高效液相色谱法测定人血浆中尼扎替丁的浓度

目的:建立用高效液相色谱法(HPLC法 )测定人血浆样品中尼扎替丁浓度的定量分析方法.方法:色谱柱为 Nucleosil100-5硅胶柱(4.6 mm×250 mm,5 μ m); 流动相为乙腈-甲醇-水-氨水(1 000 ∶200 ∶25 ∶1.25),流速为1.0 mL/min; 检测波长为325 nm.结果:血浆中尼扎替丁在15.625～2 000 μ g/mL范围内浓度与峰面积具良好线性关系(r=0.999 8),回收率在 98.99% ～104.06% 之间,日内精密度 RSD在 0.47% ～ 0.51% 之间(n=5),日间精密度 RSD在 0.27% ～ 0.52% 之间(n=5).血浆中尼扎替丁的最低检测限是15.625 μ g/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.     

RP-HPLC法测定人血浆中利福喷丁的浓度

目的:建立反相HPLC法测定人血浆中利福喷丁的浓度.方法:以利福平为内标,采用ZORBAX SB-C18色谱柱(4.6mm×250 mm,5μm),以甲醇-0.02 mol·L-1磷酸缓冲液(67:33,v/v;pH 7.0)为流动相,流速1.0 ml·min-1,柱温40℃,340 nm处紫外检测.结果:日内平均回收率为97.5%,RSD=4.1%(n=5),日间平均回收率为95.6%,RSD=5.4%(n=5),线性范围为0.54～17.28μg·ml-1(r=0.999 5).结论:本法简便快速,灵敏度高,重现性好,适用于利福喷丁化疗方案的临床监测及其药动学研究.     

人血浆中硫唑嘌呤中间代谢物6-巯嘌呤的高效液相色谱测定法

目的:建立人血浆中硫唑嘌呤中间代谢物6-巯嘌呤(6-mercaptopurine,6-MP)的高效液相色谱测定法.方法:取血浆200μL,以6-硫鸟嘌呤(6-TG)为内标,用70%高氯酸沉淀蛋白,6 mol·L-1氢氧化钠调节pH至中性后进样分析.色谱柱:Shimpack CLC-ODS(150 mm×6 mm,5 μm)柱;流动相:乙腈-水-醋酸(10:489:1);检测波长为323 nm.结果:本方法在2～200μg·L-1浓度范围内,线性关系良好(r=0.999 5),RSD为6.79%(n=10);高、中、低3个浓度质控样本的批内及批间RSD在1.3%～6.3%之间,回收率在99.1%～101.5%之间(n=10).结论:本方法简便、准确,能够满足临床研究需要.     

RP-HPLC测定大鼠静脉注射靛玉红后的血药浓度

目的 建立大鼠血浆中靛玉红浓度的测定方法.方法 采用HPLC测定,血浆样品用丙酮沉淀蛋白后直接进样,色谱柱为Diamonsil C18(150 mm×4.6 mm,5μm),流动相为甲醇-0.1 mol·L-1醋酸铵-冰醋酸(73:26:1),流速1.0 ml·min-1,检测波长287 nm.结果 靛玉红在0.025～1.600 μg·ml-1范围内线性关系良好(r=0.9997,n=7),高、中、低浓度测定的方法回收率为94.5%～105.0%,日内RSD为0.14%～5.46%(n=5),日间RSD为2.54%～6.27%(n=5).结论 所用方法预处理简便,专属性强、灵敏度高,适用于靛玉红未知样品的血药浓度测定.     

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血浆中吗氯贝胺浓度

目的:建立人血浆中吗氯贝胺的反相高效液相色谱检测方法.方法:血浆样品在碱性条件下(pH 11.0)用二氯甲烷提取处理.色谱柱为μ-BondapakTM C18 (3.9 mm×15 0mm,10 μm),柱温37.0 ℃,流动相为乙腈-0.067 mol·L-1磷酸二氢钾溶液(1∶5,pH 2.6),流速1.0 mL·min-1,内标为甲氧氯普胺,检测波长为240 nm.结果:吗氯贝胺在40～4 000 μg·L-1范围内线性关系良好(r=0.999 9,n=8),血浆中最小检测浓度为10 μg·L-1(S/N=3),提取回收率为96.48%～100.38%,方法回收率在99.39%～103.07%之间,日内RSD≤8.14%,日间RSD≤6.25%.结论:该方法快速、准确、灵敏度高、专一性强,可用于吗氯贝胺血浆浓度监测和药动学及生物利用度研究.     

高效液相色谱-质谱联用法测定人血浆中霉酚酸的浓度

目的建立高效液相色谱-质谱联用法测定人血浆中霉酚酸的浓度.方法血浆样品经处理后,采用Waters Atlantis C18色谱柱(100 mm×2.1 mm,3 μm),流动相为乙腈-0.01%甲酸溶液(70∶30),以电喷雾电离源(ESI)负离子检测,吲哚美辛为内标.结果霉酚酸血浆质量浓度的线性范围为0.010～50.4 mg·L-1(r=0.9998),最低检测质量浓度为2 μg·L-1(S/N=5),提取回收率为78.2%～88.9%(n=5),方法回收率为100.3%～101.9%(n=5),日内和日间RSD均小于5%.结论本法专属性强,样品处理方便,灵敏度高,适用于霉酚酸临床药动学研究.     

HPLC法测定替米沙坦血药浓度的方法学考察

目的 建立HPLC法测定人血浆中替米沙坦浓度的分析方法.方法 色谱柱采用Agilent ZORBAX SB-C18(150mm×4.6mm,5μm),流动相为乙腈:0.03 mol· L-1 KH2PO4溶液(47∶55,v/v),流速为1.0mL·min-1,荧光检测激发波长为306nm,发射波长为374nm.结果 线性范围为5～1500ng·mL-1,回归方程为Y=0.01852X-0.01655,r=0.9997(n=5);最低定量下限(LLOD)为5ng·mL-1.结论 本方法准确、简便,重现性好,适用于替米沙坦的临床药动学研究.     

液相色谱-质谱联用法测定人血浆中的替米沙坦

目的建立人血浆中替米沙坦测定的HPLC-MS方法.方法以艾司唑仑为内标,血浆样品以乙腈为沉淀剂处理,分析柱为Nucleodur C18(250 mm×4.6 mm,5 μm),流动相为乙腈-0.1%甲酸(50∶50,v/v),流速1 mL·min-1;电喷雾电离,正离子检测,监测m/z 516(替米沙坦)和m/z 296(艾司唑仑),以离子流大小定量.并应用该方法研究18名健康志愿者单剂量口服替米沙坦片80 mg后血药浓度和药物动力学.结果血浆中替米沙坦线性范围为2.0～1 800.0 μg·L-1,最低检测限可达0.5 μg·L-1(S/N≥3).方法回收率为99.8%～101.4%(n=5),日内、日间RSD＜5.0%(n=5).18名健康男性志愿者单剂量口服替米沙坦片80 mg后约1.5 h后血药浓度达峰值(cmax),cmax为(773.6±357.6)μg·L-1,平均AUC0～96为(3 050.6±1 209.4)h·μg·L-1,t1/2为(20.7±0.64)h.结论本方法便捷、准确,精密度高,重现性好,适用于替米沙坦人体内药物动力学研究及生物等效性研究.     

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。     

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.     

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.