High-sensitivity cardiac troponin I for cardiovascular risk stratification in apparently healthy individuals.

Troponin I and T as cardiac-specific biomarkers are highly useful tools not only in the diagnosis of acute coronary syndromes but also as independent predictors of several other clinical conditions. High-sensitivity cardiac troponin (hs-cTn) assays allow the detection of considerably low concentrations of cardiac troponin in apparently healthy and asymptomatic individuals, being a candidate tool for cardiovascular risk stratification in the general population. A group of Greek experts summarized the bulk of evidence regarding the use of hs-cTnI as a predictor of cardiovascular events and mortality in apparently healthy individuals and its additive value on top of existing risk stratification methods. This document could serve as a guide for the incorporation of hs-cTnI as an additional risk stratification tool in cardiovascular prevention strategies in apparently healthy individuals.

Accurate microRNA target prediction correlates with protein repression levels.

BACKGROUND: MicroRNAs are small endogenously expressed non-coding RNA molecules that regulate target gene expression through translation repression or messenger RNA degradation. MicroRNA regulation is performed through pairing of the microRNA to sites in the messenger RNA of protein coding genes. Since experimental identification of miRNA target genes poses difficulties, computational microRNA target prediction is one of the key means in deciphering the role of microRNAs in development and disease. RESULTS: DIANA-microT 3.0 is an algorithm for microRNA target prediction which is based on several parameters calculated individually for each microRNA and combines conserved and non-conserved microRNA recognition elements into a final prediction score, which correlates with protein production fold change. Specifically, for each predicted interaction the program reports a signal to noise ratio and a precision score which can be used as an indication of the false positive rate of the prediction. CONCLUSION: Recently, several computational target prediction programs were benchmarked based on a set of microRNA target genes identified by the pSILAC method. In this assessment DIANA-microT 3.0 was found to achieve the highest precision among the most widely used microRNA target prediction programs reaching approximately 66%. The DIANA-microT 3.0 prediction results are available online in a user friendly web server at http://www.microrna.gr/microT.

Effects of antioxidant vitamins C and E on endothelial function and thrombosis/fibrinolysis system in smokers.

Smoking is associated with endothelial dysfunction and abnormalities in thrombosis/fibrinolysis system, possibly through increased oxidative stress. In this study we investigated the effect of combined antioxidant treatment with vitamins C and E on endothelial function and plasma levels of plasminogen activator inhibitor (PAI-1), von Willebrand factor (vWF), tissue plasminogen activator (tPA) and factor VII (fVII), in smokers. Forty-one healthy smokers were randomly divided into 4 groups receiving vitamin C 2g/day (group A), vitamin C 2g/day plus vitamin E 400 IU/day (group B), vitamin C 2g/day plus vitamin E 800 IU/day (group C) or no antioxidants (controls, group D), for 4 weeks. Forearm blood flow was measured using venous occlusion strain-gauge plethysmography. Forearm vasodilatory response to reactive hyperemia (RH%) or to sublingual nitroglycerin administration (NTG%) were considered as indexes of endothelium dependent or independent dilation respectively. After treatment, RH% was increased only in groups B (p <0.05) and C (p <0.001) but not in groups A and D. Plasma levels of PAI-1 and vWF were decreased only in group C (p <0.05 for both), while PAI-1/tPA ratio was significantly decreased in both groups B and C (p <0.05 for both). NTG% and plasma levels of tPA and fVII remained invariable in all groups. In conclusion, combined administration of vitamin C and vitamin E at high dosages, improved endothelial function and decreased plasma levels of PAI-1, vWF and PAI-1/tPA ratio in chronic smokers.

Ageing mechanisms and associated lipid changes.

Ageing is related to slowdown/breakdown of the somatotropic axis (i.e. the somatopause) leading to many physiological changes. The somatopause is accompanied by DNA and other macromolecule damage, and is characterized by a progressive decline in vitality and tissue function. We still do not have a definitive understanding of the mechanism( s) of ageing. Several overlapping theories have been proposed such as: 1) The free radical theory, 2) Mitochondrial Ageing, 3) The Glycation Theory, 4) Protein Damage and Maintenance in Ageing, and, 5) DNA Damage and Repair. Furthermore, several models of ageing were introduced such as genetically programmed senescence, telomere shortening, genomic instability, heterochromatin loss, altered epigenetic patterns and long lived cells. There are certain lipid modifications associated with the somatopause, characterized mainly by an increase in total cholesterol and triglyceride levels in both genders. In this review we consider the mechanisms of ageing and the associated changes in lipid metabolism according to gender.

High prevalence and diminished awareness of overweight and obesity in a mediterranean population. An alarming call for action.

INTRODUCTION: The epidemic proportions of overweight, obesity and diabetes in most European countries stress the need for the implementation of an effective action plan for the prevention of cardiovascular (CV) disease. This ques-tionnaire study was designed to evaluate the viewpoint of the general population regarding the relative significance of CV risk factors in the cumulative risk of CV disease. METHODS: All participants answered a questionnaire regarding the self-reported presence of CV disease risk factors and the perceived notion of having excess weight. They were also asked to list CV disease risk factors, ranking them in order of perceived relative significance. Participants were also subjected to total cholesterol measurement using a portable total cholesterol testing meter. RESULTS: The survey population consisted of 32,736 individuals (49.1% males). According to participant self reporting, 32.9% were smokers, 24.7% had hypertension, 9.8% had diabetes, 74.8% reported having stress, 41.9% had insufficient physical activity and 43.3% had hyperlipidemia. The prevalence of overweight was 43.9% and the prevalence of obesity (BMI ≥30 kg/m(2)) was 18.6%. Only 24.4% of participants reported that they had excess weight. The 45.2% of the ques-tioned individuals considered that stress was the most important CV risk factor. CONCLUSIONS: Despite the high prevalence of overweight and obesity, the majority of participants were unaware of the contribution of these well-established risk factors to the occurrence of CV disease. Improving public awareness is impor-tant in order to control the epidemic proportions of these modifiable risk factors.

L-arginine in cardiovascular disease: dream or reality?

L-arginine is the substrate for endothelial nitric oxide synthase (eNOS), and the precursor for the synthesis of nitric oxide (NO). This amino acid exerts a number of actions in the cardiovascular system, mainly through the production of NO. However, it also has a number of NO-independent properties, such as the ability to regulate blood and intracellular pH and the effect on the depolarization of endothelial cell membranes. It also has antihypertensive and antioxidant properties, it influences blood viscosity and the coagulation/fibrinolysis system, and it affects the metabolism of glucose, lipids and proteins. L-arginine influences a number of atherosclerosis risk factors such as hypercholesterolemia, hypertension and smoking, improving endothelial function in these patients. However, it does not affect endothelial function in patients with diabetes mellitus. The role of L-arginine in coronary artery disease is still controversial, but it seems that oral or parenteral administration of this amino acid restores endothelial function in the brachial artery and improves coronary microcirculation. The role of L-arginine in heart failure is currently under investigation, and the first results are rather hopeful. In conclusion, L-arginine seems to provide a hopeful prospect for the treatment of cardiovascular diseases. However, more data derived from large-scale prospective studies evaluating the effects of long-term treatment with L-arginine are needed.