液相色谱-质谱联用技术在中药药代动力学研究中的应用进展

液相色谱-质谱法在中药药代动力学研究中的应用,包括中草药单一有效成分体内药物浓度测定及多组分同时测定、中草药体内代谢产物的鉴定与分析等。中草药特别是中药方剂,成分较复杂,较化学药物的药代动力学研究更困难;而液相色谱-质谱法结合了液相色谱的高分离能力和质谱的高灵敏度和极强的定性专属性,适于中药药代动力学研究。     

建国以来中草药有效成分的药物代谢动力学研究

药物代谢是研究药物的体内过程—吸收、分布、结构转化和排泄。药物代谢动力学(简称药代动力学)是用数学模式定量研究药物体内过程的动态变化。药物体内过程及其动力学研究对于指导临床合理用药有特殊重要的意义。本文评述了建国35年来中草药有效成分、包括其合成品和衍生物或有效部位的体内过程及药代动力学研究的情况,并试图对研究前景作一展望。     

中药药动学研究进展

中药的药物代谢动力学(简称中药药动学)是借助于动力学原理,研究中草药活性成分、组分、中药单方和复方在动物或人体内的吸收、分布、代谢和排泄的动态变化规律及其体内时量或时效关系,并用数学函数加以定量描述的一门新兴边缘学科[1]。近年来国内外学者在中药药动学研究方面进行了大量的实践,内容涉及生物利用度、毒动学、透皮吸收药动学、群体药动学、时辰药动学、证治药动学、活性成分在肠道的代谢处置和在体液中浓度的测定等。中药药动学的研究对阐明和揭示中草药作用机制及其科学内涵,设计及优选给药方案,促进中药新药开发和剂型改进及…     

代谢酶和转运体介导的中药-西药相互作用的药动学机制研究进展

随着中草药的广泛应用,中药-西药相互作用(herb-drug interaction,HDI)问题日益凸显。代谢酶和转运体是影响药物体内处置过程的重要因素,其表达和功能的改变常常引起药代动力学的变化,是药物相互作用的主要靶点。代谢酶负责药物的代谢清除,主要包括细胞色素P450超家族(CYP)、UDP-葡萄糖醛酸基转移酶(UGT)以及磺酸化酶(SULT);转运体参与药物的口服吸收、体内分布以及排泄,主要包括肠道转运体、肾脏转运体、肝脏转运体以及脑转运体等。葛根、银杏叶、人参、圣约翰草等中草药在临床上应用广泛,且常与西药联合应用,其成分与代谢酶以及转运体存在相互作用,容易产生HDI。本文综述代谢酶、转运体介导的HDI的药代动力学机制,阐述常用中草药在与西药联合应用时应注意的问题。     

黄连的药动学研究概况及未来研究思路

中药药动学是借助于动力学原理，研究中草药活性成分、组分、中药单方和复方体内吸收、分布、代谢和排泄（ADME）的动态变化规律及其体内时量一时效关系，并用数学函数加以定量描述的一门边缘学科。阐明药物在体内经历的变化以及与机体的相互作用，有助于阐明药物的有效性及作用原理。黄连始载于东汉《神农本草经》，列为上品，已经有几千年的临床应用史，具有抗微生物、止泻、抗炎、抗溃疡、健胃等多种药理作用。     

基于复杂网络与代谢组学的中药药代动力学研究思考与探索

药物研发模式的转变推动了药物评价技术体系的革新。中药药代动力学研究是中药现代化研究的重要组成部分,对于创新中药及现代中药复方研发具有重要意义。中药药代动力学理论近些年虽然取得了进步,但目前尚缺乏符合中药自身特征的药代动力学研究与评价技术体系。本文扼要介绍了中药药代动力学的研究现状、代谢组学及复杂网络理论,并在此基础上提出应用代谢组学和复杂网络方法来研究多组分药代动力学(网络药动学)的设想,以期揭示中药药效物质基础和作用机制。     

中药药物代谢动力学研究现状及问题分析

<正>中药药物代谢动力学是应用动力学原理,研究中药活性成分、组分、单味药和复方体内吸收、分布、代谢、排泄和毒性(ADME/Tox)的动态变化规律及其体内时-量、时-效关系,并用数学函数加以定量描述的一门新兴学科。开展中药药物代谢动力学研究对阐明和揭示中药药效物质基础和作用机制,设计及优选中药给药     

