骨骼肌卫星细胞异体移植对周围神经缺损后再生的影响

背景：有研究表明肌卫星细胞不仅在体外具有较强的增殖能力及适应能力,而且在异体内免疫原性低,免疫排斥反应低,移植后存活时间长。因此设想肌卫星细胞异体移植在促进缺损神经再生等方面可能具有良好的研究和应用前景。 目的：探讨骨骼肌卫星细胞移植对周围神经缺损后再生修复的影响。 方法：将16只Wistar大鼠随机分成移植组与对照组,每组8只,均切断右后肢坐骨神经,并通过生物可降解膜包裹缺损神经断端形成神经再生室。用微量注射器抽取已配制成的肌干细胞悬液0.2 mL注入移植组的神经再生室内。对照组注入等量的生理盐水。术后4,8和12周进行大鼠行步态测定,并用锇酸染色法制片观察缺损神经再生情况。观测大鼠坐骨神经功能指数、腓肠肌湿质量恢复率、再生的有髓神经纤维数量和直径及髓鞘厚度的变化。 结果与结论：大鼠经肌卫星细胞移植后腓肠肌湿质量残存率、再生的有髓神经纤维数目、直径及髓鞘厚度等项检测指标与对照组相比均差异有显著性意义(P < 0.05)。术后8和12周,移植组坐骨神经功能指数恢复情况明显优于对照组(P < 0.05)。实验结果提示在神经再生室中加入肌卫星细胞能促进缺损神经纤维的再生及其结构的成熟。 关键词：肌卫星细胞;生物可降解膜;异体;细胞移植;周围神经缺损;神经再生     

不同剂量神经生长因子对神经源性疼痛大鼠脊髓Fos蛋白的影响

背景：神经生长因子对神经元的存活、生长发育、分化、再生和功能维持起到调控作用。 目的：进一步验证不同剂量神经生长因子对神经源性痛大鼠的治疗作用以及对脊髓中Fos蛋白的影响。 设计、地点：随机对照动物实验，在上海第九人民医院完成。 材料：健康成年雄性Wistar大鼠72只,体质量180~200 g，随机分为4组，模型组及腹腔注射神经生长因子4， 8，16 μg组，每组18只。 方法：72只大鼠结扎左侧坐骨神经制备坐骨神经慢性缩窄性损伤模型；腹腔注射神经生长因子4， 8，16 μg组，造模后分别腹腔注射神经生长因子4，8，16 μg/(kg•d)。 主要观察指标：①于术前和术后第1，2，3，5，7，10，14天进行行为学观察和机械性痛阈测定。②于术后第2，7，14天各组分别处死大鼠各6只，取脊髓，应用免疫组织化学方法和图像分析系统检测脊髓中Fos蛋白的表达。 结果：模型组大鼠术后出现自发抬足、舔足等自发痛表现，术后第3天起开始出现痛阈下降，第14天达最低值，而注射神经生长因子组大鼠没有自发痛表现，没有出现机械性痛阈的低常期，第10，14天模型组大鼠痛阈与其余各组比较差异有显著性意义(P < 0.05)。4组大鼠术后第1天机械性痛阈普遍升高；注射神经生长因子16 μg组大鼠术后第1天机械性痛阈比其他各组低(P < 0.01)，第2天机械性痛阈恢复至术前水平，低于注射神经生长因子4 μg组(P < 0.05)。术后模型组大鼠脊髓Fos蛋白表达进行性升高，而其他各组大鼠脊髓中仅有少量Fos阳性神经元，模型组与其余各组比较差异显著(P < 0.01)。术后第2天注射神经生长因子16 μg组大鼠脊髓Fos蛋白表达最低，与模型组和注射神经生长因子4 μg组比较，差异有显著性意义(P < 0.01)。 结论：神经生长因子对大鼠神经源性痛有治疗作用，且大剂量较小剂量作用更为明显，其机制可能与抑制脊髓中Fos蛋白表达有关。     

