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

The endocrine function was studied in 9 hemodialysis patients with iron overload (IO) before and after iron depletion. Diagnosis of IO was established by high serum ferritin (> 1100 micrograms/L), high hepatic CT density (> 70 Hounsfield units), and excessive iron stores in bone marrow aspirate (grade 6). At the start of the study, 8 patients had gonadal failure, 6 of whom had hypothalamopituitary disease, and 4 manifested thyroid abnormalities. At the end of the study, the hypothalamopituitary function and thyroid abnormalities improved in all patients except one who manifested hypothalamic disease. Primary gonadal failure persisted in the 8 patients. ACTH stimulation produced adequate increments in plasma cortisol at the start and end of the study. Pancreatic (beta cell) function was adequate at the end of the study as shown by normal oral glucose tolerance test and free insulin increments during the test. The CT scan and follow-up indicated significant iron mobilization from the liver, pancreas, and the adrenal glands. Hormonal studies were repeated in 4 of the 5 patients who manifested endocrine abnormalities and had received recombinant human erythropoietin (rHuEPO), 3 mo after discontinuation of the drug. Improvement in the endocrine function persisted in those patients. Our results indicated that dialysis patients exposed to iron overload are at risk for development of multiple endocrine defects. Fortunately, aggressive iron depletion can mobilize iron from these organs and reverse some of the defects.
 ...
PMID:Endocrine abnormalities in hemodialysis patients with iron overload: reversal with iron depletion. 874 13

Although diet surveys have been made in marathon runners, as far as we know their nutritional state has not been evaluated by measurement of the so-called biological markers of nutrition, such as transferrin, retinol-binding protein, and prealbumin. We measured the levels of these substances in 18 marathon runners (11 men and 7 women; mean age 26.9 +/- 4.0 years) and in 22 controls (13 men and 9 women; mean age 26.2 +/- 3.6 years). As some of these markers are zinc-dependent, serum zinc levels also were measured. Likewise, serum calcium, phosphorus, and magnesium levels were measured to ascertain the athletes' mineral status. Calcium corrected for proteins, phosphorus, magnesium, and zinc did not differ between the marathon runners and controls; likewise, there were no differences in serum ferritin and glucose levels. As regards the biological markers of nutrition, prealbumin levels were higher in athletes than in controls (31.7 +/- 4.7 vs 28.9 +/- 4.8 mg/dl, p < 0.025). There were no differences in the levels of retinol-binding protein and transferrin between runners and controls.
 ...
PMID:Biochemical markers of nutrition in elite-marathon runners. 877 74

Merocyanine 540 (MC540)-mediated photodynamic action is a novel approach for purging tumor cells from autologous remission bone marrow explants. The purpose of this study was to evaluate the effects of hemin (ferriprotoporphyrin IX), a potential source of pro-oxidant iron in bone marrow, on in vitro photodynamic inactivation of leukemia cells. Murine L1210 cells exhibited a progressive loss of clonogenicity when irradiated with broad-band visible light in the presence of MC540. Hemin had strikingly different effects on photokilling, depending on its contact time with cells, eliciting a sizable decrease in resistance after short-term (30-min) contact but a marked increase in resistance after long-term (24-h) contact. Similar trends were observed when cells were challenged with glucose/glucose oxidase, indicating that the responses apply to more than one type of oxidative stress. Immunoblot analyses revealed that the levels of inducible heme oxygenase (HO-1) and ferritin heavy (H) chain were substantially elevated 24 h after hemin addition. HO-1 increased relatively rapidly and maximized within 4 h after adding hemin, whereas H-ferritin increased more slowly in parallel with the development of hyperresistance, maximizing after 24-36 h. Desferrioxamine, an avid iron chelator, had no effect on HO-1 induction but inhibited both ferritin induction and the increase in cell resistance, suggesting that HO-mediated release of iron from hemin was necessary for triggering these responses. Spleen apoferritin was taken up by L1210 cells and strongly inhibited photokilling, further implicating ferritin involvement in hyperresistance. Photokilling was accompanied by free radical-mediated lipid peroxidation (thiobarbituric acid reactivity), which could be suppressed substantially by 24-h hemin preincubation. A plausible explanation for the long-term effects of hemin is that excess H-ferritin generated as a result of iron-regulatory protein deactivation sequesters toxic iron, which might otherwise catalyze damaging lipid peroxidation. Chronic oxidative release of hemin from bone marrow erythroid cells could compromise the efficacy of photopurging by making tumor cells more tolerant to photooxidative insult.
 ...
PMID:Hyperresistance of leukemia cells to photodynamic inactivation after long-term exposure to hemin. 884 Sep 77

