方波电容耦合电场促进脊髓轴突再生

应用自行设计的新型非置入式电场──方形波电容耦合电场和辣根过氧化酶（ＨＲＰ）标记技 术对脊髓轴突再生进行实验研究。选取２０只Ｓｐｒａｇｕｅ－Ｄａｕｌｅｙ大白鼠，体重２５０±１５９，在２０％乌拉坦腹腔 内麻醉下（１ｇ／ｋｇ），切除Ｔ９－１０椎板，将Ｔ１０脊髓半切断。将造模动物随机分为两组，每组１０只，Ⅰ组为方 波电容耦合电场治疗组，Ⅱ组为对照组，不作任何处理。４周后，沿动物原切口再切开，将２０％ＨＲＰ注入 Ｔ１０脊髓内５ｍｌ。动物存活３６ｈ，取出脑及脊髓，置入蔗糖缓冲液１２～２４ｈ，保持４℃，然后用冰冻连续 切片机切成４０μｍ厚度的切片，以ＴＭＢ为着色剂，通过在红核、尾状核、缝核及齿状核所标记的细胞核 团计数，发现两组之间有非常显著性差异（Ｐ＜０．０１）。结果提示方波电容耦合电场能促进大白鼠的脊髓轴突再生。     

腰、骶脊神经前根撕脱伤对大鼠盆底肌运动神经元的影响

目的：观测大鼠脊神经前根撕脱伤对盆底肌运动神经元的存活及神经元中一氧化氮合酶（NOS）和N-甲基-D-天冬氨酸型受体（NMDAR）表达的影响。方法：取雄性SD大鼠25只，背部切口显露脊髓，拨断一侧L6～S2脊神经前根。动物分为5组，分别于术后第3、7、14、21、28天．取腰骶段脊髓进行还原型烟酰腺嘌呤二核侍酸（NADPH-d）组织化学、中件红复染和NMDA受体免疫组织化学染色观察及定量分析。结果：术后第3、7、14、21、28天，与对侧比较术侧前角运动神经元存活率分别为96％、85％、50％、35％和20％：术后第7d开始出现NOS阳性神经元，其标记率分圳为6％、40％、62％和41％。与对侧比较，术侧前角运动神经元NMDA受体亚单位表达改变，其中NMDAR，受体亚单位表达明显减少，NMDAR2H表达显著增高，NMDAR2A表达无明显变化。结论：前根撕脱伤可导致盆底肌运动神经元进行性死亡，NOS持续表达和NMDA受体亚单位的表达变化可能是导致神经元死亡的重要原因。     

Delayed implantation of a peripheral nerve graft reduces motoneuron survival but does not affect regeneration following spinal root avulsion in adult rats

Adult spinal motoneurons can regenerate their axons into a peripheral nerve (PN) graft following root avulsion injury if the graft is implanted immediately after the lesion is induced. The present study was designed to determine how avulsed motoneurons respond to a PN graft if implantation takes place a few days to a few weeks later. Survival, regeneration, and gene expression changes of injured motoneurons after delayed PN graft implantation were studied. The survival rates of spinal motoneurons were 78%, 65%, 57%, or 53% if a PN graft was implanted immediately, 1, 2, or 3 weeks after root avulsion, respectively. Interestingly, most of the surviving motoneurons were able to regenerate their axons into the graft regardless of the delay. All regenerating motoneurons expressed p75, but not nNOS, while all motoneurons that failed to regenerate expressed nNOS, but not p75. p75 and nNOS may, therefore, be used as markers for success or failure to regenerate axons. In the group with immediate graft implantation, 85% of the surviving motoneurons extended axons into the PN graft, while in the groups in which implantation was delayed 1, 2, or 3 weeks, 84%, 82%, and 83% of the surviving motoneurons, respectively, were found to have regenerated into the grafts. These findings indicate that avulsed spinal motoneurons retain the ability to regenerate for at least 3 weeks, and perhaps for as long as they survive. Therefore, the delayed implantation of a PN graft after root avulsion may provide a continued conducive environment to support regeneration.     

