133 research outputs found

    It Takes Two to Tango, Part II : Synthesis of A-Ring Functionalised Quinones Containing Two Redox-Active Centres with Antitumour Activities

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    In 2021, our research group published the prominent anticancer activity achieved through the successful combination of two redox centres (ortho-quinone/para-quinone or quinone/seleniumcontaining triazole) through a copper-catalyzed azide-alkyne cycloaddition (CuAAC) reaction. The combination of two naphthoquinoidal substrates towards a synergetic product was indicated, but not fully explored. Herein, we report the synthesis of 15 new quinone-based derivatives prepared from click chemistry reactions and their subsequent evaluation against nine cancer cell lines and the murine fibroblast line L929. Our strategy was based on the modification of the A-ring of paranaphthoquinones and subsequent conjugation with different ortho-quinoidal moieties. As anticipated, our study identified several compounds with IC50 values below 0.5 µM in tumour cell lines. Some of the compounds described here also exhibited an excellent selectivity index and low cytotoxicity on L929, the control cell line. The antitumour evaluation of the compounds separately and in their conjugated form proved that the activity is strongly enhanced in the derivatives containing two redox centres. Thus, our study confirms the efficiency of using A-ring functionalized para-quinones coupled with ortho-quinones to obtain a diverse range of two redox centre compounds with potential applications against cancer cell lines. Here as well, it literally takes two for an efficient tango

    Brazilian Flora 2020: Leveraging the power of a collaborative scientific network

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    The shortage of reliable primary taxonomic data limits the description of biological taxa and the understanding of biodiver sity patterns and processes, complicating biogeographical, ecological, and evolutionary studies. This deficit creates a significant taxo nomic impediment to biodiversity research and conservation planning. The taxonomic impediment and the biodiversity crisis are widely recognized, highlighting the urgent need for reliable taxonomic data. Over the past decade, numerous countries worldwide have devoted considerable effort to Target 1 of the Global Strategy for Plant Conservation (GSPC), which called for the preparation of a working list of all known plant species by 2010 and an online world Flora by 2020. Brazil is a megadiverse country, home to more of the world’s known plant species than any other country. Despite that, Flora Brasiliensis, concluded in 1906, was the last comprehensive treatment of the Brazilian flora. The lack of accurate estimates of the number of species of algae, fungi, and plants occurring in Brazil contributes to the prevailing taxonomic impediment and delays progress towards the GSPC targets. Over the past 12 years, a legion of taxonomists motivated to meet Target 1 of the GSPC, worked together to gather and integrate knowledge on the algal, plant, and fungal diversity of Brazil. Overall, a team of about 980 taxonomists joined efforts in a highly collaborative project that used cybertaxonomy to prepare an updated Flora of Brazil, showing the power of scientific collaboration to reach ambitious goals. This paper presents an overview of the Brazilian Flora 2020 and provides taxonomic and spatial updates on the algae, fungi, and plants found in one of the world’s most biodiverse countries. We further identify collection gaps and summarize future goals that extend be yond 2020. Our results show that Brazil is home to 46,975 native species of algae, fungi, and plants, of which 19,669 are endemic to the country. The data compiled to date suggests that the Atlantic Rainforest might be the most diverse Brazilian domain for all plant groups except gymnosperms, which are most diverse in the Amazon. However, scientific knowledge of Brazilian diversity is still un equally distributed, with the Atlantic Rainforest and the Cerrado being the most intensively sampled and studied biomes in the coun try. In times of “scientific reductionism”, with botanical and mycological sciences suffering pervasive depreciation in recent decades, the first online Flora of Brazil 2020 significantly enhanced the quality and quantity of taxonomic data available for algae, fungi, and plants from Brazil. This project also made all the information freely available online, providing a firm foundation for future research and for the management, conservation, and sustainable use of the Brazilian funga and flora.Fil: Gomes da Silva, Janaina. Jardim Botânico do Rio de Janeiro: Rio de Janeiro, BrasilFil: Filardi, Fabiana L.R. Jardim Botânico do Rio de Janeiro; BrasilFil: Barbosa, María Regina de V. Universidade Federal da Paraíba: Joao Pessoa; BrasilFil: Baumgratz, José Fernando Andrade. Jardim Botânico do Rio de Janeiro; BrasilFil: de Mattos Bicudo, Carlos Eduardo. Instituto de Botânica. Núcleo de Pesquisa em Ecologia; BrasilFil: Cavalcanti, Taciana. Empresa Brasileira de Pesquisa Agropecuária Recursos Genéticos e Biotecnologia; BrasilFil: Coelho, Marcus. Prefeitura Municipal de Campinas; BrasilFil: Ferreira da Costa, Andrea. Federal University of Rio de Janeiro. Museu Nacional. Department of Botany; BrasilFil: Costa, Denise. Instituto de Pesquisas Jardim Botanico do Rio de Janeiro; BrasilFil: Dalcin, Eduardo C. Rio de Janeiro Botanical Garden Research Institute; BrasilFil: Labiak, Paulo. Universidade Federal do Parana; BrasilFil: Cavalcante de Lima, Haroldo. Jardim Botânico do Rio de Janeiro; BrasilFil: Lohmann, Lucia. Universidade de São Paulo; BrasilFil: Maia, Leonor. Universidade Federal de Pernambuco; BrasilFil: Mansano, Vidal de Freitas. Instituto de Pesquisas Jardim Botânico do Rio de Janeiro; Brasil. Jardim Botânico do Rio de Janeiro; BrasilFil: Menezes, Mariângela. Federal University of Rio de Janeiro. Museu Nacional. Department of Botany; BrasilFil: Morim, Marli. Instituto de Pesquisas Jardim Botânico do Rio de Janeiro; BrasilFil: Moura, Carlos Wallace do Nascimento. Universidade Estadual de Feira de Santana. Department of Biological Science; BrasilFil: Lughadha, Eimear NIck. Royal Botanic Gardens; Reino UnidoFil: Peralta, Denilson. Instituto de Pesquisas Ambientais; BrazilFil: Prado, Jefferson. Instituto de Pesquisas Ambientais; BrasilFil: Roque, Nádia. Universidade Federal da Bahia; BrasilFil: Stehmann, Joao. Universidade Federal de Minas Gerais; BrasilFil: da Silva Sylvestre, Lana. Universidade Federal do Rio de Janeiro; BrasilFil: Trierveiler-Pereira, Larissa. Universidade Estadual de Maringá. Departamento de Análises Clínicas e Biomedicina; BrasilFil: Walter, Bruno Machado Teles. EMBRAPA Cenargen Brasília; BrasilFil: Zimbrão, Geraldo. Universidade Federal do Rio de Janeiro; BrasilFil: Forzza, Rafaela C. Jardim Botânico do Rio de Janeiro; BrasilFil: Morales, Matías. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Recursos Biológicos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Morón. Facultad de Agronomía y Ciencias Agroalimentarias; Argentin

