725 research outputs found

    CSPα, a molecular co-chaperone essential for short and long-term synaptic maintenance

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    Cysteine string protein a (CSPα) is a vesicle protein located in the presynaptic terminal of most synapses. CSPα is an essential molecular co-chaperone that facilitates the correct folding of proteins and the assembly of the exocytic machinery. The absence of this protein leads to altered neurotransmitter release and neurodegeneration in multiple model systems, from flies to mice. In humans, CSPα mutations are associated with the development of neuronal ceroid lipofuscinosis (NCL), a neurodegenerative disease characterized by intracellular accumulation of lysosomal material. Here, we review the physiological role of CSPα and the pathology resulting from the homozygous deletion of the gene or its mutations. In addition, we investigate whether long-term moderate reduction of the protein produces motor dysfunction. We found that 1-year-old CSPα heterozygous mice display a reduced ability to sustain motor unit recruitment during repetitive stimulation, which indicates that physiological levels of CSPα are required for normal neuromuscular responses in mice and, likely, in humans.Ministerio de Ciencia e Innovación BFU2013–43763-

    The mechanical performance of recycled slate waste fiber composites based on unsaturated polyester resins

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    In the last few decades, there has been increasing social awareness for environmental conservation, which is driving the development of composite materials based on natural fibers. These new materials have interesting properties that allow for their use in a variety of applications. This study deals with the development of composite materials based on unsaturated polyester resins reinforced with recycled mineral fibers, such as slate fibers obtained from slate production waste, which have similar properties to glass fiber. The mechanical properties of these composites have been determined by tensile and flexural/bending tests. The influence of various variables such as matrix composition (flexible polyester content) and the weight percentage of fiber added to mechanical properties were evaluated. The flexible/rigid polyester content varied from 0 to 40% and the fiber one from 0 to 30 wt%. Composites with ≥20 wt% of slate fiber reinforcement are shown to have tensile (35 MPa) and flexural (57 MPa) strengths that can compete with materials reinforced with artificial fibers

    The role of plant type and salinity in the selection for the denitrifying community structure in the rhizosphere of wetland vegetation

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    Coastal wetlands, as transient links from terrestrial to marine environments, are important for nitrogen removal by denitrification. Denitrification strongly depends on both the presence of emergent plants and the denitrifier communities selected by different plant species. In this study, the effects of vegetation and habitat heterogeneity on the community of denitrifying bacteria were investigated in nine coastal wetlands in two preserved areas of Spain. Sampling locations were selected to cover a range of salinity (0.81 to 31.3 mS/cm) and nitrate concentrations (0.1 to 303 μM NO3-), allowing the evaluation of environmental variables that select for denitrifier communities in the rhizosphere of Phragmites sp., Ruppia sp., and Paspalum sp. Potential nitrate reduction rates were found to be dependent on the sampling time and plant species and related to the denitrifiercommunity structure, which was assessed by terminal restriction fragment length polymorphism analysis of the functional genes nirS, nirK and nosZ. The results showed that denitrifier community structure was also governed by plant species and salinity, with significant influences of other variables, such as sampling time and location. Ruppia sp. and Phragmites sp. selected for certain communities, whereas this was not the case for Paspalum sp. The plant species effect was strongest on nirK-type denitrifiers, whereas water carbon content was a significant factor defining the structure of the nosZ-harboring community. The differences recognized using the three functional gene markers indicated that different drivers act on denitrifying populations capable of complete denitrification, compared to the overall denitrifier community. This finding may have implications for emissions of the greenhouse gas nitrous oxide. [Int Microbiol 2012; 15(2):89-99

    Quistes de colédoco, una causa inusual de ictericia en pediatría. Presentación de serie de casos

