81 research outputs found

    Identificación morfológica y molecular de Cysticercus fasciolaris aislado de un roedor (Rattus norvegicus) de la provincia de Buenos Aires (Argentina).

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    En un estudio exploratorio de roedores de la especie Rattus norvegicus de la provincia de Buenos Aires, se observó que ciertos metacestodos de tenias se encontraban enquis- tados en el hígado del hospedador. Nuestro objetivo fue identificar esta forma larval, basándonos en estudios morfológicos y moleculares. Para la caracterización molecular del parásito, se amplificó y secuenció el ADN ribosomal (28S) y mitocondrial (COI). Sobre la base de los datos tanto morfológicos como moleculares, y utilizando herramientas bio- informáticas, el metacestodo se identificó como Cysticercus fasciolaris. La forma adulta (Taenia taeniaeformis) comúnmente infecta hospedadores mamíferos félidos y cánidos. Esta es la primera vez que se caracteriza molecularmente este helminto, aislado de roe- dores de la provincia de Buenos Aires.Fil: Martinez, Mara Leila. Instituto Nacional de Tecnologia Agropecuaria. Centro Nacional de Inv. Agropecuarias. Centro de Invest.de Cs.veterinarias y Agronomicas. Instituto de Patobiologia; Argentina;Fil: Dominguez, Mariana Gabriela. Instituto Nacional de Tecnologia Agropecuaria. Centro Nacional de Inv. Agropecuarias. Centro de Invest.de Cs.veterinarias y Agronomicas. Instituto de Patobiologia; Argentina;Fil: Morici, Gabriel E.. Instituto Nacional de Tecnologia Agropecuaria. Centro Nacional de Inv. Agropecuarias. Centro de Invest.de Cs.veterinarias y Agronomicas. Instituto de Patobiologia; Argentina;Fil: Cavia, Regino. Consejo Nacional de Invest. Científ.y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Bs. As; Argentina; Universidad de Buenos Aires. Facultad de Cs.exactas y Naturales. Departamento de Ecologia, Genetica y Evolución; Argentina;Fil: Montes de Oca, Daniela Paula. INSTITUTO DE ECOLOGIA, GENETICA Y EVOLUCION DE BS. AS; ecologia;Fil: Lovera, Rosario. Universidad de Buenos Aires. Facultad de Cs.exactas y Naturales. Departamento de Ecologia, Genetica y Evolución; Argentina; Consejo Nacional de Invest. Científ.y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Bs. As; Argentina;Fil: Schapiro, Javier Hernan. Instituto Nacional de Tecnologia Agropecuaria. Centro Nacional de Inv. Agropecuarias. Centro de Invest.de Cs.veterinarias y Agronomicas. Instituto de Patobiologia; Argentina;Fil: Caracostantogolo, Jorge Luis. Consejo Nacional de Invest.cientif.y Tecnicas. Ultraestructura, Microanalisis y Espectroscopia; Arggentina

    Mechanical behavior and microstructural changes in polyurethane exposed to high doses of X rays, gamma rays or neutron irradiation

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    Polymeric materials are widely used in applications where the environmental conditions entail their exposure to different sources of irradiation (in most cases ultraviolet or low dose of electromagnetic irradiation for sterilization). In contrast, in this study we have assessed the modifications undergone by a series of polyurethane joints exposed to high radioactive doses of either X-rays or gamma rays (with doses of 20.5, 100, 300 and 900?kGy) or neutron irradiation (with a fluence of 7.23·1010 n/cm2) which are typical of the environment of nuclear reactors. Tensile tests were carried out to assess the change in mechanical properties derived from the radioactive exposure. Three mechanical parameters were used to monitor the evolution of strength, ductility and toughness: the tensile strength (?max), the strain corresponding to ?max (??max) and the density of energy absorbed prior to maximum load (U?max). With regards to X and gamma rays, a negative impact of radiation on strength, ductility and toughness was observed. The detailed statistical analysis of the results has shown that a threshold dose of 300?kGy must be overcome to trigger the damage process. For the fluence employed in this study, neutron irradiation produced very little change in the mechanical properties. The SEM fractographic study has allowed the influence of irradiation on the material failure mechanisms to be identified. Thus, the fracture surface of unirradiated samples shows evidence of plastic deformation and ductile tearing. In contrast, the fracture surface of those samples exposed to a dose of 900?kGy corresponds to brittle fracture. In a consistent way, samples exposed to neutron irradiation have a fracture surface similar to that of the non-irradiated material. In summary, electromagnetic radiation for doses above the threshold leads to the embrittlement of polyurethane. Raman spectroscopy was employed to identify the microstructural changes induced by the different sources of radiation at the molecular level. The band corresponding to the vibration of the C-H bending bonds present in the polyurethane was measured as a function of the dose, finding a strong correlation between its vibration frequency and the dose of exposure to electromagnetic radiation. This shift is more sensitive than the mechanical material response since the frequency is affected at doses of 100?kGy, below the threshold previously identified for any of the mechanical properties. This correlation opens the door for the use of Raman spectroscopy as a novel non-destructive tool to characterize the microstructural effect of irradiation on polyurethane

