Impact of diabetes on the predictive value of heart failure biomarkers

Altres ajuts: This study was funded by the Redes Temáticas de Investigación Cooperativa en Salud (RETICS); Red Cardiovascular (RD12/0042/0047) as part of the Plan Nacional de I+D+I.Patients with diabetes mellitus (DM) have an increased risk of developing heart failure (HF). Further, DM is associated with poor prognosis in patients with HF. Our aim was to determine whether DM has any impact on the predictive value of a multi-biomarker panel in patients with HF. We included 1069 consecutive ambulatory HF patients in the study: age 66.2 ± 12.8 years, 33.5 ± 13.3 left ventricular ejection fraction, 36% diabetic patients. We measured serum concentrations of N-terminal pro-brain natriuretic peptide (NT-proBNP), high-sensitivity troponin T (hs-TnT), ST2, galectin-3, high-sensitivity C reactive protein (hs-CRP), cystatin-C, soluble transferrin receptor (sTfR), and neprilysin and followed patients for 4.9 ± 2.8 years. Primary endpoints were all-cause and cardiovascular death. During follow-up, 534 patients died; 283 died of cardiovascular causes. Diabetic subjects had higher mortality (57.7 vs. 45.6%, p < 0.001). NTproBNP (p = 0.07), hs-TnT (p < 0.001), galectin-3 (p < 0.001), and cystatin-C (p = 0.001) concentrations were higher in diabetic patients, whereas sTfR levels were lower (p = 0.005). There were no interactions between DM and NTproBNP, hs-TnT, galectin-3, hs-CRP, cystatin-C, sTfR, and neprilysin relative to risk prediction for all-cause or cardiovascular death. By contrast, ST2 significantly interacted with DM for all-cause (p = 0.02) and cardiovascular (p = 0.03) death. In diabetic patients, HRs for ST2 were 1.27 (95% CI 1.16-1.40, p < 0.001) and 1.23 (95% CI 1.09-1.39, p = 0.001) for all-cause and cardiovascular death, respectively. In nondiabetic patients, HRs for ST2 were 1.53 (95% CI 1.35-1.73, p < 0.001) and 1.64 (95% CI 1.31-2.05, p < 0.001) for all-cause and cardiovascular death, respectively. The multivariable Cox regression analysis showed that hs-TnT and ST2 were the only markers that were independently associated with both all-cause and cardiovascular mortality in patients with HF and diabetes. Moreover, in these patients, the combination of these two markers significantly increased discrimination as assessed by the area under the curve. Biomarkers used in the general population to predict the clinical course of heart failure are also useful in patients with diabetes. In these patients, among all the biomarkers analysed only hs-TnT and ST2 were independently associated with both all-cause and cardiovascular mortality

Influence of Hadean crust evident in basalts and cherts from the Pilbara Craton

Application of the 147Sm–143Nd and 146Sm–142Nd chronometers has suggested that the initial differentiation of Earth’s mantle into enriched and depleted reservoirs may have begun within the first 100–200 million years of Earth’s history1. However, little is known about the differentiation of the early crust; although evidence has suggested the presence of enriched crustal material2, 3, 4, 5, data regarding the nature and composition of this crust are limited. Here we present 147Sm–143Nd data from the weakly metamorphosed basalt and layered chert–barite successions from the Dresser Formation of the Pilbara Craton, Western Australia. The Sm–Nd isochron indicates an age of 3.49±0.10 billion years, in agreement with previous estimates from Pb–Pb (ref. 6) and U–Pb (ref. 7) dating, which indicates that the Sm–Nd system has not been reset. Our measured εNd value of −3.3±1.0 for the rocks at this site is consistent with formation from an older protolith. On the basis of our modelling of trace element and isotopic compositions from these rocks, we suggest that the older component was crustal in nature, and differentiated from the convective mantle more than 4.3 billion years ago

Microfossils of sulphur-metabolizing cells in 3.4-billion-year-old rocks of Western Australia

Sulphur isotope data from early Archaean rocks suggest that microbes with metabolisms based on sulphur existed almost 3.5 billion years ago, leading to suggestions that the earliest microbial ecosystems were sulphur-based. However, morphological evidence for these sulphur-metabolizing bacteria has been elusive. Here we report the presence of microstructures from the 3.4-billion-year-old Strelley Pool Formation in Western Australia that are associated with micrometre-sized pyrite crystals. The microstructures we identify exhibit indicators of biological affinity, including hollow cell lumens, carbonaceous cell walls enriched in nitrogen, taphonomic degradation, organization into chains and clusters, and δ13 C values of -33 to -46% Vienna PeeDee Belemnite (VPDB). We therefore identify them as microfossils of spheroidal and ellipsoidal cells and tubular sheaths demonstrating the organization of multiple cells. The associated pyrite crystals have Δ33 S values between -1.65 and +1.43% and Δ34 S values ranging from -12 to +6% Vienna Canyon Diablo Troilite (VCDT) 5. We interpret the pyrite crystals as the metabolic by-products of these cells, which would have employed sulphate-reduction and sulphur-disproportionation pathways. These microfossils are about 200 million years older than previously described microfossils from Palaeoarchaean siliciclastic environments. © 2011 Macmillan Publishers Limited. All rights reserved

