TOPICS: Reticulocytes, residual RNA, reticulocyte count, corrected reticulocyte index, Hct, hemorrhage, chronic renal failure, erythropoietin, parvovirus B19, erythroid progenitor cells, aplastic crisis, aplastic anemia, hematopoietic failure, pancytopenia, anemia, thrombocytopenia, leukopenia, chemotherapy, carbamazepine, chloramphenicol, sulfonamide, benzene, gasoline, tobacco smoke, hepatitis, EBV, G-CSF, GM-CSF, bone marrow transplantation, myelophthisic process, infiltrative process