Proactive selective attention across competition contexts.

Selective attention is a cognitive function that helps filter out unwanted information. Theories such as the biased competition model (Desimone & Duncan, 1995) explain how attentional templates bias processing towards targets in contexts where multiple stimuli compete for resources. However, it is unclear how the anticipation of different levels of competition influences the nature of attentional templates, in a proactive fashion. In this study, we used electroencephalography (EEG) to investigate how the anticipated demands of attentional selection (either high or low stimuli competition contexts) modulate target-specific preparatory brain activity and its relationship with task performance. To do so, participants performed a sex/gender judgment task in a cue-target paradigm where, depending on the block, target and distractor stimuli appeared simultaneously (high competition) or sequentially (low competition). Multivariate Pattern Analysis (MVPA) showed that, in both competition contexts, there was a preactivation of the target category to select, with a ramping-up profile at the end of the preparatory interval. However, cross-classification showed no generalization across competition conditions, suggesting different preparatory formats. Notably, time-frequency analyses showed differences between anticipated competition demands, with higher theta band power for high than low competition, which mediated the impact of subsequent stimuli competition on behavioral performance. Overall, our results show that, whereas preactivation of the internal templates associated with the category to select are engaged in advance in high and low competition contexts, their underlying neural patterns differ. In addition, these codes could not be associated with theta power, suggesting that they reflect different preparatory processes. The implications of these findings are crucial to increase our understanding of the nature of top-down processes across different contexts.

Effects of Etomidate on Postintubation Hypotension, Inflammatory Markers, and Mortality in Critically Ill Patients with COVID-19: An International, Multicenter, Retrospective Study.

OBJECTIVE: To evaluate the association of etomidate with postintubation hypotension, inflammation, and mortality in critically ill patients with COVID-19. DESIGN: International, multicenter, retrospective study. PARTICIPANTS: Critically ill patients hospitalized specifically for COVID-19 from three major academic institutions in the US and Europe. MAIN OUTCOME AND MEASURES: Patients were allocated into the etomidate (ET) group or another induction agent (OA) group. The primary outcome was postintubation hypotension. Secondary outcomes included postintubation inflammatory status, in-hospital mortality, and mortality at 30 days. RESULTS: 171 patients with a median age of 68 (IQR 58-73) years were included (ET, n = 98; OA, n = 73). Etomidate was associated with lower postintubation mean arterial pressure [74.33 (64-85) mm Hg versus 81.84 (69.75-94.25) mm Hg, p = 0.005] compared to other agents. No statistically significant differences were generally observed in inflammatory markers between the two groups at 7- and 14-days after admission to the intensive care unit. In-hospital mortality [77 (79%) versus 41 (56%), p = 0.003] and mortality at 30-days [78 (80%) versus 43 (59%), p = 0.006] were higher in the ET group. In multivariate logistic regression analysis, only etomidate (p = 0.009) and postintubation mean arterial pressure (p < 0.001) had a statistically significant effect on mortality, in contrast to stress-dose steroids (p = 0.301), after adjusting for creatinine (p = 0.695), blood urea nitrogen (p = 0.153), age (p = 0.055), oxygen saturation of hemoglobin (SpO2) (p = 0.941), and fraction of inspired oxygen (FiO2) (p = 0.712). CONCLUSIONS: Administration of a single-bolus dose of etomidate in critically ill patients with COVID-19 is associated with lower postintubation mean arterial pressure and higher in-hospital and 30-day mortality compared to other induction agents.

Top-down specific preparatory activations for selective attention and perceptual expectations.

