3,539 research outputs found
Actividad bacteriocinogénica de bacterias aisladas de digestivos de peces marinos salvajes
El crecimiento exponencial que ha sufrido la acuicultura en las últimas décadas ha dado lugar a un incremento en número y virulencia de las enfermedades bacterianas que afectan a los peces cultivados. Hasta la fecha, el control de estas enfermedades se ha realizado a través del uso de vacunas y antibióticos, así como de la desinfección del agua y el control biológico, el uso de inmunoestimulantes no-específicos y suplementos dietéticos, entre otros. Pero una mala gestión de estas enfermedades, asociada sobre todo al abuso de antibióticos, ha sido asociada a la aparición de reservorios de bacterias resistentes a antibióticos, tanto en animales como en el ambiente acuático, con el consiguiente peligro para la salud humana (1, 2). El empleo de bacteriocinas como alternativa a los antibióticos parece ser una alternativa plausible para el control y tratamiento de estas enfermedades de una manera inocua y sostenible (3, 4). Pese a que en los últimos años se ha intensificado la búsqueda de cepas productoras de bacteriocinas frente a bacterias patógenas marinas, desafortunadamente todavía son pocas las cepas totalmente caracterizadas (5).
El presente estudio tiene por objetivo caracterizar cepas bacterianas con actividad bacteriocinogénica aisladas de intestinos de peces salvajes del Mar Cantábrico. Para ello se procesaron un total de 19 intestinos pertenecientes a 19 ejemplares, cada uno de una especie diferente capturados en el Mar Cantábrico (Cantabria). De estas muestras se aislaron un total de 198 colonias en medio de cultivo TSA, en base a su morfología, color y brillo, que fueron seleccionadas para comprobar su actividad antagonista frente a patógenos de peces de acuicultura. Como cepas indicadoras patógenas de peces se emplearon: Vibrio splendidus y Vibrio anguillarum, y cepas patógenas aisladas de cultivos de lenguado senegalés (Solea senegalensis). Se detectaron 15 cepas de bacterias marinas que presentaban actividad antagonista frente al menos una de las cepas patógenas, de las cuales 4 mostraron actividad inhibitoria frente a más de una especie patógena. La identificación de las cepas procedentes del medio marino seleccionadas se realizó mediante la secuenciación del gen 16S ARN, presentando una homología >99% a Myroides sp. y Alcaligenes sp. Finalmente se estudió el efecto de los parámetros físico-químicos en la actividad bactericida (pH, temperatura y proteasas)
Epigenetic Profiling and Response to CD19 Chimeric Antigen Receptor T-Cell Therapy in B-Cell Malignancies
Background: Chimeric antigen receptor (CAR) T cells directed against CD19 (CART19) are effective in B-cell malignancies, but little is known about the molecular factors predicting clinical outcome of CART19 therapy. The increasingly recognized relevance of epigenetic changes in cancer immunology prompted us to determine the impact of the DNA methylation profiles of CART19 cells on the clinical course.
Methods: We recruited 114 patients with B-cell malignancies, comprising 77 patients with acute lymphoblastic leukemia and 37 patients with non-Hodgkin lymphoma who were treated with CART19 cells. Using a comprehensive DNA methylation microarray, we determined the epigenomic changes that occur in the patient T cells upon transduction of the CAR vector. The effects of the identified DNA methylation sites on clinical response, cytokine release syndrome, immune effector cell-associated neurotoxicity syndrome, event-free survival, and overall survival were assessed. All statistical tests were 2-sided.
Results: We identified 984 genomic sites with differential DNA methylation between CAR-untransduced and CAR-transduced T cells before infusion into the patient. Eighteen of these distinct epigenetic loci were associated with complete response (CR), adjusting by multiple testing. Using the sites linked to CR, an epigenetic signature, referred to hereafter as the EPICART signature, was established in the initial discovery cohort (n = 79), which was associated with CR (Fisher exact test, P < .001) and enhanced event-free survival (hazard ratio [HR] = 0.36; 95% confidence interval [CI] = 0.19 to 0.70; P = .002; log-rank P = .003) and overall survival (HR = 0.45; 95% CI = 0.20 to 0.99; P = .047; log-rank P = .04;). Most important, the EPICART profile maintained its clinical course predictive value in the validation cohort (n = 35), where it was associated with CR (Fisher exact test, P < .001) and enhanced overall survival (HR = 0.31; 95% CI = 0.11 to 0.84; P = .02; log-rank P = .02).
