992 resultados para Chénier, André.
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BACKGROUND: Interleukin-10 (IL-10) is currently being extensively studied in clinical trials for the treatment of Crohn's disease (CD). Only marginal effects have, however, been reported, and the dose-response curve was bell-shaped contrasting with the reported data from in vitro experiments. AIM: To use another in vitro model to analyze the effect of rhIL-10 and rhIL-4 on the spontaneous mucosal TNF-alpha secretion in patients with CD, and to characterize the phenotype of the cells targeted by rhIL-10. METHODS: Non-inflamed colon biopsies from CD patients were cultured for 16 hours in presence of different concentrations of rhIL-10 or rhIL-4. The numbers of TNF-alpha-secreting cells among isolated lamina propria mononuclear cells (LPMNC) were estimated by Elispot. RESULTS: Both rhIL-10 and rhIL-4 down-regulate TNF-alpha secretion by LPMNC from CD patients, with a more pronounced effect with rhIL-10. These effects were closely linked to the cytokine concentrations used, with a bell-shaped dose-response curve. Residual TNF-alpha secretion, in the presence of optimal rhIL-10 concentration was mainly attributable to CD3+ T cells. In contrast, at higher rhIL-10 concentrations, CD3- cells contributed significantly to the TNF-alpha secretion. CONCLUSIONS: The in vitro model we used, demonstrates that IL-4, but mostly IL-10, efficiently suppresses TNF-alpha secretion in LPMNC from CD patients, with a dose-response curve similar to results obtained in vivo. Resistance at high rhIL-10 concentrations was associated with a change in the phenotype of TNF-alpha-secreting cells.
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BACKGROUND/AIMS: The intestinal immune system faces large amounts of antigens, and its regulation is tightly balanced by cytokines. In this study, the effect of intestinal flow diversion on spontaneous secretion of interleukin (IL)-4 and interferon (IFN)- gamma was analysed. METHODS: Eight patients (two with Crohn's disease, four with ulcerative colitis, and two with previous colon cancer) carrying a double lumen small bowel stoma after a total colectomy procedure were included in the study. For each patient, eight biopsy samples were taken endoscopically from both the diverted and non-diverted part of the small bowel. Intraepithelial lymphocytes (IELs) and lamina propria lymphocytes (LPLs) were isolated separately and assayed for numbers of cells spontaneously secreting IL-4 and/or IFN-gamma by an ELISPOT technique. RESULTS: Compared with the non-diverted mucosa, a significant decrease in the number of spontaneously IFN-gamma secreting CD3 lymphocytes was observed in the diverted small bowel mucosa among both IELs (p = 0.008) and LPLs (p = 0.007). The same results, although less significant, were obtained for IL-4, especially in LPLs (p = 0.01). CONCLUSION: The intestinal content influences the spontaneous secretion of IFN-gamma and IL-4 by intestinal lymphocytes. These results could help to elucidate the anti-inflammatory role of split ileostomy in patients suffering from inflammatory bowel diseases.
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BACKGROUND: In contrast to adults, ulcers are un-common in Helicobacter pylori-infected children. Since immunological determinants influence the outcome of H. pylori infection, we have investigated mucosal T cell responses in H. pylori-infected children and compared them with those of adults and negative controls. MATERIAL AND METHODS: Mucosal biopsies were obtained from 43 patients undergoing an upper GI endoscopy for dyspeptic symptoms. The concentrations of released cytokines and the density of CD3+, CD25+ and CD69+cells were evaluated by flow cytometry, and the numbers of cytokine-secreting cells were measured by ELISPOT. RESULTS: The numbers of isolated antral CD3+ lymphocytes were only significantly raised in infected adults compared with noninfected controls (p < 0.05), whereas the proportion of CD3+ cells expressing activation markers (CD25 or CD69) remained low. In the stomach, IFN-gamma concentrations increased in infected children and infected adults compared with controls (p < 0.05), but IFN-gamma concentrations were tenfold lower in children than in adults (p < 0.01). IL-2, IL-4, IL-10 and TNF-alpha concentrations were similar in infected and in uninfected children and adults. In contrast, in the duodenum, IFN-gamma, as well as IL-4 and IL-10 concentrations were only increased in infected children compared with controls (p < 0.05). The concentrations of these cytokines were similar in both groups of adults who, however, like children, displayed a higher number of duodenal IL-4-secreting cells compared to controls (p < 0.05). CONCLUSION: These results suggest that IFN-gamma secretion in the stomach of H. pylori-infected patients is lower in children than in adults. This could protect children from development of severe gastro-duodenal diseases such as ulcer disease. In addition, infected patients are characterised by a dysregulation of the mucosal cytokine secretion at distance from the infection site.
