黄芪治疗糖尿病作用机制和临床应用研究进展

目的探讨黄芪治疗糖尿病的作用机理和临床应用研究进展。方法1、从黄芪根中分离出的一种多糖（APS-G）具有双向调节血糖的作用,可使葡萄糖负荷后的小鼠血糖水平显著下降,并能对抗肾上腺素引起的小鼠血糖升高反应,对苯乙双胍所致小鼠实验性低血糖有明显的拮抗作用;对胰岛索性低血糖无明显影响,观察到黄芪注射液可降低糖尿病大鼠的血糖。2、采用放射免疫分析方法观察到黄芪甲甙溶液具有促进Wistar糖尿病大鼠血浆胰岛索和C肽分泌的作用,并随时间作用延长,分泌作用增加,其机理可能是通过刺激类胰升血糖素肽-Ⅰ（GLP—Ⅰ）的分泌,诱发β细胞内胰岛素颗粒活性恢复来实现的。结果用黄芪多糖冲剂治疗Ⅰ型DM38例,表明黄芪多糖冲剂能降低血糖,改善临床症状,疗效明显。结论黄芪是一味应用广泛、极具潜力的中药,应更深入地开展黄芪的基础研究及临床研究,以进一步了解它的作用机制,发现更多的适应证,充分开发利用黄芪中药资源,造福患者。     

薄层扫描法测定贝芪口服液中黄芪甲甙的含量

建立了测定贝芪口服液中黄芪甲甙含量的薄层扫描测定法。采用硅胶Ｇ－ＣＭＣＮａ薄层板，以氯仿－甲醇－水（６５：３５：１０）为展开剂、１０％硫酸乙醇为显色剂，测定波长（λ_s）与参比波长（λ_Ｒ）分别为６００、７００ｎｍ。黄芪甲甙的量在１～６μｇ与斑点面积呈线性关系，ｒ＝０．９９８８。方法平均回收率为９８．２６±２．７６％（ｎ＝６）．三批供试品中黄芪甲甙的含量为０．１２２～０．１８０ｍｇ／ｍｌ，方法精密度（ＲＳＤ）分别为３．１０％、３．７１％、３．７０（ｎ＝４）。     

抗栓胶囊中黄芪甲甙的含量测定

本文研究了抗栓胶囊中主要成分黄芪中的黄芪甲甙的含量测定方法，采用双波长薄层扫描方法。薄层色谱采用硅胶Ｇ板，展开剂用氯仿－甲醇（７：３），香草醛浓硫酸显色。本方法平均回收纺为９７．１６％、ＣＶ％为２．３１％。     

人参多糖口服液质量标准研究

目的：人参多糖口服液质量标准研究及主要成分含量的测定。方法：用薄层层析法对主要成分黄芪甲甙进行定性鉴别。采用草醛－硫酸比色法测定黄芪甲甙的含量。结果：测定波长λ=554nm在50－450mg范围内黄芪甲甙呈线性关系,加样回收率为100．41％,RSD＝1．71％. 结论;本法简便易行,结果稳定,可做人参多糖口服液中黄芪甲甙的含量测定方法。     

野生黄芪与栽培黄芪中黄芪甲甙含量比较

目的 对野生黄芪和栽培黄芪中黄芪甲甙含量进行比较。方法 采用双波长扫描法进行含量测定。结果 经过实验证明,野生黄芪与栽培黄芪中的黄芪甲甙含量基本一致。     

二氢埃托啡成瘾者的甲状腺功能、胰腺分泌及睾酮变化

目的：观察二氢埃托啡成瘾者的甲状腺功能、胰腺分泌及睾酮变化。方法：用放射免疫法测定１１例男性二氢埃托啡成瘾者与２９例男性海洛因成瘾者及２６例正常对照组血中ＴＳＨ，Ｔ３，Ｔ４，Ｃ肽，胰岛素及睾酮含量。结果：二氢埃托啡成瘾者与正常对照组比较，ＴＳＨ，Ｔ３下降显著（Ｐ＜０．０１）；Ｃ肽和胰岛素增加明显（Ｐ＜０．０１）；Ｔ４下降、睾酮升高，差别不显著（Ｐ＞０．０５）。二氢埃托啡组与海洛因组比较，Ｔ３下降不显著（Ｐ＞０．０５）；ＴＳＨ和Ｔ４下降显著（Ｐ＜０．０１）；Ｃ肽、胰岛素、睾酮升高显著（Ｐ＜０．０１）。结论：二氢埃托啡成瘾者垂体甲状腺功能受抑制，胰腺和睾酮分泌升高     

HPLC法测定黄芪炮制品中黄芪甲甙含量

本文报道用ＨＰＬＣ法测定黄芪的生品、蜜制、炒制、酒制、盐制及盐麸制等６种黄芪炮制品中黄芪甲甙的含量。     

抗肾衰胶囊中黄芪甲甙含量测定

本实验采用双波长薄层扫描法测定抗肾衰胶囊中甲芪甲甙的含量,经氯仿：甲醇：水（65：35：10）下层开,显色,薄层扫描,测得黄芪甲甙含量31．61％（mg/g),RSDo 3.62%,平均回收率为104．5％。结果表明测定方法准确、可靠、简便、易行。     

黄芪中有效成分环黄芪醇皂甙和黄芪甲甙的含量测定

黄芪对心血管系统作用的主要有效成分是黄芪皂甙,黄芪皂甙大部分是以环黄芪皂醇为甙元的皂甙,其中黄芪甲甙含量最高。本文以双波长薄层扫描λ_{s/sub>=500nm,λR=700nm测定环黄芪醇皂甙和黄芪甲甙的含量。}     

人参皂苷Re促进胰高血糖素样肽-1分泌的研究

目的探讨人参皂苷Re是否通过促进肠道中胰高血糖素样肽-1的分泌来发挥抗糖尿病的药理机制。方法雄性SD大鼠腹腔注射链脲佐菌素,结合高糖、高脂饮食4周后,测定空腹血糖。将造模成功的动物随机分成4组,即模型对照组,人参皂苷Re50,100mg/kg治疗组和正常对照组。连续灌胃治疗4周,在治疗期间每周测1次血糖并监测摄食量。治疗4周后,各组大鼠禁食8h,治疗组给药30min后给予葡萄糖溶液3g/kg,腹腔注射戊巴比妥钠麻醉。糖负荷后15min,取大鼠的肝门静脉血、回肠和结肠组织,分别用酶联免疫吸附试验(ELISA)测定血浆中的胰岛素含量及血浆、回肠、结肠组织中的胰高血糖素样肽-1的含量。另取一部分回肠组织用ELISA测定胰高血糖素原分泌水平。结果相对于糖尿病模型组,无论是血浆或肠道组织,人参皂苷Re治疗组显著增加了胰高血糖素样肽-1的分泌,实验还显示治疗组显著增加了血浆中胰岛素的含量、降低了血糖和摄食量,改善了糖尿病症状。结论人参皂苷Re可能通过促进肠道组织中胰高血糖素样肽-1的分泌来发挥降血糖、治疗糖尿病的作用。     

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.     

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.     

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.