Standardization of BSE rapid test performances and experiences gathered during the implementation of large-scale testing

The accumulation of pathological prion protein is used as a diagnostic marker for transmissible spongiform encephalopathies. According to European Union (EU) regulations cattle older than 30 months of age (Germany, France, Italy, and Spain by national law >24 months) and slaughtered for human consumption must be tested by using rapid tests for bovine spongiform encephalopathy (BSE). Likewise fallen stock and clinically affected animals must be tested. This article gives a short overview of the incidence of BSE in Europe. The diagnostic hierarchy, i.e., the officially approved methodology for the confirmation of suspect rapid test cases, and the organization of the numerous laboratories involved in this large-scale testing for BSE are described. Special emphasis is given to necessary quality control measures currently in place for BSE rapid testing laboratories and to measures intended to assure a consistent performance of the commercially available rapid test kits.Presented at BERM-9—Ninth International Symposium on Biological and Environmental Reference Materials, 15–19 June 2003, Berlin, Germany.     

Preparation of Functional Fluorescent Microspheres Used for HTS and Their Interaction with Biomolecules

There is considerable interest in protein adsorption onto microspheres because of its importance in a wide range of biomedical applications, such as artificial tissues and organs, drug delivery systems, biosensors, solid-phase immunoassays, immunomagnetic cell separation and immobilized enzymes or catalyst. It has been well known that the interaction between proteins and microspheres plays important roles in this process. Major interaction involved in the adsorption can be classified as electrostatic, hydrophobic and hydrogen-bonding. Indeed, adsorption of proteins onto microspheres is a complex process and often can involve many dynamic steps, from the initial attachment of the protein on the surface of microspheres to the equilibrium. Also the conformation of proteins probably occurs to a certain degree of deformation or structural change due to the large area of contact. Recently, much interest has been shown in sulfonated microspheres, since sulfonate-group itself is one of components in bio-bodies, as well as is sensitive to the change of pH or ionic strength. Indeed, so far, scanty investigations have been performed in the full range. Also few researches have involved the data on adsorption rate and the maximum amount of protein adsorbed, or the reversibility of the process and conformational change of protein adsorbed as well.In present study, BSA (bovine serum albumin) was chosen as the model protein and sulfonated PMMA [poly(methyl methacrylate)] microspheres as the matrix to investigate the adsorption process.The purpose is to show some information especially the intrinsic information involved by the adsorption process Adsorption of BSA onto sulfonated microspheres (MS) has been investigated as a function of time, protein concentration and pH. The adsorption appears to be a reversible process and the presence of sulfonate groups can play important roles in the adsorption process, so as to increase the amount of protein adsorbed and influences the interaction of BSA molecules. Fig. 1 also shows that the reciprocation between unadsorbed and adsorbed BSA or rearrangement of adsorbed BSA molecules does not produce visible change in the properties of the adsorbed protein. Close to the isoelectric point of BSA (pI 4.7), the amount of protein adsorbed exhibits a maximum. A higher or lower pH results in the significant decrease of the adsorption amount. This is related to the dependence of BSA conformations at different pH conditions.     

聚(酪氨酸酯对苯二甲酰胺)碳酸酯药物控制释放材料的研究

报道了一类生物可降解聚（酪氨酸酯对苯二甲酰胺）碳酸酯的合成和结构表征，研究了聚合物的性质和体外降解性能，并以５ 氟脲嘧啶和牛血清白蛋为模型，对它们作为药物控制释放材料的性能进行了初步评价．     

新型固液双重致孔球形离子交换剂的制备及其性能研究

以甲基丙烯酸缩水甘油酯为单体 ,采用固液联合致孔方式 ,通过一步悬浮聚合制备了一种新型双孔高分子球形载体 .经化学修饰后 ,得到含二乙胺羟丙基的阴离子交换剂 (介质A) .优化了制备条件 .并与用相同方法制备的但仅含有机溶剂致孔剂的介质B进行了比较 .介质A和B均具有较高的静态吸附容量和机械强度 .由于介质A内含有流动相可以对流通过的大孔 ,因此其动态吸附容量远高于介质B ,并且在较高的流速下表现出较好的色谱流动性能     

Characterization of Ultrathin Films of Cellulose Esters

The adsorption of cellulose acetate (CA), cellulose acetate propionate (CAP) and cellulose acetate butyrate (CAB) from solutions prepared in acetone onto silicon wafers led to ultrathin films, which were characterized by ellipsometry, atomic force microscopy (AFM) and contact angle measurements. The polysaccharides films were characterized in the air just after their formation and after annealing at temperatures higher than their glass transition temperature or melt temperature. The films thickness close to 2 nm and surface roughness did not vary significantly upon annealing. AFM images revealed the presence of small clumps dispersed on a homogeneous layer, which covered completely the Si wafers. Such topographic details were also observed after annealing. However, upon annealing the films surfaces changed from hydrophilic to hydrophobic, evidencing molecular re-orientation at the solid–air interface. The adhesion of bovine serum albumin (BSA) and lipase onto the cellulose esters films was quantified in order to evaluate the possibility of applying such films as selective support for biomolecules.     

血清蛋白-荧光素复合物单扫极谱波与应用

在0．08mol／L的HAc中，荧光素与牛血清白蛋白(BSA)或人血清白蛋白(HSA)相互作用形成复合物。复合物使荧光素在-0．58V(vs．SCE)处的还原峰电流增大，峰电流的增大值与加入的BSA或HSA的浓度在一定的范围内呈线性关系。BSA在2—24μg／mL范围内呈线性关系，检出限为1μg／mL；HSA在2—22μg／mL范围里呈线性关系，检出限为0．8μg／mL。应用该法测定了人血清蛋白样品，结果令人满意。     

刚果红与血清白蛋白相互作用的极谱分析

在pH4．7HAc-NaAc缓冲溶液中，刚果红与蛋白质(BSA或HSA)作用形成络合物，使刚果红-0．35V(vs SCE)的还原峰电流下降，峰电流的降低值同所加的BSA或HSA质量浓度在一定范围内呈线性关系；BSA和HSA的线性范围分别为0．5～12mg／L和0．5～11mg／L，检出限分别为0．25和0．20mg／L；运用该法测定了人血清白蛋白样品，结果令人满意。     

荧光法研究Ge-132对牛血清白蛋白Maillard反应的抑制作用

人体内氨基酸及蛋白质的非酶糖化反应(Maillard反应)与糖尿病及其并发症的关系已经引起广泛注意[1].有机锗化合物β-羧乙基锗倍半氧化物(Ge-132)具有预防糖尿病及调节糖代谢的作用[2].     

Fluorometric investigation of the interaction of bovine serum albumin with surfactants and 6-mercaptopurine

Fluorescence quenching in solutions of bovine serum albumin has been investigated in the presence of 6-mercaptopurine and ionic surfactants. Spectroscopic analysis of the emission quenching at different temperatures revealed that the quenching mechanism of bovine serum albumin by 6-mercaptopurine was dynamic quenching mechanism. The Stern–Volmer quenching model has been successfully applied, and the activation energy of the interaction between 6-mercaptopurine and bovine serum albumin as much as 4.26 kJ mol⁻¹ was calculated. The distance r between donor (bovine serum albumin) and acceptor (6-mercaptopurine) was obtained according to fluorescence resonance energy transfer (FRET). The result of synchronous fluorescence spectra shows that the conformation of bovine serum albumin has been changed at the present of 6-mercaptopurine.