抗艾滋病新药--度鲁特韦（dolutegravir）

度鲁特韦(dolutegravir)是一种人类免疫缺陷病毒类型1(HIV-1)整合酶链转移抑制药(INSTI),与其他抗逆转录病毒药联用治疗HIV-1感染。临床前研究结果显示其毒性小,没有基因毒性和致癌毒性,在大于临床剂量27倍时没有出现明显的生育毒性和致畸毒性。临床研究显示DTG对初次治疗的HIV感染者、当前疗法治疗失败但未使用整合酶抑制药治疗的患者的治疗效果均优于对照药;对抗病毒治疗失败、且对雷特格韦( raltegravir )和(或)埃替格韦( elvitegravir)耐药的成人患者也显示出良好的疗效。体内外试验研究均显示较强的抗HIV-1病毒活性,安全性及耐受性良好,现将其药效学、安全性、药动学及临床研究等作一综述,为临床应用提供参考。     

HIV-1整合酶抑制剂Phenalenones

逆转录酶抑制剂和蛋白酶抑制剂联用可抑制HIV-1复制,降低病毒载量并减少发病率和病死率,而由于耐药突变病毒株的出现,有时使治疗失败。为了克服这一情况需寻找作用于病毒复制过程中不同位点的高效且毒副作用小的抗HIV-1药物。HIV-1复制过程中有3种必需酶即逆转录酶、蛋白酶和整合酶。整合酶是HIV DNA进入宿主基因中进行特殊的DNA重组反应的关键酶,对整合过程中的3′末端过程和链转移过程起重要的催化作用。仅有整合酶还没作为临床已使用抑制剂的作用位点。虽然报道过很多天然的及合成的整合酶抑制剂,但仅有少数化合物对整合酶具有高…     

26-51 HIV-1整合酶抑制剂Phenalenones

逆转录酶抑制剂和蛋白酶抑制剂联用可抑制HIV-1复制，降低病毒载量并减少发病率和病死率，而由于耐药突变病毒株的出现，有时使治疗失败。为了克服这一情况需寻找作用于病毒复制过程中不同位点的高效且毒副作用小的抗HIV-1药物。HIV-1复制过程中有3种必需酶即逆转录酶、蛋白酶和整合酶。整合酶是HIV DNA进入宿主基因中进行特殊的DNA重组反应的关键酶，对整合过程中的3’末端过程和链转移过程起重要的催化作用。     

Ⅰ型人类免疫缺陷病毒整合酶及其抑制剂研究进展

目的为研究新型Ⅰ型人类免疫缺陷病毒(human immunodeficiency virus type-1,HIV-1)整合酶抑制剂提供参考。方法根据查阅的文献从HIV-1整合酶的结构与功能、HIV-1整合酶的催化机制、HIV-1整合酶抑制剂对整合酶作用环节的影响等方面进行综述。结果HIV-1整合酶是由288个氨基酸残基组成的蛋白质,由病毒pol基因编码,相对分子质量约为32000;HIV-1整合酶抑制剂通过干扰整合酶的多聚化、竞争性结合病毒DNA长末端重复序列、阻断整合酶的"3′-加工"(切割病毒DNA)和"链转移"等影响整合酶的作用。结论利用先进的计算机辅助药物设计手段,通过对现有抑制剂构效关系以及抑制剂与大分子作用方式的研究可以逐步阐明整合酶抑制剂的作用机制;应着眼于寻找高活性的整合酶抑制剂,为治疗艾滋病提供新的途径。     

抗艾滋病药Dolutegravir

将自身基因整合到宿主细胞染色质中,是包括人类免疫缺陷病毒(HIV)在内的逆转录病毒复制过程中的一个关键步骤,由病毒整合酶介导.因此,整合酶可作为阻断HIV复制的合适靶标,由美国Shionogi-ViiV Healthcare公司开发的dolutegravir(代号:S/GSK-1349572)即为一种口服有效的整合酶抑制剂,其抗HIV活性显著.临床研究显示,对整合酶抑制剂raltegravir产生耐药性的HIV感染者可对本品应答.目前,本品正处于Ⅲ期临床研究阶段.     

