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Prevalence and risk factors associated with Campylobacter spp. occurrence in healthy dogs visiting four rural community veterinary clinics in South Africa النص الكامل
2019
Karama, Musafiri(University of Pretoria Faculty of Veterinary Science Department of Paraclinical Sciences) | Cenci-Goga, Beniamino T.(University of Pretoria Faculty of Veterinary Science Department of Paraclinical Sciences,University of Perugia Laboratorio di Ispezione degli alimenti di origine animale Department of Veterinary Medicine) | Prosperi, Alice(Experimental Zooprofilattico Institute of Lombardy and Emilia-Romagna 'Bruno Ubertini ,University of Bologna Department of Veterinary Medical Sciences) | Etter, Eric(University of Pretoria Faculty of Veterinary Science Department of Production Animal Studies,University of Montpellier) | El-Ashram, Saeed(Foshan University College of Life Science and Engineering ,Kafr ElSheikh University Faculty of Science) | McCrindle, Cheryl(University of South Africa Department of Agriculture and Animal Health) | Ombui, Jackson N.(University of Nairobi College of Agriculture and Veterinary Sciences Department of Public Health, Pharmacology and Toxicology) | Kalake, Alan(Gauteng Department of Agriculture and Rural Development,)
Prevalence and risk factors associated with Campylobacter spp. occurrence in healthy dogs visiting four rural community veterinary clinics in South Africa النص الكامل
2019
Karama, Musafiri(University of Pretoria Faculty of Veterinary Science Department of Paraclinical Sciences) | Cenci-Goga, Beniamino T.(University of Pretoria Faculty of Veterinary Science Department of Paraclinical Sciences,University of Perugia Laboratorio di Ispezione degli alimenti di origine animale Department of Veterinary Medicine) | Prosperi, Alice(Experimental Zooprofilattico Institute of Lombardy and Emilia-Romagna 'Bruno Ubertini ,University of Bologna Department of Veterinary Medical Sciences) | Etter, Eric(University of Pretoria Faculty of Veterinary Science Department of Production Animal Studies,University of Montpellier) | El-Ashram, Saeed(Foshan University College of Life Science and Engineering ,Kafr ElSheikh University Faculty of Science) | McCrindle, Cheryl(University of South Africa Department of Agriculture and Animal Health) | Ombui, Jackson N.(University of Nairobi College of Agriculture and Veterinary Sciences Department of Public Health, Pharmacology and Toxicology) | Kalake, Alan(Gauteng Department of Agriculture and Rural Development,)
Reports on the occurrence of Campylobacter spp. in dogs in South Africa are non-existent. This study investigated the prevalence of Campylobacter spp. in 481 dogs visiting four rural community veterinary clinics in South Africa. Dogs were screened for Campylobacter spp. by culture and polymerase chain reaction (PCR), and logistic regression analysis was performed to assess the association between sex, clinic, breed and age and the occurrence of Campylobacter spp. in dogs. The prevalence of Campylobacter spp. was 41.50% (95% confidence interval [CI], 37.39% - 46.04%). Campylobacter jejuni, C. upsaliensis and C. coli were detected in 29.31% (95% CI, 25.42% - 33.54%), 13.10% (95% CI, 10.37% - 16.42%) and 5.41% (95% CI, 3.71% - 7.82%) of dogs, respectively. Dogs carrying more than one species of Campylobacter spp. accounted for 6.23% (95% CI, 4.40% - 8.78%). Campylobacter upsaliensis and C. jejuni were detected in 3.74% (95% CI, 2.37% - 5.86%), whereas C. coli and C. jejuni were found in 2.49% (95% CI, 1.42% - 4.34%) of dogs. Age and clinic were the risk factors significantly associated with Campylobacter spp. occurrence, while age, breed and clinic were predictors of C. jejuni carriage. Furthermore, age was the only risk factor associated with a higher likelihood of carrying C. upsaliensis. The prevalence of Campylobacter spp. C. jejuni and C. upsaliensis increased significantly as dogs grew older. In addition, the odds of carrying Campylobacter spp. were higher in the Staffordshire bull terrier breed compared to crossbreed dogs. In conclusion, this study shows that dogs visiting rural community veterinary clinics in South Africa are reservoirs of Campylobacter spp. and may be potential sources of Campylobacter spp. for humans living in close proximity of the dog populations under study.
