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  • 1
    Electronic Resource
    Electronic Resource
    Cl− Currents Activated by Extracellular Nucleotides in Human Bronchial Cells (1997)
    Springer
    The journal of membrane biology 156 (1997), S. 297 -305 
    Details
    ISSN: 1432-1424
    Keywords: Key words: Bronchial epithelial cells — Cl− currents — Cl− channels — Patch-clamp — Intracellular Ca2+— ATP — UTP
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract. The perforated-patch technique was used to study the response of human bronchial cells to extracellular nucleotides. ATP or UTP (100 μm) elicited a complex response consisting of a large transient membrane current increase followed by a relatively small sustained level. These two phases were characterized by different current kinetics. Throughout the transient phase (2–3 min) the membrane current (I p ) displayed slow activation and deactivation kinetics at depolarizing and hyperpolarizing potentials respectively. At steady-state (I s ) the relaxation at hyperpolarizing potential disappeared whereas at positive membrane potentials the current became slightly deactivating. The I s amplitude was dependent on the extracellular Ca2+ concentration, being completely inhibited in Ca2+-free medium. Cell pre-incubation with the membrane-permeable chelating agent BAPTA/AM prevented completely the response to nucleotides, thus suggesting that both I p and I s were dependent on intracellular Ca2+. The presence of a hypertonic medium during nucleotide stimulation abolished I s leaving I p unchanged. On the contrary, niflumic acid, a blocker of Ca2+-activated Cl− channels, prevented completely I p without reducing significantly I s . 1,9-dideoxyforskolin fully inhibited I s but also reduced I p . Replacement of extracellular Cl− with aspartate demonstrated that the currents activated by nucleotides were Cl− selective. I p resulted five times more Cl− selective than I s with respect to aspartate. Taken together, our results indicate that ATP and UTP activate two types of Cl− currents through a Ca2+-dependent mechanism.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002329900209
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  • 2
    Electronic Resource
    Electronic Resource
    Eosinophil locomotion and the release of IL-3 and IL-5 by allergen-stimulated mononuclear cells are effectively downregulated in vitro by budesonide (1996)
    Oxford, UK : Blackwell Publishing Ltd
    Clinical & experimental allergy 26 (1996), S. 0 
    Details
    ISSN: 1365-2222
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Background Treatment of aliergic asthma with inhaled corticosteroids, such as budesonide (BDN), results in downregulation of T-cell activation and of eosinophil recruitment.Objective Since blood concentrations of BDN, although significantly lower than those measured in the lung, may still have anti-inflammatory effects, we evaluated the activity of BDN in vitro on: allergen-induced release of lymphokines involved in eosinophil chemotaxis (i.e. IL-3 and IL-5), at drug concentrations similar to those obtained in vivo in the lung (10−8 M), and eosinophil locomotion, at ‘systemic concentrations’ of the drug (10−10 M and 10−9M).Methods Twenty-three atopic asthmatic subjects (atopics) sensitized to Dermatophagoides pteronyssinus (Dp) and seven non-atopic healthy subjects (controls) were studied. Purified blood mononuclear cells (BMC) were stimulated with Dp, with or without BDN 10−8 M and, after 6 days, the supernatants were collected and frozen to test their ehemotactie activity toward purified blood eosinophils and their levels of interleukin (IL)-3 and IL-5 by immunoassay. BMC were then pulsed for additional 18h with [3H]thymidine to evaluate allergen-induced T-cell proliferation. In addition, to test possible direct effects of ‘systemic concentrations’ of the drug on eosinophil locomotion, blood eosinophils were incubated for 1 h with BDN (10−10 M and 10−9 M) prior to test their ehemotactie response toward recombinant human IL-3 and IL-5.Results Stimulation of BMC from atopies with Dp induced a statistically significant increase in [H]thymidine incorporation (P 〈 0.05); secretion of ehemotactie factors for eosinophils (P 〈 0.001) and the release of IL-3 and IL-5 (P 〈 0.005 and P 〈 0.05 respectively). BDN, at the concentration of 10−8 M, was able to significantly down-regulate T-cell proliferation (P 〈 0.05), the secretion of ehemotactie factors for eosinophils (P 〈 0.001) and the release of IL-3 and IL-5 (P 〈 0.01 and P 〈 0.05 respectively). Similarly, “systemic concentrations” of BDN (10−10 M and 10−9 M) totally inhibited the ehemotactie response of blood eosinophils toward recombinant human IL-3 and IL-5 (P 〈 0.005).Conclusions Concentrations of BDN similar to those obtained in vivo are effective in inhibiting both the release of eosinophils chemotaxins by allergen-activated mononuclear cells and eosinophil locomotion.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2222.1996.tb00592.x