Ten patients (18 +/- 1 yr) on chronic hemodialysis (HD) with anemia were studied before and after treatment with erythropoietin (EPO) for 9 mo. Six patients had evidence of iron overload (serum ferritin over 300 ng/ml; group I) and the other four patients (serum ferritin below 300 ng/ml; group II) did not. Before treatment, both groups of patients were glucose tolerant but insulin resistant and hyperinsulinemic. There was equal correction of anemia but no significant changes in serum biochemistry (apart from iron studies) or anthropometric measurements in both groups. With amelioration of anemia and iron overload in group I, insulin sensitivity increased by 53% to within normal values. Insulin secretion also normalized. With amelioration of anemia but no change in iron status in group II, insulin sensitivity (increased by 60%) and insulin secretion also normalized. Thus correction of anemia by EPO reversed insulin resistance and hyperinsulinemia in HD patients with or without iron overload. The effects of correction of anemia rather than iron overload may be more important in the pathogenesis of insulin abnormalities in end-stage renal disease.
 ...
PMID:Correction of anemia by erythropoietin reverses insulin resistance and hyperinsulinemia in uremia. 892 46

The superimposition of pathological processes on ageing-related metabolic changes makes the interpretation of laboratory data difficult in the elderly. Therefore, in order to establish reference values of anthropometric, hematological and biochemical variables, we have carefully selected fit, health-conscious elderly subjects on the basis of clinical and biological criteria. We observed a trend for a wider range of values than in young adults. For some variables, the values were shifted down (eg: albumin, vitamin D) or up (eg: glucose, urea, cholesterol, ferritin), as a result of slow metabolic changes or progressive functional decline of different organs. The high prevalence of hypovitaminosis D was worthy of note, particularly in women, suggesting a high risk of deficiency.
 ...
PMID:[Reference intervals and biological profile in a group of healthy elderly population in the Paris region]. 895 29

Available evidence suggests that glucose, the most potent physiologic insulin secretagogue, capacitates glucose-induced insulin secretion by stimulating synthesis of various proteins in the beta cell. To obtain more clues about proteins that might be involved in insulin secretion, rat pancreatic cDNA libraries were screened by differential hybridization for non-preproinsulin transcripts that were increased when pancreatic islets were cultured for 1 day at a high (20 mM) versus a low concentration (1 mM) of glucose. More than 100,000 pfu were initially screened. After repeated rescreening, 33 transcripts were 1-3-fold higher in the presence of the high glucose. For comparison, preproinsulin transcripts were 4-8-fold higher at the high concentration of glucose. The sequences of 12 clones were > or = 85% similar to published sequences. These included annexin, calbindin, protein kinase C receptor, the G protein beta subunit, the guanyl cyclase A/atrial natriuretic peptide receptor and the serotonin 5HT-2 receptor. As previously reported, ferritin H chain transcripts were discovered to be 3-6-fold higher in the presence of the high glucose (MacDonald et al., FASEB J. 8, 777-781, 1994). Unidentified glucose responsive clones have been assigned GenBank accession numbers N55606-N55636, N65938 and N65939. The results implicate the proteins encoded by these mRNAs in insulin secretion.
 ...
PMID:Glucose-stimulated expressed sequence tags from rat pancreatic islets. 896 Dec 57

Elevated serum ferritin concentrations between 200 and 500 microg/l have been found to be a strong risk factor for acute myocardial infarction in Finnish men, but the reason for this association is still uncertain. In the Finnish population ferritin concentrations correlated with factors of insulin resistance syndrome. As these factors have been found to be associated with an LDL subfraction phenotype of increased concentrations of small, dense LDL particles, we hypothesized an association between ferritin and an atherogenic LDL subfraction profile, a finding which could be an explanation for the observed relationship between ferritin and atherosclerosis. Therefore we determined serum ferritin levels, metabolic cardiovascular risk factors, and the LDL subfraction phenotype in 93 healthy men without signs for infection or coronary heart disease. We found that men with moderately elevated ferritin levels (200-500 microg/l; n = 31) had a significantly worse coronary risk profile than men with lower levels ( < 200 microg/l; n = 62). Elevated ferritin concentrations were associated with significantly higher values for serum triglycerides, VLDL cholesterol, VLDL apolipoprotein B (P < 0.01), IDL cholesterol, fasting glucose (P < 0.05) and uric acid (P < 0.01), and lower levels for HDL2b and HDL2a cholesterol and apolipoprotein A-I (P < 0.05), and lipoprotein(a) (P < 0.01). Elevated ferritin levels were, however, not associated with an unfavourable LDL subfraction profile of increased concentrations of small, dense LDL particles.
 ...
PMID:Relationship of serum ferritin concentrations with metabolic cardiovascular risk factors in men without evidence for coronary artery disease. 905 Jul 80

