重组Bcl-2腺病毒对损伤运动神经元的保护作用

目的:观察携带Bcl-2基因的重组腺病毒(Ad/s-Bcl-2)对损伤运动神经元的保护作用.方法:采用培养脊髓运动神经元的谷氨酸损伤模型,评价重组Bcl-2腺病毒对损伤运动神经元的影响.指标是Bcl-2原位杂交和Bcl-2免疫组化染色、TUNEL阳性神经元计数、运动神经元[Ga2+]i的检测以及台盼蓝拒染法检测培养神经元存活.结果:①Ad/s-Bcl-2可转染原代培养的脊髓运动神经元并使其过表达Bcl-2.②过表达Bcl-2可延长培养神经元的生存时间.③过表达Bcl-2可显著减少谷氨酸诱导的原代培养脊髓运动神经元的凋亡,并显著降低谷氨酸诱导的神经元[ca2+]i的增高.结论:腺病毒中介Bcl-2基因过表达对神经毒性损伤的运动神经元具有保护作用.     

第10号染色体缺失的磷酸酶和张力蛋白在谷氨酸诱导海马神经元损伤中的作用研究

目的：探讨第10号染色体缺失的磷酸酶和张力蛋（PTEN）在谷氨酸（Glu）诱导海马神经元损伤的作用及机制。方法：选用新生Wistar大鼠原代培养海马神经元,建立Glu细胞毒性损伤模型,采用RT—PCR,PI染色检测神经元损伤后PTEN表达的变化,以及PTEN抑制剂对神经元损伤的保护作用,同时通过激光扫描共聚焦显微镜检测细胞内Ca^2＋浓度的变化。结果：Glu诱导神经元损伤后,PTEN的表达增加,通过抑制PTEN活性可减少神经元的死亡,并在一定程度上抑制Glu诱导的神经元Ca^2＋内流。结论：磷酸酶PTEN参与了神经元的损伤过程,利用bpv抑制PTEN的活性可对Glu诱导的神经元损伤具有保护作用,其中抑制Glu引起的神经元Ca^2＋内流可能是其保护机制之一。     

CNTF对大鼠脊髓运动神经元NF积聚影响的研究

目的 观察肌萎缩侧索硬化症（ALS）病人脑脊液和谷氨酸对体外培养SD大鼠脊髓前角运动神经元损伤及神经细丝（Neurofilament,NF）积聚的变化,探讨睫状神经营养因子（Ciliary neurophic　factor,CNTF）保护运动神经元的作用机制。方法 体外培养SD大鼠脊髓前角运动神经元,然后分组观察正常脑脊液、ALS病人脑脊液和谷氨酸对神经元损伤作用及CNTF的保护作用,免疫组化观察各组神经元中神经细丝NF积聚的情况。结果　ALS病人脑脊液和谷氨酸对体外培养的运动神经元有明显损伤作用,神经元数量减少（P<0.05）,免疫组化显示有明显的NF积聚现象,但先加入CNTF后,运动神经元数量无明显变化（P>0.05）,免疫组化显示无明显NF积聚的现象。结论 体外培养SD大鼠脊髓前角运动神经元,在加入CNTF后,可以减少ALS病人脑脊液和谷氨酸对运动神经元的直接损伤作用,并显示有抑制NF积聚的作用,提示CNTF确有保护神经元的作用。     

腺病毒介导嗜铬瘤细胞中p75神经营养因子的RNA干扰

课题前期研究发现,在急性马尾神经受压模型大鼠中,马尾神经元华勒氏变性和腰骶脊髓前角运动神经元的凋亡及马尾相应阶段脊髓中有p75NTR的高表达存在正向变化关系。本文设想用腺病毒携带shRNA的方式,进行针对p75NTR基因沉默病毒的包装及体外验证重组腺病毒的基因沉默效果。实验按照Reynolds siRNA模板寡核苷酸的设计原则,设计合成3条p75 siRNA模板寡核苷酸片段（shRNA）,随后分别克隆进Shuttle vector 1.0 CMV,与表达加强绿色荧光蛋白的腺病毒载体骨架共转染HEK293细胞成功包装出具有p75shRNA的腺病毒,所得病毒分别命名为Ad.shRNA1、Ad.shRNA2、Ad.shRNA3,重组腺病毒分别感染体外培养的PC12细胞。48h后收集PC12细胞中p75NTRmRNA及总蛋白,发现相对于阴性对照,在mRNA水平,Ad.shRNA1,Ad.shRNA2,Ad.shRNA3组RNA干扰率为分别为（98.49±0.68）％,（95.08±1.79）％,（96.60±1.14）％;在蛋白水平,其RNA干扰率分别为（72.89±2.17）％,（58.83±1.15）％,（59.88±0.44）％。由此得出重组腺病毒成功的抑制了p75NTR的表达,其中以Ad.shRNA1基因沉默效果最为显著。     

