Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P02794 (ferritin)
 17,525 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The case is described of an 8-years-old girl with consanguineous parents. She was apparently well, apart, from growth retardation, until 18 months of age when she developed severe normocytic hypochromic anaemia. Bone marrow examination revealed vacuolisation of the erythroid and myeloid precursor, and electron microscopic studies showed striking sideroblastosis with ringed arrangement of the iron granules. Porphyrin metabolism was apparently normal, whereas blood levels of iron and ferritin were high. A careful study of the exocrine pancreas showed completely normal function. Vitamin B6 administration was unsuccessful. The patient is transfusion-dependent, and iron chelation treatment has produced good results. The case could be a new entity or a variant of congenital sideroblastic anaemia, since it has some features in common with the syndrome described by Pearson et al.
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PMID:Congenital refractory anaemia with vacuolisation of bone marrow precursors, sideroblastosis and growth failure in a girl with normal endocrine pancreatic function. 269 75

Intracellular ferritin in newt (Triturus cristatus) erythroblasts was accessible to the chelating effects of EDTA and pyridoxal phosphate. EDTA (0.5-1 mM) promoted release of radioactive iron from ferritin of pulse-labelled erythroblasts during chase incubation, but its continuous presence was not necessary for ferritin iron mobilization. Brief exposure to EDTA was sufficient to release 60-70% of ferritin 59Fe content during ensuing chase in EDTA-free medium. EDTA also suppressed cellular iron uptake and utilization for heme synthesis, but these activities were restored upon its removal. Pyridoxal-5'-phosphate (0.5-5 mM) also stimulated loss of radioactive iron from ferritin; however, ferritin iron release by pyridoxal phosphate required its continued presence. Unlike EDTA, pyridoxal phosphate did not interfere with iron uptake or its utilization for heme synthesis. Chelator-mobilized ferritin iron accumulated initially in the hemolysate as a low-molecular-weight component and appeared to be eventually released into the medium. No radioactive ferritin was found in the medium of chelator-treated cells, indicating that secretion or loss of ferritin was not responsible for decreasing cellular ferritin 59Fe content. Moreover, there was no transfer of radioactive iron between the low-molecular-weight component released into the medium and plasma transferrin. These results indicate that chelator-released ferritin iron is not available for cellular utilization in heme synthesis and that ferritin iron released by this process is not an alternative or complementary iron source for heme synthesis. Correlation of these data with effects of succinylacetone inhibition of heme synthesis and with previous studies indicates that the main role of erythroid cell ferritin is absorption and storage of excess iron not used for heme synthesis.
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PMID:Mobilization of ferritin iron in erythroblasts by chelating agents. 391 75

The uptake of iron by bone marrow erythroblasts and its intracellular distribution have been studied in 23 patients with primary sideroblastic anaemia (SA), five patients with secondary SA and one patient with only non-ringed sideroblasts. EM of erythroblasts from 18 cases showed both mitochondrial iron deposits and cytoplasmic ferritin aggregates in all cases except the patient with only non-ringed sideroblasts. Iron uptake by erythroblasts in whole bone marrow was normal but there was a decreased incorporation into haem and an increased incorporation into cell stroma. Age matching of erythroblasts using Percoll density gradient centrifugation indicated that stromal iron incorporation was high at all stages of erythroblast development even before haem synthesis had become a major metabolic activity and in intermediate and late erythroblasts a real decrease in haem synthesis appeared less certain. These observations, together with the inability to correct the abnormality in vitro with either pyridoxal phosphate or delta amino-laevulinic acid suggest that the primary defect in SA may be an abnormality of mitochondrial iron metabolism rather than an abnormality of haem synthesis.
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PMID:Erythroblast iron metabolism in sideroblastic marrows. 713 90

Ninety preselected children, aged between 8 and 14 years, living in two rural West African (Gambian) villages, were randomly divided into three groups, matched for age and sex. One group received a placebo (lactose) tablet, one received riboflavin (5 mg) on 5 d every week, which was sufficient to correct an endemic riboflavin deficiency, and one received a multivitamin supplement (Protovit; Hoffmann La Roche), on 5 d every week, together with FeSO4 (200 mg) once weekly, and the supplements were given for 1 year. Neuromuscular tests, including arm tremor and manipulative skills, were performed on three occasions: once just before the introduction of the supplements; again 6 weeks after commencing the supplements; and again 1 year later. Venous blood samples were collected at the same time as the first two sets of neuromuscular tests. These samples were used for haematology and nutrient status indices: plasma ferritin, ascorbic acid, cyanocobalamin and pyridoxal phosphate, and erythrocyte tests for folate status, for riboflavin status (erythrocyte glutathione reductase activation coefficient) and thiamine status (erythrocyte transketolase activation coefficient). The riboflavin in both supplements achieved a clear-cut response in biochemical status, which was dose-dependent. The pyridoxine, ascorbic acid and Fe components of the multivitamin also affected the associated biochemical indices. Although overall the arm tremor and related neuromuscular function tests did not respond significantly to the supplements, significant improvement was seen in the boys for the arm-tremor test in both the supplemented groups.
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PMID:Biochemical indices and neuromuscular function tests in rural Gambian schoolchildren given a riboflavin, or multivitamin plus iron, supplement. 798 90