417 research outputs found
Anatomical basis of sleep
El sueño es un estado biológico activo, periódico,
en el que se distinguen las etapas NREM y REM, que se
alternan sucesivamente durante la noche. Intervienen
los relojes biológicos en la modulación del sistema, así
como neurotransmisores específicos. Se trata de una
red neuronal compleja, en la que intervienen diversas
zonas del sistema nervioso central. Los procesos oníricos
están controlados además de forma neural.
Se resume la historia de las investigaciones sobre
el tema, desde el siglo XIX hasta nuestra época. Hay
que destacar los recientes descubrimientos de Lugaresi
y su equipo, que, al describir el insomnio familiar
grave, dieron importancia al núcleo dorsomedial del
tálamo en la instauración de la fase de sueño profundo.
Al grupo de Reinoso se debe el hallazgo de que el
“director de orquesta” en la instauración del sueño
REM es la zona ventral paramediana del núcleo reticular
pontino ora
Constructing a New Body Politic: Institutional Design and Education in Simón Bolívar, Simón Rodríguez, and Andrés Bello
Santiago de Chile, September 18, 1845: General Diego José Benavente (1790-1867) read a speech about his involvement in the independence movement at the University of Chile. The attendants to his address included Manuel Bulnes, President of the Republic; Manuel Montt, Minister of Education; Andrés Bello, Rector of the University; and heads of the state institutions. In front of them, Benavente asserted that if independence heroes were alive, “cuánta ser[ía] su satisfacción y complacencia al ver la nación independiente [. . .] gozando profunda paz bajo la égida de sus instituciones [y marchando] hacia la realización de los altos fines que ellos se propusieron” (122-23). An independence figure himself, Benavente linked the emancipatory goals in the country to the consolidation of a republican state apparatus. With respect to the University of Chile, he stated that a specific aim of the founding fathers was “la erección de este templo para que sus hijos vinieran a iniciarse en los sublimes misterios de aquellas ciencias que forman, conservan, y enriquecen a los Estados” (123)
Gauger, Juan Manuel. Autoridad jesuita y saber universal: la polémica cometaria entre Carlos de Sigüenza y Góngora y Eusebio Francisco Kino. New York: Instituto de Estudios Auriseculares, 2015. (ISBN: 978-1-938795-05-3). [RESEÑA]
A non-canonical RNA silencing pathway promotes mRNA degradation in basal fungi
The increasing knowledge on the functional relevance of endogenous small RNAs (esRNAs) as riboregulators has stimulated the identification and characterization of these molecules in numerous eukaryotes. In the basal fungus Mucor circinelloides, an emerging opportunistic human pathogen, esRNAs that regulate the expression of many protein coding genes have been described. These esRNAs share common machinery for their biogenesis consisting of an RNase III endonuclease Dicer, a single Argonaute protein and two RNA-dependent RNA polymerases. We show in this study that, besides participating in this canonical dicer-dependent RNA interference (RNAi) pathway, the rdrp genes are involved in a novel dicer-independent degradation process of endogenous mRNAs. The analysis of esRNAs accumulated in wild type and silencing mutants demonstrates that this new rdrp-dependent dicer-independent regulatory pathway, which does not produce sRNA molecules of discrete sizes, controls the expression of target genes promoting the specific degradation of mRNAs by a previously unknown RNase. This pathway mainly regulates conserved genes involved in metabolism and cellular processes and signaling, such as those required for heme biosynthesis, and controls responses to specific environmental signals. Searching the Mucor genome for candidate RNases to participate in this pathway, and functional analysis of the corresponding knockout mutants, identified a new protein, R3B2. This RNase III-like protein presents unique domain architecture, it is specifically found in basal fungi and, besides its relevant role in the rdrp-dependent dicer-independent pathway, it is also involved in the canonical dicer-dependent RNAi pathway, highlighting its crucial role in the biogenesis and function of regulatory esRNAs. The involvement of RdRPs in RNA degradation could represent the first evolutionary step towards the development of an RNAi mechanism and constitutes a genetic link between mRNA degradation and post-transcriptional gene silencing
Mucosal Healing in Ulcerative Colitis: A Comprehensive Review
Ulcerative colitis (UC) is a chronic inflammatory bowel disease characterized by periods of remission and periods of relapse. Patients often present with symptoms such as rectal bleeding, diarrhea and weight loss, and may require hospitalization and even colectomy. Long-term complications of UC include decreased quality of life and productivity and an increased risk of colorectal cancer. Mucosal healing (MH) has gained progressive importance in the management of UC patients. In this article, we review the endoscopic findings that define both mucosal injury and MH, and the strengths and limitations of the scoring systems currently available in clinical practice. The basic mechanisms behind colonic injury and MH are covered, highlighting the pathways through which different drugs exert their effect towards reducing inflammation and promoting epithelial repair. A comprehensive review of the evidence for approved drugs for UC to achieve and maintain MH is provided, including a section on the pharmacokinetics of anti-tumor necrosis factor (TNF)-alpha drugs. Currently approved drugs with proven efficacy in achieving MH in UC include salicylates, corticosteroids (induction only), calcineurin inhibitors (induction only), thiopurines, vedolizumab and anti-TNF alpha drugs (infliximab, adalimumab, and golimumab). MH is of crucial relevance in the outcomes of UC, resulting in lower incidences of clinical relapse, the need for hospitalization and surgery, as well as reduced rates of dysplasia and colorectal cancer. Finally, we present recent evidence towards the need for a more strict definition of complete MH as the preferred endpoint for UC patients, using a combination of both endoscopic and histological findings.info:eu-repo/semantics/publishedVersio
El consumo de la información científico-técnica por las empresas
The use of information of the Spanish industrial firms located at the Autonomous Community of Madrid is analyzed through the bibliographic searches and copies of original documents requested to CINDOC. Subject distribution of requested
documents is shown as well as the age-dependent decrease of the demand.
