Left atrial deformation analysis by speckle tracking echocardiography to predict exercise capacity after myocardial infarction

Introduction: Left atrial (LA) size and function are associated with outcome after myocardial infarction (MI). In this study we aimed to assess the impact of LA function as a predictor of exercise capacity through speckle tracking echocardiography. Methods: A total of 94 patients (mean age 54.8 +/- 11.0 years; 82% male) were enrolled one month after MI. Echocardiography was used to assess LA volumes and various indices of LA conduit, contraction and reservoir function. LA deformation was assessed by two-dimensional speckle tracking to calculate strain and strain rate at different phases of the cardiac cycle. Exercise capacity was assessed by oxygen uptake (VO2) on cardiopulmonary exercise testing. Results: Increased LA volumes, especially LA volume before atrial contraction, were correlated with reduced peak VO2 and reduced VO2 at anaerobic threshold. Decreased peak VO2 was associated with reduced LA conduit function (p=0.24; p=0.02), but not with LA booster function (p=-0.07; p=0.53). Lower peak atrial longitudinal strain was associated with worse exercise capacity (p=0.24; p=0.02). Conclusions: After MI, increased LA volumes were markers of decreased functional capacity that was associated with decreased LA conduit function, but not with LA contractile function. In these patients, LA longitudinal strain analysis may be useful to predict reduced exercise capacity. (C) 2018 Sociedade Portuguesa de Cardiologia. Published by Elsevier Espana, S.L.U.This work was supported by the Portuguese Foundation for Science and Technology grants PEst-C/SAU/UI0051/2011 and EXCL/BIM-MEC/0055/2012 through the Cardiovascular R&D Unit and by European Commission grant FP7-Health-2010; MEDIA-261409

A linkage map for the B-genome of Arachis (Fabaceae) and its synteny to the A-genome

<p>Abstract</p> <p>Background</p> <p><it>Arachis hypogaea </it>(peanut) is an important crop worldwide, being mostly used for edible oil production, direct consumption and animal feed. Cultivated peanut is an allotetraploid species with two different genome components, A and B. Genetic linkage maps can greatly assist molecular breeding and genomic studies. However, the development of linkage maps for <it>A. hypogaea </it>is difficult because it has very low levels of polymorphism. This can be overcome by the utilization of wild species of <it>Arachis</it>, which present the A- and B-genomes in the diploid state, and show high levels of genetic variability.</p> <p>Results</p> <p>In this work, we constructed a B-genome linkage map, which will complement the previously published map for the A-genome of <it>Arachis</it>, and produced an entire framework for the tetraploid genome. This map is based on an F₂population of 93 individuals obtained from the cross between the diploid <it>A. ipaënsis </it>(K30076) and the closely related <it>A. magna </it>(K30097), the former species being the most probable B genome donor to cultivated peanut. In spite of being classified as different species, the parents showed high crossability and relatively low polymorphism (22.3%), compared to other interspecific crosses. The map has 10 linkage groups, with 149 loci spanning a total map distance of 1,294 cM. The microsatellite markers utilized, developed for other <it>Arachis </it>species, showed high transferability (81.7%). Segregation distortion was 21.5%. This B-genome map was compared to the A-genome map using 51 common markers, revealing a high degree of synteny between both genomes.</p> <p>Conclusion</p> <p>The development of genetic maps for <it>Arachis </it>diploid wild species with A- and B-genomes effectively provides a genetic map for the tetraploid cultivated peanut in two separate diploid components and is a significant advance towards the construction of a transferable reference map for <it>Arachis</it>. Additionally, we were able to identify affinities of some <it>Arachis </it>linkage groups with <it>Medicago truncatula</it>, which will allow the transfer of information from the nearly-complete genome sequences of this model legume to the peanut crop.</p

The Effect of Exercise Training on Diastolic and Systolic Function After Acute Myocardial Infarction: A Randomized Study

After acute myocardial infarction (AMI), diastolic dysfunction is frequent and an important determinant of adverse outcome. However, few interventions have proven to be effective in improving diastolic function. We aimed to determine the effect of exercise training on diastolic and systolic function after AMI.One month after AMI, 188 patients were prospectively randomized (1:1) to an 8-week supervised program of endurance and resistance exercise training (n = 86; 55.9 ± 10.8 years) versus standard of care (n = 89; 55.4 ± 10.3 years). All patients were submitted to detailed echocardiography and cardiopulmonary exercise test, at baseline and immediately after the study. Diastolic function was evaluated by the determination of tissue-Doppler derived early diastolic velocities (E' velocity at the septal and lateral sides of mitral annulus) and by the E/E' (ratio between the E wave velocity from mitral inflow and the E' velocity) as recommended in the consensus document for diastolic function assessment.At the end of the study, there was no significant change in E' septal velocity or E/E' septal ratio in the exercise group. We observed a small, although nonsignificant, improvement in E' lateral (mean change 0.1 ± 2.0 cm/s; P = 0.40) and E/E' lateral ratio (mean change of -0.3 ± 2.5; P = 0.24), while patients in the control group had a nonsignificant reduction in E' lateral (mean change -0.4 ± 1.9 cm/s; P = 0.09) and an increase in E/E' lateral ratio (mean change + 0.3 ± 3.3; P = 0.34). No relevant changes occurred in other diastolic parameters. The exercise-training program also did not improve systolic function (either tissue Doppler systolic velocities or ejection fraction).Exercise capacity improved only in the exercise-training group, with an increase of 1.6 mL/kg/min in pVO2 (P = 0.001) and of 1.9 mL/kg/min in VO2 at anaerobic threshold (P < 0.001).After AMI, an 8-week endurance plus resistance exercise-training program did not significantly improve diastolic or systolic function, although it was associated with an improvement in exercise capacity parameters

