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Query: HUMANGGP:031673 (collagen)
 124,196 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Peptidases activities were compared in human leucocytes, guinea pig and human alveolar macrophages. Seversl endo- and exopeptides were characterized; some of them were active at acid pH and others at neutral and alkaline pH. Leucocytes and alveolar macrophages had proteolygic activity for hemoglobin, fibrinogen, collagen and elastin. Using synthetic substrates, several enzymes were characterized: arylamidase, aminopeptidase, carboxypeptidases A and B and cathepsins A and C. The enzymatic activities were much higher in alveolar macrophages than in leucocytes.
Clin Chim Acta 1976 Feb 02
PMID:[Studies on the activities of peptidases from human leucocytes, and human and guinea pig alveolar macrophages (author's transl)]. 0 98

To investigate the role of immunologic hypersensitivity to collagen in the causation of type II collagen-induced arthritis in rats, passive transfer experiments were performed. Wistar/Lewis rats used in these experiments were demonstrated to be histocompatible by prolonged skin graft survival and mixed lymphocyte cultures. Popliteal lymph node weight assays excluded a potential for graft-vs.-host reactivity in this strain. 9 of 32 naive rats developed arthritis after intravenous receipt of pooled spleen and lymph node cells from donors that had been injected intradermally with type II collagen emulsified in incomplete Freund's adjuvant. This passively transferred synovitis was evident clinically as well as histologically. In control cell transfer experiments involving a total of 97 recipients, transfer of arthritis was shown to require viable cells sensitized to type II collagen. These controls included 17 rats receiving cells from unimmunized donors, 20 recipients of cells from donors injected with incomplete Freund's adjuvant alone, and 24 recipients of cells from rats injected with type I collagen in adjuvant. Deliberate addition of solubilized type II collagen to unsensitized cells at the time of transfer or injection of heat-killed sensitized cells also did not cause arthritis in a total of 36 recipients. These latter two control groups indicate that disease transfer was not the result of antigen carry-over. Intravenous injection of sera from arthritic donors was incapable of passively transferring clinical or histologic synovitis in 30 recipients. Thus, these studies directly implicate immunologic sensitivity to the cartilage type of collagen in the etiology of this autoimmune disease.
J Clin Invest 1978 Aug
PMID:Passive transfer by cells of type II collagen-induced arthritis in rats. 2 33

Soluble fibronectin is found in body fluids and media of adherent cultured cells and binds to fibrin and collagen. Insoluble fibronectin is found in tissue stroma and in extracellular matrices of cultured cells. Fibronectin is a substrate for Factor XIIIa (plasma transglutaminase) and can be cross-linked by Factor XIIIa to itself and the the alpha-chain of fibrin. We used sodium dodecyl sulfate-polyacrylamide gel electrophoresis to investigate Factor XIIIa-mediated crosslinking of fibronectin to collagen. At O degrees or 37 degrees C, fibronectin could be cross-linked to iodinated cyanogen bromide fragment 7 of the alpha 1(I) chain. At 22 degrees or 37 degrees C, fibronectin could be cross-linked to isolated alpha 1(I) chains of type I collagen. Fibronectin could also be crosslinked to types I and III collagen, but only at 37 degrees C. alpha 1(I)-CB7, alpha 1(I) collagen chains, type I collagen, type III collagen, and fibrin all blocked cross-linking between 125I-alpha 1 (I)-CB7 and fibronectin. alpha 1(I)-CB7 blocked cross-linking between fibronectin and fibrin. These results indicate that the determinants of fibronectin-fibrin and fibronectin-collagen binding and cross-linking are similar. Cross-linking of fibronectin to collagen likely occurs in vivo and may be important for normal wound healing, collagen fibrillogenesis, and embryogenesis.
J Clin Invest 1979 Sep
PMID:Cross-linking of fibronectin to collagen by blood coagulation Factor XIIIa. 3 60

The ultrastructure and adenine nucleotide metabolism of platelets from patients with acute leukemia were studied to elucidate possible mechanisms for the platelet dysfunction observed in this clinical setting. Nonstimulated (resting) platelets from leukemic patients varied greatly in size; exhibited marked variation in the number of alpha granules present per cell; had poorly delineated circumferential bands of microtubules; and often grossly dilated open channel systems or cytoplasmic vacuolization. The intracellular concentrations of ATP and ADP were significantly below normal, and the specific radioactivity of ATP and ADP of nonstimulated platelets in leukemia was equivalent to or exceeded that seen in stimulated normal platelets. Addition of ADP or collagen to platelets from leukemic patients was followed by retarded and incomplete shape change, delayed and incomplete centripetal migration of subcellular organelles, impaired degranulation, and the formation of loose aggregates composed of relatively few platelets. Stimulation of "leukemic" platelets with collagen led to the release of significantly subnormal amounts of ATP and ADP and no significant change in the specific radioactivity of the intracellular nucleotides. In contrast to the results in normal platelets, the conversion of ATP to inosine monophosphate and hypoxanthine in platelets in leukemia failed to increase significantly with collagen stimulation. The results indicate that abnormalities exist in the storage pool of adenine nucleotides and the release mechanism of platelets in acute leukemia. These defects appear to contribute to an impairment in the release reaction in these platelets. Many of the ultrastructural and metabolic defects seen in acute leukemia occur in platelets in preleukemia.
J Clin Invest 1975 Jul
PMID:The platelet defect in leukemia. Platelet ultrastructure, adenine nucleotide metabolism, and the release reaction. 4 18

