University of Lausanne

About: University of Lausanne is a education organization based out in Lausanne, Switzerland. It is known for research contribution in the topics: Population & Poison control. The organization has 20508 authors who have published 46458 publications receiving 1996655 citations. The organization is also known as: Université de Lausanne & UNIL.

Liquidity and Autocorrelations in Individual Stock Returns

Abstract: This paper documents a strong relationship between short-run reversals and stock return illiquidity, even after controlling for trading volume. The largest reversals and the potential contrarian trading strategy profits occur in the high turnover, low liquidity stocks, as the price pressures caused by non-informational demands for immediacy are accommodated. Thus, the high frequency negative autocorrelations are more likely to result from stresses in the market for liquidity. The contrarian trading strategy profits are smaller than the likely transactions costs because the high turnover, low liquidity stocks face large transaction and market impact costs. This lack of profitability and the fact that the overall findings are consistent with rational equilibrium paradigms suggest that the violation of the efficient market hypothesis due to short-term reversals is not so egregious after all.

PD-1 + and follicular helper T cells are responsible for persistent HIV-1 transcription in treated aviremic individuals

Abstract: Matthieu Perreau and colleagues show that HIV-infected lymph node PD-1+ and follicular helper T cells account for the major source of replication-competent HIV-1 in individuals who have been treated with antiretroviral drugs.

Genome-wide association study identifies six new loci influencing pulse pressure and mean arterial pressure

Abstract: Numerous genetic loci have been associated with systolic blood pressure (SBP) and diastolic blood pressure (DBP) in Europeans(1-3). We now report genome-wide association studies of pulse pressure (PP) and mean arterial pressure (MAP). In discovery (N = 74,064) and follow-up studies (N = 48,607), we identified at genome-wide significance (P = 2.7 x 10(-8) to P = 2.3 x 10(-13)) four new PP loci (at 4q12 near CHIC2, 7q22.3 near PIK3CG, 8q24.12 in NOV and 11q24.3 near ADAMTS8), two new MAP loci (3p21.31 in MAP4 and 10q25.3 near ADRB1) and one locus associated with both of these traits (2q24.3 near FIGN) that has also recently been associated with SBP in east Asians. For three of the new PP loci, the estimated effect for SBP was opposite of that for DBP, in contrast to the majority of common SBP- and DBP-associated variants, which show concordant effects on both traits. These findings suggest new genetic pathways underlying blood pressure variation, some of which may differentially influence SBP and DBP.

NLRP3 inflammasome plays a key role in the regulation of intestinal homeostasis

Abstract: Background: Attenuated innate immune responses to the intestinal microbiota have been linked to the pathogenesis of Crohn's disease (CD). Recent genetic studies have revealed that hypofunctional mutations of NLRP3, a member of the NOD-like receptor (NLR) superfamily, are associated with an increased risk of developing CD. NLRP3 is a key component of the inflammasome, an intracellular danger sensor of the innate immune system. When activated, the inflammasome triggers caspase-1-dependent processing of inflammatory mediators, such as IL-1β and IL-18. Methods: In the current study we sought to assess the role of the NLRP3 inflammasome in the maintenance of intestinal homeostasis through its regulation of innate protective processes. To investigate this role, Nlrp3−/− and wildtype mice were assessed in the dextran sulfate sodium and 2,4,6-trinitrobenzenesulfonic acid models of experimental colitis. Results: Nlrp3−/− mice were found to be more susceptible to experimental colitis, an observation that was associated with reduced IL-1β, reduced antiinflammatory cytokine IL-10, and reduced protective growth factor TGF-β. Macrophages isolated from Nlrp3−/− mice failed to respond to bacterial muramyl dipeptide. Furthermore, Nlrp3-deficient neutrophils exhibited reduced chemotaxis and enhanced spontaneous apoptosis, but no change in oxidative burst. Lastly, Nlrp3−/− mice displayed altered colonic β-defensin expression, reduced colonic antimicrobial secretions, and a unique intestinal microbiota. Conclusions: Our data confirm an essential role for the NLRP3 inflammasome in the regulation of intestinal homeostasis and provide biological insight into disease mechanisms associated with increased risk of CD in individuals with NLRP3 mutations. (Inflamm Bowel Dis 2011)

Noncanonical inflammasome signaling elicits gasdermin D–dependent neutrophil extracellular traps

Abstract: Neutrophil extrusion of neutrophil extracellular traps (NETs) and concomitant cell death (NETosis) provides host defense against extracellular pathogens, whereas macrophage death by pyroptosis enables defense against intracellular pathogens. We report the unexpected discovery that gasdermin D (GSDMD) connects these cell death modalities. We show that neutrophil exposure to cytosolic lipopolysaccharide or cytosolic Gram-negative bacteria ( Salmonella Δ sifA and Citrobacter rodentium ) activates noncanonical (caspase-4/11) inflammasome signaling and triggers GSDMD-dependent neutrophil death. GSDMD-dependent death induces neutrophils to extrude antimicrobial NETs. Caspase-11 and GSDMD are required for neutrophil plasma membrane rupture during the final stage of NET extrusion. Unexpectedly, caspase-11 and GSDMD are also required for early features of NETosis, including nuclear delobulation and DNA expansion; this is mediated by the coordinate actions of caspase-11 and GSDMD in mediating nuclear membrane permeabilization and histone degradation. In vivo application of deoxyribonuclease I to dissolve NETs during murine Salmonella Δ sifA challenge increases bacterial burden in wild-type but not in Casp11 −/− and Gsdmd −/− mice. Our studies reveal that neutrophils use an inflammasome- and GSDMD-dependent mechanism to activate NETosis as a defense response against cytosolic bacteria.