氧氟沙星和环丙沙星在老年人中的药物动力学

对氧氟沙星和环丙沙星在老年和年轻健康志愿者中的药物动力学进行同期比较研究。上述两药全部血、尿浓度均以高效液相色谱法测定。老年组单剂口服氧氟沙星３００ｍｇ后的平均血清Ｔ＿（１／２β）为７．０８±０．８１ｈ，Ｃｌ＿ｒ为９５．９±２１．０ｍｌ／ｍｉｎ，ＡＵＣ为３２．６±４．１ｈ·ｍｇ／Ｌ，与年轻组相比，血清Ｔ＿（１／２β）延长，Ｃｌ＿ｒ降低以及ＡＵＣ增大。老年组与年轻组的Ｃ＿（ｍａｘ）则相近，分别为４．６７±０．９８和４．７２±０．５１ｍｇ／Ｌ。老年组每１２ｈ口服氧氟沙星３００ｍｇ连续７天后的Ｃ＿（ｍａｘ）和ＡＵＣ较单剂者明显增高。老年组和年轻组单剂口服环丙沙星５００ｍｇ后的Ｔ＿（１／２ｋｅｌ）分别为３．３２±０．４３和２．７６±０．４３ｈ，Ｃｌ＿ｒ分别为２３１．４±６８．８和２５６．９±６４．０ｍｌ／ｍｉｎ，ＡＵＣ分别为１７．７±４．９和１５．９±３．５ｈ·ｍｇ／Ｌ。根据本研究结果，对上述两药在治疗老年人感染时给药方案的调整提出了建议。     

慢性肾功能衰竭患者环丙沙星药物动力学研究

对８例健康志愿者，１１例慢性肾功能衰竭患者（Ｃｃｒ＜１０ｍｌ／ｍｉｎ）静脉恒速滴注乳酸环丙沙星２００ｍｇ（３０ｍｉｎ）注射液后的临床药物动力学进行了研究，用高效液相色谱法对血清中环丙沙星进行测定，主要药动学参数分别是滴注完时浓度Ｃｏ健康人组为２．２６ｍｇ／Ｌ，未透析组为２．５２ｍｇ／Ｌ，血透组为２．３７ｍｇ／Ｌ，腹透组为２．３５ｍｇ／Ｌ。清除相半衰期健康人为２．７±０．８ｈ，未透析组为１５±４ｈ，血透组为５．０±１．９ｈ，腹透组为６．３±２．７ｈ。表明慢性肾功能衰竭患者的环丙沙星药物动力学过程较健康者有明显的改变，根据以上数据提出慢性肾功能衰竭时的一些给药方案     

国产司帕沙星在人体内的药物动力学研究

研究了８名健康志愿者口服单剂国产司帕沙星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佳。峰浓度（Ｃｍａｘ为１４９±０．２８ｍｇ／Ｌ,达峰时间（Ｔｍａｘ）为７．１２±１．１７ｈ,消除半衰期（Ｔ１／２β）为２２±６．８３ｈ,系统清除率（Ｃｌｍ）为８．８５±２．１６Ｌ／ｈ,表观分布容积（Ｖｄ）为２．７３Ｌ／ｋｇ,血药－时曲线下面积（ＡＵＣ）为４７．３５±１０．２４（ｍｇｈ）／Ｌ,滞后时间（Ｔｌａｇ）为０．８９±０．８８ｈ。服药后２４、９６ｈ尿药排泄率仅为９．１６％和１５．６８％。     

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。     

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。     

氟罗沙星临床药物动力学研究

氟罗沙星在健康志愿者中进行药物动力学研究。全部血、尿药物浓度以高效液相色谱法和微生物法测定。８名志愿者分别单次空腹口服氟罗沙星片剂和胶囊剂４００ｍｇ后的体内过程符合二室模型，Ｃｍａｘ分别为６．５２±１．２０和６．７４±２．３１ｍｇ／Ｌ，并分别于给药后０．９１±０．４３和１．２０±０．６７ｈ到达；其消除半衰期分别为１１．０７±１．７３和１０．８１±２．００ｈ；ＡＵＣ分别为８２．１７±１７．７９和８９．０８±１８．８９ｈｍｇ／Ｌ；给药量的６８．９５％±６．２９％和７７．２３％±６．７６％分别于给药后７２ｈ内自尿中排出。给药后２４ｈ内平均尿药浓度均超过１４０ｍｇ／Ｌ。健康志愿者单次空腹口服国产氟罗沙星片剂和胶囊剂４００ｍｇ后的药动学参数与进口片剂者相仿，平均相对生物利用度相近。根据研究结果，对氟罗沙星的给药方案提出了建议     

