Genomic lesions associated with a different clinical outcome in diffuse large B-Cell lymphoma treated with R-CHOP-21

Despite recent therapeutic improvements, the clinical course of diffuse large B-cell lymphoma (DLBCL) still differs considerably among patients. We conducted this retrospective multi-centre study to evaluate the impact of genomic aberrations detected using a high-density genome wide-single nucleotide polymorphism-based array on clinical outcome in a population of DLBCL patients treated with R-CHOP-21 (rituximab, cyclophosphamide, doxorubicine, vincristine and prednisone repeated every 21_d). 166 DNA samples were analysed using the GeneChip Human Mapping 250K NspI. Genomic anomalies were analysed regarding their impact on the clinical course of 124 patients treated with R-CHOP-21. Unsupervised clustering was performed to identify genetically related subgroups of patients with different clinical outcomes. Twenty recurrent genetic lesions showed an impact on the clinical course. Loss of genomic material at 8p23.1 showed the strongest statistical significance and was associated with additional aberrations, such as 17p- and 15q-. Unsupervised clustering identified five DLBCL clusters with distinct genetic profiles, clinical characteristics and outcomes. Genetic features and clusters, associated with a different outcome in patients treated with R-CHOP, have been identified by arrayCGH.

CLUSTER LEED - A VERY FAST METHOD FOR SURFACE-STRUCTURE DETERMINATION

A very fast method, cluster low-energy electron diffraction (LEED) is proposed for LEED I-V spectral analysis, in which three appproximations are introduced: the small-atom approximation, omission of the structure factors, and truncation of higher order ( > 2) scattering events. The method has been tested using a total of four sets of I-V spectra calculated by fully dynamic LEED for (i) the simple overlayer system, O on Ni{100}, and (ii) the reconstructed system, Cu on W{100}, and also one set of experimental data from W{100}-c(2 X 2)-Cu. In each case the correct structural parameters are recovered. It is suggested that for complex systems cluster LEED provides an efficient fast route to trial structures, which could be refined by automated tenser LEED.

VIEWING LEED PATTERNS AS ELECTRON HOLOGRAMS

It is shown theoretically that LEED patterns from ordered overlayer systems bear a strong relationship to electron holograms, and that phase information is recorded in the diffraction intensities. It is, therefore, possible to obtain structural information by direct holographic inversion from conventional LEED I-V spectra.

A DIRECT INVERSION METHOD FOR SURFACE-STRUCTURE DETERMINATION FROM LEED INTENSITIES

LOW-ENERGY electron diffraction (LEED) has become the most successful technique in surface crystallography1, but because of the complexity of the surface-electron scattering interactions, analyses of LEED data are still conducted on a trial-and-error basis: a direct-inversion method for treating LEED intensity data remains an attractive goal2. Building on recent theoretical and experimental developments in electron holography from surface structures3-16, we show here that three-dimensional images with atomic resolution can be obtained by a direct transform of conventional LEED intensity spectra.

High-dose therapy and autologous stem cell transplantation in first relapse for diffuse large B cell lymphoma in the rituximab era:an analysis based on data from the European Blood and Marrow Transplantation Registry

Autologous stem cell transplantation (ASCT) consolidation remains the treatment of choice for patients with relapsed diffuse large B cell lymphoma. The impact of rituximab combined with chemotherapy in either first- or second-line therapy on the ultimate results of ASCT remains to be determined, however. This study was designed to evaluate the benefit of ASCT in patients achieving a second complete remission after salvage chemotherapy by retrospectively comparing the disease-free survival (DFS) after ASCT for each patient with the duration of the first complete remission (CR1). Between 1990 and 2005, a total of 470 patients who had undergone ASCT and reported to the European Blood and Bone Transplantation Registry with Medical Essential Data Form B information were evaluated. Of these 470 patients, 351 (74%) had not received rituximab before ASCT, and 119 (25%) had received rituximab before ASCT. The median duration of CR1 was 11 months. The median time from diagnosis to ASCT was 24 months. The BEAM protocol was the most frequently used conditioning regimen (67%). After ASCT, the 5-year overall survival was 63% (95% confidence interval, 58%-67%) and 5-year DFS was 48% (95% confidence interval, 43%-53%) for the entire patient population. Statistical analysis showed a significant increase in DFS after ASCT compared with duration of CR1 (median, 51 months versus 11 months; P < .001). This difference was also highly significant for patients with previous exposure to rituximab (median, 10 months versus not reached; P < .001) and for patients who had experienced relapse before 1 year (median, 6 months versus 47 months; P < .001). Our data indicate that ASCT can significantly increase DFS compared with the duration of CR1 in relapsed diffuse large B cell lymphoma and can alter the disease course even in patients with high-risk disease previously treated with rituximab.

Energy Detection based Spectrum Sensing over Two-wave with Diffuse Power Fading Channels

One of the most important factors that affects the performance of energy detection (ED) is the fading channel between the wireless nodes. This article investigates the performance of ED-based spectrum sensing, for cognitive radio (CR), over two-wave with diffuse power (TWDP) fading channels. The TWDP fading model characterizes a variety of fading channels, including well-known canonical fading distributions, such as Rayleigh and Rician, as well as worse than Rayleigh fading conditions modeled by the two-ray fading model. Novel analytic expressions for the average probability of detection over TWDP fading that account for single-user and cooperative spectrum sensing as well as square law selection diversity reception are derived. These expressions are used to analyze the behavior of ED-based spectrum sensing over moderate, severe and extreme fading conditions, and to investigate the use of cooperation and diversity as a means of mitigating the fading effects. Our results indicate that TWDP fading conditions can significantly degrade the sensing performance; however, it is shown that detection performance can be improved when cooperation and diversity are employed. The presented outcomes enable us to identify the limits of ED-based spectrum sensing and quantify the trade-offs between detection performance and energy efficiency for cognitive radio systems deployed within confined environments such as in-vehicular wireless networks.

