95 research outputs found
Renal Sodium Gradient Orchestrates a Dynamic Antibacterial Defense Zone.
Lower urinary tract infections are among the most common human bacterial infections, but extension to the kidneys is rare. This has been attributed to mechanical forces, such as urine flow, that prevent the ascent of bladder microbes. Here, we show that the regional hypersalinity, required for the kidney's urine-concentrating function, instructs epithelial cells to produce chemokines that localize monocyte-derived mononuclear phagocytes (MNPs) to the medulla. This hypersaline environment also increases the intrinsic bactericidal and neutrophil chemotactic activities of MNPs to generate a zone of defense. Because MNP positioning and function are dynamically regulated by the renal salt gradient, we find that patients with urinary concentrating defects are susceptible to kidney infection. Our work reveals a critical accessory role for the homeostatic function of a vital organ in optimizing tissue defense
Liquid Galaxy POIs Controller
Per tal de contextualitzar la proposta del TFG, al llarg d'aquesta memòria, presentarem el programa Google Summer of Code (durant la memòria tambĂ© referenciat com a “GSoC”). AixĂ doncs, introduirem els conceptes de GSoC, algunes dades històricament significatives, l’estructura que el composa, la seva organitzaciĂł, el procediment per a escollir els membres que en formaran part i la meva relaciĂł amb el programa. TambĂ© explicarem breument què Ă©s el projecte Open Source Liquid Galaxy (d’aquĂ en endavant anomenat tambĂ© com “LG”), en què consisteix, la relaciĂł amb els dos projectes que vam presentar al GSoC 2015 (Liquid Galaxy POIs Controller, el qual va ser finalment escollit, i Wikipedia Liquid Galaxy Mashup) i algunes de les seves caracterĂstiques. Posteriorment, essent el nucli d’informaciĂł mĂ©s rellevant d’aquesta memòria, expliquem les tasques realitzades prèviament a l’inici del projecte com sĂłn l’aprenentatge de tecnologies i llenguatges nous, la presa de requeriments i riscs, l’establiment dels objectius del projecte i el cĂ lcul de la lĂnia de temps que guia aquest. Definim l’estructura de la base de dades de l’aplicaciĂł i exposem exemples del seu funcionament, expliquem el disseny i l’estructura de l’aplicaciĂł, tant en aspectes a nivell d’usuari com a nivell d’implementaciĂł, detallem l’evoluciĂł de l’aplicaciĂł juntament amb els problemes sorgits i les corresponents solucions i finalment determinem les tasques que s’han de realitzar per finalitzar la implementaciĂł de l’aplicaciĂł juntament amb una avaluaciĂł del treball realitzat
Beyond water homeostasis:diverse functional roles of mammalian aquaporins
Background - Aquaporin (AQP) water channels are best known as passive transporters of water that are vital for water homeostasis. Scope of review - AQP knockout studies in whole animals and cultured cells, along with naturally occurring human mutations suggest that the transport of neutral solutes through AQPs has important physiological roles. Emerging biophysical evidence suggests that AQPs may also facilitate gas (CO2) and cation transport. AQPs may be involved in cell signalling for volume regulation and controlling the subcellular localization of other proteins by forming macromolecular complexes. This review examines the evidence for these diverse functions of AQPs as well their physiological relevance. Major conclusions - As well as being crucial for water homeostasis, AQPs are involved in physiologically important transport of molecules other than water, regulation of surface expression of other membrane proteins, cell adhesion, and signalling in cell volume regulation. General significance - Elucidating the full range of functional roles of AQPs beyond the passive conduction of water will improve our understanding of mammalian physiology in health and disease. The functional variety of AQPs makes them an exciting drug target and could provide routes to a range of novel therapies
Physiological and pharmacological modulation of renal water reabsorption.
Contains fulltext :
91331.pdf (publisher's version ) (Open Access)Radboud Universiteit Nijmegen, 16 november 2011Promotores : Deen, P.M.T., Wetzels, J.F.M.
Co-promotor : Robben, J.H.235 p
In vitro fermentability of differently substituted Xylo-oligosaccharides
Xylo-oligosaccharides (XOS) with various substituents were fermented in vitro by fecal inocula (FI) from four human volunteers to study the influence of substitution on the ability and rate of fermentation and on the production of short-chain fatty acids (SCFA) and lactate. By all FI used nonsubstituted XOS (nXOS) and arabino-XOS (AXOS) were fermented more quickly than the more complex structures of acetylated XOS (AcXOS) and XOS containing a 4-O-methylglucuronic acid group (GlcAmeXOS). In the first stage (0-40 h) of the fermentations of nXOS and AXOS mainly acetate and lactate were formed. The fermentations of AcXOS and GlcAmeXOS resulted in a lower lactate production, whereas the concentration of propionate and butyrate increased. These results put emphasis on the detailed elucidation of the structural features of nondigestible oligosaccharides in general to understand their fermentation mechanisms more precisely
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