实验性流行性腹泻仔猪小肠粘膜上皮细胞及肠系膜淋巴结的超微结构

给8头生后3d的哺乳仔猪经口感染猪流行性腹泻病毒(PEDV)“吉”毒株,于感染后18、30、45和96h各扑杀2头,以透射电镜和扫描电镜观察了小肠粘膜上皮细胞及肠系膜淋巴结的超微结构。结果表明,小肠上皮细胞的病变因感染时间不同而有明显差异。上皮细胞的脱落和残留上皮细胞超微结构的破坏,以感染后30h最严重,病毒在这些上皮细胞内的增殖最显著。感染后45h,见有大量新生上皮细胞修补损伤的肠绒毛。感染后96h,小肠绒毛短缩、粗大乃至发生融合。实验仔猪肠系膜淋巴结内巨噬细胞和淋巴细胞的超微结构均遭到破坏,在巨噬细胞内见有PED冠状病毒粒子。     

Cytochemical properties of chicken blood cells resembling both thrombocytes and lymphocytes

Generally accepted criteria were used to identify typical nucleated thrombocytes and typical small lymphocytes in chicken-blood smears subjected to modified-Wright staining. Other cells, here referred to as "intermediate cells," were difficult to classify because in some aspects they resembled thrombocytes while they also had features typical of small lymphocytes. The "intermediate cells" had small, round or oval nuclei with coarsely condensed chromatin, characteristic of both thrombocytes and small lymphocytes. In addition, "intermediate cells" had moderately abundant cytoplasmic volumes, typical of thrombocytes but blue cytoplasm lacking both granules and vacuoles, which is characteristic of small lymphocytes. It made little difference to the thrombocyte count whether these cells were classified as thrombocytes or small lymphocytes; however, this decision made a substantial difference to the lymphocyte count in some chicken-blood smears. Most "intermediate cells" (351 of 410 cells examined) were nonfluorescent after treatment with formaldehyde gas. Furthermore, most "intermediate cells" failed to acquire characteristic pigments when subjected to either Grimelius staining (179 of 204 cells examined) or periodic acid-Schiff staining (173 of 206 cells examined). Typical small lymphocytes reacted in the same way, failing to fluoresce after gaseous formaldehyde treatment (65 of 65 cells examined) and failing to react during Grimelius staining (41 of 44 cells examined) or periodic acid-Schiff staining (21 of 21 cells examined). In contrast, almost all typical thrombocytes became fluorescent in response to gaseous formaldehyde (709 of 718 cells examined) and gave positive reactions when subjected to Grimelius staining (381 of 382 cells examined) or periodic acid-Schiff staining (322 of 326 cells examined). These findings suggested that "intermediate cells" should be classified as lymphocytes in differential cell counts.     

The use of cultured hepatocytes from goats and cattle to investigate xenobiotic oxidative metabolism

The oxidative metabolism of aldicarb (ALD), a carbamate pesticide, and fenbendazole (FBZ), an anthelmintic, was studied using cultured hepatocytes obtained from 4 goats and a bullock and incubated with ALD (50 mol/L) and FBZ (10 mol/L). The parent compounds and the metabolites were measured by HPLC. Both compounds are metabolized at the sulphur atom via two sequential oxidations, first to the sulphoxide (aldicarb sulphoxide and oxfendazole, respectively) and then to the sulphone. Oxfendazole and fenbendazole sulphone from FBZ, and aldicarb sulphoxide from ALD were found in both species. Aldicarb sulphone was not produced by the hepatocyte preparations from the bullock. The good correlation obtained comparing the in vitro results of FBZ metabolism with published in vivo dat obtained on FBZ kinetics in the same species confirmed the usefulness of in vitro models for predictive analysis of in vivo xenobiotic biotransformations.Abbreviations ALD aldicarb - ALDSON aldicarb sulphone - ALDSOX aldicarb sulphoxide - BSA bovine serum albumin - ID internal diameter - EGTA ethylene glycol bis(-aminoethyl ether) N,N,N,N-tetraacetic acid - FBZ fenbendazole - FBZSON fenbendazole sulphone - HBSS Hanks' balanced saline solution - HPLC high-pressure liquid chromatography - LDH lactate dehydrogenase - MFO mixed function oxidase - NCS newborn calf serum - OXF oxfendazole - WME Williams' Medium E     

