T-786→C polymorphism of the endothelial nitric oxide synthase gene is associated with insulin resistance in patients with ischemic or non ischemic cardiomyopathy

Background: Insulin resistance (IR) and endothelial dysfunction are frequently associated in cardiac disease. The T-786→C variant in the promoter region of the endothelial nitric oxide synthase (eNOS) gene has been associated with IR in both non-diabetic and diabetic subjects. Aim of the study was to assess the reciprocal relationships between T-786→C eNOS polymorphism and IR in ischemic and non-ischemic cardiomyopathy.Method: A group of 132 patients (108 males, median age 65 years) with global left ventricular (LV) dysfunction secondary to ischemic or non-ischemic heart disease was enrolled. Genotyping of T-786→C eNOS gene promoter, fasting glucose, insulin, and insulin resistance (defined as HOMA-IR index > 2.5) were determined in all patients.Results: Genotyping analysis yielded 37 patients homozygous for the T allele (TT), 70 heterozygotes (TC) and 25 homozygous for C (CC). Patients with CC genotype had significantly higher systemic arterial pressure, blood glucose, plasma insulin and HOMA index levels than TT. At multivariate logistic analysis, the history of hypertension and the genotype were the only predictors of IR. In particular, CC genotype increased the risk of IR (CI% 1.4-15.0, p < 0.01) 4.5-fold. The only parameter independently associated with the extent of LV dysfunction and the presence of heart failure (HF) was the HOMA index (2.4 CI% 1.1-5.6, p < 0.04).Conclusions: T-786→C eNOS polymorphism was the major independent determinant of IR in a population of patients with ischemic and non-ischemic cardiomyopathy. The results suggest that a condition of primitive eNOS lower expression can predispose to an impairment of glucose homeostasis, which in turn is able to affect the severity of heart disease. © 2012 Vecoli et al.; licensee BioMed Central Ltd

Palynology of the glacial sediments associated with the End Ordovician Southern Polar ice sheet

editorial reviewe

A kinetic study of gamma-glutamyltransferase (GGT)-mediated S-nitrosoglutathione catabolism.

S-Nitrosoglutathione (GSNO) is a nitric oxide (NO) donor compound which has been postulated to be involved in transport of NO in vivo. It is known that c-glutamyl transpeptidase (GGT) is one of the enzymes involved in the enzyme-mediated decomposition of GSNO, but no kinetics studies of the reaction GSNO-GGT are reported in literature. In this study we directly investigated the kinetics of GGT with respect to GSNO as a substrate and glycyl- glycine (GG) as acceptor co-substrate by spectrophotometry at 334 nm. GGT hydrolyses the c-glutamyl moiety of GSNO to give S-nitroso-cysteinylglycine (CGNO) and c-glutamyl-GG. However, as both the substrate GSNO and the first product CGNO absorb at 334 nm, we optimized an ancillary reaction coupled to the enzymatic reaction, based on the copper-mediated decomposition of CGNO yielding oxidized cysteinyl-glycine and NO. The ancillary reaction allowed us to study directly the GSNO/GGT kinetics by following the decrease of the characteristic absorbance of nitrosothiols at 334 nm. A Km of GGT for GSNO of 0.398 ± 31 mM was thus found, comparable with Km values reported for other c-glutamyl substrates of GGT

Paleoecology and Phylogenetics of an Hirnantian Freshwater Palynological Assemblage from the Arabian Plate

peer reviewe

Acritarch Palynomorph Darkness Index (PDI) as an indicator of thermal maturity in Silurian sections from Saudi Arabia

Palynomorph Darkness Index (PDI) measurements on acritarchs from Silurian strata in Saudi Arabia exhibit an irregular but potentially useful relationship to other vitrinite reflectance proxies. Four distinct stages in PDI evolution can be recognized with thermal maturity. In Stage 1, acritarch PDI is 82% and showing little change with increasing maturity. Acritarch fluorescence is totally extinguished within the oil window

Impaired myocardial metabolic reserve and substrate selection flexibility during stress in patients with idiopathic dilated cardiomyopathy.

