132 research outputs found

    PAC1 Deficiency in a Murine Model Induces Gastric Mucosa Hypertrophy and Higher Basal Gastric Acid Output

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    Pituitary adenylate cyclase-activating polypeptide (PACAP) has been shown to increase the histamine release from gastric enterochromaffin-like (ECL) cells and promote gastric acid secretion in rats. In contrast, in mice, PACAP has been demonstrated to induce a decrease of gastric acid secretion, an effect presumably due to somatostatin release. To more clearly define the role of PACAP in the regulation of gastric acid output, a knockout mouse model for the PACAP-specific receptor PAC1 was applied in this study. Measurements of the basal and stimulated gastric acid secretion and morphological studies on the gastric mucosa were performed in both wild-type and PAC1-deficient mice. Compared with the wild-type mice, the PAC1-deficient mice showed a nearly threefold higher basal gastric acid output, increased gastric mucosa thickness and glands height, and proportional increases in parietal and total cell counts in the gastric mucosa. The PAC1-deficient mice also showed a trend of increased plasma gastrin levels and gastrin gene expression in the gastric mucosa. This study indicates that the expression of PAC1 is clearly important for maintaining the homeostasis of gastric acid secretion. Loss of PACAP receptor during development may lead to a compensatory mechanism regulating gastric acid secretion

    Duodenal Bulb Mucosa with Hypertrophic Gastric Oxyntic Heterotopia in Patients with Zollinger Ellison Syndrome

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    Objectives. Zollinger-Ellison Syndrome (ZES) results in hypersecretion of gastric acid (via gastrinoma) leading to peptic ulcers, diarrhea, and abdominal pain. We describe the novel discovery of hypertrophic, heterotopic gastric mucosa in the proximal duodenal bulb in patients with ZES, which we hypothesize results in an increased incidence of postbulbar ulcers in patients with ZES (a mechanism previously unreported). We determined the incidence of the novel finding of duodenal gastric oxyntic hypertrophic heterotopia (GOH) in patients with ZES. Methods. Seven patients with ZES were enrolled. The diagnosis of ZES was established by hypergastrinemia, gastric acid hypersecretion, and a positive secretin test or based on biopsy specimens (evaluated via tissue staining). Basal acid output (BAO) and baseline gastrin secretion were determined by established methods. Endoscopic examinations with methylene blue staining and biopsy of the gastric and duodenal mucosa were conducted in all patients every 3–6 months for an average of 5 years. Results. The duodenal mucosa demonstrated hypertrophic GOH in 5 out of 7 patients with ZES and an intact stomach and duodenum. Biopsies from the bowel mucosa demonstrated patchy replacement of surface epithelium by gastric-type epithelium with hypertrophic oxyntic glands in the lamina propria in 5 patients. Two of the patients had no evidence of GOH in the duodenal bulb. Patients with GOH had an average serum gastrin level of 1245 pg/mL and BAO of 2.92 mEq/hr versus 724 pg/mL and 0.8 mEq/hr in patients without GOH. Conclusions. This study demonstrated the presence of duodenal mucosa with GOH in 5 out of 7 patients with ZES and an intact stomach and duodenum. The presence of hypertrophic and heterotopic gastric mucosa is proposed to result from increased gastrin levels and may contribute to the increased incidence of postbulbar ulcers in these patients

    Do changes in health reveal the possibility of undiagnosed pancreatic cancer? Development of a risk-prediction model based on healthcare claims data.

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    Background and objectiveEarly detection methods for pancreatic cancer are lacking. We aimed to develop a prediction model for pancreatic cancer based on changes in health captured by healthcare claims data.MethodsWe conducted a case-control study on 29,646 Medicare-enrolled patients aged 68 years and above with pancreatic ductal adenocarcinoma (PDAC) reported to the Surveillance Epidemiology an End Results (SEER) tumor registries program in 2004-2011 and 88,938 age and sex-matched controls. We developed a prediction model using multivariable logistic regression on Medicare claims for 16 risk factors and pre-diagnostic symptoms of PDAC present within 15 months prior to PDAC diagnosis. Claims within 3 months of PDAC diagnosis were excluded in sensitivity analyses. We evaluated the discriminatory power of the model with the area under the receiver operating curve (AUC) and performed cross-validation by bootstrapping.ResultsThe prediction model on all cases and controls reached AUC of 0.68. Excluding the final 3 months of claims lowered the AUC to 0.58. Among new-onset diabetes patients, the prediction model reached AUC of 0.73, which decreased to 0.63 when claims from the final 3 months were excluded. Performance measures of the prediction models was confirmed by internal validation using the bootstrap method.ConclusionModels based on healthcare claims for clinical risk factors, symptoms and signs of pancreatic cancer are limited in classifying those who go on to diagnosis of pancreatic cancer and those who do not, especially when excluding claims that immediately precede the diagnosis of PDAC

    Race affects SVR12 in a large and ethnically diverse hepatitis C-infected patient population following treatment with direct-acting antivirals: Analysis of a single-center Department of Veterans Affairs cohort.

