利用Gateway技术构建重组腺病毒pAd-NK4

目的利用Gateway技术构建含人肝细胞生长因子(HGF)NK4基因的重组腺病毒载体。方法以含有HGF/NK4基因的质粒为模板PCR扩增NK4基因,将回收的NK4PCR产物片段克隆至腺病毒穿梭载体pYr-adshuttle-6获得重组质粒pYr-adshuttle-6-NK4。从该重组质粒上,利用LR同源重组将NK4-IRES-EGPF表达框转移至腺病毒骨架质粒pAD/BL-DEST,获得重组腺病毒质粒pAd-NK4-IRES-EGFP。该质粒经pacI线性化后转染293包装细胞,获得重组腺病毒rAd-NK4-IRES-EGFP。采用TCID 50(tissue cell infectiousdosage 50,TCID 50)法测定重组腺病毒滴度。重组腺病毒分别经酶切和PCR等方法进行鉴定。荧光显微镜观察转染效果。结果证实腺病毒载体中含有NK4基因的目的片段;病毒滴度为6.3×1011 PFU.L-1;荧光显微镜发现该重组腺病毒能在HEK293细胞中高效的表达。结论利用Gateway技术可以快速地构建同时表达NK4蛋白和绿色荧光的重组腺病毒,为下一步开展关于NK4基因的肿瘤治疗提供了基础。     

LR重组法构建重组腺病毒rAd5-Vpr

目的:构建携带HIV-1Vpr基因的重组腺病毒。方法:采用限制性内切酶消化和T4DNA连接酶连接的方法,将Vpr基因克隆至腺病毒穿梭质粒pTrack-C上,然后通过重组穿梭质粒pTrack-C-Vpr和腺病毒骨架质粒pAdeno体外LR位点特异性重组的方法,将Vpr基因转移至腺病毒骨架质粒pAdeno上,最后重组骨架质粒pAdeno-Vpr鉴定正确后经PacI酶切,转染HEK293细胞,包装成重组腺病毒rAd5-Vpr。同时在HEK293细胞中进行病毒扩增,利用PCR方法对重组腺病毒进行鉴定,用微量全细胞病变法检测病毒滴度。结果:PCR鉴定重组腺病毒rAd5-Vpr构建成功;扩增后检测病毒滴度约为5×108PFU/mL。结论:应用LR重组法能成功构建携带HIV-1 Vpr基因的重组腺病毒,扩增后滴度能满足实验需要,为进一步相关研究的开展奠定了基础。     

靶向大鼠血管紧张素转换酶基因的短发夹RNA重组腺病毒载体的构建及鉴定

目的利用AdMax腺病毒载体系统构建大鼠血管紧张素转换酶-短发夹RNA(ACE-shRNA)腺病毒载体并在人胚胎肾-293细胞中扩增制备重组病毒。方法自先期构建的pGenesil-1-ACE-shRNA真核表达载体中用反转录聚合酶链反应(RT-PCR)法扩增出ACE-shRNA片段,并克隆进入穿梭质粒pDC316中,将构建好的穿梭质粒pDC316-ACE-shRNA载体和骨架病毒pBHGlox-E1,3Cre共转染293细胞,包装成重组的病毒颗粒,荧光显微镜观察绿色荧光表达。结果经限制性内切酶,聚合酶链反应(PCR)检测和绿色荧光蛋白(FGFP)表达证实成功地构建了携带ACE-shRNA的重组腺病毒载体并制备出高滴度重组病毒。结论成功地构建了携带ACE-shRNA片段的重组腺病毒载体,为进一步利用基因沉默技术抗高血压的研究奠定了基础。     

