靶向给药系统——青蒿酯脂质体的制备研究

采用乳化法制备了多层的青蒿酯脂质体,探讨了其制备工艺、荷电性、胆固醇含量及附加剂对青蒿酯脂质体包裹率的影响。结果表明,带正电荷的脂质体其包裹率明显高于中性或带负电荷的脂质体,而类脂中胆固醇含量及附加剂对包裹率均无明显影响,最佳处方组成的包裹率为3.63±0.09％。采用冷冻干燥技术可获得稳定性较好的脂质体冻     

三尖杉酯碱脂质体的制剂研究

本文探讨三尖杉酯碱脂质体的较佳制备方法。表明用转相蒸发法(REV)制备时影响三尖杉酯碱脂质体包裹率的因素与大多数水溶性药物脂质体的影响因素相同。提出并经实验证实,以稠厚型脂质体贮存可减少内包三尖杉酯碱的渗漏。实验还表明脂质体100℃30分钟灭菌和10℃以下贮存五个月,制品的结构、粒度和包裹率均无明显改变,溶血试验合格。但在40℃加速实验1至3个月制品产生溶血,此溶血与卵磷脂的氧化有明显相关性。     

阿糖腺苷脂质体的制备及其稳定性

本文比较了薄膜法、反相蒸发法、冰冻熔融法制备Ara-A脂质体的包裹率,采用正交设计法摸索Ara-A脂质体制备的最佳技术条件,利用自行设计的改良冰冻熔融法将难溶性药物Ara-A研制成脂质体,其包裹率可达约50%,为国外文献报道的采用反相蒸发法所制得的Ara-A脂质体的包裹率(5.2±0.9%)的10倍。本法操作简单、重现性好。本文还考察了Ara-A脂质体的物理和化学稳定性,实验表明:Ara-A脂质体采用100℃30min灭菌的方法,制品的形态、粒度分布、包裹率及含量均无明显改变,经恒温加速试验,表明Ara-A脂质体具有一定的化学稳定性。     

孕期疟疾的妊娠结局及青蒿琥酯治疗的安全性研究

目的探讨妊娠合并疟疾对妊娠结局的影响及孕期应用青蒿琥酯治疗的安全性。方法选择2006年8月～2007年8月妊娠合并疟疾孕妇178例,其中,妊娠6～12周88例,分为早孕治疗组58例和早孕非治疗组30例;妊娠>12～40周,为孕中后期组90例。另选妊娠6～40周无合并疟疾的孕妇49例,为对照组。结果妊娠6～12周疟疾孕妇:早孕非治疗组流产率6.67%明显高于对照组2.04%,P<0.01;早孕治疗组流产率13.79%明显高于早孕非治疗组流产率6.67%,P<0.01,其流产多发生在妊娠6～9周期间。妊娠﹥12～40周组其早产、低体重儿、死胎、新生儿窒息率明显高于对照组,均P<0.01;此期间因疟疾发作而伴有的先兆流产、先兆早产、胎儿窘迫等不良结局,应用青蒿琥酯治疗后其不良结局得以改善。结论妊娠6～12周合并疟疾可引起流产,孕早期应用青蒿琥酯治疗可导致流产,尤其是在孕6～9周期间,因此,早期妊娠应用青蒿琥酯治疗要慎重,尽量至孕10周后才用药;妊娠>12～40周合并疟疾其妊娠不良结局增加,青蒿琥酯可改善疟疾发作导致的妊娠不良结局,青蒿琥酯适用于妊娠>12～40周的孕妇。     

