41 research outputs found

    Resistance to oxidative stress shows low heritability and high common environmental variance in a wild bird

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    This is the author accepted manuscript. The final version is available from Wiley via the DOI in this record.Oxidative stress was recently demonstrated to affect several fitness-related traits and is now well recognized to shape animal life-history evolution. However, very little is known about how much resistance to oxidative stress is determined by genetic and environmental effects and hence about its potential for evolution, especially in wild populations. In addition, our knowledge of phenotypic sexual dimorphism and cross-sex genetic correlations in resistance to oxidative stress remains extremely limited despite important evolutionary implications. In free-living great tits (Parus major), we quantified heritability, common environmental effect, sexual dimorphism and cross-sex genetic correlation in offspring resistance to oxidative stress by performing a split-nest cross-fostering experiment where 155 broods were split, and all siblings (n = 791) translocated and raised in two other nests. Resistance to oxidative stress was measured as both oxidative damage to lipids and erythrocyte resistance to a controlled free-radical attack. Both measurements of oxidative stress showed low additive genetic variances, high common environmental effects and phenotypic sexual dimorphism with males showing a higher resistance to oxidative stress. Cross-sex genetic correlations were not different from unity, and we found no substantial heritability in resistance to oxidative stress at adult age measured on 39 individuals that recruited the subsequent year. Our study shows that individual ability to resist to oxidative stress is primarily influenced by the common environment and has a low heritability with a consequent low potential for evolution, at least at an early stage of life.This work was conducted under licence of the Ethical Committee of the Agricultural Office of the Canton Bern. Ringing permits were provided by the Swiss Federal Agency for Environment, Forests and Landscapes. The authors thank Julien Martin and Matthew Wolak for helpful advice and David Costantini and two anonymous reviewers for constructive comments on previous versions of the manuscript. The study was financially supported by the Swiss National Science Foundation. SL was supported by a Swiss NSF and a Marie Curie IEF Post-Doctoral Fellowships. JDB was supported by a Royal Society Research Fellowship. The authors have declared no conflict of interest

    Quantitative Flow Ratio to Predict Nontarget Vessel-Related Events at 5 Years in Patients With ST-Segment-Elevation Myocardial Infarction Undergoing Angiography-Guided Revascularization.

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    Background In ST-segment-elevation myocardial infarction, angiography-based complete revascularization is superior to culprit-lesion-only percutaneous coronary intervention. Quantitative flow ratio (QFR) is a novel, noninvasive, vasodilator-free method used to assess the hemodynamic significance of coronary stenoses. We aimed to investigate the incremental value of QFR over angiography in nonculprit lesions in patients with ST-segment-elevation myocardial infarction undergoing angiography-guided complete revascularization. Methods and Results This was a retrospective post hoc QFR analysis of untreated nontarget vessels (any degree of diameter stenosis [DS]) from the randomized multicenter COMFORTABLE AMI (Comparison of Biolimus Eluted From an Erodible Stent Coating With Bare Metal Stents in Acute ST-Elevation Myocardial Infarction) trial by assessors blinded for clinical outcomes. The primary end point was cardiac death, spontaneous nontarget vessel myocardial infarction, and clinically indicated nontarget vessel revascularization (ie, ≥70% DS by 2-dimensional quantitative coronary angiography or ≥50% DS and ischemia) at 5 years. Of 1161 patients with ST-segment-elevation myocardial infarction, 946 vessels in 617 patients were analyzable by QFR. At 5 years, the rate of the primary end point was significantly higher in patients with QFR ≤0.80 (n=35 patients, n=36 vessels) versus QFR >0.80 (n=582 patients, n=910 vessels) (62.9% versus 12.5%, respectively; hazard ratio [HR], 7.33 [95% CI, 4.54-11.83], P30% DS by 3-dimensional quantitative coronary angiography. Conclusions Our study suggests incremental value of QFR over angiography-guided percutaneous coronary intervention for nonculprit lesions among patients with ST-segment-elevation myocardial infarction undergoing primary percutaneous coronary intervention

    Ejaculate Economics: Testing the Effects of Male Sexual History on the Trade-Off between Sperm and Immune Function in Australian Crickets

