肝细胞生长因子交联于胶原导管构建神经导管用于面神经损伤修复

目的 将肝细胞生长因子(HGF)交联于胶原导管内构建神经导管,用于大鼠面神经损伤模型,观察其治疗效果。方法 购买12只雄性大鼠,将其随机分为HGF组和磷酸缓冲液(PBS)组。分离大鼠面神经颊支,剪去神经干,造成10 mm长神经缺损。术后第8周,对两组大鼠进行功能学分析和形态学观察。结果 HGF组大鼠触须运动功能显著改善,而PBS组大鼠触须运动功能没有明显变化。HGF组大鼠神经传导速度明显大于PBS组的大鼠,差别有统计学意义(P <0.01)。同时,髓鞘厚度和再生神经纤维在HGF组大鼠新生神经中显著大于PBS组(P <0.01)。结论 将HGF交联于胶原导管内构建的神经导管能有效促进面神经横断伤后功能恢复。     

听神经瘤术后面神经损伤修复的研究进展

不伴有面神经损伤的听神经瘤切除手术被认为是最难的颅内肿瘤手术之一,虽然颅内电生理监测和神经外科手术技术在不断的进步,但听神经瘤切除术后所造成的面神经麻痹仍是一个重要问题,面神经属于周围神经系统。所以本文就有关周围神经损伤后轴突与施旺细胞相互作用、生长锥的变化等神经修复机制及面神经麻痹修复的治疗的研究进展作一综述。     

骨形态发生蛋白2与壳聚糖神经支架复合体修复兔面神经损伤★

目的：应用生物可降解材料构成的导管通过载体与外源性骨形态发生蛋白（bone morphogenetic protein，BMP-2）相结合，构筑新型具有生物和人工合成材料优势的神经支架——组织工程复合体，探讨其对兔面神经损伤的修复。 方法：实验于2007-01/06在兰州大学动物实验中心完成。①自制BMP-2及壳聚糖神经支架和单纯壳聚糖神经支架。②暴露兔面神经上颊支，切除长2 mm神经，任其回缩，造成8 mm神经缺损的动物模型。③选择新西兰白兔24只，按随机数字表法分为2组，复合神经支架组和单纯壳聚糖神经支架组，每组12只。同时采用自身左右对照，设为对照组（自体神经离断后倒置，吻合于神经缺损处）。④一般观察：肉眼观察兔双侧颊肌萎缩程度及活动度。⑤形态学检查：术后16，30周，切取上颊支神经干，近侧吻合口纵切面行苏木精-伊红染色，观察神经再生情况；术后30周，透射电镜下观察再生神经超微结构；术后16，30周，用德国IBAS-I+Ⅱ型计算机图像处理系统作图像处理，计算神经纤维总数和纤维直径、轴突直径及髓鞘厚度。 结果：纳入动物24只，均进入结果分析。①大体形态：兔面神经上颊支损伤后2周面肌萎缩，复合神经支架组、单纯壳聚糖神经支架组、对照组分别于术后8，9，11周时开始逐渐恢复正常。②术后16周，单纯壳聚糖神经支架组与复合神经支架组光镜下可见神经外膜有新生血管，再生纤维呈束状分布，粗细不均匀，束间有新生血管。神经纤维排列整齐，无神经瘤形成。术后30周，光镜下可见复合神经支架组神经密集程度、血管化和髓鞘化程度优于单纯壳聚糖神经支架组。对照组形成的神经纤维束较为分散，不均匀，髓鞘处组织染色较差。③术后16,30周兔面神经再生神经图像分析结果：神经纤维的排列、血管化程度、直径和数目、髓鞘壁、轴突形状等各检测指标均优于单纯壳聚糖神经支架组。④术后30周，透射电镜下复合神经支架组神经再生超微形态学更接近对照组，优于单纯壳聚糖神经支架组。 结论：可吸收性BMP-2与壳聚糖神经支架复合体能有效地引导兔面神经再生并恢复其功能，优于单纯壳聚糖神经支架。     

槲皮素对脑卒中神经损伤修复的研究进展

槲皮素是一种在多种植物、中药材中存在的黄酮类化合物,具有抗氧化、抗炎、抗肿瘤和神经保护等药理作用。脑卒中后引发的多种继发性损伤对脑卒中的治疗有诸多不可预知的干扰。目前,多项研究表明槲皮素在脑卒中相关损伤的病理生理过程中可以起到重要的神经保护作用。本文就近年来槲皮素对脑卒中神经损伤修复的研究进行综述。     

