高效液相色谱法测定人血浆中左氧氟沙星浓度

建立测定人血浆中左氧氟沙星浓度的高效液相色谱法,并应用于人体药代动力学研究。血浆样品中加入内标洛美沙星后用乙腈沉淀蛋白,上清液用氮气吹干。色谱柱为Diamonsil C18柱,流动相为0.01mol.L-1磷酸二氢钾缓冲液(含三乙胺0.3%,磷酸调至pH 3.20)?乙腈(83∶17),流速为1.0ml.min-1。紫外检测波长294 nm。血浆中内源性物质对样品测定无干扰。本方法线性范围为0.05~5μg.ml-1(r=0.9991),最低定量浓度为0.05μg.ml-1,提取回收率大于85%,方法回收率为99.7%~103.3%,日内、日间RSD均小于4%。本法简便、准确,适用于左氧氟沙星药代动力学的研究。     

HPLC法测定人血浆中对乙酰氨基酚浓度

建立测定人血浆中对乙酰氨基酚浓度的HPLC法,并应用于人体药代动力学研究.血浆样品用6%高氯酸沉淀蛋白.色谱柱为Zorbax Eclipse XDB-C18柱,流动相为0.02 mol·L-1甲酸铵溶液(含甲酸0.2%)-甲醇-乙腈(88∶6∶6),流速为1.0mL·min-1,紫外检测波长245nm.血浆中内源性物质对样品测定无干扰.本方法线性范围为0.1～20μg·mL-1 (r=0.9996),最低定量浓度为0.1μg·mL-1,方法回收率为99.0%～100.2%,日内、日间RSD均小于6%.本法简便、准确,适用于对乙酰氨基酚药代动力学的研究.     

RP-HPLC法测定人血浆中奥美拉唑浓度及其在健康男性志愿者药代动力学研究

目的:建立人血浆中奥美拉唑的含量测定方法,用于其血药浓度测定并进行临床药代动力学研究。方法:1ml血浆样品以二氯甲烷提取,采用反相高效液相二极管阵列检测器分离测定血浆中的奥美拉唑浓度。色谱条件:krumasilC18柱(4.6mm×200mm,5μm),流动相为乙睛:三蒸水(含0.01mol·L-1磷酸氢二钠,三乙胺调pH7.5)=4555(v/v);流速:1.3ml·min-1,检测波长302nm,进样量30μl。9例健康志愿者单剂量口服40mg奥美拉唑肠溶胶囊,用高效液相色谱法测定给药后不同时间点血浆中奥美拉唑的浓度,计算其药动学参数。结果:奥美拉唑在10～2000μg·L-1浓度范围内呈良好的线性关系,最低检测浓度为10μg·L-1。高、中、低浓度的方法回收率分别为92.35%、96.90%、100.04%,RSD均小于15%。健康人体药动学研究证明,奥美拉唑的药时曲线符合一室模型。结论:本方法灵敏度高、专属性强、准确、简便,适用于奥美拉唑的人体药代动力学研究。     

HPLC测定人血浆中帕珠沙星浓度

目的建立测定人血浆中帕珠沙星浓度的高效液相色谱法。方法血浆样品用10%高氯酸沉淀蛋白。色谱柱为Diamonsil C18柱(200mm×4.6mm,5μm),流动相为0.02mol·L-1磷酸二氢钠溶液(含三乙胺0.5%,用磷酸调至pH3.0)-乙腈(82∶18),流速为1.0mL·min-1,紫外检测波长245nm。结果血浆中内源性物质对样品测定无干扰。本方法线性范围为0.05～50μg·mL-1(r=0.9999),最低定量浓度为0.05μg·mL-1,提取回收率大于80%,方法回收率为100.6%～101.4%,日内、日间RSD均小于6%。结论本法简便、灵敏、准确,适用于帕珠沙星药动学的研究。     

高效液相色谱法测定人血浆中加替沙星浓度

目的:建立HPLC法测定人血浆中加替沙星浓度的方法。方法:采用噻克硝唑为内标,色谱柱为Polaris C18-A柱(150*4.6mm),流动相为乙腈:0.05M的枸缘酸溶液(22:78),流速1.0ml/min,检测波长为295nm。结果:加替沙星血清浓度在0.015～6.48μg·ml-1范内具有良好线性关系,最低定量限为0.015μg·ml-1,方法回收率为99.1%～101.0%,日内、日间RSD均<7%。结论:本法简便、准确、灵敏,适用于加替沙星血药浓度监测及人体药代动力学研究。     

固相萃取HPLC测定人血浆中头孢西酮及在药动学研究中的应用

目的:建立反相高效液相色谱办法测定人血浆中头孢西酮浓度,并用于注射用头孢西酮钠人体药代动力学研究。方法:采用高效液相色谱紫外检测法,血浆中加入内标后经固相萃取,色谱柱为 Apollo C_(18)(5μm,250 mm×4.6 mm)。流动相为乙腈-0.02 mol·L~(-1)醋酸铵溶液(18∶82)(pH 5.0),流速1 mL·min~(-1),检测波长为278 nm。结果:本方法线性检测范围为0.5～250μg·mL~(-1),线性关系良好(r=0.9996);最低检测浓度为0.5μg·mL~(-1);方法绝对回收率为67.2%～84.0%,相对回收率为91.1%～102.1%;日内、日间 RSD 均小于8%。结论:本方法灵敏度高,操作简便,可用于人血浆中头孢西酮的浓度测定及临床药代动力学研究。     

