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Our research interests revolve around the formation, maintenance, diseases and repair of bones and muscles. Our laboratory is pursuing research problems in three areas:
- Limb development and skeletal patterning.
- The roles of retinoids (vitamin A derivatives) in regulating cell and tissue function.
- Microgravity effects on musculoskeletal tissues in embryos and adults.
Our studies of limb development focus on the role of retinoic acid and its metabolism in establishing and modifying the pattern of skeletal development in the growing limb bud. Our work in this area focuses on chick embryos and involves in vivo microsurgery and grafting studies, tissue culture models of cell and tissue differentiation and metabolism, and molecular biologic approaches to understanding the roles of various gene products in differentiation, patterning and metabolism.
Our interest in retinoids is focused on our limb development studies as described above, involving HPLC fractionation and scintillation counting to trace the metabolism of retinoic acid by cells from various regions of the chick limb. We also use in situ hybridization to map developmental changes in the distribution of retinoid binding proteins in the developing limb, and recombinant DNA/eukaryotic expression vectors to examine the roles of some of these proteins in retinoid metabolism.
In a collaboration with Dr. Brenda Klement, we will have explored the effects of microgravity on nutrient flow through the cartilage matrix to the cartilage cells (chondrocytes) that normally maintain it. In normal gravity conditions, joint cartilages undergo cyclic compression and decompression with use. During compression, fluid is squeezed out into the joint cavity where it picks up oxygen and nutrients and releases wastes. During decompression, the refreshed fluid is reabsorbed into the viscous cartilage matrix. In the absence of gravity, compression and decompression naturally play less of a role in nutrient, oxygen and waste exchange. Under these conditions, factors affecting diffusion and flow take on greater importance in nourishing the chondrocytes than they do on earth. This project was carried out with the assistance of NASA scientists at the NASA/Glenn Research Center in Cleveland OH and will first involve developing an apparatus for studying nutrient flow.
Keywords: Limb bud, Cartilage, Embryology, Bone Histology, Muscle, Vitamin A, Chondrogenesis, Retinoids, Connective tissue, Muscle, Bone, Atrophy, beta-Adrenergic agents, Microgravity.
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