稳定整合靶向性Survivin基因RNA干涉载体胶质瘤细胞系的建立

目的构建针对细胞凋亡抑制蛋白survivin（SVV）基因的特异性RNA干涉载体,并建立稳定转染该干涉载体的人胶质瘤细胞系。方法设计合成针对SVV基因和针对荧火虫荧光素酶（FLF）基因特异性RNA干涉片断,并分别克隆入pSilencer3．1-H1neo载体中,成功构建SVV基因RNA干涉载体pSilencer3．1-SVV和无关序列载体pSilencer3．1-FLF。RNA干涉载体、无关序列载体和空白载体经脂质体法转染胶质瘤细胞系U251,经G418筛选,采用实时定量反转录聚合酶链反应（real—timeRT—PCR）、免疫蛋白印迹（Western blot）和免疫细胞化学方法分别检测SVV基因在转染细胞中的表达情况。结果酶切鉴定和核苷酸序列分析证实,成功构建了SVV基因RNA干涉载体pSilencer3．1-SVV。获得了稳定转染干涉载体、无关序列载体和空白载体的细胞系分别命名为U251-S、U251-F和U251-P。U251-S细胞中SVV的mRNA和蛋白表达受到明显抑制,U251-F和U251-P细胞中SVV基因表达水平无明显变化。结论SVV基因特异性RNA干涉载体能够明显抑制SVV基因在U251细胞中的表达,这为进一步研究SVV在胶质瘤细胞系U251中的生物学功能和作用机制奠定了实验基础。     

靶向人端粒酶逆转录酶小片段干涉RNA表达载体的构建和表达

目的构建靶向人端粒酶逆转录酶（hTERT）的小片段RNA（siRNA）表达载体，为研究RNA干涉（RNAi）在哺乳动物细胞内抑制靶基因表达奠定基础。方法根据siRNA靶点设计的原则运用相关软件设计靶序列并合成其表达框，连接人质粒载体pRNAT-H1．1／Neo，转染293T细胞，荧光定量RT．PCR和Western blot法检测转染后293T细胞中hTERT表达。结果重组质粒经测序鉴定证明hTERTsiRNA转录模板完整、正确插入到pRNAT．H1．1／Neo质粒中，并筛选出一个抑制hTERT表达效率最高的序列，其hTERT表达仅达22．90％。结论利用基因重组和荧光定量PCR等技术能成功构建并筛选出一个抑制效率最好的靶向hTERT的siRNA表达载体，为以hTERT为靶点的肿瘤基因治疗的后续研究奠定基础。     

Livin基因短发卡RNA表达质粒的构建及其对胶质瘤Livin基因表达的影响

目的构建凋亡抑制基因livin基因的特异性短发卡RNA（siRNA）真核表达载体,并观察其在人脑胶质瘤细胞中对livin基因表达的抑制。方法设计有小发夹结构的2条livinβ siRNA对应的DNA序列,将其克隆入pSliencer 3.1质粒,构建重组质粒pSliencer-livinβ,对重组质粒进行酶切分析和DNA序列测定。以脂质体法将pSliencer-livinβ转染人胶质瘤细胞。采用RT-PCR和Western-blot检测Livinβ蛋白的表达,筛选最有效的一组pSliencer-livinβ质粒。结果酶切及测序证实质粒pSliencer-livinβ构建成功。转染后胶质瘤细胞livinβmRNA和蛋白表达均受到明显抑制。结论成功构建livinβ基因的特异性短发卡RNA（siRNA）真核表达载体能够显著抑制人胶质瘤细胞livinβ基因的表达。     

稳定整合靶向性14—3—3ζ基因RNA干涉载体的胶质瘤细胞系建立

目的构建针对细胞凋亡抑制蛋白14-3-3ζ基因的特异性RNA干涉载体,并建立稳定转染该干涉载体的人胶质瘤细胞系。方法根据14-3-3ζ编码序列,设计并合成针对14-3-3ζ基因的特异性RNA干涉片断,并将其克隆入pSilencer3．1．H1neo干涉载体中,构建14-3-3ζ基因shRNA真核表达载体pSilencer-14-3-3ζ。重组载体pSilencer-14-3-3ζ和pSilencer3．1-Hlneo阴性对照载体pSilencer3．1-HlneoNegative经脂质体LipofectamineTM2000介导法转染胶质瘤细胞株U251;转染细胞经过G418筛选,采用Westernblot方法分别在蛋白水平检测、筛选G418抗性的克隆细胞。结果酶切鉴定和核苷酸序列分析证实,成功构建了14-3-3ζ基因shRNA真核表达载体pSilencer-14-3-3ζ,经酶切、测序鉴定证实克隆正确。获得了稳定转染pSilencer-14-3-3ζ载体的胶质瘤细胞株。结论14-3-3ζ基因特异性RNA干涉载体能够显著抑制14-3-3ζ基因在U251细胞中的表达,这为进一步研究14-3-3ζ在胶质瘤细胞系U251中的生物学功能和作用机制奠定了实验基础。     

脯氨酰羟化酶RNA干扰慢病毒载体的构建与鉴定

背景：慢病毒载体可稳定介导基因沉默且具有较高的转染效率。 目的：构建并鉴定脯氨酰羟化酶 RNA干扰慢病毒载体。 方法：针对脯氨酰羟化酶2基因序列设计RNA干扰靶序列,合成靶序列的寡聚DNA,退火形成双链DNA,与经Age Ⅰ和EcoR Ⅰ酶切的pGCSIL-GFP连接、转化大肠杆菌感受态细胞,产生重组RNA干扰慢病毒表达载体,PCR筛选阳性克隆,测序鉴定。 结果与结论：PCR和DNA测序证实合成的含脯氨酰羟化酶短发卡RNA慢病毒载体寡核苷酸链正确插入pGCSIL-GFP载体。说明实验成功构建脯氨酰羟化酶基因RNA干扰慢病毒载体。     

