Phage-display derived single-chain fragment variable (scFv) antibodies recognizing conformational epitopes of Escherichia coli heat-labile enterotoxin B-subunit

Previously we have described studies on in vitro pentamer assembly of Escherichia coli (E. coli) derived heat-labile enterotoxin B subunit (EtxB) using conventional monoclonal antibodies (Amin et al., JBC 1995: 270, 20143-50 and Chung et al., JBC 2006: 281, 39465-70). To extend these studies further we have used phage-display to select single-chain Fragment variable (scFv) antibodies against different forms of the B-subunit. Two clones exhibiting strong and differential binding were chosen for detailed characterization. A comprehensive sequence analysis was performed to assign the framework and complementary-determining regions and a nonsense mutation present in one of these (scFv-B1.3.9) was corrected. Binding analysis showed that scFv-B1.3.9 bound in ELISA to both heat-denatured monomeric B-subunits (EtxB₁) and also displayed cross-reactivity towards pentameric EtxB (EtxB₅), although there was no reactivity towards monoganglioside (G_M1) captured EtxB₅. Another antibody (scFv-B5.2.14) had a different reactivity profile and, in ELISA, bound only to EtxB₅ but not to EtxB₁ or to EtxB₅ captured via G_M1. Surprisingly, in competition experiments, the assembled pentameric B-subunit inhibited binding of scFv-B5.2.14 to immobilized EtxB₅ only weakly, whereas reduced, but not oxidized, monomeric EtxB₁ was an efficient competitor. These results clearly demonstrate that B1.3.9 and B5.2.14 have different specificities for cryptic epitopes not accessible in the fully assembled G_M1 bound pentameric form of EtxB.Taken together our results show that we were able to successfully isolate and characterize recombinant scFvs that differentially recognize diverse denatured forms or assembly intermediates of the heat-labile enterotoxin B subunit of E. coli.     

青川县野生重楼资源的分布概况

目的 调查青川县野生重楼的种类、分布区域及资源现状.方法 通过走访调查、野外考察、样本采集、标本鉴定和资料查阅相结合的方法,调查了青川县的重楼资源.结果 在调查的青川县21个乡镇35个样品地区中,5个乡镇6个样地有野生重楼分布,主要分布在海拔1000～2200 m的阔叶林和针叶林下,主要为华重楼、黑籽重楼、多叶重楼、平伐重楼等4种,以华重楼的数量最多.初步估算,总蕴藏量为51.72吨.结论 青川县野生重楼的资源分布广泛,是平伐重楼的已知最北端的分布地,重楼野生资源蕴藏量正在急剧下降,有效保护和合理利用势在必行.     

一种新型洗胃机的研制

一种采用电子泵驱动的新型洗胃机。与传统洗胃机相比具有功能多，功能性好，无锈蚀，更安全，机动性好等方面的特点，是洗胃机的更新换代产品。     

(E)TUDE DE ENC(E)PHALE ATLAS DANS PR(E)-TRAITEMENT ET POST-TRAITEMENT DE TUMEUR C(E)R(E)BRAL PAR "KANG NO LIU KOU FU YE"

目的:探讨脑电地形图在脑瘤疗效判断上的应用价值.方法:通过对30例脑瘤治疗前后脑电地形图改变进行对比研究.结果:脑电地形图在治疗前后有明显改变.结论:脑电地形图可以作为脑瘤疗效评价的一个有价值的指标.     

牛血浆高密度脂蛋白及其载脂蛋白A-1的研究

用密度梯度区带超速离心法分离了牛血浆高密度脂蛋白(HDL),经脱脂和凝胶层析(Sephadex G-200),得到载脂蛋白A-1(apo A-1)。SDS-PAGE电泳鉴定apoA-1的分子量为25.8kD。在apo A-1中不含有半胱氨酸,极性氨基酸多达33.6％。DABITC微量分析法实验结果证明apo A-1氨基酸末端是天门冬氨酸,与北京鸭apo A-1氨基末端相同。     

Quantitation of serogroups in multivalent polysaccharide-based meningococcal vaccines: Optimisation of hydrolysis conditions and chromatographic methods

