去甲斑蝥素白蛋白微球在小鼠体内肝靶向作用

目的:研究去甲斑蝥素(NCTD)白蛋白微球在小鼠体内的组织分布、体外细胞毒性及肝靶向性。方法:采用体外细胞毒性和体内全身急性毒性试验方法,评价NCTD白蛋白微球的抗肿瘤活性及其生物安全性;通过小鼠尾静脉给药得到各主要药动学参数,并与NCTD注射液组比较得其靶向效率。结果:NCTD白蛋白微球在肝脏和肾脏的靶向效率分别为2.389 1和0.375 4。NCTD白蛋白微球体内外的生物安全性与其注射液比较无显著差异。体外细胞毒性显示其对肿瘤细胞具有特殊亲和力和靶向释药作用。结论:NCTD白蛋白微球具有肝脏靶向性,能降低肾脏分布,提高药物疗效,降低全身不良反应。     

卡铂肺靶向明胶微球的实验研究

目的：研制卡铂肺靶向微球。方法：用乳化法制备卡铂微球，正交试验设计考察影响制备工艺的因素。体外长烃药试验研究其缓释性，以微球在家兔的体内分布初步考察其靶向性。结果：所制备微球88.6%的粒径在5-25μm。药物包封率为79.2%。8小时体外药物累积释放百分率达95%并有良好的靶向性。结论：用乳化法制备的卡铂肺靶向微球有良好的应用研究前景。     

异烟肼肺靶向性微球的制备及其小鼠体内分布

目的：制备异烟肼肺靶向性微球,评价其体外释药特性及在动物体内的肺靶向性。方法：采用溶剂挥发法制备微球,动态透析法考察其体外释药性能,实验动物静脉注射后测定其各组织的药物浓度,研究其体内相对分布百分率及肺靶向性。结果：制得的微球粒径在7～30μm的占微球总数的88．8％,平均粒径为（16.7±4．6）μm,包封率为86．92％,载药量为（40．7±3.6）％（n=5）,体外释药T50为68min,轻对照组延长了4.5倍。动物实验表明,制得微球后,药物在肺内的相对分布百分率明显高于其它组织与血液,并轻对照组提高了4倍。结论：本法制得的异烟肼微球具有明显的缓释性及肺靶向性。     

紫杉醇肺靶向微球的制备及体内外评价

目的用生物可降解材料聚乳酸-聚羟基乙酸共聚物(PLGA)制备肺靶向紫杉醇缓释微球。方法在单因素考察的基础上进行正交试验设计,筛选出肺靶向紫杉醇PLGA微球的最佳制备工艺条件;利用桨板法研究了微球的体外释药规律;用小鼠为实验对象,研究了紫杉醇聚乳酸微球的体内组织药物分布。结果制得的微球形态圆整,粒径在5~15μm范围内的占总体积的87.18%,微球平均粒径为9.65μm;包封率为83.8%;载药量为19.7%;体外释药符合Higuchi方程Q=-2.193 7 22.009t0.5,r=0.990 4;体内实验表明紫杉醇微球混悬剂较普通注射剂更趋于聚集在肺组织。结论微球制备工艺稳定,具有明显的缓释作用和肺靶向性。     

新型乙型肝炎病毒表面抗原中蛋白核酸疫苗的免疫原性研究

目的 观察新型乙型肝炎病毒（HBV）表面抗原中蛋白（MHBs)核酸疫苗的免疫原性。方法 以新型人体应用载体质粒pSW3891构建MHBs核酸疫苗（pSW3891/MHBs/adr)，对照组和实验组Balb/c小鼠分别基因枪法免疫对照载体质粒（pSW3891)和MHBs核酸疫苗，采用酶联免疫吸附试验检测抗HBs,LDH释放测定法检测小鼠特异性细胞毒T淋巴细胞（CTL）杀伤活性。结果 MHBs核酸疫苗可在体外高效表达，免疫小鼠后可产生高滴度抗HBs，血清阳性终点滴度达1：97200,小鼠脾细胞HBs特异性细胞毒性T淋巴细胞（CTL）杀伤活性达78.81%。结论 新型MHBs核酸疫苗在Balb/c小鼠实验中表现出良好的体液和细胞免疫原性。     

