气相色谱法测定人血浆中卵磷脂络合碘的浓度

目的建立一种人血浆中卵磷脂络合碘浓度测定方法。方法采用衍生气相色谱法,在酸性环境下将其衍生成碘丁酮,环己烷萃取后1μL进样分析。采用毛细管色谱柱OV-1701(50m×0.53mm),电子捕获检测器。气化室温度:230℃,柱温:105℃;检测器温度:260℃,高纯氮气10mL·min-1。结果血浆中药物浓度在0.04～0.4μg·mL-1内线性关系良好(r=0.9954),最低检测限为0.02μg·mL-1,平均回收率82.55%,RSD为2.864%。结论该方法结果准确,可靠,使用于测定人血浆中卵磷脂络合碘浓度。     

LC-MS法测定人血浆中尼索地平的浓度及其药代动力学研究

目的:建立LC-MS测定人血浆中尼索地平浓度的方法,测定志愿者口服尼索地平胶囊后的血药浓度,并对试验制剂与参比制剂的生物等效性进行评价。方法:血浆中加入内标尼莫地平,碱化后经乙酸乙酯提取,进行LC-MS测定。色谱柱为Agilent ODS C18(5μm,250 mm×4.6 mm),流动相为甲醇-水(80:20),流速为1.0 mL·min-1;ESI选择性正离子检测。临床实验方案采用双交差实验设计。结果:尼索地平血浆线性范围为0.5-20 ng·mL-1,检测限为0.2 ng·mL-1,定量限为0.5ng·mL-1,方法回收率大于85％。测定了20名志愿者单剂量交叉口服试验制剂与参比制剂后的血药浓度经时过程,二者的主要药代动力学参数无显著性差异,试验制剂的相对生物利用度为(100.7±15.9)％。结论:本方法专属性强,灵敏度高,准确性好。试验制剂与参比制剂生物等效。     

间尼索地平的毛细管GC-电子捕获检测器法测定

建立了毛细管GC法测定间尼索地平的含量。以尼莫地平为内标，采用HP—1毛细管柱及Ni-63电子捕获检测器。间尼索地平在0．25～5．0μg／ml浓度范围内与其和内标的峰面积比值线性关系良好（r=0．9993）；检测限为0．52pg。     

尼索地平片在健康人体的药动学

目的 :研究 10例健康男性单剂量口服尼索地平片 2 0mg的药动学。方法 :用HPLC测定尼索地平血药浓度 ,采用 3P87药动学程序对血药浓度 时间数据进行线性拟合 ,计算药动学参数。色谱柱为C18柱 ( 2 5 0mm× 4 6mm ,10 μm) ,流动相 :甲醇 水 磷酸 ( 70∶3 0∶1,V/V) ,检测波长为 2 3 6nm。结果 :本实验建立的HPLC线性关系、回收率、日内及日间RSD均能满足药动学研究的要求 ,口服尼索地平后血药浓度 时间数据符合二室模型 ,主要的药动学参数tmax为 ( 0 9± 0 2 )h ,cmax为 ( 8 0± 3 0 )ng·mL-1,T1/ 2 为 ( 9 5± 3 4)h ,AUC0→t为 ( 60 2± 3 0 8)ng·h·mL-1。结论 :本方法可以作为尼索地平血药浓度监测的有效方法     

格拉司琼血药浓度的高效液相色谱分析

目的 :建立人血浆中格拉司琼浓度的反相高效液相色谱测定方法。方法 :液 液萃取法分离纯化血浆样品 ,采用荧光检测器 ,以甲醇 磷酸盐缓冲液 (pH 2 .2 ,0 .0 2mol·L- 1含 3 .0 %三乙胺 ) ( 6 3∶3 7)为流动相 ,色谱柱为Shim PackCLC ODS柱( 150mm× 6 .0mm) ,并阐述了血浆中格拉司琼色谱峰形变和分裂的可能机理。结果 :格拉司琼色谱峰对称、不拖尾 ,萃取回收率达 92 % ,空白血浆和代谢物不干扰测定 ,血药浓度线性范围为 0 .5～ 6 0 .0 μg·mL- 1(r =0 .9995) ,最低检测限 0 .3 μg·mL- 1,方法回收率为 98.43 %～ 10 0 .4% ,日内RSD 2 .3 %～ 3 .8% ,日间RSD 2 .9%～ 4.6 %。结论 :此法简便、准确 ,灵敏度高 ,选择性好。     

