The nose is an attractive source of airway epithelial cells, particularly in populations in which bronchoscopy may not be possible. However, substituting nasal cells for bronchial epithelial cells in ...the study of airway inflammation depends upon comparability of responses, and evidence for this is lacking. Our objective was to determine whether nasal epithelial cell inflammatory mediator release and receptor expression reflect those of bronchial epithelial cells. Paired cultures of undifferentiated nasal and bronchial epithelial cells were obtained from brushings from 35 subjects, including 5 children. Cells were subject to morphologic and immunocytochemical assessment. Mediator release from resting and cytokine-stimulated cell monolayers was determined, as was cell surface receptor expression. Nasal and bronchial cells had identical epithelial morphology and uniform expression of cytokeratin 19. There were no differences in constitutive expression of CD44, intercellular adhesion molecule-1, alphavbeta3, and alphavbeta5. Despite significantly higher constitutive release of IL-8, IL-6, RANTES (regulated on activation, normal T cell expressed and secreted), and matrix metalloproteinase (MMP)-9 from nasal compared with bronchial cells, the increments in release of all studied mediators in response to stimulation with IL-1beta and TNF-alpha were similar, and there were significant positive correlations between nasal and bronchial cell secretion of IL-6, RANTES, vascular endothelial growth factor, monocyte chemoattractant protein-1, MMP-9, and tissue inhibitor of metalloproteinase-1. Despite differences in absolute mediator levels, the responses of nasal and bronchial epithelial cells to cytokine stimulation were similar, expression of relevant surface receptors was comparable, and there were significant correlations between nasal and bronchial cell mediator release. Therefore, nasal epithelial cultures constitute an accessible surrogate for studying lower airway inflammation.
The first VERITAS telescope Holder, J.; Atkins, R.W.; Badran, H.M. ...
Astroparticle physics,
07/2006, Letnik:
25, Številka:
6
Journal Article
Recenzirano
Odprti dostop
The first atmospheric Cherenkov telescope of VERITAS (the Very Energetic Radiation Imaging Telescope Array System) has been in operation since February 2005. We present here a technical description ...of the instrument and a summary of its performance. The calibration methods are described, along with the results of Monte Carlo simulations of the telescope and comparisons between real and simulated data. The analysis of TeV γ-ray observations of the Crab Nebula, including the reconstructed energy spectrum, is shown to give results consistent with earlier measurements. The telescope is operating as expected and has met or exceeded all design specifications.
1 Department of Clinical Haematology, Aberdeen Royal Infirmary, Aberdeen
2 Department of Medicine and Therapeutics, University of Aberdeen, Aberdeen, UK
Correspondence: M.A. Vickers, Department of ...Medicine and Therapeutics, University of Aberdeen, Aberdeen AB25 2ZD, UK. E-mail: m.a.vickers{at}abdn.ac.uk
Minor CLL-like clones are found in ~3% of healthy individuals. AIHA and ITP are common in CLL and may be causally linked. We investigated the presence of CLL phenotype lymphocytes in 11 cases of primary AIHA, 18 of ITP and 2 of Evans Syndrome, compared with 26 age-matched healthy controls. A population of CLL phenotype was seen in 6/31 patients compared to 1/26 healthy controls ( 2 =3.9; p =0.05). Such clones may be important in the pathogenesis of autoimmune blood disorders.
Key words: autoimmune hemolytic anemia, immune thrombocytopenic purpura, clonal B-cells, CLL-phenotype lymphocytes.
Summary
Background Several second‐generation antihistamines have documented anti‐inflammatory effects which appear independent of H1‐receptor blockade. We investigated the inhibitory effect of ...cetirizine and its active enantiomer levocetirizine on eosinophil transendothelial migration (TEM) through monolayers of normal human dermal microvascular endothelial cells (HMVEC‐d) or human lung microvascular endothelial cells (HMVEC‐l).
Methods HMVEC‐d or HMVEC‐l were grown to confluence on micropore filters in transwells inserted into a 24‐well tissue culture dish. Eosinophils were isolated by density gradient centrifugation and negative immunomagnetic selection. Untreated eosinophils or eosinophils pre‐incubated (30 min at 37 °C) with a concentration range of cetirizine or levocetirizine (10−5 to 10−9 m) were added to the upper chamber of the transwell which was incubated for 60 min at 37 °C. Both spontaneous eosinophil TEM and TEM to 100 ng/mL of human eotaxin in the lower chamber were assessed.
