151 research outputs found

    Non-neuronal TRPA1 encodes mechanical allodynia associated with neurogenic inflammation and partial nerve injury in rats

    Get PDF
    Background and purpose: The pro-algesic transient receptor potential ankyrin 1 (TRPA1) channel, expressed by a subpopulation of primary sensory neurons, has been implicated in various pain models in mice. However, evidence in rats indicates that TRPA1 conveys nociceptive signals elicited by channel activators, but not those associated with tissue inflammation or nerve injury. Here, in rats, we explored the TRPA1 role in mechanical allodynia associated with stimulation of peptidergic primary sensory neurons (neurogenic inflammation) and moderate (partial sciatic nerve ligation, pSNL) or severe (chronic constriction injury, CCI) sciatic nerve injury. Experimental approach: Acute nociception and mechanical hypersensitivity associated with neurogenic inflammation and sciatic nerve injury (pSNL and CCI) were investigated in rats with TRPA1 pharmacological antagonism or genetic silencing. TRPA1 presence and function were analysed in cultured rat Schwann cells. Key results: Hind paw mechanical allodynia (HPMA), but not acute nociception, evoked by local injection of capsaicin or allyl isothiocyanate, the TRP vanilloid 1 (TRPV1) or the TRPA1 activators was mediated by CGRP released from peripheral sensory nerve terminals. CGRP-evoked HPMA was sustained by a ROS-dependent TRPA1 activation, probably in Schwann cells. HPMA evoked by pSNL, but not that evoked by CCI, was mediated by ROS and TRPA1 without the involvement of CGRP. Conclusions and implications: As found in mice, TRPA1 mediates mechanical allodynia associated with neurogenic inflammation and moderate nerve injury in rats. The channel contribution to mechanical hypersensitivity is a common feature in rodents and might be explored in humans

    AVALIAÇÃO ENERGÉTICA DE UM TRATOR 4X2 TDA EQUIPADO COM RODADOS PNEUMÁTICOS EM FUNÇÃO DA LASTRAGEM COM ÁGUA

    Get PDF
    O objetivo deste trabalho foi avaliar o desempenho energético deum trator agrícola 4 x 2 TDA ao desenvolver uma força na barra de tração de25 kN. O trator era equipado com dois tipos construtivos de pneus (Radial eDiagonal), em três condições de lastro líquido ( 0; 40 e 75 % de água), navelocidade teórica de 7 km.h-1, informada no painel do trator, em uma superfíciemobilizada. Foi utilizado o delineamento experimental em blocos ao acaso,com um arranjo fatorial de 2x3 (pneus e lastros) e três repetições, totalizando18 avaliações experimentais. A partir dos dados obtidos, calcularam-se apatinagem das rodas motrizes e o consumo específico de combustível do trator.E com os dados de força de tração, calculou-se a potência disponível na barrade tração em função da velocidade de deslocamento. De acordo com osresultados obtidos, foi possível concluir que os menores valores de patinagem,o consumo específico de combustível e os maiores valores de potência nabarra de tração foram obtidos para o lastro de 40% e 75% de água com o pneuradial e pneu diagonal, respectivamente

