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 distribution of a major glycoprotein (fibronectin) of human fibroblast cultures was studied in immunoelectron microscopy with peroxidase- or ferritin-labeled antibodies. External fibronectin was visualized in pericellular structures, in some areas on the growth substratum, and to a lesser degree in close association with the upper and lower surface membranes of the cell. The pericellular fibronectin-containing structures consisted of amorphous or vaguely fibrillar material forming strands or patches, 50-500 nm in diameter; the structures appeared to mediate distant cell-to-cell and cell-to-substrate contacts. When in close association with the plasma membrane, fibronectin markers were seen as discrete patches. The exact relationship between this form of fibronectin and the plasma membrane, however, remained open. Filamentous material was commonly seen in the cortical cytoplasm under patches of membrane-associated fibronectin. The distribution that we observed is consistent with the proposed roles of fibronectin in cell interactions with neighboring structures and with its presence in vivo as an extracellular glycoprotein in connective tissue matrix and basal laminae.
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PMID:External fibronectin of cultured human fibroblasts is predominantly a matrix protein. 34 28

A glycoprotein immunologically related to plasma cold-insoluble globulin (CIG) and fetal skin fibroblast fibronectin has been purified from second-trimester human amniotic fluid. This protein (amniotic fluid fibronectin) migrated more slowly than CIG on sodium dodecyl sulfate gel electrophoresis and showed greater polydispersity which could result, at least in part, from heterogeneity in glycosylation. Cloned human amniotic fluid epithelioid and fibroblastic cells synthesized and secreted a protein with similar properties into the culture medium. Fibronectin was shown to be associated with the pericellular and extracellular matrix of cultured amniotic fluid cells by immunofluorescence, lactoperoxidase-catalyzed iodination, and labeling with ferritin-conjugated antibodies. The kinetics of secretion of the protein were consistent with its role as a matrix protein. We anticipate that amniotic fluid fibronectin will prove to be the same protein which elsewhere in the body is incorporated into connective tissues and basement membranes. Amniotic fluid could, therefore, serve as a convenient source of in vivo synthesized fibronectin for biological and structural studies.
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PMID:Amniotic fluid fibronectin. Characterization and synthesis by cells in culture. 70 56

A new human extrahepatic bile duct carcinoma cell line (KMBC) was established from a serially transplanted tumor in nude mice that originated from a surgically resected tumor from a 73-year-old Japanese man; the cell line has been maintained for 5 five years. KMBC cells proliferate in a monolayered sheet with a population doubling time of 30 hours. Chromosome number was distributed in a range from 37 to 44, with modal numbers of 40 and 41. KMBC cells and the reconstituted tumor in a nude mouse showed moderately to poorly differentiated adenocarcinoma and possessed various functional characteristics of extrahepatic bile duct carcinoma. KMBC cells secreted carbohydrate antigen 19-9, tissue polypeptide antigen, carcinoembryonic antigen, ferritin, beta 2-microglobulin, fibronectin, and alpha 2-macroglobulin and produced glutamic oxaloacetic transaminase and alkaline phosphatase. KMBC is the second established cell line that originated from a human extrahepatic bile duct carcinoma in the world literature, and it will be applicable to various experiments.
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PMID:Establishment and characterization of a new human extrahepatic bile duct carcinoma cell line (KMBC). 131 90

In 71 patients with fever and bacteremia without complications, a prospective study of acute-phase reactants is done. Raises in haptoglobin, ceruloplasmin, alpha-1-antitrypsin, protein C, beta-2-microglobulin, IgA and ferritin serum levels, together with leucocytosis and GSR, were very significant when diagnosis was done. Fibronectin, sideremia and transferrin were lowered. After 3 and 6 days of treatment haptoglobins, alpha-1-antitrypsin, protein C, ferritin, leucocytosis and GSR are lowered, while immunoglobulins, sideremia, transferrin and fibronectin raised, the latter until normalization. Fibronectin as well as changes in iron metabolism were very reliable parameters of inflammation and favorable evolution.
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PMID:[Acute-phase reactants in sepsis]. 148 35

