Request for Funding

Medical Student Research Fellowship for Summer 2001

Mentor: Howard Heller, M.D.

Department: Internal Medicine

Room number: CS6.104

Mail Code: 8885

Phone number: 214-648-2117

E-mail: Howard.Heller@utsouthwestern.edu

Project title: Importance of the Bone in Severe Absorptive Hypercalciuria

Human Subjects IRB approved project number: 0899 340

Animal subjects IRB approved project number (where applicable): n/a

Project Type: Patient-oriented research, controlled prospective trial

Brief Description of the Project:

Absorptive hypercalciuria (AH), the most common cause of nephrolithiasis, results from primary enhancement of intestinal calcium absorption. Interestingly, patients with severe forms of the disease also have low bone mass and negative calcium balance. Physiologic explanation for the contradictory bone loss in the setting of excessive intestinal calcium absorption has not been fully delineated.

The goal of this project is to better elucidate the pathophysiologic mechanisms for bone loss and hypercalciuria in severe AH to allow formulation of more rational treatment modalities. Each study below will compare patients with well-characterized severe AH against matched normal volunteers and subjects with immobilization hypercalciuria, a contrasting hypercalciuric condition in characterized by excessive bone resorption and low intestinal calcium absorption.

1) Bone biopsy and bone turnover markers to evaluate whether the primary problem is increased bone resorption or decreased bone formation.

2) Baseline physiologic evaluation including blood, 24-h urine, bone density, and determination of calcium absorption.

3) Response of urinary calcium to an agent that blocks intestinal calcium absorption

4) Response of urinary calcium to an agent that blocks bone resorption

Previous Research Activities or Publications with Medical Students:

Mark Doerner completed most of a project comparing the risk of stone formation between two diets. He gave an oral presentation of his work at the Student Research Symposium. A paper resulting from his work has been submitted for publication. Laura Greer completed much of a project comparing calcium absorption between 2 commercial supplements and placebo. Her work resulted in a publication (J Clin Pharmacol 2000, 40 (11): 1237-44).

Since the above project is a long-term study, 10 weeks will not allow you to write a publication based on your results. However, you will be exposed to all aspects of clinical and research in mineral metabolism, which will be particularly useful if you choose a career in clinical research. Students rotate in our clinics and are exposed to clinical mineral metabolism (diseases we follow include osteoporosis, osteomalacia, osteogenesis imperfecta, Paget's disease of the bone, kidney stones, and calcium disorders). Participating students are taught about clinical research. Moreover, they will be involved in patient recruitment, data entry and monitoring and data analysis.

Return to UT Southwestern Homepage

Return to Student Research Projects Index