肉桂中肉桂酸的单扫描示波极谱法测定

本文报道一种测定肉桂中肉桂酸含量的单扫描示波极谱法。在０．４ｍｏｌ／Ｌ氯化铵－０．００２５ｍｏｌ／Ｌ盐酸（ｐＨ２．６±０．１）支持电解质溶液中肉桂酸在－１．３５Ｖ（ｖｓ．ＳＣＥ）有一极谱还原波。该波的一阶导数峰峰高与肉桂酸浓度在２．０×１０~（－６）～１．０×１０~（－４）ｍｏｌ／Ｌ范围内呈良好线性关系（ｒ＝０．９９９）．肉桂的其它成分如肉桂醛、肉桂醇、香豆素等不干扰测定。应用本方法测定广西肉桂中肉桂酸的含量，结果令人满意。     

胆骨化醇及其制剂的二阶导数差示脉冲极谱法定量研究

本文建立了胆骨化醇及其制剂的二阶导数差示脉冲极谱法定量测定方法。在２．０×ｌ０－５ｍｏｌ／ＬＫＣｌ底液中，于－１．６９Ｖ（ｖｓＡｇ／ＡｇＣｌ）处出现一良好的二阶导数差示脉冲极谱峰，在２．０×１０－５～１．２×１０－４ｍｏｌ／Ｌ范围内，胆骨化醇的浓度与其导数峰幅值呈非常显著的线性关系（ｐ＜０．０１），检测限为８．４×１０－９ｍｏｌ／Ｌ。方法简便、快速、灵敏，结果准确。     

碳糊电极吸附伏安法测定微量酚磺乙胺

在００５ｍｏｌ／Ｌ硫酸底液中，用碳糊电极吸附伏安法测定酚磺乙胺，阳极峰电位为０５５Ｖ（ｖｓ．ＳＣＥ），峰电位与酚磺乙胺的浓度在１０×１０－７～１０×１０－４ｍｏｌ／Ｌ范围内呈良好的线性关系。该法检测下限为５０×１０－８ｍｏｌ／Ｌ，回收范围为９５０％～１０５５％，相对标准偏差为３０％（ｎ＝１２）。对酚磺乙胺注射液用本法进行了测定，获得满意结果。本文对反应机理进行了初步探讨，酚磺乙胺在碳糊电极上是一个两电子、两质子的不可逆过程     

反相高效液相色谱法测定血浆和脑脊液中甲氨蝶呤浓度

目的：建立测定血浆和脑脊液中甲氨蝶呤的反相高效液相色谱方法。方法：采用ＯＤＳ不锈钢柱,流动相：甲醇∶０．０２５ｍｏｌ·Ｌ－１磷酸盐缓冲液（２１∶７９,ｐＨ６．７０）,检测波长：３０６ｎｍ,样品经沉淀蛋白质后直接进样。结果：血浆和脑脊液样品回收率分别为９７．５％±４．１％和１００．８％±１．５％,日内和日间误差（ＲＳＤ）均＜７％,最低检测浓度４．７５×１０－８ｍｏｌ·Ｌ－１,血浆中在１．１０×１０－７～２．２×１０－６ｍｏｌ·Ｌ－１和２．２０×１０－６～１．７６×１０－４ｍｏｌ·Ｌ－１;脑脊液中在１．１０×１０－７～２．２０×１０－６ｍｏｌ·Ｌ－１和２．２０×１０－６～１．１０×１０－３ｍｏｌ·Ｌ－１浓度范围内有良好线性关系,ｒ＝０．９９９６～０．９９９９。结论：本法简便、准确、灵敏。     

诺氟沙星的吸附伏安法研究

在ｐＨ＝７．４９氨－氯化铵缓冲液中，诺氟沙星在滴汞电极上产生一灵敏的还原峰，峰电位为－１．５２Ｖ（ｖｓ．ＳＣＥ）。在１．９８×１０（－７）～４．８８×１０（－６）ｍｏｌ／Ｌ之间有良好的线性关系。本文对其极谱性质和电极过程进行了研究，用于诺氟沙星的测定，方法简便，结果准确、可靠。     