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BACKGROUND: Cytokines secreted by intestinal T lymphocytes probably play a critical role in regulation of the gut associated immune responses. AIMS: To quantify interferon gamma (IFN-gamma) and interleukin 4 (IL-4) secreting cells (SC) among human intraepithelial (IEL) and lamina propria (LPL) lymphocytes from the duodenum and right colon in non-pathological situations and in the absence of in vitro stimulation. PATIENTS: Duodenal and right colonic biopsy specimens were obtained from patients with no inflammation of the intestinal mucosa. METHODS: Intraepithelial and lamina propria cell suspensions were assayed for numbers of cells spontaneously secreting IFN-gamma and IL-4 by a two site reverse enzyme linked immunospot technique (ELISPOT). RESULTS: The relatively high proportion of duodenal lymphocytes spontaneously secreting IFN-gamma (IEL 3.6%; LPL 1.9%) and IL-4 (IEL 1.3%; LPL 0.7%) contrasted with the very low numbers of spontaneously IFN-gamma SC and the absence of spontaneously IL-4 SC among peripheral blood mononuclear cells. In the basal state, both IFN-gamma and IL-4 were mainly produced by CD4+ cells. Within the colon, only 0.2% of IEL and LPL secreted IFN-gamma in the basal state, and 0.1% secreted IL-4. CONCLUSIONS: Compared with peripheral lymphocytes substantial proportions of intestinal epithelial and lamina propria lymphocytes spontaneously secrete IFN-gamma and/or IL-4. These cytokines are probably involved in the normal homoeostasis of the human intestinal mucosa. Disturbances in their secretion could play a role in the pathogenesis of gastrointestinal diseases.
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The bifunctional complex [Ru(TAP)(2)POQ-Nmet](2+), 1, formed with a [Ru(TAP)(2)Phen](2+) metallic unit linked to a quinoline moiety, and [Ru(TAP)(2)Phen](2+), 2, as reference, have been tested as photoprobes of DNA. Interestingly, 1 exhibits an emission enhancement of a factor of 16-17 upon binding to calf thymus DNA. Moreover, this emission is modulated by the nucleic base content of the polynucleotide. It varies by almost an order of magnitude from a polynucleotide containing 100% of G-C to a guanine-free nucleic acid where the excited-state lifetime reaches about 2 micros. The origins of these interesting properties are analyzed by comparing 1 with reference 2 in the presence of different polynucleotides.
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The immobilisation of molybdate on Mg,Al-LDH leads to an active, heterogeneous catalyst that generates singlet molecular oxygen from hydrogen peroxide in the absence of soluble base
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The bifunctional Ru(II) complex [Ru(BPY)2POQ-Nmet]2+ (1), in which the metallic unit is tethered by an aliphatic chain to an organic DNA binder, was designed in order to increase the affinity toward nucleic acids. The interaction of 1 with DNA was characterised from luminescence and absorption data and compared with the binding of its monofunctional metallic and organic analogues, [Ru(BPY)2(ac)phen]2+ (2) and Nmet-quinoline (3). The bifunctional complex has a binding affinity one order of magnitude higher than that of each of its separated moieties. Absorption changes induced upon addition of DNA at different pH indicate protonation of the organic sub-unit upon interaction with DNA under neutral conditions. The combination of the luminescence data under steady-state and time-resolved conditions shows that the attachment of the organic unit in 1 induces modifications of the association modes of the metallic unit, owing to the presence of the aliphatic chain which probably hinders the metallic moiety binding. The salt dependence of the binding constants was analysed in order to compare the thermodynamic parameters describing the association with DNA for each complex. This study demonstrates the interest of the derivatisation of a Ru(II) complex with an organic moiety (ia the bifunctional ligand POQ-Nmet) for the development of high affinity DNA probes or photoreactive agents.