Conclusions: We show that the DNA methylation landscape of patient CART19 cells influences the efficacy of the cellular immunotherapy treatment in patients with B-cell malignancy.Supported by CERCA Programme/Generalitat de Catalunya, Health Department PERIS #SLT/002/16/00374, AGAUR-project #2017SGR1080; MCI/AEI/ERDF project #RTI2018-094049-B-I00; ERC EPIPHARM; Cellex Foundation; “la Caixa” Foundation (LCF/PR/GN18/51140001 and LCF/PR/GN18/50310007), RF-2016–02364388, Accelerator Award—Cancer Research UK/AIRC—INCAR Associazione Italiana Ricerca per la Ricerca sul Cancro (AIRC) Project 5 × 1000 no. 9962, AIRC IG 2018 id. 21724, AIRC MFAG id. 21769 and id. 20450; MIUR (Grant PRIN 2017); and RCR-2019–23669115
Study of the Very High Energy emission of M87 through its broadband spectral energy distribution
The radio galaxy M87 is the central dominant galaxy of the Virgo Cluster.Very High Energy (VHE, TeV) emission, from M87 has been detectedby Imaging Air Cherenkov Telescopes (IACTs ). Recently, marginal evidence forVHE long-term emission has also been observed by the High Altitude WaterCherenkov (HAWC) Observatory, a gamma ray and cosmic-ray detector array locatedin Puebla, Mexico. The mechanism that produces VHE emission in M87 remainsunclear. This emission is originated in its prominent jet, which has beenspatially resolved from radio to X-rays. In this paper, we constructed aspectral energy distribution from radio to gamma rays that is representative ofthe non-flaring activity of the source, and in order to explain the observedemission, we fit it with a lepto-hadronic emission model. We found that thismodel is able to explain non-flaring VHE emission of M87 as well as an orphanflare reported in 2005.<br
Validation of standardized data formats and tools for ground-level particle-based gamma-ray observatories
Ground-based gamma-ray astronomy is still a rather young field of research,with strong historical connections to particle physics. This is why mostobservations are conducted by experiments with proprietary data and analysissoftware, as it is usual in the particle physics field. However in recentyears, this paradigm has been slowly shifting towards the development and useof open-source data formats and tools, driven by upcoming observatories such asthe Cherenkov Telescope Array (CTA). In this context, a community-driven,shared data format (the gamma-astro-data-format or GADF) and analysis toolssuch as Gammapy and ctools have been developed. So far these efforts have beenled by the IACT community, leaving out other types of ground-based gamma-rayinstruments.We aim to show that the data from ground particle arrays, such asthe High-Altitude Water Cherenkov (HAWC) observatory, is also compatible withthe GADF and can thus be fully analysed using the related tools, in this caseGammapy. We reproduce several published HAWC results using Gammapy and dataproducts compliant with GADF standard. We also illustrate the capabilities ofthe shared format and tools by producing a joint fit of the Crab spectrumincluding data from six different gamma-ray experiments. We find excellentagreement with the reference results, a powerful check of both the publishedresults and the tools involved. The data from particle detector arrays such asthe HAWC observatory can be adapted to the GADF and thus analysed with Gammapy.A common data format and shared analysis tools allow multi-instrument jointanalysis and effective data sharing. Given the complementary nature of pointingand wide-field instruments, this synergy will be distinctly beneficial for thejoint scientific exploitation of future observatories such as the SouthernWide-field Gamma-ray Observatory and CTA.<br
Search for Third Generation Vector Leptoquarks in p anti-p Collisions at sqrt(s) = 1.96 TeV
We describe a search for a third generation vector leptoquark (VLQ3) that
decays to a b quark and tau lepton using the CDF II detector and 322 pb^(-1) of
integrated luminosity from the Fermilab Tevatron. Vector leptoquarks have been
proposed in many extensions of the standard model (SM). Observing a number of
events in agreement with SM expectations, assuming Yang-Mills (minimal)
couplings, we obtain the most stringent upper limit on the VLQ3 pair production
cross section of 344 fb (493 fb) and lower limit on the VLQ3 mass of 317
GeV/c^2 (251 GeV/c^2) at 95% C.L.Comment: 7 pages, 2 figures, submitted to PR
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