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)

Trypanosoma lewisi bloodstream and culture forms were agglutinated differentially with low concentrations of the cationic compounds: ruthenium red, ruthenium violet, Alcian blue chloride, 1-hexadecylpyridinium chloride, lanthanum chloride, and cationized ferritin. The bloodstream form trypanosomes gave the highest agglutination levels with each of the compounds tested. Ruthenium red was the most effective inducer of cell agglutination among the several cations used. Trypsin-treated bloodstream forms were agglutinated less in the presence of ruthenium red than untreated controls. Ruthenium red-induced cell agglutination also was lowered with chondroitin sulphate and dextran sulphate, but not with alpha-D-glucose, alpha-D-mannose or with several methyl glycosides. Treatment of the bloodstream trypanosomes with alpha-amylase, dextranase, or neuraminidase had little effect on agglutination levels obtained with ruthenium red. Fine-structure cytochemical staining with ruthenium red, ruthenium violet, and Alcian blue-lanthanum nitrate was used to ascertain the presence and distribution of presumptive carbohydrates in the trypanosome cell surface. The extracellular surface coat of the bloodstream forms stained densely with each of the polycationic dyes. Trypsin treatment removed the surface coat from bloodstream trypanosomes; however, the surface membranes of the organisms were stained densely with the several dyes. Similar surface-membrane staining was obtained with the cationic compounds and the culture forms, which lack a cell surface coat. Cationized ferrin was used at the fine-structure level to visualize the negative surface charge present in the cell surface coat and external membrane of the several trypanosome stages. Results obrained from the agglutination and cytochemistry experiments indicate that complex polysaccharides are present in the surface membranes and cell surface coat of T. lewisi bloodstream forms. Similar conclusions also pertain to the surface membranes of the T. lewisi culture from trypanosomes. The carbohydrates probably represent glycopeptide and glycoprotein structural components of the surface membrane of this organism.
 ...
PMID:Cell surface saccharides of Trypanosoma lewisi. I. Polycation-induced cell agglutination and fine-structure cytochemistry. 5 63

Development of the human hand plate (stages 16-17) has been analyzed with emphasis on differentiation of elements within the extracellular matrix and the composition of the mesenchymal cell surface. The epithelial-mesenchymal interface contains a basal lamina and a sublaminar matrix exhibiting: (a) collagen fibrils with characteristic 63-64 nm banding: (b) non-banded filaments, 10-15 nm in diameter; (c) ruthenium red-positive particles, 12-15 nm in diameter; and (d) attenuated threads, 3-5-5-0 nm in diameter which inter-connect particles, fibrils, filaments and the basal lamina. Processes of mesenchymal cells penetrate this matrix network. In addition to staining with ruthenium red, components of basal laminae bind to ferritin-conjugated Concanavalin A, greatest binding being localized on the mesenchymal surface of the lamina. Asymmetry of binding is removed by incubation of exposed laminae with trypsin (5 mug/ml). Regional differences in these staining and binding characteristics within the subepithelial matrix have not been observed in the hand plate. However, precartilaginous extracellular zones deep within the plate are notably unstructured in comparison to the sublaminar region. Ruthenium red-positive materials at mesenchymal cell surfaces display sensitivity to testicular hyaluronidase, Pronase and trypsin but resist removal with neuraminidase and EDTA. These features of the substrate in situ may be important in the regulation of mesenchymal cell behavior during limb morphogenesis in man.
 ...
PMID:Ultrastructural identification of extracellular matrix and cell surface components during limb morphogenesis in man. 12 16