高效液相色谱法测定静注吡洛地尔兔血药浓度及药物动力学参数

本文应用反相高效液相色谱法测定兔静注吡洛地尔（１５ｍｇ／ｋｇ）血药浓度，样品用正庚烷提取。流动相以１０％三乙胺：甲醇液（甲醇：水＝９：１）＝５：９５。紫外检测波长为２５４ｎｍ，回收率８１．４％，日内和日间的ＲＳＤ值为２．４％、３．５％。最低检测血浓为２０ｎｇ／ｍｌ。用３Ｐ８７程序拟合为二室模型。α＝３．０８ｈ－１，β＝０．１８ｈ－１，Ｔ１／２＝４．０７ｈ，Ｋ１０＝０．９１ｈ－１，Ｋ１０＝０．６１ｈ－１，Ｖｃ＝１１．４５ＡＬ／ｋｇ，ＣＬ＝６．７３Ｌ／（ｋｇ·ｈ），ＡＵＣ＝２．２１（μｇ·ｈ）／Ｌ。     

罗红霉素胶囊剂的临床药物动力学及相对生物利用度

目的：进行国产与进口罗红霉素的生物利用度研究。方法：通过交叉试验对８名男性志愿者（２２．６ａ±ｓ２．１ａ）交叉口服罗红霉素３００ｍｇ国产胶囊剂和进口片剂,进行单剂量药物动力学研究。血药浓度采用微生物法进行测定。结果：口服国产胶囊和进口片剂的血药浓度＿时间曲线均符合二室模型,Ｃｍａｘ分别为９．５ｍｇ／Ｌ±１．３ｍｇ／Ｌ与９．０ｍｇ／Ｌ±１．０ｍｇ／Ｌ,Ｔｍａｘ为１．１４ｈ±０．１８ｈ与１．３１ｈ±０．２１ｈ,Ｔ１２β为１３．１ｈ±２．４ｈ与１３．６ｈ±２．２ｈ,ＡＵＣ为１０７ｍｇ·ｈ／Ｌ±２３ｍｇ·ｈ／Ｌ与１０８ｍｇ·ｈ／Ｌ±１４ｍｇ·ｈ／Ｌ。比较２种制剂的药物动力学参数,其差别均无显著意义（Ｐ＞０．０５）。与进口罗红霉素片相比较,国产罗红霉素胶囊剂的相对生物利用度为（９８±１３）％。口服该药４８ｈ尿药回收率为给药量的（１５±５）％。结论：国产罗红霉素胶囊体内过程与进口罗红霉素片剂相仿,２种制剂生物等效。     

甲磺酸左氧氟沙星的药代动力学研究

用微生物法测定了ＭＳＡＬＶＬＸ在狗体内的药代动力学过程符合二室模型。４、８和１６ｍｇ／ｋｇ口服给药的Ｃｍａｘ分别为１．７３、２．８９和８．２８ｍｇ／Ｌ,ＡＵＣ值分别为１５．４３、３１．９５和７０．２ｍｇｈ／Ｌ,ＭＲＴ分别为６．９６、７．５８和６６２８ｈ。大鼠口服２０ｍｇ／ｋｇ的Ｃｍａｘ为２．８６ｍｇ／Ｌ,ｔ１／２β为２．２ｈ,ＡＵＣ为７．４ｍｇｈ／Ｌ,ＭＲＴ为３ｈ。大鼠口服后７２ｈ的尿中排泄率为４２％,而７２ｈ胆汁排泄率为３８．２％。     

Azithromycin临床药物动力学研究

对１０名健康志愿者口服ａｚｉｔｈｒｏｍｙｃｉｎ的药物动力学研究以及其干糖粉的相对生物利用度测定结果显示：空腹口服ａｚｉｔｈｒｏｍｙｃｉｎ单剂５００ｍｇ后，其体内过程符合二室模型，其消除半衰期为５０．３９±８．８７ｈ；高峰血浓度为０．４０３±０．２９９ｍｇ／Ｌ；达峰时间为２．６４±１．２６ｈ，ＡＵＣ为６．３９±１．８１ｈｍｇ／Ｌ。１４４ｈ累积尿排出率为１１．５２％±２．７０％。干糖粉与胶囊比较的相对生物利用度为１１０．６％。根据其药物动力学参数和抗微生物活性，给予针对不同感染的治疗方案     

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.