药物生殖毒性试验中伴随毒代动力学研究方法介绍

<正>毒代动力学(Toxicokinetics,TK)是一门涉及到药代动力学(Pharmacokinetics,PK)和毒理学研究的边缘性分支学科。它运用药代动力学的原理和方法定量地研究毒性剂量下药物在动物体内的吸收、分布、代谢以及排泄过程和特点,进而探讨药物毒性发生和发展的规律性。药物生殖毒代动力学的研究重点是解释生殖毒性试验结果和预测人体安全性,而不是简单描述受试物的基本药代动力学参数特征,该方面的研究已经     

肝脏“代谢-转运互作”及其对药物药代动力学、疗效和毒性影响的研究进展

肝脏是药物代谢和排泄的主要器官。肝脏药物代谢酶和膜转运体对肝细胞内药物处置及其临床疗效和毒性产生重要影响。近年来,国内外学者发现被称为"代谢-转运互作"的动力学现象,其对药物药代动力学(生物利用度)、药物相互作用具有显著影响。药物代谢酶与转运体间的功能相互作用是目前药物代谢和药代动力学研究的热点之一。本文对肝脏代谢-转运互作进行了探究,并系统阐述了这种互作对药物(特别是Ⅱ相药物代谢)的药物相互作用、药代动力学、临床疗效和毒性反应的影响。今后应进一步阐明肝脏代谢-转运互作机制,有助于研究体内药物处置及药物相互作用,为临床合理用药提供新思路和新技术。     

中药注射剂药物代谢动力学研究现状

中药注射剂的安全性问题正受到越来越多的关注。药代动力学研究是揭示中药注射剂效应物质基础及其体内过程的重要途径,对于临床合理用药、提高中药注射液质量控制标准与临床用药的有效性、安全性具有十分重要的意义。本文简要分析了中药注射剂药物代谢动力学研究相关进展,指出对中药注射液药代动力学的重视程度尚有待提高。随着近年来中药药代动力学研究技术方法的进步,已逐步具备条件开展中药注射液的体内过程研究,中药注射液的质量控制、安全性评价、工艺优化以及临床合理用药研究等方面应充分利用和结合中药注射液体内过程的研究结果,以保障和提高中药注射液临床用药的有效性与安全性。     

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.

     

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.     

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.     

Glycofection: The Ubiquitous Roles of Sugar Bound on Glycoplexes

Glycofection (transfection by using sugar-substituted polylysine) was assessed in order to provide an alternative to viral vectors for the transfer of genes into vascular smooth muscle cells. A rabbit vascular smooth muscle cell line (Rb-1 cells) was selectively transfected by using glycoplexes (glycosylated polylysine/pSV2LUC complexes) in the presence of 10 mu M of the fusogenic peptide GALA. A sugar-specific transfection was obtained when the glycofection was conducted for 1 h with glycoplexes containing either alpha Gal, alpha -Glc, alpha -GalNAc, beta -GlcNAc, or beta -GalNAc residues. The gene expression was high after transfection, with glycoplexes bearing alpha Gal, alpha -GalNAc, or beta -GalNAc residues that were weakly internalized, and low with glycoplexes carrying Lact or Rha residues that were well taken up by cells. These results suggest that 1) glycofection can be a good approach for a selective transfer of genes intovascular smooth muscle cells, 2) an efficient uptake of the glycoplexes is not the unique limiting step for an efficient transfection, and 3) the sugar-dependent trafficking of the glycoplexes inside the cells may account for the transfection efficiency.     

直肠癌下切缘病理组织学分析

目的探讨直肠癌逆向浸润与下切缘的安全距离的关系。方法对36例直肠癌Miles手术和Dixon手术后标本的肿瘤下缘1.0cm、2.0cm、3.0cm的肠壁及对应的系膜病理组织学检查,观察直肠癌逆向浸润或转移的距离。结果36例直肠癌标本距癌肿下缘1.0 cm、2.0cm、3.0cm的肠壁及对应的系膜病理组织学检查均为阴性,结论直肠癌远恻逆向浸润或转移未见超过1.0cm,因此认为保肛手术时切除肿瘤远侧肠管(包括系膜)2.0cm是安全的。