Imaging predictors of incident heart failure: a systematic review and meta-analysis

BACKGROUND: Preventing the evolution of subclinical cardiac disease into overt heart failure is of paramount importance. Imaging techniques, particularly transthoracic echocardiography (TTE), are well suited to identify abnormalities in cardiac structure and function that precede the development of heart failure. METHODS: This meta-analysis provides a comprehensive evaluation of 32 studies from 11 individual cohorts, which assessed cardiac indices from TTE (63%), cardiovascular magnetic resonance (CMR; 34%) or cardiac computed tomography (CCT; 16%). Eligible studies focused on measures of left ventricular geometry and function and were highly heterogeneous. RESULTS: Among the variables that could be assessed through a meta-analytic approach, left ventricular systolic dysfunction, defined as left ventricular ejection fraction (LVEF) lower than 50%, and left ventricular dilation were associated with a five-fold [hazard ratio (HR) 4.76, 95% confidence interval (95% CI) 1.85-12.26] and three-fold (HR 3.14, 95% CI 1.37 -7.19) increased risk of heart failure development, respectively. Any degree of diastolic dysfunction conveyed an independent, albeit weaker, association with heart failure (HR 1.48, 95% CI 1.11-1.96), although there was only a trend for left ventricular hypertrophy in predicting incident heart failure (hazard ratio 2.85, 95% CI 0.82-9.85). CONCLUSION: LVEF less than 50%, left ventricular dilation and diastolic dysfunction are independent predictors of incident heart failure among asymptomatic individuals, while left ventricular hypertrophy seems less predictive. These findings may serve as a framework for implementing imaging-based screening strategies in patients at risk of heart failure and inform future studies testing preventive or therapeutic approaches aiming at thwarting or halting the progression from asymptomatic (preclinical) to overt heart failure

Structural biology of Helicobacter pylori type IV secretion system

Helicobacter pylori chronically infects the gastric mucosa of millions of people annually worldwide: it has been estimated that over 50% of the world population carries this infection. H. pylori has been associated with the development of several diseases, like chronic gastritis, gastric and duodenal ulcer, gastric adenocarcinoma and mucosa-associated lymphoma [1-3]. The complete genome sequence of two different isolates of H. pylori (J99 and 26995) is known. The strains that contain a 37 kb foreign DNA region, called cag pathogenicity island (cag-PAI), cause the most severe form of virulence [4]. The cag-PAI encodes for a functional type IV secretion apparatus homologous to the VirB/D4 Type IV Secretion System (T4SS) of the plant pathogen Agrobacterium tumefaciens and other Gram-negative bacteria [5]. T4SSs are involved in conjugal DNA transfer, in the DNA delivery to (or uptake from) the environment, for instance the release of oncogenic DNA into infected plant cells by A. tumefaciens, or in the translocation of effector proteins [6,7]. The T4SS encoded by the cag-PAI of H. pylori is responsible for the translocation into the host cell of the protein CagA, a major antigenic virulence factor encoded within the cag-PAI. Once secreted into the gastric epithelial cells, CagA induces cellular modifications, such as elongation and spreading of host cells [8]. The aim of this structural genomic project is to determine the three-dimensional structure of most of the proteins encoded by the cag-PAI, a task that will allow to elucidate the function and the organization of the entire T4SS of such a relevant pathogenic bacterium [9]

A review of tertiary BIM education for advanced engineering communication with visualization

SPECT with Tc-99m-labeled agents is better able to detect viability after nitrate administration. Nitrates induce vasoclilation and may increase blood flow to severely hypoperfused but viable myocardium, thereby enhancing tracer delivery and improving the detection of viability. Quantitative data on the changes in blood flow are lacking in SPECT but can be provided by PET. The aim of the present study was to use PET to evaluate whether nitrate administration increases blood flow to chronically dysfunctional but viable myocardium. Methods: N-13-Ammonia PET was used to quantitatively assess blood flow, and F-18-FDG PET was used as the gold standard to detect viable myocardium. Twenty-five patients with chronic ischemic left ventricular dysfunction underwent N-13-ammonia PET at rest and after nitrate administration. Results: A significant increase in nitrate-enhanced blood flow was observed in viable segments (from 0.55 +/- 0.15 to 0.68 +/- 0.24 mL/min/g, P <0.05). No statistically significant change in blood flow was observed in nonviable segments (0.60 +/- 0.20 vs. 0.55 +/- 0.18 mL/min/g). A ratio of at least 1.1 for nitrate-enhanced flow to resting flow allowed optimal detection of viable myocardium, yielding a sensitivity of 82% with a specificity of 100%. Conclusion: N-13-Ammonia PET showed a significant increase in nitrate-enhanced blood flow in viable myocardium, whereas blood flow remained unchanged after nitrate administration in nonviable myocardium. Nitrate use during myocardial perfusion imaging will lead to improved assessment of myocardial viability

Amyloid deposits and fibrosis on left ventricular endomyocardial biopsy correlate with extracellular volume in cardiac amyloidosis