اظهر المزيد [+] اقل [-]Prevalence and risk factors associated with Campylobacter spp. occurrence in healthy dogs visiting four rural community veterinary clinics in South Africa النص الكامل
2019
Musafiri Karama | Beniamino T. Cenci-Goga | Alice Prosperi | Eric Etter | Saeed El-Ashram | Cheryl McCrindle | Jackson N. Ombui | Alan Kalake
Reports on the occurrence of Campylobacter spp. in dogs in South Africa are non-existent. This study investigated the prevalence of Campylobacter spp. in 481 dogs visiting four rural community veterinary clinics in South Africa. Dogs were screened for Campylobacter spp. by culture and polymerase chain reaction (PCR), and logistic regression analysis was performed to assess the association between sex, clinic, breed and age and the occurrence of Campylobacter spp. in dogs. The prevalence of Campylobacter spp. was 41.50% (95% confidence interval [CI], 37.39% – 46.04%). Campylobacter jejuni, C. upsaliensis and C. coli were detected in 29.31% (95% CI, 25.42% – 33.54%), 13.10% (95% CI, 10.37% – 16.42%) and 5.41% (95% CI, 3.71% – 7.82%) of dogs, respectively. Dogs carrying more than one species of Campylobacter spp. accounted for 6.23% (95% CI, 4.40% – 8.78%). Campylobacter upsaliensis and C. jejuni were detected in 3.74% (95% CI, 2.37% – 5.86%), whereas C. coli and C. jejuni were found in 2.49% (95% CI, 1.42% – 4.34%) of dogs. Age and clinic were the risk factors significantly associated with Campylobacter spp. occurrence, while age, breed and clinic were predictors of C. jejuni carriage. Furthermore, age was the only risk factor associated with a higher likelihood of carrying C. upsaliensis. The prevalence of Campylobacter spp. C. jejuni and C. upsaliensis increased significantly as dogs grew older. In addition, the odds of carrying Campylobacter spp. were higher in the Staffordshire bull terrier breed compared to crossbreed dogs. In conclusion, this study shows that dogs visiting rural community veterinary clinics in South Africa are reservoirs of Campylobacter spp. and may be potential sources of Campylobacter spp. for humans living in close proximity of the dog populations under study.
اظهر المزيد [+] اقل [-]Prevalence and risk factors associated with Campylobacter spp. occurrence in healthy dogs visiting four rural community veterinary clinics in South Africa النص الكامل
2019
Karama, Musafiri | Cenci-Goga, Beniamino T. | Prosperi, Alice | Etter, Eric | El-Ashram, Saeed | Mccrindle, Cheryl | Ombui, Jackson N. | Kalake, Alan | University of Pretoria [South Africa] | Università degli Studi di Perugia = University of Perugia (UNIPG) | Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia Romagna "Bruno Ubertini" (IZSLER) | Department of Veterinary Medical Sciences ; Alma Mater Studiorum Università di Bologna = University of Bologna (UNIBO) | Animal, Santé, Territoires, Risques et Ecosystèmes (UMR ASTRE) ; Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA) | Foshan University ; Partenaires INRAE | Université de Kafr El-Cheikh | Department of Agriculture and Animal Health ; University of South Africa (UNISA) | University of Nairobi (UoN) | (Office of Research and Development) | National Research Foundation; South Africa-Italy Science and Technology Research Cooperation programme; South Africa-Kenya Science and Technology Research Cooperation programme; Faculty of Veterinary Science, University of Pretoria; Gauteng Department of Agriculture and Rural Development
International audience | Reports on the occurrence of Campylobacter spp. in dogs in South Africa are non-existent. This study investigated the prevalence of Campylobacter spp. in 481 dogs visiting four rural community veterinary clinics in South Africa. Dogs were screened for Campylobacter spp. by culture and polymerase chain reaction (PCR), and logistic regression analysis was performed to assess the association between sex, clinic, breed and age and the occurrence of Campylobacter spp. in dogs. The prevalence of Campylobacter spp. was 41.50% (95% confidence interval [CI], 37.39% - 46.04%). Campylobacter jejuni, C. upsaliensis and C. coli were detected in 29.31% (95% CI, 25.42% - 33.54%), 13.10% (95% CI, 10.37% - 16.42%) and 5.41% (95% CI, 3.71% - 7.82%) of dogs, respectively. Dogs carrying more than one species of Campylobacter spp. accounted for 6.23% (95% CI, 4.40% - 8.78%). Campylobacter upsaliensis and C. jejuni were detected in 3.74% (95% CI, 2.37% - 5.86%), whereas C. coli and C. jejuni were found in 2.49% (95% CI, 1.42% - 4.34%) of dogs. Age and clinic were the risk factors significantly associated with Campylobacter spp. occurrence, while age, breed and clinic were predictors of C. jejuni carriage. Furthermore, age was the only risk factor associated with a higher likelihood of carrying C. upsaliensis. The prevalence of Campylobacter spp. C. jejuni and C. upsaliensis increased significantly as dogs grew older. In addition, the odds of carrying Campylobacter spp. were higher in the Staffordshire bull terrier breed compared to crossbreed dogs. In conclusion, this study shows that dogs visiting rural community veterinary clinics in South Africa are reservoirs of Campylobacter spp. and may be potential sources of Campylobacter spp. for humans living in close proximity of the dog populations under study.