嗅鞘细胞移植修复坐骨神经缺损

背景：研究表明,嗅鞘细胞有利于神经元存活并促进轴突再生。 目的：验证局部注射嗅鞘细胞治疗大鼠周围神经损伤的可行性。 方法：体外分离、培养SD大鼠嗅鞘细胞。40只SD大鼠切除坐骨神经1.0 cm,植入异体神经1.0 cm。随机分为2组,嗅鞘细胞组局部注射嗅鞘细胞,生理盐水组局部注射生理盐水。术后3个月检测体感诱发电位及运动诱发电位,光镜、电镜观察神经电生理恢复情况。 结果与结论：电镜观察嗅鞘细胞组大鼠在损伤区有较多神经纤维通过,明显多于生理盐水组(P < 0.01)。嗅鞘细胞组大鼠体感诱发电位及运动诱发电位的潜伏期及波幅明显优于生理盐水组(P < 0.01)。提示局部注射嗅鞘细胞能更好地恢复周围神经损伤后的功能。     

靶肌肉注射人间充质干细胞对坐骨神经损伤保护性作用的电生理研究

目的探讨电生理在大鼠失神经支配的骨骼肌中移植间充质干细胞对坐骨神经损伤后修复中的作用。方法体外分离培养人间充质干细胞,经鉴定标记后备用。将36只SD大鼠随机分为肌肉注射干细胞组(实验组)、肌肉注射生理盐水组(对照组),每组18只,建立大鼠坐骨神经损伤模型,术后3d将干细胞和等量生理盐水注射到损伤侧坐骨神经支配的骨骼肌中。于移植后3、7、14、21、28、60d,观察坐骨神经功能指数(SFI)、腓肠肌肌电图(EMG)、运动神经传导速度(MCV),肌肉复合动作电位幅值(CMAP)检查。结果腓肠肌EMG实验组自发电位减少和动作电位出现时间均早于对照组。坐骨神经MCV和CMAP波幅呈恢复趋势。移植后:21d开始,实验组明显快于对照组(P<0.05),60d时,传导速度两组无显著性(P>0.05),波幅有显著性差异(P<0.05)。结论肌肉注射人间充质干细胞对坐骨神经损伤具有促修复作用。     

口服耐受与免疫抑制药物对移植后移植物抗宿主病抑制作用比较*

背景：移植物抗宿主病是导致异基因外周血造血干细胞移植失败的主要原因,口服耐受是研究治疗移植物抗宿主病的新模式。 目的：探讨骨髓移植前供鼠经口服受鼠脾淋巴细胞诱导耐受是否能增加异基因骨髓移植后受鼠对供者移植物的免疫耐受,从而减轻移植物抗宿主病,并与目前常用于预防移植物抗宿主病的免疫抑制药物比较作用效果。 设计、时间及地点：随机分组设计,对比观察,于2008-12在东南大学医学院中心实验室完成。 材料：供鼠为雄性纯种近交系小鼠C57BL/6J(H-2b),受鼠为雌性纯种近交系小鼠BALB/c(H-2d)。 方法：用主要组织相容性抗原完全不合的纯种近交系小鼠建立异基因骨髓移植/移植物抗宿主病动物模型,小鼠共分5组,分别给予不同的急性移植物抗宿主病预防方案：①口服耐受组：移植前口服受鼠脾淋巴细胞相当于10 μg蛋白,隔天1次,共3次。②雷帕霉素组：1.5 mg/(kg•d)灌胃,从移植后第1天(+1 d)开始用药。③环孢素A+甲氨蝶呤组：环孢素A 1.5 mg/(kg•d)腹腔注射,从移植后+1 d开始用药,当小鼠的胃肠功能逐渐恢复后,改为环孢素A 5 mg/(kg•d)灌胃,甲氨蝶呤0.4 mg/(kg•d)腹腔注射,移植后+1,+3,+6,+11 d用药。④空白对照组：移植后未用药。⑤辐照不移植组：照射后未予骨髓移植。 主要观察指标：各组小鼠骨髓移植后移植物抗宿主病的出现情况及免疫耐受指标差异。 结果：移植后小鼠出现典型的移植物抗宿主病症状,空白对照组小鼠死亡高峰在移植后第14~18天,死亡率接近100%。口服耐受组、雷帕霉素组和环孢素A+甲氨蝶呤组小鼠急性移植物抗宿主病症状明显减轻,平均生存时间较空白对照组显著延长(P < 0.05);小鼠急性移植物抗宿主病病理表现减轻,口服耐受组病理变化少于其他各组;流式细胞仪监测CD4+/CD8+比值增加,CD4+CD25+细胞增加,口服耐受组增加明显;ELISA检测移植物抗宿主病产生相应细胞因子减低,且口服耐受组明显减轻。MTT结果显示,口服耐受组免疫耐受显著增强,淋巴细胞增殖明显降低。 结论：口服耐受可以显著抑制体外T淋巴细胞增殖效应,增强小鼠对骨髓移植的免疫耐受,减轻移植物抗宿主病症状和病理损害程度,延长平均生存时间;与目前常用于预防移植物抗宿主病的免疫抑制药物比较,减轻移植物抗宿主病的作用更强。     

