替加色罗大鼠体内药代动力学研究

目的 建立大鼠血浆中替加色罗的HPLC测定法,以测定大鼠ig替加色罗后的血药浓度,并对其药代动力学进行评价。方法 血浆样品加入内标后用乙酸乙酯提取,进行HPLC分析,流动相为甲醇-乙腈-水(60∶8∶32,含0.8%冰醋酸,0.4%三乙胺,v/v),流速为1.0ml/min,检测波长为310nm。大鼠ig5.0、10.0、20.0mg·kg^-1替加色罗后,测定其血浆中替加色罗的浓度,计算主要药动学参数。结果 血浆中替加色罗在2.00ng/ml～80.00ng/ml浓度范围内线性关系良好,血浆中替加色罗的最低检测限为1.0ng/ml。大鼠ig5.0、10.0、20.0mg·kg^-1替加色罗后,估算的末端相半衰期分别为0.86、1.09、1.08h,3种剂量的半衰期相近,AUC与剂量间呈良好的线性关系(r=0.9996)。结论 本实验建立的分析方法灵敏、准确、简便。在5.0～20.0mg·kg^-1剂量范围内,替加色罗在大鼠体内符合线性药物动力学特征,平均半衰期为1.01h。     

替加色罗大鼠血浆蛋白的结合率测定

目的测定大鼠血浆蛋白结合率。方法血浆样品加入内标后用乙酸乙酯提取,进行HPLC分析。采用平衡透析法测定大鼠血浆中替加色罗的血浆蛋白结合率。结果替加色罗浓度在42.51~235.73 ng.ml-1范围内,药物血浆蛋白结合呈线性关系,替加色罗与大鼠血浆蛋白结合率为92.4%。结论替加色罗与大鼠血浆蛋白结合率较高。     

替加色罗大鼠血浆蛋白的结合率测定

目的 测定大鼠血浆蛋白结合率。方法 血浆样品加入内标后用乙酸乙酯提取,进行HPLC分析。采用平衡透析法测定大鼠血浆中替加色罗的血浆蛋白结合率。结果 替加色罗浓度在42.51～235.73 ng·ml^-1范围内,药物血浆蛋白结合呈线性关系,替加色罗与大鼠血浆蛋白结合率为92.4%。结论 替加色罗与大鼠血浆蛋白结合率较高。     

大鼠血浆中环丙沙星的HPLC荧光分析检测法及其体内药物动力学研究

建立测定大鼠血浆中环丙沙星的RP HPLC荧光检测法和研究其体内的药物动力学。以格帕沙星为内标 ,血浆样品经乙腈沉淀蛋白 ,取上清夜进行HPLC检测。流动相为 0 0 5mol/L磷酸盐缓冲液( pH3 0 )—乙腈—甲醇 ( 77∶13∶10 ,v/v/v) ,荧光检测 ,λEX=2 76nm ,λEM=448nm。血浆样品在 0 0 0 2 5～ 0 5μg/ml范围内线性关系良好 ,平均提取回收率为 97 1% ,日间和日内精密度RSD均小于 8 0 % ,最低检测限达到 1 0ng/ml。环丙沙星在大鼠体内的过程符合双隔室开放型一级吸收动力学模型、药动学参数分别为 :T1/2(ka) =0 44h ,T1/2 (α) =0 92h ,T1/2 ( β) =5 6 6h ,Tmax=1 0 4h ,Cmax=0 35 μg/ml,AUC =1 86h·μg/ml。     

