神经营养素4在面神经的转运研究

目的　探讨面神经再生微环境及神经营养素 4(NT- 4)对神经细胞的作用。方法　将新西兰兔一侧面神经干横断后置入硅胶再生室 ,再将 1 3 1 I- NT- 4(10μl/只 ,约 7.4MBq)注入其再生室。另取 1只家兔分别在注药后不同时刻行头部冠状位平面显像 ,其余取面神经干、脑干和对侧面神经干 ,利用放射性核素示踪技术测定 NT- 4在面神经的转运情况。另取 1只置入再生室的兔 ,同时在再生室注入 1m g脑源性神经营养因子 (BDNF)和7.4MBq1 3 1 I- NT- 4后 ,不同时刻行头部冠状位平面显像。结果　注药后 4小时就有 5 .0 8%的 1 3 1 I- NT- 4转运到面神经干中 ,8、12小时达高峰 ,分别为 2 0 .5 8%和 2 2 .74% ;8小时有 34 .75 %转运至脑干 ,12小时转运至脑干的量达45 .5 7% ,且 1 3 1 I- NT- 4在面神经的转运受 BDNF的明显抑制。结论　 NT- 4在面神经中存在受体介导逆行转运     

神经营养素在神经系统中的逆行转运

神经营养因子是指一组能对中枢和周围神经发挥营养作用的非常规营养物质 ,其成分为蛋白或小分子多肽〔1〕,大致可分为神经细胞因子类和神经营养素类。神经营养素类包括神经生长因子 (NGF) ,脑源性神经营养因子 (BDNF) ,神经营养素 3(NT- 3) ,神经营养素 4(NT- 4 ) ,神经营养素 6 (NT- 6 )。神经营养素通常来源于远离其作用部位神经细胞体的靶组织如肌肉、皮肤、血管内皮等处以及雪旺细胞。神经营养素的生物学效应 :与作用于其他类型细胞生长因子相比 ,神经营养素作用有两个明显特征 ,一是调节不同的神经元功能引起生长而非增殖 ,二是…     

NT-3、NT-4和BDNF在面神经逆行转运的动力学比较

目的　研究神经营养素 3(NT- 3)、神经营养素 4(NT- 4)和脑源性神经营养因子 (BDNF)在面神经中的逆行转运动力学特点。方法　将新西兰兔一侧面神经干横切断后置入硅胶再生室 ,再将 1 2 5I标记的 NT- 3或NT- 4或 BDNF或人血清白蛋白 (HSA) (10μl/只 ,约 3.7MBq)注入再生室 ,在注药后于不同时刻取兔面神经干和脑干面神经运动核 ,测定其摄取率。利用 3P87动力学处理程序分析计算各标记物在面神经的动力学参数。结果　面神经逆行转运神经营养素的转运量 :NT- 3>BDNF>NT- 4(P <0 .0 5 ) ,转运速率 :NT- 4>NT- 3>BDNF (P <0 .0 5 )。结论　研究结果提供了神经营养素在面神经逆行转运的动力学特点。     

NT—3、NT—4和BDNF在面神经逆行转运的动力学比较

OBJECTIVE: To compare the kinetic characters of retrograde transport of neurotrophin-3 (NT-3), neurotrophin-4 (NT-4) and brain-derived neurotrophin factor (BDNF) in facial nerve. METHODS: Radioactive tracer technique was used. After one lateral facial nerve trunk of adult rabbit was transected, a silicone chamber was inserted between the stumps, and 3.7 MBq of 125I-NT-3 or 125I-NT-4 or 125I-BDNF or 125I-HSA was administered into the chamber. At different time-points after injection, the facial nerve trunk and facial nerve motor neurone of brain-stem were collected and the uptake rates were measured. The kinetic parameters of each labeled compound were calculated using 3P87 program of kinetics. RESULTS: The transport amount of neurotrophin retrogradely transported by facial nerve is NT-3 > BDNF > NT-4 (P < 0.05), the transport rate is NT-4 > NT-3 > BDNF (P < 0.05). CONCLUSION: The findings could serve as the kinetic characters of retrograde transport of neurotrophins.     

神经营养素-4及其受体的研究进展

神经营养素-4(NT-4)作为神经营养素家族的新成员,与其他家族成员-神经生长因子(NGF),脑源性神经生长因子(BDNF),神经营养素-3(NT-3),神经营养素-5(NT-5),神经营养素-6(NT-6)一起对神经元的生存及发育起重要作用。近来的研究结果显示,它在基因结构,氨基酸序列,生理功能等方面与其他家族成员相比有进化的保守性,又有自己进化的特殊性。它在哺乳动物体内有广泛表达,通过低亲和力NGF受体(P75~(LNCFR)),高亲和力trkA受体,高亲和力trkB受体发挥作用。NT-4在神经退行性疾病中的临床应用价值也在研究中。     

神经营养素和面神经损伤临床研究

神经营养素(neurotrophins,NTs)是一类分子量相等、具有高度同源性的一类神经营养因子.许多资料表明,在中枢与外周神经系统,NTs能提高损伤后神经元的存活率,促进外周神经纤维的生长及再生.本文从NTs的受体特性、受体在面神经损伤后的表达和NTs 对受损后面神经的作用及机制进行了综述.     

