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

The effects of freezing localized areas of rabbit articular cartilage in vivo were studied at two to twelve months morphologically (gross and microscopic examination, including scanning electron microscopy), histochemically (toluidine blue and safranin O), and metabolically (35S uptake). Up to six months the frozen cartilage was intact but appeared to be dead, as shown by the absence of stainable chondrocytes, severely decreased acid mucopolysaccharide content, and absence of significant uptake of 35S. At twelve months fibrillation and softening were evident, clusters of new chondrocytes with surrounding acid mucopolysaccharides were visible microscopically, and scanning electron microscopy revealed an irregular pattern of collagen fibers which were larger than normal, of varying thickness, and broken in some areas. These changes resembled those seen in degenerative joint disease.
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PMID:Long-term effects of chondrocyte death on rabbit articular cartilage in vivo. 5 62

This paper examines the extent to which understanding of six of the principle disorders of connective tissue: the glycosaminoglycan storage diseases, ankylosing spondylitis, rheumatoid arthritis, systemic lupus erythematosus, chondrocalcinosis, and osteoarthrosis, has progressed during the past ten years. The paper recalls the pioneer observations of PAUL KLEMPERER on the systemic diseases of collagen, and introduces a series of reviews in which advances in present understanding of some of the connective tissue diseases will be examined in greater detail.
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PMID:New knowledge of the connective tissue diseases I. 12 Mar 50

Biochemical changes in the articular cartilage of the knees of mature dogs, one with natural and four with surgically induced osteoarthritis, have been investigated. The four dogs were killed three, six, nine and forty-eight weeks after division of the right anterior cruciate ligament, the left knees serving as controls. The cartilage of the joints operated on was thicker and more hydrated than the control cartilage; the proteoglycans were more easily extracted and had higher galactosamine/glucosamine molar ratios. The proportion of proteoglycans firmly associated with collagen, and hence not extractable, diminished before fibrillation was demonstrable by indian ink staining of the surface. These biochemical changes were present throughout the entire cartilage of the joints operated on of the dogs killed more than three weeks later, and of the dog with natural osteoarthritis. The results suggest that in response to altered mechanical stresses the chondrocytes synthesise proteoglycans that contain more chondroitin sulphate relative to keratin sulphate than normally, as in immature articular cartilage.
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PMID:Biochemical changes in the cartilage of the knee in experimental and natural osteoarthritis in the dog. 13 4

Quantitative and qualitative variations in glycosaminoglycan content were studied in fibrillated, intact, and osteophytic cartilage of the human femoral head in osteoarthrosis. Total glycosaminoglycan content was reduced in fibrillated, unchanged in intact, and raised in osteophytic cartilage. In fibrillated and osteophytic cartilage the ratio of chondroitin sulphate to keratan sulphate was high and therefore resembled immature cartilage. Hyaluronic acid was present in reduced amount in all osteoarthrotic material. Proportionally more proteoglycans were extractable by 0-15 M NaCl and 4 M guanidinium chloride from the diseased cartilage than from normal cartilage, and all proteoglycans irrespective of buoyant density were carbohydrate deficient. It is postulated that the changes described are compatible with collagen and matrix disruption due to focal overloading and the general attempt at repair.
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PMID:Biochemical changes in progressive osteoarthrosis. 14 63

In advanced osteoarthritis, all of the cartilaginous components are lost from the joint surface. Although mechanisms exist for proteoglycan degradation, there is not known to be any system for removal of the collagen. This study suggests that the loss of the collagen components may be a function of articular cartilage collagenase. The enzyme in normal human cartilage is bound to an inhibitor and appears to be present in very small amounts. Attempts to demonstrate collagenase activity in ground human articular cartilage or in its lysosomal fraction were unsuccessful. 7-Day cartilage tissue cultures also failed to demonstrate the presence of the enzyme; but the same culture fluid, incubated with trypsin, showed significant degradation of collagen, suggesting that trypsin destroyed the inhibitor. 7-Day culture fluids were then chromatographed on a heparin-charged Sepharose 4B affinity column that had been activated with cyanogen bromide. This removed the inhibitor, and the chromatographed fluid from osteoarthritic cartilage released 42% of the incorporated counts of the collagen substrate, whereas normal cartilage released 10.1% and a trypsin control, 6.4%. Electrophoresis of the degradation products of the enzyme-collagen complex incubated at 37 degrees C revealed breakdown was complete to small dialyzable fragments, while at 25 degrees C larger fragments were split off.
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PMID:Collagenase and collagenase inhibitors in osteoarthritic and normal cartilage. 18 66