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The synthesis and characterisation of a new bifunctional Ru(II) complex are presented. This compound contains a metallic unit, photo-reactive versus the guanines of DNA, and a new bifunctional ligand. An intramolecular luminescence quenching makes this complex an attractive candidate for photoprobing DNA where the intramolecular quenching process is inhibited with restoration of luminescence. © 1998 Elsevier Science S.A. All rights reserved.
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Novel bifunctional ruthenium(n) complexes, [Ru(TAP)2(POQ-Nmet)]2+ and [Ru(BPY)2(POQ-Nmet)]2+(la, 2a), containing a metallic and an organic moiety, have been prepared as photoprobes and photoreagents of DNA(TAP = 1,4,5,8-tetraazaphenanthrene, POQ-Nmet = 5-[6-(7-chloroquinolin-4-yl)-3-thia-6-azaheptanamido]-l,10phenanthroline). The ES mass spectrometry and 'H NMR data in organic solvents indicate that the quinoline moiety exists in both the protonated and non-protonated form. Moreover, the comparison of the NMR data with those of the corresponding monofunctional complexes(without quinoline) evidences that [Ru(TAP).2(POQ-Nmet)]2+ and [Ru(BPY)J(POQ-Nmet)]2+ are unfolded when the quinoline unit is protonated whereas deprotonation permits folding of the molecule. In the folded state the spatial proximity of the electron donor(the organic moiety) and electron acceptor(the metallic moiety) in [Ru(TAP)2(POQ-Nmet)]2+ favours intramolecular photo-induced electron transfer, which has been shown in a previous study to be responsible for the very low luminescence of la in non-protonating solutions. The restoration of the luminescence by protonation of the quinoline moiety as observed previously is in agreement with the unfolding of the molecule demonstrated in this work. The existence of such folding-unfolding processes related to protonation is crucial for studies of la with DNA. © The Royal Society of Chemistry 2000.
Indication of electron neutrino appearance from an accelerator-produced off-axis muon neutrino beam.
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The T2K experiment observes indications of ν(μ) → ν(e) appearance in data accumulated with 1.43×10(20) protons on target. Six events pass all selection criteria at the far detector. In a three-flavor neutrino oscillation scenario with |Δm(23)(2)| = 2.4×10(-3) eV(2), sin(2)2θ(23) = 1 and sin(2)2θ(13) = 0, the expected number of such events is 1.5±0.3(syst). Under this hypothesis, the probability to observe six or more candidate events is 7×10(-3), equivalent to 2.5σ significance. At 90% C.L., the data are consistent with 0.03(0.04) < sin(2)2θ(13) < 0.28(0.34) for δ(CP) = 0 and a normal (inverted) hierarchy.
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The basic definition of a cabaret is a café that offers live entertainment performed by singers, musicians and dancers and serves food and drink. It is generally housed in small, intimate spaces. Starting in the middle of the nineteenth century, artists, composers and writers met at Parisian cafés and salons to share their works. The cabaret was a suitable place for social activities. Artists could meet, discuss their opinions, and share their art in a relaxed setting. Even though cabaret music was often based on popular idioms, social and political commentary coupled with satirical settings represented the true soul of the genre. This trend flourished in the late nineteenth and early twentieth centuries. The first cabaret in Paris, Le Chat Noir inspired the growth of similar places in major cities throughout Europe besides Paris. The three recitals that comprise this dissertation project were performed at University of Maryland venues: the Robert & Arlene Kogod Theatre on 11 May 2011, Ulrich Recital Hall on 4 December 2011, and Gildenhorn Recital Hall on 4 March 2012. The repertoire for the first recital included works by Erik Satie with mezzo-soprano Monica Soto-Gil, Friedrich Hollaender with soprano Gabrielle DeMers, William Bolcom with baritone Ethan Watermeier and mezzo-soprano Stepanie Sadownik, and Poulenc with baritone Andrew McLaughlin. André Previn‘s Tango Song and Dance with violinist Jennifer Kim served as the instrumental interlude. The second recital included songs by Friedrich Hollaender with mezzo-soprano Monica Soto-Gil, Hanns Eisler and Viktor Ullmann with mezzo-soprano Stephanie Sadownik, and Mischa Spoliansky with soprano CarrieAnne Winter. Victor Hollaender‘s Romance and Albumblatt were the instrumental interludes with violinist Jennifer Kim. The last recital featured works for piano and violin, the Graceful Ghost Rag by William Bolcom with violinist Jenny Wu, Four Souvenirs by Paul Schoenfield with violinist Jennifer Kim, Cabaret Songs by Benjamin Britten with soprano Linda Mabbs, and Souvenirs for piano four-hands by Samuel Barber with pianist Rita Sloan. The recitals were recorded on compact discs and are archived within the Digital Repository at the University of Maryland (DRUM).
