ABIETANE DITERPENOIDS FROM PLECTRANTHUS GRANDIDENTATUS

The acetone extract of the whole plant of Plectranthus grandidentatus provided the already known abietanes royleanone, 6,7-dehydroroyleanone, horminone, 6β-hydroxyroyleanone, 7α-acetoxy-6β-hydroxyroyleanone and the abietane dimers grandidone C, grandidone D and 7-epigrandidone D, together with a mixture of fatty acid esters of 7α-acyloxy-6β,12-dihydroxy-abieta-8,12-diene-11,14-dione. Some of these compounds showed moderate antibacterial activity

Electrochemical study of simple coumarin and its determination in aqueous infusion of Mikania glomerata

The present study aims the development and application of an electrochemical method for simple coumarin determination in aqueous media by using a boron-doped diamond electrode (BDDE). The studies were carried out at pH 8.0 by cyclic voltammetry (CV) and registered an irreversible reduction process controlled by diffusion with the peak potential recorded around -1.6 V. The square wave voltammetry analysis (SWV) showed the reversible behavior of the electrochemical reduction of coumarin at the same pH. Additionally, the reversibility of the process was improved by increasing the solution pH. The chronoamperometry study showed that the coumarin reduction process involves two electrons. From the optimized SWV parameters, the analytical curve was constructed in a linear range between 0.5 × 10-5 and 10.0 × 10-5 mol L-1. The limits of detection and quantification were 1.5 × 10-6 mol L-1 and 4.5 × 10-6 mol L-1, respectively. The coumarin was determined in an aqueous infusion of Mikania glomerata, showing recovery values between 92 and 104%.O presente estudo teve por objetivos o desenvolvimento e a aplicação de um método eletroquímico para a determinação da cumarina simples em meio aquoso utilizando o eletrodo de diamante dopado com boro (BDDE). Os estudos foram realizados em pH 8,0 utilizando a voltametria cíclica (CV) e observou-se um processo de redução irreversível controlado por difusão com um pico de redução em torno de -1,6 V. Entretanto, foi possível observar por voltametria de onda quadrada (SWV) que no mesmo pH a redução da cumarina possui um caráter reversível. Além disso, esta reversibilidade se tornou mais evidente com o aumento do pH da solução. Um estudo cronoamperométrico mostrou que o processo de redução da cumarina envolve dois elétrons. A partir dos parâmetros otimizados da SWV uma curva analítica foi construída no intervalo linear de 0,5 × 10-5 a 10,0 × 10-5 mol L-1. Os limites de detecção e de quantificação foram 1,5 × 10-6 mol L-1 e 4,5 × 10-6 mol L-1, respectivamente. A cumarina foi determinada em amostras de Mikania glomerata (infusão aquosa) com valores de recuperação entre 92 e 104%.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Universidade Federal de São Paulo (UNIFESP) Instituto de Ciências Ambientais, Químicas e Farmacêuticas Departamento de Ciências Exatas e da TerraUniversidade Federal do ABC Centro de Ciências Naturais e HumanasUNIFESP, Instituto de Ciências Ambientais, Químicas e Farmacêuticas Depto. de Ciências Exatas e da Terra2008/50588-6SciEL

The blp locus of Streptococcus pneumoniae plays a limited role in the selection of which strains can co-colonize the human nasopharynx.

