Gastroenterology Commons^™

T Cell Receptor Cross-Reactivity Directed By Antigen-Dependent Tuning Of Peptide-Mhc Molecular Flexibility, Oleg Y. Borbulevych, Kurt H. Piepenbrink, Brian E. Gloor, Daniel R. Scott, Ruth F. Sommese, David K. Cole, Andrew K. Sewell, Brian M. Baker

Food for Health: Publications

Tell mediated immunity requires T cell receptor (TCR) cross-reactivity, the mechanisms behind which remain incompletely elucidated. The αβ TCR A6 recognizes both the Tax (LLFGYPVYV) and Tel1p (MLWGYLQYV) peptides presented by the human class I MHC molecule HLA-A2. Here we found that although the two ligands are ideal structural mimics, they form substantially different interfaces with A6, with conformational differences in the peptide, the TCR, and unexpectedly, the MHC molecule. The differences between the Tax and Tel1p ternary complexes could not be predicted from the free peptide-MHC structures and are inconsistent with a traditional induced-fit mechanism. Instead, the differences were …

Role Of N-Acetylcysteine In Adults With Non-Acetaminophen-Induced Acute Liver Failure In A Center Without The Facility Of Liver Transplantation., Khalid Mumtaz, Zahid Azam, Saeed Hamid, Shahab Abid, Sadik Memon,, Syed H Shah, Wasim Jafri

Section of Gastroenterology

PURPOSE:

We aimed to study the role of N-acetylcysteine (NAC) in non-acetaminophen-induced acute liver failure (NAI-ALF).

METHODS:

A total of 47 adult patients were prospectively enrolled with NAI-ALF (group 1 or NAC group) and oral NAC was given. The primary outcome was reduction in mortality with the use of NAC in NAI-ALF. The secondary outcomes were to evaluate safety of NAC and to assess factors predicting mortality. We compared these results with records of NAI-ALF patients admitted in our hospital from 2000 to 2003 (n = 44) who were not given NAC (group 2 or historical controls).

RESULTS:

The two …

Molecular Confirmation Of The Causes Of Inherited Visual Impairment In Northern Pakistan., Mehreen Adhi, Yasmin Rashid, Syed Hussain Jafr, Chris F. Inglehearn, Martin Mc Kibbin

Department of Medicine

Families with inherited visual impairment were identified and examined from January 2000 to December 2005 and given a clinical diagnosis. Known genes and loci were screened for mutations or linkage at Institute of Ophthalmology and Neurosciences, University of Leeds, in order to provide molecular confirmation. Inherited retinal disease was the most common cause of inherited visual impairment in 38 of 57 families (66.6%) with Leber’s congenital amaurosis, rod-cone dystrophy and cone-rod dystrophy being the most common diagnoses in 22, 8 and 3 families respectively. Anterior segment dysgenesis was diagnosed in 8 families (14%). Mutations in known genes or linkage to …

No Association Of Obesity And Type 2 Diabetes Mellitus Related Genetic Variants With Colon Cancer, Cheryl L. Thompson, Sarah J. Plummer, Thomas C. Tucker, Graham Casey, Li Li

Markey Cancer Center Faculty Publications

Background: Obesity and type 2 diabetes mellitus (T2D) are known risk factors for colon cancer. Recent reports from a number of genome wide association studies (GWAS) have identified several single nucleotide polymorphisms (SNPs) associated with obesity and T2D. Here we tested the hypothesis that these SNPs may also be associated with risk of colon cancer.

Methods: We genotyped nine SNPs reported in GWAS of obesity and/or T2D, including SNPs in HHEX, KCNJ11, SLC30A8, FTO, CDKN2, CDKAL1, TCF2, and the rs9300039 SNP in an intergenic region, in 561 colon cancer cases and 721 population controls.

Results: None of these SNPs were …

Distribution Of Helicobacter Pylori Virulence Markers In Patients With Gastroduodenal Diseases In Pakistan., Javed Yakoob, Shahab Abid, Z Abbas, Wasim Jafri, Zubair Ahmad, Rashida Ahmed, Muhammad Islam

Section of Gastroenterology

BACKGROUND:

Helicobacter pylori (H. pylori) infection is known to be associated with a spectrum of gastroduodenal diseases. We studied the association of H. pylori virulence markers cytotoxin-associated gene (cagA) and vacuolating associated cytotoxin gene (vacA) alleles in patients with non ulcer dyspepsia (NUD), gastric ulcer (GU), gastric carcinoma (GC) and duodenal ulcer (DU).

