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51.
Taylor WP Roeder PL Rweyemamu MM Melewas JN Majuva P Kimaro RT Mollel JN Mtei BJ Wambura P Anderson J Rossiter PB Kock R Melengeya T Van den Ende R 《Tropical animal health and production》2002,34(6):471-487
In January 1997, Tanzania requested international assistance against rinderpest on the grounds that the virus had probably entered the country from southern Kenya. Over the next few months, a variety of attempts were made to determine the extent of the incursion by searching for serological and clinical evidence of the whereabouts of the virus. At the clinical level, these attempts were hampered by the low virulence of the strain, and at the serological level by the lack of a baseline against which contemporary interpretations could be made. Once it became apparent that neither surveillance tool was likely to produce a rapid result, an infected area was declared on common-sense grounds and emergency vaccination was initiated. The vaccination programme had two objectives, firstly to prevent any further entry across the international border, and secondly to contain and if possible eliminate rinderpest from those districts into which it had already entered. On the few occasions that clinical rinderpest was subsequently found, it was always within this provisional infected area. Emergency vaccination campaigns within the infected area ran from January to the end of March 1997 but were halted by the onset of the long rains. At this time, seromonitoring in two districts showed that viral persistence was still theoretically possible and therefore a second round of emergency vaccination was immediately organized. Further seromonitoring then indicated a large number of villages with population antibody prevalences of over 85%. These populations were considered to have been `immunosterilized'. Although no clinical disease had been observed in them, it was decided to undertake additional vaccination in a group of districts to the south of the infected area. Serosurveillance indicated that rinderpest could have been present in a number of these districts prior to vaccination. Serosurveillance in 1998 suggested that numerous vaccinated animals had probably moved into districts outside the infected and additional vaccination areas, but did not rule out the continued presence of field infection. 相似文献
52.
Van den Broeck W Bouchaut H Cox E Goddeeris BM 《Veterinary immunology and immunopathology》2002,85(3-4):171-178
Oral administration of F4 fimbriae of Escherichia coli induces intestinal mucosal immune responses in F4 receptor-positive (F4R(+)) pigs, but not in F4R(-) pigs. We examined whether F4 fimbriae in F4R(-) animals behave like a food antigen and can induce oral tolerance. Therefore, F4R(+) and F4R(-) pigs were fed 2mg of F4 and challenged i.m. to evaluate the effect of oral F4 on the systemic immune system. As control antigen, two different oral doses (2 and 600 mg) of OVA were used. Thirty days after the i.m. OVA challenge, the OVA-specific serum IgG titre in 600 mg-fed pigs was lower than that in non-fed animals, indicating that tolerance was induced. Conversely, in the 2mg-fed pigs a rapid increase of OVA-specific IgG with higher titres than those in non-fed pigs was seen following challenge, indicating a priming of the systemic immune system. A similar priming was seen in both F4-fed F4R(-) and F4R(+) pigs. Upon challenge, non-fed pigs displayed a primary immune response with a slow increase of F4-specific serum IgG, whereas F4-fed F4R(-) and F4R(+) pigs showed secondary responses with a rapid increase of serum IgG. This was expected in F4R(+) pigs, as in these animals oral F4 induces F4-specific antibody-secreting cells in the spleen, suggesting a priming of the systemic immune system. However, also the F4-fed F4R(-) pigs displayed a secondary response, despite the failure to detect a response upon oral F4 administration. These findings suggest that the F4 antigen, at a dose of 2 mg, behaves like a common food antigen in F4R(-) pigs, namely it induces a systemic priming. 相似文献
53.
Cangul IT Wijnen M Van Garderen E van den Ingh TS 《Journal of veterinary medicine. A, Physiology, pathology, clinical medicine》2002,49(6):307-312
In this study the clinico-pathological aspects of cutaneous and mucocutaneous plasmacytomas were investigated in 63 dogs (one dog with two tumours). The tumours were most commonly observed in the skin of the trunk and legs. Yorkshire Terrier (n = 8) was the most commonly affected breed and males were affected more commonly than females (36 versus 23, respectively). Plasmacytomas were histologically classified into mature, hyaline, cleaved, asynchronous, monomorphous blastic and polymorphous blastic cell types. Monomorphous blastic cell type was the most frequent type (n = 21), followed by cleaved (n = 19) and asynchronous (n = 11) cell types. Secondary amyloid depositions were observed in eight cases. Immunohistochemical staining showed monoclonal lambda light chain positivity in all cases. In the immunohistochemical staining for cyclin D1, which is a prognostic marker in human plasma cell tumours, moderate numbers of positive tumour cells were observed in only one case of (muco)cutaneous plasmacytoma. All other cases were negative or contained few positive tumour cells. On the other hand, high numbers of tumorous plasma cells reacted positively with cyclin D1 in three out of six cases of canine multiple myelomas. Prognosis of the (muco)cutaneous plasmacytomas was good, except in one dog which developed a lymphoma afterwards. No significant correlations were observed between the cell type and the location of the tumour, presence of amyloid or prognosis. 相似文献
54.