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    ResumenIntroducciónLos quistes de la vía biliar o quistes de colédoco (QC) son una patología rara en nuestro medio. La etiología es desconocida, siendo la hipótesis más aceptada las anomalías en la unión biliopancreática.ObjetivoAnalizar los datos clínicos, diagnóstico y tratamiento de una serie de pacientes diagnosticados de QC y realizar una actualización sobre el tema.MetodoSe revisaron retrospectivamente los diagnósticos de QC en 20 años en un hospital terciario.Casos clínicosSe identificaron 4 casos, con predominio del sexo femenino. Rango de edad 16 meses a 4 años. Los signos y síntomas fueron ictericia y coluria (100%), vómitos (75%), dolor abdominal y acolia (50%). Ninguno tuvo masa palpable. La ecografía abdominal orientó el diagnóstico que se confirmó con colangio-resonancia magnética (colangio-RM). Se clasificaron como QC tipo I tres de los casos y uno como tipo IVa. El tratamiento fue quirúrgico, ningún paciente presentó complicaciones hasta la fecha.ConclusionesLos quistes de las vías biliares son de baja prevalencia. El tratamiento de elección es quirúrgico, requiriendo seguimiento estrecho, dado el riesgo de colangiocarcinoma.AbstractIntroductionCysts of the bile duct or choledochal cysts are rare diseases in our area. The aetiology is unknown, with the most accepted hypothesis being a pancreatobiliary maljunction anomaly.ObjectiveTo analyse the clinical data, diagnosis and treatment of a number of patients with choledochal cyst, as well as presenting an update on this condition.MethodA retrospective descriptive study was performed on paediatric patients diagnosed with choledochal cyst in the last 20 years in a tertiary hospital.Case reportsA total of 4 choledochal cyst cases in childhood, predominantly female, are pre- sented. The most frequent reason for consultation was vomiting, and presenting with jaundice and choluria in all cases. Patients with choledochal cyst were classified as type I in 3 cases, and one case of type IVa. In all cases surgical treatment was performed; any patient had complications to date.ConclusionsCysts of the bile ducts have a low prevalence. The treatment of choice is surgical, requiring close monitoring due to the risk of cholangiocarcinoma

    Estrategia de marca Laagam: identidad e imagen de la marca Laagam.

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    En los últimos años, se ha observado entre los influencers una tendencia creciente al emprendimiento, de modo que, muchos de ellos han creado sus propias marcas. El objetivo principal de este trabajo se basa en conocer las estrategias comunicativas, que ha utilizado la marca online nacida en Instagram, Laagam, liderada por la influencer Inés Arroyo, para alcanzar el éxito. Lo cual se ha conseguido mediante un profundo análisis tanto del posicionamiento de la marca, como de las plataformas utilizadas por la misma para difundir su contenido cualitativo. Por último, se ha realizado una encuesta dirigida a una muestra de 150 mujeres, con la finalidad de conocer la opinión real de las consumidoras sobre la marca. En cuanto a los resultados obtenidos, destaca, en primer lugar, que Laagam ha conseguido transmitir de manera correcta su identidad de marca, puesto que de la encuesta se ha obtenido que la imagen de marca de las consumidoras coincide con la misma. Por otro lado, destaca el sentimiento de identificación de las consumidoras con la marca, ya que comparten un sentimiento, unos valores y un estilo de consumo, es decir, algo más allá del gusto por la moda. Por último, es importante señalar la alta valoración que las consumidoras dan a su experiencia de compra, de modo que, a pesar de ser una marca online, ha sido capaz de ofrecer a sus consumidoras todos los servicios necesarios.<br /

    A structural model of the relationships between optimism and perceived emotional intelligence on bullying victimization and health.

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    Bullying is a relationship in which an individual, or a group of individuals, intentionally and repeatedly perpetrates aggressive behaviors towards someone unable to defend himself/herself. Traditional forms of bullying consist of physical, verbal and covert forms of aggressive behaviors. Recently, the new phenomenon of cyberbullying has emerged. This relatively new form of bullying is defined as a behavior displayed through electronic or digital media. Multiple variables have been related to bullying victimization including perceived emotional intelligence (PEI) and optimism. Both variables have implications on the manner in which people cope with stressful experiences as could be bullying, which in turn could affect the level of perceived health. However, there are no studies that have considered all these variables simultaneously. Therefore, the aim of the current study was to examine, via structural equation modelling, the independent contribution of EI and optimism on bullying victimization and perceived physical health in adolescents. A total of 650 secondary school students (317 boys and 333 girls, with ages ranged from 11 to 18) participated in the study. The participants completed measures of PIE (TMMS-24; Fernández-Berrocal et al., 2004), optimism (General Mood Subscale of the Emotional Quotient Inventory-Youth Version; Bar-On and Parker, 2000), bullying (School Victimization Scale; Cava et al., 2010), cyberbullying (Cyber-Victimization Scale; Buelga et al., 2012), and physical health (KIDSCREEN-10 Index; Raven-Sieberer et al., 2004). Results gave partial empirical support to the hypothesized model, and shows significant relationships between the variables: optimism on clarity and repair dimensions of IE (but not on the attention subscale), optimism and attention (but not clarity and repair dimensions) on bullying, and bullying on health. Together these findings shed light on those factors that should be considered when developing prophylactic strategies within adolescents to become more resilient to the adverse effects of bullying behavior.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    A gender- based approach to the current situation of Spanish dentists

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    To determine the perception of Spanish dentists about the situation of the profession nowadays and how the changes occurred in dental workforce (in number and gender of the past twenty years) have affected their personal and professional lives, under a g

