P. R. Harris

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To elucidate the pathogenesis of Helicobacter pylori-associated gastritis, we studied immune responses of C57BL/6J wild-type (WT), SCID, and gene deficient (IFN-gamma-/- and IL-4-/-) mice following infection with a pathogenic isolate of H. pylori (SPM326). During early infection in WT mice, mononuclear and polymorphonuclear cells accumulated in the gastric(More)
BACKGROUND & AIMS Helicobacter pylori infection in children infrequently causes gastroduodenal mucosal ulceration. Because H pylori induces T-cell dependent gastric inflammation in adults and T regulatory (Treg) cells suppress T-cell-dependent pathology, we evaluated gastric histopathology and Treg cell responses in H pylori-infected children and adults. (More)
BACKGROUND & AIMS Helicobacter pylori surface proteins induce the production of proinflammatory mediators by mononuclear phagocytes, but the protein responsible for this stimulation has not been identified. This study determined whether urease, the major component of the soluble proteins extracted from H. pylori grown in culture, activates mononuclear(More)
BACKGROUND AND AIMS Chile ranks fifth in the world among countries with the highest incidence of gastric cancer. The aim was to quantify the association between Helicobacter pylori infection and gastric cancer mortality at the county of residence. METHODS A cross-sectional household survey, a probability sample of the Chilean adult population, provided(More)
Survival among children with short bowel syndrome has increased with the use of supportive nutritional techniques including parenteral and enteral nutrition. Further improvement in outcome has been sought by using intestinal lengthening procedures to lengthen the bowel, improve intestinal motility, initiate a progressive increase in intestinal mucosal mass,(More)
We assessed the sensitivity and specificity of H. pylori IgG and IgA with a commercial immunoassay performed in Chile and a second non-commercial immunoassay performed in a reference laboratory in the United States, in serum of 80 children and adults referred for gastrointestinal endoscopies in a developing country. Overall, 56% of the patients were(More)
We investigated whether Helicobacter pylori cytotoxin induces vacuolation in primary epithelial cells from normal human mucosa. Epithelial cells purified by enzyme digestion and elutriation were evaluated for vacuolation in a blinded protocol by light and electron microscopy before and after incubation with culture supernatant (CS) from H. pylori 60190,(More)
UNLABELLED Chile has one of the highest rates of gastric cancer in the world and most children and adolescents in the country are colonized by Helicobacter pylori. This study assessed the nature and extent of the gastric lesions in 73 consecutive patients aged 5-17 y, referred for upper gastrointestinal endoscopy. Their H. pylori-associated gastric(More)
Increased apoptotic death of gastric epithelial cells is a hallmark of Helicobacter pylori infection, and altered epithelial cell turnover is an important contributor to gastric carcinogenesis. To address the fate of apoptotic gastric epithelial cells and their role in H. pylori mucosal disease, we investigated phagocyte clearance of apoptotic gastric(More)
AIMS Acute Helicobacter pylori infection is associated with transient hypochlorhydria. In H pylori-associated atrophy, hypochlorhydria has a role in iron deficiency (ID) through changes in the physiology of iron-complex absorption. The aims were to evaluate the association between H pylori-associated hypochlorhydria and ID in children. METHODS Symptomatic(More)