149 research outputs found

    Determination of total plasma hydroperoxides using a diphenyl-1- pyrenylphosphine fluorescent probe

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    Plasma hydroperoxides (HPs) are widely accepted to be good indicators of oxidative stress. By means of the method proposed here, which uses diphenyl-1-pyrenylphosphine (DPPP) as a fluorescent probe, all types of plasma HP were determined. The limits of detection and quantification of the method were 0.08 and 0.25 nmol of cumene hydroperoxide (CHP) equivalents in 40 μl of plasma, respectively. The method is satisfactory in terms of precision (5.3% for 14.5 μM CHP eq., n = 8), and the recoveries were 91% and 92% after standard additions of 26 and 52 μM CHP, respectively. The selectivity of the proposed method is higher than 96%. Moreover, optimization of the reaction conditions and the addition of ethylenediaminetetraacetic acid (EDTA) disodium salt and 2,6-di-tert-butyl-4-methylphenol (BHT) prevented the formation of HP artifacts during the analysis. Therefore, the proposed method is useful for simple and quantitative determination of total plasma HPs. © 2012 Elsevier Inc. All rights reserved.Peer Reviewe

    High-throughput analysis of lipid hydroperoxides in edible oils and fats using the fluorescent reagent diphenyl-1-pyrenylphosphine

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    A fluorometric method for the determination of hydroperoxides (HP) in edible oils and fats using the reagent diphenyl-1-pyrenylphosphine (DPPP) was developed and validated. Two solvent media containing 100% butanol or a mixture of chloroform/methanol (2:1, v/v) can be used to solubilize lipid samples. Regardless of the solvent used to solubilize the sample, the DPPP method was precise, accurate, sensitive and easy to perform. The HP content of 43 oil and fat samples was determined and the results were compared with those obtained by means of the AOCS Official Method for the determination of peroxide value (PV) and the ferrous oxidation-xylenol orange (FOX) method. The proposed method not only correlates well with the PV and FOX methods, but also presents some advantages such as requiring low sample and solvent amounts and being suitable for high-throughput sample analysis

    Noninvasive Method for a Statewide Survey of Eastern Hellbenders Cryptobranchus alleganiensis Using Environmental DNA

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    Traditional survey methods of aquatic organisms may be difficult, lengthy, and destructive to the habitat. Some methods are invasive and can be harmful to the target species. The use of environmental DNA (eDNA) has proven to be effective at detecting low population density aquatic macroorganisms. This study refined the technique to support statewide surveys. Hellbender presence was identified by using hellbender specific primers (cytochrome b gene) to detect eDNA in water samples collected at rivers, streams and creeks in Ohio and Kentucky with historical accounts of the imperiled eastern hellbender (Cryptobranchus a. alleganiensis). Two sampling protocols are described; both significantly reduced the amount of water required for collection from the previously described 6 L collection. Two-liter samples were adequate to detect hellbender presence in natural waterways where hellbenders have been previously surveyed in both Ohio and Kentucky—1 L samples were not reliable. DNA extracted from 3 L of water collected onto multiple filters (1 L/filter) could be combined and concentrated through ethanol precipitation, supporting amplification of hellbender DNA and dramatically reducing the filtration time. This method improves the efficiency and welfare implications of sampling methods for reclusive aquatic species of low population density for statewide surveys that involve collecting from multiple watersheds

    Noninvasive Method for a Statewide Survey of Eastern Hellbenders Cryptobranchus alleganiensis

    Get PDF
    Traditional survey methods of aquatic organisms may be difficult, lengthy, and destructive to the habitat. Some methods are invasive and can be harmful to the target species. The use of environmental DNA (eDNA) has proven to be effective at detecting low population density aquatic macroorganisms. This study refined the technique to support statewide surveys. Hellbender presence was identified by using hellbender specific primers (cytochrome b gene) to detect eDNA in water samples collected at rivers, streams and creeks in Ohio and Kentucky with historical accounts of the imperiled eastern hellbender (Cryptobranchus a. alleganiensis). Two sampling protocols are described; both significantly reduced the amount of water required for collection from the previously described 6 L collection. Two-liter samples were adequate to detect hellbender presence in natural waterways where hellbenders have been previously surveyed in both Ohio and Kentucky—1 L samples were not reliable. DNA extracted from 3 L of water collected onto multiple filters (1 L/filter) could be combined and concentrated through ethanol precipitation, supporting amplification of hellbender DNA and dramatically reducing the filtration time. This method improves the efficiency and welfare implications of sampling methods for reclusive aquatic species of low population density for statewide surveys that involve collecting from multiple watersheds

    Heart rate response and functional capacity in patients with chronic heart failure with preserved ejection fraction

