脂质体介导CD基因转染SHG-44胶质瘤细胞凋亡的实验研究

目的以含胞嘧啶脱氨酶（CD）基因的pCMVCD重组表达质粒转染SHG-44胶质瘤细胞，体外观察5-氟胞嘧啶（5-FC）对转染CD基因的胶质瘤细胞的凋亡诱导作用。方法体外扩增、酶切鉴定pCMVCD质粒并采用DNA序列测定pCMVCD质粒中的CD基因；脂质体Lipofectamine 2000介导pCMVCD质粒转染SHG-44细胞，G418筛选培养获取抗性细胞克隆（即SHG-44／CD细胞）；免疫细胞化学检测SHG-44／CD细胞的CD基因蛋白水平表达；流式细胞仪、TUNEL实验及透射电子显微镜观察5-FC对表达CD基因的SHG-44／CD细胞凋亡的诱导作用。结果含CD基因的pCMVCD质粒成功转染进入SHG-44细胞，获取了含CD基因的SHG-44／CD细胞，免疫细胞化学染色显示SHG-44／CD细胞成功地表达了CD。在含5-FC的培养液中培养，SHG-44／CD细胞出现典型的凋亡形态，TUNEL显示凋亡细胞比例极高；透射电镜可见凋亡改变；流式细胞术检测凋亡率达18．6％，凋亡率呈剂量依赖性。结论建立了SHG-44恶性人脑胶质瘤细胞的CD／5-FC自杀基因系统。诱导SHG-44／CD胶质瘤细胞产生凋亡可能是脑胶质瘤CD基因疗法的重要机制。     

三氧化二砷对人脑SHG-44胶质瘤细胞作用的体外实验研究

目的 探讨三氧化二砷(As2O3)对人脑SHG-44胶质瘤细胞株的增殖抑制及诱导凋亡机制.方法 将不同浓度的As2O3与体外培养的SHG-44胶质瘤细胞相互作用后,采用MTT比色法检测As2O3对胶质瘤细胞的增殖抑制;倒置显微镜、荧光显微镜下观察吉姆萨及Hochest33258染色后细胞凋亡的形态学改变;流式细胞仪检测细胞凋亡及对SHG-44胶质瘤细胞周期影响.结果 MTT比色法检测到As2O3对SHG-44胶质瘤细胞增殖具有明显的抑制作用,并呈剂量依赖性和时间依赖性;倒置显微镜及荧光显微镜下可观察到给药组细胞生长密度低以及出现细胞凋亡的特征性改变;流式细胞仪检测到给药组细胞凋亡比率明显高于空白对照组(P＜0.05),并具有剂量依赖性及时间依赖性,同时将胶质瘤细胞阻滞在S期,抑制了细胞周期的进程.结论 As2O3对SHG-44胶质瘤细胞增殖具有明显的抑制作用、可诱导SHG-44胶质瘤细胞的凋亡,并抑制细胞周期进程.     

外源性IFN—β基因稳定转染对胶质瘤细胞凋亡的影响

目的研究外源性干扰素—β(IFN-β)基因对胶质瘤细胞系SHG-44的诱导凋亡作用，探索胶质瘤基因治疗的新途径。方法利用脂质体转染方法将IFN-β真核表达载体pSV2IFNβ导入人SHG44胶质瘤细胞。应用流式细胞仪和免疫荧光法检测IFN-β基因的稳定转染及表达，利用Hoechst染色、透射电镜观察细胞凋亡情况。结果IFN-β基因成功转染SHG44胶质瘤细胞并得以表达，并诱导SHG44胶质瘤细胞凋亡。结论IFN-β能够诱导入SHG44胶质瘤细胞凋亡，本实验为IFN-β基因治疗人脑胶质瘤的应用奠定了初步基础。     

