高效液相色谱法测定人血浆中头孢羟氨苄的浓度

目的:建立人血浆中头孢羟氨苄浓度的测定方法。方法;色谱柱为Hyersil ODS柱(4.6mm×250mm,10μm),流动相:0.01 mol/L NaH₂PO₄-乙腈(96:4),流速1.0ml/min,检测波长230nm。结果:头孢羟氨苄的线性范围为0.5～40μg/ml,回归方程为y=0.0184+0.1235x(r=0.9999)。最低检测浓度为0.25μg/ml,日内RSD(％)为2.1～2.9,日间RSD(％)为4.5～7.1。结论:本法操作简便,重复性好,结果准确。     

HPLC法测定头孢羟氨苄及其有关物质含量

目的建立头孢羟氨苄有关物质的HPLC分析方法。方法采用ODS柱(Polaris250mm×4.6mm,5μm),以0.05mol/L磷酸盐缓冲液(用10mol/L氢氧化钾调节pH值为5.5)-乙腈(96∶4)为流动相,流速为0.7ml/min,检测波长为230nm。结果头孢羟氨苄、有关物质α-对羟基苯甘氨酸、7-氨基去乙酰氧基头孢烷酸(7-ADCA)的线性范围分别为0.125～1.0mg/ml(r=0.9997)、0.312～20μg/ml(r=0.9999)、0.312～20μg/ml(r=0.9999)。结论本方法可用于头孢羟氨苄及其有关物质含量的测定,方法准确、灵敏、简便。     

RP-HPLC法测定头孢羟氨苄的血药浓度与药动学的探讨

用快速、灵敏的反相高效液相色谱法测定了血浆中头孢羟氨苄的浓度,色谱柱为YWG-C_(18)柱,4.6×200mm,流动相为甲醇:水(含0.01M磷酸二氢钠)=13:87(V/V)。流速1.0ml/min,紫外检测波长 260um,灵敏度为0.005AuFs。以6％高氯酸作蛋白沉淀剂,头孢羟氨苄的平均相对回收率为98.69％,日内误差为3.5％,日间误差为3.9％,在1～50μg/ml范围内线性良好,r=0.99987。应用本法对8名健康志愿者口服头孢羟氨苄的药物动力学进行了研究。     

HPLC法测定头孢羟氨苄甲氧苄啶胶囊含量的方法改进

目的建立调整流动相比例,以HPLC法同时测定复方头孢羟氨苄甲氧苄啶胶囊中头孢羟氨苄与甲氧苄啶的含量的方法。方法色谱柱SinoChrom ODS-BP C18柱(4.6mm×250mm,5μm);流动相:1%冰醋酸(含0.005%乙二胺)溶液∶乙腈(88∶12);流速:1.0mL.min-1;检测波长:233nm。结果头孢羟氨苄在40.00~200μg.mL-1浓度范围之间线性良好,r=0.9999,平均回收率为99.8%,RSD%=0.33%(n=5);甲氧苄啶在8~40μg.mL-1浓度范围之间线性良好,r=1.000,平均回收率为100.1%,RSD%=0.28%(n=5);。结论以本文中采用的流动相,头孢羟氨苄主峰与溶剂峰、头孢羟氨苄峰与甲氧苄啶峰分离完全,结果准确稳定,可用于头孢羟氨苄甲氧苄啶胶囊的含量测定。     

HPLC法测定人血浆中头孢克洛浓度

目的:采用高效液相色谱法测定人血浆中头孢克洛浓度。方法:以头孢拉定为内标,HPLC法测定。结果:头孢克洛的线性范围为0.25～30μg/ml,回归方程为y=0.1105+0.0817x,r=0.9995,最低检测浓度为0.125μg/ml,日内RSD为1.61％～3.54％,日间RSD为2.15％～5.08％。结论:主要药代动力学参数与文献报道相似。     