BACKGROUND: The relative contribution of amyloid and fibrosis to extracellular volume expansion in cardiac amyloidosis (CA) has never been defined. METHODS AND RESULTS: We included all patients diagnosed with amyloid light-chain (AL) or transthyretin cardiac amyloidosis at a tertiary referral center between 2014 to 2020 and undergoing a left ventricular endomyocardial biopsy. Patients (n=37) were more often men (92%), with a median age of 72 years (interquartile range, 68–81). Lambda-positive AL was found in 14 of 19 AL cases (38%) and kappa-positive AL in 5 of 19 (14%), while transthyretin was detected in the other 18 cases (48%). Amyloid deposits accounted for 15% of tissue sample area (10%–30%), without significant differences between AL and transthyretin amyloidosis. All patients displayed myocardial fibrosis, with a median extent of 15% of tissue samples (10%–23%; range, 5%–60%), in the absence of spatial overlap with amyloid deposits. Interstitial fibrosis was often associated with mild and focal subendocardial fibrosis. The extent of fibrosis or the combination of amyloidosis and fibrosis did not differ significantly between transthyretin amyloidosis and AL subgroups. In 20 patients with myocardial T1 mapping at cardiac magnetic resonance, the combined amyloid and fibrosis extent displayed a modest correlation with extracellular volume (r=0.661, P=0.001). The combined amyloid and fibrosis extent correlated with high-sensitivity troponin T (P=0.035) and N-terminal pro-B-type natriuretic peptide (P=0.002) serum levels. CONCLUSIONS: Extracellular spaces in cardiac amyloidosis are enlarged to a similar extent by amyloid deposits and fibrotic tissue. Their combination can better explain the increased extracellular volume at cardiac magnetic resonance and circulating biomarkers than amyloid extent alone

A new polyacetylene from Vernonia scorpioides (Lam.) Pers. (Asteraceae) and its in vitro antitumoral activity

The dichloromethane fraction obtained from hydroalcoholic crude extract of leaves and flowers of Vernonia scorpioides (Asteraceae) was investigated, resulting in the isolation and structure elucidation of a new polyacetylene namely 5-octa-2,4,6-triynyl-furan-2(5H)-one. The structure of the isolated compound was determined based on IR, NMR (1D and 2D) and MS spectrometric data. The antitumor potential, including cytotoxicity to tumor cells and genotoxicity, was investigated. The results suggest that apoptotic cell death may have occurred, at least in part, via a caspase-dependent mechanism.A fração diclorometano obtida pelo particionamento do extrato hidroalcoólico obtido das folhas e flores de Vernonia scorpioides (Asteraceae) resultou no isolamento e caracterização de um novo poliacetileno, 5-octa-2,4,6-triinil-furan-2(5H)-ona. A determinação estrutural foi baseada em dados de espectrometria de Ressonância Magnética Nuclear mono e bidimensionais, de Massas e de Infravermelho. Foi investigado o potencial antitumoral e genotóxico do novo poliacetileno e os resultados encontrados sugerem genotoxicidade e citotoxicidade, onde a morte celular ocorreu via apoptose, envolvendo um mecanismo dependente de caspase.13271333Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

The contact angle of nanofluids as thermophysical property

Droplet volume and temperature affect contact angle significantly. Phase change heat transfer processes of nanofluids – suspensions containing nanometre-sized particles – can only be modelled properly by understanding these effects. The approach proposed here considers the limiting contact angle of a droplet asymptotically approaching zero-volume as a thermophysical property to characterise nanofluids positioned on a certain substrate under a certain atmosphere. Graphene oxide, alumina, and gold nanoparticles are suspended in deionised water. Within the framework of a round robin test carried out by nine independent European institutes the contact angle of these suspensions on a stainless steel solid substrate is measured with high accuracy. No dependence of nanofluids contact angle of sessile droplets on the measurement device is found. However, the measurements reveal clear differences of the contact angle of nanofluids compared to the pure base fluid. Physically founded correlations of the contact angle in dependency of droplet temperature and volume are obtained from the data. Extrapolating these functions to zero droplet volume delivers the searched limiting contact angle depending only on the temperature. It is for the first time, that this specific parameter, is understood as a characteristic material property of nanofluid droplets placed on a certain substrate under a certain atmosphere. Together with the surface tension it provides the foundation of proper modelling phase change heat transfer processes of nanofluids

Extracellular volume quantification in isolated hypertension - changes at the detectable limits?

The funding source (British Heart Foundation and UK National Institute for Health Research) provided salaries for research training (FZ, TT, DS, SW), but had no role in study design, collection, analysis, interpretation, writing, or decisions with regard to publication. This work was undertaken at University College London Hospital, which received a proportion of funding from the UK Department of Health National Institute for Health Research Biomedical Research Centres funding scheme. We are grateful to King’s College London Laboratories for processing the collagen biomarker panel

The Role of TiO2 Doping on RuO2-Coated Electrodes for the Water Oxidation Reaction

Electrochemical water splitting into H2 and O2 presents a significant and challenging energy loss due to the high overpotential required at the anode. Today, in industrially relevant applications, dimensionally stable anodes (DSA) based on the electrocatalytic active RuO2 are conventionally utilized. To enhance the resistance against corrosion, incorporation of TiO2 in the RuO2-coated electrodes is widely employed. In the present work we have used scanning electrochemical microscopy (SECM) to demonstrate that TiO2-doped RuO2-coated electrodes, in addition to being more durable, also show an electrocatalytic activity that is, on average, 13% higher as compared to the pure RuO2-coated electrodes. We also demonstrate that cracks in the pure RuO2 coating are the most active zones, probably because Ti from the Ti support has diffused into the first applied layer of the RuO2 coating. To reveal the nature of this enhanced activity for water oxidation displayed on TiO2-doped RuO2 electrodes, we have employed X-ray photoelectron spectroscopy (XPS) for material characterization. The results show that the electrocatalytic activity enhancement displayed on the mixed (Ru1–x:Tix)O2 coating is promoted through a charge transfer from the RuO2 to the TiO2, which provides new and more reactive sites designated as activated RuO2δ+.This study has partly been carried out in the framework of the European Commission FP7 Initial Training Network “ELCAT”, Grant Agreement No. 214936-2. Portions of this research were performed at SPring-8 with the approval of Japan Synchrotron Radiation Research Institute as Nanotechnology Support Project of the Ministry of Education, Culture, Sports, Science and Technology (Proposal No. 2007A2005 and 2008A1671/BL-47XU)