Iron absorption by intestinal epithelial cells, passage onto plasmatic apotransferrin, and regulation of the process remain largely misunderstood. To investigate this problem, we have set up an in vitro model, consisting in CaCo2 cells (a human colon adenocarcinoma line, which upon cultivation displays numerous differentiation criteria of small intestine epithelial cells). Cells are cultivated in a serum-free medium, containing 1 microgram/ml insulin, 1 ng/ml epidermal growth factor, 10 micrograms/ml albumin-linoleic acid, 100 nM hydrocortisone, and 2 nM T3 on new, transparent, Cyclopore polyethyleneterephthalate microporous membranes coated with type I collagen. Cells rapidly adhere, grow, and form confluent monolayers; after 15 days, scanning electron microscopy reveals numerous uniform microvilli. Domes, which develop on nonporous substrata, are absent on high porosity membranes. Culture medium from upper and lower compartments of microplate inserts and cell lysates were immunoprecipitated after labeling with [3H]glucosamine and leucine; analysis was done by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), followed by autoradiography. [3H]transferrin is found mainly in the lower compartment and in cells; [3H]apolipoprotein B is released in both compartments, and fibronectin almost entirely recovered in the lower compartment; [3H]transferrin receptors and ferritin are only present in cell lysates. Binding experiments also show that transferrin receptors are accessible from the lower compartment. These results suggest that CaCo2 cells, cultivated in synthetic medium on membranes of appropriate porosity, could provide an in vitro model of the intestinal barrier, with the upper compartment of the culture insert corresponding to the apical pole facing the intestinal lumen and the lower one to the basal pole in contact with blood.
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PMID:Iron absorption by intestinal epithelial cells: 1. CaCo2 cells cultivated in serum-free medium, on polyethyleneterephthalate microporous membranes, as an in vitro model. 183 Mar 3

The process of fusion from without (FFWO) induced by herpes simplex virus (HSV) was analyzed by using various inhibitors and compared to fusion from within (FFWI). The fate of certain elements of the cytoskeleton after FFWO was also investigated. Our experiments demonstrate FFWO as a very suitable system for study of early virus-cell interactions. Zn++ ions proved inhibitory for penetration whilst pretreatment of cells with Ca++ ions before infection enhanced FFWO activity. Dissociation of penetration from the fusion process itself was possible by use of Zn++ ions, low pH-treatment and antiserum on the one hand and N-ethylmaleimide and cytochalasin D on the other. Penetration itself needs only 6 min or less to proceed. FFWO is independent of inhibitors of glycosylation (tunicamycin) and intracellular vesicular traffic (monensin), protein-synthesis (cycloheximide) and energy-delivery (2.4 dinitrophenol and Na-azide). Analyzed strains of HSV-1 and -2 producing FFWI could be subgrouped into three categories: Strain ANG with high, strain HFEM and Lux with low and strains IES, Len, MP, US with no FFWO activity. The results of these experiments indicate that the property of FFWO is not purely a consequence of the number of PFU but depends on certain inherent properties of the virus particles. Addition of heparin as well as treatment of cells with heparitinase effectively prevented FFWO, indicating identical virus receptors for entrance of virus into cells and FFWO. During our studies several calf sera were found to inhibit FFWO-activity. Inhibition of FFWO by a glycoconjugate (ferritin coupled with oleic acid) indicates specific stereochemical hindrance of FFWO by this compound. Shortly after FFWO the actin filaments rearrange to form long fibres and surface fibronectin is being lost from the cell membrane.
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PMID:Characterization of fusion from without induced by herpes simplex virus. 184 50

Previous ultrastructural investigations have shown that the erythroblastic island is composed of erythroblasts at different stages of maturation which are intimately associated with a central macrophage. However, it is still unclear at which stage of erythroid differentiation this interaction occurs, mainly because of the lack of purified populations of normal erythroid progenitors [erythroid colony-forming units (CFU-E) and erythroid burst-forming units (BFU-E)] and early precursor cells (proerythroblasts) and because of our limited knowledge of their ultrastructural characteristics. In the present work we analyzed the ultrastructure of CFU-E enriched from normal human bone marrow by avidin-biotin immune rosetting and leukemic blasts of erythroid origin from two patients. Normal and leukemic CFU-Es were defined as glycophorin A (GPA)-negative blasts, devoid of rhopheocytosis, containing some ferritin molecules, either free in the cytoplasm or associated with theta-granules (theta-Gr) in the Golgi zone. Peroxidase activity was detected in the endoplasmic reticulum of these blasts. A preproerythroblast stage was identified, which corresponded to an intermediate phenotype with few GPA sites and rhopheocytosis. In contrast to hemoglobin synthesis, which was absolutely dependent on the presence of erythropoietin (Epo) during culture for 24 hours, ferritin molecules accumulated in the absence of Epo. Interestingly, leukemic CFU-E-like blasts were always in contact with bone marrow macrophages and adhesion between these cell types resisted mechanical dissociation. This result suggests that erythroid progenitors may be part of the erythroblastic island. The mechanisms involved in erythroblast-macrophage binding are still unknown, but the expression by macrophages and erythroid progenitors of receptors for fibronectin and thrombospondin (TSP), as well as their respective ligands in the case of macrophages, suggests that these molecules could be involved in the formation of the erythroblastic island.
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PMID:Association between leukemic erythroid progenitors and bone marrow macrophages. 201 49

