Open Access. Powered by Scholars. Published by Universities.®

Digestive System Commons™

Open Access. Powered by Scholars. Published by Universities.®

Discipline
Institution
Keyword
Publication Year
Publication
Publication Type

Articles 121 - 150 of 166

Full-Text Articles in Digestive System

Measurement Of The Absolute Magnitude And Time Courses Of Mitochondrial Membrane Potential In Primary And Clonal Pancreatic Beta-Cells, Akos Gerencser, Shona A. Mookerjee, Martin Jastroch, Martin D. Brand Jan 2016

Measurement Of The Absolute Magnitude And Time Courses Of Mitochondrial Membrane Potential In Primary And Clonal Pancreatic Beta-Cells, Akos Gerencser, Shona A. Mookerjee, Martin Jastroch, Martin D. Brand

Faculty Publications & Research of the TUC College of Pharmacy

The aim of this study was to simplify, improve and validate quantitative measurement of the mitochondrial membrane potential (ΔψM) in pancreatic β-cells. This built on our previously introduced calculation of the absolute magnitude of ΔψM in intact cells, using time-lapse imaging of the non-quench mode fluorescence of tetramethylrhodamine methyl ester and a bis-oxonol plasma membrane potential (ΔψP) indicator. ΔψM is a central mediator of glucose-stimulated insulin secretion in pancreatic β-cells. ΔψM is at the crossroads of cellular energy production and demand, therefore precise assay of its magnitude is a valuable tool to study how these processes interplay in insulin secretion. …


Chronic Pancreatitis, Pain, And Anxiety In An Alcohol And High Fat Mouse Model, Tiffanie Clinkinbeard Jan 2016

Chronic Pancreatitis, Pain, And Anxiety In An Alcohol And High Fat Mouse Model, Tiffanie Clinkinbeard

Theses and Dissertations--Gerontology

Homeodynamic space (HDS) shrinks as vulnerability increases with aging and repeated damage to the cells. HDS is lost in alcoholic pancreatitis patients due to overconsumption of alcohol, smoking, and high fat diets. Etiologically relevant animal models for study of chronic pancreatitis (CP) are needed. In order to begin filling this gap a central purpose of this dissertation research was to examine relationships between the alcohol and high fat diet (AHF) and pancreatitis with attention to hypersensitivity and anxiety-like behaviors. The AHF diet induced pancreatitis described here etiologically mimics human risk factors of AHF consumption for advancement to alcoholic CP.

In …


The Relationship Between Problem-Solving Ability/Eating Motivation And Perceived Quality Of Life In Individuals Diagnosed With Celiac Disease, Vincenzo Zaccheo Jan 2016

The Relationship Between Problem-Solving Ability/Eating Motivation And Perceived Quality Of Life In Individuals Diagnosed With Celiac Disease, Vincenzo Zaccheo

PCOM Psychology Dissertations

Celiac disease (CD) is a digestive disorder resulting from gluten intolerance that leads to damage of the small intestine. The only current available treatment for CD involves adherence to a strict gluten-free diet. Due to the restrictive nature of this treatment diet, and the increasing prevalence of CD in recent years, much research has been conducted examining factors that impact the quality of life (QOL) of individuals with CD. However, there has been a dearth of literature identifying those factors which can be modified within a treatment setting. Thus, a need for further research in this area was identified. Through …


Medical Students In Microscopic Anatomy And Pathology Laboratories: Design Of An E-Learning Histology And Histopathology Atlas As An Evolving Response To Interdisciplinary Pre-Clinical Curricular Needs, Michelle S. Davis, Alexandra Mills, Gisela Butera, Donald S. Karcher, Patricia S. Latham, Janette Krum, Rosalyn A. Jurjus Mar 2015

Medical Students In Microscopic Anatomy And Pathology Laboratories: Design Of An E-Learning Histology And Histopathology Atlas As An Evolving Response To Interdisciplinary Pre-Clinical Curricular Needs, Michelle S. Davis, Alexandra Mills, Gisela Butera, Donald S. Karcher, Patricia S. Latham, Janette Krum, Rosalyn A. Jurjus

Anatomy and Regenerative Biology Faculty Publications

E-learning, also known as computer-assisted learning, successfully bridges anatomical knowledge and transferrable skills, such as critical analysis, teamwork, leadership and communication. Several institutions have already integrated histology and physiology in team based laboratory approaches, but integration of histology and pathology instruction has been done to a lesser extent. Our aim was to develop an e-learning atlas that integrates microanatomy and pathology laboratory for an interdisciplinary pre-clinical medical curriculum.

