携带肝细胞生长因子的腺病毒感染脐带间充质干细胞的实验研究

目的通过检测感染携带肝细胞生长因子(HGF)腺病毒的脐带间充质干细胞(hUC-MSC)内酪氨酸羟化酶(TH)、多巴胺转运体(DAT)和多巴胺(DA)的表达水平及动态变化,探讨hUC-MSC在HGF过表达的情况下是否能向多巴胺能神经元分化,为HGF基因修饰hUC-MSC治疗帕金森病提供细胞基础。方法采用组织块法分离培养hUC-MSC,流式细胞仪检测细胞是否表达间充质干细胞分子表面标志CD29、CD44和CD105;不同感染复数(0、50、100、150、200、400)的携带绿色荧光蛋白的腺病毒(Ad-GFP)感染hUC-MSC后,流式细胞仪检测感染效率,并确定最佳感染复数;运用携带HGF的腺病毒感染hUC-MSC后,细胞免疫酶化学方法检测TH和DAT的表达情况。结果采用组织块法可从脐带中成功分离出(表达间充质干细胞分子表面标志CD29、CD44和CD105)hUC-MSC;Ad-GFP可高效感染hUC-MSC,随着感染复数的升高,感染效率可达99.99%;感染携带HGF的腺病毒(Ad-HGF)后,hUC-MSC可逐渐表达TH和DAT,同时细胞形态也逐渐由纺锤状向多角形和不规则样转变。结论腺病毒可高效感染hUC-MSC;感染Ad-HGF后,hUC-MSC可逐渐向多巴胺能样神经元分化。     

老年慢性精神分裂症和Alzheimer病的非匹性负波比较

目的 探讨老年慢性精神分裂症(SCS)和Alzheimer病(AD)在非匹性负波(MMN)检测中的特征.方法 应用美国Nicolet BRAVO脑电生理仪,对38例SCS和32例Alzheimer病(AD组)及40例正常老人(NC组)的MMN作检测.结果(1)与正常老年组比较,AD组MMN潜伏期延迟,波幅降低;(2)SCS组无上述变化;(3)AD组MMN潜伏期延迟及波幅低于SCS组.结论 MMN技术可作为P300检测的一种补充手段,而用于老年精神科临床.     

胆固醇与Alzheimer病危险性

Alzheimer病(AD)是一种病因不明的老年常见的进行性变性疾病。研究表明,胆固醇在AD的发生中起着重要的作用。本文综述了目前关于胆固醇及与AD的相关性研究报道,并对胆固醇和AD之间可能的作用机制进行探讨,为进一步研究AD的可能病因和治疗提供参考。     

老年期抑郁症和Alzheimer病的失匹性负波研究

目的 探讨老年期抑郁症(SD)和Alzheimer病(AD)患者在失匹性负波(MMN)检测中的特征.方法 应用美国Nicolet BRAVO脑电生理仪,对31例SD和30例AD及33名正常老人(NC组)的MMN进行了检测.结果 与正常老年组比较,AD组MMN潜伏期延迟,波幅降低.而SD组无上述变化.AD组MMN潜伏期延迟及波幅低于SD组.结论 MMN技术可作为P300检测的一种补充手段,用于老年精神科临床.     

阿尔茨海默病脑海马凋亡神经元发生率增高

通过对阿尔茨海默病 (Alzheimer’sdisease ,AD)和老年对照患者死后脑海马凋亡神经元的检测 ,探讨AD脑神经元丢失的可能机制。使用TUNEL(terminaltransferase mediateddUTP biotinnickendlabeling)法对 7例确诊的AD和 9例老年对照患者死后海马组织中的凋亡神经元进行标记 ,用生物图像分析系统对结果进行定量分析。AD和对照组间TUNEL阳性细胞数无显著性差异 ;AD组海马CA1和CA4区正常神经元数减少 ,其中CA1区减少具有显著性差异 (P <0 .0 5 ) ;AD组海马CA1和CA4区凋亡神经元发生率高于对照组 ,其中CA1区具有显著性差异 (P <0 .0 5 )。AD组海马组织中凋亡神经元发生率明显增高 ,说明细胞凋亡可能参与了AD海马神经元退行性变的过程。     

轻度认知功能障碍老年人的失匹配性负波研究

目的研究轻度认知功能障碍老年人(MCI)失匹配性负波(MMN)的特征.方法应用美国Nicolet BRAVO脑电生理仪,对36例MCI和30例阿尔茨海默病(AD组)及45名正常老人(NC组)的MMN作了检测.结果(1)与正常老年组比较,AD组MMN潜伏期延迟,波幅降低.(2)MCI组无上述变化.(3)AD组MMN潜伏期延迟及波幅低于MCI组.结论MMN技术可作为P300检测的一种补充手段,而用于老年精神科临床.     