Nasopharyngeal colonization is important for Streptococcus pneumoniae evolution, providing the opportunity for horizontal gene transfer when multiple strains co-occur. Although colonization with more than one strain of pneumococcus is common, the factors that influence the ability of strains to co-exist are not known. A highly variable blp (bacteriocin-like peptide) locus has been identified in all sequenced strains of S. pneumoniae This locus controls the regulation and secretion of bacteriocins, small peptides that target other bacteria. In this study, we analyzed a series of co-colonizing isolates to evaluate the impact of the blp locus on human colonization to determine whether competitive phenotypes of bacteriocin secretion restrict co-colonization.We identified a collection of 135 nasopharyngeal samples with two or more strains totaling 285 isolates. The blp locus of all strains was characterized genetically with regards to pheromone type, bacteriocin/immunity content and potential for locus functionality. Inhibitory phenotypes of bacteriocin secretion and locus activity were assessed through overlay assays. Isolates from single colonization (n=298) were characterized for comparison.Co-colonizing strains had a high diversity of blp cassettes; approximately one third displayed an inhibitory phenotype in vitro Despite in vitro evidence of competition, pneumococci co-colonized individuals independently of their blp pheromone type (p=0.577), bacteriocin/immunity content, blp locus activity (p=0.798) and inhibitory phenotype (p=0.716). In addition, no significant differences were observed when single and co-colonizing strains were compared.Despite clear evidence of blp-mediated competition in experimental models, our study suggests that the blp locus plays a limited role in restricting pneumococcal co-colonization in humans. IMPORTANCE: Nasopharyngeal colonization with Streptococcus pneumoniae (pneumococcus) is important for pneumococcal evolution as it represents the major site for horizontal gene transfer when multiple strains co-occur, a phenomenon known as co-colonization. Understanding how pneumococcal strains interact within the competitive environment of the nasopharynx is of chief importance in the context of pneumococcal ecology. In this study we used an unbiased collection of naturally co-occurring pneumococcal strains and showed that a biological process frequently used by bacteria for competition - bacteriocin production - is not decisive in the co-existence of pneumococci in the host, contrary to what has been shown in experimental models

MC1R gene polymorphisms analysis associated with human pigmentation phenotypes on the brazilian population

Dentre os genes conhecidos por infl uenciarem a variação normal de pigmentação de olhos, pele e cabelos em humanos, o gene MC1R (receptor de melanocortina 1) é o mais bem caracterizado até o momento. A atuação do MC1R ocorre pela produção de uma proteína transmembrana nos melanócitos, responsável pela regulação da produção de melanina nos mesmos. Sabe-se que a atuação do MC1R determina a proporção entre eumelanina (coloração castanha/preta) e feomelanina (amarela/vermelha) presente nos melanócitos. O presente trabalho tem como objetivo analisar os SNPs conhecidos do gene MC1R com o propósito de se avaliar a infl uência da diversidade deste gene em características como a presença de sardas e variação da pigmentação dos olhos, pele e cabelos em humanos. Foram analisados 29 SNPs conhecidos da região codifi cadora do gene MC1R em 296 indivíduos da região de Ribeirão Preto, SP. A extração do DNA foi feita pela técnica de salting-out. A região codifi cadora do gene MC1R (951pb) foi amplifi cada em uma única reação de PCR, a qual foi sequenciada em um analisador genético ABI-PRISM 310 por eletroforese capilar, utilizando-se os mesmos primers empregados para a amplifi cação. Dos 29 SNPs avaliados, 22 deles mostraram variação nas amostras estudadas, sendo que metade deles demonstrou estar associados a características de pigmentação. Observou-se um conjunto de SNPs associados claramente à fenótipos relacionados à feomelanina (+1645 A, +1831 T,+1858 T e +2260 C), enquanto outros se relacionam à ocorrência de eumelanina (+1558 G, +2322 G, +2346 A). O presente trabalho apresenta associações signifi cativas entre SNPs individuais e pigmentação de olhos, cabelos e pele, sendo que nosso dados confi rmam que tal gene também desempenha papel relevante na variação de pigmentação na população Brasileira.Among the known genes infl uencing eye, skin and hair normal pigmentation variation, the MC1R (melanocortin 1-receptor) gene is the best characterized so far. The activity of MC1R occurs due the production of a transmembrane protein in melanocytes, responsible for regulating the production of melanin. It is known that the performance of MC1R determines the ratio of eumelanin (brown /black color) and pheomelanin (yellow/ red) present in melanocytes. This study aims to analyze known SNPs of the MC1R gene in order to evaluate the infl uence of this gene diversity on features like freckles and pigmentation variation of eyes, skin and hair in humans. We analyzed 29 known SNPs in the coding region of MC1R gene in 296 individuals from the region of Ribeirão Preto, Brazil. DNA extraction was performed using the salting-out technique. The MC1R gene coding region (951pb) was amplifi ed in a single PCR reaction, which was sequenced on a ABI PRISM-310 genetic analyzer by capillary electrophoresis, using the same primers used for amplifi cation. Of the 29 SNPs evaluated, only 22 showed variation in the samples studied, half of them showing to be associated with pigmentation characteristics. We observed a set of SNPs clearly associated to pheomelanin (+1645 A, +1831 T,+1858 T e +2260 C), while others related to eumelanin occurrence (+1558 G, +2322 G, +2346 A). Our study shows signifi cant associations between individual SNPs and eyes, hair and skin pigmentation. The results presented here confi rm that this gene also plays a relevant role in the pigmentation variation in the Brazilian population

