242 results on '"Gehring, Ronette"'
Search Results
2. Potential of ESBL-producing Escherichia coli selection in bovine feces after intramammary administration of first generation cephalosporins using in vitro experiments
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Speksnijder, David C., Hopman, Nonke E. M., Kusters, Nina E., Timmerman, Arjen, Swinkels, Jantijn M., Penterman, Pleun A. A., Krömker, Volker, Bradley, Andrew J., Botteldoorn, Nadine, Gehring, Ronette, and Zomer, Aldert L.
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- 2022
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3. USE OF THE ZOOLOGICAL INFORMATION MANAGEMENT SYSTEM (ZIMS) DATABASE (2003–2023) FOR EVALUATION OF PRACTITIONER-SELECTED MELOXICAM DOSES AND THE RELATIONSHIP TO AVIAN TAXONOMY.
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Roeder, Megan, Inauen, David, van Zeeland, Yvonne R.A., Bruins-van Sonsbeek, Linda G.R., and Gehring, Ronette
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Meloxicam, a commonly used NSAID, has wide variation in pharmacokinetics between different avian species. The present study hypothesized that meloxicam dosage regimens were similar within, but differ between, groups of avian species with similar feeding habits, habitats, or migratory behaviors. Utilizing the international Zoological Information Management System (ZIMS), drug usage extracts were compiled for meloxicam across eleven major orders of birds. The orders were selected based on their prevalence in zoological collections, wildlife rehabilitation centers, the pet trade, and production environments. Each species with a record available in drug usage extracts was classified into broad categories of main habitat, diet, and migratory status. Significant patterns associated with habitat, diet, or migratory status were not identified statistically. An inverse relationship was identified statistically between the practitioner mg/kg dose and body weight in kg in birds that weigh approximately 20 kg or greater. This study includes practitioner-reported summary data of current doses used in the veterinary field to treat many different avian species. Adverse effects of meloxicam were recorded in <5% of individuals evaluated at the species level in this study. [ABSTRACT FROM AUTHOR]
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- 2024
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4. Assessment of the feed additive consisting of endo‐1,4‐beta‐xylanase (produced with Trichoderma reesei MUCL 49755) and endo‐1,3(4)‐beta‐glucanase (produced with T. reesei MUCL 49754) (AveMix® XG 10) for pigs for fattening, minor porcine species for fattening and turkeys for fattening for the renewal of its authorisation (AVEVE BV)
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Villa, Roberto Edoardo, Azimonti, Giovanna, Bonos, Eleftherios, Christensen, Henrik, Durjava, Mojca, Dusemund, Birgit, Gehring, Ronette, Glandorf, Boet, Kouba, Maryline, López‐Alonso, Marta, Marcon, Francesca, Nebbia, Carlo, Pechová, Alena, Prieto‐Maradona, Miguel, Röhe, Ilen, Theodoridou, Katerina, Anguita, Montserrat, Innocenti, Matteo Lorenzo, Tarrés‐Call, Jordi, and Pettenati, Elisa
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ALLERGENS ,CALCIUM carbonate ,FEED additives ,TRICHODERMA reesei ,FLOUR - Abstract
Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the assessment of the feed additive consisting of endo‐1,4‐beta‐xylanase (produced with Trichoderma reesei MUCL 49755) and endo‐1,3(4)‐beta‐glucanase (produced with T. reesei MUCL 49754) (AveMix® XG 10/AveMix® XG 10 L) for the renewal of its authorisation as zootechnical feed additive for pigs for fattening, minor porcine species for fattening and turkeys for fattening. The applicant declared a change in the carrier material used in AveMix® XG 10 from soybean meal to calcium carbonate + wheat flour or calcium carbonate + sepiolite. The applicant provided evidence that the additive Avemix® XG 10 with calcium carbonate + wheat flour and Avemix® XG 10 L comply with the conditions of the authorisation. The EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) noted that no data were submitted to support compliance of the formulation of Avemix® XG 10 with calcium carbonate + sepiolite with the conditions of the authorisation. The FEEDAP Panel concluded that both forms of the additive remain safe for pigs for fattening, minor porcine species for fattening and turkeys for fattening, consumers and the environment. Regarding the safety for the user, Avemix® XG 10 formulated with calcium carbonate + sepiolite and Avemix® XG 10 L are not irritant to skin and eyes. No conclusions on the irritation potential of Avemix® XG 10 formulated with calcium carbonate + wheat flour could be drawn. The additive in all its formulations is considered a respiratory and skin sensitiser. There was no need for assessing the efficacy of the additive in the context of the renewal of the authorisation. [ABSTRACT FROM AUTHOR]
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- 2024
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5. Assessment of the feed additive consisting of sodium propionate for all terrestrial animal species for the renewal of its authorisation (BASF SE).
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Villa, Roberto Edoardo, Azimonti, Giovanna, Bonos, Eleftherios, Christensen, Henrik, Durjava, Mojca, Dusemund, Birgit, Gehring, Ronette, Glandorf, Boet, Kouba, Maryline, López‐Alonso, Marta, Marcon, Francesca, Nebbia, Carlo, Pechová, Alena, Prieto‐Maradona, Miguel, Röhe, Ilen, Theodoridou, Katerina, Anguita, Montserrat, Dioni, Anna, Galobart, Jaume, and Holczknecht, Orsolya
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ALLERGENS ,ANIMAL species ,FEED additives ,ANIMAL feeds ,PROPIONATES - Abstract
Sodium propionate is authorised containing at least 98.5% of sodium propionate. The applicants requested for the renewal of the authorisation of sodium propionate when used as a feed additive for all terrestrial animal species. The applicant has provided evidence that the additive in the market complies with the conditions of the authorisation. The Panel on Additives and Products or Substances used in Animal Feed (FEEDAP Panel) confirms that the use of sodium propionate under the current authorised conditions of use is safe for the target species, the consumers and the environment. Considering the user safety, the additive is corrosive to skin, eyes and respiratory tract, but is not a skin sensitiser. There is no need for assessing the efficacy of the additive in the context of the renewal of the authorisation. [ABSTRACT FROM AUTHOR]
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- 2024
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6. Assessment of the feed additive consisting of Levilactobacillus brevis DSM 16680 for all animal species for the renewal of its authorisation (Microferm Ltd.).
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Villa, Roberto Edoardo, Azimonti, Giovanna, Bonos, Eleftherios, Christensen, Henrik, Durjava, Mojca, Dusemund, Birgit, Gehring, Ronette, Glandorf, Boet, Kouba, Maryline, López‐Alonso, Marta, Marcon, Francesca, Nebbia, Carlo, Pechová, Alena, Prieto‐Maradona, Miguel, Röhe, Ilen, Theodoridou, Katerina, Anguita, Montserrat, Bozzi Cionci, Nicole, Brozzi, Rosella, and Innocenti, Matteo Lorenzo
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ALLERGENS ,ANIMAL species ,FEED additives ,ANIMAL feeds ,FUNCTIONAL groups - Abstract
Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the assessment of the application of renewal of Levilactobacillus brevis DSM 16680 as a technological feed additive (functional group: silage additives) for all animal species. The applicant has provided evidence that the additive currently on the market complies with the existing terms of the authorisation. The EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) concluded that the additive remains safe for all animal species, consumers and the environment. Regarding user safety, the additive should be considered as an eye irritant and a skin and respiratory sensitiser. There is no need for assessing the efficacy of the additive in the context of the renewal of the authorisation. [ABSTRACT FROM AUTHOR]
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- 2024
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7. Induction of gut leakage in young broiler chickens fed a diet with low rye inclusion
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Santos, Regiane R., Ooosterveer-van der Doelen, Marjolein A.M., Tersteeg-Zijderveld, Monique H.G., Molist, Francesc, and Gehring, Ronette
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- 2021
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8. Modification of the terms of authorisation regarding the additive consisting of liquid l‐lysine base produced with Corynebacterium glutamicum NRRL B‐67439 and NRRL B‐67535 for all animal species (ADM specialty ingredients (Europe) B.V.)
