高效液相色谱法测定人血浆中异烟肼和吡嗪酰胺的浓度

目的:建立以高效液相色谱法测定人血浆中异烟肼及吡嗪酰胺浓度的方法.方法:色谱柱为Diamonsil C18( 250 mm ×4.6 mm,5μm),以0.05 mol ·L-1磷酸二氢钾溶液∶甲醇=89∶11(用三乙胺调节pH约为6.0)为流动相,柱温:室温,流速:0.9ml·min-1,检测波长为254 nm.结果:异烟肼的线性范围为0.5～30μg·ml-1(r =0.998 5),吡嗪酰胺线性范围为1～50μg ·ml -1(r =0.998 0),平均回收率分别为90.33％,103.01％.结论:本法专属性好,样品处理方法简单,可用于测定人血浆中异烟肼和吡嗪酰胺的浓度.     

HPLC法测定异福酰胺胶囊及片的含量

目的:建立异福酰胺胶囊及片的含量测定方法.方法:采用高效液相色谱法,选用Kromasil ODS C18色谱柱(4.6mm×20cm),流动相A:乙腈-0.05mol·L-1磷酸二氢铵溶液(3:97),流动相B:乙腈-0.05mol·L-1磷酸二氢铵溶液(55:45),梯度洗脱,0～4分钟,流动相A为100%,4～8分钟,流动相A由100%降到0%,8～15分钟,流动相B为100%;流速:1.0ml·min-1,检测波长:263nm.结果:利福平在20.3～101.5μg·ml-1,异烟肼在13.5～67.5μg·m-l,吡嗪酰胺在66.7～333.5μg·ml-1的浓度范围内,峰面积与浓度呈良好的线性关系,异福酰胺胶囊方法回收率分别为99.8%,99.1%,100.5%,RSD分别为0.44%,0.24%,0.40%;异福酰胺片方法回收率分别为100.1%,100.3%,100.4%,RSD分别为0.12%,0.53%,0.35%.结论:方法准确,灵敏,可靠,适用于异福酰胺胶囊及片的含量测定.     

HPLC测定吡嗪酰胺的有关物质

目的 采用HPLC测定吡嗪酰胺的有关物质.方法 采用Cosmosil C18色谱柱(250 mm×4.6 mm,5μm),流动相为甲醇-5 mmol·L-1磷酸氢二钾溶液(磷酸调pH3)(10∶90),流速1.0 mL·min-1,检测波长268 nm.结果 吡嗪-2-羧酸0.201 ～1.206 μg·mL-1与峰面积的线性关系良好;2-氰基吡嗪0.202 ～ 1.214 μg·mL-1与峰面积线性关系良好.加样回收率吡嗪-2-羧酸为99.92％,RSD =0.71％ (n =9);2-氰基吡嗪为99.77％,RSD=0.96％(n=9).结论 所用方法准确、简便、快速,适用于吡嗪酰胺有关物质的检查.     

RP-HPLC法测定注射用乙酰谷酰胺的含量

目的建立测定注射用乙酰谷酰胺含量的反相高效液相色谱法.方法采用Alltech C18色谱柱(250 mm×4.6 mm,5 μm),pH 5.8磷酸盐缓冲液-甲醇(90:10)为流动相,流速为0.8 mL·min-1,检测波长为220 nm.结果乙酰谷酰胺在0.033 25～1.064 mg·mL-1峰面积与其测定浓度呈良好的线性关系(r=0.999 8),平均回收率为99.97%,重复性试验RSD为0.51%(n=6).结论本法准确、简便、快速,适用于注射用乙酰谷酰胺的质量控制.     

高效液相色谱法测定吡嗪酰胺胶囊含量

目的建立HPLC法测定吡嗪酰胺胶囊含量的方法。方法采用高效液相色谱法。色谱柱为Kromasil C18柱(4.6mm×250mm,5μm);流动相:乙腈-0.001mol·L-1庚烷磺酸钠溶液(用稀磷酸调pH 2.2)(10∶90);流速1.0mL·min-1;柱温:30℃;检测波长268nm。结果吡嗪酰胺在1.037～51.850μg·mL-1范围内线性关系良好(r=1.0000,n=7),平均加样回收率为97.8%,RSD为1.1%,(n=9)。结论该方法简便快速,结果准确,可作为本品质量控制方法。     

