24 research outputs found

    Cell-specific conditional deletion of interleukin-1 (IL-1) ligands and its receptors : a new toolbox to study the role of IL-1 in health and disease

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    The pro-inflammatory cytokine interleukin-1 (IL-1) plays a key role in many physiological processes and during the inflammatory and immune response to most common diseases. IL-1 exists as two agonists, IL-1α and IL-1β that bind to the only signaling IL-1 type 1 receptor (IL-1R1), while a second decoy IL-1 type 2 receptor (IL-1R2) binds both forms of IL-1 without inducing cell signaling. The field of immunology and inflammation research has, over the past 35 years, unraveled many mechanisms of IL-1 actions, through in vitro manipulation of the IL-1 system or by using genetically engineered mouse models that lack either member of the IL-1 family in ubiquitous constitutive manner. However, the limitation of global mouse knockout technology has significantly hampered our understanding of the precise mechanisms of IL-1 actions in animal models of disease. Here we report and review the recent generation of new conditional mouse mutants in which exons of Il1a, Il1b, Il1r1, and Il1r2 genes flanked by loxP sites (fl/fl) can be deleted in cell-/tissue-specific constitutive or inducible manner by Cre recombinase expression. Hence, IL-1αfl/fl, IL-1βfl/fl, IL-1R1fl/fl, and IL-1R2fl/fl mice constitute a new toolbox that will provide a step change in our understanding of the cell-specific role of IL-1 and its receptor in health and disease and the potential development of targeted IL-1 therapies

    Circumstellar interaction in supernovae in dense environments - an observational perspective

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    In a supernova explosion, the ejecta interacting with the surrounding circumstellar medium (CSM) give rise to variety of radiation. Since CSM is created from the mass lost from the progenitor star, it carries footprints of the late time evolution of the star. This is one of the unique ways to get a handle on the nature of the progenitor star system. Here, I will focus mainly on the supernovae (SNe) exploding in dense environments, a.k.a. Type IIn SNe. Radio and X-ray emission from this class of SNe have revealed important modifications in their radiation properties, due to the presence of high density CSM. Forward shock dominance of the X-ray emission, internal free-free absorption of the radio emission, episodic or non-steady mass loss rate, asymmetry in the explosion seem to be common properties of this class of SNe.Comment: Fixed minor typos. 31 pages, 9 figures, accepted for publication in Space Science Reviews. Chapter in International Space Science Institute (ISSI) Book on "Supernovae" to be published in Space Science Reviews by Springe

    Detection of the rare Australian endemic blind cave eel (Ophisternon candidum) with environmental DNA: implications for threatened species management in subterranean environments

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    The blind cave eel, Ophisternon candidum (Mees in J R Soc West Aust 45: 24–32,1962), is a rare groundwater inhabitant found in geographically isolated populations of north-west Australia. The species is listed as vulnerable under Commonwealth legislation and is a priority consideration when environmental disturbance by resource companies is proposed. Detection of this species for Environmental Impact Assessment (EIA) and monitoring is difficult because individuals are naturally rare or traditional sampling techniques are ineffective. To properly manage the species, information on population distribution and connectivity is critical. We sought to examine whether environmental DNA (eDNA) of O. candidum could be detected and whether positive detection was correlated with previous locations where the species had been physically caught. We developed new eDNA species-specific PCR assays to screen groundwater sampling points and we detected O. candidum DNA in three boreholes where the species has previously been collected and five additional groundwater sampling points. Our results demonstrated that the newly designed assays were effective for detecting this rare and vulnerable subterranean species. This work sets a benchmark for the application of eDNA species-specific PCR assays for EIA and monitoring, and has potential for these assays to be expanded more broadly to high-throughput eDNA metabarcoding for subterranean groundwater communities in the future.Nicole E. White, Michelle T. Guzik, Andrew D. Austin, Glenn I. Moore, William F. Humphreys, Jason Alexander and Michael Bunc

    Rainfall as a trigger of ecological cascade effects in an Australian groundwater ecosystem