The ultrastructure of the surface of normal human mandibular condyles is described and compared with specimens from condyles in cases of degenerative joint disease (arthropathy). Normal surfaces exhibited a nearly structurless layer about 2 microns thick, which seemed to correspond with the lamina splendens of other joints. The underlying structure of dense interlacing bundles of collagen is described. Surfaces of all pathologic condyles showed loss of lamina splendens, alteration of collagen size, and evidence of dissociation of both the collagen and its surrounding ground substance. Deeper levels showed aggregations of bizarre structures, which the authors term "vermiform bodies," and which appear to be collections of abnormal amounts and types of elastic tissue. Its distribution suggests a stress elastosis, which may contribute to the loss of mechanical integrity of articular surfaces in arthropathy. The surface changes may be reflected at the clinical level as impairment of the normal low-friction qualities of joint components associated with limitation of movement and joint sounds.
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PMID:Ultrastructure of the articular surface of the condyle in temporomandibular arthropathy. 27 4

We examined patients with rheumatoid arthritis for cellular sansitivity to native human Types I, II and III collagens. Mononuclear cells from 50 patients with rheumatoid arthritis, 21 with other inflammatory arthritides, 20 with osteoarthritis and 20 normal subjects were evaluated for the in vitro production of leukocyte inhibitory factor in response to collagen and a control antigen, streptokinase-streptodornase. By this assay, cells from 37 (74 per cent) and 39 (78 per cent) of the patients with rheumatoid arthritis responded to Types II and III collagens, respectively. In contrast, cells from the 41 patients with other kinds of arthritis and the normal group did not produce this lymphokine to collagens. There was no response to Type I collagen or to denatured alpha chains of these collagens. All four groups responded equivalently to streptokinase-streptodornase. These data demonstrate that most patients with rheumatoid arthritis exhibit cellular sensitivity to Types II and III collagens.
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PMID:Cellular sensitivity to collagen in rheumatoid arthritis. 35 82

The authors discuss changes of proteoglycans and collagen in osteoarthrotic cartilage, based on their own results. During osteoarthrosis the proteoglycan molecule diminishes in size, mainly due to a diminution of the carbohydrate portion. The diminution of binding glycoprotein leads to changes in the interaction with hyaluronic acid. Collagen is more soluble and has a reduced resistance to proteolytic enzymes. In the osteoarthrotic cartilage also collagen type I and III is present.
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PMID:Cartilage and osteoarthrosis: changes of collagen and proteoglycans. 39 78

Collagen metabolism was studied in degenerative articular cartilage of dogs with spontaneous, early onset osteoarthritis. A fraction of collagen which represented about 1.5% of the total was extracted from cartilage samples with dilute phosphate buffer (pH 7.4) containing 0.2% sodium dodecyl sulfate. Agarose gel filtration in the presence of sodium dodecyl sulfate revealed that extracts of degenerative cartilage had about 24% procollagen whereas extracts of normal samples had only 3%. The isolated procollagen fraction was rechromatographed on agarose columns in the presence of mercaptoethanol. This resulted in the identification of a collagen species which migrated between marker beta and alpha collagen chains. The molecular weight of this collagen was estimated to be 150,000. Based on incorporation of [14C]proline, its ratio of hydroxy[14C]proline to total 14C was 0.32. Procollagen was not found after limited pepsin digestion (pH 3, 4 degrees C, 16 h) of degenerative cartilage samples. Since the total collagen content (microgram hydroxyproline/mg cartilage), hydroxy-[14C]proline/mg cartilage, specific radioactivity of hydroxyproline in the extractable collagen fraction were similar for normal and degenerative cartilage we propose that procollagen accumulated in the degenerative cartilage due to a partial defect in conversion of procollagen to collagen.
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PMID:Accumulation of procollagen in the degenerative articular cartilage of dogs with osteoarthritis. 44 63

Synovial fluid and serum hydroxyproline fractions were investigated in patients with osteoarthritis and microcrystalline arthritis. Synovial fluid dialysable hydroxyproline levels are higher than serum levels in both conditions. Synovial fluid total and dialysable hydroxyproline are higher in microcrystalline arthritis than in osteoarthritis, while non-dialysable hydroxyproline values are similar in both conditions. In microcrystalline arthritis, synovial fluid dialysable hydroxyproline and polymorphonuclear leukocyte counts closely parallel each other. Irrespective of the type of arthropathy, synovial fluid dialysable hydroxyproline levels correlate with urinary hydroxyproline excretion. While the data suggest overproduction of dialysable hydroxyproline by joints in both conditions, the overproduction appears to be mediated by polymorphonuclear leukocytes in microcrystalline arthritis only. The ratio of serum to synovial total hydroxyproline are further suggestive of a possible differentiation between osteoarthritis and microcrystalline arthritis. In the conditions governing the present study, urinary hydroxyproline may be used as an index of joint tissue collagen resorption. Finally the significance of synovial fluid and serum non-dialysable hydroxyproline is discussed.
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PMID:Serum and synovial fluid hydroxyproline fractions in microcrystalline arthritis and osteoarthritis. 53 14


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