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Search Results: 1 - 10 of 464085 matches for " D. Uclés "
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El valor económico del medio ambiente
D. Uclés
Ecosistemas , 2006,
Abstract: La economía ambiental y su némesis, la economía ecológica, comenzaron a preocuparse por el medio ambiente en la década de los 70, aunque desde ópticas distintas. Sin embargo, ambas visiones están de acuerdo en el valor del medio ambiente para la economía. La economía ambiental ha desarrollado numerosas metodologías de valoración, que se exponen aquí como una aproximación al concepto de desarrollo sostenible y al de valoración económica del medio.
A Conditional Mouse Mutant in the Tumor Suppressor SdhD Gene Unveils a Link between p21WAF1/Cip1 Induction and Mitochondrial Dysfunction
áfrica Millán-Uclés, Blanca Díaz-Castro, Paula García-Flores, Alicia Báez, José Antonio Pérez-Simón, José López-Barneo, José I. Piruat
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0085528
Abstract: Mutations in mitochondrial complex II (MCII; succinate dehydrogenase, Sdh) genes cause familiar pheochromocytoma/paraganglioma tumors. Several mechanisms have been proposed to account for Sdh-mutation-induced tumorigenesis, the most accepted of which is based on the constitutive expression of the hypoxia-inducible factor 1α (Hif1α) at normal oxygen tension, a theory referred to as “pseudo-hypoxic drive”. Other molecular processes, such as oxidative stress, apoptosis, or chromatin remodeling have been also proposed to play a causative role. Nevertheless, the actual contribution of each of these mechanisms has not been definitively established. Moreover, the biological factors that determine the tissue-specificity of these tumors have not been identified. In this work, we made use of the inducible SDHD-ESR mouse, a conditional mutant in the SdhD gene, which encodes the small subunit of MCII, and that acts as a tumor suppressor gene in humans. The analysis of the Hif1α pathway in SDHD-ESR tissues and in two newly derived cell lines after complete SdhD loss -a requirement for hereditary paraganglioma type-1 tumor formation in humans- partially recapitulated the “pseudo-hypoxic” response and rendered inconsistent results. Therefore, we performed microarray analysis of adrenal medulla and kidney in order to identify other early gene expression changes elicited by SdhD deletion. Our results revealed that each mutant tissue displayed different variations in their gene expression profiles affecting to different biological processes. However, we found that the Cdkn1a gene was up-regulated in both tissues. This gene encodes the cyclin-dependent kinase inhibitor p21WAF1/Cip1, a factor implicated in cell cycle, senescence, and cancer. The two SDHD-ESR cell lines also showed accumulation of this protein. This new and unprecedented evidence for a link between SdhD dysfunction and p21WAF1/Cip1 will open new avenues for the study of the mechanisms that cause tumors in Sdh mutants. Finally, we discuss the actual role of Hif1α in tumorigenesis.
Genetically Modeled Mice with Mutations in Mitochondrial Metabolic Enzymes for the Study of Cancer
José I. Piruat,áfrica Millán-Uclés
Frontiers in Oncology , 2014, DOI: 10.3389/fonc.2014.00200
Abstract: Mitochondrial dysfunction has long been implicated in progression of cancer. As a paradigm, the “Warburg effect,” which by means of a switch toward anaerobic metabolism enables cancer cells to proliferate in oxygen limiting conditions, is well established. Besides this metabolic transformation of tumors, it has been discovered that mutations in genes encoding mitochondrial proteins are the etiological factors in different types of cancer. This confers to mitochondrial dysfunction a causative role, rather than resultant, in tumor genesis beyond its role in tumor progression and development. Mitochondrial proteins encoded by tumor-suppressor genes are part of the succinate-dehydrogenase, the fumarate-hydratase, and the mitochondrial isocitrate-dehydrogenase enzymes, all of them participating in the Krebs cycle. The spectrum of tumors associated with mutations in these genes is becoming larger and varies between each enzyme. Several mechanisms of tumorigenesis have been proposed for the different enzymatic defects, most of them based on studies using cellular and animal models. Regarding the molecular pathways implicated in the oncogenic transformation, one of the first accepted theories was based on the constitutive expression of the hypoxia-inducible factor 1α (Hif1α) at normal oxygen tension, a theory referred to as “pseudo-hypoxic drive.” This mechanism has been linked to the three types of mutations, thus suggesting a central role in cancer. However, other alternative molecular processes, such as oxidative stress or altered chromatin remodeling, have been also proposed to play an onco-pathogenic role. In the recent years, the role of oncometabolites, a new concept emerged from biochemical studies upon these tumors, has acquired relevance as responsible for tumor formation. Nevertheless, the actual contribution of each of these mechanisms has not been definitively established. In this review, we summarize the results obtained from mouse strains genetically modified in the three different enzymes.
