Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0039730 (thalassemia)
 10,305 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To provide more experimental evidence for the proposed role of oxygen free radicals in red blood cell (RBC) damage in beta-thalassemia, hydroxyl radical generation was studied in thalassemic (Th) vs. normal (N) RBC. .OH fluxes were quantified by the conversion of salicylic acid (SA) into its hydroxylated products, 2,3- and 2,5-dihydroxybenzoic acids (DHBA) and catechol, assayed with HPLC coupled to electrochemical detection. No significant difference in spontaneous .OH generation between N-RBC and Th-RBC was found. Ascorbic acid (0.5-3.0 mM) induced many-fold increases in SA hydroxylation in a dose-dependent manner in both types of cells. In the presence of ascorbate (1.0 mM), the SA hydroxylated products were determined in Th-RBC vs. N-RBC as follows (nmol/ml): 2,5-DHBA, 1.45 +/- 0.06 vs. 1.81 +/- 0.05 (p = 0.001); 2,3-DHBA, 1.89 +/- 0.21 vs. 1.15 +/- 0.08 (p = 0.008) and catechol, 0.87 +/- 0.13 vs. 0.38 +/- 0.05 (p = 0.006). The results showed significant increase in the total SA hydroxylation in Th-RBC as compared to N-RBC with a tendency to form 2,3-DHBA and catechol at the expanse of 2,5-DHBA. The excessive .OH generation in Th-RBC is attributed to the abnormally high content of redox active iron in the cytosolic and/or membrane compartments of these cells.
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PMID:Hydroxyl radical generation in beta-thalassemic red blood cells. 910 Dec 55

Chronic transfusion of packed red blood cells, in addition to other ongoing treatment with warfarin, acetyl salicylic acid, desferrioxamine, and other supportive measures, was given to a splenectomized hemoglobin E/beta-thalassemia woman with pulmonary arterial hypertension (PHT). Serial measurements of plasma thrombin-antithrombin III complex (TAT) levels and right-sided cardiac catheterization were used to monitor changes after treatment. Reduction of plasma TAT levels from 7.5 to 3.8 microg/L (normal, 3 +/- 2.4 microg/L), pulmonary vascular resistance (PVR) from 553.8 to 238.6 dyne.sec.cm(-5) (normal, 67 +/- 30 dyne.sec.cm(-5)), and mean pulmonary arterial pressure from 51 to 32 mm Hg (normal, 9 to 19 mm Hg) occurred in tandem. Normalization of blood hypercoagulability as reflected in plasma TAT level by chronic blood transfusion was the likely basis for improvement of increased PVR, being secondary to thrombotic pulmonary arteriopathy and subsequently PHT.
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PMID:Correction of hypercoagulability and amelioration of pulmonary arterial hypertension by chronic blood transfusion in an asplenic hemoglobin E/beta-thalassemia patient. 1464