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。     

生物素标记葡聚糖胺神经束路示踪见证神经干细胞移植后皮质脊髓书的再生

实验旨在运用生物素标记葡聚糖胺神经束路示踪标记神经干细胞移植治疗脊髓损伤后皮质脊髓束的再生和神经的重新支配状况,结果表明神经干细胞移植治疗胸10脊髓横断损伤大鼠运动功能评分在横断损伤3周后逐渐升高。治疗后12周有部分生物素标记葡聚糖胺阳性标记的皮质脊髓束再生通过脊髓横断损伤部位,电镜检查发现再生的生物素标记葡聚糖胺阳性标记的神经终末与损伤远端神经元形成新的突触联系。说明生物素标记葡聚糖胺神经束路示踪能有效提供脊髓损伤后神经恢复的解剖形态学依据。     

接受嗅鞘细胞移植脊髓损伤大鼠电生理及后肢功能变化

背景：研究证实嗅鞘细胞有利于神经元存活,并可促进轴突再生。 目的：探讨嗅鞘细胞移植治疗大鼠脊髓损伤的效果。 方法：健康成年雌性SD大鼠40只,随机分为盐水对照组、细胞移植组,20只/组。另取10只SD大鼠用于嗅鞘细胞的分离培养。盐水对照组、细胞移植组大鼠均建立脊髓损伤模型,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嗅鞘细胞2×106个,盐水对照组局部注射等量无菌生理盐水。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;BBB后肢运动功能评分结果;通过BDA顺行神经示踪,观察运动传导束恢复情况。 结果与结论：细胞移植组大鼠体感诱发电位及运动诱发电位的潜伏期、波幅明显优于盐水对照组(P < 0.01);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);细胞移植组脊髓损伤区有较多BDA标记阳性神经纤维通过,其数量明显多于盐水对照组(P < 0.01)。证实局部注射嗅鞘细胞可以较好地恢复大鼠脊髓损伤后的神经电生理及后肢运动功能。     

BDA皮质脊髓束神经顺行示踪在大鼠脊髓损伤模型中的应用

目的本研究采用生物素标记葡聚糖(Biotin Dextran Amine,BDA)顺行示踪技术来观察大鼠皮质脊髓束(CST)在中枢神经系统中的走行及脊髓损伤后的表现特征。方法20只雌性成年Sprague-Dawley大鼠,分为脊髓损伤组(n=10)和损伤对照组(n=10)。在相当于T7椎板水平用做好标记的显微剪刀剪断脊髓的后2/3。对照组动物术中仅咬除棘突、椎板,不切断脊髓。术后第15 d,所有动物通过立体定向开颅,将10％BDA溶液注入右侧的感觉运动区皮质内。BDA注射2周后,取出大脑和脊髓组织,采用自由漂浮法行BDA染色显影。实验动物于脊髓损伤术前、术后3d、1周、2周、4周采用Basso、Beatlie、Bresnahan(BBB)评分法测量运动功能,所得数据采用两组均数比较t检验进行统计学处理。结果1.脊髓损伤组动物双后肢瘫痪,BBB运动功能评分明显低于损伤对照组,统计学比较差异十分显著(P<0.01);2.BDA顺行示踪显示大脑皮层BDA注射区内见大脑皮层的锥体细胞及其发出的轴突呈阳性染色,BDA阳性染色的皮质脊髓束神经纤维在中脑、桥脑及延髓的腹侧面行走,但在锥体交叉后皮质脊髓束主要(约99％)在对侧脊髓白质的后索中行走。在致伤组动物中,位于脊髓白质后索中的皮质脊髓束纤维在脊髓损伤处终止;在对照组皮质脊髓束纤维染色可一直延伸至L1水平。结论BDA顺行神经     

