Effects of acute and sub-acute hypobaric hypoxia on oxidative stress: a field study in the Alps.

PURPOSE: High altitude results in lower barometric pressure and hence partial pressure of O2 decrease can lead to several molecular and cellular changes, such as generation of reactive oxygen species (ROS). Electron Paramagnetic Resonance technique was adopted in the field, to evaluate the effects of acute and sub-acute hypobaric hypoxia (HH) on ROS production by micro-invasive method. Biological biomarkers, indicators of oxidative stress, renal function and inflammation were investigated too. METHODS: Fourteen lowlander subjects (mean age 27.3 ± 5.9 years) were exposed to HH at 3269 m s.l. ROS production, related oxidative damage to cellular components, systemic inflammatory response and renal function were determined through blood and urine profile performed at 1st, 2nd, 4th, 7th, and 14th days during sojourn. RESULTS: Kinetics of changes during HH exposition showed out significant (range p < 0.05-0.0001) increases that at max corresponds to 38% for ROS production rate, 140% for protein carbonyl, 44% for lipid peroxidation, 42% for DNA damage, 200% for inflammatory cytokines and modifications in renal function (assessed by neopterin concentration: 48%). Conversely, antioxidant capacity significantly (p < 0.0001) decreased - 17% at max. CONCLUSION: This 14 days in-field study describes changes of oxidative-stress biomarkers during HH exposure in lowlanders. The results show an overproduction of ROS and consequent oxidative damage to protein, lipids and DNA with a decrease in antioxidant capacity and the involvement of inflammatory status and a transient renal dysfunction. Exposure at high altitude induces a hypoxic condition during acute and sub-acute phases accompanied by molecular adaptation mechanism indicating acclimatization.

Effect of Bioactive Composites on Microhardness of Enamel Exposed to Carious Challenge.

This study verified if experimental composites containing calcium phosphate nanoparticles exert a protective effect against enamel demineralization. Three experimental resin-based composites containing 60 vol% of fillers were manipulated. Filler phase was constituted by silanized barium glass and 0%, 10% or 20% (by volume) of dicalcium phosphate dihydrate (DPCD) nanoparticles functionalized with the monomer triethylene glycol dimethacrylate (TEGDMA). Cavities (10 x 2 x 2 mm) were prepared in bovine enamel and restored using one of the experimental materials (n=10). Specimens were exposed to pH cycling (demineralizing solution: pH 5.0/4h, remineralizing solution: pH 7.0/20h, 14 days). Enamel Knoop microhardness (100g/10s) was measured on the surface (SH) and after transversal sectioning up to 90 µm depth (cross-sectional microhardness, CSH). Microhardness values and the percent of microhardness loss were analyzed ANOVA/Tukey test and Student's paired t-test (alpha: 5%). The materials did not differ in respect to SH. Enamel adjacent to DCPD-containing composite restorations showed smaller reductions in CSH (-1.2% to -3.5%) than the enamel from control group (-12.5%), while CSH of enamel restored with resin-modified glass ionomer was similar to the other groups (-4.5%). DCPD-containing composites reduced enamel demineralization in comparison to a conventional composite.

The collapse of the Sella Zerbino gravity dam.

When a severe flood wave completely filled the Ortiglieto reservoir on August 13, 1935, the 14 m high "Sella Zerbino" secondary dam failed catastrophically causing > 100 casualties. Both of the dams, Sella Zerbino-Zerbino Saddle and Bric Zerbino-Zerbino Peak (Fig. 1) were overtopped but only the Sella Zerbino failed whereas the main barrage did not suffer any damage. The lawsuit that followed this tragic event ended with a full acquittal of the dam's designers since the plaintiff experts succeeded in demonstrating that the collapse was due to an extreme rainfall storm of unpredictable intensity. The case was then officially closed and still today the failure of the Sella Zerbino dam is attributed to the unpredictable hydrological event. Recently, Natale and Petaccia (2013) re-examined the case assessing the capacity of the flood spillways which equipped the Bric Zerbino dam. This paper thoroughly reviews the mechanics of the collapse of the Sella Zerbino dam focusing on the stability of the structure. The water pressure underneath the dam and the poor quality of the foundation rock is believed to have played a major role in the sequence of events that ended in the collapse of the barrage.