Proactive cognition brain models are mainstream nowadays. Within these, preparation is understood as an endogenous, top-down function that takes place prior to the actual perception of a stimulus and improves subsequent behavior. Neuroimaging has shown the existence of such preparatory activity separately in different cognitive domains, however no research to date has sought to uncover their potential similarities and differences. Two of these, often confounded in the literature, are Selective Attention (information relevance) and Perceptual Expectation (information probability). We used EEG to characterize the mechanisms that pre-activate specific contents in Attention and Expectation. In different blocks, participants were cued to the relevance or to the probability of target categories, faces vs. names, in a gender discrimination task. Multivariate Pattern (MVPA) and Representational Similarity Analyses (RSA) during the preparation window showed that both manipulations led to a significant, ramping-up prediction of the relevant or expected target category. However, classifiers trained with data from one condition did not generalize to the other, indicating the existence of unique anticipatory neural patterns. In addition, a Canonical Template Tracking procedure showed that there was stronger anticipatory perceptual reinstatement for relevance than for expectation blocks. Overall, the results indicate that preparation during attention and expectation acts through distinguishable neural mechanisms. These findings have important implications for current models of brain functioning, as they are a first step towards characterizing and dissociating the neural mechanisms involved in top-down anticipatory processing.

Critical warm ischemia time point for cardiac donation after circulatory death.

Donation after circulatory death (DCD) represents a promising opportunity to overcome the relative shortage of donors for heart transplantation. However, the necessary period of warm ischemia is a concern. This study aims to determine the critical warm ischemia time based on in vivo biochemical changes. Sixteen DCD non-cardiac donors, without cardiovascular disease, underwent serial endomyocardial biopsies immediately before withdrawal of life-sustaining therapy (WLST), at circulatory arrest (CA) and every 2 min thereafter. Samples were processed into representative pools to assess calcium homeostasis, mitochondrial function and cellular viability. Compared to baseline, no significant deterioration was observed in any studied parameter at the time of CA (median: 9 min; IQR: 7-13 min; range: 4-19 min). Ten min after CA, phosphorylation of cAMP-dependent protein kinase-A on Thr197 and SERCA2 decreased markedly; and parallelly, mitochondrial complex II and IV activities decreased, and caspase 3/7 activity raised significantly. These results did not differ when donors with higher WLST to CA times (≥9 min) were analyzed separately. In human cardiomyocytes, the period from WLST to CA and the first 10 min after CA were not associated with a significant compromise in cellular function or viability. These findings may help to incorporate DCD into heart transplant programs.

MVPAlab: A machine learning decoding toolbox for multidimensional electroencephalography data.

BACKGROUND AND OBJECTIVE: The study of brain function has recently expanded from classical univariate to multivariate analyses. These multivariate, machine learning-based algorithms afford neuroscientists extracting more detailed and richer information from the data. However, the implementation of these procedures is usually challenging, especially for researchers with no coding experience. To address this problem, we have developed MVPAlab, a MATLAB-based, flexible decoding toolbox for multidimensional electroencephalography and magnetoencephalography data. METHODS: The MVPAlab Toolbox implements several machine learning algorithms to compute multivariate pattern analyses, cross-classification, temporal generalization matrices and feature and frequency contribution analyses. It also provides access to an extensive set of preprocessing routines for, among others, data normalization, data smoothing, dimensionality reduction and supertrial generation. To draw statistical inferences at the group level, MVPAlab includes a non-parametric cluster-based permutation approach. RESULTS: A sample electroencephalography dataset was compiled to test all the MVPAlab main functionalities. Significant clusters (p<0.01) were found for the proposed decoding analyses and different configurations, proving the software capability for discriminating between different experimental conditions. CONCLUSIONS: This toolbox has been designed to include an easy-to-use and intuitive graphic user interface and data representation software, which makes MVPAlab a very convenient tool for users with few or no previous coding experience. In addition, MVPAlab is not for beginners only, as it implements several high and low-level routines allowing more experienced users to design their own projects in a highly flexible manner.

Multivariate Pattern Analysis Techniques for Electroencephalography Data to Study Flanker Interference Effects.

A central challenge in cognitive neuroscience is to understand the neural mechanisms that underlie the capacity to control our behavior according to internal goals. Flanker tasks, which require responding to stimuli surrounded by distracters that trigger incompatible action tendencies, are frequently used to measure this conflict. Even though the interference generated in these situations has been broadly studied, multivariate analysis techniques can shed new light into the underlying neural mechanisms. The current study is an initial approximation to adapt an interference Flanker paradigm embedded in a Demand-Selection Task (DST) to a format that allows measuring concurrent high-density electroencephalography (EEG). We used multivariate pattern analysis (MVPA) to decode conflict-related electrophysiological markers associated with congruent or incongruent target events in a time-frequency resolved way. Our results replicate findings obtained with other analysis approaches and offer new information regarding the dynamics of the underlying mechanisms, which show signs of reinstantiation. Our findings, some of which could not have been obtained with classic analytical strategies, open novel avenues of research.

