Using tissue samples obtained from a previous study, the effect of naproxen on the gene expression profiles of antral mucosal tissue will be assessed. We hypothesize that there will be distinct changes in the gene expression profiles of samples taken from individuals treated with naproxen versus samples taken from individuals treated with placebo.

We will use microarray technology to quantify the transcriptome-wide changes in gene expression in said-samples.

Inclusion Criteria:

• Healthy adult between the ages of 18 and 75 inclusive
• Written informed consent prior to undergoing any study procedures
• A physical examination which reveals no clinically significant abnormalities
• Female subjects of childbearing potential must be taking an acceptable form of contraceptive

Exclusion Criteria:

• Any mucosal breaks within 2 cm of pyloric channel seen on baseline endoscopy
• Any GDU or >5 gastroduodenal erosions at baseline endoscopy
• CXB, CPG, ASA, or NS-NSAID use within the prior 2 weeks
• Previous gastrointestinal ulcer
• Hypersensitivity or allergy to NSAIDs, ASA, CPG, CXB or other contraindication to taking treatments
• Baseline complaints of abdominal pain, nausea, and/or cramping
• Any acid blocking medication including antacids, H-2 receptor blocker within the prior 2 weeks, or PPI use within the prior 30 days
• Corticosteroids use within the prior 60 days
• Any documented bleeding tendency
• Has taken warfarin within the prior 60 days
• Three or greater alcoholic beverages daily
• History of cerebro-vascular event