HPLC—MS法测定血浆中左旋黄皮酰胺的浓度

目的:建立测定血浆中左旋黄皮酰胺浓度的 LC-MS 方法。方法:血浆样品经醋酸乙酯提取处理后,以2%冰醋酸-甲醇(45∶55)为流动相,在1.0 mL·min~(-1)的流速下,用 Shimadzu ODS 色谱柱(150mm×4.6mm,5μm)分离,样品经电喷雾离子化后,通过 HP 1100 HPLC-MS 质谱仪液相色谱串联质谱法,以格列吡嗪为内标测定左旋黄皮酰胺的浓度。结果:血浆中左旋黄皮酰胺的线性范围为0.01-10μg·mL~(-1),最低定量浓度为10ng·mL~(-1),准确度在80%-90%之间,日内、日间精密度(RSD)在±10%之内。结论:该方法高效、准确,可用于左旋黄皮酰胺在体内的药代动力学研究及血浆中左旋黄皮酰胺的含量测定以控制质量。     

LC-MS/MS方法同时检测人血浆中异烟肼、乙胺丁醇和吡嗪酰胺的浓度

目的:建立同时检测人血浆中3种抗结核药物异烟肼、乙胺丁醇和吡嗪酰胺浓度的LC-MS/MS方法,用于肺结核患者及临床试验中三药血药浓度的测定。方法:以对乙酰氨基酚为内标,血浆样品经乙腈沉淀蛋白等处理后检测。采用AgilentZORBAX SB-Aq色谱柱(2.1 mm×100 mm,3.5μm)为分析柱,ZORBAX SB-Aq柱(2.1 mm×12.5 mm,5μm)为保护柱,以乙腈-5 mmol·L-1甲酸铵水溶液(含0.1%甲酸)(8:92,v/v)为流动相,使用电喷雾离子源(ESI),以正离子多反应监测(MRM)方式进行检测,异烟肼m/z 138.2→121.0,乙胺丁醇m/z 205.2→116.1,吡嗪酰胺m/z 124.1→81.1,对乙酰氨基酚m/z152.0→110.0。分析时间为5 min。结果:血浆中内源性物质对测定无干扰,异烟肼线性范围为0.1～6.0μg.mL-1,定量下限(LLOQ)为0.1μg.mL-1,乙胺丁醇线性范围为0.1～5.0μg.mL-1,定量下限(LLOQ)为0.1μg.mL-1,吡嗪酰胺线性范围为1.0～50.0μg.mL-1,定量下限(LLOQ)为1.0μg.mL-1。日内、日间精密度(RSD)均小于10%,准确率为90.4%～108.7%。结论:本方法特异性强,灵敏度高,测定结果可靠,适用于临床血浆样品的高通量分析。     

Rp-HPLC法测定人血浆中吡嗪酰胺的浓度

目的:建立以反相高效液相色谱法测定人血浆中吡嗪酰胺血药浓度的方法。方法:采用Diamonsil C₁₈（250 mm×4.6mm,5μm）色谱柱,流动相为0.05 mol·L^-1乙酸铵-乙腈（91:9）,流速为1.0 ml·min^-1,检测波长为268 nm,柱温为25℃,采用蛋白沉淀法处理血浆样品。结果:吡嗪酰胺血浆浓度在1.645～105.28μg·ml^-1（r=0.999 5）范围内线形关系良好,低、中、高三种浓度的平均相对回收率分别为（85.70±0.75）%,（99.53±2.82）%,（98.93±0.62）%,日内、日间RSD均小于10%。结论:本方法简便、快速、准确、灵敏度高,可用于吡嗪酰胺血药浓度测定和人体药动学研究。     

高效液相色谱法对乙胺吡嗪利福异烟片中利福平、异烟肼、吡嗪酰胺三项的测定

目的:用高效液相色谱法同时测定乙胺吡嗪利福异烟片中利福平、异烟肼、吡嗪酰胺的含量。方法:色谱柱以氰基键合硅胶为填充剂(250mm×4.6mm,5μm);流动相为0.01mol/L,庚烷磺酸钠溶液(稀磷酸调pH至2.2)-乙腈(44∶56);流速为1.0ml/min;检测波长为254nm。结果:利福平在24.72μg/ml～86.52μg/ml的范围内,异烟肼在19.84μg/ml～69.44μg/ml的范围内,吡嗪酰胺在59.92μg/ml～209.72μg/ml的范围内呈良好的线性关系,回收率分别为99.8%、99.8%、100.1%,重现性精密度符合要求。结论:本法可用于乙胺吡嗪利福异烟片中利福平、异烟肼、吡嗪酰胺的含量测定。     

反相高效液相色谱法测定吡嗪酰胺片的含量

采用反相高效液相色谱法测定吡嗪酰胺片的含量。选用PRODIGY ODS(250×4.60mm.5μm)色谱柱,以邻甲苯磺酰胺为内标,甲醇-水-冰乙酸(45:55:1,以三乙胺调pH=3.5)为流动相,检测波长为268nm,测得线性范围4～12μg,r=0.9999,平均回收率为99.8％,RSD为0.8％(n=3)。     

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.