人神经营养素-4的克隆及其在原核细胞的表达

目的：体外扩增人神经营养素－４（ＮＴ－４）基因,经克隆后在原核细胞中表达并鉴定人重组ＮＴ－４,为研究其生物学特性及临床应用奠定基础。方法：以人类基因组ＤＮＡ为模板,扩增ＮＴ－４成熟活性蛋白ＤＮＡ编码序列,将此ＤＮＡ片段克隆到载体ＰＢＶ２２０中,对重组质粒进行ＰＣＲ筛选和限制性酶切分析,确定后将该重组质粒转化到大肠杆菌ＤＨ５α进行诱导表达。用抗ＮＴ－４抗体进行Ｗｅｓｔｅｒｎ ｂｌｏｔ鉴定重组蛋白。结果：体外成功扩增ＮＴ－４基因,转染的大肠杆菌经诱导后表达出能被抗ＮＴ－４抗体识别的重组蛋白,其表达量为１５％。结论：在原核细胞能成功表达ＮＴ－４。     

人神经营养素-4基因的克隆及表达

目的 通过基因工程的方法扩增人神经营养素-4(hNT-4)cDNA,在大肠杆菌中表达hNT-4,为研究hNT-4的生物学作用提供材料.方法 以人胎脑RNA为模板,采用RT-PCR技术扩增hNT-4 cDNA,将其插入的质粒pGEM-T中.将经过序列分析确定的hNT-4 cDNA插入原核表达载体pGEX-6p-1中,构建重组表达载体pGEX-6p-1-NT-4,用SDS-PAGE法测定融合蛋白在大肠杆菌中的表达.结果 经序列测定分析,克隆的hNT-4 cDNA核苷酸序列与已发表序列(GenBank,M86528)完全一致,并获得了高效表达hNT-4的重组菌株.结论 体外成功扩增hNT-4 cDNA,并在原核细胞中高效表达了hNT-4.     

人神经营养素4治疗大鼠坐骨神经损伤效果观察

目的观察人神经营养素4在受损坐骨神经恢复和再生过程中的作用,为临床治疗提供参考。方法Wistar大鼠38只,随机均分2组,常规麻醉处理建立坐骨神经损伤模型,实验组局部注射人神经营养素4,对照组注射等量生理盐水。术后第4周、第20周观察两组肢体一般状况、神经功能指数、及腓肠肌中段组织学观察肌组织间质,胶原纤维,肌细胞,肌纤维密度、肌纤维直径。结果在20周后,对照组腓肠肌萎缩明显;实验组肢恢复一定行动能力,腓肠肌萎缩不明显;在第20周以后,实验组神经功能指数、肌纤维密度、肌纤维直径大于对照组;组织学观察在第20周以后,对照组肌组织间质水肿,胶原纤维排列稀疏、溶解,细胞萎缩较为明显,实验组肌纤维呈圆形或多边形,肌原纤维呈红色点状,核位于边缘,呈圆形。结论神经营养素-4对于大鼠坐骨神经损伤具有一定的修复作用,不仅能恢复由于坐骨神经损伤导致的运动功能障碍,还能修复坐骨神经对于骨骼肌的神经营养作用。     

神经营养素3及其受体在哮喘大鼠肺组织中的表达

目的研究神经营养素3(NT-3)及其受体酪氨酸激酶C(TrkC)和p75神经营养素受体(p75NTR)在哮喘大鼠肺组织中的表达情况。方法将28只4～6周龄的SD大鼠随机分为分为哮喘组(n=16)(以卵蛋白致敏和激发建立大鼠哮喘模型)和正常对照组(n=12)。取两组大鼠的肺组织制作病理切片,HE染色后光学显微镜下观察支气管和肺组织的病理学特征。采用Real-Time PCR技术检测两组大鼠肺组织中NT-3、TrkC和p75NTR mRNA的表达,并分析三者之间的相关性。结果光学显微镜观察发现:哮喘组大鼠支气管壁周围有较多淋巴细胞和嗜酸性粒细胞浸润,可见支气管气道上皮脱落、杯状细胞增生及黏液栓增多等变化;正常对照组大鼠支气管及肺泡结构未见明显异常。哮喘组大鼠肺组织中NT-3、TrkC和p75NTR mRNA的相对表达量均显著高于正常对照组,差异有统计学意义(P0.05)。相关性分析结果显示:NT-3 mRNA与TrkC mRNA的表达、NT-3mRNA与p75NTR mRNA的表达以及TrkC mRNA与p75NTR mRNA的表达均呈正相关(r分别为0.89、0.90和0.82,均P0.01)。结论致敏哮喘大鼠肺组织内NT-3 mRNA表达水平升高。NT-3通过上调TrkC和p75NTR mRNA的表达,增强NT-3的功能效应,三者共同参与了哮喘气道神经源性炎症的发生。     

