Digestive System Diseases Commons^™

Opioid Tolerance And Withdrawal In The Mouse Colon, James Fune

Theses and Dissertations

Constipation is a major clinical obstacle associated with opioids, prompting patients to discontinue treatment due to pain, discomfort, and psychosocial stressors. Moreover, chronic users become tolerant to the analgesic effects of opioids, but not to their constipating effects. Upon cessation of long-term treatment, serious diarrhea–among other somatic signs of withdrawal–may ensue. These symptoms become a driving factor for relapse, causing patients to restart opioid treatment. In this study, we aim to understand mechanisms that contribute to opioid tolerance and withdrawal in the colon. Previous findings suggest that constipation occurs partly due to the colon’s lack of tolerance to opioids’ inhibitory …

Prevalence Of The Hypervirulent Nap1/Bi/027 Strain Of C. Difficile In Southwestern Virginia And Risk Factors Associated With Infection, Andrew O. Hanna, Anthony Baffoe-Bonnie, Shikha Vasudeva

Graduate Medical Education (GME) Resident and Fellow Research Day Posters

C. difficile infection (CDI) incidence has increased over the last several decades. The BI/NAP1/027 ribotype was discovered in 2005 and has since been responsible for multiple outbreaks in the US and Canada. This subtype of C. Difficile is known to be more virulent in vivo and produce more severe disease. Limited regional data of the prevalence of this ribotype is available, which could help guide treatment. Using infection control data from a large regional hospital and a VA medical center, this study documented the prevalence of the 027 ribotype in Southwest Virginia. Patients were included if they were tested at …

Inhibition Of Cancer Stem Cells By Glycosaminoglycan Mimetics, Connor P. O'Hara

Theses and Dissertations

Connor O’Hara July 29, 2019

Inhibition of Cancer Stem Cells by Glycosaminoglycan Mimetics

In the United States cancer is the second leading cause of death, with colorectal cancer (CRC) being the third deadliest cancer and expected to cause over 51,000 fatalities in 2019 alone.¹ The current standard of care for CRC depends largely on the staging, location, and presence of metastasis.² As the tumor grows and invades nearby lymph tissue and blood vessels, CRC has the opportunity to invade not only nearby tissue but also metastasize into the liver and lung (most commonly).³ The 5-year survival rate …

Understanding The Role Of Phosphoinositide 3-Kinase And Its Function As A Driving Force Behind The Er Stress Response In Fibrostenotic Crohn’S Disease-Affected Ileal Smooth Muscle Cells, Prashant Yadav

Theses and Dissertations

Crohn’s disease (CD) affects about 780,000 people in the United States alone, and it is estimated that 6-15 per 100,000 persons will receive a diagnosis of this disease each year. There currently is no cure for Crohn’s disease, and available medical therapies simply serve to alleviate the inflammation. This does not help treat fibrostenosis that Crohn’s disease patients may develop, which can only be treated surgically. Finding alternatives to treat CD requires an understanding of mechanisms at the biochemical level. In this thesis, we attempted to gain a better understanding of certain pathways found to be active in Crohn’s disease-affected …

Epigenetic Silencing Of Socs3 Expression Contributes To Fibrosis In Crohn’S Disease, Emily T. Marshall, Chao Li, John K. Kuemmerle

MD Student Summer Research Fellowship Program Posters

Identified risk polymorphisms affecting the Jak-STAT3 pathway in patients with Crohn’s disease could affect TGF-β1 and collagen I expression and in the pathway’s negative regulator, SOCS3. Genetic factors, however, account for only ~25% of disease. Epigenetic events also shape gene expression. Recent experiments showed that autocrine IL-6 production in mesenchymal cells, subepithelial myofibroblasts (SEMF) and muscle cells, of patients with fibrostenotic Crohn’s disease causes sustained Jak-STAT3 activity, excess TGF-β1 and Collagen I production and fibrosis. SOCS3 paradoxically decreased in these cells. We now identify epigenetic mechanisms that silence SOCS3 expression in SEMF of patients with fibrostenotic Crohn’s disease. In a …

Regulation Of Biliary Progenitor Cell Proliferation By Hedgehog Signaling In In Vivo And Ex Vivo Organoid Models, Nataliya Razumilava M.D., Junya Shiota M.D., Ramon Ocadiz-Ruiz Ph.D., Nureen Hanisah Mohamad Zaki, Kais Zakharia M.D., Michael Mathew Hayes, Juanita Lynn Merchant M.D., Ph.D.

Hepatobiliary Cancers: Pathobiology and Translational Advances

No abstract provided.

Commonly Used H1 And H2 Histamine Receptor (Hr) Blockers Decrease Cholangiocarcinoma Xenograft Tumor Growth, Angiogenesis And Emt, Lindsey Kennedy, Laura Hargrove, Jennifer Demieville, Walker Karstens, Steven Smith, Heather Francis

Hepatobiliary Cancers: Pathobiology and Translational Advances

No abstract provided.

Short And Long Chain Free Fatty Acids Differentially Regulate Glucagon-Like Peptide-1 And Peptide Yy Transcript Levels In Enteroendocrine Cells (Stc-1), Colin M. Catherman

Theses and Dissertations

The regulation of glucagon-like peptide-1 and peptide YY hormone levels are regulated based on different influential factors, but primarily levels are dependent upon ingested food content. As meals today become more fat-enriched, there is greater requirement for evaluation of these hormones that regulate insulin and satiety levels within the body. We have shown that the gene expression transcript production of glucagon-like peptide-1 and peptide YY are modulated by different concentrations, and times of short-chain fatty acids and long-chain fatty acids. Although the peptide hormone levels have the influential physiological role on effector tissue, the regulation of these hormones begins at …

Effects Of Brain-Derived Neurotrophic Factor And Its Signaling Pathway On Sensory Neuronal Activation During Colitis, Fiza Hashmi

Theses and Dissertations

Visceral hypersensitivity is the heightened response to sensory stimuli. Visceral sensations are transmitted through primary afferent neurons in the dorsal root ganglion (DRG) and the sensitization of the neural pathway leads to modification in spinal ascending and descending neurons. The aim of this investigation is to determine the effects of brain-derived neurotrophic factor (BDNF) and its signaling pathway on sensory neuronal activation during colitis. In order to evaluate this, levels of calcitonin-gene related peptide (CGRP), a neuropeptide marker for nociceptive transmission, and phosphorylated cAMP-response element binding protein (pCREB), a molecular switch in neuronal plasticity, were studied in response to BDNF …