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T Sorsa

Publications and source records attributed to T Sorsa.

247 records · Page 14Linked to original sources
PubMed1986

Gold sodium thiomalate activates latent human leukocyte collagenase.

Gold sodium thiomalate, a drug used widely in the therapy of rheumatoid arthritis, was found to be an activator of latent human polymorphonuclear leukocyte collagenase. The activation was demonstrated by two distinct and independent collagenase assays: by recording with a spectrophotometer at 227 nm the enzyme-induced increase in ultraviolet difference absorbance of native type I collagen connected to the cleavage of collagen at 37 degrees C [(1986) Eur. J. Biochem. 156, 1-4] and by SDS-polyacrylamide gel electrophoresis analysis of formation of specific products of collagen resulting from collagenase cleavage at 25 degrees C. Activation of latent collagenase by gold sodium thiomalate appeared to be of the same magnitude as by the known activator phenylmercuric chloride.

Electrophoresis, Polyacrylamide Gel↗
PubMed1986

Hyperchromic effect of collagen induced by human collagenase.

Loss of the highly ordered triple-helix structure of native collagen on denaturation or enzymatic degradation involves a helix-to-coil transition, which can be seen as an increase at 227 nm in its ultraviolet difference absorption spectrum. We report here the successful use of this hyperchromic effect to quantify collagen in solution and to follow up the time-course of collagen degradation catalyzed by collagenase. Using 14C-labelled collagen substrate we show the excellent correlation between enzyme-induced increase in ultraviolet difference absorption and formation of specific cleavage products. The novel method was found to be suitable to characterize the enzymatic properties of human leukocyte collagenase. Activation of latent collagenase to the active enzyme could be followed continuously and an activation lag estimated.

Animals↗
PubMed1986

Increased collagenase activity in human rheumatoid meniscus.

Collagenase activity of the knee joint menisci of patients suffering from rheumatoid arthritis was approximately 3-fold higher than that found in menisci of control patients. The mean collagenase activity in the macroscopically more diseased parts of the rheumatoid menisci was significantly higher than that in the less damaged areas. The specific degradation products resulting from the cleavage of human meniscoid type II collagen by rheumatoid meniscoid collagenase were demonstrated by SDS-polyacrylamide gel electrophoresis. Addition of N-ethylmaleimide, which activates latent mammalian collagenases, did not further increase collagenase activity in rheumatoid menisci. Thus in rheumatoid meniscus, collagenase may be synthesized and then activated, probably by proteolytic enzymes involved in the inflammatory reaction.

Arthritis, Rheumatoid↗
PubMed1985

Partial purification and characterization of latent human leukocyte collagenase.

Latent and active collagenase were extracted from human polymorphonuclear leukocytes. Separation of the two forms of the enzyme was performed by gel filtration on Sepharose 6 B. The latent form of the enzyme was detected from chromatographic fractions after a brief treatment with trypsin or exposure of the fractions to the sulfhydryl reagent phenylmercuric chloride. Latent enzyme eluted before active enzyme from the column, indicating a higher apparent molecular weight. Partially purified latent enzyme exhibited an apparent molecular size of 70-75 kDa as estimated by gel filtration. A value of 50-55 kDa was obtained for active enzyme. Without activation the latent enzyme did not degrade soluble collagen substrate. This was demonstrated by a quantitative viscometric assay and also by sodium dodecyl sulfate polyacrylamide gel electrophoresis, when no typical cleavage products of collagen could be seen. Latent enzyme could not be obtained unless serine protease inhibitors were present during the extraction and purification procedures. The effects of the activators trypsin, phenylmercuric chloride, phenylmethyl sulfonyltrypsin, and N-ethylmaleimide on the latent human polymorphonuclear leukocyte collagenase were studied. Contrary to the suggestion that inactive proteases activate latent human polymorphonuclear leukocyte collagenase, the inactive phenylmethyl sulfonyl-trypsin could not activate latent collagenase.

Chromatography, Gel↗
PubMedDate not supplied

Collagenases (MMP-1, -8 and -13) and trypsinogen-2 in fluid from benign and malignant ovarian cysts.

Proteolytic enzymes, such as matrix metalloproteinases (MMPs) and tumor-associated trypsinogens (TAT), play a pivotal role in tumor invasion and metastasis. Among MMPs, the interstitial collagenases (MMP-1, -8 and -13) can initiate collagenolysis. In this study, we have studied the levels of MMP-1, -8 and -13 in relation to the level of trypsinogen-2 in fluid from benign and malignant ovarian cysts. Elevated MMP-8 levels occur in many ovarian cyst fluids, and high MMP-8 levels are associated with malignancy. The concentrations of trypsinogen-2 correlate with those of MMP-8, but it remains to be shown whether trypsin-2 plays a role as its activator in vivo. The strong expression of MMP-8 over MMP-1 and MMP-13 in malignant ovarian tumors may indicate that MMP-8 participates in the protease cascades associated with the invasiveness of ovarian tumors.

