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Dive into the research topics where Showkat Bashir is active.

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Featured researches published by Showkat Bashir.


Medicine | 2001

Gastric secretion in Zollinger-Ellison syndrome. Correlation with clinical expression, tumor extent and role in diagnosis--a prospective NIH study of 235 patients and a review of 984 cases in the literature.

Praveen K. Roy; David Venzon; Kathryn Feigenbaum; Pamela D. Koviack; Showkat Bashir; Jeremiah V. Ojeaburu; Fathia Gibril; Robert T. Jensen

We prospectively studied 235 patients with Zollinger-Ellison syndrome (ZES) (205 without and 30 with prior acid-reducing surgery) and compared the results with 984 patients from 182 reports in the literature. The aims of the study were to evaluate the sensitivity of proposed acid secretory criteria for the diagnosis of ZES, propose new criteria, evaluate the variability and methodology of gastric secretory testing, and correlate the symptoms and signs of ZES, tumor extent, and primary tumor size and location with the degree of gastric acid hypersecretion. Multiple endocrine neoplasia-type 1 (MEN1) occurred in 22% of patients. The mean basal acid output (BAO) in patients without and with prior acid-reducing surgery was 41.2 +/- 1.7 mEq/hr (range, 1.6-118.3 mEq/hr) and 27.6 +/- 3.5 mEq/hr (range 5.9-102.9 mEq/hr), respectively. In patients with MEN1, those with female gender, Hispanic, or Asian race had lower BAOs. Diarrhea, esophageal stricture, and pyloric scarring were associated with a higher BAO. Neither other symptoms nor the tumor extent, primary tumor location, or size correlated with the magnitude of acid hypersecretion. ZES diagnosis was delayed a mean of 5.5 +/- 0.4 yr. Patients who were misdiagnosed as having either Crohn or celiac disease had higher BAOs. The sensitivities from our study and the literature review of the proposed BAO criteria for the diagnosis of ZES in patients without previous gastric acid-reducing surgery were 91% and 90% for BAO > or = 15 mEq/hr, 86% and 82% for BAO > or = 18 mEq/hr, 69% and 67% for BAO > 25 mEq/hr, and < 60% for BAO > 31 mEq/hr, respectively. The specificities of all the proposed BAO criteria were high. Both the criterion of BAO > or = 15 mEq/hr and BAO > or = 18 mEq/hr had good specificities and equal sensitivity. With prior acid-reducing surgery, the sensitivities in our study and from the literature review were 100% and 81% for BAO > or = 5 mEq/hr, 73% and 45% for BAO > 14.4 mEq/hr, and 37% and 31% for BAO > 19.2 mEq/hr, respectively. The reported mean specificity for the criterion of BAO > or = 5 mEq/hr was 85%, while it was 100% for the other 2 criteria. The maximal acid output (MAO) criterion of > 70 mEq/hr had sensitivities in the present National Institutes of Health (NIH) study and the literature review of 39% and 31%, respectively, and the criterion of MAO > 100 mEq/hr had a sensitivity of < 15% in patients with no prior acid-reducing surgery. The proposed criterion of BAO/MAO ratio > 0.6 had a low sensitivity. The proposed criterion of the ratio of basal and maximal acid H+ concentration (BAC/MAC ratio) > or = 0.6 had an excellent sensitivity-- > or = 89% in patients with or without previous acid-reducing surgery. The reported specificity for both the BAO/MAO criterion and the BAC/MAC criterion were similar, but BAC/MAC had a better sensitivity. Combination criteria of BAO generally did not improve sensitivity. The criterion of pH < or = 1 was met by only 27% of patients, and pH < or = 0.96 by 21% of patients with previous acid-reducing surgery. For patients with MEN1 with no prior acid-reducing surgery, the sensitivities were lower compared with patients with the sporadic form of ZES. The mean gastric volume in patients without prior acid-reducing surgery was 314 +/- 10 mL/hr and 247 +/- 25 mL/hr in patients with prior acid-reducing surgery. A basal volume criteria of > 160 mL/hr in patients without prior acid-reducing surgery occurred in > 86% of patients, and > 140 mL/hr in 87% of patients with prior acid-reducing surgery; these, thus, are neglected findings that have good sensitivities. Our analysis shows criteria based on MAO, pH, and BAO/MAO ratio do not have high sensitivities and thus are not useful. In patients without prior acid-reducing surgery, the criteria of BAO > or = 15 mEq/hr, BAC/MAC ratio > or = 0.6, and basal gastric volume > 160 mL/hr are useful for the diagnosis of ZES and have good specificities. In patients with prior acid-reducing surgery, the criteria of BAO > or = 5 mEq/hr, BAC/MAC ratio > or = 0.6, and basal gastric volume > 140 mL/hr have high sensitivities. In patients with sporadic ZES without acid-reducing surgery, the criterion of BAO > or = 18 mEq/hr is recommended as it has a similar sensitivity but higher specificity than the criterion of BAO > or = 15 mEq/hr. Only 1 patient in either data set (NIH or the literature) with or without previous acid-reducing surgery had a basal gastric pH > 2, therefore this finding essentially excludes the diagnosis of ZES. Gastric secretory measurements for 30 minutes, but not 15 minutes, give results comparable to those for a full hour. On the basis of these results, a number of gastric secretory criteria are proposed, including some for the first time, and alterations in methodology are proposed that should prove useful in the diagnosis of ZES.


