一定剂量X线照射对大鼠脊髓损伤模型组织结构及功能恢复的影响

目的探讨一定剂量X线照射对大鼠压迫型脊髓损伤模型组织结构及功能恢复的影响。方法采用动脉瘤夹建立大鼠压迫型脊髓损伤模型,70只SpragueDawley大鼠均接受T2节段的脊髓损伤,然后被随机分为2组,照射组在损伤后14d接受X线照射,对照组则不接受任何治疗。所有大鼠分别在脊髓损伤后第3、7、14、21、28、35和42天接受后肢运动及斜板测定,43d将所有实验大鼠处死后取出脊髓损伤标本,进行组织学检查。结果70只实验鼠中符合设计要求的共62只,其中照射组32只,对照组30只。X线照射组大鼠的后肢运动恢复及斜板测定均明显优于对照组,两者之间的差异有统计学意义(P<0.01)。照射组大鼠脊髓损伤部位的水肿及坏死区域明显少于对照组,胶质原纤维酸性蛋白(glialfibrillaryacidicprotein,GFAP)阳性细胞数明显少于对照组,而神经元数目则明显多于对照组。结论一定剂量X线照射可以改善脊髓损伤区的组织结构并促进大鼠脊髓损伤后运动功能的恢复。     

一氧化氮合酶抑制剂对脊髓损伤后运动功能的影响

目的观察诱导型和神经型一氧化氮合酶(iNOS,nNOS)抑制剂对大鼠脊髓损伤(SCI)后运动功能的影响和机理。方法大鼠脊髓压迫伤后分别给予iNOS和nNOS抑制剂—氨基胍(AG)和7-硝基吲唑(7-NI)进行治疗,24h后用分光光度法测定组织中一氧化氮(NO)含量和一氧化氮合酶(NOS)活性,72h后用流式细胞仪检测神经细胞凋亡情况,4周后用电生理和动物行为学等指标评价运动功能的恢复情况。结果AG和7-NI均可以抑制组织中的NO含量,并使NOS活性下降,同时降低神经细胞的凋亡比率,对运动功能的恢复前者优于后者。结论脊髓损伤后应用NOS抑制剂可以使伤后运动功能得到改善,AG的作用似乎更明显,提示iNOS活性变化可能对脊髓损伤的恢复更具决定作用。     

驽药针刺对大鼠脊髓损伤后运动功能及BDNF表达的影响

目的研究驽药针刺在大鼠脊髓损伤后运动功能变化以及BDNF表达的变化。方法采用脊髓半横断损伤模型。100只SD大鼠随机分为对照组、假手术组、脊髓损伤组、单纯针刺组、驽药针刺组,每组分为3天、7天、14天、21天共4个亚组,每组5只。BBB法评定大鼠后肢运动功能变化,免疫组化法检测大鼠脊髓中BDNF的表达变化。结果 BBB评分显示驽药针刺组的各时间点评分均高于脊髓损伤组(P0.05),驽药针刺组7、14、21d的BDNF表达均高于脊髓损伤组(P0.05),且与BBB评分呈正相关(r=0.717,P0.05)。结论驽药针刺可明显改善脊髓损伤大鼠的运动功能,并可明显促进大鼠脊髓损伤后BDNF的表达。     

悬吊运动对腰段脊髓损伤患者平衡功能的疗效

目的:研究悬吊运动对腰段脊髓损伤患者平衡功能的疗效。方法 :将2014年6月—2015年9月在湖北省中西医结合医院康复医学科门诊和住院部接受康复治疗的35例腰段脊髓损伤术后患者随机分为悬吊运动组(17例)和常规康复治疗组(18例),其中悬吊运动组接受常规神经营养治疗、常规康复治疗和悬吊运动治疗,常规康复治疗组接受常规神经营养治疗和常规康复治疗,2组均治疗12周。采用计时起立行走测试(timed up and go test,TUG)和Berg平衡量表对2组患者接受康复治疗前以及康复治疗第4、8和12周的平衡功能进行评估,比较2组治疗前后以及2组之间平衡功能的变化。结果 :悬吊运动组与常规康复治疗组患者在康复治疗第8和12周的TUG评分均较治疗前显著降低(P<0.01),第4、8和12周的Berg平衡量表评分均较治疗前显著升高(P<0.01)。康复治疗第8和12周,悬吊运动组TUG评分较常规康复治疗组显著降低(P<0.05);康复治疗第12周,悬吊运动组Berg平衡量表评分较常规康复治疗组显著升高(P<0.01)。结论 :悬吊运动联合常规康复治疗可有效改善腰段脊髓损伤患者的平衡功能。     

