101 resultados para Bartra, Roger
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PURPOSE: Early assessment of radiotherapy (RT) quality in the ongoing EORTC trial comparing primary temozolomide versus RT in low-grade gliomas. MATERIALS AND METHODS: RT plans provided for dummy cases were evaluated and compared against expert plans. We analysed: (1) tumour and organs-at-risk delineation, (2) geometric and dosimetric characteristics, (3) planning parameters, compliance with dose prescription and Dmax for OAR (4) indices: RTOG conformity index (CI), coverage factor (CF), tissue protection factor (PF); conformity number (CN = PF x CF); dose homogeneity in PTV (U). RESULTS: Forty-one RT plans were evaluated. Only two (5%) centres were requested to repeat CTV-PTV delineations. Three (7%) plans had a significant under-dosage and dose homogeneity in one deviated > 10%. Dose distribution was good with mean values of 1.5, 1, 0.68, and 0.68 (ideal values = 1) for CI, CF, PF, and CN, respectively. CI and CN strongly correlated with PF and they correlated with PTV. Planning with more beams seems to increase PTV(Dmin), improving CF. U correlated with PTV(Dmax). CONCLUSION: Preliminary results of the dummy run procedure indicate that most centres conformed to protocol requirements. To quantify plan quality we recommend systematic calculation of U and either CI or CN, both of which measure the amount of irradiated normal brain tissue.
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The acquisition of neuroendocrine (NE) characteristics by prostate cancer (PCa) cells is closely related to tumour progression and hormone resistance. The mechanisms by which NE cells influence PCa growth and progression are not fully understood. Macrophage migration inhibitory factor (MIF) is a pro-inflammatory cytokine involved in oncogenic processes, and MIF serum levels correlate with aggressiveness of PCa. Here, we investigated the regulation and the functional consequences of MIF expression during NE transdifferentiation of PCa cells. NE differentiation (NED) of LNCaP cells, initiated either by increasing intracellular levels of cAMP or by culturing cells in an androgen-depleted medium, was associated with markedly increased MIF release. Yet, intracellular MIF protein and mRNA levels and MIF gene promoter activity decreased during NED of LNCaP cells, suggesting that NED favours MIF release despite decreasing MIF synthesis. Adenoviral-mediated forced MIF expression in NE-differentiated LNCaP cells increased cell proliferation without affecting the expression of NE markers. Addition of exogenous recombinant MIF to LNCaP and PC-3 cells stimulated the AKT and ERK1/2 signalling pathways, the expression of genes involved in PCa, as well as proliferation and resistance to paclitaxel and thapsigargin-induced apoptosis. Altogether, these data provide evidence that increased MIF release during NED in PCa may facilitate cancer progression or recurrence, especially following androgen deprivation. Thus, MIF could represent an attractive target for PCa therapy.
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The generation of vaccines against HIV/AIDS able to induce long-lasting protective immunity remains a major goal in the HIV field. The modest efficacy (31.2%) against HIV infection observed in the RV144 phase III clinical trial highlighted the need for further improvement of HIV vaccine candidates, formulation, and vaccine regimen. In this study, we have generated two novel NYVAC vectors, expressing HIV-1 clade C gp140(ZM96) (NYVAC-gp140) or Gag(ZM96)-Pol-Nef(CN54) (NYVAC-Gag-Pol-Nef), and defined their virological and immunological characteristics in cultured cells and in mice. The insertion of HIV genes does not affect the replication capacity of NYVAC recombinants in primary chicken embryo fibroblast cells, HIV sequences remain stable after multiple passages, and HIV antigens are correctly expressed and released from cells, with Env as a trimer (NYVAC-gp140), while in NYVAC-Gag-Pol-Nef-infected cells Gag-induced virus-like particles (VLPs) are abundant. Electron microscopy revealed that VLPs accumulated with time at the cell surface, with no interference with NYVAC morphogenesis. Both vectors trigger specific innate responses in human cells and show an attenuation profile in immunocompromised adult BALB/c and newborn CD1 mice after intracranial inoculation. Analysis of the immune responses elicited in mice after homologous NYVAC prime/NYVAC boost immunization shows that recombinant viruses induced polyfunctional Env-specific CD4 or Gag-specific CD8 T cell responses. Antibody responses against gp140 and p17/p24 were elicited. Our findings showed important insights into virus-host cell interactions of NYVAC vectors expressing HIV antigens, with the activation of specific immune parameters which will help to unravel potential correlates of protection against HIV in human clinical trials with these vectors. IMPORTANCE: We have generated two novel NYVAC-based HIV vaccine candidates expressing HIV-1 clade C trimeric soluble gp140 (ZM96) and Gag(ZM96)-Pol-Nef(CN54) as VLPs. These vectors are stable and express high levels of both HIV-1 antigens. Gag-induced VLPs do not interfere with NYVAC morphogenesis, are highly attenuated in immunocompromised and newborn mice after intracranial inoculation, trigger specific innate immune responses in human cells, and activate T (Env-specific CD4 and Gag-specific CD8) and B cell immune responses to the HIV antigens, leading to high antibody titers against gp140. For these reasons, these vectors can be considered vaccine candidates against HIV/AIDS and currently are being tested in macaques and humans.
