人血浆中头孢泊肟的RP-HPLC法测定

建立了RP—HPLC法测定人血浆中头孢泊肟的浓度。采用C18柱，以头孢氨苄为内标，流动相为乙腈-水-三氟乙酸-三乙胺（14：86：0．1：0．1），流速为1．2ml／min，检测波长254nm。血浆样品经25％高氯酸乙腈蛋白沉淀后进样测定。头孢泊肟的线性范围为0．025-4．0μg／ml，最低定量限为0．025μg／ml；日内、日间RSD均小于6．53％，相对回收率为99．6％～104．2％，提取回收率均大于85.3％。     

HPLC法测定血浆及尿液中左氧氟沙星的浓度

采用高效液相色谱－荧光法测定了血浆及尿液中左氧氟沙星的浓度。Nova－PakC18预柱，SymmetryC18分析柱，已腈－0．05mol/L枸橼酸－1mol/L醋酸铵（11．5：77：1）为流动相，激发波长300um，发射波长500um。血中左氧氟沙星回收率为100．5％，RSD为1％。尿中左氧氟沙星回收率为99．0％，RSD为1．6％。最低检测量为8ng。     

高效液相色谱-库伦阵列电化学法测定大鼠血浆中克拉霉素的浓度

目的：建立大鼠血浆中克拉霉素浓度的高效液相色谱-电化学检测（HPLC—ECD）方法。方法：采用Nova—Pak C18色谱柱（150mm×3．9mm，5μm）色谱柱；以0．085mol·L^-1磷酸二氢钾-乙腈（1：1）为流动相，pH7．1；流速1mL·min^-1；柱温为30℃；库伦阵列电化学检测器的工作电位为860mV。结果：血浆中克拉霉素检测方法的线性范围为0．1～8μg·mL^-1，检出限可达50ng·mL^-1；血浆中克拉霉素的方法回收率（n=5）为90．2％-95．7％，提取回收率（n=5）为88．7％～91．5％；日内RSD≤3．3％，日间RSD≤5．2％。结论：本法灵敏、准确，可用于克拉霉素的药代动力学研究。     

反相高效液相色谱法测定健康志愿者血浆中格列吡嗪浓度

目的建立反相高效液相色谱（RP-HPLC）测定格列吡嗪血药浓度的方法。方法血浆用活化的固相萃取小柱洗脱药物。色谱柱为MAHEREY-NAGELC18（250mm×4．6mm，5μm），流动相为乙腈-30mmol·L^-1醋酸铵水溶液（内含2．5％甲酸）（50：50），柱温50℃，流速1．0mL·min^-1，检测波长225nm。结果格列吡嗪浓度在16．8～1680．0ng·mL^-1内的线性关系良好（r=0．9999），血浆中低、中、高3种浓度的方法回收率在100．32％～103．38％，日内RSD≤8．90％，日间RSD≤9．06％。结论本法快速、灵敏、高效，适于格列吡嗪的血药浓度监测。     

高效液相色谱测定比格犬血浆中的头孢唑啉与头孢曲松的浓度

目的：建立HPLC在多项测定参数相同的基础上,分别测定比格犬血浆中头孢唑啉、头孢曲松浓度的方法。方法色谱柱：头孢唑啉为ES industries Epic C18（4．6 mm ×150 mm,5μm）,头孢曲松为Phenomenex Gemini C18（4．6 mm ×150 mm,5μm ）,流动相：头孢唑啉为甲醇－0．05 mol? L－1乙酸铵缓冲液（ pH＝4．3）＝30∶70;头孢曲松为乙腈－0．05 mol? L－1 KH2 PO4缓冲液（ pH＝6．0）＝6∶94,流速均为1．0 mL? min－1,进样量均为40μL。结果头孢唑啉标准曲线回归方程为 y ＝－1．25×104 x ＋8479．37（ r ＝0．9974）,头孢曲松为y＝1．25×104 x ＋2．72×104（ r ＝0．9976）。头孢唑啉线性范围为2～300μg? mL－1,头孢曲松为2～200μg? mL－1;日内、日间精密度相对标准偏差均≤10％,提取回收率均≥85．78％。结论本法灵敏、准确、快速,可用于比格犬血浆头孢唑啉、头孢曲松浓度的测定和药物其他方面研究。     

