Liver injury by experimental portal bacteremia: histogenetic recovery study in the rat

Abstract - To study the histogenetic recovery of hepatic lesions due to portal bacteremia, a complication of some clinical conditions, an experimental animal model had developed. Portal bacteremia was performed in 8-week rats and the morphological recovery of liver was histologically checked 1 to 6 days after bacteria inoculation. The major injuries, such as acute inflammatory exudate of the portobiliary spaces, piecemeal necrosis of muralium, micro-abscesses and areas of hepatocyte necrosis of the liver parenchyma, and thrombosis in the centrolobular vein were recorded 1 day after inoculation. Minimal signs of vacuolar degeneration, steatosis, necrosis areas, vessel congestion and focal hemosiderosis together with a small hepatocyte proliferative activity was instead appreciable with longer time. The results seem to suggest a role of vascular structures and Kupffer cells in the morphological repair. This experimental model could serve to understand better similar clinical hepatology conditions, such as portal bacteremia.Informazioni util

Characterization of dielectric properties and conductivity in encapsulation materials with high insulating filler contents

The properties of different molding-compound materials with high filler contents have been investigated in order to assess their electrical properties. The experimental part of the present work has been focused on dielectric spectroscopy and steady-state conduction measurements. The results have been used to investigate the electrical properties of the materials at different frequencies, temperatures and electric fields. Differences in the relaxation kinetics with increasing filler content have been found, which can be ascribed to the larger interface regions between the filler particles. In addition, the extracted conductivities show a hopping transport and different activation energies on the temperature range from 20 °C to 190 °C

The complex interplay among atherosclerosis, inflammation, and degeneration in ascending thoracic aortic aneurysms

OBJECTIVE: To assess the histopathological findings of a large series of ascending thoracic aortic aneurysm (TAA) surgical specimens applying the updated classification on noninflammatory degenerative and inflammatory aortic diseases proposed by the Association for European Cardiovascular Pathology and the Society for Cardiovascular Pathology clinicopathological correlations. METHODS: A total of 255 patients surgically treated for ascending TAA were enrolled. Surgical ascending aorta specimens were examined. RESULTS: The histopathological substrate of ascending TAAs was mainly degenerative (67.5%), but with a remarkable prevalence of atherosclerotic lesions (18.8%) and aortitis (13.7%). Degenerative patients more frequently had bicuspid aortic valve (37.2%; P = .002). Patients in the atherosclerotic group were older (median age, 69 years; P < .001), more often with a history of hypertension (87.5%; P = .059), hypercholesterolemia (75%; P = .019), diabetes (16.6%; P = .054), current smoking (22.9%; P = .066), and a history of coronary artery disease (18.7%; P = .063). Patients with aortitis represented the older group (median age, 75 years, P < .001), were mostly females (68.6%; P < .001), and had a larger ascending aorta diameter (median, 56 mm; P < .001). Both patients with atherosclerosis and aortitis presented a higher incidence of concomitant abdominal aortic aneurysm (20.8% and 22.8%, respectively; P < .001). CONCLUSIONS: Although degenerative histopathology is the most frequent substrate in ascending TAA, atherosclerosis and inflammation significantly contribute to the development of chronic aortic thoracic disease

Acute heart failure in patients with acute aortic syndrome: Pathophysiology and clinical-prognostic implications

Aims Although acute heart failure (AHF) is a potential complication of acute aortic syndromes (AAS), its clinical details and management implications have been scarcely evaluated. This study aimed to assess prevalence, pathophysiological mechanisms, impact on treatment, and in-hospital mortality of AHF in AAS. Methods and results Data were collected from a prospective AAS registry (398 patients diagnosed between 2000 and 2013). Patients with AHF were identified by the presence of dyspnoea as the presentation symptom or radiological signs of pulmonary congestion or cardiogenic shock, including patients with cardiac tamponade (CT). AHF frequency was 28% (Stanford type A 32% vs. type B 20%, P = 0.01). Four mechanisms leading to AHF were identified, alone or in combination: CT (26%), aortic regurgitation (25%), myocardial ischaemia (17%), and hypertensive crisis (10%). In type A patients, aortic regurgitation and CT were the most frequent mechanisms, whereas myocardial ischaemia and hypertensive crisis were the most frequent in type B patients. Although no difference was noted for diagnostic times, AHF at presentation led to a longer surgical delay in type A AAS. In-hospital mortality was higher in patients with AHF compared with those without (34% vs. 17%, P &lt; 0.001). After multivariable analysis, AHF was associated with increased risk of in-hospital death (adjusted odds ratio 1.97, 95% confidence interval 1.14-3.36, P = 0.014). Conclusion AHF occurs in more than a quarter of patients with AAS of both type A and type B, is due to a variety of pathophysiological mechanisms, and is associated with increased surgical delay and in-hospital mortality. © 2015 The Authors European Journal of Heart Failure © 2015 European Society of Cardiology

Measurement of the Gluon Polarization of the Nucleon at COMPASS

The determination of the gluon polarization $\Delta G/G$ represents one of the main goals of the COMPASS Collaboration at CERN. This quantity is experimentally accessible by selecting photon gluon fusion (PGF) events in the scattering of a polarized 160 GeV muon beam off a polarized $^{6}$LiD target. At COMPASS the PGF mechanism is tagged by means of three different channels: charmed meson production and high-$pT$ hadron pairs in either electro-production ($Q^{2} >$ 1 GeV$^{2}$) or quasi-real photo-production ($Q^{2} <$ 1 GeV$^{2}$). The status of the different analyses and the $\Delta G/G$ results obtained from the 2002-04 data samples are presented. The most precise measurement comes from the hight-$pT$ quasi-real photo-production, yielding a small gluon polarization