69 research outputs found

    A quantitative method for detection of spliced X-box binding protein-1 (XBP1) mRNA as a measure of endoplasmic reticulum (ER) stress

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    Endoplasmic reticulum (ER) stress is increasingly recognized as an important mechanism in a wide range of diseases including cystic fibrosis, alpha-1 antitrypsin deficiency, Parkinson's and Alzheimer's disease. Therefore, there is an increased need for reliable and quantitative markers for detection of ER stress in human tissues and cells. Accumulation of unfolded or misfolded proteins in the endoplasmic reticulum can cause ER stress, which leads to the activation of the unfolded protein response (UPR). UPR signaling involves splicing of X-box binding protein-1 (XBP1) mRNA, which is frequently used as a marker for ER stress. In most studies, the splicing of the XBP1 mRNA is visualized by gel electrophoresis which is laborious and difficult to quantify. In the present study, we have developed and validated a quantitative real-time RT-PCR method to detect the spliced form of XBP1 mRNA

    Regulation of YKL-40 expression by corticosteroids:effect on pro-inflammatory macrophages in vitro and its modulation in COPD in vivo

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    Macrophages constitute a heterogeneous cell population with pro- (MΦ1) and anti-inflammatory (MΦ2) cells. The soluble chitinase-like-protein YKL-40 is expressed in macrophages and various other cell types, and has been linked to a variety of inflammatory diseases, including COPD. Dexamethasone strongly reduces YKL-40 expression in peripheral blood mononuclear cells (PBMC) in vitro. We hypothesized that: a) YKL-40 is differentially expressed by MΦ1 and MΦ2, b) is decreased by corticosteroids and c) that long-term treatment with inhaled corticosteroids (ICS) affects YKL-40 levels in serum and sputum of COPD patients. Monocytes of healthy subjects were cultured in vitro for 7 days with either GM-CSF or M-CSF (for MΦ1 and MΦ2, respectively) and stimulated for 24 h with LPS, TNFα, or oncostatin M (OSM). MΦ1 and MΦ2 differentiation was assessed by measuring secretion of IL-12p40 and IL-10, respectively. YKL-40 expression in macrophages was measured by quantitative RT-PCR (qPCR) and ELISA; serum and sputum YKL-40 levels were analyzed by ELISA. Pro-inflammatory MΦ1 cells secreted significantly more YKL-40 than MΦ2, which was independent of stimulation with LPS, TNFα or OSM (p < 0.001) and confirmed by qPCR. Dexamethasone dose-dependently and significantly inhibited YKL-40 protein and mRNA levels in MΦ1. Serum YKL-40 levels of COPD patients were significantly higher than sputum YKL-40 levels but were not significantly changed by ICS treatment. YKL-40 secretion from MΦ1 cells is higher than from MΦ2 cells and is unaffected by further stimulation with pro-inflammatory agents. Furthermore, YKL-40 release from cultured monocyte-derived macrophages is inhibited by dexamethasone especially in MΦ1, but ICS treatment did not change YKL-40 serum and sputum levels in COPD. These results indicate that YKL-40 expression could be used as a marker for MΦ1 macrophages in vitro, but not for monitoring the effect of ICS in COPD. ClinicalTrials.gov, registration number: NCT0015884

    A glossary for research on human crowd dynamics

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    This article presents a glossary of terms that are frequently used in research on human crowds. This topic is inherently multidisciplinary as it includes work in and across computer science, engineering, mathematics, physics, psychology and social science, for example. We do not view the glossary presented here as a collection of finalised and formal definitions. Instead, we suggest it is a snapshot of current views and the starting point of an ongoing process that we hope will be useful in providing some guidance on the use of terminology to develop a mutual understanding across disciplines. The glossary was developed collaboratively during a multidisciplinary meeting. We deliberately allow several definitions of terms, to reflect the confluence of disciplines in the field. This also reflects the fact not all contributors necessarily agree with all definitions in this glossary

    Smoking cessation and bronchial epithelial remodelling in COPD: a cross-sectional study