A multidisciplinary team of teaching faculty and students developed an online atlas (microanatomyatlas.com) that includes a library of histology and histopathology images. Traditional laboratory manual instructions and study objectives were added onto …


Impact Of Starch Source On Equine Hindgut Microbial Ecology, Brittany Elizabeth Davis Harlow Jan 2015

Impact Of Starch Source On Equine Hindgut Microbial Ecology, Brittany Elizabeth Davis Harlow

Theses and Dissertations--Animal and Food Sciences

Grain inclusion in equine diets can allow starch to reach the hindgut where bacteria compete for the substrate. The hypothesis was that starch introduction would cause a source-dependent press disturbance in equine fecal microflora. Fecal cell suspensions were prepared by differential centrifugation and re-suspension in media with ground corn, oats or wheat. At 24 h, corn had more amylolytics and Group D Gram-positive cocci (GPC), and fewer lactate-utilizing (LU) bacteria and lactobacilli than oats, with wheat being intermediate. Predominant amylolytics were identified by their 16S RNA gene sequence as Enterococcus faecalis (corn, wheat) and Streptococcus bovis (oats). In an in …


Rare Presentation Of Pancreatitis Secondary To Intussusception Of Duodenal Duplication Cyst, A Pediatric Case Report, Valentina Shakhnovich, Jennifer Colombo, Amita A. Desai, Shawn D. St Peter Dec 2014

Rare Presentation Of Pancreatitis Secondary To Intussusception Of Duodenal Duplication Cyst, A Pediatric Case Report, Valentina Shakhnovich, Jennifer Colombo, Amita A. Desai, Shawn D. St Peter

Manuscripts, Articles, Book Chapters and Other Papers

No abstract provided.


Formulating Effective And Accessible Population-Based Colorectal Cancer Screening Programs, Danielle Luffman Dec 2014

Formulating Effective And Accessible Population-Based Colorectal Cancer Screening Programs, Danielle Luffman

Independent Study Project (ISP) Collection

Colorectal cancer, a type of carcinoma originating in cells of the colon or rectum, continues to rank as the third most prevalent cancer worldwide with 1.36 million cases and the fourth most fatal with 693,881 deaths during 2012. In an attempt to alleviate the burden of colorectal cancer throughout society, governments and non-governmental organizations continue to implement population-based cancer screening programs. These programs, typically designed by a federal authority, offer free screening tests to a given population for a certain type of cancer on a routine basis. National systematic screening programs have effectively reduced the incidence of and mortality from …


Uhplc-Ms/Ms Analysis Of Arachidonic Acid And 10 Of Its Major Cytochrome P450 Metabolites As Free Acids In Rat Livers: Effects Of Hepatic Ischemia, Vindhya Edpuganti, Reza Mehvar Aug 2014

Uhplc-Ms/Ms Analysis Of Arachidonic Acid And 10 Of Its Major Cytochrome P450 Metabolites As Free Acids In Rat Livers: Effects Of Hepatic Ischemia, Vindhya Edpuganti, Reza Mehvar

Pharmacy Faculty Articles and Research

The cytochrome P450 metabolites of arachidonic acid (AA) are mostly present in tissues, such as the liver, as bound to phospholipids, with only a small fraction available as free acids. The purpose of this study was to develop and validate a UHPLC-MS/MS method for quantitation of free liver concentrations of AA and four epoxygenated (5,6-, 8,9-, 11,12-, and 14,15-EET), four dihydroxylated (5,6-, 8,9-, 11,12-, and 14,15-DHET), and two ω/(ω-1) hydroxylated (19- and 20- HETEs) metabolites of AA in rat livers using deuterated internal standards. The analytes were rapidly and efficiently (79-92%) recovered from 100 mg of fresh liver into methanol. …


Chylomicrons Produced By Caco-2 Cells Contained Apob-48 With Diameter Of 80-200 Nm, Andromeda M. Nauli, Yuxi Sun, Judy D. Whittimore, Seif Atyia, Guha Krishnaswamy, Surya M. Nauli Jun 2014

Chylomicrons Produced By Caco-2 Cells Contained Apob-48 With Diameter Of 80-200 Nm, Andromeda M. Nauli, Yuxi Sun, Judy D. Whittimore, Seif Atyia, Guha Krishnaswamy, Surya M. Nauli