生物素葡聚糖胺皮质脊髓束顺行示踪技术在大鼠脊髓损伤模型中的应用

目的探讨生物素葡聚糖胺(BDA)神经示踪技术及脊髓半横断损伤模型在大鼠脊髓损伤修复的实验研究中应用。方法采用成年Sprague-Dawley大鼠,分为脊髓致伤组(n=10)和致伤对照组(n=10)。致伤组动物在相当于T7椎板水平横行剪断脊髓的后2/3;对照组动物术中仅切除椎板,不切断脊髓。术后第15d,右侧开颅,用10?A示踪剂注入右侧的感觉运动区皮质内。2周后取出大脑和脊髓组织,采用自由漂乳法行BDA染色显影。术后实验动物功能测评采用BBB运动功能评分,所得数据采用Student'st-test进行统计学原理。结果(1)脊髓损伤组动物双后肢瘫痪,BBB运动功能评分明显低于损伤对照组,统计学比较差异十分显著(P<0.01);(2)BDA顺行示踪显示大脑皮层BDA注射区内见大脑皮层的锥体细胞及其发出的轴突呈阳性染色,BDA阳性染色的皮质脊髓束神经纤维在同侧中脑、桥脑及延髓的腹侧面行走,在锥体交叉后皮质脊髓束主要在对侧脊髓白质的后索中行走。在致伤组动物中,位于脊髓白质后索中的皮质脊髓束纤维在脊髓损伤处终止;对照组皮质脊髓束BDA染色可一直延伸至L1水平。结论大鼠半脊髓切断结合应用BDA顺行示踪技术可以对脊髓损伤后的神经修复状况进行可靠的形态学评判,是研究脊髓损伤后中枢神经纤维再生修复较为理想的动物模型     

骨髓间充质干细胞移植脊髓全横断模型大鼠运动和体感诱发电位的评价

背景：临床常用皮质运动诱发电位和皮质体感诱发电位来分别评价脊髓损伤后运动传导路和感觉传导路的损伤或修复情况。 目的：以脊髓诱导电位监测骨髓间充质干细胞移植后急性脊髓完全性损伤大鼠下肢神经功能的变化。 方法：选取健康Wistar大鼠50只，分成5组，即生理盐水组、骨髓间充质干细胞移植组、脑源性神经营养因子修饰组、神经营养素3+骨髓间充质干细胞移植组和假手术组。除假手术组外，其余各组均制作Allen’s脊髓完全性损伤动物模型，造模后各组均行相应治疗。治疗后4，8和12周行大鼠后肢运动功能评分，并于造模后24 h，3，7，14 d行运动和体感诱发电位检测。 结果与结论：运动诱发电位检测结果提示，各治疗组的运动功能均有不同程度的恢复，与生理盐水组间差异均有显著性意义(P < 0.05)，大鼠后肢BBB评分也证实了各治疗组后肢运动功能明显优于生理盐水组(P < 0.05)。提示经脑源性神经营养因子修饰的骨髓间充质干细胞可移植到脊髓损伤处，可改善大鼠的后肢运动，神经营养素3蛋白有可能提高骨髓间充质干细胞在体内的生存率，促进受损脊髓的轴突再生。     

胎鼠神经干细胞移植对大鼠脊髓损伤后神经细胞凋亡及凋亡抑制基因Bcl-2表达的影响

目的研究胎鼠神经干细胞(NSCs)移植对大鼠脊髓损伤(SCI)后神经细胞凋亡及凋亡抑制基因Bcl-2表达的影响。方法 40只SD大鼠随机分为正常对照组(Normal组),脊髓损伤组(SCI组),神经干细胞组(NSC组),神经干细胞标记组(BrdU+NSCs组)。采用电控脊髓损伤打击装置制作模型,5-溴脱氧尿嘧啶核苷(Br-dU)法标记处于对数生长期的NSCs,SCI后即刻进行NSCs移植。免疫组化法观察BrdU标记NSCs的存活、迁移及凋亡抑制基因Bcl-2的表达,TUNEL法标记凋亡细胞(免疫组化及免疫荧光显色),改良Rivlin法观察大鼠后肢运动功能的恢复情况。结果 BrdU+NSCs组在损伤脊髓区域可检测到BrdU标记的阳性NSCs。BrdU+NSC组与NSC组各时间点凋亡阳性细胞数均比SCI组减少(P<0.01),Bcl-2免疫阳性细胞光密度值比SCI组明显增加(P<0.01),且Bcl-2表达高峰延长至伤后7d;移植后7d、14d、28d后肢运动功能评分较SCI组明显升高(P<0.01)。Br-dU+NSC组与NSC组之间比较无明显差异(P>0.05)。结论体外培养的胚胎大鼠NSCs可在脊髓损伤区域存活、迁移,并能通过上调Bcl-2的表达来抑制大鼠脊髓损伤后神经细胞的凋亡,从而促进大鼠瘫痪肢体功能的恢复。     

