135 research outputs found

    Population structure and spatial distribution of the gastropod molluscs Osilinus atrata and Osilinus sauciatus in the rocky intertidal zone of the Canary Islands (Central East Atlantic)

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    Por medio de un diseño de muestreo jerárquico se estudió la estructura poblacional y los patrones espaciales de variabilidad horizontal (diferencias entre las islas, las localidades dentro de las islas y los sitios dentro de localidades) y vertical (diferencias entre bandas de la zona intermareal) de los moluscos gasterópodos Osilinus atrata y O. sauciatus a lo largo del intermareal rocoso de las Islas Canarias. Se observaron diferencias en los patrones espaciales de distribución, abundancia y tamaño para ambas especies. Osilinus atrata fue más abundante que O. sauciatus en todo el Archipiélago Canario. Su abundancia varió entre las islas, presentando una distribución heterogénea entre las bandas intermareales de una isla a otra, si bien fue más frecuente en las bandas intermedia y superior. Osilinus sauciatus sólo se encontró en las islas orientales y no exhibió diferencias significativas entre las bandas, a pesar de que 91.35% de los individuos aparecieron en la banda superior y el resto en la banda intermedia. Osilinus sauciatus mostró una talla mayor que las de O. atrata. A su vez, ambas especies presentaron en general las mayores tallas medias en la banda superior.A hierarchical sampling design was used to study the population structure and the horizontal (differences among islands, locations within islands and sites within locations) and vertical (differences among intertidal bands) distribution patterns of the gastropod molluscs Osilinus atrata and O. sauciatus along the rocky intertidal zone of the Canary Islands. Differences in the spatial patterns of abundance, size and distribution were recorded for both species. Osilinus atrata was more abundant than O. sauciatus throughout the archipelago. Its abundance varied among islands and it presented a heterogeneous distribution in the bands from one island to another, though it was more frequent in the middle and high bands. Osilinus sauciatus was only found at the eastern islands and did not exhibit significant differences between the bands, even though 91.35% of the individuals appeared in the high band and the rest in the middle band. On the other hand, O. sauciatus had a larger mean size than O. atrata, but both species presented the largest mean sizes in the high band.Este estudio se realizó dentro del proyecto “Canarias, por una Costa Viva” del Ministerio de Medio Ambiente (Secretaría General de Costas) y la Universidad de Las Palmas de Gran Canaria (http://www.canariasporunacostaviva.org)

    Redox regulation of methylthioadenosine phosphorylase in liver cells: molecular mechanism and functional implications

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    MTAP (5'-methylthioadenosine phosphorylase) catalyses the reversible phosphorolytic cleavage of methylthioadenosine leading to the production of methylthioribose-1-phosphate and adenine. Deficient MTAP activity has been correlated with human diseases including cirrhosis and hepatocellular carcinoma. In the present study we have investigated the regulation of MTAP by ROS (reactive oxygen species). The results of the present study support the inactivation of MTAP in the liver of bacterial LPS (lipopolysaccharide)-challenged mice as well as in HepG2 cells after exposure to t-butyl hydroperoxide. Reversible inactivation of purified MTAP by hydrogen peroxide results from a reduction of V(max) and involves the specific oxidation of Cys(136) and Cys(223) thiols to sulfenic acid that may be further stabilized to sulfenyl amide intermediates. Additionally, we found that Cys(145) and Cys(211) were disulfide bonded upon hydrogen peroxide exposure. However, this modification is not relevant to the mediation of the loss of MTAP activity as assessed by site-directed mutagenesis. Regulation of MTAP by ROS might participate in the redox regulation of the methionine catabolic pathway in the liver. Reduced MTA (5'-deoxy-5'-methylthioadenosine)-degrading activity may compensate for the deficient production of the precursor S-adenosylmethionine, allowing maintenance of intracellular MTA levels that may be critical to ensure cellular adaptation to physiopathological conditions such as inflammation

    European traditional tomatoes galore: a result of farmers' selection of a few diversity-rich loci

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    A comprehensive collection of 1254 tomato accessions, corresponding to European traditional and modern varieties, early domesticated varieties, and wild relatives, was analyzed by genotyping by sequencing. A continuous genetic gradient between the traditional and modern varieties was observed. European traditional tomatoes displayed very low genetic diversity, with only 298 polymorphic loci (95% threshold) out of 64 943 total variants. European traditional tomatoes could be classified into several genetic groups. Two main clusters consisting of Spanish and Italian accessions showed higher genetic diversity than the remaining varieties, suggesting that these regions might be independent secondary centers of diversity with a different history. Other varieties seem to be the result of a more recent complex pattern of migrations and hybridizations among the European regions. Several polymorphic loci were associated in a genome-wide association study with fruit morphological traits in the European traditional collection. The corresponding alleles were found to contribute to the distinctive phenotypic characteristic of the genetic varietal groups. The few highly polymorphic loci associated with morphological traits in an otherwise a low-diversity population suggests a history of balancing selection, in which tomato farmers likely maintained the morphological variation by inadvertently applying a high selective pressure within different varietal types

