高效液相色谱法测定血浆中尼扎替丁浓度

目的:建立测定人血浆中尼扎替丁的高效液相色谱方法.方法:采用Diamonsil C18色谱柱(200 mm×4.6mm,5μm),流动相为0.1 mol·L-1醋酸铵缓冲液-甲醇(60:40),检测波长为320nm.血浆样品加盐析溶液碱化后以氯仿提取,雷尼替丁为内标.结果:尼扎替丁血药浓度线性范围为20～6 000l·L-1(r=0.999 9,n=6),最低检测浓度为10μg·L-1(S/N=3),方法回收率在96.84%～101.39%(n=5),日内和日间RSD均小于4%.结论:本法简便,快速,重现性好,适于尼扎替丁的药动学研究.     

HPLC法测定人血浆中的尼扎替丁浓度

目的:建立尼扎替丁血药浓度的HPLC测定方法。方法:血浆样品经甲醇直接沉淀蛋白进样。分析柱:Nucleosil100-5硅胶柱(4.6mm×250mm,5μm);流动相:乙腈:甲醇:水:氨水(1000:200:25:1.25,pH7.0);流速1.0mL/min;检测波长324nm。结果:该方法检测尼扎替丁的线性范围为15.625-2000ng/mL(r=0.9999),方法的日内和日间RSD<1.2%。结论:该方法简单、快速、准确、灵敏、经济,可用于尼扎替丁人体药动学研究。     

反相高效液相色谱法测定人血浆中盐酸二甲双胍浓度

目的:建立测定人血浆样品中盐酸二甲双胍浓度的定量分析方法.方法:反相高效液相色谱法(RP-HPLC法).色谱柱为Nucleosil 100-5硅胶柱(250 mm×4.6 mm,5 μm),流动相为0.03 mol/L的磷酸二氢铵溶液(pH=7.00)-乙腈(75:25,V/V),检测波长240 nm,柱温30℃,进样量40μL.结果:血浆中盐酸二甲双胍浓度线性范围是25～4 000 ng/mL(r=0.999 9),回收率在94.59%～100.84%之间,日内RSD(n=5)在0.67%～2.35%之间,日间RSD(n=5)在2.77%～4.09%之间,最低检测限是12.5 ng/mL.结论:HPLC法简便、快捷、灵敏、准确,适用于临床药代动力学及药效学的研究.     

HPLC测定血浆中尼扎替丁及其代谢物

尼扎替丁是新的H_2受体拮抗药,可治疗胃和十二指肠溃疡,进入体内后,75%以原形随尿排出,25%转化成三种代谢产物:N-去甲尼扎替丁(N_1)、尼扎替丁亚砜(N_2)和尼扎替丁-N-氧化物(非常不稳定)。本文采用混合有机溶剂从血浆中提取尼扎替丁,以HPLC法测定之,并首次测定了其它二种代谢产物。仪器与试剂Waters510型泵,Lichrosorb Si60(5μm,150 mm×4.6 mmI.D.)色谱柱,流动相为乙腈-甲醇-水-25%氨液(1000∶200∶20∶5,v/v),0.45μm膜滤过脱     

反相高效液相色谱法测定多潘立酮片的含量

目的:探讨多潘立酮片的含量测定方法.方法:采用反相高效液相色谱法 (RP- HPLC法 ),色谱柱为 KromasilTMC18柱 (4.6 mm× 250 mm, 5 μ m),以甲醇- 0.5%醋酸铵溶液 (70 : 30)为流动相,流速为 1.0 mL/min,柱温为 35℃,检测波长为 285 nm.结果:多潘立酮在 10. 7～ 214. 0 μ g/mL范围内浓度与峰面积具有良好的线性关系, r=0.999 6,回收率为 99.5%, RSD为 0.68% (n=5).结论: RP- HPLC法可用于多潘立酮片的含量测定.     

高效液相色谱法测定血浆中法莫替丁的浓度

目的:用高效液相色谱法测定血浆中法莫替丁浓度。方法:以对乙酰氨基酚为内标,血浆经乙腈提取,HPLC测定。流动相0.01m o l.L-1磷酸二氢钾-乙腈(91.5:8.5),流速1.0m l.m in-1,C 18色谱柱A lltech A po llo(4.6mm×150mm),检测波长266nm。结果:法莫替丁和内标与内源性杂质分离良好;5~160 ng.m-l 1浓度范围内线性关系良好;检测限2.5 ng.m-l 1;日内精密度RSD为1.5%~6.7%(n=6),日间精密度RSD为0.2%~14%(n=6)。结论:本法简便、灵敏度较好,可用于法莫替丁血药浓度的测定。     

高效液相色谱法测定利肺片中五味子醇甲的含量

目的:建立利肺片中五味子醇甲的含量测定方法.方法:采用高效液相色谱法,Agilent C18 色谱柱(4.6 mm×250 mm,5 μ m),流动相为甲醇-水(60 ∶40),流速为 0.8 mL/min,柱温为35℃,检测波长为250 nm.结果:五味子醇甲在 0.10～ 0.48 μ g/mL范围内浓度与峰面积有良好的线性关系(r=0.999 95),平均加样回收率为 99.98%,RSD=0.8%(n=5).结论:高效液相色谱法简便、准确、可靠.     

高效液相色谱法测定硝酸异山梨酯含量的研究

目的:建立硝酸异山梨酯葡萄糖注射液中硝酸异山梨酯高效液相色谱法(HPLC)含量测定方法。方法:采用HPLC法对其进行定量测定;以氢化泼尼松为内标,SpherigelC18柱(5μm,4.6mm×200mm);流动相:甲醇-水(54∶46);流速:1.0mL/min;柱温:25℃;检测波长:230nm。结果:此法线性范围10～150μg/mL(r=0.9998),方法精密度RSD为0.51%;平均回收率101.03%,RSD为1.40%(n=6)。结论:HPLC法简便快速、精密度高、准确度好,可作为样品的含量测定方法。     

风湿定胶囊的质量标准研究

目的建立风湿定胶囊的质量标准。方法用中和法检测了总生物碱的限量;HPLC测定了欧前胡素的含量,色谱柱:A lltech ODS(4.0mm×250mm),流动相:甲醇-水(70∶30),检测波长248nm,结果加样回收97.74%,RSD=2.92%。线性范围为0.01564mg/mL~0.1564mg/mL,r=0.999 7,重复性RSD=1.83%(n=5),精密度RSD=0.77%(n=5)。结论方法稳定、可靠,可作为该药的质量控制方法。     

高效液相色谱法测定血浆中西咪替丁的含量

目的 建立高效液相色谱法测定血浆中西咪替丁的含量.方法 采用Diamonsil C18柱（250 mm×4.6 mm,5μm）为色谱柱,以甲醇-水（35∶65）为流动相,流速1 mL/min,检测波长225 nm.结果 西咪替丁线性范围为5～25 μg/mL（r=0.999 8,n=5）,平均回收率为（102.5±0.56）%,RSD=0.79%（n=5）.结论 该方法操作简便、结果准确、重现性好.     

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.