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Villa, Roberto Edoardo, Azimonti, Giovanna, Bonos, Eleftherios, Christensen, Henrik, Durjava, Mojca, Dusemund, Birgit, Gehring, Ronette, Glandorf, Boet, Kouba, Maryline, López‐Alonso, Marta, Marcon, Francesca, Nebbia, Carlo, Pechová, Alena, Prieto‐Maradona, Miguel, Röhe, Ilen, Theodoridou, Katerina, Herman, Lieve, Anguita, Montserrat, Innocenti, Matteo L., and Pettenati, Elisa
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ESSENTIAL amino acids ,ALLERGENS ,CORYNEBACTERIUM glutamicum ,ANIMAL species ,ANIMAL feeds - Abstract
Following a request from the European Commission, the EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety and efficacy of liquid l‐lysine base produced with a genetically modified strain of Corynebacterium glutamicum as a nutritional feed additive for all animal species. The l‐lysine base liquid produced with C. glutamicum NRRL B‐67535 and NRRL B‐67439 is currently authorised as a nutritional additive for all animal species. The present application is aimed at modifying the current authorisation to include C. glutamicum NRRL B‐68248 as a production strain. The new production strain qualifies for the qualified presumption of safety approach when used for production purposes. It was unambiguously identified as C. glutamicum and was shown not to harbour acquired antimicrobial resistance determinants for antibiotics of human and veterinary importance. All the introduced sequences or mutations were considered to be safe, and no viable cells or DNA of the NRRL B‐68248 strain was detected in the final product. Therefore, the final product does not pose any safety concern associated with the production strain. l‐Lysine base produced using C. glutamicum NRRL B‐68248 does not represent a risk for the target species, the consumer or the environment. The additive was considered to be neither irritant to skin or the eyes, nor a dermal sensitiser. l‐Lysine base produced with C. glutamicum NRRL B‐68248 is considered to be an efficacious source of the essential amino acid l‐lysine for non‐ruminant animal species. For the supplemental l‐lysine to be as efficacious in ruminants as in non‐ruminant species, it would require protection against degradation in the rumen. [ABSTRACT FROM AUTHOR]
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- 2024
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9. Alfaxalone total intravenous anaesthesia in dogs: pharmacokinetics, cardiovascular data and recovery characteristics
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Dehuisser, Virginie, Bosmans, Tim, Devreese, Mathias, Gehring, Ronette, Croubels, Siska, Duchateau, Luc, and Polis, Ingeborgh
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- 2019
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10. Pollutant Exposure and Myocardial Injury: Protocol and Progress Report for a Toxicological Systematic Mapping Review.
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Roos, Tom, Leenaars, Cathalijn, Schaffert, Alexandra, Paparella, Martin, Murugadoss, Sivakumar, Mertens, Birgit, Linzalone, Nunzia, Donzelli, Gabriele, Ritskes-Hoitinga, Merel, and Gehring, Ronette
- Abstract
An increasing body of evidence identifies pollutant exposure as a risk factor for cardiovascular disease (CVD), while CVD incidence is rising steadily with the aging population. Although numerous experimental studies are now available, the mechanisms through which lifetime exposure to environmental pollutants can result in CVD are not fully understood. To comprehensively describe and understand the pathways through which pollutant exposure leads to cardiotoxicity, a systematic mapping review of the available toxicological evidence is needed. This protocol outlines a stepby- step framework for conducting this review. Using the National Toxicology Program (NTP) Health Assessment and Translation (HAT) approach for conducting toxicological systematic reviews, we selected 362 out of 8110 in vitro (17%), in vivo (67%), and combined (15%) studies for 129 potential cardiotoxic environmental pollutants, including heavy metals (29%), air pollutants (16%), pesticides (27%), and other chemicals (28%). The internal validity of included studies is being assessed with HAT and SYRCLE risk of bias tools. Tabular templates are being used to extract key study elements regarding study setup, methodology, techniques, and (qualitative and quantitative) outcomes. Subsequent synthesis will consist of an explorative meta-analysis of possible pollutant-related cardiotoxicity. Evidence maps and interactive knowledge graphs will illustrate evidence streams, cardiotoxic effects, and associated quality of evidence, helping researchers and regulators to efficiently identify pollutants of interest. The evidence will be integrated in novel adverse outcome pathways to facilitate regulatory acceptance of non-animal methods for cardiotoxicity testing. The current article describes the progress of the steps made in the systematic mapping review process. [ABSTRACT FROM AUTHOR]
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- 2024
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11. Single-Dose Pharmacokinetics of Piperacillin/Tazobactam in Hispaniolan Amazon Parrots (Amazona ventralis)
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Carpenter, James W., Tully, Thomas N., Gehring, Ronette, and Guzman, David Sanchez-Migallon
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- 2017
12. Plasma Concentrations of Fentanyl Achieved With Transdermal Application in Chickens
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Delaski, Kristina M., Gehring, Ronette, Heffron, Brendan T., Negrusz, Adam, and Gamble, Kathryn C.
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- 2017
13. Development and application of a population physiologically based pharmacokinetic model for penicillin G in swine and cattle for food safety assessment
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Li, Miao, Gehring, Ronette, Riviere, Jim E., and Lin, Zhoumeng
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- 2017
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14. A study to assess the correlation between plasma, oral fluid and urine concentrations of flunixin meglumine with the tissue residue depletion profile in finishing-age swine
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Bates, Jessica L., Karriker, Locke A., Rajewski, Suzanne M., Lin, Zhoumeng, Gehring, Ronette, Li, Mengjie, Riviere, Jim E., and Coetzee, Johann F.
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- 2020
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15. Health concerns and management of select veterinary drug residues
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Baynes, Ronald E., Dedonder, Keith, Kissell, Lindsey, Mzyk, Danielle, Marmulak, Tara, Smith, Geof, Tell, Lisa, Gehring, Ronette, Davis, Jennifer, and Riviere, Jim E.
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- 2016
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16. A Framework for Meta-Analysis of Veterinary Drug Pharmacokinetic Data Using Mixed Effect Modeling
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Li, Mengjie, Gehring, Ronette, Lin, Zhoumeng, and Riviere, Jim
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- 2015
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17. Development and Application of a Multiroute Physiologically Based Pharmacokinetic Model for Oxytetracycline in Dogs and Humans
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Lin, Zhoumeng, Li, Mengjie, Gehring, Ronette, and Riviere, Jim E.
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- 2015
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18. Tramadol Steady-State Pharmacokinetics of Immediate-Release Capsules and Sustained-Release Tablets in Dogs
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Winter, Esther, Geijlswijk, Ingeborg van, Akkerdaas, Ies, Sturkenboom, Marieke, Gehring, Ronette, IRAS OH Pharmacology, and IRAS OH Pharmacology
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tramadol ,dogs ,sustained release ,immediate release ,pharmacokinetics - Abstract
Tramadol is a veterinary analgesic for dogs. In this study, the steady-state pharmacokinetics of a sustained-release (SR) tablet (Tramagetic OD®) and immediate-release capsules (IR) were compared. In a crossover design, six dogs received five doses of IR 50 mg four times a day (qid), or two doses of SR 200 mg once a day (sid). Eight blood samples were collected per dog, per formulation, up to 6 and 24 h after the last dose, respectively. Serum concentrations of tramadol and its metabolites were measured with LC-MS/MS. Metabolite M1 levels were below the lower limit of quantification (LLOQ) in all samples. The non-compartmental analysis of the time–concentration data showed a later Tmax with the SR formulation (median 6.00 h (3.00–9.00)) and a lower Cmax/D (median 7.74 µg/L/mg/kg (0.09–25.3)) compared to the IR formulation (median Tmax 1.75 h (0.75–2.00) and median Cmax/D 11.1 µg/L/mg/kg (4.8–70.4)). AUCtau/D after SR administration was 55.5 h × kg × µg/L/mg (0–174.1) compared to 29.8 h × kg × µg/L/mg (12.2–140.8) after IR administration. The terminal elimination half-lives were 2.38 h (1.77–6.22) and 1.70 h (0.95–2.11) for the SR and IR formulations, respectively. Strong conclusions cannot be drawn from this study because of the high percentage of samples that were below LLOQ and the great interindividual variability, but these results suggest that Tramagetic OD can be administered less frequently in dogs.
