63 research outputs found
Soluble CD200 Correlates With Interleukin-6 Levels in Sera of COPD Patients: Potential Implication of the CD200/CD200R Axis in the Disease Course
BACKGROUND: COPD represents a multifactorial lung disorder with high morbidity and mortality. Despite intensive research concerning the underlying disease mechanisms, the involvement of the CD200/CD200R axis in supporting or preventing the onset of COPD has not yet been addressed. Since the CD200/CD200R axis is crucially implicated in the maintenance of pulmonary immune homeostasis, we hypothesized that it might be involved in controlling the onset of COPD. METHODS: To address this, we analyzed the serum samples from COPD patients and normal controls for soluble (s) CD200 and correlated the data to COPD-relevant clinical parameters. In addition, basic studies were conducted in CD200-deficient and wild-type mice in which COPD-like inflammation was induced with elastase/LPS followed by lung and serum component analysis. RESULTS: We observed a positive correlation between serum sCD200 and IL-6 levels as well as a trend toward a negative correlation of sCD200 with vitamin D3 in COPD patients. Further investigations in mice revealed that despite elevated serum concentration of MMP-9 in CD200KO mice, the early onset of COPD-like lung inflammation was similar in CD200-deficient and wild-type animals in terms of immune cell infiltration, emphysematous changes, and mucus overproduction. CONCLUSIONS: While our murine studies suggest that the co-inhibitory molecule CD200 does not appear to play a prominent role in the early onset of COPD-like features, correlation of sCD200 serum levels with COPD-related parameters in humans with established disease revealed that the CD200/CD200R axis may be mechanistically linked to the disease course in COPD patients
The influences of moisture content variation, number and width of gaps on the withdrawal resistance of self tapping screws inserted in cross laminated timber
A large experimental campaign comprised of 470 withdrawal tests was carried out, aiming to quantify the withdrawal resistance of self-tapping screws (STS) inserted in the side face of cross laminated timber (CLT) elements. In order to deeply understand the âCLT-STSâ composite model, the experimental tests considered two main parameters: (i) simple and cyclic changes on moisture content (MC) and (ii) number and width of gaps. Regarding (i), three individual groups of test specimens were stabilized with 8%, 12% and 18% of moisture content and one group was submitted to a six month RH cycle (between 30% and 90% RH). Concerning (ii), different test configurations with 0 (REF), 1, 2 and 3 gaps, and widths equal to 0mm (GAP0) or 4mm (GAP4), were tested. The influences of MC and number of gaps were modeled by means of least square method. Moreover, a revision of a prediction model developed by Uibel and BlaĂ (2007) was proposed.
The main findings of the experimental campaign were: the decrease of withdrawal resistance for specimens tested with MC=18% in most configurations; the unexpected increase of withdrawal resistance as the number of gaps with 0mm increased; and, the surprising increase of withdrawal resistance for REF specimens submitted to the RH cycle.The development of the present work was possible only thanks to the financial support of the
391 Portuguese Science Foundation (Fundação de CiĂȘncia e Tecnologia, FCT), through PhD grant SFRH / BD17392 / 79972 / 2011. Further, the valuable partnerships with the Institute of Timber Engineering and Wood393 Technology, at Graz University of Technology (Austria), and Rusticasa are gratefully acknowledged
The Role of Alveolar Epithelial Cells in Initiating and Shaping Pulmonary Immune Responses: Communication between Innate and Adaptive Immune Systems
Macrophages and dendritic cells have been recognized as key players in the defense against mycobacterial infection. However, more recently, other cells in the lungs such as alveolar epithelial cells (AEC) have been found to play important roles in the defense and pathogenesis of infection. In the present study we first compared AEC with pulmonary macrophages (PuM) isolated from mice in their ability to internalize and control Bacillus Calmette-Guérin (BCG) growth and their capacity as APCs. AEC were able to internalize and control bacterial growth as well as present antigen to primed T cells. Secondly, we compared both cell types in their capacity to secrete cytokines and chemokines upon stimulation with various molecules including mycobacterial products. Activated PuM and AEC displayed different patterns of secretion. Finally, we analyzed the profile of response of AEC to diverse stimuli. AEC responded to both microbial and internal stimuli exemplified by TLR ligands and IFNs, respectively. The response included synthesis by AEC of several factors, known to have various effects in other cells. Interestingly, TNF could stimulate the production of CCL2/MCP-1. Since MCP-1 plays a role in the recruitment of monocytes and macrophages to sites of infection and macrophages are the main producers of TNF, we speculate that both cell types can stimulate each other. Also, another cell-cell interaction was suggested when IFNs (produced mainly by lymphocytes) were able to induce expression of chemokines (IP-10 and RANTES) by AEC involved in the recruitment of circulating lymphocytes to areas of injury, inflammation, or viral infection. In the current paper we confirm previous data on the capacity of AEC regarding internalization of mycobacteria and their role as APC, and extend the knowledge of AEC as a multifunctional cell type by assessing the secretion of a broad array of factors in response to several different types of stimuli