    Population genomics applications for conservation: the case of the tropical dry forest dweller Peromyscus melanophrys

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    Recent advances in genomic sequencing have opened new horizons in the study of population genetics and evolution in non-model organisms. However, very few population genomic studies have been performed on wild mammals to understand how the landscape affects the genetic structure of populations, useful information for the conservation of biodiversity. Here, we applied a genomic approach to evaluate the relationship between habitat features and genetic patterns at spatial and temporal scales in an endangered ecosystem, the Tropical Dry Forest (TDF). We studied populations of the Plateau deer mouse Peromyscus melanophrys to analyse its genomic diversity and structure in a TDF protected area in the Huautla Mountain Range (HMR), Mexico based on 8,209 SNPs obtained through Genotyping-by-Sequencing. At a spatial scale, we found a significant signature of isolation-by-distance, few significant differences in genetic diversity indices among study sites, and no significant differences between habitats with different levels of human perturbation. At a temporal scale, while genetic diversity levels fluctuated significantly over time, neither seasonality nor disturbance levels had a significant effect. Also, outlier analysis revealed loci potentially under selection. Our results suggest that the population genetics of P. melanophrys may be little impacted by anthropogenic disturbances, or by natural spatial and temporal habitat heterogeneity in our study area. The genome-wide approach adopted here provides data of value for conservation planning, and a baseline to be used as a reference for future studies on the effects of habitat fragmentation and seasonality in the HMR and in TDF

    TAp73 is one of the genes responsible for the lack of response to chemotherapy depending on B-Raf mutational status

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    <p>Abstract</p> <p>Background</p> <p>Although there have been many studies on the p73 gene, some of its functions still remain unclear. There is little research on the relationship between p73 gene transcription and its protein expression and the response to certain drugs such as oxaliplatin and cetuximab, which are drugs currently used in colorectal cancer.</p> <p>The purpose of this study was to evaluate the impact of TAp73 expression on oxaliplatin and cetuximab-based chemotherapy in colorectal cancer cell lines with different K-Ras and B-Raf mutational status.</p> <p>Methods</p> <p>TAp73 was analyzed in three colorectal tumor cell lines HT-29, SW-480 and Caco-2. mRNA TAp73 was determined using Real time PCR; TAp73 protein by immunoblotting and cell viability was analyzed by the MTT method.</p> <p>Results</p> <p>We found that mRNA and TAp73 protein were decreased in cells treated with oxaliplatin (in monotherapy or combined with cetuximab) when B-Raf is mutated. This was statistically significant and was also associated with higher cell viability after the treatment.</p> <p>Conclusions</p> <p>Here, for the first time we report, that there is a signaling loop between B-Raf activation and p73 function.</p> <p>Low expression of TAp73 in colorectal cancer cell lines with mutated B-Raf may be involved in the lack of response to oxaliplatin in monotherapy or combined with cetuximab.</p

