ORCID Profile
0000-0003-3984-481X
Current Organisation
University of Queensland
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Publisher: American Dairy Science Association
Date: 11-2012
Abstract: Objectives were to (1) determine the feasibility of performing hoof biopsies without impairing locomotion (2) evaluate the feasibility of using biopsied tissue for quantitative PCR and (3) compare relative gene expression among claws for several target genes. Biopsies were performed on 6 Holstein cows, yielding 4 tissue specimens per cow from front leg, right limb, and medial claw (claw position 3) rear leg, left limb, and lateral claw (claw position 5) and rear leg, right limb, medial claw (claw position 7). Cows were monitored for lameness daily for 7 d post-biopsy and then weekly for 8 wk. Histopathological analysis confirmed that tissue collected was from between the stratum corneum and dermis. Biopsied tissue was used for RNA extraction, including evaluation of yield and purity. The profile by claw position of 19 genes with key functions in cell differentiation, proliferation, inflammation, and keratin formation was assessed via quantitative reverse transcription-PCR. Other than transient disturbances in locomotion score in some cows during 2 to 4 d post-biopsy, no signs of pain, locomotion impairment, or clinical lameness were observed post-biopsy. Total RNA yields averaged 259.7±100, 447.8±288, and 496.4±118 μg/mg of tissue for claw positions 3, 5, and 7, respectively. The biopsy procedure was successful for obtaining corium for gene expression. Among 5 keratin proteins analyzed, only keratin 5 was expressed. Transcripts related to inflammation and oxidative stress (STAT3, MYD88, SOD2, and TLR4) were among the more abundant in corium tissue, but expression did not differ between claws. Biotinidase (BTD) expression was greater in claw 3 versus claw 5, whereas the ligand-activated nuclear receptor retinoic acid receptor-α (RXRA) was greater in claws 3 + 5 compared with claw 7. Overall, results from this pilot study revealed modest differences at the transcriptome level, suggesting that biotin availability and lipid metabolism differ between claw positions, whereas inflammation and oxidative stress seem to play an important role across claws. More comprehensive studies of the hoof transcriptome are required to improve our understanding of the mechanisms that link environmental and dietary factors to development of lameness.
Publisher: Wiley
Date: 21-04-2020
DOI: 10.1111/AVJ.12950
Publisher: American Veterinary Medical Association (AVMA)
Date: 02-2014
Abstract: Objective —To determine associations of blood analysis variables and orbit and nasal planum surface temperatures with the onset and severity of Mycoplasma bovis pneumonia in calves. Animals —28 healthy calves. Procedures —Calves were challenged with M bovis (n = 24) on day 0 or not challenged (4). Blood s les were obtained for cardiac troponin I, CBC, and serum biochemical analyses on various days. Orbit and nasal planum surface temperatures were determined with infrared thermography on various days. Calves were euthanized, gross necropsies were performed, heart and lung s les were collected for histologic evaluation, and microbial cultures of lung s les were performed on day 14. Pneumonia severity was categorized as mild ( 10% lung consolidation) or moderate (≥ 10% lung consolidation). Associations between measured variables and severity of pneumonia or s le collection day were determined. Results —Plasma cardiac troponin I concentration for the 28 calves was significantly higher on day 14 than it was on day 0 or 7 (least squares mean, 0.02, 0, and 0 ng/mL, respectively). No other variables changed significantly during the study. No substantial gross or histologic abnormalities were identified in cardiac muscle s les. Day 14 plasma fibrinogen concentration was significantly different between calves with mild pneumonia and those with moderate pneumonia (mean, 0.44 and 0.74 g/dL, respectively). Calves with moderate pneumonia had significantly lower least squares mean surface temperature of the dorsal aspect of the nasal planum (18.7°C) versus calves with mild pneumonia (22.9°C). Conclusions and Clinical Relevance —Results indicated the evaluated variables had low value for assessment of bovine respiratory disease complex in calves.
Publisher: Annex Publishers, LLC
Date: 05-2017
Publisher: American Veterinary Medical Association (AVMA)
Date: 06-2013
Abstract: Objective —To assess a commercially available point-of-care assay for measurement of bovine cardiac troponin I (cTnI) concentration in blood and plasma s les. S le —Prepared bovine plasma standard s les with known concentrations (0 to 1.0 ng/mL) of cTnI and blood and plasma s les obtained from 28 healthy 2.5-month-old Holstein calves. Procedures —Coefficients of variation were calculated for concentrations of cTnI in prepared standards determined with the point-of-care assay, and values were compared with the known concentrations. The cTnI concentrations in blood s les obtained from calves determined with the point-of-care assay were compared with cTnI concentrations in plasma s les obtained from those animals determined with a validated immunoassay. Results —The coefficients of variation of cTnI concentrations determined for prepared standards by use of the point-of-care assay were low ( 20%) for standards with cTnI concentrations ≥ 0.025 ng/mL. The blood cTnI concentrations determined with the point-of-care assay were not significantly different from the plasma cTnI concentrations determined with the validated immunoassay. Conclusions and Clinical Relevance —Results of this study indicated the point-of-care assay had high precision for determination of cTnI concentrations in most evaluated prepared bovine plasma standard s les. The point-of-care assay may be useful for determination of circulating concentrations of cTnI in cattle.
Location: No location found
Location: United States of America
Location: United States of America
No related grants have been discovered for Brandon Fraser.