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- 2022
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19. The efficacy of subcutaneous slow-release melatonin implants in the prevention of canine flank alopecia recurrence is uncertain: A double-blind, randomized, placebo-controlled study
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Verschuuren, Millie U M Y, Schlotter, Yvette M, van Geijlswijk, Inge M, van der Lugt, Jaco J, Gehring, Ronette, and IRAS OH Pharmacology
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Mink mustela-vison ,Winter fur growth ,veterinary(all) ,Induction - Abstract
BACKGROUND: Canine flank alopecia (CFA) is characterized by seasonally recurring noninflammatory, occasionally hyperpigmented alopecia predominantly in the thoracolumbar area. Previous studies suggest that reduced production of endogenous melatonin may play a role in the pathogenesis of this condition, and placebo-controlled studies on the efficacy of preventative melatonin treatment are lacking. OBJECTIVE: To evaluate the efficacy of subcutaneous slow-release melatonin implants in the prevention of CFA recurrence. ANIMALS: Twenty-one client-owned dogs with a history of CFA were included in the study. MATERIALS AND METHODS: At time (T)0, a general physical and dermatological examination was performed on each dog, blood was collected for serum biochemistry analysis and two skin biopsies were taken from alopecic areas on the nonsedated affected dogs after subcutaneous injection with 2% lidocaine. Dogs with normal blood work and histological results compatible with CFA were included in the study. Participating dogs were randomly assigned to receive either placebo or 18 mg melatonin subcutaneously in the interscapular area, approximately 2 months before expected CFA onset (T1). CFA recurrence was scored qualitatively as complete, ≤50% recurrence, or no recurrence at 5 and 7 months after the intervention (T2 and T3, respectively). RESULTS: At T3, in dogs treated with placebo (nine of 17), the percentages for complete recurrence, ≤50% recurrence and no recurrence were 44%, 0% and 56%, respectively. In dogs treated with melatonin (eight of 17), these percentages were 25%, 50% and 25%, respectively. There were no statistically significant differences in the scores between melatonin-treated dogs and placebo-treated dogs (p = 0.40). In three of eight melatonin-treated dogs, mild transient swelling was observed at the injection site. CONCLUSIONS: This study did not provide evidence that an 18 mg melatonin implant treatment, although well-tolerated, is efficacious in preventing recurrence of CFA in affected dogs.
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- 2022
20. D3.2 Toxicological data matrix
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Roos, Tom, Gehring, Ronette, and Linzalone, Nunzia
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Cardiovascular disease, cardiotoxicity, toxicological evidence, data matrix, potency, literature study, bioassays - Abstract
A targeted literature study was performed to assess the toxicological evidence for a selection of cardiotoxic chemicals, for which the results were collected in a data matrix. The objective of this document is to describe the methodology of the literature study, as well as to provide a summary and description of the main results collected in the data matrix. Chemicals for the literature study were selected from an earlier review. These chemicals elicited heart failure related effects in vitro, such as effects on cardiomyocyte viability, contractility, hypertrophy, and myopathy. The data matrix contains toxicological potency estimates for these relevant in vitro endpoints, as well as study results of in vivo toxicity assays. Relevant study characteristics were collected, such as species, cell type, dosing range, incubation time, and main outcome, facilitating comparison between chemicals and therefore prioritization efforts. The data matrix can therefore help the project in various stages, ranging from chemical selection to validation, while providing a framework with mechanistic data that can explain and integrate cardiotoxicity pathways with heart failure outcomes seen in exposed populations.
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- 2022
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21. D2.1 Documentation of regulatory needs for cardiotoxicity methods and data
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Murugadoss, Sivakumar, Mertens, Birgit, Paparella, Martin, Schaffert, Alexandra, Linzalone, Nunzia, Gehring, Ronette, and Roos, Tom
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Cardiovascular diseases, cardiotoxicity, regulatory needs, new approach methodologies, heart failure - Abstract
This document aims to provide an overview on the regulatory needs for cardiotoxicity methods and data that can be used for consultation of national and European Preliminary Assessment of REgulatory Relevance (PARERE) Networks. We provide a brief overview of 1) the scientific knowledge about cardiotoxicity induced by chemical stressors, 2) the current regulatory assessment frameworks for cardiotoxicity and their needs for improvement, and 3) specific New Approach Methodologies (NAMs)-based assessment tools, which are available or in development, with a specific focus on the work performed in the European project ALTERNATIVE (https://alternative-project.eu/). In addition, a set of questions for PARERE regulators is included and we aim to receive feedback on the regulatory relevance of these three aspects.
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- 2022
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22. Variation in fluoroquinolone pharmacodynamic parameter values among isolates of two bacterial pathogens of bovine respiratory disease
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Wen, Xuesong, Gehring, Ronette, Riviere, Jim E., Lubbers, Brian V., Gaire, Tara Nath, Wyche, Bre’Anna, Fox, Breanna, Quichocho, Victoria, and Volkova, Victoriya V.
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- 2018
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23. Limitations of MIC as the sole criterion in antimicrobial drug dosage regimen design: The need for full characterization of antimicrobial pharmacodynamic profile especially for drug-resistant organisms
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Gehring, Ronette and Riviere, Jim E.
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- 2013
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24. Pharmacokinetics of oral pimobendan in healthy cats
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Hanzlicek, Andrew S., Gehring, Ronette, KuKanich, Butch, KuKanich, Kate S., Borgarelli, Michele, Smee, Nicole, Olson, Emily E., and Margiocco, Marco
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- 2012
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25. Co-formulation of ketoprofen with tulathromycin alters pharmacokinetic and pharmacodynamic profile of ketoprofen in cattle
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De Koster, Jenne, Boucher, Joseph F, Tena, Jezaniah-Kira, Gehring, Ronette, Stegemann, Michael R, IRAS OH Pharmacology, dIRAS RA-1, IRAS OH Pharmacology, and dIRAS RA-1
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Ketoprofen ,Pharmacology ,General Veterinary ,Chemistry ,Cmax ,Bovine respiratory disease ,Cattle Diseases ,Rectal temperature ,medicine.disease ,Disaccharides ,veterinary(all) ,stomatognathic diseases ,Pharmacokinetics ,Heterocyclic Compounds ,Pharmacodynamics ,medicine ,Lipopolysaccharide challenge ,Animals ,Tulathromycin ,Cattle ,medicine.drug - Abstract
The current studies aimed to evaluate the pharmacokinetic (PK) and pharmacodynamic (PD) profile and to establish a PK-PD model for ketoprofen in a new fixed combination product containing tulathromycin (2.5 mg/kg) and ketoprofen (3 mg/kg) to treat bovine respiratory disease associated with pyrexia in cattle. Firstly, the effect of different ketoprofen doses as mono-substance (1, 3, and 6 mg/kg subcutaneous) on lipopolysaccharide-induced fever was evaluated which indicated that rectal temperature reduction lasted longer in the calves receiving 3 and 6 mg/kg ketoprofen. Secondly, the PK profile of the combination product was compared with mono-substance products (3 mg/kg subcutaneous and intramuscular). The PK profile of ketoprofen in the combination product was characterized by longer t1/2 , lower Cmax and increased AUC in comparison with mono-substance products. Due to prolonged ketoprofen exposure in the combination product, the pyrexia reducing effect of the combination product lasted longer in a second lipopolysaccharide challenge study in comparison with mono-substance products. Finally, a PK-PD model for the anti-pyretic effect of ketoprofen was developed based on the data from the different studies. The PK-PD model eliminated the need for additional animal experiments and indicated that a 3 mg/kg ketoprofen dose in the combination product provided optimal efficacy.
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- 2022
26. The efficacy of subcutaneous slow‐release melatonin implants in the prevention of canine flank alopecia recurrence is uncertain: A double‐blind, randomized, placebo‐controlled study.
