Terminal deoxynucleotidyl transferase (TdT) enzyme activity in lymphocytes generates diversity in the Ag receptor repertoires by adding template-independent N nucleotides and disrupting homology-directed rearrangements. The importance of this diversity in vivo and the significance of the suppression of TdT during fetal life remain uncertain. Previous studies have shown that in TdT knockout mice...

An understanding of Ab responses to polysaccharides associated with pathogenic microorganisms is of importance for improving vaccine design, especially in neonates that respond poorly to these types of Ags. In this study, we have investigated the role of the lymphoid-specific enzyme TdT in generating B cell clones responsive to alpha-1,3 dextran (DEX). TdT is a DNA polymerase that plays a major...

We aimed to study the effect of elapsed time from AML diagnosis to treatment (TDT) on OS in a group of patients from public Hospital in Brazil. 41 AML (23 M, 18 F, 41 yrs, 18 84 yrs, from 2001 to 2004). There were 38 de novo AML and 3 secondary, median TDT was 6 days (range 1 82 d); the young ones were treated earlier than old ones (TDT 4 days vs 11, p = 0.07). Longer TDT (>10 d) was associated...

The ontogeny of cells containing the enzyme terminal deoxynucleotidyl transferase (TdT) in human fetal liver, bone marrow, and thymus has been studied using a highly specific antiserum to TdT together with monoclonal antiprecursor cell antibodies in double and triple marker immunofluorescence. TdT+ cells were first observed in fetal liver at 12 wk of gestation and accounted for 55% of the lymph...

To compare the differentiation of early B- and T-lymphoid precursors, we have used immune adherence combined with analytical flow cytometric techniques to enrich and characterize subsets of the small population of bone marrow mononuclear cells that express the enzyme terminal deoxynucleotidyl transferase (TdT) but lack the CD19 B-lymphoid marker. Two percent to five percent of bone marrow TdT +...

The 2',3'-dideoxynucleosides (ddNs) are currently undergoing clinical evaluation as antiretroviral agents in HIV-infected individuals. When phosphorylated, the ddNs (ddNTPs) function as chain-terminating substrate analogues with reverse transcriptase, thereby inhibiting HIV replication. These nucleoside analogues can also inhibit, by chain-terminating additions, the primitive lymphoid DNA polym...

OBJECTIVES Terminal deoxynucleotidyltransferase (TdT)-positive cells in non-neoplastic bone marrow are regarded as haematogones and show a characteristic morphology and immunophenotype. During our routine bone marrow trephine analysis of patients with acute myeloid leukaemia (AML) before and after treatment, we observed the presence of TdT-positive cells lacking CD34, CD10 and B cell antigens. ...

Terminal deoxynucleotidyl transferase (TdT) catalyzes the condensation of deoxyribonucleotides on 3'-hydroxyl ends of DNA strands in a template-independent manner and adds N-regions to gene segment junctions during V(D)J recombination. Although TdT is able to incorporate a few ribonucleotides in vitro, TdT discrimination between ribo- and deoxyribonucleotides has never been studied. We found th...

This study applies truth-default theory (TDT) to presidential candidates. TDT holds that people tend passively believe others without consciously considering whether they are being told the truth. But do voters have a toward candidates? In an experiment, across United States (N = 294) watched news interview in which candidate was either honest or deceptive. Party affiliation also manipulated. C...

Terminal deoxynucleotidyl transferase (TdT) is a useful marker for normal lymphocyte precursors and acute lymphoblastic leukemia (ALL). Our previous studies, however, have shown that for monitoring minimal residual disease in the circulation, assay for TdT alone is not sufficiently specific to distinguish leukemia cells from the background of rare normal blood TdT+ cells. In an attempt to incre...