Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:3.2.1.36 (hyaluronidase)
4,606 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Using cetylpyridinium chloride (CPC) in glutaraldehyde as fixative, we observed sinuous fiber-like structures 300-500 nm long and 7-14 nm thick in the spaces between the collagen fibers of rat incisor predentin. Small granules and fibrils were also detected. Electron-dense vesicles were seen inside the odontoblast processes. The plasma membrane was irregularly stained with material that adhered to its surface. In demineralized dentin, needle-like structures were seen at the periphery of globular structures which were not stained. Staining the sections with Alcian blue did not greatly improve the visualization of CPC-precipitated glycosaminoglycans. The specificity of staining was assessed on serial sections by selective dissociation of glycosaminoglycan aggregates with 2 M calcium chloride and their digestion by bovine testicular hyaluronidase. The glycosaminoglycans were probably combined with lipids, because treatment of the sections with a chloroform/methanol mixture removed the CPC-induced precipitates from both predentin and dentin.
...
PMID:Visualization of glycosaminoglycans in rat incisor predentin and dentin with cetylpyridinium chloride-glutaraldehyde as fixative. 211 May 88

The distribution of sulfated proteoglycans in Bruch's membrane of the human eye was evaluated histochemically using Cupromeronic Blue in combination with specific enzyme digestions and nitrous acid treatment. Five distinct categories of filament-shaped profiles were present following staining with this dye. Type 1 (90 +/- 13 nm long and 7 +/- 1 nm in diameter) (mean +/- S.D.) and type 2 (43 +/- 7 nm long and 5 +/- 1 nm in diameter) filaments were associated with collagen fibrils in the inner and outer collagenous zones. Type 3 profiles (70 +/- 18 nm long and 8 +/- 1 nm in diameter) were present in two locations--along the cortical border of the central elastic zone and within the basal infoldings of the pigment epithelium. Type 4 (60 +/- 11 nm long and 6 +/- 1 nm in diameter) and type 5 (200 +/- 100 nm long and 100 +/- 50 nm in diameter) filaments were associated with the basal laminae of the retinal pigment epithelium and choriocapillaris. Chondroitinase AC treatment eliminated the staining of type 1 filaments. Chondroitinase ABC treatment eliminated the staining of both type 1 and type 2 filaments. Nitrous acid eliminated the staining of type 4 and type 5 filaments. Incubations with keratanase or hyaluronidase did not alter the staining of any filament type. Type 3 filaments were resistant to all enzyme digestions and nitrous acid treatment. These results are consistent with an interpretation that Bruch's membrane contains chondroitin sulfate, dermatan sulfate and heparan sulfate-type proteoglycans. Proteoglycans containing chondroitin sulfate (type 1) and dermatan sulfate (type 2) are associated uniquely with collagen fibrils. Heparan sulfate type proteoglycans (types 4 and 5) are associated with the basal lamina of the pigment epithelium and choriocapillaris. The identity of type 3 profiles, which were resistant to all enzyme and nitrous acid digestions employed, could not be established at this time.
...
PMID:Sulfated proteoglycans in Bruch's membrane of the human eye: localization and characterization using cupromeronic blue. 212 81

This study examines the morphological and histochemical changes in the cortical vitreous of 36 rabbit eyes following C3F8 intravitreal gas injection. Eyes were examined by light microscopy (LM) using a modified cryofixation and cryosectioning technique that prevented the loss of soluble tissue moieties and permitted collagen and proteoglycan histochemistry as well as enzyme digestion with hyaluronidase. LM and scanning electron microscopy (SEM) of cryosectioned normal eyes revealed an elaborate fibrillar matrix extending 100-190 microns from the basal lamina of the retina into the vitreous proper, which seemed to be composed of collagen fibrils intimately associated or wrapped in proteoglycan. Following the full expansion of the C3F8 gas bubble in the vitreous, the cortical fibrillar meshwork was absent from the retinal surface and a dense, collagenous material accumulated in the anterior vitreous, especially between the ciliary processes and over the posterior face of the lens. At 41 days postinjection, the fibrillar matrix was reforming and the vitreal cavity was filled with fluid and numerous fibrillar-mucinous islands. These islands did not form sheets or membranes, nor did they attach to either the posterior or the anterior retinal surface. The cortical fibrillar meshwork had reformed at 61 days' recovery; however, the condensed fibrillar material against the lens and filling the spaces between the ciliary processes had not resorbed. Neither shearing of the cortical gel or fibrillar matrix nor congestion of the anterior vitreous was observed in eyes only partially filled with gas.
...
PMID:Alterations in rabbit vitreal fine structure following C3F8 injection. 226 70

