脑用表阿霉素壳聚糖微球的制备及其特性考察

目的：以壳聚糖为载体材料，表阿霉素为模型药物，制备脑内局部给药缓释微球。方法：以液体石蜡为油相，L-抗坏血酸棕榈酸酯为交联剂，司盘-80为乳化剂，采用乳化化学交联技术制备表阿霉素脑用微球。用动态透析法研究微球的体外释放特性。结果：盐酸表阿霉素/壳聚糖的质量比为1：9的载药微球形态良好，粒径分布较为均匀，平均粒径为（9．3±2．6）μm、载药量为（8．01±0．23）％、包封率为（72．9±2．2）％。体外释放具有良好的缓释效果。结论：所优化的制备工艺稳定，适用于脑用表阿霉素壳聚糖微球的制备。     

盐酸川芎嗪羧甲基壳聚糖丝素蛋白微球的制备和体外释放特性

摘要：目的:制备一种包载盐酸川芎嗪的羧甲基壳聚糖丝素蛋白微球,以期延长药物的释放时间。方法:采用乳化-化学交联法制备盐酸川芎嗪羧甲基壳聚糖丝素蛋白微球;采用高效液相色谱法测定盐酸川芎嗪的含量;采用Box-Behnken设计-效应面法优化载药微球的制备工艺;考察盐酸川芎嗪注射液和载药微球的体外释放特性。结果:优化的制备工艺条件为:丝素蛋白质量浓度3.0 mg·ml-1、盐酸川芎嗪质量浓度2.0 mg·ml-1、搅拌速度600 r·min-1;制得的载药微球的粒径为（34.4±2.3）μm、包封率为（67.6±1.3）%（n=4）,与软件模型预测值接近,偏差绝对值均小于5%。盐酸川芎嗪注射液中的药物在60 min内已完全释放;而载药微球在30 min内药物快速释放,60 min后药物释放速率较缓慢,180 min时完全释放。载药微球在6种释放介质中的体外释放过程均符合Higuchi方程,体现出良好的缓释特性。结论:优化后的盐酸川芎嗪羧甲基壳聚糖丝素蛋白微球制备工艺简便易行,微球形态圆整,包封率载药量较高,体外释放具有缓释特性。     

多柔比星海藻酸钙微球的制备及其载药、释药性质的研究

目的：考察多柔比星海藻酸钙微球的制备工艺及载药、释药性质。方法：考察不同处方微球的粒径、机械强度、降解等性质，筛选出最佳处方；以多柔比星为模型药物研究其对药物的承载能力及体外释药特性。结果：制备的微球圆整且分散性好，粒径均匀。多柔比星海藻酸钙微球的载药量达30％以上，包封率在90％以上；在体外37℃生理氯化钠溶液中释放显示具有缓释作用。结论：该微球对多柔比星具有较高的承载能力，并有较好的缓释作用，可满足临床治疗动脉栓塞需要。     

去甲斑蝥素肝动脉栓塞缓释微球的制备及其体外释放性评价

目的:制备去甲斑蝥素肝动脉栓塞缓释微球(NCTD-MS),并考察其体外释放特性。方法:以NCTD为主药,海藻酸钠ALG)/壳聚糖(CS)为复合载体,采用内部凝胶化法制备NCTD-MS;选取ALG浓度、凝胶化反应剂冰醋酸的用量、药物-载体重量比(简称药载比)为因素,以粒径偏差、载药量及包封率为指标进行正交设计优化最佳处方并进行验证;动态透析法考察微球在不同介质(磷酸盐缓冲液和生理盐水)中的体外释放特性,并与NCTD原料药的释放性进行比较。结果:最佳处方为ALG浓度2.0%、冰醋酸1.0mL、药-载重量比0.8∶1,以该处方制备的微球平均粒径为(309.75±2.19)μm、载药量为(12.65±0.87)%、包封率为(68.66±0.38)%;NCTD-MS在2种介质中24h释放可达80%,释放行为均遵循Weibull方程,而NCTD原料药在3h内即释放完毕。结论:NCTD-MS制备工艺简单,缓释效果明显。     