面神经损伤大鼠脑内移植绿色荧光蛋白转基因胎鼠神经干细胞的

背景：目前面神经损伤后的修复主要集中在外周神经干,但面神经损伤后会导致部分中枢运动神经元凋亡。现阶段关于干细胞植入面神经损伤大鼠脑后对面神经核团内凋亡神经元的影响相关报道甚少。 目的：观察大鼠面神经损伤后,脑内移植绿色荧光蛋白转基因胎鼠的神经干细胞的成活和迁移情况。 设计、时间及地点：随机对照动物实验,于2008-07/12在昆明医学院神经科学研究所完成。 材料：孕14~16 d的绿色荧光蛋白转基因蛋白小鼠1只,用于制备转基因神经干细胞。清洁级SD雄性大鼠24只,随机分为3组：面神经损伤转基因细胞组12只、面神经损伤细胞培养液组6只、面神经正常转基因细胞组6只。 方法：面神经损伤转基因细胞组、面神经损伤细胞培养液组大鼠建立面神经切断模型。造模后1周,行转基因神经干细胞立体定向移植,注射点为前囟后方11.30 mm、背侧9.00 mm、正中线位置。面神经损伤转基因细胞组、面神经正常转基因细胞组各注入10 μL转基因神经干细胞悬液(含5×106 个细胞),面神经损伤细胞培养液组注入10 μL神经干细胞培养液,4周后制作脑组织冰冻切片。 主要观察指标：荧光显微镜观察移植部位绿色荧光蛋白阳性神经干细胞的存活情况,及其向损伤侧面神经核团周围迁移的情况。 结果：①移植处：面神经损伤转基因细胞组、面神经正常转基因细胞组均可见数量不等的绿色荧光蛋白阳性细胞,其中部分绿色荧光蛋白阳性细胞位于血管内;面神经损伤细胞培养液组未见绿色荧光蛋白阳性细胞。②面神经核团周围：仅面神经损伤转基因细胞组可见数量不等的绿色荧光蛋白阳性细胞迁移于损伤侧面神经核团周围,而健侧面神经核周围未见绿色荧光蛋白阳性细胞;余2组双侧面神经核周围均未见绿色荧光蛋白阳性细胞。③移植处与面神经核团周围之间：未见绿色荧光蛋白阳性细胞相连。 结论：神经干细胞移植入面神经损伤大鼠脑内后,可以向损伤侧面神经核周围迁移。     

FK506在神经损伤修复中的应用研究进展

FK506作为强效免疫抑制剂在临床上已得到广泛应用.而随后的研究发现FK506还具有神经损伤修复的促进作用,如今对神经损伤修复的促进作用是FK506研究的热点之一.本文从FK506对于神经损伤修复相关细胞的不同作用、对于不问类型神经损伤的作用、剂量效应、FK506应用中存在的缺陷等方面对其研究现状进行简要综述.FK506,又称他克莫司,1984年被发现于链霉菌属,是一种大环内酯类抗生素.作为一种FDA批准的强效免疫抑制剂,其效力是环孢霉素A(Ciclosporin A,CsA)的10～100倍,广泛应用于预防同种异体肾、肝,心、骨髓等器官或组织移植所产生的排斥反应.     

干细胞联合组织工程学在周围神经损伤中的研究进展

周围神经损伤主要包括直接外力引起的损伤和继发性的血管缺血性损伤,如创伤、炎症、肿瘤压迫、感染或手术操作等。对于无间隙且两端无明显张力的神经断伤,直接缝合是首选的治疗方法;对于神经缺损性损伤,临床上的治疗金标准是自体神经移植。然而,自体神经移植不仅在神经选取上具有局限性,同时还不可避免地造成其他正常功能的损伤[1]。     

胶质细胞与神经损伤修复

中枢神经损伤后的再生问题一直是神经科学界的一个重大难题。胶质细胞作为神经细胞的一种辅助成分 ,历来在中枢神经系统发育及损伤修复中倍受重视。近来 ,胶质细胞通过合成分泌胶质源性神经营养因子 (glial cell ling- derived neurotrophic factor,GDNF)进而参与损伤修复 ,结果将胶质细胞在神经损伤修复中的作用推上了一个新的历史舞台。本文就胶质细胞与神经损伤修复的关系进行简要概述。1 .神经损伤后胶质细胞的形态学变化目前 ,关于神经损伤后胶质细胞的形态学改变文献已有不少报导。 Eriksson[1] 切断大鼠右侧坐骨神经及眶下神经 ,术…     

神经甾体对中枢神经损伤修复的研究进展

神经甾体包括孕烯醇酮、孕酮、别孕烯醇酮、脱氢表雄酮等,存在于中枢和外周神经系统,由胆固醇或其前体在相应酶的作用下在神经系统内合成。近来的研究认为其对减轻中枢神经损伤后的炎症及水肿,减少神经元细胞的凋亡,促进少突胶质前体细胞的发生、分化、增殖及髓鞘再生等方面发挥重要作用,可能成为甲基强的松龙的一种替代选择。而目前对其临床阶段的应用,有一些关键问题尚存在争论。     

神经细胞黏附分子在神经损伤及修复中的研究进展

神经细胞黏附分子是一种主要表达于神经系统的细胞表面糖蛋白.近年来发现,它在神经损伤及修复过程中发挥了重要作用,主要表现为促进神经细胞间的黏附、促进神经芽生及轴突生长、促进髓鞘形成与再生、参与突触可塑性等.因此,它在脊髓损伤、外周神经再生、难治性癫痫、局限性肌张力障碍等多种神经系统疾病的发生与发展以及潜在治疗应用中受到越来越多的关注.     