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    Hepatitis C virus (HCV) infection is a major cause of chronic liver disease. HCV cure has been linked to improved patient outcomes. In the era of direct-acting antivirals (DAAs), HCV cure has become the goal, as defined by sustained virological response 12 weeks (SVR12) after completion of therapy. Historically, African-Americans have had lower SVR12 rates compared to White people in the interferon era, which had been attributed to the high prevalence of non-CC interleukin 28B (IL28B) type. Less is known about the association between race/ethnicity and SVR12 in DAA-treated era. The aim of the study is to evaluate the predictors of SVR12 in a diverse, single-center Veterans Affairs population. We conducted a retrospective study of patients undergoing HCV therapy with DAAs from 2014 to 2016 at the VA Greater Los Angeles Healthcare System. We performed a multivariable logistic regression analysis to determine predictors of SVR12, adjusting for age, HCV genotype, DAA regimen and duration, human immunodeficiency virus (HIV) status, fibrosis, nonalcoholic fatty liver disease (NAFLD) fibrosis score, homelessness, mental health, and adherence. Our cohort included 1068 patients, out of which 401 (37.5%) were White people and 400 (37.5%) were African-American. Genotype 1 was the most common genotype (83.9%, N = 896). In the adjusted models, race/ethnicity and the presence of fibrosis were statistically significant predictors of non-SVR. African-Americans had 57% lower odds for reaching SVR12 (adj.OR = 0.43, 95% CI = 1.5-4.1) compared to White people. Advanced fibrosis (adj.OR = 0.40, 95% CI = 0.26-0.68) was also a significant predictor of non-SVR. In a single-center VA population on DAAs, African-Americans were less likely than White people to reach SVR12 when adjusting for covariates

    Autoimmune atrophic gastritis: current perspectives

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    At present there is no universally accepted classification for gastritis. The first successful classification (The Sydney System) that is still commonly used by medical professionals was first introduced by Misiewicz et al in Sydney in 1990. In fact, it was the first detailed classification after the discovery of Helicobacter pylori by Warren and Marshall in 1982. In 1994, the Updated Sydney System was proposed during the International Workshop on the Histopathology of Gastritis followed by the publication in The American Journal of Surgical Pathology by Dixon et al. Using the new classification, distinction between atrophic and nonatrophic gastritis was revised, and the visual scale grading was incorporated. According to the Updated Sydney System Classification, atrophic gastritis is categorized into multifocal (H. pylori, environmental factors, specific diet) and corpus-predominant (autoimmune). Since metaplasia is a key histological characteristic in patients with atrophic gastritis, it has been recommended to use the word “metaplastic” in both variants of atrophic gastritis: autoimmune metaplastic atrophic gastritis (AMAG) and environmental metaplastic atrophic gastritis. Although there are many overlaps in the course of the disease and distinction between those two entities may be challenging, the aim of this review article was to describe the etiology, epidemiology, pathogenesis, diagnosis, clinical manifestations and treatment in patients with AMAG. However, it is important to mention that H. pylori is the most common etiologic factor for the development of gastritis in the world

    A long noncoding RNA signature for ulcerative colitis identifies IFNG-AS1 as an enhancer of inflammation

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    High-throughput technologies revealed new categories of genes, including the long noncoding RNAs (lncRNAs), involved in the pathogenesis of human disease; however, the role of lncRNAs in the ulcerative colitis (UC) has not been evaluated. Gene expression profiling was used to develop lncRNA signatures in UC samples. Jurkat T cells were activated by PMA/ionomycin subsequently interferon- (IFNG) and tumor necrosis factor (TNF)- protein levels were assessed by ELISA. Anti-sense molecules were designed to block IFNG-AS1 expression. A unique set of lncRNAs was differentially expressed between UC and control samples. Of these, IFNG-AS1 was among the highest statistically significant lncRNAs (fold change: 5.27, P value: 7.07E-06). Bioinformatic analysis showed that IFNG-AS1 was associated with the IBD susceptibility loci SNP rs7134599 and its genomic location is adjacent to the inflammatory cytokine IFNG. In mouse models of colitis, active colitis samples had increased colonic expression of this lncRNA. Utilizing the Jurkat T cell model, we found IFNG-AS1 to positively regulate IFNG expression. Novel lncRNA signatures differentiate UC patients with active disease, patients in remission, and control subjects. A subset of these lncRNAs was found to be associated with the clinically validated IBD susceptibility loci. IFNG-AS1 was one of these differentially expressed lncRNAs in UC patients and found to regulate the key inflammatory cytokine, IFNG, in CD4 T cells. Taking these findings together, our study revealed novel lncRNA signatures deregulated in UC and identified IFNG-AS1 as a novel regulator of IFNG inflammatory responses, suggesting the potential importance of noncoding RNA mechanisms on regulation of inflammatory bowel disease-related inflammatory responses
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