13 research outputs found

    Methane, Microbes and Models in Amazonian Floodplains: State of the Art and Perspectives

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    Amazon floodplain ecosystems include open water and intermittent flood forest and agricultural systems with different water types. They are a significant natural source of methane (CH4) in the tropics. When soils are flooded and become anoxic, CH4 is produced by methanogenesis, while microbially mediated aerobic and anaerobic oxidation of CH4 serves as the primary biological sink of this greenhouse gas. Measurements of rates and controls on CH4 production and emission in the Amazon basin mainly come from studies on individual wetlands and floodplain lakes. Similarly, microbial communities in those Amazon floodplain habitats have been studied on individual lakes based on sequence-specific DNA analysis. Existing biogeochemical ecosystem models of CH4 from the Amazon floodplains focus on soil properties or involve factors such as pH, redox potentials, or substrates. None of these models incorporate appropriate seasonal inundation; neither the microbiota does it as a component. In this sense, our chapter will highlight how the important efforts already contributed to understand the CH4 emission and its connections with abiotic and biotic factors in Amazon floodplains, as well as emphasize the need of encouraging cooperation and exchange of experience between research teams by using different approaches and scientific methods

    Das lógicas de dominação dos Outros aos processos de (re) existência: a educação como movimento cultural emancipatório na região Sudeste do Pará/ From the logic of domination of Others to the processes of (re) existence: education as an emancipatory cultural movement in the southeastern region of Pará

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    O artigo aborda os processos históricos de dominação e (re) existência na região sudeste do estado do Pará. Particularmente, e dentro desse escopo, atem-se à construção das relações sociais entre os indivíduos e grupos que conformaram – e conformam – esse território, assim como à relação deste indivíduos e grupos sociais com o seu meio biofísico/natureza. O objetivo é estudar e analisar as dinâmicas socioculturais que encaminham práticas de uso e de significação da natureza, e da vida, mas também refletir sobre as propostas de educação emancipatória em curso, na conformação da mesorregião sudeste do Pará. Para tanto, a metodologia adotada apoiou-se em referenciais teóricos de concepções como: Culturas e Natureza, Diversidade, Identificações, Diásporas e Hibridismo Cultural. Percebe-se, ao longo da história dos povos e comunidades que viviam – e vivem – na mesorregião, que a dominação através de práticas de coerção do corpo e da natureza foi– e ainda é – um expediente adotado para cumprir as propostas de desenvolvimento exógenas pensadas para este território, e sua gente. Por outro lado, podemos ver que os indivíduos/grupos sociais não se comportam como meras vítimas testemunhais da história. Ao contrário, há respostas assentadas nas lutas dos movimentos sociais, que representam experiências pedagógicas emancipatórias, e reafirmam a diversidade de traços culturais existente no território

    COVID-19 symptoms at hospital admission vary with age and sex: results from the ISARIC prospective multinational observational study

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    Background: The ISARIC prospective multinational observational study is the largest cohort of hospitalized patients with COVID-19. We present relationships of age, sex, and nationality to presenting symptoms. Methods: International, prospective observational study of 60 109 hospitalized symptomatic patients with laboratory-confirmed COVID-19 recruited from 43 countries between 30 January and 3 August 2020. Logistic regression was performed to evaluate relationships of age and sex to published COVID-19 case definitions and the most commonly reported symptoms. Results: ‘Typical’ symptoms of fever (69%), cough (68%) and shortness of breath (66%) were the most commonly reported. 92% of patients experienced at least one of these. Prevalence of typical symptoms was greatest in 30- to 60-year-olds (respectively 80, 79, 69%; at least one 95%). They were reported less frequently in children (≤ 18 years: 69, 48, 23; 85%), older adults (≥ 70 years: 61, 62, 65; 90%), and women (66, 66, 64; 90%; vs. men 71, 70, 67; 93%, each P < 0.001). The most common atypical presentations under 60 years of age were nausea and vomiting and abdominal pain, and over 60 years was confusion. Regression models showed significant differences in symptoms with sex, age and country. Interpretation: This international collaboration has allowed us to report reliable symptom data from the largest cohort of patients admitted to hospital with COVID-19. Adults over 60 and children admitted to hospital with COVID-19 are less likely to present with typical symptoms. Nausea and vomiting are common atypical presentations under 30 years. Confusion is a frequent atypical presentation of COVID-19 in adults over 60 years. Women are less likely to experience typical symptoms than men

    Low doses of IgG from atopic individuals can modulate in vitro IFN-γ production by human intra-thymic TCD4 and TCD8 cells: An IVIg comparative approach

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    The regulatory effect of allergic responses induced by IgG antibodies on human intra-thymic cells has not been reported in the literature. The aim of this study was to evaluate the possible differential effect of purified IgG from atopic and non-atopic individuals on human intra-thymic αβT cell cytokine production. Thymic tissues were obtained from 14 patients who were less than 7 d old. Additionally, blood samples were collected from atopic and non-atopic volunteers. Thymocytes and peripheral blood mononuclear cells were cultured with purified atopic or non-atopic IgG, and intracellular cytokine production was assessed. Purified IgG did not influence the frequency or viability of human intra-thymic αβT cells. Purified non-atopic IgG induced greater IFN-γ production by intra-thymic CD4+CD8+ T cells than did the mock treatment and atopic IgG. A similar effect of purified non-atopic IgG on TCD8 cells was observed compared with the mock treatment. Atopic IgG inhibited IFN-γ and TGF-β production by intra-thymic TCD4 cells. Treatment with intravenous immunoglobulin resulted in intermediate levels of IFN-γ and TGF-β in intra-thymic TCD4 cells compared with treatment with atopic and non-atopic IgG. Peripheral TCD4 cells from non-atopic individuals produced IFN-γ only in response to atopic IgG. This report describes novel evidence revealing that IgG from atopic individuals may influence intracellular IFN-γ production by intra-thymic αβT cells in a manner that may favor allergy development

