Affiner votre recherche
Résultats 131-140 de 476
Evaluation of an improved sustained-release buprenorphine formulation for use in mice
2014
Healy, Jason R. | Tonkin, Jennifer L. | Kamarec, Stacey R. | Saludes, Mitchell A. | Ibrahim, Sherif Y. | Matsumoto, Rae R. | Wimsatt, Jeffrey H.
Objective—To evaluate analgesic effects of an improved sustained-release buprenorphine (BUP-SR) formulation administered to mice. Animals—36 male Swiss-Webster mice. Procedures—Mice were assigned to each of 3 treatment groups (n = 12 mice/group). Treatments were administered SC (vehicle [control treatment], 1.5 mg of buprenorphine hydrochloride [BUP-HCl]/kg, and 1.5 mg of BUP-SR/kg). Mice were evaluated (total activity, gastrointestinal tract motility, respiratory rate, cataleptic behavior, and tall-flick and hot plate nociception tests) to determine behavioral and physiologic responses at 4, 24, and 48 hours after treatment administration. Body weight and respiratory rate were measured before and at each time point after treatment administration. Results—SC administration of BUP-SR resulted in significant antinociception effects for 48 hours for the hot plate and tall-flick nociception tests without substantial adverse effects. Gastrointestinal tract motility and total activity were higher at 4 hours for mice receiving BUP-SR than for mice receiving the vehicle, but values were the same between these groups at 24 and 48 hours. The BUP-SR group had a lower respiratory rate than did the control group at all times after treatment administration. Mice treated with BUP-SR had no significant changes in body weight during the study, whereas mice treated with BUP-HCl had a significant decrease in body weight at 24 and 48 hours. Conclusions and Clinical Relevance—BUP-SR administration resulted in antinociception effects for 48 hours. Results of this study indicated that the improved BUP-SR formulation could be safely administered SC and conferred superior analgesia, compared with that for BUP-HCl, in mice.
Afficher plus [+] Moins [-]Radiographic, ultrasonographic, and anatomic assessment of femoral trochlea morphology in red foxes (Vulpes vulpes)
2014
Miles, James E. | Westrup, Ulrik | Svalastoga, Eiliv L. | Eriksen, Thomas
Objective—To compare repeatability and equivalency of measures of femoral trochlea depth and trochlear angle in red foxes (Vulpes vulpes) determined by use of radiography, ultrasonography, and digital photography of cadaver limbs. Sample—24 pelvic limbs from 12 red fox cadavers. Procedures—Cranioproximal-craniodistal oblique (skyline) and lateromedial radiographic views of the stifle joint and ultrasonographic images at 5 locations along the femoral trochlea were used in the study. Spacing of the 5 locations was determined on the basis of patellar position with the stifle joint at various caudal angles ranging from 96° to maximal extension (approx 170°). Ultrasonographic measurements were compared with those obtained at matched locations on photographs of anatomic preparations. Trochlear depth was assessed with all 3 image formats, and trochlear angle (measured between the trochlear ridges and sulcus) was assessed on radiographs and ultrasonographic images. Patellar thickness was measured on radiographs. Values obtained were compared by means of ANOVA, modified Bland-Altman plots, and repeatability testing. Results—Depth measurement repeatability was considered good for all modalities. Small but significant differences between mean ultrasonographic trochlear depth and anatomic (photographic) measurements were found at 3 locations; 95% limits of agreement for paired anatomic and ultrasonographic measurements were wide. The ratio of trochlear depth to radiographic patellar thickness was approximately 30% for all modalities. Trochlear angle measurements were more variable than trochlear depth measurements, especially in the distal aspect of the trochlea. Conclusions and Clinical Relevance—Paired anatomic and ultrasonographic measurements did not appear equivalent in this study, possibly attributable to imprecise probe location, which could limit quantitative use of ultrasonography in assessing proximal trochlear depth in a clinical setting.
Afficher plus [+] Moins [-]Comparison of pharmacokinetics of marbofloxacin after subcutaneous administration of various multiple-dose regimens to water buffalo calves (Bubalus bubalis)
2014
Baroni, Eduardo E. | Rubio, Sonia | Lucas, Jose J de | San Andres, Maria D. | San Andres, Manuel I.
