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Biomedical subjects

D M Easty

Publications and source records attributed to D M Easty.

6 recordsLinked to original sources

Time-lapse filming of cellular interactions within living tissues. III. The role of cell shape.

By a further development of the technique for time-lapse filming of organ cultures, it has become possible to observe the internal structure of the living tissues and to study the dynamics of intercellular contacts within the tissue. This method has been applied to a study of the interaction between the tissues of the chick chorioallantoic membrane and non-malignant fibroblasts, polyoma virus-transformed fibroblasts, and Harding-Passey melanoma cells. The behaviour of these cells in the absence and in the presence of colcemid has been investigated. From these studies it is concluded that disturbances in cell shape brought about by colcemid do not affect the invasive properties whereas the surface polypodial activity shown by the malignant cells is a major factor in tumour invasion.

Cell Membrane

Breast-cancer osteolysis, bone metastases, and anti-osteolytic effect of aspirin.

23 (60%) of 38 human breast carcinomas had significant in-vitro osteolytic activity. All patients presenting with bone metastases or hypercalcaemia had active tumours. Over a subsequent three-year follow-up period, bone metastases did not develop in any of the 15 patients with inactive tumours, and metastases at other sites developed in only 2. Of the 23 patients with active tumours, 7 either had, or have since developed bone metastases; in 4 of these hypercalcaemia also developed. 14 tumours, chosen at random, were tested for in-vitro osteolytic activity in the presence and absence of aspirin, which inhibits prostaglandin synthetase. The activity of 8 of the 9 osteolytically active tumours was significantly, though not completely inhibited by aspirin. Although the number of patients is limited, these results indicate that the in-vitro osteolysis assay may detect substances, perhaps including prostaglandins, produced by breast tumours which affect prognosis and contribute to the subsequent formation of bone metastases.

Animals

Human breast tumour-induced osteolysis and prostaglandins.

Osteolysis effected in vitro by breast carcinomas can be inhibited by aspirin. Some prostaglandins stimulate in vitro bone resorption. Our results indicate that whilst osteolytically active PGE and PGF are released by the carcinomas in most cases, some other osteolytic principle is released as well.

Aspirin