U and Th content in the Central Apennines continental crust: a contribution to the determination of the geo-neutrinos flux at LNGS

The regional contribution to the geo-neutrino signal at Gran Sasso National Laboratory (LNGS) was determined based on a detailed geological, geochemical and geophysical study of the region. U and Th abundances of more than 50 samples representative of the main lithotypes belonging to the Mesozoic and Cenozoic sedimentary cover were analyzed. Sedimentary rocks were grouped into four main "Reservoirs" based on similar paleogeographic conditions and mineralogy. Basement rocks do not outcrop in the area. Thus U and Th in the Upper and Lower Crust of Valsugana and Ivrea-Verbano areas were analyzed. Based on geological and geophysical properties, relative abundances of the various reservoirs were calculated and used to obtain the weighted U and Th abundances for each of the three geological layers (Sedimentary Cover, Upper and Lower Crust). Using the available seismic profile as well as the stratigraphic records from a number of exploration wells, a 3D modelling was developed over an area of 2^{\circ}x2^{\circ} down to the Moho depth, for a total volume of about 1.2x10^6 km^3. This model allowed us to determine the volume of the various geological layers and eventually integrate the Th and U contents of the whole crust beneath LNGS. On this base the local contribution to the geo-neutrino flux (S) was calculated and added to the contribution given by the rest of the world, yielding a Refined Reference Model prediction for the geo-neutrino signal in the Borexino detector at LNGS: S(U) = (28.7 \pm 3.9) TNU and S(Th) = (7.5 \pm 1.0) TNU. An excess over the total flux of about 4 TNU was previously obtained by Mantovani et al. (2004) who calculated, based on general worldwide assumptions, a signal of 40.5 TNU. The considerable thickness of the sedimentary rocks, almost predominantly represented by U- and Th- poor carbonatic rocks in the area near LNGS, is responsible for this difference.Comment: 45 pages, 5 figures, 12 tables; accepted for publication in GC

Epidemiology of intra-abdominal infection and sepsis in critically ill patients: “AbSeS”, a multinational observational cohort study and ESICM Trials Group Project

Purpose: To describe the epidemiology of intra-abdominal infection in an international cohort of ICU patients according to a new system that classifies cases according to setting of infection acquisition (community-acquired, early onset hospital-acquired, and late-onset hospital-acquired), anatomical disruption (absent or present with localized or diffuse peritonitis), and severity of disease expression (infection, sepsis, and septic shock). Methods: We performed a multicenter (n = 309), observational, epidemiological study including adult ICU patients diagnosed with intra-abdominal infection. Risk factors for mortality were assessed by logistic regression analysis. Results: The cohort included 2621 patients. Setting of infection acquisition was community-acquired in 31.6%, early onset hospital-acquired in 25%, and late-onset hospital-acquired in 43.4% of patients. Overall prevalence of antimicrobial resistance was 26.3% and difficult-to-treat resistant Gram-negative bacteria 4.3%, with great variation according to geographic region. No difference in prevalence of antimicrobial resistance was observed according to setting of infection acquisition. Overall mortality was 29.1%. Independent risk factors for mortality included late-onset hospital-acquired infection, diffuse peritonitis, sepsis, septic shock, older age, malnutrition, liver failure, congestive heart failure, antimicrobial resistance (either methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, extended-spectrum beta-lactamase-producing Gram-negative bacteria, or carbapenem-resistant Gram-negative bacteria) and source control failure evidenced by either the need for surgical revision or persistent inflammation. Conclusion: This multinational, heterogeneous cohort of ICU patients with intra-abdominal infection revealed that setting of infection acquisition, anatomical disruption, and severity of disease expression are disease-specific phenotypic characteristics associated with outcome, irrespective of the type of infection. Antimicrobial resistance is equally common in community-acquired as in hospital-acquired infection

Pathophysiological aspects of the sheep cardiac sarcoplasmic reticulum calcium release channel

SIGLEAvailable from British Library Document Supply Centre-DSC:DXN022782 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Miocardiopatia da Stress

Descrizione delle caratteristiche cliniche dalla miocardiopatia da stress in generale e della sindrome cosiddetta Tako-Tsubo in particolar