اظهر المزيد [+] اقل [-]Climatic and regional antibiotic resistance patterns of Staphylococcus aureus in South African dairy herds النص الكامل
2019
Karzis, Joanne(University of Pretoria Faculty of Veterinary Science Department of Production Animal Studies) | Petzer, Inge-Marie(University of Pretoria Faculty of Veterinary Science Department of Production Animal Studies) | Donkin, Edward F.(University of Pretoria Department of Animal and Wildlife Sciences) | Naidoo, Vinny(University of Pretoria Department of Research & Postgraduate Studies ,University of Pretoria Faculty of Veterinary Science Biomedical Research Centre) | Etter, Eric M.C.(University of Pretoria Faculty of Veterinary Science Department of Production Animal Studies,CIRAD, UMR Animal, Santé, Territoires, Risque et Ecosystèmes ,University Montpellier ASTRE)
Climatic and regional antibiotic resistance patterns of Staphylococcus aureus in South African dairy herds النص الكامل
2019
Karzis, Joanne(University of Pretoria Faculty of Veterinary Science Department of Production Animal Studies) | Petzer, Inge-Marie(University of Pretoria Faculty of Veterinary Science Department of Production Animal Studies) | Donkin, Edward F.(University of Pretoria Department of Animal and Wildlife Sciences) | Naidoo, Vinny(University of Pretoria Department of Research & Postgraduate Studies ,University of Pretoria Faculty of Veterinary Science Biomedical Research Centre) | Etter, Eric M.C.(University of Pretoria Faculty of Veterinary Science Department of Production Animal Studies,CIRAD, UMR Animal, Santé, Territoires, Risque et Ecosystèmes ,University Montpellier ASTRE)
South Africa is a large country of approximately 1.22 million km², made up of nine provinces with three climatic zones. Farming in the country is mostly defined by regional differences. Of the different organisms isolated from milk samples of dairy cows, Staphylococcus aureus poses a challenge to maintain udder health and wholesome dairy products for human consumption. Antibiotic resistant bacteria are therefore a potential health hazard. The objective of this study was to investigate the seasonal and regional relationships of antibiotic resistance of S. aureus, of which little is known. This study was undertaken to evaluate a data set of 3410 S. aureus isolates, taken from milk samples with a somatic cell count of > 400 000 cells/mL from commercial dairy herds. These isolates were tested for antimicrobial susceptibility using the Kirby Bauer method for ampicillin, cloxacillin, penicillin G, clindamycin, oxy-tetracycline, cephalexin, cefuroxime and tylosin. The samples were from 830 dairy herds, out of the estimated 2000 commercial dairy herds in South Africa. All the antibiotics tested, except for cephalosporins, showed a predicted prevalence of resistance of above 50% in most provinces, which is a concern. The lowest prevalence of resistance to the majority of the categories of antibiotics tested was present in KwaZulu-Natal during spring. The cephalosporins had the lowest levels of prevalence of bacterial resistance in Gauteng during winter. Resistance patterns of S. aureus to the eight antibiotics varied in the different seasons and provinces, possibly because of different weather conditions, and the action and spectrum of antibiotics.
