Strategic growth decisions in helper cichlids Heg, D; Bender, N; Hamilton, I
Proceedings of the Royal Society. B, Biological sciences,
12/2004, Volume:
271, Issue:
Suppl 6
Journal Article
Peer reviewed
Open access
Recently, it has been shown that group-living subordinate clownfish Amphiprion percula increase their growth rate after acquiring the dominant breeder male position in the group. Evidence was found ...for strategic growth adjustments of subordinate fishes depending on the threat of eviction, i.e. subordinates adjust their growth rates so they remain smaller than the dominant fish and thereby limit the threat of being expelled from the territory. However, it is impossible to exclude several alternative factors that potentially could have influenced the observed changes in growth, owing to the nature of that experiment (removing the second-ranking fish - the breeder male - caused the third-ranking fish to change sex to become breeder male and change rank). We studied strategic growth decisions in the group-living Lake Tanganyika cichlid Neolamprologus pulcher under controlled laboratory conditions with ad libitum food availability. First, we show that male breeders grow faster than subordinate male helpers of the same initial size and confirm that N. pulcher shows status-dependent growth. Second, we improved on the experimental design by not removing the dominant breeder male in the group; instead we replaced the breeder male with a new breeder male in a full factorial design and measured growth of the subordinate male helpers is a function of the size difference with the old and the new breeder male. As predicted, male helpers showed strategic growth adjustments, i.e. growing faster when the size difference with the breeder male is large. Strategic growth adjustments were less pronounced than status-dependent growth adjustments.
Objectives This study sought to study the efficacy and safety of newer-generation drug-eluting stents (DES) compared with bare-metal stents (BMS) in an appropriately powered population of patients ...with ST-segment elevation myocardial infarction (STEMI). Background Among patients with STEMI, early generation DES improved efficacy but not safety compared with BMS. Newer-generation DES, everolimus-eluting stents, and biolimus A9-eluting stents, have been shown to improve clinical outcomes compared with early generation DES. Methods Individual patient data for 2,665 STEMI patients enrolled in 2 large-scale randomized clinical trials comparing newer-generation DES with BMS were pooled: 1,326 patients received a newer-generation DES (everolimus-eluting stent or biolimus A9-eluting stent), whereas the remaining 1,329 patients received a BMS. Random-effects models were used to assess differences between the 2 groups for the device-oriented composite endpoint of cardiac death, target-vessel reinfarction, and target-lesion revascularization and the patient-oriented composite endpoint of all-cause death, any infarction, and any revascularization at 1 year. Results Newer-generation DES substantially reduce the risk of the device-oriented composite endpoint compared with BMS at 1 year (relative risk RR: 0.58; 95% confidence interval CI: 0.43 to 0.79; p = 0.0004). Similarly, the risk of the patient-oriented composite endpoint was lower with newer-generation DES than BMS (RR: 0.78; 95% CI: 0.63 to 0.96; p = 0.02). Differences in favor of newer-generation DES were driven by both a lower risk of repeat revascularization of the target lesion (RR: 0.33; 95% CI: 0.20 to 0.52; p < 0.0001) and a lower risk of target-vessel infarction (RR: 0.36; 95% CI: 0.14 to 0.92; p = 0.03). Newer-generation DES also reduced the risk of definite stent thrombosis (RR: 0.35; 95% CI: 0.16 to 0.75; p = 0.006) compared with BMS. Conclusions Among patients with STEMI, newer-generation DES improve safety and efficacy compared with BMS throughout 1 year. It remains to be determined whether the differences in favor of newer-generation DES are sustained during long-term follow-up.
In group-living animals, dominants may suppress subordinate reproduction directly and indirectly, thereby skewing reproduction in their favour. In this study, we show experimentally that this ability ...('power') is influenced by resource distribution and the body size difference between unrelated dominants and subordinates in the cichlid Neolamprologus pulcher. Reproduction was strongly skewed towards the dominant female, due to these females producing more and larger clutches and those clutches surviving egg eating better than those of subordinate females, but was not so when subordinates defended a patch. If breeding shelters were provided in two patches, subordinate females were more likely to exclusively defend a patch against the dominant female and breed, compared to when the same breeding resource was provided in one patch. Relatively large subordinate females were more likely to defend a patch and reproduce. Females also directly interfered with each other's reproduction by eating the competitors' eggs, at which dominants were more successful. Although dominant females benefited from subordinate females due to alloparental care and an increase in egg mass, they also showed costs due to reduced growth in the presence of subordinates. The results support the view that the dominant's power to control subordinate reproduction determines reproductive partitioning, in agreement with the predictions from tug-of-war models of reproductive skew.
