189 research outputs found

    Ark or park: the need to predict relative effectiveness of ex situ and in situ conservation before attempting captive breeding

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    1. When species face extinction, captive breeding may be appropriate. However, captive breeding may be unsuccessful, while reducing motivation and resources for in situ conservation and impacting wild source populations. Despite such risks, decisions are generally taken without rigorous evaluation. We develop an individual-based, stochastic population model to evaluate the potential effectiveness of captive-breeding and release programmes, illustrated by the Critically Endangered Ardeotis nigriceps Vigors great Indian bustard. 2. The model was parameterized from a comprehensive review of captive breeding and wild demography of large bustards. To handle uncertainty in the standards of captive-breeding performance that may be achieved we explored four scenarios of programme quality: ‘full-range’ (parameters sampled across the observed range), ‘below-average’, ‘above-average’ and ‘best possible’ (performance observed in exemplary breeding programmes). Results are evaluated examining i) the probability of captive population extirpation within 50 years and ii) numbers of adult females subsequently established in the wild following release, compared to an alternative strategy of in situ conservation without attempting captive breeding. 3. Successful implementation of captive breeding, involving permanent retention of 20 breeding females and release of surplus juveniles, required collection of many wild eggs and consistent ‘best possible’ performance across all aspects of the programme. Under ‘full-range’ and ‘above-average’ scenarios captive population extirpation probabilities were 73–88% % and 23‒51%% respectively, depending on egg collection rates. 4. Although most (73‒92%) ‘best possible’ programmes supported releases, re-establishment of free-living adults also required effective in situ conservation. Incremental implementation of effective conservation measures over the initial 10 years resulted in more free-living adults within 35 years if eggs were left in the wild without attempting captive breeding. 5. Synthesis and applications. For the great Indian bustard Ardeotis nigriceps, rapid implementation of in situ conservation offers a better chance to avoid extinction than captive breeding. Demographic modelling should be used to examine whether captive breeding is likely to bring net benefits to conservation programmes

    Neuregulin signaling on glucose transport in muscle cells

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    Neuregulin-1, a growth factor that potentiates myogenesis induces glucose transport through translocation of glucose transporters, in an additive manner to insulin, in muscle cells. In this study, we examined the signaling pathway required for a recombinant active neuregulin-1 isoform (rhHeregulin-β1, 177-244, HRG) to stimulate glucose uptake in L6E9 myotubes. The stimulatory effect of HRG required binding to ErbB3 in L6E9 myotubes. PI3K activity is required for HRG action in both muscle cells and tissue. In L6E9 myotubes, HRG stimulated PKBα, PKBγ, and PKCζ activities. TPCK, an inhibitor of PDK1, abolished both HRG- and insulin-induced glucose transport. To assess whether PKB was necessary for the effects of HRG on glucose uptake, cells were infected with adenoviruses encoding dominant negative mutants of PKBα. Dominant negative PKB reduced PKB activity and insulin-stimulated glucose transport but not HRG-induced glucose transport. In contrast, transduction of L6E9 myotubes with adenoviruses encoding a dominant negative kinase-inactive PKCζ abolished both HRG- and insulin-stimulated glucose uptake. In soleus muscle, HRG induced PKCζ, but not PKB phosphorylation. HRG also stimulated the activity of p70S6K, p38MAPK, and p42/p44MAPK and inhibition of p42/p44MAPK partially repressed HRG action on glucose uptake. HRG did not affect AMPKα1 or AMPKα2 activities. In all, HRG stimulated glucose transport in muscle cells by activation of a pathway that requires PI3K, PDK1, and PKCζ, but not PKB, and that shows cross-talk with the MAPK pathway. The PI3K, PDK1, and PKCζ pathway can be considered as an alternative mechanism, independent of insulin, to induce glucose uptake

    δ-Aminolevulinic acid transport in murine mammary adenocarcinoma cells is mediated by beta transporters

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    δ-aminolevulinic acid, the precursor of porphyrin biosynthesis has been used to induce the endogenous synthesis of the photosensitiser protoporphyrin IX for photodynamic therapy in the treatment of various tumours. The aim of this work was to characterise the δ-aminolevulinic acid transport system in the murine mammary adenocarcinoma cell line LM3 using 14C-δ-aminolevulinic acid, to finally improve δ-aminolevulinic acid incorporation in mammalian cells. Our results showed that δ-aminolevulinic acid is incorporated into these cells by two different mechanisms, passive diffusion which is important at the beginning of the incubation, and active transport. Specificity assays suggested that the transporter involved in δ-aminolevulinic acid incorporation is a BETA transporter, probably GAT-2

    Graph based study of allergen cross-reactivity of plant lipid transfer proteins (LTPs) using microarray in a multicenter study.