Results Between 8 and 10% of the eosinophils added to the upper chamber underwent spontaneous TEM through HMVEC‐d or HMVEC‐l. The addition of eotaxin to the lower chamber enhanced eosinophil TEM through HMVEC‐d or HMVEC‐l monolayers to over 20%, i.e. an enhanced TEM of approximately 100% in each case. Pre‐incubation of eosinophils with cetirizine or levocetirizine dose‐dependently inhibited eosinophil TEM to eotaxin through both HMVEC‐d or HMVEC‐l with total inhibition of eotaxin‐induced TEM observed at 10−8 m for HMVEC‐d and 10−7 m for HMVEC‐l. Both drugs gave a reduced but significant inhibition of eosinophil TEM at lower concentrations. No concentration of cetirizine or levocetirizine had any significant effect on expression of CD11b, CD18 or CD49d by either resting or eotaxin‐stimulated eosinophils. Furthermore, no effect on spontaneous eosinophil TEM, or eosinophil viability was seen with any concentration of cetirizine or levocetirizine.
Conclusion Levocetirizine inhibits eotaxin‐induced eosinophil TEM through both dermal and lung microvascular endothelial cells suggesting that, like cetirizine, levocetirizine has potential anti‐inflammatory effects.
This study was carried out to investigate the relationship between induced sputum eosinophil apoptosis and clinical severity score, airway obstruction and symptom scores in patients with chronic ...stable asthma. Altogether, 41 chronic stable asthmatic subjects of varying severity defined by Aas score and 17 control subjects underwent spirometry, symptom questionnaire and successful sputum induction. Sputum was processed and cytospins prepared for light microscopy to determine normal and apoptotic eosinophils. Mild asthmatic subjects had a significantly lower percentage sputum eosinophils and a significantly higher eosinophil apoptotic ratio (AR) than moderate or chronic severe asthmatics. Severe asthmatic subjects had a significantly greater age, duration of asthma and sputum eosinophil count x mL(-1) than mild asthmatic subjects. Asthmatic subjects' symptom scores, severity scores and age inversely correlated with AR and the percentage of sputum eosinophils. Baseline forced expiratory volume in one second inversely correlated with percentage sputum eosinophils and positively correlated with AR. The study demonstrates a relationship between reduced sputum eosinophil apoptosis and increased clinical severity of chronic stable asthma, providing additional evidence that eosinophil apoptosis may be important in the resolution of eosinophilic airway inflammation in asthma.
Anti-inflammatory therapy in asthma is reliant on corticosteroids, particularly in their inhaled form. However, steroids are rather non-specific in their actions and they also raise concerns ...regarding compliance and side-effect Issues. Furthermore, a small proportion of patients with asthma fail to respond to oral glucocorticoids even at high doses. This Article will review the role that steroids and membrane receptor ligation play in the induction of eosinophil apoptosis together with the mechanisms by which corticosteroids enhance the disposal of apoptotic eosinophils by both professional and non-professional phagocytes. Eosinophils are thought to be the major pro-inflammatory effector cell in asthma and their persistence in the airways is probably enhanced by the presence of several asthma-relevant cytokines that prolong eosinophil survival by inhibition of apoptosis (interleukin (IL)-3, IL-5, granulocyte-macrophage colony-stimulating factor, IL-9, IL-13, IL-15). In contrast, a number of signals have been described that accelerate apoptosis in human eosinophils including corticosteroids or ligation of membrane receptors (CD95, CD45, CD69). Thus, the load of lung eosinophils in asthmatic disease is likely to be related to a balance in the tIssue microenvironment between pro- and anti-apoptotic signals. Furthermore, removal of apoptotic eosinophils by phagocytosis by alveolar macrophages or bronchial epithelial cells in a specific receptor-mediated way is as important as the process of apoptosis induction. Corticosteroids enhance the recognition and engulfment of apoptotic eosinophils by macrophages or bronchial epithelial cells. Caspases are key intracellular molecules in the control of apoptosis and defects in caspase-induced apoptosis in eosinophils from steroid-resistant individuals may contribute to the molecular mechanisms underlying glucocorticoid insensitivity in these cells. These findings point the way to new and more targeted anti-inflammatory therapy for asthma and may provide important clues for the development of alternative therapies for glucocorticoid resistance.