Merck公司新的整合酶抑制剂

Merck公司HIV整合酶链转移抑制剂种类中的第一个药物MK-0518（Ⅰ）的Ⅱ期试验资料显示它可能具有良好临床意义。（Ⅰ）现处于Ⅱ期试验中。     

新型抗甲型流感药物——Pimodivir

Pimodivir是Vertex Pharmaceuticals公司正在开发中的一种口服抗甲型流感药物,是一种非核苷类甲型流感病毒RNA依赖的RNA聚合酶(RdRp) PB2亚基抑制剂。临床前试验研究证实,Pimodivir可以有效抑制对金刚烷胺和神经氨酸酶抑制剂耐药的各类甲型流感病毒,并且与神经氨酸酶抑制剂类药物奥司他韦有协同作用。Ⅰ期临床试验结果证实在健康志愿者中,Pimodivir 600 mg每日2次的剂量没有安全性问题,并且Pimodivir和奥司他韦联合用药未出现与临床相关的药物-药物相互作用。Ⅱ期临床实验结果显示Pimodivir不仅可以降低患者的病毒载量,而且耐受性良好。本文就Pimodivir的基本信息、作用机制、药效学、药代动力学和临床研究等作一概述。     

β—内酰胺酶研究进展

细菌主要是通过产生质粒介导的超广谱β-内酰胺酶,染色体介导的ClassC酶、增加广谱酶的产量及降低外膜的通透性等而对头孢他定、头孢噻肟等第三代头孢菌素耐药。其酶的种类繁多,特性各异。目前从临床产酶耐药菌中得到的TEM型酶已报道到TEM-68,SHV型酶到SHV-24,ClassC酶有AmpC酶和OXA酶等。随着β-内酰胺酶抑制剂与β-内酰胺类抗生素的联合应用,近年来又发现了耐抑制剂的β-内酰胺酶（inhibitor-resistant TEM β-lactamase）,简称IRT-β-内酰胺酶。它们是通过TEM型酶变异而使抑制剂的抑酶作用减弱。大多数耐抑制剂的β-内酰胺酶都是TEM-1和TEM-2的衍生酶。另外,有报道说,近年来抑制剂耐药的β-内酰胺酶在SHV型酶的家族也出现了。     

抗流感药奥司他韦

神经氨酸酶(NA)抑制剂是近年来开发的一类抗流感病毒药物，奥司他韦(oseltamivir)作为一种最新研制的神经氨酸酶抑制剂，具有对A、B型流感病毒均有效、不易耐药和患者耐受性好等优点，为流感的防治提供了一个新的有效选择。     

多羟基芳香族化合物对HIV-1整合酶的抑制作用

目的研究HIV-1整合酶抑制剂,为艾滋病的治疗提供新作用靶位的抗HIV药物。方法用HIV-1整合酶ELISA法检测3种萘醌类化合物,10种白藜芦醇及其衍生物和7种吡喃香豆素类化合物对整合酶的抑制作用。结果双羟基-1,4-萘醌(NQ-2)对HIV-1整合酶有抑制活性,IC₅₀为78.5 μmol·L^-1,发现萘醌类新化合物NQ-3对HIV-1整合酶的抑制作用优于NQ-2,IC₅₀为37.2 μmol·L^-1。用分步测定法发现NQ-2主要抑制HIV-1整合酶的链转移活性,而NQ-3则对装配和链转移都有较强的抑制。结论萘醌类化合物(NQ-2,3)对HIV-1整合酶有抑制作用,NQ-3为新化合物值得进一步研究。     

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.     

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.     

Synthesis,Cytotoxicity and Antileishmanial Activity of Some N-(2-(indol-3-yl)ethyl)-7-chloroquinolin-4-amines

We report herein the condensation of 4,7-dichloroquinoline (1) with tryptamine (2) and D-tryptophan methyl ester (3) . Hydrolysis of the methyl ester adduct (5) yielded the free acid (6) . The compounds were evaluated in vitro for activity against four different species of Leishmania promastigote forms and for cytotoxic activity against Kb and Vero cells. Compound (5) showed good activity against the Leishmania species tested, while all three compounds displayed moderate activity in both Kb and Vero cells.     

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.