Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019045 (hemoglobinopathies)
 2,704 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Red blood cell (RBC) adhesion to vessel wall endothelium is a potent catalyst of vascular occlusion and occurs in oxidative stress states such as hemoglobinopathies and cardiovascular conditions. These are often treated with vitamin E (VitE), a "classic" antioxidant. In this study, we examined the effects of VitE on RBC adhesion to vascular endothelial cells (EC), and on translocation of phosphatidylserine (PS) to RBC surface, known as a potent mediator of RBC/EC adhesion, facilitating thrombus formation. Treatment of RBC with VitE strongly induces (up to sevenfold) PS externalization and enhances (up to 20-fold) their adherence to EC. The VitE hydrophilic analogue-Trolox-does not incorporate into cell membranes. Trolox did not exhibit any of these effects, implying that the VitE effect is due to its known ability to incorporate into cell membranes. The membrane-incorporated VitE significantly reduced the level of reactive oxygen species in H(2)O(2)-treated RBC, demonstrating that VitE elevates RBC/EC adhesion despite acting as an anti-oxidant. This study demonstrates for the first time that contrary to the common view of VitE as a beneficial supplement, VitE may introduce a circulatory risk by inducing flow-disturbing RBC adherence to blood vessel wall and the pro-thrombotic PS exposure.
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PMID:Vitamin E induces phosphatidylserine externalization and red cell adhesion to endothelial cells. 2002 Mar 30

Approximately 5-10% of patients with end-stage renal disease (ESRD) exhibit hyporesponsiveness to erythropoiesis-stimulating agents (ESAs), defined as a continued need for higher than 300 IU/kg/week doses of epoetin or a 1.5 mg/kg/week dose of darbepoetin. ESA hyporesponsiveness contributes to the morbidity, mortality and health-care economic burden of ESRD patients. The most common causes of ESA resistance are absolute or functional iron deficiency and inflammation. Maintaining adequate iron stores is clearly accepted as the most important strategy for reducing the ESA requirement and for enhancing ESA efficacy. Recent clinical studies have shown that iron administration to ESRD patients is associated with an increased risk of infection and atherosclerosis. ESA hyporesponsiveness due to chronic inflammation in ESRD patients has been reported to be improved by a number of interventions, including the use of biocompatible hemodialysis membranes, ultrapure dialysate, ascorbic acid therapy, vitamin E supplementation, and statin therapy. Other causes of ESA hyporesponsiveness include inadequate dialysis, hyperparathyroidism, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, primary bone marrow disorders, myelosuppressive agents, hemoglobinopathies, hemolysis, and hypersplenism. This article summarizes the common causes of ESA hyporesponsiveness and the proposed therapeutic interventions.
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PMID:Erythropoiesis-stimulating agent hyporesponsiveness in end-stage renal disease patients. 2602 17