叶酸和聚乙二醇双修饰的壳聚糖纳米粒的制备及其性能表征

目的 利用离子交联和化学交联相结合的方法制备壳聚糖纳米粒子(NPs),并对NPs分别进行了叶酸(FA)和聚乙二醇(PEG)的修饰。方法 通过红外光谱进行结构验证;用扫描电镜和粒度分析仪对粒子的微观形态、粒径、电位等进行了表征;通过与Hela细胞摄取实验对其靶向作用进行验证。结果 离子交联和化学交联相结合的方法制备壳聚糖纳米粒子粒径在200 nm左右并且粒径分布窄,修饰后的NPs(FA-NPs、PEG-NPs及FA+PEG-NPs)粒径不受功能基团修饰的影响。激光共聚焦试验证明FA-NPs及FA+PEG-NPs能显著提高细胞对粒子的摄取,而PEG-NPs则明显降低其对粒子的摄取。结论 FA+PEG-NPs有望成为一种新型的药物载体,用于抗癌药物对癌细胞的主动靶向。     

壳聚糖修饰的托氟啶固体脂质纳米粒的制备

摘 要 目的： 研究托氟啶固体脂质纳米粒及壳聚糖修饰的托氟啶固体脂质纳米粒的制备方法。方法: 采用薄膜 超声分散法制备托氟啶固体纳米脂质粒（TFu-SLNs）及壳聚糖修饰的TFu-SLNs,并对纳米粒的形态、粒径和表面电位进行测定,通过单因素考察及正交设计优化制备方法,同时考察处方稳定性。结果: 薄膜 超声分散法制备的TFu-SLNs平均粒径为160.2 nm,Zeta电位为－33.12 mV,壳聚糖修饰TFu-SLNs平均粒径为400.3 nm,Zeta电位为+12.87 mV。经壳聚糖修饰后,随着壳聚糖浓度的增加,电位逐渐增大。优化后的处方重复性、稳定性良好。结论:通过采用正交设计法对TFu固体脂质纳米粒处方进行优化,得到TFu固体脂质纳米粒及壳聚糖修饰的TFu固体脂质纳米粒的优化处方。     

复方舒郁健脑脑靶向脂质体的制备及其在大鼠体内组织分布

摘 要 目的: 利用Angiopep修饰复方舒郁健脑脂质体,研究复方舒郁健脑脑靶向脂质体的制备方法并考察其在大鼠体内的组织分布,为复方舒郁健脑脑靶向脂质体治疗失眠等脑部疾病提供依据。方法: 采用乙醇注入法制备复方舒郁健脑脂质体,将Angiopep通过马来酰化端基聚乙二醇(PEGMAL)与复方脂质体连接,得到脑靶向脂质体;以脑内茯苓酸含量作为检测指标,研究脂质体的脑靶向性。结果:在所选工艺条件下,复方舒郁健脑脑靶向脂质体平均粒径约500 nm;与普通脂质体相比,复方舒郁健脑脑靶向脂质体在主要靶器官脑部的药物浓度显著增高(P<0.05)。结论:用多肽Angiopep修饰所得脑靶向脂质体可使药物透过血脑屏障(BBB),其作为脑靶向药物递送载体具有良好的应用前景。     

卟啉修饰的壳聚糖光敏新材料的制备与表征

目的 合成卟啉修饰的壳聚糖光敏新材料,对其进行表征,并优化其合成工艺。方法 以溴己烷苯基卟啉衍生物和壳聚糖为原料,以K₂CO₃为碱,采用四丁基溴化铵为相转移催化剂,合成卟啉-壳聚糖复合物,采用茚三酮法测定卟啉接枝率。通过单因素实验研究反应温度、反应时间、混合溶剂比例、催化剂当量等对接枝率的影响,采用正交实验法优化获得最佳制备工艺条件。结果 最佳合成条件为温度55℃、反应时间为5.5 h、混合溶剂中水和氯仿的比例为1：2、催化剂为1当量、无机碱使用K₂CO₃,卟啉的平均接枝率为41.30%。结论 通过共价偶联合成卟啉修饰壳聚糖光敏新材料的方法可行。     

