Requirement for MHC class II positive accessory cells in an antigen specific bovine T cell response   总被引：1，自引：0，他引：1  

E J Glass  R L Spooner 《Research in veterinary science》1989,46(2):196-201

Purified populations of bovine antigen presenting cells (APCs) and T cells have been isolated from peripheral blood and characterised using various monoclonal antibodies (mAbs) for cell surface markers. Bovine APCs were found in an adherent cell fraction and were non-specific esterase positive, phagocytic and expressed bovine major histocompatibility complex (MHC) class II determinants, all of which are typical macrophage characteristics. T cells were rigorously depleted of accessory cell function before being used in an antigen presenting cell assay. The generation of T helper cells in response to the soluble antigen, ovalbumin, was entirely dependent upon a critical number of APCs. Further the proliferative response was inhibited by several mAbs to bovine MHC class II molecules. Thus the interaction between bovine APCs and helper/inducer T lymphocytes (TH/I) appears to be similar to that in other species.  相似文献   

Plant Poisoning in Animals          下载免费PDF全文

Herman J. Boermans 《The Canadian veterinary journal. La revue veterinaire canadienne》1989,30(2):189-190

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Effect of Heat Stress on Grain Growth, Starch Synthesis and Protein Synthesis in Grains of Wheat (Triticum aestivum L.) Varieties Differing in Grain Weight Stability     

C. Viswanathan  & Renu Khanna-Chopra 《Journal of Agronomy and Crop Science》2001,186(1):1-7

The effect of heat stress on the components of grain weight was analysed in wheat ( Triticum aestivum L.) varieties differing in grain weight stability. The wheat varieties PBW154, Sonalika and Hindi62 were raised in the field (New Delhi, India; 77°12' E, 28°40' N, 228.6 m a.s.l.) at three dates of sowing: 19 November 1992 (DOS I), 14 December 1992 (DOS II) and 18 January 1993 (DOS III). The late-sown crop (DOS III) experienced 6–8 °C warmer temperatures during grain development than the crop sown at the normal time (DOS I). The heat susceptibility index (S) revealed that grain weight was less susceptible to heat in Sonalika and PBW154 than in Hindi62. Heat stress reduced both the grain growth duration (GGD) and the grain growth rate (GGR). The grain weight reduction in PBW154 and Sonalika was mainly due to a reduction in GGR, while that of Hindi62 was due to a reduction in GGD. In vivo studies on starch and protein synthesis in excised endosperm at 15, 25 and 35 °C revealed that both processes were more thermotolerant in Hindi62 than in PBW154. The grain starch content was stable in Hindi62 while that in PBW154 was significantly reduced under heat stress. The grain nitrogen content at maturity increased in both varieties under heat stress. It was concluded that the heat susceptibility of grain weight in Hindi62 was mainly due to a reduction in GGD, although GGR, starch and protein synthesis were more thermotolerant in developing grains of Hindi62 than in those of PBW154.  相似文献   

樟子松枯梢病的防治研究   总被引：6，自引：0，他引：6  

徐贵军  宋晓东  刘桂荣  陈江燕  吴锈钢  李淑华  吴景云 《中国森林病虫》2001,20(3):16-19

樟子松移植苗枯梢病Sphaeropsis sapinea可以通过药剂有效地进行防治。移植前以50％多菌灵wp500倍液浸苗；在人工林中，内吸性杀菌剂－甲基托布津、多菌灵为首选药剂；在树木新梢生长停止期和展叶中期（辽西北为6月初和6月中旬），70％甲基托布津wp 1000倍液或50％多菌灵wp 500倍液防治2次。保护性杀菌剂－百菌清效果不佳。适时的卫生伐对该病有明显的抑制作用。  相似文献   

Fisheries for non-native species in England and Wales: angling or the environment?   总被引：3，自引：0，他引：3  

P. Hickley  & S. Chare 《Fisheries Management and Ecology》2004,11(3-4):203-212

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白浆土的氮素分布特征     

丁光伟  赵玉萍  夏荣基 《中国农业大学学报》1990,(Z4):61-70

本文以黑龙江省三江平原耕地白浆土为主要研究对象,并以复区内存在的草甸土和暗棕壤作比较,研究了土壤各种理化性质与不同形态氮素之间的相关关系:白浆土中 HA 和 FA 的主要差别,在于前者含有较多的碱性氨基酸,而后者则含有较多的酸性氨基酸;各种不同形状 N素与土壤 pH 值,质地等相关性不显著,而与土壤有机质、全 N 和 C/N 比值等的相关性极为显著。  相似文献   

Neurotrophins and the Thymus: Morphological Analysis of Mice Carrying a Non-functional Mutation on the Trka and Trkb Genes     

German&#;  A.  Laur&#;  R.  Levanti  M.B.  Montalbano  G.  German&#;  G.P.  Abbate  F.  Ciriaco  E. 《Veterinary research communications》2004,28(1):189-192

Veterinary Research Communications -  相似文献   

Prevalence and clinical implications of anthelmintic resistance in cyathostomes of horses.     