青蒿琥酯纳米粒的制备及其体外细胞抑制试验

目的:制备青蒿琥酯纳米粒,并对其性质及体外细胞抑制作用进行研究。方法:以聚乳酸-羟基乙酸共聚物(PLGA)为载体,采用自乳化方法制备青蒿琥酯纳米粒。扫描电镜观察纳米粒的形态,激光粒度仪测定纳米粒的粒径及其分布;考察纳米粒的载药量、包封率、体外释放情况;MTT法考察纳米粒对人白血病细胞株K562在不同时间(24、48、72h)的体外细胞抑制率,并与青蒿琥酯(原料药)比较。结果:所制青蒿琥酯纳米粒为圆球形,表面光滑,平均粒径为(144±3.0)nm,Zeta电位是-31.5mV,平均载药量和包封率分别为14%、84%;体外释放试验前期有明显突释现象,前24h累积释放度为46%,其后释放均匀,120h累积释放度达65%,具有缓释作用;其在72h时对细胞抑制率高于青蒿琥酯组(76.4%vs.59.1%),有较强抑制作用(P<0.05)。结论:所制青蒿琥酯纳米粒在体外具有较好的缓释性,对K562细胞有较强的抑制作用。     

正常大鼠静脉注射PEG包裹胰岛素脂质体的降血糖作用

目的以胰岛素为模型药物,评价PEG包裹胰岛素脂质体的降血糖药效学作用.方法采用逆相蒸发法制备PEG包裹的胰岛素脂质体.正常Wistar大鼠分别静脉注射给予胰岛素溶液、胰岛素脂质体及PEG包裹的胰岛素脂质体.采用葡萄糖还原酶法测定血清中的血糖浓度.以梯形法计算血糖-时间曲线上面积(AAC),采用胰岛素溶液的AAC为对照,分别计算胰岛素脂质体和PEG包裹的胰岛素脂质体的药理相对生物利用度.结果 PEG包裹的胰岛素脂质体的包封率为18.33%,平均粒径为58.4 nm.静脉注射给予胰岛素溶液、胰岛素脂质体和PEG包裹的胰岛素脂质体后,其血糖降低的最低百分率(Cmin%)分别为:25.26±5.75%,33.92±12.42% 和42.39±10.5%;达到最低百分率的时间(Tmin)分别为:0.7±0.3,1.2±0.4和2.3±0.7 h.胰岛素脂质体和PEG包裹的胰岛素脂质体的药理相对生物利用度分别为:98.03%和99.70%.结论 PEG包裹的胰岛素脂质体具有相对的缓释作用,降血糖作用更为明显.     

氨甲喋呤(MTX)脂质体的制备及其稳定性

本文探讨了提高MTX脂质体包裹率、影响它对热稳定性的因素,并自行设计了简便、迅速、重现性好的测定MTX脂质体的方法。结果表明:采用二次乳化蒸发法制备MTX脂质体,在控制乳化温度及有机相比例的条件下,可获得50%左右较高的包裹率。另外提示,脂质体分散溶媒的离子强度和脂质体中胆固醇的含量是影响MTX脂质体对热稳定性的重要因素。以选用50mM的磷酸盐缓冲液为分散溶媒和PC/CHOL/SA的脂质体组成,则100℃加热30分钟灭菌,所包MTX可滞留90%。且灭菌前后的脂质体经电镜观察形态无明显变化。     

槐定碱阳离子脂质体的制备及体外抗肿瘤活性的研究

目的制备槐定碱阳离子脂质体,并探讨其对肿瘤细胞的抑制作用。方法采用主动载药法制备槐定碱阳离子脂质体,并对其进行表征研究,采用MTS方法考察槐定碱阳离子脂质体对3种肿瘤细胞的抑制作用。结果制备得到的槐定碱阳离子脂质体呈类圆形,表面光滑,其平均粒径和聚分散指数分别为242.2 nm和0.180,表面电荷为+32.5 m V,其包封率和载药量分别为88.62%和5.97%。槐定碱阳离子脂质体对3种肿瘤细胞的IC50值均明显高于槐定碱,而空白阳离子脂质体对细胞并无明显的抑制作用。结论采用阳离子脂质体作为槐定碱的载体有利于将药物透过细胞膜,提高抗肿瘤作用,值得进行深入的系统研究。     

