130 research outputs found

    Multitask ATPases (NBDs) of bacterial ABC importers type I and their interspecies exchangeability

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    We would like to thank Herminia de Lencastre (ITQB-AX NOVA), Adriano Henriques (ITQB-AX NOVA) and PaulaTamagnini (i3S) for the gift of chromosomal DNA, Paulo Tavares (I2BC-CNRS) and Adriano Henriques for the gift of flagellin and anti-sigmaA antibodies, respectively, and Diogo Pereira for carrying out some growth kinetic assays. This work was supported by the FundacAo para a Ciencia e a Tecnologia [Grant Numbers PTDC/BIA-MIC/30696/2017 to ISN and UID/Multi/04378/2019 to Unidade de Ciencias Biomoleculares Aplicadas UCIBIO; and fellowship PD/BD/105737/2014 to F.L.].ATP-binding cassette (ABC) type I importers are widespread in bacteria and play a crucial role in its survival and pathogenesis. They share the same modular architecture comprising two intracellular nucleotide-binding domains (NBDs), two transmembrane domains (TMDs) and a substrate-binding protein. The NBDs bind and hydrolyze ATP, thereby generating conformational changes that are coupled to the TMDs and lead to substrate translocation. A group of multitask NBDs that are able to serve as the cellular motor for multiple sugar importers was recently discovered. To understand why some ABC importers share energy-coupling components, we used the MsmX ATPase from Bacillus subtilis as a model for biological and structural studies. Here we report the first examples of functional hybrid interspecies ABC type I importers in which the NBDs could be exchanged. Furthermore, the first crystal structure of an assigned multitask NBD provides a framework to understand the molecular basis of the broader specificity of interaction with the TMDs.publishersversionpublishe

    Flora and vegetation in different physiognomies of a Mussununga in southeastern Brazil.

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    Mussununga is an understudied ecosystem within the Atlantic Forest domain, in sandy spodosol lowlands from Bahia to Esp?rito Santo. Its physiognomy varies from grassland to forest, with a transitional savannic area. We evaluated the life-form spectra differences between the grassland and savanna Mussunungas and its relationship with the depth of a soil impermeable layer (ortstein). The study area is located in the municipality of Linhares, Esp?rito Santo State. Ten plots were settled in each physiognomy. The floristic and vegetation spectra (accordingly to Raunkiaer) were compared using the G-test. A total of 35 species into three life-forms were found: Phanerophytes, hemicryptophytes and cryptophytes. The floristic spectra were similar in both physiognomies, with a greater richness of phanerophytes. However, the vegetation spectra of the two areas were different. Phanerophytes dominated in the savannas (where ortstein is deeper), while the shallower ortstein of the grasslands favored hemicryptophytes

    Tuberculose e COVID-19, o novo dueto maldito : quais as diferenças entre Brasil e Europa?

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    On April 1st, 2020, COVID-19 surpassed tuberculosis regarding the number of deaths per day worldwide. The combination of tuberculosis and COVID-19 has great potential for morbidity and mortality. In addition, the COVID-19 pandemic has had a significant impact on the diagnosis and treatment of tuberculosis. In this review article, we address concurrent tuberculosis and COVID-19, with particular regard to the differences between Brazil and Europe. In addition, we discuss priorities in clinical care, public health, and research.Em 1º de abril de 2020, a COVID-19 ultrapassou a tuberculose em número de óbitos por dia no mundo. A associação da tuberculose com a COVID-19 apresenta grande potencial de morbidade e mortalidade. Além disso, a pandemia de COVID-19 tem tido um impacto significativo no diagnóstico e tratamento da tuberculose. Neste artigo de revisão, abordamos tuberculose e COVID-19 concomitantes, com particular atenção às diferenças entre Brasil e Europa. Além disso, discutimos as prioridades em atendimento clínico, saúde pública e pesquisa

    Thalidomide is Associated With Increased T Cell Activation and Inflammation in Antiretroviral-naive HIV-infected Individuals in a Randomised Clinical Trial of Efficacy and Safety

