Gastroenterology Commons^™

Intimin Likely Used To Cause Disease During Competition With Commensal Escherichia Coli, Dominique J. Richburg

Senior Honors Theses

The intimin gene in the Locus of Enterocyte Effacement (LEE) island of pathogenicity is the primary attachment mechanism in Citrobacter rodentium. Intimin is a bacterial adhesin (protein) that attaches to obtain a niche/nutrient and thrive within the intestine. Intimin was deleted within C. rodentium to study colonization and pathogenesis in the murine intestine. Additionally, C. rodentium is an attaching/effacing pathogen, and a useful murine model in understanding Enterohemorrhagic Escherichia coli (EHEC) infection in humans. E. coli and C. rodentium cause gastroenteritis in humans and mice, respectively. C. rodentium is a murine pathogen commonly used to model gastrointestinal disease because …

Treatment And Prevention Of Human Rotavirus (Hrv) In Developing Countries: The Potential Of Avian Immunoglobulin Y, Christa Brown

Senior Honors Theses

Rotavirus gastroenteritis is a leading cause of childhood mortality, killing ~1400 children younger than five daily, primarily through severe diarrheal dehydration. Eighty-five percent of this mortality occurs in developing countries where rotavirus vaccines are not widely implemented and are only partially effective. In those countries, it has proven difficult to implement the recommended supportive therapies like oral rehydration therapy (ORT) on a wide scale due to lack of both medical infrastructure and private economic investment combined with cultural bias against ORT. IgY targeting human rotavirus (anti-HRV IgY) shows potential as a passive immunotherapy that reduces rotavirus-associated morbidity and mortality, augments …

Primary Hepatic Carcinoid Tumor With Poor Outcome, Om Parkash, Adil Ayub, Buria Naeem, Sehrish Najam, Zubair Ahmed, Wasim Jafri, Saeed Hamid

Section of Gastroenterology

Primary Hepatic Carcinoid Tumor (PHCT) represents an extremely rare clinical entity with only a few cases reported to date. These tumors are rarely associated with metastasis and surgical resection is usually curative. Herein, we report two cases of PHCT associated with poor outcomes due to late diagnosis. Both cases presented late with non-specific symptoms. One patient presented after a 2-week history of symptoms and the second case had a longstanding two years symptomatic interval during which he remained undiagnosed and not properly worked up. Both these cases were diagnosed with hepatic carcinoid tumor, which originates from neuroendocrine cells. Case 1 …

Understanding Health Seeking Behavior Of Health Care Professionals In Tertiary Care Hospitals In Pakistan, Shazia Bana,, Javed Yakoob, Nourin Jivany, Asima Faisal, Humeira Jawed, Safia Awan

Section of Gastroenterology

Background: Health seeking behaviour refers to the behaviour of people towards seeking their own health through provided health services. The medical professionals are at a higher risk of avoiding health seeking behaviour because they believe they are aware of the diseases and their symptoms as well as the pharmaceutical management of the disease. The aim of this study was to understand the healthcare seeking behaviour of nurses and doctors as well as the factors affecting it in hospitals of a major city in a developing country. Methods: A cross-sectional study was designed and a self-report questionnaire was distributed to …

Effect Of The Time Of Day And Queue Position In The Endoscopic Schedule On The Performance Characteristics Of Endoscopic Ultrasound-Guided Fine-Needle Aspiration For Diagnosing Pancreatic Malignancies., Jason Korenblit, Danielle M Tholey, Joanna Tolin, David Loren, Thomas Kowalski, Douglas G. Adler, Julie Davolos, Ali A. Siddiqui

Division of Gastroenterology and Hepatology Faculty Papers

BACKGROUND AND OBJECTIVES: Recent reports have indicated that the time of day may impact the detection rate of abnormal cytology on gynecologic cytology samples. The aim of this study was to determine if procedure time or queue position affected the performance characteristics of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) for diagnosing solid pancreatic malignancies.