Pharmacy Faculty Articles and Research

The small intestine generally transports dietary fats to circulation in triglyceride (TG)-rich lipoproteins. The two main intestinal lipoproteins are chylomicron (CM) and very low-density lipoprotein (VLDL). Unfortunately, studies on the CM biogenesis and intestinal transport of dietary fats have been hampered by the lack of an adequate in vitro model. In this study, we investigated the possible factors that might increase the efficiency of CM production by Caco-2 cells. We utilized sequential NaCl gradient ultracentrifugation to isolate the CMs that were secreted by the Caco-2 cells. To confirm the successful isolation of the CMs, we performed Fat Red 7B staining, …


Relating The Metatranscriptome And Metagenome Of The Human Gut, Eric A. Franzosa, Xochitl C. Morgan, Nicola Segata, Levi Waldron, Joshua Reyes, Ashlee M. Earl, Georgia Giannoukos, Matthew R. Boylan, Dawn Ciulla, Dirk Gevers, Jacques Izard, Wendy S. Garrett, Andrew T. Chan, Curtis Huttenhower Apr 2014

Relating The Metatranscriptome And Metagenome Of The Human Gut, Eric A. Franzosa, Xochitl C. Morgan, Nicola Segata, Levi Waldron, Joshua Reyes, Ashlee M. Earl, Georgia Giannoukos, Matthew R. Boylan, Dawn Ciulla, Dirk Gevers, Jacques Izard, Wendy S. Garrett, Andrew T. Chan, Curtis Huttenhower

Department of Food Science and Technology: Faculty Publications

Although the composition of the human microbiome is now well-studied, the microbiota’s > 8 million genes and their regulation remain largely uncharacterized. This knowledge gap is in part because of the difficulty of acquiring large numbers of samples amenable to functional studies of the microbiota. We conducted what is, to our knowledge, one of the first human microbiome studies in a well-phenotyped prospective cohort incorporating taxonomic, metagenomic, and metatranscriptomic profiling at multiple body sites using self-collected samples. Stool and saliva were provided by eight healthy subjects, with the former preserved by three different methods (freezing, ethanol, and RNAlater) to validate self-collection. …


State-By-State Variation In Emergency Versus Elective Colon Resections: Room For Improvement., Augustine C. Obirieze, Mehreen Kisat, Caitlin W. Hicks, Tolulope A. Oyetunji, Eric B. Schneider, Darrell J. Gaskin, Elliott R. Haut, David T. Efron, Edward E. Cornwell, Adil H. Haider May 2013

State-By-State Variation In Emergency Versus Elective Colon Resections: Room For Improvement., Augustine C. Obirieze, Mehreen Kisat, Caitlin W. Hicks, Tolulope A. Oyetunji, Eric B. Schneider, Darrell J. Gaskin, Elliott R. Haut, David T. Efron, Edward E. Cornwell, Adil H. Haider

Manuscripts, Articles, Book Chapters and Other Papers

BACKGROUND: Compared with elective surgical procedures, emergency procedures are associated with higher cost, morbidity, and mortality. This study seeks to investigate potential state-by-state variations in the incidence of emergent versus elective colon resections.

METHODS: A retrospective analysis of all adult patients (aged ≥18 years) included in the Nationwide Inpatient Sample from 2005 to 2009 who underwent hemicolectomy (right or left) or sigmoidectomy was conducted. Discharge-level weights were applied, and generalized linear models were used to assess the odds of a patient undergoing emergent versus elective colon surgery nationally and for each state after adjusting for patient and hospital factors. Odds …


Incomplete Polyp Resection During Colonoscopy—Results Of The Complete Adenoma Resection (Care) Study, Heiko Pohl, Amitabh Srivastava, Steve P. Bensen, Peter Anderson, Richard I. Rothstein, Stuart R. Gordon, L Campbell Levy, Arifa Toor, Todd A. Mackenzie, Thomas Rosch, Douglas J. Robertson Jan 2013

Incomplete Polyp Resection During Colonoscopy—Results Of The Complete Adenoma Resection (Care) Study, Heiko Pohl, Amitabh Srivastava, Steve P. Bensen, Peter Anderson, Richard I. Rothstein, Stuart R. Gordon, L Campbell Levy, Arifa Toor, Todd A. Mackenzie, Thomas Rosch, Douglas J. Robertson

