Phenolic compounds in plant disease resistance

We propose that an important first line in plant defense against infection is provided by the very rapid synthesis of phenolics and their polymerization in the cell wall. This rapid synthesis, which leaves no time forde novo enzyme synthesis, is regulated by the extreme pH-dependence of the hydroxylase, catalyzing the formation of caffeoyl-CoA from 4-coumaroyl-CoA. We further propose that elicitor treatment or infection causes rapid membrane changes leading to a decrease in cytoplasmic pH. This decrease would have the effect of activating the hydroxylase.     

Ultrastructure of Colonic Epithelial Cells in Vitamin E and Selenium Deficient Pigs

Pigs deficient in vitamin E and selenium had a decreased contrast of the intracellular membranes compared with pigs supplemented with vitamin E and selenium. Other common changes in the deficient animals included a reduced number of microvilli, with a short and irregular appearance, numerous swollen mitochondria with empty spaces and intercellular oedema. It is suggested that these morphological changes are attributed to the insufficient supply of vitamin E and selenium, though it is not excluded that particular intestinal factors may participate in the development of the lesions.     

Studies on the mechanism of vaccinal immunity to Marek''s disease

Current knowledge of the nature of the antigens and of the host immune responses in vaccinal immunity to Marek's disease is reviewed. It is suggested that a two-step mechanism of resistance operates. The first step involves humoral and cell-mediated responses directed against viral antigens; the second step occurs after challenge with Marek's disease virus and consists of cellmediated responses directed against tumour cells.     

不同感染量REV对鸡免疫反应和细胞毒性作用的影响

用不同剂量网状内皮增生症病毒（REV）感染肉鸡和SPF鸡后，检测血液中T淋巴细胞对ConA的反应和NK细胞、细胞毒T细胞（CTL）的细胞毒性作用以及NDV抗体生成变化等，观察REV感染对机体非特异性、特异性细胞免疫反应和体液免疫反应的影响。结果表明无论高剂量还是低剂量REV感染均造成体液免疫和非特异性细胞免疫抑制，而且高剂量比低剂量对免疫功能的抑制作用更强，但对NK细胞和细胞毒T细胞的细胞杀伤活性却有升高趋势，在抗肿瘤方面发挥一定的作用。这种结果说明REV感染对机体的免疫抑制是有选择性的，且抑制程度与感染病毒量有关。     

牛病毒性腹泻病毒持续感染的免疫学研究进展

牛病毒性腹泻病毒(BVDV)是危害养牛业的重要病原之一。BVDV感染能够引起广泛的临床症状,包括牛病毒性腹泻-黏膜病、持续感染、免疫耐受、繁殖障碍、血小板减少与出血综合征等。由于其病原的复杂性,给该病的控制及疫苗研制带来了一定的困难。近年来,对其免疫学的研究取得了一定进展,特别是在病原的基本免疫学特征、体液免疫、细胞免疫、免疫耐受和免疫调节方面做了深入研究,同时也在参与免疫应答的细胞因子方面做了研究,这些都为牛病毒性腹泻-黏膜病的预防和控制研究提供了新的思路。     

共轭亚油酸对动物免疫功能的调节

共轭亚油酸具有广泛的生物学功能,它对增加机体免疫球蛋白含量,促进免疫细胞增殖、细胞因子产生、吞噬细胞的功能,基因表达都具有调节作用。本文就共轭亚油酸的免疫调节作用进行了阐述。     

爱拔益加肉鸡和北京油鸡体液免疫及细胞免疫功能的比较研究

试验选用1日龄健康爱拔益加(AA)肉鸡和北京油鸡公雏各72只。检测新城疫抗体效价,牛血清白蛋白抗体水平,外周血T、B淋巴细胞转化率以及T淋巴细胞亚群等指标。结果表明:北京油鸡二免后第7天的新城疫抗体效价和二免后第6天的牛血清白蛋白抗体水平都比AA肉鸡的高,但均无显著性差异(P>0.05)。北京油鸡的脂多糖(LPS)刺激指数始终比AA肉鸡的高(P>0.05);21日龄时,北京油鸡的刀豆素(A ConA)刺激指数、CD4+、CD8+T淋巴细胞数量以及CD4+/CD8+都比AA肉鸡的高,但均无显著性差异(P>0.05);而42日龄时,AA肉鸡的ConA刺激指数、CD4+、CD8+T淋巴细胞数量以及CD4+/CD8+却高于北京油鸡(P<0.05)。本试验结果提示,AA肉鸡和北京油鸡的体液免疫和细胞免疫功能之间存在一定的差异,但差异不显著。     

Normal haematopoiesis,cellular components and stainable iron content in the bone marrow of camels (Camelus dromedarius)

Bone marrow samples were collected from the ribs of 20 healthy adult male Iranian camels (Camelus dromedarius). The bone marrow smears were stained using Wright's stain. Blood samples were collected at the same time for routine haematological examination. The development and morphology of the blood cells in the bone marrow of the camels were similar to those of other domestic species. The mean myeloid/erythroid ratio was 1.21, the mean erythroid percentage was 42.7% and the mean myeloid percentage was 52.0%. The mean percentage of other cells was 5.3%. The mean percentage of eosinophils in the myeloid series was higher than in other domestic species. Iron stores, estimated from Perl's stain, ranged from scant (1+) to moderate (3+) but most samples had 2+ iron content. All peripheral blood results were within reference ranges.     

黄芪多糖对猪瘟活疫苗免疫应答的佐剂作用

为研究黄芪多糖对猪瘟活疫苗的佐剂作用,分别用0.5％黄芪多糖、疫苗专用稀释液、生理盐水（对照）稀释猪瘟耐热保护剂活疫苗免疫猪,测定免疫后不同时间段内血清中 IgG 及其亚型IgG1、IgG2、IgG3、IgG4和细胞因子IL 2、IL 6的含量。结果显示,与对照组相比,黄芪多糖作为疫苗稀释液可以显著提高血清中IgG及其亚型和细胞因子IL 2、IL 6的含量。与疫苗专用稀释液组相比,在免疫后第7、14、28天,黄芪多糖组IgG含量均提高,分别提高1.6％（P＞0.05）、6.4％（P＜0.05）、7.1％（P＜0.05）,IL 2含量分别提高12.1％（P＜0.05）、2.9％（P＞0.05）、15.3％（P＜0.05）,IL 6含量差异均不显著。表明,黄芪多糖作为疫苗稀释液对猪瘟活疫苗具有良好的佐剂作用。     

Protein kinase C in the spleen of the turbot (Scophthalmus maximus L.)

PKC activity was detected in spleen extracts from the turbot, Scophthalmus maximus, a teleost flatfish that is farmed commercially in several countries, in assays with the substrate EGF- R651–658 as phosphate acceptor. The activity was purified about 700-fold by a three-step chromatographic procedure (DEAE-cellulose, phenyl-Sepharose and threonine-Sepharose). Maximal activity was obtained in the presence of the typical PKC cofactors Ca2+ (0.1 mM) PtdS (20 g ml–1) and either DAG (2 g ml–1) or PMA (2 g ml–1). Activity was dose-dependently inhibited by H7 and by the PKC-specific inhibitors PKC19–36 and N-myristoylated PKC19–31. The rate of phosphorylation was highest with the PKC-specific substrate MARCKS161–175. In immunoblotting, MC5 (a mouse monoclonal antibody raised against bovine PKC) recognized bands of 80 and 100 kDa. Immunoblotting with antibodies raised against mouse PKC isozymes (, , , , , , and ) indicated the presence of all these isozymes in turbot spleen.