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The cellular response to an inflammatory stressor requires a proinflammatory cellular activation followed by a controlled resolution of the response to restore homeostasis. We hypothesized that biliverdin reductase (BVR) by binding biliverdin (BV) quells the cellular response to endotoxin-induced inflammation through phosphorylation of endothelial nitric oxide synthase (eNOS). The generated NO, in turn, nitrosylates BVR, leading to nuclear translocation where BVR binds to the Toll-like receptor-4 (TLR4) promoter at the Ap-1 sites to block transcription. We show in macrophages that BV-induced eNOS phosphorylation (Ser-1177) and NO production are mediated in part by Ca(2+)/calmodulin-dependent kinase kinase. Furthermore, we show that BVR is S-nitrosylated on one of three cysteines and that this posttranslational modification is required for BVR-mediated signaling. BV-induced nuclear translocation of BVR and inhibition of TLR4 expression is lost in macrophages derived from Enos(-/-) mice. In vivo in mice, BV provides protection from acute liver damage and is dependent on the availability of NO. Collectively, we elucidate a mechanism for BVR in regulating the inflammatory response to endotoxin that requires eNOS-derived NO and TLR4 signaling in macrophages.
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Background: Adenovirus serotype 5 (Ad5) phase IIb vaccine trial (STEP) was prematurely stopped due to a lack of efficacy and two-fold higher incidence of HIV infection among Ad5 seropositive vaccine recipients. We have recently demonstrated that Ad5 immune complexes (Ad5 ICs)-mediated activation of the dendritic cell (DC)-T cell axis was associated with the enhancement of HIV infection in vitro. Although the direct role of Ad5 neutralizing antibodies (NAbs) in the increase of HIV susceptibility during the STEP trial is still under debate, vector-specific NAbs remain a major hurdle for vector-based gene therapies or vaccine strategies. To surmount this obstacle, vectors based on ''rare'' Ad serotypes including Ad6, Ad26, Ad36 and Ad41 were engineered.Methods: The present study aimed to determine whether Ad ICmediated DC maturation could be circumvented using these Advector candidates.Results: We found that all Ad vectors tested forming ICs with plasma containing serotype-specific NAbs had the capacity to 1) mature human DCs as monitored by the up-regulation of costimulatory molecules and the release of pro-inflammatory cytokines (TNF-a), via the stabilization of Ad capsid at endosomal but not lysosomal pH rendering Ad DNA/TLR9 interactions possible and 2) potentiate Ad-specific CD4 and CD8 T cell responses.Conclusion: In conclusion, despite a conserved DC maturation potential, the low prevalence of serotype-specific NAbs renders rare Ad vectors attractive for vaccine strategies.