    Limitação de esforço terapêutico na pessoa com lesão encefálica grave

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    As discussões a respeito das condutas de limitação de esforço terapêutico (LET) são frequentes nas unidades de terapia intensiva e na especialidade médica oncológica e são também importantes em contextos hospitalares de internação de longa permanência para vítimas de grandes traumas e agravos que necessitam de cuidados prolongados à saúde e de reinserção social. Na prática clínica, a tomada de decisão para LET é complexa e deve envolver o indivíduo, a família e a equipe multiprofissional. O objetivo deste artigo é discorrer a respeito da LET como um abrangente processo de "adequação de medidas" por agregação consensual de fatores centrado na pessoa, pautado por intensificação dos cuidados paliativos

    Characteristics and outcomes of an international cohort of 600 000 hospitalized patients with COVID-19

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    Background: We describe demographic features, treatments and clinical outcomes in the International Severe Acute Respiratory and emerging Infection Consortium (ISARIC) COVID-19 cohort, one of the world's largest international, standardized data sets concerning hospitalized patients. Methods: The data set analysed includes COVID-19 patients hospitalized between January 2020 and January 2022 in 52 countries. We investigated how symptoms on admission, co-morbidities, risk factors and treatments varied by age, sex and other characteristics. We used Cox regression models to investigate associations between demographics, symptoms, co-morbidities and other factors with risk of death, admission to an intensive care unit (ICU) and invasive mechanical ventilation (IMV). Results: Data were available for 689 572 patients with laboratory-confirmed (91.1%) or clinically diagnosed (8.9%) SARS-CoV-2 infection from 52 countries. Age [adjusted hazard ratio per 10 years 1.49 (95% CI 1.48, 1.49)] and male sex [1.23 (1.21, 1.24)] were associated with a higher risk of death. Rates of admission to an ICU and use of IMV increased with age up to age 60 years then dropped. Symptoms, co-morbidities and treatments varied by age and had varied associations with clinical outcomes. The case-fatality ratio varied by country partly due to differences in the clinical characteristics of recruited patients and was on average 21.5%. Conclusions: Age was the strongest determinant of risk of death, with a ∼30-fold difference between the oldest and youngest groups; each of the co-morbidities included was associated with up to an almost 2-fold increase in risk. Smoking and obesity were also associated with a higher risk of death. The size of our international database and the standardized data collection method make this study a comprehensive international description of COVID-19 clinical features. Our findings may inform strategies that involve prioritization of patients hospitalized with COVID-19 who have a higher risk of death

    Thrombotic and hemorrhagic complications of COVID-19 in adults hospitalized in high-income countries compared with those in adults hospitalized in low- and middle-income countries in an international registry

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    Background: COVID-19 has been associated with a broad range of thromboembolic, ischemic, and hemorrhagic complications (coagulopathy complications). Most studies have focused on patients with severe disease from high-income countries (HICs). Objectives: The main aims were to compare the frequency of coagulopathy complications in developing countries (low- and middle-income countries [LMICs]) with those in HICs, delineate the frequency across a range of treatment levels, and determine associations with in-hospital mortality. Methods: Adult patients enrolled in an observational, multinational registry, the International Severe Acute Respiratory and Emerging Infections COVID-19 study, between January 1, 2020, and September 15, 2021, met inclusion criteria, including admission to a hospital for laboratory-confirmed, acute COVID-19 and data on complications and survival. The advanced-treatment cohort received care, such as admission to the intensive care unit, mechanical ventilation, or inotropes or vasopressors; the basic-treatment cohort did not receive any of these interventions. Results: The study population included 495,682 patients from 52 countries, with 63% from LMICs and 85% in the basic treatment cohort. The frequency of coagulopathy complications was higher in HICs (0.76%-3.4%) than in LMICs (0.09%-1.22%). Complications were more frequent in the advanced-treatment cohort than in the basic-treatment cohort. Coagulopathy complications were associated with increased in-hospital mortality (odds ratio, 1.58; 95% CI, 1.52-1.64). The increased mortality associated with these complications was higher in LMICs (58.5%) than in HICs (35.4%). After controlling for coagulopathy complications, treatment intensity, and multiple other factors, the mortality was higher among patients in LMICs than among patients in HICs (odds ratio, 1.45; 95% CI, 1.39-1.51). Conclusion: In a large, international registry of patients hospitalized for COVID-19, coagulopathy complications were more frequent in HICs than in LMICs (developing countries). Increased mortality associated with coagulopathy complications was of a greater magnitude among patients in LMICs. Additional research is needed regarding timely diagnosis of and intervention for coagulation derangements associated with COVID-19, particularly for limited-resource settings
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