肿瘤坏死因子相关细胞凋亡诱导配体表达载体的制备

目的构建一种携带肿瘤坏死因子相关细胞凋亡诱导配体（TRAIL）基因的重组腺相关病毒（rAAV）载体。方法首先构建携带可溶性肿瘤坏死因子相关细胞凋亡诱导配体（sTRAIL）基因的穿梭质粒腺相关病毒穿梭质粒-可溶性肿瘤坏死因子相关细胞凋亡诱导配体（pAAV-sTRAIL），将穿梭质粒转染入HEK293细胞（人胚肾细胞系）中，采用细胞内质粒DNA同源重组法构建重组腺相关病毒载体rAAV-sTRAIL。以噬斑分析法筛选单克隆rAAV-sTRAIL；PCR法鉴定阳性rAAV-sTRAIL；氯化铯密度梯度离心法纯化rAAV-sTRAIL；紫外分光光度仪测定rAAV-sTRAIL颗粒数及纯度，噬斑分析法测定rAAV-sTRAIL感染滴度；Western免疫印迹检测rAAV-sTRAIL在HEK293细胞中的表达情况。结果成功构建了rAAV-sTRAIL，制备的病毒纯度好、滴度高，且在HEK293转导细胞中能有效表达目的基因sTRAIL。结论构建的重组腺相关病毒载体rAAV-sTRAIL，为研究TRAIL抗肿瘤细胞效应及临床应用提供先进的载体系统。     

大鼠糖皮质激素受体基因腺病毒载体的构建及在肾系膜细胞中的表达

目的 利用AdEasy系统构建大鼠糖皮质激素受体(GR)基因重组腺病毒载体,转染大鼠肾小球系膜细胞(GMC),并通过Western Blot法检测GR蛋白的表达.方法 将质粒pcDNA1 Neo-Rat GR扩增、凝胶回收获得的Rat GR cDNA双酶切片段,插入腺病毒穿梭载体质粒pShuttle-CMV的巨细胞病毒(CMV)启动子下游,构建重组穿梭载体pShuttle-CMV-Rat GR,线性化后与骨架载体AdEasy-1在细菌BJ5183内经同源重组得到腺病毒重组质粒pAd-Rat GR,经人胚肾293A细胞包装后得到复制缺陷型重组腺病毒Ad-Rat GR;用包装后的病毒上清转染大鼠GMC,提取细胞中总蛋白,通过Western Blot方法 检测GR蛋白的表达.结果 连接、重组后通过酶切和测序法筛选出pAd-Rat GR重组质粒,经人胚肾293细胞包装,48 h后观察到增强型绿色荧光蛋白(EGFP)明显表达,氯化铯梯度离心纯化最终获得1×109 PFU /ml 滴度的重组病毒;用该滴度的Ad-Rat GR,转染大鼠GMC 48 h后提取细胞总蛋白,Western Blot检测GR蛋白有明显表达.结论 构建的大鼠GR基因腺病毒载体能够在大鼠GMC 中表达GR蛋白,并有上调作用.     

携带hIGF-Ⅰ基因的腺病毒载体构建

目的 探讨构建携带hIG-Ⅰ基因腺病毒载体的可行性.方法 从pcDNA 3.1-hIGF-Ⅰ质粒中克隆出hIGF-Ⅰ基因的编码序列,酶切、连接后,插入腺病毒系统中的穿梭载体pAdshuttle-CMV,获得重组质粒pAdshuttle-CMV-hIGF-Ⅰ,将其转化含有腺病毒骨架载体pAdeasy-1的大肠杆菌BJ5183,进行同源重组,获得重组子pAdeasy-1-IGF-Ⅰ.鉴定后,将pAdeasy-1-IGF-Ⅰ转染人胚肾细胞(Ad293细胞),获得含hIGF-Ⅰ基因的重组腺病毒(rAd-hIGF-Ⅰ).再鉴定后,Ad293细胞反复感染冻融扩增腺病毒,50%组织培养感染量法(TCID50)检测病毒滴度.将病毒颗粒感染绿猴肾成纤维细胞(COS-7细胞),荧光显微镜观测绿色荧光蛋白(GFP)的表达,RT-PCR分析hIGF-Ⅰ基因在mRNA水平的表达,Western blot分析hIGF-Ⅰ在蛋白水平的表达.结果 成功构建出含有hIGF-Ⅰ基因的腺病毒载体rAd-hIGF-Ⅰ,转染COS-7细胞后发现绿色荧光蛋白表达,同时RT-PCR扩增出318 bp的目的 条带,Western blot得到7.6kDa大小的同的蛋白,证明了腺病毒载体rAd-hIGF-Ⅰ能成功转染COS-7细胞,hIGF-Ⅰ基因能在其中成功表达.结论 成功构建出含有hIGF-Ⅰ基因的腺病毒载体rAd-hIGF-Ⅰ,并且证实其能对COS-7细胞进行有效转染,为组织工程软骨的进一步改良提供了高效的基因载体.     

