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Abstract
OBJECTIVE
The objectives of the current study were to quantify laying hen sternal carina (keel) and tibiotarsal bone and muscle quality using clinical CT, tissue level, and biomechanical measures; test associations among muscle transverse sectional area, bone mineral density, and biomechanical measures of bone quality; and determine whether CT measures of bone and muscle quality would be predictive of biomechanical measures of tibiotarsal bone quality.
ANIMALS
60 40-week-old Hy-Line brown laying hens were used.
METHODS
Associations among CT imaging, tissue level, and biomechanical measures of tibiotarsal and keel bone and muscle quality were tested using multivariate correlational analyses. Bivariate and generalized regressions were performed to determine whether CT measures were predictive of biomechanical measures of tibiotarsal bone quality.
RESULTS
Low positive correlations were identified between tibiotarsal muscle transverse-sectional area (cross-sectional area [CSA]) and bone mineral density (BMD) in the proximal location of the bone (r = −0.11 to 0.31). Tibiotarsal muscle CSA was also low to moderately correlated with biomechanical measures of bone quality (r = 0.20 to 0.41). Keel muscle CSA values were not correlated with keel BMD values, but they were correlated with biomechanical measures of tibiotarsal bone quality (r = 0.18 to 0.40). Keel CT measures of bone quality were not correlated with tibiotarsal CT measures of bone quality. At the proximal location, muscle CSA and tibiotarsal BMD were predictive of biomechanical failure load (F = 9.68, P = .0003muscle CSA; F = 9.13, P = .004tibiotarsal BMD).
CLINICAL RELEVANCE
Findings supported using noninvasive CT measures of muscle and bone quality in longitudinal research studies evaluating the effects of interventions on laying hen welfare.
Abstract
OBJECTIVE
To determine setting and temperature properties of diluted polymethyl methacrylate (PMMA) bone cement in vitro to assess utility for vocal fold augmentation in horses.
SAMPLES
4 dilutions of PMMA equivalent to volumes of 15 mL, 20 mL, 25 mL, and 30 mL PMMA powder (PMMAp) in 10 mL solvent.
METHODS
For each volume PMMAp, setting times (tset), peak temperatures (Tmax), and times to peak temperature (tmax) were determined using a temperature data logger in a 4-mL volume of PMMA. Injectability was assessed in vitro by documenting the force required to inject 0.2 mL PMMA through an 18-gauge 3.5-inch spinal needle attached to a 6-mL syringe at 1-minute intervals. Working time (twork) was calculated from a linear regression of injectability.
RESULTS
Peak temperatures increased with increasing volume of PMMAp: 56 °C, 86 °C, 99 °C, and 101 °C. Times for tset, twork, and tmax were inversely proportional to PMMA concentrations, resulting in tset of 23, 21, 17, and 14 minutes; twork of 22.75, 12.25, 7, and 4 minutes; and tmax of 28, 24, 19, and 16 minutes, respectively, for 15, 20, 25, and 30 mL PMMAp. Pairwise comparisons for all analyses were significant apart from Tmax for 25 and 30 mL PMMAp (P = .96) and twork for 20 and 25 mL PMMAp (P = .06).
CLINICAL RELEVANCE
Decreasing the concentration of PMMA bone cement resulted in longer working times and setting times; however, peak temperatures did not differ between the 2 strongest concentrations. Further research is warranted to quantify diluted PMMA properties for in vivo use for vocal fold augmentation in horses.