اظهر المزيد [+] اقل [-]Climatic and regional antibiotic resistance patterns of Staphylococcus aureus in South African dairy herds النص الكامل
2019
Karzis, Joanne | Petzer, Inge-Marie | Donkin, Edward F. | Naidoo, Vinny | Etter, Eric M. C. | University of Pretoria [South Africa] | Animal, Santé, Territoires, Risques et Ecosystèmes (UMR ASTRE) ; Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA) | Département Systèmes Biologiques (Cirad-BIOS) ; Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)
International audience | South Africa is a large country of approximately 1.22 million km(2), made up of nine provinces with three climatic zones. Farming in the country is mostly defined by regional differences. Of the different organisms isolated from milk samples of dairy cows, Staphylococcus aureus poses a challenge to maintain udder health and wholesome dairy products for human consumption. Antibiotic resistant bacteria are therefore a potential health hazard. The objective of this study was to investigate the seasonal and regional relationships of antibiotic resistance of S. aureus, of which little is known. This study was undertaken to evaluate a data set of 3410 S. aureus isolates, taken from milk samples with a somatic cell count of > 400 000 cells/mL from commercial dairy herds. These isolates were tested for antimicrobial susceptibility using the Kirby Bauer method for ampicillin, cloxacillin, penicillin G, clindamycin, oxy-tetracycline, cephalexin, cefuroxime and tylosin. The samples were from 830 dairy herds, out of the estimated 2000 commercial dairy herds in South Africa. All the antibiotics tested, except for cephalosporins, showed a predicted prevalence of resistance of above 50% in most provinces, which is a concern. The lowest prevalence of resistance to the majority of the categories of antibiotics tested was present in KwaZulu-Natal during spring. The cephalosporins had the lowest levels of prevalence of bacterial resistance in Gauteng during winter. Resistance patterns of S. aureus to the eight antibiotics varied in the different seasons and provinces, possibly because of different weather conditions, and the action and spectrum of antibiotics.
اظهر المزيد [+] اقل [-]Climatic and regional antibiotic resistance patterns of Staphylococcus aureus in South African dairy herds النص الكامل
2019
Joanne Karzis | Inge-Marie Petzer | Edward F. Donkin | Vinny Naidoo | Eric M.C. Etter
South Africa is a large country of approximately 1.22 million km2, made up of nine provinces with three climatic zones. Farming in the country is mostly defined by regional differences. Of the different organisms isolated from milk samples of dairy cows, Staphylococcus aureus poses a challenge to maintain udder health and wholesome dairy products for human consumption. Antibiotic resistant bacteria are therefore a potential health hazard. The objective of this study was to investigate the seasonal and regional relationships of antibiotic resistance of S. aureus, of which little is known. This study was undertaken to evaluate a data set of 3410 S. aureus isolates, taken from milk samples with a somatic cell count of > 400 000 cells/mL from commercial dairy herds. These isolates were tested for antimicrobial susceptibility using the Kirby Bauer method for ampicillin, cloxacillin, penicillin G, clindamycin, oxy-tetracycline, cephalexin, cefuroxime and tylosin. The samples were from 830 dairy herds, out of the estimated 2000 commercial dairy herds in South Africa. All the antibiotics tested, except for cephalosporins, showed a predicted prevalence of resistance of above 50% in most provinces, which is a concern. The lowest prevalence of resistance to the majority of the categories of antibiotics tested was present in KwaZulu-Natal during spring. The cephalosporins had the lowest levels of prevalence of bacterial resistance in Gauteng during winter. Resistance patterns of S. aureus to the eight antibiotics varied in the different seasons and provinces, possibly because of different weather conditions, and the action and spectrum of antibiotics.
اظهر المزيد [+] اقل [-]Development and analytic validation of a sandwich ELISA for the measurement of α1-proteinase inhibitor concentrations in serum and feces of common marmosets (Callithrix jacchus) النص الكامل
2019
Parambeth, Joseph C. | Lidbury, Jonathan A. | Suchodolski, Jan S. | Steiner, Jörg M.