HPLC法同时测定人血浆中霉酚酸与霉酚酸葡糖苷酸的浓度

目的:建立以高效液相色谱法同时测定人血浆中霉酚酸(MPA)与霉酚酸葡糖苷酸(MPAG)浓度的方法。方法:色谱柱为LunaC18,流动相为(20mmol·L-1磷酸二氢钾+40mmol·L-1四丁基溴化铵(pH5·5))-乙腈=73:27,流速为1·6mL·min-1,MPA与MPAG采用二极管阵列检测器和荧光检测器串联检测,MPAG检测波长为250nm,MPA荧光检测波长为316nm(激发波长)、430nm(发射波长),柱温为38℃,其中血样加乙腈沉淀蛋白后进样10μL。结果:MPA、MPAG检测浓度分别在0·2～20(r=0·9993)、1～100(r=0·9999)μg·mL-1范围内与峰面积积分值呈良好线性关系,最低检测限分别为0·05、0·1μg·mL-1;平均回收率分别为95·54%、100·22%;MPA日内、日间RSD均<6%,MPAG日内、日间RSD均<4%。结论:本方法快捷、简便、灵敏,可用于测定人血浆中MPA与MPAG的浓度。     

高效液相色谱法测定间尼索地平不同对映体在血浆中的蛋白结合率

目的:建立间尼索地平不同对映体在大鼠血浆、人血浆和牛血清白蛋白中蛋白结合率的测定方法,并计算不同种属血浆蛋白的相关参数。方法:采用平衡透析法测定蛋白结合率,用高效液相色谱法测定血浆中药物总浓度及游离药物浓度。结果:R-与S-间尼索地平的血浆蛋白结合率分别为:大鼠血浆为(97.4±8.2)%、(93.0±13.4)%;人血浆为(90.8±10.5)%、(89.2±9.9)%;牛血清白蛋白为(95.3±8.7)%、(91.0±5.7)%。最低定量下限为0.01ng。结论:在体外间尼索地平不同对映体与大鼠血浆、人血浆和牛血清白蛋白结合率很高,R-间尼索地平的结合率及蛋白结合药物的表观最大能力βp均较S-间尼索地平高。随着药物血浆浓度升高,R-间尼索地平结合率下降,S-间尼索地平结合率升高,均有一定的浓度依赖性。     

高效液相色谱-质谱联用测定人体尼索地平血浆浓度及其药代动力学研究

目的 :进行高效液相色谱 质谱联用测定人血浆中尼索地平浓度的方法学及其不同制剂的药代动力学研究。方法 :采用高效液相分离系统 ,流动相为甲醇 水 醋酸 ,流速为 1ml·min-1,分流比 2 :1,固定相为HypersilC18柱。采用质谱检测系统 ,AP ESI正离子模式 ,雾化压力 0 .0 5 4Pa(40 0psi) ,保护气N210L·min-1,毛细管电压 4 0 0 0V ,离子源温度10 0℃ ,碎片电压为 2 2 0V ,离子采集方式为选择性离子检测 ,尼索地平采集质荷比为 4 11(M Na) ,尼莫地平为 4 41(M Na)。以尼莫地平为内标 ,测定尼索地平血浆浓度 ,计算其药动学参数。结果 :在 0 .2～ 5 0 μg·L-1范围内 ,尼索地平血浓度呈线性关系 ,最低检测浓度为 0 .15 μg·L-1,回收率在 72 .6 %以上 ,日内、日间的RSD均小于 9.8%。单剂量给药 ,尼索地平缓释片、缓释胶囊和普通片半衰期 (t1 2 ,h)分别为 6 .0 8± 1.4 8、7.0 6± 1.80、3.70± 0 .2 5 ;血浓度峰值 (Cmax,μg·L-1)分别为 3.4 3± 0 .5 5、3.71±0 .2 4、9.18± 3.78;达峰时间 (Tmax,h)分别为 5 .4 1±0 .72、5 .83± 0 .4 4、2 .0 2± 0 .2 3;时间曲线下面积(AUC0 -t,μg·h-1·L-1)分别为 31.11± 5 .0 0、33.6 3±7.16、32 .72± 5 .0 9;缓释片与缓释胶囊的相对生物利用度 (F)分别为 95     

