David Y. Graham, M.D.
Department of Medicine-Gastroenterology
Interaction of infectious agents and the gastrointestinal tract
The two pathogens that we focus on are Helicobacter pylori and Mycobacterium paratuberculosis. H. pylori is known to be the cause of gastritis and peptic ulcer disease, and the infection is closely related to gastric carcinoma in primary gastric lymphoma. M. paratuberculosis is thought to be intimately related to Crohn's disease and possibly to sarcoidosis.
The Helicobacter program is comprehensive, and it covers areas such as new therapies, the epidemiology and transmission of the infection, the molecular epidemiology of the infection within populations and within families, as well as evolution of potential virulence factors and their role in disease pathogenesis. We have identified an important new proinflammatory virulence factor; an outer membrane protein we designated as oipA and are currently evaluating it role in disease causation and where it interacts in the signal transduction pathway for IL-8 production. The program uses human subjects, patients, cell lines, and animal models.
The focus of our clinical research relates to endoscopy including peptic ulcer disease, the effect of NSAIDs on the gastrointestinal tract, GI bleeding, and esophageal disease.
Baylor College of Medicine
One Baylor Plaza
Houston, TX 77030
M.D., Baylor University College of Medicine
Residency, Baylor College of Medicine
Tabassam FH, Graham DY, Yamaoka Y. OipA plays a role in Helicobacter pylori-induced focal adhesion kinase activation and cytoskeletal re-organization. Cell Microbiol 2008;10:1008-1020.
Linz B, Balloux F, Moodley Y, Manica A, Liu H, Roumagnac P, Falush D, Stamer C, Prugnolle F, van der Merwe SW, Yamaoka Y, Graham DY, Perez-Trallero E, Wadstrom T, Suerbaum S, Achtman M. An African origin for the intimate association between humans and Helicobacter pylori. Nature 2007;445:915-918.
Lu H, Wu JY, Beswick EJ, Ohno T, Odenbreit S, Haas R, Reyes VE, Kita M, Graham DY, Yamaoka Y. Functional and intracellular signaling differences associated with the Helicobacter pylori AlpAB adhesin from Western and East Asian strains. J Biol Chem 2007;282:6242-6254.
Salama NR, Gonzalez-Valencia G, Deatherage B, viles-Jimenez F, Atherton JC, Graham DY, Torres J. Genetic analysis of Helicobacter pylori strain populations colonizing the stomach at different times postinfection. J Bacteriol 2007;189:3834-3845.