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  • 3
    Electronic Resource
    Electronic Resource
    Effects of “systemic” budesonide concentrations on in vitro allergen-induced activation of blood mononuclear cells isolated from asthmatic patients (1995)
    Oxford, UK : Blackwell Publishing Ltd
    Allergy 50 (1995), S. 0 
    Details
    ISSN: 1398-9995
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Blood levels of inhaled corticosteroids are significantly lower than those measured in the lung, but their concentration could still have anti-inflammatory effects. To determine whether budesonide, at concentrations similar to those obtained in blood after drug inhalation (10 −9 M), could downregulate the allergen-induced activation of mononuclear cells, we studied 21 atopic patients, sensitized to Dermatophagoides pteronyssinus (Der p). On blood mononuclear cells, isolated from these patients, incubated with Der p allergen extract and with or without budesonide, we evaluated: 1) the proliferative response of T cells; 2) the expression of two surface activation markers, the HLA-DR antigens and the interleukin (IL)-2 receptors; and 3) the release of cytokines known to modulate the allergic processes. Allergen-induced T-cell proliferation was associated with increased HLA-DR antigen and IL-2 receptor expression (P 〈 0.001), and with increased release of IL-2, interferon-gamma (IFN-γ), IL-1β, tumor necrosis factor-alpha (TNF-α), and granulocyte/macrophage colony-stimulating factor (GM-CSF). The addition of budesonide at the beginning of the cell cultures induced a dose-dependent inhibition of T-cell proliferation, still significant (P 〈 0.05) at the lowest concentrations tested (10 −9 and 10−10 M). A significant inhibitory effect on T-cell proliferation was also present when budesonide (10 −9 M) was added to the cell cultures 3 or 5 days after the beginning of the cell cultures. In addition, budesonide 10−9 M significantly decreased the expression of IL-2 receptors (P 〈 0.05), but not of HLA-DR antigens, and significantly reduced the release of IL-1β and GM-CSF (JP 〈 0.05), but not of IL-2, IFN-γ, and TNF-α. Thus, the blood concentrations of budesonide, after drug inhalation, may exert some anti-inflammatory effect, downregulating both “local” (through the bronchial circulation) and “systemic” allergen-specific immune reactions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1398-9995.1995.tb01169.x
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  • 4
    Electronic Resource
    Electronic Resource
    Bronchial and Bronchoalveolar Inflammation in Single Early and Dual Responders after Allergen Inhalation Challenge (1997)
    Springer
    Lung 175 (1997), S. 277 -285 
    Details
    ISSN: 1432-1750
    Keywords: Key words: Eosinophils—Asthma—Atopy—Bronchial hyperresponsiveness—Methacholine—Bronchoalveolar lavage—Bronchial lavage—Inflammation.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract. To characterize the cellular inflammation at the bronchial and bronchoalveolar levels, we evaluated 43 patients with asthma who were sensitized to house dust mites. On 2 consecutive days patients underwent methacholine challenge and allergen bronchial challenge. In addition, 6, 24, or 72 h after allergen challenge, fiberoptic bronchoscopy with bronchial lavage (BL) and bronchoalveolar lavage (BAL) was performed. Patients belonging to the 6-h, 24-h, or 72-h group were divided further into two subgroups: those with isolated early response to allergen (LAR−), and those with dual response to allergen (LAR+). The percentage of eosinophils and of epithelial cells in BAL fluid was significantly higher in LAR+ than in LAR− patients in the 6-h group (p 〈 0.05, each comparison), but not 24 or 72 h after (p 〉 0.05, each comparison). Similarly, the proportion of BL eosinophils was also higher in LAR+ than in LAR− patients, both in the 6-h and in the 24-h group (p 〈 0.05, each comparison). In addition, increased proportions of BL neutrophils were present in the LAR+ patients belonging to the 24-h group (p 〈 0.05). Comparing ``proximal'' = BL vs ``distal'' = BAL data, we found a significantly higher proportion of epithelial cells in BL compared with BAL, in both LAR− and LAR+ subjects, either 6, or 24, or 72 h after challenge (p 〈 0.01, each comparison) and increased percentages of BL neutrophils and eosinophils in LAR+ patients (p 〈 0.05, each comparison), but not in LAR− patients, in the 24-h group. The percentages of BL or BAL macrophages and lymphocytes did not differ significantly among the different patient groups. These data indicate that the development of LAR after allergen inhalation challenge is associated with an early recruitment of eosinophils and with epithelial desquamation in the airways. In addition, after allergen challenge epithelial desquamation is more pronounced in the proximal than in the distal airways, independently of the type of bronchial response.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/PL00007574
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