Biomedical subjects

R Christofferson

Publications and source records attributed to R Christofferson.

20 records · Page 2Linked to original sources

PubMed1988

Vascularization of the continuous human colonic cancer cell line LS 174 T deposited subcutaneously in nude rats.

The macro- and microvasculature of the human colonic cancer cell line LS 174 T, 2-8 weeks after subcutaneous deposition in both hind legs of congenitally athymic rats was investigated by light microscopy, angiography, and microvascular corrosion casting with analysis in a scanning electron microscope. The tumour blood vessels were connected to branches of the femoral artery. Only the outer 200-500 micron of the tumour was extensively vascularized, with several concentric, incomplete layers of tortuous vessels, resembling onion skin. Light microscopy revealed necrosis and bleeding in the centre of the tumour, especially in the older tumours, which corresponded well to the central avascularity observed in the casts. There was an increase in venular and capillary density and tortousity towards the tumour in the adjacent muscular fascia. It is concluded that the cell line LS 174 T grows invasively inwards and recruits its vessels from the nude rat host. The overall tumour vascular pattern was unorganized, suggesting limited control of new vessel formation. Extravasations of resin, which were encountered in all cast tumours, can be a rough indicator of enhanced vascular permeability.

Adenocarcinoma↗

PubMed1987

Uptake and efflux of copper-64 in Menkes'-disease and normal continuous lymphoid cell lines.

The accumulation of copper over 2 h by normal lymphoid cells and those from Menkes'-disease patients (Menkes' cells) was found to be biphasic, with an initial phase of rapid uptake, an approach to steady state at around 40-60 min, followed by a further accumulation phase. The accumulation of copper was not diminished by the addition of a variety of metabolic inhibitors, suggesting that copper uptake is not an active process. The presence of carbonyl cyanide m-chlorophenylhydrazone in the culture medium stimulated the uptake and accumulation of copper in both normal and Menkes' cells to the same absolute level. This effect appeared to be specific for copper, since the accumulation of Zn and Cd was unaffected. Menkes' cells did not differ from normal in their initial rate of copper uptake. Analysis of the uptake curve suggested that the membrane transport of copper involves both passive and facilitated diffusion. Initial rate of efflux from the cells was approximated by two methods. Menkes' cells did not appear to be affected in this function. It seems likely that the basic defect in Menkes' disease involves a step in intracellular copper transport rather than the membrane transport of copper.

Antimetabolites↗