Pharmacokinetic properties of transdermal flunixin in cattle and its use in pain models

Doctor of PhilosophyDepartment of Anatomy and PhysiologyJohann F. CoetzeeFlunixin meglumine has been used as an antipyretic and anti-inflammatory since the 1980s. In 2013, a novel formulation was released in the European Union for topical administration and transdermal absorption. Approval for transdermal flunixin in cattle in the United States occurred in 2017, and included a label claim for the control of pain associated with infectious pododermatitis (foot rot). This new formulation allows for needle-less delivery of flunixin with minimal restraint and training required. In this dissertation, the pharmacokinetics of transdermal flunixin in Holstein calves at 2 months of age and adult lactating cows is described. In these pharmacokinetic studies, plasma flunixin concentrations were determined using high-pressure liquid chromatography coupled with mass spectroscopy. Pharmacokinetic modeling was completed using non-compartmental modeling methods using a commercially available computer program. Ex vivo prostaglandin E₂ (PGE₂) production using a whole blood model served as a biomarker for the anti-inflammatory effects of flunixin meglumine and suppression of cyclo-oxygenase enzyme-2. The concentrations of PGE₂ were determined using a commercially available enzyme-linked immunosorbent linked assay (ELISA) kit. The effects of age and pain on the pharmacokinetics of flunixin were investigated. Both influenced the pharmacokinetics and anti-inflammatory effects of flunixin. Cautery dehorning without local anesthetic was used in the calf model to generate pain. The pain associated with dehorning caused lower absorption of the transdermal flunixin and a longer terminal half-life. This longer half-life did result in lower PGE₂ concentrations at later time points. The influence of age was determined in the same group of Holstein calves at 2 months and 8 month of age. Age related effects included lower clearance, a longer half-life, and longer suppression of PGE₂ following intravenous injection. Following transdermal administration, older animals had a prolonged absorption leading to a longer half-life and apparent ‘flip-flop’ pharmacokinetics. Additionally, the suppression of PGE₂ was not observed in older calves following transdermal flunixin administration. The analgesic properties of transdermal flunixin were tested using three different pain models. Those pain models include cautery dehorning, surgical castration, and induced lameness. The reduction in plasma cortisol following transdermal administration was the most consistent finding in each model for pain. Infrared thermography (IRT) was used to assess either activation of the autonomic nervous system or local inflammation. Flunixin did not have any effects on substance P concentration in all three pain models. Gait analysis using a floor based pressure mat was used in the assessment of castration and lameness pain. Although there were no observed effects of flunixin in those studies, the use of this technology for pain assessment is promising. Future studies of transdermal flunixin to determine its utility as part of a multi-modal analgesic plan are still warranted. Specifically, the use a of a local anesthetic block at the time of cautery dehorning, as flunixin has minimal effects on pain, and its pharmacokinetics were altered by the painful stimulus. Timing of the dose relative to the painful procedure is also needed as flunixin is rapidly absorbed. Field studies in lame cattle are needed as there is a deficiency in the literature as only models of lameness induction have been reported

Utilization of Liquid Chromatography/Mass Spectrometry to Detect Drug Residues in Milk: Applications for Research and Commercial Dairying

Prevention of drug residues in milk is a daily endeavor on dairy farms. There is increasing scrutiny from the public and government when it comes to drug residues in milk. Drug residues can result from simple human errors, disease processes not allowing for normal clearance of a drug, or malicious activity. The testing methodologies used to detect drug residues have become more sensitive with many tests available that can detect drug levels below ten parts per billion (ppb)

Entwicklung, Überprüfung und Praxiseinführung des Prognosesystems ÖKO-SIMPHYT zur gezielten Bekämpfung der Kraut- und Knollenfäule (Phytophthora infestans) im ökologischen Kartoffelanbau mit reduzierten Kupferaufwandmengen

