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  • 1
    ISSN: 1524-475X
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Wound healing can be accelerated by removing necrotic tissue. Various methods of wound debridement have been developed, including enzymatic debridement. Recently potent proteolytic enzymes were isolated from the intestine of Euphausia superba (Antarctic krill) that might be useful for degrading necrotic tissue. The purpose of this study was to evaluate the debriding properties of krill enzymes, using a specially designed animal model and a computerized analysis system. In 10 female domestic pigs, each weighing 20 kg, 6 artificial ulcers were made on each animal's back using electrokeratome, followed by application of trichloracetic acid. Ulcers were treated twice daily for 7 days with either krill enzymes at different concentrations or with saline. Reduction of necrotic tissue was measured daily using computerized wound analysis. Histological examination included the determination of bromodeoxyuridine incorporation in order to detect cell proliferation as well as routine stains. The debriding effect of krill enzymes at a concentration of ≥ 3.0 casein units per ml was significantly better than saline control treatment (p 〈 0.05). The effect was dose dependent, and granulation tissue formation was enhanced. In conclusion, krill enzymes are effective in wound debridement, as measured in this animal model.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 2
    Digitale Medien
    Digitale Medien
    Oxford, UK; Malden, USA : Munksgaard International Publishers
    Experimental dermatology 14 (2005), S. 0 
    ISSN: 1600-0625
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Abstract:  Nitric oxide (NO) is a reactive endogenous molecule with multiple functions including inflammation and immunity. NO stimulates melanogenesis by activating soluble guanylyl cyclase (sGC) resulting in increases in intracellular guanosine 3′,5′-cyclic monophosphate (cGMP). In vitro experiments showed that NO could inhibit the de novo attachment of melanocytes to extracellular matrix (ECM) suggesting that NO-induced aberrant perturbation of melanocyte–ECM interaction could be a reason for melanocyte loss in vitiliginous lesions. Here, we examined whether there might be differences between normal melanocytes and vitiliginous melanocytes (VMs) with respect to NO-induced detachment from ECM and whether cGMP is involved. We used the direct NO donor (Z)-1-[N-(3-ammoniopropyl)-N-(n-propyl)amino]diazen-1-ium-1,2-diolate and the peroxynitrite donor 3-morpholino-sydnonimine for the present studies. These donors induced detachment of both normal melanocytes and non-lesional VMs in a time- and concentration-dependent manner with comparable susceptibility and similar expression profile of sGC. Treatment of melanocytes with caspase inhibitors reduced cell detachment, indicating that a major part of the detachment is due to apoptosis. The NO-induced detachment but not apoptosis was partly inhibited in the presence of sGC and cGMP-dependent protein kinase inhibitors. In addition, the membrane-permeable cGMP analog 8-(4-chlorophenyethio/guanosine-3′,5′-cyclic monophosphate (PCPT) cGMP was not able to induce apoptosis in melanocytes, suggesting that NO-induced detachment of melanocytes via apoptosis is cGMP-independent. The present results also indicate that there are no apparent differences between NO-induced detachment of non-lesional vitiliginous and normal melanocytes from ECM.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 3
    ISSN: 1600-0757
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: In vivo, melanocytes were detected in epidermis from human tissue of 6.5 weeks estimated gestinational age (EGA) and older. We have successfully established melanocyte monocultures from tissue of 9 to 10 weeks EGA. To our knowledge, this is the first report on physiology of human foetal melanocytes in monoculture. In culture, such melanocytes retained foetal characteristics. Proliferation rates noted were markedly higher (approximately 2.7-fold) when compared to those in cultures of neonatal melanocytes. Moreover, when analyzing cellular phenotypes by markers for cells of the melanocytic lineage, foetal cells isolated from tissue of 9 weeks EGA reproducibly showed expression of the high molecular weight (HMW) antigen and c-kit to an extent intermediate to that found in neonatal melanocytes and M14 melanoma cells. Such differential expression was not observed if cells were isolated from tissue of 10 weeks EGA, indicating that the foetal environment provides essential differentiation stimuli during the 10th week of gestation. Moreover, these results are supportive of the theory that malignant transformation involves a process of dedifferentiation. In all, human foetal melanocyte culture provides a useful model to investigate pigment cell differentiation.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 4