阿尔茨海默病脑海马凋亡神经元发生率增高

通过对阿尔茨海默病(Alzheimer's disease,AD)和老年对照患者死后脑海马凋亡神经元的检测,探讨AD脑神经元丢失的可能机制.使用TUNEL(terminal transferase-mediated dUTP-biotin nick end labeling)法对7例确诊的AD和9例老年对照患者死后海马组织中的凋亡神经元进行标记,用生物图像分析系统对结果进行定量分析.AD和对照组间TUNEL阳性细胞数无显著性差异;AD组海马CAl和CA4区正常神经元数减少,其中CAl区减少具有显著性差异(P《0.05);AD组海马CAI和CA4区凋亡神经元发生率高于对照组,其中CAl区具有显著性差异(P《0.05).AD组海马组织中凋亡神经元发生率明显增高,说明细胞凋亡可能参与了AD海马神经元退行性变的过程.     

缺氧与阿尔茨海默病:低氧诱导因子-1的作用

阿尔茨海默病(Alzheimer's disease,AD)是最常见的老年神经变性疾病,其临床诊疗重视“早期发现、早期诊断、早期治疗”.体液或脑内有特定的AD生化、病理等改变,但未出现临床症状的AD称为临床前期阿尔茨海默病(Preclinical AD,PCAD).确定PCAD的危险因素,并进行早期干预对AD的防治有重要意义.缺氧是临床上常见的疾病病理过程,也是AD等多种神经变性疾病的重要危险因素.缺氧导致AD或促进AD病程进展的可能机制受到了广泛的关注和研究,本文就缺氧导致β-淀粉样蛋白(Aβ)沉积、tau蛋白异常磷酸化和神经元变性死亡的机制进行了综述,着重讨论了低氧诱导因子(hypoxia inducible factor 1,HIF-1)在其中的复杂作用.     

男性痴呆患者血清性激素的变化

目的:观察阿尔茨海默病(AD)和血管性痴呆(VD)男性患者血清性激素及促性腺激素的变化。方法:老年男性共114人,其中AD 3 2例;VD 3 0例;无痴呆正常老年人5 2名。采用化学发光法测定血中黄体生成素(LH )、促卵泡成熟素(FSH)、雌二醇(E2 )、催乳素(PRL)、睾酮(T)的含量,并计算E2 /T的比值。结果:AD组及VD组患者血清T水平较正常对照组低,差别有显著意义(P <0 .0 5 ,P <0 .0 1)。VD组患者血清E2 /T较正常对照组显著升高;也较AD组明显升高(P <0 .0 1,P <0 .0 5 )。AD、VD组患者血清E2 、LH、FSH、PRL与正常对照组比较,差别均无显著意义(P >0 .0 5 )。结论:老年男性AD及VD患者血清T水平降低。     

hUC-MSC在成神经分化过程中的趋化迁移研究

目的探究人脐带间充质干细胞(human umbilical cord mesenchymal stem cells,hUC-MSC)向神经样细胞的分化,并对其分化的神经样细胞的趋化作用进行研究。方法检测hUC-MSC细胞表面的标记;无血清的诱导培养基[含2%二甲基亚砜(DMSO)和200μmol/L丁羟基茴香醚(BHA)]诱导其向神经细胞分化,并进行神经细胞特异性标志物神经上皮干细胞蛋白(nestin)和神经元特异性烯醇化酶(NSE)的免疫荧光染色检测,并对分化的成神经诱导过程中的形态变化进行鉴定。此外,不同分化状态的hUC-MSC,在加入500μL含有20 ng/mL浓度的基质细胞衍生因子(stromal Cell-derived Factor-1α,SDF-1α)的不含血清的L-DMEM培养基,利用倒置相差显微镜下拍照,统计迁移至室膜下方的细胞数。结果成功分离出hUC-MSC,行流式细胞仪检测结果显示MSC:CD71+、CD29+,而CD34-、CD45-符合MSC的生物学特征。对不同诱导时间的hUC-MSC免疫荧光结果的统计学分析,nestin的表达呈现出先增高后降低的趋势,NSE在诱导期和维持前期均为阴性,在整个过程中末期才开始表达,到维持48 h时有62.5%的细胞表达,维持72 h时有76.5%的细胞表达。不同成神经分化状态的hUC-MSC迁移能力不同,诱导30 h,细胞向SDF-1α的趋化迁移能力达到最强。结论hUC-MSC具有易分离并扩增培养的生物特性,能诱导分化成为成神经细胞,并且具有一定的迁移能力,该研究能为中枢神经系统细胞的移植提供理论基础。     

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.     

