Molecular characterization of beta-tubulin from Phakopsora pachyrhizi, the causal agent of Asian soybean rust

β-tubulins are structural components of microtubules and the targets of benzimidazole fungicides used to control many diseases of agricultural importance. Intron polymorphisms in the intron-rich genes of these proteins have been used in phylogeographic investigations of phytopathogenic fungi. In this work, we sequenced 2764 nucleotides of the β-tubulin gene (Pp tubB) in samples of Phakopsora pachyrhizi collected from seven soybean fields in Brazil. Pp tubB contained an open reading frame of 1341 nucleotides, including nine exons and eight introns. Exon length varied from 14 to 880 nucleotides, whereas intron length varied from 76 to 102 nucleotides. The presence of only four polymorphic sites limited the usefulness of Pp tubB for phylogeographic studies in P. pachyrhizi. The gene structures of Pp tubB and orthologous β-tubulin genes of Melampsora lini and Uromyces viciae-fabae were highly conserved. The amino acid substitutions in β-tubulin proteins associated with the onset of benzimidazole resistance in model organisms, especially at His 6 , Glu 198 and Phe 200 , were absent from the predicted sequence of the P. pachyrhizi β-tubulin protein

High Glucose-Mediated Oxidative Stress Impairs Cell Migration

Deficient wound healing in diabetic patients is very frequent, but the cellular and molecular causes are poorly defined. In this study, we evaluate the hypothesis that high glucose concentrations inhibit cell migration. Using CHO.K1 cells, NIH-3T3 fibroblasts, mouse embryonic fibroblasts and primary skin fibroblasts from control and diabetic rats cultured in 5 mM D-glucose (low glucose, LG), 25 mM D-glucose (high glucose, HG) or 25 mM L-glucose medium (osmotic control - OC), we analyzed the migration speed, protrusion stability, cell polarity, adhesion maturation and the activity of the small Rho GTPase Rac1. We also analyzed the effects of reactive oxygen species by incubating cells with the antioxidant N-Acetyl-Cysteine (NAC). We observed that HG conditions inhibited cell migration when compared to LG or OC. This inhibition resulted from impaired cell polarity, protrusion destabilization and inhibition of adhesion maturation. Conversely, Rac1 activity, which promotes protrusion and blocks adhesion maturation, was increased in HG conditions, thus providing a mechanistic basis for the HG phenotype. Most of the HG effects were partially or completely rescued by treatment with NAC. These findings demonstrate that HG impairs cell migration due to an increase in oxidative stress that causes polarity loss, deficient adhesion and protrusion. These alterations arise, in large part, from increased Rac1 activity and may contribute to the poor wound healing observed in diabetic patients

uma nova ferramenta de vigilância transnacional da tuberculose no espaço lusófono

A Tuberculose (TB) permanece um grave problema de saúde pública na Comunidade dos Países de Língua Portuguesa (CPLP). Apesar da ampla variância da incidência da TB nos seus estados-membro e de um fluxo migratório contínuo entre os países que integram este grupo, existe uma enorme lacuna no que diz respeito ao conhecimento da estrutura populacional conjunta do Mycobacterium tuberculosis e circulação de estirpes entre estes países. Para fazer face a esta necessidade, foi agregado e analisado o maior conjunto de dados respeitante à diversidade genotípica e resistência fenotípica na CPLP que compreende um total de 1447 isolados clínicos, incluindo 423 isolados multirresistentes de cinco países da CPLP. Por forma a tornar estes dados disponíveis para a comunidade científica e autoridades de saúde pública, foi desenvolvida a CPLP-TB (disponível em http://cplp-tb.ff.ulisboa.pt), uma base de dados disponível online e provida de aplicativos para análise exploratória do conteúdo. Como ferramenta de saúde pública, espera-se que venha a contribuir para um conhecimento mais aprofundado da estrutura populacional do M. tuberculosis e circulação de estirpes na CPLP de forma a apoiar a avaliação de risco e tendências específicas para diversos clones. Tuberculosis (TB) remains a major health problem within the Community of Portuguese Language Speaking Countries (CPLP). Despite the marked variation in TB incidence across its member-states and continued human migratory flux between countries, a considerable gap in the knowledge on the Mycobacterium tuberculosis population structure and strain circulation between the countries still exists. To address this, we have assembled and analyzed the largest CPLP M . tuberculosis molecular and drug susceptibility dataset, comprised by a total of 1447 clinical isolates, including 423 multidrug-resistant isolates, from five CPLP countries. To make this data available to the scientific community and public health authorities we developed CPLP-TB (available at http://cplp-tb.ff.ulisboa.pt), an online database coupled with web-based tools for exploratory data analysis. As a public health tool, it is expected to contribute to improved knowledge on the M. tuberculosis population structure and strain circulation within the CPLP, thus supporting the risk assessment of strain-specific trends.publishersversionpublishe

