川芎嗪微乳的制备及不同粒径微乳体外释放对比研究

目的研究川芎嗪微乳递药系统的制备工艺,对其物理药剂学性质进行评价;以不同油相制备不同粒径大小的微乳,考察粒径因素对制剂释药行为的影响。方法以川芎嗪溶解度为指标,筛选油相、乳化剂、助乳化剂;采用伪三元相图法对微乳处方进行优化;采用超滤离心法对载药量、包封率进行研究;采用马尔文粒径仪对粒径、电位进行检测;采用透析袋法对不同粒径微乳的释药行为进行对比研究。结果成功制备了川芎嗪微乳,外观澄清透明,pH均值约为5.46;成功建立了微乳包封率的检测方法;川芎嗪载药量为1.2 mg/mL时,包封率为(87.43±0.20)%。通过改变油相(油酸乙酯、油酸、IPM)制备不同粒径的微乳,当载药量为1.2 mg/mL时3者的粒径分别为(16.80±0.91)、(129.50±1.21)、(18.51±0.24)nm。释放实验显示,在4 h内3者释放率均能达到90%以上,无显著性差异。结论成功制备了均一、稳定的川芎嗪微乳;不同粒径川芎嗪微乳的释药行为不受粒径因素的影响。     

An evaluation of the SpuncritTM infra-red analyser for measurement of haematocrit

Summary An open, single centre study was carried out to evaluate the accuracy of the Spuncrit^TM (Micro Diagnostics, Bethlehem, PA, USA) infra-red analyser which can be used for near-patient testing to measure haematocrit and estimate haemoglobin concentration. The primary comparison was with the Sysmex NE1500 (Tao Medical) analyser situated in the main hospital laboratory. Secondary comparison was with the Ciba Corning 288 (Ciba Corning Diagnostics Ltd, Halstead, UK) blood gas analyser currently used for near-patient testing in the Northern General Hospital. A total of 217 samples from 50 patients was analysed. The Pearson's correlation coefficients for haematocrit and haemoglobin concentration between the Spuncrit^TM and Sysmex NE1500 and between the Spuncrit^TM and Ciba Corning 288 were all close, between 0.85 and 0.92. The method of Bland and Altman was used to asses agreement between the results of the Spuncrit^TM and the Sysmex NE1500. The agreement for haematocrit was good with 2 SD of the Spuncrit^TM results being between – 5.66 and +4.42% of the measurement from the Sysmex NE1500. In conclusion, the Spuncrit^TM haematocrit measurement agreed well with results from the central laboratory, but the estimated haemoglobin concentrations agreed less well and three reasons are discussed.     

Leukocyte Esterase From Synovial Fluid Aspirate : A Technical Note

Accurate and efficient diagnosis of periprosthetic joint infection remains one of the most challenging tasks for orthopedic surgeons. Currently, no widely used diagnostic test allows for quick and efficient performance, low cost, and high sensitivity and specificity. Aspiration of synovial fluid from a patient's joint can be done in the clinic both quickly and easily; oftentimes, the aspirate obtained is bloody, thus rendering the use of colorimetric strip testing impractical. We describe a simple, inexpensive, and effective protocol using centrifugation to allow for leukocyte esterase (LE) testing after bloody joint aspirations. In all cases, both septic and aseptic, there was a 100% concordance in LE enzyme test results. Although further validation may be necessary, these initial results demonstrate that accuracy of LE testing is not affected by centrifugation.     

Freeze-fracture analysis of plasma membranes of isolated astrocytes from rat brain

Plasma membranes of mature rat astrocytes separated by differential centrifugation have been reported to be intact, based on electron microscopic examination of thin plastic sections. However, the effects of the separation procedure on the internal structure of the plasma membranes are unknown. The degree of membrane integrity is of concern to us since our goal is the separation of astrocytic plasma membranes and characterization of the specific intramembranous particle groups called assemblies. We have taken advantage of the astrocyte membrane-marker, the assembly, in order to monitor, by freeze-fracture, the identity of the separated astrocytes and the integrity of their cell membrane. Since some processes of an astrocyte contain assemblies whereas other processes of the same cell do not, it was also necessary to determine if processes with assemblies were separated by this technique. Astrocytic cell membranes were also examined to determine if trypsinization or the mechanical disruption steps of the separation affected the intramembranous particles. Freeze-fracture of the plasma membranes revealed that the particles were rearranged resulting in patches of clumped intramembranous particles and areas of bare membrane. The assemblies were rearranged rather than lost from the membrane since they could be identified among the clumped particles. More astrocytic plasma membranes contained non-clumped, normally distributed particles in the trypsin treated fractions. The non-trypsinized fractions had more damaged astrocytes with aggregated intramembranous particles and much more cellular debris. We interpret the findings for the non-trypsinized astrocytes as due to greater mechanical stress placed on the cells during tissue disruption. Trypsin treatment lessens this stress, thereby, tending to preserve the normal distribution of intramembranous particles.     

