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  • 1
    Digitale Medien
    Digitale Medien
    Antioxidant activity of topically applied lycopene (2004)
    Oxford, UK : Blackwell Publishing Ltd.
    Journal of the European Academy of Dermatology and Venereology 18 (2004), S. 0 
    Details
    ISSN: 1468-3083
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Background  Ultraviolet (UV) rays cause depletion of the antioxidant substances contained in the epidermis. This is the rationale for the use of topical antioxidant substances.Methods  We studied the protective activity against UV radiation of a product based on lycopene and a product containing a mixture of vitamins E and C. Photostimulation was applied with a solar simulator and the cutaneous response was evaluated instrumentally.Results  The lycopene-based product had a much greater protective ability than the product containing the mixture of vitamins.Conclusions  Lycopene has suitable characteristics to be used successfully in the prevention of cutaneous damage by free radicals. Its antioxidant ability is probably due to its high reductive power.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1111/j.1468-3083.2004.00850.x
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  • 2
    Digitale Medien
    Digitale Medien
    Semiclassical law for the apparent viscosity of non-Newtonian fluids: An analogy between thixotropy of fluids and sintering of solids (2000)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 113 (2000), S. 3434-3440 
    Details
    ISSN: 1089-7690
    Quelle: AIP Digital Archive
    Thema: Physik , Chemie und Pharmazie
    Notizen: A theory is presented to describe the apparent viscosity of thixotropic fluids as a function of the rate of shear. It represents the extension of a semiclassical approach that was previously formulated to deal with matter densification phenomena in solids starting from the state equation of the medium. In this context, the Debye expression for the Helmholtz free energy has been provided with a density of vibrational modes that accounts for atomic and microstructural changes occurring at the frequency scale of momentum transport (see diffusion). Working out the steady-state condition with respect to time gives an equation relating reduced apparent viscosity (η˜) and shear rate (γ˜) through the temperature value (θ*) that is energetically equivalent to the medium vibrations implied. Viscosity also turns out to depend on the Debye temperature θD (see cursive-phi∼θ*/θD) and an equivalent Gruneisen parameter (μ), defined with respect to viscosity variations. Increasing cursive-phi in pseudoplastic and dilatant media, respectively, increases and decreases η˜, which always increases with increasing μ. The analogy between dilatancy/sintering and pseudoplasticity/desintering is suggested, and a correspondence between matter and momentum transports is traced on the basis of the phononic spectrum properties. Application to experimental measurements are presented and discussed for aqueous monodispersions of polystyrene (PS) latex particles, aqueous glycerol solutions of partially hydrolyzed polyacrylamide (PHPAA) at different sodium chloride (NaCl) concentrations, polymethylmethacrylate (PMMA) suspensions in dioctylphthalate (DOP), and for a molecularly thin liquid film of octamethylciclotetrasiloxane (OMCTS). Best fit coefficients for cursive-phi and μ have been constrained to the Debye temperature and the effective low-shear viscosity (η0) according to their dependences upon the suspended volume fraction (φ), θD=θD(φ), and η0=η0(φ), and the agreement with experimental data is quite satisfactory in all cases here examined. It is then suggested that the viscous character of a liquid can be described in terms of a coupling between Brownian diffusion and phonon wave motion. © 2000 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.1287334
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  • 3
    Digitale Medien
    Digitale Medien
    Microkinetic analysis of methane dimerization reaction (1991)
    s.l. : American Chemical Society
    Industrial & engineering chemistry research 30 (1991), S. 2114-2123 
    Details
    ISSN: 1520-5045
    Quelle: ACS Legacy Archives
    Thema: Chemie und Pharmazie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1021/ie00057a009
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  • 4
    Digitale Medien
    Digitale Medien
    Hydration pressure induced by solid surface dissolution in ion adsorption from aqueous media: Role of structural force in proton/oxydryle isotherms of α-tricalcium phosphate/water systems (1997)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 107 (1997), S. 9214-9220 
    Details
    ISSN: 1089-7690
    Quelle: AIP Digital Archive
