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Query: UMLS:C0019045 (hemoglobinopathies)
 2,704 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Erythrocyte membrane deformability is a factor in blood viscosity. Progesterone and synthetic progestational steroids interact with the ery throcyte membrane and may be related to the decreased deformability. In women, reduction in net negative surface charge during pregnancy has bee n reported. This might overcome normal especially with a reduced rate of blood flow. These factors were investigated in blood taken from patients in a Family Planning Clinic and an Obstetrical Clinic. Patients taking oral contraceptives had used them for more than 2 months. Techniques employed are described. Erythrocyte deformability was unchanged in the contraceptive users. In pregnant women a difference in filtration time was observed, indicating decreased deformity of the erythrocytes. Net negative surface charge, as measured by electrophoretic mobility, was unchanged in oral contraceptive users and in pregnant women. The increased incidence of thrombosis in women taking oral contraceptives could not be explained by decreased erythrocyte deformability or surface charge. However, decreased deformability of erythrocytes in late pregnancy may relate to thrombosis during this period, and to increased hemolysis in patients with some hemoglobinopathies.
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PMID:Effect of oral contraceptives and pregnancy on erythrocyte deformability and surface charge. 120 49

Medroxyprogesterone acetate (MPA) - a safe depot contraceptive - is shown previously to reduce painful crises of sickle cell anemia, which is parallel with the recent findings showing progesterone induction of fetal hemoglobin genes. This would be a way to reduce transfusions for late term thalassemia major and sickle cell-disease cases with no chances left for a stem cell transplantation. In these patients, transfusional hemosiderosis causes irreversible damage to many organs despite the available iron-chelating agents. Pharmacological strategies either target the conformal structure of the defective adult hemoglobin or aim to activate fetal hemoglobin concentrations. The only concern on MPA may be its thromboembolic risks, which may be uncoupled with agents acting both anti-coagulant and inductive on the blood oxygen-carrying affinity. Such agents could be valproic acid and aspirin. Valproic acid is being safely used to treat epilepsy and its histone acetylating function may lead its induction of fetal hemoglobin. Aspirin was shown to increase oxygen affinity of hemoglobin via acetylating lysine residues and its general acetylating activity on proteins such as histones makes it also an interesting candidate to activate fetal hemoglobin. We propose that combining MPA with clinically available doses of valproic acid and aspirin would be beneficial in terms of both reduced coagulation risks and increased oxygen affinity to decrease the transfusions and to improve the prognosis in late-phase hemoglobin disorders.
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PMID:Medroxyprogesterone - valproic acid - aspirin. MVA regime to reduce transfusion associated mortality in late-term hemoglobinopathies. Hypothesis and rationale. 1716 47