Valproic acid preserves motoneurons following contusion in organotypic spinal cord slice culture

Objective: Spinal cord injury (SCI) is a devastating condition causing neuronal loss. A key challenge in treatment of SCI is how to retain neurons after injury. Valproic acid (VPA) is a drug recently has been appreciated for its neuroprotective and neurotrophic properties in various SCI models. In this study the role of VPA was assessed in organotypic spinal cord slice culture following the contusion.

Design: The lumbar enlargement of adult rat was cut transversely and slices were cultured. Seven days after culturing, injury was induced by dropping a 0.5 gram weight from 3?cm height on the slice surface. One hour after injury, the VPA was administered at 1, 5 and 10?µM concentrations. Afterward, at day 1 and 3 post injury (DPI: 1 and 3) propidium iodide (PI) and immunohistochemistry staining were performed to evaluate the cell death, NeuN and β-Tubulin expression, respectively.

Results: The PI staining of slices at DPI: 1 and 3 following treatment with VPA revealed significant decreases in the cell death in all three concentrations comparing to the non-treated group. Also immunostaining showed VPA only at 5?µM concentration considerably rescued ventral horn’ MNs from death and protected the neuronal integrity.

Conclusion: The results of this study indicate applying VPA one hour after injury can prevent the death of a majority of cells, importantly MNs and preserve the neuronal integrity. Since the first 24 hours after SCI is a critical period for employing any treatment, VPA can be considered as an option for further evaluation.     

条件性损伤对脊神经根撕脱伤后脊髓运动神经元一氧化氮合 …

目的 探索条件性损伤对脊神经根撕脱后脊髓前角运动神经元一氧化合酶（ＮＯＳ）表达及神经细胞死亡的影响。方法 雌性ＳＤ大鼠７８只,分为两组,实验组在臂丛神经干压榨术后１周行神经根撕脱术;对照组仅施行神经根撕脱术,术后３ｄ～８周于不同时间点处死动物,取Ｃ５～Ｃ６节段脊髓,行ＮＡＤＰＨ－ｄ组化染色,中性红复染。结果 单纯神经根撕脱组术后第５ｄ脊髓前角运动神经元开始表达ＮＯＳ,至术后２周ＮＯＳ阳性神经元数达     

实验性不同类型大鼠臂丛根性损伤后脊髓运动神经元存活情况观察

目的 研究臂丛神经根性切断伤与根性撕脱伤后脊髓前角运动神经元的存活情况。方法 对76只健康成年SD大鼠,按手术先后顺序分成臂丛神经根性切断伤组和根性撕脱伤组,两组按术后9个不同的时间组取材,每组4只大鼠,共72只大鼠。另外4只为正常对照组。取了脊髓标本后,观察颈髓前角运动神经元数目的变化。结果 臂丛神经根性切断伤后,各时间组的脊髓前角运动神经元数目和术前无明显变化;而根性撕脱伤组于术后1周其神经元数目开始减少,术后2周时神经元数目比正常对照组减少30％,术后6周时减少70％。撕脱伤组与切断伤组相比,损伤1周后,各时间组的差异均有显著性意义（X^2＝3．922－17．21,P＜0．01）。结论 臂丛神经根性切断伤其脊髓运动神经元和术前比无明显变化,而臂丛神经性撕脱伤后其脊髓运动神经元有死亡,死亡速度快,死亡程度高。     

大鼠臂丛神经根性回植后脊髓病理改变和轴突再生

目的 探讨臂丛神经根性撕脱后神经根再植入脊髓的可行性。方法 采用大鼠颈5-7，神经根性撕脱伤实验动物模型，伤后将C5-7，神经根即刻植入脊髓。分别于神经根植入后3周、3个月、6个月取材。应用组织病理活检、免疫组化技术及神经示踪技术，对神经中枢及吻合口下段神经干检查。观察脊髓前角运动神经元和神经元内尼氏体数目和形态的改变；周围神经纤维再生数目、距离，轴索和髓鞘发育情况。结果 臂丛神经根性撕脱伤对动物生长和存活有较大的影响。脊髓前角运动神经元数目在3个月内持续减少，3个月后趋于稳定，6个月时脊髓前角大型运动细胞坏死比率在40％左右，残存的神经元多为受损的神经元，尼氏体减少或消失。脊髓前角运动神经元再生轴突可重新生长入周围神经干，再生神经纤维轴索较细，大部分髓鞘发育不完全，轴突再生距离较短，肌皮神经6个月内无神经纤维再生。结论 臂丛神经根性撕脱伤，神经根回植入脊髓后，脊髓前角运动神经元坏死比率为40％左右，残存神经元多为受损神经元，再生神经纤维表现为动力不足和发育不全，对终末器官功能恢复没有意义。     

Intramedullary spinal cord metastases from a hypernephroma 11 years following the diagnosis and treatment of the primary lesion

Intramedullary spinal cord metastases are rare. An intramedullary spinal cord metastasis of renal origin, presenting 11 years after the diagnosis of the primary lesion, is reported.     

