RP-HPLC测定利福昔明的含量及有关物质

目的　建立测定利福昔明含量及有关物质的方法。方法　采用C18色谱柱 (5 μm ,15 0mm× 4.6mm) ,流动相为甲醇 -乙腈 - 0 .0 5mol·L-1磷酸二氢钾溶液 - 0 .5mol·L-1枸橼酸溶液 (5 0∶2 5∶2 0∶5 ) ,检测波长 2 5 4nm。结果　利福昔明在 5 0～ 2 0 0 μg·ml-1浓度范围内 ,峰面积与浓度呈良好的线性关系 (r=0 .9999) ,平均回收率为 99.9%。结论　所建方法简便 ,专属性及重复性好 ,可用于利福昔明的含量及有关物质的测定。     

HPLC测定盐酸土霉素的含量和有关物质

目的 :建立HPLC测定盐酸土霉素有关物质和含量。方法 :采用ODS柱 ( 10 μm ,4 6mm× 2 5 0mm) ,以 0 1mo1·L-1草酸铵溶液 二甲基甲酰胺 0 2mo1·L-1磷酸氢二铵溶液 ( 6 0∶30∶10 ) (用氨试液调pH8 3)为流动相 ,检测波长 2 70nm。结果 :盐酸土霉素在 0 1～ 1 0mg·ml-1浓度范围内 ,呈良好的线性关系 (r =0 9999) ,精密度RSD为1 2 % ,平均回收率为 99 6 % ,RSD为 0 8% (n =4)。结论 :该法简便、准确 ,适用于盐酸土霉素杂质的检测和含量的测定。     

RP-HPLC测定替拉扎明及其有关物质

目的　建立测定替拉扎明含量及其有关物质检查的高效液相色谱法。方法　采用HypersilC18色谱柱(2 5 0mm× 4.6mm ,id 10 μm) ,甲醇 - 5 0mmol·L-1磷酸盐缓冲液 (10∶90 ,氢氧化钠调pH =6 .5± 0 .1)为流动相 ,在检测波长 2 6 6nm处进行含量测定 ;在相同条件下 ,以甲醇 - 5 0mmol·L-1磷酸盐缓冲液 (2 5∶75 ,氢氧化钠调pH =6 .5±0 .1)为流动相 ,对有关物质进行检查。结果　替拉扎明在 1.2 7～ 5 0 .8μg·ml-1范围内 ,峰面积与其浓度线性关系良好 (r =0 .9999) ,最低检测限为 2 .5× 10 -2 ng (S/N =3) ,重复进样RSD =0 .6 9% (n =5 ) ,日内RSD =0 .83%(n =5 ) ,日间RSD =0 .39% (n =5 ) ,重复性试验RSD =0 .2 1% (n =6 ) ,加样回收率为 99.6 2 %。结论　本法准确、简便、快速 ,可用于替拉扎明原料药及其制剂的质量控制     

反相高效液相色谱法测定双氯芬酸钾片的含量及有关物质

目的 :研究反相高效液相色谱法测定双氯芬酸钾片的含量及有关物质。方法 :HypersilODSC18色谱柱 (2 5 0mm× 4 .6mm ,5 μm ) ,以甲醇 磷酸盐缓冲液 (6 6∶34)为流动相 ,流速 1.0mL·min- 1,检测波长为 2 80nm。结果 :A =30 .2 2 8C + 5 0 .95 6 (r=0 .9994 ,n =5 ) ,线性范围为 4 0 .16～ 6 0 .2 4mg·L- 1;最低检出限为 0 .39ng ;平均方法回收率为99 .33% (RSD =1.5 7% ) ;日内、日间RSD均 <5 %。结论 :采用反相HPLC法测定双氯芬酸钾片的含量及其有关物质方法简便 ,结果准确     

高效液相色谱法测定呱仑酸钠的含量及有关物质

目的 :建立一种用高效液相色谱法测定呱仑酸钠的含量及有关物质的方法。方法 :在InertsilCN - 3柱上 ,以磷酸盐缓冲液 (pH =7) -乙腈 (5 0∶5 0 )为流动相 ,于 2 90nm波长处检测 ,流速为 1 0mL·min-1。结果 :呱仑酸钠的浓度在1 0～ 6 0 μg·mL-1范围内线性关系良好 ,回归方程 :A =6 2 0 0× 10 5C 6 374× 10 4 ,r =0 9996。精密度试验RSD =0 2 9% (n =6 ) ,最低检出限为 0 2 4ng。有关物质可检出 2个杂质。结论 :本方法简单、快速、结果准确     