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Verschuuren, Millie U. M. Y., Schlotter, Yvette M., van Geijlswijk, Inge M., van der Lugt, Jaco J., and Gehring, Ronette
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MELATONIN ,BALDNESS ,SUBCUTANEOUS injections ,BLOOD serum analysis ,SKIN biopsy - Abstract
Copyright of Veterinary Dermatology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
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- 2022
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27. Effect of sub-anesthetic xylazine and ketamine (’ketamine stun’) administered to calves immediately prior to castration
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Coetzee, Johann F, Gehring, Ronette, Tarus-Sang, Jepkoech, and Anderson, David E
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- 2010
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28. Pharmacokinetics and bioavailability of tildipirosin following intravenous and subcutaneous administration in horses
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Abu-Basha, Ehab A, Bani Ismail, Zuhair, Ababneh, Mohammed M, Hamzeh, Eyad, Gehring, Ronette, IRAS OH Pharmacology, dIRAS RA-1, IRAS OH Pharmacology, and dIRAS RA-1
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040301 veterinary sciences ,Cmax ,Administration, Oral ,Biological Availability ,0403 veterinary science ,Subcutaneous injection ,Animal science ,Pharmacokinetics ,bacterial pneumonia ,In vivo ,Medicine ,Animals ,Horses ,Respiratory system ,tildipirosin ,equine ,Pharmacology ,Volume of distribution ,General Veterinary ,business.industry ,0402 animal and dairy science ,Respiratory infection ,macrolide ,04 agricultural and veterinary sciences ,040201 dairy & animal science ,Bioavailability ,Area Under Curve ,Injections, Intravenous ,adverse effects ,Tylosin ,business ,pharmacokinetics - Abstract
Tildipirosin is a semi-synthetic macrolide antibiotic commonly used in cattle and swine to treat bacterial pneumonia. The objective of this study was to investigate the pharmacokinetic profile of tildipirosin after a single intravenous (i.v.) and subcutaneous (s.c.) administration in healthy lambs. Eighteen lambs were randomly divided into three groups (n = 6 each). Lambs received a single s.c. dose of tildipirosin at 4 and 6 mg/kg b.w. in group 1 and 2, respectively. Lambs in group 3 received a single i.v. dose of tildipirosin at 4 mg/kg b.w. Blood samples were collected at 0, 0.5, 0.75, 1.5, 2, 3, 4, 6, 8, 10, 24, 36, 48 hr, and every 24 hr to day 21, and thereafter at day 28 posttildipirosin administration. The plasma concentrations of tildipirosin were determined using high-performance liquid chromatography with tandem mass spectrometry detection (LC⁄MS⁄MS). All lambs appeared to tolerate both the intravenous and subcutaneous injection of tildipirosin. Following i.v. administration, the elimination half-life (T1/2 ), mean residence time (MRT), volume of distribution (Vd/F), and total body clearance (Cl/F) were 119.6 ± 9.0 hr, 281.9 ± 25.7 hr, 521.1 ± 107.2 L, and 2.9 ± 0.5 L/hr, respectively. No significant differences in Cmax (657.0 ± 142.8 and 754.6 ± 227.1 ng/ml), Tmax (1.21 ± 0.38 and 1.35 ± 0.44 hr), T1/2 (144 ± 17.5, 156.5 ± 33.4 hr), and MRT (262.0 ± 30.2 and 250.6 ± 54.5 hr) were found in tildipirosin after s.c. dosing at 4 and 6 mg/kg b.w., respectively. The absolute bioavailability (F) of tildipirosin was 71.5% and 75.3% after s.c. administration of 4 and 6 mg/kg b.w., respectively. In conclusion, tildipirosin was rapidly absorbed and slowly eliminated after a single s.c. administration in healthy lambs. Tildipirosin could be used for the treatment and prevention of respiratory bacterial infections in sheep. However, further in vitro and in vivo studies to determine the efficacy and safety are warranted. To our knowledge, this is the first study to determine the tildipirosin pharmacokinetic parameters in sheep plasma.
- Published
- 2021
29. Susceptibility of Broiler Chickens to Deoxynivalenol Exposure via Artificial or Natural Dietary Contamination
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Santos, Regiane R, Oosterveer-van der Doelen, Marjolein A M, Tersteeg-Zijderveld, Monique H G, Molist, Francesc, Mézes, Miklós, Gehring, Ronette, IRAS OH Epidemiology Microbial Agents, dIRAS RA-I&I RA, IRAS OH Pharmacology, dIRAS RA-1, IRAS OH Epidemiology Microbial Agents, dIRAS RA-I&I RA, IRAS OH Pharmacology, and dIRAS RA-1
- Subjects
Fusarium ,animal structures ,Intestinal morphology ,nutrient transporter ,Article ,Poultry ,03 medical and health sciences ,chemistry.chemical_compound ,mycotoxins ,lcsh:Zoology ,Food science ,lcsh:QL1-991 ,Mycotoxin ,fusarium ,030304 developmental biology ,0303 health sciences ,lcsh:Veterinary medicine ,General Veterinary ,biology ,poultry ,digestive, oral, and skin physiology ,Animal production ,0402 animal and dairy science ,Broiler ,food and beverages ,04 agricultural and veterinary sciences ,Contamination ,Mycotoxins ,intestinal morphology ,biology.organism_classification ,040201 dairy & animal science ,veterinary(all) ,chemistry ,Nutrient transporter ,lcsh:SF600-1100 ,Animal Science and Zoology - Abstract
Simple Summary This study evaluated the effect of diets artificially or naturally contaminated with 4000 μg/kg deoxyvalenol (DON) on the intestinal integrity and nutrient absorption of broiler chickens. Young broiler chickens (14 days old) were more sensitive to DON than older birds (28 days old), and negative impacts were observed when diets were naturally contaminated with DON. Aside from the decrease in the villus height of the jejunum in young broilers, their capacity to absorb peptides was decreased, as shown by the down-regulation of a peptide transporter. However, this effect was compensated in older broilers by an increase in the expression of carbohydrate transporter. Abstract Multi-mycotoxin contamination of poultry diets is a recurrent problem, even if the mycotoxins levels are below EU recommendations. Deoxynivalenol (DON) is one of the main studied mycotoxins due to its risks to animal production and health. When evaluating the effects of DON, one must consider that under practical conditions diets will not be contaminated solely with this mycotoxin. In the present study, broiler chickens were fed diets with negligible mycotoxin levels or with naturally or artificially contaminated diets containing approximately 4000 μg/kg DON. Birds were sampled at D14 and D28. Naturally-contaminated diets caused the most harm to the birds, especially the young ones, which presented decreased jejunal villus height and increased lesions, down-regulation of a peptide transporter. At D28 broiler chickens seemed to have adapted to the dietary conditions, when no differences were observed in villus morphometry, together with up-regulation of a carbohydrate transporter. However, intestinal lesions remained present in these older birds.
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- 2021
30. Macrolide Resistance and In Vitro Potentiation by Peptidomimetics in Porcine Clinical Escherichia coli.
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Yibing Ma, Pirolo, Mattia, Subramani, Prabha, Gehring, Ronette, Damborg, Peter, Franzyk, Henrik, and Guardabassi, Luca
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- 2022
- Full Text
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31. Penetration of topically administered dexamethasone disodium phosphate and prednisolone acetate into the normal equine ocular fluids.
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Hermans, Hanneke, van den Berg, Els M. H., Slenter, Inge J. M., Vendrig, Dax J. C., de Nijs‐Tjon, Lilian J. L., Vernooij, Johannes C. M., Brommer, Harold, Boevé, Michael H., and Gehring, Ronette
- Abstract
Summary: Background: Topical dexamethasone and prednisolone are currently the mainstay treatment for equine ophthalmic inflammatory diseases, such as equine recurrent uveitis. Comparative pharmacokinetic studies in horses are lacking and current guidelines are mainly based on empirical data and extrapolation from other species. Objectives: To investigate the penetration and local concentrations of topically applied dexamethasone and prednisolone in normal equine ocular fluids and serum. Study design: Prospective randomised experimental pharmacokinetic study. Methods: Twenty‐one Shetland ponies without ophthalmic disease were treated bilaterally topically every 2 hours during 24 hours to obtain steady state drug concentrations. One eye was treated with 0.15 mg of dexamethasone disodium phosphate (0.1%), and the other eye was simultaneously treated with 1.5 mg of prednisolone acetate (1%). Serum samples were taken prior to the induction of general anaesthesia. Aqueous and vitreous humour samples were taken during euthanasia at time points after administration of the last dose (t = 5 min, t = 15 min, t = 30 min, t = 60 min, t = 90 min, t = 120 min, t = 180 min). Each pony was randomly assigned to one time point, and three ponies were sampled per time point. Dexamethasone and prednisolone concentrations were measured by liquid chromatography‐mass spectrometry. Results: The mean dexamethasone concentration in aqueous humour was 32.4 ng/mL (standard deviation [SD] 10.9) and the mean prednisolone concentration was 321.6 ng/mL (SD 96.0). In the vitreous and in serum samples concentrations of both corticosteroids were below the limit of detection (LOD 2.5 ng/mL). Main limitations: The study group was limited to subjects without evidence of current ophthalmic disease. A limited number of time points were measured. Conclusions: Potentially effective dexamethasone and prednisolone concentrations were measured in the anterior chamber, but vitreal concentrations were negligible. Systemic uptake was low. Therefore, treatment with only topically administered corticosteroids is deemed insufficient in horses in cases of posterior uveitis. Further studies evaluating other routes of administration are warranted. [ABSTRACT FROM AUTHOR]
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- 2022
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32. Prednisolone in Dogs-Plasma Exposure and White Blood Cell Response
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Ekstrand, Carl, Pettersson, Helena, Gehring, Ronette, Hedeland, Mikael, Adolfsson, Sara, Lilliehöök, Inger, IRAS OH Pharmacology, and dIRAS RA-1
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pharmacodynamics ,canine ,immune-suppression ,glucocorticoid ,Clinical Science ,pharmacokinetics - Abstract
Glucocorticoids such as prednisolone are commonly used in dogs but there is sparse quantitative pharmacokinetic and pharmacodynamic information of this drug in this species. The objective of this study was to quantitatively characterize the concentration-effect relationship for prednisolone in dogs on neutrophil and lymphocyte trafficking and cortisol suppression. Nine beagles, 2-12 years old and part of a group for teaching/research were used in a 4-way crossover experiment including two treatments, active or placebo, administered either per os (PO) or intravenously (IV). Plasma was analyzed for prednisolone and cortisol using ultra-high performance liquid chromatography - tandem mass spectrometry. Leucocyte counts were performed in whole blood. Data was then analyzed by non-linear mixed effect modeling to estimate pharmacokinetic and pharmacodynamic parameters. After administration of prednisolone sodium succinate IV, the typical value (between subject variation) for total body prednisolone clearance was 1,370 ml/h center dot kg (13.4%). The volumes of the central and peripheral compartment were 2,300 ml/kg (10.7%) and 600 ml/kg (16.0%), respectively. The terminal plasma half-life was 1.7 h. The prednisolone plasma concentration producing 50% of the maximum response was 10 ng/mL (90.3%), 22.5 ng/ml (52.3%) and 0.04 ng/mL (197.3%) for neutrophil, lymphocyte and cortisol response, respectively. The administered dose (1 mg/kg) increased neutrophil and decreased lymphocyte numbers but not over the entire dosage interval of 24 h, due to the short half-life. However, glucocorticoids have a wide range of responses. An anti-inflammatory response due to altered gene transcription might have a longer duration. Future studies on the anti-inflammatory potency together with data presented are needed to optimize future dosage recommendations in dogs.
