Heart and systemic effects of statin pretreatment in a rat model of abdominal sepsis. Assessment by Tc99m-sestamibi biodistribition

PURPOSE: To evaluate the heart and the Tc-99m-sestamibi biodistribution after statin pretreatment in a rat model of abdominal sepsis. METHODS: Twenty-four Wistar rats were randomly distributed into four groups (n=6 per group): 1) sepsis with simvastatin treatment, 2) sepsis with vehicle, 3) sham control with simvastatin and 4) sham control with vehicle. 24 hours after cecal ligation and puncture rats received 1.0MBq of Tc-99m-sestamibi i.v. 30min after, animals were euthanized for ex-vivo tissue counting and myocardium histological analysis. RESULTS: Myocardial histologic alterations were not detected 24 hours post-sepsis. There was significantly increased cardiac Tc-99m-sestamibi activity in the sepsis group with simvastatin treatment (1.9$\pm$0.3%ID/g, p<0.001) in comparison to the sepsis group+vehicle (1.0$\pm$0.2% ID/g), control sham group+ simvastatin (1.2$\pm$0.3% ID/g) and control sham group (1.3$\pm$0.2% ID/g). Significant Tc-99m-sestamibi activity in liver, kidney and lungs was also detected in the sepsis group treated with simvastatinin comparison to the other groups. CONCLUSIONS: Statin treatment altered the biodistribution of Tc-99m-sestamibi with increased cardiac and solid organ activity in rats with abdominal sepsis, while no impact on controls. Increased myocardial tracer activity may be a result of a possible protection effect due to increased tissue perfusion mediated by statins

Serum Albumin Is Inversely Associated With Portal Vein Thrombosis in Cirrhosis

We analyzed whether serum albumin is independently associated with portal vein thrombosis (PVT) in liver cirrhosis (LC) and if a biologic plausibility exists. This study was divided into three parts. In part 1 (retrospective analysis), 753 consecutive patients with LC with ultrasound-detected PVT were retrospectively analyzed. In part 2, 112 patients with LC and 56 matched controls were entered in the cross-sectional study. In part 3, 5 patients with cirrhosis were entered in the in vivo study and 4 healthy subjects (HSs) were entered in the in vitro study to explore if albumin may affect platelet activation by modulating oxidative stress. In the 753 patients with LC, the prevalence of PVT was 16.7%; logistic analysis showed that only age (odds ratio [OR], 1.024; P = 0.012) and serum albumin (OR, -0.422; P = 0.0001) significantly predicted patients with PVT. Analyzing the 112 patients with LC and controls, soluble clusters of differentiation (CD)40-ligand (P = 0.0238), soluble Nox2-derived peptide (sNox2-dp; P &lt; 0.0001), and urinary excretion of isoprostanes (P = 0.0078) were higher in patients with LC. In LC, albumin was correlated with sCD4OL (Spearman's rank correlation coefficient [r(s)], -0.33; P &lt; 0.001), sNox2-dp (r(s), -0.57; P &lt; 0.0001), and urinary excretion of isoprostanes (r(s), -0.48; P &lt; 0.0001) levels. The in vivo study showed a progressive decrease in platelet aggregation, sNox2-dp, and urinary 8-iso prostaglandin F2 alpha-III formation 2 hours and 3 days after albumin infusion. Finally, platelet aggregation, sNox2-dp, and isoprostane formation significantly decreased in platelets from HSs incubated with scalar concentrations of albumin. Conclusion: Low serum albumin in LC is associated with PVT, suggesting that albumin could be a modulator of the hemostatic system through interference with mechanisms regulating platelet activation

ESSAY ON INDUSTRIAL ORGANIZATION

La presente tesi fornisce un contributo originale al dibattito esistente tra gli economisti industriali sul rapporto tra concorrenza e asimmetrie informative. Infatti, l’obiettivo principale di questo lavoro consiste nell'investigare, da un punto di vista teorico (e supportato dall'evidenza empirica), come alcune barriere informative presenti nel mercato influenzano le strategie imprenditoriali in diversi contesti competitivi, fornendo implicazioni di policy per autorità garanti della concorrenza e a tutela del consumatore. Nello specifico, il primo capitolo esamina gli incentivi di una impresa dominante in un mercato a monte a offrire contratti di esclusiva ad un monopolista nel mercato a valle, quando vi è incertezza riguardo alla domanda finale dei consumatori. Nei capitoli seguenti, invece, l’analisi si caratterizza dalla presenza del concetto comportamentale di "avversione alla perdita", particolarmente rilevante nelle decisioni di acquisto dei cosiddetti "beni di esperienza". In questi mercati le imprese possono decidere liberamente di permettere test sui propri prodotti prima del loro acquisto, modificando quindi l’utilità attesa dei consumatori. Il secondo capitolo analizza le strategie di vendita per un monopolista. Il terzo capitolo, invece, esamina l’equilibrio di mercato in un contesto competitivo e come l’utilizzo di test sui prodotti possa essere adoperato come strumento collusivo.This dissertation provides an original contribution to the existing debate between industrial economists on the relationship between competition and information asymmetries. Indeed, the main goal of this work consists in investigating, from a theoretical point of view (and supported by empirical evidence), how some informational frictions in the market affect firm’s strategies in different competitive environments, providing policy implications for competition and consumer protection authorities. Specifically, the first chapter looks at the incentives of a dominant firm in an upstream market to offer exclusive dealing contracts to a monopolist in the downstream market, when there is uncertainty about consumer demand. In the following chapters, instead, the analysis is characterized by the presence of the behavioral concept of "loss aversion", which is particularly relevant in the purchase decisions of the so-called "experience goods". In these markets, firms can freely decide to allow product experimentation before purchase, thus modifying the consumers' expected utility. The second chapter analyzes the monopolist's sales strategies. The third chapter, instead, examines the market equilibrium in a competitive environment and how product experimentation can be used as a collusive device

Analisi proteomica dell'epicarpo di Limone (Citrus limon [L.] Burm.) Le qualità biochimiche del limone di Rocca Imperiale

Dottorato di Ricerca in Biologia Vegetale, XXII Ciclo, a.a.2006-2009Università della Calabri

Information sharing, personalized pricing, and collusion

We study collusion sustainability in an infinitely repeated game in which firms might price discriminate, by offering personalized prices for the share of consumers they have information about. We do not impose any restrictions to the distribution of consumers and the product characteristic space. In such a general framework we show that when firms share their personal information about consumers, collusion is more difficult to sustain. We also show that, for intermediate levels of the discount factor, an antitrust policy aiming to discourage joint profit maximization and to maximize the consumer surplus should allow information sharing between firms. Instead, a ban on information sharing is optimal only if firms have imperfect information about their own consumers