人白介素24基因重组腺病毒载体的构建与鉴定

目的构建含有人白介素24(hIL-24)基因的重组腺病毒载体,为下一步病理性瘢痕的基因治疗研究奠定实验基础。方法采用基因工程技术将hIL-24基因的cDNA亚克隆至穿梭质粒pAdTrack-CMV上,鉴定正确后在PAdEasy系统中进行细菌内同源重组,通过脂质体将正确重组体包裹并转染293A细胞以包装并扩增病毒。采用酶切及PCR方法对重组腺病毒进行鉴定。结果酶切和PCR结果证实hIL-24基因重组腺病毒载体构建成功并可在293A细胞中表达,病毒滴度达107pfu/ml。结论成功构建了有较强感染能力的含hIL-24基因的重组腺病毒载体。     

腺病毒介导的hHCN4表达载体的构建及其转染人胚肾细胞

目的构建人超极化激活环核甘酸门控通道基因4(hHCN4)的重组腺病毒载体pAV-hHCN4-IRES/eGFP,并对其进行鉴定、包装。方法利用Gateway技术构建pAV-hHCN4-IRES/eGFP,酶切鉴定并进行阳性克隆测序。将构建好的质粒转染人胚肾细胞HEK293,检测病毒液滴度。结果测序符合Genbank中的hHCN4的编码序列。转染HEK293细胞见绿色荧光蛋白表达,病毒滴度为1.26×108 pfu/ml。结论成功构建了重组腺病毒载体pAV-hHCN4-IRES/eGFP。     

表达生存素相关microRNA-494基因腺病毒载体的构建

目的构建表达生存素(survivin)相关microRNA-494基因的重组腺病毒载体。方法应用生物学软件Targetscan 5.2对microRNA-494基因与survivin mRNA作相关性分析。RT-PCR调取目的基因,将其连接线性化后的穿梭质粒载体,联合骨架质粒转染入293细胞后同源重组产生重组腺病毒载体。PCR及测序验证重组质粒,荧光显微镜下观察腺病毒荧光蛋白表达。结果重组腺病毒载体构建成功。结论成功构建了重组腺病毒载体,可用于研究其在前列腺癌PC-3细胞中对survivin基因表达的影响。     

核糖体蛋白RPS3a腺病毒载体的构建和体外表达

目的 构建核糖体蛋白RPS3a的腺病毒表达载体,并进一步验证其在细胞中的表达。方法 应用RT-PCR从人胚肾HEK293细胞的总RNA中反转录并扩增出RPS3a基因,并将RPS3a亚克隆到穿梭质粒pAdTrack-CMV中,酶切及测序鉴定后,再将含RPS3a基因的重组穿梭质粒pAdTrack-CMV-RPS3a进行Pme I酶线性化处理,转化到含有骨架质粒的BJ5183感受态菌,进行同源重组。鉴定后,经Pac I线性化转染HEK293细胞,包装重组腺病毒。病毒感染NIH3T3细胞,Western blot 分析RPS3a蛋白的表达。结果 证实pAdTrack-CMV-RPS3a及pAdEas-RPS3a质粒构建正确;Western blot检测病毒感染的NIH3T3细胞总蛋白,与pAd-GFP阴性对照组相比,RPS3a蛋白表达量显著提高。结论 成功构建了能表达RPS3a基因的重组腺病毒载体,为进一步研究其生物学功能奠定基础。     

