Atsunobu Hiraoka

A novel Ph1 chromosome positive cell line established from a patient with chronic myelogenous leukemia in blastic crisis

A novel Philadelphia (Ph1) chromosome positive cell line, designated KYO-1, was established from the peripheral blood of a patient with chronic myelogenous leukemia (CML) in blastic crisis. Although this line had a unique capacity to differentiate spontaneously along the erythroid and monocytoid lineages as evidenced by cytochemical analysis for the first several months, the capacity was gradually lost after repeated passages. The results suggest that KYO-1 is an undifferentiated myeloid cell line. This cell line provides a useful source for studying differentiation and proliferation of pluripotent stem cells from CML in blastic crisis.

Radioautographic studies on the formation and maturation of bone marrow lymphocytes in mice

Abstract. DNA labelling by [3H]thymidine and the sandwich radioimmunolabelling method were used to characterize marrow lymphoid cells and to study the kinetics of production and maturation of small lymphocytes in the bone marrow of adult mice. Marrow lymphoid cells consisted of non‐proliferating small lymphocytes, 30–40% of which had detectable surface immunoglobulin (SmIg), and proliferating large lymphoid cells lacking SmIg. Double‐labelling experiments employing [3H]thymidine in vivo followed by sandwich radioimmunolabelling in vitro indicated that marrow small lymophocytes lack detectable SmIg when they are formed but develop SmIg within the first few days after production. Marrow lymphocytopoiesis includes; (1) praliferation of large lymphoid cells, which are presumptive small lymphocyte progenitors, which have a cell cycle time of 14–15 hr, and (2) a 3–5‐day intramyeloid stage when many newly formed small lymphocytes undergo maturational changes towards the B cell lineage.