高效液相色谱法测定人血浆中头孢克肟浓度

目的:建立HPLC方法测定人血浆中头孢克肟的浓度。方法:取100μl血浆样品,加乙腈混匀离心,上清液进样;用C18分析柱,以0.02mol/L磷酸氢二钾缓冲液(用磷酸调pH=7.00):乙腈=1:1(V/V)为流动相,流速1.0ml/min,柱温25℃,紫外检测波长288nm,用峰面积定量。结果:标准曲线在0.125～4μg/ml范围内线性关系良好(r=0.9999)最低检测浓度为0.125μg/ml;回收率为100.7%～109.3%,日内RSD﹤5%,日间RSD﹤8%。结论:本法简便,准确,精密,快速,进样量少,可满足临床血药浓度测试要求。     

HPLC法测定头孢克罗胶囊的含量

本文报导采用高效液相色谱法测定头孢克罗胶囊中头孢氯氨苄的含量.用ODS柱(4.6×250mm,10μ),以乙酰苯胺为内标,流动相为醋酸(0.7mol/L);醋酸钠(0.5mol/L):甲醇:水(3:15:250:732);检测波长254nm;样品平均回收率(n=5)99.3%,RSD=0.7%;线性范围为0.05～0.35mg/ml,r=0.9994;最低检出浓度0.002mg/ml.方法简便,可靠.     

高效毛细管电泳法同时测定血浆中头孢羟氨苄和甲氧苄啶的含量

采用毛细管区带电泳法(CZE)测定血浆中头孢羟氨苄、甲氧苄啶的含量。以20mmol/L硼砂(pH7.1)为背景电解质,35cm×75μm(i.d)未涂层毛细管为色谱柱,于267nm处检测,操作温度25℃,分离电压为20kV,采用峰面积外标法定量。头孢羟氨苄和甲氧苄啶的线性范围分别为0.4~4.0和0.25~4.0μg/ml,检出限分别为0.1和0.18μg/ml(S/N=3)。该方法测得头孢羟氨苄和甲氧苄啶的在低、中、高浓度下的回收率均在95%以上,迁移时间的RSD分别为0.43%、1.44%;峰面积的RSD分别为3.34%、4.0%,日内、日间精密度均符合方法学要求。该方法用量少,简便,快速,准确,适合于血药浓度的监测。     

反相高效液相色谱法测定人血浆中盐酸头孢替安的浓度

目的建立测定人血浆中盐酸头孢替安浓度的反相高效液相色谱法(RP-HPLC)测定法,为临床盐酸头孢替安的药物浓度测定和药动学研究提供科学的分析技术。方法采用安捷伦EclipseXDBC18(250mm×4.6mm,5μm)色谱柱,以乙腈:20mM的KH2PO4缓冲液=19:81为流动相,流速1.0ml/min,检测波长254nm,进样量:20μl;血浆样品经乙腈沉淀去蛋白处理后取上清液直接进样。结果该法线性范围为0.4～150.8μg/ml,线性方程为Y=16.21X+1.03,r2=0.9991(n=7),检测浓度为0.2μg/ml,平均绝对回收率为(93.2%±4.6%)(n=18),精密度RSD均小于10%。结论本法简便灵敏,专属性好,适用于临床盐酸头孢替安血药浓度测定和人体药动学研究。     

差示分光光度法测定复方头孢羟氨苄胶囊中头孢羟氨苄的含量

目的建立复方头孢羟氨苄胶囊中头孢羟氨苄的含量测定方法。方法采用差示紫外分光光度法,检测波长248nm,不经分离,直接测定无干扰,以水和1mol.L-1氢氧化钠溶液为溶剂。结果头孢羟氨苄浓度在15~35μg.mL-1之间线性关系良好,r=0.9990(n=7),平均回收率为100.2%,RSD为0.66%(n=5)。结论该方法操作简便、快速、准确,可作为该制剂的质量控制方法。     

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.