Objective—To determine pharmacokinetics of marbofloxacin in water buffalo calves (Bubalus bubalis) after multiple SC administrations and to assess differences in regimen efficacy. Animals—18 healthy buffalo calves. Procedures—Calves (n = 6 calves/group) were assigned to receive marbofloxacin SC in the neck at 1 of 3 dosages (2 mg/kg, q 24 h for 6 days [regimen 1]; 4 mg/kg, q 48 h for 6 days [regimen 2]; and 4 mg/kg, q 24 h for 3 days [regimen 3]). Serum marbofloxacin concentrations were analyzed. Efficacy predictors were estimated on the basis of minimum inhibitory concentration and mutant prevention concentration reported for Pasteurella multocida and Mannheimia haemolytica. Results—Mean ± SD area under the concentration-time curve was 5.92 ± 0.40 μg•h/mL for regimen 1, which differed significantly from that for regimens 2 (14.26 ± 0.92 μg•h/mL) and 3 (14.17 ± 0.51 μg•h/mL). Mean residence time and mean elimination half-life for regimen 2 (9.93 ± 0.20 hours and 8.77 ± 0.71 hours) both differed significantly from those for regimens 1 (721 ± 0.11 hours and 5.71 ± 0.38 hours) and 3 (759 ± 0.13 hours and 737 ± 1.19 hours). Values obtained from indices for P multocida and M haemolytica had an excessively wide range because of the various degrees of antimicrobial susceptibility (low, medium, and high) of the strains. Conclusions and Clinical Relevance—Regimen 3 had the most favorable indices, and it would be conducive for owner compliance and require less handling of animals.
Afficher plus [+] Moins [-]Comparison of anesthetic efficacy and adverse effects associated with peribulbar injection of ropivacaine performed with and without ultrasound guidance in dogs
2014
Wagatsuma, Juliana T. | Deschk, Mauricio | Floriano, Beatriz P. | Ferreira, Joana Z. | Fioravanti, Heitor | Gasparello, Isabela F. | Oliva, Valeria N. L. S.
Objective—To compare the anesthetic efficacy and adverse effects associated with peribulbar injection of ropivacaine (1% solution) performed with and without ultrasound guidance (UG) in dogs. Animals—15 dogs without ophthalmologic abnormalities. Procedures—Each dog was sedated and anesthetized. A peribulbar injection of ropivacaine (1% solution; 0.3 mL/kg) was performed with UG in 1 eye and without UG in the contralateral eye (control). For each eye, the intraocular pressure (IOP) immediately after eye centralization and number of punctures were recorded; ophthalmic complications, postinjection corneal sensitivity (determined by Cochet-Bonnet esthesiometry), durations of the sensory and motor blockades (the latter determined as the interval to restoration of the vestibuloocular reflex, pupillary light reflex, and conjugate eye movement), and blockade quality were assessed in both eyes following anesthetic recovery. Results—Needle placement was fully visualized in 8 of the 15 eyes injected with UG. For eyes injected with or without UG, there was no difference with regard to the number of punctures, postinjection corneal sensitivity, and sensory or motor blockade duration and quality; however, restoration of conjugate eye movement occurred later in control eyes. For eyes injected with UG, mean IOP was 18.6 mm Hg, compared with 23.3 mm Hg for control eyes. Incidence of subconjunctival hemorrhage was higher for control eyes; severity of chemosis and hyperemia varied over time within both groups of eyes. Conclusion and Clinical Relevance—In dogs, peribulbar injection of ropivacaine with UG is feasible in dogs and provides effective sensory and motor blockades similar to those achieved with conventional techniques.
Afficher plus [+] Moins [-]Evaluation of a single intra-articular injection of autologous protein solution for treatment of osteoarthritis in horses
2014
Bertone, Alicia L. | Ishihara, Akikazu | Zekas, Lisa J. | Wellman, Maxey L. | Lewis, Katharine B. | Schwarze, Rebecca A. | Barnaba, Andrea R. | Schmall, Michael L. | Kanter, Peter M. | Genovese, Ron L.
