慢性癫(癎)鼠海马内移植神经干细胞的存活、迁移、分化及与宿主整合的研究

目的 研究神经干细胞(NSC)移植到慢性海人酸癫(癎)鼠海马CA3区后细胞的存活、迁移、分化及与宿主细胞的整合情况.方法 将增强型绿色荧光(EGFP)标记的原代培养NSC移植到慢性癫(癎)鼠的海马CA3区.分别在移植后第2、4、8、12周4个时间点取脑冷冻切片,在倒置荧光显微镜下观察移植细胞的存活和迁移.采用免疫荧光染色观察移植细胞的分化和整合情况.结果 NSC在移植后2周未见迁移;移植后4周,可见移植细胞迁移到距移植区最近的齿状回;8周和12周,移植细胞可迁移到齿状回和海马各区.12周仍有大量移植细胞(65 045.00±881.72)存活.NSC在移植区以分化为胶质细胞为主,在齿状回和海马各区以分化为神经元为主;γ-氨基丁酸(GABA)能神经元在齿状回门区和海马CA3区分化比例较高.突触素免疫荧光染色示移植细胞与宿主细胞间产生了有机的整合.结论 NSC移植于慢性癫(癎)鼠的海马CA3区后,能够迁移到齿状回和海马各区并长期存活,且可分化为神经元,特别是GABA能神经元,并能与宿主细胞有机整合.     

慢性癫鼠海马内移植神经干细胞的存活、迁移、分化及与宿主整合的研究

目的研究神经干细胞(NSC)移植到慢性海人酸癫疒间鼠海马CA3区后细胞的存活、迁移、分化及与宿主细胞的整合情况。方法将增强型绿色荧光(EGFP)标记的原代培养NSC移植到慢性癫疒间鼠的海马CA3区。分别在移植后第2、4、8、12周4个时间点取脑冷冻切片,在倒置荧光显微镜下观察移植细胞的存活和迁移。采用免疫荧光染色观察移植细胞的分化和整合情况。结果NSC在移植后2周未见迁移;移植后4周,可见移植细胞迁移到距移植区最近的齿状回;8周和12周,移植细胞可迁移到齿状回和海马各区。12周仍有大量移植细胞(65 045.00±881.72)存活。NSC在移植区以分化为胶质细胞为主,在齿状回和海马各区以分化为神经元为主;-γ氨基丁酸(GABA)能神经元在齿状回门区和海马CA3区分化比例较高。突触素免疫荧光染色示移植细胞与宿主细胞间产生了有机的整合。结论NSC移植于慢性癫疒间鼠的海马CA3区后,能够迁移到齿状回和海马各区并长期存活,且可分化为神经元,特别是GABA能神经元,并能与宿主细胞有机整合。     

大鼠海马干细胞移植治疗颞叶癫痫的初步研究

目的 通过神经干细胞移植至癫痫鼠后与宿主细胞的整合及其对损伤宿主的修复作用，为神经干细胞移植治疗癫痫提供理论依据。方法 分离、培养新生鼠海马干细胞，移植至海人酸(KA)所致癫痫模型鼠的右侧海马内，应用Timm、Nissl、HE染色及动态脑电记录仪记录脑电图。在光镜及电镜下比较正常对照组、移植组及KA未移植组大鼠，在移植后的1周、4周、8周及24周苔状纤维发芽(MSF)、海马CA3区锥体神经元损伤情况及海马、杏仁核的脑电变化。结果 海马干细胞的移植可以显著抑制KA引起的MFS，其抑制作用从移植后第4周开始，第8周时最强，持续至第24周；同时亦明显的减轻了KA所致的CA3区锥体细胞缺失，其作用在第8周最强；KA所致CA3区锥体神经元超微结构的损伤亦得到一定程度的修复；但是，干细胞的移植并未使宿主恢复到损伤前的水平，海马干细胞移植可减少癫痫动物脑电的痫性发放，并降低其癫痫波的波幅约50％。结论 神经干细胞移植对于KA诱发癫痫鼠具有显著的修复作用，其具体作用机制还有待于进一步的研究。     

神经干细胞和GABA能神经元治疗大鼠颞叶癫痫实验研究

目的探讨并比较神经干细胞(NSCs)和γ-氨基丁酸(GABA)能神经元移植治疗大鼠颞叶癫痫的疗效。方法取孕12 d SD大鼠胎鼠脑组织,分离培养NSCs并鉴定,取第3代NSCs定向诱导分化为GABA能神经元。48只SD大鼠随机分为4组,空白对照组、未移植组、NSCs移植组和GABA能神经元移植组,移植细胞用5-溴脱氧尿苷(BrdU)标记,在模型建立后的第4 d将上述两种细胞移植到癫痫大鼠右侧海马。分别在细胞移植后的4 w、8 w、12 w处死大鼠留取脑标本。常规HE染色和Nissl染色观察大鼠右侧海马的损伤与治疗情况并进行评价。结果 NSCs移植组和GABA能神经元移植组均于移植后第8 w时海马CA3(CA3)区神经元计数最多,组内比较时,与另外两个时间点之间的差异具有统计学意义(P<0.05)。进而取第8 w时间点进行组间比较,结果各组海马区神经元计数之间的差异均具有统计学意义(P<0.05)。结论两治疗组在移植后第8 w时海马区神经元计数最多,且NSC移植组的疗效优于GABA能神经元移植组。     

