Intérêt D’une Recherche De Thrombophilie Au Cours Des Thromboses De La Veine Porte Dans Un Service De Médecine Interne

Background: Many causes of portal vein thrombosis are described and most patients had a combination of local and systemic risk factors. In many studies, prtothombotic disorders investigations were conducted in various departments of haematologies and/or gastroenterology. In this study, we investigated the systemic risk factors associated or not to abdominal inflammation in a series of patients recruited in a department of Internal Medicine. Methods: We studied, retrospectively from 2005 to 2009, 21 cases of patients with portal vein thrombosis. Patients with cancer are not included in this study. Results: We reported 21 patients with portal vein thrombosis: 8 males (43%) and 13 females (57%). The average age of patients was 46, 6 years (20; 59). Eight (8) patients had abdominal inflammatory pathology and 21 (100%) patients had systemic prothrombotic factors. This etiologic investigation is rentable because in 18 cases, abdominal inflammation and/or prothombotic disorders are diagnosed. This diagnostic, however, can permit to discuss a specific management. Conclusion: Extensive investigation of prothrombotic disorders is necessary in portal vein thrombosis, although if local abdominal inflammation exist

Absence of MHC-II expression by lymph node stromal cells results in autoimmunity.

How lymph node stromal cells (LNSCs) shape peripheral T-cell responses remains unclear. We have previously demonstrated that murine LNSCs, lymphatic endothelial cells (LECs), blood endothelial cells (BECs), and fibroblastic reticular cells (FRCs) use the IFN-γ-inducible promoter IV (pIV) of the MHC class II (MHCII) transactivator CIITA to express MHCII. Here, we show that aging mice (>1 yr old) in which MHCII is abrogated in LNSCs by the selective deletion of pIV exhibit a significant T-cell dysregulation in LNs, including defective Treg and increased effector CD4 <sup>+</sup> and CD8 <sup>+</sup> T-cell frequencies, resulting in enhanced peripheral organ T-cell infiltration and autoantibody production. The proliferation of LN-Tregs interacting with LECs increases following MHCII up-regulation by LECs upon aging or after exposure to IFN-γ, this effect being abolished in mice in which LECs lack MHCII. Overall, our work underpins the importance of LNSCs, particularly LECs, in supporting Tregs and T-cell tolerance

Comparing HLA Shared Epitopes in French Caucasian Patients with Scleroderma

Although many studies have analyzed HLA allele frequencies in several ethnic groups in patients with scleroderma (SSc), none has been done in French Caucasian patients and none has evaluated which one of the common amino acid sequences, 67FLEDR71, shared by HLA-DRB susceptibility alleles, or 71TRAELDT77, shared by HLA-DQB1 susceptibility alleles in SSc, was the most important to develop the disease. HLA-DRB and DQB typing was performed for a total of 468 healthy controls and 282 patients with SSc allowing FLEDR and TRAELDT analyses. Results were stratified according to patient’s clinical subtypes and autoantibody status. Moreover, standardized HLA-DRß1 and DRß5 reverse transcriptase Taqman PCR assays were developed to quantify ß1 and ß5 mRNA in 20 subjects with HLA-DRB1*15 and/or DRB1*11 haplotypes. FLEDR motif is highly associated with diffuse SSc (χ2 = 28.4, p<10−6) and with anti-topoisomerase antibody (ATA) production (χ2 = 43.9, p<10−9) whereas TRAELDT association is weaker in both subgroups (χ2 = 7.2, p = 0.027 and χ2 = 14.6, p = 0.0007 respectively). Moreover, FLEDR motif- association among patients with diffuse SSc remains significant only in ATA subgroup. The risk to develop ATA positive SSc is higher with double dose FLEDR than single dose with respectively, adjusted standardised residuals of 5.1 and 2.6. The increase in FLEDR motif is mostly due to the higher frequency of HLA-DRB1*11 and DRB1*15 haplotypes. Furthermore, FLEDR is always carried by the most abundantly expressed ß chain: ß1 in HLA DRB1*11 haplotypes and ß5 in HLA-DRB1*15 haplotypes

A computational psychiatry approach identifies how alpha-2A noradrenergic agonist Guanfacine affects feature-based reinforcement learning in the macaque