OBJECTIVE To develop and validate a sandwich ELISA for the measurement of α1-proteinase inhibitor (α1-PI) concentrations in serum and fecal samples obtained from common marmosets (Callithrix jacchus). SAMPLE Leftover serum (n = 42) and fecal (23) samples submitted for diagnostic testing; paired serum and fecal samples obtained from 30 common marmosets at 2 research colonies. PROCEDURES A sandwich ELISA was developed and analytically validated by determining the lower limit of detection, linearity, accuracy, precision, and reproducibility. Reference intervals for α1-PI concentrations in serum and feces of common marmosets were calculated. RESULTS The standard curve was generated for concentrations between 1 and 100 ng/mL. Mean ± SD observed-to-expected ratio for serial dilutions of serum and fecal samples was 117.1 ± 5.6% (range, 112.2% to 123.0%) and 106.1 ± 19.7% (range, 82.6% to 130.2%), respectively. Mean observed-to-expected ratio for spiking recovery of serum and fecal samples was 102.9 ± 12.1% (range, 86.8% to 115.8%) and 97.9 ± 19.0% (range, 83.0% to 125.1%), respectively. Reference interval for serum concentrations of α1-PI was 1,254 to 1,813 μg/mL, for 3-day mean fecal concentrations was 11.5 to 42.2 μg/g of feces, and for 3-day maximum fecal concentrations was 13.2 to 51.2 μg/g of feces. CONCLUSIONS AND CLINICAL RELEVANCE The ELISA was linear, accurate, precise, and reproducible for quantification of α1-PI concentrations in serum and feces of common marmosets. However, the ELISA had limited linearity and accuracy for spiking recovery of fecal samples.
اظهر المزيد [+] اقل [-]Determination of the pharmacokinetics of a single oral dose of trazodone and its effect on the activity level of domestic pigeons (Columba livia) النص الكامل
2019
OBJECTIVE: To determine the pharmacokinetics of a single oral dose of trazodone and its effect on the activity of domestic pigeons (Columba livia). ANIMALS: 6 healthy adult male domestic pigeons. PROCEDURES: During the first of 3 experiments, birds received orally administered trazodone at doses ranging from 3 to 30 mg/kg to determine the dose for subsequent experiments. During the second experiment, each bird received 1 dose of trazodone (30 mg/kg, PO). Blood was collected for determination of plasma trazodone concentration before and at predetermined times for 24 hours after drug administration. Pharmacokinetic parameters were calculated by noncompartmental analysis. During experiment 3, birds were instrumented with ultralightweight accelerometers and received orally administered trazodone (30 mg/kg) or an equal volume of water twice at a 48-hour interval. Activity of birds was monitored for 24 hours after administration of each treatment. RESULTS: No adverse effects were observed. Mean ± SD terminal half-life of trazodone was 5.65 ± 1.75 hours. Plasma trazodone concentrations remained > 0.130 μg/mL for approximately 20 hours. Trazodone did not affect the activity of birds during the first 2 and 15 hours after administration. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that oral administration of 1 dose (30 mg/kg) of trazodone to healthy pigeons was safe and resulted in plasma drug concentrations that were similar to those considered therapeutic in humans and dogs for up to 20 hours. Further research is necessary to characterize the pharmacokinetics for repeated doses as well as the clinical effects of trazodone in birds with behavior problems.
اظهر المزيد [+] اقل [-]Abdominal lymphatic drainage after thoracic duct ligation and cisterna chyli ablation in clinically normal cats النص الكامل
2019
Dickerson, Vanna M. | Grimes, Janet A. | Secrest, Scott A. | Wallace, Mandy L. | Schmiedt, Chad W.
OBJECTIVE To characterize abdominal lymphatic drainage in cats after thoracic duct ligation (TDL) and cisterna chyli ablation (CCA). ANIMALS 7 purpose-bred research cats. PROCEDURES Baseline CT lymphangiography was performed. A popliteal lymph node was injected with iohexol, and images were acquired at 5-minute intervals for 15 minutes. Cats underwent TDL and CCA; methylene blue was used to aid in identifying lymphatic vessels. The CT lymphangiography was repeated immediately after and 30 days after surgery. All cats were euthanized and necropsied. RESULTS Results of baseline CT lymphangiography were unremarkable for all 7 cats. Only 5 cats completed the study. Leakage of contrast medium at the level of the cisterna chyli was seen on CT lymphangiography images obtained from all cats immediately after surgery. Evaluation of 30-day postoperative CT lymphangiography images revealed small branches entering the caudal vena cava in 2 cats, leakage of contrast medium into the caudal vena cava with no visible branches in 1 cat, and no contrast medium in the caudal vena cava in 2 cats. Contrast medium did not flow beyond the level of the cisterna chyli in any cat. Gross examination during necropsy revealed that all cats had small lymphatic vessels that appeared to connect to local vasculature identified in the region of the cisterna chyli. CONCLUSIONS AND CLINICAL RELEVANCE Abdominal lymphaticovenous anastomoses formed after TDL and CCA in cats. This would support use of these procedures for treatment of cats with idiopathic chylothorax, although additional studies with clinically affected cats are warranted.