乙酰左旋肉碱对大鼠脊髓损伤保护作用的实验研究

目的研究乙酰左旋肉碱对大鼠急性脊髓损伤后的干预效果,从行为学、组织形态学和线粒体结构探讨乙酰左旋肉碱对大鼠运动功能恢复的影响。方法将大鼠随机分为脊髓损伤组、乙酰左旋肉碱治疗组、假手术组3组,每组22只,构建大鼠脊髓损伤模型。于损伤后1 d、3 d、7 d、14 d、21 d、28 d和35 d评估大鼠后肢运动功能恢复情况;并取损伤后1 d、3 d的脊髓组织行HE染色,进行形态学观察;透射电镜观察脊髓损伤后24 h线粒体形态的变化。结果 Basso Beattie Bresnahan运动功能评分损伤后7 d、14 d、21 d、28 d、35 d,乙酰左旋肉碱组评分均高于SCI组,差异有统计学意义(P0.05);SCI+ALC组损伤后3 d,变性的神经元细胞结构逐渐清楚,细胞核清晰,核膜完整;神经元胞浆内线粒体含量较多且结构完整,线粒体空泡化也较损伤组减轻。结论乙酰左旋肉碱可能通过改善脊髓神经元线粒体功能,促进大鼠脊髓损伤后后肢运动功能的恢复。     

减重平板训练联合甲基强的松龙对脊髓损伤大鼠运动功能的影响

目的研究减重平板训练联合应用大剂量甲基强的松龙(MP)对脊髓损伤大鼠运动功能恢复的影响。方法成年雄性SD大鼠48只,随机分为正常对照组(A组)、损伤对照组(B组)、单纯平板组(C组)、联合治疗组(D组)各12只。采用改良Allen's撞击法制作T10不完全性脊髓损伤模型。C组损伤后1周开始平板训练,30min/d,每周5d,共4周,D组于损伤后24h内给予大剂量甲基强的松龙琥珀酸钠冲击治疗,1周后平板训练,30min/d,每周5d,共4周。B组损伤后不作处理。分别在损伤前、损伤后1周、2周、3周、4周和5周时采用斜板试验、改良Tarlov评分、BBB评分进行运动功能评定。结果(1)损伤后第1周,联合治疗组运动功能评分高于损伤对照组和单纯平板组(但P0.05)。(2)训练2周后开始,联合治疗组运动功能评分明显高于单纯平板组和损伤对照组,且单纯平板组也显著高于损伤对照组(P0.05)。结论减重平板训练可促进SCI大鼠运动功能的恢复,且减重平板联合甲基强的松龙比较单纯平板训练更能促进SCI大鼠运动功能的恢复。     

胚胎脊髓移植在恢复损伤脊髓传导功能中的作用

目的：探讨胚胎脊髓移植在恢复损伤脊髓传导功能中的作用。方法：将Ｅ１４胚胎脊髓植入成鼠损伤脊髓后３０、４５、６０天时，用单位放电记录技术观察了正常脊髓神经元和移植物神经元的自发放电活动，及其对刺激坐骨神经、红核和同时刺激的反应。结果：正常脊髓神经元的自发单位放电多是一个低频的单发脉冲活动。无论选择那种刺激方式，都可见兴奋、抑制和无反应三种反应。术后３０天时，胚胎神经元的自发单位放电以高频电脉冲活动为主，簇状放电所占比例较大，对刺激有反应的放电单位数也较少；随着动物存活时间的延长，这些单位放电的情况逐渐向着低频、单脉冲以及高反应率的方向发展。至术后６０天时，胚胎神经元单位放电的频率、形式以及对刺激的反应情况都变得和正常神经元的相似。结论：胚胎神经元移植后经历了一个逐渐发育分化过程，在这个过程中它们有可能逐渐和宿主神经元形成了功能性突触连接。     

