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   

Common and stage-specific antigens of Theileria annulata.     

M Kachani  R A Oliver  C G Brown  H Ouhelli  R L Spooner 《Veterinary immunology and immunopathology》1992,34(3-4):221-234

Western blot analysis of Theileria annulata antigens was carried out using sera collected from cattle which had been immunised and challenged with either T. annulata sporozoites or schizont-infected cells. Three antigens between 71 and 73 kDa proved to be common to the three stages of parasite studied: sporozoites, schizonts and piroplasms. An antigen was found at 32 kDa which was specific to T. annulata piroplasms. Results were reproducible using sera from Morocco and the UK. At least one of the proteins at 71-73 kDa, but not that at 32 kDa were also recognised by sera from animals infected with Babesia species.  相似文献   

Drivers,challenges and opportunities of forage technology adoption by smallholder cattle households in Cambodia     

K Ashley  S Wilson  JR Young  HP Chan  S Vitou  S Suon  PA Windsor  RD Bush 《Tropical animal health and production》2018,50(1):63-73

Forage technology has been successfully introduced into smallholder cattle systems in Cambodia as an alternative feed source to the traditional rice straw and native pastures, improving animal nutrition and reducing labour requirements of feeding cattle. Previous research has highlighted the positive impacts of forage technology including improved growth rates of cattle and household time savings. However, further research is required to understand the drivers, challenges and opportunities of forage technology for smallholder cattle households in Cambodia to facilitate widespread adoption and identify areas for further improvement. A survey of forage-growing households (n = 40) in July–September 2016 examined forage technology adoption experiences, including reasons for forage establishment, use of inputs and labour requirements of forage plot maintenance and use of forages (feeding, fattening, sale of grass or seedlings and silage). Time savings was reported as the main driver of forage adoption with household members spending approximately 1 h per day maintaining forages and feeding it to cattle. Water availability was reported as the main challenge to this activity. A small number of households also reported lack of labour, lack of fencing, competition from natural grasses, cost of irrigation and lack of experience as challenges to forage growing. Cattle fattening and sale of cut forage grass and seedlings was not found to be a widespread activity by interviewed households, with 25 and 10% of households reporting use of forages for these activities, respectively. Currently, opportunities exist for these households to better utilise forages through expansion of forage plots and cattle activities, although assistance is required to support these households in addressing current constraints, particularly availability of water, if the sustainability of this feed technology for smallholder cattle household is to be established in Cambodia.  相似文献   

Molecular and immunological characterisation of Theileria parva stocks which are components of the 'Muguga cocktail' used for vaccination against East Coast fever in cattle     

Bishop R  Geysen D  Spooner P  Skilton R  Nene V  Dolan T  Morzaria S 《Veterinary parasitology》2001,94(4):227-237

The 'Muguga cocktail' which is composed of three Theileria parva stocks Muguga, Kiambu 5 and Serengeti-transformed has been used extensively for live vaccination against East Coast fever in cattle in eastern, central and southern Africa. Herein we describe the molecular characterisation of the T. parva vaccine stocks using three techniques, an indirect fluorescent antibody test with a panel of anti-schizont monoclonal antibodies (MAb), Southern blotting with four T. parva repetitive DNA probes and polymerase chain reaction (PCR)-based assays detecting polymorphism within four single copy loci encoding antigen genes. The Muguga and Serengeti-transformed stocks exhibited no obvious differences in their reactivity with the panel of MAbs, whereas Kiambu 5 differed with several MAbs. Kiambu 5 DNA was very distinct from the Muguga and Serengeti-transformed isolates in the hybridisation pattern with all four nucleic acid probes, whereas Muguga and Serengeti-transformed isolates exhibited minor differences and could not be discriminated with one of the probes. PCR amplification in combination with restriction fragment length polymorphism analysis indicated that Kiambu 5 was also markedly divergent from the Muguga and Serengeti-transformed stocks within two of the four antigen coding genes. The T. parva Serengeti-transformed stock did not contain a 130 base pair insert within the p67 sporozoite antigen gene, which has been observed previously in most T. parva parasites isolated from buffalo, and could not be discriminated from T. parva Muguga at any of the four single copy loci. Collectively the data indicate that two of the cocktail components T. parva Serengeti-transformed and Muguga are genetically closely related, while the third component Kiambu 5 is quite distinct. Based on the findings, there may be a need to include only one of the T. parva Muguga and Serengeti-transformed components in the immunising cocktail. The study demonstrates the value of molecular characterisation data for monitoring of live vaccines.  相似文献   

Leptin, GH, PRL, Insulin and Metabolic Parameters Throughout the Dry Period and Lactation in Dairy Cows     

PA Accorsi  N Govoni  R Gaiani  C Pezzi  E Seren  C Tamanini 《Reproduction in domestic animals》2005,40(3):217-223

