Corynebacterium equi Infections in Horses, 1958-1984: A Review of 131 Cases   总被引：6，自引：0，他引：6       下载免费PDF全文

Zink MC  Yager JA  Smart NL 《The Canadian veterinary journal. La revue veterinaire canadienne》1986,27(5):213-217

Of 131 cases of Corynebacterium equi infection in horses submitted for necropsy to the Ontario Veterinary College or Veterinary Laboratory Services, OMAF, Guelph, Ontario from 1958 to 1984, 115 were diagnosed as suppurative pneumonia, and of these 55 had associated ulcerative enterocolitis. Only five animals had intestinal involvement without pulmonary lesions. The remaining 11 cases included arthritis/cellulitis, skin abscesses and submandibular lymphadenitis. While the lung, intestine and associated lymph nodes yielded C. equi most frequently, in 21% of cases C. equi was also cultured from parenchymatous organs (spleen, liver or kidney) or blood. Corynebacterium equi infection accounted for 10% of all foals submitted for postmortem examination and 45% of all foals with pneumonia. Affected foals were one to four months of age. Submissions occurred between the months of May and August with a peak during July. There was a significantly greater prevalence of C. equi infection in Standardbreds when compared with other breeds. Of foals in this study, 36% were from farms which had had other horses succumb to this disease. Of the foals with pulmonary involvement, 21% did not have fever or clinical signs referable to the respiratory or gastrointestinal systems, findings which indicated that a large percentage of cases were subclinical.  相似文献   

Experiences of recent veterinary graduates in their first employment position and their preferences for new graduate support programmes     

MC Gates  I McLachlan  S Butler  JF Weston 《New Zealand veterinary journal》2020,68(4):214-224

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Theileria orientalis: a review     

JG Watts  MC Playford  KL Hickey 《New Zealand veterinary journal》2016,64(1):3-9

Theileria orientalis (also known historically as T. sergenti and T. buffeli) is responsible for benign or non-transforming theileriosis, and exerts its major effect through erythrocyte destruction. The life cycle of T. orientalis is essentially similar to that of other Theileria species, except that the schizonts do not induce transformation and fatal lymphoproliferation. The pathogenesis of anaemia as a result of infection is not clearly established and may be multifaceted. Clinical signs of weakness, reluctance to walk and abortion are early but non-specific indications of disease, particularly if accompanied by a history of cattle being moved. Physical examination may reveal pallor (pale eyes, vaginal mucosa), pyrexia, and elevated heart and respiratory rates. T. orientalis is an economically important parasite of cattle in New Zealand, Australia and Japan, especially where naïve animals are introduced into an endemic area or in animals under stress. Increased awareness of the risks posed by the parasite is required to enable management practices to be implemented to minimise its impact.  相似文献   

Clinical efficacy of diclofenac sodium and flunixin meglumine as adjuncts to antibacterial treatment of respiratory disease of calves     

M Guzel  MC Karakurum  R Durgut  N Mamak 《Australian veterinary journal》2010,88(6):236-239

Objective To compare the efficacy of the non-steroidal antiinflammatory drugs, diclofenac sodium and flunixin meglumine as adjuncts to the antibiotic treatment of bovine respiratory disease (BRD). Procedure We randomly allocated 80 Holstein calves with BRD to three groups. All the calves received a dose of 2.5 mg/kg tulathromycin by single subcutaneous injection and two of the groups received, in addition, either 2.5 mg/kg diclofenac sodium as a single intramuscular injection (diclofenac group, n = 30) or 2.2 mg/kg flunixin meglumine as an intravenous injection on the first three consecutive days after tulathromycin administration (flunixin group, n = 30). All calves were given a clinical score prior to initial treatment (day 0) and after treatment (days 1, 2, 3, 7 and 14) by observing appetite, demeanour, rectal temperature, the rate and type of respiration, presence or absence of coughing, and nasal discharge. Results During the first 48 h, improvement of adverse signs of respiratory disease, such as pyrexia and elevated respiratory rate, and of a high clinical index score was significant in the two adjunct groups compared with the calves receiving antibiotic alone. The reduction in pyrexia was greatest in the diclofenac group. There were no statically significant differences between treatment groups with regard to eventual perceived recovery from respiratory disease in 14 days. Conclusion In this trial, a single intramuscular dose of diclofenac sodium was equally effective as three intravenous injections of flunixin meglumine given on consecutive days as adjunctive therapy for BRD.  相似文献   

Pluripotent stem cells--model of embryonic development,tool for gene targeting,and basis of cell therapy   总被引：2，自引：0，他引：2  