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    Aims: The mechanisms of exercise intolerance in heart failure with preserved ejection fraction (HFpEF) are not yet elucidated. Chronotropic incompetence has emerged as a potential mechanism. We aimed to evaluate whether heart rate (HR) response to exercise is associated to functional capacity in patients with symptomatic HFpEF. Methods and results We prospectively studied 74 HFpEF patients [35.1% New York Heart Association Class III, 53% fe- male, age (mean ± standard deviation) 72.5 ± 9.1 years, and 59.5% atrial fi brillation]. Functional performance was assessed by peak oxygen consumption (peak VO 2 ). The mean (standard deviation) peak VO 2 was 10 ± 2.8 mL/min/kg. The following chronotropic parameters were calculated: Delta-HR (HR at peak exercise - HR at rest), chronotropic index (CI) = (HR at peak exercise - resting HR)/[(220 - age) - resting HR], and CI according to the equation developed by Keteyian et al . (CIK) (HR at peak exercise - HR at rest)/[119 + (HR at rest/2) (age/2) - 5 - HR at rest]. In a bivariate setting, peak VO 2 was positively and signi fi cantly correlated with Delta-HR ( r = 0.35, P = 0.003), CI ( r = 0.27, P = 0.022), CIK ( r = 0.28, P = 0.018), and borderline with HR at peak exercise ( r = 0.22, P = 0.055). In a multivariable linear regression analysis that included clinical, analytical, echocardiographic, and functional capacity covariates, the chronotropic parameters were positively associated with peak VO 2 . We found a linear relationship between Delta-HR and peak VO 2 ( β coef fi cient of 0.03; 95% con fi dence interval: 0.004 – 0.05; P = 0.030); conversely, the association among CIs and peak VO 2 was exponen- tially shaped. Conclusions In patients with chronic HFpEF, the HR response to exercise was positively associated to patient ’ s functional capacity

    Rehospitalization burden and morbidity risk in patients with heart failure with mid-range ejection fraction

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    Heart failure with mid-range ejection fraction (HFmrEF) has been proposed as a distinct HF phenotype, but whether patients on this category fare worse, similarly, or better than those with HF with reduced EF (HFrEF) or preserved EF (HFpEF) in terms of rehospitalization risks over time remains unclear. We prospectively included 2961 consecutive patients admitted for acute HF (AHF) in our institution. Of them, 158 patients died during the index admission, leaving the sample size to be 2803 patients. Patients were categorized according to their EF: HFrEF if EF ≤ 40% (n = 908, 32.4%); HFmrEF if EF = 41-49% (n = 449, 16.0%); and HFpEF if EF ≥ 50% (n = 1446, 51.6%). Covariate-adjusted incidence rate ratios (IRRs) were used to evaluate the association between EF status and recurrent all-cause and HF-related admissions. At a median follow-up of 2.6 years (inter-quartile range: 1.0-5.3), 1663 (59.3%) patients died, and 6035 all-cause readmissions were registered in 2026 patients (72.3%), 2163 of them HF related. Rates of all-cause readmission per 100 patients-years of follow-up were 150.1, 176.9, and 163.6 in HFrEF, HFmrEF, and HFpEF, respectively (P = 0.097). After multivariable adjustment, when compared with that of patients with HFrEF and HFpEF, HFmrEF status was not significantly associated with a different risk of all-cause readmissions (IRR = 0.99; 95% confidence interval [CI], 0.77-1.27; P = 0.926; and IRR = 0.93; 95% CI, 0.74-1.18; P = 0.621, respectively) or HF-related readmissions (IRR = 1.06; 95% CI, 0.77-1.46; P = 0.725; and IRR = 1.11; 95% CI, 0.82-1.50; P = 0.511, respectively). Following an admission for AHF, patients with HFmrEF had a similar rehospitalization burden and a similar risk of recurrent all-cause and HF-related admissions than had patients with HFrEF or HFpEF. Regarding morbidity risk, HFmrEF seems not to be a distinct HF phenotype

    Right Ventricular Dysfunction Staging System for Mortality Risk Stratifiction in Heart Failure with Preserved Ejection Fraction

