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 prognostic value of different pretreatment laboratory and clinical findings at diagnosis was assessed in a series of 141 patients with generalized non-Hodgkin's lymphoma. Univariate and multivariate survival analysis (Cox's regression model) was performed, using serum analysis of deoxythymidine kinase (S-TK), beta 2-microglobulin, lactic dehydrogenase, alpha 1-acid glycoprotein = orosomucoid (S-alpha 1 AGP), haptoglobin and ferritin. In addition, Hb and the erythrocyte sedimentation rate (ESR) were measured. The clinical variables were age, presence or absence of B-symptoms, histopathology ('low-grade'; 'intermediate grade' and 'high-grade' malignancy) and bone marrow involvement. Of the 8 biochemical markers, all except Hb and the ESR showed a significant relationship to survival. Among the clinical variables, this finding was made for B-symptoms and histopathology. Using a multivariate analysis on all variables, S-TK was found to be the best factor for predicting duration of survival. The only significant additional information was provided by S-alpha 1 AGP. When only the clinical variables were taken into account, it was found that histopathology added significant information to that yielded by B-symptoms in the prediction of the survival time. When the biochemical variables were added to this model, only S-TK was of significant additional prognostic value.
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PMID:Biochemical markers in non-Hodgkin's lymphoma stages III and IV and prognosis: a multivariate analysis. 637 52

The topographic relationships of platelet membrane glycoprotein IIb and glycoprotein IIIa have been studied in stimulated and unstimulated human platelets using immunoelectron microscopy. An indirect approach with ferritin-conjugated goat anti-rabbit gamma-globulin was used to localize the rabbit antibody to glycoprotein IIIa. The second ultrastructural label was keyhole limpet hemocyanin conjugated directly to antibody to glycoprotein IIb. Using the double labels, it was demonstrated that glycoprotein IIb and glycoprotein IIIa were distributed randomly in the unstimulated platelet membrane. After platelet stimulation with thrombin, large clusters of glycoprotein IIb-glycoprotein IIIa complexes were formed. No complex formation between glycoprotein Ib and glycoprotein IIb was observed in control experiments. These observations suggest that thrombin stimulation initiates the specific glycoprotein IIb-glycoprotein IIIa macromolecular complex formation on the platelet surface, which may act as the active fibrinogen-binding site required for normal platelet aggregation.
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PMID:Thrombin-induced platelet membrane glycoprotein IIb and IIIa complex formation. An electron microscope study. 645 76

A sandwich-type radioimmunoassay for serum ferritin was developed using iron-rich human liver ferritin and evaluated for its clinical usefulness. In young healthy males and females, the mean serum ferritin concentrations were 44 micrograms/L (range 7-158) and 16 micrograms/L (range 4-56), respectively. In anemic patients lower serum ferritin concentrations were found, while in most patients with iron overload serum ferritin concentrations well above 1000 micrograms/L were measured. Comparison of our method with a commercially available radioimmunoassay kit revealed a good correlation, except for sera with very low ferritin concentrations. Comparison with serum iron and transferrin parameters in patients with iron deficiency demonstrated that serum ferritin concentrations might be subnormal in a majority of patients with otherwise normal iron indices. Up to 70% of the ferritin in serum of normal subjects could bind to concanavalin A-Sepharose, indicating its glycoprotein nature. It is concluded that our serum ferritin radioimmunoassay gave reliable results and was useful in the laboratory diagnosis of latent iron-deficiency and in the analysis of the heterogeneity of serum ferritin.
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PMID:Measurement of ferritin in serum: application in diagnostic use. 647 88