Prelle K  Zink N  Wolf E 《Anatomia, histologia, embryologia》2002,31(3):169-186

Embryonic stem (ES) cells are pluripotent cell lines with the capacity of self-renewal and a broad differentiation plasticity. They are derived from pre-implantation embryos and can be propagated as a homogeneous, uncommitted cell population for an almost unlimited period of time without losing their pluripotency and their stable karyotype. Murine ES cells are able to reintegrate fully into embryogenesis when returned into an early embryo, even after extensive genetic manipulation. In the resulting chimeric offspring produced by blastocyst injection or morula aggregation, ES cell descendants are represented among all cell types, including functional gametes. Therefore, mouse ES cells represent an important tool for genetic engineering, in particular via homologous recombination, to introduce gene knock-outs and other precise genomic modifications into the mouse germ line. Because of these properties ES cell technology is of high interest for other model organisms and for livestock species like cattle and pigs. However, in spite of tremendous research activities, no proven ES cells colonizing the germ line have yet been established for vertebrate species other than the mouse (Evans and Kaufman, 1981; Martin, 1981) and chicken (Pain et al., 1996). The in vitro differentiation capacity of ES cells provides unique opportunities for experimental analysis of gene regulation and function during cell commitment and differentiation in early embryogenesis. Recently, pluripotent stem cells were established from human embryos (Thomson et al., 1998) and early fetuses (Shamblott et al., 1998), opening new scenarios both for research in human developmental biology and for medical applications, i.e. cell replacement strategies. At about the same time, research activities focused on characteristics and differentiation potential of somatic stem cells, unravelling an unexpected plasticity of these cell types. Somatic stem cells are found in differentiated tissues and can renew themselves in addition to generating the specialized cell types of the tissue from which they originate. Additional to discoveries of somatic stem cells in tissues that were previously not thought to contain these kinds of cells, they also appear to be capable of developing into cell types of other tissues, but have a reduced differentiation potential as compared to embryo-derived stem cells. Therefore, somatic stem cells are referred to as multipotent rather than pluripotent. This review summarizes characteristics of pluripotent stem cells in the mouse and in selected livestock species, explains their use for genetic engineering and basic research on embryonic development, and evaluates their potential for cell therapy as compared to somatic stem cells.  相似文献   

Corynebacterium pseudotuberculosis exotoxin: fatal hemolytic anemia induced in gnotobiotic neonatal small ruminants by parenteral administration of preparations containing exotoxin   总被引：2，自引：0，他引：2  

T Y Hsu  H W Renshaw  C W Livingston  J L Augustine  D L Zink  B B Gauer 《American journal of veterinary research》1985,46(5):1206-1211

Inoculation of live Corynebacterium pseudotuberculosis, culture supernatant, ammonium sulfate-fractionated crude exotoxin, or chromatographically purified exotoxin preparations into gnotobiotic small ruminants (n = 13) caused death of the ruminants within 48 hours. Characteristic changes observed in animals living greater than or equal to 2 hours after inoculation included hemorrhage and edema at the site of injection, severe hemolytic anemia and hemoglobinuria, dark red fluid in body cavities, lung edema, and icterus. The crude exotoxin preparation caused a syndrome of acute shock in 2 lambs that died within 15 minutes after inoculation. Clinical and pathologic responses of animals inoculated with culture supernatant and purified toxin were similar. Histopathologic evidence indicated that the exotoxin caused necrotic changes in the proximal convoluted tubules of the kidneys. Inoculation with live organisms caused multiple foci of suppurative inflammation in skeletal muscle and adjacent adipose tissue, whereas such changes were not observed in animals administered exotoxin preparations. Although C pseudotuberculosis exotoxin induced a hemolytic anemia in the experimental animals, it did not lead to in vitro lysis of ovine, caprine, or bovine erythrocytes, unless they had been sensitized with Rhodococcus (Corynebacterium) equi filtrate. The toxic sphingomyelin-specific phospholipase D from C pseudotuberculosis had a molecular weight of 31,000 daltons and an isoelectric point of approximately 9.6. The elution profile of exotoxin on a carboxymethyl Sephadex column was studied and the majority of the enzymatic activity was eluted by a NaCl gradient (0.25M to 0.7M) with a maximum at 0.35M NaCl.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

In vitro phagocytosis and killing of Corynebacterium equi by alveolar macrophages of foals   总被引：5，自引：0，他引：5  

M C Zink  J A Yager  J F Prescott  B N Wilkie 《American journal of veterinary research》1985,46(10):2171-2174

