Dynamic morphology applied to human and animal leukemia cells.

Dynamic morphology, which describes the shape and surface architecture of fixed cells in terms related to their behavior in the living state, is based on the concurrent use of two methods: scanning electron microscopy and microcinematography. This combination has both advantages and disadvantages. In this study on leukemic cells, we were able to draw the following conclusions about the usefulness of dynamic morphology.

Intermediate-sized filaments in leukemia cells.

Electron microscopic studies on human acute leukemias have shown that leukemic populations contain spherical and polarized cells in various proportions. As recorded by time-lapse cinematography, the two cell configurations represent different functional states: resting cells are completely spherical, locomotive cells are polarized with a conspicuous extension posteriorly. In 9 out of 12 cases of acute myeloid leukemia the two cell configurations were found to coincide with a different pattern of intermediate-sized filaments (ISF).

Motility of L 5222 rat leukemia cells in the flattened state. Evidence against emperipolesis.

Emperipolesis is the term for the assumed penetration of living cells into other living cells. As reported earlier, L 5222 rat leukemia cells, migrating in vitro, change from a spherical to a spread configuration when they meet flat cells, and continue to move in this shape within the contours of the target cells. Whether or not this close cellular association corresponded to emperipolesis could not be determined with phase and interference contrast cinemicrography alone.

The role of cellular locomotion in leukemic infiltration. An organ culture study on penetration of L 5222 rat leukemia cells into the chick embryo mesonephros.

The significance of cellular locomotion for leukemic infiltration was investigated using L 5222 rat leukemia cells. Previous cinemicrographic studies have shown that these cells are able to locomote only after formation of a uropod-like posterior extension. This characteristic locomotive configuration of L 5222 cells is easily recognizable in scanning electron micrographs and appropriate sections.

Synthesis of vaccinia viral antigens in HeLa cells in the presence of isatin beta-thiosemicarbazone.

Vaccinia virus antigens, in HeLa cells treated with the antipox virus drug isatin beta-thiosemicarbazone (IBT), were analyzed by immunoprecipitation, followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The total radioactivity in the immunoprecipitate was decreased to almost 50% in the presence of the drug as compared to its absence. An inhibition also occurred with an IBT-dependent mutant (IBT(D)) when growing in the absence of IBT.

Motility of l5222 rat leukemia cells.

The locomotive behavior of cells of the transplantable rat leukemia L5222 was studied by means of microcinematography. It was found that these cells exhibit a homogeneous pattern of movement resembling that of normal lymphoblasts and stimulated lymphocytes. This is in contrast to cytochemical and ultrastructural evidence according to which the cells are completely undifferentiated.

[Recrudescence of imported malaria (apropos of 30 recent cases)].

30 cases of imported malaria were diagnosed in the Laboratoire Central de Parasitologie of the Pitié-Salpêtrière C.H.U.

[Acute amebic abscess of the liver followed by colonic ulcers. Report of 2 cases].

Two unusual cases of ruptured acute amebic liver abcess are presented one with inferior vena caval compression. Surgical drainage was followed by the development of colonic complications (haemorrhage and perforation) although the patients were under specific therapy. After a new surgical operation both cases were cured.