Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: HUMANGGP:031673 (collagen)
 124,196 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Proteoglycans were identified and localized histochemically and ultrastructurally in normal and hyperplastic arterial intimas in nonhuman primates (Macaca nemestrina). These regions were consistently more alcianophilic than the adjacent medial layers and this alcianophilia was absent after treatment with glycosaminoglycan-degradative enzymes. Ultrastructurally, the intimal intercellular matrix consisted of numerous, irregularly shaped, 200-500-A diameter granules possessing 30--60-A diameter filamentous projections, and these granules were dispersed between collagen and elastic fibers. The granules exhibited a marked affinity for ruthenium red and were interconnected via their filamentous projections. The ruthenium red-positive granules were intimately associated with the plasma membrane of intimal smooth muscle cells and attached to collagen fibrils and elastic fibers. The matrix granules were completely removed after testicular hyaluronidase or chondroitinase ABC digestion but only partially removed after leech hyaluronidase treatment. These results suggest that the matrix granules contain some hyaluronic acid and one or more isomers of chondroitin sulfate. In addition to the large ruthenium red-positive matrix granules, a smaller class of ruthenium red-positive granule (100--200-A diameter) was present within the basement membranes beneath the endothelium and surrounding the smooth muscle cells. Ruthenium red also exhibited an affinity for the surface coat of the smooth muscle cells. The potential importance of proteoglycans in arterial intimal hyperplasia is discussed.
 ...
PMID:Proteoglycans in primate arteries. I. Ultrastructural localization and distribution in the intima. 5 34

The localization of proteoglycans in the predentin of the rat incisor was investigated by ultrastructural histochemistry. Ruthenium red stained the cell coat of the odontoblasts as well as intracellular vesicles. There was also a staining of the extracellular matrix, but not of collagen fibers in the predentin. Treatment with the enzyme hyaluronidase prior to staining with ruthenium red abolished the staining of the vesicles and the extracellular matrix but not that of the cell coat. Bismuth nitrate and phosphotungstic acid gave similar staining of odontoblast vesicles and extracellular matrix. It is likely that the stained structures contain proteoglycans. The importance of these proteoglycans and their ultrastructural localization are discussed in relation to intracellular transport and the calcification process.
 ...
PMID:Ultrastructural localisation of proteoglycans in the odontoblast-predentin region of rat incisor. 5 27

Diseased skin of dogs was stained using the critical electrolyte concentration-Alcian Blue method, PAS methods, and the high iron diamine technique. Digestion with testicular hyaluronidase and chondroitinase was also used to evaluate the staining results. Diseased skin exhibits a tendency for the glycosaminoglycans to revert to the condition seen in juvenile normal skin: epidermal glycoprotein content falls, total glycosaminoglycan content and the proportion undigested by hyaluronidase rises, and sulphation falls. In collagen, both hyaluronidase-stable material and sulphation increase, but follicle basement membrane does not show this trend towards the juvenile state.
 ...
PMID:Glycosaminoglycan staining in diseasesed dog skin. 6 Nov 90

The proteoglycans of cartilage are complex molecules in which chondroitin sulphate and keratan sulphate chains are covalently linked to a protein core, forming a polydisperse population of proteoglycan monomers. By interaction with hyaluronic acid and link proteins, the monomers form large macromolecular complexes. In vivo the proteoglycans mainly occur in such aggregates. In the electron microsope, the cartilaginous matrix can be seen to be made up of thin collagen fibrils and polygonal granules about 10-50 nm in diameter Addition of the polyvalent cationic dye Ruthenium Red to glutaraldehyde and osmium tetroxide fixatives yields a dense selective staining of the matrix granules. Following a short digestion of cartilage slices with either of the chondroitin sulphate-degrading enzymes hyaluronidase and chondroitinase or with the proteolytic enzyme papain, the matrix granules were few in number or completely absent and the proteoglycan content, measured as hexosamine, decreased by up to 90%. Similarly, extraction of the cartilage with 4 M guanidine-HCl removed all matrix granules and most of the proteoglycans. From these findings, it can be concluded that the matrix granules represent proteoglycans, most probably in aggregate form, and that Ruthenium Red staining may be used to study the distribution of these macromolecules in thin sections. As a complement to chemical studies on proteoglycan structure, it is also possible to observe and measure individual molecules in the electron microscope after spreading them into a monomolecular layer with cytochrome c. This technique has been applied in investigations on proteoglycans isolated from bovine nasal cartilage and other hyaline cartilages. The molecules in the monomer fractions appeared as an extended central core filament to which about 25--30 side-chain filaments were attached at various intervals. The core filament, averaging about 300 nm in length, was interpreted as representing the polysaccharide binding part of the protein core and the side-chain filaments, averaging about 45 nm in length, as representing the clusters of chondroitin sulphate chains. Statistical treatment of the collected data indicated that no distinct subpopulations existed within the monomer fractions. The electron microscopic results correlated well with chemical data for the corresponding fractions and together with recent observations on various aggregate fractions strongly support present concepts of proteoglycan structure.
 ...
PMID:Electron microscopy of cartilage proteoglycans. 6 24