Pinocytotic vesicles have been found to be common organelles throughout the cytoplasm of Type I pneumocytes. The number of uncoated vesicles were increased in response to acute exposure to NO2. These uncoated vesicles endocytosed horseradish peroxidase. In this study, the aim was to determine plasma membrane surface properties which were induced by NO2 exposure on the Type I pneumocytes of hamster lungs. Cationic ferritin and ruthenium red were used as ionic surface probes. Transmission electron microscopy was performed on thin sections of lung tissue fixed in vivo by vascular perfusion with glutaraldehyde after exposure to NO2 and cationic ferritin. Tissues exposed and fixed were also treated with cationic ferritin or ruthenium red. Transmission electron microscopic examination of glutaraldehyde-fixed Type I pneumocytes demonstrated both coated and uncoated vesicles. Cationic ferritin, which normally binds sparingly to control Type I pneumocytes, had a high affinity for the plasma membranes of Type I pneumocytes after NO2 exposure. Many of the binding sites were associated with vesicles on the basis of presence of bound cationic ferritin in developing and formed vesicles. Cationic ferritin wals also observed in vesicles adjacent to and on the basal lamina in the lungs from hamsters incubated with ferritin for 30 minutes. This indicated that the ferritin is transported across the epithelium by the uncoated vesicles. Ruthenium red, another cationic molecule, was found in the same sites as the cationic ferritin. The data showed that NO2 induced a change in the ionic surface charge, which may have contributed to the formation of uncoated pinocytotic vesicles.
 ...
PMID:The effects of NO2 on ionic surface charge on type I pneumocytes of hamster lungs. 241 97

The charge distribution on the luminal and abluminal aspects of fixed and living lymphatic endothelium was examined with particular emphasis on the endocytotic vesicular system and interendothelial junctions. Native ferritin (NF; pl = 4.5), when administered abluminally to perfused lymphatics, entered endocytotic vesicles and abluminal and luminal caveolae; NF was also found in intercellular channels, in contrast, NF when applied luminally was largely excluded from both luminal caveolae and intercellular channels. Cationic ferritin (CF; pl = 8.4) bound to the discontinuous basal lamina and to the abluminal plasma membrane, clustering preferentially around the stomata of abluminal caveolae. CF did not, however, bind to the plasma membrane of, or enter, either the vesicular system or intercellular channels, when administered abluminally. When added to the perfusion fluid CF bound to the luminal membrane and to the infundibula of intercellular channels. Ruthenium red (RR) and alcian blue (AB), both cationic stains, bound intensely to the luminal membrane and much less so to the abluminal surface, thus simulating the binding pattern of CF. Unlike CF, however, RR and AB bound to the membranes of abluminal and luminal caveolae with the same level of staining as to the plasma membrane to which they were attached. These results reflect a marked asymmetry in the membrane charge characteristics of endothelial cells.
 ...
PMID:Distribution of charged sites on lymphatic endothelium. 242 96

Primary guinea pig epidermal cell cultures were subjected to a variety of ultrastructural surface labeling techniques specific for lectin binding sites (Concanavalin A-horseradish peroxidase, wheatgerm agglutinin-chitobiosyl-horseradish peroxidase) or anionic surface sites (Ruthenium red, cationized ferritin). All these techniques were carried out on fixed cells; with cationized ferritin, labeling was also performed on unfixed, viable cells by incubation at 4 degrees C and 37 degrees C for various time periods. Lectin labeling resulted in a diffuse pattern identical for both melanocytes and keratinocytes. Different patterns were obtained with the markers for anionic sites: with both ruthenium red and cationized ferritin, fixed keratinocytes were more heavily labeled than melanocytes, the label being diffuse with randomly distributed globular condensations. Melanocytes, in contrast, were lined by a thin uniform band-like label. On viable keratinocytes, exposed to cationized ferritin at 4 degrees C, the label was confined to randomly disseminated patches which most probably represent the "inherent" distribution of anionic surface sites. At 37 degrees C, this pattern was progressively changed by cluster formation as expression of ligand induced label redistribution, shedding and endocytosis of label material. In contrast, viable melanocytes lacked all of these activities except endocytosis, invariably displaying the same uniform diffuse labeling pattern as fixed melanocytes. It is concluded that melanocytes differ from keratinocytes with regard to quantity, distribution, and lateral mobility of anionic surface sites whereas no differences pertain to quantity and distribution of the binding sites to the lectins tested.
 ...
PMID:Differences of cell surface label distribution and redistribution patterns between mammalian keratinocytes and melanocytes in culture. 616 10