青蒿琥酯抑制新生血管生成的作用

目的　为研究青蒿琥酯成为抗血管生成药物的可能性 ,观察其对新生血管的影响 ,并初步探讨其机制。方法　采用鸡胚绒毛尿囊膜、大鼠主动脉环无血清培养、人脐静脉内皮细胞损伤迁移等实验 ,检测青蒿琥酯对新生血管增殖与迁移的抑制作用。结果　鸡胚绒毛尿囊膜实验表明 ,青蒿琥酯有较强的血管增殖抑制作用 ,对微血管作用强于大血管 ;大鼠主动脉环无血清培养实验表明 ,青蒿琥酯能明显推迟血管新生 ,减少新生血管数量 ;人脐静脉内皮细胞损伤迁移实验表明青蒿琥酯对内皮细胞具有增殖和迁移抑制作用。在这些体内外实验中 ,青蒿琥酯抑制血管生成作用呈剂量依赖性。结论　青蒿琥酯具有抑制新生血管生成作用 ,此作用可能与抑制血管内皮细胞迁移有关。     

青蒿琥酯及其与放疗联用对CNE细胞的作用

目的研究青蒿琥酯及其与放疗联用对鼻咽癌CNE细胞增殖和凋亡的影响。方法采用细胞集落计数法和原位末端标记（TUNEL）法,测定单用青蒿琥酯及其与放疗联用对CNE细胞增殖的抑制作用和对凋亡的诱导。结果青蒿琥酯能够抑制CNE细胞增殖,并呈现明显的剂量效应,药物浓度2．5～50μg／ml的细胞存活率为15．75％～93．64％。青蒿琥酯可诱导CNE细胞凋亡,高浓度组（10μg／ml）作用比低浓度组（5μg／ml）强（P〈0．05）。当青蒿琥酯与放疗联用时作用更为明显,联用组的作用效果均优于单用青蒿琥酯组或单纯放疗组。结论青蒿琥酯对CNE细胞增殖有明显的抑制和诱导凋亡作用,且和放疗联用作用更强。     

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.     

Nachweis einiger Heilmittel in der Kniegelenksynovialflüssigkeit

Zusammenfassung Mittels Gaschromatographie und Dünschichtchromatographie wiesen die Autoren 11 Substanzen nach, welche durch Injektion oder nach Verabreichung per os in die Kniegelenksynovialflüssigkeit eindrangen. In ihrer Aufstellung konnten sie eine direkte Beziehung zwischen Struktur sowie chemischphysikalischen Eigenschaften der Substanz und ihrer Fähigkeit, aus dem Blut in die Kniegelenksynovialflüssigkeit einzudringen, nicht nachweisen, außer der Tatsache, daß Substanzen mit starker Affinität zu Eiweißstoffen erst in höheren Dosen nachweisbar waren.     

Lung disease and PKCs

The lung offers a rich opportunity for development of therapeutic strategies focused on isozymes of protein kinase C (PKCs). PKCs are important in many cellular responses in the lung, and existing therapies for pulmonary disorders are inadequate. The lung poses unique challenges as it interfaces with air and blood, contains a pulmonary and systemic circulation, and consists of many cell types. Key structures are bronchial and pulmonary vessels, branching airways, and distal air sacs defined by alveolar walls containing capillaries and interstitial space. The cellular composition of each vessel, airway, and alveolar wall is heterogeneous. Injurious environmental stimuli signal through PKCs and cause a variety of disorders. Edema formation and pulmonary hypertension (PHTN) result from derangements in endothelial, smooth muscle (SM), and/or adventitial fibroblast cell phenotype. Asthma, chronic obstructive pulmonary disease (COPD), and lung cancer are characterized by distinctive pathological changes in airway epithelial, SM, and mucous-generating cells. Acute and chronic pneumonitis and fibrosis occur in the alveolar space and interstitium with type 2 pneumocytes and interstitial fibroblasts/myofibroblasts playing a prominent role. At each site, inflammatory, immune, and vascular progenitor cells contribute to the injury and repair process. Many strategies have been used to investigate PKCs in lung injury. Isolated organ preparations and whole animal studies are powerful approaches especially when genetically engineered mice are used. More analysis of PKC isozymes in normal and diseased human lung tissue and cells is needed to complement this work. Since opposing or counter-regulatory effects of selected PKCs in the same cell or tissue have been found, it may be desirable to target more than one PKC isozyme and potentially in different directions. Because multiple signaling pathways contribute to the key cellular responses important in lung biology, therapeutic strategies targeting PKCs may be more effective if combined with inhibitors of other pathways for additive or synergistic effect. Mechanisms that regulate PKC activity, including phosphorylation and interaction with isozyme-specific binding proteins, are also potential therapeutic targets. Key isotypes of PKC involved in lung pathophysiology are summarized and current and evolving therapeutic approaches to target them are identified.     