氮苯二羧基钒酸盐调控谷氨酸作用下海马神经元内钙离子的研究

目的：探讨第10号染色体缺失的磷酸酶和张力蛋白同源等位基因抑制剂氮苯二羧基钒酸盐（bpv）调控谷氨酸 （Glu）作用下海马神经元内Ca^2＋的作用及机制.方法：用孕12～14 d大鼠原代培养海马神经元,经bpv和Glu受体（GluR）阻断剂预处理后,通过激光共聚焦扫描检测高浓度Glu刺激后的细胞内Ca^2＋浓度变化.结果：Glu可诱导神经元细胞Ca^2＋ 内流,bpv可通过对Glu a-氨基羟甲基恶唑丙酸（AMDA）受体的作用而减少Ca^2＋内流.结论：bpv在脑创伤后对神经元的保护作用可能是通过抑制Glu所引起的Ca^2＋内流而实现的.     

神经营养因子-3对海马神经元缺氧损伤保护作用的研究

目的观察单纯缺氧损伤对体外培养海马神经元内源性神经营养因子-3(neurotrophin-3, NT-3)表达的影响及外源性NT-3转导对单纯缺氧所致神经元凋亡的保护作用。方法体外分散培养新生Wistar大鼠海马神经元,体外培养第7天通过充氮法建立单纯缺氧损伤模型;用重组腺病毒载体pAC- CMV-PLPA构建携带NT-3全长cDNA的重组腺病毒Ad-NT-3,并分别于损伤前后向体外培养的海马神经元转导外源性NT-3;采用Western Blot检测在缺氧损伤前后及有无外源性NT-3转导的情况下NT-3 及Bcl-2的表达水平;采用TUNEL法检测缺氧及外源性NT-3转导后神经元凋亡的情况。结果 (1)单纯缺氧损伤后海马神经元的凋亡细胞标记指数由15．2％上升至56．4％,内源性NT-3表达量下降至对照组水平的71％。(2)缺氧损伤前重组腺病毒转导可使损伤后NT-3表达量上升至对照组的1.88倍、损伤后重组腺病毒转导亦可使NT-3表达量上升至对照组的1．42倍,而Bcl-2的表达量相应地上升至对照组的 1．69倍和1．32倍,凋亡细胞标记指数降至32．8％和45．4％。(3)统计学分析显示,海马神经元NT-3与Bcl- 2表达量间呈显著性正相关,二者与凋亡细胞标记指数间均呈显著性负相关。结论单纯缺氧损伤可使体外培养的海马神经元内源性NT-3表达量下降;腺病毒转导的外源性NT-3可保护单纯缺氧损伤神经元免于凋亡;其保护作用部分可能是通过对Bcl-2表达的诱导实现的。     

力生长因子重组腺病毒载体构建及其在成骨细胞中的表达

背景：研究表明,力生长因子(mechano-growth factor,MGF)能激活卫星细胞,促进成肌细胞增殖,在治疗肌损失、预防心肌损伤和修复神经损伤等方面有重要的作用。机械拉伸可使成骨细胞表达MGF,但是MGF对骨组织生理生化行为的影响机制尚不清楚。 目的：应用携带MGF基因的重组腺病毒载体转染成骨细胞,观察MGF在成骨细胞中的表达。 方法：将MGF基因插入到腺病毒穿梭质粒pAdTrack-CMV中,构建pAdTrack-MGF重组体。pAdTrack-MGF与腺病毒骨架质粒pAdEasy-1在BJ5183菌中进行同源重组,生成重组腺病毒质粒pAdEasy-MGF。脂质体介导pAdEasy-MGF转染293A细胞,包装成整的重组腺病毒Ad/MGF。用Ad/MGF感染原代培养的大鼠成骨细胞,荧光示踪计数法测定感染效率,RT-PCR法对重组腺病毒感染结果进行鉴定。 结果与结论：实验构建的重组腺病毒载体Ad/MGF滴度可达8.5×108 pfu/mL。Ad/MGF能高效感染体外培养的Wistar大鼠成骨细胞并表达目的基因,当感染复数为100时,感染效率最高。说明实验构建的Ad/MGF重组腺病毒可在大鼠成骨细胞中有效表达。     

