| 1. |
- Huaraca Huasco, Walter, et al.
(author)
-
Fine root dynamics across pantropical rainforest ecosystems
- 2021
-
In: Global Change Biology. - : John Wiley & Sons. - 1354-1013 .- 1365-2486. ; 27:15, s. 3657-3680
-
Journal article (peer-reviewed)abstract
- Fine roots constitute a significant component of the net primary productivity (NPP) of forest ecosystems but are much less studied than aboveground NPP. Comparisons across sites and regions are also hampered by inconsistent methodologies, especially in tropical areas. Here, we present a novel dataset of fine root biomass, productivity, residence time, and allocation in tropical old-growth rainforest sites worldwide, measured using consistent methods, and examine how these variables are related to consistently determined soil and climatic characteristics. Our pantropical dataset spans intensive monitoring plots in lowland (wet, semi-deciduous, and deciduous) and montane tropical forests in South America, Africa, and Southeast Asia (n = 47). Large spatial variation in fine root dynamics was observed across montane and lowland forest types. In lowland forests, we found a strong positive linear relationship between fine root productivity and sand content, this relationship was even stronger when we considered the fractional allocation of total NPP to fine roots, demonstrating that understanding allocation adds explanatory power to understanding fine root productivity and total NPP. Fine root residence time was a function of multiple factors: soil sand content, soil pH, and maximum water deficit, with longest residence times in acidic, sandy, and water-stressed soils. In tropical montane forests, on the other hand, a different set of relationships prevailed, highlighting the very different nature of montane and lowland forest biomes. Root productivity was a strong positive linear function of mean annual temperature, root residence time was a strong positive function of soil nitrogen content in montane forests, and lastly decreasing soil P content increased allocation of productivity to fine roots. In contrast to the lowlands, environmental conditions were a better predictor for fine root productivity than for fractional allocation of total NPP to fine roots, suggesting that root productivity is a particularly strong driver of NPP allocation in tropical mountain regions.
|
|
| 2. |
- Mahmoodi, Bakhtawar K., et al.
(author)
-
Association of Factor V Leiden With Subsequent Atherothrombotic Events A GENIUS-CHD Study of Individual Participant Data
- 2020
-
In: Circulation. - : Ovid Technologies (Wolters Kluwer Health). - 0009-7322 .- 1524-4539. ; 142:6, s. 546-555
-
Journal article (peer-reviewed)abstract
- Background: Studies examining the role of factor V Leiden among patients at higher risk of atherothrombotic events, such as those with established coronary heart disease (CHD), are lacking. Given that coagulation is involved in the thrombus formation stage on atherosclerotic plaque rupture, we hypothesized that factor V Leiden may be a stronger risk factor for atherothrombotic events in patients with established CHD.Methods: We performed an individual-level meta-analysis including 25 prospective studies (18 cohorts, 3 case-cohorts, 4 randomized trials) from the GENIUS-CHD (Genetics of Subsequent Coronary Heart Disease) consortium involving patients with established CHD at baseline. Participating studies genotyped factor V Leiden status and shared risk estimates for the outcomes of interest using a centrally developed statistical code with harmonized definitions across studies. Cox proportional hazards regression models were used to obtain age- and sex-adjusted estimates. The obtained estimates were pooled using fixed-effect meta-analysis. The primary outcome was composite of myocardial infarction and CHD death. Secondary outcomes included any stroke, ischemic stroke, coronary revascularization, cardiovascular mortality, and all-cause mortality.Results: The studies included 69 681 individuals of whom 3190 (4.6%) were either heterozygous or homozygous (n=47) carriers of factor V Leiden. Median follow-up per study ranged from 1.0 to 10.6 years. A total of 20 studies with 61 147 participants and 6849 events contributed to analyses of the primary outcome. Factor V Leiden was not associated with the combined outcome of myocardial infarction and CHD death (hazard ratio, 1.03 [95% CI, 0.92-1.16];I-2=28%;P-heterogeneity=0.12). Subgroup analysis according to baseline characteristics or strata of traditional cardiovascular risk factors did not show relevant differences. Similarly, risk estimates for the secondary outcomes including stroke, coronary revascularization, cardiovascular mortality, and all-cause mortality were also close to identity.Conclusions: Factor V Leiden was not associated with increased risk of subsequent atherothrombotic events and mortality in high-risk participants with established and treated CHD. Routine assessment of factor V Leiden status is unlikely to improve atherothrombotic events risk stratification in this population.
|
|
| 3. |
- Malhi, Yadvinder, et al.