[EN] Noradrenaline is believed to support cognitive flexibility through the alpha 2A noradrenergic receptor (a2A-NAR) acting in prefrontal cortex. Enhanced flexibility has been inferred from improved working memory with the a2A-NA agonist Guanfacine. But it has been unclear whether Guanfacine improves specific attention and learning mechanisms beyond working memory, and whether the drug effects can be formalized computationally to allow single subject predictions. We tested and confirmed these suggestions in a case study with a healthy nonhuman primate performing a feature-based reversal learning task evaluating performance using Bayesian and Reinforcement learning models. In an initial dose-testing phase we found a Guanfacine dose that increased performance accuracy, decreased distractibility and improved learning. In a second experimental phase using only that dose we examined the faster feature-based reversal learning with Guanfacine with single-subject computational modeling. Parameter estimation suggested that improved learning is not accounted for by varying a single reinforcement learning mechanism, but by changing the set of parameter values to higher learning rates and stronger suppression of non-chosen over chosen feature information. These findings provide an important starting point for developing nonhuman primate models to discern the synaptic mechanisms of attention and learning functions within the context of a computational neuropsychiatry framework.This research was supported by grants from the Canadian Institutes of Health Research (CIHR), the Natural Sciences and Engineering Research Council of Canada (NSERC) and the Ontario Ministry of Economic Development and Innovation (MEDI). We thank Dr. Hongying Wang for invaluable help with drug administration and animal careHassani, SA.; Oemisch, M.; Balcarras, M.; Westendorff, S.; Ardid-Ramírez, JS.; Van Der Meer, MA.; Tiesinga, P.... (2017). 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La qualité de vie du patient brûlé, entre soins contraignants et séquelles

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Predictive approach for the design of improved HDT catalysts: Promoted Mo1-xWxS2 supported on gamma-alumina

International audienceAbstract In the field of hydrotreating (HDT) catalysis, density functional theory (DFT) calculations are of great help to explore new active phases on the basis of volcano curve relationships correlating HDT activities and the sulfur–metal (S–M) bond energy chemical descriptor, calculated in transition metal sulfides catalysts. In the present study, we synthesize Mo1−xWxS2 solid solutions supported on γ-alumina. For non-promoted systems, the catalytic tests reveal that a continuous and linear evolution of the catalytic activity is obtained for solid solutions for x varying between 0 and 1. As expected from the calculated S–M bond energy values, no synergy effect is observed in that case. For Ni and Co promoted Mo1−xWxS2 active phases (ternary metal sulfides), the S–M bond energy values determined with an interpolation model of the binary sulfides predict that NiMo1−xWxS2 phases should be more active than NiMoS and NiWS ones. In contrast, CoMo1−xWxS2 phases are expected to develop weak synergetical effect with respect to CoMoS and CoWS ones. Experiments performed on Co and Ni promoted Mo1−xWxS2 active phases confirmed the DFT-volcano curve prediction and an increment of about 30% in HDS catalytic activity is obtained for NiMo0.5W0.5S catalysts in both model molecule conversion and gas oil treatment

Thermodynamic and experimental studies of catalytic reforming of exhaust gas recirculation in gasoline engines

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Oxygen non-stoichiometry phenomena in Pr1-xZrxO2-y compounds (0.02 < x < 0.5).

New Pr1-xZrxO2-y oxides with x < 0.5 have been prepared by co-precipitation in basic medium and annealed under air at high temperatures (T≤ 1200 °C). Defined compositions with x = 0.02, 0.1, 0.2, 0.35, 0.40 and 0.5 have been characterized by XRD, Zr-K-edge EXAFS for the local structure, magnetic susceptibility measurements, and Pr LIII-edge XANES in order to identify the variation of the cell parameter and Zr local environment versus Zr content and Pr(n+) (4 < n < 3) oxidation states. The higher the Zr content, the lower the Pr valence state. The Zr amount stabilized in the distorted octahedral site is at the origin of the formation of defined compositions as discovered by Leroy Eyring et al. in the PrnO2n-2m series and the generation of oxygen vacancies stabilized in the fluorite-type network. TGA and TPR analyses help to follow the reduction properties under Ar/5% H2 and show high Pr reducible rates at low temperatures (T < 250 °C). The identification of the fluorite-type superstructure (SG: Ia3[combining macron]) of reduced compositions annealed at T = 900 °C under Ar/5% H2 shows the cationic and oxygen vacancy ordering. This feature plays a key role with Zr(4+) cations stabilized in flattened octahedral sites for the generation of oxygen vacancies and the stabilization of Pr(3+) in the reduced states

A thermogravimetric and FT-IR study of the reduction by H2 of sulfated Pt/CexZr1-xO2 solids

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