RP—HPLC法测定片剂中盐酸莫索尼定的含量

采用反相高效液相色谱法，选择苯酚为内标物，ＺＹ１１０４型ＸＷＧ－Ｃ１８柱（４．６ｍｍ×２５０ｍｍ）为分析柱，甲醇－水－０．２ｍｏｌ／Ｌ硫酸铵（１０．６８０．７２，ｐＨ＝７．７）为流动相，流速为１．０ｍＬ／ｍｉｎ，检测波长为２５４ｎｍ，进样量２０μＬ，测定片剂中盐酸莫索尼定的含量，按盐酸莫索尼定计算，理论板数为２５４４，样品峰与内标峰的分离度为３．９．线性范围为４～１００ｍｇ／Ｌ（ｒ＝０．９９９８），最低检测量为１０ｎｇ，平均回收率为９９．８２％，ＲＳＤ＝０．７９％．用该法测定３批盐酸莫索尼定片剂的含量，结果分别为（９６．８±１．９）％、（９９．４±１．７）％和（９９．３±１．６）％．本法快速、灵敏、准确，专属性高．     

吡哌酸的电化学行为研究及其单扫示波极谱测定

吡哌酸在ｐＨ４．５,０．２ｍｏｌ／Ｌ的醋酸盐缓冲溶液中有灵敏的单扫极谱吸附波。在６×１０－８～２×１０－６ｍｏｌ／Ｌ范围内吡哌酸的浓度与其波高成直线关系,检测下限２×１０－８ｍｏｌ／Ｌ。利用该波测定了吡哌酸片中吡哌酸的含量,结果满意。吡哌酸在该溶液中的汞电极上的吸附服从Ｌａｎｇｍｕｉｒ等温线,吸附系数β＝５．４×１０５;电极反应的电子传递系数α＝０．６８,表面电极反应速率常数ｋｓ＝０．６８ｓ－１。     

比色法测定维生素B1片含量的研究

本文实验比较了某些现有光度测定ＶＢ１方法，提出用盐酸苯肼－亚硝酸钠试剂与维生素Ｂ１反应生成橙红色溶液，进行光度测定，对比度△λ为９１ｎｍ，灵敏度，ε（４９７ｎｍ）＝１．１×１０４Ｌ·ｍｏｌ（－１）·ｃｍ（－１），在０～１０μｇ／ｍｌ范围内线性关系良好。用本法测定维生素Ｂ１片的含量，标准加入回收率范围为１００％～１０３％，片剂测定与中国药典１９９０年版紫外分光光度法测定结果一致。     

高效液相色谱法测定血浆中尼麦角林体内代谢物10α—甲氧基—9,10—？…

采用高效液相色谱法测定人血浆中１０α－甲氧基－９，１０－二氢麦角醇（ＭＤＬ，尼麦角林体内代谢物）的浓度。ＭＤＬ和麦角新碱（内标）有兴亡 从血浆中提取，并在ＳｐｈｅｒｓｏｒｂＣ１８柱上，以乙腈－０．１ｍｏｌ／Ｌ（ｐＨ５）醋酸铵（１：４）为流动相进行分离。在２２５ｎｍ处检测。本法简便、灵敏、专属性好。     

DrugFET的研究（Ⅴ）：四苯硼钠—麻黄碱FET的研制与应用

将离子敏感场效应晶体管（ＩＳＦＥＴ）与药物敏感膜相结合，研制成一种对麻黄三有良好响应的药物敏感场效应晶体管传感器（ＤｒｕｇＦＥＴ）。四苯硼钠作为电活性物质，不必转型，民ＰＶＣ膜ＩＳ－ＦＥＴ，对盐酸麻黄碱的线性响应范围，１．０×１０＾０－９．０×１０＾－５ｍｏｌ／Ｌ，斜率５８．８ｍｖ／ＰＣ（Ｃ＝ｍｏｌ／Ｌ），检测下限３．０×１０＾－５ｍｏｌ／Ｌ，ｐＨ５．０－８．０。用其分析麻黄碱片剂的含量，结果与药     

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.