The effector T cell response to influenza infection
Influenza virus infection induces a potent initial innate immune response, which serves to limit the extent of viral replication and virus spread. However, efficient (and eventual) viral clearance within the respiratory tract requires the subsequent activation, rapid proliferation, recruitment, and expression of effector activities by the adaptive immune system, consisting of antibody producing B cells and influenza-specific T lymphocytes with diverse functions. The ensuing effector activities of these T lymphocytes ultimately determine (along with antibodies) the capacity of the host to eliminate the viruses and the extent of tissue damage. In this review, we describe this effector T cell response to influenza virus infection. Based on information largely obtained in experimental settings (i.e., murine models), we will illustrate the factors regulating the induction of adaptive immune T cell responses to influenza, the effector activities displayed by these activated T cells, the mechanisms underlying the expression of these effector mechanisms, and the control of the activation/differentiation of these T cells, in situ, in the infected lungs
Symulacja ukĆadalnoĆci kompozytowych pĂłĆproduktĂłw tekstylnych o gradientowej charakterystyce ze zmiennym splotem tkanin
The design of 3D component parts made of fiber-reinforced composites for load bearing applications demands a load oriented fiber alignement. During the draping of the textile an undefined displacement of fibers up to wrinkle formation occurs. One possibility to influence fiber orientation during draping is the utilisation of the characteristics of different fabric weaves. By combining different weaves in a textile reinforcing fabric adjusted to the component part, gradient-drapability can be developed. This means that local zones with a high structural stability and zones with high drapability can be created in a textile semi-finished product. The design of these zones is done by simulation to produce a fabric structure suitable for the component part. For that purpose, material models for draping simulation developed at the Institute of Textile Machinery and High Performance Material Technology (ITM) are being improved. The material behaviour of each type of fabric weave is analysed and transformed to the simulation model. With the simulations performed the influence of the combination of different weave types on the shear behaviour of fabrics can be demonstrated.Projektowanie trĂłjwymiarowych kompozytĂłw wzmocnionych tkaninami wymaga takiego uĆoĆŒenia tkanin aby siĆy dziaĆaĆy zgodnie z kierunkiem nitek tkaniny. W trakcie ukĆadania tkanin trudno jest uniknÄ
Ä jej pofaĆdowania. Jednym ze sposobĂłw rozwiÄ
zania tego zagadnienia jest odpowiednie zaprojektowanie uĆoĆŒenia tkanin o rĂłĆŒnych splotach tkackich. Poprzez dobranie odpowiednich splotĂłw w tkaninach wzmacniajÄ
cych kompozyt moĆŒna rozwiÄ
zaÄ zagadnienie gradientowej ukĆadalnoĆci. Oznacza to, ĆŒe moĆŒna utworzyÄ strefy o wysokiej stabilnoĆci strukturalnej oraz dobrej ukĆadalnoĆci w tkaninie wzmacniajÄ
cej kompozyt. Zaprojektowanie tych stref uzyskuje siÄ poprzez odpowiedniÄ
symulacjÄ stref przejĆciowych. Odpowiednia procedura postÄpowania zostaĆa opracowana przez autorĂłw i zaproponowana do stosowania
Simulation-based investigations on the drape behavior of 3D woven fabrics made of commingled yarns
International audienceComposites based on 3D woven fabrics offer excellent mechanical properties due to the nearly non-crimp reinforcement fibers. Additionally, a reduced number of process steps results from the 3D nature of the reinforcement. Their in-plane and out-of-plane behaviors are purposefully adjustable to the expected loading conditions. A previously introduced modelling approach is extended to the simulation of 3D woven fabrics. The tensile, shear and bending behaviors of the fabric are considered in a material formulation for large deformations using shell elements. The model is successfully validated and parameter studies show the significant influence of shear and bending parameters on forming results. Furthermore, it is shown that also the forming process parameters have a significant influence on the draping results. It is concluded that the shearing and wrinkling can be reduced to a minimum with adapted material and process parameters
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