The HELLAS2XMM survey: XI. Unveiling the nature of X-ray Bright Optically Normal Galaxies

X-ray Bright Optically Normal Galaxies (XBONGs) constitute a small but not negligible fraction of hard X-ray selected sources in recent Chandra and XMM-Newton surveys. Even though several possibilities were proposed to explain why a relatively luminous hard X-ray source does not leave any significant signature of its presence in terms of optical emission lines, the nature of XBONGs is still subject of debate. We aim to a better understanding of their nature by means of a multiwavelength and morphological analysis of a small sample of these sources. Good-quality photometric near-infrared data (ISAAC/VLT) of four low-redshift (z=0.1-0.3) XBONGs, selected from the HELLAS2XMM survey, have been used to search for the presence of the putative nucleus, applying the surface-brightness decomposition technique through the least-squares fitting program GALFIT. The surface brightness decomposition allows us to reveal a nuclear point-like source, likely to be responsible of the X-ray emission, in two out of the four sources. The results indicate that moderate amounts of gas and dust, covering a large solid angle (possibly 4pi) at the nuclear source, combined with the low nuclear activity, may explain the lack of optical emission lines. The third XBONG is associated with an X-ray extended source and no nuclear excess is detected in the near infrared at the limits of our observations. The last source is associated to a close (d< 1 arcsec) double system and the fitting procedure cannot achieve a firm conclusion.Comment: 20 pages, 12 figures, A&A in pres

Still a Host of Hosts for Wolbachia: Analysis of Recent Data Suggests That 40% of Terrestrial Arthropod Species Are Infected

Wolbachia are intracellular bacteria that manipulate the reproduction of their arthropod hosts in remarkable ways. They are predominantly transmitted vertically from mother to offspring but also occasionally horizontally between species. In doing so, they infect a huge range of arthropod species worldwide. Recently, a statistical analysis estimated the infection frequency of Wolbachia among arthropod hosts to be 66%. At the same time, the authors of this analysis highlighted some weaknesses of the underlying data and concluded that in order to improve the estimate, a larger number of individuals per species should be assayed and species be chosen more randomly. Here we apply the statistical approach to a more appropriate data set from a recent survey that tested both a broad range of species and a sufficient number of individuals per species. Indeed, we find a substantially different infection frequency: We now estimate the proportion of Wolbachia-infected species to be around 40% which is lower than the previous estimate but still points to a surprisingly high number of arthropods harboring the bacteria. Notwithstanding this difference, we confirm the previous result that, within a given species, typically most or only a few individuals are infected. Moreover, we extend our analysis to include several reproductive parasites other than Wolbachia that were also screened for in the aforementioned empirical survey. For these symbionts we find a large variation in estimated infection frequencies and corroborate the finding that Wolbachia are the most abundant endosymbionts among arthropod species

Investigação epidemiológica e controle da Esquistossomose e demais parasitoses intestinais na Zona da Mata Mineira