心肌营养素1修饰的神经干细胞移植对癫(癎)持续状态大鼠海马损伤及苔藓纤维发芽的影响

目的 观察心肌营养素1(CT1)修饰的神经干细胞(NSCs)移植到癫(癎)持续状态(SE)大鼠海马后的存活、迁移和分化情况,探讨CT1-NSCs移植对海马神经元损伤及苔状纤维发芽(MFS)的影响.方法 建立氯化锂-匹罗卡品致SE大鼠模型,随机分为CTI-NSCs移植组、单纯NSCs移植组、模型组和正常对照组,每组18只.各组再分为移植后1、4、8周3个时间点,每个时间点6只.共聚焦免疫荧光显微镜下观察移植的NSCs在脑内存活、分化及迁移情况;Nissl染色观察海马神经元形态并计数CA1区神经细胞数;Timm染色检测海马齿状回MFS形成.结果 (1)移植后4周及8周,CT1-NSCs移植组双标阳性细胞数量明显多于单纯NSCs移植组,前者可见神经细胞向周围迁移,后者未见明显迁移现象.(2)SE后大鼠CA1区神经细胞数随时间推移进行性减少,CTI-NSCs移植组细胞数(移植后1、4,8周分别为68.85±11.49、60.89±12.17和51.51±13.34)多于单纯NSCs移植组(67.92±10.78、42.56±11.47和30.49±10.12),4、8周时差异有统计学意义(t=4.650、5.334,P<0.05).(3)SE后大鼠齿状回内分子层可见MFS形成,且MP3评分随时间推移进行性增高;移植后1、4,8周时CT1-NSCs移植组MFS分值(0.77±0.04、2.48±0.89和2.39±0.82)明显低于单纯NSCs移植组(1.12±0.62、3.17±0.64和3.88±0.51,t=6.059、9.511、9.728,P<0.05).结论 CT1能够促进NSCs在SE大鼠脑内存活、迁移和分化,CTI-NSCs移植对SE大鼠海马损伤有修复作用,并可抑制海马MFS形成.     

海马干细胞移植对癫痫鼠苔状纤维发芽抑制作用的研究

Turner等证实大鼠海马胚胎细胞移植对于海人酸（KA）所致癫痫鼠神经元的损害具有一定的修复作用，但胚胎细胞移植受细胞来源和伦理学等多方面限制。神经干细胞的发现为细胞移植治疗颞叶癫痫等神经系统疾病提供了广阔前景。本研究将分离培养的大鼠海马干细胞移植至KA所致癫痫模型鼠CA3区，     

辛伐他汀抑制慢性颞叶癫痫形成的初步研究

目的 研究辛伐他汀对慢性颞叶癫痫大鼠脑组织病理改变及癫痫发作的影响.方法 成年雄性Wistar大鼠72只按照随机数字表法分为对照组、盐水组及辛伐他汀组,每组24只.对照组大鼠单侧脑室内单次注入生理盐水1 μL;盐水组大鼠单侧脑室内注入海人酸(KA)致痫成功0.5 h后,生理盐水灌胃(1 mg每公斤体质量),每日1次,连续14d;辛伐他丁组大鼠单侧脑室注入KA致病成功0.5h后,进行辛伐他汀灌胃(1 mg每公斤体质量),每日1次,连续14d.致痫后3d、4个月、5个月、6个月4个时间点处死大鼠,制作脑组织石蜡切片进行Timm's染色、Nissl染色、GFAP染色,观察慢性颞叶癫痫大鼠脑组织病理改变:同时记录大鼠的癫痫发作,参照Racince's分级法分级并计分. 结果 与盐水组相比,辛伐他丁组小鼠CA3区和齿状回的神经元丢失减少,胶质细胞增生减少,苔状纤维发芽程度明显减轻,癫痫发作级别降低,差异有统计学意义(P＜0.05). 结论 辛伐他汀在慢性颞叶癫痫的形成过程中起到了长期的神经保护作用.     