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。     

复方奥硝唑壳聚糖阴道生物黏附膜的制备及质量控制

摘 要 目的:制备复方奥硝唑壳聚糖阴道生物黏附膜并建立其质量控制方法。方法: 以奥硝唑、盐酸环丙沙星为主药制备复方奥硝唑壳聚糖阴道生物黏附膜,采用高效液相色谱法测定其中主药的含量。结果:所制制剂为半透明淡黄色薄膜,鉴别、检查项均符合2010年版《中国药典》中的相关规定;盐酸环丙沙星、奥硝唑分别在27～540 mg·L^-1 （r=0.999 9）,26.5～530 mg·L^-1 （r=0.999 9）范围内呈良好线性关系,方法的平均回收率：盐酸环丙沙星为99.52%,RSD为1.0%;奥硝唑为97.98%,RSD为0.41%。结论:本制剂制备工艺简便可行,质量稳定可控。     

PEG修饰鳖甲肽HGRFG脂质体的药动学研究

目的 制备鳖甲肽HGRFG脂质体以及聚乙二醇（polyethylene glycol,PEG）修饰后的长循环脂质体,考察经修饰的脂质体较未修饰脂质体在动物体内分布及滞留情况。方法 采用BLB/c裸鼠荧光活体成像实验,进行脂质体体内分布及代谢研究;采用药动学实验,初步探究2种载药脂质体在血浆内的滞留时间。结果 2种载药脂质体均能广泛分布于实验动物体内。与未经修饰的脂质体载药组相比,经PEG修饰的长循环脂质体载药组中裸鼠荧光全部消失的时间明显延长,药物在血浆滞留时间也明显延长。结论 经PEG修饰后的长循环脂质体可以延长药物在实验动物体内的滞留时间,延长药物半衰期。     

喷雾干燥法制备斑蝥素壳聚糖生物黏附微球的处方工艺研究

摘 要 目的：优选斑蝥素壳聚糖生物黏附微球的最佳处方工艺。方法: 采用喷雾干燥法制备微球,运用单因素试验考察不同壳聚糖分子量对微球胃黏膜黏附率的影响,不同药载比、壳聚糖醋酸溶液浓度和蠕动泵速度对斑蝥素包封率的影响。采用效应面法,以斑蝥素的包封率为考察指标,进一步优化药载比、壳聚糖醋酸溶液浓度和蠕动泵流速3个因素。结果: 斑蝥素壳聚糖生物黏附微球的最佳处方工艺为：斑蝥素和壳聚糖的重量比为19.83%,壳聚糖醋酸溶液浓度为0.77%,蠕动泵流速为9.225 ml·min-1。以最佳处方工艺制得的斑蝥素壳聚糖生物黏附微球包封率为90.14%。结论: 采用喷雾干燥法制备微球,具有工艺稳定、可重复等优点,制备的斑蝥素壳聚糖生物黏附微球具备较好的包封率和生物黏附性能。     

依托泊苷壳聚糖胶束的制备及壳聚糖促进依托泊苷肠吸收作用的研究

目的 制备依托泊苷壳聚糖胶束,并研究壳聚糖对依托泊苷肠吸收的促进作用。方法 用透析法制备依托泊苷壳聚糖胶束,建立依托泊苷HPLC含量测定方法,测定了其包封率与载药量;采用大鼠在体肠循环实验,研究不同剂量壳聚糖对依托泊苷全肠段和各个肠段吸收的影响。结果 壳聚糖胶束平均粒径为139.5 nm,多分散系数为0.569;依托泊苷标准曲线为A=8 436.8C-4 963.8,r=1.000 0,日内、日间精密度符合要求;包封率为（47.3±2.84）%,载药量为（1.10±1.27）%;随着壳聚糖浓度的增加,依托泊苷在全肠段的单位面积吸收量有不同程度的增加;壳聚糖对依托泊苷的吸收促进作用存在着肠道特异性,作用大小顺序：回肠 >空肠 >十二指肠。结论 在十二指肠、空肠和回肠,壳聚糖都不同程度促进了药物的吸收,且在空肠和回肠有显著性的影响。     

