出血性大肠杆菌H7鞭毛抗原的诱导恢复及鉴定

从进口冻鸡翅中分离获得一株发酵山梨醇、缺失H7鞭毛抗原的出血性大肠杆菌O157:H7变异株,采用0.4%强营养软琼脂对该菌进行连续5代诱导培养,使其H7鞭毛抗原成功恢复。综合该菌的生物学特性、血清学及毒理实验结果确证为大肠杆菌O157:H7。该菌的检出为大肠杆菌O157:H7变异株的鉴定提供了有益参考。     

Gold nanoparticle/DNA/methylene blue nanocomposites for the ultrasensitive electrochemical detection of carcinoembryonic antigen

A new signal amplification strategy employing nanocomposites composed of gold nanoparticles (GNPs) with DNA and methylene blue (MB) as labels has been developed to construct a novel immunosensor for the highly sensitive bioanalysis of carcinoembryonic antigen (CEA). To fabricate the label, DNA was first linked to GNPs through the formation of an Au–S bond. Next, the resulting bioconjugates were sequentially bound with MB via the guanine (G) bases in DNA specifically and then with secondary CEA antibody (Ab₂) via the crosslinking of glutaraldehyde (GA). The receptor–analyte complex is formed by the biorecognition of the as-obtained MB labeled Ab₂ with the primary CEA antibody (Ab₁) immobilized on the surface of a modified GNP/Chitosan (Chits) composite electrode. After the receptor–analyte complex has formed, square wave voltammetry (SWV) was employed to oxidize the labeled MB in order to detect the CEA. This immunosensor shows a linear response from 0.10 to 2.0 pg mL⁻¹ CEA with an improved detection limit of 0.05 pg mL⁻¹ as compared to the conventional immunoassay. In addition, this new protocol shows acceptable stability, reproducibility and good recovery (97.5–110.0%) for CEA in human serum with great potential for clinical applications.     

生物素标记的Tn抗原的合成

以全乙酰化的2-叠氮基半乳糖基三氯乙酰亚胺酯为起始原料,通过与L-苏氨酸衍生物的糖基化反应以及叠氮还原,并同时进行N-乙酰化的一锅法反应制得全保护的Tn抗原,在脱去苏氨酸上的氨基保护基后,含生物素的琥珀酰亚胺酯与Tn抗原上的氨基发生选择性胺解得到标题化合物.目标产物及重要中间体的结构都通过 1HNMR、13CNMR和MS进行了表征.     

倍硫磷半抗原、人工抗原的合成和鉴定

为研究建立有机磷农药倍硫磷的免疫分析法,合成了1种倍硫磷半抗原和2种人工抗原。采用改进的方法将三氟硫磷与3-甲基-4-甲硫基苯酚、β-丙氨酸反应制备了倍硫磷半抗原,产物经薄层层析、^1HNMR和质谱鉴定为预期产物。分别将半抗原以活泼酯法、混合酸酐法与BSA、OVA偶联制备了人工抗原BZB和BGO,通过紫外光谱鉴定证明偶联成功。用TNBS比色法测定了BZB、BGO与载体蛋白的克分子结合比,分别为29：1和12：1。以BZB为免疫原免疫Balb／c小鼠,以BGO为包被抗原对小鼠血清进行间接竞争ELISA分析表明,小鼠经免疫后产生了针对倍硫磷的特异性抗血清,从而进一步证明抗原合成成功。本方法为研究建立倍碲磷的免疫分析方法奠定了基础。     

以赭曲霉毒素A单克隆抗体建立竞争酶联免疫吸附分析方法的研究

本研究通过活性酯法合成赭曲霉毒素A人工抗原，免疫小鼠制备单克隆抗体，在此基础上建立了竞争ELISA检测方法，线性范围为200-6000pg／ml，检测下限为150pg／ml。单抗与赭曲霉毒素B的交叉反应率为35％，与桔霉素、黄曲霉毒素B1和展青霉素等毒素交叉反应低于0．01％。在小麦样品中的加标回收率为83％～116％，变异系数为9.4％-19．8％。测试23份样品，赭曲霉毒素A的含量在0．6～2．56μg／kg之间。     

菜克多巴胺人工抗原的光谱表征及免疫鉴定研究

盐酸菜克多巴胺(Ractopamine hydrochloride,RCT)是一种β-肾上腺素受体激动剂,即使极低剂量残留对人类健康也有危害.为了建立简单、快速并适应现场检测的免疫分析方法,必须先合成它的人工抗原并进行鉴定.通过对莱克多巴胺进行结构修饰,用碳二亚胺将结构修饰了的莱克多巴胺与牛血清蛋白相偶联,经透析得到纯的莱克多巴胺人工抗原并冷冻干燥备用.结果表明,紫外光谱图中合成的人工抗原的特征吸收峰介于蛋白质和莱克多巴胺的特征吸收峰之间;人工抗原红外光谱图中呈现莱克多巴胺和牛血清蛋白的红外特征吸收峰;通过竞争ELISA实验表明用合成的人工抗原免疫的Balb/c小鼠血清中产生了莱克多巴胺的抗体,三种方法综合鉴定结果表明,莱克多巴胺人工抗原合成成功,该人工抗原可以进一步用于制备抗莱克多巴胺的单克隆抗体.     

基于人工免疫模型的在线手写签名识别方法

采集能表征签名者潜在手写习惯的签名特征,利用人工免疫模型的自学习和自适应实现在较少训练样本的条件下获得具有更高区分度的手写签名模板.实验结果表明,文中方法识别具有良好的训练效果,能获得较好的验证率和鉴别率.     

Current concept of allergic skin reactions

On the basis of literature and experimental work the present views on the mechanism of the development of allergic skin reactions of the contact type are reviewed.
Precursors of effector cells originating from stem cells are stimulated by the antigenic complex formed by the application of the hapten to the skin. Autologous skin proteins and macrophages play an important role in this preparatory and antigen recognition phases. Activated T lymphocytes proliferate in the draining lymph node and differentiate into effector and memory cells. The former react to a repeated application of the hapten with release of mediators inducing a skin inflammatory reaction. The latter produce further effector cells thus enhancing the degree of contact sensitivity (booster effect).
The hapten application also activates a specific control mechanism consisting of lymphocytes with the same specificity but adverse activity. These cells, called suppressors, restrict the development of further effector cells thus limiting the degree of contact sensitivity.
Elimination of suppressor cells leads to an enhancement of the degree of contact sensitivity whereas an intended extreme activation of these cells induces a state of specific immunological unresponsiveness (tolerance).
Concept générale des réactions allergiques cutanées     

互补的烟草花叶病毒介导表达丙型肝炎的核心抗原

ＴＭＶ两种突变体ＴＳＨｃ和ＴＢＤ，共同接种于烟草叶片。Ｎｏｒｔｈｅｒｎ杂交的结果表明这两种突变体由于功能上互补而产生了系统侵染。ＥＬＩＳＡ和Ｗｅｓｔｅｒｎ的检测结果表明烟草的上部叶片表达了丙型肝炎的核心抗原和ＴＭＶ外壳蛋白质。     

荧光免疫传感器的初步研究

本文较详细地分析了荧光免疫传感器表面膜的作用机理,给出了传感器检测灵敏度与动态范围理论值,建立了传感器检测系统,讨论了表面免疫反应的时间特性及非特异性蛋白吸附作用、吸附的消除及对传感器性能的影响,并比较了两种解离剂对表面膜使用重复性的影响。最后给出了传感器检测动态范围的实验数据,结果与理论值一致。