Dartmouth Scholarship

Although the adenoma detection rate is used as a measure of colonoscopy quality, there are limited data on the quality of endoscopic resection of detected adenomas. We determined the rate of incompletely resected neoplastic polyps in clinical practice.We performed a prospective study on 1427 patients who underwent colonoscopy at 2 medical centers and had at least 1 nonpedunculated polyp (5-20 mm). After polyp removal was considered complete macroscopically, biopsies were obtained from the resection margin. The main outcome was the percentage of incompletely resected neoplastic polyps (incomplete resection rate [IRR]) determined by the presence of neoplastic tissue in post-polypectomy biopsies. …


Composition Of The Adult Digestive Tract Bacterial Microbiome Based On Seven Mouth Surfaces, Tonsils, Throat And Stool Samples, Nicola Segata, Susan Kinder Haake, Peter Mannon, Katherine P. Lemon, Levi Waldron, Dirk Gevers, Curtis Huttenhower, Jacques Izard Jun 2012

Composition Of The Adult Digestive Tract Bacterial Microbiome Based On Seven Mouth Surfaces, Tonsils, Throat And Stool Samples, Nicola Segata, Susan Kinder Haake, Peter Mannon, Katherine P. Lemon, Levi Waldron, Dirk Gevers, Curtis Huttenhower, Jacques Izard

Publications and Research

Background: To understand the relationship between our bacterial microbiome and health, it is essential to define the microbiome in the absence of disease. The digestive tract includes diverse habitats and hosts the human body’s greatest bacterial density. We describe the bacterial community composition of ten digestive tract sites from more than 200 normal adults enrolled in the Human Microbiome Project, and metagenomically determined metabolic potentials of four representative sites.

Results: The microbiota of these diverse habitats formed four groups based on similar community compositions: buccal mucosa, keratinized gingiva, hard palate; saliva, tongue, tonsils, throat; sub- and supra-gingival plaques; and stool. …


Does The Use Of An Oral Lipase Inhibitor (Orlistat) Increase Appetite?, Sandra Boyd Jan 2012

Does The Use Of An Oral Lipase Inhibitor (Orlistat) Increase Appetite?, Sandra Boyd

PCOM Physician Assistant Studies Student Scholarship

OBJECTIVE: To determine whether or not Orlistat ingested prior to a meal causes an increased appetite response.

STUDY DESIGN: A Review of three randomized controlled trials studies from 2003-2008 that were in the English language.

DATA RESOURCES: Randomized controlled trials comparing the effect of Orlistat on satiety were found using PubMed, OVID, and Cochrane databases.

OUTOMES MEASURED: Outcomes measured in the studies were: sensation of appetite, hunger, fullness, nausea, bloating, heartburn, belching, epigastric burning, and prospective food consumption. Each study measured individual patient responses using a VAS (visual analogue scale). Demarchi et al (2004) used a gastric barostat to measure …


Mast Cell Activation And Clinical Outcome In Pediatric Cholelithiasis And Biliary Dyskinesia., Craig A. Friesen, Nancy Neilan, James F. Daniel, Kim Radford, Jennifer Verrill Schurman, Ding-You Li, Linda Andre, Shawn D. St Peter, G W. Holcomb Iii Sep 2011

Mast Cell Activation And Clinical Outcome In Pediatric Cholelithiasis And Biliary Dyskinesia., Craig A. Friesen, Nancy Neilan, James F. Daniel, Kim Radford, Jennifer Verrill Schurman, Ding-You Li, Linda Andre, Shawn D. St Peter, G W. Holcomb Iii

Manuscripts, Articles, Book Chapters and Other Papers

BACKGROUND: The current study was undertaken to determine the degree of activation of gallbladder mucosal mast cells, whether mast cell (MC) density or activation differ between patients with and without a positive clinical response to cholecystectomy, and whether either density or activation correlate with gallbladder emptying.

