NOV基因真核表达载体的构建及在大鼠真皮多能干细胞中的表达

目的 构建肾母细胞瘤过度表达(NOV)基因真核表达载体并检测其在真皮多能干细胞中的表达. 方法 利用逆转录-多聚酶链反应(RT-PCR)方法,以新生大鼠大脑组织总RNA为模板,扩增出1 178bp的NOV基因的cDNA编码区序列,然后用Hind Ⅲ和BamH Ⅰ双酶切后定向克隆入真核表达载体pEGFP-N1质粒中,用脂质体法将重组质粒转染入大鼠真皮多能干细胞中,荧光显微镜观察转染产物,RT-PCR法检测转染细胞中NOV基因表达. 结果 NOV基因cDNA正确克隆到真核表达载体pEGFP-N1质粒中;重组质粒体外转染入大鼠真皮多能干细胞后,可见转染细胞有绿色荧光表达.转染细胞中检测到NOV基因. 结论 构建成功NOV基因重组质粒,并能在大鼠真皮多能干细胞中稳定表达,为NOV基因及真皮多能干细胞的作用研究提供了有利的分子工具.     

抑制骨髓基质干细胞雌激素受体β基因表达的有效序列*☆

背景：雌激素受体β是否参与介导骨髓间充质干细胞的增殖与分化需进一步实验论证。 目的：以RNAi技术寻找和验证对大鼠骨髓基质干细胞雌激素受体β基因表达抑制的有效序列。 方法：根据GeneBank 数据库提供的SD大鼠雌激素受体β基因核苷酸序列,选择设计能转录小发卡结构RNA (Small hairpin RNAs,shRNA)的DNA 序列。再在两条互补碱基序列的5’端分别加上BamH Ⅰ(GATCC)和Hind Ⅲ (AGCTT)酶的酶切位点,最后形成两条互补的克隆入pSilencer 3.1-H1载体的发夹状siRNA模板序列,进行重组载体的碱基序列测定。 结果与结论：重组质粒碱基序列鉴定后,证实真核表达载构建正确。雌激素受体β特异性siRNA真核表达载体构建成功。     

pcDNA3/BDNF真核表达载体的构建☆

背景：脑源性神经营养因子(brain-derived neurotrophic factor,BDNF)作用广泛,但属于生物大分子,不能通过血脑屏障。基因治疗是目前解决脑源性神经营养因子给药途径最有希望的方案。 目的：拟构建大鼠脑源性神经营养因子基因真核表达载体。 方法：采用反转录聚合酶链式反应技术从SD大鼠脑组织提取总RNA,扩增脑源性神经营养因子基因cDNA序列,并将其克隆到真核表达载体pcDNA3中,分别取10 g质粒pcDNA3和纯化的目的基因分别进行EcoR Ⅰ、xho Ⅰ双酶切。将目的基因片段和pcDNA3载体连接,转入感受态DH5α细胞中,经酶切鉴定后送上海博亚生物技术有限公司测序。 结果与结论：RT-PCR产物为749 bp的特异片段,重组质粒pcDNA3/BDNF酶切后产生 749 bp和5 446 bp的片段,DNA测序证实749 bp片段的碱基序列与大鼠脑源性神经营养因子基因序列完全一致,成功构建了pcDNA3/BDNF重组质粒。     

Cdc2基因敲低逆转录病毒载体设计与构建方法

目的设计和构建cdc2基因敲低的表达siRNA的逆转录病毒重组载体。方法利用在线软件siRNASelectionProgram和siDirect设计干扰cdc2基因靶序列,合成回文DNA序列,退火后克隆至线性化pSUPER质粒载体,重组质粒载体扩增、抽提后行双酶切电泳鉴定和测序分析,再转染phoenix细胞,产生逆转录病毒,并利用NIH3T3细胞测定病毒滴度。结果pSUPER表达siRNA重组质粒载体经双酶切电泳鉴定和DNA测序分析,证实插入的60bp序列与原序列一致,位置正确。pSUPER.retro-C1、pSUPER.retro-C2病毒滴度值分别为4.25×105CFU/ml和6.00×105CFU/ml。结论cdc2基因表达siRNA逆转录病毒重组载体构建成功,可为研究胶质瘤分子病因学提供有用工具。     