We undertook an interdisciplinary biomechanical and biochemical study to explore the extent and manner in which the total pool of proteoglycans influences the kinetic and static behavior of bovine articular cartilage in tension. Two biomechanical tests were used: (a) the viscoelastic creep test and (b) a slow constant-rate uniaxial tension test; and two enzymatic proteoglycan extraction procedures were used: (a) chondroitinase ABC treatment and (b) a sequential enzymatic treatment with chondroitinase ABC, trypsin, and Streptomyces hyaluronidase. We found that the viscoelastic creep response of all cartilage specimens may be divided into two distinct phases: an initial phase (less than 15 s), characterized by a rapid increase in strain following load application, and a late phase (15 s less than or equal to t less than 25,000 s), characterized by a more gradual increase in strain. A major finding of this study is that the kinetics of the creep response is greatly influenced by the glycosaminoglycan content of the tissue. For untreated and control specimens, the initial response comprises about 50% of the total strain, while for chondroitinase ABC and sequentially extracted specimens, the initial response comprises up to 83% of the total strain. Furthermore, most untreated and control specimens did not reach equilibrium within the 25,000 s test period, while enzymatically digested specimens often reached equilibrium in less than 100 s. Thus, we conclude that through their physical restraints on collagen, the bulk of proteoglycan present in the tissue acts to retard fibrillar reorganization and alignment under tensile loading, thereby effectively preventing sudden extension of the collagen network. In contrast, the results of our slow constant-rate uniaxial tension experiment show that essentially complete extraction of proteoglycan glycosaminoglycans does not affect the intrinsic tensile stiffness and strength of cartilage specimens or the collagen network in a significant manner. Hence, an important function of the bulk proteoglycans (i.e., the large aggregating type) in cartilage is to retard the rate of stretch and alignment when a tensile load is suddenly applied. This mechanism may be useful in protecting the cartilage collagen network during physiological situations, where sudden impact forces are imposed on a joint.
...
PMID:Effects of proteoglycan extraction on the tensile behavior of articular cartilage. 232 54

Altered extracellular matrix produced by Steel mutant fetuses affects the pigmentation of neural crest cells in vitro (K. Morrison-Graham, L. West-Johnsrud, and J.A. Weston, 1990, Dev. Biol. 139). Here, we demonstrate that collagen bundle morphology and hyaluronidase sensitivity of the glycosaminoglycans associated with the collagen fibrils differ between normal and mutant dermis. Although no differences were detected in the amounts of collagen or glycosaminoglycans produced in vitro or present in vivo, hyaluronic acid was more readily extracted from Sld/Sld than from normal skin. We suggest that the Steel mutation alters the organization of collagen bundles and associated hyaluronic acid within the extracellular matrix.
...
PMID:Association between collagen and glycosaminoglycans is altered in dermal extracellular matrix of fetal Steel (Sld/Sld) mice. 233 71

Tissue culture conditions can modulate apparent levels of incorporation of the radiolabeled precursor [3H]glucosamine into hyaluronic acid in cells. A careful study was made on the effects of culture conditions on human skin fibroblasts. A newly described technique to measure hyaluronic acid was utilized based on incorporation of [3H]glucosamine into cetylpyridinium chloride-precipitable hyaluronidase-digestible material. The precipitate was collected on glass fiber filters using a manifold suction apparatus. A six-fold greater level of incorporation occurred in rapidly growing preconfluent than in confluent fibroblasts. Ascorbic acid stimulated incorporation with a maximum at 25 micrograms/ml. The same ascorbic acid optimum was observed for collagen prolylhydroxylation. When beta-hydroxybutyrate was used as an energy source instead of D-glucose, a 3.5-fold increase in levels was observed. All tissue-culture media examined supported comparable levels of incorporation, except for Roswell Park Memorial Institute Media-1640, in which cells had only half the level. Fetal calf serum supported high levels of incorporation in a dose-dependent manner, while newborn calf and calf sera supported much lower levels of incorporation. Under serum-free conditions, lactalbumin hydrolysate was best able to support incorporation of hyaluronic acid. In the search for mechanisms that modulate hyaluronic acid, it is critical to consider the tissue culture conditions under which incorporation of radiolabeled precursors are being examined.
...
PMID:Levels of [3H]glucosamine incorporation into hyaluronic acid by fibroblasts is modulated by culture conditions. 237 20

A system consisting of an interlacunar network and thick fibrils was demonstrated in the matrix of human fetal and neonatal hyaline cartilage, using an osmium-ferrocyanide mixture as a second fixative. The network appeared as irregular strands consisting of hyaluronidase-sensitive, amorphous and fine fibrillar material. The thick fibrils measured 75-125 microns in diameter, each appearing to consist of several collagen fibrils twisted into a cable and cemented by dense amorphous material. Strands of the network were seen to cross and focally distort the thick fibrils, suggesting that the strands exert some tensile forces on the thick fibrils. During the first year of life the network rapidly became undemonstrable, but the thick fibrils persisted into adulthood. This system of interlacunar network and thick fibrils appears to form an integral functional unit which may play an organizational role in the formation of cartilagenous matrix during development. Furthermore, it may contribute to the mechanical strength of the collagen framework in hyaline cartilage.
...
PMID:A system of interlacunar network and thick fibrils in human hyaline cartilage. 238 55

