大豆抗原及其对仔猪和犊牛的影响

大豆及其制品中含有一些可以引起幼龄动物胃肠道发生过敏反应的抗原物质,这些抗原物质引起的过敏反应可造成动物肠道损伤,进而导致肠道吸收障碍,生长发育受阻。本文对大豆抗原的种类、生物学特性、不同大豆制品中的可溶性抗原及大豆抗原对仔猪和犊牛的影响进行了综述。     

猪繁殖与呼吸综合征基因标记疫苗株NP49-ELISA鉴别诊断方法的建立

猪繁殖与呼吸综合征病毒（Porcine reproductive and respiratory syndrome virus,PRRSV）rHN4-△25＋NP49株是新型基因标记弱毒疫苗候选株,为了配合对该基因标记疫苗免疫猪血清抗体的鉴别诊断,本研究以标记基因编码的NP49（新城疫病毒NP蛋白C末端49个氨基酸,即NP49）多肽作为包被抗原,建立标记疫苗免疫猪血清中NP49抗体的ELISA鉴别诊断方法。通过对NP49-ELISA工作条件的优化,结果显示NP49-ELISA的多肽抗原最适包被浓度为500ng／孔,被检血清最佳稀释度为1：40。利用ROC曲线法确定S／P临界值为0．2,该方法批内与批间重复试验的变异系数均小于10％,与几种常见猪病阳性血清无交叉反应,具有较好重复性和特异性。本研究建立的NP49．ELISA鉴别诊断方法为猪繁殖与呼吸综合征新型基因标记疫苗的临床应用提供了有力保障。     

Application of a recombinant protein for the serological diagnosis of canine leishmaniasis

This work reports the results obtained by a new enzyme-linked immunosorbent assay (ELISA) test developed for the serological diagnosis of canine leishmaniasis.The new ELISA is based on a recombinant protein obtained by joining different antigens of Leishmania infantum.Test performances have been evaluated through the screening 227 sera of dogs, infected and uninfected by L. infantum. The new ELISA test has been compared to the indirect immunofluorescent-antibody test (IFAT) as a reference assay of canine leishmaniasis, and to a commercial ELISA.Excluding from the total number of IFAT positive sera the 27 sera with IFAT titre 1:40 (considered doubtful), the recombinant ELISA showed 97.0% specificity, 93.9% sensitivity and 95.5% agreement with IFAT. The commercial ELISA showed 78.2% specificity, 94.9% sensitivity and 86.5% agreement with IFAT.The results demonstrate a higher performance of the new recombinant ELISA test for the detection of negative samples, with a greater agreement with the reference test (IFAT).     

Histological and immunohistochemical studies of the proximal caecum and caecal tonsils of quail (Coturnix coturnix japonica)

The proximal caecum in quails consists of lymphoid and non‐lymphoid structures. The caecal tonsils in the proximal part of the caecum are units of gut‐associated lymphoid tissue in poultry. This study aimed to examine the histological characteristics of the proximal caecum, as well as compositions of dendritic cells (DCs) and antigen‐presenting cells (APCs) in the caecal tonsil of quails. Tissue sections were stained with Crossman's triple, periodic acid–Schiff, Gordon and Sweet's silver, Congo red and methyl green‐pyronin dyes, as well as immunohistochemically by the streptavidin–biotin–peroxidase complex method. Caecal lymphoid tissue was located in the lamina propria and submucosa. Germinative centres were observed within the lymphoid tissue. Reticular fibres were mainly distributed in the border area of the germinal centre with only a few fibres scattered in the centre. Plasma cells were observed in the subepithelial region and germinal centres. Eosinophil granulocytes were prevalent in the lymphoid tissue. Additionally, CD83‐immunoreactive DCs and MHC class II immunoreactive APCs were present in the subepithelial area and diffuse lymphoid tissue. While DCs were seen in the germinal centres of tonsillar units, APCs were rarely present in the germinal centres, but they were noticed around the germinal centres. In conclusion, the histological structure of the proximal caecum in quails and the distributions of some immunological cells in the caecal tonsils were revealed. Therefore, the defensive role of the caecal tonsils in the digestive system may be better understood, and comparative studies may be carried out.