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81.
Bruce K. Wobeser 《The Canadian veterinary journal. La revue veterinaire canadienne》2015,56(4):359-360
During a widespread anthrax outbreak in Canada, miniature horses were vaccinated using a live spore anthrax vaccine. Several of these horses died from an apparent immune-mediated vasculitis temporally associated with this vaccination. During the course of the outbreak, other miniature horses from different regions with a similar vaccination history, clinical signs, and necropsy findings were found. 相似文献
82.
Nora Denk Vikram Misra Lynne S. Sandmeyer Bianca B. Bauer Jaswant Singh George W. Forsyth Bruce H. Grahn 《Canadian journal of veterinary research》2015,79(1):31-38
The objective of this study was to develop a murine retinal/choroidal/scleral explant culture system to facilitate the intravitreous delivery of vectors. Posterior segment explants from adult mice of 2 different age groups (4 wk and 15 wk) were cultured in serum-free medium for variable time periods. Tissue viability was assessed by gross morphology, cell survival quantification, activated caspase-3 expression, and immunohistochemistry. To model ocular gene therapy, explants were exposed to varying transducing units of a lentiviral vector expressing the gene for green fluorescent protein for 48 h. Explant retinal cells remained viable for approximately 1 wk, although the ganglion cell layer developed apoptosis between 4 and 7 d. Following vector infusion into the posterior segment cups, viral transduction was noted in multiple retinal layers in both age groups. An age of donor mouse influence was noted and older mice did not transduce as well as younger mice. This explant offers an easily managed posterior segment ocular culture with minimum disturbance of the tissue, and may be useful for investigating methods of enhancing retinal gene therapy under controlled conditions. 相似文献
83.
Gabhan Chalmers John McLean D. Bruce Hunter Marina Brash Durda Slavic David L. Pearl Patrick Boerlin 《Canadian journal of veterinary research》2015,79(2):129-135
Pododermatitis is a disease of concern for mink breeders in Canada and worldwide, as it causes discomfort and lowers the breeding rates on farms affected by the disease. Unfortunately, the etiology and pathogenesis of pododermatitis are still unknown. In this study, we compared Staphylococcus spp. and Streptococcus canis isolates from healthy mink with isolates from animals with pododermatitis on 2 farms in Ontario. Almost all hemolytic Staphylococcus spp. isolated were shown to be Staphylococcus delphini Group A by 16S ribosomal ribonucleic acid (rRNA) sequence analysis and polymerase chain reaction (PCR). Pulsed-field gel electrophoresis (PFGE) did not reveal any S. delphini or S. canis clonal lineages specifically associated with pododermatitis, which suggests that these bacteria do not act as primary pathogens, but does not dismiss their potential roles as opportunistic pathogens. While S. delphini and S. canis were the most prevalent bacterial pathogens in mink pododermatitis, they were also present in samples from healthy mink. Arcanobacterium phocae is occasionally isolated from pododermatitis cases, but is difficult to recover with conventional culture methods due to its slow growth. A quantitative real-time PCR was developed for the detection of A. phocae and was tested on 138 samples of footpad tissues from 14 farms. The bacterium was detected only in pododermatitis-endemic farms in Canada and was at higher concentrations in tissues from infected footpads than in healthy tissues. This finding suggests that A. phocae is involved in the pathogenesis of pododermatitis. 相似文献
84.
85.
LoCascio RG Ninonuevo MR Freeman SL Sela DA Grimm R Lebrilla CB Mills DA German JB 《Journal of agricultural and food chemistry》2007,55(22):8914-8919
The molecular basis by which human breast milk supports the development of a protective intestinal microbiome in infants is unknown. After lactose and lipids, human milk oligosaccharides (HMOs) are quantitatively the third largest and most diverse component of breast milk. In this work, glycomic profiling of HMO consumption by bifidobacteria using Fourier transform ion cyclotron resonance mass spectrometry reveals that one species, Bifidobacterium longum biovar infantis ATCC 15697, an isolate from the infant gut, preferentially consumes small mass oligosaccharides, representing 63.9% of the total HMOs available. These HMOs were detected in human breast milk at the onset and constantly through the first month of lactation by use of high performance liquid chromatography-chip time-of-flight mass spectrometry. Further characterization revealed that strain ATCC 15697 possesses both fucosidase and sialidase activities not present in the other tested strains. This work provides evidence that these small mass HMOs are selectively metabolized by select bifidobacterial strains and represent a potential new class of bioactive molecules functioning as prebiotics to facilitate a protective gut colonization in breast-fed newborns. 相似文献
86.
