Assistant Director Core Laboratory; Assistant Director Metabolic Genetics Section Core Laboratory; Assistant Director Immunology/Serology Laboratory

• Core Laboratory
• Metabolic Genetics Section Core Laboratory
• Immunology/Serology Laboratory
• Laboratory Medicine
• Genetics and Genomic Medicine
• Patient Oriented Research
• Pathobiology

Dr. Dietzen received his Ph.D. in Biochemistry and Molecular Biology from Indiana University and completed postdoctoral research and clinical chemistry training at Washington University. Previously he was a Development Chemist at DuPont Diagnostics and the Director of Clinical Laboratories at the Memphis Veterans Affairs Medical Center.

Dr. Dietzen's basic research interests lie in cholesterol and sphingolipid-rich domains within the plasma membrane referred to as lipid rafts. The goal of the research is to define the role that these membrane domains play in both normal and pathologic physiology. We are actively studying the influence on the membrane environment on the first step of the coagulation cascade, factor VIIa/tissue factor, and its inhibition by tissue factor pathway inhibitor (TFPI). By differentially targeting TFPI to lipid raft and and non-raft portions of the plasma membrane we hope to understand the role of lipid rafts in a) the function of TFPI, b) the degradation of tissue factor, and c) transmembrane signaling by tissue factor. We are also exploring the role of lipid rafts in maintaining the asymmetric distribution of phosphatidylserine across the plasma membrane.

Dr. Dietzen is also active in the assessment of the analytic performance and diagnostic utility of a variety of laboratory tests including drug of abuse immunoassays and thyroid function tests.

Education

• B.S., Marian College, Indianapolis, In., 1986
• Ph.D., Indiana University, 1992

Training

• Clinical Chemistry Fellowship, Washington University School of Medicine, 1992-1995

Licensure and Board Certification

• American Board of Clinical Chemistry, 1997

Selected Publications

1. Dietzen DJ, Jack GG, Page KP, Tetzloff TA, Hall CL, and Mast AE: Localization of tissue factor pathway inhibitor to lipid rafts is not required for inhibition of factor VIIa/tissue factor activity. Thromb Haemost 2003; 89:65-73.

2. Dietzen DJ, Queen SF, and Solomon SS: Matrix-dependent bias in total thyroxine measurement on the Beckman Access. Clin Chimica Acta 2002; 316:171-174.

3. Dietzen DJ, Ecos K, Friedman D, and Beason, S: Positive Predictive Values of Abused Drug Immunoassays on the Beckman Synchron in a Veteran Population. J Anal Tox 2001; 25:174-178.

4. Monier S, Dietzen DJ, Hastings WR, Lublin DM and Kurzchalia TV: Oligomerization of VIP21-caveolin is stabilized by long chain fatty acylation or cholesterol. FEBS Letter 1996; 388:143-149.

5. Dietzen DJ, Hastings WR and Lublin DM: Caveolin is palmitoylated on multiple cysteine residues: palmitoylation is not necessary for localization of caveolin to caveolae. J Biol Chem 1995; 270:6838-6842.

6. Dietzen DJ and Davis EJ: Oxidation of pyruvate, malate, citrate, and cytosolic reducing equivalents by AS-30D hepatoma mitochondria. Arch Biochem Biophys 1993; 305:91-102.