Mercury and Organochlorine Pesticides in Tissues of Loggerhead Sea Turtles (Caretta caretta) Stranded Along the Southwestern Mediterranean Coastline (Andalusia, Spain).

Nineteen loggerhead sea turtles (Caretta caretta) stranded along the southwestern Mediterranean coastline (Andalusia) were used in this study. A total of 68 samples of fat (n = 18), liver (n = 15), kidney (n = 13), pectoral muscle (n = 19), and brain (n = 3) were analysed for total mercury (Hg) and organochlorine pesticides [OC: ∑Dichlorodiphenyltrichloroethanes (∑DDT), ∑Hexachlorocyclohexane (∑HCH), ∑Heptachlor, ∑Drins and ∑Endosulfan]. These loggerhead sea turtles showed tissue Hg and OC concentrations similar to or lower than those reported in other studies. Few growth-related variations in Hg or OC levels in relation to straight carapace length were found, probably because the specimens were mostly juveniles. This study will help to fill the gap on spatio-temporal exposure data and ascertain the real world-wide picture of the contamination levels in loggerhead sea turtles.

Can inorganic elements affect herpesvirus infections in European eels?

In combination, pollution and pathogens represent a serious threat to the health of European eels that has been increasingly recognized. Thus, the impact of contaminants, cadmium, lead, mercury, and selenium, on anguillid herpesvirus 1 infection in wild European eels has been evaluated. Despite the small sample size, results indicate that selenium and mercury concentrations may compromise the European eel immune system as herpesvirus infection was more prevalent in specimens with higher Hg and Se hepatic concentrations.

ILK and cytoskeletal architecture: an important determinant of AQP2 recycling and subsequent entry into the exocytotic pathway.

Within the past decade tremendous efforts have been made to understand the mechanism behind aquaporin-2 (AQP2) water channel trafficking and recycling, to open a path toward effective diabetes insipidus therapeutics. A recent study has shown that integrin-linked kinase (ILK) conditional-knockdown mice developed polyuria along with decreased AQP2 expression. To understand whether ILK also regulates AQP2 trafficking in kidney tubular cells, we performed in vitro analysis using LLCPK1 cells stably expressing rat AQP2 (LLC-AQP2 cells). Upon treatment of LLC-AQP2 cells with ILK inhibitor cpd22 and ILK-siRNA, we observed increased accumulation of AQP2 in the perinuclear region, without any significant increase in the rate of endocytosis. This perinuclear accumulation did not occur in cells expressing a serine-256-aspartic acid mutation that retains AQP2 in the plasma membrane. We then examined clathrin-mediated endocytosis after ILK inhibition using rhodamine-conjugated transferrin. Despite no differences in overall transferrin endocytosis, the endocytosed transferrin also accumulated in the perinuclear region where it colocalized with AQP2. These accumulated vesicles also contained the recycling endosome marker Rab11. In parallel, the usual vasopressin-induced AQP2 membrane accumulation was prevented after ILK inhibition; however, ILK inhibition did not measurably affect AQP2 phosphorylation at serine-256 or its dephosphorylation at serine-261. Instead, we found that inhibition of ILK increased F-actin polymerization. When F-actin was depolymerized with latrunculin, the perinuclear located AQP2 dispersed. We conclude that ILK is important in orchestrating dynamic cytoskeletal architecture during recycling of AQP2, which is necessary for its subsequent entry into the exocytotic pathway.

Renal Integrin-Linked Kinase Depletion Induces Kidney cGMP-Axis Upregulation: Consequences on Basal and Acutely Damaged Renal Function.