Ion release and mechanical properties of calcium silicate and calcium hydroxide materials used for pulp capping.

AIM: To compare the ion release and mechanical properties of a calcium hydroxide (Dycal) and two calcium silicate (MTA Angelus and Biodentine) cements. METHODOLOGY: Calcium and hydroxyl ion release in water from 24-h set cements were calculated from titration with HCl (n = 3). Calcium release after 7, 14, 21 and 28 days at pH 5.5 and 7.0 was measured using ICP-OES (n = 6). Flexural strength (FS) and modulus (E) were tested after 48-h storage, and compressive strength (CS) was tested after 48 h and 7 days (n = 10). Ion release and mechanical data were subjected to anova/Tukey and Kruskal-Wallis/Mann-Whitney tests, respectively (α = 0.05). RESULTS: Titration curves revealed that Dycal released significantly fewer ions in solution than calcium silicates (P < 0.001). Calcium release remained constant at pH 7.0, whilst at pH 5.5, it dropped significantly by 24% after 21 days (P < 0.05). At pH 5.5, MTA Angelus released significantly more calcium than Dycal (P < 0.01), whilst Biodentine had superior ion release than Dycal at pH 7.0 (P < 0.01). Biodentine had superior flexural strength, flexural modulus and compressive strength than the other cements, whilst MTA Angelus had higher modulus than Dycal (P < 0.001). CONCLUSIONS: Immediate calcium and hydroxyl ion release in solution was significantly lower for Dycal. In general, all materials released constant calcium levels over 28 days, but release from Dycal was significantly lower than Biodentine and MTA Angelus depending on pH conditions. Biodentine had substantially higher strength and modulus than MTA Angelus and Dycal, both of which demonstrated low stress-bearing capabilities.

[Clinical indications for the use of cardiac MRI. By the SIRM Study Group on Cardiac Imaging]. / Indicazioni cliniche per l'utilizzo della cardio RM. A cura del Gruppo di lavoro della Sezione di Cardio-Radiologia della SIRM.

Cardiac magnetic resonance (CMR) is considered an useful method in the evaluation of many cardiac disorders. Based on our experience and available literature, we wrote a document as a guiding tool in the clinical use of CMR. Synthetically we describe different cardiac disorders and express for each one a classification, I to IV, depending on the significance of diagnostic information expected.

Role of first pass and delayed enhancement in assessment of segmental functional recovery after acute myocardial infarction.

PURPOSE: Assessing myocardial viability is crucial in decision making and prognostic restratification after acute myocardial infarction (MI). A number of noninvasive imaging modalities have been employed in viability identification, but contrast-enhanced magnetic resonance (MR) imaging has been shown to be extremely accurate because of its transmural resolution and precise definition of microvascular obstruction. Our purpose was to assess functional recovery after acute MI, with special focus on the role of infarct transmurality and microvascular obstruction. MATERIALS AND METHODS: Forty-six consecutive patients with first acute MI, reperfused by primary percutaneous transluminal coronary angioplasty (PTCA) (n=40) or fibrinolysis (n=6), underwent MR imaging within the first week to assess oedema, microvascular obstruction, function and viability and then again after 4-6 months to assess functional recovery and scar. RESULTS: At first MR examination, postcontrast images were analysed according to three patterns, based on a combination of first-pass and delayed-enhancement data: pattern 1 (normal first pass and late hyperenhancement <50% thickness) identified viable myocardium, whereas pattern 2 (late hyperenhancement >50% thickness, with or without first-pass perfusion defect) and pattern 3 (perfusion defect at first pass and late hypoenhancement) recognised nonviable myocardium, with 93% sensitivity, 75% specificity, 92% positive predictive value and 78% negative predictive value for identifying viable tissue. Furthermore, by dividing pattern 2 into two subpatterns, 2A and 2B, based on absence or presence of microvascular obstruction in >50% transmural infarcts, we were able to better identify the segments without recovery or that were nonviable with a 1.39 relative risk of failed recovery. CONCLUSIONS: After acute MI, not all infarcts with transmurality >50% can be considered nonviable; microvascular obstruction detected at first pass can help to better stratify these cases.

Correlation between clinical presentation and delayed-enhancement MRI pattern in myocarditis.