面神经损伤的修复机制研究

面神经是极易受损的颅神经,外伤、手术操作、炎症或肿瘤等均可造成它的损伤。至今对于修复和重建受损神经的技术并未达到令人满意的地步,其中一个主要原因是神经修复及再生生物学机制尚未完全清楚。最新文献表明,神经损伤后的修复不仅与神经细胞自身密切相关,而且周围非神经细胞也参与了神经组织的再生。本文旨在综述近年来这方面的实验研究进展。     

大鼠面神经切断和切断修复后面神经核内鞘脂激活蛋白原的变化

BACKGROUND： Studies have demonstrated that damaged facial nerves synthesize prosaposin to promote repair of facial neurons. OBJECTIVE： To observe time-course changes of prosaposin expression in the facial nerve nucleus of Sprague Dawley rats following facial nerve transection and repair. DESIGN, TIME AND SETTING： A randomized control neuropathological animal experiment was performed in Chongqing Medical University between March 2007 and September 2008. MATERIALS： A total of 48 adult, male, Sprague Dawley rats were selected and randomly divided into transection and transection ＋ end-to-end anastomosis groups （n =24）. Rabbit anti-rat prosaposin antibody, instant SABC immunohistochemical kit, and antibody dilution solution were purchased from Wuhan Uscn Science Co., Ltd., China. METHODS： In the transection group, the nerve trunk of the distal retroauricular branch of the left facial nerves was ligated in Sprague Dawley rats, and a 5-mm nerve trunk at the distal end of the ligation site was removed. In the transection ＋ end-to-end anastomosis group, epineurial anastomosis was performed immediately following transection of the left facial nerves. The right facial nerves in the two groups served as the normal control group. MAIN OUTCOME MEASURES： The number of prosaposin-positive neurons, as welt as intensity of immunostaining in facial nerve nucleus, following transection and end-to-end anastomosis were determined by immunohistochemistry at 1, 3, 7, 14, 21, and 35 days after injury. RESULTS： Transection group： transection of facial nerves resulted in increased number of prosaposin-positive neurons and immunoreactivity intensity in the facial nucleus on day 1. These values significantly increased by day 3. Expression was greater than in the control side. The peak of the reduction was reached at 7 days post-surgery. Transection ＋ end-to-end anastomosis group： the number of prosaposin-positive neurons and immunoreactivity intensity was reduced in the facial nerve nucleus following immediate end-to-end anastomosis on day 7 post-surgery. These values began to gradually increase by day 14 post-anastomosis. By day 35 post-anastomosis, the number of prosaposin-positive neurons in the operated side recovered to normal levels. The number of prosaposin-positive neurons, as well as immunoreactivity intensity, was significantly greater in the facial nerve nucleus, compared with the transection group on days 14, 21, and 35 post-surgery （P 〈 0.05）. The rhythmic whisking of vibrissa recovered, and recovery time was consistent with increased numbers of prosaposin-positive neurons. CONCLUSION： Within 7 days after injury, prosaposin expression in the facial nerve nucleus exhibited an initial increase, followed by a decrease, and was not affected by facial nerve repair. Following facial nerve damage, neural anastomosis was shown to increase prosaposin expression in the facial nerve nucleus after 14 days. Recovery of prosaposin occurred simultaneously with reinnervation.     

Amniotic membrane covering for facial nerve repair

Amniotic membranes have been widely used in ophthalmology and skin injury repair because of their anti-inflammatory properties. In this study, we measured therapeutic efficacy and determined if amniotic membranes could be used for facial nerve repair. The facial nerves of eight rats were dissected and end-to-end anastomosis was performed. Amniotic membranes were covered on the anastomosis sites in four rats. Electromyography results showed that, at the end of the 3 rd and 8 th weeks after amniotic membrane covering, the latency values of the facial nerves covered by amniotic membranes were significantly shortened and the amplitude values were significantly increased. Compared with simple facial nerve anastomosis, after histopathological examination, facial nerve anastomosed with amniotic membrane showed better continuity, milder inflammatory reactions, and more satisfactory nerve conduction. These findings suggest that amniotic membrane covering has great potential in facial nerve repair.     