PATIENTS AND METHODS: We conducted a retrospective study evaluating patients with solid pancreatic lesions in whom EUS-FNA was performed. Three timing variables were evaluated as surrogate markers for endoscopist fatigue: Procedure start times, morning versus afternoon procedures, and endoscopy queue position. Statistical analyses were performed to determine …

Colorectal Cancer Prevention: Perspectives Of Key Players From Social Networks In A Low-Income Rural Us Region, Nancy E. Schoenberg, Kathryn Eddens, Adam Jonas, Claire Snell-Rood, Christina R. Studts, Benjamin Broder-Oldach, Mira L. Katz

Behavioral Science Faculty Publications

Social networks influence health behavior and health status. Within social networks, “key players” often influence those around them, particularly in traditionally underserved areas like the Appalachian region in the USA. From a total sample of 787 Appalachian residents, we identified and interviewed 10 key players in complex networks, asking them what comprises a key player, their role in their network and community, and ideas to overcome and increase colorectal cancer (CRC) screening. Key players emphasized their communication skills, resourcefulness, and special occupational and educational status in the community. Barriers to CRC screening included negative perceptions of the colonoscopy screening procedure, …

Differential Expression Of Pancreatic Protein And Chemosensing Receptor Mrnas In Nkcc1-Null Intestine, Emily M. Bradford, Kanimozhi Vairamani, Gary E. Shull

Internal Medicine Faculty Publications

AIM: To investigate the intestinal functions of the NKCC1 Na⁺-K⁺-2Cl cotransporter (SLC12a2 gene), differential mRNA expression changes in NKCC1-null intestine were analyzed.

METHODS: Microarray analysis of mRNA from intestines of adult wild-type mice and gene-targeted NKCC1-null mice (n = 6 of each genotype) was performed to identify patterns of differential gene expression changes. Differential expression patterns were further examined by Gene Ontology analysis using the online Gorilla program, and expression changes of selected genes were verified using northern blot analysis and quantitative real time-polymerase chain reaction. Histological staining and immunofluorescence were performed …

Therapeutic Effect Of Melatonin On Pediatric Functional Dyspepsia: A Pilot Study., Katherine Zybach, Craig A. Friesen, Jennifer V. Schurman

Manuscripts, Articles, Book Chapters and Other Papers

AIM: To study the effectiveness of melatonin vs placebo in children with functional dyspepsia (FD).

METHODS: The study was conducted as a double blind, randomized, placebo controlled crossover trial. Subjects were aged 8-17 years and diagnosed with FD based on Rome III criteria. All subjects had failed to respond to 4 wk of acid suppression. Subjects receive a continuous two weeks of placebo and a continuous two weeks of melatonin in an order blinded to the participant and the study team. A Global Clinical Score was obtained to assess changes in abdominal pain. Pain was self-reported to be worse (grade …

Structural And Evolutionary Analyses Show Unique Stabilization Strategies In The Type Iv Pili Of Clostridium Difficile, Kurt H. Piepenbrink, Grace A. Maldarelli, Claudia F. Martinez De La Pena, Tanis C. Dingle, George L. Mulvey, Amanda Lee, Erik Von Rosenvinge, Glen D. Armstrong, Michael S. Donnenberg, Eric J. Sundberg

Food for Health: Publications

Type IV pili are produced by many pathogenic Gram-negative bacteria and are important for processes as diverse as twitching motility, biofilm formation, cellular adhesion and horizontal gene transfer. However, many Gram-positive species, including C. difficile, also produce Type IV pili. Here, we identify the major subunit of the Type IV pili of C. difficile, PilA1, and describe multiple three-dimensional structures of PilA1, demonstrating the diversity found in three strains of C. difficile. We also model the incorporation of both PilA1 and a minor pilin, PilJ, into the pilus fiber. Although PilA1 contains no cysteine residues, and therefore cannot form the …

Differences And Similarities In The Clinicopathological Features Of Pancreatic Neuroendocrine Tumors In China And The United States: A Multicenter Study, Li-Ming Zhu, Laura Tang, Xin-Wei Qiao, Edward M. Wolin, Nicholas N. Nissen, Deepti Dhall, Jie Chen, Lin Shen, Yihebali Chi, Yao-Zong Yuan, Qi-Wen Ben, Bin Lv, Ya-Ru Zhou, Chun-Mei Bai, Jie Chen, Yu-Li Song, Tian-Tian Song, Chong-Mei Lu, Run Yu, Yuan-Jia Chen

Markey Cancer Center Faculty Publications

The presentation, pathology, and prognosis of pancreatic neuroendocrine tumors (PNETs) in Asian patients have not been studied in large cohorts. We hypothesized that the clinicopathological features of PNETs of Chinese patients might be different from those of US patients. The objectives of this study were to address whether PNETs in Chinese patients exhibit unique clinicopathological features and natural history, and can be graded and staged using the WHO/ENETS criteria.