术中放疗对面神经轴浆运输影响的实验研究

目的:探讨术中放疗对面神经轴浆运输的影响.方法:制作术中放射预防剂量13 Gy治疗刑量15 Gy、组织细胞坏死剂量17 Gy动物模型,测量兔面神经放射损伤后不同距离段的放射活性及同一距离段不同剂量、不同时期放射活性变化的脉冲值.结果:各组面神经轴浆转运蛋白放射活性脉冲值随距近心端的增加而下降,且实验组都低于对照组;在同一神经段的脉冲值:13 Gy组和15 Cy组术后能恢复(P＞0.05),17 Cy组术后未能恢复(P＜0.01).结论:术中放疗影响神经轴浆运输,预防剂量及治疗剂量不影响面神经功能恢复.     

神经导航下经岩骨幕上下联合入路中面神经管的解剖研究

OBJECTIVE: To study the value of neuronavigation in the transpetroal approach, and to provide anatomic data for the protection of the nerves in the facial nerve canal (FNC) during surgeries. METHODS: Simulated surgery through the transpetroal approach was performed on 16 sides of 8 adult cadaver heads with the assistance by neuronavigation. The anatomy of the facial nerve and the relationship of related structures were observed and the distances from the utmost external edge of the mastoid to different segments of the FNC were measured. RESULTS: Neuronavigation was successful with all the FNC, with the mean error of less than 0.9 mm. The FNC could be divided into 3 segments, the labyrinthine, the tympanic and the mastoid segments, stretching 3.6+/-1.2 mm, 11.2+/-2.5 mm and 16.1+/-3.6 mm respectively and with diameters of 1.2+/-0.3 mm, 1.4+/-0.1 mm and 1.7+/-0.2 mm, respectively. CONCLUSION: Neuronavigation may help protect the FNC during surgical procedures, and a thorough knowledge of the anatomic features of the FNC can be significant for preservation of the facial nerves.     

面神经ENoG和EMP检查在面肌麻痹诊断及预后方面的应用

Electroneurography (ENoG), an objective electrophysiologic measurement of compound muscle action potentials (CMAPs), is used to assess the integrity of a peripheral motor nerve. This method has been used for many years. In our study using an electrophysiologic instrument (Medelec MS6), the stimulating electrode was placed over the facial nerve anterior to the tip of the mastoid process and was manipulated to obtain the maximum CMAPs amplitude from the frontal muscle. With 30 normal subjects and 20 patients with facial nerve palsy, the results showed that the latencies and amplitudes were different between the two groups. Motor evoked potential (MEP) is a new method. Ipsilateral facial muscles are excited by magnetic stimulation over the scalp when the coil is placed over the parieto-occipital region. Using a magnetic stimulator and EMG instrument (1500C4 DISA), CMAPs from the orbicularis oris and frontal muscle were measured. In 30 normal subjects, the CMAPs were similar in form but of longer latency than those obtained with electrical stimulation (ENoG). In 20 patients with lateral facial nerve palsy due to Bell's palsy, Hunt's syndrome or trauma, the latencies on the lesion sides were apparently longer and the amplitudes much lower than in the normals. Our studies suggest that magnetic stimulation will detect facial nerves in the region inside the temporal bone where they cannot be touched by electrical stimulation from in front of mastoid process. The use of both ENoG and MEP methods together allows for accurate measurement of proximal facial nerve conduction and also provides some quantitative measurement: thus, we can detect conduction block or axonal degeneration early.(ABSTRACT TRUNCATED AT 250 WORDS)     