PURPOSE: The exact incidence of myocarditis is unknown, as the diagnosis is frequently delayed or missed. Clinical presentation and disease course are extremely variable, as there may be acute onset with acute coronary syndrome, or cardiogenic shock, or progressive heart failure or arrhythmias. The purpose of this study was to identify prognostic factors on magnetic resonance imaging (MRI) performed in patients with bioptically proven myocarditis at presentation and after 6 months. MATERIALS AND METHODS: Fifty-six consecutive patients with different presentations of myocarditis (20 with acute coronary syndrome, 20 with heart failure, 16 with arrhythmias) were enrolled. All patients underwent B-mode echocardiography (echo) and tissue Doppler imaging, coronarography, ventriculography, endomyocardial biopsy and contrast-enhanced MRI examination, as well as clinical and echo follow-up at 6 months. RESULTS: At 6-month follow-up, patients were divided in two groups according to values of end-systolic volume and ejection fraction: patients with negative remodelling and those with positive remodelling. Late enhancement was found to be an independent predictor of negative remodelling. CONCLUSIONS: Contrast-enhanced MRI is useful both in the diagnosis and as a prognostic indicator in the clinical suspicion of myocarditis.

Clinical indications for cardiac computed tomography. From the Working Group of the Cardiac Radiology Section of the Italian Society of Medical Radiology (SIRM).

Cardiac computed tomography (CCT) has grown as a useful means in different clinical contexts. Technological development has progressively extended the indications for CCT while reducing the required radiation dose. Even today there is little documentation from the main international scientific societies describing the proper use and clinical indications of CCT; in particular, there are no complete guidelines. This document reflects the position of the Working Group of the Cardiac Radiology Section of the Italian Society of Radiology concerning the indications for CCT.

Contrast transoesophageal echocardiography remains superior to contrast-enhanced cardiac magnetic resonance imaging for the diagnosis of patent foramen ovale.

AIMS: In 30-40% of patients with acute ischaemic stroke, the cause remains undefined (cryptogenic stroke). Contrast transoesophageal echocardiography (TEE) is considered the gold standard for patent foramen ovale (PFO) detection. Recently, however, cardiac magnetic resonance (CMR) has also been applied to detect PFO. In this study, we compared the diagnostic value of CMR and TEE in detecting PFO in a group of patients with apparently cryptogenic stroke. METHODS AND RESULTS: Twenty-five patients (age 50 ± 13 years, 16 males) with apparently cryptogenic ischaemic stroke underwent contrast-enhanced TEE and contrast CMR for detection of possible PFO. Both imaging studies were performed during Valsalva manoeuvre. PFO grading results were assessed visually both for TEE and for CMR, according to the entity of contrast passage in the left atrium (grade 0 = no PFO; grades 1, 2, and 3 = mild, medium, and wide PFO, respectively). TEE detected PFO in 16 patients (64%). Contrast-enhanced CMR identified a PFO in 7 (44%) of these patients. TEE showed a grade 1 PFO in five patients, a grade 2 PFO in eight patients, and a grade 3 PFO in three patients. Of these patients, CMR failed to identify PFO in all five patients with a grade 1 PFO, in one patient with a grade 2 PFO, and one patient with grade 3 PFO according to TEE. None of the nine patients without PFO at TEE was shown to have a PFO at CMR. When compared with TEE, the present methodology of CMR had a sensitivity of 50%, specificity of 100%, negative predictive value of 31%, and a positive predictive value of 100%. CONCLUSION: Our data suggest that TEE is the cornerstone imaging diagnostic test to detect and characterize PFO in patients with ischaemic stroke, and is shown to be better compared with the current CMR sequences.

A highly selective oligopeptide binding protein from the archaeon Sulfolobus solfataricus.