人血浆中尼索地平浓度的LC-MS测定

建立了LC—MS法测定人血浆中尼索地平的浓度。血浆在碱性条件下用乙醚-正己烷(1：1)提取，以尼莫地平为内标，采用Inertsil C18色谱柱，AP—ESI质谱检测器，正离子模式，采集方式为SIM。流动相为甲醇-水-醋酸(75：25：0．1)。尼索地平在O．2～40ng／ml范围内线性关系良好，提取回收率大于80％，RSD小于10％，定量限为O．2ng／ml。     

气相色谱-质谱联用法测定间尼索地平含量

目的：建立气相色谱-质谱联用（GC—MS）技术测定间尼索地平含量的方法。方法：采用GC—MS法，选择离子模式（SIM）检测，以尼莫地平为内标，以DB-1ms（0．25mm&#215;30m，0．25μm）为毛细管柱，高纯氦气为载气，流速为0．8mL&#183;min-1，选择特征离子m／z 266．0，210．0和m／z296．0，254．0分别对间尼索地平和尼莫地平定量。结果：问尼索地平浓度在2．5～30μg&#183;mL-1范围内呈良好的线性关系（r=0．9993，n=5）；精密度、重复性好，RSD分别为1．6％和1．8％；平均回收率为99．1％（RSD=1．3％，n=9），检测限为0．10ng。结论：该法快速、准确，灵敏度高，可用于间尼索地平的质量控制。     

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.

     

In vitro studies on sterically stabilized liposomes (SL) as enzyme carriers in organophosphorus (OP) antagonism

This study describes a new approach for organophosphorous (OP) antidotal treatment by encapsulating an OP hydrolyzing enzyme, OPA anhydrolase (OPAA), within sterically stabilized liposomes. The recombinant OPAA enzyme was derived from Alteromonas strain JD6. It has broad substrate specificity to a wide range of OP compounds: DFP and the nerve agents, soman and sarin. Liposomes encapsulating OPAA (SL)* were made by mechanical dispersion method. Hydrolysis of DFP by (SL)* was measured by following an increase of fluoride ion concentration using a fluoride ion selective electrode. OPAA entrapped in the carrier liposomes rapidly hydrolyze DFP, with the rate of DFP hydrolysis directly proportional to the amount of (SL)* added to the solution. Liposomal carriers containing no enzyme did not hydrolyze DFP. The reaction was linear and the rate of hydrolysis was first order in the substrate. This enzyme carrier system serves as a biodegradable protective environment for the recombinant OP-metabolizing enzyme, OPAA, resulting in prolongation of enzymatic concentration in the body. These studies suggest that the protection of OP intoxication can be strikingly enhanced by adding OPAA encapsulated within (SL)* to pralidoxime and atropine.     

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.     

Steroidal sapogenin contents in some domestic plants

In order to find out the values of the steroid resources for the future use. the compositions and contents of steroidal sapogenins from 13 domestic plants have been investigated. As a result,Dioscorea nipponica, D. quinqueloba andSmilax china were found to have large amount of diosgenin. And pennogenin inTrillium kamtschaticum andParis verticillata, yuccagenin inAllium fistulosum, hecogenin inAgave americana and neochlorogenin inSolanum nigum were appeared to be major steroidal sapogenins.