Jet energy measurement with the ATLAS detector in proton-proton collisions at root s=7 TeV

The jet energy scale and its systematic uncertainty are determined for jets measured with the ATLAS detector at the LHC in proton-proton collision data at a centre-of-mass energy of √s = 7TeV corresponding to an integrated luminosity of 38 pb-1. Jets are reconstructed with the anti-kt algorithm with distance parameters R=0. 4 or R=0. 6. Jet energy and angle corrections are determined from Monte Carlo simulations to calibrate jets with transverse momenta pT≥20 GeV and pseudorapidities {pipe}η{pipe}<4. 5. The jet energy systematic uncertainty is estimated using the single isolated hadron response measured in situ and in test-beams, exploiting the transverse momentum balance between central and forward jets in events with dijet topologies and studying systematic variations in Monte Carlo simulations. The jet energy uncertainty is less than 2. 5 % in the central calorimeter region ({pipe}η{pipe}<0. 8) for jets with 60≤pT<800 GeV, and is maximally 14 % for pT<30 GeV in the most forward region 3. 2≤{pipe}η{pipe}<4. 5. The jet energy is validated for jet transverse momenta up to 1 TeV to the level of a few percent using several in situ techniques by comparing a well-known reference such as the recoiling photon pT, the sum of the transverse momenta of tracks associated to the jet, or a system of low-pT jets recoiling against a high-pT jet. More sophisticated jet calibration schemes are presented based on calorimeter cell energy density weighting or hadronic properties of jets, aiming for an improved jet energy resolution and a reduced flavour dependence of the jet response. The systematic uncertainty of the jet energy determined from a combination of in situ techniques is consistent with the one derived from single hadron response measurements over a wide kinematic range. The nominal corrections and uncertainties are derived for isolated jets in an inclusive sample of high-pT jets. Special cases such as event topologies with close-by jets, or selections of samples with an enhanced content of jets originating from light quarks, heavy quarks or gluons are also discussed and the corresponding uncertainties are determined. © 2013 CERN for the benefit of the ATLAS collaboration

Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

The inclusive and dijet production cross-sections have been measured for jets containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The measurements use data corresponding to an integrated luminosity of 34 pb^-1. The b-jets are identified using either a lifetime-based method, where secondary decay vertices of b-hadrons in jets are reconstructed using information from the tracking detectors, or a muon-based method where the presence of a muon is used to identify semileptonic decays of b-hadrons inside jets. The inclusive b-jet cross-section is measured as a function of transverse momentum in the range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet cross-section is measured as a function of the dijet invariant mass in the range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets and the angular variable chi in two dijet mass regions. The results are compared with next-to-leading-order QCD predictions. Good agreement is observed between the measured cross-sections and the predictions obtained using POWHEG + Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet cross-section. However, it does not reproduce the measured inclusive cross-section well, particularly for central b-jets with large transverse momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final version published in European Physical Journal

Induction of APOBEC3 Exacerbates DNA Replication Stress and Chromosomal Instability in Early Breast and Lung Cancer Evolution

APOBEC3 enzymes are cytosine deaminases implicated in cancer. Precisely when APOBEC3 expression is induced during cancer development remains to be defined. Here we show that specific APOBEC3 genes are upregulated in breast DCIS, and in pre-invasive lung cancer lesions coincident with cellular proliferation. We observe evidence of APOBEC3-mediated subclonal mutagenesis propagated from TRACERx pre-invasive to invasive NSCLC lesions. We find that APOBEC3B exacerbates DNA replication stress and chromosomal instability through incomplete replication of genomic DNA, manifested by accumulation of mitotic ultrafine bridges and 53BP1 nuclear bodies in the G1 phase of the cell cycle. Analysis of TRACERx NSCLC clinical samples and mouse lung cancer models, revealed APOBEC3B expression driving replication stress and chromosome missegregation. We propose that APOBEC3 is functionally implicated in the onset of chromosomal instability and somatic mutational heterogeneity in pre-invasive disease, providing fuel for selection early in cancer evolution