载环孢素A海藻酸钙-壳聚糖微球的制备及体外释放特性

目的:针对角膜移植术后免疫抑制治疗需求,制备眼部局部给药的小粒径载环孢素A缓释微球,并进行体外释放考察。方法:以海藻酸钠、壳聚糖为载体材料,采用静电液滴工艺,通过向制备体系添加表面活性剂,制备小粒径载环孢素A微球,设计正交试验优化处方工艺,扫描电镜观察微球表面形态,动态透析法考察微球的体外释放特性。结果:所制微球形态良好,粒径分布窄,平均粒径为(12.4±0.8)μm,包封率为(82.8±1.8)%,载药量为(50.1±1.2)%,体外释放行为用Higuchi方程拟合效果最好。结论:采用静电液滴工艺,通过减小制备体系的表面张力,制备了球形度优良、粒径小、包封率和载药量较高的载环孢素A的壳聚糖-海藻酸盐缓释微球,所得制剂的体外释药规律服从扩散机制。     

奥沙普秦壳聚糖-海藻酸钠缓释微球的制备

目的：目的：选择奥沙普秦作为模型药制备壳聚糖-海藻酸钠缓释微球。方法：采用滴制法制备奥沙普秦壳聚糖-海藻酸钠缓释微球，通过正交试验设计优化了处方和工艺，考察其理化特征及体外释药行为。结果：优化处方制得的微球包封率及载药量分别为98．36％和16．26％，平均粒径为（346．6±164．1）μm；1h药物释放达到36％，随后药物的释药行为是一个缓释过程。结论：制得了载药量较大，包封率较高的奥沙普秦壳聚糖-海藻酸钠缓释微球。     

一种新型普鲁兰微球的制备及其释药性能研究

目的 构建一种白血病治疗药物甲氨蝶呤（MTX）的新载体,探讨其对MTX的负载效率及其缓释性。方法 采用动态光散射（DLS）和扫描电镜（SEM）对载体载药前后的粒径、电位及形貌进行表征,紫外分光光度法测定MTX的含量。结果 平均粒径大小为1098 nm,Zeta电位为0.835 mV,载药后分别为1324 nm、0.727 mV,载药后粒径略有增加。MTX的载药量和包封率分别未（13.44±2.13）%、（58.7±4.6）%。SEM显示,该载体载药前后均为球形结构,证明微球制备成功。体外释放研究表明,微球负载的药物释放明显减缓,游离药物在10 h内可完全释放,但此时微球中的药物释放量仅30.0%左右,72 h仅释放78.6%。结论 负载MTX的胆甾醇疏水改性普鲁兰（CHP）微球属于微米级,具有较高的载药量和明显的缓释性。     

多柔比星壳聚糖纳米粒的制备及其体外评价

目的 制备多柔比星壳聚糖纳米粒,并研究其包封情况和控释能力.方法 采用离子交联法制备多柔比星壳聚糖纳米粒,激光粒度仪测定粒径的分布,HPLC法测定纳米粒的包封率,透析法测定多柔比星壳聚糖纳米粒的体外释放情况.结果 壳聚糖的浓度增加,纳米粒的粒径增加、包封多柔比星的效率也增加;壳聚糖溶液的pH增加,纳米粒的粒径降低而包封多柔比星的效率增加;壳聚糖分子量增加对多柔比星的包封效率影响较小,但粒径增加,多柔比星突释减小,释放速率降低.结论 多柔比星可以通过离子交联法制备壳聚精纳米粒,其粒径、包封率可控,具有缓释效果.     