凝血酶对原代培养海马神经元游离钙浓度的影响

目的研究凝血酶对原代培养海马神经元内游离Ca^2 水平的影响。方法采用原代培养大鼠海马神经元方法，用钙离子指示剂Fura-2双波长荧光检测凝血酶对海马神经元内游离钙浓度的影响。结果(1～40)U／ml凝血酶可使海马神经元内游离Ca^2 水平显著升高，且呈剂量依赖性。凝血酶受体激活肽可明显升高细胞内游离[Ca^2 ]i。当胞外Ca^2 为1．3mmol／L时，40U／ml凝血酶可使海马神经元游离[Ca^2 ]i明显增加；而当胞外Ca^2 为0．0mmol／L时，40U／ml凝血酶不影响海马神经元游离[Ca^2 ]i。预先加入MK-801可显著降低凝血酶的升钙作用。结论凝血酶使神经细胞内游离Ca^2 浓度异常升高的作用机制可能是通过激活凝血酶受体，继而激活NMDA受体门控的Ca^2 通道介导胞外Ca^2 大量内流。     

腺病毒介导的GDNF基因转移体外表达及生物学活性研究

为利用重组腺病毒介导的胶质细胞源性神经营养因子（GDNF）基因转移治疗帕金森病（PD）提供依据。方法：采用免疫组化、RT－PCR及ELISA定量分析观察人GDNF腺病毒（Ad-GDNF)在大鼠星形胶质 PC12细胞的表达,通过观察病毒直接感染及病毒感染的PC12细胞上清对中脑原代培养细胞中的TH阳性细胞（DA能神经元）生存能力和形态分化的影响来验证其生物学活性。结果Ad-GDNF在星形胶质细胞、PC12细胞及大鼠中脑原代培养细胞均可有效表达,其表达产物对中脑DNA能神经元的生存和形态分化均有显著的促进作用。结论：腺病毒介导的GDNF基因转移可在体外有效表达,且表达产物具有生物学活性,提示该手段在PD治疗方面具有良好的应用前景。     

重组腺病毒载体AxCA-BDNF基因转染修复坐骨神经损伤*☆

背景：如何促进周围神经损伤修复与再生一直是基础与临床研究的热点。基因治疗有可能成为今后解决该问题的主要手段之一。 目的：观察携带小鼠脑源性神经营养因子(brain-derived neurotrophic factor,BDNF) cDNA表达片段的重组腺病毒载体AxCA-BDNF转染大鼠损伤坐骨神经后BDNF的表达,以及脊髓前角运动神经元的存活和神经生长情况。 方法：切除成年Wistar大鼠股中部10 mm长的坐骨神经,AxCA-BDNF转染组、BDNF组和对照组分别用硅胶管内置AxCA-BDNF原液,BDNF溶液或空白病毒稀释液桥接坐骨神经两断端。术后3,7,14 d,1,2,4个月应用原位杂交和免疫组织化学方法检测损伤坐骨神经及相应脊髓节段BDNF mRNA和蛋白的表达,并观察损伤坐骨神经的组织学及超微结构改变,再生的神经元及有髓神经纤维数目和髓鞘厚度。 结果与结论：术后3,7,14 d及1个月时,AxCA-BDNF转染组损伤坐骨神经近、远端神经干及脊髓(L3~6)中BDNF mRNA和蛋白水平明显高于BDNF组和对照组(P < 0.01)。光、电镜病理组织学检查和图像分析证实,BDNF基因转染后,脊髓前角运动神经元存活数量、新生神经纤维数目及其髓鞘厚度、神经联接的再形成均明显优于对照组(P < 0.01)。说明经腺病毒介导转染的BDNF基因可在大鼠坐骨神经内有效表达,并通过轴突逆行转运到了相应的脊髓神经元,不仅能促进损伤神经纤维再生,也能保护损伤的脊髓神经元。 关键词：坐骨神经损伤;重组腺病毒;脑源性神经营养因子;基因转染;免疫组织化学;原位分子杂交;神经再生     

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.     

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.     

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.     

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.     

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.     

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.