短发卡RNA特异性抑制Survivin基因在U251细胞中的表达

目的构建针对人Survivin基因的特异性短发卡RNA(shRNA)真核表达载体,并观察其在人脑胶质母细胞瘤U251细胞中对Survivin基因表达的抑制作用.方法根据Survivin cDNA编码序列,设计并合成针对Survivin基因的特异性RNA干涉片断,将其克隆入pWH1质粒载体,构建Survivin基因shRNA真核表达载体pWH1-SR.通过脂质体介导将pWH1-SR载体和空载体pWH1分别转染入U251细胞,经G418筛选,建立稳定转染的细胞系U251-SR和U251-P.采用RT-PCR、Western blot和免疫组化方法检测Survivin mRNA和蛋白在U251、U251-P和U251-SR细胞中的表达水平.结果成功构建了Survivin基因shRNA真核表达载体pWH1-SR,经酶切鉴定证实克隆正确.获得了稳定转染pWH1-SR载体和空载体pWH1的细胞系U251-SR和U251-P.U251-SR细胞Survivin mRNA和蛋白表达均受到明显抑制,抑制率分别达87%和91%;U251-P细胞Survivin基因表达水平无明显变化.结论特异性shRNA能够明显抑制Survivin基因在U251细胞中的表达,这为进一步研究Survivin在U251细胞中的生物学功能和作用机制奠定了实验基础.     

Smad3基因siRNA表达载体的构建及沉默效应

背景：研究提示抑制Smad3可望抑制纤维增生和胶原的大量产生。 目的：构建针对Smad3基因的siRNA表达载体,观察RNA干扰对增生性瘢痕成纤维细胞Smad3基因表达的抑制作用。 方法：根据siRNA设计原则,设计3条针对Smad3基因的siRNA靶序列,分别合成两条互补的寡核苷酸链,退火后与载体pRNAT-U6连接,然后进行酶切鉴定和DNA序列测定。用脂质体包裹转染增生性瘢痕成纤维细胞,荧光定量PCR和Western blot方法检测Smad3基因的表达情况。 结果与结论：测序分析结果显示：克隆入pRNAT-U6载体的针对Smad3基因的siRNA的双链寡核苷酸片段插入正确;荧光定量PCR和Western blot检测显示：转染的增生性瘢痕成纤维细胞Smad3基因的表达水平明显降低,尤以AGA CAG ACT GTG ACC AGT A(1156)为靶序列的siRNA沉默作用最强,抑制效率于转染后48 h可达45%。证实实验构建的沉默增生性瘢痕成纤维细胞Smad3基因表达的siRNA载体获得成功。     

线粒体加工肽酶干扰RNA真核表达载体转染PC12细胞系的构建及鉴定

目的利用干扰RNA技术构建线粒体加工肽酶(MPPs)的干扰RNA真核表达载体,稳定转染大鼠PC12细胞来抑制MPPs基因的表达,为研究MPPs蛋白的功能提供实验基础。方法脂质体转染已经构建好的4个MPPs干扰RNA真核表达载体和阴性对照干扰RNA真核表达载体到大鼠PC12细胞株,G418筛选阳性转染细胞克隆,制备稳定转染5个MPPs干扰RNA真核表达载体的PC12细胞系。用RT-PCR检测MPPs基因表达。结果获得稳定转染5个MPPs干扰RNA真核表达载体的PC12细胞系,RT-PCR证实所有4个干扰组(siRNA1,siRNA2,siRNA3 and siRNA4)MPPs-mRNA表达均下调,分别达到28%、38%、26%、16%。结论成功建立稳定转染MPPs干扰RNA的PC12细胞系。通过RT-PCR等相关方法证实MPPs干扰RNA真核表达载体转染PC12细胞成功。     

LRIG3特异性RNA干扰真核表达载体的构建及稳定株筛选

目的构建LRIG3（leucine-rich repeats and immunoglobulin-like domains 3,LRIG3）基因特异的RNA干扰质粒,为探讨抑制LRIG3基因表达对脑胶质瘤细胞生物学行为调控的研究奠定基础。方法根据GenBank数据库提供的LRIG3基因核苷酸序列,选择设计2条能转录短发卡RNA（shRNA）的DNA序列,命名为LRIG3-shRNA1、LRIG3-shRNA2,同时设计1条非特异性序列作为阴性对照,命名为negative-shRNA。并与pGenesil2质粒载体连接,转化感受态大肠杆菌,挑选阳性克隆,抽取重组质粒,使用限制性内切酶SalⅠ酶切电泳,DNA测序鉴定。3种重组表达载体转染胶质瘤细胞系GL15细胞,用G418筛选后挑选单克隆并扩增获得稳定株。逆转录酶-聚合酶链反应（RT-PCR）和Western blot分别在mRNA和蛋白水平上检测LRIG3的表达。结果重组质粒成功转化感受态大肠杆菌,经SalⅠ酶切琼脂糖凝胶电泳分析,结果表明寡核苷酸成功插入到预计位点,经测序鉴定,序列完全正确。G418筛选出稳定转染三种质粒的GL15细胞,转染pGenesil2-LRIG3-shRNA组细胞LRIG3 mRNA和蛋白表达明显低于转染pGenesil2-negative-shRNA组。结论成功构建针对LRIG3基因的特异性shRNA真核表达载体,转染细胞后可抑制LRIG3基因表达,为进一步研究其基因功能奠定了基础。     

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.     

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.     

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.     

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.