pEGFP-C2基因核转染兔原代骨髓基质细胞的实验研究

目的探讨以最近发展起来的核转染技术直接将编码绿色荧光蛋白DNA质粒转染到兔原代骨髓基质细胞的细胞核内进行基因修饰的可行性。方法从兔股骨抽取骨髓,密度梯度离心法获取原代骨髓基质细胞。以NucleofectorTM技术转染pEGFP-C2(EGFP组),以同期培养未转染的细胞作为对照组。测定细胞的活力、贴壁率、生长曲线以及转染的效率。结果在转染后24h成功发现EGFP的表达。两组细胞具有相似的形态学变化、贴壁率以及生长曲线。EGFP的表达逐渐增强,至第6天达到最高峰(47.8%),观察一个月未发现表达减弱。结论pEGFP-C2基因核转染对兔原代骨髓基质细胞的体外增殖无明显影响;EGFP可以作为兔骨髓基质细胞有效的基因表达标记;NucleofectorTM技术是一种简易而高效的转染兔原代骨髓基质细胞的方法。     

骨髓基质细胞诱导后与神经细胞的比较研究

目的 通过体外诱导骨髓基质细胞（BMSCs)与神经细胞作比较。探索BMSCs体外诱导分化为神经细胞的可行性。方法 应用bFGF,BHA,EGF,Forskolin等配成诱导前剂，诱导剂和长期诱导剂，对大鼠BMSCs进行诱导，全程观察其变化，并聚诱导后4d细胞行神经元特异烯醇化酶（NSE），胶质纤维酸性蛋白（GFAP）的免疫组化染色和Western Blot检测，与大鼠脊髓来源的神经细胞对比。结果 BMSCs诱导前后细胞形态。免疫组化，West-ern Blot检测有明显区别；诱导后细胞与神经细胞极为相似；诱导后细胞13-17d凋亡。结论 BMSCs诱导前后细胞形态，生长，凋亡和NSE，GFAP表达变化支持BMSCs可以体外诱导成神经细胞。     

pEGFP-C2基因因转染恒河猴骨髓源神经干细胞的实验研究

目的 探讨恒河猴骨髓基质源神经干细胞进行基因修饰的可行性。方法 分离恒河猴骨髓基质细胞(BMSCs)，体外培养，bFGF诱导增殖，细胞生长至神经干细胞期时以Nucleofector^TM核转染仪行pEGFP—C2转染，倒置荧光显微镜观察基因表达情况，并检测细胞的活力。另外，对同期培养的未转染细胞进行神经干细胞特异性抗原-nestin和CD133抗原的免疫细胞化学检测。结果 分离得到的BMSCs能在体外培养液中进行增殖和分化．而在bFGF诱导的情况下．细胞的增殖更为明显；转染pEGFP—C2的细胞于转染后24h后即表达强绿色荧光蛋白，转染率达30％以上，且细胞的活力基本不受影响；免疫细胞化学检测可见有nestin和CD133抗原在同期培养的未转染细胞内表达。结论 灵长类骨髓基质细胞具有向神经干细胞分化、增殖的能力，bFGF能促进细胞的增殖，在神经干细胞培养条件下，可发育分化成神经干细胞；在神经干细胞阶段，应用电转染技术进行神经干细胞基因修饰是可行的，可应用于骨髓基质源神经干细胞的基因治疗领域。     

脐带间充质干细胞分离、鉴定与神经分化

目的原代分离培养脐带间充质干细胞（UCMSCs），并就其向神经细胞方向分化潜能予以研究，为脑创伤后神经组织再生修复提供理论依据。方法采用原代贴壁培养法分离培养人UCMSCs，取第4代UCMSCs进行流式细胞术检测UCMSCs表面特异标志物表达；经神经诱导后应用细胞免疫荧光技术检测神经胶质细胞标志物胶质纤维酸性蛋白（GFAP）表达和神经元标志物神经元特异性烯醇化酶（NSE）、微管相关蛋白（MAP-2）表达。结果流式细胞术结果显示UCMSCs强表达CD29、CD44、CD105，极低表达CD31、CD34、CD45，检测结果符合人UCMSCs特征。细胞免疫荧光结果显示UCMSCs经诱导后GFAP阳性表达率为56．23％，NSE阳性表达率为22．15％，MAP-2阳性表达率为27．34％。结论采用原代细胞贴壁培养法可成功分离培养人UCMSCs，在适当诱导条件下，UCMSCs可实现向神经细胞方向的成功分化，为脑创伤后神经组织修复、再生提供可能。     

