1,721,283 research outputs found
ABNORMAL INVITRO DIFFERENTIATION OF PERIPHERAL-BLOOD CLONOGENIC B-CELLS IN COMMON ACUTE LYMPHOBLASTIC-LEUKEMIA DURING COMPLETE REMISSION
No full textAn in vitro B cell colony assay system was used to evaluate B cell growth from peripheral blood precursors in common acute lymphoblastic leukemia (CALL) patients in remission during maintenance therapy and in normal controls. Major differences between the two groups were found in the phenotypic and morphologic features of pooled colony cells. In both cases, the cells were E-. Controls' cells were surface immunoglobulin (sIg)-positive, and some (mean, 25%) expressed la determinants. By Wright-Giemsa staining, they appeared as plasmacytoid cells. In contrast, patients' cells had predominantly a lymphoblastoid appearance, fewer cells had developed sIg, and a large fraction (mean, 43%) were Ia-positive. Moreover, the CALL antigen (CALLA) was expressed by a mean of 18% (range, 2% to 72%) of the patients' colony cells, whereas CALLA was never found in control colonies. Thus, cells with immature features persist in the colonies of CALL patients. Secondary colonies could be generated from the patients' cultured cells, indicating their self-renewal capacity. CALLA + cells were also present in the secondary colonies. Finally, cytogenetic studies showed that a fraction of the patients' colony cells had karyotypic abnormalities similar to that of the original lymphoblasts. It is believed that in CALL patients this B cell assay permits the clonal expansion of residual circulating cells linked to malignant clones that are not detectable by classic hematologic and cytologic methods
HUMAN rIL4 FAILS TO DIFFERENTIATE LEUKEMIC B-CELL PROGENITORS GROWING UPON S17 STROMAL CELL LINE
No full textStromal cells appear to be key regulatory elements in hematopoiesis and lymphopoiesis. Several stromal cell lines can support B lineage by creating a hematopoietic microenvironment via cell contact or regulatory humoral molecules. These activities have been efficiently mediated by an adipocytic stromal cell line 14F1.1 on infant leukemia cells expressing a hybrid pre-B myeloid phenotype. Several murine cell clones, however, are known to have different ability to support growth and/or differentiation of leukemic cells depending on the maturational stage in which malignant cells are frozen. Pre-B-cell lines and fresh leukemias were therefore cultivated on S17 stromal cell line, before and after exposure to human recombinant interleukin 4 (rIL4), a cytokine whose effects on the growth and differentiation of the B-cell compartment depend on the developmental stage of the target B cell. In the present work, leukemic cells, both in suspension and in close contact with stromal cells, maintained their original phenotype throughout the whole period of co-culture with S17, either before or after exposure lo human rIL4
La malattia Residua Minima: significato, approccio metodologico e implicazioni nella leucemia linfoblastica acuta
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STUDY ON COMMON ACUTE LYMPHOBLASTIC-LEUKEMIA (CALL) PATIENTS DURING COMPLETE REMISSION (CR) USING A COLONY ASSAY
No full textEvaluation of T-lymphoblastoid cell line derived factors on human B and T cell precursors
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