一阶导数高速脉冲极谱法用于盐酸普鲁卡因的定量分析

研究了一阶导数高速脉冲极谱法,并运用于盐酸普鲁卡因及其注射制剂的定量分析。在-0.04 V(对 Ag/AgCl)处出现的良好导数峰,于1.0～6.0×10~(-4)mol/L 范围内,导数峰电流与浓度呈线性关系。检测限为3.0×10~(-8)mol/L。操作简便、快速、灵敏,结果准确。     

氯霉素在汞膜电极上的伏安行为及其测定

目的:建立测定氯霉素滴眼液含量的方法。方法:氯霉素在浓度为0.1mol/L的HAc-NaAc(pH4.5)溶液中,汞膜电极上有一还原峰,峰电位为-0.24V(vsAg/AgCl),用方波伏安和循环伏安法研究了体系的性质。结果:氯霉素的浓度在1.0×10-7~5.0×10-5mol/L范围内与峰电流成正比。检出限为5.0×10-8mol/L。结论:在汞膜电极上氯霉素的还原为不可逆过程,该方法用于氯霉素滴眼液含量的测定结果满意。     

奋乃静的二阶导数高速脉冲极谱测定法

运用二阶导数高速脉冲极谱法对奋乃静及其制剂进行定量测定。在含氢氧化钠-磷酸二氢钾的乙醇和水的底液中,于0.10V(vs Ag/AgCl)处出现良好的导数峰,于1.4×10~(-4)～7.4×10~(-4)mol/L 范围内,导数峰幅值与药物浓度呈线性关系。检测限为7.4×10~(-9)mol/L。方法简便、快速、灵敏,结果准确。     

高效液相色谱法测定复方新诺明片的含量

本文研究一阶导数高速脉冲极谱法,并将其运用于氟哌啶醇及其制剂的定量分析中,在无水乙醇溶液中,于-0.38V(Vs Ag/AgCl)处出现一良好的导数峰,在0.33～1.70×10~(-3)mol/L范围内,浓度与峰电流呈线性关系。检测限为10~(-10)mol/L。方法简便、快速、灵敏,结果准确。     

利用聚茜素红薄膜修饰电极测定阿昔洛韦

目的利用聚茜素红薄膜修饰电极(PARSE)对阿昔洛韦(ACV)的电催化作用,建立了一种新的对ACV含量进行定量分析的电化学分析方法。方法在0.05mol/L PBS(pH=6.86) 0.3mol/L NaC l体系中,利用PARSE为工作电极,以100mV/s的扫描速率在0~1.2V电位范围内进行循环伏安扫描,根据循环伏安图上氧化峰电流的大小,对ACV进行定量分析。结果ACV的浓度在5.0×10-6~6.8×10-4mol/L范围内与峰电流呈良好的线性关系,r=0.9998,检出限为8.0×10-7mol/L。平行实验的RSD=0.9%(n=10),回收率为94.6%~104.3%。结论该法简单、灵敏、可靠,用于药剂样品中ACV的含量分析,得到满意结果。     

雷尼替丁的单扫描示波极谱测定法

在 pH 5的 HOAc-NaOAc 缓冲溶液中,雷尼替丁呈现两个示波极谱峰,其峰电位分别为-0.98及-1.47 V。第一个峰的峰电流与雷尼替丁浓度在15×10~(?)～2.4×10~(-4)mol/L 的范围内呈线性关系。用于测定片剂中雷尼替丁的含量,结果与药典法一致。     