اظهر المزيد [+] اقل [-]Use of standard diagnostic techniques to determine eradication of infection in experimental equine septic arthritis النص الكامل
2019
Koziv, R. V. | Yoshimura, S. | Dickinson, R. | Rybicka, J. M. | Moshynskyy, I. | Ngeleka, M. | Bracamonte, J. L. | Simko, E.
Septic arthritis is an important disease in horses, necessitating aggressive and prolonged therapy. In order to guide therapy, reliable methods of detecting the eradication of infection are needed. Therefore, the objective of this study was to investigate detection of eradication of infection in an experimental model of equine septic arthritis using standard diagnostic techniques. For this purpose, 17 adult horses were assigned to 3 experimental groups. The middle carpal joint of each horse was injected with Escherichia coli (Septic group, n = 8), lipopolysaccharide (LPS) (LPS group, n = 6), or sterile saline (Control group, n = 3) at day 0. Contralateral joints were not injected. Standard therapy was applied to all joints except non-injected joints in the Control group at day 1. Sequential samples of synovial fluid (SF) were collected for bacterial culture using 3 culture media [Columbia blood agar (CBA), brain heart infusion broth (BHI), and Signal blood culture medium] and for cytological evaluation [percentage neutrophils (PN), total nucleated cell count (TNCC), and total protein (TP)]. Escherichia coli-specific polymerase chain reaction (PCR) was carried out to detect E. coli DNA in synovial fluid. Culture and PCR were positive for E. coli in all joints injected with E. coli at day 1 and 1 joint was positive on BHI at day 4. Based on the results of bacterial culture, PCR, and TNCC, the elimination of infection in our experimental model occurred by day 4 post-infection in 6 out of 7 cases. Total protein (TP) and PN remained elevated at clinical threshold used for diagnosis of septic arthritis until day 14. In our experimental model of E. coli-induced arthritis, we conclude that TP and PN may not be good indicators for detecting the eradication of bacterial infection caused by E. coli from infected and subsequently treated joints.
اظهر المزيد [+] اقل [-]The effect of transfixation pins on the biomechanical properties of angled acrylic connecting bars النص الكامل
2019
Montasell, X. | Herndon, G. | Szwec, D. | Beauchamp, G.
With acrylic external-fixation frames for fracture repair the acrylic columns can be contoured to allow greater versatility in the placement of transfixation pins, thus minimizing damage to the surrounding soft tissue and making mandibular and transarticular fixation easier. However, contouring affects the stiffness and ultimate strength of the construct under axial compression. In this study, polymethylmethacrylate columns 21 mm in diameter angled at 0°, 30°, 45°, 60°, or 90° with clamps were constructed. For each angulation group, pins 3.2-mm long were placed in 6 columns, 2 pins at each end, 1.5 cm from each other, and 6 columns had no pins. Each column was allowed to polymerize for a minimum of 10 min, then was placed in a biomechanical-testing machine, the load cell at the bottom end of the column and the actuator on top, with a preload of 10 to 12 N to prevent slippage. The columns underwent axial loading at a rate of 8 mm/s until catastrophic failure occurred. Data on force and deformation were collected every 0.025 s. Both stiffness and ultimate strength of the column decreased significantly (P < 0.01), up to 77% and 70%, respectively, with each increase of angulation. The columns with pins were significantly less stiff (P < 0.05) than those without pins at angulations of 45° and 60°. However, the columns with pins did not show significant differences in ultimate strength from the columns without pins at any of the angulations. The point of failure was always at the angle of the column, demonstrating that in axial compression the weakest point is not the pin-acrylic interface when pins are eccentrically located within the column.
اظهر المزيد [+] اقل [-]Evaluation of effects of radiation therapy combined with either pamidronate or zoledronate on canine osteosarcoma cells النص الكامل
2019
Hoddinott, K. | Oblak, M. L. | Wood, G. A. | Boston, S. | Mutsaers, A. J.
