Leigh Darryl Quarles

My major interests include: (1) functional characterization of a novel cation sensing receptor in bone, (2) identification of a possible bone-kidney hormonal axis that regulates phosphate transport and mineralization, (3) discovery of Cbfa1 transcription factor isoforms that likely differentially regulate osteoblast differentiation, (4) establishing clinical parameters for managing secondary hyperparathyroidism. Finally, in collaboration with Dr. Peter Conlon, I participated in the identification of familial forms of focal and segmental glomerulosclerosis. I am currently involved in working with Dr. Michelle Winn, a Nephrology fellow and Dr. Vance in the Center for Human Genetics on a project to positionally clone the gene for autosomal dominant FSGS.

Specifics of Laboratory Research:

1. Isolation and cloning of the calcium sensing receptor in osteoblast.
2. Defining the functional role and regulation of Cbfa1 isoforms in osteoblast development in vitro.
3. Establishing the function of PHEX in osteoblasts.
4. Developing retroviral vectors for transfection of osteoblasts.

Description of Clinical Trials:

1. Prospective clinical trial evaluating calcitriol and calcium in the treatment of mild secondary hyperparathyroidism in dialysis patients.


Special Areas of Expertise or National Recognition:

I have special expertise in the areas of bone histomorphometry, and molecular and cellular biology of the osteoblast. I am currently a member of the Orthopedic and Musculoskeletal (ORTH) Study Section. I am also the Deputy Editor for the Journal of Bone and Mineral Research. I have given lectures at national meetings, been visiting professor at a number of institutions, conducted training courses for nephrology fellows, and organized workshops at both the American Society of Nephrology and American Society of Bone and Mineral Research. In 1999, I am an invited speaker at the American Society of Nephrology annual meeting. Moreover, I have authored the renal osteodystrophy section of the electronic textbook, UP-TO-DATE in Medicine.

Key Words: Bone histomorphometry, bone and mineral metabolism, cation-sensing receptor, molecular biology, osteoblast differentiation, renal osteodystrophy, Retreoviral Expression Vectors