抗癌丝裂霉素白蛋白微球的制备及体外释药性能

以人血清白蛋白为载体材料,精制棉籽油为油相,采用乳化热固法制备了抗癌丝裂霉素C白蛋白微球,对丝裂霉素C白蛋白微球的粒径、载药量、包封率以及药物的体外释药等特性进行了研究。结果表明,采用乳化热固法制备的白蛋白微球平均粒径为500 nm;丝裂霉素C白蛋白微球的平均载药量为2.98μg/m g,包封率为61.2%,在体外具有明显的药物缓释效果。     

美他环素与牛血清白蛋白相互作用的光谱研究

利用紫外光谱法、 荧光光谱法研究了美他环素（METC）与牛血清白蛋白（BSA）相互作用的机理; 考察了温度、 溶液酸碱度、 金属离子对METC与BSA相互作用的影响. 实验结果表明, METC对BSA的猝灭属于静态猝灭过程; 它们的结合主要以静电引力为主, 根据Frster非辐射能量转移原理计算了METC与BSA的结合距离; 金属配合物对BSA的猝灭属于静态猝灭过程, 但结合常数相对于在常温时METC直接猝灭BSA的结合常数有很大差异, 而且结合位点数也有相应的改变, 表明金属离子的介入对METC的结构及疏水性能都有不同程度的影响.     

Sperm competition, immunity, selfish genes and cancer

Sperm competition is widespread and has played an important role in shaping male reproductive characters such as testis size and numbers of sperm produced, and this is reflected in the rapid evolution of many reproductive genes. Additionally, sperm competition has been implicated in the rapid evolution of seminal fluids. However, our understanding of the molecular basis of many traits thought to be important in sperm competition is rudimentary. Furthermore, links between sperm competition and a range of issues not directly related to reproduction are only just beginning to be explored. These include associations between sperm competition and selfish genes, immunity and diseases such as cancer.We briefly review these topics and suggest areas we consider worthy of additional research.     

Molecular mechanisms of spider silk

Spiders spin high-performance silks through the expression and assembly of tissue-restricted fibroin proteins. Spider silks are composite protein biopolymers that have complex microstructures. Retrieval of cDNAs and genomic DNAs encoding silk fibroins has revealed an association between the protein sequences and structure-property relationships. However, before spider silks can be subject to genetic engineering for commercial applications, the complete protein sequences and their functions, as well as the details of the spinning mechanism, will require additional progress and collaborative efforts in the areas of biochemistry, molecular biology and material science. Novel approaches to reveal additional molecular constituents embedded in the spider fibers, as well as cloning strategies to manipulate the genes for expression, will continue to be important aspects of spider biology research. Here we summarize the molecular characteristics of the different spider fibroins, the mechanical properties and assembly process of spidroins and the advances in protein expression systems used for recombinant silk production. We also highlight different technical approaches being used to elucidate the molecular constituents of silk fibers. Received 28 February 2006; received after revision 14 April 2006; accepted 22 May 2006 X. Hu and K. Vasanthavada contributed equally to this work.     

诺氟沙星与牛血清白蛋白相互作用的拉曼光谱研究

用拉曼光谱技术研究了固态和水溶液中诺氟沙星和牛血清白蛋白的相互作用.通过对诺氟沙星和牛血清白蛋白的拉曼光谱比较,发现其作用产物的拉曼特征峰发生了较明显的变化,解释了可能的作用机理.     

盐酸左氧氟沙星与牛血清白蛋白的相互作用

研究了盐酸左氧氟沙星(OFLX)与牛血清白蛋白(BSA)间的相互作用,证实了二者间的相互作用为单一的静态猝灭过程,求出了结合常数与结合位点,并依据能量转移理论确定了药物与蛋白的最近距离。     

Male panda (Ailuropoda melanoleuca) urine contains kinship information

Chemical communication plays an important role in kin selection and mate choice in mammals. The covariance of odor-genes of rodents has been documented and kinship odor has been proposed and termed, yet little is known of the relationship between genetic relatedness and chemical composition of kinship odors. Giant pandas (Ailuropoda melanoleuca) rely substantially on chemical communication to mediate their social interactions. To examine the relationship between genetic relatedness and compounds in the urine/anogenital gland secretions, we compared the similarities between genetic relatedness and the chemical profiles of anogenital gland secretions and urine via lineage construction and GC-MS (gas chromatography and mass spectrometry). We found that information about kinship odors was present only in the urine of male adults in the mating season but absent in the non-mating season. Adult females and all sub-adults did not have such kinship odors in either mating or non-mating season. Therefore, kinship odor in the panda was contingent on age, sex, and season. This is the first report about the condition-dependent expression of kinship odor, which may have a sig- nificant implication in the practice of panda conservation in relation to chemical communication and sexual selection.     

力竭运动对小鼠体内脂质过氧化作用及肾上腺超微结构的影响

观察了力竭运动对小鼠体内脂质过氧化作用及对肾上腺超微结构的影响．结果表明：连续７次力竭运动后，小鼠肝内丙二醛（ＭＤＡ）含量明显升高；肾上腺皮质及髓质细胞呈现了高度的可变性．提示力竭运动后，小鼠体内所产生的脂质过氧化代谢产物增加，进而可导致细胞膜系及超微结构的改变     

Circadian rhythms and their mechanisms

Summary Recent work concerning the number, site(s) and means of adjustment to the 24-h day of internal clocks is reviewed. Work on humans is considered wherever possible though much of the work involving ablation and in vitro techniques necessarily involves other species, particularly rodents. It is concluded that, though recent advances have been impressive and present techniques appear likely to continue to produce results and stimulate discussion, more attention should be directed to considering the circadian system as a whole rather than as an assemblage of individual components.     

白蛋白在毛细血管壁内的扩散、吸附和渗流作用

建立白蛋白在毛细血管壁孔隙中运动的物理模型，并对白蛋白在毛细血管壁孔隙中的吸附、扩散及渗透作用进行数值求解．计算结果表明，扩散使白蛋白在毛细血管壁孔隙中的浓度下降，吸附使白蛋白损耗，导致浓度传播滞后，根据白蛋白在毛细血管壁孔隙中的吸附、扩散及渗透作用，提出了“胶体蛋白墙”的概念及理论，并解释了水肿的形成机理。