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Purpose: Clear recommendations on how to guide patients with cancer on home parenteral nutrition (HPN) are lacking as the use of HPN in this population remains a controversial issue. Therefore, the aims of this study were to rank treatment recommendations and main outcome indicators to ensure high-quality care and to indicate differences in care concerning benign versus malignant patients. Methods: Treatment recommendations, identified from published guidelines, were used as a starting point for a two-round Delphi approach. Comments and additional interventions proposed in the first round were reevaluated in the second round. Ordinal logistic regression with SPSS 2.0 was used to identify differences in care concerning benign versus malignant patients. Results: Twenty-seven experts from five European countries completed two Delphi rounds. After the second Delphi round, the top three most important outcome indicators were (1) quality of life (QoL), (2) incidence of hospital readmission and (3) incidence of catheter-related infections. Forty-two interventions were considered as important for quality of care (28/42 based on published guidelines; 14/42 newly suggested by Delphi panel). The topics 'Liver disease' and 'Metabolic bone disease' were considered less important for cancer patients, together with use of infusion pumps (p = 0.004) and monitoring of vitamins and trace elements (p = 0.000). Monitoring of QoL is considered more important for cancer patients (p = 0.03). Conclusion: Using a two-round Delphi approach, we developed a minimal set of 42 interventions that may be used to determine quality of care in HPN patients with malignancies. This set of interventions differs from a similar set developed for benign patients. © 2012 Springer-Verlag Berlin Heidelberg.
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Background: The role of home parenteral nutrition (HPN) in incurable cachectic cancer patients unable to eat is extremely controversial. The aim of this study is to analyse which factors can influence the outcome. Patients and methods: We studied prospectively 414 incurable cachectic (sub)obstructed cancer patients receiving HPN and analysed the association between patient or clinical characteristics and surviving status. Results: Median weight loss, versus pre-disease and last 6-month period, was 24% and 16%, respectively. Median body mass index was 19.5, median KPS was 60, median life expectancy was 3 months. Mean/median survival was 4.7/3.0 months; 50.0% and 22.9% of patients survived 3 and 6 months, respectively. At the multivariable analysis, the variables significantly associated with 3- and 6-month survival were Glasgow Prognostic Score (GPS) and KPS, and GPS, KPS and tumour spread, respectively. By the aggregation of the significant variables, it was possible to dissect several classes of patients with different survival probabilities. Conclusions: The outcome of cachectic incurable cancer patients on HPN is not homogeneous. It is possible to identify groups of patients with a ≥6-month survival (possibly longer than that allowed in starvation). The indications for HPN can be modulated on these clinical/biochemical indices. © The Author 2013. Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved.
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The authors present 2 cases of AIDS revealed by severe recurrent genital herpes simplex. The patients are 2 young, previously healthy, African women without histories of homosexuality or drug abuse. The first patient died after 5 months of follow-up (post mortem findings: viral bronchopneumonia with positive cultures for herpes and cytomegalovirus (CMV), viral colitis due to CMV). The second patient survived. She has been treated, during the last 11 months, for filariasis, buccal and vaginal candidiasis and cerebral toxoplasmosis.
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Doctorat en Sciences