Hydroxyurea Promotes The Reduction Of Spontaneous Bfu-e To Normal Levels In Ss And S/β Thalassemic Patients

We have studied the effects of hydroxyurea on growth and differentiation of early erythroid progenitor cells (BFU-e) from peripheral blood of sickle cell disease patients (five SS and two Hb S/β-thalassemia) in the presence or absence of exogenous stimulating factors. When the mononuclear cells from the sickle cell disease patients were cultured at diagnosis (before hydroxyurea treatment), there was an increased number of BFU-e in relation to controls (p < 0.05, Wilcoxon test) when cells were grown in the presence or absence of 5637 conditioned medium and erythropoietin. Colonies that developed in the absence of added growth factors were considered "spontaneous". A significant difference was observed after hydroxyurea treatment in the number of BFU-e obtained in the presence and absence of stimulus, with a higher reduction in the spontaneous BFU-e number. As expected, there was an increased Hb F level in these patients when compared with their pretreatment levels. There was no correlation between spontaneous BFU-e and hemoglobin levels in all patients studied.25117Bincoletto, C., Saad, S.T.O., Silva, E., Queiroz, M.L.S., Bcl-2 expression and autonomous proliferation in patients with acute myeloid leukaemia (1999) Eur. J. Haematol., 62, pp. 38-42Löwenberg, B., Van Putten, W.L.J., Touw, I.P., Delwel, R., Santini, V., Autonomous proliferation of leukemic cells in vitro as a determinant of prognosis in adult acute myeloid leukemia (1993) N. Engl. J. Med., 328, pp. 614-619Hunter, A.E., Rogers, S.Y., Roberts, I.A.G., Barrett, A.J., Russell, N., Autonomous growth of blast cells is associated with reduced survival in acute myeloblastic leukemia (1993) Blood, 82, pp. 899-903Norgaard, J.M., Langkjer, S.T., Palshof, T., Clausen, N., Pedersen, B., Hokland, P., Relation of blast cell survival and proliferation to chemotherapy resistance in AML (1996) Br. J. 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Genet., 14, pp. 168-171Yang, Y., Pace, B., Kitchens, D., Ballas, S.K., Shah, A., Baliga, B.S., BFU-e colony growth in response to hydroxyurea: Correlation between in vitro and in vivo fetal hemoglobin induction (1997) Am. J. Hematol., 56, pp. 252-258Huang, S.Z., Fibach, E., Gu, X.F., Schechter, A.N., Rogers, G.P., Zeng, Y.T., Hydroxyurea enhances β-globin expression and decreases aberrant splicing in cultured β-thalassemia cells (1995) Blood, 86, pp. 482aGoldberg, M.A., Brugnara, C., Dover, G.J., Schapira, L., Lacroix, L., Bunn, H.F., Hydroxyurea and erythropoietin therapy in sickle cells anemia (1992) Semin. Oncol., 19, pp. 74-81Dover, G.J., Charache, S., Hydroxyurea induction of fetal hemoglobin synthesis in sickle-cell disease (1992) Semin. 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Inc.: Amsterdam, The NetherlandsPerlingeiro, R.C.R., Costa, F.F., Saad, S.T.O., Queiroz, M.L.S., Early circulating erythroid progenitor cells and expression of erythropoietin receptors in sickle cell disease (1998) Eur. J. Haematol., 60, pp. 226-232Ikuta, T., Atweh, G., Boosalis, V., Ewhite, G.L., Da Fonseca, S., Boosalis, M., Faller, D.V., Perrine, S.P., Cellular and molecular effects of a pulse butyrate regimen and new induces of globin gene expression and hematopoiesis (1998) Ann. N.Y. Acad. Sci., 850, pp. 87-99Charache, S., Mechanism of action of hydroxyurea in the management of sickle cell anemia in adults (1997) Semin. Hematol., 34, pp. 15-21Saleh A.W., Jr., Hillen, H.F.P., Pharmacological induction of foetal haemoglobin synthesis in sickle-cell disease (1997) Neth. J. Med., 51, pp. 169-17

Immunoglgbulin Levels And Cellular Immune Function In Lead Exposed Workers

The immunological status of lead acid batters workers with blood lead levels and urinary delta-aminolevulinic acid (ALA-U) concentrations ranging from safe to toxic levels has been examined and compared with those of non-exposed, age and sex matched controls. No differences in the serum concentrations of IgG, IgA and IgM between the populations were observed and there existed no correlation between blood lead level or ALA-U concentrations and serum immunoglobulin levels. In addition assessment was made of the capacity of peripheral blood mononuclear cells to respond to the mitogen phytohaemagglutin in (PHA), a correlate of T cell function. As before, there was no difference between exposed and control populations and no correlation between reactivity and blood lead concentration. Our data suggest that chronic exposure to lead fail to compromise lymphocyte function in man. © 1994 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted.16111512