993 resultados para Cellular culture
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Does culture shape the demand for social insurance against risks to health and work? We study this issue across language groups in Switzerland where a language border sharply separates social groups at identical actual levels of publicly provided social insurance. We find substantially stronger support for expansions of social insurance among residents of French, Italian or Romansh-speaking language border municipalities compared with their German-speaking neighbours in adjacent municipalities. Informal insurance does not vary enough to explain stark differences in social insurance but differences in ideology and segmented media markets potentially contribute to the discrepancy in demand for social insurance.
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Understanding the extent of genomic transcription and its functional relevance is a central goal in genomics research. However, detailed genome-wide investigations of transcriptome complexity in major mammalian organs have been scarce. Here, using extensive RNA-seq data, we show that transcription of the genome is substantially more widespread in the testis than in other organs across representative mammals. Furthermore, we reveal that meiotic spermatocytes and especially postmeiotic round spermatids have remarkably diverse transcriptomes, which explains the high transcriptome complexity of the testis as a whole. The widespread transcriptional activity in spermatocytes and spermatids encompasses protein-coding and long noncoding RNA genes but also poorly conserves intergenic sequences, suggesting that it may not be of immediate functional relevance. Rather, our analyses of genome-wide epigenetic data suggest that this prevalent transcription, which most likely promoted the birth of new genes during evolution, is facilitated by an overall permissive chromatin in these germ cells that results from extensive chromatin remodeling.
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Collection : Bibliothèque sociologique internationale ; 50
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Résumé de l'étude La surveillance de la prescription des antibiotiques en milieu hospitalier est une des mesures recommandées pour prévenir l'émergence de bactéries résistantes. La consommation d'antibiotiques est généralement exprimée en termes de DDD (defined daily dose) rapporté au taux d'occupation (jours patients). Cette mesure ne tient cependant pas compte de la variation de la casuistique d'un service au cours du temps. La consommation d'antibiotiques est influencée par l'incidence des infections, qui peut être saisonnière ou varier selon les circonstances épidémiologiques, ainsi que par les habitudes des médecins en termes de prescription. Une échelle de mesure adaptée à ces paramètres est donc capitale pour rendre compte de la consommation d'antibiotiques au sein d'un service et identifier de possibles dérivations dans les habitudes de prescriptions. Nous avons émis l'hypothèse que le nombre de demandes d'hémocultures pouvait servir d'indicateur de la charge infectieuse d'un service. Une analyse préliminaire a permis d'établir une bonne relation entre ce paramètre et l'incidence d'événements infectieux en comparaison à d'autres paramètres testés (nombre de prélèvements microbiologiques provenant de sites stériles ou nombre total de prélèvements microbiologiques). Sur la base de cette hypothèse, nous avons analysé la consommation d'antibiotiques d'une unité de médecine générale (Service de Médecine Interne du CHUV) sur seize trimestres consécutifs en comparant deux échelles de mesures : la méthode standard en DDD par jours patients et une échelle ajustée à la charge infectieuse (DDD par nombre de demandes d'hémocultures). L'échelle ajustée aux hémocultures a permis d'identifier trois trimestres avec une consommation anormalement élevée qui n'avaient pas été classés comme tels par l'échelle standard (consommation dans les normes en DDD par jours patients). Une analyse détaillée d'un de ces trimestres a confirmé une incidence d'infections moins élevée en comparaison à un trimestre de référence (proche de la norme selon les deux échelles), alors que la corrélation entre infections et demandes d'hémocultures était similaire pour les deux périodes. De même, l'échelle ajustée ä la charge infectieuse a démontré une consommation dans la norme pour un trimestre avec une consommation en apparence trop élevée selon l'échelle standard en raison d'une incidence d'infections plus élevée pour cette période. Cette étude a donc permis une identification plus performante et plus précise de périodes avec des dérivations dans la pratique de la prescription des antibiotiques en utilisant une échelle de mesure ajustée à la charge infectieuse d'un service au cours du temps. Nous avons démontré que le nombre d'hémocultures prélevées était un indicateur stable de la charge infectieuse dans un service de médecine générale. Ceci ne permet cependant pas de généraliser l'usage de cet indicateur pour tous les types de service. La pratique des hémocultures peut, en effet, varier d'une unité à l'autre, ou entres différentes institutions. ll convient donc de tester la validité de ce paramètre dans un service avant de l'appliquer.