音速波状蛋白促进骨髓间充质干细胞向多巴胺能神经元分化

目的探讨音速波状蛋白（Shh）促进人骨髓间充质干细胞（MSCs）体外定向分化为多巴胺能神经元样细胞的作用。方法体外分离、扩增和鉴定人骨髓MSCs。采用不同诱导方案诱导MSCs向神经元和多巴胺能神经元样细胞定向转化后,进行抗神经巢蛋白（Nestin）、神经元特异烯醇化酶（NSE）、神经胶质纤维酸性蛋白（GFAP）、酪氨酸羟化酶（TH）和多巴胺转运体（DAT）等免疫细胞化学染色,并计算阳性细胞百分率。结果实验组诱导后MSCs能分化为具有典型神经元形态的细胞,可见NSE、Nestin、GFAP、TH和DAT等神经细胞标志表达;对照组MSCs细胞形态无明显变化,上述特异性标志物表达均为阴性。实验2组（诱导方案含Shh）与1组（诱导方案不含Shh）的NSE、Nestin、GFAP阳性细胞百分率的差异无统计学意义,但实验2组TH和DAT阳性细胞百分率明显高于实验1组,差异具有统计学意义（P〈0.05）。结论Shh可促进MSCs分化为多巴胺能神经元样细胞。     

成年骨髓间质干细胞体外诱导分化成神经细胞研究

目的：探索成年骨髓间质干细胞（ABMMSC）诱导分化为神经细胞（神经元和神经胶质细胞）的可行性，为ABMMSC在神经科学领域内的应用提供 参考。方法：以成年犬ABMMSC为实验对象，利用碱性成纤维细胞生长因子（bFGF）、表皮生长因子（FGF）、维甲酸（RA）、脑源性神经营养因子（BDNF）、胶质细胞系源性神经营养因子（GDNF）等作为增殖及分化诱导因子，采用两步法进行增殖培养，分化诱导；免疫细胞化学法进行细胞性质鉴定。结果：加入bFGF、EGF后增殖培养48h，换液、去除非粘附细胞，再增殖培养72h ,可见细胞分裂相（成纤维细胞样细胞）和簇样克隆形成（中小型细胞）。加入RA、BDNF、GDNF诱导3d，部分细胞有神经元特异性烯醇酶（NSE）、胶质纤维酸性蛋白（GFAP）成分表达；第10d可见有神经元、神经胶质形态样细胞形成。经细胞成分（NSE、GFAP）鉴定证实为神经元、神经胶质细胞。结论：ABMSC在体外培养条件下，经过bFGF、EGF、RA、BDNF、GDNF等因子的“程序性”作用，可以向神经元、神经胶质前体细胞及其终末细胞方向分化。     

胶质细胞源性神经营养因子诱导骨髓基质细胞向多巴胺能神经元分化的观察

目的 探讨胶质细胞源性神经营养因子（GDNF）在体外能否诱导骨髓基质细胞（BMSCs）向多巴胺（DA）能神经元分化及可能机制。方法无菌条件下，抽取成年SD大鼠胫骨内骨髓组织，分离制备成单细胞悬液进行培养。将增殖传代至第5代的BMSCs随机分为GDNF诱导组和对照组。继续培养7d后，应用BrdU／GFAP、BrdU/NeuN和TH免疫荧光单标和双标技术检测BMSCs增殖和分化情况。结果两组BMSCs继续培养7d后，增殖仍然活跃，有部分细胞向神经元和胶质样细胞分化，呈Brdu，GFAP、BrdU/NeuN和TH阳性表达，但GDNF组的增殖力更强，向神经元和TH神经元分化的数量明显多于对照组（P〈0．05）。结论GDNF能促进BMSCs的增殖和诱导BMSCs分化成神经元和胶质样细胞，其中少部分可分化为TH神经元（即DA能神经元）。     