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    The study of cross-reactivity in allergy is key to both understanding. the allergic response of many patients and providing them with a rational treatment In the present study, protein microarrays and a co-sensitization graph approach were used in conjunction with an allergen microarray immunoassay. This enabled us to include a wide number of proteins and a large number of patients, and to study sensitization profiles among members of the LTP family. Fourteen LTPs from the most frequent plant food-induced allergies in the geographical area studied were printed into a microarray specifically designed for this research. 212 patients with fruit allergy and 117 food-tolerant pollen allergic subjects were recruited from seven regions of Spain with different pollen profiles, and their sera were tested with allergen microarray. This approach has proven itself to be a good tool to study cross-reactivity between members of LTP family, and could become a useful strategy to analyze other families of allergens

    Mechanistic studies on δ-aminolevulinic acid uptake and efflux in a mammary adenocarcinoma cell line

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    δ-aminolevulinic acid (ALA) is the precursor in the biosynthesis of porphyrins. The knowledge of both the regulation of ALA entrance and efflux from the cells and the control of porphyrin biosynthesis is essential to improve ALA-mediated photodynamic therapy. In this work, we studied the regulation of ALA uptake and efflux by endogenously accumulated ALA and/or porphyrins in murine mammary adenocarcinoma cells. Under our set of conditions, the haem synthesis inhibitor succinyl acetone completely prevented porphobilinogen and porphyrin synthesis from ALA, and led to an increase in the intracellular ALA pool. However, neither intracellular ALA nor porphyrin pools regulate ALA uptake or efflux during the first 15 min of the process. Based on temperature dependence data, ALA but not γ-aminobutyric acid (GABA) efflux is mediated by a diffusion mechanism. Moreover, the addition of extracellular GABA not only did not influence the rate of ALA efflux but on the contrary it affected ALA uptake, showing the contribution of a saturable mechanism for the uptake, but not for the efflux of ALA from the cells. © 2003 Cancer Research UK.Fil:Correa García, S. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Casas, A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Perotti, C. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Batlle, A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Bermúdez Moretti, M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina

    Programa de Atención al Ictus en Aragón (PAIA). Estrategia del cambio y resultados en el periodo 2009-2014

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    Introducción En 2008, Aragón tenía tasas de morbimortalidad y discapacidad por ictus superiores a las del conjunto de España. Se estableció la necesidad de desarrollar un Programa de Atención al Ictus (PAIA). Material y métodos Damos a conocer la dinámica de planificación, implantación, evaluación y mejora que se ha desarrollado entre los años 2009-2014 y sus resultados a 5 años. Resultados Se ha mejorado en la estructura, en los procesos y en los resultados, con mejoría en los indicadores clave de la asistencia (audit 2008-2010-2012) y otros: tasa ictus 2013: 2, 07 (2008: 2, 36); 78% ictus atendidos en áreas/unidades en 2014 (30%, 2008); tasa fibrinólisis 8, 3% en 2014 (4, 4%, 2010); fibrinólisis hospitales secundarios (30% total); fibrinólisis con teleictus 9%; descenso de la mortalidad por ictus, 38%; años de vida prematura perdidos 67, 7 (2013)/144 (2008); capacitación de enfermería, desarrollo de la neurosonología, trabajo en red, con protocolos y buenas prácticas compartidos entre sectores sanitarios, etc. Conclusiones La gestión por procesos y equipos multidisciplinares desplegados en una distribución territorial integral, con protocolos y referencias establecidas y una dinámica de evaluación y mejora continua, ha demostrado ser una herramienta potente para garantizar la calidad y la equidad. El PAIA, por su dinámica de mejora sostenida y la implicación de los clínicos, es un buen ejemplo de gestión clínica y trabajo en red. Introduction: In 2008, stroke mortality, morbidity, and disability rates in Aragon were higher than the average in Spain. These data underscored the need to develop a stroke care programme (PAIA). Material and methods: We present the dynamics of planning, implementation, evaluation, and improvement developed between 2009 and 2014 as well as the results of the PAIA after that 5-year period. Results: Structure, processes, and outcomes have improved with reference to the key indicators of healthcare (audit: 2008, 2010, 2012) among others: stroke rate in 2013 was 2.07 (2.36 in 2008); 78% of strokes were managed in stroke units in 2014 (30% in 2008); rate of fibrinolysis was 8.3% in 2014 (4.4% in 2010); fibrinolysis was administered in secondary hospitals (30% of the total); fibrinolysis was administered by Telestroke in 9%; stroke mortality decreased (38%); 67.7 years of potential life lost (YPLL) in 2013 (144 in 2008); nurse training; development of neurosonology; networking; sharing protocols and best practices between health sectors, etc. Conclusions: Integrated process management and multidisciplinary teams distributed and deployed over an entire territory with established protocols, references, evaluations, and continuous development, have been proven powerful tools to ensure both quality and equality. The PAIA is a good example of clinical governance and networking due to its dynamic and sustained improvement and cooperation between clinicians

    Early-onset and classical forms of type 2 diabetes show impaired expression of genes involved in muscle branched-chain amino acids metabolism