Chemical analysis of ascitic fluid may be helpful in determining the underlying disease. We discuss the diagnostic accuracy of the common and newer chemical parameters (protein, LDH, lactate, glucose, cholesterol, triglycerides, phospholipids, fibronectin, albumin gradient [value of serum minus value of ascites], ferritin, tumor markers, immunomodulators, leukocytes, bacterial and cytologic examinations). We also review the pathogenesis and clinical findings of the most frequent ascites forms (benign hepatic, infective, malignant ascites, ascites associated with liver metastases or hepatocellular carcinoma, cardiac and pancreatic ascites) and the most important diagnosis criteria. In the malignant ascites a high cholesterol, a narrow albumin gradient or a high ferritin value have high diagnostic accuracy, but diagnosis is by the finding of malignant cells. For the diagnosis of infective ascites, bacteriology is mandatory even though the results are negative in most cases, particularly in spontaneous bacterial peritonitis where diagnosis has to be established clinically, by a low pH or by a high leukocyte count. Benign hepatic ascites is diagnosed by demonstrating an underlying chronic liver disease and laboratory examinations of the peritoneal fluid to exclude other causes. The laboratory tests in ascites associated with liver metastases or with hepatocellular carcinoma were similar to those in benign hepatic ascites and the two ascites forms must be separated by other clinical and technical findings. Pancreatic ascites can easily be distinguished from the other forms by the high amylase and lipase content.
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PMID:[Laboratory chemical analysis in ascites]. 203 10

Histochemical features of aperiodic microfibrils (AMF) in mouse tooth germs were examined at the electron microscopic level. Intact and EDTA-isolated materials obtained from one day old first molars were used for ruthenium red (RR) staining, ferritin permeability, periodic acid-silver methenamine (PAM) impregnation, fibronectin localisation, negative staining on cryo-sections and tannic acid fixation. Electron microscopy and negative staining demonstrated that AMF traverse the basal lamina and penetrate below the inner enamel epithelium. In addition to RR staining, PAM impregnation and tannic acid fixation showed deposition on the AMF which was associated with basal laminae. RR staining and tannic acid fixation also indicated the presence of glycoprotein-rich materials in the lamina lucida. The AMF were derived from the lamina lucida which was closely associated with tannic acid-positive granular materials. The precipitation of silver particles by PAM impregnation was seen on banded collagen fibrils, basal lamina and AMF, but the staining features of AMF differed distinctly from those of collagen fibrils. The distribution of ferritin particles revealed that the basal lamina covering EDTA-isolated papilla tissue is a continuous structure. Immuno-reactions for fibronectin were detected on the basal lamina and AMF. Our results suggest that AMF are derived from the glycoprotein-rich lamina lucida and that their histochemical characteristics resemble those of basal lamina.
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PMID:Features of the aperiodic microfibrils associated with mouse dental basement membrane demonstrated by ultrastructural histochemistry. 207 19

The pathogenic protozoan Tritrichomonas foetus is able to ingest polystyrene particles with a diameter up to 1.0 micron. Trichomonas vaginalis, however, ingest particles as large as 4.4 microns in diameter. The particles are found within cytoplasmic membrane-bounded vacuoles. Morphometrical analysis showed that T. vaginalis presents a higher endocytic activity than T. foetus. Coating of the polystyrene particles with cationized ferritin increases their binding to the parasite surface but does not interfere with their ingestion. In contrast, coating with laminin significantly increased the uptake of the particles by both parasites while coating with fibronectin potentiates the ingestion of the particles only by T. foetus. These observations suggest the presence of laminin- and fibronectin-binding sites on the surface of trichomonads, an observation which is in agreement with the recent description of a receptor for laminin on the surface of trichomonads.
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PMID:Fibronectin- and laminin-mediated endocytic activity in the parasitic protozoa Trichomonas vaginalis and Tritrichomonas foetus. 213 55


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