This is a retrospective review of medical records of patients with PNETs in multiple academic medical centers in China (7) and the United States (2). Tumor grading and staging were based …

Modified Appleby Procedure With Arterial Reconstruction For Locally Advanced Pancreatic Adenocarcinoma: A Literature Review And Report Of Three Unusual Cases., Jessica A. Latona, Kathleen M. Lamb, Michael J. Pucci, Warren R. Maley, Charles J. Yeo

Department of Surgery Faculty Papers

BACKGROUND: Pancreatic body and tail ductal adenocarcinomas are often diagnosed with local vascular invasion of the celiac axis (CA) and its various branches. With such involvement, these tumors have traditionally been considered unresectable. The modified Appleby procedure allows for margin negative resection of some such locally advanced tumors. This procedure involves distal pancreatectomy with en bloc splenectomy and CA resection and relies on the presence of collateral arterial circulation via an intact pancreaticoduodenal arcade and the gastroduodenal artery to maintain prograde hepatic arterial perfusion. When the resultant collateral circulation is inadequate to provide sufficient hepatic and gastric arterial inflow, arterial …

Use Of Macrophage Inhibitory Cytokine-1 As A Biomarker In Screening And Surveillance Of Colorectal Neoplasia, Ethan Bortniker, Joseph C. Anderson

Dartmouth Scholarship

No abstract provided.

Genomic Diversity Of Epec Associated With Clinical Presentations Of Differing Severity, Tracy H. Hazen, Michael S. Donnenberg, Sandra Panchalingam, Martin Antonio, Anowar Hossain, Inacio Mandomando, John Benjamin Ochieng, Shahida Qureshi, Farheen Quadri, Anita K. M. Zaidi

Department of Paediatrics and Child Health

Enteropathogenic Escherichia coli (EPEC) are diarrhoeagenic E. coli, and are a significant cause of gastrointestinal illness among young children in developing countries. Typical EPEC are identified by the presence of the bundle-forming pilus encoded by a virulence plasmid, which has been linked to an increased severity of illness, while atypical EPEC lack this feature. Comparative genomics of 70 total EPEC from lethal (LI), non-lethal symptomatic (NSI) or asymptomatic (AI) cases of diarrhoeal illness in children enrolled in the Global Enteric Multicenter Study was used to investigate the genomic differences in EPEC isolates obtained from individuals with various clinical outcomes. A …

Does Normalizing Gut Microbiota Decrease Exacerbation In Ibd, Franchesca Cook

Physician Assistant Scholarly Project Posters

Inflammatory bowel disease (IBD) including Crohn’s Disease (CD) and Ulcerative Colitis (UC) has become a more common diagnosis. The number of screenings for IBD has increased, drawing more attention to finding the cause. Researchers are finding that a change in diet, increased stress levels, and overuse of antibiotics may contribute to IBD by changing the gut microbiota (Skrautvol et al., 2011; Bernstein, 2010). Prebiotics and probiotics, an individualized anti-inflammatory diet, and lifestyle modification to decrease stress are all currently undergoing evaluation to discover a possible role in the reversal of IBD insult to the normal flora of the gut. This …

A Review Of Barrett's Esophagus, Suzanne M. Zayan

Physician Assistant Scholarly Project Posters

Barrett’s Esophagus is a premalignant condition that predisposes patients to the development of esophageal adenocarcinoma.

•Esophageal adenocarcinoma dramatically rising over several decades; survival rates of less than 17% in a five year period.

•Management and treatment continues to evolve: use of radio-frequency ablation effective to treat low grade dysplasia

•Studies of risk factors and treatment options explored:

Efficacy and durability of endoscopic radiofrequency ablation for treatment of low grade dysplasia as option for metaplasia eradication

–Gastrointestinal pathologist expert reviews ensure identification of dysplasia prior to treatment
–Appropriate endoscopic surveillance intervals
–Gastroenterology guidelines for screening and surveillance for long term management …

Screening Of Exosomal Micrornas From Colorectal Cancer Cells, Cillian Clancy, Sonja Khan, Claire L. Glynn, Emma Holian, Peter Dockery, Pierce Lalor, James A.L. Brown, Myles Joyce, Michael J. Kerin, Roisin M. Dwyer