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The subcellular localization and function of variant subtelomeric multigene families in Plasmodium vivax remain vastly unknown. Among them, the vir superfamily is putatively involved in antigenic variation and in mediating adherence to endothelial receptors. In the absence of a continuous in vitro culture system for P. vivax, we have generated P. falciparum transgenic lines expressing VIR proteins to infer location and function. We chose three proteins pertaining to subfamilies A (VIR17), C (VIR14) and D (VIR10), with domains and secondary structures that predictably traffic these proteins to different subcellular compartments. Here, we showed that VIR17 remained inside the parasite and around merozoites, whereas VIR14 and VIR10 were exported to the membrane of infected red blood cells (iRBCs) in an apparent independent pathway of Maurer's clefts. Remarkably, VIR14 was exposed at the surface of iRBCs and mediated adherence to different endothelial receptors expressed in CHO cells under static conditions. Under physiological flow conditions, however, cytoadherence was only observed to ICAM-1, which was the only receptor whose adherence was specifically and significantly inhibited by antibodies against conserved motifs of VIR proteins. Immunofluorescence studies using these antibodies also showed different subcellular localizations of VIR proteins in P. vivax-infected reticulocytes from natural infections. These data suggest that VIR proteins are trafficked to different cellular compartments and functionally demonstrates that VIR proteins can specifically mediate cytoadherence to the ICAM-1 endothelial receptor.
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Three pyrenyl-arene ruthenium complexes (M(1)-M(3)) of the general formula [Ru(η(6)-arene-pyrenyl)Cl(2)(pta)] (pta = 1,3,5-triaza-7-phosphaadamantane) have been synthesised and characterised. Prior to the coordination to ruthenium, pyrene was connected to the arene ligand via an alkane chain containing different functional groups: ester (L(1)), ether (L(2)) and amide (L(3)), respectively. Furthermore, the pyrenyl moieties of the M(n) complexes were encapsulated within the hydrophobic cavity of the water soluble metalla-cage, [Ru(6)(η(6)-p-cymene)(6)(tpt)(2)(donq)(3)](6+) (tpt = 2,4,6-tri-(pyridin-4-yl)-1,3,5-triazine; donq = 5,8-dioxydo-1,4-naphthoquinonato), while the arene ruthenium end was pointing out of the cage, thus giving rise to the corresponding host-guest systems [M(n)⊂Ru(6)(η(6)-p-cymene)(6)(tpt)(2)(donq)(3)](6+) ([M(n)⊂cage](6+)). The antitumor activity of the pyrenyl-arene ruthenium complexes (M(n)) and the corresponding host-guest systems [M(n)⊂cage][CF(3)SO(3)](6) were evaluated in vitro in different types of human cancer cell lines (A549, A2780, A2780cisR, Me300 and HeLa). Complex M(2), which contains an ether group within the alkane chain, demonstrated at least a 10 times higher cytotoxicity than the reference compound [Ru(η(6)-p-cymene)Cl(2)(pta)] (RAPTA-C). All host-guest systems [M(n)⊂cage](6+) showed good anticancer activity with IC(50) values ranging from 2 to 8 μM after 72 h exposure. The fluorescence of the pyrenyl moiety allowed the monitoring of the cellular uptake and revealed an increase of uptake by a factor two of the M(2) complex when encapsulated in the metalla-cage [Ru(6)(η(6)-p-cymene)(6)(tpt)(2)(donq)(3)](6+).
