66 research outputs found

    Innate Immunity Provides Biomarkers of Health for Teleosts Exposed to Nanoparticles

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    In recent years, the unique properties of nanoparticles have fostered novel applications in various fields such as biology, pharmaceuticals, agriculture, and others. Unfortunately, their rapid integration into daily life has also led to environmental concerns due to uncontrolled release of nanoparticles into the aquatic environment. Despite increasing awareness of nanoparticle bioaccumulation in the aquatic environment, much remains to be learned about their impact on aquatic organisms and how to best monitor these effects. Herein, we provide the first review of innate immunity as an emerging tool to assess the health of fish following nanoparticle exposure. Fish are widely used as sentinels for aquatic ecosystem pollution and innate immune parameters offer sensitive and reliable tools that can be harnessed for evaluation of contamination events. The most frequent biomarkers highlighted in literature to date include, but are not limited to, parameters associated with leukocyte dynamics, oxidative stress, and cytokine production. Taken together, innate immunity offers finite and sensitive biomarkers for assessment of the impact of nanoparticles on fish health

    Modified Annexin V/Propidium Iodide Apoptosis Assay For Accurate Assessment of Cell Death

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    Studies of cellular apoptosis have been significantly impacted since the introduction of flow cytometry-based methods. Propidium iodide (PI) is widely used in conjunction with Annexin V to determine if cells are viable, apoptotic, or necrotic through differences in plasma membrane integrity and permeability1,2. The Annexin V/ PI protocol is a commonly used approach for studying apoptotic cells3. PI is used more often than other nuclear stains because it is economical, stable and a good indicator of cell viability, based on its capacity to exclude dye in living cells 4,5. The ability of PI to enter a cell is dependent upon the permeability of the membrane; PI does not stain live or early apoptotic cells due to the presence of an intact plasma membrane 1,2,6. In late apoptotic and necrotic cells, the integrity of the plasma and nuclear membranes decreases7,8, allowing PI to pass through the membranes, intercalate into nucleic acids, and display red fluorescence 1,2,9. Unfortunately, we find that conventional Annexin V/ PI protocols lead to a significant number of false positive events (up to 40%), which are associated with PI staining of RNA within the cytoplasmic compartment10. Primary cells and cell lines in a broad range of animal models are affected, with large cells (nuclear: cytoplasmic ratios <0.5) showing the highest occurrence10. Herein, we demonstrate a modified Annexin V/ PI method that provides a significant improvement for assessment of cell death compared to conventional methods. This protocol takes advantage of changes in cellular permeability during cell fixing to promote entry of RNase A into cells following staining. Both the timing and concentration of RNase A have been optimized for removal of cytoplasmic RNA. The result is a significant improvement over conventional Annexin V/ PI protocols (< 5% events with cytoplasmic PI staining)

    Distinct Differentiation Programs Triggered by IL-6 And LPS in Teleost IgM+ B Cells in the Absence of Germinal Centers

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    We would like to thank Lucia Gonzalez and Maria Sanz for technical assistance. Professor Øystein Evensen is also acknowledged for providing us with the inactivated IPNV. This work was supported by the European Research Council (ERC Starting Grant 2011 280469) and by the European Commission under the 7th Framework Programme for Research and Technological Development (FP7) of the European Union (Grant Agreement 311993 TARGETFISH). T. W. received funding from the MASTS pooling initiative (The Marine Alliance for Science and Technology for Scotland). MASTS is funded by the Scottish Funding Council (grant reference HR09011).Peer reviewedPublisher PD

    Skipper-CCD Sensors for the Oscura Experiment: Requirements and Preliminary Tests

