38 research outputs found
Probiotic Bacteria Induce a ‘Glow of Health’
Radiant skin and hair are universally recognized as indications of good health. However, this ‘glow of health’ display remains poorly understood. We found that feeding of probiotic bacteria to aged mice induced integumentary changes mimicking peak health and reproductive fitness characteristic of much younger animals. Eating probiotic yogurt triggered epithelial follicular anagen-phase shift with sebocytogenesis resulting in thick lustrous fur due to a bacteria-triggered interleukin-10-dependent mechanism. Aged male animals eating probiotics exhibited increased subcuticular folliculogenesis, when compared with matched controls, yielding luxuriant fur only in probiotic-fed subjects. Female animals displayed probiotic-induced hyperacidity coinciding with shinier hair, a feature that also aligns with fertility in human females. Together these data provide insights into mammalian evolution and novel strategies for integumentary health
Oral Probiotic Control Skin Inflammation by Acting on Both Effector and Regulatory T Cells
Probiotics are believed to alleviate allergic and inflammatory skin disorders, but their impact on pathogenic effector T cells remains poorly documented. Here we show that oral treatment with the probiotic bacteria L. casei (DN-114 001) alone alleviates antigen-specific skin inflammation mediated by either protein-specific CD4+ T cells or hapten-specific CD8+ T cells. In the model of CD8+ T cell-mediated skin inflammation, which reproduces allergic contact dermatitis in human, inhibition of skin inflammation by L. casei is not due to impaired priming of hapten-specific IFNγ-producing cytolytic CD8+ effector T cells. Alternatively, L. casei treatment reduces the recruitment of CD8+ effector T cells into the skin during the elicitation (i.e. symptomatic) phase of CHS. Inhibition of skin inflammation by L. casei requires MHC class II-restricted CD4+ T cells but not CD1d-restricted NK-T cells. L casei treatment enhanced the frequency of FoxP3+ Treg in the skin and increased the production of IL-10 by CD4+CD25+ regulatory T cells in skin draining lymph nodes of hapten-sensitized mice. These data demonstrate that orally administered L. casei (DN-114 001) efficiently alleviate T cell-mediated skin inflammation without causing immune suppression, via mechanisms that include control of CD8+ effector T cells and involve regulatory CD4+ T cells. L. casei (DN-114 001) may thus represent a probiotic of potential interest for immunomodulation of T cell-mediated allergic skin diseases in human
Utilisation de quelques marqueurs physiologiques et biochimiques dans l’expression de tolérance au stress hydrique chez 10 génotypes de blé dur (Triticum durum Desf )
Ne pouvant lutter ou édifier une stratégie contre les facteurs incontournables de l’environnement, l’homme a essayé de domestiquer des plantes qui ont pu progressivement s’adapter aux contraintes imposées. Parmi les voies préconisées, la gestion rationnelle des ressources naturelles, notamment hydriques, figurent parmi les plus privilégiées. L’exploration des mécanismes physiologiques d’adaptation au déficit hydrique chez les céréales permet d’en sélectionner quelques uns pour enfin les introduire dans un programme national d’intensification. A cet effet, dix génotypes de blé dur ont fait l’objet d’étude au plan physiologique, biochimique, histologique ainsi que sur le plan de la vigueur et la viabilité des semences. Les résultats montrent que l’essai topographique au Tétrazolium semble accorder une plus grande vigueur chez les génotypes 1, 3 et 4. L’étude histologique met en valeur les variétés 1, 4, 5, 9, 10 qui montrent une bonne présentation de tous les tissus et ce, sous conditions de stress hydrique. Les osmoprotecteurs tels que la proline et les sucres solubles augmentent avec le stress, démontrant ainsi leur rôle de tolérance ou forme adaptative. La turgescence enfin, montre que V1 et V8 sont plus efficientes à gérer l’échange hydrique foliaire.Mots clés : Blé dur - Déficit hydrique - Adaptation - Physiologie - GénétiqueAs long as man enables to build a strategy against environmental factors, he tried to domesticate plants which were progressively able to be adapted to those imposed constraints. Among those ways, efficient use of natural resources, water resources in particular, was a prevalent mean. Adaptative physiological mechanisms exploration to water deficit for cereals has permitted to select some of them in order to incorporate them within national intensification program. For this purpose, ten genotypes of durum wheat have been submitted to physiological, biochemical, histological study and viability and seed vigor as well. Results that have been obtained show that Tetrazolium test seems to accord a greater seed vigor for genotypes 1, 3, and 4. Histological study points out varieties 1, 4, 5, 9, and 10 which show a good presentation of all tissues under water stress conditions. Osmoprotectors, such as free proline and soluble sugars have increased with stress. This enables us to confirm tolerance role or adaptative pathway. Cell turgor show that V1 and V8 are more efficient for water exchanges and equilibrium in leaves.Keywords : Durum wheat – Water deficit- Adaptation-Physiology - Geneti
Geophysical Investigations for Hydrogeological Characterization at the Kappelen Test Site (Switzerland)
Vertical electric soundings, 2D resistivity imaging and several logging measurements were performed at Kappelen test site to identify the various geolelectric facies that allowed determining the tabular and horizontal structure of the aquifer. The surface-based geoelectric methods allowed for a reliable characterization of the overall structure and the geometry of the aquifer, while geophysical logging methods allowed for inferring detailed hydrogeophysical characteristics, such as the electrical resistivity, total porosity, global and matrix density and hydraulic conductivity. The synoptic interpretation and integration of this broad and diverse database allows for constraining the key hydrological characteristics and hence forms the basis for the detailed hydraulic modelling of flow and transport process