红景天苷诱导间充质干细胞向多巴胺神经分化

目的探讨红景天苷（SD）诱导大鼠骨髓间充质干细胞（BMSCs）向多巴胺能神经细胞分化的影响。方法实验分为红景天苷组,维甲酸（RA）组和空白对照组,SD和RA分别诱导BMSCs1d、3d、6d和9d,细胞免疫荧光化学法检测神经细胞相关标志分子神经元特异性烯醇化酶（NSE）、神经微管相关蛋白2（MAP2）、抗微管蛋白（B—Tubulin III）和神经胶质原纤维酸性蛋白质（GFAP）以及与多巴胺能神经元相关的关键酶多巴脱羧酶（DBH）和多巴胺-β-羟化酶（DDC）的表达;逆转录-聚合酶链反应（RT-PCR）检测诱导前后神经元特异性烯醇化酶和神经胶质纤维酸性蛋白、核受体相关因子1（Nurrl）、神经营养因子-3（NT-3）和酪氨酸羟化酶（TH）mRNA的表达;酶联免疫吸附法评价诱导前后细胞表达NT-3、脑源性神经营养因子（BDNF）的水平。结果SD和RA分别诱导BMSCs6d和9d时细胞增殖明显增强,与空白对照组相比差异有统计学意义（P〈0．05）,诱导3d后NSE、MAP2和13-Tublin III表达阳性,红景天苷组GFAP表达阳性,维甲酸组GFAP表达阳性。6d时NSE表达丰度上调;1d、3d和6d诱导组NurrlmRNA表达丰度上调,红景天苷组NT-3mRNA表达水平与维甲酸组比较明显上调,SD组6d时THmRNA表达上调。诱导组DBH和DDC阳性率与对照组相比差异具有统计学意义（P〈0．05）。诱导组NT-3和BDNF细胞因子含量增加与对照组相比差异具有统计学意义（P〈0．01）。结论红景天苷能诱导BMSCs分化为具有多巴胺功能的神经细胞。     

碱性成纤维细胞生长因子预诱导对骨髓基质干细胞向多巴胺能神经元分化的影响

目的探讨碱性成纤维细胞生长因子（bFGF）预诱导对骨髓基质干细胞（MSCs）向多巴胺（DA）能神经元分化的影响。方法取雄性Wistar大鼠股骨和胫骨骨髓，进行MSCs的体外培养、传代扩增及纯化。bFGF预诱导24h后，依据加入的神经营养因子不同分为单唾液酸四己糖神经节苷脂（GMl）组、胶质源性神经营养因子（GDNF）组和GDNF＋GMl组，以及对照组。倒置显微镜下观察细胞形态变化，分别在预诱导第3d、7d进行神经元特异性烯醇化酶（NSE）、神经胶质酸性蛋白（GFAP）、酪氨酸羟化酶（TH）免疫细胞化学检测。计数NSE和TH阳性细胞数，并计算阳性细胞百分比。结果对照组见少量NSE阳性细胞。实验组于诱导第3d、7d见较多数量的NSE、TH阳性细胞，GFAP阴性。bFGF预诱导各组中GDNF＋GMl组NSE、TH阳性细胞率最高，GDNF组次之，GMl组最低，组间比较差异有统计学意义（均P〈0．01）。结论bF—GF预诱导不仅可明显促进GDNF、GMl诱导MSCs向神经元样细胞分化，表达神经元细胞标志物——NSE；还可促进MSCs向DA能神经元分化，表达DA能神经元标志物——TH。     