人淀粉样前体蛋白基因与绿色荧光蛋白融合基因筛选系统的建立

目的 构建携带人淀粉样前体蛋白（APP）的增强型绿色荧光蛋白（EGFP）载体。以利于初步筛选对APP mRNA水平作用的药物。方法 将pEGFP质粒和携带野生型APP695亚型的pXCJL经Hind Ⅲ酶切，连接．PCR初筛，酶切鉴定。进一步经测序证实。携带野生型人类APP751亚型cDNA的pCDNA3．1质粒用XbaⅠ酶切．Klenow酶填平．再用HindⅢ酶切．回收APP751片段；质粒EGFP用SmaⅠ和Hind Ⅲ酶切。将目的基因APP751片段与EGFP载体片段连接生成重组质粒．酶切鉴定．测序证实。构建好的重组质粒转染COS-7细胞．观察EGFP的表达情况。结果 APP695和APP751重组质粒上的EGFP在COS-7细胞内得以表达。结论 构建的APP—EGFP融合基因重组质粒．有助于方便、快速地初筛出作用于APP mRNA水平的药物。     

保守性多巴胺能神经营养因子重组杆状病毒转移载体的构建及鉴定

目的 构建并鉴定小鼠保守性多巴胺能神经营养因子(mCDNF)重组杆状病毒转移载体pFastBacHTb-mCDNF. 方法 应用Trizol法提取小鼠组织总RNA,反转成cDNA,经PCR扩增得到带有预定酶切位点(BamH Ⅰ、Xho Ⅰ)的mCDNF基因全长(564 bp),回收片段并克隆至pGEM-T载体,测序验证PCR结果的准确性.将mCDNF定向克隆到pFastBacHTb载体,构建含有mCDNF基因的重组质粒pFastBacHTb-mCDNF,转化大肠杆菌DH5α感受态细胞,氨苄青霉素抗性筛选阳性克隆,摇菌抽取质粒进行测序和双酶切鉴定. 结果 RT-PCR扩增产物经琼脂糖凝胶电泳显示得到预定大小的目的 条带(564 bp),mCDNF的T-A克隆经蓝白斑抗性筛选获得阳性克隆,PCR及测序均提示pGEM-T-CDNF载体成功构建.重组质粒pGEM-T-mCDNF和pFastBacHTb载体进行BamH Ⅰ、Xho Ⅰ限制性内切酶酶切后再连接,得到pFastBacHTb-mCDNF重组质粒,并经PCR、酶切及测序验证无误. 结论 本实验成功构建了mCDNF重组杆状病毒转移载体pFastBacHTb-mCDNF,为该营养因子的进一步研究奠定了一定基础.     

构建人HCN4基因重组腺病毒载体及其对大鼠骨髓间充质干细胞的感染效率

背景：超极化激活及环化核苷酸门控阳离子通道(hyperpolarization-activated cyclic nucleotide-gated cation channel, HCN)基因由于具有不增加诱发心律失常的风险、能够接受自主神经系统调节等优势,成为目前最受关注的生物起搏备选基因。 目的：构建携带人HCN4基因的重组腺病毒载体,并测定其对大鼠骨髓间充质干细胞的感染效率。 设计、时间及地点：细胞-基因学体外实验,于2008-02/09在中山大学附属第二医院林百欣实验中心完成。 材料：SD大鼠10只,由中山大学实验动物中心提供。携带目的基因人HCN4 cDNA的质粒pcDNA3.1-HCN4、人胚肾293细胞、大肠杆菌DH5α由中山大学附属第二医院林百欣实验中心保存。腺病毒穿梭质粒pShuttle-CMV、骨架质粒pAdxsi购自北京诺赛基因组研究中心有限公司。 方法：质粒pcDNA3.1-HCN4用Hind Ⅲ+Xba Ⅰ双酶切后回收HCN4片段,亚克隆至pShuttle-CMV中,得到重组穿梭质粒;I-Ceu Ⅰ+I-Sce Ⅰ双酶切处理pShuttle-CMV-HCN4,回收CMV-HCN4片段,亚克隆至腺病毒骨架载体pAdxsi,得到重组腺病毒质粒;重组腺病毒质粒酶切线性化后,应用脂质体法转染293细胞进行包装扩增,得到重组腺病毒AdHCN4;应用AdHCN4转染大鼠骨髓间充质干细胞。 主要观察指标：重组腺病毒质粒载体的鉴定,重组腺病毒的鉴定及滴度测定,重组腺病毒的感染效率。 结果：构建的重组穿梭质粒pShuttle-CMV-HCN4用Hind Ⅲ+Xho Ⅰ双酶切,得到大小为3 600 bp(HCN4)和5 100 bp (pShuttle-CMV)两个片段,DNA测序结果证实人HCN4基因的全长序列已正确插入到pShuttle-CMV穿梭质粒中;重组腺病毒质粒pAdxsi-CMV-HCN4用XhoⅠ酶切得到7个片段,而作为对照的空腺病毒质粒只得到6个片段;重组腺病毒质粒在293细胞中包装后产生的重组腺病毒对293细胞有致病作用;重组腺病毒AdHCN4 PCR鉴定可见657 bp的阳性扩增条带;经多次重复感染后,病毒滴度检测达2.5×1011PFU/mL。成功转染AdHCN4的大鼠骨髓间充质干细胞可表达绿色荧光蛋白,当病毒感染复数值为800,转染效率最高,达90%。 结论：实验成功构建携带人HCN4基因的重组腺病毒载体,并可在体外有效转染大鼠骨髓间充质干细胞。     