Soluble guanylyl cyclase (sGC) is activated by nitric oxide (NO) and produces cGMP, which activates cGMP-dependent protein kinases (PKG) and is hydrolyzed by specific phosphodiesterases (PDE). The vasodilatory and cytoprotective capacity of cGMP-axis activation results in a therapeutic strategy for several pathologies. Integrin-linked kinase (ILK), a major scaffold protein between the extracellular matrix and intracellular signaling pathways, may modulate the expression and functionality of the cGMP-axis-related proteins. We introduce ILK as a novel modulator in renal homeostasis as well as a potential target for cisplatin (CIS)-induced acute kidney injury (AKI) improvement. We used an adult mice model of depletion of ILK (cKD-ILK), which showed basal increase of sGC and PKG expressions and activities in renal cortex when compared with wildtype (WT) littermates. Twenty-four h activation of sGC activation with NO enhanced the filtration rate in cKD-ILK. During AKI, cKD-ILK maintained the cGMP-axis upregulation with consequent filtration rates enhancement and ameliorated CIS-dependent tubular epithelial-to-mesenchymal transition and inflammation and markers. To emphasize the role of cGMP-axis upregulation due to ILK depletion, we modulated the cGMP axis under AKI in vivo and in renal cultured cells. A suboptimal dose of the PDE inhibitor ZAP enhanced the beneficial effects of the ILK depletion in AKI mice. On the other hand, CIS increased contractility-related events in cultured glomerular mesangial cells and necrosis rates in cultured tubular cells; ILK depletion protected the cells while sGC blockade with ODQ fully recovered the damage.

The European eel may tolerate multiple infections at a low biological cost.

Most animals are concurrently infected with multiple parasites, and interactions among them may influence both disease dynamics and host fitness. However, the sublethal costs of parasite infections are difficult to measure and the effects of concomitant infections with multiple parasite species on individual physiology and fitness are poorly described for wild hosts. To understand the costs of co-infection, we investigated the relationships among 189 European eel (Anguilla anguilla) from Mar Menor, parasites (richness and intensity) and eel's 'health status' (fluctuant asymmetry, splenic somatic index and the scaled mass index) by partial least squares regression. We found a positive relationship with 44% of the health status variance explained by parasites. Contracaecum sp. (Nematoda: Anisakidae) was the strongest predictor variable (44·72%) followed by Bucephalus anguillae (Platyhelminthes: Bucephalidae), (29·26%), considered the two most relevant parasites in the analysis. Subsequently, 15·67 and 12·01% of the response variables block were explained by parasite richness and Deropristis inflata (Platyhelminthes: Deropristiidae), respectively. Thus, the presence of multiple parasitic exposures with little effect on condition, strongly suggests that eels from Mar Menor tolerate multiparasitism.

The active form of vitamin D, calcitriol, induces a complex dual upregulation of endothelin and nitric oxide in cultured endothelial cells.

Despite the presence of vitamin D receptor (VDR) in endothelial cells, the effect of vitamin D on endothelial function is unknown. An unbalanced production of vasoactive endothelial factors such as nitric oxide (NO) or endothelin-1 (ET-1) results in endothelial dysfunction, which can alter the normal cardiovascular function. Present experiments were devoted to assess the effect of active vitamin D (calcitriol) on the synthesis of endothelial vasoactive factors. The results were that, in cells, calcitriol increased ET-1 and NO productions, which were measured by ELISA and fluorimetric assay, respectively. Calcitriol also increased endothelin-converting enzyme-1 (ECE-1) and endothelial-nitric oxide synthase (eNOS) activities, their mRNA (qPCR), their protein expressions (Western-blot), and their promoter activities (transfection assays). Calcitriol did not change prepro-ET-1 mRNA. The effect was specific to VDR activation because when VDR was silenced by siRNA, the observed effects disappeared. Mechanisms involved in each upregulation differed. ECE-1 upregulation depended on AP-1 activation, whereas eNOS upregulation depended directly on VDR activation. To evaluate the in vivo consequences of acute calcitriol treatment, normal Wistar rats were treated with a single ip injection of 400 ng/kg calcitriol and euthanized 24 h later. Results confirmed those observed in cells, that production and expression of both factors were increased by calcitriol. Besides, calcitriol-treated rats showed a slight rise in mean blood pressure, which decreased when pretreated with FR-901533, an ECE-1 antagonist. We conclude that calcitriol increases the synthesis of both ET-1 and NO in endothelial cells. However, the ET-1 upregulation seems to be biologically more relevant, as animals acutely treated with calcitriol show slight increases in blood pressure.

