Browsing by Author "Sawyere, Dominique M."

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    Bead size has a greater effect on in vitro elution from antimicrobial-impregnated calcium sulfate beads than drug concentration
    Olsen, Ronald S.; Sawyere, Dominique M.; Davis, Jennifer L.; Lanz, Otto I.; Werre, Stephen R. (American Veterinary Medical Association, 2023-05)
    OBJECTIVE To compare the elution characteristics of amikacin-impregnated calcium sulfate (CaSO4) beads based on different drug concentrations and bead size configurations. SAMPLE Six groups of amikacin-impregnated CaSO4 beads and one negative control group. PROCEDURES Amikacin-impregnated CaSO4 beads were formed with either 500 mg (low-concentration) or 1 g (high-concentration) of amikacin per 15 g CaSO4 hemihydrate powder. The number of beads necessary to approximate 150 mg of amikacin for each of the 3 bead sizes (3 mm, 5 mm, and 7 mm) at both low and high concentrations were placed in 6 mL of phosphate-buffered saline. The saline was sampled at 14 time points over 28 days. Amikacin concentrations were determined using liquid chromatography-mass spectrometry. RESULTS Smaller beads reached higher mean peak concentrations than larger beads (P < .0006). Peak concentrations for the low-and high-concentration groups were 20.5 mg/mL and 27.4 mg/mL, 13.1 mg/mL and 14.0 mg/mL, and 8.85 mg/mL and 6.75 mg/mL for the 3 mm, 5 mm, and 7 mm beads, respectively. Bead size also affected the length of therapeutic duration, lasting 6 days for the 3 mm and 5 mm beads and 9 days for the 7 mm beads. However, this was only statistically evident among the high-concentration beads (P < .044). Antimicrobial concentration within the same bead sizes did not affect elution. CLINICAL RELEVANCE Amikacin-impregnated CaSO4 beads achieved extreme supratherapeutic eluent concentrations. While additional studies are needed, bead size significantly affected elution with smaller beads reaching higher peak concentrations and 7 mm, high-concentration beads demonstrating a longer therapeutic duration than smaller beads.
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    Cytokine and Growth Factor Concentrations in Canine Autologous Conditioned Serum
    Sawyere, Dominique M. (Virginia Tech, 2016-05-27)
    The object of this study was to compare growth factor and cytokine profiles in canine autologous conditioned serum (ACS) to canine plasma. Blood collected from 16 medium to large breed dogs was used to produce ACS (Orthokine® vet irap 10 syringes) and citrated plasma (control). Canine-specific ELISA assays were run per manufacturers’ instructions for interleukin (IL)-10, IL-4, tumor necrosis factor (TNF)-α, insulin-like growth factor (IGF)-1, fibroblast growth factor (FGF)-2, transforming growth factor (TGF)-β1, IL-1β, and interleukin-1 receptor antagonist (IL-1ra). Serum, in addition to plasma and ACS, was collected from an additional 6 dogs for TNF-α, IL-1β, and IL-1ra analysis (total of 22 dogs). Data were analyzed for differences in cytokine concentrations between ACS, plasma, and serum using the Wilcoxon signed-rank test with significance set at P<.05.There was a large variability in growth factor and cytokine concentrations between individual dogs in both plasma and ACS. There were no significant differences in IL-10, TNF-α, IGF-1, FGF-2, and TGF-β1 concentrations between ACS, plasma, or serum. ACS concentrations of IL-1β (median, range; 46.3 pg/mL, 0-828.8) and IL-4 (0.0 pg/mL, 0-244.1) were significantly increased compared to plasma (36.6 pg/mL, 0-657.1 and 0.0 pg/mL, 0-0, respectively). IL-1ra concentrations in ACS (median, range; 3458.9 pg/mL, 1,243.1-12,089.0) were significantly higher than plasma (692.3 pg/mL, 422.5- 1,475.6), as was the IL-1ra:IL-1β ratio (39.9 and 7.2, respectively).