组分百日咳疫苗安全性检测体外替代方法的应用和初步评价

目的：用一种组分百日咳疫苗残留毒性的体外替代检测方法，更稳定和客观地评价疫苗成品的生产一致性。方法：验证直接定性法和间接定量法2种中华仓鼠卵巢细胞簇集试验方法，分别对6个国内外厂家的10种组分百日咳疫苗产品毒性进行定量和定性检测，并使用百日咳毒素参考品将体外法与小鼠组胺致敏试验进行桥接和初步评价。结果：体外定量试验的灵敏度为0.0026±0.0003 IU·mL^-1，几何变异系数为13%，体外定性试验的灵敏度为0.0067±0.0016 IU·mL^-1，几何变异系数为24%，组胺致敏试验的灵敏度为3.3 IU·mL^-1；所有样品的体外定性结果均为阴性，小鼠组胺致敏试验结果均合格，体外定量结果与小鼠组胺致敏结果具有良好的相关性（r=0.737，P＜0.05）。结论：本研究在国内首次使用 CHO细胞簇集试验方法检测百日咳疫苗成品，并进行了初步评价。该方法灵敏度高于小鼠组胺致敏试验，可应用于百日咳疫苗毒性及毒性逆转检测。该方法需要更广泛的推广应用和数据积累，以达到完全替代动物实验的目标。     

壳聚糖-海藻酸钠幽门螺杆菌全菌蛋白微球的制备及表征

目的以壳聚糖、海藻酸钠为主要材料包裹幽门螺杆菌(HP)全菌超声蛋白抗原,制备新型HP疫苗制剂。方法将海藻酸钠、壳聚糖、大豆油以及HP超声全菌抗原制备成W/O/W型微球。通过扫描电镜、粒径分布仪等检测微球粒径大小;药物溶出度仪、BCA蛋白试剂盒检测微球的蛋白包封率及药物释放速率。结果所制备的微球形态规则,平均粒径3.33μm;蛋白包封率约为64.8%;微球呈显著缓释模式,缓释时间可达6d。结论壳聚糖-海藻酸钠微球包裹全菌蛋白可以作为HP疫苗的新型缓释制剂。     

多柔比星磁性蛋白微球的研制及体内外抗癌作用的实验研究

利用加热固化蛋白质原理制备多柔比星（１）磁性蛋白微球（２）并检测其理论性质,以改良ＭＴＴ法分析其体外细胞毒作用,观察经消化道靶向给药后对鼠移植性胃肿瘤的治疗作用。结果表明：２上有磁性药物微球的形态特征,体外对恶性肿瘤细胞的杀伤作用与游离１相似（Ｐ〉０．０５）,与恒定磁场联合应用对鼠移植性胃肿瘤生长的体内抑制明显高于单纯１组（Ｐ〈０．０１）。因而２是抗癌药物的一种新型制剂,在体内外可发挥靶向的抗肿瘤     

Notel长效微球制剂的制备和评价

目的：制备并评价Notel聚乳酸-羟基乙酸共聚物（PLGA）长效缓释微球。方法：采用乳化-溶剂挥发法制备Notel缓释微球,以载药量、包封率、体外释放为评价指标,考察高分子材料、高分子溶液浓度、硬脂酸、不同pH的聚乙烯醇（PVA）溶液等因素对微球的影响,筛选最优处方并制备微球,考察大鼠药动学及对db/db小鼠的降血糖作用。结果：按最优处方制备的微球形态圆整,平均粒径为60 μm,载药量12.5%,体外释药可达1个月。微球在大鼠体内1 h即有药物释放,第8天血药浓度达到峰值C_max（52.96±3.20） ng·mL^-1并持续释放30 d。db/db小鼠的空腹血糖浓度在1个月内有效降低。结论：Notel缓释微球作为1个月长效制剂治疗2型糖尿病（T2DM）具有良好的开发前景。     

