Search PubMed⌕ Search

Biomedical subjects

E K Pettersen

Publications and source records attributed to E K Pettersen.

10 recordsLinked to original sources
PubMed1988

Resistance to avirulent Toxoplasma gondii in normal and vaccinated rats.

Investigation of the innate resistance to infection with Toxoplasma gondii showed that the Toxoplasma-hostile factor present in rats has an important lytic effect on the parasites but is unable to prevent an infection alone. Vaccination experiments showed that innate resistance was also related to specific immunity, which appeared faster in rats than in rodents with less innate resistance. Complete resistance to toxoplasmosis was only present in rats vaccinated with live parasites. In rats vaccinated with killed parasites, avirulent parasites were able to encyst themselves almost as readily as in unvaccinated rats.

Animals↗
PubMed1984

Investigation of two commercially available kits for determination of IgG and IgM to Toxoplasma gondii by enzyme-linked immunosorbent assay (ELISA).

Enzyme-linked immunosorbent assay (ELISA) kits for determination of IgG and IgM to Toxoplasma gondii provided by Labsystems Oy, Finland, were tested on a number of human sera. It was found that the IgG kit agreed well with the dye test (DT) in differentiating positive and negative results. A deviation from a straight line relationship in the positive results obtained was considered due to the different antigens involved in the two tests. The correlation between the results obtained in the IgM kit and DS-ELISA was remarkably good. Only a small fraction of the false negative results due to high IgG titres and false positive results due to rheumatic factor, experienced in the indirect fluorescent antibody test, were apparent in the IgM kit. False positive results due to the presence of rheumatic factor could be corrected for by the use of an IgM confirmatory test kit. The influence of antinuclear factor was not apparent in any of the tests used in this work.

Antigens, Protozoan↗
PubMed1984

Transmission of toxoplasmosis via milk from lactating mice.

Lactating mother mice were infected with an avirulent strain of Toxoplasma gondii. When the milk from these mice was exposed to HCl, it was found that some of the parasites present were "acid-resistant" cystozoites. Hence there is an obvious risk of acquiring toxoplasmosis by consuming milk from infected donors.

Animals↗
PubMed1979

Destruction of Toxoplasma gondii by HC1 solution.

It was shown that the destruction of Toxoplasma gondii by pepsin-HCl solution was due to the acid only. Endozoites were destroyed faster by hydrochloric acid than cystozoites. Furthermore, endozoites were stained faster than cystozoites in an alkaline solution of methylene blue. For this reason, endozoites were assumed to have a higher permeability than cystozoites. The action of hydrochloric acid was used for demonstration of cystozoites in mouse peritoneum cavity. No cystozoites were found after inoculation of virulent parasites.

Hydrochloric Acid↗
PubMed1977

Experimental toxoplasmosis in mice and rabbits. Virulence and cyst formation of Toxoplasma gondii.

Avirulent Toxoplasma gondii were made virulent by passages in mice, and then attenuated by storage. In contrast to the avirulent parasites, attenuated organisms did not appear to form cysts in mice and rabbits, although parasites could be isolated from such animals as long as three months after their inoculation. Rabbits infected with parasites of attenuated virulence had high antibody levels, and survived challenge with virulent Toxoplasma gondii. Cysts were not detected in the brains of such rabbits following this second infection. By following the generation of Toxoplasma gondii in mouse peritoneal cavities, it was found that attenuated parasites resembled avirulent more than virulent organisms. Although the effect of attenuation was mainly on the parental generation of parasites, some genetic effect seemed to be involved as well.

Animals↗
PubMed1972

Column dialysis.

Explore the source record for details and available documents.

Dialysis↗