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- 2021
33. The disposition of trimethoprim and sulfadiazine in neonatal foals after intravenous administration.
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Ekstrand, Carl, Nostell, Katarina, Gehring, Ronette, Bondesson, Ulf, and Bröjer, Johan
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NEONATAL sepsis ,PHARMACOKINETICS ,SULFADIAZINE ,INTRAVENOUS therapy ,TRIMETHOPRIM ,FOALS ,GRAM-negative bacteria - Abstract
Background: Septicaemia in the neonatal foal is caused by both Gram positive and Gram negative bacteria. The life‐threatening nature of this condition requires treatment to be initiated with broad spectrum antimicrobial drugs pending antimicrobial susceptibility testing. Potentiated sulphonamides, for example, trimethoprim combined with sulfadiazine, could be clinically relevant options but their pharmacokinetics in the neonatal foal are unknown. Objectives: To describe the plasma disposition of trimethoprim and sulfadiazine in neonatal foals and to relate the results to patterns in the minimum inhibitory concentration (MIC) for Escherichia coli, a recognized pathogen in neonatal foal sepsis. Method: A total of five doses of trimethoprim (2.5 mg/kg) and sulfadiazine (12.5 mg/kg) were administered intravenously every 12 h to eight neonatal foals that were 3 days old at inclusion. A non‐linear mixed effects model was fitted to the trimethoprim and sulfadiazine experimental data. The 24 h area under the free plasma trimethoprim and sulfadiazine concentration‐time curves (fAUC) and the pharmacokinetic/pharmacodynamik (PK/PD)‐index fAUC/MIC was calculated to evaluate the potential clinical benefits of the administered dose. Results: For trimethoprim, the typical values were 1.99 L/kg, 0.33 L/h·kg and 4.2 h for the apparent volume of distribution, clearance and terminal half‐life, respectively. The 24 h fAUC for trimethoprim was 11.3 μg·h/ml (7.2–15.2) and the fAUC/MIC ratio for E. coli was 23 (16.4–29.2) (population mean (range)). For sulfadiazine, the typical values were 0.61 L/kg, 0.09 L/h·kg and 5.3 h for the apparent volume of distribution, clearance and terminal half‐life, respectively. The 24 h fAUC for sulfadiazine was 246.8 μg·h/ml (175.6–335.4). Conclusion: For trimethoprim, the plasma exposure is insufficient in some foals to successfully treat bacterial infections with an MIC‐value of 0.5 μg/ml using the studied dosing regimen. [ABSTRACT FROM AUTHOR]
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- 2022
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34. Comparative Pharmacokinetics of Meloxicam Between Healthy Post-partum vs. Mid-lactation Dairy Cattle
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Warber, Rochelle, Ydstie, Joshua, Wulf, Larry, Gehring, Ronette, Coetzee, Johann, Mochel, Jonathan, Gorden, Patrick, IRAS OH Pharmacology, and dIRAS RA-1
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dairy ,post-partum ,pharmacokinetics ,meloxicam ,NSAID - Abstract
Lactating dairy cattle are at risk for various painful conditions throughout their life, such as lameness, parturition, mastitis, and metabolic disorders. These conditions necessitate adequate methods of analgesia to address welfare concerns through efficacious pain mitigation. As no method of analgesia has been approved for lactating dairy cattle, to date, research is necessary to determine effective pain management strategies for dairy cattle. In both the European Union and Canada, meloxicam has been approved for use in lactating dairy cattle as a methodology for pain control. The objective of this study was to characterize the pharmacokinetics of meloxicam administered orally and intravenously to lactating dairy cattle in the post-partum vs. mid-lactation period. In this parallel study design, 12 healthy, lactating Holsteins were enrolled within 24 h of freshening and randomly allocated to intravenous (0.2 mg/kg) or oral (1.0 mg/kg) meloxicam administration treatment groups. They were matched based on parity to 12, healthy cows that were considered mid-lactation [>150 days-in-milk (DIM)] to receive the same treatment. Based on meloxicam formulation, sampling times varied and plasma was collection via jugular venipuncture for 6 days. Plasma drug concentrations were evaluated using liquid chromatography coupled with mass spectroscopy and pharmacokinetic properties were evaluated using non-compartmental (i.e., statistical moments) analysis. Results indicated a decreased systemic clearance of meloxicam in post-partum relative to mid-lactation cows, which resulted in a longer half-life and increased total exposure independent of mode of administration. These results suggest a need for dose adjustments based on stage in lactation and further assessment of the impact of days-in-milk on milk withholding period.
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- 2020
35. Corrigendum: Comparative Pharmacokinetics of Meloxicam Between Healthy Post-partum vs. Mid-lactation Dairy Cattle
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Warber, Rochelle, Ydstie, Joshua, Wulf, Larry, Gehring, Ronette, Coetzee, Johann, Mochel, Jonathan, Gorden, Patrick, IRAS OH Pharmacology, and dIRAS RA-1
- Subjects
040301 veterinary sciences ,0403 veterinary science ,Animal science ,Pharmacokinetics ,Lactation ,Medicine ,media_common.cataloged_instance ,European union ,Dairy cattle ,meloxicam ,media_common ,Original Research ,Venipuncture ,lcsh:Veterinary medicine ,General Veterinary ,business.industry ,0402 animal and dairy science ,Correction ,post-partum ,04 agricultural and veterinary sciences ,medicine.disease ,040201 dairy & animal science ,NSAID ,Mastitis ,Meloxicam ,medicine.anatomical_structure ,Lameness ,dairy ,lcsh:SF600-1100 ,Veterinary Science ,business ,pharmacokinetics ,medicine.drug - Abstract
Lactating dairy cattle are at risk for various painful conditions throughout their life, such as lameness, parturition, mastitis, and metabolic disorders. These conditions necessitate adequate methods of analgesia to address welfare concerns through efficacious pain mitigation. As no method of analgesia has been approved for lactating dairy cattle, to date, research is necessary to determine effective pain management strategies for dairy cattle. In both the European Union and Canada, meloxicam has been approved for use in lactating dairy cattle as a methodology for pain control. The objective of this study was to characterize the pharmacokinetics of meloxicam administered orally and intravenously to lactating dairy cattle in the post-partum vs. mid-lactation period. In this parallel study design, 12 healthy, lactating Holsteins were enrolled within 24 h of freshening and randomly allocated to intravenous (0.2 mg/kg) or oral (1.0 mg/kg) meloxicam administration treatment groups. They were matched based on parity to 12, healthy cows that were considered mid-lactation [>150 days-in-milk (DIM)] to receive the same treatment. Based on meloxicam formulation, sampling times varied and plasma was collection via jugular venipuncture for 6 days. Plasma drug concentrations were evaluated using liquid chromatography coupled with mass spectroscopy and pharmacokinetic properties were evaluated using non-compartmental (i.e., statistical moments) analysis. Results indicated a decreased systemic clearance of meloxicam in post-partum relative to mid-lactation cows, which resulted in a longer half-life and increased total exposure independent of mode of administration. These results suggest a need for dose adjustments based on stage in lactation and further assessment of the impact of days-in-milk on milk withholding period.