Integrin-linked kinase regulates tubular aquaporin-2 content and intracellular location: a link between the extracellular matrix and water reabsorption.

One of the clinical alterations observed in chronic renal disease (CRD) is the impaired urine concentration, known as diabetes insipidus (DI). Tubulointerstitial fibrosis of the kidney is also a pathological finding observed in CRD and involves composition of extracellular matrix (ECM). However, an association between these two events has not been elucidated. In this study, we showed that the extracellular-to-intracellular scaffold protein integrin-linked kinase (ILK) regulates expression of tubular water channel aquaporin-2 (AQP2) and its apical membrane presence in the renal tubule. Basally, polyuria and decreased urine osmolality were present in ILK conditional-knockdown (cKD-ILK) adult mice compared with nondepleted ILK littermates. No changes were observed in arginine-vasopressin (AVP) blood levels, renal receptor (V2R), or AQP3 expression. However, tubular AQP2 was decreased in expression and apical membrane presence in cKD-ILK mice, where the canonical V2R/cAMP axis activation is still functional, but independent of the absence of ILK. Thus, cKD-ILK constitutes a nephrogenic diabetes insipidus (NDI) model. AQP2 and ILK colocalize in cultured inner medullary collecting duct (mIMCD3) cells. Specific ILK siRNAs and collagen I (Col) decrease ILK and AQP2 levels and AQP2 presence on the membrane of tubular mIMCD3 cells, which impairs the capacity of the cells to transport water under hypotonic stress. The present work points to ILK as a therapeutic target in NDI.

The European eel--the swim bladder-nematode system provides a new view of the invasion paradox.

It is widely assumed that the likelihood of invasion decreases with increased species richness in the recipient community. However, the invasion paradox supports a negative and a positive relationship between native biodiversity and the success of an invader. Here, we show that for a host-parasite system (Anguilla anguilla as host and Anguillicoloides crassus as parasitic invader), invasion increases with native micro- and macroparasitic species richness. In fact, about 30% of the A. crassus intensity in eels could be explained by the number of both micro- and macroparasite species. This pattern could be due to the fact that A. crassus exploits a niche (the swim bladder) that is unoccupied by native parasite species and by the Th1/Th2 trade-off between native microparasites and the invader. We conclude that the host-parasite system resistance to invasion may depend on both niche availability and the Th1/Th2 trade-off. As well, we encourage researchers to incorporate native parasite richness as a risk factor in epidemiological models of A. crassus.

La elaboración psíquica, sus fracasos, los desbordes pulsionales / Psychic elaboration, its failures, the unlinked drives

La elaboración, término introducido por Freud en , parte del trabajo psíquico necesario para convertir las excitaciones primordiales en procesos de pensamiento. Se abren dos vías: la creación de vida mental a que esto da lugar de una parte, regida por la pulsión de vida, y de otra la vía corta de la descarga desligada a través de la acción, la alucinación o la somatización impulsadas por la pulsión de muerte. Los sueños, síntomas neuróticos, el chiste o el trabajo del duelo son consecuencias de un buen funcionamiento del trabajo de elaboración. Más adelante, desde una revaluación del narcisismo, Freud entiende cómo el Yo se deforma, se fragmenta en el ejercicio imposible de esta misión. De la importancia de estos aportes se ha derivado una visión centrada en el objeto y quizá excesivamente alejada de la pulsión. Pulsión y objeto se construyen mutuamente en un acto creador, y a la compresión de los fallos en esta tarea nos han ayudado autores como Winnicott con su concepto de trauma negativo, Bion con el de identificación proyectiva patológica o Green con su descripción del trabajo de lo negativo, cuyo mayor exponente es la alucinación negativa fuente de verdaderas lagunas en el psiquismo. Dos viñetas clínicas ilustran y ayudan a aclarar estos conceptos (AU)