Background
No data are available on the long‐term performance of ultrathin strut biodegradable polymer sirolimus‐eluting stents (BP‐SES). We reported 2‐year clinical outcomes of the BIOSCIENCE ...(Ultrathin Strut Biodegradable Polymer Sirolimus‐Eluting Stent Versus Durable Polymer Everolimus‐Eluting Stent for Percutaneous Coronary Revascularisation) trial, which compared BP‐SES with durable‐polymer everolimus‐eluting stents (DP‐EES) in patients undergoing percutaneous coronary intervention.
Methods and Results
A total of 2119 patients with minimal exclusion criteria were assigned to treatment with BP‐SES (n=1063) or DP‐EES (n=1056). Follow‐up at 2 years was available for 2048 patients (97%). The primary end point was target‐lesion failure, a composite of cardiac death, target‐vessel myocardial infarction, or clinically indicated target‐lesion revascularization. At 2 years, target‐lesion failure occurred in 107 patients (10.5%) in the BP‐SES arm and 107 patients (10.4%) in the DP‐EES arm (risk ratio RR 1.00, 95% CI 0.77–1.31, P=0.979). There were no significant differences between BP‐SES and DP‐EES with respect to cardiac death (RR 1.01, 95% CI 0.62–1.63, P=0.984), target‐vessel myocardial infarction (RR 0.91, 95% CI 0.60–1.39, P=0.669), target‐lesion revascularization (RR 1.17, 95% CI 0.81–1.71, P=0.403), and definite stent thrombosis (RR 1.38, 95% CI 0.56–3.44, P=0.485). There were 2 cases (0.2%) of definite very late stent thrombosis in the BP‐SES arm and 4 cases (0.4%) in the DP‐EES arm (P=0.423). In the prespecified subgroup of patients with ST‐segment elevation myocardial infarction, BP‐SES was associated with a lower risk of target‐lesion failure compared with DP‐EES (RR 0.48, 95% CI 0.23–0.99, P=0.043, Pinteraction=0.026).
Conclusions
Comparable safety and efficacy profiles of BP‐SES and DP‐EES were maintained throughout 2 years of follow‐up.
Clinical Trial Registration
URL: https://www.clinicaltrials.gov. Unique identifier: NCT01443104.
Structured secondary cardiovascular prevention programs (SSCP) following acute coronary syndromes (ACS) may reduce major adverse cardiovascular events (MACE) through better adherence to post-ACS ...recommendations.
Through a prospective multicenter cohort study, we compared the outcomes of two sequential post-ACS patient cohorts, the initial one receiving standard care (SC) followed by one receiving additional interventions (SSCP) aimed at improving patient education as well as healthcare provider and hospital systems. The primary endpoint was MACE at one year. Secondary endpoints included adherence to recommended therapies, attendance to cardiac rehabilitation (CR) and successful achievement of cardiovascular risk factor (CVRF) targets.
In total, 2498 post-ACS patients from 4 Swiss university hospitals were included: 1210 vs 1288 in the SC and SSCP groups, respectively. The SSCP group demonstrated a significant increase in attendance to CR programs (RR 1.08, 95%CI 1.02-1.14, P = 0.006), despite not achieving the primary MACE endpoint (HR 0.97, 95%CI 0.77-1.22, P = 0.79). After age-stratification, significant reductions in cardiac death, MI and stroke events (HR 0.53, 95%CI 0.30-0.93, P for interaction = 0.016) were observed for SSCP patients ≤ 65 years old. The SSCP group also scored significantly better for the LDL cholesterol target (RR 1.07, 95%CI 1.02-1.13, P = 0.012), systolic blood pressure target (RR 1.06, 95%CI 1.01-1.13, P = 0.029) and physical activity (RR 1.10, 95%CI 1.01-1.20, P = 0.021).
The implementation of an SSCP post ACS was associated with an improvement in the control of CVRF and attendance to CR programs, and was also associated with significant reductions in cardiac death, MI and stroke at one year for patients ≤65years old.