The Importance of Right Otitis Media in Childhood Language Disorders
Paulino Uclés,María Francisca Alonso,Elena Aznar,Carlos Lapresta
International Journal of Otolaryngology , 2012, DOI: 10.1155/2012/818927
Abstract: Studies relating chronic otitis media and language disorders in children have not reported consistent findings. We carried out the first selective study aimed at discerning the role of chronic right otitis media in children less than 3 years of age in language development. A total of 35 children were studied using a full linguistic protocol, auditory brainstem responses, and middle latency responses. Twelve children had a history of chronic exclusive right otitis media. Seventeen age-matched children were selected as controls. Also, three children having a history of chronic left otitis media were compared with three age-matched controls. Linguistic tests showed significant differences between patients and controls in phonetic, phonological, and syntax scores but not semantics. Correlation studies between linguistic scores and auditory evoked responses in the whole cohort showed a significant coefficient in phonetic and phonological domains. These results emphasize the causative effect of right ear chronic otitis media and indicate that it mainly impairs phonetic and phonological coding of sounds, which may have implications for prophylactic treatment of at-risk children.
The Importance of Right Otitis Media in Childhood Language Disorders
Paulino Uclés,María Francisca Alonso,Elena Aznar,Carlos Lapresta
International Journal of Otolaryngology , 2012, DOI: 10.1155/2012/818927
Abstract: Studies relating chronic otitis media and language disorders in children have not reported consistent findings. We carried out the first selective study aimed at discerning the role of chronic right otitis media in children less than 3 years of age in language development. A total of 35 children were studied using a full linguistic protocol, auditory brainstem responses, and middle latency responses. Twelve children had a history of chronic exclusive right otitis media. Seventeen age-matched children were selected as controls. Also, three children having a history of chronic left otitis media were compared with three age-matched controls. Linguistic tests showed significant differences between patients and controls in phonetic, phonological, and syntax scores but not semantics. Correlation studies between linguistic scores and auditory evoked responses in the whole cohort showed a significant coefficient in phonetic and phonological domains. These results emphasize the causative effect of right ear chronic otitis media and indicate that it mainly impairs phonetic and phonological coding of sounds, which may have implications for prophylactic treatment of at-risk children. 1. Introduction In recent decades, neuropsychology has provided consistent data on brain topography for different functions and association areas, and clinical neurophysiology has developed techniques for event-related potentials to accurately measure brain functions. These advancements have expanded the possibilities for investigating both language and audition by joint methods. In clinical practice, neuropaediatrics consulting face an increasing number of language disorders, which sometimes constitute a challenge for diagnosis at the level of impairment; thus, language disorders in children have to be defined by exclusion in most cases [1]. Verbal language is a conventional system of signs by which individuals communicate with each other, and maturation of the nervous system encompasses language development. Acquisition of language starts the first day of extrauterine life, and several language milestones, also called critical periods, have been defined over the maturation period [2]. Myelination of central prethalamic acoustic pathways occurs during the first year of life, whereas much slower myelination of the postthalamic pathway takes five years. The primary auditory cortex shows a peak of synaptic growth during the first two years of life, that is, the plastic changes for hearing are most conspicuous at this age. In 90% of children a functional asymmetry is permanently confined
PREDICCIóN NUTRICIONAL PARA PASTOS TROPICALES POR ESPECTROSCOPíA DE REFLECTANCIA EN EL INFRARROJO CERCANO
Luis Alberto Sandoval-Mejía,Francisco Javier Bueso-Uclés,Miguel Vélez-Nauer
Agronomía Mesoamericana , 2008,
Abstract:
Magnetic resonance spectroscopy of normal appearing white matter in early relapsing-remitting multiple sclerosis: correlations between disability and spectroscopy
Juan Luis Ruiz-Pe?a, Pilar Pi?ero, Guillermo Sellers, Joaquín Argente, Alfredo Casado, Jesus Foronda, Antonio Uclés, Guillermo Izquierdo
BMC Neurology , 2004, DOI: 10.1186/1471-2377-4-8
Abstract: Thirty one patients (9 male and 22 female) with relapsing remitting Multiple Sclerosis and a Kurtzke Expanded Disability Scale Score of 0–5.5 were recruited from four hospitals in Andalusia, Spain and included in the study. Magnetic resonance spectroscopy scans and neurological disability assessments were performed the same day.A statistically significant correlation was found (r = -0.38 p < 0.05) between disability (measured by Expanded Disability Scale Score) and N-Acetyl Aspartate (NAA/Cr ratio) levels in normal appearing white matter in these patients. No correlation was found between the NAA/Cr ratio and disability measured by any of the other disability assessment scales.There is correlation between disability (measured by Expanded Disability Scale Score) and the NAA/Cr ratio in normal appearing white matter. The lack of correlation between the NAA/Cr ratio