HPLC 法测定盐酸雷诺嗪在不同种属血浆中的蛋白结合率

目的：研究盐酸雷诺嗪与不同种属血浆的蛋白结合情况。方法采用高效液相色谱法（ HPLC法）和平衡透析法测定管状半透膜内的血浆药物浓度及管状半透膜外的缓冲液中药物浓度,并计算蛋白结合率。结果盐酸雷诺嗪在不同种属血浆（大鼠血浆、人血浆和牛血清白蛋白）中的蛋白结合率均大于50％,分别为：大鼠血浆：（63．43±1．9）％;人血浆：（61．58±4．1）％;牛血清白蛋白：（62．16±2．9）％。且盐酸雷诺嗪在各种属血浆中最低定量下限均为0．05 mg/L。结论盐酸雷诺嗪在不同种属血浆（大鼠血浆、人血浆和牛血清白蛋白）中的蛋白结合率及蛋白结合药物的表观最大能力均较高。随着药物血浆浓度升高,盐酸雷诺嗪结合率升高,有较强的浓度依赖性。     

雷诺嗪有关物质及其含量的HPLC快速测定

目的：建立雷诺嗪有关物质及其含量的HPLC测定方法。方法：以YMC—Pack ODS—A C18（4．6mm×150．0mm,5μm）为色谱柱;流动相为0．05mol／L磷酸二氢钾缓冲溶液（含0．2％的三乙胺）-乙腈（48：52）;流速为1．0ml／min;进样量为10μl;检测波长为215nm。结果：在0．06-150．00μg／ml浓度范围内呈良好的线性关系,相关系数r=0．9999,日内精密度RSD为0．61％,日间精密度RSD为1．40％（n=6）;平均回收率为100．5％,RSD为1．3％（n=9）。结论：本文所建立的方法,简便、重现性好、准确度高,可适用于雷诺嗪及其有关物质的含量测定。     

高效液相色谱法测定人血浆中奥沙普嗪浓度

目的建立奥沙普嗪血药浓度的高效液相色谱法（HPLC法）。方法血浆样品经甲醇直接沉淀蛋白进样，分析柱为Kromasil C18 100-5柱（250mm×4．6mm，5μm），流动相为甲醇-0．166mol／L磷酸二氢钠（80：20，pH=2．22），流速为1．0mL／min，检测波长为285nm。结果奥沙普嗪的线性范围为0．25-60μg／mL（r=0．9999），方法的日内和日间RSD〈2．52％。结论该方法简单、快速、准确、灵敏、经济，适用于奥沙普嗪人体药代动力学研究。     

毛细管电色谱手性配体交换法检测生物样品中的硝基精氨酸异构体研究

目的：建立毛细管电色谱（CEC）分离检测生物样品中硝基精氨酸异构体的方法。方法：采用CEC手性配体交换模式检测血浆样品中D-硝基精氨酸（D—NNA）和L-硝基精氨酸（L—NNA），流动相为50mmol／L醋酸缓冲液[pH5．0，含2mmol／Laspartame，1mmol／L Cu^2＋和5％（v／v）甲醇]；流速为0．02mL／min；操作压为1000psi；检测波长为UV280nm。结果：L—NNA和D—NNA在0．025～0．75mmol／L的浓度范围内峰面积／浓度的相关系数均可达0．99以上，日内变异系数均小于3．0％，日间变异系数分别为3．1％和3．4％。结论：本研究方法具有快速、高分辨、检测样品量和流动相用量少等优点。     

高效液相色谱法测定人血浆中非那雄胺的浓度

目的建立测定人血浆中非那雄胺浓度的高效液相色谱（HPLC）法。方法以乙腈-10mmol／L磷酸二氢钾（40：60）为流动相，炔雌醇为内标，血浆样品经乙酸乙酯萃取。结果非那雄胺质量浓度线性范围是9．44～944μg／L，平均相对回收率为94．5％～98．9％，日内和日间RSD均小于10％，非那雄胺的最低定量限为5μg／L。结论该方法快速、准确、灵敏，可用于非那雄胺的药代动力学研究。     

