Implementation of multi-layer techniques using FEDERICA, PASITO and OneLab network infrastructures

Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. V. López, J. L. Añamuro, V. Moreno, J. E. L. De Vergara, J. Aracil, C. García, J. P. Fernández-Palacios, and M. Izal, "Implementation of multi-layer techniques using FEDERICA, PASITO and OneLab network infrastructures", in 17th IEEE International Conference on Networks, ICON 2011, p. 89-94This paper describes an implementation of multilayer techniques using the network infrastructure provided by FEDERICA, PASITO and OneLab projects. FEDERICA project provides a network infrastructure, based on virtualization capabilities in both network and computing resources, which creates custom-made virtual environments. PASITO is a layer- 2 network that connects universities and research centers in Spain. OneLab measurements tools allow carrying out highaccuracy active network measurements. Thanks to FEDERICA and PASITO, we have a multi-layer architecture where the traffic is routed based on the measurements of OneLab equipment. To carry out this experiment, we have developed a Multi-layer Traffic Engineering manager and an implementation of the Path Computation Element Protocol to solve the lack of a control plane in IP oriented networks. This work shows the feasibility of multilayer techniques as a convenient solution for network operators and it validates our Path Computation Element implementation.This work has been partially funded by the Spanish Ministry of Education and Science under project ANFORA (TEC2009-13385), by the Spanish Ministry of Industry, Tourism and Trade under PASITO project, and by the European Union under project OneLab2 (FP7-224263). Authors would like to thank Mauro Campanella (GARR, the project coordinator of FEDERICA) and Miguel Angel Sotos (RedIris) for their support to carry out this work

Combined Risk Allele Score of Eight Type 2 Diabetes Genes Is Associated With Reduced First-Phase Glucose-Stimulated Insulin Secretion During Hyperglycemic Clamps

OBJECTIVE - At least 20 type 2 diabetes loci have now been identified, and several of these are associated with altered β-cell function. In this study, we have investigated the combined effects of eight known β-cell loci on insulin secretion stimulated by three different secretagogues during hyperglycemic clamps. RESEARCH DESIGN AND METHODS - A total of 447 subjects originating from four independent studies in the Netherlands and Germany (256 with normal glucose tolerance [NGT]/ 191 with impaired glucose tolerance [IGT]) underwent a hyperglycemic clamp. A subset had an extended clamp with additional glucagon-like peptide (GLP)-1 and arginine (n = 224). We next genotyped single nucleotide polymorphisms in TCF7L2, KCNJ11, CDKAL1, IGF2BP2, HHEX/IDE, CDKN2A/B, SLC30A8, and MTNR1B and calculated a risk allele score by risk allele counting. RESULTS - The risk allele score was associated with lower first-phase glucose-stimulated insulin secretion (GSIS) (P = 7.1 × 1

Gastric variceal bleeding caused by an intrahepatic arterioportal fistula that formed after liver biopsy: a case report and review of the literature

An intrahepatic arterioportal fistula is a rare cause of portal hypertension and variceal bleeding. We report on a patient with an intrahepatic arterioportal fistula following liver biopsy who was successfully treated by hepatectomy after unsuccessful arterial embolization. We also review the literature on symptomatic intrahepatic arterioportal fistulas after liver biopsy. A 48-year-old male with bleeding gastric varices and hepatitis B virus-associated liver cirrhosis was transferred to our hospital; this patient previously underwent percutaneous liver biopsies 3 and 6 years ago. Abdominal examination revealed a bruit over the liver, tenderness in the right upper quadrant, and splenomegaly. Ultrasonographic examination, computed tomography, and angiography confirmed an arterioportal fistula between the right hepatic artery and the right portal vein with portal hypertension. After admission, the patient suffered a large hematemesis and developed shock. He was treated with emergency transarterial embolization using microcoils. Since some collateral vessels bypassed the obstructive coils and still fed the fistulous area, embolization was performed again. Despite the second embolization, the collateral vessels could not be completely controlled. Radical treatment involving resection of his right hepatic lobe was performed. For nearly 6 years postoperatively, this patient has had no further episodes of variceal bleeding

The impact of left ventricular hypertrophy on survival in candidates for liver transplantation: LVH in Cirrhosis