(author)
-
The Global Ecosystems Monitoring network : Monitoring ecosystem productivity and carbon cycling across the tropics
- 2021
-
In: Biological Conservation. - : Elsevier BV. - 0006-3207. ; 253
-
Journal article (peer-reviewed)abstract
- A rich understanding of the productivity, carbon and nutrient cycling of terrestrial ecosystems is essential in the context of understanding, modelling and managing the future response of the biosphere to global change. This need is particularly acute in tropical ecosystems, home to over 60% of global terrestrial productivity, over half of planetary biodiversity, and hotspots of anthropogenic pressure. In recent years there has been a surge of activity in collecting data on the carbon cycle, productivity, and plant functional traits of tropical ecosystems, most intensively through the Global Ecosystems Monitoring network (GEM). The GEM approach provides valuable insights by linking field-based ecosystem ecology with the needs of Earth system science. In this paper, we review and synthesize the context, history and recent scientific output from the GEM network. Key insights have emerged on the spatial and temporal variability of ecosystem productivity and on the role of temperature and drought stress on ecosystem function and resilience. New work across the network is now linking carbon cycling to nutrient cycling and plant functional traits, and subsequently to airborne remote sensing. We discuss some of the novel emerging patterns and practical and methodological challenges of this approach, and examine current and possible future directions, both within this network and as lessons for a more general terrestrial ecosystem observation scheme.
|
|
| 4. |
- Schunk, Stefan J., et al.
(author)
-
Genetically determined NLRP3 inflammasome activation associates with systemic inflammation and cardiovascular mortality
- 2021
-
In: European Heart Journal. - : Oxford University Press. - 0195-668X .- 1522-9645. ; 42:18, s. 1742-1756
-
Journal article (peer-reviewed)abstract
- AimsInflammation plays an important role in cardiovascular disease (CVD) development. The NOD-like receptor protein-3 (NLRP3) inflammasome contributes to the development of atherosclerosis in animal models. Components of the NLRP3 inflammasome pathway such as interleukin-1β can therapeutically be targeted. Associations of genetically determined inflammasome-mediated systemic inflammation with CVD and mortality in humans are unknown.Methods and resultsWe explored the association of genetic NLRP3 variants with prevalent CVD and cardiovascular mortality in 538 167 subjects on the individual participant level in an explorative gene-centric approach without performing multiple testing. Functional relevance of single-nucleotide polymorphisms on NLRP3 inflammasome activation has been evaluated in monocyte-enriched peripheral blood mononuclear cells (PBMCs). Genetic analyses identified the highly prevalent (minor allele frequency 39.9%) intronic NLRP3 variant rs10754555 to affect NLRP3 gene expression. rs10754555 carriers showed significantly higher C-reactive protein and serum amyloid A plasma levels. Carriers of the G allele showed higher NLRP3 inflammasome activation in isolated human PBMCs. In carriers of the rs10754555 variant, the prevalence of coronary artery disease was significantly higher as compared to non-carriers with a significant interaction between rs10754555 and age. Importantly, rs10754555 carriers had significantly higher risk for cardiovascular mortality during follow-up. Inflammasome inducers (e.g. urate, triglycerides, apolipoprotein C3) modulated the association between rs10754555 and mortality.ConclusionThe NLRP3 intronic variant rs10754555 is associated with increased systemic inflammation, inflammasome activation, prevalent coronary artery disease, and mortality. This study provides evidence for a substantial role of genetically driven systemic inflammation in CVD and highlights the NLRP3 inflammasome as a therapeutic target.
|
|
| 5. |
- Schillemans, Tessa, et al.
