47 research outputs found

    Chemical profile and antioxidant, anti-inflammatory, antimutagenic and antimicrobial activities of geopropolis from the stingless bee Melipona orbignyi

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    Licensee MDPI, Basel, Switzerland. Geopropolis is a resin mixed with mud, produced only by stingless bees. Despite being popularly known for its medicinal properties, few scientific studies have proven its biological activities. In this context, the objective of this study was to determine the chemical composition and antioxidant, anti-inflammatory, antimutagenic and antimicrobial activities of the Melipona orbignyi geopropolis. The hydroalcoholic extract of geopropolis (HEGP) was prepared and its chemical composition determined by high performance liquid chromatography coupled to diode array detector and mass spectrometry (HPLC-DAD-MS). The antioxidant activity was determined by the capture of free radicals and inhibition of lipid peroxidation in human erythrocytes. The anti-inflammatory activity was evaluated by the inhibition of the hyaluronidase enzyme and the antimutagenic action was investigated in Saccharomyces cerevisiae colonies. The antimicrobial activities were determined against bacteria and yeasts, isolated from reference strains and hospital origin. The chemical composition of HEGP included flavonoids, derivatives of glycosylated phenolic acids and terpenoids. HEGP showed high antioxidant activity, it inhibited the activity of the inflammatory enzyme hyaluronidase and reduced the mutagenic effects in S. cerevisiae. In relation to the antimicrobial activity, it promoted the death of all microorganisms evaluated. In conclusion, this study reveals for the first time the chemical composition of the HEGP of M. orbignyi and demonstrates its pharmacological properties.This work was supported by grants from Foundation to Support to Fundação de Apoio ao Desenvolvimento do Ensino, Ciência e Tecnologia do Estado de Mato Grosso do Sul (FUNDECT, Brazil), Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES, Brazil), Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq, Brazil) and PRODER, (24.073 – Â, Portugal).info:eu-repo/semantics/publishedVersio

    Papain gel containing methylene blue for simultaneous caries removal and antimicrobial photoinactivation against Streptococcus mutans biofilms

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    This study intended to evaluate the effects of a papain-gel with a red-light absorbing pigment (methylene blue – MB) to mediate photodynamic therapy (PDT) against Streptococcus mutans biofilms. The PapaMBlue was compared with free MB to generate reactive oxygen species using fluorescence probes (SOSG and HPF). PDT (660-nm light) was carried out against S. mutans biofilms grown on either plastic dishes or on collagen membrane and assayed by CFU, live-dead staining using confocal microscopy, transmission electron microscopy and H&E staining for collagen films. Cytotoxicity and subcellular localization was studied in human fibroblasts. Sponges of bioabsorbable type I collagen membrane were exposed to papain based gel, irradiated with laser and analyzed about their integrity by ATR-FTIR. The PapaMBlue produced higher amounts of singlet oxygen and hydroxyl radicals than free MB, possibly due to better disaggregation of the dye in solution. The PapaMBlue antimicrobial effects on biofilms proved to be capable of reducing the S. mutans. Both MTT and PrestoBlue assays showed higher cell viability and metabolism scores in fibroblasts treated with PapaMBlue and MB, possibly due to stimulation of mitochondrial activity and that collagen triple helix is unaffected. The PapaMBlue is equally effective as MB in destroying S. mutans biofilms growing on plastic or collagen without affecting fibroblasts.National Institutes of Health (U.S.) (Grant R01AI050875

    Serological evidence of hantavirus infection in rural and urban regions in the state of Amazonas, Brazil

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    Hantavirus disease is caused by the hantavirus, which is an RNA virus belonging to the family Bunyaviridae. Hantavirus disease is an anthropozoonotic infection transmitted through the inhalation of aerosols from the excreta of hantavirus-infected rodents. In the county of Itacoatiara in the state of Amazonas (AM), Brazil, the first human cases of hantavirus pulmonary and cardiovascular syndrome were described in July 2004. These first cases were followed by two fatal cases, one in the municipality of Maues in 2005 and another in Itacoatiara in 2007. In this study, we investigated the antibody levels to hantavirus in a population of 1,731 individuals from four different counties of AM. Sera were tested by IgG/IgM-enzyme-linked immune-sorbent assay using a recombinant nucleocapsid protein of the Araraquara hantavirus as an antigen. Ten sera were IgG positive to hantavirus (0.6%). Among the positive sera, 0.8% (1/122), 0.4% (1/256), 0.2% (1/556) and 0.9% (7/797) were from Atalaia do Norte, Careiro Castanho, Itacoatiara and Labrea, respectively. None of the sera in this survey were IgM-positive. Because these counties are distributed in different areas of AM, we can assume that infected individuals are found throughout the entire state, which suggests that hantavirus disease could be a local emerging health problem.FAPEAMFAPEAMCNPqCNPqCAPESCAPESSUFRAMASUFRAM