    Thema: Physik , Chemie und Pharmazie
    Notizen: By experimental titration measurements—which were conducted on α-Ca3(PO4)2/H2O (l) dispersions to follow H+/OH−adsorption from aqueous solution onto the solid surface—an unexpected shape transition (S→L, in the Giles classification) was observed in the adsorption isotherm when the solid mass concentration reached the (critical) value cNc=0.54±0.01. This phenomenon did not occur when acid/basic aqueous solutions containing Ca2+ and PO43−ions were employed as titrants. Formulation and application of an Ising-based model suggested that solid solubility phenomena can influence the adsorption mechanism by inducing an additional (inhomogeneous) hydration pressure, which seems to be related to interfacial order perturbations produced by the surface dissolution. In the end, the predicted critical solid mass concentration was cNc&dbigwig;=0.53±0.01and, correspondingly, extrapolated values from the model of water correlation length were in agreement with the current literature concerning TCP (tricalcium phosphate) wettability and inhomogeneous structural forces. © 1997 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.475213
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  • 5
    Digitale Medien
    Digitale Medien
    Airway eosinophilia and expression of interleukin-5 protein in asthma and in exacerbations of chronic bronchitis (1996)
    Oxford, UK : Blackwell Publishing Ltd
    Clinical & experimental allergy 26 (1996), S. 0 
    Details
    ISSN: 1365-2222
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Background An increased nutnber of eosinophils in the bronchial mucosa has been demonstrated both in asthma and in exacerbations of chronic bronchitis. Oiyective To investigate whether the airway eosinophilia present in asthma and in chronic bronchitis during exacerbations is associated with interleukin (IL)-5 protein expression in the bronchial mucosa.Methods We obtained bronchial biopsies in 18 subjects with asthma (four intrinsic, seven extrinsic and seven occupational) and in II subjects with chronic bronchitis examined during an exacerbation. The findings were compared wilh those of bronchial biopsies from 10 subjects with chronic bronchitis examined under baseline conditions and from seven normal subjects, taken as controls. By immunohistochemistry, we assessed the expression of IL-5 protein and the number of eosinophils (EG2), mast cells ftryptase), and T-lymphocytes (CD3) in the submucosa.Results As compared with controls, the number of eosinophils was increased to a similar degree in both asthma (P 〈 0.001) and in exacerbations of ehronic bronchitis (P 〈 0.001). whereas the number of I L-5 immunopositive cells was increased significantly only in asthma (P 〈 0.01). No diflerences were observed in the number of tnast cells and T-lymphocytes between the four groups of subjects examined. Conciusions This study shows that the degree of airway eosinophilia is similar in asthma and in exacerbations of ehronic bronchitis, but only in asthma is it associated with an increased expression of I L-5 protein in the bronchial tnucosa.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1111/j.1365-2222.1996.tb00606.x
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  • 6
    Digitale Medien
    Digitale Medien
    Sputum eosinophilia after asthmatic responses induced by isocyanates in sensitized subjects (1994)
    Oxford, UK : Blackwell Publishing Ltd
    Clinical & experimental allergy 24 (1994), S. 0 
    Details
    ISSN: 1365-2222
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: To assess the nature and the time–course of the cellular component of airway inflammation induced by isocyanates, we examined nine subjects with occupational asthma induced by toluene– or methylene diphenyl–diisocyanate (TDI, MDI) and four control subjects never exposed to isocyanates. Sputum was induced by inhalation of ultrasonically nebulized hypertonic saline (3–4% NaCl) before and 8, 24, 48 h after inhalation challenge with TDI or MDI. Expectorated samples were incubated with dithiothreitol, washed and cytocentrifuged. Differential cell counts were obtained on slides stained with May–Grünwald–Giemsa. Metachromatic cells (mast cells and basophils) were counted on slides stained with toluidine blue at pH 0.1. One occupational asthmatic exhibited a dual reaction to TDI, two exhibited a single early asthmatic reaction to M DI, six exhibited a late asthmatic reaction to TDI (n= 5) or M DI (n= 1), whereas no reactions were observed in control subjects after TDI challenge. In sensitized subjects eosinophils increased from a median value (interquartile range) of 5 (15)% before challenge to 29 (29)% (P= 0.014) and to 30 (31)% (P= 0.031) 8 and 24 h after TDI/MDI challenges, respectively. Sputum eosinophilia was observed both in early and late reactors and declined to near to baseline values 48 hr after challenge. Percentages of eosinophils in control subjects did not exceed 7% during the study. There was a significant correlation between the increase in eosinophil counts and the magnitude of the bronchoconstriction expressed as the area of FEV1 response to isocyanate challenge (rank correlation coefficient = 0–71, P= 0.014). No significant changes in sputum neutrophils, macrophages, lymphocytes and mast cells were detected. The results indicate that isocyanate–induced asthmatic responses are associated with influx of eosinophils in airway secretion lasting up to 24 h.