大鼠脊髓损伤后运动诱发电位的变化及与病理改变之比较

目的：观察脊髓损伤（SCI）对运动诱发电位（MEP）的影响,方法：27只大鼠以改良Allen法致伤脊髓,于损伤前和伤后6h内观察MEP变化,并测算脊髓出血坏死区相对面积比。结果：SCI后50gcf组和70gcf组动物MEP早成份波幅立即减低或消失,以后有所恢复。100gcf组大部分动物MEP波消失,脊髓损伤面积与伤后1h MEP最大波幅呈显相关。结论：MEP检查可以准确反映脊髓损伤程度。     

非损伤区低剂量局部X射线照射可能诱导和促进骨髓间充质干细胞向脊髓损伤小鼠损伤部位的归巢

摘要：间充质干细胞（MSCs）移植为脊髓损伤后神经功能的恢复带来新的起点,但是MSCs在受者体内的归巢特点仍不甚明了。有研究表明,低剂量照射可诱发机体产生适应性反应,对疾病的预防及治疗具有兴奋效应;同时,也有学者发现低剂量照射可以促进骨髓间充质干细胞向暴露部位聚集。本实验通过建立小鼠脊髓损伤模型,研究低剂量局部照射对间充质干细胞归巢及损伤愈合的影响。间充质干细胞源自4名健康供者的骨髓。参照改良的重物坠落法制作小鼠脊髓损伤模型。然后将脊髓损伤小鼠随机分为A、B两组,每只小鼠均经尾静脉注入2×106 CFDA-SE 标记的MSCs。两组的区别是：A组小鼠不经照射直接输注MSCs,而B组小鼠在输注MSCs之前2h辅以2.5Gy局部照射。分别在移植后12h、24h及144h处死小鼠,观察照射部位皮肤及脊髓损伤部位MSCs归巢情况,并在移植前及移植后10d、20d、30d行小鼠脊髓受损节段MRI检查,观察损伤愈合情况。结果显示,移植后1天B组小鼠损伤部位BMSCs的数目明显大于A组（P＜0.05）,照射部位皮肤BMSCs的数目亦明显大于A组（P＜0.05）,照射组小鼠损伤部位的水肿坏死区明显低于对照组（P＜0.05）。以上研究表明低剂量照射可以促进MSCs向损伤部位聚集,加快损伤愈合。换言之,低剂量局部照射对MSCs的归巢及损伤愈合具有兴奋效应。     

Adoptive transfer of M2 macrophages promotes locomotor recovery in adult rats after spinal cord injury

Classically activated pro-inflammatory (M1) and alternatively activated anti-inflammatory (M2) macrophages populate the local microenvironment after spinal cord injury (SCI). The former type is neurotoxic while the latter has positive effects on neuroregeneration and is less toxic. In addition, while the M1 macrophage response is rapidly induced and sustained, M2 induction is transient. A promising strategy for the repair of SCI is to increase the fraction of M2 cells and prolong their residence time. This study investigated the effect of M2 macrophages induced from bone marrow-derived macrophages on the local microenvironment and their possible role in neuroprotection after SCI. M2 macrophages produced anti-inflammatory cytokines such as interleukin (IL)-10 and transforming growth factor β and infiltrated into the injured spinal cord, stimulated M2 and helper T (Th)2 cells, and produced high levels of IL-10 and -13 at the site of injury. M2 cell transfer decreased spinal cord lesion volume and resulted in increased myelination of axons and preservation of neurons. This was accompanied by significant locomotor improvement as revealed by Basso, Beattie and Bresnahan locomotor rating scale, grid walk and footprint analyses. These results indicate that M2 adoptive transfer has beneficial effects for the injured spinal cord, in which the increased number of M2 macrophages causes a shift in the immunological response from Th1- to Th2-dominated through the production of anti-inflammatory cytokines, which in turn induces the polarization of local microglia and/or macrophages to the M2 subtype, and creates a local microenvironment that is conducive to the rescue of residual myelin and neurons and preservation of neuronal function.     