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    Groundwaters host vital resources playing a key role in the near future. Subterranean fauna and microbes are crucial in regulating organic cycles in environments characterized by low energy and scarce carbon availability. However, our knowledge about the functioning of groundwater ecosystems is limited, despite being increasingly exposed to anthropic impacts and climate change-related processes. In this work we apply novel biochemical and genetic techniques to investigate the ecological dynamics of an Australian calcrete under two contrasting rainfall periods (LR—low rainfall and HR—high rainfall). Our results indicate that the microbial gut community of copepods and amphipods experienced a shift in taxonomic diversity and predicted organic functional metabolic pathways during HR. The HR regime triggered a cascade effect driven by microbes (OM processors) and exploited by copepods and amphipods (primary and secondary consumers), which was finally transferred to the aquatic beetles (top predators). Our findings highlight that rainfall triggers ecological shifts towards more deterministic dynamics, revealing a complex web of interactions in seemingly simple environmental settings. Here we show how a combined isotopic-molecular approach can untangle the mechanisms shaping a calcrete community. This design will help manage and preserve one of the most vital but underrated ecosystems worldwide.Mattia Saccò, Alison J. Blyth, William F. Humphreys, Steven J. B. Cooper, Nicole E. White, Matthew Campbell, Mahsa Mousavi, Derazmahalleh, Quan Hua, Debashish Mazumder, Colin Smith, Christian Griebler, Kliti Gric

    Brucelose em bovinos com bursite cervical diagnosticada em abatedouro sob inspeção federal Brucelosis in cattle with supraspinous bursitis diagnosed in an abattoir under federal inspection

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    Estudo epidemiológico tipo caso-controle realizado em Uberlândia, Minas Gerais (MG), Brasil, pesquisou a ocorrência de brucelose em bovinos com bursite cervical, abatidos no período de agosto de 1993 a julho de 1994. O diagnóstico sorológico de brucelose foi realizado mediante a prova de soroaglutinação rápida em placa. Os casos de bursite foram identificados por técnico do Serviço de Inspeção Federal (SIF), com base em características morfológicas, previamente padronizadas. Para a determinação da "Razão de Odds" e do risco atribuível entre bursite e brucelose, utilizaram-se 30 animais com o quadro e, como controle, 90 bovinos sem a patologia. Dos animais com bursite, 13,3% eram brucélicos, contra 5,6% do grupo controle (P=0,115). Dentre aqueles com brucelose e bursite, as bolsas continham fibrina (40,0%) e projeções digitiformes (33,3%); apenas nas bursites dos sorologicamente negativos encontraram-se presença de pus, de nódulos e de líquido viscoso. A "Razão de Odds" encontrada entre brucelose e bursite foi da ordem de 2,61, não sendo demonstrado associação entre bursite cervical e sorologia positiva para brucelose (P>0,05). No âmbito da Saúde Pública e ocupacional, sugere-se a atenção de técnicos e profissionais, visando diminuir o risco de infecção e evitar contaminação de carcaças, equipamentos e instalações.<br>Epidemiological study case-control type carried out in Triângulo abattoir in the city of Uberlândia in the State of Minas Gerais, Brazil, has identified the ocorrence of brucelosis in bovine with supraspinous bursitis, slaughtered from August, 1993 to July, 1994. To diagnose brucelosis "Rapid Agglutination" test was performed on plate with the padronizated antigen count considered positive over 100. The bursas examined were identified by technicians of the Federal Inspection Service based on the presence of ten standardized morphological characteristics. Using the case-control design, 30 animals identified as having supraspinous bursitis were compared with 90 animals randomly selected, without bursitis- but with other characteristics (sex, background, lot, conformation) similar to those affected. All animals were, then, tested for brucelosis. Within the animals with bursitis, 13.33% were found to have brucelosis against 5.56% in the control group (P=0.115). The presence of pus, nodules and viscous fluid was found only among animals who tested negative for brucelosis. The odds ratio found between brucelosis and supraspinous bursitis was 2.61 (P>0.05). As a conclusion it’s suggested attention of technicians and profesionals employed in slaughter houses aiming to reduce the risk of human infection, as well as of carcasses, equipment and installations contamination
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