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)

We evaluated musculoskeletal complaints related to arthropathy in 28 patients with end stage renal failure receiving maintenance dialysis. Twenty-three of 28 patients had arthritic complaints and 14 had an arthropathy. Six of 14 patients with arthropathy had a pattern resembling calcium pyrophosphate dihydrate deposition (CPPD) disease, 4 patients had moderately severe osteoarthritis, 3 had calcific periarthritis, and 1 patient had acute arthritis with intermittent pain and swelling. Factors which predispose to metabolic arthropathies were observed as follows: 29% elevated ferritin; 39% history of hyperparathyroidism; 68% elevated parathormone; 54% hyperphosphatemia; 36% hypercalcemia, 29% HLA haplotypes A3, B7, or B14; and 60% hyperaluminemia. The arthropathy group had more abnormalities per patient (mean 3.6) than the group without arthropathy (mean 2.7) (p less than 0.05). Our data suggest that (1) arthritic complaints occur frequently in patients receiving dialysis; (2) arthropathy accounted for 61% of the complaints; (3) 43% of patients with arthropathy had CPPD-type; (4) renal osteodystrophy caused 17% of arthritic complaints; and (5) in patients receiving dialysis, there is a high incidence of metabolic abnormalities that are known to be associated with arthropathy.
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PMID:Musculoskeletal symptoms related to arthropathy in patients receiving dialysis. 323 May 70

Mast cells isolated from the peritoneal fluid of Wistar rats were purified by centrifugation on Percoll gradient with a yield of 2x10(6) cells/ml. Cell morphology was well preserved as shown by light and electron microscopy. The mast cells capacity to bind histamine was assayed using either [3H]-histamine or histamine-ferritin conjugate as electron-opaque probe for electron microscopic examination. The [3H]-histamine binding performed at 4 degrees C in Ca2+-free phosphate-buffered saline pH 7.3 completed within 30 min was found to be specific, with an IC50 value of 0.72 +/- 0.23 nM. The data analyses by Scatchard and Hill's representations showed a KD of 0.60 +/- 0.24 nM and Bmax of 4.9 +/- 1.2 pM/10(6) cells suggesting that on mast cells the histamine receptors are restricted to the plasma membrane. According to Hill's analysis neither positive nor negative cooperativity (n = 1.06) appeared to be involved in the specific histamine-receptor binding. Competition experiments with 4-methylhistamine and SK&F 93479, revealed that mast cells express H2-histamine receptors. At electron microscopic level, the histamine-ferritin conjugate interstitially injected in the hamster cheek pouch was localized on the mast cell membrane.
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PMID:Histamine receptor on mast cells. 325 80

Outer hair cell (OHC) shortening has previously been induced in vitro by the application of solutions containing high potassium (a depolarizing agent), acetylcholine (a suggested efferent transmitter) and cationized ferritin (a positively charged macromolecule), as well as by electrical current. The application of caffeine, which causes contractures in skeletal and smooth muscle by releasing calcium from intracellular stores to activate actin and myosin interaction, also causes shortening of OHCs. Tetracaine, which interferes with calcium movement in muscle and non-muscle cells, blocks potassium-induced and caffeine-induced shortening of OHCs, but does not block electrically-induced shortening. Sodium dantrolene which is an inhibitor of intracellular calcium release in skeletal muscle does not block potassium-induced OHC shortening. Immunocytochemical studies using antibodies to muscle-like contractile and regulatory proteins on unfixed, freeze-dried OHCs demonstrate the co-localization of calmodulin with actin throughout the OHC cytoplasm. These results support the ideas that in OHCs, intracellular calcium release is involved in the activation of shortening and that an actin-mediated cell shape change may be regulated by calmodulin in a manner similar to that which occurs in contraction of smooth muscle.
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PMID:Effects of caffeine and tetracaine on outer hair cell shortening suggest intracellular calcium involvement. 335 Jul 71

