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  • Articles: DFG German National Licenses  (7)
  • 2005-2009  (2)
  • 1980-1984  (3)
  • 1975-1979  (2)
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  • Articles: DFG German National Licenses  (7)
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  • 1
    ISSN: 1365-2133
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Background  Fibulin-5 was recently found as a secreted extracellular matrix protein that functions as a scaffold for elastic fibres. However, the distribution of fibulin-5 in human skin and its changes during the ageing process are not known.Objectives  To explore the involvement of fibulin-5 in skin ageing, the age-dependent changes in fibulin-5 localization in human skin were examined compared with those of other elastic fibre components including elastin, fibrillin-1 and fibulin-2.Methods  The distribution of elastin, fibrillin-1, fibrillin-2, fibulin-2 and fibulin-5 was investigated by means of immunohistochemistry using their specific antibodies. Skin samples were recovered from 12 healthy subjects undergoing plastic surgery. Ultraviolet (UV) B-irradiated or control nonirradiated buttock skin samples were obtained from two healthy volunteers at 2 days after the irradiation at 2 minimal erythemal doses.Results  In the reticular dermis of young sun-protected skin from the upper arm, fibulin-5 colocalized with the other elastic fibre components, while in the papillary dermis fibulin-5 showed candelabra-like structures perpendicular to the epidermis with an unstained area just beneath the epidermis, which was similar to that of elastin but not fibrillin-1. Fibulin-5 in the reticular dermis decreased and disappeared with age even in sun-protected skin from the thigh, abdomen and upper arm. In sun-exposed skin, fibulin-5 was extremely reduced in the dermis of cheek skin even from a 20-year-old man. UVB irradiation reduced fibulin-5, fibulin-2 and elastin markedly, moderately and weakly, respectively, compared with levels in control nontreated skin. Interestingly, the deposition of fibulin-5 was increased in solar elastosis, like that of other elastic fibre components.Conclusions  These results suggest that fibulin-5 is a good marker of skin ageing and that the earlier loss of fibulin-5 may involve age-dependent changes in other elastic fibre components.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1365-2133
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Background  The epidermal basement membrane (BM) plays important roles in adhesion between epidermis and dermis, and in controlling epidermal differentiation. The BM has been reported to be damaged in sun-exposed skin. Although matrix metalloproteinases (MMPs) are believed to be involved in the BM damage, there is no good in vitro model for examining BM damage by MMPs or for exploring methods to protect the BM.Objectives  To examine the involvement of MMPs in BM damage and approaches to protect the BM from such damage by using an in vitro skin-equivalent (SE) model.Method  SE was prepared by culturing human keratinocytes on contracted collagen gel including human fibroblasts. MMP-1, -2, -3 and -9, laminin 5 and type IV and VII collagens were determined by specific sandwich ELISAs, and MMP-2 and MMP-9 were analysed by gelatin zymography. Histological examination of SE was also carried out.Results  Despite production of BM components such as laminin 5 and type IV and VII collagens in SEs, BM was rarely observed at the dermal–epidermal junction. Several MMPs, such as MMP-1, -2, -3 and -9, were observed to be present in conditioned media and some of them were in active forms. Tissue inhibitor of metalloproteinase (TIMP)-2 was not detected, although TIMP-1 was present. Synthetic MMP inhibitors, CGS27023A and MMP-inhibitor I, which inhibit MMP-1, -2, -3 and -9, markedly augmented deposition of laminin 5 and type IV and VII collagens at the dermal–epidermal junction, resulting in the formation of continuous epidermal BM.Conclusions  Our results indicate that MMPs are involved in the degradation of BM in SEs, and that MMP inhibitors exert a protective effect against BM damage.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Colloid & polymer science 254 (1976), S. 942-943 
    ISSN: 1435-1536
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Colloid & polymer science 255 (1977), S. 817-817 
    ISSN: 1435-1536
