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600 Highland Ave - H6/5
Madison, WI 53792-4108
The major focus of the Eldridge Laboratory is integrative cardiopulmonary physiology and pathophysiology as it occurs in isolated heart-lung preparations, non-anaesthetized animals and humans, with specific applications to the effects of exercise, acute hypoxia, altitude, hyperbaria and environmental exposure (particulates, endotoxin and ozone). A center focus of our studies is novel regulatory mechanisms of the pulmonary microcirculation and there impact on pulmonary gas exchange. Currently, our specific research activities emphasize the following:
Structural and Functional Characterization and Regulation of Inducible Intrapulmonary Arteriovenous Shunt Pathways
We are investigating the effects of pulmonary vascular pressures and flows, oxygen tension, and vasoactive mediators on the recruitment of inducible intrapulmonary arteriovenous shunt pathways. These investigations involve measuring trans-pulmonary passage of various sized fluorescent-labeled polymer (confocal microscopy) and soda lime glass microspheres (micro-CT angiography) in isolated perfused and ventilated rat, and pig lungs. We are using contrast echocardiography to determine the prevalence and exercise-intensity dependence of intrapulmonary arteriovenous shunts in a large number of healthy male and female subjects with varying levels of VO2max and A-aDO2. We are also attempting to quantify the shunt fraction through the intrapulmonary arteriovenous channels at rest and with exercise in healthy humans using whole body 99mTc-labeled albumin macroaggregates (MAA) nuclear medicine scanning. We are conducting similar studies in non-anaesthetized pigs using neutron-activated, fluorescent-labeled polymer microspheres of various size ranges. We are also interested in the developmental aspect of these shunt pathways and what role they may play in the high incidence of cryptogenic stroke in the neonatal and pediatric populations. We are also interested in the role of inducible intrapulmonary shunts in other disease states such as bronchopulmonary dysplasia, hepatopulmonary syndrome and high altitude pulmonary edema. These research programs are supported by a NIH-NHLBI R01 HL086897 (Eldridge), an AHA Post-Doctoral Fellowship Award (Bate: post-doctoral fellow/Eldridge: mentor) and a NIH-NHLBI T32:Respiratory Neurobiology (Cramer: post-doctoral fellow /Eldridge mentor).
Cellular Therapies for Lung Injury and Disease
This is a new endeavor to test the safety, potency and efficacy of cellular therapies (specifically mesenchymal and embryotic stem cells) in a variety of lung diseases including bronchopulmonary dysplasia, lung fibrosis, and bronchoiltis obliterans following lung transplant. We use preterm, neonatal, pediatric and adult swine as our primary model. Our lung injury laboratory includes a Large Animal Cardiac Catheterization Laboratory, Large Animal Surgical Suite, and Piglet Intensive Care Unit. This program is supported by a NIH-NHLBI PACT Contract.
Diving Physiology and Medicine
Another major area of interest is the development of protective strategies following saturation dives using the UW Sheep Model. We are also investigating the mechanisms of decompression injury for both acute (neurological and respiratory) and chronic (dysbaric osteonecrosis) decompression injury using MRI (diffusion tensor imaging), and nuclear medicine scanning respectively. The Diving Physiology studies are funded by the DOD and US Navy.