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  • 1
    ISSN: 1420-908X
    Keywords: β-adrenergic receptor ; cAMP ; Endothelial cells ; Smooth muscle cells ; Theophylline
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Activation of vascularβ-adrenergic receptors prevents an increase in vascular permeability caused by free radicals or inflammatory peptides. Methylxanthines seem to have similar protective effects on vascular endothelium. In the present study we investigated the effect of theophylline on theβ-adrenergic receptor expression and cAMP concentrations in cultured endothelial and smooth muscle cells from bovine aorta. Comparable values forβ-receptor density and binding affinity were detected in both cell types. Isoproterenol induced significant downregulation ofβ-receptors in endothelial (BAEC: −60.5%) and smooth muscle cells (BASMC: −52.5%; P 〈 0.01). Incubation of endothelial cells with theophylline (4 µg/ml and 40 µg/ml) for 24 hours did not affectβ-receptor expression, whereas in smooth muscle cells theβ-receptor density was reduced for −31.5% and −28.7, respectively. In endothelial cells a transient effect on cAMP concentrations was observed after stimulation with isoproterenol (1 µM), but no effect was found in theophylline treated endothelial cells. Stimulation of intact smooth muscle cells with isoproterenol and theophylline (4 µg/ml and 40 µg/ml) resulted in a significant increase of cAMP concentrations after 60 and 240 minutes. The present data suggest a novel, celltype specific effect of theophylline on theβ-adrenergic receptor expression in vascular smooth muscle cells in vitro.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    [s.l.] : Nature Publishing Group
    Nature 180 (1957), S. 1289-1290 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] The linear polyethylene 'Marlex 50' was crystallized by cooling a hot solution in xylene. Plate-like crystals were obtained with habits varying between that of regular lozenges and dendrites2'8. The thinnest parts were about 100 A. thick, thickening taking place by a stepwise accretion of new ...
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Cities 2 (1985), S. 369 
    ISSN: 0264-2751
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Architecture, Civil Engineering, Surveying , Geography
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Women's Studies International Forum 11 (1988), S. 281-285 
    ISSN: 0277-5395
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Sociology
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Women's Studies International Forum 11 (1988), S. 379-380 
    ISSN: 0277-5395
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Sociology
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Oxford, UK : Munksgaard International Publishers
    Journal of clinical periodontology 30 (2003), S. 0 
    ISSN: 1600-051X
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Background, aims: Neutrophil cells constitute the first defense barrier against the oral bacterial challenge in the periodontium. Reduction of neutrophils could impair this response against periopathogenic bacteria such as Porphyromonas gingivalis. Our previous work implicates the apoptosis of neutrophils in the pathogenesis of periodontitis. We now demonstrate that granulocyte monocyte-colony stimulating factor (GM-CSF) present in the gingival crevicular fluid (GCF) and secreted during the immune response reduces the apoptosis of neutrophils.Method: In this study, the presence of GM-CSF and tumor necrosis factor-alpha (TNF-α) in GCF was determined in samples obtained from adult patients with periodontitis and from control subjects with clinically healthy gingiva. GCF was collected for 30 s using Periopaper® strips, and cytokines were quantified by ELISA. We used ex vivo culture of gingival tissue biopsies for 2 and 4 days in the presence of GM-CSF. Apoptosis was determined using the terminal TdT-mediated dUTP-biotin nick end labeling (TUNEL) technique, and expression of Bax by immunohistochemistry.Results: The presence of GM-CSF and TNF-α was detected in the majority of sites from periodontal patients (83.3% and 63.3%, respectively), presenting a total amount of 27.65 and 42.38 pg, respectively. GM-CSF reduces the neutrophil apoptosis determined by double staining with TUNEL and myeloperoxidase and by a reduction of Bax expression.Conclusions: These findings suggest a novel mechanism by which neutrophils specifically accumulate in adult patients with periodontitis.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1365-2222
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Background The neurotrophins Nerve Growth Factor (NGF), Brain-Derived Neurotrophic Factor (BDNF) and Neurotrophin (NT)-3 are produced, stored and released by various immunological cells. The influence of NTs upon the function of these cells is described. Elevated plasma levels were found in inflammatory, autoimmune and allergic diseases with the highest levels in allergic asthma. A connection between bronchial hyper-responsiveness and serum levels has been reported.Objective Little is known about the influence of treatment with inhaled corticosteroids (ICS) on serum NT levels and their influence on the asthmatic state.Methods Eighty-seven volunteers were studied. Thirty-eight were stable allergic asthmatics with constant ICS doses, 29 were asthmatics not receiving anti-asthmatic treatment and 20 were age- and sex-matched healthy controls. Demographic and lung function data were evaluated. NT serum levels were determined by ELISA.Results NGF and BDNF levels were significantly increased in untreated asthmatics compared to the control and the treated group, while NT-3 demonstrated significantly higher levels in treated asthmatics compared to healthy controls. After stabilization of untreated subjects with ICS, the NT levels decreased significantly.Conclusions These results suggest that NTs participate in allergic inflammation and asthma. Effective treatment leads to a decrease of circulating neurotrophic factors.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Science, Ltd