    2-Pyridyl thiazoles as novel anti-Trypanosoma cruzi agents: structural design, synthesis and pharmacological evaluation

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    The present work reports on the synthesis, anti-Trypanosoma cruzi activities and docking studies of a novel series of 2-(pyridin-2-yl)-1,3- thiazoles derived from 2-pyridine thiosemicarbazone. The majority of these compounds are potent cruzain inhibitors and showed excellent inhibition on the trypomastigote form of the parasite, and the resulting structure-activity relationships are discussed. Together, these data present a novel series of thiazolyl hydrazones with potential effects against Chagas disease and they could be important leads in continuing development against Chagas disease

    Anti-malarial activity and toxicity assessment of Himatanthus articulatus, a plant used to treat malaria in the Brazilian Amazon

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    Background: Plasmodium falciparum has become resistant to some of the available drugs. Several plant species are used for the treatment of malaria, such as Himatanthus articulatus in parts of Brazil. The present paper reports the phyto-chemistry, the anti-plasmodial and anti-malarial activity, as well as the toxicity of H. articulatus. Methods: Ethanol and dichloromethane extracts were obtained from the powder of stem barks of H. articulates and later fractionated and analysed. The anti-plasmodial activity was assessed against a chloroquine resistant strain P. falciparum (W2) in vitro, whilst in vivo anti-malarial activity against Plasmodium berghei (ANKA strain) was tested in mice, evaluating the role of oxidative stress (total antioxidant capacity - TEAC; lipid peroxidation – TBARS, and nitrites and nitrates - NN). In addition, cytotoxicity was evaluated using the HepG2 A16 cell-line. The acute oral and sub-chronic toxicity of the ethanol extract were evaluated in both male and female mice. Results: Plumieride was isolated from the ethyl acetate fraction of ethanol extract, Only the dichloromethane extract was active against clone W2. Nevertheless, both extracts reduced parasitaemia in P. berghei-infected mice. Besides, a significant reduction in pulmonary and cerebral levels of NN (nitrites and nitrates) was found, as well as in pulmonary TBARS, indicating a reduced oxidative damage to these organs. The ethanol extract showed low cytotoxicity to HepG2 A16 cells in the concentrations used. No significant changes were observed in the in vivo toxicity studies. Conclusions: The ethanol extract of H. articulatus proved to be promising as anti-malarial medicine and showed low toxicity

    Height and body-mass index trajectories of school-aged children and adolescents from 1985 to 2019 in 200 countries and territories: a pooled analysis of 2181 population-based studies with 65 million participants

