21 resultados para Nuclear changes

em Archivo Digital para la Docencia y la Investigación - Repositorio Institucional de la Universidad del País Vasco


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[ENG]Aiming at an integrated and mechanistic view of the early biological effects of selected metals in the marine sentinel organism Mytilus galloprovincialis, we exposed mussels for 48 hours to 50, 100 and 200 nM solutions of equimolar Cd, Cu and Hg salts and measured cytological and molecular biomarkers in parallel. Focusing on the mussel gills, first target of toxic water contaminants and actively proliferating tissue, we detected significant dose-related increases of cells with micronuclei and other nuclear abnormalities in the treated mussels, with differences in the bioconcentration of the three metals determined in the mussel flesh by atomic absorption spectrometry. Gene expression profiles, determined in the same individual gills in parallel, revealed some transcriptional changes at the 50 nM dose, and substantial increases of differentially expressed genes at the 100 and 200 nM doses, with roughly similar amounts of up- and down-regulated genes. The functional annotation of gill transcripts with consistent expression trends and significantly altered at least in one dose point disclosed the complexity of the induced cell response. The most evident transcriptional changes concerned protein synthesis and turnover, ion homeostasis, cell cycle regulation and apoptosis, and intracellular trafficking (transcript sequences denoting heat shock proteins, metal binding thioneins, sequestosome 1 and proteasome subunits, and GADD45 exemplify up-regulated genes while transcript sequences denoting actin, tubulins and the apoptosis inhibitor 1 exemplify down-regulated genes). Overall, nanomolar doses of co-occurring free metal ions have induced significant structural and functional changes in the mussel gills: the intensity of response to the stimulus measured in laboratory supports the additional validation of molecular markers of metal exposure to be used in Mussel Watch programs

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4 p.

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Published as an article in: Journal of Applied Economics, 2004, vol. VII, pages 47-76.

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Overexpression of the mammalian homolog of the unc-18 gene (munc18-1) has been described in the brain of subjects with schizophrenia. Munc18-1 protein is involved in membrane fusion processes, exocytosis and neurotransmitter release. A transgenic mouse strain that overexpresses the protein isoform munc18-1a in the brain was characterized. This animal displays several schizophrenia-related behaviors, supersensitivity to hallucinogenic drugs and deficits in prepulse inhibition that reverse after antipsychotic treatment. Relevant brain areas (that is, cortex and striatum) exhibit reduced expression of dopamine D-1 receptors and dopamine transporters together with enhanced amphetamine-induced in vivo dopamine release. Magnetic resonance imaging demonstrates decreased gray matter volume in the transgenic animal. In conclusion, the mouse overexpressing brain munc18-1a represents a new valid animal model that resembles functional and structural abnormalities in patients with schizophrenia.

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Background: A remarkable range of biological functions have been ascribed to resveratrol. Recently, this polyphenol has been shown to have body fat lowering effects. The aim of the present study was to assess some of the potential underlying mechanisms of action which take place in adipose tissue. Methods: Sixteen male Sprague-Dawley rats were randomly divided into two groups: control and treated with 30 mg resveratrol/kg body weight/d. All rats were fed an obesogenic diet and after six weeks of treatment white adipose tissues were dissected. Lipoprotein lipase activity was assessed by fluorimetry, acetyl-CoA carboxylase by radiometry, and malic enzyme, glucose-6P-dehydrogenase and fatty acid synthase by spectrophotometry. Gene expression levels of acetyl-CoA carboxylase, fatty acid synthase, lipoprotein lipase, hormone-sensitive lipase, adipose triglyceride lipase, PPAR-gamma, SREBP-1c and perilipin were assessed by Real time RT-PCR. The amount of resveratrol metabolites in adipose tissue was measured by chromatography. Results: There was no difference in the final body weight of the rats; however, adipose tissues were significantly decreased in the resveratrol-treated group. Resveratrol reduced the activity of lipogenic enzymes, as well as that of heparin-releasable lipoprotein lipase. Moreover, a significant reduction was induced by this polyphenol in hormone-sensitive lipase mRNA levels. No significant changes were observed in other genes. Total amount of resveratrol metabolites in adipose tissue was 2.66 +/- 0.55 nmol/g tissue. Conclusions: It can be proposed that the body fat-lowering effect of resveratrol is mediated, at least in part, by a reduction in fatty acid uptake from circulating triacylglycerols and also in de novo lipogenesis.

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The loss of species is known to have significant effects on ecosystem functioning, but only recently has it been recognized that species loss might rival the effects of other forms of environmental change on ecosystem processes. There is a need for experimental studies that explicitly manipulate species richness and environmental factors concurrently to determine their relative impacts on key ecosystem processes such as plant litter decomposition. It is crucial to understand what factors affect the rate of plant litter decomposition and the relative magnitude of such effects because the rate at which plant litter is lost and transformed to other forms of organic and inorganic carbon determines the capacity for carbon storage in ecosystems and the rate at which greenhouse gasses such as carbon dioxide are outgassed. Here we compared how an increase in water temperature of 5 degrees C and loss of detritivorous invertebrate and plant litter species affect decomposition rates in a laboratory experiment simulating stream conditions. Like some prior studies, we found that species identity, rather than species richness per se, is a key driver of decomposition, but additionally we showed that the loss of particular species can equal or exceed temperature change in its impact on decomposition. Our results indicate that the loss of particular species can be as important a driver of decomposition as substantial temperature change, but also that predicting the relative consequences of species loss and other forms of environmental change on decomposition requires knowledge of assemblages and their constituent species' ecology and ecophysiology.