    HERC 1 Ubiquitin Ligase Mutation Affects Neocortical, CA3 Hippocampal and Spinal Cord Projection Neurons: An Ultrastructural Study

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    The spontaneous mutation tambaleante is caused by the Gly483Glu substitution in the highly conserved N terminal RCC1-like domain of the HERC1 protein, which leads to the increase of mutated protein levels responsible for cerebellar Purkinje cell death by autophagy. Until now, Purkinje cells have been the only central nervous neurons reported as being targeted by the mutation, and their degeneration elicits an ataxic syndrome in adult mutant mice. However, the ultrastructural analysis performed here demonstrates that signs of autophagy, such as autophagosomes, lysosomes, and altered mitochondria, are present in neocortical pyramidal, CA3 hippocampal pyramidal, and spinal cord motor neurons. The main difference is that the reduction in the number of neurons affected in the tarnbaleante mutation in the neocortex, the hippocampus, and the spinal cord is not so evident as the dramatic loss of cerebellar Purkinje cells. Interestingly, signs of autophagy are absent in both interneurons and neuroglia cells. Affected neurons have in common that they are projection neurons which receive strong and varied synaptic inputs, and possess the highest degree of neuronal activity. Therefore, because the integrity of the ubiquitin-proteasome system is essential for protein degradation and hence, for normal protein turnover, it could be hypothesized that the deleterious effects of the misrouting of these pathways would depend directly on the neuronal activity

    Efectos del consumo de alcohol etílico en la cavidad oral: relación con el cáncer oral

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    El consumo de bebidas alcohólicas se encuentra asociado desde un punto de vista epidemiológico con un riesgo aumentado de desarrollar cáncer del tracto gastrointestinal superior. La realización de estudios que establezcan esa asociación resulta complicada, debido tanto a la confluencia de varios factores de riesgo en una misma persona, por ejemplo alcohol y tabaco, como a la falta de datos que puedan ser comprobables por el clínico. Por ello no se conoce con exactitud cual es el mecanismo patogénico responsable de este aumento de riesgo, ya que el etanol per se no ha demostrado ser carcinógeno. Se han propuesto distintas hipótesis que tratan de explicar como el etanol, ya sea por vía local o sistémica puede actuar como factor de riesgo en el desarrollo de un cáncer oral. Este trabajo supone una revisión de la situación actual de los potenciales mecanismos patogénicos, dividiéndolos en efectos locales y sistémicos. Dentro de los primeros se hace especial referencia a la alteración de la permeabilidad de la mucosa oral, a la acción del acetaldehído y al papel de los retinoidesIn an epidemiologic point of view the consumption of alcoholic beverages is found to be associated to an increased risk for developing an upper gastrointestinal tract cancer. The relation of the studies that establish this connection is complicated due to both the confluence of various risk factors within the same person such as alcohol and tobacco, and to the lack of data that can be verifiable by the clinician. For this reason the exact pathogenic mechanism responsible for this increase of risk is not known since ethanol per se was not confirmed to be carcinogenic. Different hypotheses have been proposed, explaining how ethanol, by oral or systemic route, can act as a risk factor for the development of oral cancer. This article serves as a review of the actual situation of the potential pathogenic mechanisms, dividing them in local and systemic effects. Within the aforementioned special reference is made on the alteration of the oral mucosa permeability, the action of acetaldehyde and the role of retinoids

    The HERC proteins and the nervous system

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    The HERC protein family is one of three subfamilies of Homologous to E6AP C-terminus (HECT) E3 ubiquitin ligases. Six HERC genes have been described in humans, two of which encode Large HERC proteins -HERC1 and HERC2- with molecular weights above 520 kDa that are constitutively expressed in the brain. There is a large body of evidence that mutations in these Large HERC genes produce clinical syndromes in which key neurodevelopmental events are altered, resulting in intellectual disability and other neurological disorders like epileptic seizures, dementia and/or signs of autism. In line with these consequences in humans, two mice carrying mutations in the Large HERC genes have been studied quite intensely: the tambaleante mutant for Herc1 and the Herc2+/530 mutant for Herc2. In both these mutant mice there are clear signs that autophagy is dysregulated, eliciting cerebellar Purkinje cell death and impairing motor control. The tambaleante mouse was the first of these mice to appear and is the best studied, in which the Herc1 mutation elicits: (i) delayed neural transmission in the peripheral nervous system; (ii) impaired learning, memory and motor control; and (iii) altered presynaptic membrane dynamics. In this review, we discuss the information currently available on HERC proteins in the nervous system and their biological activity, the dysregulation of which could explain certain neurodevelopmental syndromes and/or neurodegenerative diseases
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