University of Bordeaux

About: University of Bordeaux is a education organization based out in Bordeaux, France. It is known for research contribution in the topics: Population & Laser. The organization has 28811 authors who have published 55536 publications receiving 1619635 citations. The organization is also known as: UB.

Recovery of extracellular vesicles from human breast milk is influenced by sample collection and vesicle isolation procedures

Abstract: Extracellular vesicles (EV) in breast milk carry immune relevant proteins and could play an important role in the instruction of the neonatal immune system. To further analyze these EV and to elucidate their function it is important that native populations of EV can be recovered from (stored) breast milk samples in a reproducible fashion. However, the impact of isolation and storage procedures on recovery of breast milk EV has remained underexposed. Here, we aimed to define parameters important for EV recovery from fresh and stored breast milk. To compare various protocols across different donors, breast milk was spiked with a well-defined murine EV population. We found that centrifugation of EV down into density gradients largely improved density-based separation and isolation of EV, compared to floatation up into gradients after high-force pelleting of EV. Using cryo-electron microscopy, we identified different subpopulations of human breast milk EV and a not previously described population of lipid tubules. Additionally, the impact of cold storage on breast milk EV was investigated. We determined that storing unprocessed breast milk at -80°C or 4°C caused death of cells present in breast milk, leading to contamination of the breast milk EV population with storage-induced EV. Here, an alternative method is proposed to store breast milk samples for EV analysis at later time points. The proposed adaptations to the breast milk storage and EV isolation procedures can be applied for EV-based biomarker profiling of breast milk and functional analysis of the role of breast milk EV in the development of the neonatal immune system.

Oak genome reveals facets of long lifespan.

Abstract: Oaks are an important part of our natural and cultural heritage. Not only are they ubiquitous in our most common landscapes1 but they have also supplied human societies with invaluable services, including food and shelter, since prehistoric times2. With 450 species spread throughout Asia, Europe and America3, oaks constitute a critical global renewable resource. The longevity of oaks (several hundred years) probably underlies their emblematic cultural and historical importance. Such long-lived sessile organisms must persist in the face of a wide range of abiotic and biotic threats over their lifespans. We investigated the genomic features associated with such a long lifespan by sequencing, assembling and annotating the oak genome. We then used the growing number of whole-genome sequences for plants (including tree and herbaceous species) to investigate the parallel evolution of genomic characteristics potentially underpinning tree longevity. A further consequence of the long lifespan of trees is their accumulation of somatic mutations during mitotic divisions of stem cells present in the shoot apical meristems. Empirical4 and modelling5 approaches have shown that intra-organismal genetic heterogeneity can be selected for6 and provides direct fitness benefits in the arms race with short-lived pests and pathogens through a patchwork of intra-organismal phenotypes7. However, there is no clear proof that large-statured trees consist of a genetic mosaic of clonally distinct cell lineages within and between branches. Through this case study of oak, we demonstrate the accumulation and transmission of somatic mutations and the expansion of disease-resistance gene families in trees.

Validation of Horne and Ostberg Morningness-Eveningness Questionnaire in a Middle-Aged Population of French Workers

Abstract: As suggested by the authors, the Horne and Ostberg morning/evening questionnaire (MEQ) has never been adapted to evaluate a nonstudent population. The purpose of this study was to validate this MEQ in a sample of middle-aged workers by modifying only the cutoffs. It was administered in 566 non-shift-workers aged 51.2 to 3.2 years who presented no sleep disorders. According to the Horne and Ostberg classification, the sample consisted of 62.1% morning type, 36.6% neither type, and 2.2% evening type. Multiple correspondence analysis, which determines the principal components, was performed on all MEQ items. Then an ascending hierarchical classification was applied to determine 3 clusters from these principal components. On the basis of these 3 clusters, new cutoffs were determined: evening types were considered as scoring under 53 and morning types above 64, thus giving 28.1% morning type, 51.7% neither type, and 20.2% evening type. As an external validation, eveningness was associated with later bedtime an...