离子对高效液相色谱法测定美洛昔康含量及有关物质

目的 :为控制美洛昔康的含量和有关物质 ,建立了离子对高效液相色谱测定法。方法 :色谱柱为Alltech公司AlltimaODS柱 (2 5 0mm× 4 6mm) ,流动相 :乙腈 -含 0 2 5 %辛烷磺酸钠的 0 1mol·L- 1 磷酸二氢钠 (磷酸调至pH 2 5 ) (6 5∶35 ) ,流速 :1mL·min- 1 ,检测波长分别为 35 5nm (含量测定 )和 2 71nm (有关物质测定 )。结果 :美洛昔康在 9～ 110 μg·mL- 1 范围内呈良好的线性关系 ,r=0 9998。结论 :本文改进的离子对高效液相色谱法为测定美洛昔康及其制剂的含量和有关物质提供了可靠基础。     

HPLC法测定替卡西林钠的含量及有关物质

目的　采用HPLC法测定替卡西林钠的含量及有关物质。方法　色谱柱 :日本岛津液相填充柱C18(2 5 0× 4 6mm5 μm) ;流动相 :磷酸盐缓冲液 (pH4 3) -乙腈 (92∶8) ;UV检测波长 :2 2 0nm。 结果　含量测定在 0 4 1～ 1 19mg·ml-1范围内峰面积与浓度有良好的线性关系 (r =0 9997) ,有关物质测定在 30 84～ 71 96 μg·ml-1范围内峰面积与浓度呈良好的线性关系(r=0 9998)。结论　本方法在测定过程中具有良好的稳定性、专属性及重现性     

高效液相色谱法同时测定滴鼻剂中盐酸麻黄素和氢化可的松的含量

目的 :用HPLC法同时测定滴鼻剂中盐酸麻黄素氢化可的松的含量。方法 :采用C18色谱柱 ,流动相为甲醇 0 .0 5mol·L-1KH2 PO4 三乙胺 (5 0∶5 0∶0 .2 ) ,用磷酸调 pH3.7,检测波长 2 5 7nm。结果 :盐酸麻黄素在 36 0～ 6 0 0 μg·ml-1浓度范围内线性关系良好 (r =0 .9999) ,回收率 10 1.3% ,RSD为 1.0 %。氢化可的松在 36～ 6 0 μg·ml-1浓度范围内线性关系良好 (r =0 .9998) ,回收率 10 1.5 % ,RSD为 1.0 %。结论 :该方法可同时测定滴鼻剂中盐酸麻黄素氢化可的松含量。     

法莫替丁氯化钠注射液质量标准的相关研究

目的建立法莫替丁氯化钠注射液中法莫替丁含量及有关物质检测的高效液相色谱方法.方法采用Agilent ZORBAX SB-C18(4.6×250mm,5μm)色谱柱,以0.2%(g·L-1)庚烷磺酸钠溶液(用冰醋酸调pH值为3.7)-乙腈-甲醇(33∶7∶3)为流动相,流速1.2mL·min-1,柱温为35℃,检测波长为254nm.结果法莫替丁的浓度在0.0794～0.238mg·L-1范围内有良好的线性关系,r=0.9999,样品的平均回收率为99.58%,RSD为0.91%.结论高效液相色谱法测定法莫替丁氯化钠注射液中的法莫替丁含量和有关物质,方法准确度、精密度高,适合应用于该制剂的质量控制.     

RP-HPLC测定盐酸西替利嗪的含量及相关物质

目的　采用RP -HPLC法测定盐酸西替利嗪的含量及其有关物质。方法　采用ODS色谱柱 (5 μm ,4 .6mm× 15 0mm) ,流动相为乙腈 -水 -冰醋酸 (36∶6 4∶0 .1) ,流速 1.0ml·min-1,检测波长 2 2 9nm ,柱温为室温 (2 5℃ )。结果　盐酸西替利嗪测定的线性范围为 12 .5～ 15 0 μg·ml-1(r=0 .9998,n =6 ) ;日内RSD =0 .36 % (n =5 ) ,日间RSD =0 .6 4 % (n =5 ) ;最低检出限 0 .3ng。结论　所用方法简便、准确 ,专属性好     

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.