Cytotoxicity of cytosine arabinoside on mouse progenitor stem cells.

In vitro colonogenic assay of mouse marrow granulocytic progenitor cells (spleen and agar colony forming cells) was carried out to determine the cytotoxic effect of 1-B-D-arabinofuranosyl cytosine on granulopoiesis. Mainly, the drug cytotoxicity on progenitor cells depended upon exposure time. Endotoxin stimulated colony forming cells showed enhanced cytotoxicity with shorter (25 min) exposure time as compared to a longer exposure of 60 min.

Transformation of hemopoietic stem cells by phytohemagglutinin (PHA) II. Mechanism of action.

It has long been known that phytohemagglutinin (PHA) stimulates transformation and growth of immune competent lymphocytes. Lymphoid cell colonies have previously been shown in the spleen with PHA treated lymph node cells from donor mice were injected into irradiated mice. This communication reports the results of in vivo effects of PHA stimulation on agar colony forming units and spleen colony forming units (CFU).

Cell mediated immune responses in experimental amebiasis.

Cell migration was inhibited when Entamoeba histolytica antigen-sensitized peritoneal exudate cells were cultured in the presence of specific antigen. The inhibition of cell migration was caused due to interaction of antigen with sensitized lymphocytes. This migration inhibition was well correlated with cell mediated immune responses, but not with circulating antibody levels.