Oxidative stress specifically downregulates survivin to promote breast tumour formation.

BackgroundBreast cancer, a heterogeneous disease has been broadly classified into oestrogen receptor positive (ER+) or oestrogen receptor negative (ER-) tumour types. Each of these tumours is dependent on specific signalling pathways for their progression. While high levels of survivin, an anti-apoptotic protein, increases aggressive behaviour in ER- breast tumours, oxidative stress (OS) promotes the progression of ER+ breast tumours. Mechanisms and molecular targets by which OS promotes tumourigenesis remain poorly understood.ResultsDETA-NONOate, a nitric oxide (NO)-donor induces OS in breast cancer cell lines by early re-localisation and downregulation of cellular survivin. Using in vivo models of HMLE(HRAS) xenografts and E2-induced breast tumours in ACI rats, we demonstrate that high OS downregulates survivin during initiation of tumourigenesis. Overexpression of survivin in HMLE(HRAS) cells led to a significant delay in tumour initiation and tumour volume in nude mice. This inverse relationship between survivin and OS was also observed in ER+ human breast tumours. We also demonstrate an upregulation of NADPH oxidase-1 (NOX1) and its activating protein p67, which are novel markers of OS in E2-induced tumours in ACI rats and as well as in ER+ human breast tumours.ConclusionOur data, therefore, suggest that downregulation of survivin could be an important early event by which OS initiates breast tumour formation

Fish, Corumbataí and Jacaré-Pepira river basins, São Paulo State, Brazil

Fish were studied in two river basins (Corumbataí and Jacaré-Pepira) subjected to strong human pressure, in the interior of the State of São Paulo, southeastern Brazil. In the Corumbataí basin, four sites were sampled: Cabeça river, Lapa stream, Passa-Cinco river, and Corumbataí river; in the Jacaré-Pepira basin, three sites were sampled: Tamanduá stream, Jacaré-Pepira river, and Água Branca stream. A total of 4,050 specimens belonging to 48 species and 13 families were caught and analyzed

Células de inovação : experiências educacionais em CTS+I

Neste artigo pretende-se mostrar uma investigação que vem sendo feita em escolas de formação profissional brasileiras com o uso de Células de Inovação (CI). As CI's são grupos de estudantes envolvidos com a tarefa de solucionar um problema concreto da de sua escola ou bairro utilizando-se de conhecimentos técnico-científicos. Procurou-se investigar, através de uma metodologia etnográfica, como esses alunos aprendem os conteúdos de ciência ao solucionar seu problema e se a inovação é algo que possa ser aprendido. As situações trabalhados são problematizadas numa perspectiva CTS e, em seguida, são discutidas soluções. A implementação das melhores soluções gera nova discussão CTS sobre seu impacto. O trabalho aqui descrito cobre apenas uma célula. Pretende-se que a partir de 2010 que a investigação estenda-se para várias células trabalhando em rede

Análises patentométrica, bibliométrica e do portfólio de projetos da Embrapa relacionados a Elaeis sp.

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Aspectos históricos do bicudo do algodoeiro (Anthonomus grandis Baheman).

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Dengue disease, basic reproduction number and control

Dengue is one of the major international public health concerns. Although progress is underway, developing a vaccine against the disease is challenging. Thus, the main approach to fight the disease is vector control. A model for the transmission of Dengue disease is presented. It consists of eight mutually exclusive compartments representing the human and vector dynamics. It also includes a control parameter (insecticide) in order to fight the mosquito. The model presents three possible equilibria: two disease-free equilibria (DFE) and another endemic equilibrium. It has been proved that a DFE is locally asymptotically stable, whenever a certain epidemiological threshold, known as the basic reproduction number, is less than one. We show that if we apply a minimum level of insecticide, it is possible to maintain the basic reproduction number below unity. A case study, using data of the outbreak that occurred in 2009 in Cape Verde, is presented.Comment: This is a preprint of a paper whose final and definitive form has appeared in International Journal of Computer Mathematics (2011), DOI: 10.1080/00207160.2011.55454