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Query: UNIPROT:P02794 (ferritin)
 17,525 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Serum ferritins from a patient with haemochromatosis and from a patient with transfusional siderosis were compared with tissue isoferritins on the basis of their iron content, isoferritin spectrum and immunological properties. Both serum ferritins had a low iron content and corresponded to only the most basic isoferritins in liver. The serum ferritins were very similar to the natural apoferritin from liver in all respects.
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PMID:Characterization of serum ferritin in iron overload: possible identity to natural apoferritin. 87 33

The disruption of lysosomes with release of their content of lytic enzymes was an early concept for the possible role of these organelles in the pathogenesis of tissue damage. Many examples are known of primary lysosomal storage diseases due to a congenital deficiency of certain acid hydrolases. It is suggested that iron overload due to either primary haemochromatosis or transfusional siderosis is a form of acquired secondary lysosomal storage disease. Subcellular fractionation experiments and electron microscopic studies have shown that liver tissue from patients with iron overload has iron-laden lysosomes. Similar results have been found in iron-overloaded rats. In patients, but not in experimental animals, enzymic analyses have shown increased activities of acid hydrolases and strikingly enhanced lysosomal fragility in liver homogenates. When it has been possible to deplete the patients of the excessive iron, these parameters have returned to normal. The possible mechanisms by which the iron compounds disrupt lysosomes, including distension with ferritin or haemosiderin or free-radical-mediated membrane damage, will be discussed.
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PMID:Lysosomal disruption in the pathogenesis of hepatic damage in primary and secondary haemochromatosis. 105 36

Purified tissue ferritins isolated from Bantu subjects with gross haemosiderosis, from a patient with idiopathic haemochromatosis (HC) treated by phlebotomy, and from rats with experimental iron overload were studied in order to determine the significance of the abnormality previously demonstrated in tissue isoferritins in patients with IHC. The isoferrin profile of the tissues from the Bantu subjects and the iron-loaded rats showed a similar abnormality to that previously found in patients with untreated IHC--that is, an abnormally uniform distribution of iron-containing isoferritins with an increase in the more basic isoferritins and an apparent absence of the more acidic ones. In contrast, tissues from the patient with treated IHC, who was iron depleted at the time of death, showed the normal organ-specific isoferritin distribution. These findings strongly suggest that the abnormal distribution of tissue isoferritins in IHC is an acquired phenomenon and unlikely to be related to an underlying genetic defect in ferritin or iron metabolism.
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PMID:Alterations in tissue ferritins in iron storage disorders. 119 19

We investigated 33 of 58 members of two families with latent or precirrhotic hemochromatosis to determine its pattern of inheritance and to evaluate the serum ferritin levels as an index of iron stores. In both families, the pattern of inheritance was as an autosomal dominant trait with incomplete expressivity. Mean serum ferritin values in the affected family members were 88.5 ng per milliliter (range, 28.0 to 201.9) for males and 65.2 ng per milliter (range 23.7 to 97.0) for females, which were no different from controls (P is less than 0.5). Furthermore, the serum ferritin values did not correlate with or reflect mobilizable iron stores, and there were no relations between the serum iron, iron-binding capacity and transferrin saturation (P is less than 0.2). Thus, serum ferritin concentrations in precirrhotic familial hemochromatosis appear to underestimate iron stores. Serum ferritin levels do not help to identify such patients with increased iron stores for therapeutic phlebotomy.
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PMID:Normal serum ferritin concentrations in precirrhotic hemochromatosis. 124 69