EU water framework directive: will the nitrate load reduction from diffuse sources produce the same results in all estuaries?

The impact of urban waste-water and non-point nitrate discharges in estuarine and near-shore coastal waters are analyzed. The study is focused on the effects of applying the European directives 91/271/EEC and 91/676/EEC to these systems. 4 Portuguese estuaries and two coastal lagoons with different characteristics are studied. A modelling system is applied and calibrated in each system. Three nitrate load scenarios are examined. It is shown that the morphologic and hydrodynamic characteristics of the domain largely control the ecological processes in these systems. The primary production limitation factors are split into “biologic” and “hydrodynamic” components. The physical limitation due to hydrodynamic and residence time is the most important factor. The combined limitation of “biologic” factors (temperature, light and nutrients availability) control productivity only in the systems where physical limitation is not important.

Projet Namur - Jean-Talon O. TOD, Leed-ND ou astuce de vente?

Affiche de projet terminal, baccalauréat en Urbanisme. Institut d'urbanisme, Université de Montréal.

Le droit à un environnement de qualité au Québec : une réponse aux problèmes de pollution diffuse?

Les Québécois sont de plus en plus conscients de l’environnement qui les entoure et de l’importance d’en assurer la qualité et la pérennité. Certains phénomènes, tels les changements climatiques, l’accumulation de polluants organiques persistants et l’amincissement de la couche d’ozone, que nous qualifierons de phénomènes environnementaux diffus, sont engendrés par de multiples émetteurs de polluants et ont des effets globaux qui ne peuvent être liés à un événement précis et dont les impacts sont difficiles à identifier et à quantifier pour le moment. En l’absence de preuve quant aux effets qu’auront ces phénomènes diffus sur les citoyens et les difficultés liées à la preuve scientifique du lien causal entre ce dommage et un émetteur de polluant donné, les recours classiques en responsabilité civile et pour troubles de voisinage, prévus aux articles 1457 et 976 C.c.Q., apparaissent inopérants. Nous nous interrogeons donc sur l’existence d’un droit à l’environnement qui conférerait aux citoyens le droit de vivre dans un environnement sain et leur permettrait ainsi de réclamer que cesse toute atteinte environnementale engendrée par ces phénomènes, même si elle n’a pas d’effet directement sur eux. Considérant l’importance de l’efficacité des recours qui pourraient permettre une mise en œuvre de ce droit, nous procéderons à l’analyse de trois sources potentielles d’un droit à l’environnement sous cet angle. À cet effet, nous étudierons les recours constitutionnels et quasi-constitutionnels liés à la Charte canadienne des droits et libertés, à la Charte des droits et libertés de la personne et au recours institutionnel prévu dans la Loi sur la qualité de l’environnement. Considérant l’absence de reconnaissance suffisante d’un droit à l’environnement et de recours efficaces pour en assurer la mise en œuvre, nous proposerons ensuite des pistes de solution afin que puisse être développé un mécanisme permettant une réponse judiciaire aux phénomènes environnementaux diffus.

L’apolipoprotéine A-I interagit avec l’adhésine impliquée dans l’adhérence diffuse (AIDA-I) d’Escherichia coli : rôle lors du processus d’adhésion et d’invasion

L’adhésine impliquée dans l’adhérence diffuse (AIDA-I) est une adhésine bactérienne présente chez certaines souches d’Escherichia coli qui, associée aux toxines Stx2e ou STb, contribue à l’apparition de la maladie de l’œdème ou de la diarrhée post-sevrage chez les porcelets. AIDA-I est un autotransporteur qui confère des capacités d’autoaggrégation, de formation de biofilms et d’adhésion. L’objectif principal du projet de recherche consistait en la recherche de récepteur(s) potentiel(s) d’AIDA-I. Les bactéries pathogènes adhèrent aux cellules-cibles soit en liant directement des molécules à la surface cellulaire ou en utilisant des molécules intermédiaires qui permettent de diminuer la distance séparant la bactérie de la cellule-cible. Puisque le sérum est un fluide qui contient de nombreuses molécules, celui-ci a été utilisé comme matériel de départ pour l’isolement de récepteur(s) potentiels. Nous avons isolé un récepteur potentiel à partir du sérum porcin : l’apolipoprotéine A-I. L’interaction entre l’apolipoprotéine A-I et AIDA-I a été confirmée par ELISA et microscopie à fluorescence. La capacité à envahir les cellules épithéliales offre aux pathogènes la possibilité d’établir une niche intracellulaire qui les protègent contre les attaques du milieu extérieur. La présente étude a démontré que la présence d’AIDA-I en tant que seul facteur de virulence chez une souche de laboratoire permet de conférer la capacité d’envahir les cellules sans promouvoir la survie intracellulaire. L’étude de la souche sauvage 2787, exprimant AIDA-I en association avec d’autres facteurs de virulence, a démontré une différence significative pour les phénotypes d’invasion et de survie intracellulaire face à la souche de laboratoire exprimant AIDA-I.