Mecanismos neurogénicos en respuesta a hipoxia en el cuerpo carotídeo. Presencia de neuronas inmaduras en el sistema nervioso periférico adulto

El cuerpo carotídeo (CC) es un pequeño órgano localizado bilateralmente en la bifurcación de la arteria carótida, y cuya principal función es la de quimiorreceptor de parámetros tan importantes como la presión parcial de oxígeno en sangre. Este órgano, que deriva de la cresta neural embrionaria y por tanto forma parte del sistema nervioso periférico, se ha definido recientemente como un nicho germinal en el adulto. En condiciones de hipoxemia persistente, la célula madre del nicho se activa y se diferencia, tanto hacia neuronas del CC (células glómicas) como hacia vasos sanguíneos, en un proceso que requiere unos 7 días para completarse. El antígeno HNK-1, utilizado clásicamente en el estudio de la cresta neural embrionaria, identifica una subpoblación de células neuronales en el CC adulto con fenotipo inmaduro. Estos neuroblastos se encuentran quiescentes y pre-diferenciados, conservando cierta capacidad proliferativa. En respuesta a hipoxia mantenida, estas células inician un proceso rápido de proliferación (con 1 o 2 divisiones), y de diferenciación hacia célula glómica madura y plenamente funcional. Este proceso comienza durante el primer día de estímulo hipóxico, y en sólo 3-4 días se genera una población amplificada de células glómicas, acelerando enormemente la neurogénesis adaptativa que tiene lugar en este órgano en respuesta a hipoxia crónica. Hemos puesto a punto el aislamiento prospectivo de neuroblastos y células glómicas maduras a partir de CC disperso, lo que nos ha permitido llevar a cabo una caracterización comparativa en profundidad. Los resultados de este estudio nos permiten concluir que aunque existen numerosas similitudes entre ambos tipos celulares, las principales diferencias entre ambos son la capacidad de división que conserva el neuroblasto, y la capacidad para detectar la presión parcial de oxígeno en sangre, una característica exclusiva de las células glómicas maduras. Igualmente hemos estudiado, con ensayos funcionales y con estudios de expresión diferencial de genes por microarray, las rutas de señalización implicadas en la biología de los neuroblastos y en su comunicación con las células maduras

Influència del bloqueig directe i l’un contra un en l’èxit del llançament en basquetbol

El present estudi té com a objectiu analitzar l’impacte de l’un contra un i el bloqueig directe sobre l’eficàcia en els llançaments. Es va desenvolupar un instrument ad hoc denominat sistema d’observació de conceptes fonamentals en basquetbol (SOCFB) per estudiar les accions ofensives del Futbol Club Barcelona Regal a la Copa del Rei en la temporada 2013-2014. Es van analitzar un total de 643 accions ofensives on es destaquen les troballes següents: a) el 34 % de les accions del jugador amb pilota van acabar en llançament mentre que el 66 % van acabar en passades; b) la principal conseqüència de l’un contra un interior van ser els llançaments (z = 6,2, p

Influencia del bloqueo directo y el uno contra uno en el éxito del lanzamiento en baloncesto

El presente estudio tiene como objetivo analizar el impacto del uno contra uno y el bloqueo directo sobre la eficacia en los lanzamientos. Se desarrolló un instrumento ad hoc denominado sistema de observación de conceptos fundamentales en baloncesto (SOCFB) para estudiar las acciones ofensivas del Fútbol Club Barcelona Regal en la Copa del Rey en la temporada 2013-2014. Se analizaron un total de 643 acciones ofensivas donde se destacan los siguientes hallazgos: a) el 34 % de las acciones del jugador con balón finalizaron en lanzamiento mientras que el 66 % terminaron en pases; b) la principal consecuencia del uno contra uno interior fueron los lanzamientos (z = 6,2, p

A single amino acid substitution in the capsid of foot-and-mouth disease virus can increase acid resistance