In the present study in Munich-Wistar rats during the initial stages of autologous immune complex nephritis (protein excretion 3 to 50 mg/24 hours) we examined the sequential changes in binding of cationized ferritin to anionic sites, as well as alterations in staining with colloidal iron of podocyte membrane sialoglycoprotein and correlated these with changes in glomerular basement membrane permeability to native ferritin. The results are compared with those obtained from rats with advanced autologous immune complex nephritis (protein excretion 100 to 350 mg/24 hours) and with normal control rats. The formation of the smallest detectable immune complex deposits was associated with a concomitant decrease in binding of cationized ferritin to anionic sites in the lamina rara externa in the area of the deposits. This was accompanied by a diminution in staining by colloidal iron of the epithelial cell coat overlying the deposits. The staining of the remainder of the epithelial cell glycocalyx, however, remained unaltered even in the presence of severe proteinuria. Alterations in the permeability of the glomerular basement membrane to native ferritin could not be documented until protein excretion exceeded 10 mg/24 hours. The gradual loss of staining of the epithelial cell glycocalyx adjacent to immune complexes supports the concept that, as immune complexes are formed in situ by the interaction of antibodies with a glycoprotein present on the epithelial cell surface, they are shed and gradually accumulate in the lamina rara externa. Furthermore, as the immune complex deposits enlarge they destroy and/or mask the heparan sulfate anionic sites in the lamina rara externa resulting in a decreased number of anionic binding sites for cationized ferritin.
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PMID:Alterations in glomerular anionic sites in autologous immune complex nephritis. 662 Sep 83

Fibronectin, a glycoprotein that binds to collagen and modifies the adhesion properties and motility of cells in culture, is present in the interstitium of rat hearts. To localize fibronectin more precisely and to assess its relationship to the myocyte and to connective tissue elements, we employed a double antibody technique to label myocardial fibronectin with electron-dense ferritin to permit an ultrastructural analysis. Fibronectin was found to be associated with collagen, and in some cases appeared to link collagen fibers. Fibronectin was also found inserted along the surfaces of cardiac myocytes, connecting these cells to perimyocytic collagen. These ultrastructural relationships imply that fibronectin is a major component of the myocardial interstitium, and may affect myocardial compliance and control the motion of myocytes during the contraction and relaxation of the heart.
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PMID:Fibronectin in rat heart: a link between cardiac myocytes and collagen. 670 62

Microtubules have been classified as either stable or labile, according to their resistance towards depolymerizing agents. The highest stability belongs to those organized in composite structures, in which many other proteins are associated with the tubulin. Among these microtubular systems, the marginal band of amphibian erythrocytes is unusually stable. This system can be readily isolated from Triturus red blood cells, and therefore lends itself very readily to ultrastructural and biochemical analyses. Immunofluorescence and electrophoretic analyses of the isolated bands reveal 14 components, among which tubulin, actin, myosin and a 90K glycoprotein were identified. Tannic acid-glutaraldehyde fixation reveals a conspicuous opaque material surrounding the microtubules. Cationized ferritin binding suggests the presence of anionic sites. Moreover, neuraminidase causes the disorganization of the microtubule-associated opaque material. The 90K glycoprotein is presumed to be related to the unusual stability of the microtubular system forming the marginal band.
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PMID:Observations on the molecular components stabilizing the microtubular system of the marginal band in the newt erythrocyte. 676 28

Acidic isoferritins have been identified as leukemia-associated inhibitory activity (LIA), which suppresses colony and cluster formation of colony-forming unit-granulocyte macrophages from normal donors but not from patients with leukemia. LIA was detected in all ferritin preparations tested, including ferritin isolated from normal heart, spleen, liver, and placental tissues, and from the spleens of patients with chronic myelogenous leukemia and Hodgkin's disease. Purified preparations of LIA were composed almost entirely of acidic isoferritins, as determined by immunoassay, radioimmunoassay, and isoelectric focusing. The inhibitory activity in the LIA and ferritin samples was inactivated by a battery of antisera specific for ferritin, including those prepared against acidic isoferritins from normal heart and spleen tissues from patients with Hodgkin's disease, and those previously absorbed with basic isoferritins. Antisera absorbed with acidic isoferritins did not inactivate the inhibitory activity. Separation of LIA and chronic myelogenous leukemia and normal spleen ferritin by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and isoelectric focusing confirmed that the regions of peak inhibitory activity corresponded in each to an apparent molecular weight of approximately 550,000 and to a pI value of 4.7. Similar physicochemical characteristics included inactivation by methods that dissociate ferritin molecules into subunits and by treatment with trypsin, chymotrypsin, pronase, and periodate. The purified preparations were extremely stable to heat treatment. The glycoprotein nature of the inhibitory activity was substantiated because it bound to concanavalin A-Sepharose and was eluted off by alpha-methyl mannose. Inhibitory activity of the activity of the acidic isoferritins was detected at concentrations as low as 10(-17)-10(-19) M and iron saturation did not appear to be necessary for its action. These results implicate acidic isoferritins in the regulation of normal myelopoiesis and suggest a role for them in the progression of leukemia.
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PMID:Identification of leukemia-associated inhibitory activity as acidic isoferritins. A regulatory role for acidic isoferritins in the production of granulocytes and macrophages. 697 99