高压氧联合神经干细胞移植治疗大鼠脊髓损伤

背景：单纯神经干细胞移植已应用于对受损脊髓组织的修复。 目的：以神经干细胞移植同时应用高压氧治疗大鼠脊髓损伤,观察联合作用对脊髓损伤大鼠运动功能恢复的影响。 方法：雌性SD大鼠60只,以半切法制成胸段脊髓半横断大鼠模型。随机分成单纯损伤组、神经干细胞移植组及高压氧治疗组,每组20只。伤后第4周取材行病理切片苏木精-伊红染色及BrdU免疫组织化学染色,第8周取材行辣根过氧化物酶示踪,透射电镜观察轴突的再生情况,通过体感诱发电位观察神经电生理恢复情况。造模后1,2,4,6,8周进行BBB评分和斜板实验等运动功能检测。 结果与结论：观察伤后4周病理切片,单纯损伤组未见神经轴索通过,神经干细胞移植组可见少量神经轴索样结构,高压氧治疗组可见较多神经轴索样结构。BrdU的阳性细胞数及辣根过氧化物酶阳性神经纤维数,高压氧治疗组最多,神经干细胞移植组次之,单纯损伤组最少,且各组之间差异有显著性意义(P < 0.05)。透射电镜下神经干细胞移植组、高压氧治疗组正中横断面可见新生的无髓及有髓神经纤维。高压氧治疗组大鼠体感诱发电位的潜伏期短于神经干细胞移植组,波幅高于神经干细胞移植组(P < 0.05),明显优于单纯损伤组(P < 0.01)。伤后4周神经干细胞移植组、高压氧治疗组大鼠后肢运动功能均有较明显恢复,高压氧治疗组较神经干细胞移植组恢复快(P < 0.05);单纯损伤组亦有所恢复,但程度较轻。提示神经干细胞移植对于脊髓损伤大鼠后肢功能的恢复有促进作用,联合应用高压氧有协同效果。     

异体骨髓间充质干细胞移植治疗大鼠脊髓损伤

背景：脊髓损伤的修复目前尚无良好的治疗手段,细胞移植能促进神经轴突再生及脊髓功能恢复,为治疗脊髓损伤提供了可能,但因脊髓损伤模型及移植方式不同,其治疗效果并不相同。 目的：验证异体骨髓间充质干细胞移植对大鼠脊髓损伤的治疗作用。 方法：全骨髓贴壁法分离大鼠骨髓间充质干细胞。健康SD大鼠随机分为3组,细胞移植组、对照组和假手术组。细胞移植组和对照组采用改良Allen重物打击法制造大鼠脊髓损伤模型,假手术组仅暴露脊髓。术后4周,每周进行运动功能评分,ELISA检测脊髓损伤组织中脑源性神经营养因子、神经生长因子表达;免疫荧光染色检测脊髓组织中NF200和胶质纤维酸性蛋白表达。 结果与结论：与对照组比较,细胞移植组大鼠运动功能明显改善,脊髓组织中脑源性神经营养因子、神经生长因子蛋白含量明显增高(P < 0.05);移植组大鼠脊髓囊腔较小,NF200表达明显增加,胶质纤维酸性蛋白表达减少。提示异体骨髓间充质干细胞移植能增加损伤脊髓神经生长因子含量,抑制胶质瘢痕形成,促进神经轴突再生,改善大鼠脊髓损伤后运动功能恢复。     

干细胞移植治疗脊髓损伤研究进展

学术背景：目前治疗脊髓损伤应用比较多的方法是细胞移植治疗和神经营养因子的应用。移植的细胞可在损伤部位存活、整合入宿主组织中，分化出神经元、星形胶质细胞和少突胶质细胞，并且和宿主细胞之间可形成突触样结构，使中枢神经系统的功能得到部分恢复。 目的：总结神经干细胞移植治疗大鼠脊髓损伤的研究进展。 检索策略：应用计算机检索Pubmed数据库1985-01/2007-10期间的相关文献，检索词为“Spinal Cord Injuries ,Neural,Stem Cell Transplantation”。并限定文章语言种类为English。同时计算机检索中文科技期刊数据库1989-01/2007-06期间的相关文章，检索词为“脊髓损伤，神经干细胞，神经元，干细胞移植”，并限定文章语言种类为中文。对资料进行初审，并查看每篇文献后的引文。纳入标准：文章所述内容应与移植干细胞后脊髓损伤后神经轴突的再生与修复等研究进展中的应用相关。排除标准：重复研究或Meta分析类文章。共收集到66篇相关文献，31篇文献符合纳入标准，排除的35篇为内容陈旧或重复文献。 文献评价：符合纳入标准的31篇文献中，23篇涉及移植后损伤脊髓神经元和轴突、髓鞘的再生及功能修复的研究，8篇涉及存在的问题与展望。 资料综合：①在脊柱骨折中约有16%~40%并发脊髓损伤。脊髓损伤传统治疗仅限于脊柱骨折脱位的复位固定、解除脊髓压迫、对症及康复治疗，疗效较差。②近年来随着神经病理生理及神经发育学研究的不断深人，神经组织或非神经组织移植逐渐应用于脊髓损伤并取得了肯定的成绩。③干细胞具有自我更新能力，植入受损部位后，其释放的营养因子能促进神经元的再生，且再生轴突能快速穿越移植物与宿主组织的边界，重建轴突的连续性。④关于干细胞及营养因子在损伤脊髓修复方面的研究虽已取得较大进展，但仍存在对神经再生的不利因素，如髓鞘相关抑制分子和胶质瘢痕形成，免疫排斥等。 结论：干细胞移植是治疗脊髓损伤的理想方案，可恢复损伤大鼠脊髓的部分功能。     