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The application of high hydrostatic pressure (200 MPa) to meat batter just before sausage fermentation and the inoculation of starter culture were studied to improve the safety and quality of traditional Spanish fermented sausages (fuet and chorizo). Higher amounts of biogenic amines were formed in chorizo than in fuet. Without interfering with the ripening performance in terms of acidification, drying and proteolysis, hydrostatic pressure prevented enterobacteria growth but did not affect Gram-positive bacteria significantly. Subsequently, a strong inhibition of diamine (putrescine and cadaverine) accumulation was observed, but that of tyramine was not affected. The inoculated decarboxylase-negative strains, selected from indigenous bacteria of traditional sausages, were resistant to the HHP treatment, being able to lead the fermentation process, prevent enterococci development and significantly reduce enterobacteria counts. In sausages manufactured with either non-pressurized or pressurized meat batter, starter culture was the most protective measure against the accumulation of tyramine and both diamines.
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The addition of starter culture and high pressure processing after ripening improved the microbial quality of low-acid fermented sausages (fuet and chorizo). The use of Lactobacillus sakei CTC6626 and Staphylococcus xylosus CTC6013 as starter culture significantly reduced Enterobacteriaceae and Enterococcus levels in the finished sausages. Moreover, the addition of starter culture produced sausages of similar quality to traditional low-acid fermented sausages. Slightly lower pH values and higher cohesiveness were obtained for both fuet and chorizo with starter culture. Sensory analysis showed no differences between lots of chorizo whereas starter fuet was more acid and gummy. High pressure induced an additional reduction of Enterobacteriaceae in non-starter sausages. An increase of textural properties was observed after pressurization. No other differences were observed between non-treated and pressurized sausages.
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Observations gained from model organisms are essential, yet it remains unclear to which degree they are applicable to distant relatives. For example, in the dicotyledon Arabidopsis thaliana (Arabidopsis), auxin biosynthesis via indole-3-pyruvic acid (IPA) is essential for root development and requires redundant TRYPTOPHAN AMINOTRANSFERASE OF ARABIDOPSIS 1 (TAA1) and TAA1-RELATED (TAR) genes. A promoter T-DNA insertion in the monocotyledon Brachypodium distachyon (Brachypodium) TAR2-LIKE gene (BdTAR2L) severely down-regulates expression, suggesting reduced tryptophan aminotransferase activity in this mutant, which thus represents a hypomorphic Bdtar2l allele (Bdtar2l(hypo) ). Counterintuitive however, Bdtar2l(hypo) mutants display dramatically elongated seminal roots because of enhanced cell elongation. This phenotype is also observed in another, stronger Bdtar2l allele and can be mimicked by treating wild type with L-kynerunine, a specific TAA1/TAR inhibitor. Surprisingly, L-kynerunine-treated as well as Bdtar2l roots display elevated rather than reduced auxin levels. This does not appear to result from compensation by alternative auxin biosynthesis pathways. Rather, expression of YUCCA genes, which are rate-limiting for conversion of IPA to auxin, is increased in Bdtar2l mutants. Consistent with suppression of Bdtar2l(hypo) root phenotypes upon application of the ethylene precursor 1-aminocyclopropane-1-carboxylic-acid (ACC), BdYUCCA genes are down-regulated upon ACC treatment. Moreover, they are up-regulated in a downstream ethylene-signaling component homolog mutant, Bd ethylene insensitive 2-like 1, which also displays a Bdtar2l root phenotype. In summary, Bdtar2l phenotypes contrast with gradually reduced root growth and auxin levels described for Arabidopsis taa1/tar mutants. This could be explained if in Brachypodium, ethylene inhibits the rate-limiting step of auxin biosynthesis in an IPA-dependent manner to confer auxin levels that are sub-optimal for root cell elongation, as suggested by our observations. Thus, our results reveal a delicate homeostasis of local auxin and ethylene activity to control cell elongation in Brachypodium roots and suggest alternative wiring of auxin-ethylene crosstalk as compared to Arabidopsis.