Stlmnltary The mechanism by which Helicobacter eylori, a noninvasive bacterium, initiates chronic antral gastritis in humans is unknown. We now show that H. Fflori rdeases products with chemotactic activity for monocytes and neutrophils. This chemotactic activity was inhibited by antisera to either H. ~lori whole bacteria or H. pylor/-derived urease. Moreover, surface proteins extracted from H....

Background. The association of gallstones with Helicobacter pylori has been investigated but not clearly demonstrated. In this study, the presence of H. pylori in the gallbladder mucosa of patients with symptomatic gallstones was investigated. Method. Ninety-four consecutive patients with symptomatic gallstone disease were enrolled for the study. Gastroscopy and gastric H. pylori urease test we...

OBJECTIVES To show molecular similarity between two sequences of Proteus mirabilis (haemolysin--ESRRAL; urease--IRRET) with HLA-DR antigens (EQRRAA) which are associated with rheumatoid arthritis (RA) and type XI collagen (LRREI), respectively; and, in patients with RA, to measure levels of antibody against a 16-mer synthetic peptide containing the ESRRAL sequence, and the haemolysin and urease...

Urease catalyzes the hydrolysis of urea to ammonia and carbamate and has been found to be an important pathogenic factor for certain bacteria. Cryptococcus neoformans is a significant human pathogenic fungus that produces large amounts of urease; thus we wanted to investigate the importance of urease in the pathogenesis of cryptococcosis. We cloned and sequenced the genomic locus containing the...

PURPOSE The role of the Ferric Uptake Regulator (FUR) in the acid resistance of Helicobacter pylori (H. pylori) has been thought to be independent of urease. However, we demonstrated in this study that Fur influences urease activity. MATERIALS AND METHODS A fur knockout mutant of H. pylori was constructed by replacing the Fur gene with a kanamycin resistant marker gene. The wild-type H. pylor...

Urease is a virulence factor found in various pathogenic bacteria. It is essential in colonization of a host organism and in maintenance of bacterial cells in tissues. Due to its enzymatic activity, urease has a toxic effect on human cells. The presence of ureolytic activity is an important marker of a number of bacterial infections. Urease is also an immunogenic protein and is recognized by an...

If the activity of an enzyme preparation is determined under conditions in which a further increase in substrate concentration is without demonstrable effect, all other factors being held constant, it is ordinarily assumed that the specific activity of the enzyme, expressed in terms of arbitrary units per unit weight of the enzyme, is independent of the absolute enzyme concentration (1, 2). How...

A total of 140 mycobacterial isolates from patients treated at Fitzsimons Army Medical Center or the National Jewish Hospital and Research Center and from animal specimens submitted to the National Veterinary Services Laboratory were tested by using a urease procedure modified for use with a BACTEC model 301. Mycobacterial suspensions were prepared by using Middlebrook 7H10 Tween broth. Of the ...

Helicobacter pylori, a gram-negative, microaerophilic, spiral-shaped bacterium, is an etiologic agent of human gastritis and peptic ulceration and is highly restricted to the gastric mucosa of humans. Urease, synthesized at up to 6% of the soluble cell protein, hydrolyzes urea, thereby releasing ammonia, which may neutralize acid, allowing survival of the bacterium and initial colonization of t...

PURPOSE Helicobacter pylori is the etiological agent in duodenal and peptic ulcers. The growing problem of antibiotic resistance by the organism demands the search for novel compounds, especially from natural sources. This study was conducted to evaluate the effect of Camellia sinensis extracts on the urease enzyme that is a major colonization factor for H. pylori. METHODS Minimum inhibitory ...