导电聚合物膜修饰电极用于对乙酰氨基酚和抗坏血酸的同时测定

目的:研究对乙酰氨基酚和抗坏血酸在4-(2-吡啶偶氮)间苯二酚(PAR)导电聚合膜修饰电极上的电化学行为,建立同时测定对乙酰氮基酚和抗坏血酸含量的电化学分析新方法。方法:采用循环伏安法研究对乙酰氨基酚和抗坏血酸在膜修饰电极上的电化学行为,以差示脉冲伏安对二者含量进行测定。结果:聚 PAR 膜修饰电极对对乙酰氨基酚和抗坏血酸有很强电催化作用,明显增强了电极反应的可逆性。在 pH 6.0磷酸盐缓冲液中,对乙酰氨基酚氧化峰电流与其浓度在1.0×10~(-8)～1.5×10~(-5),5×10~(-5)～4×10~(-4)mol·L~(-1)范围内呈良好的线性关系,抗坏血酸氧化峰电流与其浓度在1.0×10~(-6)～3.0×10~(-4)mol·L~(-1)范围内呈良好的线性关系,检出限分别为5.0×10~(-9)mol·L~(-1)和5.0×10~(-7)mol·L~(-1)。结论:该修饰电极可以对对乙酰氨基酚和抗坏血酸进行单独或同时的测定,并用于实际样品维 C 银翘片中对乙酰氨基酚和抗坏血酸的含量检测,结果令人满意。     

β-环糊精修饰电极直接测定肾上腺素注射液的含量

目的:研究肾卜腺素(EP)在β-环糊精修饰聚乙酰苯胺玻碳电极(β-CD/PNAANI/GCE)上的电化学行为,建立一种新的测定 EP 的电化学分析方法。方法:用循环伏安法研究 EP 在修饰电极上的氧化还原特性,用差分脉冲伏安法直接测定肾上腺素的含量。结果:该修饰电极能很好地催化 EP,与裸玻碳电极(GCE)相比,还原峰电流增强近30倍。在 pH 7.5磷酸盐缓冲液中,还原峰电流与 EP 的浓度在6.0×10~(-6)～1.0×10~(-4) mol·L~(-1)范围内呈良好的线性关系,其线性回归方程为 I_p=1.68 6.92×10~(-6)C_(EP),相关系数为0.9975,检测限为1.0×10~(-7)mol·L~(-1)。回收率在97.5%～104.5%之间。结论:该方法操作简单,可用于注射液中盐酸肾上腺素含量的测定,结果令人满意。     

耐无环鸟苷单纯疱疹病毒对其他抗病毒药物的敏感性

目的探讨耐无环鸟苷的Ⅰ型单纯疱疹病毒(HSV-1)对其他抗病毒药物的敏感性。方法将HSV-1接种于单层非洲绿猴肾细胞(VERO cell)中,加入不同的抗病毒药物:无环鸟苷(ACV)、酞丁安(TDA)、更昔洛韦(GCV)、膦甲酸(PFA)、阿糖腺苷(Ara-A)或Carbocyclic Oxetano-cin G(C.OXT-G),应用空斑抑制法测定药物的半数有效剂量(ED50)。将HSV-1在含ACV的环境中连续培养10代,得到耐ACV的HSV-1(ACVr),测定所加5种药物对ACVr的ED50。结果药物对HSV-1野生株和ACVr株的ED50分别为0·396×10-6mol/L和10·66×10-6mol/L,差异有显著性(P<0·01);GCV和C·OXT-G分别为0·304×10-6mol/L、11·20×10-6mol/L和0·228×10-6mol/L、2·829×10-6mol/L,差异有显著性(P<0·05);PFA、TDA和Ara-A分别为168·9×10-6mol/L、180·1×10-6mol/L、173·1×10-6mol/L、229·0×10-6mol/L和20·18×10-6mol/L、23·11×10-6mol/L,差异无显著性(P>0·05)。结论ACVr对GCV、C·OXT-G不敏感,而对PFA、TDA及Ara-A敏感。     

大黄素甲醚和牛血清蛋白相互作用的电化学性质研究

在pH4.0的Britton-Robinson(B-R)缓冲体系中,应用循环伏安法和示差脉冲伏安法对大黄素甲醚与牛血清白蛋白(BSA)相互作用的电化学性质进行研究。结果表明,二者结合生成了一种非电活性的超分子化合物,同时对结合反应的机理进行了探讨。BSA的存在导致大黄素甲醚氧化还原峰电流降低,峰电位基本不变,峰电流的下降值同所加入的BSA浓度在一定范围内呈线性关系。线性范围5.0×10-6~1.0×10-7mol/L,检出限3×10-7mol/L。     

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.