- Published
- 2020
36. Pharmacokinetics of imidocarb dipropionate in white-tailed deer (Odocoileus virginianus) after single intramuscular administration
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Milnes, Ellie L, Delnatte, Pauline, Woodbury, Murray, Hering, Adam, Lee, Sam, Smith, Dale A, Nemeth, Nicole M, Gu, Yu, Gehring, Ronette, Johnson, Ron, One Health Pharma, dIRAS RA-1, One Health Pharma, and dIRAS RA-1
- Subjects
040301 veterinary sciences ,Antiprotozoal Agents ,Babesia ,Odocoileus ,Injections, Intramuscular ,01 natural sciences ,0403 veterinary science ,chemistry.chemical_compound ,Animal science ,Pharmacokinetics ,Animals ,Distribution (pharmacology) ,0101 mathematics ,cervid babesiosis ,Pharmacology ,Volume of distribution ,Imidocarb ,imidocarb dipropiate ,General Veterinary ,biology ,Chemistry ,Deer ,Total body ,04 agricultural and veterinary sciences ,biology.organism_classification ,010101 applied mathematics ,white-tailed deer ,Area Under Curve ,Female ,Open model ,Imidocarb dipropionate ,Odocoileus virginianus ,Half-Life - Abstract
This study was designed to investigate the pharmacokinetics of imidocarb, a carbanilide derivative, in white-tailed deer (Odocoileus virginianus). The pharmacokinetic properties of a single intramuscular (IM) dose of imidocarb were determined in 10 deer. A single IM injection of 3.0 mg/kg imidocarb dipropionate was administered, and blood samples were collected prior to, and up to 48 hr after imidocarb administration. Plasma imidocarb concentrations were determined by high-performance liquid chromatography with ultraviolet detection. The disposition of plasma imidocarb was best characterized by a two-compartment open model. The mean ± SE maximal imidocarb concentration in deer was 880.78 ± 81.12 ng/ml at 38.63 ± 5.30 min postinjection. The distribution phase had a half-life (t1/2α ) of 25.90 ± 10.21 min, and plasma imidocarb concentration declined with a terminal elimination half-life (t1/2β ) of 464.06 ± 104.08 min (7.73 ± 1.73 hr). Apparent volume of distribution based on the terminal phase (VZ /F) was 9.20 ± 2.70 L/kg, and apparent total body clearance (Cl/F) was 15.97 ± 1.28 ml min-1 kg-1 .
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- 2020
37. Tumor necrosis factor alpha increases P-glycoprotein expression in a BME-UV in vitro model of mammary epithelial cells
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Al-Bataineh, Mohammad M., van der Merwe, Deon, Schultz, Bruce D., and Gehring, Ronette
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- 2010
- Full Text
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38. Pharmacokinetics and bioavailability of ketoprofen when compounded with iron dextran for use in nursing piglets.
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Reynolds, Kristen J., Johnson, Ron, Friendship, Robert M., Brown, Jennifer, Enouri, Saad, Gehring, Ronette, and O’Sullivan, Terri L.
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PIGLETS ,IRON compounds ,NONSTEROIDAL anti-inflammatory agents ,PHARMACOKINETICS ,BIOAVAILABILITY ,IRON ,DEXTRAN ,FENTANYL - Abstract
Copyright of Canadian Veterinary Journal / Revue Vétérinaire Canadienne is the property of Canadian Veterinary Medical Association and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
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- 2021
39. An integrated experimental and physiologically based pharmacokinetic modeling study of penicillin G in heavy sows
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Li, Miao, Mainquist-Whigham, Christine, Karriker, Locke A, Wulf, Larry W, Zeng, Dongping, Gehring, Ronette, Riviere, Jim E, Coetzee, Johann F, Lin, Zhoumeng, One Health Pharma, and dIRAS RA-1
- Subjects
food safety ,heavy sow ,extralabel withdrawal interval ,procaine penicillin G (PPG) ,physiologically based pharmacokinetic (PBPK) model ,tissue residue - Abstract
Penicillin G is widely used in food-producing animals at extralabel doses and is one of the most frequently identified violative drug residues in animal-derived food products. In this study, the plasma pharmacokinetics and tissue residue depletion of penicillin G in heavy sows after repeated intramuscular administrations at label (6.5 mg/kg) and 5 × label (32.5 mg/kg) doses were determined. Plasma, urine, and environmental samples were tested as potential antemortem markers for penicillin G residues. The collected new data and other available data from the literature were used to develop a population physiologically based pharmacokinetic (PBPK) model for penicillin G in heavy sows. The results showed that antemortem testing of urine provided potential correlation with tissue residue levels. Based on the United States Department of Agriculture Food Safety and Inspection Service action limit of 25 ng/g, the model estimated a withdrawal interval of 38 days for penicillin G in heavy sows after 3 repeated intramuscular injections at 5 × label dose. This study improves our understanding of penicillin G pharmacokinetics and tissue residue depletion in heavy sows and provides a tool to predict proper withdrawal intervals after extralabel use of penicillin G in heavy sows, thereby helping safety assessment of sow-derived meat products.
- Published
- 2019
40. Insights into In Vivo Absolute Oral Bioavailability, Biotransformation, and Toxicokinetics of Zearalenone, α-Zearalenol, β-Zearalenol, Zearalenone-14-glucoside, and Zearalenone-14-sulfate in Pigs
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Catteuw, Amelie, Broekaert, Nathan, De Baere, Siegrid, Lauwers, Marianne, Gasthuys, Elke, Huybrechts, Bart, Callebaut, Alfons, Ivanova, Lada, Uhlig, Silvio, De Boevre, Marthe, De Saeger, Sarah, Gehring, Ronette, Devreese, Mathias, Croubels, Siska, One Health Pharma, and dIRAS RA-1
- Subjects
Male ,Kinetics ,Sulfates/chemistry ,Zeranol/analogs & derivatives ,Mycotoxins/chemistry ,Animals ,Biological Availability ,Glucosides/chemistry ,Zearalenone/chemistry ,Biotransformation ,Swine/metabolism ,Toxicokinetics - Abstract
The aim of this study was to determine the toxicokinetic characteristics of ZEN and its modified forms, α-zearalenol (α-ZEL), β-zearalenol (β-ZEL), zearalenone-14-glucoside (ZEN14G), and zearalenone-14-sulfate (ZEN14S), including presystemic and systemic hydrolysis in pigs. Crossover pig trials were performed by means of intravenous and oral administration of ZEN and its modified forms. Systemic plasma concentrations of the administered toxins and their metabolites were quantified and further processed via tailor-made compartmental toxicokinetic models. Furthermore, portal plasma was analyzed to unravel the site of hydrolysis, and urine samples were analyzed to determine urinary excretion. Results demonstrate complete presystemic hydrolysis of ZEN14G and ZEN14S to ZEN and high oral bioavailability for all administered compounds, with further extensive first-pass glucuronidation. Conclusively, the modified-ZEN forms α-ZEL, β-ZEL, ZEN14G, and ZEN14S contribute to overall ZEN systemic toxicity in pigs and should be taken into account for risk assessment.
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- 2019
41. Chapter 8 - Toxicokinetics in Veterinary Toxicology
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van der Merwe, Deon, Gehring, Ronette, and Buur, Jennifer L.