Left ventricular hypertrophy (LVH) occurs in 12% to 30% of patients with cirrhosis; however, its prognostic significance is not well studied. We assessed the association of LVH with survival in patients undergoing a liver transplantation (LT) evaluation. We performed a multicenter cohort study of patients undergoing an evaluation for LT. LVH was defined with transthoracic echocardiography. The outcome of interest was all-cause mortality. LVH was present in 138 of 485 patients (28%). Patients with LVH were older, more likely to be male and African American, and were more likely to have hypertension. Three hundred forty-five patients did not undergo transplantation (212 declined, and 133 were waiting): 36 of 110 patients with LVH (33%) died, whereas 57 of 235 patients without LVH (24%) died (P = 0.23). After LT, 8 of 28 patients with LVH (29%) died over the course of 3 years, whereas 9 of 112 patients without LVH (8%) died (P = 0.007). This finding was independent of conventional risk factors for LVH, and all deaths for patients with LVH occurred within 9 months of LT. No clinical or demographic characteristics were associated with mortality among LVH patients. In conclusion, the presence of LVH is associated with an early increase in mortality after LT, and this is independent of conventional risk factors for LVH. Further studies are needed to confirm these findings and identify factors associated with mortality after transplantation to improve outcomes

Novel Meta-Analysis-Derived Type 2 Diabetes Risk Loci Do Not Determine Prediabetic Phenotypes

BACKGROUND: Genome-wide association (GWA) studies identified a series of novel type 2 diabetes risk loci. Most of them were subsequently demonstrated to affect insulin secretion of pancreatic beta-cells. Very recently, a meta-analysis of GWA data revealed nine additional risk loci with still undefined roles in the pathogenesis of type 2 diabetes. Using our thoroughly phenotyped cohort of subjects at an increased risk for type 2 diabetes, we assessed the association of the nine latest genetic variants with the predominant prediabetes traits, i.e., obesity, impaired insulin secretion, and insulin resistance. METHODOLOGY/PRINCIPAL FINDINGS: One thousand five hundred and seventy-eight metabolically characterized non-diabetic German subjects were genotyped for the reported candidate single nucleotide polymorphisms (SNPs) JAZF1 rs864745, CDC123/CAMK1D rs12779790, TSPAN8/LGR5 rs7961581, THADA rs7578597, ADAMTS9 rs4607103, NOTCH2 rs10923931, DCD rs1153188, VEGFA rs9472138, and BCL11A rs10490072. Insulin sensitivity was derived from fasting glucose and insulin concentrations, oral glucose tolerance test (OGTT), and hyperinsulinemic-euglycemic clamp. Insulin secretion was estimated from OGTT data. After appropriate adjustment for confounding variables and Bonferroni correction for multiple comparisons (corrected alpha-level: p = 0.0014), none of the SNPs was reliably associated with adiposity, insulin sensitivity, or insulin secretion (all p > or = 0.0117, dominant inheritance model). The risk alleles of ADAMTS9 SNP rs4607103 and VEGFA SNP rs9472138 tended to associate with more than one measure of insulin sensitivity and insulin secretion, respectively, but did not reach formal statistical significance. The study was sufficiently powered (1-beta = 0.8) to detect effect sizes of 0.19 < or = d < or = 0.25 (alpha = 0.0014) and 0.13 < or = d < or = 0.16 (alpha = 0.05). CONCLUSIONS/SIGNIFICANCE: In contrast to the first series of GWA-derived type 2 diabetes candidate SNPs, we could not detect reliable associations of the novel risk loci with prediabetic phenotypes. Possible weak effects of ADAMTS9 SNP rs4607103 and VEGFA SNP rs9472138 on insulin sensitivity and insulin secretion, respectively, await further confirmation by larger studies

Phenotypic and genotypic differences between Indian and Scandinavian women with gestational diabetes mellitus

Objective Gestational diabetes mellitus (GDM) is a transient form of diabetes characterized by impaired insulin secretion and action during pregnancy. Population-based differences in prevalence exist which could be explained by phenotypic and genetic differences. The aim of this study was to examine these differences in pregnant women from Punjab, India and Scandinavia. Methods Eighty-five GDM/T2D loci in European and/or Indian populations from previous studies were assessed for association with GDM based on Swedish GDM criteria in 4018 Punjabi Indian and 507 Swedish pregnant women. Selected loci were replicated in Scandinavian cohorts, Radiel (N = 398, Finnish) and STORK/STORK-G (N = 780, Norwegian). Results Punjabi Indian women had higher GDM prevalence, lower insulin secretion and better insulin sensitivity than Swedish women. There were significant frequency differences of GDM/T2D risk alleles between both populations. rs7178572 at HMG20A, previously associated with GDM in South Indian and European women, was replicated in North Indian women. The T2D risk SNP rs11605924 in the CRY2 gene was associated with increased GDM risk in Scandinavian but decreased GDM risk in Punjabi Indian women. No other overlap was seen between GDM loci in both populations. Conclusions Gestational diabetes mellitus is more common in Indian than Swedish women, which partially can be attributed to differences in insulin secretion and action. There was marked heterogeneity in the GDM phenotypes between the populations which could only partially be explained by genetic differences.Peer reviewe

