The reaction of hydroxyurea with the oxyhaemocyanins of Astacus leptodactylus and Helix pomatia yielded methaemocyanins which could be regenerated with hydroxylamine. Hydroxyurea did not react with Astacus methaemocyanin, but quantitatively regenerated Helix methaemocyanin under N2. The reaction of hydroxyurea with Helix haemocyanin at pH 5.7 under air thus led to a steady state, with an oxyhae...

Hydroxyurea is a potent teratogen; free radical scavengers or antioxidants reduce its teratogenicity. Activator Protein-1 (AP-1) and NF-kappaB are redox-sensitive transcription factors with important roles in normal development and the stress response. This study was designed to determine if exposure to teratogenic doses of hydroxyurea induces oxidative stress and alters gene expression by acti...

study of hydroxyurea in sickle cell disease. French Study Group on Sickle Cell Disease. Arch Dis Child 1999; 81:437-9. 6. Kinney TR, Helms RW, O’Branski EE, et al. Safety of hydroxyurea in children with sickle cell anemia: results of the HUG-KIDS study, a phase I/II trial. Pediatric Hydroxyurea Group. Blood 1999; 94:1550-4. 7. Wiger R, Hongslo JK, Evenson DP, De Angelis P, Schwarze PE, Holme JA...

SUMMARY In a strain of E. coli resistant to isohydroxyurea (E. coli C600/isoHU), hydroxyurea inhibits protein synthesis prefer entially. This is in contrast to the effects of hydroxyurea in all other systems studied including E. coli C600, in which hy droxyurea inhibits DNA synthesis selectively. A scheme is pro posed to explain the metabolic conversions of hydroxyurea, isohydroxyurea, and hydr...

conclusions: hydroxyurea can be safely used in some transfusion-dependent β-thalassemia patients to decrease their transfusion needs. background: β-thalassemia is an inherited hemoglobin disorder caused by defective synthesis of ß-globin chains. hemoglobin (hb) f induction is a possible therapeutic approach which can partially compensate for α and non-α globin chains imbalance. objectives: we a...

We report a 41 year old male with sickle cell disease who developed a myelodysplastic syndrome and acute myeloid leukemia with complex karyotype involving chromosomes 5, 7 and 17 after 15 years of hydroxyurea treatment. He responded poorly to induction chemotherapy with cytarabine/idarubicin followed by high dose cytarabine and succumbed to neutropenic sepsis. Multiple systematic reviews, obser...

Hydroxyurea therapy has proven laboratory and clinical efficacies for children with sickle cell anemia (SCA). When administered at maximum tolerated dose (MTD), hydroxyurea increases fetal hemoglobin (HbF) to levels ranging from 10% to 40%. However, interpatient variability of percentage of HbF (%HbF) response is high, MTD itself is variable, and accurate predictors of hydroxyurea responses do ...

Sickle cell anemia is characterized by chronic hemolysis coupled with extensive vascular inflammation. This inflammatory state also mechanistically promotes a high risk of lethal, invasive pneumococcal infection. Current treatments to reduce vaso-occlusive complications include chronic hydroxyurea therapy to induce fetal hemoglobin. Because hydroxyurea also reduces leukocytosis, an understandin...

Cytotoxic drugs increase circulating fetal hemoglobin levels. We examined the mechanism by measuring the fetal hemoglobin produced per BFU-E-derived erythroblast following hydroxyurea treatment in vivo and in vitro. Treatment of four sickle cell patients increased the percentage of circulating F reticulocytes. The frequencies of bone marrow or peripheral blood BFU-E or CFU-E-derived colonies an...

Hydroxyurea has many characteristics of an ideal drug for sickle cell anemia (SCA) and provides therapeutic benefit through multiple mechanisms of action. Over the past 25 years, substantial experience has accumulated regarding its safety and efficacy for patients with SCA. Early proof-ofprinciple studies were followed by prospective phase 1/2 trials demonstrating efficacy in affected adults, t...