离心沉淀-离心超滤法测定盐酸青藤碱脂质体的包封率

目的 建立盐酸青藤碱（sinomenine hydrochloride,SM-HCl）脂质体包封率的测定方法,并阐明药物在脂质体中的滞留特性。方法 采用薄膜分散法制备SM-HCl脂质体。以HPLC法测定脂质体药物的量,色谱柱为Kromasil ODS C₁₈柱（250 mm×4.6 mm,5 μm）,流动相为甲醇-水-乙二胺（55∶45∶0.225）,体积流量1.0 mL/min,检测波长265 nm。以离心沉淀-离心超滤法测定SM-HCl脂质体的包封率,并与以枸橼酸缓冲液（pH 7.0）水化的脂质体样品稀释前后的包封率进行对比。结果 辅料与溶剂对青藤碱的定量测定无干扰,青藤碱在9.82～78.56 μg/mL线性关系良好（r＝0.999 7）,平均回收率在99.29%～100.8%,日内与日间精密度良好（RSD≤2.1%）。50 μL药液可使超滤膜对药物的吸附达到饱和。以枸橼酸缓冲液（pH 7.0）水化的脂质体样品的包封率为33.16%,稀释1倍后该样品的包封率降至14.75%。结论 HPLC法与离心沉淀-离心超滤法结合可用于测定SM-HCl脂质体的包封率,该方法快速、准确;离心超滤中应弃去50 μL初滤液以确保滤液与脂质体外水相药物浓度一致;青藤碱与脂质双分子层有一定的亲和力,但在脂质体中的滞留性较差。     

Selective inhibition of herpesvirus DAN synthesis by foscarnet

The inhibition of cellular and herpesvirus DNA synthesis by phosphonoformate (INN; foscarnet sodium) has been determined after isopycnic separation of cellular and viral DNA in CsCl gradients. The DNA synthesis was determined as the incorporation of ortho[³²P]phosphate and [³H]thymidine into DNA. A 50% inhibition of herpes simplex virus DNA synthesis was observed at 50 μM phosphonoformate. At this concentration cellular DNA synthesis was not inhibited. At 500 μM phosphonoformate more than 95% of the viral DNA synthesis was inhibited, while the cellular DNA synthesis in infected and uninfected cells were inhibited to about 10%. The same results were obtained in both Vero and GMK cells and using either ortho[³²P]phosphate or [³H]thymidine to label the newly synthesized DNA. The 50% inhibitory concentration of phosphonoformate was similar for inhibition of herpes DNA synthesis and plaque reduction.     

脑梗死病人急性期血小板密度、细胞内游离钙及其功能的变化

目的 观察脑梗死病人急性期血小板密度、细胞内游离钙浓度及血小板聚集和释放的变化。方法 以梯度离心制备血小板密度亚群,激光共聚焦显微镜法测定Ｆｌｕｏ－３／ＡＭ负载后血小板细胞内游离钙荧光强度的变化,以透光度法和介质同中ＡＴＰ的量评价血小板的释放反映。对照组和实验组血小板分别来自于正常志愿者和脑梗死病人急性期的静脉血。     

Progress involving new techniques for liposome preparation

The article presents a review of new techniques being used for the preparation of liposomes. A total of 28 publications were examined. In addition to the theories, characteristics and problems associated with traditional methods, the advantages and drawbacks of the latest techniques were reviewed. In the light of developments in many relevant areas, a variety of new techniques are being used for liposome preparation and each of these new technique has particular advantages over conventional preparation methods. However, there are still some problems associated with these new techniques that could hinder their applications and further improvements are needed. Generally speaking, due to the introduction of these latest techniques, liposome preparation is now an improved procedure. These applications promote not only advances in liposome research but also the methods for their production on an industrial scale.