FGF Signaling Pathway in the Developing Chick Lung: Expression and Inhibition Studies

Background: Fibroblast growth factors (FGF) are essential key players during embryonic development. Through their specific cognate receptors (FGFR) they activate intracellular cascades, finely regulated by modulators such as Sprouty. Several FGF ligands (FGF1, 2, 7, 9, 10 and 18) signaling through the four known FGFRs, have been implicated in lung morphogenesis. Although much is known about mammalian lung, so far, the avian model has not been explored for lung studies. Methodology/Principal Findings: In this study we provide the first description of fgf10, fgfr1-4 and spry2 expression patterns in early stages of chick lung development by in situ hybridization and observe that they are expressed similarly to their mammalian counterparts. Furthermore, aiming to determine a role for FGF signaling in chick lung development, in vitro FGFR inhibition studies were performed. Lung explants treated with an FGF receptor antagonist (SU5402) presented an impairment of secondary branch formation after 48 h of culture; moreover, abnormal lung growth with a cystic appearance of secondary bronchi and reduction of the mesenchymal tissue was observed. Branching and morphometric analysis of lung explants confirmed that FGFR inhibition impaired branching morphogenesis and induced a significant reduction of the mesenchyme. Conclusions/Significance: This work demonstrates that FGFRs are essential for the epithelial-mesenchymal interactions tha

Uma capitania dos novos tempos: economia, sociedade e política na São Paulo restaurada (1765-1822)

O artigo reflete sobre a trajetória da Capitania de São Paulo, a partir de 1750, apontando sua transformação, de fronteira e "boca do sertão", para território estratégico da conquista e defesa das partes meridionais e área economicamente integrada aos circuitos mercantis atlânticos.In this article, we reflect upon the history of the Captaincy of São Paulo as from 1750, drawing attention to its transformation from frontier land and "door to the backcountry" into a territory of strategic value for the purposes of conquest and defense of the southern regions, and economically integrated into the Atlantic trade routes

Relações interfirmas e emprego na rede de empresas: a experiência de externalização de uma empresa no setor de telecomunicações<a name=volta1></a> Intercompany relations and employment in the businesses network: the experience of internalization of one company from the telecommunications industry

A reestruturação do setor de telecomunicações vem implicando a formação de estruturas empresariais na forma de rede. Neste artigo, examinam-se os padrões de relacionamento interfirmas e de emprego na rede de empresas liderada pela Companhia Riograndense de Telecomunicações (CRT). A análise abrange onze empresas, prestadoras de diferentes tipos de serviços (digitalização de centrais de comutação, cabeamento e instalação de terminais telefônicos) e localizadas em diversos níveis da rede ("empresas terceiras", "quartas", "quintas" e "sextas"). Conclui-se que existe grande diversidade no relacionamento interempresas (relacionadas à interação entre a estratégia competitiva da empresa central e os tipos de serviços prestados) e nas práticas de emprego (associadas às relações interfirmas e à posição das empresas nos níveis da rede).<br>Restructuring in the telecommunications industry has implied the construction of network business structures. In this article, patterns of relationship between companies and employment within the network led by CRT (Companhia Riograndense de Telecomunicações, the Telecommunications Company in the southern Brazilian State of Rio Grande do Sul) are examined. The analysis encompasses eleven companies providing different kinds of services (switch units digitalization, cables and phone lines installation) and located at several levels of the network ("third", "fourth", "fifth" and "sixth" companies). We come to the conclusion that there is a great variety within the relationship between companies (regarding the interaction between competitive strategy of the leading company and the kind of services provided) and in employment practices (associated to intercompany relationships and the position of each company at the network levels)