健康志愿者口服左氟沙星的体内药物动力学研究

８名健康志愿者单次及多次口服２００ｍｇ左氟沙星的药物动力学，血及尿药浓度均采用ＨＰＬＣ测定，数据用３Ｐ８７及ＳＳＤ程序处理，药—时曲线符合二室模型。单次口服２００ｍｇ，平均达峰时间为１．１８ｈ，峰浓度为２．８７ｍｇ／Ｌ，消除半衰期为６．１１ｈ，药—曲线下面积为１９．４９ｈμｇ／ｍｌ，０～２４ｈ尿药回收率为６９．２８％。在每日２００ｍｇｑ８ｈ连续８天的多次口服给药实验中，第１天与第８天的药物动力学参数经ｔ检验无显著性差异（Ｐ＞０．０５），说明本品每天６００ｍｇ的重复给药无明显蓄积性     

硫酸奈替米星在肾功能受损时的药物动力学

目的：测定不同肾功能患者体内单剂量静脉滴注５ｍｇ·ｋｇ－１硫酸奈替米星（ＮＴＭ）后的血清药物浓度，并计算药物动力学参数；同时测定了尿药浓度及原形药物回收率。方法：采用高效液相色谱－间接光度检测（ＨＰＬＣ－ＩＰＤ）法，以烟酰胺为检测剂，庚烷磺酸钠为反离子。结果：ＮＴＭ在肾功能正常组和受损组的Ｔ１／２β分别为３．５±１．４ｈ和５．８±１．４ｈ，ＡＵＣ０～２４ｈ６３．４±３２．１ｍｇ·ｈ·Ｌ－１和８９．５±３５．９ｍｇ·ｈ·Ｌ－１，２４ｈ尿中回收率也有明显差异。结论：表明肾功能受损患者每２４ｈ给药一次体内仍有蓄积     

头孢克肟在正常人中的药物代谢动力学研究

本文报道头孢克肟在正常人中的药物代谢动力学和测定头孢克肟血浓度的高效液相色谱（ＨＰＬＣ）方法学。８位健康志愿者交叉单次空腹及进食后口胺头孢克厉２００ｍｇ后平均Ｃｍａｘ分别为２．７±０．９和１．７±０．４ｍｇ／Ｌ，平均Ｔ１／２Ｋｅ为３．７±０．４和３．３±０．７ｈ，平均ＡＵＣ为２５．４±８．５和１３．９±４．０ｈ／ｍｇ／Ｌ。２４ｈ内分别排出给药量的２３．７±７．６％和１３，６±４．５％。服药后１２ｈ的平均血药浓度分别为０．８３ｔ０．２６和０．４５±０．１８ｍｇ／Ｌ。经统计学处理（配对Ｔ检验），空腹与进食后口服头孢克肟后的Ｃｍａｘ、ＡＵＣ和２４ｈ内尿排出卒间的差异具极显著意义（Ｐ＜０．０１）。本文建立的高效液相色谱法准确性高、具重复性。以ＨＰＬＣ法测得血药浓度与微生物法测得者相符。     

头孢唑林临床药物动力学研究及其血药浓度高效液相色谱测定法

本文报告头孢唑林正常人药物动力学研究结果及其体液浓度高效液相色谱测定法的建立。结果表明，头孢唑林１ｇ静滴和肌注后的平均高峰血药浓度分别达１５９．８±１７．ｌｍｇ／Ｌ和７４．１±１４．２ｍｇ／Ｌ，８ｈ时仍可分别测得５．６±３．５ｍｇ／Ｌ和１０．０±４．２ｍｇ／Ｌ。静滴和肌注后的消除半衰期分别为１．９４±０．２６和２．１１±０．５９ｈ。头孢唑林肌注后吸收完全，绝对生物利用度为９２．０±５．６％。静滴和肌注头孢唑林１ｇ后尿药平均峰浓度分别为４１９０±２２９４ｍｇ／Ｌ和２３２０±１７００ｍｇ／Ｌ２４ｈ累积排出率分别为８６．３±４．２％和８７．５±９．６％。以ＨＰＬＣ法测定头孢唑林血药浓度方法准确，其重复性、特异性高，且方法简单易行，适用于特殊生理或病理情况下头孢唑林血药浓度监测。     

国产氟罗沙星健康志愿者药物动力学研究

研究了７名健康志愿者口服单剂国产氟罗沙星４００ｍｇ后的药物动力学特征。用高效液相色谱法（ＨＰＬＣ）测定血清和尿中药物浓度。该药在体内转运过程以二室模型拟合为优，其显著特点是消除半衰期长（１１．２７ｈ）、血药峰浓度高（４．５９μｇ／ｍｌ）、表观分布容积大（０．８７Ｌ／ｋｇ）、血药时曲线下面积和系统清除率分别为６７．７８μｇｈ／ｍｌ和１０２．１ｍｌ／ｍｉｎ。尿药浓度在服药后２～４ｈ达到高峰为２９８±１１５μｇ／ｍｌ，４８～６０ｈ仍可达１４．３±８．４μｇ／ｍｌ。服药后２４、６０ｈ，尿药排泄率分别为５２．６％和６７．６％。结果表明：口服单剂国产氟罗沙星４００ｍｇ后血和尿中可迅速达到有效抗菌浓度且维持时间长     