The ultrastructural identification and characterization of lung proteoglycans was studied using the polycationic dye, ruthenium red. Treating lung parenchyma with the detergent Triton X-100 increased epithelial permeability and allowed the dye to penetrate alveolar walls and stain the alveolar basement membrane and lung collagen. Ruthenium red stained numerous 10- to 40-nm granules concentrated at the lamina surface of basement membrane and attached to the major doublet collagen band. The granules attached to collagen were digested by chondroitinase ABC and papain, indicating that they represent proteoglycan aggregates containing chondroitin or dermatan sulfate. Granules observed on the alveolar basement membrane were resistant to digestion by collagenase and by all glycosidases, suggesting that heparin or heparan sulfate is the predominant glycosaminoglycan in epithelial basement membrane. Ruthenium red in association with tannic acid also stained a fine network of 3- to 10-nm filaments in which collagen was enmeshed, forming the interfibrillar matrix. This network was resistant to collagenase and glycosidase digestion but was removed after papain digestion, suggesting that it was a protein or glycoprotein that did not contain glycosaminoglycans. These methods have allowed visualization of lung proteoglycans and have identified a structure that does not contain glycosaminoglycan that is intimately associated with collagen. This technique can now be applied to explore the potential role of proteoglycans in lung development and in restructuring the lung in various disease states.
 ...
PMID:Ultrastructural localization and characterization of proteoglycans in the pulmonary alveolus. 9 9

Adult rat heart was dissociated into a single cell suspension by a perfusion technique which used 0.05% collagenase and 0.1% hyaluronidase in Krebs-Ringer phosphate buffer (KRP). The non-muscle cells of the suspension were separated from the myocytes by centrifugation through 3% Ficoll solution in KRP with 0.01 mM Ca2+. An approximately 90% pure suspension of isolated single muscle cells was obtained with this method. The effects of the successive steps in the dissociation procedure on the ultrastructure of the heart were studied by scanning and transmission electron microscopy. After 30 minutes of enzyme digestion, dissociation of the inner endothelial lining of the ventricle into single cells or small groups of cells became apparent. In addition, the underlying cardiac skeleton began to disintegrate and linear arrays of cardiac muscle cells were observed. After 45 minutes of enzyme digestion the number of released single cells was higher because of the separation of intercalated discs. The majority of non-muscle cells were by now dissociated from the surfaces of muscle cells. Widening of the lateral intercellular spaces between the myocardial cells was associated with separation of desmosomes. In some regions of the heart, intact desmosomes, fasciae adherentes and gap junctions were observed even though lateral intercellular spaces had widened greatly. The majority of myocardial cells had become separated from one another after 60 minutes of enzyme digestion. Separation of gap junctional sites took place in two ways: (1) by 'unzipping' them through enzyme action; (2) by tearing them mechanically. Gap junction remnants were sometimes observed in a vesiculated state within the cell. The dissociation of the heart was ineffective when perfused with media containing 1.0 or 2 mM Ca2+. Alcian blue treatment after 60 minutes of enzyme digestion revealed that the basement membrane, and its accompanying collagen fibrils, was still present on the plasma membrane of dissociated single cells. The isolated myocardial cells retained their normal morphological characteristics. This study has enabled us to understand in detail how dismantlement of highly ordered adult cardiac tissue into a single cell suspension takes place. Cell suspensions of this type should be invaluable in the study of metabolic and synthetic activities in adult myocardial cells.
 ...
PMID:Dissociation of adult mammalian heart into single cell suspension: an ultrastructural study. 12 Mar 52