Journal articles account for 95% of requests, their scattering, distribution by countries and obsolescence according to subjects is also determined. Industrial firms in
the Biomedical and Chemical sectors are the biggest users of information , as contained in United States and Western European journals and the Spanish journals are
also heavily used. More of 60% of requested articles has been published in the 90s, while only 5% were published before 1970. Highest degree obsolescence appears in
Medicine, Pharmacy and BiologyEstudio del consumo de información de las empresas españolas a través de la demanda de consultas bibliográficas y copias de documentos recibida en el CINDOC, procedente de las empresas de la Comunidad de Madrid. Para los diferentes tipos de documentos solicitados se determina la distribución por materias y su antigüedad, y para los artículos de revistas que constituyen más del 95% de los documentos
requeridos se determina también la dispersión por títulos de las revistas y la procedencia de éstas por países de edición. Los datos ponen de manifiesto que las empresas de los sectores biomédico (Medicina, Farmacia y Biología) y químico
son las que más información externa utilizan, publicada sobre todo en revistas de Estados Unidos y de los países europeos occidentales, y que las revistas españolas tienen también una alta utilización. Más del 60% de la información solicitada es de
la década actual y sólo un 5% de los trabajos solicitados es anterior a 1970. De las materias más demandadas, Medicina, Farmacia y Biología son las que muestran mayor obsolescenci
RNAi-Based Functional Genomics Identifies New Virulence Determinants in Mucormycosis
Mucorales are an emerging group of human pathogens that are responsible for the lethal disease mucormycosis. Unfortunately, functional studies on the genetic factors behind the virulence of these organisms are hampered by their limited genetic tractability, since they are reluctant to classical genetic tools like transposable elements or gene mapping. Here, we describe an RNAi-based functional genomic platform that allows the identification of new virulence factors through a forward genetic approach firstly described in Mucorales. This platform contains a whole-genome collection of Mucor circinelloides silenced transformants that presented a broad assortment of phenotypes related to the main physiological processes in fungi, including virulence, hyphae morphology, mycelial and yeast growth, carotenogenesis and asexual sporulation. Selection of transformants with reduced virulence allowed the identification of mcplD, which encodes a Phospholipase D, and mcmyo5, encoding a probably essential cargo transporter of the Myosin V family, as required for a fully virulent phenotype of M. circinelloides. Knock-out mutants for those genes showed reduced virulence in both Galleria mellonella and Mus musculus models, probably due to a delayed germination and polarized growth within macrophages. This study provides a robust approach to study virulence in Mucorales and as a proof of concept identified new virulence determinants in M. circinelloides that could represent promising targets for future antifungal therapies
High Levels of Proinflammatory Cytokines, but Not Markers of Tissue Injury, in Unaffected Intestinal Areas from Patients with IBD
Intestinal alterations in IBD are triggered and maintained by an overexpression of proinflammatory cytokines. Additionally, increased immune activation has been found in the adjacent intestinal areas without displaying any apparent histological alterations, however, the regulatory environment is not well established. Biopsy specimens from patients with ulcerative colitis (UC) and Crohn's disease (CD), from both affected and unaffected areas, and also from a group of colonic biopsies from healthy controls, were included in our study. Cytokines and markers of mucosal damage were analyzed by real-time PCR, and some of the results confirmed by western-blot and ELISA. Levels of IFNγ, TNFα, IL-6, IL-15, IL-18, and IL-23 were increased (above healthy controls) in both affected and unaffected areas from IBD. IL-1β, IL-6, IL-12, and IL-27 were higher in affected areas compared to unaffected ones in UC but not CD. In general, a correlation was observed between mRNA levels of these cytokines and both iNOS and Granzyme B. SOCS-2 and SOCS-3 were also increased in the affected areas. In conclusion, the unaffected areas from IBD show increased levels of a restricted set of cytokines that may exert immune activating roles in these areas without being able to trigger tissue damage
Effects of Genetic Variants in ADCY5, GIPR, GCKR and VPS13C on Early Impairment of Glucose and Insulin Metabolism in Children
OBJECTIVE: Recent genome-wide association studies identified novel candidate genes for fasting and 2 h blood glucose and insulin levels in adults. We investigated the role of four of these loci (ADCY5, GIPR, GCKR and VPS13C) in early impairment of glucose and insulin metabolism in children. RESEARCH DESIGN AND METHODS: We genotyped four variants (rs2877716; rs1260326; rs10423928; rs17271305) in 638 Caucasian children with detailed metabolic testing including an oGTT and assessed associations with measures of glucose and insulin metabolism (including fasting blood glucose, insulin levels and insulin sensitivity/secretion indices) by linear regression analyses adjusted for age, sex, BMI-SDS and pubertal stage. RESULTS: The major allele (C) of rs2877716 (ADCY5) was nominally associated with decreased fasting plasma insulin (P = 0.008), peak insulin (P = 0.009) and increased QUICKI (P = 0.016) and Matsuda insulin sensitivity index (P = 0.013). rs17271305 (VPS13C) was nominally associated with 2 h blood glucose (P = 0.009), but not with any of the insulin or insulin sensitivity parameters. We found no association of the GIPR and GCKR variants with parameters of glucose and insulin metabolism. None of the variants correlated with anthropometric traits such as height, WHR or BMI-SDS, which excluded potential underlying associations with obesity. CONCLUSIONS: Our data on obese children indicate effects of genetic variation within ADCY5 in early impairment of insulin metabolism and VPS13C in early impairment of blood glucose homeostasis
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