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V. Leiss, Katarina Flockerzie, A. Novakovic, M. Rath, Annika Schönsiegel, L. Birnbaumer, A. Schürmann, C. Harteneck et al.

Bordetella pertussis toxin (PTx), also known as islet-activating protein, induces insulin secretion by ADP-ribosylation of inhibitory G proteins. PTx-induced insulin secretion may result either from inactivation of Gα(o) proteins or from combined inactivation of Gα(o), Gα(i1), Gα(i2), and Gα(i3) isoforms. However, the specific role of Gα(i2) in pancreatic β-cells still remains unknown. In global (Gα(i2)(-/-)) and β-cell-specific (Gα(i2)(βcko)) gene-targeted Gα(i2) mouse models, we studied glucose homeostasis and islet functions. Insulin secretion experiments and intracellular Ca²⁺ measurements were used to characterize Gα(i2) function in vitro. Gα(i2)(-/-) and Gα(i2)(βcko) mice showed an unexpected metabolic phenotype, i.e., significantly lower plasma insulin levels upon intraperitoneal glucose challenge in Gα(i2)(-/-) and Gα(i2)(βcko) mice, whereas plasma glucose concentrations were unchanged in Gα(i2)(-/-) but significantly increased in Gα(i2)(βcko) mice. These findings indicate a novel albeit unexpected role for Gα(i2) in the expression, turnover, and/or release of insulin from islets. Detection of insulin secretion in isolated islets did not show differences in response to high (16 mM) glucose concentrations between control and β-cell-specific Gα(i2)-deficient mice. In contrast, the two- to threefold increase in insulin secretion evoked by L-arginine or L-ornithine (in the presence of 16 mM glucose) was significantly reduced in islets lacking Gα(i2). In accord with a reduced level of insulin secretion, intracellular calcium concentrations induced by the agonistic amino acid L-arginine did not reach control levels in β-cells. The presented analysis of gene-targeted mice provides novel insights in the role of β-cell Gα(i2) showing that amino acid-induced insulin-release depends on Gα(i2).

R. Bugiardini, O. Manfrini, Marta Majstorović Stakić, E. Cenko, S. Boytsov, B. Merkely, D. Becker, M. Dilić et al.

INTRODUCTION The aim of the current study was to investigate the outcomes of coronary reperfusion therapies and ST-segment elevation myocardial infarction (STEMI) in patients of Eastern countries with economies in transition. Federation, and Serbia. The overall population consisted of 23,486 consecutive patients admitted to hospitals from January 1(st) to December 31(st) 2009. Registry data and statistics from the Organization for Economic Cooperation and Development (OECD) countries for the same period were used for comparison (2009-2010). In-hospital mortality was between 4% and 5% in the Western countries. In comparison mortality data were significantly larger in Serbia (10.8%) and Bosnia and Herzegovina (11.2%), intermediate in Russian Federation (7.2%) and similar in Hungary (5.0%). The rates of primary percutaneous coronary intervention (primary PCI) were very low in Bosnia and Herzegovina (18.3%), low in Russian Federation (20.6%) and Serbia (22%), and high in Hungary (70%). Major risk factors for death appear to be lack of reperfusion therapy, longer time delay from symptoms onset to hospital presentation as well as the higher percentage of patients with clinical presentation in Killip class III/IV. CONCLUSION In-hospital STEMI case-fatality rates ranges widely in the former Eastern Bloc countries. Beyond the quality of care provided in hospitals, differences in time delay from symptoms onset to hospital admission may strongly influence STEMI patients' outcome.

I. Netinger, M. Rukavina, M. Serdar, D. Bjegović

Wen Huang, S. Koric, Xin Yu, K. J. Hsia, Xiuling Li

Micro- and nanoscale tubular structures can be formed by strain-induced self-rolled-up nanomembranes. Precision engineering of the shape and dimension determines the performance of devices based on this platform for electronic, optical, and biological applications. A transient quasi-static finite element method (FEM) with moving boundary conditions is proposed as a general approach to design diverse types of three-dimensional (3D) rolled-up geometries. This method captures the dynamic release process of membranes through etching driven by mismatch strain and accurately predicts the final dimensions of rolled-up structures. Guided by the FEM modeling, experimental demonstration using silicon nitride membranes was achieved with unprecedented precision including controlling fractional turns of a rolled-up membrane, anisotropic rolling to form helical structures, and local stress control for 3D hierarchical architectures.

Abstract We derive approximate formulas for the logarithmic derivative of the Selberg and the Ruelle zeta functions over compact, even-dimensional, locally symmetric spaces of real rank one. The obtained formulas are given in terms of zeta singularities.

For compact, even-dimensional, locally symmetric spaces, we obtain precise estimates on the number of singularities of Selberg's and Ruelle's zeta functions considered by U. Bunke and M. Olbrich.

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