人体血浆及尿液甲磺酸加替沙星浓度的HPLC测定法

目的建立高效液相色谱法测定血浆和尿液中甲磺酸加替沙星药物浓度.方法待测血浆和尿液中加入甲磺酸加替沙星与内标环丙沙星后,分别以盐酸反提法和直接进样,进行高效液相色谱荧光检测,色谱柱为zorbax SB-C18,流动相为0.1 mol·L-1磷酸甲醇三乙胺(64.7350.3,v/v/v),pH值为3.0;流速1.0ml·min-1,激发波长295nm,发射波长495nm.结果本测定方法血浆和尿液的线形范围为0.0156～1mg·L-1和0.434～111.11mg·L-1,相关系数均为0.9997,血浆及尿的相对回收率分别为88.7%～94.6%,96.70%～109.96%;绝对回收率分别78.01%～117.1%,96.73～106.50%,日内日间变异系数(RSD)均小于13%,血浆和尿液中甲磺酸加替沙星的最低检测限分别为0.0156、0.434mg·L-1.结论高效液相色谱法测定血浆与尿中药物浓度精确、灵敏、可靠,可用于甲磺酸加替沙星的药代动力学、生物利用度研究及临床血药浓度监测.     

高效液相色谱法测定人体血浆及尿液中多西环素的药物浓度

目的:建市人体血浆及尿液中多西环素药物浓度的高效液相色谱分析方法。方法:美他环素作为内标,待测血浆和尿液分别以高氯酸和甲醇沉淀蛋白,离心后取上清液进行高效液相色谱紫外检测,色谱柱为 Kromasil C_(18)柱(5μm,4.6mm×250mm);流动相为乙腈-水(30:70,含5 mmol·L~(-1)的柠檬酸),流速1.0 mL·min~(-1),检测波长350 nm。结果:本测定方法血浆和尿液的线性范围分别为O.1～6.13 mg·L~(-1)和0.085～13.62 mg·L~(-1),相关系数分别为0.9995和0.9991,血浆及尿液的相对回收率分别为95.2%～101.4%,95.6%～105.5%;日内日间 RSD 均小于10%,最低检测限分别为0.026 mg·L~(-1)及0.034mg·L~(-1)。结论:高效液相色谱法测定血浆与尿液中药物浓度简单、快速、可靠,可用于多西环素的药代动力学及生物利用度研究。     

反相高效液相色谱法测定人血浆中马来酸氟伏沙明浓度

目的:建立高效液相色谱法测定人血浆中马来酸氟伏沙明浓度。方法:以安定为内标,待测血浆样品经乙醚萃取后,用高效液相色谱法紫外进行检测。色谱柱为 Discovery~(?)RP Amide C_(16)(5μm,150 mm×4.6 mm),柱温35 ℃;流动相为乙腈-0.05 mol·L~(-1)醋酸铵(40:60),流速1.2 mL·min~(-1);检测波长250 nm。结果:血浆中马来酸氟伏沙明浓度线性范围为1.56～99.6 ng·mL~(-1),最低定量浓度1.56 ng·mL~(-1);回收率为95.7%～106.1%。结论:本法分离效果良好,灵敏度高,回收率高,能满足于人体血药浓度测定及药代动力学研究。     

反相离子对高效液相色谱法测定人血浆中羟苯磺酸

目的:建立测定羟苯磺酸血浆浓度的反相离子对高效液相色谱法,并用于临床药物动力学研究。方法:0.5 mL 血浆样品经乙腈沉淀蛋白处理后,以0.05 mol·L~(-1)磷酸二氢钾缓冲液(pH 3.0)-乙腈(87:13,v/v)为流动相(流动相中含0.1%四丁基氢氧化铵),Diamonsil C_(18)柱分离,检测波长为300 nm,流速为1.0 mL·min~(-1)。结果:测定血浆中羟苯磺酸方法的线性范围为0.364～36.4 mg·L~(-1),定量下限为0.364 mg·L~(-1)。日内、日间精密度(RSD)均小于8.7%,准确度(RE)在±4.5%以内。羟苯磺酸和内标对氨基苯甲酸的平均血浆样品处理回收率分别为74.8%和94.8%。结论:该方法选择性强,操作简单,适用于羟苯磺酸钙的临床药物动力学研究。     