    ISSN: 1600-0757
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: An ex vivo model system was developed to investigate melanocyte migration. Within this model system, melanocytes migrate among other epidermal cells in the epibolic outgrowth of skin explants. This process is initiated by loss of contact inhibition of epidermal cells at the rim of the explants and by locally produced chemotactic factors. Punch biopsies provided explants of reproducible diameter. Optimal culture conditions include medium consisting of Dulbecco's Minimal Essential Medium containing 10% inactivated normal human serum and placement of explants epidermal side up at the air-liquid interphase. Within 7 days, epidermal cells completely surround the explant. Approximately 3 days after the onset of keratinocyte migration, melanocytes distribute themselves within the newly formed epidermis. Throughout the 7-day culture period, melanocytes and keratinocytes show maintenance of subcellular morphology, and the dermo-epidermal junction remains intact. Melanocyte migration was quantified using immunoperoxidase staining in combination with light microscopy and computer-aided image analysis. Preliminary results using the model system to compare migration in control and nonlesional vitiligo skin indicate that no inherent migration defect is responsible for impaired repigmentation of vitiligo lesions. The organotypic culture model system allows for investigations on melanocytes within their environment of autologous epidermal and dermal components, closely resembling in vivo circumstances in human skin.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 5
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    FEMS microbiology letters 76 (1991), S. 0 
    ISSN: 1574-6968
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Biologie
    Notizen: A B-cell epitope on the carboxy-terminal region of the mycobacterial 65-kDa heat shock protein that distinguishes Mycobacterium tuberculosis/Mycobacterium bovis BCG from Mycobacterium leprae was identified by two novel monoclonal antibodies (mAbs), Ne5 and Nd4. These mAbs also showed a limited cross reactivity with mycobacterial species belonging to M. tuberculosis complex and Mycobacterium avium complex with the exception of Mycobacterium vaccae. Characterization of the epitope recognized by these mAbs was done with M. bovis BCG 65-kDa fusion proteins expressed in Escherichia coli encoding various segments of the 65-kDa protein. Our results together with those reported in literature indicated that this epitope resides in the highly divergent region of amino acid residues 525 to 540. This B-cell epitope on the 65-kDa protein of M. tuberculosis/M. bovis BCG has not been recognized by previously reported mAbs, although the analogous epitope sequence of M. leprae 65-kDa has been identified by a known mAb (IIIC8) reported in the literature. Therefore Ne5/Nd4 epitope could be considered important in studying the differential immune response of the host against infections with M. tuberculosis complex /M. avium complex and M. leprae.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 6
    ISSN: 1432-069X
    Schlagwort(e): Key words Langerhans cells ; Migration ; MMP
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Emigration of Langerhans cells (LC) from the epidermis upon exposure to contact sensitizers is regarded as an essential event in the development of contact sensitization. Since migration of several types of cells depends on the activity of matrix metalloproteinases (MMPs), in the present study we tested whether MMP inhibitors (BB94, BB2116 and CT1166) can prevent the emigration of LC in cultured skin explants, which were exposed to a contact sensitizer (NiSO4). Epicutaneous application of NiSO4 significantly reduced the number of LC within the epidermis and the remaining LC were localized along the epidermal-dermal junction indicating the emigration of LC. In the presence of each of the MMP inhibitors tested, NiSO4-induced migration of LC was strongly decreased. Since after the epicutaneous application of contact sensitizer, its presentation by skin LC is essential for the development of contact sensitization instead of the development of antigen-specific tolerance, our results suggest that the use of MMP inhibitors may be beneficial for the prevention of contact sensitization of the host.
    Materialart: Digitale Medien
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