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Arbuscular mycorrhizal fungi (AMF) form symbioses with most plant species. They are ecologically important determinants of plant growth and diversity. Considerable genetic variation occurs in AMF populations. Thus, plants are exposed to AMF of varying relatedness to each other. Very little is known about either the effects of coexisting AMF on plant growth or which factors influence intraspecific AMF coexistence within roots. No studies have addressed whether the genetics of coexisting AMF, and more specifically their relatedness, influences plant growth and AMF coexistence. Relatedness is expected to influence coexistence between individuals, and it has been suggested that decreasing ability of symbionts to coexist can have negative effects on the growth of the host. We tested the effect of a gradient of AMF genetic relatedness on the growth of two plant species. Increasing relatedness between AMFs lead to markedly greater plant growth (27% biomass increase with closely related compared to distantly related AMF). In one plant species, closely related AMF coexisted in fairly equal proportions but decreasing relatedness lead to a very strong disequilibrium between AMF in roots, indicating much stronger competition. Given the strength of the effects with such a shallow relatedness gradient and the fact that in the field plants are exposed to a steeper gradient, we consider that AMF relatedness can have a strong role in plant growth and the ability of AMF to coexist. We conclude that AMF relatedness is a driver of plant growth and that relatedness is also a strong driver of intraspecific coexistence of these ecologically important symbionts.
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Cet article présente les résultats de la revue systématique: Inglis SC, Clark RA, McAlister FA, et al. Structured telephone support or telemonitoring programmes for patients with chronic heart failure. Cochrane Database Systematic Reviews 2010, Issue 8. Art. No.:CD007228. DOI:10.1002/14651858.CD007228.pub2. PMID: 20687083.
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Background: Second generation surveillance is a central feature of HIV/AIDS policy in Switzerland. Behavioural surveys in the general population, men having sex with men (MSM) and injecting drug users (IDU) have been regularly conducted since the early nineties. After peaking at 2144 cases in 1991, the number of new HIV cases notified to the Ministry of Health decreased in each subpopulation until 2000 (n=578) and then rose again to 735 in 2006. The recent increase is mainly due to MSM. Methods: In the general population, representative cross-sectional telephone surveys have been conducted 11 times since 1987. Surveys in convenience samples of MSM, recruited through gay newspapers and gay organisations, have been conducted 5 times since 1992. Surveys among IDU's attending needle exchange programmes have been conducted 5 times since 1993. Condom statistics, available since 1986, are included in the behavioural surveillance system. Results: In the general population aged 17-30, systematic condom use with casual partners in the last six months increased from 8.0% in 1987 to 75.8% in 2007. The proportion of MSM reporting anal intercourse with casual partners in the last 12 months increased from 61% in 1992 to 79% in 2007 (lowest value 56% in 1994) and unprotected anal intercourse with these partners increased from 14 % in 1992 to 24% in 2007 (lowest value 9% in 1994). The proportion of IDUs reporting borrowing used injection equipment decreased from 16.5% in 1993 to 8.9% in 2006. The ratio condoms released to retail/population aged 15-65 increased from 1.68 in 1986 to 3.8 in 2006. Conclusions: It has been possible to maintain a coherent behavioural surveillance system on a long-term basis, allowing for the monitoring of HIV prevention policy outcome and forseeing the development and distribution of new HIV cases in the population.
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Many firms around the world are managed and partially owned by entrepreneurs. These entrepreneurs hold under diversified portfolios and, therefore, bear idiosyncratic risk in addition to systematic risk. To compensate the additional risk borne, they extract private benefits. In this paper, we analyse how an entrepreneur's overconfidence affects the market performance of the firm, through the channel of private benefits. We show that two dimensions of overconfidence, namely overestimation of future cash-flows and underestimation of idiosyncratic risk (called miscalibration), have opposite effects on the private benefits extracted by the entrepreneur. As a consequence, firms managed and partially owned by overconfident entrepreneurs can deliver overperformance or underperformance, depending on the prevalence of overestimation or miscalibration of the beliefs of the entrepreneur.
