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  • 1
    Electronic Resource
    Electronic Resource
    Cysteinyl leukotrienes induce human eosinophil locomotion and adhesion molecule expression via a CysLT1 receptor-mediated mechanism (2002)
    Oxford, UK : Blackwell Science Ltd
    Clinical & experimental allergy 32 (2002), S. 0 
    Details
    ISSN: 1365-2222
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Background The mechanisms involved in eosinophil recruitment by cysteinyl-leukotrienes (CysLTs) remain to be defined.Objective We investigated whether CysLTs LTC4, LTD4 and LTE4 could directly stimulate in vitro adhesion molecule expression and cell locomotion of blood eosinophils from atopic asthmatic donors. Methods Mab staining and FACS analysis were used to evaluate Mac-1 and LFA-1 expression on eosinophils before and after CysLTs stimulation. Eosinophil locomotion was tested using a 48-well Boyden microchamber. Results CysLTs, at the concentrations of 1 and 10 nM, were able to significantly up-regulate Mac-1 expression (P 〈 0.05, each comparison) but not LFA-1 expression (P 〉 0.05, each comparison). A dose-dependent, eosinophil chemotaxis was also induced by LTC4, LTD4 and LTE4 (0.1–10 nM) (P 〈 0.01, each comparison). Montelukast (0.01 nM to 10 nM), a specific CysLT1 receptor antagonist, significantly down-regulated LTC4, LTD4 and LTE4-induced Mac-1 expression (P 〈 0.01, each comparison) and the CysLT-induced eosinophil migration (P 〈 0.01, each comparison). In contrast, montelukast did not affect Mac-1 expression or cell migration when eosinophils were stimulated by the ‘non-specific activators’, such as fMLP or C5a (P 〉 0.05, each comparison).Conclusion These data demonstrate that CysLTs are active in vitro in directly up-regulating human eosinophil functions involved in eosinophil recruitment. The down-regulation of Mac-1 expression and eosinophil chemotaxis by the potent and selective CysLT1 receptor antagonist montelukast indicated the specificity of the LTC4-, LTD4- and LTE4-induced response.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-2222.2002.01384.x
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  • 2
    Electronic Resource
    Electronic Resource
    UV-B radiation causes early ripening and reduction in size of fruits in two lines of tomato (Lycopersicon esculentum Mill.) (1999)
    Oxford, UK : Blackwell Science Ltd
    Global change biology 5 (1999), S. 0 
    Details
    ISSN: 1365-2486
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Geography
    Notes: An open-air experiment was performed in Pistoia (Italy) to investigate the possible protective role played by different contents of UV-B absorbing compounds to realistic UV-B supplementation and to study its effect on plant fruit production. A mutant line and its normal counterpart of Lycopersicon esculentum Mill, which differ in the content of UV-B absorbing compounds, were used. Additional UV-B radiation in the field was supplied to simulate a 20% stratospheric ozone depletion. Two groups of plants were grown: ‘control’, where plants received only natural solar UV-B radiation, and ‘UV-B’ treatment, where plants were grown under supplemental UV-B. The results of the experiment showed that the content of UV-B absorbing compounds of treated plants did not differ from that of the control in both lines. This indicates that natural sunlight, in Mediterranean areas, is saturating for synthesis of these compounds also in plants with normal content of UV-B absorbing compounds. Consequently, plants are not able to produce significant additional amounts of them, in response to a realistic UV-B supplementation, in order to protect the plant from additional UV-B radiation. No different responses to the UV-B supplementation were found between the two lines. The most significant UV-B effect was an earlier reddening of fruits in comparison with the ‘control’ accompanied by a reduction in the size of mature fruits. No significant effects of UV-B treatment were observed in biomass accumulation, leaf ontogeny, flowering or productivity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-2486.1999.00258.x
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  • 3
    Electronic Resource
    Electronic Resource
    In allergic asthma experimental exposure to allergens is associated with depletion of blood eosinophils overexpressing LFA-1 (2002)
    Oxford, UK : Munksgaard International Publishers
    Allergy 57 (2002), S. 0 
    Details
    ISSN: 1398-9995
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Background: In atopic individuals, exposure to allergens is followed by recruitment of blood eosinophils in the target tissue. We investigated whether allergen inhalation challenge could result in depletion of blood eosinophils overexpressing adhesion molecules involved in eosinophil migration.Methods: Blood eosinophils were isolated from seven atopic asthmatic patients and seven control subjects and the “at baseline” expression of lymphocyte function-associated antigen-1 (LFA-1), macrophage antigen-1 (Mac-1) and very late antigen-4 (VLA-4) was assessed by monoclonal antibody staining and flow cytometry analysis. Asthmatic patients underwent allergen challenge and the expression of LFA-1, Mac-1 and VLA-4 by blood eosinophils was again evaluated 3 h and 24 h after allergen challenge.Results: As compared to controls, eosinophils from atopics showed at baseline enhanced LFA-1 expression (P=0.0012), but similar Mac-1 or VLA-4 expression (P 〉 0.1, each comparison). In atopics, the percentage