METHODS:

H. pylori infection established by both rapid urease test and histology were studied. The cagA and vacA allelic status was determined by polymerase chain reaction (PCR). Sequencing of vacA i1 and i2 PCR product was carried out.

RESULTS:

Two hundred and twenty-four patients were included, 141 …

Model For End-Stage Liver Disease (Meld) Score As A Useful Prognostic Marker In Cirrhotic Patients With Infection, Rustam Khan, Shahab Abid, Wasim Jafri, Safia Awan, Saeed Hamid, Hasnain Shah, Shahid Pervez

Section of Gastroenterology

OBJECTIVE: To determine the association of Model for End stage liver disease (MELD) score to the outcome of cirrhotic patients with bacterial infection and to compare it with Child-Turcott-Pugh (CTP) score.

STUDY DESIGN: Descriptive study.

PLACE AND DURATION OF STUDY: The Aga Khan University Hospital, Karachi, from January 2005 to December 2007.

METHODOLOGY: Patients with diagnosis of liver cirrhosis and bacterial infection were included. Demographic features, laboratory data and type of infection were recorded. Multiple logistic regression assays were applied to determine the factors associated with poor outcome in cirrhotics with infection. Receiver-Operating Characteristics (ROC) were used to determine the …

Is Furazolidone Therapy For Helicobacter Pylori Effective And Safe? Reply, Z Abbas, Javed Yakoob, Shahab Abid, Wasim Jafri, Muhammad Islam, Zahid Azam, Imran Hilal

Section of Gastroenterology

No abstract provided.

Ras Activity Levels Control The Development Of Pancreatic Diseases, Baoan Ji, Lilian Tsou, Huamin Wang, Sebastian Gaiser, David Chang, Jaroslaw Daniluk, Yan Bi, Tobias Grote, Daniel Longnecker, Craig Logsdon

Dartmouth Scholarship

Differentiated pancreatic acinar cells expressing endogenous levels of mutant K-Ras do not spontaneously develop pancreatic ductal adenocarcinoma (PDAC). However, we hypothesized that acinar cells would develop PDAC in the presence of Ras activity levels mimicking those of human tumor cells.We measured Ras activity in PDAC cells from mice and humans using a Raf pull-down assay. We compared the effects of acinar cell expression of mutant K-Ras at endogenous and elevated levels on Ras activity and on the development of PDAC.

Esophageal Polypoidal Mass: Presentation Of An Uncommon Pleomorphic Carcinoma, Javed Yakoob, Z Abbas, Wasim Jafri, Najamul Sahar Azad

Section of Gastroenterology

Pleomorphic carcinomas are primary malignant tumours that are known to arise in the lungs, pancreas, gall bladder and intestine. A patient with polypoid tumour of the esophagus is described in this report. The patient presented with dysphagia. Diagnostic and therapeutic intervention required endoscopic evaluation and treatment. Benign esophageal tumours are rarely seen and originate from the upper third of esophagus. We observed an esophageal tumour which was interpreted as spindle cell carcinoma of the esophagus that caused obstruction. We present the clinical picture and histopathological findings of the tumour. To our knowledge this is the first local report of spindle …

Furazolidone, Co-Amoxiclav, Colloidal Bismuth Subcitrate, And Esomeprazole For Patients Who Failed To Eradicate Helicobacter Pylori With Triple Therapy, Z Abbas, Javed Yakoob, Shahab Abid, Wasim Jafri, Muhammad Islam, Zahid Azam, Imran Hilal

Department of Medicine

There is increasing evidence of Helicobacter pylori (H. pylori) resistance to the classical triple therapy consisting of a proton-pump inhibitor and clarithromycin with either amoxicillin or metronidazole. This study is aimed at establishing the efficacy and safety of a 14-day regimen to eradicate H. pylori in patients who have failed with the classical triple therapy given for 14 days. One hundred seventy-six patients diagnosed to have H. pylori infection were given triple therapy for 14 days. Fifty-two patients who failed to respond as evident from positive 14C-urea breath test (UBT) done 4–6 weeks after the completion of triple therapy were …

Low Prevalence Of The Intact Cag Pathogenicity Island In Clinical Isolates Of Helicobacter Pylori In Karachi, Pakistan, Javed Yakoob, Wasim Jafri, Zaigham Abbas, Shahab Abid, R. Khan, N. Jafri, Z. Ahmad

Department of Medicine

Clinical diseases that follow Helicobacter pylori infection are associated with expression of the cagA gene, a part of cytotoxin-associated gene pathogenicity island (cag-PAI). This study aims to determined whether or not the presence of cagA is associated with the presence of complete cag-PAI and to evaluate inflammatory changes associated with the five loci in the cag-PAI of H. pylori comprising cagA, cagA promoter region (cagAP), cagE, cagT and the left end of the cagA gene (LEC). H. pylori isolates were obtained from patients with dyspeptic symptoms. Clinical strains of H. pylori were screened by the polymerase chain reaction (PCR) for …

H. Pylori Infection In Children: Population-Based Age-Specific Prevalence And Risk Factors In A Developing Country, Wasim Jafri, Javed Yakoob, Shahab Abid, S Siddiqui, Nasim Jafri, Safia Awan, Shaikh Qamaruddin Nizami

Section of Gastroenterology

No abstract provided.