TNF-α基因与依托泊甙联合诱导胶质瘤凋亡的实验研究

目的在体外水平(invitro)建立对胶质瘤杀伤作用的TNF-α基因/VP16系统,研究该系统诱导胶质瘤凋亡的作用。方法用逆转录病毒载体将TNF-α基因转染人胶质瘤细胞株SHG-44,经生长抑制试验,比较转TNF-α基因前后SHG-44细胞对依托泊甙(Etioposide,VP16)的敏感性,并通过形态学及流式细胞仪检测VP16诱导转基因细胞凋亡的情况。结果生长抑制试验表明,转染TNF-α基因后的SHG-44细胞对VP16的敏感性是转基因前细胞的10倍(P＜0.01),IC50为0.8μg/mL。流式细胞检测表明,VP16对转TNF-α基因细胞有较强的诱导凋亡的能力。结论VP16对转TNF-α基因SHG-44细胞诱导凋亡的能力大大增加,表明TNF-α基因/VP16系统对胶质瘤的基因治疗有效。     

白藜芦醇抑制SHG-44胶质瘤细胞生长实验研究

目的探讨白藜芦醇(Res)在体外诱导脑胶质瘤SHG-44细胞凋亡并抑制其生长的作用。方法四甲基偶氮唑蓝(MTT)比色法测量不同剂量的Res作用6h、24h和48h后对SHG-44胶质瘤细胞增殖的影响。HE染色、Hoechst33342荧光染色观察细胞形态改变,DNAladder检测细胞DNA裂解情况,流式细胞仪用异硫氰酸荧光素标记的膜联蛋白V(AnnexinV-FITC)和碘化丙啶(PI)双染检测凋亡率,并测定细胞周期的改变。结果Res明显抑制SHG-44细胞的生长和增殖(P<0.01),呈浓度及时间依赖性反应;Res所致的SHG-44胶质瘤细胞凋亡为浓度依赖关系,随着浓度的增高,凋亡更明显。此凋亡细胞周期主要发生G1期比例升高,S、G2期比例降低。结论Res明显抑制SHG-44细胞生长并诱导其发生凋亡和细胞周期改变,为Res用于治疗脑胶质细胞瘤提供了实验依据。     

胞嘧啶脱氨酶自杀基因转染SHG-44胶质瘤细胞的实验表达研究

目的以含胞嘧啶脱氨酶（CD）基因的重组表达质粒（recombinant plasmid vector）pCMVCD转染SHG-44胶质瘤细胞，建立胶质瘤嘧啶脱氨酶／5-氟胞嘧啶（CD／5-FC）自杀基因治疗系统。方法体外扩增、酶切鉴定pCMVCD质粒并采用DNA序列测定pCMVCD质粒中的CD基因；改良Eagle培养基（DMEM）培养SHG-44胶质瘤细胞；脂质体lipofectamine2000介导pCMVCD质粒转染SHG-44细胞，G418筛选重组子；免疫细胞化学检测表达情况。结果测序证实pCMVCD质粒含有CD基因；脂质体成功介导pCMVCD质粒转染SHG-44细胞，获取了抗性细胞克隆（定名SHG-44／CD细胞）；免疫细胞化学染色显示SHG-44／CD细胞成功地表达了CD。结论脂质体介导pCMVCD质粒转染SHG-44细胞的方法简单、高效；成功建立了胶质瘤CD／5-FC自杀基因治疗系统，为后续实验研究打下了基础。     

脂质体转染人IFN-β基因诱导胶质瘤细胞SHG44凋亡的实验研究

目的探讨人β干扰素(IFN-β)与胶质瘤细胞凋亡的关系及意义.方法利用脂质体转染方法将IFN-β真核表达载体pSV2IFN-β导入SHG44胶质瘤细胞.细胞免疫荧光和免疫组化检测IFN-β基因的稳定转染及表达,利用流式细胞仪、透射电镜观察细胞凋亡情况.结果IFN-β基因成功转染SHG44胶质瘤细胞并得以表达.转染细胞的凋亡细胞数与未转染细胞相比有显著性差异.结论IFN-β能够诱导人SHG44胶质瘤细胞凋亡.     