高效液相色谱法测定血浆中甲磺酸加替沙星的含量

目的建立测定血浆中甲磺酸加替沙星浓度的高效液相色谱法.方法待测血浆中加入内标环丙沙星后,以甲醇直接沉淀蛋白,进行高效液相荧光检测,色谱柱为ZORBAX SB--C18,流动相为0.1mol.L-1磷酸盐缓冲液甲醇(6832),0.1mol.L-1磷酸盐缓冲液中含0.005mol.L-1离子对试剂氢氧化四丁基铵(IPR--A),pH值为2.35.流速1.0ml/min,激发波长295nm,发射波长495nm.结果本测定方法的线形范围为0.0625～1μg.ml-1,r=0.9990,日内、日间RSD均小于10%,回收率为93.1～94.0%,血浆中甲磺酸加替沙星的最低检测限为0.0313μg.ml-1.结论本法精密、准确,适用于临床上血药浓度监测,人体药代动力学和生物利用度研究.     

RP-HPLC柱前衍生化法测定白舒非血药浓度

目的建立测定人血浆中白舒非浓度的柱前衍生高效液相色谱法。方法以1,5-戊二醇二甲磺酸酯为内标,血浆样品经二乙基二硫代氨基甲酸钠衍生化处理后,以乙腈-0.7%冰醋酸水溶液(69∶31)为流动相,流速1.0mL·min-1,采用XterraP18色谱柱分离,在280nm波长下进行检测。结果白舒非线性范围为0.20～4.00mg·L-1,以加权最小二乘法计算得到回归方程为Y=2.56X+16.7(r=0.9993,n=7),提取回收率81.01%～82.72%,方法回收率96.50%～97.90%,日内、日间精密度(RSD)均小于10%。最低血浆检测质量浓度为0.080mg·L-1。结论柱前衍生高效液相色谱法准确、灵敏,适用于白舒非血浆浓度的测定及其药代动力学研究。     

高效液相色谱法测定注射用头孢西酮在健康人血浆和尿中的浓度

目的 建立测定注射用头孢西酮(头孢类抗生素)在人血浆和尿中浓度的高效液相色谱法.方法 血浆样品经10%三氯醋酸沉淀蛋白,以塞克硝唑为内标,用乙腈-0.02 mol·L-1磷酸二氢钠溶液(13:87)为流动相,尿液直接稀释,经Capcell Pak MG C18柱分离,278 nm波长检测.结果 头孢西酮血浆样品和尿样线性范围分别为0.4～640.0和2～3 200 mg·L-1;提取回收率分别为38.9%～41.5%和100.8%～107.4%;日内、日间RSD均低于15%.结论 本方法准确性好、操作简单,可满足药代动力学研究的要求.     

加替沙星血药浓度HPLC测定方法研究

目的:建立加替沙星血药浓度的高效液相色谱分析方法。方法:以乳酸司帕沙星为内标,采用10％高氯酸为沉淀剂处理人血浆样品,分析柱为Phenomenex(Luna,C_(18),5μm粒径,150 mm×4.6 mm);Easyguard C_(18)保护柱。流动相为0.01mol·L~(-1)磷酸二氢钾缓冲液-乙腈 (18:5,用磷酸调pH为3.05),流速1.0 mL·min~(-1),柱温25℃,在292 nm波长处检测,按内标法定量。结果:血药浓度线性范围为0.025～8μg·mL~(-1)(r=0.999 9),最低检测浓度为0.025μg·mL~(-1)(S/N>3),萃取回收率在76.31％～87.70％(n=5),方法回收率在98.3％～102.3％(n=5),日内和日间RSD分别为3.3％～5.6％和4.8％～9.8％(n=5)。结论:本方法简便、准确,精密度高,重现性好,适用于加替沙星人体内药代动力学研究及生物等效性研究。     

反相高效液相色谱法测定人血浆及尿液中甲磺酸帕珠沙星浓度

目的:建立血浆及尿液中甲磺酸帕珠沙星浓度的反相高效液相色谱分析方法。方法:用甲醇沉淀血浆蛋白,离心后取上清液进行色谱分析;尿样稀释后离心取上清液进样。分析柱为DiamonsilC18,流动相为乙腈-0.05mol/L磷酸二氢钾(含1%四丁基溴化铵)(8∶92,V/V),流速为1.4ml/min,激发波长320nm,发射波长400nm。结果:甲磺酸帕珠沙星在血浆和尿液中的检测浓度线性范围均为31.25～10000ng/ml(r=0.9999);在血浆、尿液中的相对回收率分别为97.77%～99.87%、98.31%～100.82%,RSD<1.0%～3.0%。结论:本方法准确可靠、操作简便,适用于甲磺酸帕珠沙星的临床药动学及常规血药浓度监测。     

