Current Research

Dr. Benson Akingbemi:  Role of Estrogen, the ER, and Growth Factor Receptors in Mediating the Effects of Environmental Stressors in Leydig Cells. The laboratory has interests in male reproductive biology and toxicology.  There is evidence that excessive exposure of the male reproductive tract to estrogen and estrogen receptor (ER) agonists and antagonists exert detrimental effects on tissue function.  Thus, there is growing public concern that chemicals in the environment (food, air, water), which have estrogenic properties, may cause adverse effects on male reproductive health.  These compounds, which are designated xenoestrogens or endocrine disruptors, impact the endocrine profile by acting through steroid hormone receptors.  However, estrogenic signals are also mediated in part by growth factor receptors (e.g., epidermal growth factor and insulin growth factor-1 receptors, EGFR and IGF-1R).  Studies in our laboratory are designed to investigate the role of estrogen, the ER, and growth factor receptors in mediating the effects of environmental stressors in Leydig cells and disrupt the endocrine function of the testis. 

Dr. Frank Bartol:  Research in the Bartol lab focusses on identification of factors affecting uterine development and function with emphasis given to domestic ungulate species and companion animals.  Techniques employed include advanced histotechniques such as multispectral imaging and laser microdissection.  Recent publications and reviews of this work can be found via Pubmed using the following PMID numbers:  23136302, 23100582, 22033320, 22133692, 22959316

Dr. Pete W. Christopherson and Dr. Mary K. Boudreaux:   Inherited Diseases of Platelets. Our laboratory is involved with evaluating inherited platelet disorders in dogs, horses, and cows at the functional, biochemical, and molecular level. Students working in my laboratory would have exposure to a broad array of experiences ranging from blood collection, platelet isolation, platelet function testing, DNA isolation, PCR techniques, and flow cytometry.

Dr. Sue Duran:  Formulations and Preparations of Transdermal Pharmaceuticals to Treat Infectious Diseases  Various enhancers will be developed to treat infectious diseases from topical formulations.  The students will learn to formulate products, then test them in-vitro and in-vivo for efficacy.  Good manufacturing practices (GMP) will be taught to include product development, formulations and quality control to meet FDA standards.  This is a good introduction for a student who has interest in becoming an industrial pharmaceutical veterinarian.

Dr. Julie Gard and Dr. Ray Wilhite  - Research projects involving in vivo and vitro embryo development in the bovine. Also, research projects involving specific evaluation of the use of housing and management to create positive changes in the bovine and foot to prevent lameness as adults. The positive changes being evaluated are an increase in the amount of bone resulting in more surface area to bear weight, and an increase in the size and thickness of the digital cushion.

Dr. Reid Hanson:   A Study of the Visco-elastic and Friction Profiles of Equine Cartilage Surfaces. Our lab seeks to characterize and compare the material properties of cartilage located within various joints of the equine limb.  Specifically, we will investigate the visco-elastic stiffness and friction coefficient of the biphasic cartilage structure.  These biphasic properties affect the performance of the joint as it carries different loads and motions. This study is to determine if different types of joints with different ranges of motion possess different material properties best suited for the joint’s individual conditions. Analyzing the various cartilage surfaces within each joint and between joints will lead to a better understanding of the mechanisms controlling the performance of healthy joints in horses and humans. This data will be used to translate into the design of better artificial joints.

Articular cartilage samples will be extracted from a recently deceased horse and analyzed in the Multiscale Tribology Laboratory in Mechanical Engineering. The tests will be performed using a CETR-UMT-3 high load heavy duty tribometer which is capable of performed indentation tests on the cartilage and rotating friction tests. The indentation tests will measure stiffness by recording the force versus displacement curves of a punch as it is pressed into the cartilage.  The friction coefficient of cartilage samples will be measured by either sliding a sample of cartilage against a metal probe or against another sample of cartilage, while recording normal and tangential forces.  In addition, a Veeco Dektak 150 Stylus Surface Profilometer fitted with the N-Lite Low Force package and 3-D mapping option will be used to measure the surface roughness of the cartilage to the nanoscale level.