Die drei Teilbereiche des Projekts wurden erfolgreich bearbeitet: 1.) Reduzierung des Primärbefalls durch eine Pflanzgutbeizung mit Kupfer Für die Kupferbeizung zur Reduktion des Primärbefalls wurde das ULV-Verfahren (Mantis) als am effektivsten eingestuft. Hierbei wird mit einer minimalen Kupfermenge von 120g Kupfer/ha gearbeitet. Die Beizung hatte keine negativen Auswirkungen auf das Auflaufverhalten der Knollen und konnte den Primärbefall (Stängelbefall) reduzieren. 2.) Entwicklung von Kupferminimierungsstrategien zur Kontrolle des Sekundärbefalls Unter den niedrigen Infektionsbedingungen der ersten zwei Projektjahre haben sich die durchgeführten Kupferminimierungsstrategien auf Basis des Prognosemodells ÖKO-SIMPHYT bewährt. Diese Ergebnisse konnten im letzten Projektjahr bei hohem Infektionsdruck in Teilen bestätigt werden. Hier zeigte sich, dass gerade der Spritzstart eine entscheidende Rolle für eine erfolgreiche Bekämpfung der Krautfäule spielt. Das Modell muss speziell im Hinblick hierauf noch weiterentwickelt werden, um den Spritzstart zuverlässig prognostizieren zu können. 3.) Entwicklung, Validierung und Praxiseinführung des Prognosesystems ÖKO-SIMPHYT Das Modell ÖKO-SIMPHYT wurde aus dem Modell SIMPHYT anhand der erhobenen Daten speziell für die Belange des ökologischen Landbaus entwickelt. Spritzstart und Spritzabstand werden schlagspezifisch berechnet. Bei niedrigem Infektionsdruck ermöglicht das Modell eine Spritzpause und verhindert somit unnötige Spritzungen. Durch die Berechnung des Infektionsdruckes ist ein angepasster Kupfereinsatz möglich, was bei vergleichbar hohen Erträgen in vielen Fällen zu Kupfereinsparungen führt. Das Modell steht unter www.isip.de zur Verfügung

Entwicklung, Überprüfung und Praxiseinführung des Prognosemodells ÖKO-SIMPHYT zur gezielten Bekämpfung der Kraut- und Knollenfäule (P. infestans) im ökologischen Kartoffelanbau mit dem Ziel, den Einsatz kupferhaltige Fungizide auf ein Minimum zu reduzieren

Die anhand des entwickelten Prognosemodells ÖKOSIMPHYT angepassten Spritzintervalle und Kupferaufwandmengen ermöglichten in Jahren mit niedrigem Infektionsdruck im Vergleich mit routinemäßigen Applikationen gleichwertige Erträge bei reduzierten Kupfermengen. Vereinzelt waren so Einsparungen von bis zu 1000g Kupfer möglich. Durchschnittlich wurden 0,6 Behandlungen bzw. 535g Kupfer pro Hektar im Vergleich zur wöchentlichen Behandlung eingespart. Auch der Einsatz von neuen, kupferreduzierten Fungiziden nach den Modellempfehlungen erwies sich als erfolgreich, so dass hier ein weiteres Einsparpotential zur Verfügung steht. Zugang zum Modell ÖKOSIMPHYT ist für Landwirte und Berater unter www.isip.de im Internet möglich. Die Prognose hat sich als zuverlässiges Hilfsmittel bei der Krautfäulebekämpfung erwiesen. Einzig der bislang nicht mit ausreichender Sicherheit prognostizierbare primäre Stängelbefall kann in Einzelfällen zu einer verspäteten Spritzstart-Empfehlung führen. Hier herrscht weiterhin Forschungsbedarf, um die Prognose des Primärbefalls zu optimieren. Um diese Lücke zu schließen und den primären Stängelbefall, welcher bislang durch Pflanzenschutzmaßnahmen nicht verhindert werden kann, zu regulieren, wurde die Kupferbeizung des Saatgutes eingesetzt. Die hierzu in den Versuchen verwendete ULV-Methode ermöglicht eine Beizung der Pflanzknollen mit geringen Kupfermengen (120g/ha). Durch dieses Verfahren konnte der Stängelbefall vielfach signifikant reduziert werden, was sich in Mehrerträgen von bis zu 55% wiederspiegelte. Anhand molekularbiologischer Methoden konnte gezeigt werden, dass die latente, also nicht sichtbare Verseuchung des Pflanzgutes mit dem Krautfäuleerreger ein ernst zu nehmendes und bislang unterschätztes Problem darstellt. So waren durchschnittlich 11% der untersuchten Saatkartoffeln latent befallen und nur ein geringer Anteil der Pflanzgutpartien erwies sich als befallsfrei