RESULTS: Fifteen biliary dyskinesia (BD) and 13 symptomatic cholelithiasis (CL) patients undergoing cholecystectomy were prospectively enrolled. Gallbladder wall MC density (by immunohistochemistry) and activation (by electron microscopy) were determined. Clinical response was evaluated 30 days post-cholecystectomy on a 5-point Likert-type scale. A complete or nearly complete clinical response was seen in 100% of CL …


Protection And Attachment Of Vibrio Cholerae Mediated By The Toxin-Coregulated Pilus In The Infant Mouse Model, Shelly J. Krebs, Ronald K. Taylor Jul 2011

Protection And Attachment Of Vibrio Cholerae Mediated By The Toxin-Coregulated Pilus In The Infant Mouse Model, Shelly J. Krebs, Ronald K. Taylor

Dartmouth Scholarship

Colonization of the human small intestine by Vibrio cholerae is an essential step in pathogenesis that requires the type IV toxin-coregulated pilus (TCP). To date, three functions of TCP have been characterized: it serves as the CTXΦ receptor, secretes the colonization factor TcpF, and functions in microcolony formation by mediating bacterium-bacterium interactions. Although type IV pili in other pathogenic bacteria have been characterized as playing a major role in attachment to epithelial cells, there are very few studies to suggest that TCP acts as an attachment factor. Taking this into consideration, we investigated the function of TCP in attachment to …


Minimal Vs Extensive Esophageal Mobilization During Laparoscopic Fundoplication: A Prospective Randomized Trial., Shawn D. St Peter, Douglas C. Barnhart, Daniel J. Ostlie, Kuojen Tsao, Charles M. Leys, Susan W. Sharp, Donna Bartle, Tracey Morgan, Carroll M. Harmon, Keith E. Georgeson, G W. Holcomb Iii Jan 2011

Minimal Vs Extensive Esophageal Mobilization During Laparoscopic Fundoplication: A Prospective Randomized Trial., Shawn D. St Peter, Douglas C. Barnhart, Daniel J. Ostlie, Kuojen Tsao, Charles M. Leys, Susan W. Sharp, Donna Bartle, Tracey Morgan, Carroll M. Harmon, Keith E. Georgeson, G W. Holcomb Iii

Manuscripts, Articles, Book Chapters and Other Papers

PURPOSE: Laparoscopic Nissen fundoplication has been traditionally performed with extensive esophageal dissection to create 2 to 3 cm of intraabdominal esophagus. Retrospective data have suggested that minimal esophageal mobilization may reduce the risk of postoperative herniation of the wrap into the lower mediastinum. To compare complete esophageal dissection to leaving the phrenoesophageal attachment intact, we conducted a 2-center, prospective, randomized trial.

METHODS: After obtaining permission/assent, patients were randomized to circumferential division of the phrenoesophageal attachments (MAX) or minimal mobilization with no violation of the phrenoesophageal membrane (MIN). A contrast study was performed at 1 year. The primary outcome variable was …


Should We Be Concerned About Jejunoileal Atresia During Repair Of Duodenal Atresia?, Shawn D. St Peter, Danny C. Little, Katherine A. Barsness, Daniel R. Copeland, Casey M. Calkins, Suzanne Yoder, Steve S. Rothenberg, Saleem Islam, Kuojen Tsao, Daniel J. Ostlie Nov 2010

Should We Be Concerned About Jejunoileal Atresia During Repair Of Duodenal Atresia?, Shawn D. St Peter, Danny C. Little, Katherine A. Barsness, Daniel R. Copeland, Casey M. Calkins, Suzanne Yoder, Steve S. Rothenberg, Saleem Islam, Kuojen Tsao, Daniel J. Ostlie

Manuscripts, Articles, Book Chapters and Other Papers

INTRODUCTION: During repair for duodenal atresia, it has been emphasized that inspection of the small bowel to identify a second atresia is required. The laparoscopic approach for repair of duodenal atresia has been criticized for its limitation to perform this step. Given that duodenal atresia and jejunoileal atresias do not share common embryologic origins, we question the validity of this concern. Therefore, we conducted a multicenter retrospective review of duodenal atresia patients to quantify the incidence of jejunoileal atresia in this population.

METHODS: After institutional review board approval (IRB #07-12-187X), a retrospective review was conducted on all patients who have …


Asian Race/Ethnicity As A Risk Factor For Bile Duct Injury During Cholecystectomy., Stephanie R. Downing, Ghazala Datoo, Tolulope A. Oyetunji, Terrence Fullum, David C. Chang, Nita Ahuja Aug 2010

Asian Race/Ethnicity As A Risk Factor For Bile Duct Injury During Cholecystectomy., Stephanie R. Downing, Ghazala Datoo, Tolulope A. Oyetunji, Terrence Fullum, David C. Chang, Nita Ahuja