Pervasive gaps in Amazonian ecological research

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

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

Calogênese e teores de fenóis e tatinos totais em barbatimão [stryphnodendron adstringens (mart.) coville] Callogenesis and contents of total phenols and tannins in barbatimão [Stryphnodendron adsrtingens (Mart.) Coville]

Atualmente, culturas de células ou de suspensões celulares têm sido frequentemente empregadas para produzir fitoterápicos com maiores concentrações de princípios ativos. O barbatimão é uma importante espécie medicinal do Cerrado, com taninos nas cascas do caule. Objetivando-se induzir calos em barbatimão e avaliar os teores de fenóis e taninos totais, explantes foliares foram inoculados em meio MS suplementado com 30 g L-1 sacarose e acrescidos de 2,4-D (0; 4,52; 9,05; 18,10 &#956;M ) e BAP (0; 4,44; 8,88; 17,75 &#956;M ), na presença e ausência de luz. A calogênese ocorreu em meios contendo 2,4-D, na presença de luz. O número de calos não variou com as concentrações de 2,4-D e maiores valores de matérias fresca e seca de calos e teores de fenóis totais foram observados em meios com 9,05 &#956;M e 18,10 &#956;M de 2,4-D, na presença e ausência de luz. Com BAP, a calogênese ocorreu na ausência de luz, com maior produção de calos na presença de 4,44 e 8,88 &#956;M de BAP e maiores valores de matéria fresca e seca em meios com 4,44 &#956;M de BAP. Calos crescidos em meios suplementados 4,44 e 17,75 &#956;M de BAP apresentaram maiores teores de fenóis totais. Não se detectaram taninos, independente do regulador empregado.<br>Recently, cell cultures and cell suspensions have been frequently employed to produce phytotherapics with high amounts of active principles. Barbatimão is a native species from the Cerrado, with tannins in the stem bark. In order to induce callus in barbatimão and evaluate the content of total phenols and tannins, leaf explants were inoculated on MS medium, supplemented with sucrose 30 g L¹ and 2,4-D (0, 4.52, 9.05, 18.10 &#956;M ) and BA (0, 4.44, 8.88, 17.75 &#956;M ), in the presence and absence of light. The callogenesis occurred on medium containing 2,4-D, in the presence of light. The callus number did not alter with the different concentrations of 2,4-D but higher values of dry and fresh matter of the callus and total phenol contents were observed in medium with 9.05 &#956;M and 18.10 &#956;M of 2,4-D, independently of the light treatment. In treatments with BA, the callogenesis occurred in the absence of light and higher callus induction was observed in medium supplemented with 4.44 and 8.88 &#956;M BA in the absence of light and higher values of dry and fresh matter of the callus were observed in medium increased with 4.44 &#956;M BA. Callus grown on medium supplemented with 4.44 and 17.75 &#956;M BA showed higher total phenol content. Tannins were not detected independently of the regulator used

Hydrolysis of galacto&#45;oligosaccharides in soy molasses by &#945; &#45;galactosidases and invertase from Aspergillus terreus

Two &#945; -galactosidase (P1 and P2) and one invertase present in the culture of Aspergillus terreus grown on wheat straw for 168 h at 28ºC were partially purified by gel filtration and hydrophobic interaction chromatographies. Optimum pH and temperatures for P1, P2 and invertase preparations were 4.5-5.0, 5.5 and 4.0 and 60, 55 and 65ºC, respectively. The K M app for Ï� -nitrophenyl-&#945; -D-galactopyranoside were 1.32 mM and 0.72 mM for P1 and P2, respectively, while the K M app value for invertase, using sacarose as a substrate was 15.66 mM. Enzyme preparations P1 and P2 maintained their activities after pre-incubation for 3 h at 50ºC and invertase maintained about 90% after 6 h at 55 ºC. P1 and P2 presented different inhibition sensitivities by Ag+, D-galactose, and SDS. All enzyme preparations hydrolyzed galacto-ologosaccharides present in soymolasses.<br>Duas &#945;-galactosidases (P1 e P2) e uma invertase produzidas no sobrenadante da cultura do fungo Aspergillus terreus quando crescido por 168 h a 28ºC com farelo de trigo como fonte de carbono foram parcialmente purificadas por cromatografias de gel filtração e interação hidrofóbica. O pH e temperatura ótimos para as preparações P1, P2 e invertase foram entre 4,5-5,0, 5,5 e 4,0 e 60, 55 e 65ºC, respectivamente. O K M app para Ï�-nitrofenil-&#945;-D-galactopiranosideo foi 1.32 mM e 0.72 mM para P1 e P2, respectivamente. O valor de K M app para invertase usando sacarose como substrato foi de 15,66 mM. As preparações enzimáticas P1 e P2 mantiveram suas atividades após 3 h de pré-incubação a 50 ºC e a invertase manteve cerca de 90% após 6 h a 55 ºC. P1 e P2 foram diferentemente sensíveis à inibição por Ag+, D-galactose e SDS. As preparações enzimáticas hidrolisaram os galactooligossacarídeos presentes em melaço de soja