Early dihydrotachysterol-induced calcification of the rat aorta occurs in elastic lamellae. The first deposition of inorganic substance leads to the formation of very thin filament-like structures of low electron density. The characteristic shape of these structures suggests that they could correspond to calcified filamentous components of the elastic tissue. When calcification spreads from the calcified elastic lamellae into the adjacent tissue, the inorganic substance is initially collected in roundish structures, probably of cellular origin, and is successively laid down in the entire matrix of the aortic wall, including collagen fibrils. All the calcified areas contain glycoproteins and acid proteoglycans. A cartilage-like tissue often develops near calcified areas. Its fine structure is very similar to that of the normal hyaline cartilage. It can be calcified, but usually the inorganic substance is not crystalline as it is in normal cartilage. It seems to consist of very small, linearly aggregated inorganic granules which form irregular structures. These seem to develop in close relationship with the fibrillar, probably collagenic, network of the matrix. No ultrastructural findings have been obtained for explaining cartilage induction near calcified areas of the aortic wall. It is possible that cartilage differentiation is regulated by diffusible substances which cannot be recognized under the electron microscope.
Clin Orthop Relat Res 1975
PMID:Dihydrotachysterol-induced aortic calcification. A histochemical and ultrastructural investigation. 4 44

The universal features of the histopathology of fibrotic lung disease are derangement of parenchymal collagen and infiltration of the parenchyma with chronic inflammatory cells. To determine if this cellular reaction might be associated with autoimmunity to a consitituent of the alveolar interstitium, peripheral blood lymphocytes were exposed to human type I collagen in vitro and evaluated for the production of migration inhibition factor and cytotoxicity. Data from 18 patients with idiopathic pulmonary fibrosis, 8 patients with pulmonary fibrosis other than idiopathic pulmonary fibrosis, 12 patients with nonfibrotic lung disease, and 9 normals demonstrated that circulating lymphocytes from more than 94% of patients with fibrotic lung disease take part in processes where the recognition of collagen results in migration inhibition factor production and lysis of collagen-coated sheep red blood cells. These collagen-induced cell-mediated phenomena are obviated with human T-lymphocyte antiserum. Collagen-induced migration inhibition factor production and cytotoxicity were found in less than 20% of patients with nonfibrotic disease and were not found in normals. Qualitatively, there was no organ (lung, skin) or species (human, rabbit) collagen specificity in these assays, but human lung alpha 2 chains were recognized more often than alpha 1(I) chains. Circulating lymphocytes from patients with fibrotic disease are present in a normal T to B ratio. These lymphocytes did not incorporate [3H]thymidine when exposed to collagen but did when exposed to T-cell mitogens. These in vitro observations suggest that circulating T-lymphocytes and lung collagen may be intimately associated in the pathogenesis of human fibrotic lung disease.
J Clin Invest 1976 Nov
PMID:Pathogenic mechanisms in pulmonary fibrosis: collagen-induced migration inhibition factor production and cytotoxicity mediated by lymphocytes. 6 60

Pulmonary fibrosis was induced in eight baboons with bleomycin; five untreated animals were controls. After 45-65 U/kg of bleomycin, lung volumes and diffusing capacity were reduced, and static lung pressure-volume curves were shifted to the right. Right middle lobes were resected at this time in five bleomycin-treated and two control animals. Compared to controls, right middle lobes from bleomycintreated animals had increased weight and contained increased amounts of total protein, collagen, elastin, and DNA; synthesis of collagen and noncollagen protein were also elevated. Occasional alveolar septae were edematous and infiltrated by mononuclear inflammatory cells; a slight increase in collagen was demonstrable histologically. Four of six treated animals died with extensive diffuse interstitial fibrosis after 95 U/kg of bleomycin. Biochemical analyses revealed significantly elevated lobar contents of dry weight, protein, elastin, and collagen. Two animals survived 95 U/kg of bleomycin and were terminated 6 mo after treatment. In these animals, physiologic studies were indicative of restrictive lung disease, but lung histology was nearly normal. Lung weight, total protein, and DNA had returned to control values, but collagen and elastin were increased in amount and concentration. Bleomycin induces an intense inflammatory response in the lung. During this inflammation, connective tissue proliferation occurs in concert with proliferation of other tissue components. Cessation of bleomycin treatment is followed by resolution of inflammation manifested by decreases in tissue mass, cellular content, and nonconnective tissue protein. Collagen and elastin deposited during inflammation are less successfully removed during resolution, leading to a stage characterized by increased concentrations of these proteins. A similar sequence of tissue alterations may occur in idiopathic diffuse interstitial fibrosis of man in response to various lung injuries.
J Clin Invest 1978 Jan
PMID:Bleomycin-induced diffuse interstitial pulmonary fibrosis in baboons. 7 49