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PURPOSE: Early-onset sepsis (EOS) is one of the main causes for the admission of newborns to the neonatal intensive care unit. However, traditional infection markers are poor diagnostic markers of EOS. Pancreatic stone protein (PSP) is a promising sepsis marker in adults. The aim of this study was to investigate whether determining PSP improves the diagnosis of EOS in comparison with other infection markers. METHODS: This was a prospective multicentre study involving 137 infants with a gestational age of >34 weeks who were admitted with suspected EOS. PSP, procalcitonin (PCT), soluble human triggering receptor expressed on myeloid cells-1 (sTREM-1), macrophage migration inhibitory factor (MIF) and C-reactive protein (CRP) were measured at admission. Receiver-operating characteristic (ROC) curve analysis was performed. RESULTS: The level of PSP in infected infants was significantly higher than that in uninfected ones (median 11.3 vs. 7.5 ng/ml, respectively; p = 0.001). The ROC area under the curve was 0.69 [95 % confidence interval (CI) 0.59-0.80; p < 0.001] for PSP, 0.77 (95 % CI 0.66-0.87; p < 0.001) for PCT, 0.66 (95 % CI 0.55-0.77; p = 0.006) for CRP, 0.62 (0.51-0.73; p = 0.055) for sTREM-1 and 0.54 (0.41-0.67; p = 0.54) for MIF. PSP independently of PCT predicted EOS (p < 0.001), and the use of both markers concomitantly significantly increased the ability to diagnose EOS. A bioscore combining PSP (>9 ng/ml) and PCT (>2 ng/ml) was the best predictor of EOS (0.83; 95 % CI 0.74-0.93; p < 0.001) and resulted in a negative predictive value of 100 % and a positive predictive value of 71 %. CONCLUSIONS: In this prospective study, the diagnostic performance of PSP and PCT was superior to that of traditional markers and a combination bioscore improved the diagnosis of sepsis. Our findings suggest that PSP is a valuable biomarker in combination with PCT in EOS.
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Les déacetylases d'histones (HDACs) déacétylent non seulement les histones, ce qui a généralement pour effet d'augmenter la transcription et l'expression génique, mais également d'autres protéines comme par exemple des protéines de choc thermique (HSP90), la tubuline alpha, certains récepteurs aux stéroïdes ainsi que de nombreux facteurs de transcription (NF-kB p65, Sp1, etc.). Ainsi les HDACs participent au contrôle de nombreux processus cellulaires. Les inhibiteurs des HDACs (ou HDACi), de part leur capacité à induire la différenciation cellulaire et l'apoptose, sont parmi les anti-cancéreux les plus prometteurs en cours de développement pour dans le traitement des néoplasies solides et hématologiques. Récemment, l'activité anti-inflammatoire et immuno- modulatrice des HDACi a été mise en évidence et exploitée avec succès pour le traitement de pathologies auto-immunes dans des modèles précliniques. L'effet des HDACi sur la réponse immunitaire innée restant largement inconnu, nous avons entrepris la première étude d'envergure dans ce domaine. Dans un premier article, nous démontrons que les HDACi inhibent l'expression de nombreux gènes (récepteurs aux produits microbiens, cytokines, chimiokines, molécules d'adhésion et co-stimulatrices, facteurs de croissance, etc.) impliqués dans les défenses anti¬infectieuses in vitro. En accord avec ces données, les HDACi augmentent la mortalité d'animaux infectés dans des modèles de pneumonie et de candidose bénignes. De manière congruente, les HDACi protègent les animaux de mortalité induite par choc toxique et septique en inhibant la réponse inflammatoire exubérante qui caractérise ces pathologies (Roger T. et al., Blood 2011). Afin de caractériser plus en détails l'influence des HDACi sur la réponse immunitaire innée, nous avons également analysé l'impact de deux HDACi, l'acide valproïque (VPA) et la trichostatin A (TSA), sur les principaux mécanismes de défenses antimicrobiennes des macrophages. Dans un second article (Mombelli et al., Journal of Infectious Diseases 2011), nous rapportons que la VPA et la TSA diminuent la capacité des macrophages à phagocyter et à détruire les bactéries Gram-positives Staphylococcus aureus et Gram-négatives Escherichia coli. En accord avec ces données, les HDACi inhibent l'expression de molécules impliquées dans la phagocytose comme les récepteurs éboueurs (Msr 1 et CD14) et de type lectine (Dectin 1), ainsi que les récepteurs aux opsonines (intégrines). Par ailleurs, les HDACi interfèrent avec l'expression de différentes sous unités de la NADPH oxydase (gp91p"ox, p22 phox, p47 phox, p40 phox, p67 phox et Rac2) et de l'oxyde nitrique (NO) synthétase inductible (iNOS), qui sont responsables de la production de dérivés oxygénés (ROS) et nitrogénés (NO) essentiels à la destruction des microorganismes dans le phagolysosome. En résumé, cette étude décrit des mécanismes par lesquels les HDACi diminuent la capacité d'ingérer et de détruire les bactéries, et ainsi augmentent la susceptibilité aux infections. Globalement, nos données indiquent que les HDACi sont de puissants anti¬inflammatoires qui pourraient favoriser la survenue d'infections chez les patients cancéreux traités avec ces drogues, comme semble par ailleurs le suggérer des études cliniques rapportées dans la littérature. Nous proposons un suivi clinique infectieux strict chez les patients traités avec ces agents.