外源性神经生长因子诱导下自体静脉桥接修复神经缺损

背景：采用自体神经游离移植修复神经缺损效果比较理想,但有其弊端。为此寻求一种更佳修复神经缺损的治疗方法。 目的：验证及外源性神经生长因子诱导下自体静脉桥接神经缺损对神经再生的影响。 方法：采用Wistar大鼠建立周围神经缺损模型。随机将大鼠分为3组。实验组采用自体静脉桥接并注入神经生长因子;对照组采用自体静脉桥接并注入生理盐水;标准组采用自体神经桥接。分别于术后1,3个月,对实验动物进行活体观察,电生理检测及组织学检测。 结果与结论：3组实验动物均有神经再生及修复表现,但程度不同。实验组失神经表现恢复的较对照组早,电生理检测运动神经传导速度快,组织学检查再生神经纤维数量及质量明显高于对照组(P < 0.05);与“金标准”的自体神经桥接组比较无显著性意义(P > 0.05)。结果提示采用自体静脉桥接+神经生长因子诱导对周围神经缺损后的再生、修复具有有促进作用,可以使再生神经纤维的数量增加并显著提高再生神经纤维质量。     

胎鼠神经干细胞局部注射移植大鼠高位脊髓损伤缺损处：体感及运动诱发电位与后肢运动功能评价

背景：如何促进脊髓损伤后的神经再生和功能恢复始终是医学界一大难题,胚胎神经干细胞有利于神经元的存活,并能促进轴突再生。 目的：观察胚胎鼠神经干细胞局部注射移植治疗高位脊髓损伤大鼠的可行性,以神经电生理及后肢运动功能评分评价其效果。 设计、时间及地点：细胞学体内实验,于2007-06/2008-06在哈尔滨医科大学动物实验中心完成。 材料：健康成年雌性SD大鼠40只,随机分为生理盐水组、细胞移植组,20只/组。另取孕14 d的SD大鼠5只用于制备胚胎神经干细胞。 方法：生理盐水组、细胞移植组大鼠均建立高位脊髓损伤模型,取双侧第8~10对肋间神经各2 cm,交叉植入脊髓缺损处(近端白质与远端灰质、远端白质与近端灰质),细胞移植组局部注射鼠胚胎神经干细胞2×106个,生理盐水组局部注射等量无菌生理盐水。 主要观察指标：通过体感诱发电位和运动诱发电位的检测,观察神经电生理恢复情况;通过BDA顺行神经示踪,观察运动传导束恢复情况;BBB后肢运动功能评分结果。 结果：细胞移植组大鼠体感诱发电位及运动诱发电位的潜伏期、波幅明显优于生理盐水组(P < 0.01);细胞移植组大鼠在损伤区有较多BDA标记阳性神经纤维通过,而生理盐水组未见BDA标记阳性神经纤维;细胞移植组大鼠BBB后肢运动功能评分较生理盐水组明显提高(P < 0.01)。 结论：胎鼠神经干细胞局部注射可以较好地恢复高位脊髓损伤后的神经电生理及后肢运动功能。     

