G protein modulation of K2P potassium channel TASK-2 : a role of basic residues in the C terminus domain.

TASK-2 (K2P5.1) is a background K(+) channel opened by extra- or intracellular alkalinisation that plays a role in renal bicarbonate handling, central chemoreception and cell volume regulation. Here, we present results that suggest that TASK-2 is also modulated by Gßγ subunits of heterotrimeric G protein. TASK-2 was strongly inhibited when GTP-γ-S was used as a replacement for intracellular GTP. No inhibition was present using GDP-ß-S instead. Purified Gßγ introduced intracellularly also inhibited TASK-2 independently of whether GTP or GDP-ß-S was present. The effects of GTP-γ-S and Gßγ subunits were abolished by neutralisation of TASK-2 C terminus double lysine residues K257-K258 or K296-K297. Use of membrane yeast two hybrid (MYTH) experiments and immunoprecipitation assays using tagged proteins gave evidence for a physical interaction between Gß1 and Gß2 subunits and TASK-2, in agreement with expression of these subunits in proximal tubule cells. Co-immunoprecipitation was impeded by mutating C terminus K257-K258 (but not K296-K297) to alanines. Gating by extra- or intracellular pH was unaltered in GTP-γ-S-insensitive TASK-2-K257A-K258A mutant. Shrinking TASK-2-expressing cells in hypertonic solution decreased the current to 36 % of its initial value. The same manoeuvre had a significantly diminished effect on TASK-2-K257A-K258A- or TASK-2-K296-K297-expressing cells, or in cells containing intracellular GDP-ß-S. Our data are compatible with the concept that TASK-2 channels are modulated by Gßγ subunits of heterotrimeric G protein. We propose that this modulation is a novel way in which TASK-2 can be tuned to its physiological functions.

Critical care echocardiography in prone position patients during COVID-19 pandemic: a feasibility study.

PURPOSE: Critical care echocardiography is a fundamental tool in the hemodynamic evaluation of critically ill patients and prone position ventilation might limit its application. We aim to evaluate the feasibility of transthoracic echocardiography to assess different measurements performed in prone vs supine position in patients during COVID-19 pandemic to answer our research question: What is the feasibility of classic echocardiographic measurements in COVID-19 patients in prone position ventilation? METHODS: Patients with covid-19 admitted to ICUs in four academic hospitals with respiratory failure and on mechanical ventilation were evaluated with critical care echocardiography. The first ultrasound assessment was compared between prone and supine patients recording feasibility of several echocardiographic measurements, using Fisher's exact test complementing with Crombach's Alpha. RESULTS: 139 patients were included. Sixty-eight (49%) were evaluated in prone position and seventy one (51%) in supine position. Most variables were highly feasible, left ventricular volumes and ejection fraction were more possible to obtain in prone position, while cardiac output was in supine position. Tricuspid regurgitation was the least feasible overall measurement. CONCLUSION: Prone position ultrasound achieved a high feasibility of measurements compared with supine ultrasound in critically ill patients with COVID-19 respiratory failure and on mechanical ventilation. REGISTRATION: Post hoc analysis of Echo-COVID study (NTC04628195, registered November 13, 2020, retrospectively registered).

Cardiac function in critically ill patients with severe COVID: A prospective cross-sectional study in mechanically ventilated patients.

PURPOSE: To evaluate cardiac function in mechanically ventilated patients with COVID-19. MATERIALS AND METHODS: Prospective, cross-sectional multicenter study in four university-affiliated hospitals in Chile. All consecutive patients with COVID-19 ARDS requiring mechanical ventilation admitted between April and July 2020 were included. We performed systematic transthoracic echocardiography assessing right and left ventricular function within 24 h of intubation. RESULTS: 140 patients aged 57 ± 11, 29% female were included. Cardiac output was 5.1 L/min [IQR 4.5-6.2] and 86% of the patients required norepinephrine. ICU mortality was 29% (40 patients). Fifty-four patients (39%) exhibited right ventricle dilation out of whom 20 patients (14%) exhibited acute cor pulmonale (ACP). Eight out of the twenty patients with ACP exhibited pulmonary embolism (40%). Thirteen patients (9%) exhibited left ventricular systolic dysfunction (ejection fraction <45%). In the multivariate analysis acute cor pulmonale and PaO2/FiO2 ratio were independent predictors of ICU mortality. CONCLUSIONS: Right ventricular dilation is highly prevalent in mechanically ventilated patients with COVID-19 ARDS. Acute cor pulmonale was associated with reduced pulmonary function and, in only 40% of patients, with co-existing pulmonary embolism. Acute cor pulmonale is an independent risk factor for ICU mortality.

