476 research outputs found

    Legal efficiency and consistency

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    © 2019 Elsevier B.V. We analyze the efficiency and consistency of court decisions under common and civil law. As a leading example, we study the enforcement of property rights. Judges are of two types: some are conservative and follow the precedent or the statute, while others maximize social welfare. When courts intervene ex-post, after the relevant economic choices have been made, welfare-maximizing courts face a “commitment problem.” Such an ex-post bias has implications on the relative “consistency” and efficiency of each legal system. Surprisingly, we find that court decisions are more consistent under common law than under civil law. The welfare comparison between the two systems is, instead, ambiguous. However, in changing economic environments, common law is more likely to dominate civil law because of its greater adaptability

    Phosphatidylinositol 3-Kinase/AKT pathway regulates the endoplasmic reticulum to Golgi traffic of ceramide in glioma cells : a link between lipid signaling pathways involved in the control of cell survival

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    Different lines of evidence indicate that both aberrant activation of the phosphatidylinositol 3-OH kinase (PI3K)/Akt survival pathway and down-regulation of the death mediator ceramide play a critical role in the aggressive behavior, apoptosis resistance, and adverse clinical outcome of glioblastoma multiforme. Furthermore, the inhibition of the PI3K/Akt pathway and the up-regulation of ceramide have been found functional to the activity of many cytotoxic treatments against glioma cell lines and glioblastomas as well. A reciprocal control between PI3K/Akt and ceramide signaling in glioma cell survival/death is suggested by data demonstrating a protective role of PI3K/Akt on ceramide-induced cell death in glial cells. In this study we investigated the role of the PI3K/Akt pathway in the regulation of the ceramide metabolism in C6 glioma cells, a cell line in which the PI3K/Akt pathway is constitutively activated. Metabolic experiments performed with different radioactive metabolic precursors of sphingolipids and microscopy studies with fluorescent ceramides demonstrated that the chemical inhibition of PI3K and the transfection with a dominant negative Akt strongly inhibited ceramide utilization for the biosynthesis of complex sphingolipids by controlling the endoplasmic reticulum (ER) to Golgi vesicular transport of ceramide. These findings constitute the first evidence for a PI3K/Akt-dependent regulation of vesicle-mediated movements of ceramide in the ER-Golgi district. Moreover, the findings also suggest the activation of the PI3K/Akt pathway as crucial to coordinate the biosynthesis of membrane complex sphingolipids with cell proliferation and growth and/or to maintain low ceramide levels, especially as concerns those treatments that promote ceramide biosynthesis in the ER

    Sphingosine-1-Phosphate in the Tumor Microenvironment: A Signaling Hub Regulating Cancer Hallmarks

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    As a key hub of malignant properties, the cancer microenvironment plays a crucial role intimately connected to tumor properties. Accumulating evidence supports that the lysophospholipid sphingosine-1-phosphate acts as a key signal in the cancer extracellular milieu. In this review, we have a particular focus on glioblastoma, representative of a highly aggressive and deleterious neoplasm in humans. First, we highlight recent advances and emerging concepts for how tumor cells and different recruited normal cells contribute to the sphingosine-1-phosphate enrichment in the cancer microenvironment. Then, we describe and discuss how sphingosine-1-phosphate signaling contributes to favor cancer hallmarks including enhancement of proliferation, stemness, invasion, death resistance, angiogenesis, immune evasion and, possibly, aberrant metabolism. We also discuss the potential of how sphingosine-1-phosphate control mechanisms are coordinated across distinct cancer microenvironments. Further progress in understanding the role of S1P signaling in cancer will depend crucially on increasing knowledge of its participation in the tumor microenvironment

    Why stare decisis?

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    © 2014 Elsevier Inc. All Courts rule ex-post, after most economic decisions are sunk. This can generate a time-inconsistency problem. From an ex-ante perspective, Courts will have the ex-post temptation to be excessively lenient. This observation is at the root of the rule of precedent, known as stare decisis.Stare decisis forces Courts to weigh the benefits of leniency towards the current parties against the beneficial effects that tougher decisions have on future ones.We study these dynamics and find that stare decisis guarantees that precedents evolve towards ex-ante efficient decisions, thus alleviating the Courts' time-inconsistency problem. However, the dynamics do not converge to full efficiency

    Legal institutions, innovation, and growth

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    We analyze the relationship between legal institutions, innovation, and growth. We compare a rigid legal system (the law is set before the technological innovation) and a flexible one (the law is set after observing the new technology). The flexible system dominates in terms of welfare, amount of innovation, and output growth at intermediate stages of technological development-periods when legal change is needed. The rigid system is preferable at early stages of technological development, when commitment problems are severe. For mature technologies, the two legal systems are equivalent. We find that rigid legal systems may induce excessive R&D investmen

    Fostering inflammatory bowel disease: sphingolipid strategies to join forces

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    Complex sphingolipids are essential structural components of intestinal membranes, providing protection and integrity to the intestinal mucosa and regulating intestinal absorption processes. The role of sphingolipid signaling has been established in numerous cellular events, including intestinal cell survival, growth, differentiation, and apoptosis. A significant body of knowledge demonstrates that intestinal sphingolipids play a crucial role, as such and through their signaling pathways, in immunity and inflammatory disorders. In this review, we report on and discuss the current knowledge on the metabolism, signaling, and functional implications of sphingolipids in inflammatory bowel disease (IBD), focusing on the different aspects of sphingolipid actions on inflammatory responses and on the potential of sphingolipid-targeted molecules as anti-IBD therapeutic agents

    Sphingolipids : key regulators of apoptosis and pivotal players in cancer drug resistance

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    Drug resistance elicited by cancer cells still constitutes a huge problem that frequently impairs the efficacy of both conventional and novel molecular therapies. Chemotherapy usually acts to induce apoptosis in cancer cells; therefore, the investigation of apoptosis control and of the mechanisms used by cancer cells to evade apoptosis could be translated in an improvement of therapies. Among many tools acquired by cancer cells to this end, the de-regulated synthesis and metabolism of sphingolipids have been well documented. Sphingolipids are known to play many structural and signalling roles in cells, as they are involved in the control of growth, survival, adhesion, and motility. In particular, in order to increase survival, cancer cells: (a) counteract the accumulation of ceramide that is endowed with pro-apoptotic potential and is induced by many drugs; (b) increase the synthesis of sphingosine-1-phosphate and glucosylceramide that are pro-survivals signals; (c) modify the synthesis and the metabolism of complex glycosphingolipids, particularly increasing the levels of modified species of gangliosides such as 9-O acetylated GD3 (\u3b1Neu5Ac(2-8)\u3b1Neu5Ac(2-3)\u3b2Gal(1-4)\u3b2Glc(1-1)Cer) or N-glycolyl GM3 (\u3b1Neu5Ac (2-3)\u3b2Gal(1-4)\u3b2Glc(1-1)Cer) and de-N-acetyl GM3 (NeuNH(2)\u3b2Gal(1-4)\u3b2Glc(1-1)Cer) endowed with anti-apoptotic roles and of globoside Gb3 related to a higher expression of the multidrug resistance gene MDR1. In light of this evidence, the employment of chemical or genetic approaches specifically targeting sphingolipid dysregulations appears a promising tool for the improvement of current chemotherapy efficacy
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