Iron deficiency is one of the most serious nutritional problems confronting the United States and the world today. An understanding of the mechanisms operative in the control of uptake and utilization of iron is essential to develop suitable prophylactic and therapeutic strategies. Iron excess can also be a serious health hazard. Studies on Bantu siderosis, hemochromatosis and other overload pathologies also provide insight into the intake and storage of this metal. Several models for iron transport across the mucosal membrane are developed. The most satisfactory seems to involve chelation of the iron to provide solubility diffusion passively across the gut membrane, and equilibrium binding to various storage sites within the tissue. Both ferric and ferrous forms are available. The solution chemistry of iron governs its biological behavior. Low-molecular-weight compounds present in normal dietary foodstuffs, as well as those prepared synthetically, can enhance the uptake of oral iron. Suitable application of complexes of iron with fructose, nitrilotriacetate, citrate and other molecules should be efficacious in the treatment of iron deficiency anemia. Potential dangers of food fortification with iron are acknowledged, and application of immunoassay techniques for measuring circulating ferritin suggest it as a rapid and inexpensive monitor for overload.
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PMID:Tired blood and rusty livers. 125 66

The absorption of radioactive iron from a solution of ferrous ascorbate, and from a standard meal containing intrinsically labelled haemoglobin and wheat, was measured in 12 Indian housewives, 18 white hospital patients and 12 subjects with idiopathic haemochromatosis. Eight of the latter had been fully treated by multiple venesections, so that their serum ferritin concentrations were below 25 mug/1. Since the serum ferritin concentrations of the housewives and the hospital patients were comparable, their body iron stores were considered to be depleted to a similar degree. There were no significant differences between the absorptions of ferrous ascorbate or of the haem iron in the standard meal by each group, but the housewives and the hospital patients absorbed significantly less of the non-haem food iron. The mean non-haem food iron absorptions were 36.4%, 5.8% and 18.9% for the treated haemochromatotic subjects, the Indian housewives and the white hospital patients respectively. The discrepancies between the absorptions of the different forms of food iron were highlighted by calculating the ratios between them. The mean non-haem: haem food iron absorption ratio for the group of treated haemochromatotic subjects was 0.98, and for the Indian housewives only 0.18. The white hospital patients did not form a homogenous population: the ratios of the five males and three of the females were greater than 1.0, whereas those of the remaining 10 females were less than 0.5. The results of this study suggest that mal-absorption of non-haem iron from a meal containing bread, presumably due to a defect at the luminal level, may be an important factor in the pathogenesis of iron deficiency in some subjects. The abnormality appears to be particularly prevalent among Indian women living in Durban.
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PMID:Patterns of food iron absorption in iron-deficient white and indian subjects and in venesected haemochromatotic patients. 127 86

A 64-year-old man was admitted due to ascites. Laboratory data showed hemoglobin 6.7 g/dl, mean corpuscular volume 82 fl, and ferritin 2,360 ng/ml. Liver biopsy showed hemochromatosis. The diagnosis of beta-thalassemia was suggested by a decreased ratio of beta/alpha-globin synthesis in vitro (0.26). Cloning of the beta-globin gene showed A-to-G mutation in the first base of the ATA box. He was confirmed to be homozygous for this specific allele by beta-gene complex analysis and analysis of Southern blot hybridization of the alpha- and beta-globin genes. His two sons were confirmed to be heterozygous for this allele.
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PMID:Beta(+)-thalassemia with hemochromatosis. 136 99

We surveyed 140 clinical chemistry laboratories in Australia to establish which laboratory methods they used to determine serum iron status: 125 measured serum iron (Fe), 85 measured transferrin (TRF), 47 measured total iron-binding capacity (TIBC), and 14 measured both TRF and TIBC. Of the 55 laboratories routinely reporting TRF saturation (TS), 16 calculated TS directly as (Fe/TIBC) x 100, and 9 used [Fe/(TRF x 2)] x 100. Thirty laboratories measured TRF and converted it to an equivalent TIBC concentration; the derived TIBC was then used to calculate TS. We measured iron, TIBC, and TRF concentrations in 94 control subjects, 59 patients with alcoholic liver disease (ALD), and 20 with proven genetic hemochromatosis (GH). TS was compared with a transferrin index (TI = Fe/TRF) to determine whether both methods were sensitive for GH screening and which method gave the fewest false-positive results with discrimination limits of > 55% and > 1.0, respectively. All GH patients were detected by both TS and TI at these limits. One control subject had a TI > 1.0, whereas three control subjects had a TS > 55%. Nine patients with ALD had a TI > 1.0 and 11 ALD patients had a TS > 55%. Some iron-overload patients had lower than expected TS values compared with TI, possibly because of ferritin interference in the TIBC assay. Also, the precision of the TRF assay was better than that of the TIBC assay: CVs of 1.85-3.68% vs 6.17%. We therefore recommend that calculated TI replace TS in screening for iron overload.
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PMID:Transferrin index: an alternative method for calculating the iron saturation of transferrin. 822 43