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Basic calcium phosphate (BCP) crystals are associated with severe osteoarthritis and acute periarticular inflammation. Three main forms of BCP crystals have been identified from pathological tissues: octacalcium phosphate, carbonate-substituted apatite, and hydroxyapatite. We investigated the proinflammatory effects of these BCP crystals in vitro with special regard to the involvement of the NLRP3-inflammasome in THP-1 cells, primary human monocytes and macrophages, and mouse bone marrow-derived macrophages (BMDM). THP-1 cells stimulated with BCP crystals produced IL-1β in a dose-dependent manner. Similarly, primary human cells and BMDM from wild-type mice also produced high concentrations of IL-1β after crystal stimulation. THP-1 cells transfected with short hairpin RNA against the components of the NLRP3 inflammasome and mouse BMDM from mice deficient for NLRP3, apoptosis-associated speck-like protein, or caspase-1 did not produce IL-1β after BCP crystal stimulation. BCP crystals induced macrophage apoptosis/necrosis as demonstrated by MTT and flow cytometric analysis. Collectively, these results demonstrate that BCP crystals induce IL-1β secretion through activating the NLRP3 inflammasome. Furthermore, we speculate that IL-1 blockade could be a novel strategy to inhibit BCP-induced inflammation in human disease.
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Background. Aspergillus fumigatus causes invasive aspergillosis, a potentially fatal infection in oncohematological patients. Innate immune detection of A. fumigatus involves Toll-like receptor (TLR) 4 and TLR2, which forms a heterodimer with either TLR1 or TLR6. The role of those coreceptors in Aspergillus sensing is unknown. Methods. Cytokine production was measured in bone marrow-derived macrophages (BMDMs) from wild-type (WT) and TLR-deficient mice after incubation with a WT and an immunogenic RodA-deficient (ΔrodA-47) strain of A. fumigatus and in lungs from these mice after intranasal mold inoculation. Aspergillus fumigatus-mediated NF-κB activation was measured in HEK293T cells transfected with plasmids expressing mouse or human TLRs. Results. Bone marrow-derived macrophages from TLR1- and TLR6-deficient mice produced lower amounts of interleukin 12p40, CXCL2, interleukin 6, and tumor necrosis factor α than BMDMs from WT mice after stimulation with A. fumigatus. Lungs from TLR1- and TLR6-deficient mice had diminished CXCL1 and CXCL2 production and increased fungal burden after intranasal inoculation of ΔrodA A. fumigatus compared with lungs from WT mice. ΔrodA strain-mediated NF-κB activation was observed in HEK293T cells expressing mouse TLR2/1, mouse TLR2/6, and human TLR2/1 but not human TLR2/6. Conclusions. Innate immune detection of A. fumigatus is mediated by TLR4 and TLR2 together with TLR1 or TLR6 in mice and TLR1 but not TLR6 in humans.