SSO1273 of Sulfolobus solfataricus was identified as a cell surface-bound protein by a proteomics approach. Sequence inspection of the genome revealed that the open reading frame of sso1273 is associated in an operon-like structure with genes encoding all the remaining components of a canonical protein-dependent ATP-binding cassette (ABC) transporter. sso1273 gene expression and SSO1273 protein accumulation on the cell surface were demonstrated to be strongly induced by the addition of a peptide mixture (tryptone) to the culture medium. The native protein was obtained in multimeric form, mostly hexameric, under the purification conditions used, and it was characterized as an oligopeptide binding protein, named S. solfataricus OppA (OppA(Ss)). OppaA(Ss) possesses typical sequence patterns required for glycosylphosphatidylinositol lipid anchoring, resulting in an N-linked glycoprotein with carbohydrate moieties likely composed of high mannose and/or hybrid complex carbohydrates. OppA(Ss) specifically binds oligopeptides and shows a marked selectivity for the amino acid composition of substrates when assayed in complex peptide mixtures. Moreover, a truncated version of OppA(Ss), produced in recombinant form and including the putative binding domain, showed a low but significant oligopeptide binding activity.

Association between familial mediterranean fever and retroperitoneal fibrosis: retroperitoneal fibrosis regression after colchicine therapy.

Retroperitoneal fibrosis (RPF) is a disease characterized by inflammatory fibrotic processes affecting the retroperitoneal structures. Familial Mediterranean Fever (FMF) is an autosomal recessive disorder, characterized by fever and attacks of sterile serositis. Colchicine is the only suitable drug for prevention of acute episodes. We describe a case of association between RPF and FMF in a 48-year-old male, in whom therapy with colchicine, besides preventing acute episodes, allowed RPF regression. To date the association between FMF and RPF and the use of colchicine therapy alone for RPF has not been described.

Design and Implementation of a YARP Device Driver Interface: The Depth-Sensor Case.

This work illustrates the design phases leading to the development of a new YARP device interface along with its client/server implementation. In order to obtain a smoother integration and a more reliable software usability, while avoiding common errors during the design phases, a new interface is created in the YARP network when a new family of devices is introduced.

Cardiac magnetic resonance in systemic sclerosis patients with cardiac symptoms.

OBJECTIVE: Systemic sclerosis (SSc) is characterized by widespread vascular lesions and skin and internal organs fibrosis, including the heart; all cardiac layers, endocardium, myocardium, and pericardium, may be involved. We report the relevance of cardiac MRI findings in scleroderma patients with cardiac symptoms. PATIENTS AND METHODS: 50 patients, all fulfilling the ACR SSc criteria (19 with limited and 31 with diffused skin involvement) were evaluated using a 1.5T MR scanner. Images were acquired before and after contrast medium administration; the exams were considered positive with one or more of these findings: enlarged volumes, reduced EF, regional kinetic anomalies, edema, DE or pericardial effusion. RESULTS: 40 patients (80%) had one or more cardiac abnormalities: 5 patients had myocardial edema; 2 an increased interventricular septum thickness; 22 dilated ventricles or reduced EF; 12 an abnormal regional ventricular motion (2 of these with akinetic segments); 17 a delayed enhancement with different patterns, all without coronary distribution; 22 a pericardial effusion CONCLUSIONS: Pathologic findings were documented in 80% of the cases confirming a high occurrence of abnormal MR data. Myocardial involvement in systemic sclerosis can be assumed by the presence of multiple pathologic MRI findings. CMR seems to be a valuable tool to identify and assess the presence of cardiac involvement.

A Nutritional Approach to the Prevention of Cancer: from Assessment to Personalized Intervention.

Among lifestyle factors, nutrition is one of the most important determinants of health, and represents a pivotal element of cancer risk. Nonetheless, epidemiological evidences of the relationship between several cancers and specific foods and nutrients is still inadequate, and solid conclusions are missing. Indeed, caloric restriction without malnutrition is associated to cancer prevention. Food may be also the primary route of exposure to contaminants such as metals, persistent organic pollutants, and pesticides. Exposuredisease associations and the interplay with genetic susceptibility requires further studies on genetic variation, environment, lifestyle, and chronic disease in order to eliminate and reduce associated health risks, thus contributing to improve health outcomes for the population. A primary nutritional approach for Active and Healthy Ageing (AHA) has been developed by the Nutrition group of the European Innovation Partnership (EIP) on AHA. The working group on lifestyles of the Italian Ministry of Health has developed a comprehensive approach to adequate nutrition using a consensus methodology to collect and integrate the available evidences from the literature and from the Italian experiences at the regional level, to raise the interest of other experts and relevant stakeholders to outline and scale-up joint strategies for a primary nutritional approach to cancer prevention.

