醋酸地塞米松PEG-PLGA纳米粒的制备及表征

目的 研究醋酸地塞米松PEG-PLGA纳米粒的制备工艺及影响因素,并优化冻干粉针工艺.方法 采用乳化/溶剂蒸发法制备醋酸地塞米松PEG-PLGA纳米粒,并考察其粒径分布、包封率、载药量等;采用单因素试验筛选出合适的冻干保护剂.结果 醋酸地塞米松PEG-PLGA纳米粒的粒径为91.43±1.00 nm,Zeta电位为-22.73 ±0.57 mv,包封率为88.78％ ±2.10％,载药量为4.95％-±0.23％;10％蔗糖作为冻干保护剂的效果最好,冻于复溶后粒径约117.27 nm.结论 所用制备工艺简单易行,可用于制备醋酸地塞米松PEG-PLGA纳米粒.     

替尼泊苷磷脂复合物白蛋白纳米粒的制备与表征

目的 制备替尼泊苷磷脂复合物白蛋白纳米粒,并表征其理化性质.方法 以人血清白蛋白和蛋黄卵磷脂E80为辅料,替尼泊苷为主药,采用超声法制备替尼泊苷磷脂复合物白蛋白纳米粒及其冻干制剂.以粒径和多分散系数(PDI)为主要考察指标来优化纳米粒的处方及制备工艺;用激光粒度分析仪和透射电镜对其形态和结构进行表征;用葡聚糖凝胶柱法测定纳米粒的包封率和载药量.结果 成功制备了替尼泊苷磷脂复合物白蛋白纳米粒,平均粒径为182.3 ±11.7 nm,PDI为0.168 ±0.02,Zeta电位为-10.75±1.42 mV,包封率为82.27％±2.74％,载药量为4.29％±0.11％;冻干制剂的外观良好,复溶后的粒径和PDI均符合要求.结论 所用方法简单新颖,具有较好的应用前景.     

超声法制备齐多夫定碳酸胆固醇酯牛血清白蛋白纳米粒

目的建立一种不使用交联剂制备白蛋白纳米粒的新方法。方法以牛血清白蛋白(bovineserumalbumin,BSA)为材料,以本实验室合成的齐多夫定的前药—齐多夫定碳酸胆固醇酯(cholesteryl carbonate azidothymidine,AZTC)为主药,采用超声法制备齐多夫定碳酸胆固醇酯牛血清白蛋白(AZTC-BSA)纳米粒及其冻干制剂。以粒径为考察指标确定纳米粒的最佳处方及工艺;以冻干制剂外观、水化时间及复溶后粒径为考察指标确定冻干制剂的处方及工艺。结果成功制备了AZTC-BSA纳米粒,最佳超声时间为6 min,纳米粒平均粒径为137.9 nm,zeta电位为-54.6 mV,包封率为98.6%;冻干制剂外观良好,复溶后平均粒径为148.9 nm。结论超声法制备AZTC-BSA纳米粒新颖、简单、可靠。     

聚乙二醇修饰青蒿素脂质纳米粒冻干工艺优化及其表征

目的筛选聚乙二醇(PEG)修饰青蒿素脂质纳米粒(PEG-ART-NLC)最优冻干保护剂处方,研究其冷冻干燥工艺及质量表征。方法制备含不同冻干保护剂的PEG-ART-NLC冻干粉,以外观、再分散性、复溶后外观、粒径、Zeta电位为指标,优化保护剂处方,并对比冻干前后脂质纳米粒质量变化。结果 4%甘露醇和4%蔗糖具良好的保护作用和再分散性,冻干后纳米粒粒径增大14.0 nm,Zeta电位绝对值降低8.8 m V,包封率降低14.5%,电镜下冻干前后纳米粒形态均为圆形或椭圆形,无明显差异。结论 4%甘露醇和4%蔗糖为最优保护剂处方,可用于制备稳定的PEG-ART-NLC冻干粉。     

姜黄素白蛋白纳米粒的制备与评价

目的:优化姜黄素白蛋白纳米粒的处方工艺并对其特性进行表征。方法:以牛血清白蛋白为载体、通过反溶剂沉淀法制备载姜黄素纳米粒,以粒径为评价指标优选制剂处方及工艺,并考察所得纳米粒的放置稳定性、饱和溶解度及体外溶出度。结果:当有机相和水相体积之比为1∶20、药物与白蛋白用量之比为1∶1.5、保护剂为0.5%(V/V)甘露醇时,所得纳米粒冻干粉平均粒径约为320 nm。其在水、p H 6.8、p H 7.4 PBS中的溶解度显著高于原料药及物理共混物,体外溶出更快,且冻干粉的放置稳定性优于纳米混悬液。结论:白蛋白纳米粒处方能够改善姜黄素的水溶性及溶出度,放置稳定性较佳。     