植物抗氧化剂TA9901保护臂丛撕脱后运动神经元的实验研究

目的　观察植物抗氧化剂TA990 1对臂丛撕脱后脊髓运动神经元c jun基因的表达和存活的影响。方法　成年SD雌性大鼠 90只分成 2组 ,治疗组行右侧臂丛神经根撕脱术后 ,每天腹腔注射质量浓度为 0 .5%的TA990 1溶液 1ml,对照组注射生理盐水。治疗后 4h～ 6周处死动物行c jun免疫组织化学和中性红染色 ,定量比较两组大鼠损伤侧c jun基因表达阳性和存活运动神经元数目。结果　治疗后 3d ,5d ,1周和 2周 ,治疗组的c jun基因表达阳性运动神经元数目均多于对照组 ,两组间各时间点的差异均具有非常显著意义 (P <0 .0 1)。治疗后 2、4、6周 ,治疗组存活运动神经元数目多于对照组 ,两组间的差异均有非常显著意义 (P <0 .0 1)。结论　TA990 1能增强受损运动神经元c jun基因的表达 ,提高臂丛撕脱后运动神经元的存活率     

Neuronal populations capable of regeneration following a combined treatment in rats with spinal cord transection

Axonal regeneration after spinal cord injury (SCI) in adult mammals is limited by inhibitors associated with myelin and the glial scar. To overcome these inhibitors, a combined approach will be required. We have previously demonstrated that, following complete SCI in rats, a combination of bridging the lesion with Schwann cell (SC)-filled guidance channels, olfactory ensheathing glia implantation, and chondroitinase ABC delivery promoted regeneration of serotonergic fibers into the lumbar spinal cord. In addition, this combined treatment significantly improved locomotor recovery. To complement these findings, we repeated this combined treatment to assess whether fibers other than serotonergic axons were able to regenerate into the caudal spinal cord. In this experiment, we injected the retrograde tracer FluoroGold (FG) into the spinal cord caudal to a complete transection in a control and a treated group. FG-positive cells rostral to the lesion and in the brainstem of animals in the treated group showed that axons were able to regenerate across the SC bridge and into the caudal spinal cord. Treated rats had labeled cells in the reticulospinal nuclei, vestibular nuclei, and the raphe nucleus as well as in the spinal cord. Cell numbers were highest in the thoracic spinal cord and the lateral vestibular nucleus. Determining the mechanisms for the superior capability of these cell populations to regenerate may provide valuable clues in the design of future treatment approaches.     

Peripheral nerve surgery

周围神经损伤以后的功能恢复，仍然是21世纪的主要目标。脊髓水平的神经修复是一个新而具有挑战性的技术，对神经元再生的深入理解（包括神经元误向生长与存活问题）与实验手段的完善（包括基因调控的成纤维细胞和雪旺细胞种植等），将使臂丛外科（学）进入一个新的水平。鉴于运动轴突对肌皮瓣再神经化的意义，区分感觉和运动神经束的选择性神经缝合，在游离神经血管肌肉移植术中取得了较好的效果。用纤维蛋白胶或激光缝合的无缝线缝合技术，因两端神经连接不牢，故只能是一种辅助的神经修复手段。应用邻近正常神经行部分端端或端侧缝合，对解决供体神经的来源和保存供体神经功能来说，是一个有前途的方法。然而，正常的供体神经切除后的代偿机制及神经端侧缝合效果，尚需进一步研究。神经移植术的结果仍不令人满意。在长段神经缺损，神经主干移植及组织床为瘢痕或骨质时，可考虑用带血管的自体神经移植术。预变性神经或预处理神经移植术，能调控雪旺细胞和成纤维细胞，从而影响神经再生，但对离体/在体及预变性时间方面，仍存在着争议。随着细胞培养学和组织工程学技术的广泛应用，人工生物神经移植物将代替自体神经移植物。顾玉东院士首创“寄养法”预防手内部肌萎缩，也可应用感觉神经和背根神经节预防肌肉萎缩。总之，随着对神经再生的神经生物学和分子水平进一步的深入研究，周围神经外科学将会取得更大的进展。     