(author)
-
Associations of Polymorphisms in the Peroxisome Proliferator-Activated Receptor Gamma Coactivator-1 Alpha Gene With Subsequent Coronary Heart Disease : An Individual-Level Meta-Analysis
- 2022
-
In: Frontiers in Physiology. - : Frontiers Media S.A.. - 1664-042X. ; 13
-
Journal article (peer-reviewed)abstract
- Background: The knowledge of factors influencing disease progression in patients with established coronary heart disease (CHD) is still relatively limited. One potential pathway is related to peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PPARGC1A), a transcription factor linked to energy metabolism which may play a role in the heart function. Thus, its associations with subsequent CHD events remain unclear. We aimed to investigate the effect of three different SNPs in the PPARGC1A gene on the risk of subsequent CHD in a population with established CHD.Methods: We employed an individual-level meta-analysis using 23 studies from the GENetIcs of sUbSequent Coronary Heart Disease (GENIUS-CHD) consortium, which included participants (n = 80,900) with either acute coronary syndrome, stable CHD, or a mixture of both at baseline. Three variants in the PPARGC1A gene (rs8192678, G482S; rs7672915, intron 2; and rs3755863, T528T) were tested for their associations with subsequent events during the follow-up using a Cox proportional hazards model adjusted for age and sex. The primary outcome was subsequent CHD death or myocardial infarction (CHD death/myocardial infarction). Stratified analyses of the participant or study characteristics as well as additional analyses for secondary outcomes of specific cardiovascular disease diagnoses and all-cause death were also performed.Results: Meta-analysis revealed no significant association between any of the three variants in the PPARGC1A gene and the primary outcome of CHD death/myocardial infarction among those with established CHD at baseline: rs8192678, hazard ratio (HR): 1.01, 95% confidence interval (CI) 0.98-1.05 and rs7672915, HR: 0.97, 95% CI 0.94-1.00; rs3755863, HR: 1.02, 95% CI 0.99-1.06. Similarly, no significant associations were observed for any of the secondary outcomes. The results from stratified analyses showed null results, except for significant inverse associations between rs7672915 (intron 2) and the primary outcome among 1) individuals aged >= 65, 2) individuals with renal impairment, and 3) antiplatelet users.Conclusion: We found no clear associations between polymorphisms in the PPARGC1A gene and subsequent CHD events in patients with established CHD at baseline.
|
|
| 6. |
- Vergaro, Giuseppe, et al.
(author)
-
Cardiac biomarkers retain prognostic significance in patients with heart failure and chronic obstructive pulmonary disease
- 2021
-
In: Journal of Cardiovascular Medicine. - : Wolters Kluwer. - 1558-2027 .- 1558-2035. ; 23:1, s. 28-36
-
Journal article (peer-reviewed)abstract
- Aim: Chronic obstructive pulmonary disease (COPD) is a frequent comorbidity in patients with heart failure (HF). We assessed the influence of COPD on circulating levels and prognostic value of three HF biomarkers: N-terminal pro-B-type natriuretic peptide (NT-proBNP), high-sensitivity troponin T (hs-TnT), and soluble suppression of tumorigenesis-2 (sST2).Methods: Individual data from patients with chronic HF, known COPD status, NT-proBNP and hs-TnT values (n = 8088) were analysed. A subgroup (n = 3414) had also sST2 values.Results: Patients had a median age of 66 years (interquartile interval 57–74), 77% were men and 82% had HF with reduced ejection fraction. NT-proBNP, hs-TnT and sST2 were 1207 ng/l (487–2725), 17 ng/l (9–31) and 30 ng/ml (22–44), respectively. Patients with COPD (n = 1249, 15%) had higher NT-proBNP (P = 0.042) and hs-TnT (P < 0.001), but not sST2 (P = 0.165). Over a median 2.0-year follow-up (1.5–2.5), 1717 patients (21%) died, and 1298 (16%) died from cardiovascular causes; 2255 patients (28%) were hospitalized for HF over 1.8 years (0.9–2.1). NT-proBNP, hs-TnT and sST2 predicted the three end points regardless of COPD status. The best cut-offs from receiver-operating characteristics analysis were higher in patients with COPD than in those without. Patients with all three biomarkers higher than or equal to end-point- and COPD-status-specific cut-offs were also those with the worst prognosis.Conclusions: Among patients with HF, those with COPD have higher NT-proBNP and hs-TnT, but not sST2. All these biomarkers yield prognostic significance regardless of the COPD status.
|
|
| 7. |
- Vergaro, Giuseppe, et al.