RP-HPLC法测定加替沙星血药浓度

目的:建立高效液相色谱法测定血浆中加替沙星浓度.方法:血浆用二氯甲烷提取,色谱柱为ZorbaxC18(4.6mm×250mm),流动相为0.01mol*L-1磷酸二氢钾-甲醇-三乙胺(65∶34.8∶0.2),检测波长292nm,流速1.0ml*min-1,以司帕沙星为内标.结果:加替沙星浓度线性范围0.01～5μg*ml-1,最低检测浓度0.01μg*ml-1,绝对回收率为85.1%,相对回收率为100.6%.日内,日间RSD分别为3.0%和3.7%.结论:该方法适用于人体药物动力学研究.     

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.

     

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.     

2-(Acetoxyphenyl)-(Z)-styryl sulfides as cyclooxygenase inhibitors

2-(Acetoxyphenyl)-(Z)-styryl sulfides are described as selective cyclooxygenase-2 (COX-2) inhibitors, useful for treating inflammation and COX-2-mediated disorders including neoplasia. 2-(Acetoxyphenyl)-(Z)-styryl sulfide is claimed to be the most potent COX inhibitor in the series with a COX-2 selectivity ratio of 33. This compound is also claimed to be superior to celecoxib (Celebrex^®, Pfizer) in inhibiting cell growth of colorectal carcinoma cells. In this evaluation, the COX inhibitory activity of this compound is compared to that previously disclosed for diarylheterocycles and 2-(acetoxyphenyl)alkyl sulfides. The validity of the DLD-1 cell line in the growth inhibition studies is questioned based on recent literature reports indicating the lack of COX-2 expression in this cell line.     

Sleep-disordered breathing with chronic opioid use

Chronic opioid use for pain relief or as substitution therapy for illicit drug abuse is prevalent in our societies. In the US, retail distribution of methadone and oxycodone has increased by 824 and 660%, respectively, between 1997 and 2003. μ-Opioids depress respiration and deaths related to illicit and non illicit chronic opioid use are not uncommon. Since 2001 there has been an emerging literature that suggests that chronic opioid use is related to central sleep apnoea of both periodic and non-periodic breathing types, and occurs in ～ 30% of these subjects. The clinical significance of these sleep-related abnormalities are unknown. This review addresses the present knowledge of control of ventilation mechanisms during wakefulness and sleep, the effects of opioids on ventilatory control mechanisms, the sleep-disordered breathing found with chronic opioid use and a discussion regarding the future research directions in this area.     

Drug targets for cognitive enhancement in neuropsychiatric disorders

The investigation of novel drug targets for treating cognitive impairments associated with neurological and psychiatric disorders remains a primary focus of study in central nervous system (CNS) research. Many promising new therapies are progressing through preclinical and clinical development, and offer the potential of improved treatment options for neurodegenerative diseases such as Alzheimer's disease (AD) as well as other disorders that have not been particularly well treated to date like the cognitive impairments associated with schizophrenia (CIAS). Among targets under investigation, cholinergic receptors have received much attention with several nicotinic agonists (α7 and α4β2) actively in clinical trials for the treatment of AD, CIAS and attention deficit hyperactivity disorder (ADHD). Both glutamatergic and serotonergic (5-HT) agonists and antagonists have profound effects on neurotransmission and improve cognitive function in preclinical experiments with animals; some of these compounds are now in proof-of-concept studies in humans. Several histamine H3 receptor antagonists are in clinical development not only for cognitive enhancement, but also for the treatment of narcolepsy and cognitive deficits due to sleep deprivation because of their expression in brain sleep centers. Compounds that dampen inhibitory tone (e.g., GABA_A α5 inverse agonists) or elevate excitatory tone (e.g., glycine transporter inhibitors) offer novel approaches for treating diseases such as schizophrenia, AD and Down syndrome. In addition to cell surface receptors, intracellular drug targets such as the phosphodiesterases (PDEs) are known to impact signaling pathways that affect long-term memory formation and working memory. Overall, there is a genuine need to treat cognitive deficits associated with many neuropsychiatric conditions as well as an increasingly aging population.