Alimentary Pharmacology & Therapeutics | 2002

Prospective study of the ability of histamine, serotonin or serum chromogranin A levels to identify gastric carcinoids in patients with gastrinomas

Showkat Bashir; Fathia Gibril; Jeremiah V. Ojeaburu; Behnam Asgharian; Laurence K. Entsuah; Gabriella Ferraro; P. Crafa; Cesare Bordi; Robert T. Jensen

Chronic hypergastrinaemia causes gastric enterochromaffin cell proliferation and carcinoid tumours. The only reliable means to diagnose enterochromaffin cell changes/carcinoids is by biopsy.


ACG Case Reports Journal | 2016

Metastatic Pancreatic Adenocarcinoma During Pregnancy

Jessica Davis; Showkat Bashir; Helmae Wubneh; Marie L. Borum

We present a rare case of metastatic pancreatic adenocarcinoma diagnosed antepartum. A high index of suspicion must be maintained to diagnose pancreatic cancer during pregnancy. We recommend a thorough history and physical and aggressive pursuit of sensitive imaging in patients with persistent symptoms. If pancreatic adenocarcinoma is diagnosed, a multidisciplinary approach that focuses on patient goals should be undertaken. The effect of pregnancy on tumor growth rates is unknown.


The Journal of Clinical Endocrinology and Metabolism | 2001

Prospective Study of the Natural History of Gastrinoma in Patients with MEN1: Definition of an Aggressive and a Nonaggressive Form

Fathia Gibril; David Venzon; Jeremiah V. Ojeaburu; Showkat Bashir; Robert T. Jensen


Cancer | 2003

Prospective study of the ability of serial measurements of serum chromogranin A and gastrin to detect changes in tumor burden in patients with gastrinomas

Alaa Abou‐Saif; Fathia Gibril; Jeremiah V. Ojeaburu; Showkat Bashir; Laurence K. Entsuah; Behnam Asgharian; Robert T. Jensen


Journal of Gastrointestinal and Digestive System | 2016

Acute Myopericarditis due to Hepatitis E Virus Infection: The First Reported Case in the Western Hemisphere

Timothy Dougherty; Showkat Bashir; Mahmuda Khan Jason Adam; Marie L. Borum


Gastroenterology | 2011

Esophageal Inlet Patch: Experience in a Tertiary Care Center

Showkat Bashir; Amy Doran; Marie L. Borum


Gastroenterology | 2001

Occurrence of prolonged extreme acid hypersecretion post-curative gastrinoma resection: Prospective study

Jeremiah V. Ojeaburu; Showkat Bashir; Homayoun Shojamanesh; Alaa Abou-Saif; Fathia Gibrill; Robert T. Jensen


Gastroenterology | 2001

Prospective study of efficacy of interferon-2α (INF-2α) in metastatic gastrinoma

Alaa Abou-Saif; Homayoun Shojamanesh; Showkat Bashir; Jeremiah V. Ojeaburu; Fathia Gibril; Robert T. Jensen


Gastroenterology | 2001

Long-term continuous use of omeprazole in patients with sporadic Zollinger-Ellison syndrome (ZES): A prospective 17-year study of efficacy and safety

Fathia Gibril; Alla Abou-Saif; Homayoun Shojamanesh; Showkat Bashir; Jeremiah V. Ojeaburu; Robert T. Jensen

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Jeremiah V. Ojeaburu

National Institutes of Health

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Robert T. Jensen

National Bureau of Economic Research

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Fathia Gibril

National Institutes of Health

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Homayoun Shojamanesh

National Institutes of Health

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Marie L. Borum

George Washington University

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Behnam Asgharian

National Institutes of Health

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David Venzon

National Institutes of Health

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Laurence K. Entsuah

National Institutes of Health

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Adeline Louie

National Institutes of Health

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