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    Trial Design: Open-label, randomised, controlled, pilot proof-of-concept clinical trial. Methods: Participants: Antiretroviral naive adult males with CD4 count >= 350 cells/mm(3). Interventions: Patients were randomised to receive thalidomide 200 mg QD for 3 weeks (Thalidomide group) or not (Control group) and followed for 48 weeks. Objective: We hypothesized that short-term Thalidomide use would reduce HIV related inflammation and HIV replication among antiretroviral naive HIV infected individuals. Outcome: Viral loads, CD4/CD8 counts, ultra-sensitive C-reactive protein (US-CRP), cell activation markers, and plasma lipopolysaccharide (LPS) were analyzed. Randomisation: Unrestricted randomisation. Blinding: No blinding was used. Results: Numbers randomised: Thirty recruited individuals were randomised to Thalidomide (16 patients) or Control (14 patients) groups. Recruitment: Patients were recruited from April 2011 to January 2013. Outcome: Viral loads remained stable in both groups. During thalidomide treatment, a decrease in CD4/CD8 ratio (p = 0.04), a decrease in CD4 count (p = 0.04), an increase in cell activation calculated by the percentage of CD38 (+)/HLA-DR+ CD8 cells (p < 0.05) and an increase in US-CRP (p < 0.01) were observed in the Thalidomide group, with all parameters returning to baseline levels after thalidomide interruption. We confirmed that thalidomide increased HIV replication in vitro of 6 of 7 samples from long-term antiretroviral suppressed individuals. Harms: No class 3/4 adverse events occurred. Conclusions: Short-termuse of thalidomide led to an intense transient increase in T cell activation and inflammation, with a decrease in the CD4(+) cell count without changes to the CD8(+) cell count. We confirmed that thalidomide acts in vitro as a latency reversal agent and speculate that the in vivo results obtained were due to an increase in HIV replication. (C) 2017 The Authors. Published by Elsevier B.V.Fundação de Amparo a Pesquisa do Estado de São Paulo (FAPESP)Univ Fed São Paulo, Lab Retrovirol, São Paulo, BrazilFiocruz MS, Inst Oswaldo Cruz, Lab Interdisciplinar Pesquisas Med, Rio De Janeiro, BrazilSecretaria Municipal Saude Antonio Ribeiro Neto, Rio De Janeiro, BrazilOncohiv, Rio De Janeiro, BrazilUniv Fed Rio de Janeiro, Rio De Janeiro, BrazilInst Fed Educ Ciencia & Tecnol Rio de Janeiro IF, Rio De Janeiro, BrazilUniv Fed São Paulo, Lab Retrovirol, São Paulo, BrazilFAPESP: 04/15856-9Web of Scienc

    Human N-acetyltransferase 2 (NAT2) gene variability in Brazilian populations from different geographical areas

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    Introduction: Several polymorphisms altering the NAT2 activity have already been identified. The geographical distribution of NAT2 variants has been extensively studied and has been demonstrated to vary significantly among different ethnic population. Here, we describe the genetic variability of human N-acetyltransferase 2 (NAT2) gene and the predominant genotype-deduced acetylation profiles of Brazilians.Methods: A total of 964 individuals, from five geographical different regions, were genotyped for NAT2 by sequencing the entire coding exon.Results: Twenty-three previously described NAT2 single nucleotide polymorphisms (SNPs) were identified, including the seven most common ones globally (c.191G&gt;A, c.282C&gt;T, c.341T&gt;C, c.481C&gt;T, c.590G&gt;A, c.803A&gt;G and c.857G&gt;A). The main allelic groups were NAT2*5 (36%) and NAT2*6 (18.2%), followed to the reference allele NAT2*4 (20.4%). Combined into genotypes, the most prevalent allelic groups were NAT2*5/*5 (14.6%), NAT2*5/*6 (11.9%) and NAT2*6/*6 (6.2%). The genotype deduced NAT2 slow acetylation phenotype was predominant but showed significant variability between geographical regions. The prevalence of slow acetylation phenotype was higher in the Northeast, North and Midwest (51.3%, 45.5% and 41.5%, respectively) of the country. In the Southeast, the intermediate acetylation phenotype was the most prevalent (40.3%) and, in the South, the prevalence of rapid acetylation phenotype was significantly higher (36.7%), when compared to other Brazilian states (p &lt; 0.0001). Comparison of the predicted acetylation profile among regions showed homogeneity among the North and Northeast but was significantly different when compared to the Southeast (p = 0.0396). The Southern region was significantly different from all other regions (p &lt; 0.0001).Discussion: This study contributes not only to current knowledge of the NAT2 population genetic diversity in different geographical regions of Brazil, but also to the reconstruction of a more accurate phenotypic picture of NAT2 acetylator profiles in those regions

    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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