Acute promyelocytic leukemia developing in untreated essential thrombocythemia.

We describe a patient with untreated essential thrombocythemia (ET) who developed microgranular variant of acute promyelocytic leukemia, 9 years after the initial diagnosis of ET. He achieved complete remission (CR) but relapsed 11 months later. After achieving the second CR, he received peripheral stem cell transplantation from his HLA complete-matched sibling.

Prediction of the ability to purge clonogenic B cell lymphoma from normal BM in vitro by heat: their survival curves correspond to a curve reflecting mortality in humans.

To develop new purging regimens for ABMT the ability to predict potential for purging of tumor cells from BM is important. Since the sensitivity of human B cell lymphoma to hyperthermia is not known, we examined its effect on the growth of B cell lymphoma cell lines (Raji and Daudi) in vitro to evaluate potential for purging clonogenic tumor cells from normal marrow by heat, using a limiting dilution assay to measure log depletion of tumor cells in a 20-fold excess of normal BM. When exposed to heat (42-43 degrees C) for 120 min, both clonogenic Raji and Daudi cells were dramatically reduced (a 4-to-6 log reduction) with time, whereas at 42 degrees C over half and at 43 degrees C 10% of normal granulocyte-macrophage progenitor cells survived for the same time period.