一种阻断乙肝病毒衣壳组装的抗病毒药物的体外荧光筛选方法

病毒组装过程通常不作为开发抗病毒药物的靶标，部分由于缺乏易于操作的体外筛选方法。本研究基于染料标记的衣壳蛋白荧光猝灭原理，建立了体外检测乙型肝炎病毒（HBV）衣壳组装的方法，用于筛选可能的抑制剂。此方法适用于高通量筛选，能快速筛选出抑制病毒组装过程的小分子化合物，它们能阻止、不适当地加快和／或误导衣壳形成从而产生异常颗粒的小分子。     

小核糖核酸病毒用作重组活疫苗载体

以脊髓灰质炎病毒为代表的小核糖核酸类病毒,是当前发展重组活疫苗的一组重要载体。由于其遗传背景清楚,操作方便且高效和多价性,一直为世人所关注。目前此类载体已从最早的适应嵌合病毒技术开始发展到了今天能适应杂交病毒复制子、杂交病毒等新技术,并且逐步从实验阶段走向了实用阶段。可以相信,随着这些技术的不断完善和发展,小核糖核酸类病毒必将为人类提供新一代的活疫苗载体。     

环球快讯

日本发现抑制丙型肝炎病毒的物质 日本工业技术院最近发现抑制丙型肝炎病毒增殖的物质,这种物质有可能被用于制造抗病毒剂。 据《日本经济新闻》报道,日本科技人员在研究过程中得到百万亿种核糖核酸,并从中筛选与丙型肝炎病毒蛋白相结合的核糖核酸。科技人员在将这种筛选办法重复11次后,终于找到了与丙型肝炎病毒蛋白强烈结合的核糖核酸。丙肝病毒蛋白与这种核糖核酸结合后,其活性被控制在原来的1/10以下,病毒已经不能再增     

HIV-1衣壳蛋白抑制剂的研究进展

艾滋病是由 HIV-1 引起的传染性和致死性疾病,目前临床使用的抗艾滋病药物容易产生耐药性和不良反应等问题,急需开发具有全新作用机制的高效、低毒的抗艾滋病药物。衣壳蛋白在 HIV-1 病毒颗粒装配和成熟过程中发挥着至关重要的作用,它的稳定性直接影响 HIV-1 的感染能力。近年来对衣壳蛋白结构和作用机制的阐明为人类寻找艾滋病治疗新途径带来了希望。该文综述了抗艾滋病作用新靶点衣壳蛋白的结构、功能及其抑制剂的最新研究进展。     

抗鼻病毒感染药物的研究进展*

人鼻病毒属小核糖核酸病毒。40%～60%的普通感冒由鼻病毒感染引起。它还能导致急、慢性支气管炎以及其他呼吸道感染疾病,并引发并发症,研究抗鼻病毒感染药物来有效地预防和治疗鼻病毒感染是非常必要的。现根据抗鼻病毒感染药物的作用机制,将其分为鼻病毒蛋白合成抑制剂、鼻病毒吸附和脱壳抑制剂以及鼻病毒RNA复制抑制剂等3类,分别对其作用机制、化学结构、抗鼻病毒活性以及临床应用进行了综述。     

柯萨奇-腺病毒受体在恶性肿瘤细胞中的表达研究

柯萨奇-腺病毒受体(CAR)是柯萨奇B组病毒(CBV)和腺病毒(Ad)与靶细胞结合的共同体.柯萨奇病毒是无衣壳的核糖核酸(RNA)病毒,属于微小的RNA病毒家族,有A、B、C、D、E、F六种血清型.腺病毒为无衣壳的DNA病毒,这是两种在种系发育过程中不相干的病毒,却有一个共同的受体--CAR.CAR是一种跨膜糖蛋白,属于免疫球蛋白超家族成员之一.由于其在生物学领域的特殊作用,近年来已经成为肿瘤学领域中的热点问题.     

流感病毒血凝素共价抑制剂的设计、合成及活性研究（英文）

近年来流感频发,针对传统靶点抗流感药物(如扎那米韦和奥司他韦)的耐药病毒大量出现,迫切需求开发新靶点、新作用机制的抗流感药物。本研究针对流感病毒血凝素(HA)底物结合位点附近的赖氨酸(Lys133和Lys222),设计了系列具有共价结合潜力的唾液酸类化合物(1a–1h)。活性研究表明该系列化合物对两种流感病毒HA蛋白的结合力较母体化合物唾液酸(SA)有明显提升,其中化合物1d与阳性化合物2,6-唾液酸乳糖胺(2,6-SLN)持平(K_D=38.2和39.6μM);该系列化合物安全无毒(对MDCK细胞CC₅₀>1 m M),其中化合物1d可有效抑制流感病毒在MDCK细胞中的复制。本研究提出了基于流感病毒HA的共价抑制新策略,深入发掘有望获得新型强效HA抑制剂。     

09085 CPMP要求减少疫苗中使用硫柳汞

ECCPMP公布了有关要求减少、取消和替代人用疫苗中有机汞化合物硫柳汞(thiomersal)的指南。这类化合物在灭活疫苗的最终配方阶段或在制造过程早期可能被用作为抗微生物防腐剂。它们不用在活疫苗中,因为它们与活性物质有相互作用。CPMP担心疫苗内这些含汞化合物的潜在风险,尤其是对儿童。     

Galenea公司新型siRNA技术药物获SBIR基金

2005年11月17日Galenea公司宣布国际变态反应和感染性疾病学会授予他们I期小型业务革新研究(SBIR)基金以扩大其小片段干扰核糖核酸(siRNA)技术治疗流行性感冒。siRNA是一种最新发现的细胞内特异性调节基因,可使某些病毒的特定基因“沉默”并失去功能,或将RNA病毒的基因组分解,而被分解的片段成为新的siRNA来消灭其它病毒。如果使用和病毒关键基因相同的或同源的siR-NA可以破坏复制前期的病毒RNA,杀死病毒。通过改变siRNA核甘酸序列还可以控制由于病毒遗传密码的改变而产生的抗药性。G00101是此次SBIR基金资助的siRNA抗流行性…     

潮汕地区中草药金丝草的研究概况

金丝草为潮汕地区常见中草药,本文对金丝草的化学成分与生物活性等方面的研究进行综述。金丝草主要含有黄酮类化合物、酚类物质、氨基酸、有机酸和糖类物质。有治疗糖尿病、慢性肾功能衰竭、护肝、抗HVB病毒等活性,具有进一步研究开发的潜力。     

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.