Influence of laminin or fibroblasts upon colony formation in the mouse by B16 melanoma cell spheroids: a morphometric analysis.

By microscopical observation and using an original morphometric method, we analyzed on histological sections the rate of lung colony formation after the intravenous injection into the mouse of B16 melanoma cells previously cultivated in vitro as aggregates. After the injection of B16 pure spheroids, superficial lung colonies were more numerous than internal lung colonies. After the injection of mixed spheroids (B16 + 3T3 fibroblasts), the size of colony sections was increased.

Fc receptors on granulocytes from patients with rheumatoid arthritis and Felty's syndrome.

Receptors for the Fc part of IgG on polymorphonuclear cells (FcR) of patients with rheumatoid arthritis (RA), Felty's syndrome (FS) and healthy controls (HC) were studied by means of a rosetting technique with rabbit IgG coated ox erythrocytes. When cold isolated polymorphonuclear cells (PMN) were incubated at room temperature the percentage of rosette forming PMN (RF-PMN) from HC was more than twice that measured directly after isolation at 4 degrees C. The same phenomenon was observed for PMN from patients with RA although the RF-PMN increased by only 1/3.