HPLC法测定人血浆中盐酸二甲双胍浓度

目的:建立血浆中盐酸二甲双胍浓度测定方法。方法:血浆在酸性条件下以乙腈沉淀蛋白后,用二氯甲烷萃取纯化,以乙腈-5 mmol·L~(-1)磷酸盐缓冲液(pH 4．8)(45:55,每100 mL流动相中含十二烷基硫酸钠0．17 g)为流动相,色谱柱为DIAMONSIL~(TM)C_(18)柱(250 mm×4．6 mm,5μm),检测波长为233 nm,柱温为40℃。流速为1．2 mL·min~(-1)。结果:在此色谱条件下,盐酸二甲双胍与血浆中其他成分分离完全,线性范围为60．06～4 004 ng·mL~(-1),最低检测浓度为60．06 ng·mL~(-1),相对回收率在101．3％～108．3％,日内精密度RSD＜5．4％,日间精密度RSD＜13％。结论:该法稳定、灵敏、可靠,可用于人体血浆中盐酸二甲双胍浓度的测定。     

RP-HPLC法测定人血浆中氟比洛芬的浓度

目的:建立以反相高效液相色谱法测定人血浆中氟比洛芬浓度的方法。方法:采用外标法,以乙腈沉淀法处理样品后进样测定,色谱柱为Symmetry shield C_(18),流动相为磷酸盐缓冲液(pH7.0):乙腈=75:25,流速为1.0 mL·min~(-1),紫外检测波长为247 nm。结果:氟比洛芬血药浓度在0.05～20μg·mL~(-1)范围内线性关系良好(r=0.999 1),检测限为0.05μg·mL~(-1);低、中、高浓度的回收率在96.1%～107.1%之间,日内及日间RSD均<10%,符合方法学要求。结论:本方法简便、准确、快速,适用于人血浆中氟比洛芬浓度监测及药动学研究。     

固相萃取反相高效液相色谱法检测人血浆中辛伐他汀浓度

目的:建立反相高效液相色谱法测定人血浆中辛伐他订。方法:应用OASIS因相萃取小柱提取血浆中辛伐他汀,采用反相高效液相色谱法二极管阵列检测器检测,色谱柱为Symmetry C_(18)柱(250mm×4.6mm,5μm),内标物为洛伐他汀,流动相为0.1％磷酸液(用氢氧化钠调pH4.0)-乙腈(40:60),检测波长238um,流速1.2mL·min~(-1)。结果:辛伐他汀在1.0～35.0ng·mL~(-1)范围内线性良好(r=0.9997)。低、中、高浓度加样回收率在97.3％～108.0％之间,日内、日间RSD在5.9％～8.8％之间,最低检测浓度为0.8ng·mL~(-1)。结论:本法快速、灵敏、高效,适于辛伐他汀的血药浓度检测。     

昂丹司琼人体血药浓度的RP—HPLC测定法

目的:建立人血浆中昂丹司琼的RP-HPLC测定法,用于昂丹司琼片的人体药代动力学研究。方法:血浆样品加乙腈脱蛋白后,离心,取上清液,挥干,用少量流动相溶解,供进样分析。采用Alltima C_(18)柱(4.6 mm×250 mm,5 μm),预柱:Beckman-ultrasphere ODS(4.6 mm×45 mm,5μm),以醋酸钠缓冲液(pH=4.2)-乙腈(75:25)为流动相,流速:1mL·min~(-1),于310 nm波长处检测,灵敏度:0.0001 AUFS。测定了10名健康志愿者单剂量口服昂丹司琼8 mg后的血药浓度-时间过程。结果:最低检测限达0.5 ng·mL~(-1),线性范围为1～80 ng·mL~(-1)(r=0.992 2),日内和日间精密度均小于10％,平均回收率为88.7％～98.2％,符合生物样品分析要求。结论:本法操作简单,准确,灵敏度高,可用于昂丹司琼片的药代动力学研究。     

反相高效液相色谱法测定人体血浆中扑尔敏的浓度

目的:建立一种测定人体血浆中扑尔敏浓度的高效液相色谱法。方法:取人体血浆1.5 mL,加内标右美沙芬后,用三氯甲烷提取,取其有机相于60℃水浴挥干,剩余物加流动相复溶,并用乙酸乙酯洗涤,取水相20μL进样。流动相为0.025mol·L~(-1)磷酸二氢铵(用磷酸调pH为3.5)-乙腈(70:30),色谱柱为Diamonsil ODS C_(18)柱(5μm,4.6mm×150mm),检测波长为200 nm,流速为1.0mL·min~(-1),柱温为室温。结果:本方法线性范围为0.5～16ng·mL~(-1),,r=0.998 7,最低检测限为0.25ng·mL~(-1),方法回收率为96.6％～108.0％,日内RSD为4.1％～5.9％,日间RSD为4.6％～5.9％。结论:本方法灵敏度高,特异性强,重现性好,可用于人体血浆中扑尔敏浓度的测定。     