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Introducción: La medición de la concentración de hierro hepática (CHH) por RM es una técnica no invasiva de gran utilidad en el diagnóstico de los pacientes con sospecha de sobrecarga férrica en hígado. Objetivo:Validar la eficacia de la RM 1 Tesla en la determinación de la (CHH) en pacientes con sospecha de sobrecarga férrica. Validar su capacidad para diagnosticar o descartar la presencia de una CHH sugestiva de hemocromatosis. Pacientes y métodos:Estudio observacional, transversal, con inclusión prospectiva de pacientes consecutivos. De 2002 a 2010 hemos obtenido la CHH estimada mediante RM 1 Tesla (método Gandon) y de RM 1,5 Tesla (método Alústiza), y mediante BH, en 56 pacientes consecutivos (58RM:35/23). Resultados:Grupo RM 1 Tesla: de acuerdo con CHH en BH, 15 pacientes clasificados como normales (<36µmol/g)-la RM valoró correctamente 7; sobreestimó 8-; 15 grupo hemosiderosis (36-80 µmol/g)-RM valoró correctamente 5, sobreestimó 10-; 5 grupo hemocromatosis (>80 µmol/g)-valoró correctamente las 5-. Existió una correlación entre la determinación de la CHH por BH y RM 1 Tesla con r=0.619. Existieron diferencias estadísticamente significativas (p<0.05) entre CHH media por biopsia (53.43/DE45.67/IC95%37.74 a 69.12) y por RM 1 Tesla (76.14/DE47.31/IC95% 60.46 a 92.97), con sobrevaloración por parte de la RM. Grupo RM 1,5 Tesla: de acuerdo con CHH en BH, normal en 14, hemosiderosis en 6 y hemocromatosis en 3. La RM valoró correctamente 6 y sobreestimó 8 en grupo normal; grupo hemosiderosis, 3 correctamente, 3 sobrevalorados; grupo hemocromatosis, valoró correctamente los 3. La correlación entre CHH por BH y RM 1,5 Tesla fue de r=0.815. La CHH media obtenida por BH (69,34/DE152.1/IC95% 3.57 a 135.1 ) y RM 1,5 Tesla (70.43/DE 57.63/IC95% 45.51 a 95.36) no demostraron diferencias significativas (p>0.05). Conclusiones: La determinación de CHH por RM 1 Tesla (método Gandon) es útil para diagnosticar o descartar hemocromatosis y para diagnosticar CHH normal. Existe una importante tendencia a la sobreestimación en pacientes sin y con sobrecarga férrica en la CHH obtenida por RM 1 Tesla. La determinación de CHH por RM 1,5 Tesla (método Alústiza) es superior a la de RM 1 Tesla, aunque también existe una tendencia a sobreestimar. La CHH media obtenida por BH o RM 1,5 Tesla no tuvieron diferencias significativas. En cambio si existieron entre BH y RM 1 Tesla.

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18 p.

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[ES]Este trabajo surge de la inquietud del alumno sobre la energía nuclear y mas concretamente sobre la energía de fusión. Esta inquietud se plasma en una recopilación de información sobre los combustibles necesarios , su abundancia y su forma de obtención actual. Analizaremos la posibilidad de implantar alguna de estas plantas de combustible en el País Vasco, junto con un estudio de una posible central nuclear de fusión con la suma de la potencia de cada uno de los reactores de fisión que se encuentran actualmente en funcionamiento en el estado Español. Compararemos las cantidades de combustible necesarias en un año de uranio y el combustible de fusión, así como el coste de construcción de cada una.

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Background: Health expectancy is a useful tool to monitor health inequalities. The evidence about the recent changes in social inequalities in healthy expectancy is relatively scarce and inconclusive, and most studies have focused on Anglo-Saxon and central or northern European countries. The objective of this study was to analyse the changes in socioeconomic inequalities in disability-free life expectancy in a Southern European population, the Basque Country, during the first decade of the 21st century. Methods: This was an ecological cross-sectional study of temporal trends on the Basque population in 1999-2003 and 2004-2008. All-cause mortality rate, life expectancy, prevalence of disability and disability free-life expectancy were calculated for each period according to the deprivation level of the area of residence. The slope index of inequality and the relative index of inequality were calculated to summarize and compare the inequalities in the two periods. Results: Disability free-life expectancy decreased as area deprivation increased both in men and in women. The difference between the most extreme groups in 2004-2008 was 6.7 years in men and 3.7 in women. Between 1999-2003 and 2004-2008, socioeconomic inequalities in life expectancy decreased, and inequalities in disability-free expectancy increased in men and decreased in women. Conclusions: This study found important socioeconomic inequalities in health expectancy in the Basque Country. These inequalities increased in men and decreased in women in the first decade of the 21st century, during which the Basque Country saw considerable economic growth.