    Identification of NTMC2T5, a new lipid transfer protein family at ER-chloroplast contact sites involved in stress response

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    Plants are sessile organisms and they have perfected a complex molecular signalling network to detect and respond to different environmental stresses. In plants, fatty acid synthesis takes place at chloroplasts, and they are assembled into glycerolipids and sphingolipids at the ER. Then, the newly synthetized lipids in the ER are delivered to chloroplast via a non-vesicular pathway, likely through lipid transport proteins. These LTP would be localized in ER-chloroplast membrane contact sites (MCS), which are microdomains where membranes of these two different organelles are closely apposed but not fussing. SMP domain proteins are evolutionarily conserved LTP in eukaryotes that localize at MCS. We have studied the occurrence of SMP proteins in A. thaliana and S. lycopersicum. By using transient expression in N. benthamiana leaves and confocal microscopy, we have identified the NTMC2T5 family with two homologs in A. thaliana and only one in S. lycopersicum that are anchored to the chloroplast outer membrane and are interacting with the ER (at ER-chloroplast MCS. Our preliminary data have demonstrated that NTMC2T5 proteins are anchored to the chloroplast, and they bind in trans the ER. Additionally, it is predicted that these proteins contain a SMP domain which is a lipid-transfer domain, indicating that these proteins could be responsible for some of the lipid transferring events at ER-chloroplast MCS that are still unknown. We show the results of the lipidomic analysis we have performed in order to understand the role of these proteins. And our phenotypic analyses have shown that these proteins are involved in salt tolerance. Additionally, we have observed that clustering of chloroplasts occurred when we overexpressed these proteins. And Arabidopsis double knock-out mutant for these proteins showed less chloroplasts attached to the nucleus in epidermal cells, suggesting that these proteins could be involved in these chloroplast signalling events after stress.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Cognitive Biases Questionnaire for Psychosis (CBQp): Spanish Validation and Relationship With Cognitive Insight in Psychotic Patients

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    Introduction: Cognitive biases are key factors in the development and persistence of delusions in psychosis. The Cognitive Biases Questionnaire for Psychosis (CBQp) is a new self-reported questionnaire of 30 relevant situations to evaluate five types of cognitive biases in psychosis. In the context of the validation of the Spanish version of the CBQp, our objectives were to (1) analyze the factorial structure of the questionnaire with a confirmatory factor analysis (CFA), (2) relate cognitive biases with a widely used scale in the field of delusion cognitive therapies for assessing metacognition, specifically, Beck's Cognitive Insight Scale (BCIS) (1), and, finally, (3) associate cognitive biases with delusional experiences, evaluated with the Peters Delusions Inventory (PDI) (2). Materials and Methods: An authorized Spanish version of the CBQp, by a translation and back-translation procedure, was obtained. A sample of 171 patients with different diagnoses of psychoses was included. A CFA was used to test three different construct models. Associations between CBQp biases, the BCIS, and the PDI were made by correlation and mean differences. Comparisons of the CBQp scores between a control group and patients with psychosis were analyzed. Results: The CFA showed comparative fit index (CFI) values of 0.94 and 0.95 for the models with one, two, and five factors, with root mean square error of approximation values of 0.031 and 0.029. The CBQp reliability was 0.87. Associations between cognitive biases, self-certainty, and cognitive insight subscales of the BCIS were found. Similarly, associations between total punctuation, conviction, distress, and concern subscales of the PDI were also found. When compared with the group of healthy subjects, patients with psychoses scored significantly higher in several cognitive biases. Conclusion: Given the correlation between biases, a one-factor model might be more appropriate to explain the scale's underlying construct. Biases were associated with a greater frequency of delusions, distress, conviction, and concern as well as worse cognitive insight in patients with psychosis

    Los pacientes con placas coronarias vulnerables presentan mayores niveles séricos de metaloproteinasa-1

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    Fundamento. Las placas ateroscleróticas que producen la mayoría de los síndromes coronarios agudos al romperse son los fibroateromas de cápsula fina, denominados placas vulnerables. Éstas pueden ser detectadas únicamente con técnicas invasivas de imagen intracoronaria. Es preciso encontrar un biomarcador no invasivo que permita identificar a los pacientes con estas placas sin necesidad de cateterismo cardiaco. La metaloproteinasa-1 es una enzima involucrada en el metabolismo de la matriz extracelular que ha sido relacionada con la ruptura de las placas ateroscleróticas. Se desconocen sus niveles séricos en pacientes con placas vulnerables. Material y métodos. Se incluyeron pacientes sometidos a cateterismo cardiaco por enfermedad coronaria estable. Se estudiaron las arterias coronarias con tomografía de coherencia óptica para detectar placas vulnerables. Se extrajeron muestras de sangre periférica y del seno coronario para analizar la concentración de metaloproteinasa-1. Resultados. Se incluyeron 51 pacientes. Trece tenían al menos un fibroateroma de cápsula fina. No se encontraron diferencias significativas en las características clínicas, perfil lipídico ni proteína C reactiva entre los pacientes con y sin placas vulnerables. Los pacientes con placas vulnerables presentaron concentraciones significativamente mayores de metaloproteinasa-1, tanto en sangre periférica (7330±5541 vs 2894±1783 pg/ml, p=0,025) como en seno coronario (6012±3854 vs 2707±1252 pg/ml, p=0,047). Conclusiones. Los pacientes con placas vulnerables presentaron niveles séricos significativamente mayores de metaloproteinasa- 1. Se requieren estudios con seguimiento clínico para evaluar el valor pronóstico de la metaloproteinasa-1 sérica