Sigauque I Van den Bossche P Moiana M Jamal S Neves L 《The Onderstepoort journal of veterinary research》2000,67(3):167-172
A tsetse and bovine trypanosomosis survey was conducted during 1998 and 1999 in the Matutuine District of Maputo Province (Mozambique). A total of 59 Glossina brevipalpis and 17 Glossina austeni were captured throughout the district. Survey results suggest that Glossina brevipalpis is mainly concentrated in dense vegetation along the Maputo River and in the wetlands east of the river. G. austeni, on the other hand, was captured mainly in dense thickets in drier areas. Both tsetse species are suspected to be vectors of bovine trypanosomosis. Bovine trypanosomosis (75,5% Trypanosoma congolense) was diagnosed in 53 animals (13,9%) from seven sampling sites distributed throughout the district. The prevalence of cattle with anti-trypanosomal antibodies was high (29,9%).The incidence of trypanosomal infections in sentinel cattle was also high. The widespread distribution of bovine trypanosomosis and the high prevalence of infection are likely to have a significant impact on cattle production and, hence, the cattle restocking exercise in the district. 相似文献
55.
Extrahepatic biliary atresia in a border collie 总被引:2,自引:0,他引:2
Schulze C Rothuizen J van Sluijs FJ Hazewinkel HA van den Ingh TS 《The Journal of small animal practice》2000,41(1):27-30
Progressive lameness and leg pain were the predominant clinical signs in a 17-week-old male border collie presented for examination. On clinical investigation, extrahepatic cholestasis in association with rickets due to inadequate vitamin D resorption was diagnosed. The dog was treated parenterally with vitamin D and a cholecystoduodenostomy was performed. At 25 days postsurgery the lameness had resolved and bone structure was radiographically normal. However, at six weeks postsurgery, the dog's condition deteriorated rapidly and euthanasia was finally performed at eight weeks postsurgery. At postmortem examination, Toxocara canis nematodes were found to have invaded the biliary system via the anastomosis between the gallbladder and duodenum, causing biliary and hepatic toxocariasis. The cause of the primary extrahepatic cholestasis was atresia of the common bile duct at the hepatic end. The liver tissue showed microscopic lesions of chronic extrahepatic cholestasis as well as acute inflammation associated with the nematode invasion. There was no postmortem evidence of bone lesions. Extrahepatic biliary atresia is extremely rare in animals and has not been described before in dogs. In contrast, it represents the most common cause of congenital cholestasis in children, occurring in approximately one per 10,000 to 15,000 live births. 相似文献
56.
57.
Nucleic acid vaccines: research tool or commercial reality 总被引:3,自引:0,他引:3
Babiuk LA Babiuk SL Loehr BI van Drunnen Littel-van den Hur 《Veterinary immunology and immunopathology》2000,76(1-2):1-23
Polynucleotide immunization has captured the imagination of numerous researchers and commercial companies around the world as a novel approach for inducing immunity in animals. Clearly, the 'proof-of-principle' has been demonstrated both in rodents and various animal species. However, to date, no commercial veterinary vaccine has been developed, or to our knowledge, is in the licensing phase. The present review summarizes the types of pathogens and host species for which polynucleotide immunization has been tried. We have tried to identify possible barriers to commercialization of this technology and areas that need attention if this promising technology is ever to become a reality in the commercial arena. 相似文献
58.
Drén CN Kant A Van Roozelaar DJ Hartog L Noteborn MH Koch G 《Acta veterinaria Hungarica》2000,48(4):455-467
The pathogenesis of chicken infectious anaemia virus (CAV) infection was studied in 6-week-old and one-day-old SPF chickens inoculated intramuscularly with graded doses of Cux-1 strain (10(6)-10(2) TCID50/chicken). Viraemia, virus shedding, development of virus neutralizing (VN) antibodies and CAV distribution in the thymus were studied by virus isolation, polymerase chain reaction (PCR), immunocytochemistry (IP) and in situ hybridization until postinfection day (PID) 28. In 6-week-old chickens infected with high doses of CAV, viraemia and VN antibodies could be detected 4 PID and onward without virus shedding or contact transmission to sentinel birds. However, virus shedding and contact transmission were demonstrated in one-day-old infected chickens. In the 6-week-old groups infected with lower doses, VN antibodies developed by PID 14, transient viraemia and virus shedding were detected. The thymus cortex of all 1-day-old inoculated chickens stained with VP3-specific mAb. Cells with positive in situ hybridization signal were fewer and scattered throughout the thymus tissue of the one-day-old inoculated chickens as compared to IP-positive cells. These results suggest that early immune response induced by high doses of CAV in 6-week-old chickens curtails viral replication and prevents virus shedding. 相似文献
59.
60.
In a 2 × 2 factorial arrangement, 16 groups of 12 pigs were assigned to one of two housing systems (straw bedding, S vs. Barren, B) and to one of two starch types (native, N vs. pregelatinized potato starch, P, each included at 35%) to study effects on apparent faecal digestible nutrient intakes. Intake of straw from bedding material was estimated, using several markers, and results are discussed. Straw intake of the S-pigs was estimated between 143 and 234 g DM/d for P-pigs and between 96 and 156 g DM/d for N-pigs, depending on the method used. Nutrient digestibility was reduced in N-pigs when compared with P-pigs. Intake of digestible dry matter, energy, starch and ADF was increased in S-pigs, but the intake of digestible protein was reduced. Despite greatly reduced nutrient digestibility in S-pigs, additional digestible nutrient intake due to housing on a straw bedding can be considerable. 相似文献