Right ventricular aneurysm associated with advanced hypertrophic cardiomyopathy.

A previously undescribed case of right ventricular aneurysm (RVA) associated with hypertrophic cardiomyopathy in an advanced stage is reported. The diagnosis was established by noninvasive (cardiac two-dimensional echocardiogram and nuclear MRI) and invasive (cardiac catheterization, angiography, and biventricular endomyocardial biopsy) cardiac examinations, which documented hypertrophied, dilated and hypokinetic biventricular chambers associated with typical histologic findings (histologic hypertrophic cardiomyopathy index of 66%). A prominent narrowing of myocardial arterioles, extended to the right ventricular myocardium, has been identified and has been hypothesized as being responsible for RVA formation.

Necrotizing myocardial vasculitis in Churg-Strauss syndrome: clinicohistologic evaluation of steroids and immunosuppressive therapy.

Treatment of cardiac dysfunction associated with Churg-Strauss syndrome (CSS) is empiric since the histologic findings provided by endomyocardial biopsy are rare and often nondiagnostic. Myocardial necrotizing vasculitis presenting as restrictive cardiomyopathy has not been reported before. A case of CSS, presenting with fever and progressive heart failure due to pericarditis, eosinophilic endomyocarditis, and myocardial necrotizing vasculitis, is reported. Cardiac involvement assessed by noninvasive (cardiac two-dimensional echocardiogram and nuclear magnetic resonance [NMR] imaging) and invasive (cardiac catheterization, angiography, and biopsy) studies showed a moderate degree of pericardial effusion and left ventricular (LV) dysfunction (ejection fraction 0.40), severe diastolic dysfunction (increased right and LV filling pressure with a dip and plateau pattern) and a severe reduction of cardiac index (1.6 L/min/m2). Histologic characteristics showed marked eosinophilic infiltration of the endocardium and myocardium with myocitolysis and fibrinoid necrosis of arterioles, venules, and capillaries. Combination therapy of steroids and cyclophosphamide resulted in both a clinical (regression of pericardial effusion, normalization of systolic and diastolic dysfunction, and increase of cardiac index to 2.8 L/min/m2) and histologic (sequential endomyocardial biopsies at 1, 3, and 6 months of follow-up) resolution of cardiac involvement. No recurrences were registered at 12-month follow-up with the patient receiving a maintenance drug regimen.

Coronary angiodysplasia of epicardial and intramural vessels.

A case of coronary angiodysplasia combining large aneurysms of epicardial arteries with diffuse malformation of intramural vessels is reported. Clinical presentation may mimic a vascularized cardiac tumor. Although leaking of the aneurysms in the pericardial space may occur, this entity seems to have a benign prognosis not requiring surgical repair.

In vivo detection of coronary artery anomalies in asymptomatic athletes by echocardiographic screening.

BACKGROUND: Anomalous origin of coronary arteries (AOCA) is a rare congenital disease. Although it may have a benign course, it has been identified as a frequent cause of sports-related sudden death. Unfortunately, in vivo detection of AOCA is not easy, as individuals with this anomaly often are asymptomatic and show no signs of myocardial ischemia. Presently, transthoracic two-dimensional echocardiography (TTE) is the only noninvasive, widely available tool to visualize the ostia and first tracts of coronary arteries. OBJECTIVE: To assess the efficacy of TTE in the screening of AOCA in a large athletic population. STUDY DESIGN: In a prospective study, we assessed the ostia and first tracts of coronary arteries in 3,650 subjects (mean age, 30+/-12 years) practicing different sports at various competitive levels. Subjects underwent a TTE examination in our laboratory for scientific or diagnostic purposes. RESULTS: Technically satisfactory echocardiograms were obtained in 3,504 subjects (96%); a clear visualization of the ostia and first tracts of both coronary arteries was obtained in 3,150 cases (90%). Three asymptomatic athletes (0.09%) were suspected to have an AOCA; two with a right coronary artery origin from the left sinus, and one with a left coronary artery origin from the right sinus. Diagnosis was confirmed by coronary angiography. CONCLUSIONS: Our study indicated that AOCA is rare in asymptomatic athletes. Systematic and accurate exploration of coronary anatomy in athletes referred for a diagnostic TTE examination may be useful in identifying those with AOCA.