and absolute number of blood eosinophils were significantly decreased 3 h after allergen challenge (P=0.001 and P=0.022, respectively) but returned to similar values to prechallenge values after an additional 21 h (P 〉 0.1). Allergen challenge was also followed by a significant decrease in LFA-1 expression by eosinophils, at 3 h (P=0.002) and at 24 h (P=0.038), while no changes in Mac-1 and VLA-4 were observed. A significant correlation between postchallenge decrease in LFA-1 expression and in blood eosinophilia, both expressed as percentage (r=0.88; P 〈 0.01) or absolute number (r=0.87; P 〈 0.01) was demonstrated at 3 h (r=0.88; P 〈 0.01) but not at 24 h (r=0.64, P 〉 0.05 and r=0.11; P 〉 0.05, respectively).Conclusion: In allergic asthma, an early recruitment of blood eosinophils overexpressing LFA-1 occurs in the first hours after allergen challenge.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1034/j.1398-9995.2002.23826.x
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  • 4
    Electronic Resource
    Electronic Resource
    Nasal inflammation and bronchial reactivity to methacholine in atopic children with respiratory symptoms (2003)
    Oxford, UK : Munksgaard International Publishers
    Allergy 58 (2003), S. 0 
    Details
    ISSN: 1398-9995
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Background: In atopic subjects, dysfunctions of the upper and lower airways frequently coexist and allergic rhinitis seems to constitute a risk factor for the occurrence of asthma in predisposed individuals.Aim of the study: To evaluate whether in atopic subjects nasal inflammation could reflect changes in respiratory functions, 11 allergic children, sensitized to house dust mites (HDM), with rhinoconjunctivitis and asthma and 10 nonatopic controls (ctrs) were studied.Methods: All subjects underwent nasal brushing to detect percentages of nasal eosinophils (Eos %) and intercellular adhesion molecule-1 (ICAM-1) expression by nasal epithelial cells. In the same day pulmonary function tests, i.e. forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), forced expiratory flows at 25–75% of the vital capacity (FEF25−75%) and methacholine (MCh) bronchial inhalation challenge were also evaluated.Results: Pulmonary function parameters were not significantly different in allergic children and in ctrs (P 〉 0.05), while a significant increase in bronchial reactivity to MCh, expressed as Pd20 MCh, was detected in the former population (P 〈 0.05). As compared with ctrs, allergic children showed elevated Eos % and ICAM-1 expression (P 〈 0.05). When nasal inflammation and pulmonary function parameters were compared, a significant correlation was found between nasal Eos % and bronchial reactivity to MCh (P = 0.002).Conclusions: These data support the concept of significant links between upper and lower respiratory tract involvement in atopic children sensitized to HDM.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1034/j.1398-9995.2003.00286.x
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  • 5
    Electronic Resource
    Electronic Resource
    Morphological and physiological responses of bean plants to supplemental UV radiation in a Mediterranean climate (1997)
    Springer
    Plant ecology 128 (1997), S. 127-136 
    Details
    ISSN: 1573-5052
    Keywords: Bean ; Field experiment ; Plant growth ; Stratospheric ozone depletion ; UV-A radiation ; UV-B radiation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract During the last few decades many experiments have been performed to evaluate the responses of plants to enhanced solar UV-B radiation (280–320 nm) that may occur because of stratospheric ozone depletion; most of them were performed in controlled environment conditions where plants were exposed to low photosynthetically active radiation (PAR) levels and high UV-B irradiance. Since environmental radiative regimes can play a role in the response of plants to UV-B enhancement, it appears doubtful whether it is valid to extrapolate the results from these experiments to plants grown in natural conditions. The objective of this work was to evaluate the effects on physiology and morphology of a bean (Phaseolus vulgaris L.) cultivar Nano Bobis, exposed to supplemental UV radiation in the open-air. UV-B radiation was supplied by fluorescent lamps to simulate a 20% stratospheric ozone reduction. Three groups of plants were grown: control (no supplemental UV), UV-A treatment (supplementation in the UV-A band) and UV-B treatment (supplemental UV-B and UV-A radiation). Each group was replicated three times. After 33 days of treatment plants grown under UV-B treatment had lower biomass, leaf area and reduced leaf elongation compared to UV-A treatment. No significant differences were detected in photosynthetic parameters, photosynthetic pigments and UV-B absorbing compounds among the three groups of plants. However, plants exposed to UV-A treatment showed a sort of 'stimulation' of their growth when compared to the control. The results of this experiment showed that plants may be sensitive to UV-A radiation, thus it is difficult to evaluate the specific effects of UV-B (280–320 nm) radiation from fluorescent lamps and it is important to choose the appropriate control. Environmental conditions strongly affect plant response to UV radiation so further field studies are necessary to assess the interaction between UV-B exposure and meteorological variability.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009702729514
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