Robert Leunk

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Broth-culture filtrates of Campylobacter pylori induced non-lethal cytopathic effects in vitro in 7 of 9 mammalian cell lines tested. Transmission electronmicroscopy revealed that the response consisted of intracellular vacuolisation. Intestine 407 cells were among the most responsive and were used for routine assay. About 55% of isolates of C. pylori(More)
Mice challenged intravenously with 10(6) viable Candida albicans died between 1 and 16 days after infection. Near the time of death, over 98% of the recoverable fungi came from the kidneys. Physiologically, animals were in renal failure near the time of death as evidenced by elevated blood urea nitrogen (BUN) and blood creatinine levels and a creatinine(More)
Campylobacter pylori, a gram-negative microaerophilic bacterium, has been implicated in the genesis of human gastritis, dyspepsia, and gastroduodenal ulceration. Previous attempts to reproduce the diseases in conventional laboratory animal species have been unsuccessful. To determine if neonatal gnotobiotic piglets were susceptible to C. pylori, we orally(More)
Helicobacter pylori produces a cytotoxin that was initially detected as the ability of broth culture filtrates of this bacterium to induce intracellular vacuolation of cultured cells. Fifty-three percent of more than 200 isolates of H. pylori tested produce the cytotoxin, which appears to be unique to H. pylori. Results of characterization studies suggest(More)
Gastrointestinal disease and colonization by Helicobacter pylori were determined in 36 asymptomatic volunteers and 30 symptomatic individuals undergoing endoscopy and biopsy. Serum antibody immunoglobulin G (IgG) and IgA to H. pylori were measured by enzyme-linked immunosorbent assay. Serum antibody to a cytotoxin produced by H. pylori was detected with a(More)
Selection of resistant strains in Streptococcus pneumoniae was studied in vitro with nemonoxacin, a novel nonfluorinated quinolone (NFQ), in comparison with quinolone benchmarks, ciprofloxacin, garenoxacin, and gatifloxacin. In stepwise resistance selection studies, a 256-fold loss of potency was observed after three to four steps of exposure to(More)
Helicobacter pylori, a human gastric bacterial pathogen, was inoculated into gnotobiotic piglets and manifestations of the resultant gastric inflammation was analyzed by in situ immunochemistry and flow cytometric analysis of isolated lamina propria leukocytes (LPL) and peripheral blood leukocytes (PBL) recovered from infected and control piglets. Gastric(More)
Gnotobiotic piglets infected with Helicobacter pylori were treated with various antimicrobials as monotherapy and dual therapy, and the results were compared to those for piglets treated with a triple-therapy regimen (bismuth subsalicyclate at 5.7 mg/kg of body weight, metronidazole at 4.4 mg/kg, and amoxicillin at 6.8 mg/kg four times a day [QID]).(More)
On the basis of analysis of protein profiles, isolates of Helicobacter pylori and Helicobacter mustelae were less than 40% similar. Cytotoxin produced by H. pylori was not detected in isolates of H. mustelae. Both bacterial species agglutinated human erythrocytes. These results substantiate a taxonomic difference between H. pylori and H. mustelae.
The role of type 1 pili in the adherence of Salmonella typhimurium strain SR-11 to hepatic sinusoidal cells was investigated. An average of 66.7% of piliated organisms was cleared by perfused livers on a single pass. Mannose and alpha-methyl-D-mannoside inhibited such trapping in a dose-dependent manner. Preincubation of the bacteria, but not the liver,(More)