叶酸介导肿瘤靶向紫杉醇纳米粒冷冻干燥工艺及其表征

目的:研究了叶酸介导紫杉醇白蛋白纳米粒的冻于工艺及其表征.方法:选用甘露醇、牛血清白蛋白及海藻糖三种冻干保护剂,以叶酸介导紫杉醇白蛋白纳米粒冻干前与复溶后聚集状态(平均粒径和多分散系数)、表现形态、稳定性系数fc及Zeta电位为指标,筛选冻干保护的合适浓度,并考察在适当浓度下纳米粒微观形态及复溶后8小时连续稳定性.结果:三种冻干保护剂在浓度不小于1％时起到保护作用.与无保护剂样品相比,冻干后紫杉醇纳米粒粒径更小,分布范围更窄,能够在水相中充分溶解,且在复溶后连续8小时内有良好的稳定性.结论:通过对叶酸介导紫杉醇白蛋白纳米粒冻干工艺及表征的研究,证明合适的冻干保护剂浓度条件下可以获得稳定的紫杉醇纳米粒冻干注射剂.     

5-氟尿嘧啶-N-琥珀酰壳聚糖纳米粒冻干粉针制备

目的:考察5-氟尿嘧啶-N-琥珀酰壳聚糖纳米粒(5-FU-Suc-Chi/NPs)稳定性,制备纳米粒冻干粉针.方法:采用乳化溶剂挥发法制备5-FU-Suc-Chi/NPs;考察纳米粒溶液稳定性;优化纳米粒冻干粉针处方.结果:选定12%的甘露醇为5-FU-Suc-Chi/NPs的支架剂,制备纳米粒冻干粉.结论:5-FU-...     

5-氟尿嘧啶壳聚糖纳米粒冻干粉的制备

目的 为研究5-氟尿嘧啶壳聚糖纳米粒冻干粉的制备工艺,提高5-氟尿嘧啶壳聚糖纳米粒的稳定性。方法 首先制备5-氟尿嘧啶壳聚糖纳米粒,并以外观和再分散性为指标,进行单因素考察并利用正交实验优化工艺。结果 5-氟尿嘧啶壳聚糖纳米粒冻干粉的最佳制备工艺为预冻时间24 h、冻干保护剂为甘露醇、用量为80 mg、浓度为10%。冻干前后包封率差异无统计学意义（P>0.05）,冻干后的粒径和冻干前相比有一定增大。结论 5-氟尿嘧啶壳聚糖纳米粒冻干粉有望成为新剂型。     

不同冻干保护剂对硼替佐米冻干粉针的影响研究

目的研究Emprove低内毒素蔗糖、Emprove低内毒素甘露醇、Emprove低内毒素甘氨酸3种不同类型冻干保护剂对硼替佐米冻干粉针性能的影响。方法以硼替佐米冻干粉针和空白冻干粉针的外观和复溶效果为指标,考察预冻时间、冻干保护剂用量、冻干时间、叔丁醇体积分数的影响。比较了硼替佐米冻干粉针和空白冻干粉针的含水量、p H值和硼替佐米的质量分数。结果 3种冻干保护剂均能在适宜条件下制备硼替佐米冻干粉针,以Emprove低内毒素蔗糖为冻干保护剂,预冻时间24 h,用量15%,冻干时间15 h,叔丁醇体积分数40%;以Emprove低内毒素甘露醇为冻干保护剂,预冻时间6 h,用量4%,冻干时间6 h,叔丁醇体积分数40%;以Emprove低内毒素甘氨酸为冻干保护剂,预冻时间6 h,用量4%,冻干时间6 h,叔丁醇体积分数20%;所得产品饱满、平整,完全复溶。冻干后含水量5%,p H值和硼替佐米的质量分数变化不显著。结论 Emprove低内毒素蔗糖、Emprove低内毒素甘露醇、Emprove低内毒素甘氨酸均适合用作硼替佐米冻干粉针剂制备的冻干保护剂,实验为难溶性药物冻干制剂的制备提供了参考。     

叔丁醇-水共溶剂体系冷冻干燥法制备紫杉醇白蛋白亚微粒

采用叔丁醇-水共溶剂体系冷冻干燥法制备了紫杉醇白蛋白亚微粒.以冻干溶液外观,复溶后平均粒径及分布、放置稳定性等为指标,优化了处方和制备工艺.结果表明,以乳糖为冻干保护剂为最佳,所得亚微粒平均粒径在300～400 nm,复溶后室温放置8h内稳定.     

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。