MIBP1基因敲除载体的构建

目的:构建MIBP1基因敲除载体。方法:以小鼠129胚胎干细胞基因组DNA为模板,根据GenBank注册序列,扩增小鼠MBP-2基因启动子区5′端片段(5′arm)和内含子区3′端片段(3′arm),然后分别克隆进敲除载体pKOScramblerNTKV-1906,酶切鉴定后即得到MIBP1基因敲除载体pNTKV-3′,5′arm。用SalⅠ对pNTKV-3′,5′arm线性化,用于胚胎干细胞电转染。结果:成功扩增并克隆到小鼠129胚胎干细胞MBP-2基因的5′arm和3′arm片段,构建了MIBP1基因敲除载体。结论:成功构建了MIBP1基因敲除载体。     

hPARP-1基因cDNA翻译起始区域的T载体克隆

目的 克隆及构建含限制性内切酶位点BamHⅠ、SacⅠ的人聚腺苷二磷酸核糖聚合酶-1(hPARP-1)基因cDNA翻译起始区域的pGEM-T-S载体，为以后的亚克隆和毒理学研究提供实验材料。方法 采用RT-PCR方法，用正常人胚肺成纤维细胞(HLF)抽提的总RNA逆转录成cDNA，再以cDNA为模板，扩增hPARP-1基因片段，并直接与T载体连接后转化大肠埃希菌DH5α，用蓝(白)斑试验筛选出阳性克隆，抽提重组质粒并进行PCR及酶切鉴定，再行序列分析。结果 经RT-PCR获得507bp含限制性内切酶位点的阳性产物，T载体克隆、PCR及酶切鉴定和序列分析后证实，克隆片段与Genbank中该基因的序列同源性为99．9％。结论 该实验成功地构建了含hPAR-1基因cDNA翻译起始区域的T载体克隆，为亚克隆及缺陷细胞株的建立提供工具。     

2a型丙型肝炎病毒非结构基因5区(NS5)全长克隆的构建

目的 构建2a型丙型肝炎病毒(HCV)非结构基因(NS)5区全长克隆质粒。方法 用聚合酶链反应(PCR)从HCV NS5A和NS5B质粒中扩增出NS5A和NS5BPCR片段，再采用融合PCR技术扩增出全长NS5的cDNA片段，克隆后RFLP和序列分析鉴定重组子。结果 融合PCR获得约2．8kb全长NS5序列，同源性分析表明：与HC-J6的核苷酸同源性为91．2％，推导的氨基酸同源性为95．5％。结论 利用融合PCR技术简单方便，利用该技术获得了2a型HCV NS5全长序列，构建了全长基因克隆质粒。     

大鼠脑源性神经营养因子基因克隆及其真核表达载体的构建

目的 克隆大鼠脑源性神经营养因子(BDNF)基因的表达序列,构建大鼠BDNF基因真核表达载体.方法 以RT-PCR从大鼠脑组织总RNA中扩增BDNF cDNA,将其克隆到真核表达载体pcDNA3中构建重组质粒pcDNA3-BN,以限制酶酶切鉴定和DNA序列分析鉴定重组质粒.结果 RT-PCR产物为783bp特异片段,重组质粒酶切后产生783bp和5.2 kb的片段,DNA测序证实783bp片段的碱基序列与大鼠BDNF基因序列完全一致.结论 成功克隆大鼠BDNF基因表达序列并构建了BDNF基因真核表达栽体pcDNA3-BN.     

小鼠脂肪组织脂联素基因编码区的克隆及序列分析

目的：克隆小鼠脂肪组织脂联素（ACRP30）编码区基因并进行序列分析。方法：用TRIzol试剂从小鼠脂肪组织提取总RNA，经RT-CR方法扩增全长的ACRP30 cDNA片段，将PCR产物克隆于pGEM-T载体，对重组质粒pGEM-ACRP30进行序列验证。结果：小鼠脂肪组织ACRP30基因编码序列不同于来自3T3-L1脂肪细胞的编码序列．IRM-2（Institute of Radimion Medicine-2）小鼠和C57BL／6J小鼠脂肪组织的ACRP30基因编码序列相同。337位点上的碱基A被G置换导致在113位的蛋氨酸被缬氨酸取代。来自脂肪组织的ACR30基因编码序列已被提交到GenBank^TM数据库。C57BL／6J小鼠的收录编号为AY749429。IRM-2小鼠为AY754346。结论：小鼠脂肪组织ACRP30编码序列是ACRP30序列的新成员，cDNA克隆的构建为进一步的蛋白表达和生物学活性研究奠定了基础。     

