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)

In the first part of this study we have shown how the serum levels of four selected tumour markers, namely tissue polypeptide antigen (TPA), carcino-embryonic antigen (CEA), hyaluronic acid (HA) and ferritin, display patterns characteristic of mesothelioma (M) or bronchogenic carcinoma (BC) in asbestos-exposed workers, and we hypothesize that the differences in marker patterns correspond to differences in carcinogenesis mechanisms. In a preliminary study, we found these specific marker patterns in 5/19 exposed workers of whom only one demonstrated any radiological signs of disease. Thus these specific marker patterns may be early events, occurring long (possibly years) before the classical radiological signs of exposure to asbestos. Accordingly they afford an optimal opportunity for prevention which should be adapted to the carcinogenesis mechanism as it is revealed by the marker pattern; it is aimed at antagonizing free radical carcinogenesis in all persons with TPA levels in excess of 100 U/l or Ferritin in excess of 400 ng/ml, and at inhibiting chemical carcinogenesis in those having elevated CEA levels (over 3 ng/ml). The mechanisms involved in these inhibitory processes are described and discussed, as well as the practical implementations that proceed from them. A prevention trial is now being started among 300 active and retired workers of an asbestos-cement works in northern France; the design of the study is presented. This prevention programme should be maintained over many years and holds a strong potential for reducing the untoward effects of exposure to asbestos.
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PMID:Biomarker assessments in asbestos-exposed workers as indicators for selective prevention of mesothelioma or bronchogenic carcinoma: rationale and practical implementations. 146 74

Interactions between macrophages and articular surfaces were studied in an in vitro model which has been described before. Either stimulated peritoneal macrophages or a purified population of bone marrow macrophages were incubated with mice femoral heads which were either untreated or were digested with collagenase, trypsin or hyaluronidase prior to incubation. Scanning electron microscopy (EM) examination showed that macrophages attached to the surface and in their vicinity tags and fibers were visible. Transmission EM was used after labeling the surfaces with cationized ferritin employed as a sensitive marker to define the integrity of the articular surface. Alterations of the surface of various degrees of intensity were seen in all the sections examined. No adhering macrophages were found, due probably to detachment of cells during tissue processing for transmission EM. Attachment of macrophages to the surface and alterations of the latter were seen also when hyaluronic acid was added to the incubation medium or when the surfaces had been treated with hyaluronidase before incubation.
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PMID:Interaction between macrophages and articular surfaces: an in vitro transmission and scanning electron microscopy study. 237 23

To study the roles played by cardiac valvular endothelium in normal and pathologic conditions, we have established and characterized a system of bovine valvular endothelial cells (VEC) in culture. Viable VEC from calf atrioventricular valves were obtained by a non-enzymatic procedure using 3 mM ethylenediamine-tetraacetic acid (EDTA) as dissociating agent. The cells grown in Dulbecco's modified Eagle's medium supplemented with non-essential amino acids, vitamins and 20% fetal calf serum, developed as monolayers of closely apposed polygonal cells which were subcultured for up to seven passages. VEC maintained in culture the general ultrastructure displayed in vivo, expressed von Willebrand factor, presented angiotensin converting enzyme activity and synthesized a rich extracellular matrix. VEC preserved the cell surface anionic sites (detected with cationized ferritin, pI 8.4) and cationic sites (visualized with haemeundecapeptide pI 4.85), and took up, especially by adsorptive endocytosis, albumin-gold conjugate. The cells were coupled by functional communicating (gap) junctions, as demonstrated by microinjection of 6-carboxyfluorescein. VEC in culture produced fibronectin, prostacyclin, hyaluronic acid and heparin-like glycosaminoglycans (identified by electrophoresis, enzyme digestion, and deaminative cleavage of molecules). These properties render cultured VEC a suitable model for investigating their functions and involvement in normal and pathologic heart valves.
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PMID:Calf cardiac valvular endothelial cells in culture: production of glycosaminoglycans, prostacyclin and fibronectin. 284 May 11