面神经超兴奋性的临床和实验研究

目的:研究面神经麻痹、面神经超兴奋性的临床表现、意义及产生机制。方法:应用神经兴奋性测试仪测试100名正常人面神经兴奋性阈值的范围,并与190例面神经麻痹患者的兴奋性测试结果对照。制作豚鼠面神经麻痹试验模型,应用诱发肌电图测试肌动电位,透射电镜观测神经纤维髓鞘的改变。比较超兴奋性组及非超兴奋性组的临床治愈天数。结果:正常人双侧面神经兴奋性阈值的范围为1.72~-1.57 mA,190例面神经麻痹中29例面神经呈超兴奋性。超兴奋性组临床治愈平均需(3.4±6.0)d,非超兴奋性组临床治愈平均需(42.6±11.2)d,两组差异有统计学意义(P<0.01)。23只豚鼠中,8只面神经压迫后阈值比压迫前下降,呈超兴奋性,电镜下可见神经纤维髓鞘板层轻度开离。结论:面神经麻痹呈面神经超兴奋性者预后良好。呈现超兴奋性与髓鞘板层开离及与使神经兴奋性增强的离子浓度增加有关。     

Prevention of the zygomatic branch of the facial nerve in rhytidectomy: an anatomical study]

OBJECTIVE: To investigate the anatomical distribution of the zygomatic branch of the facial nerve and discuss its clinical significance in the rhytidectomy. METHODS: The distribution of the zygomatic branch of the facial nerve was observed on 30 halves of the fifteen candaveric specimens (10 antiseptic cadaveric specimens and 5 fresh cadavers). RESULTS: The zygomatic branch made its way through the upper or the anterior border of the parotid gland, giving rise to 2 or 3 rami, which could be divided into the superior and the inferior rami. The superior rami, which were thin and superficial, crossed the zygomatic arch at its inner one-third or ran along the inferior margin of the zygomatic arch, and then entered beneath the zygomatic ligaments. The inferior rami were comparatively thick and deep, lying 1.0+/-0.3 cm inferior to the superior rami. The inferior and superior rami joined each other on the surface and deep side of the zygomatic major muscle. CONCLUSION: In the prevention of the zygomatic branch damage in rhytidectomy, the areas where caution should taken were the anterior border of the zygomatic major muscle in sub-SMAS dissection and the zygomatic arch in the subperiosteal dissection. The sharp dissection and excess tension should be avoided to reduce the nerve injury.     

颞骨骨折性面瘫手术减压时机的实验研究

目的制作颞骨骨折性面瘫的动物模型，初步探讨大鼠面瘫的自然发展过程，了解不同手术减压时机面瘫的治疗效果及减压后面瘫的恢复变化过程。方法选用Wistar大鼠32只，制作颞骨骨折性面瘫动物模型。将完全面瘫的大鼠随机分成4组：对照组即不减压组，2周减压组，4周减压组，8周减压组。分别于以上不同的时间行面神经减压术，并于不同时间测定面神经刺激阈值，以观察面神经的恢复情况。结果对完全面瘫的大鼠于面瘫后1周行面神经阈值检查，对最大电流刺激（3mA）无反应。4组大鼠面神经刺激阈值的恢复速度相比，2周、4周减压组比不减压组及8周减压组快；2周减压组面神经的恢复速度比4周减压组快。结论通过血管钳钳夹大鼠的面神经骨管，可以造成颞骨骨折性面瘫的大鼠模型。面神经减压术在面神经受损后4周内进行，可缩短其面神经阈值的恢复时间；且减压时间越早，面神经的恢复速度越快。     

面神经瘤误诊18例的回顾性分析

 目的   提高临床医师对面神经瘤的认识。方法   回顾分析18例有误诊经历的面神经瘤患者的临床资料,主要包括年龄、性别、临床表现、听力、面神经功能、面神经电图、颞骨CT和MRI结果、手术径路以及术后病理报告。结果   18例患者年龄7～62岁,平均43岁。其中12例患者被误诊为贝尔式面瘫(66.7%),3例患者被误诊为胆脂瘤(16.7%),另外3例患者分别被误诊为颞骨占位、中耳新生物和腮腺肿块。患者被误诊的时间为1～192个月,平均39个月。面神经麻痹(77.8%)和听力下降(66.7%)是最常见的临床表现,耳鸣、耳溢液、面肌痉挛、耳痛和眩晕等症状也较为常见。16例为神经鞘膜瘤(88.9%),面神经纤维瘤和骨血管瘤各1例(5.6%)。结论   若患者面瘫进行性加重,6个月内未见好转;或诊断为中耳炎但抗感染治疗无效者; 或腮腺肿块患者若肿物与面神经关系密切,均应考虑面神经瘤可能。影像学检查和病理学检查对于面神经瘤的诊断至关重要,手术切除是面神经瘤的首选治疗方法,并应积极考虑面神经重建。     

家兔急性实验性面神经损伤的组织病理观察

目的 观察家兔面神经急性损伤后髓鞘和轴索的组织病理变化。方法 用丝线结扎茎乳孔以外的面神经总干，观察结扎后1天、3天及5天面神经的组织病理改变；结果 家兔面神经受损后，先后在髓鞘和轴索结扎天数的增加，面神经损伤亦呈加重的趋势。