模型对照组与芬苯达唑组的BBB运动评分分别为（3.10±0.29）分、（3.23±0.48）分,差异尚无统计学意义;而在脊髓损伤后的第7、14、21、28天,芬苯达唑组的BBB评分均高于模型对照组,差异均有统计学意义（均P＜0.05）。免疫组化检查证实损伤部位脊髓标本的IgG水平显著升高,第7天开始,芬苯达唑组各个时间点的IgG免疫反应水平均低于模型对照组,差异均有统计学意义（均P＜0.05）。免疫荧光检查证实脊髓损伤后损伤部位脊髓节段CD45R阳性B细胞信号水平显著升高,第7天开始,芬苯达唑组各个时间点脊髓损伤部位的CD45R阳性B细胞的信号水平均低于模型对照组,差异均有统计学意义（均P＜0.05）。结论芬苯达唑预处理可降低脊髓组织中IgG的表达水平及脊髓损伤部位的CD45R阳性B细胞的信号水平,促进脊髓损伤后的神经功能恢复。     

重复经颅磁刺激不同干预时机对脊髓半横断损伤大鼠运动功能的影响

目的:观察重复经颅磁刺激不同干预时机对脊髓半横断损伤大鼠运动功能的影响。方法:将42只SD大鼠随机分为正常对照组(n=6)、假手术组(n=6)、脊髓损伤组(SCI组,n=10)、急性期刺激组(ArTMS组,n=10)和亚急性期刺激组(SrTMS组,n=10),SCI组、ArTMS组和SrTMS组大鼠建立T10脊髓右半侧横断损伤模型,假手术组仅行椎板切开,不横断脊髓,正常对照组不行手术处理。ArTMS组和SrTMS组大鼠分别于术后4d和18d开始重复经颅磁刺激治疗,刺激强度为最大输出强度的35%,刺激频率为10Hz,每序列5s,间歇2min,连续10个序列,每日1次,每周5d,连续2周;正常对照组、假手术组和SCI组不行经颅磁刺激治疗。大鼠术前与术后3d、10d、17d、24d、31d和38d分别进行BBB评分和水平梯子实验评价右后肢运动功能;术后38d取右后肢胫前肌,采用ATP酶法(pH 4.6)行肌肉病理染色,观察肌肉形态并测量不同类型肌纤维直径。结果:5组大鼠术前BBB评分均为21分,水平梯子实验步态正确率均为100%。假手术组术后各时间点BBB评分和水平梯子实验步态正确率与术前比较无变化。SCI组、ArTMS组、SrTMS组术后3d BBB评分和水平梯子实验步态正确率明显下降,与术前比较差异显著。SCI组和SrTMS组术后31d和38d BBB评分有所恢复,与术后3d和10d比较差异显著(P<0.05),SCI组和SrTMS组术后24d、31d、38d水平梯子实验步态正确率与术后3d和10d比较差异显著(P<0.05)。ArTMS组术后17d、24d、31d、38d时的BBB评分和水平梯子实验步态正确率明显高于术后3d和10d(P<0.05)。SCI组和SrTMS组术后3~38d各时间点BBB评分、水平梯子实验步态正确率组间比较无显著性差异(P>0.05);ArTMS组术后3d和10d BBB评分、水平梯子实验步态正确率与SCI组和SrTMS组比较无显著性差异(P>0.05)。ArTMS组术后17d、24d、31d、38d BBB评分明显高于SCI组和SrTMS组(P<0.05);术后17d、24d、31d、38d水平梯子实验步态正确率明显高于SCI组(P<0.05);术后24d、31d、38d水平梯子实验步态正确率明显高于SrTMS组(P<0.05)。术后38d时,SCI组大鼠右后肢胫前肌1型、2A型、2B型肌纤维直径与正常对照组和假手术组比较均明显变小(P<0.05);ArTMS组2A型肌纤维直径与正常对照组和假手术组比较变小(P<0.05),2A型和2B型肌纤维较SCI组明显增粗(P<0.05),1型与SCI组比较无显著性差异(P>0.05);SrTMS组大鼠2A型和2B型肌纤维与正常对照组和假手术组比较变细(P<0.05),2B型肌纤维与ArTMS组比较明显变细(P<0.05)。结论:重复经颅磁刺激早期干预可促进脊髓半横断损伤大鼠运动功能恢复,改善部分肌肉萎缩,急性期治疗效果明显优于亚急性期治疗的效果。     

骨髓基质干细胞在损伤脊髓内向少突胶质细胞定向分化的研究

目的 探讨移植骨髓基质干细胞(BMSCs)在损伤脊髓内向少突胶质细胞分化的可能性.方法 应用低温包埋免疫电镜技术观察迁移在损伤脊髓内1、3、5周的移植BMSCs超微结构,应用免疫荧光标记和激光共聚焦技术观察迁移在损伤脊髓内1、3、5周的移植BMSCs表达髓磷脂碱性蛋白(MBP)、髓鞘蛋白前脂蛋白(PLP)的情况.结果 移植1周,迁移在损伤脊髓白质内的BMSCs体积较小,突起少,细胞核较小,核仁清楚,染色质分布尚均匀,线粒体、粗面内质网和核糖体等细胞器发达,具有少突胶质细胞的超微结构特点;移植3周和5周,迁移在损伤脊髓白质内的BMSCs具有成熟少突胶质细胞的超微结构特点,并形成髓鞘样结构.移植1周后,迁移在损伤脊髓白质内的BMSCs开始表达MBP和PLP;移植3周和5周后,迁移在损伤脊髓白质内的BMSCs继续表达MBP和PLP.结论 移植BMSCs在损伤脊髓内可能会部分分化为功能性少突胶质细胞.     