液质联用测定人血浆中氯雷他定的浓度及人体药动学研究

目的:建立测定人血浆氯雷他定浓度的高效液相色谱/质谱联用的方法,并研究了氯雷他定片在健康人体内的药动学。方法:色谱条件为 Aglient Zorbax Extend-C_(18),(5 μm,2.1mm×150 mm),Aglient Zorbax Extend-C_(18)保护柱,流动相:甲醇-水溶液(500 mL水中加入醋酸500 μL和三乙胺100 μL,pH=3.1)(83:17),流速0.25 mL·min~(-1),柱温20℃,进样量20 μL。质谱条件为电喷雾电离源(ESI),选择性监测质荷比(m/z)为384(氯雷他定)、479(内标)带正电荷的分子离子峰。样品用固相革取小柱提取处理。结果:线性范围为0.5～80 ng·mL~(-1),最低检测浓度为 0.5 ng·mL~(-1),萃取回收率均在80％以上,日内、日间的RSD皆小于15％。结论:适用于临床上测定血浆中氯雷他定浓度及进行人体药动学的研究。     

柱前衍生HPLC法结合固相萃取测定血浆中卡托普利

目的:建立测定血浆中卡托普利浓度的方法,用于卡托普利人体药动学及相对生物利用度研究。方法:以对溴苯甲酸甲基溴为衍生化试剂,固相萃取法从生物样本中提取纯化衍生化产物,以反相高效液相色谱法测定衍生物含量而确定卡托普利血药浓度。结果:卡托普利血药浓度在10～1000ng·mL~(-1)范围内线性良好,相关系数为0.9987,测得平均回收率为98.65％,日内、日间RSD均小于10％。结论:本方法简便、准确、干扰小,适合用于卡托普利血药浓度监测及药动学研究。     

反相高效液相色谱荧光检测法测定人血浆中阿呋唑嗪浓度

目的:建立血浆中阿呋唑嗪的反相高效液相荧光检测方法。方法:采用Shimadzu LC-6高效液相色谱仪,ShimadzuC_(18)柱(150mm×4.6 mm),0.02 mol·L~(-1)磷酸盐缓冲液(pH2.5)-乙腈(40:60)为流动相,激发波长374nm,发射波长378nm,流速:1mL·min~(-1)。结果:血浆中阿呋唑嗪能得到较好的分离,无明显的干扰峰。本方法专属性好,可信度高。最低检测浓度为0.78ng·mL~(-1),最低检测限是39pg,线性范围0.78～50 ng·mL~(-1),标准曲线:Y=8648.7X+767.8(r=0.999,P<0.05),回收率高于70%,日间、日内RSD均在10％以下。结论:符合生物样品的分析要求。     

HPLC—MS测定人血浆中的依那普利及其人体药动学和相对生物利用度研究

目的:建立人血浆中依那普利的高效液相色谱-质谱测定方法,用于研究依那普利片的人体相对生物利用度。方法:血浆样品中加入内标阿普唑仑后,离心取上清液上固相萃取小柱,以甲醇洗脱,采用高效液相色谱-质谱法,电喷雾电离源正源选择离子峰检测。色谱柱为ODS C_(18),流动相为甲醇-0.1％甲酸(45:55),流速为0.8mL·min~(-1),毛细管电喷雾电压:3.81kV,取样锥孔电压:39.00 V。用建立的方法测定16名健康男性志愿者单剂量口服依那普利片实验制剂或参比制剂的体内经时过程,由血药浓度数据获得各自的主要药动学参数,以双单侧t检验进行生物等效性判定。结果:依那普利在2.5～400 ng·mL~(-1)范围内呈良好的线性关系。r=0.999 6,平均回收率为102.2％,日内RSD≤4.6％,日间RSD≤8.2％。16名健康男性志愿者单次服用20 mg依那普利片实验制剂或参比制剂后的药动学参数AUC_(0→6)、C_(max)、T_(1/2)分别为(322.6±79.1)和(323.1±70.5)ng·h·mL~(-1)、(229.8±54.4)和(237.3±48.1)ng·mL~(-1)、(1.80±0.60)和(1.50±0.30)h。相对生物利用度为(99.7±8.2)％。结论:该方法灵敏度高,无杂质干扰,结果准确。测得的实验制剂与参比制剂的主要药动学参数之间无明显差异,2种片剂为生物等效制剂。     

双氯芬酸钠微丸人体内药动学

目的:研究双氯芬酸钠微丸在人体内的药动学。方法:8名健康志愿者单剂量口服双氯芬酸钠微丸。以地西泮为内标,采用RP-HPLC法测定给药后不同时间点双氯芬酸钠的血药浓度。应用3P87程序软件计算药动学参数。结果:双氯芬酸钠浓度在0.02～1.50μg·mL~(-1)范围内线性关系良好(r=0.999 7)。方法回收率为102.3％;日内RSD为2.0％～7.9％,日间RSD为3.1％～11.2％;AUC_(0→∞)为(4.445±1.201)h·μg·mL~(-1);c_(max)为(1.031±0.346)μg·mL~(-1);t_(max)为(2.630±0.520)h。结论:双氯芬酸钠微丸在人体内药动学过程符合一室开放模型,本研究可为双氯芬酸钠微丸的临床应用提供药动学参数。     

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.