27 research outputs found

    Hippocampal Memory Recovery After Acute Stress: A Behavioral, Morphological and Molecular Study

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    IndexaciĂłn: Scopus.Laboratory of Neuroplasticity and Neurogenetics, Department of Biochemistry and Molecular Biology, Faculty of Chemistry and Pharmaceutical Sciences, Universidad de Chile, Santiago, Chile, 2Laboratorio FarmacologĂ­a del Comportamiento, ICBM, Facultad de Medicina, Universidad de Chile, Santiago, Chile, 3Department of Kinesiology, Faculty of Health Sciences, Universidad CatĂłlica del Maule, Talca, Chile, 4Facultad de PsicologĂ­a, Universidad de Talca, Talca, Chile, 5Instituto de Ciencias BiomĂ©dicas, Facultad de Ciencias de la Salud, Universidad AutĂłnoma de Chile, Santiago, Chile, 6Escuela de QuĂ­mica y Farmacia, Facultad de Medicina, Universidad Andres Bello, Santiago, Chile.This study was supported by the following grants: Fondo Nacional de Desarrollo CientĂ­fico y TecnolĂłgico (FONDECYT) 1120528 (JLF), Fondo Central de InvestigaciĂłn, Universidad de Chile ENL025/16 (JLF).Several studies have shown that a single exposure to stress may improve or impair learning and memory processes, depending on the timing in which the stress event occurs with relation to the acquisition phase. However, to date there is no information about the molecular changes that occur at the synapse during the stress-induced memory modification and after a recovery period. In particular, there are no studies that have evaluated—at the same time—the temporality of stress and stress recovery period in hippocampal short-term memory and the effects on dendritic spine morphology, along with variations in N-methyl-D-aspartate (NMDA) and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor subunits. The aim of our study was to take a multidimensional approach to investigate concomitant behavioral, morphological and molecular changes induced by a single restraint stress exposure (2.5 h) and a recovery period of 6 and 24 h in rats. We found that acute stress elicited a reduced preference to explore an object placed in a novel position (a hippocampal-dependent task). These changes were accompanied by increased activity of LIM kinase I (LIMK; an actin-remodeling protein) and increased levels of NR2A subunits of NMDA receptors. After 6 h of recovery from stress, rats showed similar preference to explore an object placed in a novel or familiar position, but density of immature spines increased in secondary CA1 apical dendrites, along with a transient rise in GluA2 AMPA receptor subunits. After 24 h of recovery from stress, the animals showed a preference to explore an object placed in a novel position, which was accompanied by a normalization of NMDA and AMPA receptor subunits to control values. Our data suggest that acute stress produces reversible molecular and behavioral changes 24 h after stress, allowing a full reestablishment of hippocampal-related memory. Further studies need to be conducted to deepen our understanding of these changes and their reciprocal interactions.Adaptive stress responses are a promising avenue to develop interventions aiming at restoring hippocampal function impaired by repetitive stress exposure. © 2018 Aguayo, Tejos-Bravo, DĂ­az-VĂ©liz, Pacheco, GarcĂ­a-Rojo, Corrales, Olave, Aliaga, Ulloa, Avalos, RomĂĄn-Albasini, Rojas and Fiedler.https://www.frontiersin.org/articles/10.3389/fnmol.2018.00283/ful

    Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)

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    Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

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    Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

    Sonochemical cycloadditions of o-quinones. The search for a cation radical pathway

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    Diels-Alder cycloadditions of an o-quinone monoketal with different furans, under argon, are considerably accelerated by ultrasonic irradiation. Moreover, these sonochemical reactions are regiospecific and proceed with a high diastereoselectivity. The results can be ascribed to the chemical role of ultrasounds which may favor a single electron transfer mechanism with respect to ionic or nonpolar pathways

    Homodimeric cross-over structure of the human granulocyte colony-stimulating factor (GCSF) receptor signaling complex

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    A crystal structure of the signaling complex between human granulocyte colony-stimulating factor (GCSF) and a ligand binding region of GCSF receptor (GCSF-R), has been determined to 2.8 Å resolution. The GCSF:GCSF-R complex formed a 2:2 stoichiometry by means of a cross-over interaction between the Ig-like domains of GCSF-R and GCSF. The conformation of the complex is quite different from that between human GCSF and the cytokine receptor homologous domain of mouse GCSF-R, but similar to that of the IL-6/gp130 signaling complex. The Ig-like domain cross-over structure necessary for GCSF-R activation is consistent with previously reported thermodynamic and mutational analyses
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