高效液相色谱法及紫外分光光度法测定替加色罗片的含量

目的 :建立替加色罗片剂含量测定的HPLC法和UV法。方法 :HPLC法———采用C18柱 ,流动相为乙腈∶1%十二烷基硫酸钠缓冲溶液 (含0 .95 %冰醋酸 ) =5 6∶4 4。流速 :2mL·min- 1。检测波长 :314nm。柱温 :4 0℃。UV法———在 314nm处测定替加色罗的吸收度。结果 :HPLC法在 0 .1～ 12 0mg·L- 1的范围内 ,将峰面积A与浓度C进行回归处理 ,A =2 8.93C - 14 .4 6 (r =0 .9999,n =6 ) ,日内RSD≤ 1.11% ,日间RSD≤ 3.0 9% ,回收率在 10 0 .4 2 %～ 10 3.82 %之间。UV法在 2～ 2 0mg·L- 1范围内线性良好 ,回归方程为A =5 4.2 8C +0 .0 14 8(r =0 .9998,n =7) ,日内RSD≤ 0 .70 % ,日间RSD≤ 0 .92 % ,回收率在 10 1.0 6 %～ 10 3.0 2 %之间。 2种方法测得 3批样品的标示量百分含量均在规定范围内 (90 %～ 110 % )。结论 :HPLC法和UV法均适用于替加色罗片剂的含量测定 ,由于UV法更简便易行 ,在对有关物质进行了较好控制的情况下 ,此法更为适用     

吡喃霉素在乳腺癌患者体内的药代动力学

目的 :建立HPLC分离和检测人血浆中吡喃霉素 (Pir)的分析方法 ,并研究Pir在乳腺癌患者体内的药代动力学。方法 :以正定霉素为内标 ,1ml血浆加0 1ml(0 4mol/L ,pH=9 0)的氯化铵缓冲液碱化后以氯仿 -甲醇 (2∶1 ,v/v)混合溶剂提取2次。在Phe nomenex(C18)柱上 ,以0 04mol/L磷酸二氢钾 (pH=3 0)∶乙腈=68∶32为流动相 ,荧光检测波长480nm/550nm(Ex/Em )。结果 :血浆中Pir的线性范围5～1000ng/ml(r=0 9997) ,方法回收率为95 3 % ,日内及日间变异性RSD均小于5 % ;Pir在人体的药代动力学特征为开放性二室模型 ,消除相半衰期T1/2β、清除率CLs、表观分布容积Vd及曲线下面积AUC分别依次为 (12 8±5 9)h、(128 3±52 6)L/(m2·h)、(1754 3±478 2)L/m2 和 (428 7±137 2)ng/(h·ml)。结论 :本方法适用于临床Pir的血药浓度监测和药代动力学研究。     

大黄素对2型糖尿病大鼠胃动力的影响及机制研究

目的:研究大黄素对2型糖尿病大鼠胃动力的影响及其机制。方法:以小剂量链脲佐菌素(STZ,30mg·kg-1)加长期高脂高糖饲料喂养复制大鼠2型糖尿病模型。复制成功后分别用大黄素、替加色罗、多潘立酮进行药物干预治疗6周,并设立正常对照组与模型组进行同期比较。实验结束时用单光子发射计算机断层扫描技术(SPECT)测定胃半排空时间(GET1/2)与90min胃内核素残留率(RIH);常规检测空腹血糖、血清胰岛素、三酰甘油(TG)、总胆固醇(TC)、高密度脂蛋白-胆固醇(HDL-C);并用放免法检测血浆和胃肠组织P物质(SP)、生长抑素(SS)的含量。结果:模型组大鼠的胃排空较正常对照组显著减慢(P<0·01),而大黄素、替加色罗及多潘立酮组大鼠的胃排空较模型组显著加快(P<0·01或P<0·05)。大黄素、替加色罗及多潘立酮组大鼠的血浆和胃肠组织SP较模型组显著升高,而SS显著降低(P<0·01或P<0·05)。模型、替加色罗及多潘立酮组大鼠血清TG和TC较正常对照组显著升高,而HDL-C显著降低(P<0·01),但大黄素组大鼠TG、TC和HDL-C可以得到纠正(P<0·01)。结论:大黄素可能通过纠正部分胃肠激素的异常表达提高2型糖尿病大鼠的胃动力。     

