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  • 1
    Electronic Resource
    Electronic Resource
    The localization and characterization of proteinases for the initial cleavage of porcine amelogenin (1992)
    Springer
    Calcified tissue international 51 (1992), S. 213-217 
    Details
    ISSN: 1432-0827
    Keywords: Porcine secretory enamel ; Degradation of amelogenin ; Proteinases ; 25kDa amelogenin ; Enzymography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary In the outermost layer of porcine-developing enamel adjacent to the ameloblasts in the secretory stage, the activities of two proteinases having molecular masses of 76 and 78kDa were detected by enzymography using gelatin as a substrate. On the other hand, high activities of known 30 and 34kDa proteinases were localized in the inner layer of the enamel. The 76kDa proteinase cleaved the carboxylterminal peptide of porcine 25kDa amelogenin to convert it to 20kDa amelogenin. The 78kDa proteinase also acted on the 25kDa amelogenin similarly, but its activity was weak. The results indicate that the 25kDa amelogenin synthesized and secreted by ameloblasts is converted to 20kDa amelogenin by the action of proteinase localized in the outermost layer of the secretory enamel, and then further degraded by the proteinases in the inner layer of the enamel associated with the increase of mineralization.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00334549
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    Paper (German National Licenses)
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  • 2
    Electronic Resource
    Electronic Resource
    Action of metalloproteinases on porcine dentin mineralization (1994)
    Springer
    Calcified tissue international 55 (1994), S. 426-435 
    Details
    ISSN: 1432-0827
    Keywords: Dentin mineralization ; Enzymography ; Geatinases ; Proteoglycanases ; Protoglycans
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract Samples containing predentin and mineralized dentin involving the mineralized front (newly formed dentin) were prepared by scraping developing porcine teeth after odontoblastic cell debris had been removed from the predentin surfaces. An extract was obtained separately from the matrices of predentin and of the newly formed dentin with a 4 M guanidine solution before and after demineralization with acetic acid solution. Enzymography detected 56 and 61 kDa gelatinases and 25 kDa proteoglycanase as neutral metalloproteinases in both extracts and proved them to be in an active form. Approximately half of the 56 and 61 kDa gelaunases binds to collagen fibers in predentin matrix. Three high molecular weight proteoglycans (70–85 kDa, 130–180 kDa, and 290 kDa) were found in the predentin matrix, but not in the newly formed dentin. The proteoglycanases in predentin degraded 290 kDa proteoglycan, if incubated together with calcium (Ca) ions. The results of this investigation indicate that active proteoglycanases with existed in the predentin perform no substantial work in proteoglycan degradation because the Ca ions are masked in the predentin matrix by coexisting proteoglycans. When mineralization occurs, however, they can degrade the proteoglycan at the mineralization front because excess Ca ions may be supplied via odontoblastic processes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00298556
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    Paper (German National Licenses)
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  • 3
    Electronic Resource
    Electronic Resource
    Mechanisms of oxyradical production in substance P stimulated rheumatoid synovial cells (1996)
    Springer
    Rheumatology international 16 (1996), S. 159-167 
    Details
    ISSN: 1437-160X
    Keywords: Substance P ; Synovial cells ; Oxyradical production ; Intracellular Ca2+ ; PKC
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We examined the intracellular mechanisms of substance P induced oxyradical production in rheumatoid synovial cells by the luminol-dependent chemiluminescence method. After stimulation with substance P (30 μM), single synovial A (macrophage-like) or B (fibroblast-like) cells released oxyradicals such as superoxide anions (OZ) and/or hypochlorous anions (OCl−) under a microscope equipped with an ultrasensitive photonic image intensifier. The substance P induced oxyradical production was blocked by a tachykinin NK1 (NK1) receptor antagonist, GR82334, GTP-binding protein (G-protein) inactivators, GDPβS and islet-activating protein (IAP), and a phospholipase C (PLC) inhibitor, U-73122. Substance P (30 μM) also induced a transient increase in the intracellular Ca2+ concentration ([Ca2+]i) in both synovial A and B cells as measured by a Ca2+ indicator, fura 2. BAPTA-AM and an inositol-1,4-5-triphosphate (IP3) receptor antagonist, heparin, inhibited the substance P induced increase in [Ca2+]i, but they had no effects on oxyradical production. In contrast to the effects of BAPTA-AM and heparin, protein kinase C (PKC) inhibitors, H-7 and calphostin C, completely inhibited substance P induced oxyradical production without any significant effects on [Ca2+]i increase. These findings suggest that the NK1 receptor/PLC-linked diacylglycerol (DAG) formation with the resulting activation of PKC is the main signal transduction pathway for substance P stimulated oxyradical production in synovial cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01419729
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    Paper (German National Licenses)
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  • 4
    Electronic Resource
    Electronic Resource
    Participation of substance P distribution in the cytokine production of rheumatoid synovium (2000)
    Springer
    Modern rheumatology 10 (2000), S. 83-87 
    Details
    ISSN: 1439-7609
    Keywords: Key words Cytokine production ; Substance P ; Synovial cells ; Rheumatoid arthritis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Based on findings which suggested the involvement of the neuropeptide substance P in the pathogenesis of rheumatoid arthritis (RA), we investigated the mechanism of synovial pannus formation in RA, and examined the interaction between the cytokine production of synovial tissues and the concentration of substance P in the cartilage–pannus junction (CPJ). The CPJ and other peripheral synovial tissues were separately obtained from each part of the synovium from the knee joints of seven RA patients. The concentrations of substance P and the cytokines interleukin (IL)-1β and IL-6 in the CPJ and peripheral synovial tissues were determined by enzyme-linked immunosorbent assays. In addition, synovial cells were isolated from the CPJ and peripheral synovial tissues and treated with substance P or neurokinin-1 receptor antagonist to analyze the changes in cytokine production. The substance P levels were 211.2 and 50.5 pg/mg protein in the CPJ and the peripheral synovium, respectively. The IL-1β and IL-6 levels in the CPJ were 24.6 and 12.8 pg/mg protein, respectively. In the peripheral synovium, these levels were 4.3 and 2.5 pg/mg protein, respectively. In the CPJ, the IL-1β and IL-6 levels in tissue containing a high concentration of substance P (〉200 pg/mg protein) were 39.4 and 21.6 pg/mg protein, respectively, and those in tissue containing a low concentration of substance P (≤200 pg/mg protein) were 11.6 and 5.1 pg/mg protein, respectively. Synovial cells from the CPJ produced higher levels of IL-1β and IL-6 than those from peripheral tissues. In addition, treatment of the cells with an NK-1 antagonist significantly reduced the production of these cytokines by the synovial cells. The theory that substance P plays a role in the pathogenesis of RA via the upregulation of cytokine production should be considered in further studies on the immunomodulatory properties of substance P in arthritis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s101650050004
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    Paper (German National Licenses)
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