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1111/j.1365-2222.1994.tb00913.x
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  • 7
    Digitale Medien
    Digitale Medien
    Decreased T lymphocyte infiltration in bronchial biopsies of subjects with severe chronic obstructive pulmonary disease (2001)
    Oxford, UK : Blackwell Science, Ltd
    Clinical & experimental allergy 31 (2001), S. 0 
    Details
    ISSN: 1365-2222
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Background Studies on the inflammatory process in the large airways of patients with mild/moderate COPD have shown a prevalent T lymphocyte and macrophage infiltration of the bronchial mucosa. However, bronchial inflammation in more severe disease has not been extensively studied.Objective The aim of the present study was to characterize the lymphocyte infiltration in the bronchial mucosa of subjects with severe, compared to mild, COPD, and to examine the relationship between airflow limitation and T lymphocyte numbers in the bronchial mucosa.Methods We examined bronchial biopsies obtained from nine smokers with severe airflow limitation, nine smokers with mild/moderate airflow limitation and 14 smokers with normal lung function. Immunohistochemical methods on cryostat sections were used to assess the number of CD3+, CD4+, CD8+ cells and the number of CD3+ cells coexpressing the chemokine receptor CCR5 (CCR5+CD3+) in the subepithelium.Results Subjects with severe COPD had lower numbers of CD3+, CD8+ and CCR5+CD3+ cells than mild/moderate COPD (P 〈 0.012, P 〈 0.02 and P 〈 0.02, respectively) and control smokers (P 〈 0.015, P 〈 0.005 and P 〈 0.015, respectively). In subjects with airflow limitation the number of CD3+ and CD8+ cells was inversely correlated with the degree of airway obstruction (r = 0.59, P 〈 0.015 and r = 0.52, P 〈 0.032, respectively).Conclusions Bronchial inflammation in severe COPD is characterized by lower numbers of CD3+ and CD8+ cells and decreased numbers of CD3+ cells coexpressing the chemokine receptor CCR5. T lymphocyte infiltration is inversely correlated with the degree of airflow limitation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1046/j.1365-2222.2001.01098.x
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  • 8
    Digitale Medien
    Digitale Medien
    Cellular and molecular mechanisms in chronic obstructive pulmonary disease: an overview (2004)
    Oxford, UK : Blackwell Science Ltd
    Clinical & experimental allergy 34 (2004), S. 0 
    Details
    ISSN: 1365-2222
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: In the last decade, the analysis of bronchial biopsies and lung parenchyma obtained from chronic obstructive pulmonary disease (COPD) patients compared with those from smokers with normal lung function and non-smokers has provided new insights on the role of the different inflammatory and structural cells, their signalling pathways and mediators, contributing to a better knowledge of the pathogenesis of COPD. This review summarizes and discusses the lung pathology of COPD patients with emphasis on inflammatory cell phenotypes that predominate in different clinical conditions. In bronchial biopsies, a cascade of events takes place during progression from mild-to-severe disease. T lymphocytes, particularly CD8+ cells and macrophages are the prevalent inflammatory cells in the lung of healthy smokers and patients with mild COPD, while total and activated neutrophils predominate in severe COPD. The number of CD4+, CD8+ cells and macrophages expressing nuclear factor-kappa B (NF-κB), STAT-4 and IFN-γ proteins as well as endothelial adhesion molecule-1 in endothelium is increased in mild/moderate disease. In contrast, activated neutrophils (MPO+ cells) and increased nitrotyrosine immunoreactivity develops in severe COPD. In bronchial biopsies obtained during COPD exacerbations, some studies have shown an increased T cell and granulocyte infiltration. Regular treatment with high doses of inhaled glucocorticoids does not significantly change the number of inflammatory cells in bronchial biopsies from patients with moderate COPD. The profile in lung parenchyma is similar to bronchial biopsies. ‘Healthy’ smokers and mild/moderate diseased patients show increased T lymphocyte infiltration in the peripheral airways. Pulmonary emphysema is associated with a general increase of inflammatory cells in the alveolar septa. The molecular mechanisms driving the lymphocyte and neutrophilic prevalence in mild and severe disease, respectively, needs to be extensively studied. Up-regulation of pro-inflammatory transcription factors NF-κB and STAT-4 in mild, activated epithelial and endothelial cells in the more severe disease may contribute to this differential prevalence of infiltrating cells.