Pathogenic mechanisms of caprine arthritis-encephalitis virus

Goats infected with caprine arthritis-encephalitis virus (CAEV) show chronic arthritis and cachexia, which are progressive in nature. The immunopathogenic mechanisms responsible for these progressive clinical symptoms have not been fully elucidated. Various haematological and immunological parameters were evaluated in experimentally-infected goats showing typical signs of CAEV-induced disease. Infected goats showed recurrent lymphocytosis that may be due to constant presentation of antigen by infected cells of a monocyte/macrophage lineage. The serum alkaline phosphatase and -glutamyl transferase concentrations were elevated in infected goats, a characteristic of hepatic and bone disorders. All other serum chemistry parameters were similar between infected and control goats. Importantly, the serum tumour necrosis factor- (TNF-) levels were higher in infected goats. The cachexia seen in infected goats may be at least partly due to altered metabolism as a result of prolonged elevation of serum TNF- levels. Depressed natural killer cell activity was observed in infected goats and may contribute towards the establishment of a persistent infection with CAEV.Abbreviations AIDS acquired immunodeficiency syndrome - CAEV caprine arthritis-encephalitis virus - GGT -glutamyl transferase - HBSS Hanks' balanced salt solution - HIV human immunodeficiency virus - NK natural killer - PBMC peripheral blood mononuclear cells - PCR polymerase chain reaction - SAP serum alkaline phosphatase - TNF tumour necrosis factor     

黑米天然黑(紫)色素的研究

特种稻黑米品种的糙米果皮中,含有大量的稀有天然黑(紫)色素。本文研究了这种色素的提取与分离方法、化学结构及其稳定性,并对其药理作用和应用前景作了简要分析。     

Prospects for improving potato crop protection against aphid vectors

Conventional ways to control aphid vectors on potato crops rely essentially on cultural and chemical methods. The extensive use of insecticides, too often applied regardless of real needs and consequences, has resulted in more and more failures in both controlling aphids and virus spread. This paper stresses the need to introduce more rationale in the operation of existing methods by improving the efficiency of some of them like forecasting systems, to assess the potential of others like fertilization and semiochemicals and to put most efforts on resistant cultivars so that integrated pest management can be operated in the near future.     

马铃薯渣酶法水解液制备单细胞蛋白饲料的研究

本文研究了酶法水解马铃薯渣制备膳食纤维后的滤液制备单细胞蛋白的可行性。试验结果表明,单细胞蛋白边糖化边发酵的摇瓶培养的较优工艺条件为:底物浓度为8%(添加8%的麸皮水)、初始pH值为4.5、接种量为15%、葡萄糖淀粉酶加入量为100U/g(原料中淀粉)、青霉素加入量为80U/g(原料)、培养温度为28℃、培养时间为6h、转速为250r/min。在此条件下,干酵母产量最高为19.920g/L,单细胞蛋白中的蛋白质含量达12.27%。     

酵母蛋白饲料培养条件的研究

对啤酒酵母进行发酵试验,结果表明:该酵母最优的培养条件是麦芽汁培养基稀释倍数2.5,培养时间20h,蔗糖添加量10Brix,尿素添加量0.02%,且酵母菌耐酸耐铜的性能好。     

成年(黄占)鹿耳皮肤成纤维细胞的分离与培养

本试验对1头黄占鹿的耳缘皮肤组织采用0.1%胶原酶(Ⅰ型)消化组织块法进行原代培养,反复传代纯化,获得了成纤维细胞,进行了生物学特性观察,并对各代细胞进行了常规冷冻保存。利用Photoshop软件对F12代细胞染色体进行了核型分析,结果表明该黄占鹿的染色体数目为68,常染色体中1号和7号为M染色体,其余的均为A常染色体;X染色体是最大的A染色体,Y染色体是最小的M染色体;该黄占鹿的核型式为4(M)+62(A),XY(A,M);对部分冷冻细胞进行了解冻培养,解冻存活率和贴壁率分别为61.04%、38.85%。