基因重组BDNF蛋白在大肠杆菌中的表达纯化与功能鉴定

目的构建脑源性神经营养因子（BDNF）基因的原核表达载体，并在大肠杆菌中进行表达，以获取高产量、低成本、高纯度且具有生物学活性的BDNF蛋白。方法以人的全长BDNF cDNA为模板，用PCR方法扩增成熟区BDNF的cDNA，应用基因重组技术将人BDNF cDNA克隆到质粒pET-30a（＋）中，进行限制性内切酶酶切分析和DNA测序鉴定。将重组质粒转化大肠杆菌BL21（DE3）LysS，经IPTG诱导表达后，用Ni-NTA亲和层析纯化获取蛋白，用SDS-PAGE和western blot方法鉴别，噻唑蓝（MTT）法检测重组蛋白对PC12细胞增殖的影响。结果扩增出的人BDNF cDNA片段克隆进了原核表达载体，经酶切和核酸测序鉴定，得到了正确的重组质粒pET-BDNF，并在大肠杆菌中获得了表达。纯化后的蛋白经考马氏亮蓝染色呈单一条带；用抗BDNF的抗体进行western blot分析证明目的蛋白获得了表达。基因重组BDNF蛋白能够促进PC12细胞增殖。结论本研究成功构建了表达基因重组人BDNF的原核表达载体，基因重组人BDNF蛋白在大肠杆菌中获得了表达和纯化，所获得的基因重组蛋白具有较好的生物学活性。     

携带DREAM基因小分子干扰RNA重组质粒的构建☆

背景：DREAM是一种多功能蛋白,在细胞中不同位置与不同靶蛋白结合,体外细胞培养和动物实验均证明DREAM参与了许多疾病的发病机制。 目的：构建携带DREAM基因的小分子干扰RNA重组质粒。 方法：设计并合成shRNA对应的两条互补的寡核苷酸链,pDC316-EGFP-U6质粒经BamHⅠ和HindⅢ双酶切与退火后的寡核苷酸连接,转化感受态E.coli DH5α,获得阳性克隆进行PCR和测序鉴定。 结果与结论：经PCR、酶切及测序证实,重组质粒pDC316-EGFP-DREAM-shRNA-U6片段大小为473 bp,其中插入的片断序列和位点与预期完全一致,说明pDC316-EGFP-DREAM-shRNA-U6重组质粒构建成功。     

动脉内皮细胞中TIE2启动CREG真核表达质粒pTIE2-CREG-EGFP-N1的表达

背景：血管内皮发生的分子机制是细胞及基因替代治疗的首要前提。 目的：构建一种通过血管内皮细胞特异蛋白TIE2启动子来启动表达的E1A激活基因阻遏子(cellular repressor of E1A-stimulated genes, CREG)和增强绿色荧光蛋白(enhanced green fluorescence protein, EGFP)融合的真核表达质粒。 方法：根据GenBank中公布的TIE2基因的启动子序列,人工合成TIE2启动子DNA序列,经AseⅠ和NheⅠ双酶切后,亚克隆入表达质粒pEGFP-N1中构建pTIE2-EGFP-N1。同时,用BamHⅠ和EcoRⅠ 双酶切pcDNA3.1 myc-His/hCREG质粒得到CREG基因,亚克隆入质粒pTIE2-EGFP-N1中构建pTIE2-CREG-EGFP-N1,酶切鉴定。应用脂质体法将该质粒转染至体外培养的小鼠动脉内皮细胞,荧光显微镜下观察EGFP的表达;Western blot检测CREG蛋白的表达。 结果与结论：经酶切鉴定证实实验构建的pTIE2-CREG-EGFP-N1质粒正确;体外转染48 h,荧光显微镜下可见EGFP的表达,Western blot检测到CREG蛋白的表达。说明实验成功构建了pTIE2-CREG-EGFP-N1重组质粒,其可携带目的基因在小鼠动脉内皮细胞中有效表达。     

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.     

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.     

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.     

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.     

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.     

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.