David Welsh, MD, received training in Internal Medicine at Vanderbilt University Medical Center before completing a fellowship in Pulmonary and Critical Care at LSU. His clinical interests include HIV-associated lung disorders and Chronic Obstructive Pulmonary Disease (COPD) / emphysema. His research activities range from laboratory investigations to clinical studies. His laboratory focuses on the biology of adult bone marrow derived stem cells as it relates to lung disease. Ongoing projects use pre-clinical models to determine the role of deficient stem cell trafficking to the lung in the pathogenesis of emphysema and to define the mechanisms involved in stem cell mobilization and engraftment in the lung.  His translational research interests include the role of CD44 in bone marrow stem cell function in human emphysema. Additionally, Dr. Welsh serves as Associate Director of the Louisiana Healthy Aging Study, for which he has developed a panel of fitness indices that may function as genetic and metabolic determinants of successful aging.