title: Analysis of human thymocyte subpopulations using discontinuous gradients of albumin: precursor lymphocytes in human thymus.
abstract: Precursor lymphocytes, obtained from human tissue on bovine serum albumin (BSA) gradients followed by removal of sheep erythrocyte (E)-reactive thymocytes on Ficoll, are the predominant lymphoid subpopulation found in young fetal thymuses. This subpopulation shows a progressive decline in relative numbers during fetal life, accompanied by a rise in both the relative and absolute numbers of E-reactive thymocytes. Precursor thymocytes differentiate in vitro to E-reactive cells resembling T cells in their morphology, sedimentation on BSA gradients, and response to phytohemagglutinin. Agents tending to increase intracellular concentrations of cyclic-AMP accelerate the rate of differentiation of precursor cells to lymphocytes which closely resemble T cells.
mesh_terms: D000367:Age Factors; D003994:Bucladesine / Q000494:pharmacology; D002448:Cell Adhesion; D002454:Cell Differentiation; D002469:Cell Separation; D002478:Cells, Cultured; D002499:Centrifugation, Density Gradient; D005865:Gestational Age; D006801:Humans; D008214:Lymphocytes / Q000276:immunology*; D008934:Mitogens; D011947:Receptors, Antigen, B-Cell / Q000032:analysis; D013601:T-Lymphocytes / Q000648:ultrastructure; D013950:Thymus Gland / Q000196:embryology / Q000276:immunology*; D013997:Time Factors
chemical_list: D008934:Mitogens; D011947:Receptors, Antigen, B-Cell; D003994:Bucladesine