- Published
- 2018
- Full Text
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42. Oral doxycycline pharmacokinetics: Lambs in comparison with sheep
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Mileva, Rositsa, Subev, Sasho, Gehring, Ronette, Milanova, Aneliya, IRAS OH Pharmacology, dIRAS RA-1, IRAS OH Pharmacology, and dIRAS RA-1
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Aging ,040301 veterinary sciences ,Population ,Administration, Oral ,age differences ,0403 veterinary science ,03 medical and health sciences ,Rumen ,Animal science ,Pharmacokinetics ,Oral administration ,Animals ,Lactation ,Medicine ,small ruminants ,Alanine aminotransferase ,education ,030304 developmental biology ,Pharmacology ,Doxycycline ,0303 health sciences ,education.field_of_study ,Sheep ,General Veterinary ,doxycycline ,business.industry ,food and beverages ,04 agricultural and veterinary sciences ,Animals, Suckling ,Anti-Bacterial Agents ,Pharmacokinetic analysis ,Milk ,Female ,Liver function ,business ,pharmacokinetics ,medicine.drug - Abstract
The pharmacokinetics of doxycycline was investigated in lactating sheep and lambs after oral administration at a dose of 10 mg/kg. Concentrations in plasma and milk were assayed with HPLC-PDA analysis. Doxycycline penetrates into the milk, and levels (0.38 ± 0.21 μg/ml) were found 0.5 hr after the treatment. The results suggest that the lambs can be exposed to doxycycline by suckling milk from their treated mothers. Population pharmacokinetic analysis showed a positive relationship between age, which reflects the stage of development of rumen function, and clearance. Possible explanations for the observed differences include the undeveloped rumen in lambs, the differences in the feed and liver function as evidenced by the blood biochemical parameters aspartate aminotransferase (AST) and alanine aminotransferase (ALT), which were significantly lower in lambs (62.67 ± 27.83 U/L and 8.50 ± 6.80 U/L) than in sheep (114.33 ± 20.77 U/L and 18.00 ± 3.16 U/L).
- Published
- 2020
43. Pharmacokinetics and effect of intravenous meloxicam in weaned Holstein calves following scoop dehorning without local anesthesia
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Coetzee Johann F, Mosher Ruby A, KuKanich Butch, Gehring Ronette, Robert Brad, Reinbold J, and White Brad J
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Analgesia ,Meloxicam ,Dehorning ,Substance P ,Cortisol ,Heart rate ,Accelerometers ,Performance ,Veterinary medicine ,SF600-1100 - Abstract
Abstract Background Dehorning is a common practice involving calves on dairy operations in the United States. However, less than 20% of producers report using analgesics or anesthetics during dehorning. Administration of a systemic analgesic drug at the time of dehorning may be attractive to dairy producers since cornual nerve blocks require 10 – 15 min to take effect and only provide pain relief for a few hours. The primary objectives of this trial were to (1) describe the compartmental pharmacokinetics of meloxicam in calves after IV administration at 0.5 mg/kg and (2) to determine the effect of meloxicam (n = 6) or placebo (n = 6) treatment on serum cortisol response, plasma substance P (SP) concentrations, heart rate (HR), activity and weight gain in calves after scoop dehorning and thermocautery without local anesthesia. Results Plasma meloxicam concentrations were detectable for 50 h post-administration and fit a 2-compartment model with a rapid distribution phase (mean T½α = 0.22 ± 0.087 h) and a slower elimination phase (mean T½β = 21.86 ± 3.03 h). Dehorning caused a significant increase in serum cortisol concentrations and HR (P Conclusions To our knowledge, this is the first published report examining the effects of meloxicam without local anesthesia on SP, activity and performance of calves post-dehorning. These findings suggest that administration of meloxicam alone immediately prior to dehorning does not mitigate signs of acute distress but may have long term physiological, behavior and performance effects.
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- 2012
- Full Text
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44. Pharmacokinetics and Pharmacodynamics of Tildipirosin Against in a Murine Lung Infection Model
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Zeng, Dongping, Sun, Meizhen, Lin, Zhoumeng, Li, Miao, Gehring, Ronette, Zeng, Zhenling, One Health Pharma, and dIRAS RA-1
- Subjects
Pasteurella multocida ,minimum inhibitory concentration (MIC) ,pharmacokinetic/pharmacodynamic (PK/PD) ,murine lung infection model ,tildipirosin - Abstract
Tildipirosin, a 16-membered-ring macrolide antimicrobial, has recently been approved for the treatment of swine respiratory disease and bovine respiratory disease. This macrolide is extensively distributed to the site of respiratory infection followed by slow elimination. Clinical efficacy has been demonstrated in cattle and swine clinical field trials. However, the pharmacokinetic/pharmacodynamic (PK/PD) index that best correlates with the efficacy of tildipirosin remains undefined. The objective of this study was to develop a PK/PD model following subcutaneous injection of tildipirosin against Pasteurella multocida in a murine lung infection model. The PK studies of unbound (f) tildipirosin in plasma were determined following subcutaneous injection of single doses of 1, 2, 4, 6, and 8 mg/kg of body weight in neutropenic lung-infected mice. The PD studies were conducted over 24 h based on twenty intermittent dosing regimens, of which total daily dose ranged from 1 to 32 mg/kg and dosage intervals included 6, 8, 12, and 24 h. The minimum inhibitory concentration (MIC) of tildipirosin against P. multocida was determined in serum. The inhibitory effect Imax model was employed for PK/PD modeling. The area under the unbound concentration-time profile over 24 h to MIC (fAUC0-24 h/MIC) was the PK/PD index that best described the antibacterial activity in the murine infection model. The fAUC0-24 h/MIC targets required to achieve the bacteriostatic action, a 1-log10 kill and 2-log10 kill of bacterial counts were 19.93, 31.89, and 53.27 h, respectively. These results can facilitate efforts to define more rational designs of dosage regimens of tildipirosin using classical PK/PD concepts for the treatment of respiratory diseases in pigs and cattle.
- Published
- 2018
45. Comparative pharmacokinetics and bioavailability of two tylosin formulations in chickens after oral administration
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ABU-BASHA, EHAB A, AL-SHUNNAQ, AHMAD F., and GEHRING, RONETTE
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φαρμακοκινητική ,chicken ,βιοδιαθεσιμότητα ,tylsoin ,τυλοσίνη ,κοτόπουλο ,bioavailability ,pharmacokinetics - Abstract
Η φαρμακοκινητική και βιοδιαθεσιμότητα δύο σκευασμάτων τυλοσίνης χορηγούμενων από το στόμα πραγματοποιήθηκε σε κοτόπουλα κρεατοπαραγωγής με την μέθοδο απλής δόσης, τυχαιοποιημένου και παράλληλου σχεδιασμού. Τα δύο σκευάσματα της τυλοσίνης (Tylosina® και Tylan®) χορηγήθηκαν από το στόμα σε δόση 25 mg/kg σ.β. μετά από νηστεία μιας βραδιάς (n=15 κοτόπουλα/ομάδα). Για τον υπολογισμό της βιοδιαθεσιμότητας της τυλοσίνης, δεκαπέντε επιπλέον κοτόπουλα ορίστηκαν ως ομάδα 3 και τους χορηγήθηκε μια απλή ενδοφλέβια δόση τυλοσίνης 25 mg/kg σ.β. Δείγματα αίματος συλλέχθηκαν σε διάφορους χρόνους μέχρι και 24 ώρες μετά τη χορήγηση του φαρμάκου. Η μέθοδος της υγροχρωματογραφίας υψηλής απόδοσης (HPLC) χρησιμοποιήθηκε για τον προσδιορισμό των συγκεντρώσεων της τυλοσίνης στο πλάσμα. Η φαρμακοκινητική ανάλυση των δεδομένων πραγματοποιήθηκε χρησιμοποιώντας την ανάλυση του μη διαμερισματικού προτύπου με τη στατιστική θεωρεία στιγμής και τη βοήθεια εμπορικά διαθέσιμου υπολογιστικού προγράμματος (WinNonlin®, Pharsight Corporation, Cary, NC, USA). Δεν υπήρχαν σημαντικές διαφορές στην τιμή Cmax (3.05±0.63, 2.63±0.74 μg/ml), tmax (2.36±0.42, 2.30±0.38 h), t1/2β (1.99±0.38, 2.67±0.60 h), AUC0-12h (6.11±0.97, 5.37±1.16 μg.h/ml), AUC0-∞ (6.38±0.94, 5.57±1.15 μg.h/ml), MRT (3.53±0.24, 3.67±0.32 h), ClB/F (90.59±13.81, 169.38±54.44 ml/min/kg) και Vdz/F (16.85±4.74, 43.96±18.24 l/kg) μεταξύ των σκευασμάτων Tylosina® και Tylan®, αντίστοιχα. Η υπολογισμένη βιοδιαθεσιμότητα (F) από το στόμα ήταν 40,56 και 35,41%, αντίστοιχα. Επιπλέον, η σχετική βιοδιαθεσιμότητα του Tylosina® ήταν 113,9% σε σχέση με το Tylan®. Συμπερασματικά, το σκεύασμα Tylosina® είναι συγκρίσιμο με το σκεύασμα Tylan® και αμφότερα τα σκευάσματα μπορούν να χρησιμοποιηθούν για την αντιμετώπιση ευαίσθητων μικροοργανισμών στην κτηνιατρική πράξη σε δόση 25 mg/kg σ.β., The pharmacokinetics and oral bioavailability of two tylosin formulations was carried out in broiler chickens according to a single dose, randomized, parallel design. The two formulations of tylosin (Tylosina® and Tylan®) were given orally at a dose level of 25 mg/kg b.w. after an overnight fasting (n=15 chicken/group). To calculate tylosin bioavailability, fifteen more chickens was assigned as group 3 and was given a single intravenous dose of tylosin (25 mg/kg b.w.). Serial blood samples were collected at different time points up to 24 hour post-drug administration. A high performance liquid chromatography (HPLC) method was used for the determination of tylosin concentrations in chicken plasma. The pharmacokinetics analysis of the data was performed using non-compartmental analysis based on statistical moment theory with the help of commercially available software (WinNonlin®, Pharsight Corporation, Cary, NC, USA). There were no significant differences in the Cmax (3.05±0.63, 2.63±0.74 μg/ml), tmax (2.36±0.42, 2.30±0.38 h), t1/2β (1.99±0.38, 2.67±0.60 h), AUC0-12h (6.11±0.97, 5.37±1.16 μg.h/ml), AUC0-∞ (6.38±0.94, 5.57±1.15 μg.h/ml), MRT (3.53±0.24, 3.67±0.32 h), ClB/F (90.59±13.81, 169.38±54.44 ml/min/kg) and Vdz/F (16.85±4.74, 43.96±18.24 l/kg) between Tylosina® and Tylan®, respectively. The calculated oral bioavailability (F) for Tylosina® and Tylan® were 40.56 and 35.41%, respectively. Moreover, the relative bioavailability of Tylosina® was 113.9% when compared to Tylan®. In conclusion, Tylosina® is comparable to Tylan® and both formulations can be used for treatment of susceptible microorganisms in veterinary medicine practice at a dose level of 25 mg/kg b.w.