树突状细胞介导的CTL在裸鼠体内外抑制白血病细胞生长的研究

目的研究白血病细胞可溶性蛋白抗原（SPA）致敏树突状细胞（DC）介导的细胞毒性T淋巴细胞（CTL）反应在裸鼠体内、外抑制白血病细胞生长的效应,为白血病DC免疫治疗提供理论依据。方法利用人骨髓单个核细胞（MNC）体外培养DC,经形态、表型及功能综合鉴定。用纳米粒包裹白血病细胞SPA并致敏DC,在体外诱导出特异性CTL,用MTT法测定其活性。另分别将HL-60细胞与淋巴细胞（LC）或与CTL同时注入裸鼠体内,通过肿瘤体积、成瘤时间、肿瘤抑制率等对比各组抑制肿瘤生长的效果。结果（1）培养的DC具有DC的形态特征并高表达CD1a、CD83。（2）MTT法测定各组CTL活性,发现A1组较A2组和A3组、B1组较B2组和B3组有明显差异（均P〈0.05）。A3组及B3组CTL活性最高,A2组及B2组活性次之。（3）在裸鼠体内实验中,1组与2组、3组的肿瘤体积及成瘤天数比较均有明显统计学差异（P〈0.05）,而2组与3组比较却无显著性差异（P〉0.05）;2组与3组肿瘤抑制率分别为（50.70±13.74）%和（52.29±13.68）%。结论在体外实验用白血病细胞SPA及纳米粒包裹的SPA致敏DC,均能可介导较强的CTL作用,且纳米粒包裹SPA组的CTL活性更高。用白血病细胞SPA及纳米粒包裹的SPA致敏的DC在裸鼠体内同样可诱导出较强的CTL作用,表现为肿瘤体积明显小于对照组,成瘤天数也明显晚于对照组,但纳米粒包裹SPA致敏DC组在体内试验中未显示出更强的抑瘤活性。通过DC介导特异性的CTL可有效的抑制白血病细胞,是一种有良好临床应用前景的细胞免疫治疗方法。     

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.

     

In vitro studies on sterically stabilized liposomes (SL) as enzyme carriers in organophosphorus (OP) antagonism

This study describes a new approach for organophosphorous (OP) antidotal treatment by encapsulating an OP hydrolyzing enzyme, OPA anhydrolase (OPAA), within sterically stabilized liposomes. The recombinant OPAA enzyme was derived from Alteromonas strain JD6. It has broad substrate specificity to a wide range of OP compounds: DFP and the nerve agents, soman and sarin. Liposomes encapsulating OPAA (SL)* were made by mechanical dispersion method. Hydrolysis of DFP by (SL)* was measured by following an increase of fluoride ion concentration using a fluoride ion selective electrode. OPAA entrapped in the carrier liposomes rapidly hydrolyze DFP, with the rate of DFP hydrolysis directly proportional to the amount of (SL)* added to the solution. Liposomal carriers containing no enzyme did not hydrolyze DFP. The reaction was linear and the rate of hydrolysis was first order in the substrate. This enzyme carrier system serves as a biodegradable protective environment for the recombinant OP-metabolizing enzyme, OPAA, resulting in prolongation of enzymatic concentration in the body. These studies suggest that the protection of OP intoxication can be strikingly enhanced by adding OPAA encapsulated within (SL)* to pralidoxime and atropine.     

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.     

Steroidal sapogenin contents in some domestic plants

In order to find out the values of the steroid resources for the future use. the compositions and contents of steroidal sapogenins from 13 domestic plants have been investigated. As a result,Dioscorea nipponica, D. quinqueloba andSmilax china were found to have large amount of diosgenin. And pennogenin inTrillium kamtschaticum andParis verticillata, yuccagenin inAllium fistulosum, hecogenin inAgave americana and neochlorogenin inSolanum nigum were appeared to be major steroidal sapogenins.