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1111/j.1365-2222.2004.02030.x
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  • 9
    Digitale Medien
    Digitale Medien
    Proliferation and inflammation in bronchial epithelium after allergen in atopic asthmatics (2003)
    Oxford, UK : Blackwell Science Ltd
    Clinical & experimental allergy 33 (2003), S. 0 
    Details
    ISSN: 1365-2222
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Background The mechanisms that regulate epithelial integrity and repair in asthma are poorly understood. We hypothesized that allergen exposure could alter epithelial inflammation, damage and proliferation in atopic asthma.Objective We studied epithelial cell infiltration, shedding, expression of the proliferation marker Ki-67 and the epithelial cell–cell adhesion molecules Ep-CAM and E-cadherin in bronchial biopsies of 10 atopic mild asthmatics 48 h after experimental diluent (D) and allergen (A) challenge in a cross-over design.Methods Epithelial shedding, expressed as percentage of not intact epithelium, Ki-67+, eosinophil/EG-2+, CD4+ and CD8+ cells were quantified by image analysis in bronchial epithelium, and adhesion molecules were analysed semi-quantitatively.Results Epithelial shedding was not altered by A (D: 88.1±3.1% vs. A: 89.2±3.7%; P=0.63). The numbers of Ki-67+ epithelial (D: 10.2±0.2 vs. A: 19.9±0.3 cells/mm; P=0.03), EG-2+ (D: 4.3±0.5 vs. A: 27±0.3 cells/mm; P=0.04) and CD4+ cells (D: 1.7±1.2 vs. A: 12.3±0.6 cells/mm; P=0.04) were significantly increased after A, whilst CD8+ numbers were not significantly changed (P〉0.05). E-cadherin and Ep-CAM epithelial staining showed a similar intensity after D and A (P〉0.05). We found a positive correlation between EG-2+ and Ki-67+ cells in the epithelium (Rs: 0.63; P=0.02).Conclusion Our study indicates that allergen challenge increases epithelial proliferation in conjunction with inflammation at 2 days after exposure. This favours the hypothesis that long-lasting epithelial restitution is involved in the pathogenesis of asthma.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1046/j.1365-2222.2003.01686.x
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  • 10
    Digitale Medien
    Digitale Medien
    Effects of Ultraviolet Irradiation on the Cell Cycle (1994)
    Oxford, UK : Blackwell Publishing Ltd
    Periodontology 2000 7 (1994), S. 0 
    Details
    ISSN: 1600-0757
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Cultured mouse Cloudman melanoma cells, EMT6 breast carcinoma cells, and 3T3 fibroblasts all accumulated in the G2/M phase of the cell cycle when exposed to UVB radiation. The effects of UVB were maximal at 20–30 mJ/cm2 for all three cell lines, and could be observed by flow cytometry as early as 12 hr post irradiation. It has been known since the mid-1970s that MSH receptor binding activity is highest on Cloudman melanoma cells when they are in the G2/M phase of their cycle. Here we show that either UVB irradiation or synchronization of Cloudman cells with colchicine results in a stimulation of MSH binding within 24 hr following treatment, a time when both treatments have resulted in accumulation of cells in the G2/M phase of the cycle. Furthermore, the two treatments performed together on the melanoma cells stimulated MSH receptor activity to the same extent as either treatment performed separately, suggesting that each may be influencing MSH receptor activity solely through a G2/M accumulation of cells. Together, these results raise the possibility that an increase in the number of cells in the G2 phase of the cell cycle is a generalized cellular response to injury, such as UV irradiation. However, in the case of pigment cells this response includes a mechanism for increasing melanin formation, i.e., increased MSH receptor activity. Should this be the case, similar G2/M “injury responses” of other cell types might be expected, consistent with their differentiated phenotypes.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1111/j.1600-0749.1994.tb00634.x
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