Bronchoalveolar lavage was performed 5 times, sequentially, on 3 healthy foals while each foal was 6 to 63 days of age. Phagocytosis and bactericidal assays were performed on recovered alveolar macrophages. Corynebacterium equi and alveolar macrophages at a ratio of 10:1 were incubated for 1 hour in medium containing 1% heat-inactivated rabbit anti-C equi serum. After incubation, greater than 90% of the alveolar macrophages contained at least 1 ingested bacterium and each alveolar macrophage contained 9.4 +/- 1.0 bacteria (mean +/- SE). After alveolar macrophages and C equi were incubated for 1 hour in medium containing heat-inactivated pooled normal horse serum, approximately 24% of the alveolar macrophages contained at least 1 bacterium and each alveolar macrophage contained 0.8 +/- 0.7 bacteria. From 6 to 61 days of age, each foal had significantly (P less than 0.05) decreased phagocytic activity by alveolar macrophages, but a significant change in killing of C equi by alveolar macrophages was not found in the foals from 21 to 61 days of age. After incubating alveolar macrophages and C equi for 4 hours in vitro, approximately 75% of ingested C equi remained viable.  相似文献   

A stress transformation approach to predicting the failure mode of wood     

A. G. Zink  P. J. Pellicane  R. W. Anthony 《Wood Science and Technology》1995,30(1):21-30

Summary A simple model, based on the use of transformations of second-order tensors, is presented in this paper to predict the failure mode of wood members stressed in various degrees of parallel-and perpendicular-to-grain tension and parallel-to-grain shear. This type of loading is indicative of structural wood members with cross grain or grain deviations in the vicinity of knots subjected to bending or tension. The model is based on the assumptions that failure is dictated by the presence of any of the aforementioned stresses that exceed the clear wood strength in that mode and that failure does not result from stress interactions. The magnitudes of the applied stresses are normalized relative to the wood strength in that mode. The ratio of applied stress to material strength that is greatest at any particular angle of load to grain is presumed to be the failure mode at that angle. To verify model predictions, optical and microscopic analyses of surfaces of failed specimens loaded in uniaxial tension at angles between 0° and 90° to grain were compared to previously obtained, or otherwise known, surfaces of specimens tested in tension and shear. Specimens tested at various angles to grain demonstrated failed surfaces very much like those associated with specimens loaded in the modes predicted by the model.  相似文献   

A comparison of the autecology of Quercus robur L. and Q. pyrenaica Wild.: present habitat in Galicia, NW Spain     

Diaz-Maroto  IJ; Vila-Lameiro  P; Guchu  E; Diaz-Maroto  MC 《Forestry》2007,80(3):223-239

The biotopes occupied by pedunculate oak (Quercus robur L.)and rebollo oak (Quercus pyrenaica Willd.) in Galicia were characterizedusing different parameters, enabling a comparative analysisof its habitats. Thirty-nine plots of pedunculate oak and 40of rebollo oak were inventoried and 25 ecological parameters(physiographic, climatic and edaphic) were measured to describethe biotopes, along with 14 stand parameters to characterizethe structure and the silviculture of these forests; some ofthem were used in previous works about the autecology of bothspecies. Quercus robur was found to occupy a wider range ofecological habitats and their distribution is oceanic; Q. pyrenaicapresents a more Mediterranean phytoclimatic position. The resultsindicated that the distribution of oak forests in Galicia ismore closely related to physiographic and climatic featuresthan to edaphic, because the nature of the substrates that theyoccupy is similar. Analysis of fragility/aggressiveness betweenboth species and chestnut shows that the aggressiveness of bothoaks, mainly pedunculate, was much higher, except at high altitudes,and in areas with a high mean temperature, where rebollo ismore aggressiveness. Comparison of the two Quercus shows formost of the parameters that Q. robur is the more aggressivespecies.  相似文献   

Microbial origin of the abdominal swelling affecting farmed larvae of gilt-head seabream, Sparus aurata L.     

J Sedano  I Zorrilla  MA Moriñigo  MC Balebona  A Vidaurreta  MA Bordas  JJ Borrego 《Aquaculture Research》1996,27(5):323-333

The aetiological agents of the abdominal swelling affecting farmed larvae of gilt-head seabream, Sparus aurata L., were studied. Four Vibrio strains were isolated from larvae of S. aurata affected by this disease, and all strains reproduced the disease in healthy larvae under controlled infection experiments, producing a significant increase of the mortality rates compared to the control (non-inoculated larvae). Several enzymatic properties, which can act as .virulence factors, were demonstrated both in the extracellular products (ECPs) and In live cells of the strains tested. Histopathological examinations of the infected fish larvae revealed important changes of the anterior intestine and liver characterized by a marked hyperthrophy of the intestinal epithelium and hepatocytes, and by a separation of the mucosal and submucosal layers in the digestive tube. These histological alterations were associated with the constant presence of cocobacillar bacteria in the anterior intestine and in the liver. However, the precise pathogenic mechanisms of the strains tested have not been completely elucidated yet.  相似文献