Postinjury estrogen treatment of chronic spinal cord injury improves locomotor function in rats

Spinal cord injury (SCI) causes loss of neurological function and, depending on serverity, may cause paralysis. The only recommended pharmacotherapy for the treatment of SCI is high‐dose methylprednisolone, and its use is controversial. We have previously shown that estrogen treatment attenuated cell death, axonal and myelin damage, calpain and caspase activities, and inflammation in acute SCI. The aim of this study was to examine whether posttreatment of SCI with estrogen would improve locomotor function by protecting cells and axons and reducing inflammation during the chronic phase following injury. Moderately severe injury (40 g · cm force) was induced in male Sprague‐Dawley rats following laminectomy at T10. Three groups of animals were used: sham (laminectomy only), vehicle (dimethyl sulfoxide; DMSO)‐treated injury group, and estrogen‐treated injury group. Animals were treated with 4 mg/kg estrogen at 15 min and 24 hr postnjury, followed by 2 mg/kg estrogen daily for the next 5 days. After treatment, animals were sacrificed at the end of 6 weeks following injury, and 1‐cm segments of spinal cord (lesion, rostral to lesion, and caudal to lesion) were removed for biochemical analyses. Estrogen treatment reduced COX‐2 activity, blocked nuclear factor‐κB translocation, prevented glial reactivity, attenuated neuron death, inhibited activation and activity of calpain and caspase‐3, decreased axonal damage, reduced myelin loss in the lesion and penumbra, and improved locomotor function compared with vehicle‐treated animals. These findings suggest that estrogen may be useful as a promising therapeutic agent for prevention of damage and improvement of locomotor function in chronic SCI. © 2010 Wiley‐Liss, Inc.     

Tissue displacement and impact force are important contributors to outcome after spinal cord contusion injury

Spinal cord contusion injury in rodents is widely used as a model for spinal cord trauma in humans. Several biomechanical variables can influence injury outcome. In this work, we have assessed the influence of impact force and displacement of the spinal cord at the time of contusion injury on the severity of locomotor deficits and histopathological changes. Our work indicates that there is a linear relationship between force and tissue displacement, and that both these factors contribute to injury outcome. Furthermore, our work also suggests that setting narrow limits for the actual force applied (+/-5 kdyn) and tissue displacement (within a 200 microm range) will yield more consistent outcomes and provide greater sensitivity in detecting changes, regardless of the type of impactor device used.     

丹酚酸B促进大鼠急性脊髓损伤修复及量效关系探讨

目的 研究腹腔注射丹酚酸B(Sal B)对大鼠急性脊髓损伤(SCI)模型的神经保护作用和促功能恢复作用,探讨Sal B在急性SCI治疗的应用价值,并探讨其量效关系. 方法参照Allen法制作SD大鼠T9脊髓节段急性损伤模型,腹腔注射Sal B或PBS液,按照注射液的不同分为4组:Sal B高剂量组(20 mg/kg组),Sal B中剂量组(10 mg/kg组),Sal B低剂量组(2 mg/kg组)和对照组(注射PBS液),每组12只.用比色法检测髓过氧化物酶活性;用免疫组织化学染色法检测损伤脊髓节段MMP-1、c-Fos抗体表达情况,用干湿重法评价的水肿程度,并采用后肢功能评分(BBB)评分评价10 d内大鼠的运动功能恢复情况. 结果损伤后4 h Sal B治疗组髓过氧化物酶活性下降,损伤后1 dHE染色切片显示SalB组治疗后局部组织损伤减轻,炎性细胞浸润数量减少,损伤后1d免疫组化染色结果显示,Sal B治疗组比对照组MMP-1表达减少,c-Fos表达下调;Sal B治疗组水肿程度轻于对照组,从SCI后第7天起,SalB组高剂量组(20 mg/kg组)和对照组之间的BBB评分有显著性差异(P<0.05).各指标改善情况与Sal B剂量呈正相关性. 结论 Sal B可减轻大鼠SCI后的组织损伤,下调损伤相关因子MMP-1和c-Fos的表达,降低损伤局部髓过氧化物酶活性,减轻组织水肿,并能促进损伤大鼠的功能恢复.     