    TRANSTORNO DE ANSIEDADE GENERALIZADA: SINTOMAS, CAUSAS E ESTRATÉGIAS DE TRATAMENTO

    Get PDF
    The objective of this study is to discuss generalized anxiety disorder (GAD), which is one of the most frequent anxiety disorders in today's society, due to the significant decrease in the quality of life of the affected population. It causes a lot of anxiety that interferes with the subject's mental functioning. In this sense, this article aims to understand generalized anxiety disorder (GAD) from a cognitive-behavioral perspective (CBT), showing how the cognitive approach and intervention methods used in its treatment are considered. Studies carried out by several authors point to this approach as the most effective form of treatment compared to other available options, and programs that can be improved with permanent effect, the more experience the patient has in quality of life. The work presents as a methodological project a study of literature from 2017 to 2022, based on the degree of scientific work on the proposed project. After analyzing the applications, we will determine the mentioned approaches and methods that are effective in treating GAD. However, each patient has a unique situation and, with this in mind, it is necessary to evaluate how to determine the GAD treatment method, treat patients considering them to be more effective and efficient.O objetivo deste estudo é discutir o transtorno de ansiedade generalizada (TAG), que é um dos transtornos de ansiedade mais frequentes na sociedade atual, devido à diminuição significativa da qualidade de vida da população afetada. Causa muita ansiedade que interfere no funcionamento mental do sujeito. Nesse sentido, este artigo tem como objetivo compreender o transtorno de ansiedade generalizada (TAG) sob uma perspectiva cognitivo-comportamental (TCC), mostrando como são consideradas a abordagem cognitiva e os métodos de intervenção utilizados em seu tratamento. Estudos realizados por diversos autores apontam a referida abordagem como a forma de tratamento mais eficaz em comparação com outras opções disponíveis, e programas que podem ser aprimorados com efeito permanente, quanto mais experiência o paciente tiver qualidade de vida. O trabalho apresenta como projeto metodológico um estudo da literatura de 2017 a 2022, com base no grau de trabalho científico sobre o projeto proposto. Após analisar as aplicações, determinaremos as abordagens e métodos mencionados que são eficazes no tratamento do TAG. Porém, cada paciente possui uma situação única e, pensando nisso, é necessário avaliar como determinar o método de tratamento do TAG, trate os pacientes considerando-os mais eficazes e eficientes

    A list of land plants of Parque Nacional do Caparaó, Brazil, highlights the presence of sampling gaps within this protected area

    Get PDF
    Brazilian protected areas are essential for plant conservation in the Atlantic Forest domain, one of the 36 global biodiversity hotspots. A major challenge for improving conservation actions is to know the plant richness, protected by these areas. Online databases offer an accessible way to build plant species lists and to provide relevant information about biodiversity. A list of land plants of “Parque Nacional do Caparaó” (PNC) was previously built using online databases and published on the website "Catálogo de Plantas das Unidades de Conservação do Brasil." Here, we provide and discuss additional information about plant species richness, endemism and conservation in the PNC that could not be included in the List. We documented 1,791 species of land plants as occurring in PNC, of which 63 are cited as threatened (CR, EN or VU) by the Brazilian National Red List, seven as data deficient (DD) and five as priorities for conservation. Fifity-one species were possible new ocurrences for ES and MG states

    Convalescent plasma for COVID-19 in hospitalised patients : an open-label, randomised clinical trial

    Get PDF
    Background: The effects of convalescent plasma (CP) therapy in hospitalised patients with coronavirus disease 2019 (COVID-19) remain uncertain. This study investigates the effect of CP on clinical improvement in these patients. Methods: This is an investigator-initiated, randomised, parallel arm, open-label, superiority clinical trial. Patients were randomly (1:1) assigned to two infusions of CP plus standard of care (SOC) or SOC alone. The primary outcome was the proportion of patients with clinical improvement 28 days after enrolment. Results: A total of 160 (80 in each arm) patients (66.3% critically ill, 33.7% severely ill) completed the trial. The median (interquartile range (IQR)) age was 60.5 (48–68) years; 58.1% were male and the median (IQR) time from symptom onset to randomisation was 10 (8–12) days. Neutralising antibody titres >1:80 were present in 133 (83.1%) patients at baseline. The proportion of patients with clinical improvement on day 28 was 61.3% in the CP+SOC group and 65.0% in the SOC group (difference −3.7%, 95% CI −18.8–11.3%). The results were similar in the severe and critically ill subgroups. There was no significant difference between CP+SOC and SOC groups in pre-specified secondary outcomes, including 28-day mortality, days alive and free of respiratory support and duration of invasive ventilatory support. Inflammatory and other laboratory marker values on days 3, 7 and 14 were similar between groups. Conclusions: CP+SOC did not result in a higher proportion of clinical improvement on day 28 in hospitalised patients with COVID-19 compared to SOC alone