Changes in a rat facial muscle after facial nerve injury and repair

This study describes changes in a rat facial muscle innervated by the mandibular and buccal facial nerve branches 4 months after nerve injury and repair. The following groups were studied: (A) normal controls; (B) spontaneous reinnervation by collateral or terminal sprouting; (C) reinnervation after surgical repair of the mandibular branch; and (D) chronic denervation. The normal muscle contained 1200 exclusively fast fibers, mainly myosin heavy chain (MyHC) IIB fibers. In group B, fiber number and fiber type proportions were normal. In group C, fiber number was subnormal. Diameters and proportions of MyHC IIA and hybrid fibers were above normal. The proportion of MyHC IIB fibers was subnormal. Immediate and delayed repair gave similar results with respect to the parameters examined. Group D rats underwent severe atrophic and degenerative changes. Hybrid fibers prevailed. These data suggest that spontaneous regeneration of the rat facial nerve is superior to regeneration after surgical repair and that immediacy does not give better results than moderate delay with respect to surgical repair. Long delays are shown to be detrimental.     

Chitosan conduits combined with nerve growth factor microspheres repair facial nerve defects

Microspheres containing nerve growth factor for sustained release were prepared by a compound method, and implanted into chitosan conduits to repair 10-mm defects on the right buccal branches of the facial nerve in rabbits. In addition, chitosan conduits combined with nerve growth factor or normal saline, as well as autologous nerve, were used as controls. At 90 days post-surgery, the muscular atrophy on the right upper lip was more evident in the nerve growth factor and normal sa- line groups than in the nerve growth factor-microspheres and autologous nerve groups. Electro- physiological analysis revealed that the nerve conduction velocity and amplitude were significantly higher in the nerve growth factor-microspheres and autologous nerve groups than in the nerve growth factor and normal saline groups. Moreover, histological observation illustrated that the di- ameter, number, alignment and myelin sheath thickness of myelinated nerves derived from rabbits were higher in the nerve growth factor-microspheres and autologous nerve groups than in the nerve growth factor and normal saline groups. These findings indicate that chitosan nerve conduits com- bined with microspheres for sustained release of nerve growth factor can significantly improve facial nerve defect repair in rabbits.     

The development of synkinesis after facial nerve paralysis

In this study, the development of clinical synkinesis after facial nerve paralysis (FP) and its relationship to electrophysiological findings were investigated. Thirty-four patients who were examined within the first 5 days after onset of FP and who could also be followed up for at least 4 months were included in the study. Electrophysiological investigations consisted of: (1) recording of the direct responses by facial nerve stimulation at the stylomastoid fossa; (2) recording of the 'synkinetic spread' of the supraorbital nerve reflex to the lower facial muscles; (3) recording of the 'lateral spread responses' by stimulating the mandible and zygomatic branches of the facial nerve. Clinical synkinesis developed in 14 of 18 patients (78%) with a direct response ratio (DRr) of less than 40%. Among the 16 patients with a DRr of 40% or more, synkinesis was observed in 3 cases (18.7%) only. The DRr provided reliable information concerning the development of synkinesis. Forty percent seemed to be a reasonable limit to distinguish the high-risk group for the development of clinical synkinesis.     

Contralateral trigeminal nerve lesion reduces polyneuronal muscle innervation after facial nerve repair in rats

Functional recovery after facial nerve surgery is poor. Axotomized motoneurons (hyperexcitable upon intracellular current injections, but unable to discharge upon afferent stimulation) outgrow supernumerary branches which are misrouted towards improper muscles. We hypothesized that alterations in the trigeminal input to axotomized electrophysiologically silent facial motoneurons might improve specificity of reinnervation. To test this we compared, in the rat, behavioural, electrophysiological, and morphological parameters after transection and suture of the buccal facial nerve (buccal-buccal anastomosis, BBA) with those after BBA plus excision of the ipsi- or contralateral infraorbital nerve (ION). After BBA, the mystacial vibrissae dropped and remained motionless until 18-21 days post operation (days PO). After BBA plus ipsilateral ION excision, there was no recovery of vibrissae whisking at all. Following BBA plus contralateral ION excision, full restoration of whisking occurred at 7-10 days PO. Electromyography of whiskerpad muscles showed normal waveform and amplitude was also most rapidly restored after BBA plus contralateral ION excision. Neuron counts after retrograde tracing showed that the intact buccal nerve contained axons of the superior (91%) and inferior (9%) buccolabial nerves. After BBA, the superior nerve comprised 56%, the inferior 21%, and 23% of the motoneurons projected within both nerves. After BBA plus ipsilateral ION excision, misdirection worsened and values changed to 48, 39 and 13%, respectively. After BBA plus contralateral ION excision, portions improved to 69, 23 and 8%. We conclude that, by reducing the redundant axon branching, lesion of contralateral ION provides the best conditions for recovery of vibrissae rhythmical whisking after reconstructive surgery on the facial nerve.