高效液相外标法测定人血浆中缬沙坦、氢氯噻嗪浓度

目的建立测定血浆中缬沙坦、氢氯噻嗪浓度的高效液相外标法。方法采用RP-HPLC法测定血浆中的缬沙坦和氢氯噻嗪,分别用沉淀法和萃取法去除蛋白,荧光检测器和紫外检测器测定,外标法定量。结果缬沙坦的线性范围为0.05～8.00 mg/L(r=0.9999),相对回收率为89.7%～99.7%(n=5),绝对回收率为78.9%～90.7%(n=5),日内精密度RSD为1.1%～3.2%,日间精密度RSD为1.5%～3.9%;氢氯噻嗪的线性范围为2.5～300μg/L(r=0.9995),相对回收率为91.5%～98.4%(n=5),绝对回收率为78.2%～91.5%(n=5);日内精密度RSD为2.1%～7.4%,日间精密度RSD为2.4%～7.7%。结论高效液相外标法具有特异性强、快速、准确的优点,可用于血浆中缬沙坦、氢氯噻嗪的快速测定及人体药动学研究。     

反相高效液相色谱法测定珍菊降压片中氢氯噻嗪和芦丁的含量

目的建立一种RP-HPLC测定珍菊降压片中氢氯噻嗪和芦丁的含量.方法色谱柱为Penomenex C18反相柱(250 mm×4.6 mm,5 μm),流动相为0.05 mmol·L-1磷酸二氢钾溶液-乙腈(80∶20,pH 3.0),检测波长为271 nm,柱温为35℃,流速为1.0 mL·min-1,采用外标法定量.结果氢氯噻嗪和芦丁的线性范围分别为10.06～100.6 μg·mL-1(r=0.999 9)和40.08～400.8 μg·mL-1(r=0.999 9),平均回收率分别为99.86%和99.70%(n=9);精密度良好.结论本法简便、灵敏、准确,适于珍菊降压片中氢氯噻嗪和芦丁的质量控制.     

HPLC法同时测定缬沙坦氢氯噻嗪片中两组分的含量

目的采用高效液相色谱法同时测定缬沙坦氢氯噻嗪片中缬沙坦、氢氯噻嗪的含量。方法采用Agilent Zorbax Eclipse XDB-CN色谱柱(4.6 mm×250 mm,5μm),以乙腈-水-磷酸(450∶550∶1)为流动相,流速1 mL.min-1,检测波长225 nm,柱温30℃。结果缬沙坦在19.82～118.92μg.mL-1范围内线性关系良好(r=0.999 9),氢氯噻嗪在3.01～18.08μg.mL-1范围内线性关系良好(r=0.999 9),平均回收率分别为100.08%(RSD=0.68%,n=6)、99.51%(RSD=0.89%,n=6)。结论本方法简便、快速、准确,重复性好,可用于缬沙坦氢氯噻嗪片中两组分含量的测定。     

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.     

UPLC法同时测定缬沙坦氢氯噻嗪片中缬沙坦和氢氯噻嗪的含量

目的:建立同时测定缬沙坦氢氯噻嗪片中缬沙坦和氢氯噻嗪含量的方法。方法:采用超高效液相色谱法。色谱柱为Phenomenex C_(18),流动相为[0.1%磷酸溶液-乙腈(95∶5,V/V)]-[0.1%磷酸溶液-乙腈(5∶95,V/V)](梯度洗脱),流速为0.25 mL/min,检测波长为272 nm,柱温为35℃,进样量为1.5μL。结果:缬沙坦和氢氯噻嗪检测质量浓度线性范围分别为8.1~324.2μg/mL(r=0.999 9)、1.2~50.1μg/mL(r=0.999 9);定量限分别为0.24、0.04 ng,检测限分别为0.06、0.01 ng;精密度、稳定性、重复性试验的RSD<2.0%;加样回收率分别为97.69%~100.35%(RSD=1.03%,n=9)、98.27%~100.60%(RSD=0.83%,n=9)。结论:该方法操作简单、快速,结果准确,可用于缬沙坦氢氯噻嗪片中缬沙坦和氢氯噻嗪含量的同时测定。     