    Paricalcitol reduces oxidative stress and inflammation in hemodialysis patients

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    Background: Treatment with selective vitamin D receptor activators such as paricalcitol have been shown to exert an anti-inflammatory effect in patients on hemodialysis, in addition to their action on mineral metabolism and independently of parathyroid hormone (PTH) levels. The objective of this study was to evaluate the additional antioxidant capacity of paricalcitol in a clinical setting. Methods: The study included 19 patients with renal disease on hemodialysis, of whom peripheral blood was obtained for analysis at baseline and three months after starting intravenous paricalcitol treatment. The following oxidizing and inflammatory markers were quantified: malondialdehyde (MDA), nitrites and carbonyl groups, indoleamine 2,3-dioxygenase (IDO), tumor necrosis factor alfa (TNF-α), interleukin-6 (IL-6), interleukin-18 (IL-18) and C-reactive protein (CRP). Of the antioxidants and anti-inflammatory markers, superoxide dismutase (SOD), catalase, reduced glutathione (GSH), thioredoxin, and interleukin-10 (IL-10) levels were obtained. Results: Baseline levels of oxidation markers MDA, nitric oxide and protein carbonyl groups significantly decreased after three months on paricalcitol treatment, while levels of GSH, thioredoxin, catalase and SOD activity significantly increased. After paricalcitol treatment, levels of the inflammatory markers CRP, TNF-α, IL-6 and IL-18 were significantly reduced in serum and the level of anti-inflammatory cytokine IL-10 was increased. Conclusions: In renal patients undergoing hemodialysis, paricalcitol treatment significantly reduces oxidative stress and inflammation, two well known factors leading to cardiovascular damageBackground: Treatment with selective vitamin D receptor activators such as paricalcitol have been shown to exert an anti-inflammatory effect in patients on hemodialysis, in addition to their action on mineral metabolism and independently of parathyroid hormone (PTH) levels. The objective of this study was to evaluate the additional antioxidant capacity of paricalcitol in a clinical setting. Methods: The study included 19 patients with renal disease on hemodialysis, of whom peripheral blood was obtained for analysis at baseline and three months after starting intravenous paricalcitol treatment. The following oxidizing and inflammatory markers were quantified: malondialdehyde (MDA), nitrites and carbonyl groups, indoleamine 2,3-dioxygenase (IDO), tumor necrosis factor alfa (TNF-α), interleukin-6 (IL-6), interleukin-18 (IL-18) and C-reactive protein (CRP). Of the antioxidants and anti-inflammatory markers, superoxide dismutase (SOD), catalase, reduced glutathione (GSH), thioredoxin, and interleukin-10 (IL-10) levels were obtained. Results: Baseline levels of oxidation markers MDA, nitric oxide and protein carbonyl groups significantly decreased after three months on paricalcitol treatment, while levels of GSH, thioredoxin, catalase and SOD activity significantly increased. After paricalcitol treatment, levels of the inflammatory markers CRP, TNF-α, IL-6 and IL-18 were significantly reduced in serum and the level of anti-inflammatory cytokine IL-10 was increased. Conclusions: In renal patients undergoing hemodialysis, paricalcitol treatment significantly reduces oxidative stress and inflammation, two well known factors leading to cardiovascular damage

    The democracy of Green Infrastructure

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    With the understanding of nature in terms of ecosystem services and the recognition of the vital role these play for human wellbeing (Millennium Assessment, 2005), the value of the natural realm is scientifically and socially defined while at the same time institutionalised. Within this frame of interpretation, nature is a supplier of provision-ing, regulating, supporting welfare and cultural services, thus becoming not only a life-enabling factor for humanity but also a conceptual construct comparable to cornerstones of democracy, such as equality, freedom and citizenship. The idea of green infrastructure is another recently coined term envisioning nature in cities in the form of a net-work and enabling a broad life-furthering vision of society. Standards for green open spaces embedded in some planning frameworks further state the right for all to a common good. Yet, evidence shows that this common right is not always met. Within the current context of advanced and neoliberal capitalism, green areas are sometimes used as an added financial value for real estate, thus increasing restrictions to their free access and full utilization. In developing countries with young democracies, such as Brazil, this process implies another significant factor of social inequality insofar the restricted access to nature by the poorest people means also diminished food safety, and the jeopardizing of certain cultural practices. In developed countries, loss of land for food production and movements reclaiming the right to the city by squatting unoccupied open spaces to initiate community gar-dens, demonstrates that the access to green spaces is also problematic, although in different ways if compared to developing countries. This chapter contributes to this topic by discussing the inequality in provision of green spaces in informal settlements and social housing development in Brazil, as well as in the globalised north. The chapter concludes with recommendations to enhance democracy through a just provision of nature in cities

    DIPLOCAT’s public diplomacy role and the perceptions towards Catalonia among international correspondents

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    This qualitative study analyses the public diplomacy (PD) role of the Public Diplomacy Council of Catalonia (DIPLOCAT) and delves into the perceptions that international correspondents have towards this region. The objective of DIPLOCAT is to influence foreign public opinion in relation to Catalonia’s will of self-determination. This study proves that international correspondents who have established prior contact with DIPLOCAT in turn also have a positive perception of Catalonia. The research has also found a correlation between the professional needs of correspondents (information sources and materials) and the PD activities being provided by DIPLOCAT. This fact shows that correspondents’ interests are in line with what DIPLOCAT is strategically offering. These achievements demonstrate that, within the new information age, a small PD structure such as DIPLOCAT is able to achieve remarkable profits in terms of reputation gaining for the territory it represents if the right tools and strategies are used
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