Dr. Michael H. Irwin and Dr. Carl A. Pinkert:  Genetic Engineering of Animals. Ongoing studies revolve around innovative approaches toward manipulation of mitochondrial genetics in mice, swine and cattle. Using gene transfer techniques targeting the mitochondrial DNA (mtDNA) genome, we are developing genetically modified animal models of: 1) increased production efficiency – harnessing mitochondrial genetics to enhance metabolic and production performance and 2) severely debilitating (and often lethal) human disorders caused by genetic mutations that affect mitochondrial function. Our genetically altered animal models will be used to provide a greater understanding of mitochondrial dynamics and pave the way for a host of basic and translational technologies including targeted gene therapies. Possible summer projects will focus on: 1) animal characterizations, 2) developing molecular/cloning skills and 3) participating in the creation of engineered laboratory and domestic animal models.

Dr. Jacob Johnson.  Avian Anesthesia and Pain Management. The drugs available to provide balanced anesthesia to birds are limited and most anesthesia has been provided through the exclusive use of inhalants, such as Isoflurane. While this approach has been overall effective, it is not ideal as the high concentrations needed to produce complete immobility in the face of surgical stimulation suppress the ventilatory and cardiovascular system. I am investigating two new drugs in avian anesthesia: dexmedetomidine and rocuronium. Opioid analgesics have variable success in providing intraoperative analgesia to avian species, so the hypothesis being investigated is that dexmedetomidine would provide more reliable analgesia without significant cardiovascular effects. Rocuronium is a paralytic that could allow for muscle relaxation, therefore reducing inhalant requirements. Because a bird’s iris is partially controlled by skeletal muscle it may also allow for ocular surgeries that require pupil dilation, such as cataract surgery.

Dr. Robert Judd: Regulation of Adipokine Trafficking and Secretion. Adipokines are proteins secreted primarily by adipose tissue and have been shown to regulate energy metabolism and consumption. Over the past 9 years, we have been particularly interested in the physiological role and regulation of the adipokines resistin, leptin and adiponectin. Adiponectin has insulin sensitizing and anti-atherogenic properties which make it an excellent marker of the metabolic syndrome and cardiovascular disease. However, little is known about the factors which regulate adiponectin synthesis and secretion. Recent investigations from our laboratory suggest that a novel G-protein coupled receptor for niacin (vitamin B3) (GPR109A) decreases lipolysis and increases adiponectin secretion from adipocytes in a coordinated fashion. Other studies from our laboratory and others have shown the involvement of other G-protein coupled receptors in the modulation of lipolysis. However, there is no information regarding the regulation of adiponectin secretion. Studies conducted in the Summer of 2012 will be focused on identifying the downstream intermediates that are required for adiponectin secretion from the GPR109A receptor and other G-protein coupled receptors. The results of these studies will provide important information regarding the regulation and secretion of adiponectin and could lead to the development of pharmacological and molecular biology strategies to regulate lipolysis and adiponectin secretion. The prospective student will be exposed to a number of adipocyte cell and molecular biology techniques including: 3T3-L1 and primary adipocyte cell culture, rodent handling and care, electron microscopy, confocal microscopy, real-time polymerase chain reaction, western blotting and ELISAs.

Dr. Douglas Martin:  Molecular Therapy of Neurodegenerative Disease. The laboratory’s model of neurodegenerative disease is feline gangliosidosis, similar to human Tay-Sachs disease, a disorder in which abnormal function of lysosomes causes progressive nervous system dysfunction and death. Though first reported in 1881, Tay-Sachs disease remains virtually untreatable, and affected children die by 5 years of age after spending several years in a semi-vegetative state. However, new gene therapy strategies have been tested in mouse models of gangliosidosis with excellent results. Before inclusion in human clinical trials, new therapies are tested in the feline model for safety and therapeutic benefit. The laboratory employs a variety of experimental techniques including intracranial injection of therapeutic agents, MRI-based analyses of disease progression, and biochemical and molecular biological evaluation of therapeutic benefit. Students may participate in both experimental procedures and laboratory research. This work is part of an international effort of collaborative scientists and physicians, the Tay-Sachs Gene Therapy Consortium, whose goal is to begin gene therapy clinical trials in humans.

