Neurotensin is a regulator of insulin secretion in pancreatic beta-cells.

Neurotensin (NT) is secreted from neurons and gastrointestinal endocrine cells. We previously reported that the three NT receptors (NTSRs) are expressed in pancreatic islets and beta cell lines on which we observed a protective effect of NT against cytotoxic agents. In this study, we explored the role of NT on insulin secretion in the endocrine pancreatic beta cells. We observed that NT stimulates insulin secretion at low glucose level and has a small inhibiting effect on stimulated insulin secretion from isolated islets or INS-1E cells. We studied the mechanisms by which NT elicited calcium concentration changes using fura-2 loaded islets or INS-1E cells. NT increases calcium influx through the opening of cationic channels. Similar calcium influxes were observed after treatment with NTSR selective ligands. NT-evoked calcium regulation involves PKC and the translocation of PKCalpha and PKCepsilon to the plasma membrane. Part of NT effects appears to be also mediated by PKA but not via the Erk pathway. Taken together, these data provide evidence for an important endocrine role of NT in the regulation of the secretory function of beta cells.

Vasoactive intestinal peptide, pituitary adenylate cyclase-activating peptide, and noradrenaline induce the transcription factors CCAAT/enhancer binding protein (C/EBP)-beta and C/EBP delta in mouse cortical astrocytes: involvement in cAMP-regulated glycogen metabolism.

We have described previously a transcription-dependent induction of glycogen resynthesis by the vasoactive intestinal peptide (VIP) or noradrenaline (NA) in astrocytes, which is mediated by cAMP. Because it has been postulated that the cAMP-mediated regulation of energy balance in hepatocytes and adipocytes is channeled at least in part through the CCAAT/enhancer binding protein (C/EBP) family of transcription factors, we tested the hypothesis that C/EBP isoforms could be expressed in mouse cortical astrocytes and that their level of expression could be regulated by VIP, by the VIP-related neuropeptide pituitary adenylate cyclase-activating peptide (PACAP), or by NA. We report in this study that in these cells, C/EBP beta and C/EBP delta are induced by VIP, PACAP, or NA via the cAMP second-messenger pathway. Induction of C/EBP beta and -delta mRNA by VIP occurs in the presence of a protein synthesis inhibitor. Thus, c/ebp beta and c/ebp delta behave as cAMP-inducible immediate-early genes in astrocytes. Moreover, transfection of astrocytes with expression vectors selectively producing the transcriptionally active form of C/EBP beta, termed liver-enriched transcriptional activator protein, or C/EBP delta enhance the glycogen resynthesis elicited by NA, whereas an expression vector producing the transcriptionally inactive form of C/EBP beta, termed liver-enriched transcriptional inhibitory protein, reduces this resynthesis. These results support the idea that C/EBP beta and -delta regulate gene expression of energy metabolism-related enzymes in astrocytes.

The Efficacy of Minimum Unit Pricing, Fiscal and other Pricing Public Policies for Alcohol

This report was commissioned from CJP Consultants Limited by the Department of Health. It sets out the issues relating to hazardous and harmful consumption of alcohol in Ireland. It looks at the international experience and policy response;and makes recommendations about how the problems caused by hazardous alcohol consumption can and should be tackled in Ireland. Click here to download Report on The Efficacy of Minimum Unit Pricing, Fiscal and other Pricing Public Policies for Alcohol PDF 1MB