Canine osteosarcoma is a devastating disease with an overall poor prognosis. Radiation therapy and bisphosphonates are currently used in combination for palliative treatment, despite a paucity of literature that investigates their combined use. The objectives of this study were to assess the in vitro effects of radiation therapy and bisphosphonates on canine osteosarcoma cells when used in combination. Canine osteosarcoma cell lines D17 and Dharma were treated with radiation and pamidronate or zoledronate, both alone and in combination. The effects of these treatments were assessed using clonogenic survival and cell viability assays. Dose-dependent decreases in clonogenic survival and cell viability were observed for both radiation and bisphosphonate treatment. Combination index analysis revealed antagonistic interactions when radiation and bisphosphonates were used in combination at specific doses for both D17 and Dharma osteosarcoma cells. Further investigation of the combined effects of radiation and bisphosphonates for the palliative treatment of canine osteosarcoma is warranted.
اظهر المزيد [+] اقل [-]Pharmacokinetics and competitive pharmacodynamics of ADP-induced platelet activation after oral administration of clopidogrel to horses النص الكامل
2019
Norris, Jeffrey W. | Watson, Johanna L. | Tablin, Fern | Kozikowski, Tania A. | Knych, Heather K.
OBJECTIVE To determine pharmacokinetics and pharmacodynamics after oral administration of a single dose of clopidogrel to horses. ANIMALS 6 healthy adult horses. PROCEDURES Blood samples were collected before and at various times up to 24 hours after oral administration of clopidogrel (2 mg/kg). Reactivity of platelets from each blood sample was determined by optical aggregometry and phosphorylation of vasodilator-stimulated phosphoprotein (VASP). Concentrations of clopidogrel and the clopidogrel active metabolite derivative (CAMD) were measured in each blood sample by use of liquid chromatography–tandem mass spectrometry, and pharmacokinetic parameters were determined with a noncompartmental model. RESULTS Compared with results for preadministration samples, platelet aggregation in response to 12.5μM ADP decreased significantly within 4 hours after clopidogrel administration for 5 of 6 horses. After 24 hours, platelet aggregation was identical to that measured before administration. Platelet aggregation in response to 25μM ADP was identical between samples obtained before and after administration. Phosphorylation of VASP in response to ADP (20μM) and prostaglandin E1 (3.3μM) was also unchanged by administration of clopidogrel. Time to maximum concentration of clopidogrel and CAMD was 0.54 and 0.71 hours, respectively, and calculated terminal-phase half-life of clopidogrel and CAMD was 1.81 and 0.97 hours, respectively. CONCLUSIONS AND CLINICAL RELEVANCE Clopidogrel or CAMD caused competitive inhibition of ADP-induced platelet aggregation during the first 24 hours after clopidogrel administration. Because CAMD was rapidly eliminated from horses, clopidogrel administration may be needed more frequently than in other species in which clopidogrel causes irreversible platelet inhibition.
اظهر المزيد [+] اقل [-]Ex vivo evaluation of arytenoid corniculectomy, compared with three other airway interventions, performed on cadaveric equine larynges with simulated recurrent laryngeal neuropathy النص الكامل
2019
OBJECTIVE To compare laryngeal impedance, in terms of air flow and pressure, following arytenoid corniculectomy (COR) versus 3 other airway interventions (left-sided laryngoplasty with ipsilateral ventriculocordectomy [LLP], LLP combined with COR [LLPCOR], and partial arytenoidectomy [PA]) performed on cadaveric equine larynges with simulated left recurrent laryngeal neuropathy (RLN) and to determine whether relative laryngeal collapse correlated with the interventions performed. SAMPLE 28 cadaveric equine larynges. PROCEDURES Each larynx in states of simulated left RLN alone and with airway interventions in the order LLP, LLPCOR, COR, and PA was evaluated in a box model construct that replicated upper airway flow mechanics consistent with peak exercise in horses. Results for impedance, calculated from airflow and pressure changes, were compared between states for each larynx. Multivariable mixed-effects analysis controlling for repeated measures within larynx was performed to calculate the predicted mean impedance for each state. RESULTS Results indicated that tracheal adapter diameter, individual larynx properties, airway intervention, and relative laryngeal collapse affected laryngeal impedance. The LLP and LLPCOR interventions had the lowest impedance, whereas the COR and PA interventions did not differ substantially from the simulated left RLN state. Residual intraclass correlation of the model was 27.6 %. CONCLUSIONS AND CLINICAL RELEVANCE Although impedance was higher for the simulated left RLN with the COR intervention state than with the LLP intervention state, given the clinical success of PA for treating RLN in horses and the similar results for the COR and PA intervention states in the present study, the use of COR warrants further investigation. The residual interclass correlation suggested that individual laryngeal variation affected impedance and may have a clinical effect.
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