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    Trade-offs between investment into male sexual traits and immune function provide the foundation for some of the most prominent models of sexual selection. Post-copulatory sexual selection on the male ejaculate is intense, and therefore trade-offs should occur between investment into the ejaculate and the immune system. Examples of such trade-offs exist, including that between sperm quality and immunity in the Australian cricket, Teleogryllus oceanicus. Here, we explore the dynamics of this trade-off, examining the effects that increased levels of sexual interaction have on the viability of a male's sperm across time, and the concomitant effects on immune function. Males were assigned to a treatment, whereby they cohabited with females that were sexually immature, sexually mature but incapable of copulation, or sexually mature and capable of copulation. Sperm viability of each male was then assessed at two time points: six and 13 days into the treatment, and immune function at day 13. Sperm viability decreased across the time points, but only for males exposed to treatment classes involving sexually mature females. This decrease was similar in magnitude across both sexually mature classes, indicating that costs to the expression of high sperm viability are incurred largely through levels of pre-copulatory investment. Males exposed to immature females produced sperm of low viability at both time points. Although we confirmed a weak negative association between sperm viability and lytic activity (a measure of immune response to bacterial infection) at day 13, this relationship was not altered across the mating treatment. Our results highlight that sperm viability is a labile trait, costly to produce, and subject to strategic allocation in these crickets

    Immune Activation Reduces Sperm Quality in the Great Tit

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    Mounting an immune response against pathogens incurs costs to organisms by its effects on important life-history traits, such as reproductive investment and survival. As shown recently, immune activation produces large amounts of reactive species and is suggested to induce oxidative stress. Sperm are highly susceptible to oxidative stress, which can negatively impact sperm function and ultimately male fertilizing efficiency. Here we address the question as to whether mounting an immune response affects sperm quality through the damaging effects of oxidative stress. It has been demonstrated recently in birds that carotenoid-based ornaments can be reliable signals of a male's ability to protect sperm from oxidative damage. In a full-factorial design, we immune-challenged great tit males while simultaneously increasing their vitamin E availability, and assessed the effect on sperm quality and oxidative damage. We conducted this experiment in a natural population and tested the males' response to the experimental treatment in relation to their carotenoid-based breast coloration, a condition-dependent trait. Immune activation induced a steeper decline in sperm swimming velocity, thus highlighting the potential costs of an induced immune response on sperm competitive ability and fertilizing efficiency. We found sperm oxidative damage to be negatively correlated with sperm swimming velocity. However, blood resistance to a free-radical attack (a measure of somatic antioxidant capacity) as well as plasma and sperm levels of oxidative damage (lipid peroxidation) remained unaffected, thus suggesting that the observed effect did not arise through oxidative stress. Towards the end of their breeding cycle, swimming velocity of sperm of more intensely colored males was higher, which has important implications for the evolution of mate choice and multiple mating in females because females may accrue both direct and indirect benefits by mating with males having better quality sperm

    Complex primary percutaneous coronary intervention with ultrathin-strut biodegradable versus thin-strut durable polymer drug-eluting stents in patients with ST-segment elevation myocardial infarction: A subgroup analysis from the BIOSTEMI randomized trial.

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    Ultrathin-strut biodegradable polymer sirolimus-eluting stents (BP-SES) are superior to thin-strut durable polymer everolimus-eluting stents (DP-EES) with respect to target lesion failure (TLF) at 2 years among patients with ST-segment elevation myocardial infarction (STEMI). We sought to determine the impact of primary percutaneous coronary intervention (pPCI) complexity on long-term clinical outcomes with BP-SES versus DP-EES in STEMI patients. We performed a post hoc subgroup analysis from the BIOSTEMI (NCT02579031) randomized trial, which included individual data from 407 STEMI patients enrolled in the BIOSCIENCE trial (NCT01443104). STEMI patients were randomly assigned to treatment with ultrathin-strut BP-SES or thin-strut DP-EES, and further categorized into those undergoing complex versus noncomplex pPCI. Complex pPCI was defined by the presence of ≥1 of the following criteria: 3 vessel treatment, ≥3 stents implanted, ≥3 lesions treated, bifurcation lesion with ≥2 stents implanted, total stent length ≥60 mm, and/or chronic total occlusion treatment. The primary endpoint was TLF, a composite of cardiac death, target-vessel myocardial reinfarction, or clinically indicated target lesion revascularization, within 2 years. Among a total of 1707 STEMI patients, 421 (24.7%) underwent complex pPCI. Baseline characteristics were similar between groups. At 2 years, TLF occurred in 14 patients (7.1%) treated with BP-SES and 25 patients (11.6%) treated with DP-EES (hazard ratio [HR]: 0.62; 95% confidence interval [CI]: 0.32-1.19; p = 0.15) in the complex pPCI group, and in 28 patients (4.4%) treated with BP-SES and 49 patients (8.2%) treated with DP-EES (HR: 0.54; 95% CI: 0.34-0.86; p = 0.008; p for interaction = 0.74) in the noncomplex pPCI group. Individual TLF components and stent thrombosis rates did not significantly differ between groups. In a post hoc subgroup analysis from the BIOSTEMI randomized trial, ultrathin-strut BP-SES were superior to thin-strut DP-EES with respect to TLF at 2 years among STEMI patients undergoing both complex and noncomplex pPCI