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.     

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.     

Anticonvulsant Drugs and Cognitive Function: A Review of the Literature

Summary: Alterations of cognitive function are separate from disturbances of behavior seen in association with epilepsy. The nature of the cognitive disability may to a certain extent depend on the seizure type. Partial seizures, mainly derived from a temporal lobe focus, impair memory tasks, while generalized seizures seem to have more effect on attentional abilities. A number of studies, reviewed in this paper, suggest that anticonvulsant drugs further impair cognitive function. Maximal impairments are seen in patients receiving polytherapy: rationalization of polytherapy improves cognitive abilities. Studies in children and adults have allowed differentiation of the effects of various commonly used antiepileptic agents. Maximal cognitive deficits are seen with. phenytoin, while phenobarbital and sodium valproate induce moderate disturbances, and carbamazepine seems relatively free from such toxicity. Further research is needed on the interrelationship between types of seizure disorders, types of anticonvulsant medications, and cognitive function.     

Treatment Considerations in Anticonvulsant Monotherapy

Summary: The long-standing practice of polypharmacy in treating epilepsy is giving way to use of monotherapy. Monotherapy can improve seizure control as well as reduce the risk of serious idiosyncratic reactions, dose-related side effects, and complex drug interactions. Monotherapy also offers improved compliance and cost-effectiveness. The basis of monotherapy is accurate diagnosis and assessment of the patient's seizure type(s), followed by selection of a single appropriate anticonvulsant drug. Many patients currently treated with multiple anticonvulsants can be successfully converted to monotherapy with a carefully monitored program in which troublesome and redundant drugs are gradually withdrawn from the therapeutic regimen.     

Effects of NMD A- and AMPA-Receptor Antagonists on Different Forms of Epileptiform Activity in Rat Temporal Cortex Slices

Summary: Lowering extracellular magnesium induces different patterns of epileptiform activity in rat hippocampus and entorhinal cortex. Short recurrent epileptiform discharges in the hippocampus are stable over time, whereas seizurelike events (SLEs) in the entorhinal cortex, the subiculum, and the neighboring neocortex develop into late recurrent discharges which are not blocked by clinically employed antiepileptic drugs. We tested the sensitivity of the different epileptiform discharge patterns to. /V-methyl-D-aspartate (NMDA)- and non-NMDA-receptor antagonists. As NMDA-receptor antagonist we used dextrorphan, ket-amine, and 2-aminophosphonovalerate (2APV); as α-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA)-receptor antagonist we employed the quinoxaline derivative glutamate 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX). The findings show that the different patterns of epileptiform activity, including the late recurrent discharges, are sensitive to all NMDA-receptor antagonists. However, when dextrorphan was employed to suppress seizure-like events, later recurrent discharges did not develop during the remaining time course of the experiment. CNQX reversibly suppressed recurrent discharges in the hippocampus and SLEs in the entorhinal cortex. However, late recurrent discharges become insensitive to CNQX, even at a high concentration of 60 μM m. This finding suggests a prominent role for NMDA receptors in the generation of late recurrent discharges.     

Dextromethorphan: Cellular Effects Reducing Neuronal Hyperactivity

Summary: Dextromethorphan is a dextrorotary morphinan without affinity for opioid receptors, commonly used as an antitussive medication. During the past 5 years, interest in the compound and its demethylated derivative, dextrorphan, has been revived because additional neuroprotective and an-tiepileptic properties were found in in vitro studies, animal experiments, and a few clinical cases. Both morphinans are able to inhibit N -methyl-D-aspartate (NMDA) receptor channels and voltage-operated calcium and sodium channels with different potencies. The inhibition of the NMDA receptor is believed to be the predominant mechanism of action responsible for the anticonvulsant and neuroprotective properties of the compounds.