J L Tarigo-Martinie  A R Wyatt  R M Kaplan 《Journal of the American Veterinary Medical Association》2001,218(12):1957-1960

OBJECTIVE: To determine the prevalence and clinical implications of anthelmintic resistance in cyathostomes of horses. DESIGN: Prospective study. ANIMALS: 80 horses on 10 farms in a 5-county region of northeast Georgia. PROCEDURE: On each farm, horses were stratified in descending order according to pretreatment fecal egg count (FEC), blocked into groups of 4, and then randomly assigned to 1 of 4 treatment groups: no treatment (controls), and treatment with pyrantel pamoate, fenbendazole, or ivermectin. Fecal samples were collected 24 hours prior to treatment and 2, 4, and 6 weeks after treatment for determination of FEC. Mean percentage of reduction in FEC was then calculated for each treatment group. For horses from each farm, the efficacy of each anthelmintic was categorized on the basis of mean percentage of reduction in FEC at 2 weeks after treatment (< 80% reduction = ineffective; 80 to 90% reduction = equivocal; and > 90% reduction = effective). RESULTS: Pyrantel pamoate was effective at reducing FEC in horses from 7 farms, ineffective in horses from 2 farms, and equivocal in horses from 1 farm. Fenbendazole was ineffective at reducing FEC in horses from 9 farms and equivocal in horses from 1 farm. Ivermectin was effective at reducing FEC in horses from all 10 farms. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that cyathostome resistance to fenbendazole is highly prevalent, and resistance to pyrantel pamoate is high enough to warrant concern. Resistance to ivermectin was not detected. On the basis of these data, it appears that ivermectin continues to be fully effective in horses. However, too few farms were used in this study to determine the prevalence of cyathostome resistance to ivermectin. Therefore, the efficacy of ivermectin should continue to be monitored closely.  相似文献   

微量元素相对生物学利用率的研究方法     

S.Durosoy 《中国饲料》2004,(23):18-19

有机微量元素具有多种优点,本文阐述了有关外源微量元素生物学利用率,回顾了微量元素不同添加方法的研究成果并进行比较。1影响动物对微量元素吸收的因素微量元素的吸收水平直接影响动物机体对微量元素的利用。如果饲喂量超过机体的代谢量,微量元素的吸收下降;如果饲喂量不足,机体则会提高对微量元素的吸收,这就说明机体自我平衡作用可以调节营养素的吸收。日粮总体消化率及各营养素间的相互作用均会影响矿物质吸收,这种相互作用包括协同作用(如铁和维生素C)和拮抗作用(如钙和锌,铜和钼、硫)。动物种类、品种、年龄、性别等也会影响微量元…  相似文献   

Maladies de l'eucalyptus1     

L. LANIER 《EPPO Bulletin》1986,16(2):255-263

Les eucalyptus constituent—au moins au meme titre que les genres Pinus et Populus—l'un des genres d'arbres forestiers les plus importants à l'échelle mondiale, et en particulier par l'extension considérable des reboisements (plus de 4 millions d'ha) en régions tropicales, sahéliennes et tempérées chaudes. L'article tente de faire le point sur les problèmes posés par les maladies pouvant gener cet effort de reboisement, notamment en région méditerranéenne, et souligne l'importance et l'avenir des eucalyptus dans cette région. Il est procédéà un inventaire général, à l'échelle mondiale, des maladies des eucalyptus et de l'importance des parasites en cause. Un certain nombre d'entre eux sont étudiés plus en détail, selon qu'ils sont présents dans le pays d'origine des eucalyptus ou dans les zones où ils ont été introduits. Une section est réservée à la région méditerranéenne, où certaines maladies s'en prenant aux racines, aux rameaux, aux feuilles ou au bois ont été identifiées; pour l'instant, la plupart d'entre elles ne sont pas trop graves. Enfin, des propositions et des règles de protection phytosanitaire, visant à restreindre les risques d'introduction des parasites les plus dangereux ou d'extension de ceux existant actuellement, sont citées, en insistant sur les risques de transport de maladies d'une région à une autre par l'intermédiaire des échanges de matériel végétal autres que les graines.  相似文献