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    Summary Background Comparable global data on health and nutrition of school-aged children and adolescents are scarce. We aimed to estimate age trajectories and time trends in mean height and mean body-mass index (BMI), which measures weight gain beyond what is expected from height gain, for school-aged children and adolescents. Methods For this pooled analysis, we used a database of cardiometabolic risk factors collated by the Non-Communicable Disease Risk Factor Collaboration. We applied a Bayesian hierarchical model to estimate trends from 1985 to 2019 in mean height and mean BMI in 1-year age groups for ages 5–19 years. The model allowed for non-linear changes over time in mean height and mean BMI and for non-linear changes with age of children and adolescents, including periods of rapid growth during adolescence. Findings We pooled data from 2181 population-based studies, with measurements of height and weight in 65 million participants in 200 countries and territories. In 2019, we estimated a difference of 20 cm or higher in mean height of 19-year-old adolescents between countries with the tallest populations (the Netherlands, Montenegro, Estonia, and Bosnia and Herzegovina for boys; and the Netherlands, Montenegro, Denmark, and Iceland for girls) and those with the shortest populations (Timor-Leste, Laos, Solomon Islands, and Papua New Guinea for boys; and Guatemala, Bangladesh, Nepal, and Timor-Leste for girls). In the same year, the difference between the highest mean BMI (in Pacific island countries, Kuwait, Bahrain, The Bahamas, Chile, the USA, and New Zealand for both boys and girls and in South Africa for girls) and lowest mean BMI (in India, Bangladesh, Timor-Leste, Ethiopia, and Chad for boys and girls; and in Japan and Romania for girls) was approximately 9–10 kg/m2. In some countries, children aged 5 years started with healthier height or BMI than the global median and, in some cases, as healthy as the best performing countries, but they became progressively less healthy compared with their comparators as they grew older by not growing as tall (eg, boys in Austria and Barbados, and girls in Belgium and Puerto Rico) or gaining too much weight for their height (eg, girls and boys in Kuwait, Bahrain, Fiji, Jamaica, and Mexico; and girls in South Africa and New Zealand). In other countries, growing children overtook the height of their comparators (eg, Latvia, Czech Republic, Morocco, and Iran) or curbed their weight gain (eg, Italy, France, and Croatia) in late childhood and adolescence. When changes in both height and BMI were considered, girls in South Korea, Vietnam, Saudi Arabia, Turkey, and some central Asian countries (eg, Armenia and Azerbaijan), and boys in central and western Europe (eg, Portugal, Denmark, Poland, and Montenegro) had the healthiest changes in anthropometric status over the past 3·5 decades because, compared with children and adolescents in other countries, they had a much larger gain in height than they did in BMI. The unhealthiest changes—gaining too little height, too much weight for their height compared with children in other countries, or both—occurred in many countries in sub-Saharan Africa, New Zealand, and the USA for boys and girls; in Malaysia and some Pacific island nations for boys; and in Mexico for girls. Interpretation The height and BMI trajectories over age and time of school-aged children and adolescents are highly variable across countries, which indicates heterogeneous nutritional quality and lifelong health advantages and risks

    Rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART): Study protocol for a randomized controlled trial

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    Background: Acute respiratory distress syndrome (ARDS) is associated with high in-hospital mortality. Alveolar recruitment followed by ventilation at optimal titrated PEEP may reduce ventilator-induced lung injury and improve oxygenation in patients with ARDS, but the effects on mortality and other clinical outcomes remain unknown. This article reports the rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART). Methods/Design: ART is a pragmatic, multicenter, randomized (concealed), controlled trial, which aims to determine if maximum stepwise alveolar recruitment associated with PEEP titration is able to increase 28-day survival in patients with ARDS compared to conventional treatment (ARDSNet strategy). We will enroll adult patients with ARDS of less than 72 h duration. The intervention group will receive an alveolar recruitment maneuver, with stepwise increases of PEEP achieving 45 cmH(2)O and peak pressure of 60 cmH2O, followed by ventilation with optimal PEEP titrated according to the static compliance of the respiratory system. In the control group, mechanical ventilation will follow a conventional protocol (ARDSNet). In both groups, we will use controlled volume mode with low tidal volumes (4 to 6 mL/kg of predicted body weight) and targeting plateau pressure <= 30 cmH2O. The primary outcome is 28-day survival, and the secondary outcomes are: length of ICU stay; length of hospital stay; pneumothorax requiring chest tube during first 7 days; barotrauma during first 7 days; mechanical ventilation-free days from days 1 to 28; ICU, in-hospital, and 6-month survival. ART is an event-guided trial planned to last until 520 events (deaths within 28 days) are observed. These events allow detection of a hazard ratio of 0.75, with 90% power and two-tailed type I error of 5%. All analysis will follow the intention-to-treat principle. Discussion: If the ART strategy with maximum recruitment and PEEP titration improves 28-day survival, this will represent a notable advance to the care of ARDS patients. Conversely, if the ART strategy is similar or inferior to the current evidence-based strategy (ARDSNet), this should also change current practice as many institutions routinely employ recruitment maneuvers and set PEEP levels according to some titration method.Hospital do Coracao (HCor) as part of the Program 'Hospitais de Excelencia a Servico do SUS (PROADI-SUS)'Brazilian Ministry of Healt
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