The anionic macromolecules at the glomerular endothelial cell surface are visualized only when stained with cationic stains. We investigated the arrangement and composition of this anionic matrix at the luminal surface. Rat kidneys were perfused with anionic ferritin (pI 4.5), ferritin (pI 7.4), or cationized ferritin (CF, pI 8.3). Anionic ferritin (pI 4.5) did not bind to the capillary wall, ferritin (pI 7.4) bound discontinuously only to the laminae rarae of the basement membrane, but cationized ferritin (CF, pI 8.3) bound as a thick continuous layer to the cell plasmalemma and bound to the anionic matrix in the fenestral spaces. These observations show that an anionic matrix lines the entire capillary lumen surface, fills the fenestrae, and is interposed between the blood and the basement membrane at the fenestrae. The anionic constituents at the capillary luminal surface were identified by in vivo digestion with specific enzymes. Absence of CF binding following digestion with specific enzymes was taken to indicate the presence of the particular glycoprotein known to be susceptible to the enzyme used. Neuraminidase digestion revealed that anionic sites over the surface plasmalemma are mainly from sialoproteins. In contrast, the matrix in fenestral channels contains heparan sulfate, hyaluronic acid, and sialoproteins. Papain digestion showed no glycolipids at the luminal surface. The functions of this continuous anionic layer located at the luminal surface of glomerular capillaries have not yet been established.
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PMID:The anionic matrix at the rat glomerular endothelial surface. 296 99

Proteodermatan sulfate was isolated from the skin of human, female breast in 6-M urea and proteolytic inhibitors at 70 degrees C and purified on Sephacryl S-200. It was composed of 55% protein and 45% dermatan sulfate, displayed one protein and carbohydrate-stainable band on agarose-polyacrylamide gels, yielded dermatan sulfate after digestion by papain, and its calculated E0.1% 1 cm, 280 nm was 16.2. Its mucopolysaccharide portion was digested by chondroitinase ABC but not by chondroitinase AC. This proteoglycan was used to immunize rabbits. Double diffusion of antiserum against the antigen or its core protein resulted in one precipitation band. Antiserum did not cross-react with bovine collagen type I, human fibronectin, dermatan sulfate, hyaluronic acid, heparin, heparan sulfate or the chondroitin sulfates by double diffusion. The antiserum titer determined by radioimmunoassay was 1:16,000. This assay was not affected by a 40-fold excess of dermatan sulfate. Purified IgG molecules were apparently associated with collagen in human breast mid-dermis as demonstrated by indirect immunoelectron microscopy with ferritin-labeled goat antirabbit IgG. The results indicate that rabbit anti-human, anti-proteodermatan sulfate IgG is highly specific for the core protein of dermatan sulfate and confirm the hypothesis that in vivo proteodermatan sulfate is closely associated with collagen.
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PMID:Immunoelectron microscopy of proteodermatan sulfate in human mid-dermis. 315 40

Four cases of mesothelioma were studied histologically and electron microscopically. One of them showed a pure epithelial type of the peritoneal origin, characterised by a tremendous production of hyaluronic acid. The other three tumors originated from the pleura revealed a histology of biphasic type mesothelioma, which showed an admixed tubular and fibrous pattern and consisted of small-sized cells with slight atypia. However, in some places of these tumors they showed considerable atypical features appearing like an anaplastic or squamoid carcinoma and/or spindle cell sarcoma. Hyaluronic acid was histologically demonstrated in the cytoplasmic vacuoles as well as in the luminal space surrounded by the tumor cells. Electron microscopically, varied numbers of microvilli and desmosome-like attachments were found on the surface of the tumor cells. Mitochondria were small and round. Well-developed rERs tended to encircle mitochondria and to dilate forming cisternae. Various amounts of microfilaments were found in the cytoplasm. The tumor cells which were rich in the latter two components, dilated rERs and microfilaments, resembled fibroblasts. Some tumor cells had phagosomes including dense and fine granules similar to ferritin, suggesting their phagocytotic activity. The hyaline matrix, common to the biphasic type tumor which was largely composed of dense collagenous tissues, was demonstrated to contain hyaluronic acid by histochemistry, and it was suggested that some secretory substances of the tumor cell may participate in composing the hyaline matrix to some extent.
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PMID:Mesothelioma. Histological and electron microscopic study of human cases. 608 95

Oxygen free radicals generated by xanthine oxidase are able to depolymerize hyaluronic acid in the presence of ferritin-bound iron. This suggests that ferritin can catalyse the Haber-Weiss reaction, leading to the formation of highly damaging hydroxyl radicals.
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PMID:Xanthine oxidase induced depolymerization of hyaluronic acid in the presence of ferritin. 609 41