Efficacy of gut lavage,hemodialysis, and hemoperfusion in the therapy of paraquat or diquat intoxication

Clinical and in vitro investigations were carried out to test the efficacy of gut lavage, hemodialysis, and hemoperfusion in the treatment of poisoning with paraquat or diquat. In a patient suffering from diquat intoxication 130 times more diquat was removed by gut lavage 30 h after ingestion than was removed by complete aspiration of the gastric contents.Determination of in vitro clearances for paraquat and diquat by hemodialysis showed that, at serum concentrations of 1–2 ppm, such as are frequently encountered in poisoning in man, toxicologically relevant quantities of herbicide cannot be removed from the body. At a concentration of 20 ppm, on the other hand, hemodialysis proved to be effective, the clearance being 70 ml/min at a blood flow rate of 100 ml/min. The efficacy of hemoperfusion with coated activated charcoal was on the whole better. Especially at concentrations around 1–2 ppm, the clearance values for hemoperfusion were some 5–7 times higher than those for hemodialysis.In a patient suffering from paraquat poisoning, both hemodialysis as well as hemoperfusion were carried out. The in vitro results could be confirmed: At serum concentrations of paraquat less than 1 ppm no clearance could be obtained by hemodialysis while by hemoperfusion with activated charcoal quite high clearance values were measured and the serum level dropped down to zero.

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Zusammenfassung Klinische Untersuchungen und Laboratoriumsversuche wurden durchgeführt, um die Wirksamkeit von Darmspülung, Hämodialyse und Hämoperfusion bei Paraquat- und Deiquat-Vergiftungen zu prüfen.Bei einem Patienten wurde 30 Std nach Deiquat-Aufnahme durch Darmspülung 130mal mehr Deiquat entfernt als durch vollständige Aspiration des Mageninhaltes. In vitro-Versuche ergaben, daß bei Blutserumkonzentrationen von 1–2 ppm, die bei Vergiftungen oft gemessen werden, durch Hämodialyse keine toxikologisch relevanten Paraquat- oder Deiquat-Mengen entfernt werden können. Dagegen erwies sich die Hämodialyse bei 20 ppm und einer Blutumlaufgeschwindigkeit von 100 ml/min mit einer Clearance von 70 ml/min als wirksam. Die Hämoperfusion mit beschicheter Aktivkohle war in diesen Versuchen aber eindeutig überlegen, denn insbesondere bei Konzentrationen um 1–2 ppm waren die Clearance-Werte 5–7mal höher als bei der Hämodialyse.Die in vitro-Ergebnisse wurden bei einem Patienten mit einer Paraquat-Vergiftung bestätigt: Bei Konzentrationen unter 1 ppm war die Hämodialyse wirkungslos, während durch Hämoperfusion relativ hohe Clearance-Werte erreicht wurden, so daß der Serumspiegel rasch unter die Nachweisgrenze abfiel.

     

In vitro studies on sterically stabilized liposomes (SL) as enzyme carriers in organophosphorus (OP) antagonism

This study describes a new approach for organophosphorous (OP) antidotal treatment by encapsulating an OP hydrolyzing enzyme, OPA anhydrolase (OPAA), within sterically stabilized liposomes. The recombinant OPAA enzyme was derived from Alteromonas strain JD6. It has broad substrate specificity to a wide range of OP compounds: DFP and the nerve agents, soman and sarin. Liposomes encapsulating OPAA (SL)* were made by mechanical dispersion method. Hydrolysis of DFP by (SL)* was measured by following an increase of fluoride ion concentration using a fluoride ion selective electrode. OPAA entrapped in the carrier liposomes rapidly hydrolyze DFP, with the rate of DFP hydrolysis directly proportional to the amount of (SL)* added to the solution. Liposomal carriers containing no enzyme did not hydrolyze DFP. The reaction was linear and the rate of hydrolysis was first order in the substrate. This enzyme carrier system serves as a biodegradable protective environment for the recombinant OP-metabolizing enzyme, OPAA, resulting in prolongation of enzymatic concentration in the body. These studies suggest that the protection of OP intoxication can be strikingly enhanced by adding OPAA encapsulated within (SL)* to pralidoxime and atropine.     

