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)

Superoxide ions (O2-) oxidized oxyhaemoglobin to methaemoglobin and reduced methaemoglobin to oxyhaemoglobin. The reactions of superoxide and H2O2 with oxyhaemoglobin or methaemoglobin and their inhibition by superoxide dismutase or catalase were used to detect the formation of superoxide or H2O2 on autoxidation of oxyhaemoglobin. The rate of autoxidation was decreased at about 35% in the presence of both enzymes. The copper-catalysed autoxidation of Hb (haemoglobin) was also shown to involve superoxide production. Superoxide was released on autoxidation of three unstable haemoglobins and isolated alpha and beta chains, at rates faster than with Hb A. Reactions of superoxide with Hb Christchurch and Hb Belfast were identical with those with Hb A, and occurred at the same rate. Hb Koln contrasted with the other haemoglobins in that the thiol groups of residue beta-93 as well as the haem groups reacted with superoxide. Haemichrome formation from methaemoglobin occurred very rapidly with Hb Christchurch and Hb Belfast, as well as the isolated chains, compared with Hb A. The process did not involve superoxide production or utilization. The relative importance of autoxidation and superoxide production compared with haemichrome formation in the haemolytic process associated with these abnormal haemoglobins and thalassaemia is considered.
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PMID:Reactions involving superoxide and normal and unstable haemoglobins. 18 28

Oxygen free radicals and other oxygen derived species (Superoxide, O2-; Hydroperoxide, HOO; Singlet oxygen, 1O2-; Hydroxyl radical, OH; and Hydrogen peroxide, H2O2) including lipid peroxides have been suggested as important causative agents of aging and several human diseases, including cancer, multiple sclerosis, Parkinson's disease, autoimmune disease, ischemia, anemia, senile dementia, asbestosis and in thalassemia. This paper aims to communicate some of the theories and rationales in aging process and thalassemia.
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PMID:Role of lipid peroxidation and antioxidants in aging process and thalassemia. 134 11

Superoxide anion production in resting and PMA- or zymosan-stimulated neutrophils was evaluated in 21 beta-thalassemia patients. The results were correlated with ferritin values, hepatitis B virus serum markers, liver pathology, immunoglobulin levels and T-cell subsets. Superoxide anion generation from resting or PMA-stimulated neutrophils was significantly higher in patients than in controls. On the contrary, zymosan-stimulated neutrophils showed reduced superoxide anion production. Increased superoxide anion production in resting neutrophils showed a significant correlation to the values of ferritin. In addition, patients with biopsy-proven chronic liver disease showed significantly increased ferritin levels and superoxide anion production as compared to the remaining patients. No correlation was observed between superoxide anion production and the presence or the absence of hepatitis B virus serum markers, immunoglobulin levels and T-cell subsets. A possible role of interreactions between iron and oxygen radicals in determining liver damage in beta-thalassemia patients is suggested.
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PMID:Changes in superoxide anion production in neutrophils from multitransfused beta-thalassemia patients: correlation with ferritin levels and liver damage. 633 Oct 44