1102/异种神经脱细胞移植物桥接大鼠坐骨神经缺损

目的　探讨异种神经脱细胞移植物桥接大鼠坐骨神经缺损后的神经再生及其再生过程中免疫排斥反应。 方法　用脱细胞兔周围神经作为移植物桥接大鼠坐骨神经1cm缺损;术后3、5、8、11、15天检测血液中淋巴细胞占白细胞百分比;3个月后取移植物及腓肠肌,用甲苯胺蓝、乙酰胆碱酯酶(AchE)、琥珀酸脱氢酶(SDH)组化染色,光、电镜观察神经再生及腓肠肌运动终板的恢复情况。　 结果　术后大鼠血液中淋巴细胞占白细胞的百分比与正常大鼠相比较无显著性差异,3个月后大鼠术侧下肢足趾能分开,行走时后蹬动作有力,针刺足底有逃避反应,桥接物内见有大量再生的坐骨神经纤维,腓肠肌肌纤维上见有呈AchE阳性的运动终板和神经纤维。　 结论　异种神经脱细胞移植物桥接大鼠坐骨神经缺损具有促进其再生的作用。     

转化生长因子β1对坐骨神经移植后免疫耐受的影响

背景：转化生长因子β1是一种强效细胞生长增殖调节蛋白,在移植免疫的抗排斥反应、移植物血管病发展中扮演重要角色。 目的：观察经冷冻处理异体神经移植后，局部注射转化生长因子β1对移植免疫排斥反应的影响。 设计、时间及地点：随机对照动物实验，于2007-06/2008-06在哈尔滨医科大学动物实验中心完成。 材料：受体为清洁级SD大鼠60只，分为3组：自体神经移植组、异体神经移植组、转化生长因子β1质粒+异体神经移植组，每组20只。供体为40只Wistar雄性大鼠。pAdTrack-CMV-TGF-β1质粒、pAdEasy-1-Bj51833细胞由哈尔滨医科大学附属四院骨科实验室惠赠。 方法：取供体大鼠40只作双侧股后外侧纵切口,分离显露坐骨神经,切取双侧整段坐骨神经,置于无菌冷冻管中保存1周,备用。手术显微镜下将受体鼠自骨二头肌与半腱肌和半膜肌间隙剪开结缔组织，显露坐骨神经，从犁状肌孔下0.5 cm处整齐剪下长约1 cm的坐骨神经。自体神经移植组、异体神经移植组选择粗细相等、已预制冷冻的自体及异体神经移植；转化生长因子β1质粒+异体神经移植组异体神经移植后于大鼠局部肌肉及神经两断端内注射pAdTrack-CMV-TGF-β1质粒40 μg/只。 主要观察指标：术后3，6，9周各组大鼠运动神经传导速度、病理学和轴突计数检查。 结果：转化生长因子β1质粒+异体神经移植组运动神经传导速度高于新鲜异体神经移植组(P < 0.01)，与自体神经移植组比较差异无显著性意义。自体神经移植组、转化生长因子β1质粒+异体神经移植组术后9周轴突计数较新鲜异体神经移植组高(P < 0.01)。转化生长因子β1质粒+异体神经移植组光镜及电镜可见神经纤维走行正常，排列完好，神经纤维可见血管增生，髓鞘结构较好，神经纤维内见有大量再生髓鞘，许旺细胞明显增多，胞质较发达，大量粗面内质网，线粒体结构清晰，再生的轴突内微丝密集排列，与自体神经移植组接近。异体神经移植组光镜及电镜可见神经纤维数量少、排列紊乱，髓鞘轴突变性明显，大部分神经纤维脱髓鞘崩解，轴突消失，未见再生的神经纤维。 结论：局部注射转化生长因子β1质粒联合冷冻处理的冷藏异体神经移植可以协同减轻移植后产生的免疫排斥反应。     