Background: We previously demonstrated receptor-mediated apoptotic-eosinophil engulfment by human small airway epithelial cells, which may represent a potentially important mechanism in the ...resolution of allergic and asthmatic inflammation. Objective: A549 cells were selected as being representative of alveolar epithelial cells, and their ability to ingest human apoptotic eosinophils was examined in terms of the effects of dexamethasone treatment and the receptor-mediated recognition mechanisms important in this process. Methods: A549 epithelial-cell expression of αvβ3, αvβ5, CD36, and the phosphatidylserine receptor was established by using immunostaining and flow cytometry, and inhibition assays were examined by using the role of these receptors in apoptotic-eosinophil recognition by resting and dexamethasone-treated A549 epithelial cells. Electron microscopy confirmed engulfment of apoptotic eosinophils, and receptor clustering around apoptotic eosinophils was examined by using immunofluorescent labeling. Results: A549 epithelial cells recognized and engulfed apoptotic eosinophils but not freshly isolated cells. Dexamethasone enhanced the number of A549 cells ingesting apoptotic eosinophils and dose dependently increased their capacity for ingestion. The tetrapeptide RGDS significantly inhibited apoptotic-eosinophil uptake by A549 cells, indicating a role for integrins in the recognition process. A549 cells expressed αvβ3, αvβ5, β5, CD36, and the phosphatidylserine receptor, and expression of these receptors was not significantly increased after dexamethasone treatment. Engulfment of apoptotic eosinophils by A549 cells involved αvβ3-, CD36-, αvβ5-, and phosphatidylserine receptor–mediated recognition mechanisms and was associated with the formation of integrin focal adhesion complexes around apoptotic eosinophils. Conclusions: These data further suggest a nonpassive role for airway epithelium in the resolution of eosinophilic inflammation in asthma. (J Allergy Clin Immunol 2001;108:962-9.)
Summary
Background
We have previously demonstrated that human bronchial epithelial cells engulf apoptotic eosinophils.
Objectives
To compare and contrast the phagocytic capabilities of ...monocyte‐derived macrophage and primary airway epithelial cells for apoptotic granulocytes.
Results
Here we compared phagocytosis of human apoptotic eosinophils and neutrophils by small and large airway epithelial cells (SAEC and LAEC) and monocyte‐derived macrophages. Confocal microscopy of F‐actin staining and scanning and transmission electron microscopy revealed phagocytic cup formation around apoptotic eosinophils by airway epithelial cells (AEC) membranes with evidence of their digestion. Resting and cytokine‐stimulated AEC did not recognize and ingest apoptotic neutrophils. The latter were phagocytosed by macrophages that exhibited greater ingestion of and higher capacity for, apoptotic eosinophils over apoptotic neutrophils. Cytochalasin D completely abolished uptake of apoptotic eosinophils by SAEC, LAEC or macrophage monolayers. Ligation of epithelial cell CD44 receptors for 24 h increased phagocytosis of apoptotic eosinophils by SAEC and LAEC with a potency comparable with that of IL‐1. Phagocytosis was a specific receptor‐mediated process involving integrin‐ (αvβ3, αvβ5, CD36), phosphatidylserine receptor‐ and lectin‐dependent mechanisms. No significant differences were observed in avarice for apoptotic eosinophils by SAEC or LAEC either resting, CD44 monoclonal antibodies‐ or cytokine‐ stimulated, or in their usage and expression of recognition receptors.
Conclusion
These findings further suggest and define an important role for the bronchial epithelium in the selective removal of apoptotic eosinophils from the airways in asthma.
We present observations of the dwarf galaxies Draco and Ursa Minor, the Local Group galaxies M32 and M33, and the globular cluster M15 conducted with the Whipple 10 m gamma-ray telescope to search ...for the gamma-ray signature of self-annihilating weakly interacting massive particles (WIMPs), which may constitute astrophysical dark matter (DM). We review the motivations for selecting these sources based on their unique astrophysical environments and report the results of the data analysis that produced upper limits on the excess rate of gamma rays for each source. We consider models for the DM distribution in each source based on the available observational constraints and discuss possible scenarios for the enhancement of the gamma-ray luminosity. Limits on the thermally averaged product of the total self- annihilation cross section and velocity of the WIMP, image, are derived using conservative estimates for the magnitude of the astrophysical contribution to the gamma-ray flux. Although these limits do not constrain predictions from the currently favored theoretical models of supersymmetry (SUSY), future observations with VERITAS will probe a larger region of the WIMP parameter phase space, image, and WIMP particle mass.
Galaxy clusters might be sources of TeV gamma rays emitted by high-energy protons and electrons accelerated by large-scale structure formation shocks, galactic winds, or active galactic nuclei. ...Furthermore, gamma rays may be produced in dark matter particle annihilation processes at the cluster cores. We report on observations of the galaxy clusters Perseus and A2029 using the 10 m Whipple Cerenkov telescope during the 2003-2004 and 2004-2005 observing seasons. We apply a two-dimensional analysis technique to scrutinize the clusters for TeV emission. In this paper we first determine flux upper limits on TeV gamma-ray emission from point sources within the clusters. Second, we derive upper limits on the extended cluster emission. We subsequently compare the flux upper limits with EGRET upper limits at 100 MeV and theoretical models. Assuming that the gamma-ray surface brightness profile mimics that of the thermal X-ray emission and that the spectrum of cluster cosmic rays extends all the way from thermal energies to multi-TeV energies with a differential spectral index of-2.1, our results imply that the cosmic-ray proton energy density is less than 7.9% of the thermal energy density for the Perseus Cluster.
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