Future strategies of reverse remodeling prevention of hibernation

A complex interrelationship exists among chronic ischemic left ventricular dysfunction, persistence of myocardial viability and possibility to limit progression of chronic heart failure. Cardiac remodeling is influenced by several factors still under investigation. Hibernation is basically an adaptive mechanism to chronically abnormal coronary blood flow, characterized by metabolic and structural alterations of the cardiac tissue, that are fully recovered upon revascularization. The estimate of the prevalence of myocardial viability in patients with chronic ischemic left ventricular dysfunction is crucial and different figures can be obtained by applying different diagnostic techniques and analyzing different cohorts of patients. In patients with chronic heart failure and substantial areas of myocardial ischemia and viability, revascularization is likely to prolong survival. The amount of viable myocardium needed to be clinically relevant remains to be established: only randomized prospective studies, focusing on both functional improvement and prognosis, will give an evidence-based conclusion. An aggressive and thoughtful surgical approach to patients with ischemic heart failure can yield satisfying long-term results, with survival rates superior to medical management alone, and can constitute a true and valid alternative to heart transplantation

INIBIZIONE DEI CANALI IF: PROSPETTIVE FUTURE

Heart rate is increasingly being considered as a prognostic factor in cardiovascular disease, and the need to measure and control heart rate in all coronary patients is clear. When comparisons of heart rate and life expectancy are adjusted for body weight in mammals, it appears that life span is pre-determined by the basic energetics of living cells. This inverse relationship between heart rate and life expectancy reflects an epiphenomenon, in which heart rate is a marker for, or a determinant of, metabolic rate and energetic needs. The heart rate is controlled by the If current, which plays a central role as a pacemaker in the sinoatrial node. Ivabradine, the first representative of a new class of exclusive heart rate-reducing agents, selectively inhibits the If current in the sinoatrial node. The direct electrophysiological consequence of this inhibition is a reduction in the slope of the diastolic depolarization curve and a decrease in heart rate. Pharmacological inhibition of the If current with ivabradine has been shown to preserve coronary vasodilation upon exercise, i.e. myocardial perfusion, with no negative inotropic effects and maintenance of cardiac contractility. Ivabradine also protects the myocardium during ischaemia, improves left ventricular function in congestive heart failure, and reduces remodeling subsequent to myocardial infarction. Pure heart rate reduction by specific and selective If inhibition decreases oxygen demand and improves myocardial energetics, and so we can expect distinc

Beta-adrenergic receptors and intracellular signalling pathway in stunned and non-ischemic regions of pig myocardium.

The beta-adrenergic pathway may have a role in the pathophysiology of ischemic syndromes characterised by reversible left ventricular dysfunction, such as myocardial stunning and other clinical conditions of unstable angina or coronary spasms, or chronic reversible left ventricular dysfunction, which might be a consequence of repeated events of short-term ischemia ("repetitive stunning"). A partial-to-total occlusion of the left anterior descending coronary artery in pigs was used to induce short periods of ischemia (total ischemic time 12 +/- 2 min). Hypokinesis and dyskinesis of the myocardium were considered signs of myocardial dysfunction. We found a maintained function of the beta-adrenergic signalling system. Density and affinity of beta-adrenergic receptors were not different in stunned and non-ischemic regions, nor were cyclic AMP and cyclic GMP intracellular contents and ratio, nor well as the ratio of stimulatory/inhibitory G protein a subunits. Our findings are in agreement with a maintained beta-adrenergic signalling system in the pathophysiology of chronic reversible left ventricular dysfunction

Protection of the ischemic myocardium by the converting-enzyme inhibitor zofenopril: insight into its mechanism of action.

We assessed whether local inhibition of myocardial converting enzyme by captopril and zofenopril reduces the functional and metabolic damage caused by ischemia and reperfusion. First we investigated the effects of zofenopril and captopril on the mechanical function, cellular redox state, and norepinephrine (NE) content of isolated and aerobically perfused rabbit hearts. Both drugs failed to modify the myocardial redox state. At concentrations > 10(-6) M, zofenopril, but not captopril, caused a reduction in myocardial NE content. At 10(-4) M, both drugs caused a reduction in developed pressure and an increase in diastolic pressure and release of creatine phosphokinase (CPK). Second we investigated their effects on ischemic and reperfused myocardium. Both drugs exerted a cardioprotection; zofenopril was always more potent than captopril. Recovery of developed pressure on reperfusion improved, and peak release of NE was reduced, as was release of CPK. Calcium homeostasis and mitochondrial function were maintained. Captopril had no effect on occurrence of oxidative stress during reperfusion, whereas zofenopril reduced it. In hearts treated with the converting enzyme inhibitors, peak release of NE was correlated to mitochondrial calcium content, production of ATP, and recovery of mechanical function on reperfusion. These data suggest that the cardioprotective effect of zofenopril and captopril is independent of hemodynamic changes or reduction of the toxicity of oxygen free radicals and that it could be related to a reduction in release of NE