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    Right ventricular dysfunction (RVD) parameters are increasingly important features in heart failure with preserved ejection fraction (HFpEF). We sought to evaluate the prognostic impact of a progressive RVD staging system by combining the tricuspid annular plane systolic excursion (TAPSE) to pulmonary artery systolic pressure (TAPSE/PASP) ratio with functional tricuspid regurgitation (TR) severity. We prospectively included 1355 consecutive HFpEF patients discharged for acute heart failure (HF). Of them, in 471 (34.7%) patients, PASP could not be accurately measured, leaving the final sample size to be 884 patients. Patients were categorized as Stage 1: TAPSE/PASP ≥ 0.36 without significant TR; stage 2: TAPSE/PASP ≥ 0.36 with significant TR; stage 3: TAPSE/PASP < 0.36 without significant TR; and stage 4: TAPSE/PASP < 0.36 with significant TR. By the 1 year follow-up, 207 (23.4%) patients had died. We found a significant and graded association between RVD stages and mortality rates (15.8%, 25%, 31.2%, and 45.4% from stage 1 to stage 4, respectively; log-rank test, p < 0.001). After multivariable adjustment, and compared to stage 1, stages 3 and 4 were independently associated with mortality risk (HR: 1.8219; 95% CI 1.308-2.538; p < 0.001 and HR = 2.2632; 95% CI 1.540-3.325; p < 0.001, respectively). A RVD staging system, integrating TAPSE/PASP and TR, provides a comprehensive and widely available tool for risk stratification in HFpEF

    Sex-Related Differences in Mortality Following Admission for Acute Heart Failure Across the Left Ventricular Ejection Fraction Spectrum

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    Following a heart failure (HF)-decompensation, there is scarce data about sex-related prognostic differences across left ventricular ejection fraction (LVEF) status. We sought to evaluate sex-related differences in 6-month mortality risk across LVEF following admission for acute HF. We retrospectively evaluated 4812 patients consecutively admitted for acute HF in a multicenter registry from 3 hospitals. Study end points were all-cause, cardiovascular, and HF-related mortality at 6-month follow-up. Multivariable Cox regression models were fitted to investigate sex-related differences across LVEF. A total of 2243 (46.6%) patients were women, 2569 (53.4%) were men, and 2608 (54.2%) showed LVEF≥50%. At 6-month follow-up, 645 patients died (13.4%), being 544 (11.3%) and 416 (8.6%) cardiovascular and HF-related deaths, respectively. LVEF was not independently associated with mortality (HR, 1.02; 95% CI 0.99-1.05; P =0.135). After multivariable adjustment, we found no sex-related differences in all-cause mortality (P value for interaction=0.168). However, a significant interaction between sex and cardiovascular and HF mortality risks was found across LVEF (P value for interaction=0.030 and 0.007, respectively). Compared with men, women had a significantly lower risk of cardiovascular and HF-mortality at LVEF80%). Following an admission for acute HF, no sex-related differences were found in all-cause mortality risk. However, when compared with men, women showed a lower risk of cardiovascular and HF-mortality at the lower extreme of LVEF. On the contrary, they showed a higher risk of HF death at the upper extreme

    Impact of dapagliflozin on cardiac remodelling in patients with chronic heart failure: The DAPA-MODA study.

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    AIMS Dapagliflozin improves the prognosis of patients with heart failure (HF), regardless of left ventricular ejection fraction (LVEF). However, its effect on cardiac remodelling parameters, specifically left atrial (LA) remodelling, is not well established. METHODS AND RESULTS The DAPA-MODA trial (NCT04707352) is a multicentre, single-arm, open-label, prospective and interventional study that aimed to evaluate the effect of dapagliflozin on cardiac remodelling parameters over 6 months. Patients with stable chronic HF receiving optimized guideline-directed therapy, except for any sodium-glucose cotransporter 2 inhibitor, were included. Echocardiography was performed at baseline, 30 and 180 days, and analysed by a central core-lab in a blinded manner to both patient and time. The primary endpoint was the change in maximal LA volume index (LAVI). A total of 162 patients (64.2% men, 70.5 ± 10.6 years, 52% LVEF >40%) were included in the study. At baseline, LA dilatation was observed (LAVI 48.1 ± 22.6 ml/m2 ) and LA parameters were similar between LVEF-based phenotypes (≤40% vs. >40%). LAVI showed a significant reduction at 180 days (-6.6% [95% confidence interval -11.1, -1.8], p = 0.008), primarily due to a decrease in reservoir volume (-13.8% [95% confidence interval -22.5, -4], p = 0.007). Left ventricular geometry improved with significant reductions in left ventricular mass index (-13.9% [95% confidence interval -18.7, -8.7], p < 0.001), end-diastolic volume (-8.0% [95% confidence interval -11.6, -4.2], p < 0.001) and end-systolic volume (-11.9% [95% confidence interval -16.7, -6.8], p < 0.001) at 180 days. N-terminal pro-B-type natriuretic peptide (NT-proBNP) showed a significant reduction at 180 days (-18.2% [95% confidence interval -27.1, -8.2], p < 0.001), without changes in filling Doppler measures. CONCLUSION Dapagliflozin administration in stable out-setting patients with chronic HF and optimized therapy results in global reverse remodelling of cardiac structure, including reductions in LA volumes and improvement in left ventricular geometry and NT-proBNP concentrations.This study has been sponsored by Sociedad Española de Cardiología and has received funding by a non-conditional investigational grant from AstraZeneca Farmacéutica Spain.S
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