P.-Y. L'Esperance

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Granulocyte colonies can be grown from leukocyte-rich plasma obtained from normal human peripheral blood. Purification of lymphocytes by the Ficoll-Hypaque gradient method and subsequent removal of monocytes achieved a 10-fold increase in the number of colonies formed, suggesting that the colony-forming cell is nonadherent, nonphagocytic, and(More)
Congenital neutropenia is a lethal disease characterized by recurrent infections beginning in the neonatal period, absence of neutrophils in the peripheral blood, eosinophilia, and monocytosis. The bone marrow shows an apparent "maturation arrest" of the neutrophil series at the promyelocyte stage. Granulocytic colonies grown in vitro in soft agar medium(More)
Children with congenital neutropenia (Kostman disease) present a syndrome of recurrent and eventually fatal bacterial infections. The disease is uniformly lethal and the mean age at death is 24 months. To attempt to better understand the nature of this inborn error, we have studied marrow and peripheral blood of 3 children with the disease. Along with(More)
A 56-year-old man developed chronic mucocutaneous candidiasis (MCC) and pernicious anemia. Nine years later he developed aplastic anemia which ultimately was fatal. A small thymoma was found at autopsy. He was anergic and his mononuclear leukocytes (MNL) failed to undergo a proliferative response in culture to soluble antigens. His monocytes did not mediate(More)
The manner by which human and calf thymic extracts induce precursor cells of human marrow to differentiate in vitro into T lymphocytes has been studied using as a T-cell marker the spontaneous rosette formation technique of human T lymphocytes with sheep erythrocytes (E rosette). These findings confirm previous observations made in the study of the same(More)