The association between elevated brain aluminum levels and Alzheimer's disease (AD) is examined and critically reviewed. We found elevated aluminum levels in the brains of patients with AD (greater than 4 micrograms/g dry wt.) compared with normal subjects (approximately 1.5 micrograms/g dry wt.). Nine laboratories from different geographical regions have confirmed this finding. Two laboratories did not find any differences between AD and control brains. This discrepancy is traced to differences in sample sizes used for the aluminum assay and the sample selection criteria. It is found that it is essential to use small sizes (approximately 10 mg dry wt.) and to ensure that control brains do not contain neurofibrillary tangles (NFT) and that AD brains do. The exact pathogenic role of aluminum in AD is, as yet, unclear. It is the only element (other than calcium, which non-specifically accumulates at all degenerating tissue sites) that is found in elevated concentrations in NFTs. It is found elevated at four loci in the brain, i.e. the DNA-containing structures of the nucleus, the protein moities of NFTs, the amyloid cores of senile plaques and cerebral ferritin. The evidence thus far indicates that aluminum is toxic to the brain and it is probable that it has a pathogenic role in Alzheimer's disease.
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PMID:Aluminum toxicity to the brain. 335 18

When cytochemical reaction products are homogeneously distributed within an organelle, point analyses suffice for the quantitative approach. However, quantitative analysis becomes tedious, when the elements in the reaction product are inhomogeneously distributed. Problems arise when elements from two reaction products have to be related to each other, or to endogenous cytological products (ferritin, haemosiderin, calcium, electron dense markers), either topographically or in concentration. When analyzing inhomogeneous/heteromorphical reaction product-containing organelles special attention has to be paid to measure and relate both volume and concentration. In this paper a relative simple structure (eosinophil granules) is chosen to demonstrate that the acquisition of the requested morphometrical plus chemical information and their integration is possible. The following points will be covered to acquire the morphometrical and chemical information: a). How to estimate the total cell cross-sectioned area. b). How to estimate the total cross-sectioned area of all reaction product-containing particles inside that cell. The ratio of these two areas will provide the requested information about the particle volume fraction. By using the X-ray detector in addition: c). How to acquire the chemical information at the requested resolution, within a reasonable total acquisition time d). How to integrate the morphometrical and chemical data per organelle, by matrix analysis in a reduced scan area. e). How to acquire quantitative chemical information, by the use of cross-sectioned standards. f). How to make this acquisition method independent from changes in the instrumental conditions during the acquisition.
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PMID:Image analysis and X-ray microanalysis in cytochemistry. 343 56

A cross-sectional epidemiological study was carried out among 141 male subjects exposed to inorganic manganese (Mn) in a Mn oxide and salt producing plant (mean age 34.3 years; duration of exposure, mean 7.1 years, range 1-19 years). The results were compared with those of a matched control group of 104 subjects. The intensity of Mn exposure was moderate as reflected by the airborne Mn levels and the concentrations of Mn in blood (Mn-B) and in urine (Mn-U). A significantly higher prevalence of cough in cold season, dyspnea during exercise, and recent episodes of acute bronchitis was found in the Mn group. Lung ventilatory parameters (forced vital capacity, FVC; forced expiratory volume in one second, FEV1; peak expiratory flow rate, PEFR) were only mildly altered in the Mn group (smokers) and the intensity and the prevalence of these changes were not related to Mn-B, Mn-U, or duration of exposure. There was no synergistic effect between Mn exposure and smoking on the spirometric parameters. Except for a few nonspecific symptoms (fatigue, tinnitus, trembling of fingers, increased irritability), the prevalence of the other subjective complaints did not differ significantly between the control and Mn groups. Psychomotor tests were more sensitive than the standardized neurological examination for the early detection of adverse effects of Mn on the central nervous system (CNS). Significant alterations were found in simple reaction time (visual), audioverbal short-term memory capacity, and hand tremor (eye-hand coordination, hand steadiness). A slight increase in the number of circulating neutrophils and in the values of several serum parameters (ie, calcium, ceruloplasmin, copper, and ferritin) was also found in the Mn group. There were no clear-cut dose-response relationships between Mn-U or duration of Mn exposure and the prevalence of abnormal CNS or biological findings. The prevalences of disturbances in hand tremor and that of increased levels of serum calcium were related to Mn-B. The response to the eye-hand coordination test suggests the existence of a Mn-B threshold at about 1 microgram Mn/100 ml of whole blood. This study demonstrates that a time-weighted average exposure to airborne Mn dust (total dust) of about 1 mg/m3 for less than 20 years may present preclinical signs of intoxication.
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PMID:Epidemiological survey among workers exposed to manganese: effects on lung, central nervous system, and some biological indices. 357 89