Background The choice of optimal drug-eluting stent therapy for patients with diabetes mellitus (DM) undergoing percutaneous coronary intervention remains uncertain. We aimed to assess the long-term ...clinical outcomes after percutaneous coronary intervention with biodegradable polymer sirolimus-eluting stents (BP-SES) versus durable polymer everolimus-eluting stents (DP-EES) in patients with DM. Methods and Results In a prespecified subgroup analysis of the BIOSCIENCE (Ultrathin Strut Biodegradable Polymer Sirolimus-Eluting Stent Versus Durable Polymer Everolimus-Eluting Stent for Percutaneous Coronary Revascularization) trial (NCT01443104), patients randomly assigned to ultrathin-strut BP-SES or thin-strut DP-EES were stratified according to diabetic status. The primary end point was target lesion failure, a composite of cardiac death, target vessel myocardial infarction, and clinically indicated target lesion revascularization, at 5 years. Among 2119 patients, 486 (22.9%) presented with DM. Compared with individuals without DM, patients with DM were older and had a greater baseline cardiac risk profile. In patients with DM, target lesion failure at 5 years occurred in 74 patients (cumulative incidence, 31.0%) treated with BP-SES and 57 patients (25.8%) treated with DP-EES (risk ratio, 1.23; 95% CI, 0.87-1.73
=0.24). In individuals without DM, target lesion failure at 5 years occurred in 124 patients (16.8%) treated with BP-SES and 132 patients (16.8%) treated with DP-EES (risk ratio, 0.98; 95% CI, 0.77-1.26
=0.90;
for interaction=0.31). Cumulative 5-year incidence rates of cardiac death, target vessel myocardial infarction, clinically indicated target lesion revascularization, and definite stent thrombosis were similar among patients with DM treated with BP-SES or DP-EES. There was no interaction between diabetic status and treatment effect of BP-SES versus DP-EES. Conclusions In a prespecified subgroup analysis of the BIOSCIENCE trial, we found no difference in clinical outcomes throughout 5 years between patients with DM treated with ultrathin-strut BP-SES or thin-strut DP-EES. Clinical Trial Registration URL: https://www.clinicaltrials.gov/. Unique identifier: NCT01443104.
Co-operative breeding in vertebrates may emerge due to subordinates delaying dispersal when free breeding habitat is not available ('habitat saturation' hypothesis, HS). However, delayed dispersal ...might also be due to younger individuals postponing dispersal to when they are more competitively able or have more to gain from breeding independently ("benefits-of-philopatry" hypothesis, BP) or to when inclusive fitness benefits no longer outweigh the benefits from independent breeding ("kin selection" hypothesis, KS). Here, we show in three experiments that both HS and BP determine the extent of co-operative breeding in the cichlid Neolamprologus pulcher. Contrary to the KS, individuals significantly avoided settlement with related individuals, and an additional settlement experiment confirmed this result. Our results suggest that kin structure in these cichlids emerges from limits on dispersal, but if such barriers are absent, cichlids prefer to settle with unrelated individuals to maximize the benefits of direct reproductive participation.
Background
The American College of Cardiology (ACC) and European Society of Cardiology/European Atherosclerosis Society (ESC/EAS) have recently published recommendations for the use of proprotein ...convertase subtilisin/kexin‐9 (PCSK9) inhibitors in situations of very high risk. We aim to assess in the real world the suitability of PCSK9 inhibitors for acute coronary syndromes.
Methods and Results
We analyzed a prospective Swiss cohort of 2023 patients hospitalized for acute coronary syndromes between 2009 and 2014 with available data for low‐density lipoprotein cholesterol and lipid‐lowering therapy at 1 year. Clinical familial hypercholesterolemia was defined using the Dutch Lipid Clinic Network algorithm as unlikely, possible, probable, or definite. We simulated a fixed relative reduction of 24% in low‐density lipoprotein cholesterol levels at 1 year in all patients not treated with ezetimibe, irrespective of the low‐density lipoprotein cholesterol levels and statin regimen. At 1 year, 94.3% of patients were treated with statin, 5.8% with ezetimibe, and 35.8% of patients had on‐target low‐density lipoprotein cholesterol levels (<1.8 mmol/L); 25.6% met criteria for possible or probable/definite familial hypercholesterolemia. After a simulation of the lipid‐lowering effect of ezetimibe, the proportion of patients who would be eligible for PCSK9 inhibitors at 1 year was 13.4% using American College of Cardiology criteria and 2.7% using European Society of Cardiology/European Atherosclerosis Society criteria. Patients with possible or probable/definite familial hypercholesterolemia were more eligible for PCSK9 inhibitors compared with their non–familial hypercholesterolemia counterparts: 27.6% versus 8.8% according to American College of Cardiology criteria and 6.6% versus 1.8% according to European Society of Cardiology/European Atherosclerosis Society criteria (P<0.001).