Glomerular development was studied in the newborn rat kidney by electron microscopy and cytochemistry. Glomerular structure at different developmental stages was related to the permeability properties of its components and to the differentiation of anionic sites in the glomerular basement membrane (GBM) and on endothelial and epithelia cell surfaces. Cationic probes (cationized ferritin, ruthenium red, colloidal iron) were used to determine the time of appearance and distribution of anionic sites, and digestion with specific enzymes (neuraminidase, heparinase, chondroitinases, hyaluronidases) was used to determine their nature. Native (anionic) ferritin was used to investigate glomerular permeability. The main findings were: (a) The first endothelial fenestrae (which appear before the GBM is fully assembled) possess transient, negatively charged diaphragms that bind cationized ferritin and are impermeable to native ferritin. (b). Two types of glycosaminoglycan particles can be identified by staining with ruthenium red. Large (30-nm) granules are seen only in the cleft of the S-shaped body at the time of mesenchymal migration into the renal vesicle. They consist of hyaluronic acid and possibly also chondroitin sulfate. Smaller (10-15-nm) particles are seen in the earliest endothelial and epithelial basement membranes (S-shaped body stage), become concentrated in the laminae rarae after fusion of these two membranes to form the GBM, and contain heparan sulfate. They are assumed to be precursors of the heparan sulfate-rich granules present in the mature GBM. (c) Distinctive sialic acid-rich, and sialic acid-poor plasmalemmal domains have been delineated on both the epithelial and endothelial cell surfaces. (d) The appearance of sialoglycoproteins on the epithelial cell surface concides with the development of foot processes and filtration slits. (e) Initially the GBM is loosely organized and quite permeable to native ferritin ;it becomes increasinly impermeable to ferritin as the lamina densa becomes more compact. (f) The number of endothelial fenestrae and open epithelial slits increases as the GBM matures and becomes organized into an effective barrier to the passage of native ferritin.
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PMID:Assembly of the glomerular filtration surface. Differentiation of anionic sites in glomerular capillaries of newborn rat kidney. 615 76

The surface of rat arterial smooth muscle cells was characterized with respect to some of its chemical and functional properties. The effects of selective enzymic degradations (hyaluronidase, chondroitinases, heparitinase or neuraminidase) on [35S]sulphate-prelabelled cells and on binding sites for cationized ferritin (CF) were examined to assess the presence and relative importance of individual species of macromolecules on the cell surface. The results indicate that about half of the strongly anionic sites on the cell surface (binding CF at pH 2.0) could be ascribed to sulphate groups of glycosaminoglycans and about half to carboxyl groups of sialic acid residues in glycoproteins and/or glycolipids. Weaker anionic sites (binding CF at pH 7.0) largely originated from carboxyl groups of glycosaminoglycans. Chondroitin sulphate and heparan sulphate were the main glycosaminoglycans. The surface of cells from young animals showed a higher glycosaminoglycan and a lower sialic acid content than that of cells from adult animals. Continuous treatment of the cultures with neuraminidase stimulated serum-induced initiation of DNA synthesis, while treatment with hyaluronidase or heparitinase inhibited it. Addition of hyaluronic acid, heparin or heparan sulphate to the culture medium inhibited initiation of DNA synthesis as well as cell proliferation. The effect was more marked in cultures of cells from young animals than from adults, although the latter cells were found to grow at a higher rate and to higher densities. These results suggest a role for cell-surface and pericellular glycoconjugates in growth regulation. A possible mechanism of action is that these molecules, due to their anionic charge or by steric exclusion, interfere with the binding of platelet-derived growth factor, a highly cationic polypeptide, to its cell-surface receptor.
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PMID:Cell surface components and growth regulation in cultivated arterial smooth muscle cells. 642 Apr 21

Glomerular basement membranes (GBM's) were subjected to digestion in situ with glycosaminoglycan-degrading enzymes to assess the effect of removing glycosaminoglycans (GAG) on the permeability of the GBM to native ferritin (NF). Kidneys were digested by perfusion with enzyme solutions followed by perfusion with NF. In controls treated with buffer alone, NF was seen in high concentration in the capillary lumina, but the tracer did not penetrate to any extent beyond the lamina rara interna (LRI) of the GBM, and litte or no NF reached the urinary spaces. Findings in kidneys perfused with Streptomyces hyaluronidase (removes hyaluronic acid) and chondroitinase-ABC (removes hyaluronic acid, chondroitin 4- and 6-sulfates, and dermatan sulfate, but not heparan sulfate) were the same as in controls. In kidneys digested with heparinase (which removes most GAG including heparan sulfate), NF penetrated the GBM in large amounts and reached the urinary spaces. Increased numbers of tracer molecules were found in the lamina densa (LD) and lamina rara externa (LRE) of the GBM. In control kidneys perfused with cationized ferritin (CF), CF bound to heparan-sulfate rich sites demonstrated previously in the laminae rarae; however, no CF binding was seen in heparinase-digested GBM's, confirming that the sites had been removed by the enzyme treatment. The results demonstrated that removal of heparan sulfate (but not other GAG) leads to a dramatic increase in the permeability of the GBM to NF.
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PMID:Increased permeability of the glomerular basement membrane to ferritin after removal of glycosaminoglycans (heparan sulfate) by enzyme digestion. 644 56


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