Associations Of The Plasticity Region Ofh. Pyloriin Patients With Gastroduodenal Diseases, Javed Yakoob, Z Abbas, Shagufta Naz, Shahab Abid, Wasim Jafri

Section of Gastroenterology

No abstract provided.

Prevalence Of Hepatitis D In Hbsag Positive Patients Visiting Liver Clinics, Naresh Kumar Seetlani, Zaigham Abbas, Sajjad Raza, Javed Yakoob, Wasim Jafri

Section of Gastroenterology

Objective: To estimate the prevalence of hepatitis D in HBsAg (hepatitis B surface antigen) positive patients visiting liver clinics.

Methodology: All HbsAg positive patients who had visited two liver clinics; in Karachi and in Jacobabad, from October 2007 to March 2008, were included in this study. These patients were tested for HBV DNA and HDV RNA by PCR technique, HBeAg and anti-HDV. Clinical status of the patients was evaluated by examination, routine biochemical tests and ultrasound.

Results: Total numbers of patients included in the study were 362 comprising of 151 patients from the clinic in Jacobabad and 211 from Karachi. …

Adult Onset Stills Disease In A Tertiary Care Hospital Of Pakistan., Naushad Abid, A. B. Khalid

Department of Medicine

Objective: To study the clinical characteristics of Stills disease in a tertiary care hospital of Pakistan and compare it with similar published studies.

Materials and Methods: (Retrospective descriptive study) Thirteen patients with Adult onset stills disease were identified by chart review of last ten years from 1995 to 2005 at Aga Khan University Hospital (AKU), a tertiary care private medical university in Karachi Pakistan. Demographic and other specific information was recorded on standardized data sheet and analyzed by SPSS 11.5 software.

Results: Mean age of patients was 26.54±10.34 years, of which 8 (61.5%) were males. The most common presenting features …

Helicobacter Pylori Infection: Approach Of Primary Care Physicians In A Developing Country, Shahid Ahmed, Mohammad Salih, Wasim Jafri, Syed H Shah, Saeed Hamid

Section of Gastroenterology

Background:The aim of the study was to assess the knowledge and practices of primary care physicians in diagnosis and management of Helicobacter pylori ( H. pylori) infection in developing country.

Methods: This convenient sample based, cross sectional study was conducted in primary care physicians of Karachi, Pakistan from March 2008 to August 2008 through a pretested self-designed questionnaire, which contained 11 items pertaining to H. pylori route of transmission, diagnosis, indication for testing, treatment options, follow up and source of information.

Results: Out of 509 primary care physicians, 451 consented to participate with the response rate of 88.6%. Responses …

Dengue Fever With Hepatitis E And Hepatitis A Infection, Javed Yakoob, Wasim Jafri, Shaheer Siddiqui, Mehmood Riaz

Section of Gastroenterology

Infection with dengue viruses produces a spectrum of clinical illness ranging from a nonspecific viral syndrome to severe and fatal haemorrhagic disease. Important risk factors include the strain and serotype of the infecting virus, as well as the age, immune status, and genetic predisposition of the patient. The teaching point in this case study was Dengue fever which occurred concomitantly with Hepatitis A and Hepatitis E virus infection.

Helicobacter Pylori Infection Rate Decreases In Symptomatic Children: A Retrospective Analysis Of 13 Years (1993-2005) From A Gastroenterology Clinic In West Virginia, Yoram Elitsur, Yulia Dementieva, Mary Rewalt, Zanda Lawrence

Pediatrics

Background: The rate of Helicobacter pylori is decreasing in the developed countries, but few long-term studies are available from the United States. We retrospectively assessed the annual H. pylori infection rate in symptomatic children seen in our clinic over a 13-year study period.

Study: A retrospective analysis of all children who had histologic diagnosis of H. pylori infection between January 1993 and December 2005 in our pediatric gastroenterology clinic was performed. The annual infection rate and the overall infection rate were calculated.

Results: A total of 1743 upper endoscopy reports were reviewed, of which 212 (12.1%) were diagnosed with H. …