-O presente trabalho avalia a cobertura e a qualidade do cadastro das famílias nos municípios mineiros de Coronel Pacheco, Goianá, e Piau, através da comparação entre a ficha A aplicada pelo agente comunitário de saúde e os dados obtidos de investigações realizadas diretamente nos domicílios. Foram entrevistadas, no período de novembro a dezembro de 2006, 192 famílias selecionadas de forma aleatória. A alta cobertura do cadastro das famílias verificada (97,9%) assim como a fidedignidade para os campos “família corresponde ao endereço” e “família está completa” (95,7% e 93,1%), observados nos três municípios, indicaram a confiabilidade do cadastro realizado pelo PSF. Os dados referentes à atualização das gestantes, hipertensos, e crianças menores de um ano, não tiveram a mesma confiabilidade. Quanto ao perfil dos agentes comunitários de saúde, que atuaram nos três municípios, a maioria dos entrevistados eram mulheres, com menos de 25 anos e estavam estudando ou já haviam completado o segundo grau. O tempo médio de permanência dos profissionais no PSF foi de 10 meses, sendo que 45% dos agentes foram submetidos a concurso municipal e os demais contratados. Os autores concluem que o cadastro do PSF (ficha A/SIAB) nos três municípios é confiável como base populacional para o cálculo amostral, justificando sua utilização como ferramenta legítima para a realização de pesquisas de campo nas áreas básicas e clínicas

A social-ecological approach to identify and quantify biodiversity tipping points in South America’s seasonal dry ecosystems

ropical dry forests and savannas harbour unique biodiversity and provide critical ES, yet they are under severe pressure globally. We need to improve our understanding of how and when this pressure provokes tipping points in biodiversity and the associated social-ecological systems. We propose an approach to investigate how drivers leading to natural vegetation decline trigger biodiversity tipping and illustrate it using the example of the Dry Diagonal in South America, an understudied deforestation frontier. The Dry Diagonal represents the largest continuous area of dry forests and savannas in South America, extending over three million km² across Argentina, Bolivia, Brazil, and Paraguay. Natural vegetation in the Dry Diagonal has been undergoing large-scale transformations for the past 30 years due to massive agricultural expansion and intensification. Many signs indicate that natural vegetation decline has reached critical levels. Major research gaps prevail, however, in our understanding of how these transformations affect the unique and rich biodiversity of the Dry Diagonal, and how this affects the ecological integrity and the provisioning of ES that are critical both for local livelihoods and commercial agriculture.Fil: Thonicke, Kirsten. Institute for Climate Impact Research ; AlemaniaFil: Langerwisch, Fanny. Institute for Climate Impact Research ; Alemania. Czech University of Life Sciences Prague; República ChecaFil: Baumann, Matthias. Humboldt Universität zu Berlin; Alemania. Technische Universitat Carolo Wilhelmina Zu Braunschweig.; AlemaniaFil: Leitão, Pedro J.. Humboldt Universität zu Berlin; Alemania. Technische Universitat Carolo Wilhelmina Zu Braunschweig.; AlemaniaFil: Václavík, Tomáš. Helmholtz Centre for Environmental Research; Alemania. Palacký University Olomouc; República ChecaFil: Alencar, Anne. Ministerio da Agricultura Pecuaria e Abastecimento de Brasil. Empresa Brasileira de Pesquisa Agropecuaria; BrasilFil: Simões, Margareth. Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA); BrasilFil: Scheiter, Simon. Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA); Brasil. Universidade Federal do Rio de Janeiro; BrasilFil: Langan, Liam. Senckenberg Biodiversity and Climate Research Centre; AlemaniaFil: Bustamante, Mercedes. Universidade do Brasília; BrasilFil: Gasparri, Nestor Ignacio. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Instituto de Ecología Regional; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; ArgentinaFil: Hirota, Marina. Universidade Federal de Santa Catarina; Brasil. Universidade Estadual de Campinas; BrasilFil: Börner, Jan. Universitat Bonn; AlemaniaFil: Rajao, Raoni. Universidade Federal de Minas Gerais; BrasilFil: Soares Filho, Britaldo. Universidade Federal de Minas Gerais; BrasilFil: Yanosky, Alberto. Consejo Nacional de Ciencia y Tecnología; ParaguayFil: Ochoa Quinteiro, José Manuel. Instituto de Investigación de Recursos Biológicos Alexander von Humboldt; ColombiaFil: Seghezzo, Lucas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones en Energía no Convencional. Universidad Nacional de Salta. Facultad de Ciencias Exactas. Departamento de Física. Instituto de Investigaciones en Energía no Convencional; ArgentinaFil: Conti, Georgina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: de la Vega Leiner, Anne Cristina. Universität Greifswald; Alemani