Quantitative determination of the individual polysaccharide components in multivalent meningococcal vaccines is an important step in manufacturing and regulatory control. Current methods are complicated due to the use of multiple chromatographic setups and/or other analytical techniques for the four meningococcal serogroup polysaccharides (A, C, Y, W135). In addition, different methods are sometimes used depending on whether or not the polysaccharide is conjugated to a carrier protein. In an effort to simplify such analyses, hydrolysis conditions were determined for the optimal yield of each characteristic saccharide from the respective repeating units. One condition was identified for mannosamine-6-phosphate from MenA, one for neuraminic acid from MenC, and one for both glucose and galactose from MenY and MenW135, respectively. These conditions, initially assessed for monovalent solutions, were then confirmed for a quadrivalent solution. The monosaccharide products were separated, identified and quantitated using a single HPAEC-PAD protocol, with a customised multi-stage linear gradient eluent profile and one column setup, for determination of all four serogroup components. Comparison to calibration curves constructed from sets of monosaccharide or hydrolysed polysaccharide standards allowed for the quantitation of each characteristic serogroup monosaccharide in polysaccharide and polysaccharide-conjugate vaccines. When required, molecular size separation using a non-cellulosic centrifugal filter device effectively removed all interfering saccharide excipient without loss of serogroup polysaccharides. These methods were used to analyse multiple lots of a number of different monovalent or multivalent real polysaccharide-based vaccine products, in liquid or lyophilised powder formulations, with or without excipients. The methods were demonstrated to be highly reproducible and very useful for the evaluation of antigen content and lot-to-lot consistency of manufacture. The methods described here represent an increase in precision, level of accuracy and efficiency compared to current methods, and may be adaptable for evaluation of other types of polysaccharide-based vaccines.     

接种卡介苗后淋巴结炎综述

对国内外近些年来有关接种卡介苗后淋巴结炎和淋巴结结核的现场调查、诊断特征、医疗救治措施及处置等相关研究进行综述，为接种卡介苗后淋巴结炎的规范处理提供参考。     

心电散点图快速诊断普通12导心电图难以判别的心律失常三例

运用心电散点图诊断普通心电图难以明确或捕捉的心律失常。本文对我院住院期间行动态心电图检查的三例患者的特征性心电散点图图形进行分析诊断。心电散点图不仅记录信息量大，且定性诊断明确，简单易懂，避免了漏诊及误诊，能够给临床提供一定的帮助。     

针刺人迎穴为主配合星状申经节阻滞术治疗周围性面瘫:随机对照研究

目的:探寻治疗周围性面瘫的较佳疗法.方法:120例患者随机分为常规针刺组(穴取阳白、四白、迎香为主)、人迎针刺组(人迎穴为主)以及术针组(人迎穴为主针刺配合星状神经节阻滞术),每组40例.每天治疗1次,7次为一疗程,3个疗程后,比较3组治疗前后的面神经直接刺激诱发电位(ENoG)潜伏期和波幅,以及瞬目反射(BR)的R1值、R2值,并评定临床总疗效.结果:3组治疗均能显著缩短ENoG潜伏期,且诱发电位波幅显著升高;治疗后术针组ENoG潜伏期较常规针刺组显著降低(P＜0.05),人迎针刺组诱发电位波幅较其他两组升高(均P＜0.05);各组治疗后R1、R2值显著缩短,人迎针刺组和术针组治疗前后R1差值、R2差值均显著大于常规针刺组(均P＜0.05),且术针组R1差值显著大于人迎针刺组(P＜0.05);术针组临床愈显率为87.5％(35/40),优于人迎针刺组的77.5％(31/40),且显著高于常规针刺组的65.0％(26/40,P＜0.05).结论:与常规针刺比较,人迎针刺组和术针组治疗周围性面瘫疗效更优,且术针组较人迎针刺组能更好地恢复受损面神经的早发反射功能.     

A randomized, parallel group, double-blind, multicentre study comparing the efficacy and safety of Avandamet (rosiglitazone/metformin) and metformin on long-term glycaemic control and bone mineral density after 80 weeks of treatment in drug-naïve type 2 diabetes mellitus patients

Aim: The purpose of this study was to evaluate if superior glycaemic control could be achieved with Avandamet® (rosiglitazone/metformin/AVM) compared with metformin (MET) monotherapy, and if glycaemic effects attained with AVM are durable over 18 months of treatment. Bone mineral density (BMD) and bone biomarkers were evaluated in a subgroup of patients. Methods: This was a phase IV, randomized, double‐blind, multi‐centre study in 688, drug naÏve, male and female patients who had an established clinical diagnosis of type 2 diabetes mellitus (T2DM). Patients were randomized in a 1 : 1 ratio either to AVM or MET. Results: As initial therapy in patients with T2DM, AVM was superior to MET in achieving statistically significant reductions in glycated haemoglobin (HbA1c) (p < 0.0001) and fasting plasma glucose (FPG) (p < 0.001), with more patients reaching recommended HbA1c and FPG targets for intensive glycaemic control. The glycaemic effects attained with AVM compared to MET monotherapy were durable over 18 months of treatment. In the bone substudy, AVM was associated with a significantly lower BMD in comparison with MET at week 80 in the lumbar spine and total hip (p < 0.0012 and p = 0.0005, respectively). Between‐treatment differences were not statistically significant for distal one‐third of radius BMD, femoral neck BMD or total BMD. Conclusion: Superior glycaemic control was achieved with AVM compared with MET monotherapy. The superior glycaemic effects were shown to be durable over 18 months of treatment. AVM was associated with a significantly reduced BMD in comparison with MET at week 80 in the lumbar spine and total hip.