薄层扫描法测定大败毒胶囊中大黄素的含量

采用薄层扫描法对大败毒胶囊中大黄素的含量进行了测定 ,试样经盐酸 -甲醇 (6∶ 1 0 0 )提取 ,氯仿萃取 ,甲醇定容 ,双波长锯齿扫描 ,λS=450 nm,λR=680 nm,大黄素线性范围 53ng～ 42 4 ng     

消结涂膜剂的质量标准研究

［摘要］目的探讨消结涂膜剂的质量控制标准。方法采用薄层色谱法对消结涂膜剂中赤芍、大黄、黄芩进行定性鉴别；双波长薄层扫描法测定连翘酚含量；其测定波长λs=440 nm，参比波长λr=700 nm。结果3批样品中连翘酚含量分别为0.168，0.181，0.175 mg·mL-1，平均回收率为101.13%, RSD 1.42%。结论采用双波长薄层扫描法测定消结涂膜剂中连翘酚的含量，方法简便，快速准确。     

冰黄栓中冰片和大黄素的含量测定

目的建立冰黄栓含量测定的质量标准。方法采用气相色谱法,以聚二乙二醇丁二酸酯为固定液,涂布浓度为15％,担体ChromosorbWAW(DMCS),柱温105℃,进样口温度250℃,测定其中冰片含量。采用双波长薄层扫描法,以石油醚（30～60℃)-甲酸乙酯-甲酸(15∶5∶1)的上层液为展开剂,波长λs=440nm,λR=670nm,Sx=3,0.4×0.4的锯齿扫描,测定其中大黄素的含量。结果冰片线性范围0.283～2.262μg(r=0.9999),平均回收率100.5％;大黄素线性范围0.056～0.448μg（r=0.998),平均回收率98.7%,其含量测定方法稳定,精确。结论制定的含量测定方法可行。     

双波长薄层扫描法测定茵虎黄片中大黄素的含量

目的：对立双波长薄层扫描法测定茵虎黄片中大黄素含量。方法：茵虎黄片的甲醇提取液为浓盐酸水解,用乙醚萃取。薄层条件：硅胶G薄层板,展开剂：石油醚：甲酸乙酯：甲酸15：5：1,参比波长587nm,检测波长437nm。结果：大黄素在0.2-1.7μg范围内呈线性关系（r=0.9991）,平均回收率为97.1%（RSD=2.62%）。结论：该方法简便、可靠。     

双波长薄层扫描法测定如意金黄散中盐酸小檗碱的含量

目的建立如意金黄散中盐酸小檗碱的双波长薄层扫描测定方法。方法采用双波长飞点薄层扫描法测定如意金黄散中盐酸小檗碱的含量,展开剂为正丁醇-冰醋酸-水(7∶3∶3),λS=350 nm,λR=368 nm。结果测得如意金黄散中盐酸小檗碱含量在0.98~1.25 mg/g之间,平均回收率是100.47%(n=5)。结论该方法操作简便,结果准确可靠。     

TLC—分光光度法测定感冒灵片主药的含量

建立了高效薄层扫描法测定维生素E霜中维生素E含量的方法。以乙酸乙酯、乙醚、冰醋酸（7：3：0.2）为展开剂，采用双波长反射锯齿法，测维生素E时λs=285nm,λr=320nm。加样回收率为98.7%，RSD为2.5%。     

薄层扫描法测定复方黄槐颗粒中大黄素的含量

目的建立复方黄槐颗粒中大黄素的含量测定方法。方法采用薄层扫描法。展开剂：正己烷．乙酸乙酯．甲酸（30：10：0．5），检测波长λS=442nm，λR=610nm。结果大黄素在0．048～0．240μg范围内呈良好线性关系，r=0．998O，平均回收率=99．29％，RSD=1．09％。结论本法简单，准确，重现性好，可用于复方黄槐颗粒中大黄素的含量测定。     

薄层扫描法测定安钠咖注射液的含量

以石油醚—丙酮—冰醋酸(5：25：2)为展开剂，在薄层硅胶板上分离咖啡因Rf=o.24，和苯甲酸 钠(Rf=0.69),然后采用双波长薄层扫描法测定咖啡因(λS=270nm，λR=320nm)和苯甲酸钠(λS=227nm，λR =320nm))的含量。     

薄层扫描法测定感冒康胶囊中穿心莲内酯的含量

目的：建立感冒康胶囊中穿心莲内酯的含量测定方法。方法：采用乙醇提取，双波长薄层扫描法测定感冒康胶囊中穿心莲内酯的含量（λs=228nm,λR=370nm)。结果：平均回收率为97.74%，RSD=1.4%(n=5)，3批样品含量分别为0.84%,0.96%,0.96%。结论：该方法稳定、可行，具有实用性。     

双波长薄层扫描法测定氢醌酯霜中氢醌酯的含量

本文建立了氢醌酯的薄层扫描测定方法。以甲苯:乙醚(4:1)为展开剂,氢氧化钠的醇溶液浸渍显色,λ_R=620nm,λ_?=375nm,对氢醌酯的含量进行了双波长薄层扫描法测定,结果回收率99.5%,CV=1.2%,表明该法简单,可行。     

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.