(author)
-
Circulating levels and prognostic cut-offs of sST2, hs-cTnT, and NT-proBNP in women vs. men with chronic heart failure
- 2022
-
In: ESC Heart Failure. - : John Wiley & Sons. - 2055-5822. ; 9:4, s. 2084-2095
-
Journal article (peer-reviewed)abstract
- Aims To define plasma concentrations, determinants, and optimal prognostic cut-offs of soluble suppression of tumorigenesis-2 (sST2), high-sensitivity cardiac troponin T (hs-cTnT), and N-terminal pro-B-type natriuretic peptide (NT-proBNP) in women and men with chronic heart failure (HF). Methods and results Individual data of patients from the Biomarkers In Heart Failure Outpatient Study (BIOS) Consortium with sST2, hs-cTnT, and NT-proBNP measured were analysed. The primary endpoint was a composite of 1 year cardiovascular death and HF hospitalization. The secondary endpoints were 5 year cardiovascular and all-cause death. The cohort included 4540 patients (age 67 +/- 12 years, left ventricular ejection fraction 33 +/- 13%, 1111 women, 25%). Women showed lower sST2 (24 vs. 27 ng/mL, P < 0.001) and hs-cTnT level (15 vs. 20 ng/L, P < 0.001), and similar concentrations of NT-proBNP (1540 vs. 1505 ng/L, P = 0.408). Although the three biomarkers were confirmed as independent predictors of outcome in both sexes, the optimal prognostic cut-off was lower in women for sST2 (28 vs. 31 ng/mL) and hs-cTnT (22 vs. 25 ng/L), while NT-proBNP cut-off was higher in women (2339 ng/L vs. 2145 ng/L). The use of sex-specific cut-offs improved risk prediction compared with the use of previously standardized prognostic cut-offs and allowed to reclassify the risk of many patients, to a greater extent in women than men, and for hs-cTnT than sST2 or NT-proBNP. Specifically, up to 18% men and up to 57% women were reclassified, by using the sex-specific cut-off of hs-cTnT for the endpoint of 5 year cardiovascular death. Conclusions In patients with chronic HF, concentrations of sST2 and hs-cTnT, but not of NT-proBNP, are lower in women. Lower sST2 and hs-cTnT and higher NT-proBNP cut-offs for risk stratification could be used in women.
|
|
| 8. |
- Vergaro, Giuseppe, et al.
(author)
-
NT-proBNP for Risk Prediction in Heart Failure : Identification of Optimal Cutoffs Across Body Mass Index Categories
- 2021
-
In: JACC. Heart failure. - : American College of Cardiology. - 2213-1779 .- 2213-1787. ; 9:9, s. 653-663
-
Journal article (peer-reviewed)abstract
- ObjectivesThe goal of this study was to assess the predictive power of N-terminal pro–B-type natriuretic peptide (NT-proBNP) and the decision cutoffs in heart failure (HF) across body mass index (BMI) categories.BackgroundConcentrations of NT-proBNP predict outcome in HF. Although the influence of BMI to reduce levels of NT-proBNP is known, the impact of obesity on prognostic value remains uncertain.MethodsIndividual data from the BIOS (Biomarkers In Heart Failure Outpatient Study) consortium were analyzed. Patients with stable HF were classified as underweight (BMI <18.5 kg/m2), normal weight (BMI 18.5-24.9 kg/m2), overweight (BMI 25-29.9 kg/m2), and mildly (BMI 30-34.9 kg/m2), moderately (BMI 35-39.9 kg/m2), or severely (BMI ≥40 kg/m2) obese. The prognostic role of NT-proBNP was tested for the endpoints of all-cause and cardiac death.ResultsThe study population included 12,763 patients (mean age 66 ± 12 years; 25% women; mean left ventricular ejection fraction 33% ± 13%). Most patients were overweight (n = 5,176), followed by normal weight (n = 4,299), mildly obese (n = 2,157), moderately obese (n = 612), severely obese (n = 314), and underweight (n = 205). NT-proBNP inversely correlated with BMI (β = –0.174 for 1 kg/m2; P < 0.001). Adding NT-proBNP to clinical models improved risk prediction across BMI categories, with the exception of severely obese patients. The best cutoffs of NT-proBNP for 5-year all-cause death prediction were lower as BMI increased (3,785 ng/L, 2,193 ng/L, 1,554 ng/L, 1,045 ng/L, 755 ng/L, and 879 ng/L, for underweight, normal weight, overweight, and mildly, moderately, and severely obese patients, respectively) and were higher in women than in men.ConclusionsNT-proBNP maintains its independent prognostic value up to 40 kg/m2 BMI, and lower optimal risk-prediction cutoffs are observed in overweight and obese patients.
|
|