    Optimal level of inbreeding in the common lizard

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    Mate choice with regard to genetic similarity has been rarely considered as a dynamic process. We examined this possibility in breeding populations of the common lizard (Lacerta vivipara) kept for several years in semi-natural conditions. We investigated whether they displayed a pattern of mate choice according to the genetic similarity and whether it was context-dependent. Mate choice depended on genetic similarity with the partner and also on age and condition. There was no systematic avoidance of inbreeding. Females of intermediate ages, more monogamous, did not mate with genetically similar partners, whereas younger and older females, more polyandrous, did but highest clutch proportions were associated with intermediate values of pair-relatedness. These results indicate dynamic mate choice, suggesting that individuals of different phenotypes select their partners in different ways according to their genetic similarity. We consider our results in the light of diverse and apparently contradictory theories concerning genetic compatibility, and particularly, optimal inbreeding and inclusive fitness

    Validation of the Academic Research Consortium for High Bleeding Risk (ARC-HBR) criteria in patients undergoing percutaneous coronary intervention and comparison with contemporary bleeding risk scores

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    AIMS: The Academic Research Consortium for High Bleeding Risk (ARC-HBR) defined consensus-based criteria for patients at high bleeding risk (HBR) undergoing percutaneous coronary intervention (PCI). We aimed to validate the ARC-HBR criteria for the bleeding outcomes using a large cohort of patients undergoing PCI. METHODS AND RESULTS: Between 2009 and 2016, patients undergoing PCI were prospectively included in the Bern PCI Registry. Patients were considered to be at HBR if at least one major criterion or two minor criteria were met. The primary endpoint was Bleeding Academic Research Consortium (BARC) 3 or 5 bleeding at one year; ischaemic outcomes were assessed using the device-oriented composite endpoints (DOCE) of cardiac death, target vessel myocardial infarction, and target lesion revascularisation. Among 12,121 patients, those at HBR (n=4,781, 39.4%) had an increased risk of BARC 3 or 5 bleeding (6.4% vs 1.9%; p<0.001) and DOCE (12.5% vs 6.1%; p<0.001) compared with those without HBR. The degree of risk and prognostic value were related to the risk factors composing the criteria. The ARC-HBR criteria had higher sensitivity than the PRECISE-DAPT score and the PARIS bleeding risk score (63.8%, 53.1%, 31.9%), but lower specificity (62.7%, 71.3%, 86.5%) for BARC 3 or 5 bleeding. CONCLUSIONS: Patients at HBR defined by the ARC-HBR criteria had a higher risk of BARC 3 or 5 bleeding as well as DOCE. The bleeding risk was related to its individual components. The ARC-HBR criteria were more sensitive for identifying patients with future bleedings than other contemporary risk scores at the cost of specificity. ClinicalTrials.gov Identifier: NCT02241291 Visual summary. According to the ARC-HBR criteria, 40% of patients undergoing PCI were at HBR. Compared with patients without HBR, those at HBR had an increased risk of BARC 3 or 5 bleeding (6.4% vs 1.9%, p<0.001). There was a gradual risk increase for BARC 3 or 5 bleeding and DOCE as a function of the ARC-HBR score. BARC: Bleeding Academic Research Consortium; DOCE: device-oriented composite endpoints; HBR: high bleeding risk
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