Epilepsy and anomalies of neuronal migration: MRI and clinical aspects

Neuronal migration disorders are the result of disturbed brain development. In such disorders, neurons are abnormally located. In diagnosing these conditions, magnetic resonance imaging is superior to any other imaging technique. This enables us to improve our knowledge of the clinical correlates of neuronal migration. With reference to migrational disorder, a retrospective study of all 303 patients with epileptic seizures referred for magnetic resonance imaging during a 3-year period was performed, 13 patients (aged 12-41, mean age 27) were identified. They represent 4.3% of the entire study group. Of the patients with known epilepsy, 6.7% and of the mentally retarded, 13.7% had migrational disorders. Four patients had schizencephaly as the dominant finding, one was classified as hemimegalencephaly, 2 had isolated heterotopias, and 6 had localized pachy- and/or poly-microgyria. The clinical pictures are complex. Ectopias of grey matter are recognised foci of epilepsy, but from an epileptological and a clinical viewpoint little attention has been given to these disorders. The present study shows that malmigration is not rare in epilepsy patients, especially not in the mentally retarded.     

Hepatic Considerations in the Use of Antiepileptic Drugs

Summary: Virtually all of the major antiepileptic drugs (AEDs) can cause hepatotoxicity, although fatal hepatic reactions are rare. The mechanisms, incidences, and risk profiles for such reactions differ from drug to drug. With carbamazepine and phenytoin, hepatotoxicity may be due to drug hypersensitivity. Although the profiles of patients at risk have not been well-defined for these two antiepileptic drugs, it would appear from reports in the literature that older adolescents and adults are at higher risk than children of developing serious or fatal hepatotoxicity. Once hepatotoxicity develops, mortality rates are 10–38% with phenytoin and 25% for carbamazepine. The risk profile for valproate fatal hepatotoxicity has been more clearly defined. Those at primary risk of fatal hepatic dysfunction are children under the age of 2 years who are receiving multiple anticonvulsants and also have significant medical problems in addition to severe epilepsy. The risk is considerably lower for patients over the age of 2 years on valproate monotherapy. In contrast to the risk profile with other AEDs, adults receiving valproate as monotherapy have the lowest risk of hepatotoxicity. Fatal hepatic dysfunction coincident with valproate may be the result of aberrant drug metabolism. Concomitant use of AEDs that induce microsomal P450 enzymes (e.g., phenytoin and phenobarbital) may enhance the production of a toxic metabolite, and hence the greater risk of hepatotoxicity with polypharmacy.     

Vascular Malformations and Epilepsy: Clinical Considerations and Basic Mechanisms

Summary: Vascular malformations (VMs) are associated with epilepsy. The natural history of the various VMs, clinical presentation, and tendency to provoke epilepsy determine treatment strategies. Investigations have probed the mechanisms of epileptogenesis associated with these lesions. Electrophysiologic changes are associated with epileptogenic cortex adjacent to VMs. Putative pathophysiologic mechanisms of epileptogenesis include neuronal cell loss, glial proliferation and abnormal glial physiology, altered neurotransmitter levels, free radical formation, and aberrant second messenger physiology.     