骨髓间充质细胞构建组织工程神经修复坐骨神经缺损

背景：许旺细胞是周围神经组织工程的种子细胞,但体外分离、培养、纯化许旺细胞较困难。脱细胞同种异体神经移植物具有较强的修复外周神经缺损的能力,且可诱导骨髓间充质细胞分化为类许旺细胞,理论上骨髓间充质细胞可替代许旺细胞作为种子细胞应用于周围神经组织工程。 目的：观察骨髓间充质细胞构建组织工程神经修复坐骨神经缺损的效果,评估骨髓间充质细胞作为种子细胞修复周围神经缺损的可行性。 设计、时间及地点：随机对照动物实验,于2008-07/12在大理学院基础医学院实验室完成。 材料：将30只SD大鼠按随机数字表法分为3组,每组10只。骨髓间充质细胞+异体移植组将骨髓间充质细胞复合脱细胞同种异体神经移植物培养的组织工程神经与两断端用10/0 无创线端端吻合;异体移植组将脱细胞同种异体神经移植物桥接;自体移植组将切断的坐骨神经旋转180°端端吻合。 方法：运用骨髓间充质细胞构建的组织工程神经修复大鼠10 mm坐骨神经缺损,移植后12周通过坐骨神经功能指数、腓肠肌湿质量恢复率、S-100免疫组织化学染色、电镜等方法观察移植物修复效果。 主要观察指标：复合物培养时观察细胞形态的变化;移植后观察坐骨神经功能指数及腓肠肌湿质量恢复率;通过甲苯胺蓝染色观察新生髓鞘形成和轴突生长及神经纤维的分布情况,结合透射电镜及S-100蛋白免疫组织化学染色,观察许旺细胞生长和神经纤维再生情况。 结果：坐骨神经功能指数及腓肠肌湿质量恢复率的检测结果显示骨髓间充质细胞+异体移植组优于异体移植组(P < 0.05)。骨髓间充质细胞+异体移植组复合物中S-100的表达明显高于异体移植组,有髓神经纤维数量、有髓纤维直径和髓鞘厚度均大于异体移植组(P < 0.05),修复效果接近自体移植组。 结论：骨髓间充质细胞构建的组织工程神经修复周围神经缺损的效果优于单纯的脱细胞同种异体神经移植物,骨髓间充质细胞作为种子细胞在周围神经组织工程中具有较强的应用价值。     

Interfascicular suture with nerve autografts for median, ulnar and radial nerve lesions

Interfascicular nerve suture with autografts is the operation of choice for repairing peripheral nerve injuries because it ensures more precise alignment of the fasciculi and so better chances of reinnervation of the sectioned nerve. The procedure as described by Millesi et al has been used at the Istituto Neurologico di Milano in 30 patients with traumatic lesions of the median, ulnar and radial nerves. All have been followed up for 2 to 7 years since operation. The results obtained are compared with those of other series obtained with interfascicular suture and with epineural suture. Microsurgery is essential. The best time to operate is discussed.

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Sommario La sutura nervosa interfascicolare con innesti autoplastici è la tecnica di elezione per ripara le lesioni traumatiche dei nervi periferici, dato che essa garantisce un più preciso allineamento dei fascicoli e quindi una maggiore possibilità di reinnervazione del moncone periferico. Questa tecnica, come è stata descritta da Millesi, è stata adottata all'Istituto Neurologico di Milano in 30 pazienti, affetti da lesioni traumatiche dei nervi mediano, ulnare e radiale. Tutti i pazienti sono stati controllati a distanza di tempo variabile da due a sette anni dall'intervento. I risultati ottenuti sono paragonati a quelli di altre casistiche, ottenuti sia con la tecnica della sutura interfascicolare che con la sutura epineurale; viene anche discussa la tecnica microchirurgica e il momento ottimale per l'intervento.

     

Changes in nerve microcirculation following peripheral nerve compression

Following peripheral nerve compression, peripheral nerve microcirculation plays important roles in regulating the nerve microenvironment and neurotrophic substances, supplying blood and oxygen and maintaining neural conduction and axonal transport. This paper has retrospectively analyzed the articles published in the past 10 years that addressed the relationship between peripheral nerve compression and changes in intraneural microcirculation. In addition, we describe changes in different peripheral nerves, with the aim of providing help for further studies in peripheral nerve microcirculation and understanding its protective mechanism, and exploring new clinical methods for treating peripheral nerve compression from the perspective of neural microcirculation.     

Anatomical feasibility of vagus nerve esophageal branch transfer to the phrenic nerve

This study measured the vagus and phrenic nerves from 12 adult cadavers. We found that the width and thickness of the vagus and phrenic nerves were different in the chest. The distance from the point of the vagus nerve and phrenic nerve on the plane of the inferior border of portal pulmonary arteries (T point) was approximately 7 cm to the diaphragm and was approximately 10 cm to the clavicle level. The number of motor fibers in the vagus nerves was 1 716 ± 362, and the number of nerve fibers was 4 473 ± 653. The number of motor fibers in the phrenic nerves ranged from 3 078 ± 684 to 4 794 ± 638, and the number of nerve fibers ranged from 3 437 ± 642 to 5 071 ± 723. No significant difference was found in the total number of nerve fibers. The results suggest that width, thickness, and total number of nerve fibers are similar between the vagus and phrenic nerves, but the number of motor fibers is different between them.     