Common polymorphisms within the NR4A3 locus, encoding the orphan nuclear receptor Nor-1, are associated with enhanced β-cell function in non-diabetic subjects

<p>Abstract</p> <p>Background</p> <p>Neuron-derived orphan receptor (Nor) 1, nuclear receptor (Nur) 77, and nuclear receptor-related protein (Nurr) 1 constitute the NR4A family of orphan nuclear receptors which were recently found to modulate hepatic glucose production, insulin signalling in adipocytes, and oxidative metabolism in skeletal muscle. In this study, we assessed whether common genetic variation within the <it>NR4A3 </it>locus, encoding Nor-1, contributes to the development of prediabetic phenotypes, such as glucose intolerance, insulin resistance, or β-cell dysfunction.</p> <p>Methods</p> <p>We genotyped 1495 non-diabetic subjects from Southern Germany for the five tagging single nucleotide polymorphisms (SNPs) rs7047636, rs1526267, rs2416879, rs12686676, and rs10819699 (minor allele frequencies ≥ 0.05) covering 100% of genetic variation within the <it>NR4A3 </it>locus (with D' = 1.0, r²≥ 0.9) and assessed their association with metabolic data derived from the fasting state, an oral glucose tolerance test (OGTT), and a hyperinsulinemic-euglycemic clamp (subgroup, N = 506). SNPs that revealed consistent associations with prediabetic phenotypes were subsequently genotyped in a second cohort (METSIM Study; Finland; N = 5265) for replication.</p> <p>Results</p> <p>All five SNPs were in Hardy-Weinberg equilibrium (p ≥ 0.7, all). The minor alleles of three SNPs, i.e., rs1526267, rs12686676, and rs10819699, consistently tended to associate with higher insulin release as derived from plasma insulin at 30 min(OGTT), AUC_C-peptide-to-AUC_Glucratio and the AUC_Ins30-to-AUC_Gluc30ratio with rs12686676 reaching the level of significance (p ≤ 0.03, all; additive model). The association of the SNP rs12686676 with insulin secretion was replicated in the METSIM cohort (p ≤ 0.03, additive model). There was no consistent association with glucose tolerance or insulin resistance in both study cohorts.</p> <p>Conclusion</p> <p>We conclude that common genetic variation within the <it>NR4A3 </it>locus determines insulin secretion. Thus, <it>NR4A3 </it>represents a novel candidate gene for β-cell function which was not covered by the SNP arrays of recent genome-wide association studies for type 2 diabetes mellitus.</p

Polymorphisms within the Novel Type 2 Diabetes Risk Locus MTNR1B Determine β-Cell Function

BACKGROUND:Very recently, a novel type 2 diabetes risk gene, i.e., MTNR1B, was identified and reported to affect fasting glycemia. Using our thoroughly phenotyped cohort of subjects at an increased risk for type 2 diabetes, we assessed the association of common genetic variation within the MTNR1B locus with obesity and prediabetes traits, namely impaired insulin secretion and insulin resistance. METHODOLOGY/PRINCIPAL FINDINGS:We genotyped 1,578 non-diabetic subjects, metabolically characterized by oral glucose tolerance test, for five tagging single nucleotide polymorphisms (SNPs) covering 100% of common genetic variation (minor allele frequency > 0.05) within the MTNR1B locus (rs10830962, rs4753426, rs12804291, rs10830963, rs3781638). In a subgroup (N = 513), insulin sensitivity was assessed by hyperinsulinemic-euglycemic clamp, and in a further subgroup (N = 301), glucose-stimulated insulin secretion was determined by intravenous glucose tolerance test. After appropriate adjustment for confounding variables and Bonferroni correction for multiple comparisons, none of the tagging SNPs was reliably associated with measures of adiposity. SNPs rs10830962, rs4753426, and rs10830963 were significantly associated with higher fasting plasma glucose concentrations (p < 0.0001) and reduced OGTT- and IVGTT-induced insulin release (p < or = 0.0007 and p < or = 0.01, respectively). By contrast, SNP rs3781638 displayed significant association with lower fasting plasma glucose levels and increased OGTT-induced insulin release (p<0.0001 and p < or = 0.0002, respectively). Moreover, SNP rs3781638 revealed significant association with elevated fasting- and OGTT-derived insulin sensitivity (p < or = 0.0021). None of the MTNR1B tagging SNPs altered proinsulin-to-insulin conversion. CONCLUSIONS/SIGNIFICANCE:In conclusion, common genetic variation within MTNR1B determines glucose-stimulated insulin secretion and plasma glucose concentrations. Their impact on beta-cell function might represent the prevailing pathomechanism how MTNR1B variants increase the type 2 diabetes risk