高效液相-质谱串联法测定大鼠血浆中辛伐他汀及辛伐他汀酸的浓度

目的:建立HPLC-MS法测定大鼠血浆中辛伐他汀及其代谢物辛伐他汀酸的浓度。方法:血浆样本加入适量内标和醋酸铵缓冲液,以甲基叔丁基醚萃取后采用LC-MS进行分析。色谱柱采用Inertsil ODS-3柱(150 mm×2.1 mm,5.0μm);流动相由乙腈-2.5 mmol.L-1醋酸铵(含0.1%甲酸)(75∶25)组成,柱温35°C;流速0.3 mL.min-1;采用电喷雾离子源(ESI),以多反应监测方式(MRM)进行定量分析。辛伐他汀和内标洛伐他汀在正离子模式下定量分析离子对分别为m/z 419.2→m/z199.2和m/z 405.2→m/z 199.2;辛伐他汀酸和内标洛伐他汀酸在负离子模式下定量分析离子对分别为m/z 435.2→m/z319.2和m/z 421.4→m/z 319.2。结果:辛伐他汀和辛伐他汀酸在5.0～6 400 ng.mL-1内线性关系良好(r>0.999),最低定量限为0.1 ng.mL-1,提取回收率为87.91%～99.77%,日内、日间精密度均不高于8.95%。结论:该方法分析速度快、灵敏、准确,为临床进一步研究辛伐他汀提供了基础。     

UHPLC-MS/MS同时测定人血浆中辛伐他汀及其代谢产物

目的采用UHPLC-MS/MS同时测定人血浆中辛伐他汀及其代谢产物辛伐他汀酸,并研究辛伐他汀、辛伐他汀酸在人体内的药动学特征。方法血浆样品以乙醚萃取,采用UHPLC-MS/MS进行分析。色谱柱:Agilent ZORBAX SB-C18(100mm×2.1mm,3.5μm);乙腈-1mmol·L-1醋酸铵(甲酸调pH 4.5)为流动相梯度洗脱,流速:0.2 m L·min-1。采用电喷雾离子源(ESI),以多反应监测方式(MRM)进行定量分析。辛伐他汀和内标洛伐他汀在正离子模式下定量分析,离子对分别为m/z 419.4→199.3和m/z 405.3→199.3;辛伐他汀酸和内标洛伐他汀酸在负离子模式下定量分析,离子对分别为m/z435.5→115.2和m/z 421.4→101.2。结果辛伐他汀和辛伐他汀酸的线性范围均为0.2~50 ng·m L-1(r>0.99),最低定量限均为0.2 ng·m L-1,日内和日间精密度(RSD)均≤11.10%,提取回收率均≥63.71%。结论该方法专属性强、灵敏度高、重现性好,适用于辛伐他汀的药动学研究。     

LC-MS/MS测定人血浆中的辛伐他汀

目的 建立测定人血浆中辛伐他汀的LC-MS/MS方法.方法 血浆样品经乙酸乙酯提取后,以乙腈-水(含0.1%乙酸和2.5 mmol·L-1甲酸胺)(90:10)为流动相,通过Agilent1100 VL型离子阱质谱仪,电喷雾离子源正离子模式,采用多反应离子监测方式测定辛伐他汀的浓度(MRM,m/z 441→325).结果 血浆中辛伐他汀的线性范围为0.5～10.0 ng·ml-1.定量下限为0.5 ng·ml-1.平均回收率85%～115%,日内、日间精密度在±15%之内.结论 所用方法高效、准确,特异性强,可用于辛伐他汀的药物动力学研究.     

Beagle犬血浆中辛伐他汀的LC-MS测定

建立了LC-MS法测定Beagle犬血浆中的辛伐他汀。采用C_(18)柱,流动相为乙腈-0.1%甲酸溶液(60:40),以洛伐他汀为内标,采用电喷雾离子化法(ESI)采集正离子,单离子方式检测m/z 419(辛伐他汀)和m/z 405(洛伐他汀)。辛伐他汀在0.5～160ng/ml浓度范围内线性良好,检测限为0.25ng/ml。血浆样品的日内、日间RSD均小于7.7%,方法回收率为92.2%～99.2%,提取回收率为92.8%～100.9%。     

液相色谱-串联质谱法同时测定人血浆中辛伐他汀和辛伐他汀酸

目的:建立LC-MS/MS法测定人血浆中辛伐他汀和辛伐他汀酸。方法:血浆样本以乙醚-二氯甲烷(3∶2)液液萃取后,选用Inertsil ODS-SP色谱柱(75 mm×2.1 mm,3μm),以乙腈-1 mmol.L-1乙酸铵(pH 4.50)(75∶25)为流动相,流速为0.25 mL.min-1;选用API3200型三重四极杆串联质谱仪的多重反应监测(MRM)扫描方式进行监测,电喷雾离子化源,同一分析周期内正负离子扫描切换。辛伐他汀及其内标洛伐他汀采用正离子检测,选择监测离子反应分别为m/z 436.4→m/z199.3(辛伐他汀)和m/z 405.4→m/z 199.3(洛伐他汀);辛伐他汀酸及其内标洛伐他汀酸采用负离子检测,选择监测离子反应分别为m/z 435.3→m/z 115.0(辛伐他汀酸)和m/z 421.2→m/z 101.0(洛伐他汀酸)。结果:辛伐他汀、洛伐他汀、辛伐他汀酸、洛伐他汀酸的保留时间分别为2.78,2.33,1.47,1.38 min;血浆中辛伐他汀和辛伐他汀酸的线性范围均为0.100～15.0μg.L-1(r>0.9950),定量下限均为0.100μg.L-1;日内、日间精密度(RSD)均小于15%;准确度(RE)均在±15%的范围以内;辛伐他汀和辛伐他汀酸的平均提取回收率分别为(77.9±2.6)%和(86.1±6.1)%;平均基质效应因子分别为(95.3±4.5)%和(73.2±3.5)%;稳定性试验中,在各种贮存条件下血浆中辛伐他汀和辛伐他汀酸均较稳定。结论:该方法专属性强,灵敏度高,重现性好,适用于辛伐他汀临床药代动力学研究。     