高效液相色谱-质谱法测定伪麻黄碱血药浓度

目的建立高效液相色谱-质谱（HPLC-MS）法测定伪麻黄酸碱的血药浓度。方法将血浆样品采用甲醇沉淀后，以格列吡嗪为内标进行测定。色谱柱为Agitent Zorbax SB-C18柱（150mm×4．6mm，5μm），流动相为5mmol／L醋酸铵-甲醇（10：90，V／V），流速为1．0mL／min，离子检测方式设为选择性离子检测（SIM），检测离子极性为正离子，采用气动辅助电喷雾离子化（ESI）方式．检测对象为伪麻黄碱（M＋H离子，m／z148．4），内标格列吡嗪（M＋Na离子，m／z468．1）。结果线性范围为5．01～1002μg／L（r=0．9997），最低检测限为5／μg／L。方法回收率为89．6％～95.1％，日内、日间精密度RSD分别小于5.2％和7.1％。结论该方法选择性好，灵敏度高．简便易行，适用于伪麻黄碱药代动力学和生物等效性研究。     

高效液相色谱法测定盐酸二甲双胍的血药浓度

目的建立高效液相色谱法测定人血浆中盐酸二甲双胍的浓度。方法以阿替洛尔为内标，采用Lichrospher C18柱（250mm×4．6mm，5μm）为色谱柱，以3mmol／L十二烷基硫酸钠（SDS，含0．5％三乙胺，用磷酸调pH值至4．0）-乙腈（65：35）为流动相，流速为1．0mL／min，检测波长232nm。结果血浆盐酸二甲双胍质量浓度线性范围是50～3000μg／L，标准曲线方程为Y=0．3391X-0．0073（r=0．9999）。结论该方法灵敏、简便、快速、准确，适用于盐酸二甲双胍的血药浓度测定及临床药代动力学研究。     

恩曲他滨及其有关物质的胶束电动毛细管色谱法测定

建立了胶束电动毛细管色谱法测定恩曲他滨及其有关物质5-氟胞嘧啶。采用未涂层石英毛细管柱，20mmol／L硼砂缓冲液-30mmol／L十二烷基磺酸钠溶液（pH9．5）为运行缓冲液，工作电压20kV、进样电压2kV，检测波长282nm。恩曲他滨与5-氟胞嘧啶分别在31．2～1000μg／ml和15．6～1000μg／ml浓度范围内线性关系良好，检出限为8、4μg／ml，平均回收率为100．0％、99．8％，RSD为1．6％、1．5％。     

RP-HPLC法测定大鼠血浆中香柑内酯、欧前胡素和蛇床子素及其药动学研究

目的：建立测定大鼠血浆中香豆素类成分香柑内酯、欧前胡素和蛇床子素血药浓度的方法,并研究其在大鼠体内的药动学。方法：大鼠灌胃蛇床子提取物（900mg／kg）,分别于给药前及给药后0．25、0．5、0．75、1、2、3、4、6、8、12h取血,以反相高效液相色谱法测定血浆中香豆素类成分香柑内酯、欧前胡素和蛇床子素的血药浓度。色谱柱为Diamonsil C18（150mm×4．6mm,5gm）,流动相为乙腈．150mmol／L醋酸铵水溶液（50：50,V／V,醋酸调pH值至4．3）,流速为1．0ml／min,紫外检测波长为320nm,进样量为10μl。以非房室模型法（统计矩法）分析药动学参数。结果：香柑内酯、欧前胡素和蛇床子素质量浓度在0．1～5．0、0．5～25．0、2．0～100．0μg／ml范围内与各指标成分和相对应的峰面积积分值比呈良好线性关系。香柑内酯、欧前胡素、蛇床子素精密度试验的RsD≤8．8％,准确度在（91．8±2．01）％～（102．6±0．40）％之间,提取回收率在81．3％～92．8％之间,稳定性试验的RSD〈15％。香柑内酯、欧前胡素、蛇床子素的AUC0-∞分别为（5．53±1．07）、（22．67±3．65）、（39．60±4．56）μg·h／ml;t1/2分别为（3．33±0．39）、（2．27±0．55）、（2．24±0．35）h;Cmax分别为（1．18±0．22）、（7．03±1．27）、（13．16±1．37）μg／ml。结论：该方法简便、灵敏、专属性好,可用于大鼠体内香柑内酯、欧前胡素和蛇床子素的药动学研究。     

噻氯匹啶对血小板聚集功能的抑制作用研究

观察了噻氯匹啶（TP）对血小板聚集的影响，结果表明在体外可显著抑制ADP、花生四烯酸和凝血酶诱导的大鼠或人血小板聚集，其IC50分别为1．035、1.047和0．092mmol／L，在体内连到给药（TP：50－200mg／kg·d－1）7d可抑制ADP和凝血酶诱导的大鼠血小板聚单，提示TP是一个较强的血小板聚集抑制剂。     

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.