Crashes and recoveries in illiquid markets

We study the dynamics of liquidity provision by dealers during an asset market crash, described as a temporary negative shock to investors’ aggregate asset demand. We consider a class of dynamic market settings where dealers can trade continuously with each other, while trading between dealers and investors is subject to delays and involves bargaining. We derive conditions on fundamentals, such as preferences, market structure and the characteristics of the market crash (e.g., severity, persistence) under which dealers provide liquidity to investors following the crash. We also characterize the conditions under which dealers’ incentives to provide liquidity are consistent with market efficiency.Asset pricing ; Portfolio management ; Financial crises ; Liquidity (Economics)

Crises and Liquidity in Over-the-Counter Markets

We study the efficiency of dealers’ liquidity provision and the desirability of policy intervention in over-the-counter (OTC) markets during crises. Our theory emphasizes two key frictions in OTC markets: finding counterparties takes time, and trade is bilateral, with quantities and prices determined by bargaining. We model a crisis as a negative shock to investors’ asset demands that lasts until a random recovery time. In this context, dealers can provide liquidity to outside investors by acting as counterparties in trades and by accumulating asset inventories. We find that, when frictions are severe, even well capitalized dealers may not find it optimal to accumulate inventories, given that investors choose asset positions that require small reallocations. In such circumstances, the market allocative efficiency can increase if the government steps in, purchases private assets on its own account, and resells them when the economy recovers.

Crashes and Recoveries in Illiquid Markets

We study the dynamics of liquidity provision by dealers during an asset market crash, described as a temporary negative shock to investors aggregate asset demand. We consider a class of dynamic market settings where dealers can trade continuously with each other, while trading between dealers and investors is subject to delays and involves bargaining. We derive conditions on fundamentals, such as preferences, market structure and the characteristics of the market crash (e.g., severity, persistence) under which dealers provide liquidity to investors following the crash. We also characterize the conditions under which dealers incentives to provide liquidity are consistent with market efficiency.

Stimulation of innate immune cells Induced by probiotics: participation of toll- like receptors

Objective: The present work aimed to study the functionality of macrophages from different locations (peritoneum, spleen and Peyer´s patches) when they were stimulated with probiotics microorganisms: Lactobacillus casei CRL 431 and Lactobacillus paracasei CNCM I-1518 or a Probiotic Fermented Milk (PFM) through Toll-Like Receptors (TLRs), prior challenged with agonists or antagonists of TLRs. Methods: BALB/c mice received in the drinking water, the probiotic bacteria (L. casei CRL 431 and L. paracasei CNCM I-1518) or the PFM. We focused our investigation mainly on the phagocytic activity of macrophages from peritoneum, spleen and Peyer?s patches and cytokine production were evaluated prior challenged with TLR2 and TLR4 agonists or antagonists. The microbicidal activity of macrophages and against an infection with Salmonella typhimurium was also studied. To assess the role of TLR in probiotic stimulation, we evaluated the phagocytic activity, cytokine production and Immunoglobin G (IgG) anti-OVA in C57BL/6 knockout mice to MyD88, TLR2 and TLR4. Results: In BALB/c mice, the best effect in the phagocytosis assay was obtained with the probiotic bacteria L. casei CRL 431, this effect was reinforced with TLR2 agonist. The production of different cytokines (IL-10 and IL-6) was improved with the probiotic treatments and this production was ameliorated with TLRs agonists. The antimicrobial activity was increased with L. casei CRL 431 and L. paracasei CNCM I-1518, TLR2 and TLR4 antagonists had a negative effect on microbicidal activity. The administration of probiotic bacteria or PFM improved the host response against S. typhimurium controlling the infection during the first hours post-infection. In C57BL/6 knockout mice, phagocytic activity was significantly diminished in comparison to wild type mice and the probiotic bacteria or PFM administration was not able to improve this activity. The IL-10 production was increased at a concentration of 108 cells/ml of L. casei CRL 431 in TLR2-/- and TLR4-/-, but not in MyD88-/- mice. The administration of probiotic bacteria or PFM did not play a stimulating effect in the systemic immune response against to OVA antigen in knockout mice. Conclusions: Probiotics modulate the different signaling pathways of innate immune cells through the TLRs. The macrophages activation depends on location of them and that different probiotic strains of Lactobacilli can evoke different intensity of responses. The data suggest that probiotic not only promote a major expression of TLRs but also use these receptors via the innate immune cells as macrophages to stimulate and modulate the immune response.Fil: Maldonado Galdeano, María Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; Argentina. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Microbiología; ArgentinaFil: Lemme Dumit, José María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; Argentina. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Microbiología; ArgentinaFil: Thieblemont, Nathalie. Inserm; Francia. Center of Excellence; FranciaFil: Carmuega, Esteban. Centro de Estudios Nutricionales Infantiles; ArgentinaFil: Weill, Ricardo. DANONE; ArgentinaFil: Perdigon, Gabriela del Valle. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; Argentina. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Microbiología; Argentin

