Biomedical subjects

G Brunius

Publications and source records attributed to G Brunius.

22 records · Page 2Linked to original sources

PubMed1983

Interaction between Yersinia pseudotuberculosis and the HeLa cell surface.

The adherence of Yersinia pseudotuberculosis to the surface of HeLa cells at 4 degrees C was studied. This temperature allows adhesion of bacteria but prevents engulfment. Adhesion between the bacteria and the cells was not dependent upon the presence of serum, Ca2+ or Mg2+ in the medium. Maximum adhesion was obtained at pH 6.5-7.9 and pretreatment of the cells with formaldehyde or glutaraldehyde inhibited the attachment of the bacteria. The interaction between the bacteria and the cell surface seems to involve cellular processes that are mostly microvilli. An intimate association between the bacteria and the cellular glycocalyx was found. Three virulent bacterial strains adhered more easily to the cell surface than five avirulent strains. Maximum adherence was obtained with bacteria from late logarithmic and early stationary phases of growth. The bacteria gradually lose their adhesive property when cultivated for several generations at 37 degrees C in nutrient broth but not when cultivated at 20 degrees C. Treatment of the bacteria with protease IV from Streptomyces caespitosus markedly reduced the efficiency of attachment.

Adhesiveness↗

PubMed1983

Variation in cell surface morphology of two 90Sr-induced osteosarcomas serially transplanted in CBA mice.

The induction of skeletal tumours, which can be classified as osteosarcomas of many different types, is considered to be the primary carcinogenic effect of radiostrontium. In the present report the cell surface morphology in vivo of 90Sr-induced osteosarcoma cells was investigated, since a variety of tumour cells--and especially those investigated in vitro--have been shown to possess morphologic changes compared with their normal counterparts. Using scanning electron microscopy, variations in cell surface morphology were observed in 2 tumour series, which were serially transplanted in mice for 45 and 60 transfer generations, respectively. The slow-growing osteosarcoma cells of the early transfer generations, of osteoblastic as well as fibroblastic type, seemed to have more cytopodia than the fast-growing osteosarcoma cells from later generations. This may be due to the fact that slowly growing cell populations have a large proportion of cells in G1, in which stage there is a higher frequency of cellular cytopodia.

Animals↗

PubMed1980

Ingestion of Yersinia pseudotuberculosis into human fibroblasts in vitro.

The ingestion into human fibroblasts of different strains (avirulent and virulent) of Yersinia pseudotuberculosis was investigated. The kinetics of ingestion was studied with the addition of 10(7) bacteria to human lung fibroblast cultures. The number of ingested bacteria after 0.5-3 h was measured with viable count technique. All strains were ingested except for one avirulent strain. The other strains were ingested at roughly the same rate. The bacterial uptake seemed to be mediated by a phagocytic-like procedure and the intracellular bacteria resided in vacuoles. The bacteria survived and also multiplied in the cells (for at least 7 days).

Cell Line↗

PubMed1979

Luminescence immunoassay (LIA): a solid-phase immunoassay monitored by chemiluminescence.

A luminescence immunoassay (LIA) has been developed utilizing the chemiluminescent luminol reaction with heme as catalyst. Rabbit antibody against human serum albumin was quantitated in antigen coated plastic tubes using commercially available goat anti-rabbit IgG conjugated to horseradish peroxidase which was the source of heme. The measurable range of antibody is considerably wider by LIA than by enzyme immunoassays. The time to develop and measure activity is short and constant which makes LIA suitable for automation. In its present form, LIA is slightly less sensitive but has better day-to-day reproducibility than corresponding enzymes immunoassays.

Immunoassay↗