    Pervasive gaps in Amazonian ecological research

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    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

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    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 understanding 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,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 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 underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities 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 organism 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 neglected 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 lost

    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

    O Estrangeiro nas Diásporas Contemporâneas: Refugiados da Violência e Imigrantes Econômicos

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    O objetivo deste artigo é analisar as experiências de imigrantes e refugiados na cidade de Uberlândia, enquanto fenômeno diaspórico. A pesquisa é orientada pela abordagem qualitativa e utiliza de entrevistas semiestruturadas com imigrantes e refugiados, as quais foram analisadas pela técnica de análise de narrativas. A pesquisa aborda a exploração sofrida por outsiders advinda de estabelecidos, especialmente no contexto do trabalho, caracterizando uma relação de poder e colonialidade no âmbito organizacional. Os resultados são agrupados em três narrativas: a) a vida na terra da gente; b) diáspora contemporânea – o viver na terra dos outros; c) a diáspora contemporânea – trabalhar na terra dos outros. A pesquisa contribui com os estudos sobre as relações de poder no âmbito do trabalho, ampliando as discussões sobre crise migratória e a relação de opressão e hostilidade existente entre estabelecidos e outsiders

    Atividade antimutagênica de geoprópolis de melípona quadrifasciata anthidioides (HYMENOPTERA, APIDAE)

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    O câncer é caracterizado por distúrbios na proliferação e diferenciação celular, apresentando causas diversas e complexas. A patogenia molecular da maioria dos cânceres é atribuída a lesões ou mutações genéticas, resultando em graves alterações celulares. Assim, a busca por compostos com potencial antimutagênico é crescente, os quais podem reduzir ou reverter os danos no DNA. Neste contexto, o objetivo deste estudo foi investigar a atividade antimutagênica do extrato hidroetanólico de geoprópolis da abelha sem ferrão Melipona quadrifasciata anthidioides. Metodologia: O extrato hidroetanólico de geoprópolis (EHGP) foi preparado a partir da mistura de 80 g de geoprópolis em 240 mL de etanol 70%, sob agitação por 24 horas a temperatura ambiente. Posteriormente, a solução foi filtrada, rotaevaporada e liofilizada. Para determinar a atividade antimutagênica do EHGP, foram utilizadas células de Saccharomyces cerevisiae ATCC 201137 (linhagem D7 diploide) as quais foram usadas para determinar a frequência de convertentes espontâneas no locus de triptofano (trp) e revertentes no locus de isoleucina (ilv). As células foram plaqueadas a 2 x 108 células/mL e incubadas com o composto mutagênico (ethyl methanesulfonate) e o EHGP (0,15 e 0,30 %) por 2 h a 37 °C. Em seguida, as células foram transferidas para meio seletivo para determinar a sobrevivência, trp convertentes e ilv revertentes. Resultados: O EHGP reduziu a sobrevivência da S. cerevisiae D7 em torno de 50%, por sua ação fungicida, e apresentou efeito antimutagênico inibindo os danos promovidos pelo composto mutagênico. O extrato apresentou redução das frequências de conversão de gene em 30,7 ± 4,8 e 41,5 ± 1,7 %, nas concentrações de 0,15 e 0,30 %, respectivamente. Adicionalmente, reduziu significativamente o número de colônias mutantes em 79,4 ± 0,8 (concentração de 0,15 %) e 89,3 ± 0,5 % (concentração de 0,30 %).Conclusão: Em suma, os resultados obtidos mostram que o extrato de geoprópolis de Melipona quadrifasciata anthidioides apresenta potencial em inibir lesões ou mutações genéticas induzidas por compostos mutagênicos em leveduras.CAPES; Fundect; CNPqinfo:eu-repo/semantics/publishedVersio
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