地奥司明栓剂的制备及质量控制研究

目的 制备地奥司明栓剂,建立其质量控制方法。方法 以地奥司明为原料药,以聚乙二醇6000、聚乙二醇400和甘油为基质,用热熔法制备含药栓剂,并对其外观、含量均匀度、融变时限、质量差异进行评价。结果 地奥司明栓剂外观呈棕色,室温下能保持较好的硬度,含量均匀度、质量差异、融变时限、溶出度均符合栓剂要求。结论 本方法制备的地奥司明栓剂符合栓剂的质量要求,适合作为地奥司明的新剂型进行开发。     

Interindividual variability in metabolic activation in humans in vivo

In assessing interindividual variability in metabolic activation, the toxic metabolite is often too unstable for conventional analysis. Possible alternatives include a stable product of the reactive metabolite e.g. cysteinyl derivatives of N-acetyl-4-benzoquinoneimine, the toxic metabolite of paracetamol, adducts with DNA or protein, and indirect measurement of the activity of the enzyme(s) producing the active metabolite. An example of the last approach is the use of furafylline, a highly specific inhibitor of human CYP1A2, to determine the extent of the metabolic activation of the cooked food mutagens PhIP and MeIQx. The extent of inhibition, determined from levels of unchanged amine in urine, is an indirect measure of the activity of the activation pathway. Further refinement of this approach, allied to improved measures of the biological process of interest should prove of value in evaluating interindividual variability and its role in the risk assessment process.     

Quantitative in vivo and in vitro sex differences in artemisinin metabolism in rat

1. The pharmacokinetics of the antimalarial compound artemisinin were compared in the male and female Sprague-Dawley rat after single dose i.v. (20 mg.kg) or i.p. (50 mg.kg) administration of an emulsion formulation. 2. Plasma clearance of artemisinin was 12.0 (95% confidence interval: 10.4, 13.0) l.h. kg in the male rat and 10.6 (95% CI: 7.5, 15.0) l.h. kg in the female rat suggesting high hepatic extraction in combination with erythrocyte uptake or clearance. Artemisinin half-life was 0.5 h after both routes of administration in both sexes. Values for plasma clearance and half-lives did not statistically differ between the sexes. 3. After i.p. administration artemisinin AUCs were 2-fold higher in the female compared with male rat (p 0.001). Artemisinin disappearance was 3.9-fold greater in microsomes from male compared with female livers and it was inhibited in male microsomes by goat or rabbit serum containing antibodies against CYP2C11 and CYP3A2 but not CYP2B1 or CYP2E1. 4. The unbound fraction of artemisinin in plasma was lower (p 0.001) in plasma obtained from the male (8.8 2.0%) compared with the female rat (11.7 2.2%). 5. The possibility of a marked sex difference, dependent on the route of administration, has to be taken into account in the design and interpretation of toxicological studies of artemisinin in this species.     