Transferrin receptors have been previously found on human macrophages and it has also been shown that transferrin iron is taken up by these cells. It has therefore been inferred that the uptake is receptor mediated and involves an endocytic pathway. The subject was addressed directly in the present study in which the transferrin-iron-receptor interaction was characterized in cultured human blood monocytes. Specific, saturable diferric transferrin binding was demonstrated, with a kDa of 3.6 X 10(-8) M and a calculated receptor density of 1.25-2.5 X 10(5) receptors per cell. Incubation at 4 degrees C markedly reduced transferrin binding and completely inhibited iron uptake. Chase experiments confirmed progressive cellular loading of iron, with concomitant loss of transferrin. Inhibitors of endocytic vesicle acidification (ammonium chloride and 2,4-dinitrophenol) inhibited iron unloading from endocytosed diferric transferrin, while microtubular inhibitors (colchicine and vindesine) and a microfilament inhibitor (cytochalasin B) reduced diferric transferrin uptake but had little effect on the iron unloading pathway. A similar effect was noted with a calcium ion antagonist (verapamil) and with 2 calmodulin antagonists (chlorpromazine and imipramine). These latter findings suggest the importance of cytoskeleton-membrane interactions via a calcium, calmodulin and protein kinase C mediated system. Endocytosed iron accumulated progressively as ferritin within the cultured monocytes.
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PMID:Transferrin receptors and transferrin iron uptake by cultured human blood monocytes. 362 25

Three different procedures were employed to induce contraction of isolated cochlear outer hair cells. When cells were permeabilized and exposed to calcium and ATP both a shortening of cell length (14%) and a decrease in cell diameter (12-16%) was observed indicating a longitudinal and a circumferential contraction. When intact cells were treated with positively charged ferritin a shortening of about 10% was observed together with an increase in cell diameter. Application of solutions containing high potassium concentrations gave similar but more rapid results as compared with positively charged ferritin. The observed responses of inner ear sensory cells together with their morphological and immunohistochemical characteristics further support the idea that the hearing organ acts as a motile system.
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PMID:Motility in auditory sensory cells. 363 Jul 30

Recent evidence suggests that the hepatic iron-loading characteristic of hemochromatosis may result in part from efficient hepatic clearance of non-transferrin-bound iron, which is increased in this disorder. However, this hypothesis assumes that hepatic clearance remains highly efficient despite excess iron stores. We therefore studied hepatic uptake of non-transferrin-bound iron in the single-pass perfused rat liver under varying conditions. Animals were iron loaded or depleted by dietary manipulation, but no changes in the efficiency of ferrous iron uptake or the kinetic parameters were seen (single-pass extraction, 59-74%; Km, 16-19 microM; Vmax, 30-32 nmol X min-1 X g liver-1). Added divalent zinc, cobalt, and manganese ions reversibly inhibited ferrous iron uptake and the inhibition by zinc was shown to be competitive. Uptake required calcium, was markedly temperature-sensitive (delta E = 14.3 Kcal/mol), and was relatively insensitive to inhibition of cellular energy metabolism. Particles consistent with ferritin cores were seen in lysosomes of hepatic parenchymal cells within 30 min of perfusion with ferrous iron. These results suggest that ferrous iron is cleared from plasma by a passive, saturable transport process that is not regulated by the iron content of the liver and that may be shared with other transition metal ions. Because clearance is highly efficient, increased levels of non-transferrin-bound iron in plasma may present the liver with an obligatory iron load resulting in progressive accumulation and toxicity.
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PMID:Characterization of non-transferrin-bound iron clearance by rat liver. 373 37

Mean daily intakes from 3-day dietary records for calories, energy-providing nutrients, and selected minerals were calculated for 51 highly trained women runners. Selected blood constituents relating to mineral status were also measured. Intakes of calcium, magnesium, iron, and copper were above the amounts recommended by the National Research Council whereas zinc intake was below the recommended dietary allowances (RDA). Caloric intakes, although above the RDA for sedentary women, appeared low for women running 10 miles/day. Concentrations of serum ferritin and plasma zinc were indicative of marginal iron and zinc status in many of the women. Whether the nutrient content of the diets consumed by these women is adequate relative to energy output or whether training lowers nutrient requirements by enhancing metabolic efficiency will require further investigation.
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PMID:Nutritional survey of highly trained women runners. 378 42


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