We studied concentrations of serum ferritin, glycosylated ferritin, and non-glycosylated ferritin in elderly patients with diabetes. The subjects were 111 people who were at least 60 years old: 54 healthy controls, 14 diabetic patients without retinopathy, and 43 diabetic patients with retinopathy. The mean levels of ferritin, glycosylated ferritin, and non-glycosylated ferritin in serum were significantly higher in the patients with retinopathy than in healthy controls. The mean percent glycosylated ferritin did not differ between patients with retinopathy and healthy controls. The mean levels of serum ferritin, glycosylated ferritin, and non-glycosylated ferritin, and the percent glycosylated ferritin did not differ significantly between patients without retinopathy and health controls. None of these values differed between subjects with macroangiopathy and those without macroangiopathy, in both groups of patients. In patients with diabetes, none of the values measured was significantly related to fasting plasma glucose, HbA1c, or the duration of diabetes. These results suggest that diabetic microangiopathy is associated with abnormally high levels of ferritin in serum.
 ...
PMID:[High levels of serum ferritin in elderly patients with non-insulin-dependent diabetes mellitus]. 921 86

The hypothesis was tested that high-volume endurance training can be monitored using hematological and blood-chemical parameters as markers of an early stage in the overtraining process. Eight experienced distance runners participated in a prospective, experimental, controlled study. The study consisted of an unaccustomed average 103% increase in training volume (ITV) within 4 weeks (average final volume: 174.6 km per week). A year later, 9 runners performed the additional 4-week control study that consisted of an unaccustomed average 152% increase in intensive training measures (ITI). Average total volume amounted to 61.7 km (week 1) and 84.7 km (week 4). Seven athletes participated in both studies. Simultaneously to performance diagnostics, a comprehensive pattern of hematological and blood-chemical parameters was determined. During ITV, submaximum running performance was improved after 2 weeks, stopped improving between week 3 and 4; maximum performance did not increase rather was decreased after week 4 compared to baseline as indication of an early stage in the overtraining process. During ITI, submaximum and maximum running performances increased continuously. In contrast to ITI, the following parameters decreased significantly during ITV: White blood cell count, serum iron, ferritin, VLDL-(very low density lipoproteins), LDL (low density lipoproteins)-cholesterol, albumin, resting and maximum free fatty acid, maximum lactate, resting, submaximum and maximum glucose, summed amino acid, resting, submaximum and maximum ammonia concentrations, whereas prothrombin time increased significantly. During high-volume endurance training a multifactorial and longitudinal approach considering either a performance incompetence and an individually different range of symptoms and alterations in hematological and blood-chemical parameters can help to recognize an early stage in the overtraining process.
 ...
PMID:Influence of an unaccustomed increase in training volume vs intensity on performance, hematological and blood-chemical parameters in distance runners. 923 88

Hemin (ferriprotoporphyrin IX), the oxidized prosthetic group of hemoglobin, is a source of potentially cytotoxic iron, but in chronic low doses can induce cytoprotection against iron-stimulated oxidative stress. The latter property of hemin has been examined, using murine L1210 cells and three different oxidant generating systems: (i) glucose/glucose oxidase, (ii) near-ultraviolet irradiation, and (iii) dye-mediated photodynamic action. Cells treated with the lipophilic iron donor ferric-8-hydroxyquinoline, Fe(HQ)2 (1 microM, 30 min) were found to be more sensitive to oxidative killing than nontreated controls. However, cells challenged after long-term (20-24 h) exposure to hemin (10 microM) were substantially more resistant than controls and were sensitized far less by Fe(HQ)2. Immunoblot analyses of 24-h hemin-treated cells indicated that the ferritin heavy (H) subunit was elevated 12- to 15-fold, whereas the light (L) subunit was essentially unchanged. Experiments carried out with 55Fe(HQ)2 showed that iron uptake capacity of cells was greatly enhanced after hemin treatment. More specifically, hemin-stimulated cells were found to contain approximately 9 times more immunoprecipitable ferritin iron after incubation with saturating levels (4-5 microM) of 55Fe(HQ)2 and approximately 3 times more iron per ferritin molecule compared with nonstimulated controls. The nonferritin iron content of the latter was estimated to be approximately 40 times greater than that of the former following low-level (0.5 microM) 55Fe(HQ)2 treatment. These results are consistent with the idea that induced ferritin, enriched in H-chain, sequesters redox active iron rapidly and copiously, thereby enhancing cellular resistance to oxidants.
 ...
PMID:Elevated ferritin production, iron containment, and oxidant resistance in hemin-treated leukemia cells. 932 93


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>