Serum pepsinogen levels, Helicobacter pylori CagA Status, and cytokine gene polymorphisms associated with gastric premalignant lesions in Costa Rica.

The detection of gastric premalignant lesions, atrophic gastritis, corpus atrophic gastritis, and intestinal metaplasia, using several potential markers was examined in Costa Rica. Depending on the lesion investigated, from a total of 223 dyspeptic patients, 58 (26.0%), 31 (13.

Helicobacter pylori CagA status associated with gastric cancer incidence rate variability in Costa Rican regions.

Background: We evaluated several risk factors for gastric cancer in Costa Rican regions having contrasting gastric cancer incidence rates, despite the small dimensions of the country.

Methods: A total of 180 dyspeptic patients were classified into two groups according to the gastric cancer incidence (GCI) rate in their Costa Rican region: group A, with a high GCI rate (n = 91) and group B, with a low GCI rate (n = 89). Helicobacter pylori infection was detected by rapid urease test, Gram staining, and histological observation.

Polyamines, equilibrium between ribosomal particles and protein synthesis in bacteria.

When putrescine is added to polyamine starved cultures of an E. coli strain difficient in the biosynthesis of putrescine, the protein synthesis is enhanced almost immediately and the ribosomal pattern changes concomitantly, increasing the ratio 70S monomer/ribosomal subparticles. Studies with cell-free systems derived from polyamine starved or unstarved bacteria show that the translation of synthetic and natural mRNAs is several fold higher in system prepared from cells grown in the presence of polyamines.

Ribosomal distribution in a polyamine auxotroph of Escherichia coli.

The distribution of ribosomal particles has been studied in a polyamine-deficient mutant of Escherichia coli by sucrose gradient centrifugation analysis. Lysates from starved cells contained less 70S monomers and 30S subunits but more 50S particles than those prepared from bacteria supplemented with putrescine. The addition of the polyamine to putrescine-depleted cells induced a rapid change of the ribosomal profile.