Two distinct classes of granulocyte progenitor cells present in normal mouse bone marrow are expressed sequentially in the vivo plasma clot diffusion chamber culture system. By several criteria, progenitor cells giving rise to granulocyte colonies on day 4 of culture (CFU-D4) are different from those giving rise to colonies on day 7 (CFU-D7). These differences include: cell cycle activity as me...

Low doses of cytosine arabinoside (ara-C) have recently been administered by intravenous (IV) infusion and intermittent subcutaneous (SC) injection to patients with pre-leukemia and acute leukemia. Our studies have demonstrated that the continuous IV infusion of low-dose (20 mg/m2/d) ara-C produces hematologic improvement in patients with preleukemic syndromes. The present work has monitored pl...

Retinal dysplasia was produced in newborn rats treated postnatally with the antimitotic substance, cytosine arabinoside (ara-C). In rats examined from 6 to 60 days, there were numerous retinal rosettes surrounded by photoreceptor cells and bipolar cells containing photoreceptor cell processes, displaced nuclei, and cellular debris. Abnormal development and alignment of photoreceptor cell proces...

19 years old, male was diagnosed as a case of acute myeloid leukaemia (AML M5). Subsequent to standard induction chemotherapy (daunorubicin and cytosine-arabinoside) and consolidation with highdose cytosine-arabinoside, he developed non-pruritic, papulo-nodular erythematous lesions localised over the chest (Fig. 1). The differential diagnoses considered were Drug rash, Cutaneous infections, Swe...

with the scanning electron microscope and quantitated by cell volume determination. Agents that raise intracellular levels of cAMP were found to increase the cell volume of L-cells. Because cAMP is a known inhibitor of cell division, we investigated other inhibitors of cell division and their effects on L-cells. In addition to cAMP-elevating com pounds, cytosine arabinoside and Colcemid caused ...

We report an unusual case of a 6-year-old male child who presented with fever and a cough of one month's duration. A bone marrow aspiration and cytogenetics were suggestive of acute myeloid leukaemia with t(8;21)(q22;q22). A chest x-ray and computed tomography of the thorax showed a soft tissue lesion in the right lung. The fine needle aspiration cytology (FNAC) of this lesion was suggestive of...

Combined immunochemotherapy regimens using the investigational biotherapeutic agent B43(anti-CD19)-poke-weed antiviral protein (PAP) immunotoxin may offer an effective treatment for refractory B-cell precursor leukemias. The purpose of the present study was to explore and identify effective combinations of B43-PAP with standard chemotherapeutic drugs, including the anthracyclin doxorubicin, the...

The thymus is a site of active T-Iymphoid cell proliferation and DNA synthesis. In this study, the capacity of human thymocytes for nucleoside transport was assessed both by cytosine arabinoside influx and by equilibrium binding of nitrobenzylmercaptopurine riboside (NBMPR). a specific ligand for the equilibrative nucleoside transporter of leukocytes. The proportion of freshly isolated thymocyt...

Two girls, each less than 2 yr of age, developed acute megakaryoblastic leukemia (malignant myelosclerosis). Both presented with anemia, severe thrombocytopenia, and a low percentage of blasts in their peripheral blood. Their marrow showed marked reticulin fibrosis with an increase in blasts and immature megakaryocytes. The blasts stained negatively for myeloperoxidase and Sudan Black B, but sh...