大鼠骨髓基质细胞体外培养向神经干细胞的诱导分化

目的：已证实骨髓基质细胞可分化为中胚层组织细胞，实验予进一步探讨体外分离培养的骨髓基质细胞向神经干细胞分化的可能性，以及是否能继续定向分化为神经细胞及神经胶质细胞，为神经系统疾病细胞移植治疗提供种子细胞。 方法：实验于2007-02/09在泸州医学院神经生物学研究室进行。①动物：选择5只普通级SD大鼠，由泸州医学院实验动物中心提供，实验过程中对动物的处置符合动物伦理学标准。②实验方法：大鼠戊巴比妥钠腹腔麻醉，取双侧胫骨和股骨，磷酸盐缓冲液冲洗骨髓腔，采用密度梯度离心法从大鼠骨髓中分离培养骨髓基质细胞，胰蛋白酶与EDTA联合消化，传至第4代，用含20 μg/L碱性成纤维细胞生长因子、20 μg/L表皮生长因子、N2辅助因子的DMEM/F12培养液向神经干细胞诱导分化。③实验评估：观察原代、传代培养及诱导分化后的骨髓基质细胞生长情况和形态变化，采用SABC法进行免疫细胞化学检测神经细胞特异性标志的表达。 结果：①骨髓基质细胞形态观察：原代细胞接种1 d后开始贴壁增殖，3 d后多数贴壁，贴壁细胞呈梭形或扁平形；10 d后90%细胞融合，以长梭形为主，突起粗大，形成网状、片状；传代后细胞贴壁速度加快，增殖能力更强，7 d左右达到融合。②诱导分化后细胞生长情况和形态变化：第4代骨髓基质细胞向神经干细胞诱导分化7 d，成球的细胞脱离瓶底，悬浮在细胞液中。将细胞离心弃上清，换成血清分化液后，细胞球逐渐贴壁，球周围很快发出突起，分化为星形胶质细胞样细胞、神经元样细胞及少突胶质细胞样细胞。③神经细胞特异性标志的表达：骨髓源性细胞球表达巢蛋白，呈棕黄色，为神经干细胞；从细胞球分化的细胞抗胶质纤维酸性蛋白、微管相关蛋白2及半乳糖脑苷脂均呈阳性。 结论：骨髓基质细胞能在体外诱导分化出神经干细胞，且骨髓源性神经干细胞可进一步定向分化为神经细胞及神经胶质细胞。     

Diagnostic Difficulties and Treatment Implications

Summary: Differentiation between types of epileptic seizures has been aided in recent years by the introduction of intensive neurodiagnostic techniques and the development of increasingly detailed classification systems. Paradoxically, these developments have not simplified the task of matching the appropriate antiepileptic drug to a particular seizure type. It is reasonable to assume that anticonvulsant drugs will have different effects on different types of seizures, but faulty, circular reasoning can enter the picture if one also assumes that responses of seizures to different drugs signify different seizure types. There are several examples of differential diagnoses that can fall prey to this problem, including the diagnosis between partial seizures with secondary generalization and generalized tonic-clonic seizures, and the diagnosis between complex partial seizures and absence seizures with automatisms, among others. Considerations of etiology in future classification systems can further complicate the problem: should one then choose an anticonvulsant drug on the basis of individual seizure type or on the basis of the type of epilepsy? Ramifications of this issue extend even to the drug approval process. Official sanction is not given for use of a drug for a seizure type not included in the original efficacy studies, even if later scientific evidence shows that seizure type to be related to a type that is included. New trials must be undertaken. These problems arise from how we choose to classify seizures.     