Aquatic Insects and Trace Metals: Bioavailability,Bioaccumulation, and Toxicity

Abstract

The uptake of metals from food and water sources by insects is thought to be additive. For a given metal, the proportions taken up from water and food will depend both on the bioavailable concentration of the metal associated with each source and the mechanism and rate by which the metal enters the insect. Attempts to correlate insect trace metal concentrations with the trophic level of insects should be made with a knowledge of the feeding relationships of the individual taxa concerned. Pathways for the uptake of essential metals, such as copper and zinc, exist at the cellular level, and other nonessential metals, such as cadmium, also appear to enter via these routes. Within cells, trace metals can be bound to proteins or stored in granules. The internal distribution of metals among body tissues is very heterogeneous, and distribution patterns tend to be both metal and taxon specific. Trace metals associated with insects can be both bound on the surface of their chitinous exoskeleton and incorporated into body tissues. The quantities of trace meals accumulated by an individual reflect the net balance between the rate of metal influx from both dissolved and particulate sources and the rate of metal efflux from the organism. The toxicity of metals has been demonstrated at all levels of biological organization: cell, tissue, individual, population, and community. Much of the literature pertaining to the toxic effects of metals on aquatic insects is based on laboratory observations and, as such, it is difficult to extrapolate the data to insects in nature. The few experimental studies in nature suggest that trace metal contaminants can affect both the distribution and the abundance of aquatic insects. Insects have a largely unexploited potential as biomonitors of metal contamination in nature. A better understanding of the physico-chemical and biological mechanisms mediating trace metal bioavailability and exchange will facilitate the development of general predictive models relating trace metal concentrations in insects to those in their environment. Such models will facilitate the use of insects as contaminant biomonitors.     

Alzheimer’s disease – current trends in basic and clinical research. Highlights from the 16th ECNP

Advances in the molecular biological knowledge of neuronal nicotinic acetylcholine receptors (nAChRs) have led to a growing interest by the pharmaceutical industry in the development of novel compounds that selectively modulate nAChR function. The ability of (-)-nicotine, an activator of nAChRs, to enhance attentional aspects of cognition in animals and humans, to exert neuroprotective and anxiolytic-like effects, and presumably to mediate the negative correlation between smoking and Alzheimer's (and Parkinson's) Disease, has focused interest on the potential therapeutic utility of modulators of nAChR function for treatment of some of the deficits associated with these progressive, neurodegenerative conditions. Numerous compounds are known which activate nAChRs and which might serve as lead compounds toward the development of such agents. The pharmacologic diversity of neuronal nAChR subtypes suggests the possibility of developing selective compounds which would have more favourable side-effect profiles than existing agents. This broader class of agents, collectively called cholinergic channel modulators (ChCMs), is anticipated to encompass compounds which would have more favourable side-effect profiles than existing agents, which generally exhibit low selectivity. This selectivity may be achieved by preferentially activating some subtypes of nAChRs (i.e., Cholinergic Channel Activators, ChCAs) or inhibiting the function of other subtypes (Cholinergic Channel Inhibitors, ChCIs). An overview of the biology of nAChRs and the rationale for the use of ChCMs for the treatment of dementia related to neurodegenerative diseases are presented, followed by a discussion of lead compounds and compounds under consideration for clinical evaluation.     

Steroidal sapogenin contents in some domestic plants

In order to find out the values of the steroid resources for the future use. the compositions and contents of steroidal sapogenins from 13 domestic plants have been investigated. As a result,Dioscorea nipponica, D. quinqueloba andSmilax china were found to have large amount of diosgenin. And pennogenin inTrillium kamtschaticum andParis verticillata, yuccagenin inAllium fistulosum, hecogenin inAgave americana and neochlorogenin inSolanum nigum were appeared to be major steroidal sapogenins.