ORBi Open Repository and Bibliography
In may 2007, the ULg's Administrative Board (joined in June 2007 by the FUSAGx) decided to create an institutional repository and defined a strong institutional self-archiving policy to increase the visibility, accessibility and impact of the University's publications (Board's decision).
This decision led to the official launch, in November 2008, of the ORBi platform including both the Academic Bibliography and the Institutional Repository of the Wallonia-Europe University Academy.
Human health sciences => Hematology
Mostrando recursos 601 - 620 de 791
Transferrin receptors in rat plasma. - Beguin, Yves; Huebers, H A; Josephson, B; Finch, C A
Antigenic material in rat plasma reacting with rat transferrin receptor antibodies was identified as an intact receptor molecule complexed with transferrin. Plasma transferrin receptors were measured by ELISA in rats of different age and sex, of different iron status, with different degrees of erythropoiesis, and with inflammation. An inverse relationship between iron status and receptor number was found, whereas a direct relationship existed between erythropoiesis and receptors. These changes in receptor number can be explained by assuming that the number of tissue receptors determined the number of plasma receptors and that the erythroid cells possessed most of the body's receptors....
Random distribution of iron among the two binding sites of transferrin in patients with various hematologic disorders. - Beguin, Yves; Huebers, H; Finch, C A
The distribution of iron among the two binding sites of transferrin was studied by isoelectric focusing in 41 patients with a variety of disorders of iron metabolism and erythropoiesis. The proportion of diferric and the two monoferric transferrins were very close to the values predicted from the transferring saturation. It is concluded that iron distribution on transferrin is random or close to random within the experimental error in patients with a variety of clinical disorders.
The behavior of asialotransferrin-iron in the rat. - Beguin, Yves; Bergamaschi, G; Huebers, H A; Finch, C A
The effect of desialylation of rat and human transferrins on hepatocyte processing of the protein and its iron was studied in rats. No alteration in early transferrin catabolism was observed. Radioiron disappearance from the plasma and liver iron uptake were more rapid for asialotransferrins than for normal transferrins (P less than .001). Furthermore, radioiron plasma clearance of human tri-sialotransferrin was faster (P less than .05) and liver uptake higher (P less than .002) than for human pentasialotransferrin. When the asialoglycoprotein receptor was blocked by the prior injection of asialofetuin, asialotransferrin behaved like normal transferrin. When the transferrin receptor was blocked...
Experience with a totally implantable catheter in adult patients: a single institution retrospective study of 114 cases. - Defraigne, Jean-Olivier; Closon, Marie-Thérèse; Bruyninx, Luc; Dewandre, Jocelyne; Hourlay, Paul; Meurisse, Michel; Honore, Pierre; Bury, J; Beguin, Yves
One hundred and fourteen consecutive totally implantable catheters were inserted in 114 patients between April 1984 and April 1987. Catheters were inserted under neuroleptanalgesia, through the jugular vein in 101 cases or the internal saphenous vein in 13 cases. No problem was encountered during the insertion procedure. Infection occurred in 5.2% of the patients but removal of the device was required in only 2.6%. Occlusion of the catheter occurred in 6.1% of the patients but never during the first 2 months. This complication rate is lower than the one observed with external tunnelled catheters. The comfort of the patient is...
Hepatocyte iron release in rats. - Beguin, Yves; Huebers, H A; Weber, Géraldine; Englebert, Micheline; Finch, C A
Hepatocyte iron release was studied in vivo in rats. After the injection of iron 59-labeled ferritin, hemoglobin, or human asialotransferrin, the proportions of the radioactive iron returned to the plasma and incorporated into stores were determined under various conditions. Iron 55-labeled rat transferrin was injected at the same time as the 59Fe-labeled compound, and storage iron release was calculated from the cumulative incorporation of the two isotopes in the red cell mass over 2 weeks. The various 59Fe-labeled compounds were processed differently by the hepatocyte, but the radioactive iron was incorporated in the same iron stores. About 6% of the...
Model of reticuloendothelial iron metabolism in humans: abnormal behavior in idiopathic hemochromatosis and in inflammation. - Fillet, Georges; Baldelli, L; BEGUIN, Yves
Iron transport in the reticuloendothelial (RE) system plays a central role in iron metabolism, but its regulation has not been characterized physiologically in vivo in humans. In particular, why serum iron is elevated and RE cells are much less iron-loaded than parenchymal cells in idiopathic hemochromatosis is not known. The processing of erythrocyte iron by the RE system was studied after intravenous (IV) injection of 59Fe heat-damaged RBCs (HDRBCs) and 55Fe transferrin in normal subjects and in patients with iron deficiency, idiopathic hemochromatosis, inflammation, marrow aplasia, or hyperplastic erythropoiesis. Early release of 59Fe by the RE system was calculated from...