Integration of observational and analytical methodolgoies to characterize organic matter in early Archean rocks: distinguishing biological from abiotically synthesized carbonaceous matter structures

Transmission Electron Microscopy (TEM) was applied to observe and characterize carbonaceous materials (CM) extracted from black cherts and argillite in drill core from the Warrawoona Group of the Pilbara Craton, Western Australia. The black chert came from a 'white smoker type' seafloor deposit in the ca. 3.49 Ga Dresser Formation, whereas the black argillites were obtained from the 3.46 Ga Apex Basalt. The samples were observed and analyzed in TEM combined with electron dispersive spectral analysis (EDS), high resolution TEM (HRTEM) to determine molecular ordering, and C-isotope geochemistry. The TEM and HRTEM observations revealed significant morphological and structural differences between the carbonaceous materials of the Dresser and Apex samples enabling interpretations in terms of primary and secondary origins, as well as metamorphic history. Organic petrology using reflected light microscopy was used on whole rock-samples to observe mineral-organic matter relationship and CM structure relative to host rock texture. The results support an in situ, syn-depositional origin for the Dresser Formation CM. Reflectance % (Ro) of CM determined on polished whole rock-samples and polished resin-embedded CM-concentrates enabled the reconstruction of thermal history. Several Ro populations were identified in the Dresser Formation samples: probable microbial cells preserved in fluid inclusions within quartz crystals, thermally degraded CM originally belonging to microbial cells, CM coating mineral grains and reworked CM particles. In contrast, the Apex Basalt samples yielded-consistently very high Ro values corresponding to graphite stage organic-metamorphism. The weak optical anisotropy of the Apex graphite is inconsistent with formation during regional metamorphism. Two main graphite forms were identified, namely platy and tubular varieties. In HRTEM the tubular form showed nano-tubes and fullerenes within mono-layered spheres. Furthermore, TEM and HRTEM show that the void enclosed mono-layered carbon nano-spheres are more often detached from tubular graphite, forming clusters outside the nano-tubes. These forms are a key to the distinction between biologically and abiotically synthesized CM bodies, both by their small size, perfect outline and especially their resistance to thermal degradation. Dresser Formation samples are isotopically light in the range of-32.1‰ to-38.2‰ consistent with a biological source. Although TEM indicated four distinct types of CM, C-isotope analysis was undertaken on mixed CM concentrates. Nevertheless, the isotopically lighter samples contain a notable input from less thermally degraded low Ro material. On the other hand the isotopically heavier samples contain-predominantly thermally degraded high Ro CM. C-isotope compositions of the Apex CM are generally heavier than Dresser samples, between-22.5‰ and-28.6‰ consistent with high thermal stress. The samples show a C-isotope trend in which CM at 143 m depth is isotopically lighter, whereas above and below this level CM becomes increasingly and consistently isotopically heavier. The upper part of the section is dominated by platy graphite with rare nano-tubes. Predominantly tubular graphite and fullerenes characterize sample SAL-13 at 142 m depth coinciding with the isotopically lightest values. Below 143 m CM is less well preserved and predominantly of the fragmented platy graphite type, becoming increasingly isotopically heavier signifying close association with peridotite intrusion

Globally asynchronous sulphur isotope signals require re-definition of the Great Oxidation Event

© 2018 The Author(s). The Great Oxidation Event (GOE) has been defined as the time interval when sufficient atmospheric oxygen accumulated to prevent the generation and preservation of mass-independent fractionation of sulphur isotopes (MIF-S) in sedimentary rocks. Existing correlations suggest that the GOE was rapid and globally synchronous. Here we apply sulphur isotope analysis of diagenetic sulphides combined with U-Pb and Re-Os geochronology to document the sulphur cycle evolution in Western Australia spanning the GOE. Our data indicate that, from ~2.45 Gyr to beyond 2.31 Gyr, MIF-S was preserved in sulphides punctuated by several episodes of MIF-S disappearance. These results establish the MIF-S record as asynchronous between South Africa, North America and Australia, argue for regional-scale modulation of MIF-S memory effects due to oxidative weathering after the onset of the GOE, and suggest that the current paradigm of placing the GOE at 2.33-2.32 Ga based on the last occurrence of MIF-S in South Africa should be re-evaluated

Group identity, group networks, and political participation: Moroccan and Turkish immigrants in the Netherlands

This article examines how social identification and group networks, and their interactions, affect Moroccan and Turkish immigrants’ political participation in the Netherlands. It uses the data generated by Roex et al. (Salafisme in Nederland. IMES Report Series, Institute for Migration and Ethnic Studies (IMES), Amsterdam, 2010) and conducts logistic regression analyses. It conceptualizes how social identifications, networks, and their interactions relate to voting, other institutionalized political participation, and noninstitutionalized political participation separately. Our main finding is that immigrants’ origin-country identification affects voting turnout negatively, but other forms of political participation positively, for those who are more embedded in origin-country friend networks, and who visit the mosque more frequently. A difference between the two immigrant groups appears when we consider religious identification and networks. Religious identification has mostly positive effects on the political participation of Moroccan immigrants who are also embedded in religious networks, while it has solely negative effects among Turkish immigrants who are more embedded in religious networks