Abstract
Treatment options for human dementia remain limited, and additional research is needed to develop and validate translational models. Canine cognitive decline (CCD) is common in older dogs and a major source of morbidity. The decline includes physiological and behavioral changes comparable to those in humans diagnosed with dementia. There are also corresponding changes in plasma neurodegenerative biomarkers and neuropathology. Biomarkers for both human and canine cognitive decline can be used to identify and quantify the onset of behavioral data suggestive of CCD. Successful correlations would provide reference values for the early identification of neurodegeneration in canine patients. This could allow for the subsequent testing of interventions directed at ameliorating CCD and offer translational value leading to safe and effective treatment of dementia in people. Research can help exploit, track, and provide benefits from the rapid progression of spontaneous naturally occurring CCD in a large heterogenous community of companion dogs. Research efforts should work to deliver information using blood biomarkers, comorbidities, and wearable technologies to track and evaluate biometric data associated with neurodegeneration and cognitive decline that can be used by both human and companion animal researchers. The synergistic approach between human and veterinary medicine epitomized in one health underscores the interconnectedness of the well-being of both species. Leveraging the insights gained from studying CCD can not only lead to innovative interventions for pets but will also shed light on the complex mechanisms of human dementia.
Abstract
OBJECTIVE
To evaluate the role of simulation models and previous surgical experience on subjective and objective stress levels of students performing their 1st elective surgery within the veterinary curriculum.
SAMPLE
141 third-year veterinary students
METHODS
Using a pre–post experimental design, salivary alpha-amylase, and cortisol were evaluated as markers of physiologic stress response before students’ first elective surgery. Student self-reported State-Trait Anxiety Inventory (STAI) scores and quantitative measures of experience were correlated to biomarker results.
RESULTS
No association was found for change in salivary biomarkers of stress, alpha-amylase, and cortisol, between baseline and presurgical samples accounting for gender, age, type of elective surgery performed, previous surgical experience, or simulation model use. Salivary cortisol levels were markedly elevated falling between the 66th and 99th percentile compared to an age and gender-matched population. Salivary alpha-amylase levels were also 2 to 3 times higher than those recorded by other health professionals. Veterinary student STAI scores were high falling between the 65th and 73rd percentile compared to working adults in the general population.
CLINICAL RELEVANCE
Veterinary students’ salivary cortisol, alpha-amylase, and STAI scores fell into the upper 2/3rds of the general population, demonstrating a high level of stress. Simulation models and previous surgical experience were not associated with decreased stress. Further evaluation of the implementation of high-fidelity simulation models and the role of stress on performance is indicated.
Abstract
OBJECTIVE
To investigate matrix metalloproteinase (MMP) and their inhibitors tissue inhibitor matrix metalloproteinase (TIMP) gene expression and secretion during equine deep digital flexor tendon (DDFT) tenocyte and macrophage (undifferentiated, proinflammatory, and regulatory) co-culture.
SAMPLE
Third passage DDF tenocytes and donor-matched macrophages differentiated from peripheral blood CD14+ monocytes from 5 healthy horses ages 9–11 years, euthanized for reasons unrelated to musculoskeletal conditions.
METHODS
Passage 3 DDT tenocyte aggregate cultures were co-cultured with undifferentiated (control), proinflammatory (granulocyte-macrophage colony-stimulating factor; GM-CSF pretreated and lipopolysaccharide + interferon gamma-primed; LPS+IFN-γ) or regulatory (interleukin-4 and interleukin-10-primed; IL-4 + IL-10) macrophages in direct and transwell co-cultures for 72 hours. MMP-1, -2, -3, -9, -13, and TIMP -1, -2 mRNA were measured via real-time Polymerase Chain Reaction (rtPCR). Co-culture media MMP -3, -9, and TIMP -1, -2 concentrations were quantified via ELISA.
RESULTS
Direct co-culture of DDF tenocytes with proinflammatory macrophages for 72 hours increased MMP-1, -3, and -13 mRNA levels whereas, MMP-9 mRNA levels decreased. Direct and transwell co-culture with proinflammatory and regulatory macrophages resulted in increased MMP-3 and decreased MMP-9 media concentrations. While direct co-culture with regulatory macrophages significantly increased TIMP-1 mRNA, overall, TIMP mRNA and culture media concentrations were largely unchanged.
CLINICAL RELEVANCE
Cell-to-cell contact between DDF tenocytes and macrophages is not essential to induce MMP gene expression and secretion. Co-culture systems offer a viable in vitro platform to screen and evaluate immunomodulatory properties of therapies aimed at improving equine intrasynovial tendon healing.