Foot-and-mouth disease virus (FMDV) particles lose infectivity due to their disassembly at pH values slightly below neutrality. This acid-dependent disassembly process is required for viral RNA release inside endosomes. To study the molecular determinants of viral resistance to acid-induced disassembly, six FMDV variants with increased resistance to acid inactivation were isolated. Infection by these mutants was more sensitive to drugs that raise the endosomal pH (NH4Cl and concanamycin A) than was infection by the parental C-S8c1 virus, confirming that the increase in acid resistance is related to a lower pH requirement for productive uncoating. Amino acid replacement N17D at the N terminus of VP1 capsid protein was found in all six mutants. This single substitution was shown to be responsible for increased acid resistance when introduced into an infectious FMDV clone. The increased resistance of this mutant against acid-induced inactivation was shown to be due to its increased resistance against capsid dissociation into pentameric subunits. Interestingly, the N17D mutation was located close to but not at the interpentamer interfaces. The mutants described here extend the panel of FMDV variants exhibiting different pH sensitivities and illustrate the adaptive flexibility of viral quasispecies to pH variations.Work at the F.S. laboratory was supported by grants from Ministerio de Ciencia e Innovación (MICINN) BIO2008-0447-C03-01 and CSD2006-0007; work at the M.G.M. laboratory was supported by grants from MICINN (BIO2009-10092) and Comunidad de Madrid (S-2009/MAT/1467). An institutional grant from Fundación Ramón Areces is also acknowledged.Peer Reviewe

Canine leishmaniasis: the key points for qPCR result interpretation

Background: Diagnosis and follow up of CanL is difficult since the range of clinical signs is varied and seroprevalence is high in endemic areas. The aims of this study were: i) demonstrate the advantages of Leishmania qPCR to diagnose and control CanL and highlight its prognostic value and ii) propose guidelines for tissue selection and infection monitoring. Findings: This study included 710 dogs living in an endemic area of leishmaniasis. Forty percent (285/710) exhibited clinical signs consistent with CanL. Infection was detected in 36.3% (258/710) of the dogs of which 4.5% (32/710) were detected by qPCR, 16.2% (115/710) detected by ELISA and 15.6% (111/710) tested positive for both tests. Only 17.9% (127/710) of the dogs were classified sick (affected) with CanL. All symptomatic dogs with medium or high ELISA titers were qPCR-positive in blood samples. All dogs with inconclusive or low ELISA results with high or medium qPCR parasitemia values developed the disease. Seventy one percent of asymptomatic ELISA-positive dogs confirmed by qPCR (medium to high parasitemia) developed the disease. Bone marrow or lymph node aspirate should be selected to ensure the absence of the parasite in asymptomatic dogs: 100-1,000 parasites/ml in bone marrow are detectable in blood, whereas lower parasite loads are usually negative. Almost 10% of negative samples in blood were positive in conjunctival swabs. Conclusions: Because qPCR allows parasite quantification, it is an effective tool to confirm a diagnosis of CanL in (i) cases of inconclusive ELISA results, (ii) when the dog has not yet seroconverted, or (iii) for treatment monitoring

Clinical utility of urinary gluten immunogenic peptides in the follow-up of patients with coeliac disease

[Background] Gluten-free diet (GFD) is the only treatment for patients with coeliac disease (CD) and its compliance should be monitored to avoid cumulative damage.[Aims] To analyse gluten exposures of coeliac patients on GFD for at least 24 months using different monitoring tools and its impact on duodenal histology at 12-month follow-up and evaluate the interval of determination of urinary gluten immunogenic peptides (u-GIP) for the monitoring of GFD adherence.[Methods] Ninety-four patients with CD on a GFD for at least 24 months were prospectively included. Symptoms, serology, CDAT questionnaire, and u-GIP (three samples/visit) were analysed at inclusion, 3, 6, and 12 months. Duodenal biopsy was performed at inclusion and 12 months.[Results] At inclusion, 25.8% presented duodenal mucosal damage; at 12 months, this percentage reduced by half. This histological improvement was indicated by a reduction in u-GIP but did not correlate with the remaining tools. The determination of u-GIP detected a higher number of transgressions than serology, regardless of histological evolution type. The presence of >4 u-GIP-positive samples out of 12 collected during 12 months predicted histological lesion with a specificity of 93%. Most patients (94%) with negative u-GIP in ≥2 follow-up visits showed the absence of histological lesions (p < 0.05).[Conclusion] This study suggests that the frequency of recurrent gluten exposures, according to serial determination of u-GIP, could be related to the persistence of villous atrophy and that a more regular follow-up every 6 months, instead of annually, provides more useful data about the adequate adherence to GFD and mucosal healing.This study was funded in part by Fundación Progreso y Salud, Consejería de Salud, Junta de Andalucía (PI-0427-2017 and PI-0053-2018).Peer reviewe