丹酚酸B促进大鼠急性脊髓损伤修复及量效关系探讨

目的 研究腹腔注射丹酚酸B(Sal B)对大鼠急性脊髓损伤(SCI)模型的神经保护作用和促功能恢复作用,探讨Sal B在急性SCI治疗的应用价值,并探讨其量效关系. 方法参照Allen法制作SD大鼠T9脊髓节段急性损伤模型,腹腔注射Sal B或PBS液,按照注射液的不同分为4组:Sal B高剂量组(20 mg/kg组),Sal B中剂量组(10 mg/kg组),Sal B低剂量组(2 mg/kg组)和对照组(注射PBS液),每组12只.用比色法检测髓过氧化物酶活性;用免疫组织化学染色法检测损伤脊髓节段MMP-1、c-Fos抗体表达情况,用干湿重法评价的水肿程度,并采用后肢功能评分(BBB)评分评价10 d内大鼠的运动功能恢复情况. 结果损伤后4 h Sal B治疗组髓过氧化物酶活性下降,损伤后1 dHE染色切片显示SalB组治疗后局部组织损伤减轻,炎性细胞浸润数量减少,损伤后1d免疫组化染色结果显示,Sal B治疗组比对照组MMP-1表达减少,c-Fos表达下调;Sal B治疗组水肿程度轻于对照组,从SCI后第7天起,SalB组高剂量组(20 mg/kg组)和对照组之间的BBB评分有显著性差异(P<0.05).各指标改善情况与Sal B剂量呈正相关性. 结论 Sal B可减轻大鼠SCI后的组织损伤,下调损伤相关因子MMP-1和c-Fos的表达,降低损伤局部髓过氧化物酶活性,减轻组织水肿,并能促进损伤大鼠的功能恢复.     

Modulation of spinal reflex by assisted locomotion in humans with chronic complete spinal cord injury

Objective

In healthy subjects, spinal reflexes (SR) evoked by non-noxious tibial nerve stimulation consist of an early (60–120 ms latency) and an occasional late-appearing (120–450 ms latency) component in the ipsilateral tibialis anterior. In chronic (>1 year) complete spinal cord injured (cSCI) subjects early components are small or lacking while late components are dominant. Here we report on the modulation of SR by assisted locomotion in healthy and chronic motor cSCI subjects.

Methods

SR was evoked by tibial nerve stimulation at the terminal stance phase during assisted locomotion and was compared to SR recorded during upright stance.

Results

In chronic cSCI subjects only a late SR component was consistently present during upright stance. However during assisted locomotion, an early SR component appeared, while amplitude of the late SR component became small. In contrast, in healthy subjects the early SR component dominated in all conditions, but a small late component appeared during assisted locomotion.

Conclusion

A more balanced activity of early and late SR components occurred in both subject groups if an appropriate proprioceptive input was provided.

Significance

Early and late SR components are assumed to reflect the activity of separate neuronal circuits, which are associated with the locomotor circuitry possibly by shaping the pattern.     

大鼠脊髓损伤后巢蛋白表达

目的探讨成年大鼠脊髓损伤后损伤区局部巢蛋白（nestin）的表达及意义。方法应用Allen＇s法建立大鼠脊髓拟伤模型，行为学评分采用BBB评分（Basso，Beattie＆Bresnahan locomotor rating scale，BBB scale），观察局部病理组织学改变及用免疫荧光组织化学方法检测局部脊髓在不同时段nestin的阳性表达变化。结果伤后1w BBB评分最低，随后增加，到4w以后达到最高并进入平台期。常规病理学检查显示拟伤模型类似于临床常见的脊髓损伤。损伤后1W，可见损伤区附近nestin表达升高，2W达高峰，4W后nestin表达明显下调。结论脊髓损伤可诱导损伤区周围短暂的nestin阳性表达，后者可能存在脊髓损伤后的再生与修复中起重要作用。     

X-irradiation of the contusion site improves locomotor and histological outcomes in spinal cord-injured rats.