甲硝唑缓释微球结肠溶胶囊的制备及体外释放

目的：研制甲硝唑缓释微球并装于结肠溶胶囊，评价其体外释放特性。方法：用乳化交联法制备甲硝唑羧甲基壳聚糖微球，测定平均粒径、载药量、包封存率等指标；将微球和原料药分别装于结肠溶胶囊，测定微球、原料药及结肠溶胶囊剂型在人工胃液、人工小肠液、人工结肠液中的释放性能。结果：重复制备6批微球，微球平均粒径为（197．1±3．9）μm，载药量为（48．2±1．5）％，包封率为（37．5±1．9）％；体外释放甲硝唑原料药0．75h释放完全，甲硝唑微球7h释放完全；甲硝唑原料药结肠溶胶囊和甲硝唑微球结肠溶胶囊，在人工胃液、人工小肠液5h均无释放，移至人工结肠液后，前者于6．25h释放完全，后者于13h释放完全。结论：甲硝唑羧甲基壳聚糖微球的制备工艺稳定，甲硝唑羧甲基壳聚糖微球结肠囊胶囊具有结肠定位及缓释性能。     

槲皮素包合物微球的制备及其体外释放研究

目的:制备槲皮素β-环糊精包合物-壳聚糖微球(QT-CD-CM),并考察其理化性质和药物体外释放性能。方法:采用有机溶剂挥发法制备槲皮素β-环糊精包合物,再用乳化分散-离子交联法、以三聚磷酸钠为交联剂制备壳聚糖微球,并考察其形态、粒径、包封率、载药量和体外释放情况。结果:制备的QT-CD-CM形态规则、均质、无粘连,平均粒径(3.327±0.124)μm,包封率为32.4%,载药量为12.3%,在5%乙醇-磷酸盐缓冲液介质中72h可以达到完全释药,释药过程符合一级动力学模型。结论:QT-CD-CM理化性质及体外释药性能良好,制备工艺简单,有望成为理想的槲皮素给药系统。     

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.

     

Synthesis,Cytotoxicity and Antileishmanial Activity of Some N-(2-(indol-3-yl)ethyl)-7-chloroquinolin-4-amines

We report herein the condensation of 4,7-dichloroquinoline (1) with tryptamine (2) and D-tryptophan methyl ester (3) . Hydrolysis of the methyl ester adduct (5) yielded the free acid (6) . The compounds were evaluated in vitro for activity against four different species of Leishmania promastigote forms and for cytotoxic activity against Kb and Vero cells. Compound (5) showed good activity against the Leishmania species tested, while all three compounds displayed moderate activity in both Kb and Vero cells.     

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.     

Glycofection: The Ubiquitous Roles of Sugar Bound on Glycoplexes

Glycofection (transfection by using sugar-substituted polylysine) was assessed in order to provide an alternative to viral vectors for the transfer of genes into vascular smooth muscle cells. A rabbit vascular smooth muscle cell line (Rb-1 cells) was selectively transfected by using glycoplexes (glycosylated polylysine/pSV2LUC complexes) in the presence of 10 mu M of the fusogenic peptide GALA. A sugar-specific transfection was obtained when the glycofection was conducted for 1 h with glycoplexes containing either alpha Gal, alpha -Glc, alpha -GalNAc, beta -GlcNAc, or beta -GalNAc residues. The gene expression was high after transfection, with glycoplexes bearing alpha Gal, alpha -GalNAc, or beta -GalNAc residues that were weakly internalized, and low with glycoplexes carrying Lact or Rha residues that were well taken up by cells. These results suggest that 1) glycofection can be a good approach for a selective transfer of genes intovascular smooth muscle cells, 2) an efficient uptake of the glycoplexes is not the unique limiting step for an efficient transfection, and 3) the sugar-dependent trafficking of the glycoplexes inside the cells may account for the transfection efficiency.     

直肠癌下切缘病理组织学分析

目的探讨直肠癌逆向浸润与下切缘的安全距离的关系。方法对36例直肠癌Miles手术和Dixon手术后标本的肿瘤下缘1.0cm、2.0cm、3.0cm的肠壁及对应的系膜病理组织学检查,观察直肠癌逆向浸润或转移的距离。结果36例直肠癌标本距癌肿下缘1.0 cm、2.0cm、3.0cm的肠壁及对应的系膜病理组织学检查均为阴性,结论直肠癌远恻逆向浸润或转移未见超过1.0cm,因此认为保肛手术时切除肿瘤远侧肠管(包括系膜)2.0cm是安全的。