The role of vascularization in nerve regeneration of nerve graft

Vascularization is an important factor in nerve graft survival and function. The specific molecular regulations and patterns of angiogenesis following peripheral nerve injury are in a broad complex of pathways. This review aims to summarize current knowledge on the role of vascularization in nerve regeneration, including the key regulation molecules, and mechanisms and patterns of revascularization after nerve injury. Angiogenesis, the maturation of pre-existing vessels into new areas, is stimulated through angiogenic factors such as vascular endothelial growth factor and precedes the repair of damaged nerves. Vascular endothelial growth factor administration to nerves has demonstrated to increase revascularization after injury in basic science research. In the clinical setting, vascularized nerve grafts could be used in the reconstruction of large segmental peripheral nerve injuries. Vascularized nerve grafts are postulated to accelerate revascularization and enhance nerve regeneration by providing an optimal nutritional environment, especially in scarred beds, and decrease fibroblast infiltration. This could improve functional recovery after nerve grafting, however, conclusive evidence of the superiority of vascularized nerve grafts is lacking in human studies. A well-designed randomized controlled trial comparing vascularized nerve grafts to non-vascularized nerve grafts involving patients with similar injuries, nerve graft repair and follow-up times is necessary to demonstrate the efficacy of vascularized nerve grafts. Due to technical challenges, composite transfer of a nerve graft along with its adipose tissue has been proposed to provide a healthy tissue bed. Basic science research has shown that a vascularized fascial flap containing adipose tissue and a vascular bundle improves revascularization through excreted angiogenic factors, provided by the stem cells in the adipose tissue as well as by the blood supply and environmental support. While it was previously believed that revascularization occurred from both nerve ends, recent studies propose that revascularization occurs primarily from the proximal nerve coaptation. Fascial flaps or vascularized nerve grafts have limited applicability and future directions could lead towards off-the-shelf alternatives to autografting, such as biodegradable nerve scaffolds which include capillary-like networks to enable vascularization and avoid graft necrosis and ischemia.     

Changes in nerve fiber numbers distal to a nerve repair in the rat sciatic nerve model.

Changes in nerve fiber numbers distal to a nerve repair in the sciatic nerve of 48 rats were evaluated over a 1- to 24-month period. The results of the morphometric evaluation in the sciatic nerve distal to the nerve repair demonstrated an increase in nerve fiber counts as early as 1 month following the nerve repair. The number of nerve fibers in the distal nerve was greatest at 3 months and did not return to normal levels until 24 months. The results of this study will influence the timing of experimental studies in which nerve fiber counts are critical for evaluation, and provides a better understanding of the clinical events occurring following nerve repair.     

Dorsal nerve of the penis nerve conduction velocity: a new technique

In the evaluation of a possible peripheral neuropathic process as the etiology of erectile dysfunction, studies of the dorsal nerve of the penis may be unique in that they allow examination of the most distal segment of pudendal nerve in isolation. This study describes a new technique using a simple traction device for elongation of the penis to determine the orthodromic nerve conduction of the dorsal nerve of the penis. With stimulation at the glans, and recording at the base of the penis, the value obtained in 20 normal subjects was 36.2 +/- 3.2 m/s with an amplitude of 2.29 +/- 1.08 mV.     