Gender-related symptoms and correlates of alcohol dependence among men and women with a lifetime diagnosis of alcohol use disorders

This study explored gender-related symptoms and correlates of alcohol dependence in a crosssectional study of 150 men and 150 women with a lifetime diagnosis of alcohol use disorders (AUD). Participants were recruited in equal numbers from treatment settings, correctional centres and the general community. Standardized measures were used to determine participants' use of substances, history of psychiatric disorders and psychosocial stress, their sensation seeking and family history of substance use and mental health disorders. Multivariate analyses were used to detect patterns of variables associated with gender and the lifetime severity of AUD. Men had a longer history of severe AUD than women. Women had similar levels of alcohol dependence and medical and psychological sequelae as men, despite 6 fewer years of AUD. More women than men had a history of severe psychosocial stress, severe dependence on other substances and antecedent mental health problems, especially mood and anxiety disorders. There were differences in family history of alcohol-related problems approximating same-gender aggregation. The severity of a lifetime AUD was predicted by its earlier age at onset and the occurrence of other disorders, especially anxiety, among both men and women. The limitations in the generalizability of these findings due to sample idiosyncrasies are discussed.     

Biochemical and molecular characterisation of cubozoan protein toxins

Class Cubozoa includes several species of box jellyfish that are harmful to humans. The venoms of box jellyfish are stored and discharged by nematocysts and contain a variety of bioactive proteins that are cytolytic, cytotoxic, inflammatory or lethal. Although cubozoan venoms generally share similar biological activities, the diverse range and severity of effects caused by different species indicate that their venoms vary in protein composition, activity and potency. To date, few individual venom proteins have been thoroughly characterised, however, accumulating evidence suggests that cubozoan jellyfish produce at least one group of homologous bioactive proteins that are labile, basic, haemolytic and similar in molecular mass (42-46 kDa). The novel box jellyfish toxins are also potentially lethal and the cause of cutaneous pain, inflammation and necrosis, similar to that observed in envenomed humans. Secondary structure analysis and remote protein homology predictions suggest that the box jellyfish toxins may act as α-pore-forming toxins. However, more research is required to elucidate their structures and investigate their mechanism(s) of action. The biological, biochemical and molecular characteristics of cubozoan venoms and their bioactive protein components are reviewed, with particular focus on cubozoan cytolysins and the newly emerging family of box jellyfish toxins.     

Dose tolerability of chronically inhaled voriconazole solution in rodents

Invasive pulmonary aspergillosis (IPA) is a fungal disease of the lung associated with high mortality rates in immunosuppressed patients despite treatment. Targeted drug delivery of aqueous voriconazole solutions has been shown in previous studies to produce high tissue and plasma drug concentrations as well as improved survival in a murine model of IPA. In the present study, rats were exposed to 20 min nebulizations of normal saline (control group) or aerosolized aqueous solutions of voriconazole at 15.625 mg (low dose group) or 31.25 mg (high dose group). Peak voriconazole concentrations in rat lung tissue and plasma after 3 days of twice daily dosing in the high dose group were 0.85 ± 0.63 μg/g wet lung weight and 0.58 ± 0.30 μg/mL, with low dose group lung and plasma concentrations of 0.38 ± 0.01 μg/g wet lung weight and 0.09 ± 0.06 μg/mL, respectively. Trough plasma concentrations were low but demonstrated some drug accumulation over 21 days of inhaled voriconazole administered twice daily. Following multiple inhaled doses, statistically significant but clinically irrelevant abnormalities in laboratory values were observed. Histopathology also revealed an increase in the number of alveolar macrophages but without inflammation or ulceration of the airway, interstitial changes, or edema. Inhaled voriconazole was well tolerated in a rat model of drug inhalation.