Manuscripts, Articles, Book Chapters and Other Papers

Iatrogenic bile duct injury (BDI) is an uncommon but serious complication of cholecystectomy, with identified risk factors of acute cholecystitis, male sex, older age, and aberrant biliary anatomy. The Nationwide Inpatient Sample (1998-2006) was queried for cholecystectomy performed on hospital day 0 or 1. Bile duct injury repair procedure codes were used as a surrogate for BDI. We identified 377,424 patients who underwent cholecystectomy, with 1124 BDIs (0.3%). On multivariate logistic regression analysis, Asian race/ethnicity was a significant risk factor for BDI (odds ratio [OR], 2.26; 95% confidence interval [CI], 1.59-3.23; P < .001). This persisted for laparoscopic (OR, 2.62; 95% CI, 1.28-5.39; P = .009) and open (2.21; 1.59-3.07; P < .001) cholecystectomies. No other race/ethnicity was identified as a risk factor for BDI. We report a new finding that Asian race/ethnicity is a significant risk factor for BDI in laparoscopic and open cholecystectomies.


Levels Of The Secreted Vibrio Cholerae Attachment Factor Gbpa Are Modulated By Quorum-Sensing-Induced Proteolysis, Brooke A. Jude, Raquel M. Martinez, Karen Skorupski, Ronald K. Taylor Nov 2009

Levels Of The Secreted Vibrio Cholerae Attachment Factor Gbpa Are Modulated By Quorum-Sensing-Induced Proteolysis, Brooke A. Jude, Raquel M. Martinez, Karen Skorupski, Ronald K. Taylor

Dartmouth Scholarship

Vibrio cholerae is the etiologic agent of cholera in humans. Intestinal colonization occurs in a stepwise fashion, initiating with attachment to the small intestinal epithelium. This attachment is followed by expression of the toxin-coregulated pilus, microcolony formation, and cholera toxin (CT) production. We have recently characterized a secreted attachment factor, GlcNAc binding protein A (GbpA), which functions in attachment to environmental chitin sources as well as to intestinal substrates. Studies have been initiated to define the regulatory network involved in GbpA induction. At low cell density, GbpA was detected in the culture supernatant of all wild-type (WT) strains examined. In …


Liquid Chromatography-Tandem Mass Spectrometry For The Determination Of Methylprednisolone In Rat Plasma And Liver After Intravenous Administration Of Its Liver-Targeted Dextran Prodrug, Shuang-Qing Zhang, Helen R. Thorsheim, Suman Penugonda, Venkateswaran C. Pillai, Quentin R. Smith, Reza Mehvar Jan 2009

Liquid Chromatography-Tandem Mass Spectrometry For The Determination Of Methylprednisolone In Rat Plasma And Liver After Intravenous Administration Of Its Liver-Targeted Dextran Prodrug, Shuang-Qing Zhang, Helen R. Thorsheim, Suman Penugonda, Venkateswaran C. Pillai, Quentin R. Smith, Reza Mehvar

Pharmacy Faculty Articles and Research

A specific and sensitive liquid chromatography (LC)-tandem mass spectrometric method for quantitative determination of methylprednisolone (MP) in rat plasma and liver was developed and validated using triamcinolone acetonide as an internal standard. Liquid-liquid extraction using tert-butyl methyl ether was used to extract the drug and the internal standard from plasma and liver. The separation of MP was performed on a C(18) column with a mobile phase of acetonitrile:0.5% formic acid aqueous solution (85:15, v/v) over 4 min. The assay was based on the selected reaction monitoring transitions at m/z 375 -> 161 for MP in plasma, 375 -> 357 for …


The Guinea Pig Ileum Lacks The Direct, High-Potency, M2-Muscarinic, Contractile Mechanism Characteristic Of The Mouse Ileum, Michael T. Griffin, Minoru Matsui, Rennolds S. Ostrom, Frederick J. Ehlert Jan 2009

The Guinea Pig Ileum Lacks The Direct, High-Potency, M2-Muscarinic, Contractile Mechanism Characteristic Of The Mouse Ileum, Michael T. Griffin, Minoru Matsui, Rennolds S. Ostrom, Frederick J. Ehlert