Topical Flunixin Meglumine Effects on Pain Associated Biomarkers after Dehorning

Twenty-four calves were dehorned and treated with either topical flunixin meglumine formulated for systemic absorption or a placebo. Biomarkers associated with pain were evaluated for up to 72 hour after the dehorning procedure. Plasma cortisol concentrations, 90 minutes post-dehorning, and mechanical nociception threshold at the control site were the only tested biomarkers where a significant difference was demonstrated. No other differences of biomarkers between the two dehorned groups were observed for any time points. Although this product is easy to dose and dispense, its effects on pain biomarkers appears to be negligible

Testing of a Liquid Oxygen/Liquid Methane Reaction Control Thruster in a New Altitude Rocket Engine Test Facility

A relocated rocket engine test facility, the Altitude Combustion Stand (ACS), was activated in 2009 at the NASA Glenn Research Center. This facility has the capability to test with a variety of propellants and up to a thrust level of 2000 lbf (8.9 kN) with precise measurement of propellant conditions, propellant flow rates, thrust and altitude conditions. These measurements enable accurate determination of a thruster and/or nozzle s altitude performance for both technology development and flight qualification purposes. In addition the facility was designed to enable efficient test operations to control costs for technology and advanced development projects. A liquid oxygen-liquid methane technology development test program was conducted in the ACS from the fall of 2009 to the fall of 2010. Three test phases were conducted investigating different operational modes and in addition, the project required the complexity of controlling propellant inlet temperatures over an extremely wide range. Despite the challenges of a unique propellant (liquid methane) and wide operating conditions, the facility performed well and delivered up to 24 hot fire tests in a single test day. The resulting data validated the feasibility of utilizing this propellant combination for future deep space applications

Altered Plasma Pharmacokinetics of Ceftiofur Hydrochloride in Cows Affected with Severe Clinical Mastitis

Ceftiofur is the most commonly used antimicrobial in lactating dairy cows. Recently, there has been an increase in the number of violative residues of ceftiofur in the tissues of cull dairy cows. This was the first project in a series of projects we will be completing aimed at characterizing the pharmacokinetics of ceftiofur in disease challenged animals. The results of this study indicate that diseased animals have lower plasma concentrations and altered pharmacokinetics compared to healthy animals. Future work will investigate the influence of altered pharmacokinetics on the presence of violative residues

