固相萃取—HPLC法测定法莫替丁血药浓度

目的:建立法莫替丁血药浓度测定方法。方法:采用固相萃取高效液相色谱法。样品先经Waters Oasis HLB固相萃取小柱处理。色谱柱:Shim-pack C_8 150mm×4.6mm,10μm;柱温:35℃;流动相为乙腈-0.019mol·L~(-1)磷酸(10:90);流速:1mL·min~(-1);检测波长:265nm。结果:线性范围5～200μg·L~(-1),线性关系良好,最小可测定浓度为5μg·L~(-1)。回收率80％以上,日内及日间RSD小于10％。结论:采用新型固相萃取柱能快速可靠地测定法莫替丁血药浓度。     

HPLC法测定盐酸氯环利嗪乳膏的含量

目的:建立盐酸氯环利嗪乳膏含量测定方法。方法:用高效液相色谱法测定。选用Lichrosorb C18 柱,5μm,4.6mm×200mm;流动相:乙腈—0.01mol·L~(-1)磷酸二氢钠溶液—0.02mol·L~(-1)庚烷磺酸钠溶液(45:55:10);流速:1ml·min~(-1),检测波长:230nm,柱温:室温。结果:本法简便、灵敏、准确。线性范围:40～160μg·ml~(-1)。方法回收率为 100.5％,RSD=2.1％,n=9。结论:建立的定量方法专属性强,可用于盐酸氯环利嗪乳膏的质量控制。     

LC-MS法测定人血浆中氯雷他定浓度

目的:建立以液-质联用法测定人血浆中氯雷他定的方法。方法:血浆样品中加入内标地西泮,用液相萃取法处理后测定,色谱柱为AgilentTC-C18,流动相为乙腈(含1%甲酸)-0.02mol·L-1甲酸铵水溶液(90∶10),流速为0.8mL·min-1,柱温为40℃。通过电喷雾电离源(ESI),质谱在正离子多反应监测模式(MRM)下行特征母-子离子对信号采集,以m/z383.2→337.0(氯雷他定)和m/z285.1→154.0(地西泮)进行定量分析。结果:氯雷他定检测浓度在0.5~100μg·L-1范围内线性关系良好(r=0.9960),定量下限为0.5μg·L-1;提取回收率在61.15%~67.11%之间,日内、日间RSD均≤16.54%。结论:本方法简便、灵敏,适用于人体内氯雷他定血药浓度测定及临床药动学研究。     

改良高效液相色谱荧光检测法测定人血浆氢溴酸加兰他敏浓度

目的:改进高效液相色谱荧光法测定人血浆中氢溴酸加兰他敏浓度的方法,提高其灵敏度和精确度。方法:采用Hypersil-C_8色谱柱,以乙腈-水(30:70)作为流动相(pH=5.9,含三乙胺0.2％)。碱化血浆后经无水乙醚2次提取,合并2次提取的有机层,挥干乙醚后,残渣经溶有参照标准品阿替洛尔的流动相溶解后进行测定。荧光检测的激发波长为290nm,发射波长为320nm。结果:本法测定氢溴酸加兰他敏的线性范围为1～50μg·L~(-1)(r=0.999),最低检测限0.2ng,最低检测浓度为1μg·L~(-1)。日内变异系数为11.86％,日间变异系数为8.40％,萃取回收率和方法回收率均>80％。1μg·L~(-1)的回收率大于60％。结论:本方法精密、准确,适用于加兰他敏的临床检测。     

反相高效液相色谱法测定人血浆中非诺贝特活性代谢物非诺贝酸

目的:建立以高效液相色谱法测定人血浆中非诺贝特活性代谢物非诺贝酸的方法。方法:血浆样品酸化后用乙醚萃取;色谱柱为Shim-pack VP-ODS(150mm×4．6mm),柱温为40℃,流动相为甲醇-水-10％磷酸(80:19:1),流速为1．0mL·min-1,检测波长为290nm,外标法峰高定量。结果:非诺贝酸的保留时间约为5．6min,定量线性范围为0．25～18．75μg·mL-1,绝对回收率>85％(n=5),方法回收率为96％～103％(n=5),日内、日间RSD<10％(n=5)。结论:本方法简便快速、定量准确,适用于非诺贝特临床药动学研究。     