载脂蛋白M基因启动子的克隆及荧光素酶报告基因载体的构建

目的为深入研究载脂蛋白M(ApoM)基因的表达调控机制,对ApoM基因启动子序列进行克隆,并构建不同长度启动子荧光素酶报告基因载体。方法在NCBI人类基因组数据库中截取并下载ApoM基因转录起始位点5’侧翼区约2kb的基因组序列设计PCR扩增引物,从健康外周血中扩增获得该片段,以此序列为基础进行亚克隆,分别获得6条5’端不等、3’端平齐的片段,最后插入pGL3-Basic表达载体。结果获得了6条长度差别约为200bpApoM启动子片段,并构建了不同长度的pGL3-ApoM真核表达载体。结论上述载体的成功构建及序列分析为进一步研究ApoM基因的启动子活性及基因表达调控奠定了基础。     

小鼠睫状神经营养因子基因的克隆及真核表达载体的构建

目的：分别构建野生型和截短型小鼠睫状神经营养因子（CNTF）基因的真核表达载体。方法：通过逆转录聚合酶链反应（RT—PCR）扩增小鼠CNTF野生型全长编码序列，体外定点突变获取截短型CNTF的互补DNA（cDNA）编码序列．将上述两序列分别克隆至pGEM—T Easy载体，经限制性内切酶EcoRI和XbaI双酶切后，将野生型和截短型CNTF基因连入pTracer—CMV真核表达载体，DNA测序鉴定。结果：PCR成功扩增了野生型和截短型CNTF基因，DNA序列分析证实两种真核表达载体中的CNTF序列与GeneBank中目的序列一致。结论：野生型和截短型CNTF基因真核表达载体的成功构建为视网膜色素变性（RP）的基因治疗研究奠定了基础。     

小鼠H—2D^d基因的克隆及其逆转录病毒表达载体的构建

目的：构建BALB／c小鼠H－2D^d基因的逆转录病毒表达载体。方法：采用反转录PCR从BALB／c小鼠脾细胞基因组中，扩增H－2D^d的编码基因，插入克隆载体pGEM-T中。经EcoR I和Xho I双酶切后，亚克隆法于逆转录病毒载体pMSCV的相应酶切位点，构建pMSCV-H2D^d重组表达质粒，并经双酶切和序列测定鉴定。结果：用EcoR I和Xho I双酶切鉴定证实，克隆基因正确插入载体pMSCV。克隆H－2D^d的编码基因经序列测定证实，与献报道完全一致。结论：成功构建小鼠H－2D^d编码基因的逆转录病毒载体，为进一步研究MHC分子在移植免疫中的作用及临床移植的基因治疗应用奠定了基础。     

小鼠CD1d2编码区基因的克隆与鉴定

目的:克隆小鼠CD1d2编码区基因。方法:提取小鼠胸腺组织总RNA,用RT-PCR技术扩增CD1d2cDNA,PCR产物连接pGEM-T载体,转化大肠杆菌,用限制性酶切反应和DNA测序对阳性克隆进行鉴定,用BLAST软件进行序列分析。结果:扩增出一条特异DNA条带,DNA序列测定表明获取了大小为1008bp的小鼠CD1d2基因编码区基因。结论:成功克隆了小鼠CD1d2编码区基因。     

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.     

Pharmacological treatment of COVID-19: an opinion paper

The precocity and efficacy of the vaccines developed so far against COVID-19 has been the most significant and saving advance against the pandemic. The development of vaccines has not prevented, during the whole period of the pandemic, the constant search for therapeutic medicines, both among existing drugs with different indications and in the development of new drugs. The Scientific Committee of the COVID-19 of the Illustrious College of Physicians of Madrid wanted to offer an early, simplified and critical approach to these new drugs, to new developments in immunotherapy and to what has been learned from the immune response modulators already known and which have proven effective against the virus, in order to help understand the current situation.     

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.