Three essays in international finance

Executive Summary The first essay of this dissertation investigates whether greater exchange rate uncertainty (i.e., variation over time in the exchange rate) fosters or depresses the foreign investment of multinational firms. In addition to the direct capital financing it supplies, foreign investment can be a source of valuable technology and know-how, which can have substantial positive effects on a host country's economic growth. Thus, it is critically important for policy makers and central bankers, among others, to understand how multinationals base their investment decisions on the characteristics of foreign exchange markets. In this essay, I first develop a theoretical framework to improve our knowledge regarding how the aggregate level of foreign investment responds to exchange rate uncertainty when an economy consists of many firms, each of which is making decisions. The analysis predicts a U-shaped effect of exchange rate uncertainty on the total level of foreign investment of the economy. That is, the effect is negative for low levels of uncertainty and positive for higher levels of uncertainty. This pattern emerges because the relationship between exchange rate volatility and 'the probability of investment is negative for firms with low productivity at home (i.e., firms that find it profitable to invest abroad) and the relationship is positive for firms with high productivity at home (i.e., firms that prefer exporting their product). This finding stands in sharp contrast to predictions in the existing literature that consider a single firm's decision to invest in a unique project. The main contribution of this research is to show that the aggregation over many firms produces a U-shaped pattern between exchange rate uncertainty and the probability of investment. Using data from industrialized countries for the period of 1982-2002, this essay offers a comprehensive empirical analysis that provides evidence in support of the theoretical prediction. In the second essay, I aim to explain the time variation in sovereign credit risk, which captures the risk that a government may be unable to repay its debt. The importance of correctly evaluating such a risk is illustrated by the central role of sovereign debt in previous international lending crises. In addition, sovereign debt is the largest asset class in emerging markets. In this essay, I provide a pricing formula for the evaluation of sovereign credit risk in which the decision to default on sovereign debt is made by the government. The pricing formula explains the variation across time in daily credit spreads - a widely used measure of credit risk - to a degree not offered by existing theoretical and empirical models. I use information on a country's stock market to compute the prevailing sovereign credit spread in that country. The pricing formula explains a substantial fraction of the time variation in daily credit spread changes for Brazil, Mexico, Peru, and Russia for the 1998-2008 period, particularly during the recent subprime crisis. I also show that when a government incentive to default is allowed to depend on current economic conditions, one can best explain the level of credit spreads, especially during the recent period of financial distress. In the third essay, I show that the risk of sovereign default abroad can produce adverse consequences for the U.S. equity market through a decrease in returns and an increase in volatility. The risk of sovereign default, which is no longer limited to emerging economies, has recently become a major concern for financial markets. While sovereign debt plays an increasing role in today's financial environment, the effects of sovereign credit risk on the U.S. financial markets have been largely ignored in the literature. In this essay, I develop a theoretical framework that explores how the risk of sovereign default abroad helps explain the level and the volatility of U.S. equity returns. The intuition for this effect is that negative economic shocks deteriorate the fiscal situation of foreign governments, thereby increasing the risk of a sovereign default that would trigger a local contraction in economic growth. The increased risk of an economic slowdown abroad amplifies the direct effect of these shocks on the level and the volatility of equity returns in the U.S. through two channels. The first channel involves a decrease in the future earnings of U.S. exporters resulting from unfavorable adjustments to the exchange rate. The second channel involves investors' incentives to rebalance their portfolios toward safer assets, which depresses U.S. equity prices. An empirical estimation of the model with monthly data for the 1994-2008 period provides evidence that the risk of sovereign default abroad generates a strong leverage effect during economic downturns, which helps to substantially explain the level and the volatility of U.S. equity returns.

Down-modulation of lymphoproliferation and interferon-gamma production by beta-glucan derived from Saccharomyces cerevisiae

beta-glucan, one of the major cell wall components of Saccharomyces cerevisiae, has been found to enhance immune functions. This study investigated in vivo and in vitro effects of beta-glucan on lymphoproliferation and interferon-gamma (IFN-gamma) production by splenic cells from C57BL/6 female mice. All experiments were performed with particulate beta-glucan derived from S. cerevisiae. Data demonstrated that both, i.p administration of particulate beta-glucan (20 or 100 µg/animal) and in vitro stimulation of splenic cells (20 or 100 µg/ml of culture) decreased lymphoproliferation and IFN-gamma production induced by concanavalin A. These results suggest that beta-glucan can trigger a down-modulatory effect regulating a deleterious immune system hyperactivity in the presence of a strong stimulus.

Evaluation of four methods for detecting the beta-lactamase activity in Neisseria gonorrhoeae isolated in Cuba

Four methods (chromogenic, acidimetric, inhibition, and iodometric) for demonstration of the beta-lactamase production by 70 isolates of Neisseria gonorrhoeae, were evaluated in Cuba. There was 100% correlation between all beta-lactamase methods and the standardized penicillin dilution susceptibility test for penicillinase-non-producing N. gonorrhoeae. For penicillinase-producing N. gonorrhoeae strains, there was a perfect correlation between the chromogenic method and penicillin susceptibility testing, but one and two strains failed to give a positive result for beta-lactamase with the inhibition/acidimetric and the iodometric methods, respectively. There was a high concordance between the chromogenic method, considered as gold standard and the rest of penicillinase tests evaluated: Kappa Index (KI) = 0.98 for inhibition/acidimetric methods and KI = 0.97 for the iodometric method. The four methods evaluated were accurate, reproducible, easily readable, economical, and ease to use for screening primary isolates of N. gonorrhoeae in Cuba. We recommended the use of the inhibition method, when testing the penicillinase activity in gonococcal isolates in provincial and municipal reference laboratories.