    Promoter hypomethylation of the LINE-1 retrotransposable elements activates sense/antisense transcription and marks the progression of chronic myeloid leukemia

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    Aberrant genome-wide hypomethylation is thought to be related to tumorigenesis by promoting genomic instability. Since DNA methylation is considered an important mechanism for the silencingof retroelements, hypomethylation in human tumors may lead to their reactivation. However, the role of DNA hypomethylation in chronic myeloid leukemia (CML) remains to be elucidated. In this study, the methylation status of the LINE-1 (L1) retrotransposon promoter was analysed in CML samples from the chronicphase (CP, n¼140) and the blast crisis (BC, n¼47). L1 hypomethylation was significantly more frequent in BC (74.5%) than in CP (38%) (Po0.0001). Furthermore, L1 hypomethylation led to activation of both ORF1 sense transcription (Po0.0001) and c-MET gene antisense transcription (Po0.0001), and was significantly associated with high levels of BCR–ABL (P¼0.02) and DNMT3b4 (P¼0.001) transcripts. Interestingly, in CP-CML, extensive L1 hypomethylation was associated with poorer prognosis in terms of cytogenetic response to interferon (P¼0.004) or imatinib (P¼0.034) and progression-free survival (P¼0.005). The above results strongly suggest that activation of both sense and antisense transcriptions by aberrant promoter hypomethylation of the L1 elements plays a role in the progression and clinical behavior of the CML

    Radar interferometry techniques for the study of ground subsidence phenomena: a review of practical issues through cases in Spain

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    Subsidence related to multiple natural and human-induced processes affects an increasing number of areas worldwide. Although this phenomenon may involve surface deformation with 3D displacement components, negative vertical movement, either progressive or episodic, tends to dominate. Over the last decades, differential SAR interferometry (DInSAR) has become a very useful remote sensing tool for accurately measuring the spatial and temporal evolution of surface displacements over broad areas. This work discusses the main advantages and limitations of addressing active subsidence phenomena by means of DInSAR techniques from an end-user point of view. Special attention is paid to the spatial and temporal resolution, the precision of the measurements, and the usefulness of the data. The presented analysis is focused on DInSAR results exploitation of various ground subsidence phenomena (groundwater withdrawal, soil compaction, mining subsidence, evaporite dissolution subsidence, and volcanic deformation) with different displacement patterns in a selection of subsidence areas in Spain. Finally, a cost comparative study is performed for the different techniques applied.The different research areas included in this paper has been supported by the projects: CGL2005-05500-C02, CGL2008-06426-C01-01/BTE, AYA2 010-17448, IPT-2011-1234-310000, TEC-2008-06764, ACOMP/2010/082, AGL2009-08931/AGR, 2012GA-LC-036, 2003-03-4.3-I-014, CGL2006-05415, BEST-2011/225, CGL2010-16775, TEC2011-28201, 2012GA-LC-021 and the Banting Postdoctoral Fellowship to PJG

    Autologous intramyocardial injection of cultured skeletal muscle-derived stem cells in patients with non-acute myocardial infarction

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    AIM: Experimental animal studies suggest that the use of skeletal myoblast in patients with myocardial infarction may result in improved cardiac function. The aim of the study was to assess the feasibility and safety of this therapy in patients with myocardial infarction. METHODS AND RESULTS: Twelve patients with old myocardial infarction and ischaemic coronary artery disease underwent treatment with coronary artery bypass surgery and intramyocardial injection of autologous skeletal myoblasts obtained from a muscle biopsy of vastus lateralis and cultured with autologous serum for 3 weeks. Global and regional cardiac function was assessed by 2D and ABD echocardiogram. 18F-FDG and 13N-ammonia PET studies were used to determine perfusion and viability. Left ventricular ejection fraction (LVEF) improved from 35.5+/-2.3% before surgery to 53.5+/-4.98% at 3 months (P=0.002). Echocardiography revealed a marked improvement in regional contractility in those cardiac segments treated with skeletal myoblast (wall motion score index 2.64+/-0.13 at baseline vs 1.64+/-0.16 at 3 months P=0.0001). Quantitative 18F-FDG PET studies showed a significant (P=0.012) increased in cardiac viability in the infarct zone 3 months after surgery. No statistically significant differences were found in 13N-ammonia PET studies. Skeletal myoblast implant was not associated with an increase in adverse events. No cardiac arrhythmias were detected during early follow-up. CONCLUSIONS: In patients with old myocardial infarction, treatment with skeletal myoblast in conjunction with coronary artery bypass is safe and feasible and is associated with an increased global and regional left ventricular function,improvement in the viability of cardiac tissue in the infarct area and no induction of arrhythmias
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