盐酸特拉唑嗪胶囊人体生物利用度及药物动力学研究

目的：对盐酸特拉唑嗪胶囊的人体内生物利用度进行研究。方法：单剂量口服盐酸特拉唑嗪胶囊和片剂２ｍｇ。血药浓度采用ＨＰＬＣ测定，数据用３Ｐ８７计算药动学参数。结果：盐酸特拉唑嗪胶囊剂的药动学参数：Ｋａ为８．２±４．０ｈ－１，Ｔ１／２为８．２±２．５ｈ，Ｔｍａｘ为０．６１±０．１１ｈ，Ｃｍａｘ为４３．５±８．５ｎｇ·ｍｌ－１，ＡＵＣ为３６７．４±３４．６ｎｇ·ｈ·ｍｌ－１；盐酸特拉唑嗪片剂的药动学参数：Ｋａ为６．４±７．４ｈ－１，Ｔ１／２为７．４±２．１ｈ，Ｔｍａｘ为０．９±０．４ｈ，Ｃｍａｘ为４３．１±４．８ｎｇ·ｍｌ－１，ＡＵＣ为３７１．３±４４．４ｎｇ·ｈ·ｍｌ－１。结论：两种剂型的药物动力学参数之间差异均无显著性（Ｐ＞０．０５），胶囊剂的相对生物利用度为９９．８８％。     

盐酸特拉唑嗪在健康人体内的药物动力学

目的：在８名健康志愿者体内研究了国产盐酸特拉唑嗪胶囊和进口片剂的药物动力学和生物利用度。方法：受试者交叉口服单剂量（２ｍｇ）盐酸特拉唑嗪胶囊和片剂后,采用高效液相色谱法和荧光检测器测定血药浓度。结果：胶囊和片剂的药时曲线均符合二室模型,其Ｔｍａｘ分别为１．３±０．６ｈ和１．３±０．４ｈ,Ｃｍａｘ分别为４９．５±８．６ｎｇ·ｍｌ－１和５０．３±５．２ｎｇ·ｍｌ－１,ＡＵＣ０→∞分别为５３６．５±３９．８ｎｇ·ｍｌ－１和５８６．６±５２．８ｎｇ·ｍｌ－１·ｈ,测试药品的相对生物利用度为９２．３０％±１２．９１％。结论：经方差分析两药药物动力学参数间差异均无显著性（Ｐ＞０．０５）;结果表明两药具有生物等效性。     

国产与进口地高辛片人体生物利用度的研究

目的：国产地高辛片长期以来存在着生物利用度差的问题,为此杭州民生药厂进行了工艺改进。方法：以英国Ｌａｎｏｘｉｎ片为对照,采用荧光偏振免疫分析法测定了８名健康男性受试者口服单剂量０．５ｍｇ地高辛片的药时数值,经ＰＫＢＰＮ１程序拟合,计算其药动学参数。结果：国产和进口的Ｃｍａｘ分别为３．０±０．６ｎｇ·ｍｌ－１和２．５±０．５ｎｇ·ｍｌ－１;Ｔｍａｘ分别为１．１±０．６ｈ和１．１±０．４ｈ;ＡＵＣ分别为３７．９±４．２ｎｇ·ｈ·ｍｌ－１和３７．２±６．１ｎｇ·ｈ·ｍｌ－１;杭州民生药厂工艺改进后的片剂相对生物利用度为１０３．８％±１７．０％。结论：国产片与进口片地高辛完全等效。这为临床应用提供参考,也为药品的国际接轨提供依据     

进口和国产索他洛尔片剂的相对生物利用度研究

目的：本文对进口和国产索他洛尔片剂在１２名男性健康志愿者中的药物动力学和相对生物利用度进行了研究。方法：建立了一个检测血清中索他洛尔浓度的反相高效液相色谱－荧光检测法。结果：单剂量口服索他洛尔１６０ｍｇ后的血药浓度数据用３Ｐ８７药物动力学程序进行模型拟合，国产片剂ＡＵＣ、Ｃｍａｘ、Ｔｍａｘ、Ｔ１／２分别为１６．２±３．６ｈ·μｇ·ｍｌ－１，１．２±０．２μｇ·ｍｌ－１，２．１±０．７ｈ，１７．０±７．２ｈ；进口片剂ＡＵＣ、Ｃｍａｘ、Ｔｍａｘ、Ｔ１／２分别为１５．９±３．５ｈ·μｇ·ｍｌ－１，１．２±０．４μｇ·ｍｌ－１，２．１±０．６ｈ，１８．６±９．４ｈ。国产片剂的相对生物利用度为１０３．５％。结论：两种片剂的所有药动学参数经统计学（ＳＰＳＳ软件）处理差异均无显著性（Ｐ＞０．０５）。     