Discovery of amino acid variants in the human glucose-dependent insulinotropic polypeptide (GIP) receptor: the impact on the pancreatic beta cell responses and functional expression studies in Chinese hamster fibroblast cells.

The two incretins, glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1), are insulinotropic factors released from the small intestine to the blood stream in response to oral glucose ingestion. The insulinotropic effect of GLP-1 is maintained in patients with Type II (non-insulin-dependent) diabetes mellitus, whereas, for unknown reasons, the effect of GIP is diminished or lacking. We defined the exon-intron boundaries of the human GIP receptor, made a mutational analysis of the gene and identified two amino acid substitutions, A207 V and E354Q. In an association study of 227 Caucasian Type II diabetic patients and 224 matched glucose tolerant control subjects, the allelic frequency of the A207 V polymorphism was 1.1% in Type II diabetic patients and 0.7% in control subjects (p = 0.48), whereas the allelic frequency of the codon 354 polymorphism was 24.9% in Type II diabetic patients versus 23.2% in control subjects. Interestingly, the glucose tolerant subjects (6% of the population) who were homozygous for the codon 354 variant had on average a 14% decrease in fasting serum C-peptide concentration (p = 0.01) and an 11% decrease in the same variable 30 min after an oral glucose load (p = 0.03) compared with subjects with the wild-type receptor. Investigation of the function of the two GIP receptor variants in Chinese hamster fibroblasts showed, however, that the GIP-induced cAMP formation and the binding of GIP to cells expressing the variant receptors were not different from the findings in cells expressing the wildtype GIP receptor. In conclusion, amino acid variants in the GIP receptor are not associated with random Type II diabetes in patients of Danish Caucasian origin or with altered GIP binding and GIP-induced cAMP production when stably transfected in Chinese hamster fibroblasts. The finding of an association between homozygosity for the codon 354 variant and reduced fasting and post oral glucose tolerance test (OGTT) serum C-peptide concentrations, however, calls for further investigations and could suggest that GIP even in the fasting state regulates the beta-cell secretory response.

A proline-rich TGF-beta-responsive transcriptional activator interacts with histone H3.

The molecular mechanisms involved in the regulation of gene expression by transforming growth factor-beta (TGF-beta) have been analyzed. We show that TGF-beta specifically induces the activity of the proline-rich trans-activation domain of CTF-1, a member of the CTF/NF-I family of transcription factors. A TGF-beta-responsive domain (TRD) in the proline-rich transcriptional activation sequence of CTF-1 was shown to mediate TGF-beta induction in NIH-3T3 cells. Mutagenesis studies indicated that this domain is not the primary target of regulatory phosphorylations, suggesting that the growth factor may regulate a CTF-1-interacting protein. A two-hybrid screening assay identified a nucleosome component, histone H3, as a specific CTF-1-interacting protein in yeast. Furthermore, the CTF-1 trans-activation domain was shown to interact with histone H3 in both transiently and stably transfected mammalian cells. This interaction requires the TRD, and it appears to be upregulated by TGF-beta in vivo. Moreover, point mutations in the TRD that inhibit TGF-beta induction also reduce interaction with histone H3. In vitro, the trans-activation domain of CTF-1 specifically contacts histone H3 and oligomers of histones H3 and H4, and full-length CTF-1 was shown to alter the interaction of reconstituted nucleosomal cores with DNA. Thus, the growth factor-regulated trans-activation domain of CTF-1 can interact with chromatin components through histone H3. These findings suggest that such interactions may regulate chromatin dynamics in response to growth factor signaling.