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    <p>Abstract</p> <p>Background</p> <p>Chronic Obstructive Pulmonary Disease (COPD) is associated with bronchial epithelial changes, including squamous cell metaplasia and goblet cell hyperplasia. These features are partially attributed to activation of the epidermal growth factor receptor (EGFR). Whereas smoking cessation reduces respiratory symptoms and lung function decline in COPD, inflammation persists. We determined epithelial proliferation and composition in bronchial biopsies from current and ex-smokers with COPD, and its relation to duration of smoking cessation.</p> <p>Methods</p> <p>114 COPD patients were studied cross-sectionally: 99 males/15 females, age 62 ± 8 years, median 42 pack-years, no corticosteroids, current (n = 72) or ex-smokers (n = 42, median cessation duration 3.5 years), postbronchodilator FEV<sub>1 </sub>63 ± 9% predicted. Squamous cell metaplasia (%), goblet cell (PAS/Alcian Blue<sup>+</sup>) area (%), proliferating (Ki-67<sup>+</sup>) cell numbers (/mm basement membrane), and EGFR expression (%) were measured in intact epithelium of bronchial biopsies.</p> <p>Results</p> <p>Ex-smokers with COPD had significantly less epithelial squamous cell metaplasia, proliferating cell numbers, and a trend towards reduced goblet cell area than current smokers with COPD (p = 0.025, p = 0.001, p = 0.081, respectively), but no significant difference in EGFR expression. Epithelial features were not different between short-term quitters (<3.5 years) and current smokers. Long-term quitters (≥3.5 years) had less goblet cell area than both current smokers and short-term quitters (medians: 7.9% vs. 14.4%, p = 0.005; 7.9% vs. 13.5%, p = 0.008; respectively), and less proliferating cell numbers than current smokers (2.8% vs. 18.6%, p < 0.001).</p> <p>Conclusion</p> <p>Ex-smokers with COPD had less bronchial epithelial remodelling than current smokers, which was only observed after long-term smoking cessation (>3.5 years).</p> <p>Trial registration</p> <p>NCT00158847</p

    Multidrug resistance-associated protein-1 (MRP1) genetic variants, MRP1 protein levels and severity of COPD

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    <p>Abstract</p> <p>Background</p> <p>Multidrug resistance-associated protein-1 (MRP1) protects against oxidative stress and toxic compounds generated by cigarette smoking, which is the main risk factor for chronic obstructive pulmonary disease (COPD). We have previously shown that single nucleotide polymorphisms (SNPs) in <it>MRP1 </it>significantly associate with level of FEV<sub>1 </sub>in two independent population based cohorts. The aim of our study was to assess the associations of <it>MRP1 </it>SNPs with FEV<sub>1 </sub>level, MRP1 protein levels and inflammatory markers in bronchial biopsies and sputum of COPD patients.</p> <p>Methods</p> <p>Five SNPs (rs212093, rs4148382, rs504348, rs4781699, rs35621) in <it>MRP1 </it>were genotyped in 110 COPD patients. The effects of <it>MRP1 </it>SNPs were analyzed using linear regression models.</p> <p>Results</p> <p>One SNP, rs212093 was significantly associated with a higher FEV<sub>1 </sub>level and less airway wall inflammation. Another SNP, rs4148382 was significantly associated with a lower FEV<sub>1 </sub>level, higher number of inflammatory cells in induced sputum and with a higher MRP1 protein level in bronchial biopsies.</p> <p>Conclusions</p> <p>This is the first study linking <it>MRP1 </it>SNPs with lung function and inflammatory markers in COPD patients, suggesting a role of <it>MRP1 </it>SNPs in the severity of COPD in addition to their association with MRP1 protein level in bronchial biopsies.</p

    Ecological campus: Research into a more sustainable TU Delft campus

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    Research into a more sustainable TU Delft campus. This document contains a presentation for an ecologically sustainable campus centre for the TU Delft. The aim of the design was the creation of an attractive study environment, while at the same time strengthening the ecological quality of the surrounding area. The building takes into account the local water system en green infrastructure.ExplorelabArchitectur
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