Immunofluorescence and immunoferritin staining with monospecific antibodies to dipeptidyl peptidase IV purified from rat liver plasma membrane showed that the antigenic sites of this glycoprotein was exposed only on the outer surface of the liver cell. In a vesiculated plasma membrane preparation the peptidase was located exclusively on right-side-out elements, which differed in their degrees of ferritin staining, and could be separated into subfractions of different buoyant densities corresponding to their concentration of dipeptidyl peptidase IV. The concomitant density perturbation of nucleotide pyrophosphatase was similar, but not identical, to that of the peptidase itself, indicating that these two marker enzymes are somewhat differently distributed in the plane of the liver plasma membrane. Since essentially all the galactosyl transferase in plasma membrane and none of that in Golgi membrane could be density-perturbed with the antipeptidase, the activity in the plasma membrane preparation could not be ascribed to contamination with discrete Golgi elements. On the other hand, the small amount of dipeptidyl peptidase IV found in the Golgi preparations was itself perturbed by the antipeptidase, indicating that it represented contaminating right-side-out plasma membrane vesicles. In preliminary experiments similar separations were also obtained with wheat germ agglutinin as the plasma membrane ligand. Density perturbation, mediated by the recognition of specific surface markers, should be a useful adjunct in the separation and characterization of subcellular components in other systems.
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PMID:Subfractionation of liver membrane preparations by specific ligand-induced density perturbation. 698 98

We have localized fibronectin, a major extracellular glycoprotein of cultured fibroblasts, in chick embryo fibroblasts at the ultrastructural level using affinity-purified antibodies to fibronectin. The use of a ferritin bridge procedure permitted quantitation of localization in various organelles. These results provide the first intracellular ultrastructural localization of fibronectin. Extracellular labeling was confined to aggregates and fibrils, with little or no labeling of the plasma membrane. The principal sites of intracellular localization were the rough endoplasmic reticulum and the Golgi apparatus. Treatment of cells with the protein synthesis inhibitors cycloheximide and pactamycin reduced fibronectin localization in the endoplasmic reticulum to 50% of normal levels. Removal of cycloheximide permitted recovery of labeling to 85% of control levels in the endoplasmic reticulum. Similar, but much reduced, changes also occurred in the Golgi apparatus.
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PMID:Intracellular localization of fibronectin by immunoelectron microscopy. 699 70

The proteinase from culture supernatants of Candida albicans strain CBS-2730 was purified virtually to homogeneity by ion-exchange chromatography and affinity chromatography. The enzyme consists of a single polypeptide chain with tryptophan at the N- and leucine at the C-terminus. Its molecular weight is approx. 45,000 and the isoelectric point is at pH 4.4. With albumin as a substrate an apparent Km was determined to be 7 . 10(-5) M. The enzyme is inhibited by pepstatin at equimolar ratio and thus is a carboxyl proteinase (EC 3.4.23.6). Other group-specific inhibitors, though, did not efficiently block the enzyme. Above pH 8.4 the enzyme undergoes alkaline denaturation which is accompanied by dimerization. The enzyme is a glycoprotein. It is stable in presence of non-ionic detergents and can be freeze-dried. The enzyme clots milk at pH 5.5 and has trypsinogen kinase activity. Among several purified proteins that have been tested as a substrate, only horse ferritin was resistant to proteolysis, while myeloma proteins of the A1- and A2-type were readily cleaved, as were two proteinase inhibitors of human serum. Antibodies against purified enzyme did not react with several commercial Candida antigen preparations; antibodies against the enzyme, though, have been detected repeatedly in sera from patients with manifest candidiasis.
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PMID:Properties of a purified proteinase from the yeast Candida albicans. 701 86


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