A multi-country test of brief reappraisal interventions on emotions during the COVID-19 pandemic.

The COVID-19 pandemic has increased negative emotions and decreased positive emotions globally. Left unchecked, these emotional changes might have a wide array of adverse impacts. To reduce negative emotions and increase positive emotions, we tested the effectiveness of reappraisal, an emotion-regulation strategy that modifies how one thinks about a situation. Participants from 87 countries and regions (n = 21,644) were randomly assigned to one of two brief reappraisal interventions (reconstrual or repurposing) or one of two control conditions (active or passive). Results revealed that both reappraisal interventions (vesus both control conditions) consistently reduced negative emotions and increased positive emotions across different measures. Reconstrual and repurposing interventions had similar effects. Importantly, planned exploratory analyses indicated that reappraisal interventions did not reduce intentions to practice preventive health behaviours. The findings demonstrate the viability of creating scalable, low-cost interventions for use around the world

Doseamento electroquímico do monóxido de azoto em células endoteliais humanas

© Faculdade de Medicina da Universidade de LisboaO estudo in vivo ou in vitro da produção de monóxido de azoto (NO) em células endoteliais requer o uso de eléctrodos específicos de NO, que permitem compreender melhor os mecanismos de transducção de sinal a nível intracelular. Neste trabalho estudou-se a hipótese da acetilcolina (ACh) ser um modulador do metabolismo do NO através da acetilcolinesterase (AChE), funcionando como receptor de transducção de sinal para este mensageiro intracelular, utilizando a velnacrina maleato como inibidor da AChE. As células endoteliais da veia do cordão umbilical humano (HUVECs) em cultura foram estimuladas com ACh 10-5M e velnacrina maleato 10-5M (VM), medindo-se a produção e/ou libertação de NO pelas HUVECs, utilizando um eléctrodo sensor de NO. Os resultados obtidos de concentração de NO nas HUVECs foram de 1,83 ± 0,54 nM (n=5) na presença de ACh 10-5M e de 0,83 ± 0,19 nM na presença de VM 10-5M. Com a adição simultânea destes dois compostos obteve-se uma concentração de NO de 1,12 ± 0,18 nM. A presença de VM inibe significativamente o efeito que a ACh produz no aumento da concentração de NO (P=0,009). Os resultados experimentais permitem chegar à conclusão que a formação do complexo AChE-velnacrina maleato pouco activo interfere com mecanismos de transducção de sinal desconhecidos. A hipótese colocada de que a acetilcolina modula o metabolismo do NO, através da acetilcolinesterase, podendo funcionar como receptor de transducção de sinal, parece ser válida embora o seu mecanismo continue a ser desconhecido.info:eu-repo/semantics/publishedVersio

Acetylcholine and choline effects on erythrocyte nitrite and nitrate levels

Copyright © 2004 John Wiley & Sons, Ltd.Acetylcholine has been detected in human blood. Acetylcholine receptors and acetylcholinesterase are present in erythrocyte membranes. We tested the acetylcholine and choline effects on nitric oxide metabolites (NOx), namely nitrites and nitrates, and observed if they are dependent on interactions with muscarinic receptors and acetylcholinesterase. Human erythrocyte suspensions were incubated with acetylcholine and choline in the absence or presence of 10 microM atropine or 10 microM velnacrine maleate. The nitrite and nitrate concentrations were determined by the Griess method. Acetylcholine or choline increased NOx control concentrations (P <0.001). The nitrite concentrations decreased in the presence of atropine or velnacrine maleate (P <0.03). The nitrate concentrations only decreased when velnacrine maleate was incubated with acetylcholine or choline (10 microM, P <0.03). These results demonstrated that acetylcholine and choline modulate nitric oxide metabolites on erythrocytes and this effect is mediated by interactions with erythrocyte membrane muscarinic receptors and membrane enzyme acetylcholinesterase. A hypothesis for the signal transduction mechanism has been discussed for acetylcholinesterase and muscarinic receptor (M1) participation.This work was supportedby grants from the ‘Fundação da Ciência e Tecnologia’, Portugal.info:eu-repo/semantics/publishedVersio

Redox thiol status plays a central role in the mobilization and metabolism of nitric oxide in human red blood cells