Dr. Amelia Munsterman and Dr. Reid Hanson:  Risk Factors and Complications of Colic in Horses.  Colic is a common intestinal disorder that affects horses evaluated on emergency by the equine veterinarian.  Our goal is to further identify common risk factors that may contribute to colic, as well as evaluate laboratory data and physical exam findings to determine any effect on prognosis and outcome.  Students working with us will have the opportunity to assist us in gathering epidemiologic and patient information to add to the growing data base on colic at Auburn.  A specific portion of this research will involve measurement of pressures in the abdominal cavity of the horse to further define normal values.  Abnormal abdominal pressures in humans have been linked to incisional infections, ileus and poor outcomes, however the effect of abdominal hypertension still being investigated in veterinary medicine.  As part of this research, students will be able to participate in examination and treatment of horses suffering from colic. 

Dr. Satyanrayana Pondugula:  Role of Pregnane Xenobiotic Receptor in Hepatic Drug Metabolism and Leydig Cell Steroidogenesis.   Pregnane xenobiotic receptor (PXR) is a promiscuous orphan nuclear hormone receptor that is activated by both endobiotics and xenobiotics, including steroids, clinically-used drugs, and environmental chemicals. The major function of PXR is to sense the presence of toxic substances in the body and in response upregulate the expression of hepatic drug metabolizing and transport proteins to detoxify and clear these substances from the body. The cellular mechanisms regulating PXR activity are largely unknown. We will investigate the cellular signaling pathways regulating PXR activity in hepatocytes.

Some environmental endocrine disruptors, which impair testosterone homeostasis, have been shown to bind to and activate PXR. However, it is not known whether PXR has a role in testicular Leydig cell steroidognesis and whether PXR activation impairs testicular steroidogenesis. We will study the role of PXR in rodent Leydig cell steroidognesis using in vitro and in vivo approaches.

Dr. Bruce F. Smith: Molecular Genetics Of Inherited Disease And Cancer.   Several projects are available in the area of gene therapy for muscular dystrophy and a variety of cancers.  In the area of muscular dystrophy, students may work directly with affected and carrier dogs assessing the disease and its progression.  In addition, the latest genetic approaches may be used to understand the basis of components of the disease.  Cancer projects include laboratory studies and pre-clinical and clinical trials for dogs with osteosarcoma, lymphoma, melanoma, mast cell tumor and breast cancer.  These studies involve the administration of gene therapy vectors and novel biological molecules, and the assessment of patient progress, as well as detailed laboratory assessments of the impact of the therapy.  Projects involve the use of a wide variety of techniques including RNA and DNA isolation, quantitative PCR amplification, cell culture and flow cytometry as well as animal handling, phlebotomy, tissue biopsy and necropsy.

Dr. Elizabeth Spangler:  Application of Thromboelastography (TEG®) to evaluate coagulation status in dogs.  TEG® is a method that evaluates coagulation in a whole blood sample, and thus includes contributions from both plasma coagulation factors and cellular elements (RBCs, platelets).  Modifications of the standard TEG® protocol have been developed to evaluate the effects of heparin on coagulation, and to isolate the contribution of platelets to clot formation (Platelet Mapping).   Future research projects will investigate the use of TEG to monitor hemostasis in dogs with various clinical abnormalities, as compared to standard coagulation tests.  In addition, in vitro studies are planned to examine the impact of therapeutic measures on TEG results.

Dr. Allison Stewart:   Interested students should have an interest in equine medicine and pharmacology. Previous horse handling ability is required. An antiseizure medication will be administered to 8 horses for 10 days. The selected student will assist with medication administration, collection and analysis of samples. Sample collection will be performed intermittently from previously placed jugular and intrathecal catheters. Some sampling days will require sample collection after hours so students must be willing to participate some evenings and some weekends. Time will also be spent in the pharmacology laboratory helping with sample analysis. 

Dr. Frederick van Ginkel:  Our research is focused on measuring and inducing mucosal and systemic immunity to infectious bronchitis virus, an avian pathogen that causes considerable economic losses in the poultry industry despite vaccination.  Specifically, we analyze the ability of IBV vaccines to generate protective immune responses in the mucosal compartment employing techniques such as quantitative RT-PCR, ELISA, ELISPOT assays and peptide arrays.

Dr. Robyn Wilborn and Dr. Aime Johnson:   Equine Theriogenology.   The student will be conducting a research project involving mares.  The project will involve heat/estrus suppression in mares by using a subcutaneous hormone implant.  The student will be responsible for placing the implants and evaluating estrus behavior in the mares using a stallion as well as trans-rectal palpation and blood collection twice weekly.  This is a follow-up project to a previous study using similar implants.