Theophylline kinetics in peripheral tissues in vivo in humans

Several biochemical and cellular effects have been described for methylxanthines under in vitro conditions. However, it is unknown, whether threshold concentrations required to exert these effects are attained in target tissues in vivo. We therefore employed the microdialysis technique for measuring theophylline concentrations in peripheral tissues under in vivo conditions.Following in vitro and in vivo calibration, microdialysis probes were inserted into the medial vastus muscle and into the periumbilical subcutaneous adipose layer of healthy volunteers. Following single oral dose administration of 300 mg or i.v. infusion of 240 mg theophylline, in vivo time courses of theophylline concentrations were monitored in tissues and plasma. Major pharmacokinetic parameters (c_max, t_max, AUC) were calculated for plasma and tissue time courses. The mean AUC_tissue /AUC_plasma-ratio was 0.56 (p.o.) and 0.55 (i.v.) for muscle and 0.55 (p.o.) and 0.72 (i.v.) for subcutaneous adipose tissue.We conclude that microdialysis provides important information on the distribution and the tissue pharmacokinetics of theophylline.Abbreviations FPIA Fluorescence polarisation immuno assay - AUC Area under the curve - t_max Time to peak concentration - c_max Peak concentration     

休克时血中氧自由基的变化

本实验测定10名休克患者血浆和红细胞的丙二醛(MDA)、血浆总抗的氧化活性(AOA)的含量。结果表明:休克病人红细胞膜和血浆 MDA 含量(4.298±0.722;5.348±0.834)与对照组(3.235±0.682;4.356±1.081)比较明显增高(P<0.05);血浆 AOA(39.65±7.858)与对照组(48.21±10.81)比较明显降低(P<0.01)。提示:休克时,患者机体内自由基反应增强是引起组织细胞损伤的原因之一。     

Polymorphisms in genes involved in neurotransmission in relation to smoking

Smoking behavior is influenced by both genetic and environmental factors. The genetic contribution to smoking behavior is at least as great as its contribution to alcoholism. Much progress has been achieved in genomic research related to cigarette-smoking within recent years. Linkage studies indicate that there are several loci linked to smoking, and candidate genes that are related to neurotransmission have been examined. Possible associated genes include cytochrome P450 subfamily polypeptide 6 (CYP2A6), dopamine D₁, D₂, and D₄ receptors, dopamine transporter, and serotonin transporter genes. There are other important candidate genes but studies evaluating the link with smoking have not been reported. These include genes encoding the dopamine D₃ and D₅ receptors, serotonin receptors, tyrosine hydroxylase, trytophan 2,3-dioxygenase, opioid receptors, and cannabinoid receptors. Since smoking-related factors are extremely complex, studies of diverse populations and of many aspects of smoking behavior including initiation, maintenance, cessation, relapse, and influence of environmental factors are needed to identify smoking-associated genes. We now review genetic polymorphisms reported to be involved in neurotransmission in relation to smoking.     

Tramadol concentrations in blood and in cerebrospinal fluid in a neonate

Based on blood and cerebrospinal fluid samples collected in a full-term neonate, the penetration of tramadol in the central nervous system is described. Following intravenous administration of tramadol, a lag time of about 4 h was observed until full blood–brain equilibration was achieved. This pharmacokinetic observation is in line with a recent pharmacodynamic evaluation of the central opioid effects of tramadol in adults.     

Disease control in asthmatic children seen in private practice in Switzerland

ABSTRACT

Background: Asthma is the most common chronic childhood disease in Switzerland with a prevalence of 10%. Asthma has a high economic burden accounting for high medical costs. Assessment of disease control is likely to be of help in the implementation of strategies to improve asthma. Therefore, we aimed to evaluate asthma control and therapy regimens among children in private practice.

Methods: We assessed asthma control as well as therapy regimens in 575 asthmatic children in an experience programme in Switzerland by using an abbreviated questionnaire based on the asthma control questionnaire and the child health questionnaire on Visit 1 and Visit 2.

Results: Good asthma control at Visit 1 was only present in 25.7% of asthmatic children. Occasional asthma symptoms, limitation of physical activity, nocturnal awakening and anxiety of the parent was present in 80.5%, 41.2%, 46.8% and 57% of the children, respectively. After adjustment of therapy regimens at Visit 1, mainly by adding a leukotriene receptor antagonist, asthma control was reported to be much better in 53.4% of the children at Visit 2.

Conclusions: As asthma control is inadequately achieved within a major portion of asthmatic children, it is imperative to find measures to improve asthma control and hence, to reduce the burden of disease.