Acellular nerve allografts in peripheral nerve regeneration: a comparative study

Introduction: Processed nerve allografts offer a promising alternative to nerve autografts in the surgical management of peripheral nerve injuries where short deficits exist. Methods: Three established models of acellular nerve allograft (cold‐preserved, detergent‐processed, and AxoGen‐processed nerve allografts) were compared with nerve isografts and silicone nerve guidance conduits in a 14‐mm rat sciatic nerve defect. Results: All acellular nerve grafts were superior to silicone nerve conduits in support of nerve regeneration. Detergent‐processed allografts were similar to isografts at 6 weeks postoperatively, whereas AxoGen‐processed and cold‐preserved allografts supported significantly fewer regenerating nerve fibers. Measurement of muscle force confirmed that detergent‐processed allografts promoted isograft‐equivalent levels of motor recovery 16 weeks postoperatively. All acellular allografts promoted greater amounts of motor recovery compared with silicone conduits. Conclusion: These findings provide evidence that differential processing for removal of cellular constituents in preparing acellular nerve allografts affects recovery in vivo. Muscle Nerve, 2011     

Peripheral nerve regeneration through nerve guides seeded with adult Schwann cells

A.D. Ansselin, T. Fink and D.F. Davey (1997) Neuropathology and Applied Neurobiology 23 , 387–398
Peripheral nerve regeneration through nerve guides seeded with adult Schwann cells
This study tested the usefulness of Schwann cells in the repair of a severed nerve with a biosynthetic bridge or guide. Reinforced collagen nerve guides were used to bridge an 18 mm gap in the sciatic nerve of 21 young adult rats. The animals were divided into three groups and the guides were filled with: (i) more than 0.5 × 10⁶ cultured syngeneic adult Schwann cells (group L, n = 12); (ii) less than 0.5 × 10⁶ Schwann cells (Group S, n = 6); and (iii) phosphate buffered saline (control, n = 3). Schwann cells were pre-labelled with Hoechst dye. Regeneration was assessed functionally and histologically at 1, 2, 3 and 6+ months after surgery. Group L animals showed numerous regenerated axons surrounded by implanted Schwann cells within the first month. The total number of myelinated fibres (12.5 × 10³) remained above normal unoperated values (7 × 10³) in long-term animals. Regenerated axons were found in Group S in the third month, but no Hoechst labelled cells were found. The number of myelinated fibres (3.9 × 10³) remained below normal values in long-term animals. Control guides failed to support axonal regeneration. Functional recovery was evident at week 20 (Group L) and week 30 (Group S) after surgery, with no difference in function between the two groups by the end of the study. Supplementing guides with Schwann cells enhances regeneration of peripheral axons over a distance normally prohibitive. This effect is greatest in the early stages of regeneration (1–3 months) and is dependent on the number of cells implanted.     

Evaluation of artificial nerve conduit and autografts in peripheral nerve repair in the rat model of sciatic nerve injury

Objective: To investigate the therapeutic effect of artificial nerve conduit in the sciatic nerve injury and repair in the rat model.

Methods: A total of 60 adult male Sprague Dawley rats were evenly randomized into five groups to build the model of sciatic nerve injury and perform the injury repair experiment. The five groups were: group A which was treated with artificial nerve conduit, group B which was treated with common carotid artery (CCA) autograft, group C which was treated with sciatic nerve autograft, group D which was treated with sham operation, and group E as the normal control. The injury was repaired by direct coaptation of the nerve ends. Postoperatively, the rats’ behavior, motor nerve conduction velocity (MNCV), incubation period, amplitude, remaining rate of wet weight of the gastrocnemius muscle, the diameter and section area of the gastrocnemius cell, and the histological changes were assessed. The results were analyzed by one-way ANOVA and two-way ANOVA.

Results: Twelve days postoperatively, 36 rats in groups A, B, and C presented with denervated adermotrophia on the injured ankle. The electrophysiological indicators in groups D and E were constant and similar. The values of MNCV and amplitude were group C > group A > group B, with an increasing tendency. The values of the incubation period were group C < group A < group B with statistical difference (p < 0.05) and showed a decreasing tendency. The wet gastrocnemius muscle in groups D and E showed plump morphology with luster and elasticity. Groups A and C had similar atrophic gastrocnemius muscles and reduced flexibility while the phenomena were more severe in group B. Progressive decrease of the cell diameter and sectional area was observed in groups A, B, and C. The adhesion between the sciatic nerve and the surrounding area in groups A, B, and C had statistical significance (P < 0.05), with group B the most serious.

Conclusions: The results suggest that artificial nerve conduit facilitated functional and morphological regeneration of the nerve. It seemed more effective than CCA but inferior to sciatic nerve autograft in repairing sciatic nerve injury in the rat model.