65 research outputs found
Inheritance of porcine receptors for enterotoxigenic Escherichia coli with fimbriae F4ad and their relation to other F4 receptors
Enteric Escherichia coli infections are a highly relevant cause of disease and death in young pigs. Breeding genetically resistant pigs is an economical and sustainable method of prevention. Resistant pigs are protected against colonization of the intestine through the absence of receptors for the bacterial fimbriae, which mediate adhesion to the intestinal surface. The present work aimed at elucidation of the mode of inheritance of the F4ad receptor which according to former investigations appeared quite confusing. Intestines of 489 pigs of an experimental herd were examined by a microscopic adhesion test modified in such a manner that four small intestinal sites instead of one were tested for adhesion of the fimbrial variant F4ad. Segregation analysis revealed that the mixed inheritance model explained our data best. The heritability of the F4ad phenotype was estimated to be 0.7±0.1. There are no relations to the strong receptors for variants F4ab and F4ac. Targeted matings allowed the discrimination between two F4ad receptors, that is, a fully adhesive receptor (F4adRFA) expressed on all enterocytes and at all small intestinal sites, and a partially adhesive receptor (F4adRPA) variably expressed at different sites and often leading to partial bacterial adhesion. In pigs with both F4ad receptors, the F4adRPA receptor is masked by the F4adRFA. The hypothesis that F4adRFA must be encoded by at least two complementary or epistatic dominant genes is supported by the Hardy-Weinberg equilibrium statistics. The F4adRPA receptor is inherited as a monogenetic dominant trait. A comparable partially adhesive receptor for variant F4ab (F4abRPA) was also observed but the limited data did not allow a prediction of the mode of inheritance. Pigs were therefore classified into one of eight receptor phenotypes: A1 (F4abRFA/F4acR+/F4adRFA); A2 (F4abRFA/F4acR+/F4adRPA); B (F4abRFA/F4acR+/F4adRâ); C1 (F4abRPA/F4acRâ/F4adRFA); C2 (F4abRPA/F4acRâ/F4adRPA); D1 (F4abRâ/F4acRâ/F4adRFA); D2 (F4abRâ/F4acRâ/F4adRPA); E (F4abRâ/F4acRâ/F4adRâ
Allosteric effects in cyclophilin mutants may be explained by changes in nano-microsecond time scale motions
The relationship between molecular motion and catalysis in enzymes is debated. Here, simulations of cyclophilin A and three catalytically-impaired mutants reveal a nanosecond-scale interconversion between active and inactive conformations, orders of magnitude faster than previously suggested
Mit weniger Therapiesitzungen sicher und effizienter ans Ziel
Hypofraktionierung bedeutet in der Strahlentherapie, im Vergleich mit gĂ€ngigen Therapieschemata in weniger Therapiesitzungen mit höherer Einzeldosis und in der Regel in einer kĂŒrzeren Gesamtbehandlungsdauer die Bestrahlung durchzufĂŒhren. Hypofraktionierung zur postoperativen Radiotherapie beim brusterhaltend operierten Mammakarzinom wird (wie auch bei anderen onkologischen Indikationen) seit einigen Jahren diskutiert. Gleiche Resultate in Bezug auf lokale Kontrolle und Kosmetik mir kĂŒrzerer Behandlungszeit? Auch in Zeiten gesundheitsökonomischer Ăberlegungen ein âheisses Eisenâ
Consensus 2012 - diagnosis and treatment of patients with dementia in Switzerland
Le consensus 2012 sur le diagnostic et le traitement des patients atteints de dĂ©mence en Suisse a Ă©tĂ© Ă©laborĂ© par une confĂ©rence dâexperts qui sâest dĂ©roulĂ©e du 23 au 25 mars 2012 Ă Lucerne. AprĂšs revue des donnĂ©es scientifiques rĂ©centes, les auteurs ont rĂ©digĂ© un projet qui a Ă©tĂ© soumis Ă de nombreux experts de la dĂ©mence en Suisse dans le cadre dâune procĂ©dure de consultation. AprĂšs adaptation et rĂ©visions du document initial en fonction des remarques exprimĂ©es, lâensemble des spĂ©cialistes consultĂ©s et les membres du groupe dâexperts adhĂšrent expressĂ©ment aux prises de position Ă©noncĂ©es dans ce document. La confĂ©rence dâexperts a Ă©tĂ© financĂ©e par le Forum Alzheimer Suisse.The 2012 Swiss consensus paper on diagnosis and management of patients suffering from dementia resulted from the work of an expert panel who met on March 23d to 25th in Luzern. Based on a literature review, panel members wrote a first draft that was subsequently circulated among multiple dementia experts in Switzerland. After adaptation and revisions according to comments, all consulted dementia specialists and panel members fully endorse the consensus content. The conference was financed by the Swiss Alzheimer Forum
Evidence for senescence in survival but not in reproduction in a short-lived passerine
Senescence has been studied since a long time by theoreticians in ecology and evolution, but empirical support in natural population has only recently been accumulating. One of the current challenges is the investigation of senescence of multiple fitness components and the study of differences between sexes. Until now, studies have been more frequently conducted on females than on males and rather in long-lived than in short-lived species. To reach a more fundamental understanding of the evolution of senescence, it is critical to investigate age-specific survival and reproduction performance in both sexes and in a large range of species with contrasting life histories. In this study, we present results on patterns of age-specific and sex-specific variation in survival and reproduction in the whinchat Saxicola rubetra, a short-lived passerine. We compiled individual-based long-term datasets from seven populations that were jointly analyzed within a Bayesian modeling framework. We found evidence for senescence in survival with a continuous decline after the age of 1 year, but no evidence of reproductive senescence. Furthermore, we found no clear evidence for sex effects on these patterns. We discuss these results in light of previous studies documenting senescence in short-lived birds. We note that most of them have been conducted in populations breeding in nest boxes, and we question the potential effect of the nest boxes on the shape of age-reproductive trajectories
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