    Clinical & experimental allergy 32 (2002), S. 0 
    ISSN: 1365-2222
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Background πβ-endorphin is a derivative of pro-opiomelanocortin. Cells of the immune system can also synthesize and secrete β-endorphin. Its concentration is increased during the allergic reaction and during stress. Increased reactivity during psychological stress of allergic subjects is also well known.Objective Is β-endorphin one physiological link between stress and an exacerbation of the allergic reaction?Methods First, intranasal β-endorphin challenges with subsequent lavages to determine histamine and albumin levels and measurements of nasal flow and resistance in dose-response and time course experiments were performed. Secondly, we examined whether β-endorphin pre-treatment increased the antigen-induced release of histamine and albumin in nasal lavages and the clinical symptoms.Results Exogenous β-endorphin (100 pM−10 µM/mL) induced a dose-dependent increase in nasal symptoms in asymptomatic allergic subjects with rhinitis (n = 14) as well as in non-allergic controls (n = 10), but did not release any mediators into nasal secretion. However, comparing the antigen-evoked release of mediators into nasal secretions with that of a β-endorphin pre-treated antigen challenge we could note a significant enhancement of human serum albumin influx (P 〈 0.05) and histamine liberation (P 〈 0.05) 10 min after antigen challenge compared with the allergen challenge alone, with also a correlation with the more pronounced decrease in nasal flow (P 〈 0.05).Conclusion These results suggest that β-endorphin-induced increase in nasal congestion is mediated through direct neuroendocrine receptor activation independent of mast cell activation and that during the allergic reaction there is a β-endorphin/mast cell interaction that enhances the mediator response to nasal allergen challenge.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Clinical & experimental allergy 22 (1992), S. 0 
    ISSN: 1365-2222
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The MAGIC LITE system, a newly developed immunochemiluminometric assay for specific and total IgE antibody using paramagnetic particles coupled with standardized allergens as solid phase, was compared to the CAP system, a recently introduced immunoassay based on a cellulose polymer encased in a capsule. A total of 357 serum samples of patients with suspected inhalant allergies and a positive skin prick test (SPT) to common allergens (birch, timothy-grass, mugwort, cat dander, Dermatophagoides pteronyssinus, Alternaria) were investigated. Fifty SPT negative subjects served as controls (total number of tests in each assays = 1600). Both assays were highly precise (overall intra-assay and inter-assay coefficients of variation were 2.9% and 4.5% in MAGIC LITE, 4.7% and 5.5% in CAP) and showed excellent linearity (mean r2 of eightfold log2 serum dilutions were 99.7% and 99.3% in MAGIC LITE and CAP). Good correlations were found between the absolute specific IgE antibody values detected by both methods (correlation coefficient r: birth 0.86, grass 0.93, mugwort 0.96, cat 0.91, D. pteronyssinus 0.73, Alternaria 0.90). Excellent specificity (.98%) occurred in both assays and with all allergens, and sensitivity was related to the allergen (MAGIC LITE/CAP): birch 91%/89%, grass 83%/90%, mugwort 50%/69%, cat 83%/83%, D. pteronyssinus 72%/78%, Alternaria 75%/81 %. Our results indicate that both in vitro tests are useful tools for the detection of specific IgE antibody.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Clinical & experimental allergy 27 (1997), S. 0 
    ISSN: 1365-2222
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Background Bradykinin, a potent inflammatory mediator, is released during allergic and non-allergic rhinitis and asthma in man. Nasal bradykinin challenge induces a dose-dependent plasma leakage into the nasal cavity and relevant symptoms of rhinitis.Objective We now report on substance P generation during nasal bradykinin challenge in vivo.Methods The effect ot locally applied bradykinin on substance P generation was studied in nine individuals, allergic to grass pollen and six non-allergic controls. In the allergies TAME-esterase activity, histamine and substance P concentrations were measured in nasal lavages and correlated to the clinical symptoms.Results Substance P concentrations in nasal lavages increased in a dose-dependent fashion during nasal bradykinin challenge in both groups. In the allergic group Substance P-increases correlated with the production of TAME-esterase activity (r= 0.9. P 〈 0.05) whereas these allergic individuals did not produce any histamine increases. The generation of substance P and the increase of TAME-esterase activity was associated with the onset of clinical symptoms. Correlation of oedema and hypersecretion to substance P were signiticant by linear regression analysis (r = 0.88, P 〈 0.005 and r= 0.89. P 〈 0.02, respectively). Bradykinin induced irritations like burning and itching were shortterm and rare. Serial dilutions of nasal washes produced Substance P-RIA displacement curves that paralleled the standard curve and recovery of standard substance P that was added to nasal washes was 76 ± 4% (mean ± sem), n= 8.Conclusion Bradykinin induces in vivo a dose-dependent plasma leakage into the nasal cavity without affecting mast cells, but stimulates nerve endings resulting in the release of the neuropeptide substance P.
    Type of Medium: Electronic Resource
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