Conclusions
Recommendations made by the American College of Cardiology guidelines would lead to 5‐fold higher eligibility rates for PCSK9 inhibitors compared to the European Society of Cardiology/European Atherosclerosis Society consensus statement in acute coronary syndrome patients.
The comparative performance of different drug-eluting stents (DES) among female patients has not been assessed in a randomized manner.
The SPIRIT Women Clinical Evaluation trial compared the durable ...polymer everolimus-eluting XIENCE stent (DP-EES) with the durable polymer sirolimus-eluting Cypher stent (DP-SES) in women undergoing percutaneous coronary intervention (PCI).
A total of 455 female patients with stable CAD were randomly assigned to receive DP-EES (n = 304) or DP-SES (n = 151). The powered angiographic outcome of the trial was in-stent late lumen loss (LLL) at 9 months after the index procedure. Secondary angiographic end points included in-segment LLL, in-stent and in-segment binary restenosis and percent diameter stenosis. The primary clinical outcome was a composite of all-cause death, myocardial infarction (MI) or target vessel revascularization (TVR).
At 9-month follow-up, in-stent LLL was 0.19±0.38 mm and 0.11±0.37 mm in patients assigned to DP-EES and DP-SES, respectively. The one-sided upper 95% CI of the difference in in-stent LLL between the groups of 0.08 mm was 0.15 and therefore within the pre-specified non-inferiority margin of 0.17 mm (p for non-inferiority = 0.013). However, the test for superiority showed a borderline significant difference in terms of LLL between DP-EES and DP-SES (p for superiority = 0.044). There were no significant differences in binary restenosis (2.0% vs. 0.72%, p = 0.44) and percent diameter stenosis (14.97±12.17 vs. 13.36±10.82, p = 0.19). The rate of definite stent thrombosis at 12 months was lower in patients treated with DP-EES (0% vs. 2.0%, p = 0.036).
Among women undergoing PCI, DP-EES was associated with a small but probably clinically relevant increase in in-stent LLL at 9 months as compared to DP-SES and with a lower risk of definite stent thrombosis at 12 months.
ClinicalTrials.gov NCT01182428. https://clinicaltrials.gov/.
The impact of baseline renal dysfunction on early and late clinical outcomes after transcatheter aortic valve implantation (TAVI) remains to be defined.
927 patients included in the prospective Bern ...TAVI registry were classified on the basis of the baseline estimated glomerular filtration rate (eGFR), as having none or mild (eGFR ≥60mL/min/1.73m2, n=284, 30.6%), moderate (eGFR between 30 and 59mL/min/1.73m2, n=535, 57.7%) and severe (eGFR <30mL/min/1.73m2, n=108, 11.7%) renal dysfunction.
A graded relationship between stages of renal dysfunction and increasing risk profile was observed with higher STS score and lower left ventricular ejection fraction among patients with eGFR<30 (p<0.001 across groups). In patients with none or mild, moderate, and severe renal dysfunction the rate of all-cause mortality was 1.8%, 5.2% and 8.3% at 30-day and 11.0%, 15.0% and 19.5% at 1-year, respectively. After adjusting for relevant confounders, severe renal dysfunction was associated with an increased risk of cardiovascular death (adjusted Hazard Ratio, HRadj, 3.90, 95% Confidence Interval, CI 1.15–13.2) and stage 3 acute kidney injury (HRadj 5.15, 95% CI 1.72–15.5) at 30-day follow-up, however no significant association was found for clinical outcomes at 1-year follow-up. Moreover, moderate and severe renal dysfunction were found to be associated with bleeding at 1-year follow-up (HRadj, 1.36, 95% CI 1.04–1.78 and HRadj 1.49, 95% CI 1.00–2.21, respectively).
Pre-procedural renal dysfunction differentially affects early clinical outcomes, although the magnitude of this association is diluted over time by the overriding effect of underlying risk and comorbidities.
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