LC-MS/MS法测定人血浆中替加色罗的浓度及其

目的:建立灵敏、快速的LC-MS/MS法测定人血浆中替加色罗,并用于制剂生物等效性研究。方法:血浆样品经有机溶剂提取后,以乙腈-5 mmol.L-1乙酸铵-甲酸(70∶30∶0.01)为流动相,采用Zorbax XDB-C18柱(150 mm×4.6 mm,5μm)分离,通过电喷雾离子化四极杆串联质谱,以多反应监测(MRM)方式进行检测。用于定量分析的离子反应分别为m/z302→173(替加色罗)和m/z256→167(内标苯海拉明)。结果:替加色罗测定方法的线性范围为0.010~10 ng.mL-1,定量下限为0.010 ng.mL-1,日内、日间精密度(RSD)均<7.3%,准确度(RE)在±1.4%之内。应用此法研究比较了22例健康受试者单剂量口服替加色罗参比制剂和受试制剂6 mg后的主要药动学参数,受试制剂和参比制剂Tmax分别为(0.86±0.22)和(1.01±0.24)h,Cmax分别为(2.21±0.69)和(2.05±0.64)ng.mL-1,t1/2α分别为(1.18±0.44)和(1.24±0.56)h,t1/2β分别为(10.10±3.07)和(8.81±2.35)h,AUC0~36 h分别为(6.35±2.48)和(6.47±1.99)ng.h.mL-1,AUC0~∞分别为(6.69±2.59)和(6.70±2.03)ng.h.mL-1。马来酸替加色罗分散片的相对生物利用度平均为(98.2±22.1)%。结论:该法灵敏、快速、准确,适用于替加色罗制剂的人体生物等效性评价。     

盐酸替利定的依赖性评价

目的:评价阿片类镇痛药盐酸替利定的身体依赖性和精神依赖性潜力。方法:采用小鼠、大鼠催促戒断试验、大鼠自然戒断试验、大鼠条件性位置偏爱试验和大鼠药物辨别试验对盐酸替利定进行评价,并与吗啡进行比较。结果:在小鼠、大鼠催促戒断试验中,ig替利定后有不同程度的催促戒断反应。长期给予大剂量的替利定(30d),大鼠体重明显下降(P<0·01)。在大鼠条件性位置偏爱试验中,替利定表现有明显的强化效应。在大鼠药物辨别试验中,吗啡和替利定(ig)可分别替代2·5mg·kg-1吗啡(sc)的辨别效应,其完全替代的ED50值为8·4mg·kg-1和5·6mg·kg-1。结论:盐酸替利定具有产生身体依赖性和精神依赖性的潜力,但其产生身体依赖性的潜力比等剂量的吗啡小。     

高效液相色谱法测定马来酸替加色罗片剂的含量、有关物质及对其稳定性的初步研究

目的:建立一种测定马来酸替加色罗片剂的含量及有关物质的HPLC方法,并对马来酸替加色罗片剂的稳定性进行初步研究。方法:使用Agilent 1100型高效液相色谱仪,色谱柱为Diamonsil(钻石)C18 150 mm×4.6mm(5μm),流动相为乙腈-1％十二烷基硫酸钠缓冲溶液(含0.95％冰醋酸)(56:44),检测波长为314 nm,流速:1 mL·min-1(有关物质考察),或2 mL·min-1(含量测定),柱温:40℃。结果:本法测定马来酸替加色罗在0.0001-0.12 mg·mL-1的范围内线性良好,线性方程为A=28.93C-14.46(r=0.9999,n=6);日内精密度RSD<1.1％;日间精密度RSD<3.1％;高、中、低浓度的平均加样回收率在100.4％-103.8％之间;定量限为4.08 ng(S／N=10)。结论:本方法检测马来酸替加色罗及其有关物质,专属性强,灵敏度高,重现性好。稳定性研究结果表明,马来酸替加色罗片剂应被储存于干燥、阴凉的环境中。     

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.