高效液相色谱法测定盐酸塞利洛尔血浆浓度及人体生物利用度

目的：研究盐酸塞利洛尔片的相对生物利用度，双单侧Ｔ检验、方差分析等方法判断生物等效性。方法：９名健康志愿受试者交叉服用两药厂产的盐酸塞利洛尔片２００ｍｇ，以ＨＰＬＣ法测定。结果：药－时曲线符合一级吸收一室模型，其主要药动学参数Ｔ１／２Ｋ３．４５～３．５６ｈ，Ｔｍａｘ３．５８～３．６２ｈ，Ｃｍａｘ５０１．４３～５３１．９２ｎｇ·ｍｌ－１，ＡＵＣ４５０８．３８～４６０５．９０μｇ·ｈ·Ｌ－１。结论：国产药与进口药的药动学参数相似，相对生物利用度９８．１％±９．９％。综合分析两制剂生物等效。     

替硝唑胶囊剂的相对生物利用度

目的：研究替硝唑胶囊剂的相对生物利用度。方法：８名健康男性志愿者交叉口服２ｇ替硝唑胶囊和片剂，用高效液相色谱法测定其血药浓度经时过程。结果：替硝唑胶囊与片剂的药时曲线符合一房室模型，胶囊与片剂的Ｔ１／２（Ｋｅ）分别为１３．７±１．５ｈ、１４．２±２．０ｈ、Ｔｍａｘ分别为１．４±０．４ｈ、１．９±０．８ｈ；Ｃｍａｘ分别为５２．１±９．１μｇ·ｍｌ－１、５１．１±１０．３μｇ·ｍｌ－１；ＡＵＣ分别为１０９３．０±１１１．８、１１２３．０±１２８．２（μｇ·ｍｌ－１）·ｈ，胶囊剂的相对生物利用度为９７．６％，经统计学分析处理，差异无显著性（Ｐ＞０．０５）。结论：替硝唑胶囊与片剂具有生物等效性     

萘普生肠溶胶囊人体药物动力学和相对生物利用度

目的：测血药浓度，３Ｐ８７药动学程序进行药物动力学参数模拟，双单侧检验法作生物等效性判别。方法：８名健康男性志愿者交叉服用萘普生肠溶和胃溶胶囊各５００ｍｇ，以ＨＰＬＣ法测定。结果：药－时曲线符合一级吸收二室模型，萘普生肠溶胶囊的主要药动学参数分别为Ｋａ０．７５±０．２８ｈ－１，ＡＵＣ１５３３．０±２１７．６μｇ·ｈ·ｍｌ－１，Ｔｍａｘ３．６±１．６ｈ，Ｃｍａｘ７８．１±１４．１μｇ·ｍｌ－１。结论：胃溶胶囊的药动学参数与肠溶胶囊的药动学参数相似，肠溶胶囊的相对生物利用度为１０４．０１％。     

复方卡托普利片中卡托普利在人体内的药物动力学

１６名健康志愿者单剂量口服５片复方卡托普利片，用ＨＰＬＣ方法测定血药浓度，体内符合二室开放模型。结果表明，卡托普利片的平均药动学参数为Ｔ１／２β２．３ｈ，Ｔｐｅａｋ０．４９ｈ，Ｃｍａｘ６４０ｎｇ·ｍｌ－１，ＡＵＣ１０４０ｎｇ·ｍｌ－１·ｈ－１。与文献报道一致。     

环孢素A微乳浓缩液的药代动力学和生物等效性评价

将雄性Ｗｉｓｔａｒ大鼠１６只随机分为两组,分别口服自制和进口环孢素Ａ（ＣｙＡ）微乳浓缩液,采用高效液相色谱法测定血药浓度,对其药代动力学和相对生物利用度进行了研究。试验结果表明两种制剂中ＣｙＡ的药动学过程均符合口服吸收二室模型。自制和进口环孢素Ａ微乳浓缩液的全血药物浓度达峰时间分别为１．５７±０．５５和１．６８±０．４３ｈ;Ｃｍ ａｘ 分别为１７５５．６±２２６．０和１８３２．２±５９８．８ｎｇ／ｍｌ;Ｔ１／２ 分别为１９．９３±６．４４和１９．７９±６．９８ｈ;ＡＵＣ分别为３０６３７．９±７５５２．４和３０３１６．６±６５７８．９ｎｇ·ｈ／ｍ ｌ;自制环孢素Ａ微乳浓缩液的相对生物利用度为１０１．１％ 。经统计分析,两种制剂的药代动力学参数均无显著性差异（Ｐ＞ ０．０５）,两种制剂具有生物等效性。     

奥美拉唑在健康人体内的药物动力学研究

本实验建立了奥美拉唑在人体内血药浓度的ＨＰＬＣ测定方法，并对奥美拉唑片（供试品）及胶囊剂（对照品）在健康人体内的药物动力学进行了研究。结果表明，奥美拉唑片与胶囊剂的达峰时间（Ｔｍ）分别为３．３ｈ和３．５ｈ（Ｐ＞０．０５）；Ｃｍ分别为７７４．５ｎｇ／ｍｌ和６１６．５ｎｇ／ｍｌ（Ｐ＜０．０５）；ＡＵＣ分别为３２７４．９（ｎｇ·ｈ）／ｍｌ和２９６８．１（ｎｇ·ｈ）／ｍｌ（Ｐ＜０．０５）。供试品的相对生物利用度为１０７．０±０．０９％，显示奥美拉唑片生物利用度优于对照品。但以２０％作为等效性判断检验标准，两者显示生物等效。     

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.