液相色谱-电喷雾串联质谱法测定人血浆中辛伐他汀浓度

目的:建立液相色谱-电喷雾串联质谱联用测定人血浆中辛伐他汀浓度的方法。方法:色谱条件为 Discovery ODS C_(18)(2.1 mm×100 mm,3μm)色谱柱;流动相为乙腈-0.1%甲酸溶液(65:35,v/v);柱温30℃;流速0.2 mL·min~(-1);进样量5μL。质谱条件为电喷雾电离源(ESI),选择性检测定量离子为 m/z 441.3/325.0(辛伐他汀)和 m/z 427.2/325.0(洛伐他汀,内标)带正电荷的离子峰。样品用乙酸乙酯提取。结果:血浆中辛伐他汀浓度在0.20～20.0 ng·mL~(-1)内呈良好线性关系,r=0.9996。提取回收率为90.0%～92.4%(RSD 6.0%～14.9%),方法回收率在85%～115%之内,日内和日间精密度试验的RSD 均<15%,最低检测浓度为0.2 ng·mL~(-1)。结论:该测定方法经全面考察符合血浆样品的测定要求,可以应用于辛伐他汀的人体药动学研究和生物等效性评价。     

UPLC-MS/MS法同时测定人血浆中辛伐他汀和辛伐他汀羟基酸的浓度

目的:建立UPLC-MS/MS法同时测定人血浆中辛伐他汀和辛伐他汀羟基酸的浓度。方法:血浆样品用甲基叔丁基醚提取,离心后取上清液氮气吹干,流动相复溶后进行UPLC-MS/MS测定。色谱柱:BEH C18(2.1 mm×50 mm,1.7μm);流动相:乙腈-0.01 mol.L-1醋酸铵(72∶28);流速:0.15 mL.min-1;柱温:40℃,进样量:8μL。电喷雾离子化(ESI),正离子模式多重反应选择离子检测(MRM),辛伐他汀、辛伐他汀羟基酸及内标洛伐他汀的检测离子对分别为:m/z 419→199,437→303,405→199。结果:血浆样品中辛伐他汀、辛伐他汀羟基酸线性范围分别为0.241～61.76 ng.mL-1(r=0.999,n=5)和0.344～88.16 ng.mL-1(r=0.997,n=5),日内、日间精密度(RSD)均小于15%,方法的平均回收率分别为100.6%和106.0%,血浆基质对血浆中的辛伐他汀和辛伐他汀羟基酸测定无干扰。结论:建立的UPLC-MS/MS法处理简单、灵敏、特异性高,定量准确,为辛伐他汀制剂的临床药代动力学研究提供了简便、准确的分析测定方法。     

人血浆中孟鲁司特的LC-MS/MS法测定

建立了液相色谱-串联质谱法测定人血浆中的孟鲁司特.采用C18色谱柱,以辛伐他汀为内标,乙腈-水-甲酸(86∶14∶0.3)为流动相,ESI源正离子检测方式,多反应监测,监测离子对m/z 586.3→422.5(孟鲁司特)、m/z441.4→325.2(辛伐他汀).孟鲁司特在1～1 000 ng/ml浓度范围内线性关系良好.回收率为96.7％～110.6％,RSD小于7.0％.     

LC-MS/MS法同时测定人血浆中的辛伐他汀和辛伐他汀酸

目的 采用LC-MS/MS法同时测定人血浆中的辛伐他汀和辛伐他汀酸.方法 采用BEH C18色谱柱(50 mm ×2.1mm,1.7 μm),流动相为乙腈-0.01 mol·L-1醋酸铵(72∶28),流速0.15 mL·min-1,柱温40℃,进样量8μL.辛伐他汀、辛伐他汀酸及内标洛伐他汀的检测离子对分别为:m/z 419.43→199.12、437.38→303.26、405.45→199.14.结果 辛伐他汀、辛伐他汀酸的线性范围分别为0.241 ～61.76 ng·mL-1(r =0.999)、0.344 ～ 88.16 ng·mL-1(r =0.997).在人血浆基质中,高、中、低浓度(0.482、3.86、30.88 ng· mL-1)的日内、日间RSD均小于15％,方法回收率分别为95％～104％、97％ ～108％.样品预处理方法对血浆中的辛伐他汀和辛伐他汀酸测定无干扰.结论 所用方法处理简单、灵敏、特异性高,定量准确,可为辛伐他汀制剂的药动学研究提供方法.     

LC-MS/MS法测定人血浆中的氨氯地平

目的 采用LC-MS/MS测定人血浆中的氨氯地平.方法 血浆样品经氢氧化钠碱化,乙酸乙酯萃取后进行分析.使用Gmini C18 110A(50 mm×3 mm,5 μm)色谱柱,流动相为甲醇-水-甲酸(55:45:0.025),流速0.2 ml·min-1,通过电喷雾离子化四极串联质谱,以多反应离子方式检测.氨氯地平m/z 409.4→237.9和莫沙比利m/z 422.1→198.0.结果 线性范围为0.0313～20 ng·ml-1,最低定量限为0.0313 ng·ml-1,萃取回收率为74.4%～83.1%,方法回收率为96.1%～108.7%,日内和日间RSD均<8%.结论 所用方法快速、简便、灵敏度高,适用于人血浆中药物浓度的测定及药物动力学和生物利用度的研究.     

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.