Type X collagen was extracted with 1 M-NaCl and 10 mM-dithiothreitol at neutral pH from fetal-bovine growth cartilage and purified to homogeneity by using f.p.l.c. gel filtration on a Superose 12 column, followed by ion-exchange chromatography on a Mono Q column. The purified protein migrates in SDS/polyacrylamide gels with an apparent Mr of 58,000 under reducing conditions and as a high-Mr oligomer in its unreduced form. The amino acid composition is similar to the published composition of chick type X collagen. Pepsin digestion at 4 degrees C decreases the Mr of the monomer to 43,000; purified bacterial collagenase digests most of the molecule, leaving a non-collagenous domain of apparent Mr 15,000, which probably represents the C-terminal globular domain. The IgG fraction from a rabbit antiserum raised against purified bovine type X collagen was specific for this collagen by the criteria of e.l.i.s.a. and immunoblotting after immunoabsorption with collagen types I, II, IX and XI. Immunofluorescence localization of type X collagen in sections of fetal-bovine and human cartilage was possible after acetone fixation of sections and hyaluronidase treatment. Type X collagen was restricted to the zone of hypertrophic and calcified cartilage inside the bone spicules of the growth plate.
...
PMID:Isolation of bovine type X collagen and immunolocalization in growth-plate cartilage. 240 43

A series of monoclonal antibodies was prepared against the pepsin-resistant fragment of type IX collagen designated HMW. One of these antibodies (called 2C2) was selected for further analysis. Antibody 2C2 showed no cross-reactivity with other collagen types by inhibition enzyme-linked immunosorbent assays. It recognized an epitope present in native HMW, but failed to recognize any of the three chains of HMW fractionated after denaturation followed by reduction and alkylation of interchain disulfide bridges. Electron microscopic observations after rotary shadowing showed that the location of the epitope for antibody 2C2 was close to the carboxy-terminus of HMW. Immunofluorescent staining of sections of embryonic and adult cartilage with antibody 2C2 after removal of proteoglycans by testicular hyaluronidase digestion showed that type IX collagen is distributed throughout the cartilage matrix, and is not present in other connective tissues or skeletal muscle. The intact type IX collagen molecule, which was secreted by a suspension culture of freshly isolated embryonic chick chondrocytes, was recognized by rotary shadowing in the presence of antibody 2C2 after first precipitating the procollagens from the culture medium with ammonium sulfate (30%). Two different collagenous molecules were present in the precipitate: a longer molecule of type II procollagen (average length, 335 nm) with both amino- and carboxy-propeptides still remaining uncleaved, and a shorter molecule (average length, 190 nm) which was identified as type IX collagen. Antibody 2C2 consistently bound to the shorter molecules at a site located 136 nm from a distinctive knob at one end of the molecule, and did not bind to any specific site on the type II procollagen molecules. The structure of the intact type IX collagen molecule with the location of both collagenous and noncollagenous domains was as predicted after converting the nucleotide sequence of a cDNA clone encoding for one of the chains of type IX collagen to an amino acid sequence (Ninomiya, Y., and B. R. Olsen, 1984, Proc. Natl. Acad. Sci. USA, 81:3014-3018).
...
PMID:Monoclonal antibody against chicken type IX collagen: preparation, characterization, and recognition of the intact form of type IX collagen secreted by chondrocytes. 241 37

The penetration and distribution of ruthenium red in the axon-myelin-Schwann cell complex of developing rabbit peripheral nerve fibers are investigated. Ruthenium red positive material is established in the axoplasm, axolemma, periaxonal space, major dense lines and intraperiod lines of the compact myelin, mesaxons, split peripheral myelin lamellae, Schmidt-Lanterman and longitudinal incisures, paranodal loops and axo-glial contacts, Schwann cell cytoplasm and basal lamina, nodal extracellular matrix, desmosome-like structures, endoneural collagen. Some features of the distribution of the contrast material in the developing myelin sheath are described. Regional differences of the axolemma and of the Schwann cell cytoplasm and plasmalemma are established. The prevalence of glycoproteins or glycolipids in the ruthenium red stained material in its different localizations is discussed on the basis of trypsin and hyaluronidase digestion performed.
...
PMID:Localizations of ruthenium red positive material in rabbit peripheral nerves. 242 14


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

---