高效液相色谱法测定头孢泊肟酯及其制剂的含量

建立一种用高效液相色谱法测定头孢泊肟酯及其片剂，胶囊剂的含量及有关物质的方法。方法：以ODS为固定相。甲醇－水（41：59）为流动相；检测波长为240nm。结果：头孢泊肟酯的浓度在0.3-0.9mg/ml范围内线性关系良好，回归方程为：Y＝1460374，8X-4983．9，r=0.9999。头孢泊肟酯，头孢泊肟酯片和头孢泊肟酯胶囊重现性良好（n=9)，RSD分别为0．5％，1．0％和1．2％。头孢泊肟酯片和头孢泊肟酯胶囊平均回收率分别为100．6％（RSD＝1．0％，n=9)和99．8％（RSD＝0．8％，n=90。本方法简单，快速，结果准确。     

高效液相色谱法测定人血浆中恩曲他滨

目的：建立高效液相色谱测定人血浆中恩曲他滨浓度的方法。方法：血浆样品0．4mL，加入0．5mL水混匀后上柱抽干，先后用1mL水洗去杂质，用0．5mL甲醇洗脱样品，洗脱液吹干后用0．2mL流动相溶解，10μL进样检测。分析柱：Inertisil C8（150mm×4．6mm，5μm）；保护柱：EXT-C18（12．5mm×4．6mm，5μm）；流动相：0．02mol·L^-1磷酸二氢钾溶液（含0．002％四丁基氢氧化铵）-乙腈（88：12），流速：1mL·min^-1柱温：30℃；紫光检测波长：280nm。结果：血浆中恩曲他滨浓度在0．05～8μg·mL^-1范围内，A与C呈良好的线性关系，典型的回归方程为：A=37．98C＋0．0284（r=0．9993），最低检测浓度为0．05μg·mL^-1，平均提取回收率为91．4％，日内RSD〈6．6％，日间RSD〈5．9％。结论：方法简便、快速，灵敏度高，可用于恩曲他滨的药动学研究。     

高效液相色谱法测定乳酸羟醋酸共聚物微球中纳美芬的含量

目的：建立高效液相色谱法测定纳美芬缓释微球载药量的方法。方法：色谱柱为C18柱，流动相为甲醇-0．02mol·L^-1，磷酸缓冲液（pH4．0）-三乙胺（40：60：0．2），检测波长为284mm。结果：在5．24～83．84mg·L^-1范围内，峰面积对质量浓度有良好的线性关系，日内RSD≤0．77％，日间RSD≤1．10％，回收率为92．8％。结论：HPLC法专属性强，结果准确。     

RP—HPLC法测定猪血浆中头孢喹肟浓度

目的：建立测定头孢喹肟血药浓度的RP—HPLC法。方法：血浆样品经乙腈沉淀蛋白后取上清进样测定，色谱柱为C18柱（150mm×4．6mm，5μm），流动相为磷酸盐缓冲液（0．83％磷酸用三乙醇胺调pH为2．8）-乙腈（86：14），流速为1mL·min^-1，检测波长270nm，柱温25℃。结果：头孢喹肟血药浓度在0．05—20μg·mL^-1范围内线性关系良好（r=0．9994）；最低检测限为0．05μg·mL^-1；方法回收率88．0％～96．8％；日内RSD和日间RSD均小于10％。结论：方法快速简便、灵敏准确，适用于头孢喹肟在动物体内的药物动力学研究。     

RP-HPLC法测定人血浆中头孢他美浓度

目的:建立以RP-HPLC法测定人血浆中头孢他美浓度的方法。方法:色谱柱为Hypersil C18,流动相为0.04%高氯酸溶液-乙腈(83∶17),柱温为40℃,流速为1.0mL.min-1,检测波长为265nm。结果:头孢他美检测浓度在0.125~8.0μg.mL-1范围内与峰面积线性关系良好(r=0.999 8),最低检出浓度为0.125μg.mL-1,平均回收率为100.6%(RSD=1.2%);日内RSD≤5.3%(n=5),日间RSD≤4.0%(n=5)。结论:本方法简便、灵敏、准确、重现性好,可为头孢他美酯胶囊药动学和生物利用度研究提供参考。     

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.