Probiotic lactobacilli as a promising strategy to ameliorate disorders associated with intestinal inflammation induced by a non-steroidal anti-inflammatory drug

Damage to the small intestine caused by non-steroidal anti-inflammatory drugs (NSAIDs) occurs more frequently than in the upper gastrointestinal tract, is more difficult to diagnose and no effective treatments exist. Hence, we investigated whether probiotics can control the onset of this severe condition in a murine model of intestinal inflammation induced by the NSAID, indomethacin. Probiotic supplementation to mice reduce the body weight loss, anemia, shortening of the small intestine, cell infiltration into the intestinal tissue and the loss of Paneth and Goblet cells associated with intestinal inflammation. Furthermore, a high antimicrobial activity in the intestinal fluids of mice fed with probiotics compared to animals on a conventional diet was elicited against several pathogens. Interestingly, probiotics dampened the oxidative stress and several local and systemic markers of an inflammatory process, as well as increased the secretion of IL-10 by regulatory T cells. Even more importantly, probiotics induced important changes in the large intestine microbiota characterized by an increase in anaerobes and lactobacilli, and a significant decrease in total enterobacteria. We conclude that oral probiotic supplementation in NSAID-induced inflammation increases intestinal antimicrobial activity and reinforces the intestinal epithelial barrier in order to avoid pathogens and commensal invasion and maintain intestinal homeostasis.Fil: Martínez Monteros, María José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Maldonado Galdeano, María Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; Argentina. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia; ArgentinaFil: Balcells, Maria Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Weill, Ricardo. Universidad Isalud; ArgentinaFil: De Paula, Juan Andrés. Hospital Italiano; ArgentinaFil: Perdigon, Gabriela del Valle. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Cazorla, Silvia Ines. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; Argentina. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia; Argentin

Impact of a probiotic fermented milk in the gut ecosystem and in the systemic immunity using a non-severe protein-energy-malnutrition model in mice

<p>Abstract</p> <p>Background</p> <p>Malnutrition affects the immune response, causing a decrease of defence mechanisms and making the host more susceptible to infections. Probiotics can reconstitute the intestinal mucosa and stimulate local and systemic immunity. The aim of this work was evaluate the effects of a probiotic fermented milk as a complement of a re-nutrition diet, on the recovery of the intestinal barrier, and mucosal and systemic immune functions in a murine model of non-severe protein-energy-malnutrition. Its potential protection against <it>Salmonella enterica </it>serovar Typhimurium (<it>S</it>. Typhimurium) infection was also analyzed.</p> <p>Methods</p> <p>Mice were undernourished and divided into 3 groups according to the dietary supplement received during re-nutrition (milk, probiotic fermented milk or its bacterial free supernatant) and compared to well-nourished and malnourished mice. They were sacrificed previous to the re-nutrition and 5 days post re-nutrition. The phagocytic activity of macrophages from spleen and peritoneum and the changes in the intestinal histology and microbiota were evaluated. Different immune cell populations and cytokine productions were analyzed in the small intestine tissues. The effect of the re-nutrition supplements on the systemic immunity using OVA antigen and against an infection with <it>S. </it>Typhimurium was also studied.</p> <p>Results</p> <p>Probiotic fermented milk was the most effective re-nutrition diet that improved the intestinal microbiota. Its administration also increased the number of IgA+ cells, macrophages and dendritic cells. The production of different cytokine (IFN-γ, TNF-α, IL-12) by these cells and the phagocytic activity in peritoneum and spleen was also increased. This re-nutrition diet also stimulated the systemic immune response against OVA antigen which was diminished after the malnutrition period and also improved the host response against <it>S. </it>Typhimurium, decreasing the spread of pathogenic bacteria to the liver and the spleen. The importance of the metabolites released during milk fermentation was also demonstrated through the analysis of the bacterial free supernatant obtained from the probiotic fermented milk, but the whole product showed the best effects in the parameters evaluated in this study.</p> <p>Conclusions</p> <p>The administration of probiotic fermented milk as a dietary supplement during the re-nutrition process in a murine immunodeficiency model by malnutrition could be a good adjuvant diet to improve the gut and systemic immune response for the protection against <it>Salmonella </it>infection.</p