Biomedical subjects

K Rosberg

Publications and source records attributed to K Rosberg.

4 recordsLinked to original sources

PubMed1992

Topographic mapping of Helicobacter pylori colonization in long-term-infected pigs.

Four barrier-born pigs were inoculated with Helicobacter pylori during gastroscopy. Infection in all pigs was established after 3 weeks, and the animals were kept isolated from other pigs in ordinary experimental sites. The pigs were sacrificed and examined 3, 5, 6, and 6.5 months postinoculation. A detailed urease mapping of the pig stomachs showed a patchy distribution of H. pylori. The bacteria colonized in all pigs, with a concentration of H. pylori-positive areas in the antrum and fundus. Furthermore, the number of colonized areas tended to increase with time, and some of these areas showed a strong urease reaction, indicating a heavy colonization with H. pylori. Biopsies from these areas contained 10(2) to 10(5) CFU per 2-mm-wide biopsy. We conclude that persistence of H. pylori infection in barrier-born pigs can be demonstrated for at least 6.5 months. The patchy distribution and the variability of viable bacteria were similar to those described for humans.

Animals↗

PubMed1991

Studies of Helicobacter pylori in a gastric mucosa in vitro animal model.

A gastric mucosa in vitro model for studies of experimental Helicobacter pylori infections has been developed. Biopsy specimens were taken from pig gastric mucosa, infected with H. pylori, and cultured for up to 72 h. To determine the degree of H. pylori adhesion, specimens were vigorously rinsed by vortexing five times before measuring viable count and urease activity. The results showed that it is possible to culture pig gastric mucosa in vitro with maintained viability for at least 72 h. According to the viable count, the bacteria survived and multiplied during the whole culture period. The percentage viable H. pylori in the specimens after rinsing and the urease activity increased with time of culture. The results indicate that the bacteria in the gastric specimens were viable after 72 h and that there was a time-dependent increase in bacterial adhesion to the specimens. This in vitro gastric mucosa model promises to be an applicable and reproducible method, with high capacity, for both pathogenic and mechanistic studies of H. pylori infection.

Animals↗

PubMed1991

Adhesion of Helicobacter pylori to human gastric mucosal biopsy specimens cultivated in vitro.

The therapeutic advances in Helicobacter pylori infection is hampered by the lack of suitable animal model systems. We have previously reported on successful adherence of H. pylori to pig gastric mucosa cultured in vitro. The aim of this study was to verify the technique in human biopsy specimens cultured in vitro. Mucosal samples were taken from H. pylori-negative and H. pylori-positive patients undergoing gastric surgery. The non-infected tissue was infected with H. pylori in vitro, and the infected tissue was put into culture immediately. Total number and those H. pylori firmly attached were checked throughout a 72-h culture. Viability of cultured human gastric mucosa was good and unaffected by the presence of H. pylori. The amount of bacteria adhering, increased with time from 0.01% to 2-4% after 72 h in culture. In vivo-infected specimens initially had a low number of firmly attached H. pylori, but total H. pylori increased with time in culture. It is concluded that human gastric biopsy specimens show good viability for 72 h and that viability and cell division of H. pylori were maintained in both in vivo and in vitro H. pylori-infected tissue. In both cases the total number of viable bacteria attached to the specimens increased with incubation time.

Animals↗

PubMed1986

Autonomic nerve function tests. Reference values in healthy subjects.

Autonomic nerve function was evaluated by deep breathing (E/I heart rate ratio) and tilt table tests (acceleration index, brake index, and blood pressures) in 56 healthy subjects in order to find reference values. The results showed that the E/I ratio, the acceleration index and the brake index fell with increasing age. There was no influence of age on the systolic and the diastolic blood pressure reactions to tilt. Age-related reference values are needed in the evaluation of autonomic neuropathy indices.

Adolescent↗