雪旺细胞悬液植入成鼠正常脊髓

目的：了解雪旺细胞（ＳＣ）促进脊髓受损轴索再生作用。方法：将Ｗｉｓｔａｒ大鼠２０只随机分为两组,各１０只,实验组将自成鼠坐骨神经培养获取的雪旺细胞悬液（ＳＣＳ）采用显微注射植入成鼠正常胸段（Ｔ７）脊髓,对照组以相同量的Ｄｕｌｂｅｃｃｏ改良细胞培养液（ＤＭＥＭ）植入。移植术后２周、６周通过组织学及免疫组织化学检查,观察移植物的存活及促进轴索再生能力。结果：实验组宿主中ＳＣ形态正常,束状排列,轴索可长入移植物中。束状排列的ＳＣ间有髓鞘碱性蛋白（ＭＢＰ）阳性纤维存在,相伴随的ＳＣ胞质亦呈ＭＢＰ阳性。对照组无再生轴索长入。结论：ＳＣ植入成鼠正常脊髓后,与宿主融合好,可存活,促进宿主再生轴索越过宿主－移植物交界面长入移植物,并形成髓鞘。     

胚胎脊髓组织移植联合应用神经生长因子对损伤脊髓再生修复的形态学影响

选择胎龄为１４～１５天的大鼠胚胎脊髓植入成年大鼠半横断的脊髓损伤腔，同时局部应用神经生长因子。术后２～８个月，用组织学、免疫细胞化学、辣根过氧化酶示踪及超微结构的检查方法证实，移植组织在宿主脊髓内的存活率为９０％，并且分化成熟，具有正常的神经组织结构特征，大多数移植物充满损伤腔，与宿主脊髓形成良好的融合，移植组织与宿主组织出现新的纤维联系，使脊髓损伤的两端恢复了解剖的连续性。     

The recovery of 5-HT transporter and 5-HT immunoreactivity in injured rat spinal cord

Study design  Experimental spinal cord injury. Objective  To determine the role of serotonin (5-HT) and 5-HT transporter in recovery from spinal cord injury. Method  We examined 5-HT and 5-HT transporter of spinal cord immunohistologically and assessed locomotor recovery after extradural compression at the thoracic (T8) spinal cord in 21 rats. Eighteen rats had laminectomy and spinal cord injury, while the remaining three rats received laminectomy only. All rats were evaluated every other day for 4 weeks, using a 0–14 point scale open field test. Results  Extradural compression markedly reduced mean hindlimbs scores from 14 to 1.5 ± 2.0 (mean ± standard error of mean). The rats recovered apparently normal walking by 4 weeks. The animals were perfused with fixative 1–3 days, 1, 2 and 4 weeks (three rats in each) after a spinal cord injury. The 5-HT transporter immunohistological study revealed a marked reduction of 5-HT transporter-containing terminals by 1 day after injury. By 4 weeks after injury, 5-HT transporter immunoreactive terminals returned to the control level. The 5-HT immunohistological study revealed a reduction of 5-HT-containing terminals by 1 week after injury. By 4 weeks after injury, 5-HT immunoreactive fibers and terminals returned to the control level. Conclusion  We estimated the recovery of 5-HT transporter and 5-HT neural elements in lumbosacral ventral horn by ranking 5-HT transporter and 5-HT staining intensity and counting 5-HT and 5-HT transporter terminals. The return of 5-HT transporter and 5-HT immunoreactivity of the lumbosacral ventral horn correlated with locomotor recovery, while 5-HT transporter showed closer relationship with locomotor recovery than 5-HT. The presence of 5-HT transporter indicates that the 5-HT fibers certainly function. This study shows that return of the function of 5-HT fibers predict the time course and extent of locomotory recovery after thoracic spinal cord injury.     

骨髓间充质干细胞移植对大鼠脊髓损伤后功能恢复的影响

目的 观察骨髓间充质干细胞(MSCs)移植对脊髓损伤修复的促进作用.方法 用改良Allen法制作大鼠脊髓损伤动物模型.随机分成对照组(A组),脊髓损伤9 d后脊髓内微量注射生理盐水溶液5μl;骨髓间充质干细胞移植组(B组),脊髓损伤9 d后脊髓内注射骨髓间充质干细胞悬液5μl.移植后7、14、28 d采用斜板实验、脊髓运动功能BBB评分法观察大鼠运动功能恢复情况,脊髓诱发电位的检测观察神经功能恢复,苏木素-伊红(HE)染色观察脊髓损伤处空洞面积的改变情况,免疫组织化学法观察移植的骨髓间充质干细胞的存活及分化情况,损伤部位神经纤维的再生情况.结果 移植后28 d,两组斜板倾斜角度差异有统计学意义[A组(44.96±5.70)度,B组(53.19±6.51)度,P＜0.05];两组BBB评分差异有统计学意义[A组(6.8±1.2),B组(10.1±3.5),P＜0.05].同时,两组MEP潜伏期差异有统计学意义[A组(4.69±0.47)ms,B组(3.97±0.83)ms,P＜0.05],两组SEP潜伏期差异有统计学意义[A组(4.19±1.97)ms,B组(2.60±0.92)ms,P＜0.05].两组神经轴突计数差异有统计学意义[A组(32.8±6.1)条/mm2,B组(39.0±4.6)条/mm2,P＜0.05].实验组可见明显星形胶质细胞和神经纤维再生,脊髓损伤处的空洞面积明显减小.结论 骨髓间充质干细胞可在脊髓损伤处分化为神经元和神经胶质细胞,能够减小脊髓损伤处的空洞面积,促进受损轴突的再生和运动功能的恢复.