Mutagenesis-Mediated Virus Extinction: Virus-Dependent Effect of Viral Load on Sensitivity to Lethal Defection

Background: Lethal mutagenesis is a transition towards virus extinction mediated by enhanced mutation rates during viral genome replication, and it is currently under investigation as a potential new antiviral strategy. Viral load and virus fitness are known to influence virus extinction. Here we examine the effect or the multiplicity of infection (MOI) on progeny production of several RNA viruses under enhanced mutagenesis. Results: The effect of the mutagenic base analogue 5-fluorouracil (FU) on the replication of the arenavirus lymphocytic choriomeningitis virus (LCMV) can result either in inhibition of progeny production and virus extinction in infections carried out at low multiplicity of infection (MOI), or in a moderate titer decrease without extinction at high MOI. The effect of the MOI is similar for LCMV and vesicular stomatitis virus (VSV), but minimal or absent for the picornaviruses foot-and-mouth disease virus (FMDV) and encephalomyocarditis virus (EMCV). The increase in mutation frequency and Shannon entropy (mutant spectrum complexity) as a result of virus passage in the presence of FU was more accentuated at low MOI for LCMV and VSV, and at high MOI for FMDV and EMCV. We present an extension of the lethal defection model that agrees with the experimental results. Conclusions: (i) Low infecting load favoured the extinction of negative strand viruses, LCMV or VSV, with an increase of mutant spectrum complexity. (ii) This behaviour is not observed in RNA positive strand viruses, FMDV or EMCV. (iii) The accumulation of defector genomes may underlie the MOI-dependent behaviour. (iv) LCMV coinfections are allowed but superinfection is strongly restricted in BHK-21 cells. (v) The dissimilar effects of the MOI on the efficiency of mutagenic-based extinction of different RNA viruses can have implications for the design of antiviral protocols based on lethal mutagenesis, presently under development. © 2012 Moreno et al.Centro de Biología Molecular Severo Ochoa; Ministerio de Ciencia e Innovación (MICINN); Fundación Ramón ArecesPeer Reviewe

Currículum, saberes y prácticas ¿Qué dicen algunos medios masivos? ¿Hacia dónde y cómo puede evolucionar el tema en los próximos 10 años? ‒ De cómo la futuridad supera la prospectiva

Fil: Nakayama, Lilia. Universidad Católica de Córdoba. Facultad de Educación; Argentina.Fil: Calneggia, María Isabel. Universidad Católica de Córdoba. Facultad de Educación; ArgentinaFil: Di Francesco, Adriana Carlota. Universidad Católica de Córdoba. Facultad de Educación; ArgentinaFil: Cignoli, María de los Ángeles. Universidad Católica de Córdoba. Facultad de Educación; Argentin

Estudios de prospectiva en educación. Currículum, saberes y prácticas ¿Hacia dónde y cómo puede evolucionar el tema en los próximos 10 años?

Fil: Ferreyra, Horacio Ademar. Universidad Católica de Córdoba. Facultad de Educación; ArgentinaFil: Di Francesco, Adriana Carlota. Universidad Católica de Córdoba. Facultad de Educación; ArgentinaFil: Tenutto, Marta Alicia. Universidad Católica de Córdoba. Facultad de Educación; Argentin