Modulation of in vitro chemosensitivity in acute myelogenous leukemia cell line by GM-CSF: opposing effects observed with different cytotoxic drugs and time exposure.

In some studies the GM-CSF (granulocyte-macrophage colony-stimulating factor) increased the in vitro sensitivity of acute myeloid leukemia (AML) cells to cytosine arabinoside (Ara-C), however, in clinical trials no favorable effects were shown. We used a GM-CSF responsive AML cell line (AML 193) to test the effects of growth stimulation on in vitro efficacy of Ara-C and methotrexate (MTX). In 6 days continuous exposure, dose dependent Ara-C cytotoxicity was counteracted by GM-CSF.

[Mixed IgM kappa-IgM lambda cryoglobulinemia with a double monoclonal serum component. A case report].

The paper describes a case of mixed cryoglobulinemia with a double serum monoclonal component. The serum immunofixation revealed that a monoclonal component was IgG lambda while the other was positive for antisera anti-IgM, anti-k and anti-lambda even if the EP proved monoclonal. Resuspended cryoglobulins had the same electrophoresis pattern and the same reactivity for the antisera as the IgM serum component.

[Determination of free light chains in biological fluids by a latex test].

A novel latex test for the detection and characterization of free light chains in different biological fluids is presented. Accuracy, reliability and sensitivity of the method are evaluated, by comparing experimental results with reference techniques for light chain detection. The assay is tested for quickness and easiness, in order to be routinely used in laboratories of Clinical Chemistry, Haematology, Nephrology and Radiology.

Enhancement of methotrexate cytotoxicity by modulation of proliferative activity in normal and neoplastic T lymphocytes and in a myeloid leukemia cell line.

Recent advances in the modulation of cell kinetics with growth factors suggest that the effect of cycle-specific cytostatic drugs can be enhanced by combination with such factors. The truth of this hypothesis was investigated by studying the effect of phytohemagglutinin and/or interleukin 2 on the sensitivity to methotrexate (MTX) of normal T lymphocytes and of lymphoblasts of a patient with acute T-cell lymphoid leukemia. In both cases, inhibition of proliferation by MTX was increased from less than 30% in resting cells or those suboptimally stimulated, in the case of leukemic blasts, to 68-83% in maximally stimulated cells.