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- 2017
46. Analysis of polymorphisms of canine Cytochrome P 450‐CYP2D15.
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Hagen, Marjan A. E., Schipper, Louska, Oosterveer‐van der Doelen, Marjolein A. M., Vos‐Loohuis, Manon, Gehring, Ronette, and Leegwater, Peter A.
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DOG breeds ,DNA analysis ,VETERINARY medicine ,CYTOCHROME P-450 ,INTRONS ,TREATMENT effectiveness - Abstract
Cytochrome P450 (CYP) proteins constitute a large ancient family of oxidative enzymes essential for the efficient elimination of a wide variety of clinically used drugs. Polymorphic variants of human CYP2D6 are associated with the conversion rate and efficacy of several drugs such as antidepressants. Polymorphisms of the canine orthologue CYP2D15 are of interest because these antidepressants are also used in dogs with behavioral problems and the outcome of the treatment is variable. However, the annotated CYP2D15 gene is incomplete and inaccurately assembled in CanFam3.1, hampering DNA sequence analysis of the gene in individual dogs. We elucidated the complete exon–intron structure of CYP2D15 to enable comprehensive genotyping of the gene using genomic DNA. We surveyed variations of the gene in four diverse dog breeds and identified novel polymorphisms in exon 2 in border collies. Further investigation to establish the impact of these canine CYP2D15 polymorphisms on interindividual variability in expression and function of this metabolizing enzyme is now feasible. Further knowledge of CYP pharmacogenetics will help individualize therapy and thereby increase therapeutic efficacy, especially in the use of antidepressants in veterinary behavioral medicine. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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47. Considerations for extralabel drug use in calves
- Author
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Mzyk, Danielle A, Gehring, Ronette, Tell, Lisa A, Vickroy, Thomas W, Riviere, Jim E, Ragan, Gail, Baynes, Ronald E, Smith, Geof W, LS Pharma, dIRAS RA-1, LS Pharma, and dIRAS RA-1
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Drug ,Veterinary medicine ,medicine.medical_specialty ,Meat ,040301 veterinary sciences ,media_common.quotation_subject ,MEDLINE ,Food Contamination ,0403 veterinary science ,Medicine ,Animals ,Intensive care medicine ,media_common ,Drug Labeling ,Drug labeling ,General Veterinary ,business.industry ,0402 animal and dairy science ,Veterinary Drugs ,04 agricultural and veterinary sciences ,040201 dairy & animal science ,Drug Residues ,Milk ,Animals, Newborn ,Cattle ,business - Published
- 2017
48. Pharmacokinetics of a single dose of voriconazole administered orally with and without food to red-tailed hawks (Buteo jamaicensus)
- Author
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Parsley, Ruth A, Tell, Lisa A, Gehring, Ronette, LS Pharma, dIRAS RA-1, LS Pharma, and dIRAS RA-1
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Oral ,0301 basic medicine ,Male ,040301 veterinary sciences ,030106 microbiology ,Buteo ,Administration, Oral ,Biological Availability ,Absorption (skin) ,Pharmacology ,0403 veterinary science ,03 medical and health sciences ,Mice ,Animal science ,Pharmacokinetics ,Blood plasma ,Journal Article ,Medicine ,Animals ,Voriconazole ,Cross-Over Studies ,General Veterinary ,biology ,business.industry ,Half-life ,04 agricultural and veterinary sciences ,General Medicine ,biology.organism_classification ,Crossover study ,Bioavailability ,Hawks ,Administration ,Randomized Controlled Trial ,Female ,business ,medicine.drug ,Half-Life - Abstract
OBJECTIVE To determine the pharmacokinetics of voriconazole administered PO with or without food to red-tailed hawks (Buteo jamaicensus) and whether any observed variability could be explained by measured covariates to inform dose adjustments. ANIMALS 7 adult red-tailed hawks. PROCEDURES In a crossover study design, hawks were randomly assigned to first receive voriconazole (15 mg/kg, PO) injected into a dead mouse (n = 3; fed birds) or without food (4; unfed birds). Sixteen days later, treatments were reversed. Blood samples were collected at various points to measure plasma voriconazole concentrations by ultraperformance liquid chromatography. Pharmacokinetic data were analyzed by noncompartmental methods and fit to a compartmental model through nonlinear mixed-effects regression, with feeding status and body weight investigated as covariates. RESULTS Voriconazole was well absorbed, with quantifiable plasma concentrations up to 24 hours after administration. Mean plasma half-life was approximately 2 hours in fed and unfed birds. Administration of the voriconazole in food delayed absorption, resulting in a significant delay in time to maximum plasma concentration. The final compartmental model included a categorical covariate to account for this lag in absorption as well as body weight as a covariate of total body clearance (relative to unknown bioavailability). CONCLUSIONS AND CLINICAL RELEVANCE A single dose of voriconazole (15 mg/kg) administered PO to red-tailed hawks resulted in mean plasma voriconazole concentrations greater than the targeted value (1 μg/mL). Additional studies with larger sample sizes and multidose regimens are required before the model developed here can be applied in clinical settings.
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- 2017
49. Avoiding violative flunixin meglumine residues in cattle and swine
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Sidhu, Pritam K, Gehring, Ronette, Mzyk, Danielle A, Marmulak, Tara, Tell, Lisa A, Baynes, Ronald E, Vickroy, Thomas W, Riviere, Jim E, LS Pharma, dIRAS RA-1, LS Pharma, and dIRAS RA-1
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0301 basic medicine ,General Veterinary ,040301 veterinary sciences ,business.industry ,Swine ,Anti-Inflammatory Agents, Non-Steroidal ,Anti-Inflammatory Agents ,04 agricultural and veterinary sciences ,Pharmacology ,Clonixin ,Drug Residues ,0403 veterinary science ,03 medical and health sciences ,chemistry.chemical_compound ,030104 developmental biology ,chemistry ,FLUNIXIN MEGLUMINE ,Medicine ,Animals ,Cattle ,business ,Non-Steroidal - Published
- 2017
50. Population pharmacokinetic modeling of the glomerular filtration rate in growing piglets using iohexol
- Author
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Elke Gasthuys, Joske Millecam, Siska Croubels, Gehring, Ronette, and Mathias Devreese
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glomerular filtration rate ,Piglet ,animal model ,population pharmacokinetic modeling ,Veterinary Sciences ,iohexol - Published
- 2017
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