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 19 (1981), S. 311-330 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: (+) (S)- and (-) (R)-trans-1,2-cyclopropanedicarboxylic acids (C3A), (+) (S)- and (-) (R)-trans-1,2-diaminocyclopropanes (C3B), (+) (S)- and (-) (R)-trans-2-phenylcyclopropylamines (øC3B), (+) (S)- and (-) (R)-trans-1,2-bis(methylamino)-cyclopropanes (C3MB), and (+) (S)- and (-) (R)-trans-(2-phenylcyclopropyl)-methylamines (øC3MB) were prepared.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 19 (1981), S. 331-348 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The polyamides were prepared from the dicarbonyl chloride of (+) (S)- or (-)(R)-trans-1,2-cyclopropanedicarboxylic acid (C3A) with either the dihydrochloride salt of (+)(S)- or (-)(R)-trans-1,2-diaminocyclopropane (C3B) or the dihydrobromide salt of (+)(S)- or (-)(R)-trans-1,2-bis(methylamino)cyclopropane (C3MB) by interfacial polycondensation. Several diamide model compounds composed of these monomers were also synthesized. The polyamides [poly(C3A-C3B)] derived from C3A and C3B have the capability of hydrogen bonding, while the polyamides [poly-(C3A-C3MB)] derived from C3A and C3MB do not. Poly(C3A-C3B) were insoluble in common organic solvents except strong acids. Poly(C3A-C3MB) were soluble in common organic solvents. Poly(C3A-C3B) had melting points higher than 300°C. Poly(C3A-C3MB) melted at 180-235°C. The ORD and CD study has shown that poly(+)C3A(+)C3B in methane sulfonic acid (MSA), 2,2,2-trifluoroethanol (TFE) (5 v % MSA), and tetramethylenesulfone (TMS) (5 v % MSA) exhibits a very strong Cotton effect or CD peak at 212-218 mμ, attributable to a component of the split π-π* transition of the amide chromophores. Poly(+)C3A(+)C3MB in MSA and TFE (5 v % MSA) shows a strong Cotton effect or CD peak at 217-223 mμ and an intermediate Cotton effect or CD trough at 202-204 mμ as well as an intermediate Cotton effect or CD trough at 220-222 mμ and an intermediate Cotton effect or CD peak at 202-204 mμ in TFE and TMS. These peaks and troughs may be assigned to splitting of the π-π* transition. The CD spectra of poly(+)C3A(+)C3MB in nonacidic media are quite different from those in acidic media: they are almost mirror images. The CD spectra in this transition induced by MSA suggests that a transition from a compact helix to another more extended helix with opposite handedness occurs similar to poly-L-proline I ⇄ II. This transition may be explained by electrostatic repulsion between protonated amide groups. Viscosity data have shown that the conformation is changed to a highly extended from in acidic media. The polyamides and diamides derived from enantiomers exhibit mirror image spectra. Poly(+)C3A(+)C3B and poly(+)C3A(+)C3MB in every solvent studied exhibit a marked enhancement of the rotatory strength of ORD and CD with respect to the corresponding diamide models.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 19 (1981), S. 349-361 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The synthesis and optical properties of the polyamides [poly(C3A·C3B) and poly(C3A-C3MB)] derived from asymmetric trans-1,2-cyclopropanedicarboxylic acids (C3A), asymmetric trans-1,2-diaminocyclopropanes (C3B), and asymmetric trans-1,2-bis(methylamino) cyclopropanes (C3MB) were reported in the preceding article. This paper describes the NMR studies and conformations of the polyamides. The NMR studies of the polyamides and their diamide models have suggested that the polyamides have about a 90° torsional angle for NH (or CH3) CH. This angle seems to be reasonable because of less steric interaction, especially for poly(+)C3A(+)C3MB. The N—CH3 of the poly(+)C3A(+)C3MB in sulfuric acid-d2 (D2SO4) is a singlet and is tentatively assigned to trans to the carbonyl oxygen of the amide group. In 2,2,2-trifluoroethanol-d3 (TFE-d3) and chloroform-d (CDCl3) it is also a singlet and is tentatively assigned to cis. The overall results obtained suggest that poly(+)C3A(+)C3MB exists in a compact helical conformation in TFE and TMS, while some conformational transition to a highly extended helical form with opposite handedness is induced by the addition of MSA. Likewise, poly(+)C3A(+)C3B must exist in some ordered conformation in the solvents studied. Possible ordered conformations of the polyamides have been proposed based on the experimental results and some assumptions.
    Additional Material: 16 Ill.
    Type of Medium: Electronic Resource
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