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    The molecular mechanisms responsible for the pathophysiological traits of type 2 diabetes are incompletely understood. Here we have performed transcriptomic analysis in skeletal muscle, and plasma metabolomics from subjects with classical and early-onset forms of type 2 diabetes (T2D). Focused studies were also performed in tissues from ob/ob and db/db mice. We document that T2D, both early and late onset, are characterized by reduced muscle expression of genes involved in branched-chain amino acids (BCAA) metabolism. Weighted Co-expression Networks Analysis provided support to idea that the BCAA genes are relevant in the pathophysiology of type 2 diabetes, and that mitochondrial BCAA management is impaired in skeletal muscle from T2D patients. In diabetic mice model we detected alterations in skeletal muscle proteins involved in BCAA metabolism but not in obese mice. Metabolomic analysis revealed increased levels of branched-chain keto acids (BCKA), and BCAA in plasma of T2D patients, which may result from the disruption of muscle BCAA management. Our data support the view that inhibition of genes involved in BCAA handling in skeletal muscle takes place as part of the pathophysiology of type 2 diabetes, and this occurs both in early-onset and in classical type 2 diabetes

    Dysfunctional LAT2 amino acid transporter is associated with cataract in mouse and humans

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    Cataract, the loss of ocular lens transparency, accounts for ∼50% of worldwide blindness and has been associated with water and solute transport dysfunction across lens cellular barriers. We show that neutral amino acid antiporter LAT2 (Slc7a8) and uniporter TAT1 (Slc16a10) are expressed on mouse ciliary epithelium and LAT2 also in lens epithelium. Correspondingly, deletion of LAT2 induced a dramatic decrease in lens essential amino acid levels that was modulated by TAT1 defect. Interestingly, the absence of LAT2 led to increased incidence of cataract in mice, in particular in older females, and a synergistic effect was observed with simultaneous lack of TAT1. Screening SLC7A8 in patients diagnosed with congenital or age-related cataract yielded one homozygous single nucleotide deletion segregating in a family with congenital cataract. Expressed in HeLa cells, this LAT2 mutation did not support amino acid uptake. Heterozygous LAT2 variants were also found in patients with cataract some of which showed a reduced transport function when expressed in HeLa cells. Whether heterozygous LAT2 variants may contribute to the pathology of cataract needs to be further investigated. Overall, our results suggest that defects of amino acid transporter LAT2 are implicated in cataract formation, a situation that may be aggravated by TAT1 defects

    Clinical Outcomes of a Zika Virus Mother-Child Pair Cohort in Spain

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    BACKGROUND: Zika virus (ZIKV) infection has been associated with congenital microcephaly and other neurodevelopmental abnormalities. There is little published research on the effect of maternal ZIKV infection in a non-endemic European region. We aimed to describe the outcomes of pregnant travelers diagnosed as ZIKV-infected in Spain, and their exposed children. METHODS: This prospective observational cohort study of nine referral hospitals enrolled pregnant women (PW) who travelled to endemic areas during their pregnancy or the two previous months, or those whose sexual partners visited endemic areas in the previous 6 months. Infants of ZIKV-infected mothers were followed for about two years. RESULTS: ZIKV infection was diagnosed in 163 PW; 112 (70%) were asymptomatic and 24 (14.7%) were confirmed cases. Among 143 infants, 14 (9.8%) had adverse outcomes during follow-up; three had a congenital Zika syndrome (CZS), and 11 other potential Zika-related outcomes. The overall incidence of CZS was 2.1% (95%CI: 0.4-6.0%), but among infants born to ZIKV-confirmed mothers, this increased to 15.8% (95%CI: 3.4-39.6%). CONCLUSIONS: A nearly 10% overall risk of neurologic and hearing adverse outcomes was found in ZIKV-exposed children born to a ZIKV-infected traveler PW. Longer-term follow-up of these children is needed to assess whether there are any later-onset manifestations

    Sea Urchins Predation Facilitates Coral Invasion in a Marine Reserve

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    Macroalgae is the dominant trophic group on Mediterranean infralittoral rocky bottoms, whereas zooxanthellate corals are extremely rare. However, in recent years, the invasive coral Oculina patagonica appears to be increasing its abundance through unknown means. Here we examine the pattern of variation of this species at a marine reserve between 2002 and 2010 and contribute to the understanding of the mechanisms that allow its current increase. Because indirect interactions between species can play a relevant role in the establishment of species, a parallel assessment of the sea urchin Paracentrotus lividus, the main herbivorous invertebrate in this habitat and thus a key species, was conducted. O. patagonica has shown a 3-fold increase in abundance over the last 8 years and has become the most abundant invertebrate in the shallow waters of the marine reserve, matching some dominant erect macroalgae in abundance. High recruitment played an important role in this increasing coral abundance. The results from this study provide compelling evidence that the increase in sea urchin abundance may be one of the main drivers of the observed increase in coral abundance. Sea urchins overgraze macroalgae and create barren patches in the space-limited macroalgal community that subsequently facilitate coral recruitment. This study indicates that trophic interactions contributed to the success of an invasive coral in the Mediterranean because sea urchins grazing activity indirectly facilitated expansion of the coral. Current coral abundance at the marine reserve has ended the monopolization of algae in rocky infralittoral assemblages, an event that could greatly modify both the underwater seascape and the sources of primary production in the ecosystem
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