2006 merck/merial - School of Veterinary Medicine - Louisiana State ...

Markers of Oxidative Stress in plasma, laminar tissue, and skin of horses administered black walnutextractBrent Credille*, Laura Riggs1, Karolina Burda, Thomas Krunkosky.Department of Anatomy and Radiology, Department of Large Animal Medicine1, College of VeterinaryMedicine, University of Georgia, Athens GA 30602Evolving from multiple etiologies, laminitis is a complicated and somewhat poorly understood condition that affectsnumerous horses worldwide. Recent research suggests that oxidative stress may play a role in the acute phase of laminitis.Collectively, studies have demonstrated an increase in activated neutrophils, reactive oxygen species (ROS) andmyeloperoxidase levels in plasma, skin and laminar tissue from laminitic horses induced with Black Walnut HeartwoodExtract (BWHE). As a consequence of increased myeloperoxidase release and ROS production in skin and laminar tissue,multiple oxidant sensitive cellular signaling pathways may be upregulated. Our general hypothesis is that since the skin andthe lamina share a common developmental origin as part of the integument, both of these tissues are affected by the sameinflammatory events during the course of laminitis. With this in mind, the long term objective of this project is to develop anovel skin biopsy technique to detect animals at risk for developing laminitis. Specifically, we hypothesize that nitrotyrosineand 8-isoprostane levels, which are both markers of oxidative stress, are increased in tissues of laminitic horses. To test ourhypothesis, tissue samples from control horses and horses in which laminitis has been induced using BWHE will beinvestigated. Utilizing slot blot, western blot, and enzyme immunoassay (EIA) techniques, we will attempt to quantify theexpression of these compounds. The results of this study may help assist in the detection of acute laminitis and aid indeveloping more effective treatments during the early stages of the disease. Understanding the role of oxidative stress in skinand laminar tissue obtained from BWHE induced laminitic horses will help us understand the physiological events that leadto the acute onset of laminitis and assist veterinarians in detecting horses at risk for developing laminitis and institutetreatment before serious damage has occurred to the hoof tissue.A Novel Approach to Atypical Interstitial Pneumonia in feedlot cattle: Pancreatitis as an Etiology.Keith D. DeDonder* and Daniel U. ThomsonDepartment of Clinical Sciences, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506Atypical Interstitial Pneumonia (AIP) is a sporadic, respiratory disease of feedlot cattle. According to recentsurveys, AIP is the second leading cause of mortality in the feedlot. Treatment of AIP is unrewarding. Therefore preventionof this syndrome is key for saving millions of dollars for the beef industry. A specific etiology of AIP in feeder cattle to dateis unknown. It is agreed that the cause of AIP in feedlot calves is complex, probably involving many factors. A wide arrayof infectious and noninfectious etiologies have been proposed including but not limited to: feeding melengestrol acetate(MGA), Bovine Respiratory Syncytial Virus (BRSV), hypersensitivities, allergens, dust, toxic gases, bacterial pneumonia,and endotoxins. Rat models studying an equivalent disease in humans (Acute Respiratory Distress Syndrome or ARDS)have shown a link between pancreatitis and lung pathology similar to AIP. Feeder cattle are exposed to diets rich in solublecarbohydrates and fats 150 to 250 days. It has also been confirmed that cattle succumbing to AIP do so later in the feedingperiod (> 90 DOF) after some type of digestive upset. The type of diet and timing of the syndrome would lead one to thinkthat pancreatitis could be a possibility. Therefore the objectives of this study are to determine the prevalence of acute orsubacute pancreatitis in cattle confirmed with AIP. Live animals suffering from AIP will be transported to the Kansas StateUniversity Diagnostic Laboratory for a complete necropsy investigation. A complete diagnostic work up will be doneincluding complete blood counts, serum chemistry, bacteriology and histological examination. Results from this pilot studywill be used to direct future studies correlating AIP with pancreatitis.Ecotoxicogenomics of Small Mammal Populations in the Tri-State Mining DistrictJoy Delamaide 1 *, Lindsey Crawford 1 , Samantha M. Wisely Ph.D. 2 , Susan J. Brown Ph.D. 2College of Veterinary Medicine, Kansas State University 1Division of Biology, Kansas State University 2The Tri-State Mining District includes Cherokee County, which flourished from 1870-1970 because of its profitablelead and zinc production. Waste produced during mining exposed surrounding habitats to high levels of lead, zinc, andcadmium. The contamination was remediated for human habitation via the Cherokee County Superfund. Ecotoxicologicalassessment of the small mammal community will help evaluate if remediation was sufficient to restore healthy habitats.Peromyscus maniculatus and P. leucopus were trapped in the Neosho Wildlife Area (control) and Galena, KS (treatment).We trapped at each site for six nights using Sherman Live Traps. Fifty-nine animals were trapped, including P. leucopus, P.maniculatus, and Neotoma floridana. A Shannon Diversity index of 1.3 was calculated for the control site, compared to anindex of 1.2 for the treatment site. P. maniculatus collected in Galena had an average shorter left hind foot length (17.2 +/_0.2 mm (average +/- SE)) than those found at the control site (19.8 +/- 1.1 mm) (P= 0.04, U= 3.5). However, P. maniculatusin Galena did not have a lower average body weight (15.22 +/- 0.57 g) than P. maniculatus collected at the control site (20.896