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    Oscura is a proposed multi-kg skipper-CCD experiment designed for a dark matter (DM) direct detection search that will reach unprecedented sensitivity to sub-GeV DM-electron interactions with its 10 kg detector array. Oscura is planning to operate at SNOLAB with 2070 m overburden, and aims to reach a background goal of less than one event in each electron bin in the 2-10 electron ionization-signal region for the full 30 kg-year exposure, with a radiation background rate of 0.01 dru. In order to achieve this goal, Oscura must address each potential source of background events, including instrumental backgrounds. In this work, we discuss the main instrumental background sources and the strategy to control them, establishing a set of constraints on the sensors' performance parameters. We present results from the tests of the first fabricated Oscura prototype sensors, evaluate their performance in the context of the established constraints and estimate the Oscura instrumental background based on these results

    Early Science with the Oscura Integration Test

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    Oscura is a planned light-dark matter search experiment using Skipper-CCDs with a total active mass of 10 kg. As part of the detector development, the collaboration plans to build the Oscura Integration Test (OIT), an engineering test experiment with 10% of the Oscura's total mass. Here we discuss the early science opportunities with the OIT to search for millicharged particles (mCPs) using the NuMI beam at Fermilab. mCPs would be produced at low energies through photon-mediated processes from decays of scalar, pseudoscalar, and vector mesons, or direct Drell-Yan productions. Estimates show that the OIT would be a world-leading probe for low-mass mCPs.Comment: 21 pages, 13 figure

    Kwapa: Gente del río. Estrategias transmedia de impacto social

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    PAP Alter Código produce materiales de interacción audiovisual que se organizan en un universo transmedia, trabaja con personas de todas las edades, su meta es difundir representaciones no estigmatizantes de grupos socialmente desfavorecidos, además de compartir esta visión a todo aquel que colabore en el proyecto. En la temporada de verano 2023, el equipo Alter CÓDIGO continuó con el desarrollo del videojuego “A la orilla del río”, para ello la organización del trabajo se dividió en múltiples áreas tanto como comunitarias como digitales para dar una mayor profundidad al producto. Los avances más significativos van desde una versión más actualizada del guion, storyboards, una primera animación, un demo, este último de lo que sería el gameplay, y un minijuego. Asimismo, se muestra la vinculación comunitaria e impacto social que se logró con el desarrollo de los talleres de intervención fotográfica con niños acerca de su territorio. Paralelamente se aborda la creación de redes sociales y página web para la difusión del proyecto por fuera del PAP. En los dos meses de trabajo se cumplieron con los ideales del Proyecto de Aplicación Profesional y se logró una difusión transmedia. A pesar de que el proyecto aún no llega a su finalización, los avances y el alcance superaron las metas que se otorgaron al inicio de la temporada.ITESO, A.C

    Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

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    The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

    Acute Inflammation in Tissue Healing

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    There are well-established links between acute inflammation and successful tissue repair across evolution. Innate immune reactions contribute significantly to pathogen clearance and activation of subsequent reparative events. A network of molecular and cellular regulators supports antimicrobial and tissue repair functions throughout the healing process. A delicate balance must be achieved between protection and the potential for collateral tissue damage associated with overt inflammation. In this review, we summarize the contributions of key cellular and molecular components to the acute inflammatory process and the effective and timely transition toward activation of tissue repair mechanisms. We further discuss how the disruption of inflammatory responses ultimately results in chronic non-healing injuries

    Neutrophil Development, Migration, and Function in Teleost Fish

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    It is now widely recognized that neutrophils are sophisticated cells that are critical to host defense and the maintenance of homeostasis. In addition, concepts such as neutrophil plasticity are helping to define the range of phenotypic profiles available to cells in this group and the physiological conditions that contribute to their differentiation. Herein, we discuss key features of the life of a teleost neutrophil including their development, migration to an inflammatory site, and contributions to pathogen killing and the control of acute inflammation. The potent anti-microbial mechanisms elicited by these cells in bony fish are a testament to their long-standing evolutionary contributions in host defense. In addition, recent insights into their active roles in the control of inflammation prior to induction of apoptosis highlight their importance to the maintenance of host integrity in these early vertebrates. Overall, our goal is to summarize recent progress in our understanding of this cell type in teleost fish, and to provide evolutionary context for the contributions of this hematopoietic lineage in host defense and an efficient return to homeostasis following injury or infection
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