272 research outputs found
PoPe (Projection on Proper elements) for code control: verification, numerical convergence and reduced models. Application to plasma turbulence simulations
The Projection on Proper elements (PoPe) is a novel method of code control dedicated to 1) checking the correct implementation of models, 2) determining the convergence of numerical methods and 3) characterizing the residual errors of any given solution at very low cost. The basic idea is to establish a bijection between a simulation and a set of equations that generate it. Recovering equations is direct and relies on a statistical measure of the weight of the various operators. This method can be used in any dimensions and any regime, including chaotic ones. This method also provides a procedure to design reduced models and quantify the ratio costs to benefits. PoPe is applied to a kinetic and a fluid code of plasma turbulence
Association of combined PD- L1 expression and tumour- infiltrating lymphocyte features with survival and treatment outcomes in patients with metastatic melanoma
BackgroundRecent advances obtained with immune checkpoint inhibitors (ICIs) targeting the programmed cell death- 1 (PD- 1) protein have significantly improved the outcome of patients with metastatic melanoma. The PD- L1 expression in tumour cells as detected by immunohistochemistry is a predictive biomarker in some solid tumours, but appears insufficient as prognostic or predictive factor of response to ICIs in metastatic melanomas.ObjectivesWe investigated whether the presence and the features of pretreatment CD8+tumour- infiltrating T lymphocytes (TILs) could be a complementary prognostic or predictive biomarker in patients with metastatic melanoma.MethodsIn this retrospective study, we evaluated the association of PD- L1 expression - ¥5% of tumour cells combined with TIL features (CD8, CD28, Ki67) with the overall survival (OS) among 51 patients treated with ICIs and 54 patients treated with other treatment options (non- ICIs).ResultsPD- L1 positivity was observed in 33% and 39% of primary melanomas and matched metastases, respectively, with, however, poor concordance between the primary and the matched metastatic site (κ = 0.283). No significant association was noted between PD- L1 expression and CD8+TIL profile analysed as single markers and OS or response to immunotherapy. Instead, their combined analysis in primary melanoma samples showed that the PD- L1- /CD8+status was significantly associated with prolonged OS in the whole population (P = 0.04) and in the subgroup treated with non- ICIs (P = 0.009). Conversely, the PD- L1+/CD8+ status was a good prognostic factor in patients treated with ICIs (P = 0.022), whereas was significantly associated with poor prognosis in patients treated with non- ICIs (P = 0.014). While the expression of CD28 was not related to outcome, the Ki67 expression was significantly associated with poor OS in the subgroup CD8+TIL+/PD- L1- (P = 0.02).ConclusionsThe pretreatment combination of PD- L1 expression with the level of CD8+TILs could better assess OS and predict therapeutic response of patients with metastatic melanoma treated by either immunotherapy or other treatment regimens.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/155478/1/jdv16016_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/155478/2/jdv16016.pd
Non-linear magnetohydrodynamic modeling of plasma response to resonant magnetic perturbations
The interaction of static Resonant Magnetic Perturbations (RMPs) with
the plasma flows is modeled in toroidal geometry, using the non-linear
resistive MHD code JOREK, which includes the X-point and the
scrape-off-layer. Two-fluid diamagnetic effects, the neoclassical
poloidal friction and a source of toroidal rotation are introduced in
the model to describe realistic plasma flows. RMP penetration is studied
taking self-consistently into account the effects of these flows and the
radial electric field evolution. JET-like, MAST, and ITER parameters are
used in modeling. For JET-like parameters, three regimes of plasma
response are found depending on the plasma resistivity and the
diamagnetic rotation: at high resistivity and slow rotation, the islands
generated by the RMPs at the edge resonant surfaces rotate in the ion
diamagnetic direction and their size oscillates. At faster rotation, the
generated islands are static and are more screened by the plasma. An
intermediate regime with static islands which slightly oscillate is
found at lower resistivity. In ITER simulations, the RMPs generate
static islands, which forms an ergodic layer at the very edge (ψ
≥0.96) characterized by lobe structures near the X-point and results
in a small strike point splitting on the divertor targets. In MAST
