HPLC法测定人血浆中盐酸特拉唑嗪的浓度

目的:建立以反相高效液相色谱法测定人血浆中盐酸特拉唑嗪浓度的方法。方法:血样采用二氯甲烷-乙醚(2:3)提取后测定,其中色谱柱为Diamonsil C18,流动相为0·05mol·L-1(pH4·8)磷酸二氢钾缓冲液-甲醇-乙腈(61:25:14),流速为1·0mL·min-1,荧光检测器激发波长为334nm,发射波长为385nm。结果:盐酸特拉唑嗪检测浓度在0·25～64ng·mL-1范围内线性关系良好(r=0·9995),最低检测限为0·1ng·mL-1;平均提取回收率为84·0%,平均方法回收率为100·8%;日内RSD≤3·4,日间RSD≤3·0。结论:本方法简便、准确、灵敏,可用于人血浆中盐酸特拉唑嗪的临床药动学研究和血药浓度检测。     

高效液相色谱法测定替米沙坦血药浓度

目的:建立测定人血浆中替米沙坦浓度的方法。方法:血浆样品用甲醇提取及沉淀蛋白。采用反相高效液相色谱-荧光法进行分离、测定。色谱柱采用Diamonsil~(TM)C_(18)(200mm×4．6mm,5μm),流动相为水-乙腈-三乙胺(73:27:0．1),柱温25℃,流速为1．0mL·min~(-1),荧光激发波长为305nm,发射波长为380nm。结果:线性范围为1～200ng·mL~(-1)(r=0．9999),最低检测浓度为1．0ng·mL~(-1),高、中、低3种浓度的方法回收率为97%～103%,提取回收率均大于93%。日内及日间精密度均＜7%。结论:本方法简单、快速,灵敏度和准确度较高,能满足替米沙坦临床药动学研究的需要。     

司氟沙星血药浓度测定及药动学研究

目的:建立测定血浆中司氟沙星浓度的反相高效液相色谱法,并用此方法对正常人口服司氟沙星片进行药动学研究。方法:血浆标本经乙腈沉淀蛋白后,以5％冰醋酸(pH 2.8)-甲醇-乙腈(80:10:10)为流动相,以紫外分光光度计305nm波长处检测。结果:线性范围:31.25～4 000.00ng·mL~(-1),日内RSD为2.83％～5.61％,日间RSD为2.30％～7.05％;平均回收率(98.06±3.78)％,最低检测浓度20ng·mL~(-1)。结论:此方法简便可靠,灵敏度高,可用于司氟沙星药动学研究。     

固相萃取反相高效液相色谱法检测人血浆中辛伐他汀浓度

目的:建立反相高效液相色谱法测定人血浆中辛伐他订。方法:应用OASIS因相萃取小柱提取血浆中辛伐他汀,采用反相高效液相色谱法二极管阵列检测器检测,色谱柱为Symmetry C_(18)柱(250mm×4.6mm,5μm),内标物为洛伐他汀,流动相为0.1％磷酸液(用氢氧化钠调pH4.0)-乙腈(40:60),检测波长238um,流速1.2mL·min~(-1)。结果:辛伐他汀在1.0～35.0ng·mL~(-1)范围内线性良好(r=0.9997)。低、中、高浓度加样回收率在97.3％～108.0％之间,日内、日间RSD在5.9％～8.8％之间,最低检测浓度为0.8ng·mL~(-1)。结论:本法快速、灵敏、高效,适于辛伐他汀的血药浓度检测。     

反相高效液相色谱法测定人体血浆中扑尔敏的浓度

目的:建立一种测定人体血浆中扑尔敏浓度的高效液相色谱法。方法:取人体血浆1.5 mL,加内标右美沙芬后,用三氯甲烷提取,取其有机相于60℃水浴挥干,剩余物加流动相复溶,并用乙酸乙酯洗涤,取水相20μL进样。流动相为0.025mol·L~(-1)磷酸二氢铵(用磷酸调pH为3.5)-乙腈(70:30),色谱柱为Diamonsil ODS C_(18)柱(5μm,4.6mm×150mm),检测波长为200 nm,流速为1.0mL·min~(-1),柱温为室温。结果:本方法线性范围为0.5～16ng·mL~(-1),,r=0.998 7,最低检测限为0.25ng·mL~(-1),方法回收率为96.6％～108.0％,日内RSD为4.1％～5.9％,日间RSD为4.6％～5.9％。结论:本方法灵敏度高,特异性强,重现性好,可用于人体血浆中扑尔敏浓度的测定。     