and the Multiple Sclerosis Functional Composite score indicates that the Multiple Sclerosis Functional Composite is not able to measure irreversible disability and would be more useful as a marker in stages where axonal damage is not a predominant factor.Multiple sclerosis (MS) is a chronic disease of the central nervous system characterised by multicentral inflammation and myelin destruction. Although axonal pathology in Multiple Sclerosis (MS) has been recognized since the initial description of Charcot [1], emphasis generally has been placed on the relative sparing of axons in traversing lesions. Recent pathology studies [2-5] have stressed the importance of axonal pathology in MS, in addition to demyelination, in lesions and in Normal Appearing White Matter (NAWM).Magnetic resonance imaging (MRI) is now widely used for diagnosing MS and detecting clinically silent lesions in clinical trials on MS treatment. However, correlations found between conventional techniques, such as T2-weighted lesion load, and disability, are weak or absent [6-8] and therefore, neither the magnetic resonance techniques used so
Cronicidad de los trastornos del estado de ánimo: relaciones con actitudes cognitivas disfuncionales y con alteraciones de la personalidad
Prieto Cuéllar,Mercedes; Vera Guerrero,M.a Nieves; Pérez Marfil,M.a Nieves; Ramírez Uclés,Isabel;
Clínica y Salud , 2007,
Abstract: the objective of this study was to assess the triple relationship between the chronicity of mood disorders, the co-morbidity with personality alterations and the dysfunctional cognitive attitudes. the prediction is that the higher the chronicity the higher the probability of co-morbidity and the dysfunctional attitudes scores. a sample of 37 outpatients diagnosed with depressive disorders was assigned to two different groups according to the chronicity of their depression. a number of self-report measures were administered: millon?s clinical inventory-ii (mcmi-ii) (1999), spielberger?s state-trait anxiety inventory (stai) (1982), beck?s depression inventory (bdi)(1961), and weissman and beck?s dysfunctional attitudes scale (das) (1978). as hypothesized, there were no between-group differences in the dysfunctional attitude scale. there was a high co-morbidity between mood and personality disorders. however, no between-group differences were found in the triple relationship, although the tendency was as expected. the high degree of chronicity of patients sent to specialized mental health services is questioned.
In Beam Tests of Implanted Helium Targets
J. E. McDonald,R. H. France III,R. A. Jarvis,M. W. Ahmed,M. A. Blackston,Th. Delbar,M. Gai,T. J. Kading,Y. Parpottas,B. A. Perdue,R. M. Prior,D. A. Rubin,M. C. Spraker,J. D. Yeomans,L. Weissman,H. R. Weller,E. L. Wilds Jr,;,UHartford,GCSU,LNS/UConn,TUNL/Duke,UCL/LLN,Yale,NGCSU
Physics , 2006, DOI: 10.1088/1748-0221/1/09/P09003
Abstract: Targets consisting of 3,4He implanted into thin aluminum foils (approximately 100, 200 or 600 ug/cm^2) were prepared using intense (a few uA) helium beams at low energy (approximately 20, 40 or 100 keV). Uniformity of the implantation was achieved by a beam raster across a 12 mm diameter tantalum collimator at the rates of 0.1 Hz in the vertical direction and 1 Hz in the horizontal direction. Helium implantation into the very thin (approximately 80-100 ug/cm^2) aluminum foils failed to produce useful targets (with only approximately 10% of the helium retained) due to an under estimation of the range by the code SRIM. The range of low energy helium in aluminum predicted by Northcliffe and Shilling and the NIST online tabulation are observed on the other hand to over estimate the range of low energy helium ions in aluminum. An attempt to increase the amount of helium by implanting a second deeper layer was also carried out, but it did not significantly increase the helium content beyond the blistering limit (approximately 6 x 10^17 helium/cm^2). The implanted targets were bombarded with moderately intense 4He and 16O beams of 50-100 particle nA . Rutherford Back Scattering of 1.0 and 2.5 MeV proton beams and recoil helium from 15.0 MeV oxygen beams were used to study the helium content and profile before, during and after bombardments. We observed the helium content and profile to be very stable even after a prolonged bombardment (up to two days) with moderately intense beams of 16O or 4He. Helium implanted into thin (aluminum) foils is a good choice for thin helium targets needed, for example, for a measurement of the 3he(a,g)7Be reaction and the associated S34 astrophysical cross section factor (S-factor).
The Role of Electric Field and Ultrasonication in the Deposition and Alignment of Single-Walled Carbon Nanotube Networks Using Dielectrophoresis  [PDF]
S. Ammu, D. Heskett
World Journal of Condensed Matter Physics (WJCMP) , 2013, DOI: 10.4236/wjcmp.2013.34025
Abstract:

The effects of electric field and ultrasonication on the deposition and alignment of single-walled carbon nanotubes (SWCNTs) across a 10 μm electrode gap have been studied. It was found that a frequency of ~1 MHz of the applied field yields the largest current independent of the magnitude of the voltage or the ultrasonication time of the sample. Increasing the ultrasonication time of a SWCNT solution changes the I-V characteristics of the deposited nanotubes from linear to nonlinear for all the voltages and frequencies of the applied field. Even in the absence of an electric field, SWCNTs bridged the electrode gap up to a critical sonication time which depends on the concentration of nanotubes in the solution.

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