The determinants of sickle red blood cell (RBC) life span have not been well-defined but may include both intrinsic factors (eg, the tendency to sickle) and extrinsic factors (eg, the capacity of the reticuloendothelial system to remove defective RBCs). Fetal hemoglobin (HbF) is heterogeneously distributed among sickle RBCs; F cells contain 20% to 25% HbF, whereas the remainder have no detectab...

BACKGROUND β-thalassemia is the most common monogenic disorder in human. The (C-->T) polymorphism at -158 upstream region of the γG-globin gene and pharmacological factors such as hydroxyurea have been reported to influence γ-globin gene expression and the severity of clinical symptoms of β-thalassemia. METHODS In the present study, 51 β-thalassemia intermediate patients were studied. Xmn1γG ...

Accumulation of HbF and HbA in individual erythroid clones, or bursts, grown in culture from early human erythroid progenitor cells (BFUe, erythroid burst-forming unit) was measured using sensitive and speciiic radioimmunoassays. HbF and HbA could be quantitated simultaneously in individual bursts and total hemoglobin levels as low as several hundred picograms per burst could be measured. Burst...

Pharmacological stimulation of fetal hemoglobin (HbF) expression may be a promising approach for the treatment of beta-thalassemia. In this study, the effects of Fructus trichosanthis (FT) were investigated in human erythroleukemic K562 cells for their gamma-globin mRNA and HbF-induction activities. The role of signaling pathways, including extracellular regulated protein kinase (ERK) and p38 m...

Hydroxyurea has been shown to be efficacious for the treatment of sickle cell anemia (SCA), primarily through the induction of fetal hemoglobin (HbF). However, the exact mechanisms by which hydroxyurea can induce HbF remain incompletely defined, although direct transcriptional effects and altered cell cycle kinetics have been proposed. In this study, we investigated potential epigenetic and alt...

INTRODUCTION Glycated hemoglobin (HbA1c) is used as a cumulative estimate of mean blood glucose levels from the preceding 5-12 weeks. This is the gold standard in assessing glycemic control in patients with diabetes. The ADA criteria for the diagnosis of diabetes, including HbA1c level, contribute to the importance of recognizing any variation pertaining to the HbA1c measurement. HbA1c is often...

Fetal hemoglobin (HbF) and adult hemoglobin (HbA) synthesis was studied in fetal baboons, Papio cynocephalus, to determine the normal pattern of hemoglobin production during fetal development. Fetuses ranging from 53 to 180 days gestation (term gestation 184 days) were used. Erythroid cells were incubated with 3H-L-leucine, and the rates of globin chain synthesis and the distribution of radioac...

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 ...