Glucose and leptin induce apoptosis in human beta-cells and impair glucose-stimulated insulin secretion through activation of c-Jun N-terminal kinases.

c-Jun N-terminal kinases (SAPK/JNKs) are activated by inflammatory cytokines, and JNK signaling is involved in insulin resistance and beta-cell secretory function and survival. Chronic high glucose concentrations and leptin induce interleukin-1beta (IL-1beta) secretion from pancreatic islets, an event that is possibly causal in promoting beta-cell dysfunction and death. The present study provides evidence that chronically elevated concentrations of leptin and glucose induce beta-cell apoptosis through activation of the JNK pathway in human islets and in insulinoma (INS 832/13) cells. JNK inhibition by the dominant inhibitor JNK-binding domain of IB1/JIP-1 (JNKi) reduced JNK activity and apoptosis induced by leptin and glucose. Exposure of human islets to leptin and high glucose concentrations leads to a decrease of glucose-induced insulin secretion, which was partly restored by JNKi. We detected an interplay between the JNK cascade and the caspase 1/IL-1beta-converting enzyme in human islets. The caspase 1 gene, which contains a potential activating protein-1 binding site, was up-regulated in pancreatic sections and in isolated islets from type 2 diabetic patients. Similarly, cultured human islets exposed to high glucose- and leptin-induced caspase 1 and JNK inhibition prevented this up-regulation. Therefore, JNK inhibition may protect beta-cells from the deleterious effects of high glucose and leptin in diabetes.

Cloning and expression of rat pancreatic beta-cell malonyl-CoA decarboxylase.

To gain insight into the function and regulation of malonyl-CoA decarboxylase (MCD) we have cloned rat MCD cDNA from a differentiated insulin-secreting pancreatic beta-cell-line cDNA library. The full-length cDNA sequence shows 69% identity with the cDNA cloned previously from the goose uropygial gland, and predicts a 492 amino acid protein of 54.7 kDa. The open reading frame contains an N-terminal mitochondrial targeting sequence and the C-terminal part of the enzyme ends with a peroxisomal (Ser-Lys-Leu) targeting motif. Since the sequence does not reveal hydrophobic domains, MCD is most likely expressed in the mitochondrial matrix and inside the peroxisomes. A second methionine residue, located 3' of the mitochondrial presequence, might be the first amino acid of a putative cytosolic MCD, since the nucleotide sequence around it fits fairly well with a consensus Kozak site for translation initiation. However, primer extension detects the presence of only one transcript initiating upstream of the first ATG, indicating that the major, if not exclusive, transcript expressed in the pancreatic beta-cell encodes MCD with its mitochondrial presequence. The sequence also shows multiple possible sites of phosphorylation by casein kinase II and protein kinase C. mRNA tissue-distribution analysis indicates a transcript of 2.2 kb, and that the MCD gene is expressed over a wide range of rat tissues. The distribution of the enzyme shows a broad range of activities from very low in the brain to elevated in the liver and heart. The results provide the foundations for further studies of the role of MCD in lipid metabolism and metabolic signalling in various tissues.

What Kind of Justice Today ? Expectations Of 'Good Justice', Convergences And Divergences Between Managerial And Judicial Actors And How They Fit Within Management-Oriented Values

This research aims toward a better understanding of the organizational culture(s) of the judiciary in Switzerland by analysing what 'good justice' means nowadays in this country. It seeks to clarify whether, and to what extent, expectations of 'good justice' of judicial actors (judges without managerial experience) and of managerial actors (court managers) are similar and to describe possible managerial implications that may result from this. As judges are at the heart of the judicial organization and exert a strong influence on other groups of actors (Sullivan, Warren et al. 1994), the congruence of their expectations with those of court managers will be at the centre of the analysis. Additionally, referring to the conceptual worlds of Boltanski and Thévenaut (1991), we analyze how closely these expectations are to management-oriented values. We found that almost half of expectations are common to the two groups examined and the main quoted ones are compatible to new public management (NPM) concepts. On the other hand, those expectations shared exclusively by judges relate to the human side of justice, whereas those specific to court managers focus on the way justice functions.

Degree Dissertation Report Asset Management

L'objectiu d'aquest treball no és oferir els mateixos serveis que els productes comercials, sinó utilitzar el coneixement bàsic en aquest sector per crear una aplicació simple

Role of the transcriptional factor C/EBPbeta in free fatty acid-elicited beta-cell failure.

