The serial study of c-myc expression in bone marrow biopsy specimens during treatment for acute myelogenous leukaemia.

The AMEX method of fixation permitted the serial study of c-myc expression in bone-marrow (BM) biopsies obtained from 6 patients with acute myelogenous leukaemia (AML) and one with myelodysplastic syndrome (MDS) during therapy with various cytotoxic and bioactive agents. BM cytotoxic therapy and therapy with bioactive agents was capable of altering c-myc expression in vivo. While cytotoxic therapy was generally associated with a fall in myc expression, it did not produce a dramatic effect on myc expression. Recombinant human granulocyte-macrophage colony-stimulating factor (RhGM-CSF) can increase and retinoic acid/alpha-interferon can decrease c-myc expression in myeloid cells in vivo.

Cell-cycle characteristics - alterable determinants of remission duration in a study of 179 standard risk newly diagnosed patients with acute myeloid-leukemia.

Prognostic factors were related to remission duration among 179 standard risk newly diagnosed acute myeloid leukemia (AML) patients who received identical induction and consolidation therapies. Following a bromodeoxyuridine infusion, labeling indices of bone marrow aspirate/biopsy, durations of S-phase and cell cycle (Tc) were determined. Patients with slowly cycling myeloblasts had longer remissions (Log rank p=0.03) than those with rapidly cycling myeloblasts. Multivariate analysis demonstrated that both WBC and Tc contributed to remission duration (p=0.01 and 0.005 respectively). Patients with slowly proliferating leukemias have longer remissions probably due to slower regrowth of leukemia between chemotherapy courses.

In situ localization of transforming growth factor beta and S-phase cells in patients with acute myeloid leukemia and myelodysplastic syndrome.

In situ localization of transforming growth factor beta (TGF-B) was accomplished in 16 acute myeloid leukemia (AML) and 11 myelodysplastic syndrome (MDS) cases. A modified and greatly shortened procedure for immunohistochemical localization of TGF-B using a monoclonal antibody was undertaken in plastic embedded bone marrow biopsy sections that demonstrated excellent preservation of morphologic detail. In addition, a double-label procedure was developed for the simultaneous detection of TGF-B and cells actively engaged in DNA-synthesis which were labeled in vivo by infusing thymidine analogues. Marked variation in intensity of TGF-B staining in interstitial areas of biopsies was noted among different patients. TGF-B was also conspicuously present in the basement membrane of blood vessel endothelial cells and the cytoplasm of megakaryocytes. Double-labeling revealed that S-phase cells in a number of MDS cases appeared clustered together and that megakaryocytes in S-phase were completely devoid of TGF-B.