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

We explored whether the M2 muscarinic receptor in the guinea pig ileum elicits a highly potent, direct-contractile response, like that from the M3 muscarinic receptor knockout mouse. First, we characterized the irreversible receptor-blocking activity of 4-DAMP mustard in ileum from muscarinic receptor knockout mice to verify its M3 selectivity. Then, we used 4-DAMP mustard to inactivate M3 responses in the guinea pig ileum to attempt to reveal direct, M2 receptor-mediated contractions. The muscarinic agonist, oxotremorine-M, elicited potent contractions in ileum from wild-type, M2 receptor knockout, and M3 receptor knockout mice characterized by negative log EC50 (pEC 50 ) values ± …


Management Of Pediatric Acute Appendicitis In The Computed Tomographic Era., Kuojen Tsao, Shawn D. St Peter, Patricia A. Valusek, Troy L. Spilde, Scott J. Keckler, Abhilash Nair, Daniel J. Ostlie, G W. Holcomb Iii Jun 2008

Management Of Pediatric Acute Appendicitis In The Computed Tomographic Era., Kuojen Tsao, Shawn D. St Peter, Patricia A. Valusek, Troy L. Spilde, Scott J. Keckler, Abhilash Nair, Daniel J. Ostlie, G W. Holcomb Iii

Manuscripts, Articles, Book Chapters and Other Papers

BACKGROUND/PURPOSE: The treatment options for complicated appendicitis in children continue to evolve. Optimal management of complicated appendicitis relies on an accurate preoperative diagnosis. We examined the accuracy of our preoperative diagnosis including computed tomography (CT) and the influence on the management of children with perforated and nonperforated appendicitis.

METHODS: Following IRB approval, a 6-year review of all patients that underwent an appendectomy for suspected appendicitis was performed. Treatments included immediate operations and initial nonoperative management (antibiotic therapy +/- percutaneous drainage of abscess). Appendicitis was confirmed by histological examination.

RESULTS: One thousand seventy-eight patients underwent appendectomy for suspected appendicitis. Preoperative CT …


Analysis Of The Cyc1 Promoter In Candida Albicans, Tomica Blocker May 2008

Analysis Of The Cyc1 Promoter In Candida Albicans, Tomica Blocker

McCabe Thesis Collection

Scientists are considering two factors that may be important in the pathogenesis of C. albicans', it's capability to morph from yeast to hyphal phase, and its differences in colony morphology, cell shape, cell surface and cell permeability. (5) Unfortunately, unlike the bacteria, yeasts do not yet have proven virulence factors. However, science is suggesting that some of the major factors which contribute to the virulence of Candida are its ability to form hyphae, its ability to resist phagocytosis, its ability to adhere to epithelial cell surfaces, its ability to grow well at 37 degrees Celsius, and its ability to secrete …


Current Significance Of Meconium Plug Syndrome., Scott J. Keckler, Shawn D. St Peter, Troy L. Spilde, Kuojen Tsao, Daniel J. Ostlie, G W. Holcomb Iii, Charles L. Snyder May 2008

Current Significance Of Meconium Plug Syndrome., Scott J. Keckler, Shawn D. St Peter, Troy L. Spilde, Kuojen Tsao, Daniel J. Ostlie, G W. Holcomb Iii, Charles L. Snyder

Manuscripts, Articles, Book Chapters and Other Papers

BACKGROUND: The significance of meconium plug syndrome is dependent on the underlying diagnosis. The incidence of pathologic finding, particularly Hirschsprung's disease, contributing to the presence of these plugs, has been debated. However, there are little recent data in the literature. Therefore, we reviewed our experience with meconium plugs as a cause of abdominal distension to evaluate the associated conditions and incidence of Hirschsprung's disease.

METHODS: We reviewed the records of newborns with meconium plugs found in the distal colon on contrast enema from 1994 to 2007. Demographics, radiologic findings, histologic findings, operative findings, and clinical courses were reviewed.

RESULTS: During …


The Nestin Progenitor Lineage Is The Compartment Of Origin For Pancreatic Intraepithelial Neoplasia, Catherine Carriere, Elliot S. Seeley, Tobias Goetze, Daniel S. Longnecker, Murray Korc Mar 2007

The Nestin Progenitor Lineage Is The Compartment Of Origin For Pancreatic Intraepithelial Neoplasia, Catherine Carriere, Elliot S. Seeley, Tobias Goetze, Daniel S. Longnecker, Murray Korc