Leptin may play a role in the endocrine-metabolic processes that guarantee the physiological course of lactation in dairy cattle. This study was aimed at determining the changes in plasma concentrations of leptin and some of the main hormones and metabolites involved in the lactogenetic process in high-yielding dairy cows throughout lactation; we also wanted to assess whether leptin secretion is subjected to seasonal influences. Blood samples were collected from 23 Italian Friesian dairy cows from the end of a lactation to the ninth month of the subsequent one; in addition, blood was sampled from 47 dairy cows in different phases of lactation during February and July. Plasma concentrations of leptin, growth hormone (GH), insulin, prolactin (PRL), glucose, non-esterified fatty acids (NEFA) and urea were quantified by either validated radioimmunoassay (RIA) or enzymatic colorimetric methods. At the beginning of lactation, GH concentrations significantly increased, while a significant reduction occurred in leptin and insulin. This endocrine condition, such as the significant increase in NEFA plasma concentrations, is indicative of a marked lipid mobilization. In the more advanced stages of lactation, when both energy and protein balances become positive, leptin plasma concentrations increased, whereas GH and NEFA concentrations declined. During the summer months, a significant increase in leptin plasma concentrations, irrespective of the phase of lactation, was observed. Collectively, our findings suggest that, in dairy cows, leptin may represent a 'metabolic signal' of animal's status of fattening and nutritional level; in addition, leptin seems to be influenced by photoperiod and environmental temperature.  相似文献   

Hepatic vasculopathy and encephalopathy in Brahman-type calves     

PA GILL  WL TOWNSEND 《Australian veterinary journal》1993,70(2):69-69

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The effect of dose and line on immunisation of cattle with lymphoblastoid cells infected with Theileria annulata   总被引：1，自引：0，他引：1  

H Ouhelli  E A Innes  C G Brown  A R Walker  S P Simpson  R L Spooner 《Veterinary parasitology》1989,31(3-4):217-228

Thirty-one Friesian calves in Morocco susceptible to tropical theileriosis were protected against a lethal sporozoite challenge by prior infection with lymphoblastoid cell lines infected and transformed in vitro by a Moroccan stock of Theileria annulata. The challenge infection of cryopreserved sporozoites killed all four susceptible control calves within 20 days. Four schizont-infected cell cultures at Passage 3 were inoculated at four different doses, 10(8), 10(6), 10(4) and 10(2), into pairs of calves. The recipient animals showed great variation in severity of disease symptoms, which did not show a linear correlation with the cell dose inoculated. The most severe disease symptoms were recorded, prior to challenge, in the 10(2) cell dose recipients; one animal died of acute theileriosis and another had to be treated. One of the four cell lines used was more virulent than the other three. Two years after the completion of this experiment, immunised animals have shown normal productivity traits.  相似文献   

Genetics of disease resistance and the potential of genome mapping     

Spooner  Roger L. 《Tropical animal health and production》1997,29(4):95S-97S

Tropical Animal Health and Production -  相似文献   

A thermogravimetric study of the pyrolysis of the bark and chemically-modified bark of jack pine,pinus banksiana lamb     

C. Faibridge  R. A. Ross  P. Spooner 《Wood Science and Technology》1975,9(4):257-274

The pyrolysis of native jack pine bark has been studied from 200 to 340°C by thermogravimetric (TG), and isothermal weight-loss methods. The effects of particle size, solvent extraction and additions of zinc (II) and iron (III) chlorides on the pyrolysis behaviour have also been examined. The bark was characterized by infrared spectroscopy and low-temperature gas adsorption. Residues were analysed for CHN contents and structural changes which occurred on heating were examined by optical and scanning electron microscopy. The TG characteristics were not affected by solvent extraction or particle size variation while the metal chloride additions inhibited the loss of volatile materials from the bark probably by stabilizing chemical bonding in the bark components. Isothermal decomposition data were found to fit established kinetic expressions associated with inorganic decompositions. The physical mechanics of pyrolysis have been interpreted on the assumption that pyrolysis is initiated through the formation of planes of lateral strain which are sites for decomposition and which decrease in number inversely with time. It is suggested that these sites are produced by an oxidation mechanism which may be rate-controlling in the pyrolysis. This hypothesis is supported by the observation that the data fit a reaction rate compensation curve, often associated with oxidation processes but more generally with heterogeneous catalytic reactions. The compensation curve also relates the kinetic parameters found by other workers for a large variety of wood-derived materials.  相似文献   

In vitro interaction of some drug combinations to inhibit rapidly growing mycobacteria isolates from cats and dogs and these isolates' susceptibility to cefovecin and clofazimine          下载免费PDF全文

CJM Bennie  JLK To  PA Martin  M Govendir 《Australian veterinary journal》2015,93(1-2):40-45

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