Noggin参与海人酸损伤后成年大鼠海马颗粒下区颗粒细胞增殖

目的 探讨侧脑室注射海人酸(KA)致大鼠海马损伤后Noggin的表达变化及其与颗粒细胞增殖的关系.方法 健康雄性SD大鼠32只采用随机数字表法分为实验组(16只)及对照组(16只).对照组又分为生理盐水对照组和空白对照组,各8只.实验组大鼠侧脑室注射KA,生理盐水对照组注射等剂量生理盐水.空白对照组不作处理.侧脑室注射KA 1周内,尼氏染色检测海马神经元的丢失.免疫荧光染色与原位杂交的方法检测海马齿状回BrdU标记细胞与Noggin mRNA阳性细胞的变化.结果 在侧脑室注射KA致海马损伤后1周,海马CA3、CA4区神经元丢失明显.与生理盐水对照组比较,实验组海马齿状回BrdU阳性细胞升高,差异有统计学意义(P=0.006),其中注射侧较对侧更为明显.海马Noggin mRNA阳性细胞在第3天时升高,第7天时下降.结论 侧脑室注射KA致海马损伤后.成年大鼠海马齿状回颗粒细胞异常增殖可能与Noggin表达波动有关.     

雌激素和姜黄素对海人酸杏仁核点燃大鼠行为学、脑电图及海马神经元损伤的影响

目的了解雌激素和姜黄素对海人酸(kainic acid,KA)杏仁核点燃大鼠癫痫发作的影响。方法给去势的雌性大鼠添加雌激素治疗,添加姜黄素治疗,或添加雌激素和姜黄素治疗,比较各组大鼠致痫后癫痫发作的行为学、脑电图和海马神经元损伤的变化。结果给雌激素治疗的大鼠重型发作(Racine 4/5级)评分最高,而雌激素加姜黄素治疗组评分最低(P<0.05)。脑电图的变化与行为学的改变基本一致。致痫后大鼠注射KA侧海马CA3区、CA4区可见到明显的细胞损伤,而该侧海马CA1区、齿状回区(DG)及对侧海马CA3区、CA1区及DG区神经元损害不明显。雌激素组大鼠双侧海马CA3区均出现加重的神经元损害,姜黄素组及雌激素加姜黄素组大鼠海马注射对侧CA3区存活神经元较雌激素组明显增加(P<0.01)。结论高水平的雌激素可以加重癫痫的发作,给姜黄素治疗可以减轻大鼠海马CA3区神经元损害。     

大鼠骨髓源性神经干细胞移植治疗颞叶癫痫实验研究

目的 探讨骨髓源性神经干细胞移植至KA大鼠海马后与宿主细胞的整合及其对损伤宿主的修复作用,从而为干细胞移植治疗颞叶癫痫提供理论依据.方法 首先分离大鼠骨髓基质细胞,并在特定的条件下培养使其诱导分化为神经干细胞,且使用Feridex对干细胞进行标记.然后建立大鼠颞叶癫痫模型,将Feridex标记的神经干细胞自体移植至KA大鼠的海马内,观察移植后1周、2周、4周、8周和16周大鼠海马的脑电图、病理学和MRI改变情况.结果 与KA未移植组相比,移植组大鼠海马脑电图的波幅明显降低,最高降低达40%以上;KA移植组海马CA3区锥体细胞数与未移植组相比有极显著性差异（P＜0.01）;KA移植组海马损伤侧的Timm染色与未移植组相比也有极显著性差异（P＜0.01）;MRI检查发现在神经干细胞移植后1周和2周时低信号改变区比较局限,但移植4周、8周和16周后低信号改变明显增大,且随着时间的推移低信号改变区逐渐增大.结论 骨髓源性神经干细胞移植至KA大鼠后能与宿主细胞进行整合,且对宿主海马具有显著的修复作用,但其具体的作用机制尚待进一步研究.     

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.     

Special Pharmacokinetic Considerations in Children

Summary: Pediatric patients have greater degrees of pharmacokinetic variability and unpredictability than adults. This variability results from the effects of pharmacogenetics, age and growth, prior and current comedication, and disease. Newborns with seizures have the least predictable dosage requirements, and their needs change as drug-eliminating mechanisms mature in the neonatal period. Infants have the highest relative capacities to eliminate antiepileptics of any age group and require the largest relative doses. In addition to age-related trends, children demonstrate the same drug-specific, pharmacokinetic phenomena that adults do, including nonlinear phenytoin elimination, nonlinear valproate binding, and autoinduction of carbamazepine. Intercurrent illness and drug interactions further modify the age-related pharmacokinetic patterns in children and make dosage requirements even more unpredictable. Recent studies have shown that febrile illness can affect drug elimination, sometimes decreasing drug levels by 50% or more. Intermittent treatment with benzodiazepines administered either orally or rectally can be an important adjunct and help minimize this type of problem for children with marginally controlled epilepsy. Intermittent benzodiazepines are also helpful for children who have febrile seizures and who need only occasional antiepileptic protection.