The relationship of pretreatment serum ferritin and hepatic iron concentration to body iron removed by venesections was evaluated in 33 patients with genetic hemochromatosis. The median values of the three variables considered were 1,950 micrograms/L (range = 255 to 10,000), 1,175 micrograms/100 mg dry weight (range = 270 to 4,310) and 10 gm (range = 2 to 41), respectively. At basal liver biopsy 18 patients had cirrhosis, 6 patients had fibrosis and 9 patients had a normal pattern; siderosis was degree 3 in 6 patients and degree 4 in 27 patients. The results of fitting a polynomial regression of second degree showed that the curve of serum ferritin on iron removed was a straight line (R2 = 0.79, with a significant coefficient of linearity, p less than 0.01, and a nonsignificant coefficient of curvature), whereas that of hepatic iron concentration on iron removed showed a curvature (R2 = 0.62, with significant coefficient of linearity and curvature, p less than 0.01) and reached a plateau. The sigmoid model fit the curve of hepatic iron concentration on iron removed (R2 = 0.61), which suggested a saturation of hepatic iron storage capability; the asymptote corresponded to a hepatic iron concentration of about 2,000 micrograms/100 mg. In alcoholic patients (17 cases) the location of the sigmoid was greater than in nonalcoholic patients. Our results suggest that iron deposition occurs in the liver before other organs are involved and that with massive iron overload hepatic deposits reach saturation, after which hepatic iron concentration does not always reflect the amount of total stores. Alcohol consumption could slow the saturation of hepatic iron deposits.
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PMID:Saturability of hepatic iron deposits in genetic hemochromatosis. 139 2

Iron-deficient female Wistar rats were fed a diet which contained 0.5% 3,5,5-trimethylhexanoyl (TMH)-ferrocene over a 57-week period. The state of iron deficiency was characterized by means of the absence of stainable iron in the bone marrow. After the first days on the iron-enriched diet, ferritin-containing siderosomes were found, in numerous erythroblasts up to orthochromatic normoblasts and in reticulocytes, i.e. the dispensed iron was used for haemoglobin synthesis. After 1 week the first macrophages showed a positive Perls' Prussian blue reaction. In the cytoplasm they stored the iron in the form of free ferritin molecules and lysosomally as aggregated ferritin and/or haemosiderin. The iron loading of the macrophages increased in both of the storage qualities proportionally with duration of the feeding period and reached a maximum after 38 weeks. Final stages showed extremely iron-loaded macrophages with high concentrations of free ferritin molecules and large siderosomes, partially flowing together to still greater units. Iron deposits within endothelial cells of bone marrow sinusoids can be observed for the first time after 4 weeks. In these cells the iron is stored as ferritin in siderosomes of relatively small and uniform size; free ferritin molecules in the cytosol were of only slight concentration. The TMH-ferrocene model of iron overload shows in the bone marrow: (1) an unimpeded utilization of the iron component for erythropoiesis, (2) development of excessive iron overload of the bone marrow in macrophages and endothelial cells of sinusoids and (3) a pattern of distribution of iron as seen in secondary haemochromatosis.
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PMID:Iron overload of the bone marrow by trimethylhexanoyl-ferrocene in rats. 141 92


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