Teratocarcinoma-derived endodermal PYS-2 cells are known to synthesize an extracellular matrix containing the basement membrane molecules laminin, type IV collagen, and heparan sulfate proteoglycan as major constituents (I. Leivo, K. Alitalo, L. Risteli, A. Vaheri, R. Timpl, J. Wartiovaara, Exp Cell Res 137:15-23, 1982). Immunoferritin techniques with specific antibodies were used in the present study to define the ultrastructural localization of the above constituents in the fibrillar network. Laminin was detected in matrix network adjacent to the basal cell membrane and in protruding matrix fibrils that connect the matrix to the cell membrane. Ruthenium red-stainable heparinase-sensitive 10- to 20-nm particles were often present at the junction of the attachment fibrils and the matrix network, or along the attachment fibrils. A corresponding distribution of ferritin label was observed for basement membrane heparan sulfate proteoglycan. Type IV collagen was found in the matrix network but not in the attachment fibrils. The results suggest that the PYS-2 cells are connected to their pericellular matrix by fibrils containing laminin associated with heparan sulfate-containing particles. These results may also have relevance for the attachment of epithelial cells to basement membranes.
 ...
PMID:Basement membrane-like matrix of teratocarcinoma-derived endodermal cells: presence of laminin and heparan sulfate in the matrix at points of attachment to cells. 618 2

Ferritin derivatives with different pI values and the basic dye ruthenium red have been used as cationic probes to localize anionic sites associated with fenestrated brain capillaries. Cationic ferritin was found in the endothelial basement membrane and the basement membrane of the perivascular cellular linings in amounts far exceeding those observed with anionic derivatives, the degree being greater for the more cationized ferritin molecules. Labeling of the luminal endothelial front with cationic ferritin was only achieved when a serum- or albumin-free medium was applied. Furthermore, the striated collagen fibers were coated with cationic ferritin molecules in a highly ordered fashion. Ruthenium red localized to the same sites. The findings suggest the existence of a perivascular charge filter around fenestrated capillaries of the brain. Some physiological roles of this filter are discussed, as related to its possible function in regulating homeostasis of cerebrospinal fluid.
 ...
PMID:Surface charges associated with fenestrated brain capillaries. I. In vitro labeling of anionic sites. 619 52

The Con A-peroxidase reaction has demonstrated glycoproteins with molecular masses of 200 and 50 kilodalton on the polyacrylamide gel-SDS electrophoregrams of the molecular matrices isolated from rat liver, hepatoma 27 and Zajdela's ascites hepatoma. Both hepatomas contained an additional band of about 38 kilodalton, whereas Zajdela's hepatoma distinct bands of 54 kilodalton and less demonstrable of over 200 and about 105 and 68 kilodalton. Electron microscopy showed Con A-ferritin staining, more prominent in hepatomas than in the liver, at the periphery of isolated nuclear matrix preparations. Ruthenium red staining characteristic of acidic polysaccharides (glycosaminoglycans), on the contrary, was more pronounced in liver nuclear matrices.
 ...
PMID:[Carbohydrate components of the nuclear matrix in rat liver and hepatoma]. 619 9

Ruthenium red binding demonstrates that the extensive microvesicle system of isolated rat adipocytes is, for the most part, open to and continuous with the plasmalemma proper. Morphometric estimates indicate that insulin treatment has no effect on the relationship between microvesicles and the cell surface. Neither does insulin affect the apparent lack of pinocytotic activity of these vesicles as judged by a time course analysis of cells incubated with horseradish peroxidase, which is bound to the membrane of the vesicles, but is not internalized. Insulin does produce a small but repeatable and measurable increase in average diameter of the microvesicles from 73 to 78 nm. Unlike the positively charged ruthenium red, which binds to both plasmalemmal as well as microvesicular surfaces, cationic ferritin did not readily bind to microvesicle membranes, a result indicating some distinction between the two membrane surfaces. The implications of the lack of dramatic visible morphological effects of insulin upon the adipocyte plasmalemma and it's associated microvesicles are discussed in light of the proposed role of insulin as a mediater of translocation of membrane-associated transporters to and from the cytoplasm.
 ...
PMID:The relationship of microvesicles to the plasmalemma of rat adipocytes. 619 5

The surface coating of the pneumonocytes in the lungs of five human neonates was studied by conventional electron microscopy and by cytochemical techniques. These techniques included staining with colloidal iron oxide, cationic ferritin, Ruthenium red, Ruthenium hexamine trichloride, high iron diamine and the periodic acid-thiocarbohydrazide-silver proteinate sequence. The results of the study indicate that the surface-bound coat of the pneumonocytes in human neonatal lung is a periodate-reactive sialomucin.
 ...
PMID:The surface coating of the pneumonocytes in human neonatal lung. 620 80


1 2 Next >>