Double Null Divertor geometry, lobes are also found near the X-point and
the 3D-deformation of the density and temperature profiles is observed
Epidermolysis bullosa simplex generalized severe induces a T helper 17 response and is improved by apremilast treatment
International audienceBACKGROUND: Epidermolysis bullosa simplex generalized severe is a genetic disorder caused by mutation in KRT5 or KRT14 genes. Usually considered as a mechanical disease, recent data argue for additional inflammatory mechanisms. OBJECTIVES: The aim of this study was to assess the inflammation in the skin of patients with EBS. METHODS: A first immunohistochemical retrospective study was performed on frozen skin samples from 17 EBS-gen sev patients. A second multicenter prospective study was conducted on 10 patients with severe EBS-gen sev. Blister fluid and epidermis were processed for immunochemistry analysis and quantitative real time PCR. Cytokine expression was analyzed in blister fluid and compared with controls. RESULTS: Histological analysis showed a constant dermal perivascular CD4+ lymphocytes infiltrate in skin biopsies of blister (n=17) as well as in rubbed skin (n=5), an epidermal infiltration of neutrophils and eosinophils in 70% of cases and an increased immunostaining for CXCL9 and CXCL10 in blistering skin. High levels of Th17 cytokines were detected in lesional skin. Three adult patients with EBS-gen sev were treated with apremilast with a dramatic improvement of skin blistering and good tolerance. CONCLUSION: Our study demonstrates the importance of inflammation in EBS-gen sev patients and underlines the key role for Th17 cells in its pathogenesis. In addition, this study provides promising new therapeutic approaches for this disabling disorder. This article is protected by copyright. All rights reserved
The role of Probiotics in allergic diseases
Allergic disorders are very common in the pediatric age group. While the exact etiology is unclear, evidence is mounting to incriminate environmental factors and an aberrant gut microbiota with a shift of the Th1/Th2 balance towards a Th2 response. Probiotics have been shown to modulate the immune system back to a Th1 response. Several in vitro studies suggest a role for probiotics in treating allergic disorders. Human trials demonstrate a limited benefit for the use of probiotics in atopic dermatitis in a preventive as well as a therapeutic capacity. Data supporting their use in allergic rhinitis are less robust. Currently, there is no role for probiotic therapy in the treatment of bronchial asthma. Future studies will be critical in determining the exact role of probiotics in allergic disorders
Maggot secretions suppress pro-inflammatory responses of human monocytes through elevation of cyclic AMP
AIMS/HYPOTHESIS: Maggots of the blowfly Lucilia sericata are used for the treatment of chronic wounds. As monocytes may contribute to the excessive inflammatory responses in such wounds, this study focussed on the effects of maggot secretions on the pro-inflammatory activities of these cells. METHODS: Freshly isolated monocytes were incubated with a range of secretions for 1 h and then stimulated with lipopolysaccharides (range 0-100 ng/ml) or lipoteichoic acid (range 0-5 microg/ml) for 18 h. The expression of cell surface molecules, cytokine and chemokine levels in culture supernatants, cell viability, chemotaxis, and phagocytosis and killing of Staphylococcus aureus were measured. RESULTS: Maggot secretions dose-dependently inhibited production of the pro-inflammatory cytokines TNF-alpha, IL-12p40 and macrophage migration inhibitory factor by lipopolysaccharides- and lipoteichoic acid-stimulated monocytes, while enhancing production of the anti-inflammatory cytokine IL-10. Expression of cell surface receptors involved in pathogen recognition remained unaffected by secretions. In addition, maggot secretions altered the chemokine profile of monocytes by downregulating macrophage inflammatory protein-1beta and upregulating monocyte chemoattractant protein-1 and IL-8. Nevertheless, chemotactic responses of monocytes were inhibited by secretions. Furthermore, maggot secretions did not affect phagocytosis and intracellular killing of S. aureus by human monocytes. Finally, secretions induced a transient rise in the intracellular cyclic AMP concentration in monocytes and Rp-cyclic AMPS inhibited the effects of secretions. CONCLUSIONS/INTERPRETATION: Maggot secretions inhibit the pro-inflammatory responses of human monocytes through a cyclic AMP-dependent mechanism. Regulation of the inflammatory processes by maggots contributes to their beneficial effects on chronic wound
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