Electron microscopic studies of the bursa of Fabricius during the 15th and 16th day of embryonic development in the chick have shown the following findings in the submicroscopic structure of the cellular elements of the lympho-epithelial follicles. In the medulla, basal endodermal epithelial cells undergo mitosis and differentiation into lymphoblasts. During this transformation, there is a redu...

Bone marrow hematogones (B-lymphocyte precursors) may cause problems in diagnosis because of their morphologic and immunophenotypic similarities to neoplastic lymphoblasts. The purposes of this prospective, multiparametric flow cytometry study were to quantify hematogones across age groups and a spectrum of clinical conditions, to identify factors that affect the relative quantity of hematogone...

Lymphoblasts from seven children with T-cell lymphoblastic malignancies and three children with non-T, non-B acute lymphoblastic leukemia (ALL) were analyzed for ganglioside content. Nonmalignant T-cells from thymus served as controls. Both ganglioside and glycoprotein sialic acid were increased approximately 3-3.5-fold in T-cell disease compared to thymic tissue when expressed on a per cell ba...

BACKGROUND Mutations in the progranulin (PGRN) gene, leading to haploinsufficiency, cause familial frontotemporal lobar degeneration (FTLD-TDP), although the pathogenic mechanism of PGRN deficit is largely unknown. Allelic loss of PGRN was previously shown to increase the activity of cyclin-dependent kinase (CDK) CDK6/pRb pathway in lymphoblasts expressing the c.709-1G>A PGRN mutation. Since me...

Cellular accumulation of methotrexate polyglutamates (MTXPGs) is recognized as an important determinant of the cytotoxicity and selectivity of methotrexate in acute lymphoblastic leukemia (ALL). We identified a significantly lower cellular accumulation of MTXPGs in T-lineage versus B-lineage lymphoblasts in children with ALL, which is consistent with the worse prognosis of T-lineage ALL when tr...

Although cytosine arabinoside (araC) can induce a remission in a majority of patients presenting with acute myeloblastic leukemia (AML), a minority fail to respond and moreover the drug has less effect in acute lymphoblastic leukemia (ALL). The carrier-mediated influx of araC into purified blasts from patients with AML, ALL, and acute undifferentiated leukemia (AUL) has been compared to that of...

An experimental model to investigate orbital granuloma formation in inbred rats was established. Animals sensitized to trinitrophenyl ovalbumin (TNP-OA) and challenged retro-orbitally with TNP-OA covalently linked o Sepharose 4B beads specifically developed a granulomatous response. This granulomatous reactivity was passively transferred into normal animals by lymph node cells, but not by serum...

Interleukin 4 (IL-4) suppresses the growth of acute lymphoblastic leukemia (ALL) cells, but its clinical usefulness is limited by proinflammatory activity due mainly to the interaction of cytokine with endothelial cells and fibroblasts. Stroma-supported cultures of leukemic lymphoblasts were used to test the antileukemic activity of an IL-4 variant, BAY 36-1677, in which the mutations Arg 121 t...