Copyright © 2008 International Federation for Cell Biology. Published by Elsevier Ltd. All rights reserved.We assessed the redox thiol status influence on nitric oxide (NO) metabolism and efflux in erythrocytes stimulated with acetylcholinesterase substrate (acetylcholine, ACh) and inhibitor (velnacrine maleate, VM). Erythrocyte suspensions from healthy donors were incubated with increasing concentrations of dithiothreitol (1-50microM), in the presence and absence of acetylcholine/velnacrine (10microM). Levels of NO, nitrite/nitrate, S-nitrosohemoglobin, peroxynitrite and S-nitrosoglutathione were determined by spectrofluorimetric and spectrophotometric methods. Dithiothreitol significantly mobilized NO toward nitrite/nitrate and S-nitrosoglutathione, and decreased the amount of NO efflux. Both ACh/VM induce changes on the levels of erythrocyte nitrite/nitrate dependent on the DTT concentration. Higher levels of peroxynitrite and S-nitrosoglutathione were seen with velnacrine in presence of DTT 1 and 50microM. We concluded that dithiothreitol-induced activation of erythrocyte thiol status decreases NO efflux and allows greater intracellular NO mobilization onto different derivative molecules, both in the absence and presence of acetylcholinesterase substrate and inhibitor.This study was supported by grants from the GAPIC Department (Gabinete de Apoio à Investigação Científica, Tecnológica e de Inovação) of Lisbon University Faculty of Medicine.info:eu-repo/semantics/publishedVersio

Maturation, temperature and breaking dormancy of Comanthera seeds

Given the importance of “everlasting” plants for their ornamental value and vulnerability to extractive practices, studies to ensure the propagation of the species are indispensable. The aim of this study was to assess whether there is an association between seed coat color and the quality of everlasting seeds, in the presence or absence of dormancy. Four species (Comanthera elegans, C. nitida, C. bisculata, and Comanthera sp.) were separated with respect to seed coat color and underwent germination first count, germination, and germination speed index testing in a substrate moistened with water or 0.1% fluridone solution, in alternating temperatures of 10/25°C and 15/25°C. A completely randomized experimental design was used in a 4 x 2 x 2 factorial arrangement [seed coat color (green, beige, red, brown) × temperature (10/25°C and 15/25°C) × dormancy breaking (with or without)]. In general, the alternating 15/25°C temperature is favorable for germination of everlasting plants. The use of fluridone is favorable to germination and seed vigor, especially when using the alternating temperature of 10/25°C. The effect of seed coat color varies among species; higher germination and vigor values are seen in green seeds for Comanthera sp. and lower values in C. bisculata. For C. nitida and C. elegans, seed coat color does not influence seed quality. Direct relationships between fluoridone efficiency in breaking dormancy of seeds of different species of everlasting plants and classification in different colors are not observed

Efeito da temperatura e do tegumento na germinação de sementes de Calophyllum brasiliense Effect of temperature and coat in the germination of Calophyllum brasiliense seeds

A crescente demanda por informações de espécies com potencial para serem implantadas em ambientes degradados, torna fundamental o conhecimento fisiológico da germinação de sementes, visando sua exploração mais racional. Objetivou-se neste trabalho, estudar o comportamento da embebição das sementes, determinar a temperatura ótima da germinação e o efeito da retirada de tegumento sobre a germinação de sementes de Calophyllum brasiliense Cambess. O teste de germinação foi realizado em rolos de papel, com quatro repetições de 25 sementes, em delineamento inteiramente casualizado. Os resultados da curva de embebição demonstraram que o envoltório (endocarpo + tegumento) dificulta a absorção de água pela semente. Quanto à temperatura, observou-se uma maior germinabilidade nos regimes térmicos de 30ºC (constante) e 30/20ºC (alternada), sendo que, o maior índice de velocidade de germinação (IVG) também ocorreu a 30ºC. As sementes incubadas a 10ºC, 15ºC e 40ºC não germinaram. Menores valores de tempo médio de germinação foram observados nos regimes térmicos de 30ºC, 30/20ºC e 35ºC. Não foram verificadas diferenças significativas quanto à germinabilidade das sementes com e sem tegumento, porém, o tegumento reduziu a velocidade de germinação.<br>Due to the increasing demand for informations about species with potential for being introduced in degraded environment, it is important the physiological knowledge of seeds germination, aiming their rational exploration. The objective of this research was to evaluate the behaviour of seed imbibition, to determine the germination optimum temperature and the effect of coat seeds withdrawing in the germination of Calophyllum brasiliense Cambess. The germination was performed in paper rolls, with four replicates of 25 seeds each, disposed in a complete randomized design. The results of imbibition curve showed that seed-coat has as hindance for the water absorption by seed. In relation to temperature, it was observed a higher germination percentage at 30ºC (constant) and 30/20ºC (alternate). Higher speed germination index (IVG) was also observed at 30ºC. The seeds incubated at 10ºC, 15ºC and 40ºC did not germinate. The lowest values of germination mean time was at 30ºC, 30/20ºC and 35ºC. No significative differences were verified in relation to germinability with and without tegument, although the tegument reduced the germination rate