Elaboration, a term introduced by Freud in , initiates the psychic work necessary to transform the basic excitation into thought processes. Two roads come to the case: the creation of the mental life which this psychic work makes possible, and on the contrary, the unbinding of drives through action, hallucination or somatization, activated by de death instinct. Dreams, neurotic symptoms jokes and the capacity for grief are the consequence of a good functioning of the work of elaboration. Later, through a reevaluation of narcissism, Freud saw how the ego is fragmented by the impossible exercise of this mission. By means of these theoretic formulations, a view centered in the object ant too far from the subject has been constituted. Drive and the object both are constructed mutually in a creative act, and an understanding of the failure of this act has been given by authors like Winnicott with his concept of negative trauma, Bion with his concept of pathologic proyective identification and Green with his description of the work of the negative whose mayor exponent is the negative hallucination, which is the source of gaps in the psychic apparatus. Two clinical vignettes help to illustrate these concepts (AU)

El dolor entre el soma y la psique / Pain between the soma and the psyche

El dolor o sufrimiento psíquico es a veces imposible de ser elaborado por el psiquismo. Las distintas manifestaciones somáticas, así como las manifestaciones auto-calmantes presentadas por algunos pacientes ponen de manifiesto los esfuerzos para defenderse de un desastre primitivo, catástrofe que permanece como una herida abierta en el psiquismo, donde los límites entre la psique y el soma y el mundo externo se confunden. La experiencia analítica a través del caso presentado permite observar la posibilidad de elaborar ciertos contenidos ausentes y su constitución en fantasmas, pudiendo así el sufrimiento mental ser contenido y elaborado po la psique, permitiendo al mismo tiempo desarrollarse un espacio imaginario (AU)

Painor psychical suffering is at times imposible for the psyche to work out. Different somatic manisfestations, as well as self-calming manifestations in some patients reveal their effort to defend themselves from a primitive disaster, a catastrophe which remains as an open wound in the psyche, in which limits between the psyche and the soma and the external world are blurred. The analytical experience in the case described permits observation of the possibility to work out certain absent contents and their constitution into fantasies, which allows mental suffering to be contained and worked out by the psyche, and at the same time permits the development of an imaginary space (AU)

Las instancias psíquicas

El autor hace un recorrido por la obra freudiana, señalando una primera concepción del psiquismo como metáfora espacial, representada por los sistemas Inconsciente, Preconsciente y Consciente. A partir del estudio de la formación de los sueños se impuso a Freud la distinción del funcionamiento de los tres sistemas. Desde este momento, el Inconsciente cesa con el psicoanálisis de ser un principio filosófico, para convertirse en un sistema psíquico. Esta primera forma de concebir el aparato psíquico la denominó primera tópica. Sin embargo, cuanto más se interesaba Freud por las nuevas patologías, más la teoría psicoanalítica necesitaba ser modificada. Con su nueva teoría pulsional, Freud se ve obligado a abandonar su concepción espacial-topo gráfica para privilegiar la noción de instancia, dividiendo el aparato psíquico en tres instancias: Yo, Ello y Superyó. Freud pasa en unos años desde el concepto de un Inconsciente conservador de los deseos inextinguibles de la infancia a un Ello radical, repleto de extrañas nociones pulsionales que buscan descargas. En esta nueva concepción denominada segunda tópica, Freud pone el acento en la transformación por el Yo del quantum pulsional. Es importante señalar que esta segunda tópica no excluye la primera tópica, sino que la engloba, poniendo el acento en la transformación de la energía psíquica (AU)

Introducción al concepto

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El Superyo y la patología límite / The Superego and limit pathology

El autor, apoyándose en las ideas de Freud, concibe la organización del Superyo Ideal a través de la sedimentación y transformación de las identificaciones más primitivas y las relaciones con éstas establecidas. Sobre la base de estos ideales y exigencias, se irán transformando en diferentes figuras que el Complejo de Edipo remodelará. En los pacientes límites, es constante el fracado del objeto en generar un sentimiento de confianza y fiabilidad, y amenaza al Yo, dando lugar a un exceso de clivaje entre los aspectos idealizados de los objetos, así como los persecutores. La introyección de las relaciones con estos objetos internos constituirá el Superyo patológico de estos pacientes que no corresponderá con un Superyo primario (AU)