健康受试者口服复方缬沙坦后血浆中氢氯噻嗪和缬沙坦浓度测定

目的 建立高效液相色谱法测定健康受试者口服复方缬沙坦后血浆中氢氯噻嗪、缬沙坦的浓度. 方法 以奥硝唑为氢氯噻嗪内标、坎地沙坦为缬沙坦内标. 氢氯噻嗪色谱条件, Eurospher-100 C₁₈色谱柱 （250 mm×4.6 mm, 5 μm）;流动相：乙腈 水（30：70,V/V）;流速：1 mL&#8226;min^-1;柱温：室温;检测波长：272 nm;进样量：50 μL. 缬沙坦色谱条件：Eurospher-100 C18色谱柱（250 mm×4.6 mm, 5 μm）;流动相：甲醇 0.02 mol&#8226;L^-1 磷酸二氢钾（70：30,V/V）磷酸调pH值 2.40;流速：1 mL&#8226;min^-1;柱温：室温;检测波长：激发波长265 nm,发射波长395 nm;进样量：20 μL. 结果 氢氯噻嗪在5～1 000 ng&#8226;mL^-1范围内、缬沙坦在0.025～10.000 μg&#8226;mL^-1范围内线性关系良好（r＝0.999 5,r＝0.999 5）,定量下限分别为2.5,10 ng&#8226;mL^-1,氢氯噻嗪日内精密度RSD为1.42%～5.22%,日间精密度为2.62%～9.04%;缬沙坦日内精密度RSD为0.52%～3.30%,日间精密度为2.00%～9.01%. 结论 该法简便灵敏准确、重现性好,可用于血浆中氢氯噻嗪、缬沙坦的测定.     

高效液相色谱法测定复方利血平片中4种成分的含量

目的:建立同时测定复方利血平片中硫酸双肼屈嗪、氢氯噻嗪、维生素B_1和维生素B_6含量的高效液相色谱法。方法:采用Hypersil BDS C_(18)柱(200mm×4.6mm,5μm);流动相为0.01mol·L~(-1)庚烷磺酸钠溶液-乙腈-甲醇-三乙胺(65:20:15:0.02),用5%磷酸溶液调节pH至3.6;检测波长为240nm。结果:硫酸双肼屈嗪在32.5～406.7μg·ml~(-1)(r=0.999 2),氢氯噻嗪在24.4～304.4μg·ml~(-1)(r=0.999 4),维生素B_1在8.5～106.6μg·ml~(-1)(r=0.999 3),维生素B_6在8.5～106.0μg·ml~(-1) (r=0.999 1)浓度范围内线性关系良好;硫酸双肼屈嗪回收率为100.2%,RSD为0.8%(n=9),氢氯噻嗪回收率为99.7%,RSD为1.0%(n=9),维生素B_1回收率为100.0%,RSD为0.9%(n=9),维生素B_6回收率为100.5%,RSD为0.9%(n=9)。结论:本法操作简便、快捷,结果准确,可用于复方利血平片的质量控制。     

反相高效液相色谱法测定人血浆中头孢地尼的浓度

目的:建立人血浆中头孢地尼浓度的反相高效液相色谱测定方法.方法:以甲硝唑为内标,血浆样品经三氯乙酸(TCA)沉淀蛋白处理,色谱柱为Nucleodur C18(250 mm×4.6 mm,5 μm),保护柱为自填C18柱,流动相为0.025 mol·L-1磷酸二氢铵溶液(pH 3.0)-乙腈(90.5:9.5),检测波长为286 nm,流速为1.0 ml·min-1.结果:头孢地尼的线性范围为0.05～2.00 μg·ml-1(r=0.999 8).日内精密度RSD为3.7%～5.9%,日间精密度RSD为3.5%～5.7%.绝对回收率为65.0%～72.4%.结论:该法灵敏、准确、简便,检测限低(LOQ),重现性好,可用于血浆头孢地尼浓度的测定.     

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.     

高效液相色谱法测定缬沙坦氢氯噻嗪分散片中两组分含量

目的:建立测定缬沙坦氢氯噻嗪分散片中缬沙坦、氢氯噻嗪含量的高效液相色谱法(high-performance liquid chromatography,HPLC)方法.方法:采用Shimadzu VP-ODS(4.6 mm×250 mm,5μm)色谱柱,以乙腈-0.1％磷酸溶液(用三乙胺调至pH4.0)(47∶53)为流动相,检测波长271 nm,流速1.0 mL/min,柱温25℃,进样量20 μL.结果:缬沙坦在32.05～160.25 μg/mL(y=0.9999)、氢氯噻嗪在5.05～25.25 μg/mL(y=0.9999)的范围内有良好的线性关系,平均回收率分别为98.7％(RSD=1.77％,n=9)、101.4％ (RSD=1.94％,n=9).结论:本方法简便、快速、准确,重复性好,可用于缬沙坦氧氯噻嗪分散片中两组分含量的测定.     

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.     

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.