Viral respiratory tract infections and asthma: The course ahead

Inquiries into the relationships between viral respiratory tract illnesses and the inception and exacerbation of asthma are being facilitated by recent advances in research approaches and technology. In this article we identify important knowledge gaps and future research questions, and we discuss how new investigational tools, including improved respiratory tract virus detection techniques, will permit current and future researchers to define these relationships and the host, virus, developmental, and environmental mechanisms that regulate them. A better understanding of these processes should facilitate the development of improved strategies for the prevention and treatment of virus-induced wheezing illnesses and asthma exacerbations and, possibly, the ultimate goal of discovering effective approaches for the primary prevention of asthma. © 2010 American Academy of Allergy, Asthma & Immunology

Host-derived interleukin-5 promotes adenocarcinoma-induced malignant pleural effusion

Rationale: IL-5 is a T helper 2 cytokine important in the trafficking and survival of eosinophils. Because eosinophils can be found in malignant pleural effusions (MPE) from mice and humans, we asked whether IL-5 is involved in the pathogenesis of MPE. Objectives: To determine the role of IL-5 in MPE formation. Methods: The effects of IL-5 on experimental MPE induced in C57BL/6 mice by intrapleural injection of syngeneic lung (Lewis lung cancer [LLC]) or colon (MC38) adenocarcinoma cells were determined using wild-type (il5+/+) and IL-5-deficient (il5-/-) mice, exogenous administration of recombinant mouse (rm) IL-5, and in vivo antibody-mediated neutralization of endogenous IL-5. The direct effects of rmIL-5 on LLC cell proliferation and gene expression in vitro were determined by substrate reduction and microarray. Measurements and Main Results: Eosinophils and IL-5 were present in human and mouse MPE, but the cytokine was not detected in mouse (LLC) or human (A549) lung and mouse colon (MC38) adenocarcinoma-conditioned medium, suggesting production by host cells in MPE. Compared with il5+/+ mice, il5-/- mice showed markedly diminished MPE formation in response to both LLC and MC38 cells. Exogenous IL-5 promoted MPE formation in il5+/+ and il5 -/- mice, whereas anti-IL-5 antibody treatment limited experimental MPE in il5+/+ mice. Exogenous IL-5 had no effects on LLC cell proliferation and gene expression; however, IL-5 was found to be responsible for recruitment of eosinophils and tumor-promoting myeloid suppressor cells to MPE in vivo. Conclusions: Host-derived IL-5 promotes experimental MPE and may be involved in the pathogenesis of human MPE

Influência do óleo de linhaça sobre o desempenho e a qualidade dos ovos de poedeiras semipesadas Influence of linseed oil on performance and egg quality of semi-heavy laying hens

O experimento foi conduzido para avaliar a influência da adição de óleo de linhaça em substituição ao óleo de soja em rações para poedeiras semipesadas sobre o desempenho e a qualidade interna e externa dos ovos. Utilizaram-se 192 poedeiras da linhagem Bovans Godline com 29 semanas de idade, distribuídas em seis tratamentos, que consistiram de uma dieta controle (sem óleo vegetal) e de cinco dietas contendo 0,0; 0,5; 1,0; 1,5 e 2,0% de óleo de linhaça em substituição, respectivamente, a 100, 75, 50, 25 ou 0% do óleo de soja. Avaliaram-se a produção (PROD), o peso (PO) e a massa de ovo (MO), as conversões por massa (CMO) e por dúzia de ovos (CDZ), os pesos e as porcentagens de albúmen, gema e casca, a gravidade específica, os teores de matéria seca, cinzas e proteína do albúmen e da gema e o teor de colesterol e a coloração da gema. A produção, o peso do ovo, a massa de ovo e as conversões por massa e por dúzia de ovos, bem como a qualidade interna e externa dos ovos, não foram influenciados pelos níveis de óleo de linhaça na ração. Do mesmo modo, não houve efeito da inclusão de óleo de linhaça sobre a composição química dos ovos e somente a coloração da gema foi intensificada quando utilizados níveis acima de 1% de óleo de linhaça na dieta. A adição de até 2% de óleo de linhaça na ração não altera o desempenho de poedeiras semipesadas nem a qualidade interna e externa e o teor de colesterol dos ovos.<br>This experiment was carried out to evaluate the influence of the linseed oil addition in replacement of soybean oil in laying hens diets on performance and internal and external egg quality. A total of 192 laying hens Bovans Godline line with 29 week-old, were distributed to six treatments, that consisted of a control diet (without vegetal oil) and of five diets containing 2% of linseed oil in replacement of 0, 25, 50, 75 and 100% of soybean oil, generating levels of 0.0, 0.5, 1.0, 1.5 and 2.0 % of linseed oil in the diets. The evaluated parameters were: production (PROD), egg weight (EW) and mass (EM), feed:egg mass ratio (FEM) and feed:egg dozen ratio (FED), albumen, yolk and shell weights and percentages, specific gravity, albumen and yolk dry matter, ashes and protein, yolk cholesterol and coloration. The production , EW, EM, FEM and FED, as for internal and external egg quality, were not influenced by the linseed oil levels in the diet. Likewise, no effect was observed on egg chemical composition and only yolk coloration was intensified with the levels above 1% of linseed oil in the diet. The addition of up to 2% f linseed oil on diet did not alter the performance on semi-heavy laying hens, and the internal and external egg quality and cholesterol