Compost for Columbus: A Policy Benchmarking Project

Course Code: ENR/AEDE 4567The purpose of this report is to help the Compost Exchange and other composting stakeholders better understand how composting services can be increased in Central Ohio amid the landscape of policy and infrastructure dynamics that influence the economics and logistics of composting services. In order to do so, our team benchmarked other cities that have implemented waste bans, researched current compost policies and regulations statewide and in Central Ohio, examined the demographics of Ohio suburbs to identify likely communities where composting can be enhanced, considered political barriers to composting policy, and examined infrastructure dynamics, particularly in relation to the Solid Waste Authority of Central Ohio (SWACO). We conducted key informant interviews with staff at SWACO, Ohio Environmental Protection Agency (EPA), Ohio State University, and other municipalities to complement information we obtained through literature and online research, and we combined the results from all of these methods to produce a list of recommendations for how to improve composting in Central Ohio. Seven cities in the United States currently have food waste bans that serve as a benchmark to compare to a Central Ohio baseline. Austin, TX proved to be the most similar city to Columbus that currently has a food waste ban. Analysis of local demographics provided perspective on which composting policies might be most likely to be developed around Central Ohio. Key informant interviews added detail to our understanding and also provided a number of specific recommendations. Key barriers to food waste policies being passed in Central Ohio are political considerations, infrastructure, contamination, funding, and enforcement. As Central Ohio does not have any current food waste policies, this project focused on the steps necessary to prepare for one but also considered future barriers. This report highlighted recommendations to overcome these barriers, with a focus on collaboration between government agencies, the private sector, and stakeholders to efficiently use resources and support available.Academic Major: Environment, Economy, Development, and Sustainabilit

3D molecule generation by denoising voxel grids

We propose a new score-based approach to generate 3D molecules represented as atomic densities on regular grids. First, we train a denoising neural network that learns to map from a smooth distribution of noisy molecules to the distribution of real molecules. Then, we follow the neural empirical Bayes framework (Saremi and Hyvarinen, 19) and generate molecules in two steps: (i) sample noisy density grids from a smooth distribution via underdamped Langevin Markov chain Monte Carlo, and (ii) recover the "clean" molecule by denoising the noisy grid with a single step. Our method, VoxMol, generates molecules in a fundamentally different way than the current state of the art (ie, diffusion models applied to atom point clouds). It differs in terms of the data representation, the noise model, the network architecture and the generative modeling algorithm. Our experiments show that VoxMol captures the distribution of drug-like molecules better than state of the art, while being faster to generate samples

Association between antimicrobial drug class for treatment and retreatment of bovine respiratory disease (BRD) and frequency of resistant BRD pathogen isolation from veterinary diagnostic laboratory samples

Although 90% of BRD relapses are reported to receive retreatment with a different class of antimicrobial, studies examining the impact of antimicrobial selection (i.e. bactericidal or bacteriostatic) on retreatment outcomes and the emergence of antimicrobial resistance (AMR) are deficient in the published literature. This survey was conducted to determine the association between antimicrobial class selection for treatment and retreatment of BRD relapses on antimicrobial susceptibility of Mannheimia haemolytica, Pasteurella multocida, and Histophilus somni. Pathogens were isolated from samples submitted to the Iowa State University Veterinary Diagnostic Laboratory from January 2013 to December 2015. A total of 781 isolates with corresponding animal case histories, including treatment protocols, were included in the analysis. Original susceptibility testing of these isolates for ceftiofur, danofloxacin, enrofloxacin, florfenicol, oxytetracycline, spectinomycin, tilmicosin, and tulathromycin was performed using Clinical and Laboratory Standards Institute guidelines. Data were analyzed using a Bayesian approach to evaluate whether retreatment with antimicrobials of different mechanistic classes (bactericidal or bacteriostatic) increased the probability of resistant BRD pathogen isolation in calves. The posterior distribution we calculated suggests that an increased number of treatments is associated with a greater probability of isolates resistant to at least one antimicrobial. Furthermore, the frequency of resistant BRD bacterial isolates was greater with retreatment using antimicrobials of different mechanistic classes than retreatment with the same class. Specifically, treatment protocols using a bacteriostatic drug first followed by retreatment with a bactericidal drug were associated with a higher frequency of resistant BRD pathogen isolation. In particular, first treatment with tulathromycin (bacteriostatic) followed by ceftiofur (bactericidal) was associated with the highest probability of resistant M. haemolytica among all antimicrobial combinations. These observations suggest that consideration should be given to antimicrobial pharmacodynamics when selecting drugs for retreatment of BRD. However, prospective studies are needed to determine the clinical relevance to antimicrobial stewardship programs in livestock production systems