雪旺细胞源神经营养因子对脊神经根性撕脱所致运动神经元死亡的保护作用

目的研究雪旺细胞源神经营养因子（ＳＤＮＦ）对臂丛神经根性撕脱所致前角运动神经元死亡的保护作用。方法于颈神经根性撕脱处应用ＳＤＮＦ,３周后观察损伤侧脊髓前角运动神经元的存活率和形态学变化以及ＮＯＳ表达的情况。结果对照组６８．６％的神经元死亡,存活神经元胞体明显萎缩,同时表达ＮＯＳ神经元增多;实验组的死亡率较对照组降低３５％,存活神经元胞体无萎缩,表达ＮＯＳ神经元未见增多。结论ＳＤＮＦ对脊髓前角运动神经元死亡有明显的保护作用,ＮＯ在臂丛神经根性撕脱所致运动神经元死亡中起一定作用。     

Axon regeneration and vascularisation of nerve grafts an experimental study

An experimental model has been designed to assess the effect of vascularisation on axon regeneration in nerve grafts. The vascular status of the grafts has been demonstrated by microangiography and histology. Rat sciatic nerve grafts in which the vascular pedicles were left intact retained a normal vascular pattern which was not adversely affected by wrapping the graft in a polythene sleeve. In devascularised grafts, revascularisation commenced at three days and was complete at nine days. If the devascularised grafts were wrapped in a polythene sleeve, revascularisation was impeded and at fifteen days the middle segment of the graft was avascular and infarcted. The rate of axon regeneration was measured electrophysiologically in the above four groups of nerve grafts. There was a linear relationship between the rate of axon regeneration with time post-graft, axon growth proceeding at a mean rate of 1.150mm/day (S.E. +/- 0.084) after a mean delay of 4.85 days. There was no significant difference in the rate of axon regeneration in the four groups.     

Survival of injured spinal motoneurons in adult rat upon treatment with glial cell line-derived neurotrophic factor at 2 weeks but not at 4 weeks after root avulsion

We conducted a study of whether treatment with glial cell line-derived neurotrophic factor (GDNF) initiated at 2 or 4 weeks after spinal-root avulsion could promote survival and regulate neuronal nitric oxide synthase (nNOS) expression in adult rat spinal motoneurons. By 6 weeks after root avulsion, the treatment given at 2 weeks not only increased motoneuron survival (86.1% vs. 27.9%), but also reversed the atrophy of injured motoneurons and increased their somatic size (101.3% vs. 52.9%) in comparison to the untreated control group of animals. All surviving motoneurons in the GDNF-treated group showed immunoreactivity for choline acetyltransferase. In contrast, GDNF treatment at 4 weeks post-injury failed to promote motoneuron survival (33.1% vs. 27.9%) at 6 weeks compared to the control group. Both the 2- and 4-week post-injury treatments downregulated nNOS expression. This finding suggests that injured adult motoneurons die shortly (a few weeks in the rat) after root avulsion injury, but can be saved from degeneration by treatment within the proper time frame after injury, which in the case of GDNF treatment in rats, appears to be within 2 weeks of the avulsion injury of the spinal root. These findings provide useful information for choosing the best time frame for the potential clinical treatment of brachial plexus avulsion.     

Intervertebral dysfunction: a discussion of the manipulable spinal lesion

The concept of the manipulable spinal lesion — a musculoskeletal disturbance that can be detected with manual palpation and corrected with manipulation — is examined and evidence for the theories of the dysfunction is discussed. A model for intervertebral dysfunction is presented that describes both mechanical and neurological sequelae to spinal injury, leading to a deficit in regional proprioception, changes in segmental and polysegmental muscle activity and motor control, and predisposing the segment to further strain. The evidence for the proposed model and mechanisms of manual treatment is discussed. Recommendations and directions are outlined for future research.