Periodontal ligaments from unerupted, partially erupted and mature teeth were extracted with 0.15 M NaCl. The major reducible collagen cross-link in each insoluble fraction was dehydrodihydroxylysinonorleucine; the dehydroydroxylysinonorleucine contents were smaller. There was no significant difference in the quantities of these cross-links relative to collagen contents in the three speciments, but one of the precursors, hydroxyallysine, markedly decreased in the older tissue. The amino acid compositions of the trypsin-resistant insoluble fractions were generally characteristic of collagen. Analyses of separated glycopeptides revealed the presence of insoluble non-collagenous glycoproteins and collagen hexoses. The latter were lower in the mature ligament. Hyaluronic acid progressively decreased relative to chondroitin sulphate on eruption and maturation. A hyaluronidase-resistant glycosaminoglycan, probably dermatan sulphate, occurred in the NaCl-insoluble fraction of the mature ligament and in appreciable amounts in all NaCl extracts.
 ...
PMID:Bovine periodontal ligament. An invesitation of the collagen, glycosaminoglycan and insoluble glycoprotein components at different stages of tissue development. 12 33

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

Electron microscopy of ruthenium red stained bovine aorta before and after chondroitinase digestion demonstrates proteoglycans on and between collagen fibrils. The collagen-associated proteoglycans include a proteoglycan previously purified from this tissue as demonstrated by immunocytochemistry and are extractable with high molar guanidine HC1. In loci rich in proteoglycans such as areas of turbulent flow in calves, more proteoglycan can be demonstrated morphologically, and these molecules also coat elastin.
 ...
PMID:The ground substance of the arterial wall. Part 2. Electron-microscopic studies. 13 92

The changes in levels of glycosaminoglycans (GAGs) of the intima and media of the human artery in atherosclerosis were determined by a recently introduced two-dimensional electrophoresis technique that permits direct measurments of each of these macromolecules. To identify the arterial GAGs, they were fractionated by chromatography on a DEAE-Sephadex A-25 column, and the resulting three fractions (hyaluronic acid [HA], heparan sulfate [HS], and the partially separated chondroitin sulfates B [CSB] and C [CSC]) were analyzed for their electrophoretic mobilities by this electrophoretic method, for their digestability by highly specific hydrolases (leech hyaluronidase, heparinase, and chondroitinases ABC and AC) and for their iduronic acid content. From these studies we concluded that normal and atherosclerotic human aortas contain CSB, CSC, HA, and HS. Further, we demonstrated that CSB is a hybrid consisting of approximately 40% CSA and 60% CSB and that CSC appears to be a polymer consisting essentially of glucuronic acid and N-acetylgalactosamine-6-sulfate. Classical CSA as well as chondroitin (CH) were not present in detectable amounts. In the relatively normal intima, the mean concentrations of the GAGs were found to be 4.7, 20.9, 1.3, and 5.1 mg/g of dry, defatted, decalcified tissue for CSB, CSC, HA, and HS, respectively. With the progression of atherosclerosis, there was a pronounced decrease in the total GAG content (from 32 to 18 mg) associated with a decrease in the CSC and HS levels but without a change in the HA concentrations. Of particular interest, however, was the increase in the CSB level. In the media whose total GAG content averaged approximately 20 mg, no significant changes in these GAG levels were noted with the progression of the disease except for that of CSC. These findings may be important in explaining the increased lipoprotein and collagen deposition in the diseased aorta.
 ...
PMID:The glycosaminoglycans of the human artery and their changes in atherosclerosis. 13 44


1 2 3 4 5 6 7 8 9 10 Next >>