Adolescent↗
PubMedDate not supplied

Otitis externa sicca/fibrotising external otitis (FEO) as a complication of Sjögren's syndrome.

Sjögren's syndrome (SS) is a condition characterized by sicca symptoms and by autoimmune features. We describe two SS patients with otitis externa fibroticans/sicca. One of these 2 patients developed a lesion of the tympanic membrane making it necessary to perform a tympantomy and meatoplasty. Our findings suggest firstly that the epithelial cell-mediated secretion of lamellar bodies and the production of the permeability barrier are defective in SS. Secondly, local moisturing and/or topical corticosteroid treatment in SS patients with sicca symptoms in the auditory canal could help to avoid reconstructive surgical treatment.

Deafness↗
PubMedDate not supplied

Tumor necrosis factor-alpha and receptors for it in labial salivary glands in Sjögren's syndrome.

OBJECTIVE: Modulation of TNF-alpha by neutralizing antibodies, soluble receptors and TNFR: Fc fusion proteins are being developed for the therapeutic modulation of immune inflammation. It is becoming increasingly important to understand the state and involvement of the TNF-alpha/TNFR system in various rheumatic diseases. Tumor necrosis factor-alpha (TNF-alpha) affects its target cells through binding to two different receptors, TNFR-p55 and TNFR-p75. Mitogenic, cytostatic and cytotoxic effects of TNF-alpha on various cells have been reported. In Sjögren's syndrome (SS) focal sialadenitis leads to salivary gland destruction and loss of function. Although TNF-alpha is one possible mediator in these processes, nothing is known about the spatial distribution of TNF-alpha in relation to its receptors/target cells in salivary gland tissue. METHODS: Labial salivary glands (LSG) were obtained from 16 SS patients and 13 healthy controls and stained using the immunohistochemical peroxidase-anti-peroxidase (PAP) method for TNF-alpha, TNFR-p55 and TNFR-p75. RESULTS: TNF-alpha, TNFR-p55 and TNFR-p75 staining was absent, weak or relatively inextensive in controls compared to SS patients. Infiltrating mononuclear inflammatory cells in SS patients displayed moderate to strong TNF-alpha and TNFR expression. In addition, resident vascular endothelial cells, ductal epithelial cells and fibroblasts co-expressed TNF-alpha and TNFR. In contrast, acinar end piece cells did not express TNF-alpha or TNFR-p75 although TNFR-p55 was expressed. CONCLUSION: The interrelated localization of TNF receptors and their ligand TNF-alpha in inflammatory and in endothelial cells suggests a proinflammatory role of TNF-alpha in SS. The expression of TNF-alpha and its receptors in fibroblasts and ductal cells may contribute to ductal hyperplasia and glandular fibrosis. However, in contrast to expectations, the cellular localization of the TNF-alpha/TNRF system argues against its role in acinar cell atrophy.

Antigens, CD↗
PubMedDate not supplied

Distribution of vasoactive intestinal peptide (VIP) and its binding sites in labial salivary glands in Sjögren's syndrome and in normal controls.

OBJECTIVE: Tissue distribution of vasoactive intestinal peptide (VIP)-containing nerves and their target cells were studied in labial salivary glands in patients with Sjögren's syndrome and in healthy controls. METHODS: Immunoperoxidase staining was used to demonstrate VIP-containing nerve fibers, and receptor autoradiography with 125I-Bolton Hunter (BH)-VIP was used to demonstrate VIP positive binding sites. RESULTS: VIP-containing nerves were seen around salivary acini, salivary ducts, blood vessels and deep parenchyma, but were absent from large inflammatory cell foci in patients with Sjögren's syndrome. Receptor autoradiography with 125I-BH-VIP disclosed VIP binding sites on mucous acinar cells and blood vessels, whereas salivary ducts contained no VIP receptors. VIP binding sites were also absent from the centers of large inflammatory cell foci/acinar atrophy. CONCLUSION: The topology of VIP and its receptor suggests that VIP may act on the vascular and secretory components of the salivary gland. However, VIP causes only a slight increase in non-adrenergic, non-cholinergic salivary secretion. It is therefore more likely that this extensive tissue distribution of VIP and its receptors reflects its recently suggested trophic effects on salivary gland tissue. This is further supported by the observation that VIP-IR nerves/VIP binding sites were absent in areas of focal lymphocytoid infiltrates/acinar atrophy in patients with Sjögren's syndrome.

Adult↗