Purine nucleoside phosphorylase (PNP) activity has been measured in the lymphoblasts of 22 patients with acute lymphoblastic leukemia (ALL) and correlated with routine immunologic cell surface markers. Fourteen of the 22 patients were considered to have non-T, non-B-cell ALL; 8 patients had T-cell disease. The median PNP activity in 21 control samples of normal peripheral blood mononuclear cell...

Hyperdiploidy (>50 chromosomes, or a DNA index >1.16) confers a favorable prognosis in B-lineage acute lymphoblastic leukemia of childhood. Children with B-lineage acute lymphoblastic leukemia whose lymphoblasts at diagnosis accumulate high levels of methotrexate (MTX) and MTX polyglutamates (MTXPGs) in vitro experience a better eventfree survival than those whose lymphoblasts do not (Blood 76:...

We present findings on an infant with neonatal megaloblastic anemia, homocystinuria, and neurologic dysfunction that included developmental delay and tonic seizures. There was no methylmalonic aciduria. Cyanocobalamin therapy was accompanied by complete hematologic and neurologic recovery, diminished homocystine excretion, and subsequently normal neurologic development. Cultured fibroblasts and...

these patients, in general, have a more aggressive form of disease (2, 28, 29). Most patients have lymphoblasts that lack identifiable surface markers. Thus, the subcategories of acute Iymphocytic leukemia in humans probably repre sent proliferation of different clones of lymphoblasts. There are known differences in glucocorticoid susceptibility among functional subcategories of lymphocytes in ...

these patients, in general, have a more aggressive form of disease (2, 28, 29). Most patients have lymphoblasts that lack identifiable surface markers. Thus, the subcategories of acute Iymphocytic leukemia in humans probably repre sent proliferation of different clones of lymphoblasts. There are known differences in glucocorticoid susceptibility among functional subcategories of lymphocytes in ...

A purine nucleotide (inosinate) cycle is demonstrated with human lymphoblasts. The lymphoblast requires approximately 50 nmol of purine/10(6) cell increment. When the inosinate cycle is interrupted by the genetic, severe deficiency of either or both purine nucleoside phosphorylase (PNP) or hypoxanthine phosphoribosyltransferase (HPRT), purine accumulates in the culture medium as inosine, guanos...

Peripheral blood samples from 57 children with newly diagnosed E-rosette-negative, surface-immunoglobulin negative acute lymphocytic leukemia (ALL) were studied for the presence of a leukemia-associated antigen (ALLA). Ficoll-Hypaque separated cells were tested using a rabbit antiserum to human null lymphoblasts and an indirect immunofluorescent assay. The percentage of ALLA-positive cells were...

BACKGROUND Chemotherapy plays a very important role in the treatment of leukemia but the resistance properties of the lymphoblasts limit the effect of chemotherapy. One of the main mechanisms of resistance to chemotherapy is the increased expression of MDR1 gene. The aim of this study was to explore the effect of resveratrol on the expression of MDR1 gene in leukemic lymphoblast of new cases of...

Low activity of 5'-nucleotidase (5'-ribonucleotide phosphohydrolase, EC 3.1.3.5) in T lymphoblasts may explain the marked sensitivity of this cell to deoxynucleotide accumulation when compared to B lymphoblasts. The relevance of such observations with cultured cells to the normal immune system requires the demonstration of similar differences in the 5'-nucleotidase activity of normal human lymp...

A modification of the double rosette method of Mendes et al. was used to examine lymphoblasts from 22 children with acute lymphoblastic leukemia and 1 child with lymphoblastic lymphoma. This method was used since it directly and simultaneously detected T, B, and null lymphocytes as well as monocytes. In addition it detected the D lymphocyte which has both Tand Bcell surface markers. Based on su...