头孢拉定对奈替米星药代动力学的影响

目的 观察头孢拉定对奈替米星药代动力学的影响。方法１４例感染患者随机分成单用奈替米星组（ＮＴＭ）和奈替米星＋头孢拉定组（ＮＴＭ＋ＣＰＲ）。采用高效液相色谱一间接光度检测（ＨＰＬＣ－ＩＰＤ）法，测定患者单剂量静脉滴注 ５ ｍｇ ＮＴＭ后的血清药物浓度，并计算主要药动学参数；同时测定尿液药物浓度及药物回收率。结果ＮＴＭ组和ＮＴＭ＋ＣＰＲ组的Ｔ１／１／２β分别为２．４０±１．０１ｈ和 ４．３３± １．４３ｈ（Ｐ＜ ０．０１），ＡＵＣ０～２４ｈ６３．４２± ３０．００ｍｇ／Ｌ·ｈ和 ７８．５４± ３２．８８ｍｇ／Ｌ·ｈ（ｐ＜ ０．０ １），２４ｈ尿中 ＮＴＭ Ｗ收率也有显著性差异。结论 ＮＴＭ＋ＣＰＲ联用时 ＮＴＭ生物利用度增高，尿中回收率下降，连续长期联用将导致体内蓄积。     

氟康唑的药物动力学和生物利用度的研究

采用高效液相色谱柱切换法，研究了单剂口服国产氟康唑胶囊剂２００、１５０ｍｇ与进口氟康唑１５０ｍｇ胶囊剂的志愿受试者体内药物动力学过程。结果表明：单剂口服不同剂量的两种胶囊血药浓度－时间曲线符合二至模型。国产氟康唑胶囊２００、１５０ｍｇ及进口氟康唑胶囊剂１５０ｍｇ的药物动力学参数依序如后：消除半衰期（Ｔ１／２β）分别为３４．５５±５．９７、３４．７６±２．６８及３１．０７±２．４２ｈ。达峰时间（Ｔｍａｘ）分别为１．５５±０．２８、１．６１±０．８９及１．９７±０．４４ｈ。峰浓度（Ｃｍａｘ）分别为４．６３±０．３３、３。７７±０．５３及３．９２±０．５２ｍｇ／Ｌ。曲线下面积（ＡＵＣ）分别为１９９．５４±２３．５２、１６８．２４±１３．８２及１６４．３１±１４。９１ｍｇ·ｈ／Ｌ。Ｖ／Ｆ（ｃ）值分别为３２．９７±４．３６、３１．３２±７．６７及３０．１２±２．４６Ｌ。清除率（Ｃｌ（ｓ））分别为１．０１±０．１１、０．９０±０．０７及０．９２±０．０９Ｌ／ｈ。国产胶囊剂对美国进口胶囊剂的平均相对生物利用度为１０２．８７％。     

氧氟沙星注射液的人体药物动力学

对１０例健康志愿者静脉恒速滴注氧氟沙星２００ｍｇ（３０ｍｉｎ）注射液后的药物动力学进行了研究。用高效液相色谱法及微生物法分别对血清及尿中氧氟沙星进行测定。其体内过程符合二室开放模型，主要药动学参数分别是：滴注完时浓度Ｃ０为５．１５±１．６３ｍｇ／Ｌ，清除相半衰期为４．８６±０．１８ｈ，ＡＵＣ为１５．８９±２．８６ｈ·ｍｇ／Ｌ，中央室表现分布容积Ｖｃ为３５．０６±１１．０４Ｌ，０～２４小时内尿中排泄原药的７８．９％±１０．９％。     

环丙沙星片剂的人体生物利用度及药代动力学研究

本文报道８例健康青年志愿者交叉口服两个药厂生产的盐酸环丙沙星的人体生物利用度及药代动力学研究。用反相高效液相色谱法测定人血清中环丙沙星浓度。单剂量空腹口服两种片剂５００ｍｇ后，体内过程符合单室模型。达峰时间为１．７３９±０．６６５ｈ和１．５７９±０．５７８ｈ；峰浓度为１．４４１±０．２４９ｍｇ·Ｌ（－１）和１．３０８±０．２０２ｍｇ·Ｌ（－１）；曲线下面积为９．５３４±２．１３８ｍｇ·Ｌ（－１）·ｈ和８．９５２±２．１６３ｍｇ·Ｌ（－１）·ｈ；消除半衰期为３．３２７±０．７２５ｈ和３．７２４±１．１２８ｈ。以对照制剂为标准，样品制剂的相对生物利用度为１０６．５％，两药的主要药代动力学参数无显著性差异（ｐ＞０．０５）。     

洛美沙星的临床药物动力学研究

本文报道国产洛美沙星在正常志愿者中的药物动力学研究结果。８名正常志愿者单次空腹口服洛美沙星片剂４００ｍｇ后的体内过程符合二室模型，其吸收迅速，平均血药峰浓度为４．１３±１．２０ｍｇ／Ｌ，于给药后１．２６±１．０９ｈ到达，其消除半衰期（Ｔ１／β）为６，７８±０．８１ｈ。给药量的５９．９±７．３％和６７．０±６．６％分别于服药后２４ｈ和７２ｈ内自尿中排出，尿药峰浓度平均为３９１±１８７ｍｇ／Ｌ。正常志愿者单次空腹口服国产片剂及胶囊４００ｍｇ后的体内过程与进口胶囊相仿，主要药代参数亦相近，相对生物利用度相仿。正常志愿者单次空腹口服国产洛美沙星片剂１００～８００ｍｇ剂量后均能很好耐受。根据研究结果，对洛美沙星的给药方案提出建议。     

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.     

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.     

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.