Acetic orcein stains formol- and Carnoy-fixed tissues, coloring mast cells, nuclei, basophilic cytoplasm, cerebral corpora amylacea, and cartilage strongly; keratin and erythrocytes moderately; muscle and collagen weakly. Guinea pig Brunner gland and rat colonic goblet cell mucins did not stain. The red nuclear stain contrasts well with the Prussian blue reaction of hemosiderin and the ferric ferricyanide (Turnbull's blue) reaction of enterochromaffin. A weak (0.01%) fast-green FCF stain changes collagen and sometimes smooth muscle to green, without impairing nucleic acid or mast cell staining. Picroindigocarmine gives blue collagen, yellow muscle, and red elastin, nucleic acids and mast cells. Picro-methyl blue tends to override the red nuclear stain. Carnoy fixation is somewhat better for nuclei, formol for basophil cytoplasms.
Am J Clin Pathol 1978 May
PMID:Acetic orcein staining of prefixed tissue sections. 7 35

24 hour hydroxyprolinuria was measured in 50 chronic alcoholics divided up into those with simple alcoholism and those complicated by cirrhosis. All the patients had a significant increase in hydroxyprolinuria. Without there being any difference between cirrhotics and alcoholics without cirrhosis. Comparison between hydroxyprolinuria and the tests usually used to follow the course of hepatic involvement in chronic alcoholism: IgA, transferrin, electrophoresis of serum proteins, alkaline phosphatase, show that there is no correlation between hydroxyprolinuria and the diagnostic or prognostic tests of an alcoholic liver among which the variable IgA is the most significant. On the other hand, hydroxyprolinuria has a linear correlation with the calciuria, which suggests that the increase in hydroxyprolinuria in chronic alcoholics is more related to changes in the collagen of bone tissue than with those in liver tissue.
Ann Biol Clin (Paris) 1978
PMID:[Discussion of the interest of estimation of hydroxyprolinuria in chronic alcoholism (author's transl)]. 8 Jan 46

To assess potential abnormalities in collagen metabolism in systemic scleroderma, skin fibroblast lines from patients with this disease were established and compared to control cell lines derived from healthy subjects. For studies on the biosynthesis of procollagen, the cells were incubated with [(14)C]proline in a medium supplemented with ascorbic acid and beta-aminopropionitrile, and the synthesis of nondialyzable [(14)C]hydroxyproline, in relation to DNA or cell protein, was taken as an index of procollagen formation. Five of eight scleroderma fibroblast cell lines demonstrated procollagen biosynthesis rates significantly higher than the controls, and the mean rate of procollagen synthesis by scleroderma fibroblasts was about twice that of the control cells. Control experiments demonstrated that the specific activity of the intracellular free proline was not different in scleroderma and control fibroblasts, and the mean population doubling times of the scleroderma and the control fibroblast cell lines were the same. The relative synthesis of the genetically distinct procollagens was examined by isolating type I and type III procollagens from the cell culture medium using DEAE-cellulose chromatography. The ratios of type I/III procollagens in scleroderma cell lines did not differ from the controls. The helical stability of the collagenous portion of type I and type III procollagens, estimated by the resistance of (14)C-collagen to limited proteolytic digestion with pepsin under nondenaturing conditions, was the same in both scleroderma and control cultures. The capacity of the cells to synthesize enzymatically active and immunologically reacting collagenase was also studied; no marked differences in these parameters could be observed. The results suggest that cultured skin fibroblasts from patients with scleroderma demonstrate a metabolic abnormality expressed as increased synthesis of type I and type III procollagens in a normal ratio. This abnormality may play a role in the excessive accumulation of collagen in the skin and other organs affected in scleroderma.
J Clin Invest 1979 Oct
PMID:Scleroderma: increased biosynthesis of triple-helical type I and type III procollagens associated with unaltered expression of collagenase by skin fibroblasts in culture. 9 59


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