Under resting conditions, the failing heart shifts fuel use toward greater glucose and lower free fatty acid (FFA) oxidation. We hypothesized that chronic metabolic abnormalities in patients with dilated cardiomyopathy (DCM) are associated with the absence of the normal increase in myocardial glucose uptake and maintenance of cardiac mechanical efficiency in response to pacing stress. In 10 DCM patients and 6 control subjects, we measured coronary flow by intravascular ultrasonometry and sampled arterial and coronary sinus blood. Myocardial metabolism was determined at baseline, during atrial pacing at 130 beats/min, and at 15 min of recovery by infusion of [(3)H]oleate and [(13)C]lactate and measurement of transmyocardial arteriovenous differences of oxygen and metabolites. At baseline, DCM patients showed depressed coronary flow, reduced uptake and oxidation of FFA, and preferential utilization of carbohydrates. During pacing, glucose uptake increased by 106% in control subjects but did not change from baseline in DCM patients. Lactate release increased by 122% in DCM patients but not in control subjects. Cardiac mechanical efficiency in DCM patients was not different compared with control subjects at baseline but was 34% lower during stress. Fatty acid uptake and oxidation did not change with pacing in either group. Our results show that in DCM there is preferential utilization of carbohydrates, which is associated with reduced flow and oxygen consumption at rest and an impaired ability to increase glucose uptake during stress. These metabolic abnormalities might contribute to progressive cardiac deterioration and represent a target for therapeutic strategies aimed at modulating cardiac substrate utilization

Standards for Libraries in Higher Education

The Standards for Libraries in Higher Education are designed to guide academic libraries in advancing and sustaining their role as partners in educating students, achieving their institutions’ missions, and positioning libraries as leaders in assessment and continuous improvement on their campuses. Libraries must demonstrate their value and document their contributions to overall institutional effectiveness and be prepared to address changes in higher education. These Standards were developed through study and consideration of new and emerging issues and trends in libraries, higher education, and accrediting practices. These Standards differ from previous versions by articulating expectations for library contributions to institutional effectiveness. These Standards differ structurally by providing a comprehensive framework using an outcomes-based approach, with evidence collected in ways most appropriate for each institution

Palaeoenvironmental interpretation of microphytoplankton diversity trends in the Cambrian-Ordovician of the northern Sahara Platform

Analysis of vertical fluctuations in assemblage diversity and relative abundances of microphytoplankton morphological classes permits palaeoenvironmental reconstructions of the Cambrian-Ordovician stratal sequences in the Hassi-R'Mel area (north-central Algeria) and northern Rhadames Basin (southern Tunisia). Abundance fluctuations of acritarch morphological classes and assemblage diversity appear to be related to changes in depositional facies. The present palaeoenvironmental interpretation is primarily based on a comparison with microphytoplankton distributional trends in modern depositional environments. Where possible, the observations are tested against palaeoenvironmental information derived independently from previous lithostratigraphical, macropalaeontological, and petrographical studies of the formations investigated. The present data support the following palaeoenvironmental scenario: during Late Cambrian times, relatively shallow water, neritic conditions prevailed throughout the study area, with evidence for a more proximal environment in southern Tunisia. In the early Tremadoc, open marine, offshore conditions characterized the central Algerian region, but a shallower water setting is indicated for southern Tunisia. During the late Arenig-Llanvirn interval, an open marine, offshore setting is envisaged for the southern Tunisian region, with more proximal conditions prevailing in the Algerian Hassi-R'Mel area. During the entire Ashgill, an essentially restricted marine environment was established throughout the study area. Some stratigraphically important acritarch species (e.g. Acanthodiacrodium angustum) appear to be facies-sensitive; the recognition of palaeoecological control on microphytoplankton distribution has important consequences on the biostratigraphic application of these microfossils. (C) 2000 Elsevier Science B.V. All rights reserved