积雪草酸大鼠体内药动学考察

目的建立大鼠血浆中积雪草酸(asiatic acid,AA)的柱前衍生化HPLC,探讨AA在大鼠体内的药动学。方法 SD大鼠,♂,尾静脉注射AA(10mg·kg-1),于给药后不同时间采取血浆,经DIKMA Proelut PLS柱固相萃取,柱前衍生化HPLC测定血浆中AA浓度(以甘草次酸为内标),药物统计软件(PKS 1.0)拟合统计药动学参数。结果血药浓度在0.1~20μg·m L-1内线性良好(r=0.999 6),平均提取回收率为71.1~79.9%,日内、日间精密度RSD均<13%,样品在-20℃放置,经2次冻融循环后基本稳定。AA在大鼠体内药-时曲线符合一室开放模型,主要药动学参数为:tmax=2.0min,Cmax=14.7μg·m L-1,t1/2=35.1min,AUC0-t=217.0μg·min·m L-1,AUC0-∞=234.3μg·min·m L-1。结论 AA在大鼠体内消除迅速,所建立的提取及柱前衍生化HPLC适用于体内AA的测定。     

HPLC法测定兔血浆中利多卡因和亚甲蓝浓度

目的:建立利多卡因和亚甲蓝同时给药后两药血药浓度的 HPLC 测定方法。方法:血浆样品用氯仿-环己烷-异丙醇(60:30:10)萃取,采用 Shim-pack VP-ODS 分析柱(150 mm×4.6 mm,5μm),以醋酸盐缓冲液-甲醇-乙腈(45:45:10)为流动相,流速1.0 mL·min~(-1),检测波长235 nm,以布比卡因为内标,测定血浆样品中利多卡因;血浆样品以乙腈沉淀蛋白,采用 Sphericorb NH_2分析柱(150 mm×4.6 mm,5 μm),以磷酸盐缓冲液-乙腈(40:60)为流动相;流速1.0 mL·min~(-1),检测波长600 nm,测定血浆样品中亚甲蓝浓度。结果:利多卡因血药浓度测定:线性范围0.16～10.08μg·mL~(-1),绝对回收率大于73%,方法回收率98.49%～107.2%,日内、日间精密度 RSD 均小于8%;亚甲蓝血药浓度测定:线性范围为0.052～3.328μg·mL~(-1),绝对回收率大于72%,方法回收率95.19%～104.3%,日内和日间精密度 RSD 均小于9%。结论:该方法简便、准确,重复性好,可用于利多卡因和亚甲蓝同时给药后两药的家兔体内药代动力学研究。     

HPLC-MS/MS法测定恒河猴血浆中地尔硫卓的质量浓度

目的建立恒河猴血浆中地尔硫卓质量浓度的HPLC-MS/MS测定方法。方法采用Agilent Zorbax SB-C18色谱柱(2.1 mm×100 mm,3.5μm),以乙腈-10 mmol·L-1醋酸铵(体积比75∶25)为流动相,流速为0.3 mL·min-1,柱温30℃。血浆样品采用叔丁基甲醚沉淀蛋白法处理,质谱采用电喷雾离子源,正离子化检测,扫描方式为多离子反应监测(MRM)。结果地尔硫卓的线性范围为0.2²00.0μg·L-1,r=0.995 8,日内、日间精密度RSD<15%,平均提取回收率为70.5%200.0μg·L-1,r=0.995 8,日内、日间精密度RSD<15%,平均提取回收率为70.5%⁷4.0%,基质效应符合相关规定。地尔硫卓在恒河猴体内主要药代动力学参数:t1/2为(4.06±0.64)h,ρmax为(95.68±13.39)μg·L-1,AUC0-t为(746.09±45.14)μg·h·L-1。结论该方法适用于地尔硫卓在恒河猴体内的血药质量浓度检测及药代动力学研究。     

HPLC法测定兔血浆中羟基喜树碱浓度

建立测定兔血浆中羟基喜树碱浓度的高效液相色谱-紫外检测法.色谱柱:Lichrospher C18柱(250mm×4.6mm,5μm),C18预柱(10mm×4.6mm,5μm);流动相:乙腈-0.075mol·L-1醋酸铵缓冲液(pH6.4)(30:70),含5mmol的三乙胺;流速:1.0ml·min-1;检测波长:384nm.羟基喜树碱保留时间为5.0min,线性范围为40～1600ng·ml-1,最低检测限为25ng·ml-1.血浆中羟基喜树碱的回收率为96.32%～106.1%.本法简便实用,定量准确,可用于羟基喜树碱药代动力学研究.     

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.     

Pharmacological treatment of COVID-19: an opinion paper

The precocity and efficacy of the vaccines developed so far against COVID-19 has been the most significant and saving advance against the pandemic. The development of vaccines has not prevented, during the whole period of the pandemic, the constant search for therapeutic medicines, both among existing drugs with different indications and in the development of new drugs. The Scientific Committee of the COVID-19 of the Illustrious College of Physicians of Madrid wanted to offer an early, simplified and critical approach to these new drugs, to new developments in immunotherapy and to what has been learned from the immune response modulators already known and which have proven effective against the virus, in order to help understand the current situation.     

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.