Gastroenterology Commons^™

The Role Of Inflammation In Colitis-Associated Cancer, Hayley Good

Electronic Thesis and Dissertation Repository

Colitis-associated cancer (CAC) is a major complication associated with Inflammatory bowel disease (IBD). Unfortunately, there are currently few, if any, effective chemopreventative strategies against CAC. Furthermore, the exact mechanism by which inflammation leads to CAC remains poorly understood. In this thesis, we focus on two inflammatory signaling pathways, the cyclooxygenase (COX) and NF-κB pathways, that have been shown to link inflammation and cancer. For instance, non-steroidal anti-inflammatory drugs (NSAIDs) that target COX-1 and/or -2 have previously been shown to be effective in chemoprevention of sporadic colorectal cancer. However, the ability of NSAIDs to prevent CAC has not fully been explored. …

Force Application During Colonoscopy As A Marker Of Competence: Development Of A Novel Training Device, Jeffrey D. Hawel

Electronic Thesis and Dissertation Repository

Colonoscopy is a technically challenging procedure to learn. The colonoscope is prone to forming loops in the colon, which can lead patient discomfort and even perforation. We hypothesized that expert endoscopists use techniques to avoid loop formation, and identify and straighten loops earlier, and thus exert less force.

Using a physical colon simulator model, electromagnetic tracking markers were used to follow the motion of the colon as the scope was advanced. Attending physicians exerted significantly lower mean colonic displacement than trainees.

To allow portability to any simulator, and even the clinical setting, we designed and tested the construct validity of …

Drug Response And Metabolism In Crohn's Disease, Aze Wilson

Electronic Thesis and Dissertation Repository

Inflammatory bowel disease (IBD) is an illness of chronic intestinal inflammation comprised of Crohn's disease (CD) and ulcerative colitis (UC). Specialists rely heavily on drugs that target a dysregulated immune system. There is a staggering degree of variation in drug response in CD. Our understanding of drug metabolism and response in IBD is limited. Gaining new insights into IBD-specific modifications of drug metabolism may allow for improved drug efficacy and reduced toxicity. Cytochrome P450 (CYP) 3A4 is the most relevant determinant of drug metabolism and exposure for medications prescribed today. CYP3A4 is highly expressed in the liver, but is also …

Development Of Clinical Prediction Models For Surgery And Complications In Crohn’S Disease, Leonard M. Guizzetti

Electronic Thesis and Dissertation Repository

Background and Objective: Crohn’s disease (CD)-related complications account for a substantial proportion of IBD-related healthcare expenditure. Identifying patients at risk for complications may allow for targeted use of early therapeutic interventions to alter this natural course. The objective of this project was to develop risk prediction models of CD-related surgery and complications.

Methods: Using data from the REACT cluster-randomized clinical trial (N=1898 from 41 community practices), prediction models were developed and internally validated for CD-related surgery and CD-related complications, defined as the first CD-related surgery, hospitalization or complication within 24 months. Performance of each model was assessed in terms of …