The mucoid switch in pseudomonas aeruginosa represses quorum sensing systems and leads to complex changes to stationary phase virulence factor regulation

The opportunistic pathogen Pseudomonas aeruginosa chronically infects the airways of Cystic Fibrosis (CF) patients during which it adapts and undergoes clonal expansion within the lung. It commonly acquires inactivating mutations of the anti-sigma factor MucA leading to a mucoid phenotype, caused by excessive production of the extracellular polysaccharide alginate that is associated with a decline in lung function. Alginate production is believed to be the key benefit of mucA mutations to the bacterium in the CF lung. A phenotypic and gene expression characterisation of the stationary phase physiology of mucA22 mutants demonstrated complex and subtle changes in virulence factor production, including cyanide and pyocyanin, that results in their down-regulation upon entry into stationary phase but, (and in contrast to wildtype strains) continued production in prolonged stationary phase. These findings may have consequences for chronic infection if mucoid P. aeruginosa were to continue to make virulence factors under non-growing conditions during infection. These changes resulted in part from a severe down-regulation of both AHL-and AQ (PQS)-dependent quorum sensing systems. In trans expression of the cAMP-dependent transcription factor Vfr restored both quorum sensing defects and virulence factor production in early stationary phase. Our findings have implications for understanding the evolution of P. aeruginosa during CF lung infection and it demonstrates that mucA22 mutation provides a second mechanism, in addition to the commonly occurring lasR mutations, of down-regulating quorum sensing during chronic infection this may provide a selection pressure for the mucoid switch in the CF lung

Impact of landscape composition and configuration on forest specialist and generalist bird species in the fragmented Lacandona rainforest, Mexico

With accelerated land-use change throughout the tropics, an increasing proportion of global biodiversity is located in human-modified landscapes. Understanding the relative effects of landscape composition and configuration on biodiversity is needed to design effective conservation strategies. Yet this topic is poorly understood because most studies have been performed at the patch scale, and do not assess the impact of landscape structure on species. Using a multi-model inference approach, we assessed the relative effect of landscape composition (i.e. percentage of forest cover and matrix composition) and landscape configuration (i.e. number of forest patches and forest edge density) on α- and β-diversity of birds in 17 forest fragments and three areas of continuous forest within the Lacandona rainforest, Mexico. We tested these impacts at two spatial scales (100 and 500. ha) for forest specialist and generalist birds. In general, forest specialist birds showed stronger responses to landscape characteristics than generalist species, particularly to variations in landscape composition at the 100-ha scale. The loss of forest cover represented the main threat to forest specialist birds, with a negative impact on α-diversity that was consistent across the two spatial scales. In contrast, at the two spatial scales generalist birds seemed to be favored

Pancreatic cyst surveillance imposes low psychological burden

Background/Objectives: For the currently recommended pancreatic cyst surveillance to be feasible, participant adherence is a prerequisite. Our objective was to evaluate the psychological burden of pancreatic cyst surveillance from a participant's perspective. Methods: The present participant survey is part of an international cohort study (PACYFIC study, www.pacyfic.net), which prospectively records the outcome of surveillance of asymptomatic pancreatic cysts. Participants are invited to complete questionnaires before and during cyst surveillance. Results: 109 participants, 31 enrolled before and 78 during surveillance (median time since cyst diagnosis 16.5 (IQR 36) months), returned a total of 179 questionnaires. The majority indicated that surveillance reduces concerns of developing pancreatic cancer (82%), gives a sense of certainty (81%) and is a good method to detect cancer (91%). Participants already undergoing surveillance reported more negative aspects than those still to commence, like sleeping worse (30% vs 13%, P = 0.035), postponing plans (32% vs 13%, P = 0.031), and finding the follow-up burdensome (33% vs 13%, P = 0.044). Overall, the vast majority (94%) deemed advantages to outweigh disadvantages. Anxiety and depression scores were low (median Hospital Anxiety and Depression Scale 4 for anxiety (IQR 6), 2 for depression (IQR 5)). Conclusion: The psychological burden of pancreatic cyst surveillance is low. Therefore, participant adherence is expected to be high and annual surveillance seems feasible

Óleo de copaíba (Copaifera sp.): histórico, extração, aplicações industriais e propriedades medicinais Copaiba oil (Copaifera sp.): history, extraction, industrial applications and medicinal properties

Este trabalho teve como objetivo realizar uma revisão de literatura sobre o gênero Copaifera sp. Foi realizado levantamento bibliográfico do período de 1792 a 2008 utilizando bibliotecas da Universidade de São Paulo, Universidade Federal de Viçosa, Universidade Federal de Alfenas e Universidade José do Rosário Vellano, pesquisas às bases de dados SCOPUS e PubMed, além de ferramentas de busca na web. Utilizou-se para a busca palavras chave como "Copaiba", "Copaifera", "Copaíba oil" "Óleo de Copaíba". Como resultado desta pesquisa obteve-se a seleção de 63 referências incluindo livros, artigos, cadernos técnicos, resumos de congressos, teses, dissertações e patentes. Estes dados apontaram o óleo de copaíba como um exsudato produzido pelas copaibeiras como defesa contra seus predadores, que vem sendo utilizado pela medicina tradicional popular e silvícola há mais de 500 anos. Ele é extraído destas árvores através de perfurações realizadas em seus troncos. Além das inúmeras aplicações do óleo em cosméticos e outras indústrias, ainda há uma série de indicações para seu uso na medicina. Existem hoje descritas algumas dezenas de propriedades medicinais diferentes, que vem sendo em alguns casos comprovadas cientificamente, como atividade antimicrobiana, antiinflamatória, anti-neoplásica entre outras. Estudos recentes têm demonstrado também grande potencial de uso do óleo de copaíba na odontologia, na composição de cimentos endodônticos e na prevenção e combate da doença periodontal. As informações contidas neste trabalho demonstram uma grande variabilidade de aplicações do óleo de copaíba. Entretanto uma quantidade limitada de pesquisas sobre suas propriedades medicinais tem sido realizada, apresentando assim a necessidade de novas pesquisas sobre estas.<br>The aim of this study was to conduct a literature review concerning the genus Copaifera sp. The survey involved the period from 1792 to 2008 and was done in the libraries of University of São Paulo, Federal University of Viçosa, Federal University of Alfenas and University Jose do Rosario Vellano, using SCOPUS and PubMed databases, and web search engines. The words "Copaiba", "Copaifera," "Óleo de copaiba" and "Copaiba oil" were used. This research resulted in the selection of 63 references including books, articles, technical specifications, conference abstracts, theses, dissertations and patents. These data indicate copaiba oil is an exudate from copaiba trees, produced as a defense against their predators and that has been used in traditional, popular and forestry medicine for over 500 years. It is extracted from trees through holes made in their trunks. Besides the oil applications in cosmetic and other industries, there are still a number of indications for its use in medicine. So far, dozens of different medicinal properties have been described and, in some cases, scientifically proven, including antimicrobial, anti-inflammatory, and anti-cancer activity. Recent studies have also shown great potential for the use of copaiba oil in dentistry like in endodontic cement composition, as well as in the prevention and therapy of periodontal diseases. This work showed a great variety of applications to copaiba oil. However, few studies on its medicinal properties have been performed, showing thus the need for further research