Bruce TJ Hooper AM Ireland L Jones OT Martin JL Smart LE Oakley J Wadhams LJ 《Pest management science》2007,63(1):49-56
Field-trapping experiments with synthetic 2,7-nonadiyl dibutyrate, the female-produced sex pheromone of the orange wheat blossom midge, Sitodiplosis mosellana (Géhin), demonstrated that pheromone traps were highly attractive to males and caught very few non-target organisms. Different formulations of pheromone were tested to identify the optimum release rate and dispenser type for use in pheromone traps in the UK. Key findings were that racemic pheromone was as effective as enantiomerically pure (2S,7R)-2,7-nonadiyl dibutyrate, that release rates higher than 0.5 microg day(-1) were not necessary and that the optimal formulation was a 1 mg pheromone loading in a rubber septum. Pheromone traps gave a reliable indication of peak midge emergence, onset of flight and abundance of midges throughout the season. A strong correlation between maximum trap catch and crop infestation levels was obtained. 相似文献
87.
88.
Weiwei Yan Kang-Soon Shin Shih-Jon Wang Hua Xiang Thomas Divers Sean McDonough James Bowman Anne Rowlands Bruce Akey Hussni Mohamed Yung-Fu Chang 《Journal of veterinary science (Suw?n-si, Korea)》2014,15(2):249-258
Clostridium (C.) difficile is a common cause of nosocomial diarrhea in horses. Vancomycin and metronidazole have been used as standard treatments but are only moderately effective, which highlights the need for a novel alternative therapy. In the current study, we prepared antiserum of equine origin against both C. difficile toxins A and B as well as whole-cell bacteria. The toxin-neutralizing activities of the antibodies were evaluated in vitro and the prophylactic effects of in vivo passive immunotherapy were demonstrated using a conventional mouse model. The data demonstrated that immunized horses generated antibodies against both toxins A and B that possessed toxin-neutralizing activity. Additionally, mice treated with the antiserum lost less weight without any sign of illness and regained weight back to a normal range more rapidly compared to the control group when challenged orally with 107
C. difficile spores 1 day after serum injection. These results indicate that intravenous delivery of hyperimmune serum can protect animals from C. difficile challenge in a dose-dependent manner. Hence, immunotherapy may be a promising prophylactic strategy for preventing C. difficile infection in horses. 相似文献
89.
Assessing the opportunities for upstream migration of non-salmonid fishes in the weir-regulated River Vecht 总被引:3,自引:1,他引:3
The degree of obstruction posed by weirs to potential upstream movements of non-salmonid fish (predominantly cyprinids) in the River Vecht, the Netherlands, was assessed. This rain-fed river showed high variability in discharge, providing opportunities for passage at high discharge when weirs were free flowing. Daily recorded discharge and water levels between 1960 and 1984, and an analysis of swimming capacities and migratory behaviour, were used to assess whether hydraulic conditions each day and for each species were suitable for ascent. The assessment demonstrated that migratory opportunities along the six weirs were extremely limited. Only 10 of 32 species were able to ascend all weirs in 5–30% of the years. Opportunities were the greatest for large-sized species during November–March at the downstream-situated weirs, whereas small-sized species had no opportunities year-round. The approach used is widely applicable for barrier assessment in other rivers, because it requires only basic hydraulic measurements that are often available. 相似文献
90.
Reducing rice field algae and cyanobacteria abundance by altering phosphorus fertilizer applications
In California’s water-seeded rice systems, algal/cyanobacterial biomass can be a problem during rice establishment and can lead to yield reductions. Laboratory, enclosure, and field-scale experiments were established to evaluate the effects of fertilizer P management on algal/cyanobacterial growth. Two field-scale experiments evaluated the response of algal/cyanobacterial growth to three P management strategies: conventional surface applied, incorporated into the soil, and delaying P applications by 30 days. Results from these experiments indicated rice fields that received conventional surface-applied P fertilizer had 4–8 times more algal/cyanobacterial biomass and 3–11 times higher concentrations of soluble reactive phosphate (SRP) than those in which P fertilizer was incorporated or delayed. Laboratory experiments evaluated the ability of field water to support growth of Nostoc spongiaeforme. Results indicate that water from the incorporated or delayed P application fields was P limited for N. spongiaeforme growth. Water from the surface-applied fields was not P limited. Enclosure experiments evaluated the effects of delayed P applications on algal/cyanobacterial biomass and rice yields. Algal/cyanobacterial cover and biomass increased in enclosures which received added P. Soluble reactive phosphate concentrations were also significantly greater in these enclosures. Delaying the application by up to 28 days did not reduce rice yields in the enclosures. One management implication is that reducing SRP concentrations early in the season in rice field water will result in reduced algal/cyanobacterial biomass. Strategies to reduce water SRP include incorporating fertilizer P or delaying the P application by up to 30 days. 相似文献