    Neuroproteção na ressecção cirúrgica de gliomas cerebrais: revisão da evidência atual

    Get PDF
    Os gliomas cerebrais são tumores primários do sistema nervoso central que se desenvolvem a partir de células gliais e têm alta morbimortalidade. Seu tratamento padrão envolve a ressecção cirúrgica, radioterapia e quimioterapia, os quais possivelmente podem levar os pacientes a um prognóstico desfavorável. Nesse contexto, a neuroproteção entra como uma aliada para minimizar os efeitos colaterais da ressecção cirúrgica e melhorar a sobrevida e a qualidade de vida dos pacientes. Nesse sentido, o presente estudo tem como objetivo discutir sobre a evidência atual da neuroproteção na ressecção cirúrgica de gliomas cerebrais. Para isso, foram selecionados quatro artigos que que abordavam sobre a evidência atual da neuroproteção na ressecção cirúrgica de gliomas cerebrais, por meio de uma estratégia de busca com recorte temporal entre 2014 e 2023, nas bases de dados PubMed (Medline), Embase e Cochrane Library. Os resultados indicam que o grupo de pacientes que recebeu dexmedetomidina apresentou melhora significativa na cognição e redução da inflamação cerebral em comparação com o grupo-controle pós-ressecção dos gliomas cerebrais, além de menor incidência de efeitos colaterais anestésicos, como náusea e vômitos (p < 0,05). Ademais, foi observado que a modulação da via metabólica do glutamato/glutamina pode inibir o crescimento de gliomas e proteger o parênquima cerebral. Nesse sentido, as evidências atuais indicam que proteger as células nervosas é uma estratégia importante para minimizar os efeitos colaterais da ressecção cirúrgica de gliomas cerebrais, e a dexmedetomidina e a co-cultura de células de glioma e astrócitos que aumenta a concentração extracelular de glutamato e glutamina parecem ser importantes aliadas nessa profilaxia

    Pervasive gaps in Amazonian ecological research

    Get PDF
    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

    Pervasive gaps in Amazonian ecological research

    Get PDF

    Geography and ecology shape the phylogenetic composition of Amazonian tree communities

    Get PDF
    Aim: Amazonia hosts more tree species from numerous evolutionary lineages, both young and ancient, than any other biogeographic region. Previous studies have shown that tree lineages colonized multiple edaphic environments and dispersed widely across Amazonia, leading to a hypothesis, which we test, that lineages should not be strongly associated with either geographic regions or edaphic forest types. Location: Amazonia. Taxon: Angiosperms (Magnoliids; Monocots; Eudicots). Methods: Data for the abundance of 5082 tree species in 1989 plots were combined with a mega-phylogeny. We applied evolutionary ordination to assess how phylogenetic composition varies across Amazonia. We used variation partitioning and Moran\u27s eigenvector maps (MEM) to test and quantify the separate and joint contributions of spatial and environmental variables to explain the phylogenetic composition of plots. We tested the indicator value of lineages for geographic regions and edaphic forest types and mapped associations onto the phylogeny. Results: In the terra firme and várzea forest types, the phylogenetic composition varies by geographic region, but the igapó and white-sand forest types retain a unique evolutionary signature regardless of region. Overall, we find that soil chemistry, climate and topography explain 24% of the variation in phylogenetic composition, with 79% of that variation being spatially structured (R2^{2} = 19% overall for combined spatial/environmental effects). The phylogenetic composition also shows substantial spatial patterns not related to the environmental variables we quantified (R2^{2} = 28%). A greater number of lineages were significant indicators of geographic regions than forest types. Main Conclusion: Numerous tree lineages, including some ancient ones (>66 Ma), show strong associations with geographic regions and edaphic forest types of Amazonia. This shows that specialization in specific edaphic environments has played a long-standing role in the evolutionary assembly of Amazonian forests. Furthermore, many lineages, even those that have dispersed across Amazonia, dominate within a specific region, likely because of phylogenetically conserved niches for environmental conditions that are prevalent within regions
    corecore