五味子甲素通过ATP结合盒转运子B1逆转胶质瘤干/祖细胞耐药性研究

目的探讨五味子甲素对胶质瘤干/祖细胞耐药性的影响及作用机制。方法自人胶质瘤细胞系SHG-44中分离培养胶质瘤干/祖细胞SHG-44s,予五味子甲素0、12.50、25.00和50.00μmol/L联合长春新碱400、800和1200 nmol/L,细胞活性检测试剂盒CCK-8细胞毒性实验检测SHG-44s细胞增殖活性,罗丹明123染色检测SHG-44s细胞泵出药物能力,实时聚合酶链反应(PCR)和Western blotting法检测SHG-44s细胞ATP结合盒转运子B1(ABCB1)基因转录和翻译能力。结果五味子甲素50μmol/L即可抑制SHG-44s细胞增殖活性(P=0.001,0.001,0.039),剔除这一浓度后无论长春新碱浓度为400、800或1200 nmol/L,联合应用五味子甲素均可抑制SHG-44s细胞增殖活性(长春新碱400 nmol/L组:P=0.007,0.001;长春新碱800 nmol/L组:P=0.001,0.000;长春新碱1200 nmol/L组:P=0.000,0.000)。倒置荧光显微镜观察,五味子甲素12.50μmol/L组和25.00μmol/L组SHG-44s细胞可见明显绿色荧光。流式细胞术显示,随着五味子甲素浓度的增加,SHG-44s细胞罗丹明123染色阳性细胞比例分别为10.40%、39.20%和45.20%。实时PCR法显示,五味子甲素12.50μmol/L组和25.00μmol/L组SHG-44s细胞ABCB1基因表达水平较0μmol/L组降低(P=0.027,0.006),尤以25.00μmol/L组显著(P=0.034)。Western blotting法显示,随着五味子甲素浓度的增加,SHG-44s细胞P-糖蛋白表达水平下降。结论五味子甲素通过抑制胶质瘤干/祖细胞表面已存在的ABCB1基因编码的P-糖蛋白泵出药物能力并降低ABCB1基因转录和翻译能力,逆转胶质瘤干/祖细胞耐药性。     

NEDD4-1 shRNA对U251胶质瘤细胞增殖和凋亡的影响

目的探讨NEDD4-1 shRNA对U251胶质瘤细胞增殖及凋亡的影响。方法构建NEDD4-1 shRNA表达载体。以不同比例质粒和脂质体转染U251细胞,通过荧光显微镜观察细胞存活情况,优化转染效率。转染48 h后采用Western blot、RT-PCR分别检测NEDD4-1蛋白及mRNA的表达,流式细胞术检测细胞周期,MTT法检测细胞增殖,DAPI荧光染色检测细胞凋亡。结果 NEDD4-1 shRNA表达载体构建成功。脂质体与质粒的最佳转染效率比例为2.5μl∶1μg,48 h转染效率在60%～70%。与对照组比较,转染NEDD4-1 shRNA后,U251胶质瘤细胞NEDD4-1的蛋白及mRNA表达水平均下降(均P<0.05),细胞大多停滞在G0-G1期(均P<0.05),增殖率明显降低(均P<0.05),凋亡率显著增加(均P<0.05)。结论 NEDD4-1作为PTEN泛素连接酶,为胶质瘤基因治疗提供靶点。     

针对MAGE-1基因RNAi在恶性胶质瘤SHG-44细胞中的作用研究

目的构建抑制黑色素瘤抗原-1(MAGE-1)的siRNA表达载体,鉴定其在人恶性胶质瘤细胞系SHG-44细胞中对MAGE-1基因表达的干涉作用。方法化学合成2对编码短发夹RNA序列的靶向MAGE-1基因寡核苷酸链,克隆到经BglⅡ、HindⅢ双酶切的pSUPER载体上,重组构建RNA干涉(RNAi)质粒载体。利用逆转录多聚酶链反应(RT-PCR)、流式细胞术和荧光显微镜,检测经稳定转染后SHG-44细胞中MAGE-1的表达,以了解siRNA的干扰效果。结果重组构建的pSUPER-MAGE-1载体经双酶切电泳及插入基因片段序列分析,表明寡核苷酸链成功插入到预计位点,并且序列与预期完全一致。稳定转染后G418筛选出的SHG-44多克隆细胞MAGE-1的表达经RT-PCR、流式细胞术和荧光显微镜检测,2对siRNA均有较明显的干涉作用。结论成功构建了针对MAGE-1基因的siRNA表达载体,抑制SHG-44细胞中的MAGE-1分子的表达。     

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.