24 research outputs found
Manufacturing and Installation of the Compound Cryogenic Distribution Line for the Large Hadron Collider
The Large Hadron Collider (LHC) [1] currently under construction at CERN will make use of superconducting magnets operating in superfluid helium below 2 K. A compound cryogenic distribution line (QRL) will feed with helium at different temperatures and pressures the local elementary cooling loops in the cryomagnet strings. Low heat inleak to all temperature levels is essential for the overall LHC cryogenic performance. Following a competitive tendering, CERN adjudicated in 2001 the contract for the series line to Air Liquide (France). This paper recalls the main features of the technical specification and shows the project status. The basic choices and achievements for the industrialization phase of the series production are also presented, as well as the installation issues and status
Structural Basis of Cytotoxicity Mediated by the Type III Secretion Toxin ExoU from Pseudomonas aeruginosa
The type III secretion system (T3SS) is a complex macromolecular machinery employed by a number of Gram-negative pathogens to inject effectors directly into the cytoplasm of eukaryotic cells. ExoU from the opportunistic pathogen Pseudomonas aeruginosa is one of the most aggressive toxins injected by a T3SS, leading to rapid cell necrosis. Here we report the crystal structure of ExoU in complex with its chaperone, SpcU. ExoU folds into membrane-binding, bridging, and phospholipase domains. SpcU maintains the N-terminus of ExoU in an unfolded state, required for secretion. The phospholipase domain carries an embedded catalytic site whose position within ExoU does not permit direct interaction with the bilayer, which suggests that ExoU must undergo a conformational rearrangement in order to access lipids within the target membrane. The bridging domain connects catalytic domain and membrane-binding domains, the latter of which displays specificity to PI(4,5)P2. Both transfection experiments and infection of eukaryotic cells with ExoU-secreting bacteria show that ExoU ubiquitination results in its co-localization with endosomal markers. This could reflect an attempt of the infected cell to target ExoU for degradation in order to protect itself from its aggressive cytotoxic action
Utilisation du liraglutide 3 mg dans l’obésité hypothalamique secondaire au craniopharyngiome après échec de chirurgie bariatrique: à propos d’un cas
THIS IS AN ABSTRAC
Specific binding of antigenic peptides to cell-associated MHC class I molecules.
T lymphocytes recognize antigen in the form of peptides that associate with specific alleles of class I or class II major histocompatibility (MHC) molecules. By contrast with the clear MHC allele-specific binding of peptides to purified class II molecules purified solubilized class I molecules either bind relatively poorly or show degenerate specificity. Using photo-affinity labelling, we demonstrate here the specific interaction of peptides with cell-associated MHC class I molecules and show that this involves metabolically active processes
Reduction of macrophage infiltration and chemoattractant gene expression changes in white adipose tissue of morbidly obese subjects after surgery-induced weight loss
In human obesity, the stroma vascular fraction (SVF) of
white adipose tissue (WAT) is enriched in macrophages.
These cells may contribute to low-grade inflammation and
to its metabolic complications. Little is known about the
effect of weight loss on macrophages and genes involved in
macrophage attraction. We examined subcutaneous WAT
(scWAT) of 7 lean and 17 morbidly obese subjects before
and 3 months after bypass surgery. Immunomorphological
changes of the number of scWAT-infiltrating macrophages
were evaluated, along with concomitant changes in expression
of SVF-overexpressed genes. The number of sc-
WAT-infiltrating macrophages before surgery was higher
in obese than in lean subjects (HAM56+/CD68+; 22.6 +
4.3 vs. 1.4 + 0.6%, P < 0.001). Typical “crowns” of
macrophages were observed around adipocytes. Drastic
weight loss resulted in a significant decrease in macrophage
number (-11.63 + 2.3%, P < 0.001), and remaining
macrophages stained positive for the anti-inflammatory
protein interleukin 10. Genes involved in macrophage
attraction (monocyte chemotactic protein [MCP]-1, plasminogen
activator urokinase receptor [PLAUR], and colony-
stimulating factor [CSF]-3) and hypoxia (hypoxiainducible
factor-1a [HIF-1a]), expression of which
increases in obesity and decreases after surgery, were
predominantly expressed in the SVF. We show that improvement
of the inflammatory profile after weight loss is
related to a reduced number of macrophages in scWAT.
MCP-1, PLAUR, CSF-3, and HIF-1a may play roles in the
attraction of macrophages in scWAT