Forensic Science Publications

BACKGROUND: Cells release extracellular membrane vesicles including microvesicles known as exosomes. Exosomes contain microRNAs (miRNAs) however the full range within colorectal cancer cell secreted exosomes is unknown. OBJECTIVE: To identify the full range of exosome encapsulated miRNAs secreted from 2 colorectal cancer cell lines and to investigate engineering of exosomes over-expressing miRNAs. METHODS: Exosomes were isolated from HCT-116 and HT-29 cell lines. RNA was extracted from exosomes and microRNA array performed. Cells were engineered to express miR-379 (HCT-116-379) or a non-targeting control (HCT-116-NTC) and functional effects were determined. Exosomes secreted by engineered cells were transferred to recipient cells and the …

Electrophysiological Changes In Patients With Liver Cirrhosis In A Tertiary Care Hospital In Karachi, Pakistan, Om Parkash, Ghulam Rehman Mohyuddin, Adil Ayub, Irfan Nazir, Arslan Arif Maan, Saeed Hamid

Section of Gastroenterology

Background: Electrophysiological changes in cirrhosis are well known but least investigated especially in our country hence we wanted to see electrophysiological changes especially QT interval in cirrhotic patients.

Methods: A cross-sectional study was conducted at Aga Khan University Hospital Karachi (AKUH) in which medical records (duration 2008-2010) of cirrhotic patients were reviewed.

Results: Three hundred and eighty cirrhotic patients' charts were studied, 227 (59.7 %) were male and mean age of this cohort was 52.8±12.6 years. The most common cause for CLD was Hepatitis C (CHC) in 260 (68.4%), NBNC in 56(14.7%) and HBV in 51 (13.4%). Only 225 …

Selective Induced Altered Coccidians To Immunize And Prevent Enteritis, Helieh S. Oz

Physiology Faculty Publications

Microbiomic flora in digestive tract is pivotal to the state of our health and disease. Antibiotics affect GI, control composition of microbiome, and shift equilibrium from health into disease status. Coccidiosis causes gastrointestinal inflammation. Antibiotic additives contaminate animal products and enter food chain, consumed by humans with possible allergic, antibiotic resistance and enigmatic side effects. Purposed study induced nonpathogenic, immunogenic organisms to protect against disease and abolish antibiotics’ use in food animals and side effects in man. Diverse species of Coccidia were used as model. Immature organisms were treated with serial purification procedure prior to developmental stages to obtain altered …

Clinical Practice Guidelines On The Management Of Variceal Bleeding, Javed Iqbal Farooqi, Hasnain Ali Shah, Anwaar A. Khan, Amjad Salamat, Altaf Alam, Abbas Khan Khattak, Nazish Butt, Muhammed Salih, Sher Sher Rehman, Arif Amir Nawaz, Nasir Khokhar, Ghias-Un-Nabi Tayyab, Javed Aslam Butt, Kashif Malik, Shakeel Ahmad Mirza, Mohammad Akram

Department of Medicine

Gastroesophageal variceal bleeding occurs in 30 - 50% of patients of liver cirrhosis with portal hypertension, with 20-70% mortality in one year. Therefore, it is essential to screen these patients for varices and prevent first episode of bleeding by treating them with β-blockers or endoscopic variceal band ligation. Ideally, the patients with variceal bleeding should be treated in a unit where the personnel are familiar with the management of such patients and where routine therapeutic interventions can be undertaken. Proper management of such patients include: initial assessment, resuscitation, blood volume replacement, vasoactive agents, prevention of associated complications such as bacterial …

Consistent Prebiotic Effect On Gut Microbiota With Altered Fodmap Intake In Patients With Crohn's Disease: A Randomised, Controlled Cross-Over Trial Of Well-Defined Diets, Emma P. Halmos, Claus T. Christophersen, Anthony R. Bird, Susan J. Shepherd, Jane G. Muir, Peter R. Gibson

Research outputs 2014 to 2021

OBJECTIVES:

Altering FODMAP (fermentable oligosaccharides, disaccharides, monosaccharides and polyols) intake has substantial effects on gut microbiota. This study aimed to investigate effects of altering FODMAP intake on markers of colonic health in patients with Crohn’s disease.

METHODS:

After evaluation of their habitual diet, 9 patients with clinically quiescent Crohn’s disease were randomised to 21 days of provided low or typical (“Australian”) FODMAP diets with ≥ 21-day washout in between. Five-day fecal samples were collected at the end of each diet and analyzed for calprotectin, pH, short-chain fatty acids (SCFA) and bacterial abundance. Gastrointestinal symptoms were recorded daily.

RESULTS:

Eight participants …