Cognitive Dysfunction Associated with Antiepileptic Drug Therapy

Summary: Epilepsy is frequently associated with cognitive dysfunction. However, the reasons for this correlation are unclear. Possible influential factors include patient age; duration, frequency, etiology, and type of seizures; hereditary factors; psychosocial issues; and antiepileptic drug (AED) therapy. Whereas many of these factors are beyond the physician's control, AED therapy is one element that can be addressed in treatment decisions by recognizing the potential cognitive effects of particular AEDs. For example, phenobarbital impairs memory and concentration; phenytoin affects attention, problem solving ability, and performance of visuomotor tasks. In contrast, carbamazepine may affect concentration, while valproate would appear to have minimal effects on cognition. Moreover, cognitive effects of AEDs are amplified with coadministration of multiple anticonvulsants (polytherapy). A review of studies on the cognitive effects of monotherapy with AEDs, as opposed to those of polytherapy, provides evidence that drug-related cognitive dysfunction can be reversed if patients are switched to a simpler therapeutic regimen. Future research should be directed toward developing reliable measures for assessing and monitoring cognition, and understanding the particular cognitive side effects of each AED. Physicians also need to revise their opinions about which side effects are "tolerable" for epileptic patients.     

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.     

Carbamazepine Efficacy in Adults With Partial and Generalized Tonic-Clonic Seizures

Summary: Carbamazepine and phenytoin are drugs of choice in initial monotherapy for adult partial and secondarily generalized tonic-clonic seizures. These designations reflect the results of the Veterans Administration Epilepsy Cooperative Study Group of 1985. An earlier comparative study of carbamazepine and phenytoin by Ramsay and associates found both drugs equally effective in controlling new-onset seizures. Among the advantages of carbamazepine is that it causes relatively few cognitive and dysmorphic side effects. Its disadvantages are its unavailability in parenteral formulation and its metabolic autoinduction. The latter must be compensated for by planned dosage increases to maintain therapeutic plasma steady-state levels during the first 2 or 3 months of treatment. Carbamazepine is judged a drug of choice in the treatment of these secondarily generalized tonic-clonic seizures, and the drug of choice in children, adolescents, and women susceptible to the dysmorphic side effects associated with other anticonvulsant agents.     

Etiologic and Preventive Aspects of Epilepsy in the Child–Bridging the Gap Between Laboratory and Clinic

Summary: Four broad categories of basic phenomena are pertinent to developing ways to prevent epilepsy. These include mechanisms of epileptogenesis, ictal initiation and temporary entrainment by the seizure discharge of normally functioning brain, seizure propagation, and control mechanisms that function both to restrain the cascade of epileptic events culminating in a seizure and to arrest the epileptic event and restore the interictal state. In newborns and children, hypoxia-ischemia is a major factor leading to epileptogenesis, and several schemes are proposed to classify, quantify, and prevent hypoxic-ischemic encephalopathy. Control mechanisms must be better understood in order to develop prophylactic recommendations for epilepsy, and an experimental model of "kindling antagonism" may increase our understanding of these. Programs of prevention of seizures in children will evolve only if basic researchers and clinicians work productively together to develop an adequate understanding of factors important in epileptogenesis and antiepileptogenic control mechanisms.     

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.     

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.     

Predisposing and Causative Factors in Childhood Epilepsy

Summary: We review information from large studies of defined populations, examining the role of known factors and especially of prenatal and perinatal factors in contributing to nonfebrile seizure disorders of early childhood. We depend especially, but not exclusively, on the recently completed analyses from the Collaborative Perinatal Project of the National Institute of Neurological and Communicative Disorders and Stroke, the NCPP. About 4% of children in the NCPP who had at least one non-febrile nonsymptomatic seizure by the age of 7 years had a previous seizure during acute neurologic illness, such as meningitis or during the acute illness after trauma. Many such seizures should potentially be preventable. Of children with seizures, 10% had had a neonatal seizure and 13% had had a febrile seizure. Among the hundreds of prenatal and perinatal factors explored as predictors of childhood seizure disorders, the principal predictors identified were congenital malformations of the fetus, cerebral and noncerebral; family history of certain neurologic disorders; and neonatal seizures. In agreement with the British National Child Development Study, labor and delivery factors in the NCPP appeared to contribute very little to childhood seizure disorders. Maldevelopment, rather than damage at birth to an initially intact nervous system, appeared to be the more common mechanism. Most seizure disorders of early childhood remained unexplained by the large set of prenatal and perinatal characteristics examined.     

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.