HPLC法测定人血浆中咪达唑仑的浓度

目的:建立以高效液相色谱法测定人血浆中咪达唑仑浓度的方法。方法:以安定为内标,色谱柱为Agilent Eclipse XDB C18,流动相为0.02mol·L-1NaH2PO4水溶液(pH7.6,内含0.02%三乙胺)-乙腈(52∶48),流速为1.0mL.min-1,检测波长为223nm,灵敏度为0.001AUFS,进样量为50μL,柱温为40℃。结果:咪达唑仑血浆浓度在10~1 600ng·mL-1范围内线性关系良好(r=0.999 1),最低检测限为1ng·mL-1;日内、日间RSD≤7.25%。结论:本方法简便、灵敏、准确、快速,检测范围广,可用于咪达唑仑的血药浓度监测及临床药动学研究。     

RP-HPLC法测定人血浆中血管紧张素Ⅱ的浓度

目的:建立以反相高效液相色谱(RP-HPLC)-荧光法检测人血浆中血管紧张素Ⅱ浓度的方法。方法:采用固相萃取法纯化血浆样本,以荧光胺柱前衍生后进样测定。以乙腈-10mmol·L-1三羟甲基氨基甲烷盐缓冲液(pH8.5)作为流动相,梯度洗脱,流速为1mL·min-1,色谱柱为LunaC5,激发波长为273nm,发射波长为476nm。结果:血管紧张素Ⅱ血药浓度在10～200ng·mL-1范围内线性关系良好(r=0.9995),最低检出限(S/N=3)为5ng·mL-1,日内、日间RSD分别为1.65%和4.20%。结论:本方法快速、灵敏、准确、重复性好,可用于血浆中血管紧张素Ⅱ浓度的检测。     

高效液相色谱法测定人血浆中阿立哌唑浓度

目的:建立以高效液相色谱法测定人血浆中阿立哌唑浓度的方法。方法:血浆样品经液-液提取后,采用高效液相色谱法检测。色谱柱为C18,流动相为0．03mol·L-1醋酸铵-乙腈(34:66),流速为0．8mL·min-1,柱温为40℃,检测波长为257nm,灵敏度为0．01 AUFS。结果:阿立哌唑检测浓度线性范围为5．0～600．0ng·mL-1(r=0．999 5),提取回收率均大于90％。结论:该方法灵敏、准确、快速,适用于人血浆中阿立哌唑浓度的检测。     

2种盐酸阿呋唑嗪制剂的生物等效性研究

目的:比较盐酸阿呋唑嗪缓释片和盐酸阿呋唑嗪进口普通片的人体生物等效性。方法:20名健康男性志愿者自身交叉单剂量口服盐酸阿呋唑嗪缓释片和盐酸阿呋唑嗪进口普通片5mg,用高效液相色谱法测定人血浆中盐酸阿呋唑嗪浓度,计算药动学参数,并进行统计学分析及生物等效性评价。结果:盐酸阿呋唑嗪缓释片和盐酸阿呋唑嗪进口普通片的Cmax分别为(28·92±9·63)、(32·92±10·23)μg·L-1,tmax分别为(2·7±0·6)、(1·4±1·0)h,AUC0～∞分别为(221·14±59·46)、(245·68±67·20)μg·h·L-1,t1/2分别为(6·68±0·85)、(4·73±1·22)h,AUC0～24分别为(215·20±49·63)、(226·30±53·60)μg·h·L-1。盐酸阿呋唑嗪缓释片的相对生物利用度为(92·2±13·2)%。结论:2种制剂具有生物等效性。     

HPLC法测定沙纳唑的含量及其有关物质

目的:建立高效液相色谱法测定沙纳唑的含量及其有关物质。方法:采用 Kromasil KR 100 C_(18)色谱柱(4.6 mm×250mm,5μm)。流动相:甲醇-水-冰醋酸(200:800:3),流速:1 mL·min~(-1)。检测波长:248 nm。结果:HPLC法测定的线性范围为50～300μg·mL~(-1),r=0.9999,最低检测限为0.5 ng,本方法重复性和精密度良好(RSD<2％)。结论:采用HPLC法测定沙纳唑及其注射液的含量及有关物质,方法简便,结果准确。     

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.