Fatty acids can favour the development of Type 2 diabetes by reducing insulin secretion and inducing apoptosis of pancreatic beta-cells. Here, we show that sustained exposure of the beta-cell line MIN6 or of isolated pancreatic islets to the most abundant circulating fatty acid palmitate increases the level of C/EBPbeta, an insulin transcriptional repressor. In contrast, two unsaturated fatty acids, oleate and linoleate were without effect. The induction of C/EBPbeta elicited by palmitate was prevented by inhibiting the ERK1/2 MAP kinase pathway or by reducing mitochondrial fatty acid oxidation with an inhibitor of Carnitine Palmitoyl Transferase-1. Overexpression of C/EBPbeta mimicked the detrimental effects of palmitate and resulted in a drastic reduction in insulin promoter activity, impairment in the capacity to respond to secretory stimuli and an increase in apoptosis. Our data suggest a potential involvement of C/EBPbeta as mediator of the deleterious effects of unsaturated free fatty acids on beta-cell function.

Analysis of the beta-oxidation of trans-unsaturated fatty acid in recombinant Saccharomyces cerevisiae expressing a peroxisomal PHA synthase reveals the involvement of a reductase-dependent pathway.

The degradation of fatty acids having cis- or trans-unsaturated bond at an even carbon was analyzed in Saccharomyces cerevisiae by monitoring polyhydroxyalkanoate production in the peroxisome. Polyhydroxyalkanaote is synthesized by the polymerization of the beta-oxidation intermediates 3-hydroxy-acyl-CoAs via a bacterial polyhydroxyalkanoate synthase targeted to the peroxisome. The synthesis of polyhydroxyalkanoate in cells grown in media containing 10-cis-heptadecenoic acid was dependent on the presence of 2,4-dienoyl-CoA reductase activity as well as on Delta3,Delta2-enoyl-CoA isomerase activity. The synthesis of polyhydroxyalkanoate from 10-trans-heptadecenoic acid in mutants devoid of 2,4-dienoyl-CoA reductase revealed degradation of the trans fatty acid directly via the enoyl-CoA hydratase II activity of the multifunctional enzyme (MFE), although the level of polyhydroxyalkanoate was 10-25% to that of wild type cells. Polyhydroxyalkanoate produced from 10-trans-heptadecenoic acid in wild type cells showed substantial carbon flux through both a reductase-dependent and a direct MFE-dependent pathway. Flux through beta-oxidation was more severely reduced in mutants devoid of Delta3,Delta2-enoyl-CoA isomerase compared to mutants devoid of 2,4-dienoyl-CoA reductase. It is concluded that the intermediate 2-trans,4-trans-dienoyl-CoA is metabolized in vivo in yeast by both the enoyl-CoA hydratase II activity of the multifunctional protein and the 2,4-dienoyl-CoA reductase, and that the synthesis of the intermediate 3-trans-enoyl-CoA in the absence of the Delta3,Delta2-enoyl-CoA isomerase leads to the blockage of the direct MFE-dependent pathway in vivo.

The alpha v beta 3 integrin as a tumor homing ligand for lymphocytes.

Despite the presence of tumor-specific effector cells in the circulation of cancer patients, the immune response of the majority of these patients is not sufficient to prevent the growth and spread of their tumors. That tumor cells can be killed in vitro by tumor-reactive cytotoxic T cells is testimony to the fact that the tumors are not inherently resistant to T cell killing, but rather that there is a failure in immune recognition and effector cell activation. Many reasons for this failure of the body's defense system have been suggested, including the inability of tumor-reactive lymphocytes to migrate to tumor tissue. Here we designed a strategy to improve homing of primary lymphocytes into vascularized tumors. As a homing molecule we selected the integrin alpha v beta 3 since it is expressed by angiogenic vascular endothelium in tumors. To promote lymphocyte adhesion to alpha v beta 3 we "painted" primary lymphocytes with a recombinant, glycosylphosphatidylinositol-linked high-affinity ligand for alpha v beta 3. These painted lymphocytes specifically bound to alpha v beta 3 in vitro and homed to vascularized, solid tumors in vivo. This novel strategy may provide a significant advance in anti-tumor treatment such as adoptive immune therapy.