Objective-To evaluate intra-articular autologous protein solution (APS) for the treatment of osteoarthritis in horses. Animals-40 client-owned horses with naturally occuring osteoarthritis. Procedures-APS was generated from a dual-device system that concentrated plasma and WBC proteins and enriched platelet growth factors. Horses were randomly assigned to receive an intra-articular injection of 5 mL of saline (0.9% NaCl) solution (n = 20) or APS (20), exercised on a treadmill, and evaluated on the basis of lameness grades, kinetic gait analysis, joint circumference, and range of motion for 14 days. Horses that received saline solution were administered APS at termination of the study, and clients scored horses for lameness and discomfort before, 12 weeks after, and 52 weeks after the APS injection. Results-The APS group had significant improvements in lameness grade, asymmetry indices of vertical peak force, and range of joint motion by 14 days, compared with baseline or control group values. No adverse effects associated with APS treatment were evident. Clients assessed lameness and comfort as improved at 12 and 52 weeks. The APS had greater likelihood (OR, 4.3 to 30.0) of a therapeutic response in horses with a lameness score < 4, < 10% vertical force asymmetry, or absence of marked osteophyte formation, subchondral sclerosis, or joint space narrowing. Concentration of interleukin-1 receptor antagonist in APS was 5.8 times that in blood. Conclusions and Clinical Relevance-Intra-articular administration of APS can be considered an effective treatment option for equine osteoarthritis, with the potential for disease-modifying effects.
Afficher plus [+] Moins [-]Stochastic model of porcine reproductive and respiratory syndrome virus control strategies on a swine farm in the United States
2014
Jeong, Jaewoon | Aly, Sharif S. | Cano, Jean Paul | Polson, Dale | Kass, Philip H. | Perez, Andres M.
Objective-To use mathematical modeling to assess the effectiveness of control strategies for porcine reproductive and respiratory syndrome (PRRS) virus on a swine farm. Sample-A hypothetical small, medium, or large farrow-to-weaning swine farm in the Midwestern United States. Procedures-Stochastic models were formulated to simulate an outbreak of PRRS on a farm. Control strategies assessed in those models included none (baseline) and various combinations of mass immunization, herd closure, and gilt acclimatization. Nine different models resulting from the combination of low, moderate, or high PRRS virus virulence and small, medium, or large herd size were simulated. A stabilized status, the outcome of interest, was defined as the absence of positive PCR assay results for PRRS virus in 3-week-old piglets. For each scenario, the percentage of simulations with a stabilized status was used as a proxy for the probability of disease control. Results-Increasing PRRS virus virulence and herd size were negatively associated with the probability of achieving a stabilized status. Repeated mass immunization with herd closure or gilt acclimitization was a better alternative than was single mass immunization for disease control within a farm. Conclusions and Clinical Relevance-Repeated mass immunization with a PRRS modified-live virus vaccine with herd closure or gilt acclimitization was the scenario most likely to achieve a stabilized status. Estimation of the cost of various PRRS control strategies is necessary.
Afficher plus [+] Moins [-]Comparison of bronchoalveolar lavage fluid obtained by manual aspiration with a handheld syringe with that obtained by automated suction pump aspiration from healthy dogs
2014
Woods, Katharine S. | Defarges, Alice M.N. | Abrams-Ogg, Anthony C.G. | Dobson, Howard | Brisson, Brigitte A. | Viel, Laure | Bienzle, Dorothee
Objective-To compare bronchoalveolar lavage (BAL) fluid obtained by manual aspiration (MA) with a handheld syringe with that obtained by suction pump aspiration (SPA) in healthy dogs. Animals-13 adult Beagles. Procedures-Each dog was anesthetized and bronchoscopic BAL was performed. The MA technique was accomplished with a 35-mL syringe attached to the bronchoscope biopsy channel. The SPA technique was achieved with negative pressure (5 kPa) applied to the bronchoscope suction valve with a disposable suction trap. Both aspiration techniques were performed in each dog in randomized order on opposite caudal lung lobes. Two 1 mL/kg aliquots of warm saline (0.9% NaCl) solution were infused per site. For each BAL fluid sample, the percentage of retrieved fluid was calculated, the total nucleated cell count (TNCC) and differential cell count were determined, and semiquantitative assessment of slide quality was performed. Comparisons were made between MA and SPA techniques for each outcome. Results-1 dog was removed from the study because of illness. The mean percentage of fluid retrieved (mean difference, 23%) and median TNCC (median distribution of differences, 100 cells/μL) for samples obtained by SPA were significantly greater than those for samples obtained by MA. Conclusions and Clinical Relevance-In healthy dogs, BAL by SPA resulted in a significantly higher percentage of fluid retrieval and samples with a higher TNCC than did MA. Further evaluation of aspiration techniques in dogs with respiratory tract disease is required to assess whether SPA improves the diagnostic yield of BAL samples.