Ferrokinetic study of splenic erythropoiesis: relationships among clinical diagnosis, myelofibrosis, splenomegaly, and extramedullary erythropoiesis. - Beguin, Yves; Fillet, Georges; Bury, J; Fairon, Yvette
Splenic erythropoiesis was demonstrated by surface counting of 59Fe in 129 of 1,350 ferrokinetic studies performed over a 15 year period. These 129 studies were carried out in 108 patients, including 40 with chronic myelogenous leukemia (CML), 24 with agnogenic myeloid metaplasia (AMM), 18 with polycythemia vera (PV), six with a myelodysplastic syndrome, five with acute leukemia, three with prostate or breast carcinoma, two each with aplastic anemia or Hodgkin's disease, and one each with idiopathic thrombocythemia, multiple myeloma, chronic renal failure, or treated hypopituitarism. Splenomegaly was present in 83% of the studies and hepatomegaly in 72%. Grade II-III myelofibrosis...
Intact transferrin receptors in human plasma and their relation to erythropoiesis. - Huebers, H A; Beguin, Yves; Pootrakul, P; Einspahr, D; Finch, C A
Intact transferrin receptor molecules complexed with transferrin were found in human plasma. The concentration of receptors was determined by an enzyme-linked immunosorbent assay that uses polyclonal antibodies. The mean concentration of 8,279 micrograms/L in 56 normal adults appears to be unrelated to age or sex. Additional receptor measurements were performed on plasmas from 260 subjects with erythropoietic disorders. Decreased concentration of plasma receptors was found in patients with erythroid hypoplasia and increased numbers in those with erythroid hyperplasia. Ferrokinetic measurements of erythropoiesis were compared with numbers of receptors in 148 subjects, and a close correlation was found (r = .86)....
Serum immunoreactive erythropoietin during pregnancy and in the early postpartum. - Beguin, Yves; Lipscei, G; Oris, Renée; Thoumsin, H; Fillet, Georges
We studied 209 women during normal pregnancy, at delivery, or in the early postpartum, to determine whether erythropoietin (EPO) response was appropriate for the degree of anaemia. Serum immunoreactive EPO was measured in 74 nonpregnant women, including 33 normal subjects (16.4 +/- 4.1 mU/ml) and 41 women with hypoplastic, haemolytic, dyserythropoietic, or iron-deficient anaemia. An inverse linear relationship (R = -0.88, P less than 0.0001) between log(EPO) and Hct was observed. Predicted EPO values were derived for each Hct and an O/P ratio of observed/predicted log(EPO) was calculated for each sample (1.00 +/- 0.10, range 0.80-1.20). Serum EPO levels (mU/ml)...
Circulating erythropoietin levels after bone marrow transplantation: inappropriate response to anemia in allogeneic transplants. - Beguin, Yves; Clemons, G K; Oris, Renée; Fillet, Georges
We studied 24 recipients of autologous bone marrow transplantation (ABMT) or allogeneic BMT (BMT) to determine whether impaired erythropoietin (Epo) response to anemia could delay full erythropoietic recovery. Observed Epo levels were compared with predicted levels based on the relationship between Epo and hematocrit in 125 control subjects. Circulating Epo levels were normal during conditioning and the early posttransplant period. Between days 21 and 180, Epo levels remained normal in ABMT patients but were inappropriately low for the degree of anemia in BMT patients. Median time to full erythropoietic engraftment was longer in BMT than in ABMT recipients. Circulating Epo...
Blunted erythropoietin production and decreased erythropoiesis in early pregnancy. - Beguin, Yves; Lipscei, G; Thoumsin, H; Fillet, Georges
After decreasing in the first trimester of pregnancy, the total red blood cell mass increases in the second and third trimesters to peak at term at about 120% to 125% of nonpregnant values, but how this is brought about by changes in the rate of erythropoiesis is not known. We evaluated erythropoiesis by measuring serum transferrin receptor (TfR) levels in 406 women during normal pregnancy (N = 317), at delivery (N = 63), or in the early postpartum (N = 27). Despite the presence of the placenta and the frequent occurrence of iron deficiency, TfR levels remained low in the...
The soluble transferrin receptor: biological aspects and clinical usefulness as quantitative measure of erythropoiesis. - Beguin, Yves
Iron transport in plasma is carried out by transferrin, which donates iron to cells through interaction with a specific membrane receptor. In this review, we summarize the current knowledge on the structure, intracellular cycle, distribution, and regulation of the tissue transferrin receptor. A soluble form of the transferrin receptor has been identified in animal and human serum. We review the molecular form and origin of the soluble receptor, its dosage in normal serum and its relationship with erythropoiesis, iron status, and cancer. Lastly, we discuss the clinical usefulness of the soluble transferrin receptor for the quantitative determination of marrow erythropoietic...
Subcutaneous erythropoietin for treatment of refractory anemia in hematologic disorders. Results of a phase I/II clinical trial. - Cazzola, M; Ponchio, L; Beguin, Yves; Rosti, V; Bergamaschi, G; Liberato, N L; Fregoni, V; Nalli, G; Barosi, G; Ascari, E
We have used recombinant human erythropoietin (rHuEPO) in a phase I/II clinical trial to evaluate its ability to reverse refractory anemia in hematologic disorders. rHuEPO was administered subcutaneously 5 days per week at escalating doses (50 to 150 U/kg per day). The aim of treatment was a hemoglobin (Hb) level greater than or equal to 10 g/dL without blood transfusion. Of 25 patients treated, 17 were evaluable, most of them with a regular need for transfusion. Eight of these had lymphoproliferative disorders (three cases of malignant lymphoma and five of monoclonal gammopathy) and were exposed to cytotoxic therapy. The other...