We have determined whether X-irradiation of the injury site can oppose tissue loss and improve recovery of locomotor function following contusion injury of the spinal cord. Contusion injury was produced in rats at the level of T10 with a weight drop device. Localized X-irradiation (20 Gy) of the injury site was performed at 20 min and 1, 2, 4, 7, and 17 days postinjury. Locomotor recovery was then determined with the 21-point Basso, Beattie, and Bresnahan (BBB) scale. X-irradiation enhanced recovery of locomotor function during a subsequent 6-week observation period when administered 20 min and 1 or 2 days following contusion injury (final BBB score approximately 7-8). X-irradiation at 4-17 days postinjury did not significantly affect final locomotor scores compared with unirradiated rats (final BBB score approximately 2), in marked contrast to previous studies where X-irradiation applied only at 17-18 days benefitted transection injury. The extent of recovery was directly related to measurements of sparing of spinal cord tissue at the contusion center. Because the treatment time window occurred earlier in contusion than reported for transection injury, the results suggest that contusion injury rapidly initiates underlying radiation-sensitive processes that occur only following a delay of several weeks after transection injury. Further optimization of X-ray treatment may lead to a useful therapeutic modality for use in spinal cord contusion injury.     

Dietary restriction started after spinal cord injury improves functional recovery

Spinal cord injury typically results in limited functional recovery. Here we investigated whether therapeutic dietary restriction, a multi-faceted, safe, and clinically-feasible treatment, can improve outcome from cervical spinal cord injury. The well-established notion that dietary restriction increases longevity has kindled interest in its potential benefits in injury and disease. When followed for several months prior to insult, prophylactic dietary restriction triggers multiple molecular responses and improves outcome in animal models of stroke and myocardial infarction. However, the efficacy of the clinically-relevant treatment of post-injury dietary restriction is unknown. Here we report that “every-other-day fasting” (EODF), a form of dietary restriction, implemented after rat cervical spinal cord injury was neuroprotective, promoted plasticity, and improved behavioral recovery. Without causing weight loss, EODF improved gait-pattern, forelimb function during ladder-crossing, and vertical exploration. In agreement, EODF preserved neuronal integrity, dramatically reduced lesion volume by > 50%, and increased sprouting of corticospinal axons. As expected, blood β-hydroxybutyrate levels, a ketone known to be neuroprotective, were increased by 2–3 fold on the fasting days. In addition, we found increased ratios of full-length to truncated trkB (receptor for brain-derived neurotrophic factor) in the spinal cord by 2–6 folds at both 5 days (lesion site) and 3 weeks after injury (caudal to lesion site) which may further enhance neuroprotection and plasticity. Because EODF is a safe, non-invasive, and low-cost treatment, it could be readily translated into the clinical setting of spinal cord injury and possibly other insults.     

The effect of locomotor training combined with functional electrical stimulation in chronic spinal cord injured subjects: walking and reflex studies

With the new developments in traumatology medicine, the majority of spinal cord injuries sustained are clinically incomplete and the proportion is likely to continue to rise. Thus, it is necessary to continue to develop new treatment and rehabilitation strategies and understand the factors that can enhance recovery of walking following spinal cord injury (SCI). One new development is the use of functional electrical stimulation (FES) device to assist locomotion. The objective of this review is to present findings from some recent studies on the effect of long-term locomotor training with FES in subjects with SCI. Promising results are shown in all outcome measures of walking, such as functional mobility, speed, spatio–temporal parameters, and the physiological cost of walking. Furthermore, the change in the walking behavior could be associated with plasticity in the CNS organization, as seen by the modification of the stretch reflex and changes in the corticospinal projection to muscles of the lower leg. In conclusion, recovery of walking is an increasing possibility for a large number of people with SCI. New modalities of treatment have become available for this population but most still need to be evaluated for their efficacy. This review has focused on FES assisted walking as a therapeutic modality in subjects with chronic SCI, but it is envisaged that the care and recovery of SCI in the early phase of recovery could also be improved.