Afficher plus [+] Moins [-]Abdominal anatomic features and reference values determined by use of ultrasonography in healthy common rats (Rattus norvegicus)
2014
Banzato, Tommaso | Bellini, Luca | Contiero, Barbara | Martin, Andrea | Balikçi, Sema | Zotti, Alessandro
Objective-To determine ultrasonographic features and reference values of the anatomy of the abdomen of common rats (Rattus norvegicus). Animals-20 adult male and 20 adult female rats. Procedures-A complete abdominal ultrasonographic examination was performed with the rats sedated. The cadavers of 4 rats were used for anatomic comparisons. Two cadavers were dissected and 2 cadavers were frozen and then cross-sectioned by use of an electric bandsaw. Slices were cleaned with water and photographed on each side. Correlations between variables were determined. Results-The ultrasonographic anatomy of the abdomen was determined, including measurements of the kidneys and adrenal glands and thickness of the walls of the stomach (saccus caecus, fundus, and pylorus), duodenum, and cecum. A significant positive correlation between kidney size and body weight was detected. The dorsoventral measurements of the left and right adrenal gland were significantly different, regardless of sex. Dorsoventral measurements of the right adrenal gland were significantly different between males and females. Conclusions and Clinical Relevance-The ultrasonographic images and data provided an atlas of the ultrasonographic anatomy of common rats that may be useful to veterinary radiologists, clinicians, and researchers.
Afficher plus [+] Moins [-]Surveillance of antimicrobial resistance in clinical isolates of Pasteurella multocida and Streptococcus suis from Ontario swine
2014
Glass-Kaastra, Shiona K. | Pearl, David L. | Reid-Smith, Richard J. | McEwen, Beverly | Slavic, Durda | Fairles, Jim | McEwen, Scott A.
Susceptibility results for Pasteurella multocida and Streptococcus suis isolated from swine clinical samples were obtained from January 1998 to October 2010 from the Animal Health Laboratory at the University of Guelph, Guelph, Ontario, and used to describe variation in antimicrobial resistance (AMR) to 4 drugs of importance in the Ontario swine industry: ampicillin, tetracycline, tiamulin, and trimethoprim–sulfamethoxazole. Four temporal data-analysis options were used: visualization of trends in 12-month rolling averages, logistic-regression modeling, temporal-scan statistics, and a scan with the “What’s strange about recent events?” (WSARE) algorithm. The AMR trends varied among the antimicrobial drugs for a single pathogen and between pathogens for a single antimicrobial, suggesting that pathogen-specific AMR surveillance may be preferable to indicator data. The 4 methods provided complementary and, at times, redundant results. The most appropriate combination of analysis methods for surveillance using these data included temporal-scan statistics with a visualization method (rolling-average or predicted-probability plots following logistic-regression models). The WSARE algorithm provided interesting results for quality control and has the potential to detect new resistance patterns; however, missing data created problems for displaying the results in a way that would be meaningful to all surveillance stakeholders.
Afficher plus [+] Moins [-]Immunologic study and optimization of Salmonella delivery strains expressing adhesin and toxin antigens for protection against progressive atrophic rhinitis in a murine model
2014
Hur, Jin | Byeon, Hoyeon | Lee, John Hwa
Mice were intranasally inoculated at various times to optimize the vaccination strategy with a new live candidate vaccine expressing the antigens CP39, FimA, PtfA, and ToxA of Pasteurella multocida and F1P2 of Bordetella bronchiseptica in an attenuated live Salmonella system to protect against progressive atrophic rhinitis (PAR). Sixty BALB/c mice were divided equally into 4 groups. The group A mice were vaccinated only at 12 wk of age, the group B mice received a primary vaccination at 9 wk of age and a booster at 12 wk of age, the group C mice received a primary vaccination at 6 wk of age and boosters at 9 and 12 wk of age, and the group D mice were inoculated intranasally with sterile phosphate-buffered saline as a control. The humoral and mucosal immune responses of groups A, B, and C increased significantly compared with those of the control group. Expression of the cytokines interleukin-4 and interferon-γ in splenocytes also increased significantly. In addition, the group B mice exhibited significantly fewer gross lesions in lung tissue compared with the other vaccinated groups after challenge with a virulent P. multocida strain. These results indicate that a strategy of double intranasal vaccination can optimize protection against PAR.
Afficher plus [+] Moins [-]