液质联用法测定犬血浆中阿普唑仑及其代谢物α-羟基阿普唑仑的浓度

目的建立测定Beagle犬血浆中阿普唑仑及其代谢物α-羟基阿普唑仑浓度的液相色谱-质谱联用(LC-MS)法。方法血浆样品采用1 mol·L~(-1)硼酸盐缓冲液(pH 9.0)碱化、乙酸乙酯-正庚烷(85:15,V:V)萃取后LC-MS测定。色谱柱:Zorbax SB-C_(18)柱(150 mm×3 mm,3.5μm);流动相:乙腈-0.01 mol·L~(-1)乙酸胺缓冲液(含1%甲酸)(45:55,V:V);流速:0.3 mL·min~(-1);柱温:40℃。采用电喷雾正离子模式离子化,用于定量分析的离子分别为m/z 309.2(阿普唑仑)、m/z 325.2(α-羟基阿普唑仑)和m/z 343.2(三唑仑,内标)。结果阿普唑仑和α-羟基阿普唑仑的线性范围分别为0.5～50μg·L~(-1)和0.5～32μg·L~(-1),两者定量下限均为0.5μg·L~(-1),提取回收率均>80%,方法回收率为97.3%～102.5%,批内RSD≤10.4%,批间RSD≤12.2%。结论本方法灵敏、准确、重现性好,适用于阿普唑仑犬体内药动学研究。     

LC-MS/MS法测定地氯雷他定的浓度及其在生物等效性研究中的应用

目的建立液相色谱-串联质谱(LC-MS/MS)法测定人血浆中地氯雷他定的浓度,并应用于2种地氯雷他定制剂的人体生物等效性研究。方法采用双周期自身随机交叉试验设计,18名男性健康志愿者分别单剂量口服地氯雷他定口腔崩解片(受试制剂)和地氯雷他定片(参比制剂)10 mg,采用LC- MS/MS法测定人血浆中地氯雷他定的浓度,利用3P97程序计算主要药动学参数,并对2种制剂进行生物等效性评价。结果受试制剂和参比制剂的t_(max)分别为(2.8±s 0.6)和(2.9±0.6)h,c_(max)分别为(4.8±2.1)和(5.0±2.2)μg·L~(-1),A UC_(0～96)分别为(59±30)和(58±26)μg·h·L~(-1),A UC_(0～∞)分别为(64±29)和(62±26)μg·h·L~(-1)。受试制剂的相对生物利用度为(103±32)%。经统计学检验,2种制剂的主要药动学参数间无显著差异。结论所建立的LC-MS/MS法适合于人体血浆中地氯雷他定的测定。地氯雷他定受试制剂和参比制剂具有生物等效性。     

固相萃取-高效液相色谱法测定人血浆中吡格列酮浓度及其药动学

目的:建立测定人血浆中吡格列酮浓度的高效液相色谱方法。方法:采用Hypersil C_(18)色谱柱,以0.1 mol·L~(-1)醋酸铵-乙腈(305:195)为流动相,罗通定为内标,流速1 mL·min~(-1),检测波长269 nm,血浆样品经固相萃取后直接进样。结果:该法线性范围为50～1600 μg·L~(-1),回归方程为A_s/A_i=0.0127+2.6242×10~(-3) C,r=0.9997(n=5),最低检测浓度为25 μg·L~(-1),提取回收率大于80％,日内日间RSD均小于10％。结论:本法简便灵敏,适用于盐酸吡格列酮血药浓度测定和人体药动学研究。     

氯酚伪麻缓释片中氯雷他定在健康志愿者体内的药动学(英文)

目的:研究健康受试者单剂量及多剂量口服氯酚伪麻缓释片后氯雷他定的药动学特征。方法:24名健康受试者随机分为Ⅰ、Ⅱ两组,每组男、女受试者各6名,Ⅰ组受试者首先单次口服氯酚伪麻缓释片1片;间隔1 wk清洗期后,该组继续进行多次给药试验,受试者连续5 d,每日2次,每次1片,d 6早晨服药1次;Ⅱ组受试者单次口服氯酚伪麻缓释片2片。用HPLC-MS法测定血浆中氯雷他定的浓度,计算药动学参数。结果:健康受试者单次口服氯酚伪麻缓释片1片、2片后,氯雷他定的药动学参数分别为:c_(max)为(1.5±s 0.7)和(3.1±1.3)μg·L~(-1),AUC为(5.7±2.7)和(11±5)μg·h·L~(-1),2组的t_(1/2)和t_(max)相近。多次给药后氯雷他定的药动学参数:AUC~(ss)为(5.9±2.4)μg·h·L~(-1),c_(max)~(ss)、c_(min)~(ss)和c_(av)~(ss)分别为(1.8±0.9)、(0.15±0.06)和(0.49±0.20)μg·L~(-1),D(F)为(3_3±0.8)%。结论:单次口服氯酚伪麻缓释片后,氯雷他定呈线性药动学特征;多次给药后氯雷他定的体内药动学特征无显著变化。     

差示分光光度法测定盐酸头孢他美酯片的含量

目的:建立盐酸头孢他美酯片的含量测定方法。方法;差示分光光度法。结果:以盐酸头孢他美酯在0.1mol·L~(-1)氢氧化钠溶液与0.1mol·L~(-1)盐酸溶液中在波长283nm处测得的差示吸收值(△A),作为定量依据,其浓度在18～45μg·ml~(-1)之间线性关系良好,γ=0.9999(n=5),平均回收率为99.9％,RSD=0.2％(n=5)。结论:本法稳定性可靠,重复性好。     

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.