Dartmouth Scholarship

To determine the cell compartment in which initial oncogenic mutations occur in pancreatic ductal adenocarcinoma (PDAC), we generated a mouse model in which endogenous expression of mutated Kras (Kras(G12D)) was initially directed to a population of pancreatic exocrine progenitors characterized by the expression of Nestin. Targeting of oncogenic Kras to such a restricted cell compartment was sufficient for the formation of pancreatic intraepithelial neoplasias (PanINs), putative precursors to PDAC. PanINs appeared with the same grade and frequency as observed when Kras(G12D) was targeted to the whole pancreas by a Pdx1-driven Cre recombinase strategy. Thus, the Nestin cell lineage is highly …


Using Pareto Fronts To Evaluate Polyp Detection Algorithms For Ct Colonography, Adam Huang, Jiang Li, Ronald M. Summers, Nicholas Petrick, Amy K. Hara Jan 2007

Using Pareto Fronts To Evaluate Polyp Detection Algorithms For Ct Colonography, Adam Huang, Jiang Li, Ronald M. Summers, Nicholas Petrick, Amy K. Hara

Electrical & Computer Engineering Faculty Publications

We evaluate and improve an existing curvature-based region growing algorithm for colonic polyp detection for our CT colonography (CTC) computer-aided detection (CAD) system by using Pareto fronts. The performance of a polyp detection algorithm involves two conflicting objectives, minimizing both false negative (FN) and false positive (FP) detection rates. This problem does not produce a single optimal solution but a set of solutions known as a Pareto front. Any solution in a Pareto front can only outperform other solutions in one of the two competing objectives. Using evolutionary algorithms to find the Pareto fronts for multi-objective optimization problems has been …


Gastroesophageal Reflux Disease And Fundoplication In Infants And Children, Shawn D. St Peter, G W. Holcomb Iii Jan 2007

Gastroesophageal Reflux Disease And Fundoplication In Infants And Children, Shawn D. St Peter, G W. Holcomb Iii

Manuscripts, Articles, Book Chapters and Other Papers

Gastroesophageal reflux disease (GERD) can be one of the most distressing conditions developing at different ages in infants and children. The disease itself is a complex process along with ongoing dynamic anatomic and physiologic changes occurring during normal development. Therefore among referring physicians, considerations regarding the role of surgery for GERD in children varies widely depending on individual experiences in managing these patients. These varied opinions result in discrepancies in the operative experience with fundoplication among pediatric surgeons. It is unclear how much of the current opinions stem from published evidence, particularly with regard to the safety and efficacy of …


Validating Pareto Optimal Operation Parameters Of Polyp Detection Algorithms For Ct Colonography, Jiang Li, Adam Huang, Nicholas Petrick, Jianhua Yao, Ronald M. Summers, Maryellen L. Giger (Ed.), Nico Karssemeijer (Ed.) Jan 2007

Validating Pareto Optimal Operation Parameters Of Polyp Detection Algorithms For Ct Colonography, Jiang Li, Adam Huang, Nicholas Petrick, Jianhua Yao, Ronald M. Summers, Maryellen L. Giger (Ed.), Nico Karssemeijer (Ed.)

Electrical & Computer Engineering Faculty Publications

We evaluated a Pareto front-based multi-objective evolutionary algorithm for optimizing our CT colonography (CTC) computer-aided detection (CAD) system. The system identifies colonic polyps based on curvature and volumetric based features, where a set of thresholds for these features was optimized by the evolutionary algorithm. We utilized a two-fold cross-validation (CV) method to test if the optimized thresholds can be generalized to new data sets. We performed the CV method on 133 patients; each patient had a prone and a supine scan. There were 103 colonoscopically confirmed polyps resulting in 188 positive detections in CTC reading from either the prone or …


Molecular Screening Of Azoreductase Gene And Its Activity In Human Intestinal Bacteria, Syndia S. Todd Dec 2006

Molecular Screening Of Azoreductase Gene And Its Activity In Human Intestinal Bacteria, Syndia S. Todd

McCabe Thesis Collection

The intestinal microflora are capable of performing a wide variety of metabolic transformations. "The intestinal bacteria can enhance the function of the entire gastrointestinal tract, protect against pathogenic, maintain the vital chemical balance of the gastrointestinal system, and produce needed vitamins and hormones" (http;//www.upwardquest.com/crit2.html). Some of the products of this metabolism have been associated with carcinogenic processes, such as cancer, tumor formation, gastrointestinal disease, and infections. The ability of human intestinal microbes to interact with metabolites directly or after recirculation may contribute toward different toxicological disorders and disease.

The purpose of this study is to characterize and isolate the azoreductase …