Classification of methods in transcranial Electrical Stimulation (tES) and evolving strategy from historical approaches to contemporary innovations

Transcranial Electrical Stimulation (tES) encompasses all methods of non-invasive current application to the brain used in research and clinical practice. We present the first comprehensive and technical review, explaining the evolution of tES in both terminology and dosage over the past 100 years of research to present day. Current transcranial Pulsed Current Stimulation (tPCS) approaches such as Cranial Electrotherapy Stimulation (CES) descended from Electrosleep (ES) through Cranial Electro-stimulation Therapy (CET), Transcerebral Electrotherapy (TCET), and NeuroElectric Therapy (NET) while others like Transcutaneous Cranial Electrical Stimulation (TCES) descended from Electroanesthesia (EA) through Limoge, and Interferential Stimulation. Prior to a contemporary resurgence in interest, variations of transcranial Direct Current Stimulation were explored intermittently, including Polarizing current, Galvanic Vestibular Stimulation (GVS), and Transcranial Micropolarization. The development of these approaches alongside Electroconvulsive Therapy (ECT) and pharmacological developments are considered. Both the roots and unique features of contemporary approaches such as transcranial Alternating Current Stimulation (tACS) and transcranial Random Noise Stimulation (tRNS) are discussed. Trends and incremental developments in electrode montage and waveform spanning decades are presented leading to the present day. Commercial devices, seminal conferences, and regulatory decisions are noted. We conclude with six rules on how increasing medical and technological sophistication may now be leveraged for broader success and adoption of tES.     

Carbamazepine Efficacy and Utilization in Children

Summary: Carbamazepine is effective for preventing partial and generalized tonic-clonic seizures in children. Although absence epilepsies are more common in children than adults, an estimated 80% of children with epilepsy have seizure types or epilepsies that are potentially responsive to carbamazepine. The differential diagnosis of ictal staring is an especially important issue in children because absence and atypical absence seizures are more prevalent in children than adults. Age-related pharmacokinetic differences and drug interactions are major considerations in children. On average, children have higher clearance rates of carbamazepine, shorter half-lives, and higher ratios of carbamazepine-10, 11-epoxide to carbamazepine than adults. In addition, children with severe epilepsy are more likely to require multiple-drug therapy, which can lead to complex drug interactions. When carbamazepine is administered along with valproate, drug protein binding interactions can cause intermittent side effects.     

Neonatal Seizures: Problems in Diagnosis and Classification

Summary: The clinical identification of neonatal seizures is critical for the recognition of brain dysfunction; however, diagnosis is often difficult because of the poorly organized and varied nature of these behaviors. Current classification systems are limited in their ability to communicate motor, autonomic, and electroencephalo-graphic features of seizures precisely and to provide a basis for uniform effective diagnosis, therapy, and determination of prognosis. Recent investigations of neonates, utilizing bedside electroencephalographic/polygraphic/ video monitoring techniques, have provided the basis for improved diagnosis and classification of seizures in the newborn. These studies have demonstrated that not all clinical phenomena currently considered to be seizures require electrocortical epileptiform activity for their initiation or elaboration. In addition, the specific clinical character of the phenomena considered to be seizures, the clinical state of the infant, and the character of the EEG indicate the probable pathophysiological mechanisms involved and suggest probable etiologies, prognosis, and therapy. Similarities between animal models that demonstrate reflex physiology and neonates with motor automatisms and tonic posturing suggest that these clinical behaviors may not be epileptic in origin but, rather, primitive movements of progression and posture mediated by brainstem mechanisms. Although not all clinical behaviors currently considered to be neonatal seizures may have similar pathophysiological mechanisms, they are clinically significant because they all indicate brain dysfunction.     

Valproate Monotherapy in the Management of Generalized and Partial Seizures

Summary: For decades, therapeutic tradition has promoted the concept of polypharmacy in the management of epilepsy. In recent years, however, studies have shown that, for most patients, monotherapy can provide comparable or better seizure control than administration of multiple anticonvulsants, while diminishing the potential for adverse reactions, drug interactions, and poor compliance. Valproate is an important monotherapeutic agent that is highly effective in the control of idiopathic primary and secondarily generalized epilepsies, and partial seizures that do not generalize. Comparative studies have found that valproate is at least as effective as phenytoin and carbamazepine in the treatment of generalized and partial seizures. Given the similar efficacy, other factors such as pharmacokinetics and side effects may therefore determine anticonvulsant selection for monotherapy.     

Un nouveau cadre conceptuel de travail pour la psychiatrie

In an attempt to place psychiatric thinking and the training of future psychiatrists more centrally into the context of modern biology, the author outlines the beginnings of a new intellectual framework for psychiatry that derives from current biological thinking about the relationship of mind to brain. The purpose of this framework is twofold. First, it is designed to emphasize that the professional requirements for future psychiatrists will demand a greater knowledge of the structure and functioning of the brain than is currently available in most training programs. Second, it is designed to illustrate that the unique domain which psychiatry occupies within academic medicine, the analysis of the interaction between social and biological determinants of behavior, can best be studied by also having a full understanding of the biological components of behavior.