头孢泊肟酯侧链的合成研究——1-氯乙基异丙基碳酸酯的制备

通过氯化、酯化反应合成了β 内酰胺类抗生素———头孢泊肟酯４位侧链１ 氯乙基异丙基碳酸酯，产品纯度达９０％，收率为５０％，接近文献值，工艺简单，适于工业化生产．     

合成头孢泊肟酯中间体的气相色谱跟踪分析

目的对合成头孢泊肟酯中间体1-氯乙基氯甲酸酯、1-氯乙基异丙基碳酸酯,1-碘代乙基异丙基碳酸酯作定性、定量的跟踪分析,帮助确定最佳的合成工艺条件.方法用GC-MS、核磁共振、SE-54(30m×0.53mm×0.25μm)毛细管柱气相色谱法进行定性、定量.结果合成1-氯乙基氯甲酸酯最高含量达61.3%,1-氯乙基异丙基碳酸酯含量达95.4%,1-碘代乙基异丙基碳酸酯含量达87.5%.结论实验表明本色谱方法分离度好,重现性好,对探索最佳合成工艺路线具有指导意义.     

高效液相色谱法测定头孢泊肟酯及其制剂的含量

建立一种用高效液相色谱法测定头孢泊肟酯及其片剂，胶囊剂的含量及有关物质的方法。方法：以ODS为固定相。甲醇－水（41：59）为流动相；检测波长为240nm。结果：头孢泊肟酯的浓度在0.3-0.9mg/ml范围内线性关系良好，回归方程为：Y＝1460374，8X-4983．9，r=0.9999。头孢泊肟酯，头孢泊肟酯片和头孢泊肟酯胶囊重现性良好（n=9)，RSD分别为0．5％，1．0％和1．2％。头孢泊肟酯片和头孢泊肟酯胶囊平均回收率分别为100．6％（RSD＝1．0％，n=9)和99．8％（RSD＝0．8％，n=90。本方法简单，快速，结果准确。     

HPLC法测定人血浆中头孢泊肟的浓度

目的建立测定人血浆中头孢泊肟酯的活性代谢产物头孢泊肟浓度的高效液相色谱法,并应用于头孢泊肟酯干混悬剂在健康人体内的药动学研究。方法采用沉淀蛋白法进行样品预处理,色谱柱为Agilent Zorbax SB-C18柱(150 mm×4.6 mm,5μm),流动相为乙腈-20 mmol.L-1磷酸二氢铵缓冲液(体积比为9∶91,含6.6 mmol.L-1三乙胺,磷酸调pH值至2.0),流速为1.0 mL.min-1,检测波长为254 nm,内标为头孢克洛。结果头孢泊肟浓度线性范围为0.102～6.528 mg.L-1,低、中、高3个质量浓度的提取回收率分别为92.0%、93.3%和92.1%,日内和日间精密度RSD(n=6)分别为3.3%、3.8%、2.0%和14.2%、2.9%、6.3%。头孢泊肟血浆样品室温放置2 h、预处理后室温放置24 h、经历1次及3次冷冻-解冻循环和-20℃冷冻情况下保存40 d均可保持稳定。结论此法适用于头孢泊肟酯药动学研究。     

头孢泊肟酯的合成

头孢泊肟酯是第三代头孢菌素中第一个口服衍生物,具有广谱抗菌活性,对很多革兰氏阴、阳性菌有效,且很少见细菌对本品耐药。文献报道本品的合成方法有多种。笔者以国产氨噻肟头孢为原料经酰化、甲氧基化.酯化和水解4步反应制得。     

国产头孢泊肟酯片治疗下呼吸道细菌性感染40例

目的评价国产头孢泊肟酯片治疗下呼吸道细菌性感染的有效性和安全性。方法将78例轻度及中度下呼吸道细菌性感染患者随机分为2组，治疗组40倒口服头孢泊肟酯片200mg（2次／d），对照组38例口服头孢克洛片500mg（3次／d），疗程均为7～14d。结果治疗组与对照组临床有效率分别为87.5％与81．6％，细菌清除率分别为89.2％与85.0％，两组均无明显不良反应。结论采用头孢泊肟酯片治疗下呼吸道细菌性感染安全、有效。     

浅谈头孢泊肟酯的临床应用

头孢泊肟酯是一种口服方式用药的头孢菌素,属于第三代药物。临床中具有很好的抗菌效果,特别是对革兰阴性菌,比起前两代的头孢菌素药物效果更加突出。头孢泊肟酯在临床中主要应用于多种细菌引起的感染,能够治疗大肠杆菌、卡他莫拉菌、葡萄球菌、链球菌等所导致的细菌感染,对中-重度感染患者效果比较好。现探讨临床中使用头孢泊肟酯的方法,报告如下。     

高效液相色谱法测定头孢泊肟酯含量的方法学研究

目的对头孢泊肟酯及其制剂含量的高效液相色谱检测法进行改进,并与紫外分光光度法作比较。方法以ODS-C18为固定相,甲醇-水(50∶50)为流动相,流速为1.5 mL.min-1,柱温为40℃,检测波长235 nm。结果头孢泊肟酯的浓度在25~150μg.mL-1内线性关系良好,回归方程为:A=7.457C-1.1287,r=0.999 9(n=7),测定头孢泊肟酯胶囊含量重复性良好,RSD为1%(n=9)。头孢泊肟酯胶囊的平均回收率为98.56%,平均含量为101.54%。结论本法简便、快速、准确、灵敏,可用于头孢泊肟酯及其制剂的含量测定。     

头孢泊肟酯片和颗粒人体相对生物等效性试验研究

目的研究国产头孢泊肟酯片及颗粒与进口头孢泊肟酯片在24名男性健康志愿者体内的生物等效性。方法采用标准3制剂、3周期的二重3×3拉丁方式自身对照试验设计,24例男性健康志愿受试者单剂量口服国产头孢泊肟酯颗粒（受试制剂A）、头孢泊肟酯片（受试制剂B）和进口头孢泊肟酯片（参比制剂R）。药物血清质量浓度以高效液相色谱法测量,药代动力学参数采用3P97和ndst21w软件处理。结果头孢泊肟酯受试制剂A、受试制剂B和参比制剂R的达峰时间（Tmax）分别为（2.81±0.51）h,（2.85±0.54）h,（2.92±0.52）h,峰浓度（Cmax）分别为（3.44±0.93）μg/mL,（3.32±0.74）μg/mL,（3.47±0.80）μg/mL,0～12h药时曲线下面积（AUC0-12h）分别为（20.02±5.61）μg·h/mL,（19.28±4.23）μg·h/mL,（19.59±5.18）μg·h/mL。受试制剂A和受试制剂B对参比制剂R的相对生物利用度分别为103.16%和100.65%。结论 3种头孢泊肟酯制剂在人体内具有生物等效性。     

头孢泊肟酯与头孢克肟治疗急性细菌性感染随机对照研究

目的比较头孢泊肟酯与头孢克肟治疗急性细菌性感染的安全性、有效性。方法采用随机对照研究方法,以头孢克肟为对照,入选细菌感染性疾病115例,其中头孢泊肟酯试验组60例,头孢克肟对照组55例,2组的用量,用法试验组为100 m g,po,b id,对照组为200m g,po,b id,疗程均为7~12d。结果2组临床总痊愈率分别为73%和69%,总有效率分别为92%和91%,细菌清除率分别为98%和94%,不良反应率分别为7%和6%,经统计学处理均无显著差异(P>0.05)。结论头孢泊肟酯治疗急性细菌性感染临床安全,有效。     

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.