Plant galls recorded from Guanacaste Conservation Area-Costa Rica as an integrated concept of a biological database / Registro de galhas em plantas da Área de Conservação Guanacaste, Costa Rica, como conceito integrado de um banco de dados biológico

Abstract: Galling insects are specialist herbivorous that have the ability of manipulating plant tissue to form complex biological structures called galls. Even though different organisms have the ability to induce galls in plants, insect galls have the highest degree of structural complexity. The main goal of this study was to obtain a preliminary systematic record of plant gall morphotypes from the Guanacaste Conservation Area in Costa Rica and integrate the information into a biological database. Plant gall morphotypes were recorded, characterized and deposited into a specialized herbarium established as a reference for the inventory. Moreover, organisms associated with gall morphotypes were included in the inventory when it was possible to obtain and identify them. Galls were collected in the rainy season over a period of three years. In total, we recorded forty-four families, seventy genera, and eighty-seven host plant species. One hundred thirty-one morphotypes of plant galls were identified in the Guanacaste Conservation Area. The family with the highest number of gall morphotypes was Fabaceae (8.4%). Leaves were the organ with the largest number of galls (71%), followed by stems (17.6%), and apical buds (6.9%). The predominant gall shape was globular (25.2%), followed by discoid (18.3%). Fifty-nine percent of the galls had a glabrous texture, which was most common on leaves, with 77%. One hundred twenty of our field records (91.6%) of plant galls were new morphotypes not only for Costa Rica but also the world. As a consequence of this research and considering the prospect of future increases in new gall records (and associated organisms), we proposed having the biological entities resulting from the inventory placed in a cecidiarium. This repository represents a standardized and comprehensive way to manage the data and biological materials associated with the plant galls. We also suggest a nomenclature for standardizing gall morphotype registries and identifications. This work is the first and most detailed inventory of plant galls carried out thus far in the Guanacaste Conservation Area.

Resumo: Os insetos galhadores são herbívoros especializados, que têm a habilidade de manipular os tecidos vegetais, formando uma complexa estrutura biológica. Diferentes organismos têm a capacidade de induzir galhas, porém as de insetos têm maior grau de complexidade estrutural. O principal objetivo desse estudo foi realizar um levantamento sistemático preliminar das galhas de insetos na Área de Conservação Guanacaste, na Costa Rica, e inserir as informações em uma base de dados biológicos. Os morfotipos de galhas foram registrados, caraterizados e depositados em um herbário estabelecido como base de referência deste inventário. Além disso, quando foi possível obter e identificar os organismos associados a cada morfotipo de galha, eles foram incluídos no inventário. As amostras de galhas foram coletadas na estação chuvosa, durante três anos. No total, foram registradas 44 famílias, 70 gêneros e 87 espécies de plantas hospedeiras. Cento e trinta e um morfotipos de galhas foram identificados na Área de Conservação de Guanacaste. A família com o maior número de morfotipos de galhas foi Fabaceae (8.4%). Os órgãos vegetais com o maior número de galhas foram as folhas (71,0%), seguidas dos caules (17,6%), e das gemas apicais com 6,9%. A forma predominante das galhas foi globoide (25,2%), seguida da lenticular (18,3%) e 59% das galhas apresentaram textura glabra, observada mais frequentemente folhas (77%). Cento e vinte morfotipos de galhas (91.6%) representaram novos registros não só na Costa Rica como também no mundo. Como consequência desta pesquisa e considerando as perspectivas de aumentos futuros de novos registros de galhas (e organismos associados), nós propomos que as entidades biológicas resultantes deste inventário sejam depositadas em um cecidiário. Este repositório representa uma maneira padronizada e abrangente de gerenciar e integrar os dados e os materiais biológicos associados às galhas das plantas. Também sugerimos uma terminologia para padronizar os registros e identificações dos morfotipos de galhas. Este inventário de galhas em plantas é o primeiro e o mais detalhado já realizado na Área de Conservação Guanacaste.

La influencia de los procesos controlados en el razonamiento con Teoría de la Mente (ToM) en niños con y sin discapacidad intelectual / The influence of controlled processes reasoning with Theory of Mind (ToM) in children with and without intellectual disabilities

La capacidad o mecanismo tácito de atribuir estados mentales a los otros y a uno mismo, con el objeto de anticipar, comprender y predecir la conducta, es conocida como Teoría de la Mente (ToM). Parte de la discusión se centra en comprender si este razonamiento es un proceso independiente o subordinado a los procesos ejecutivos de control consciente. En esta investigación se analiza el efecto de las funciones ejecutivas de control consciente en tareas de razonamiento con ToM, en niños con y sin discapacidad intelectual. La muestra la constituyen 30 niños con discapacidad intelectual y 20 niños sin discapacidad intelectual. Se hipotetizó que la habilidad para responderlas preguntas de control, una operacionalización de las funciones ejecutivas de control consciente, se asocia más a las tareas de segundo orden que a las de primer orden, ya que estas requieren mayor carga representacional. Los resultados obtenidos, sugieren que los procesos de control consciente no sólo se asocian a las tareas que requieren una mayor carga representacional, sino a todas las tareas que requieren razonar con estados mentales, sean ellos de primer o segundo orden.

The ability to attribute mental states to others and oneself, to anticipate, understand and predict behavior is known as Theory of Mind (ToM). Part of the current discussion focuses on understanding whether this reasoning is a separate process or subordinate to the executive process of conscious control. We analyze the effect of executive functions of conscious control on reasoning tasks with ToM, in children with and without intellectual disabilities. The sample included 30 children with intellectual disabilities and 20 children without intellectual disabilities. We hypothesize that the ability to answer the questions of control, an operational definition of the executive functions of conscious control, is most often associated with the tasks of second order to first order, because the second order task requiring increased representational capability. The results suggest that the processes of conscious control are not only associated with tasks requiring a higher representational, but to all the tasks that require reasoning with mental states, be they first or second order.