Kimura N

Enhancement of cell killing of HL-60 cells by ultrasound in the presence of the photosensitizing drug Photofrin II

Enhancement of acute cell killing of HL-60 cells by low-level ultrasound in the presence of the photosensitizing drug Photofrin II was examined. HL-60 cells were exposed to ultrasound (270 kHz) at intensities of 150, 300 and 450 mW/cm2 for 60 s in the presence of Photofrin II (200 micrograms/ml). Cell survival after treatment was 49.6 +/- 5.1%, 34.5 +/- 3.1% and 27.4 +/- 3.9%, respectively. Ultrasound exposure alone at 150, 300 and 450 mW/cm2 resulted in a decrease in cell survival to 92.9 +/- 1.5%, 82.3 +/- 2.2% and 77.9 +/- 7.2%, respectively. The cell survival rate after the addition of Photofrin II alone showed no significant cell killing. These results indicate that Photofrin II was sensitized by low-level, non-thermal ultrasound to enhance the cell killing of HL-60 cells.

Clinical and biologic characteristics of CD7+ acute myeloid leukemia: Our experience and literature review

Six patients with acute myeloid leukemia (AML) expressing CD7 antigen (CD7+ AML) were studied. They consisted of five patients with M1 and one with an M2 morphology. Two cases expressed other lymphoid-associated antigens, in addition to CD7. The complete remission rate was 50%. One patient had central nervous system recurrence. Cytogenetic analysis demonstrated normal karyotypes in all the cases. All but one had germline configurations of the T-cell receptor (TCR) genes and immunoglobulin heavy chain gene. However, all did not have detectable recombinase activating gene-1 activity by the RT-PCR technique. We performed colony formation assay in two patients, and no enhancement of colony formation by granulocyte colony-stimulating factor was noted. The results presented here, together with those reported previously, suggest that CD7+ AML may demonstrate lineage infidelity.