264 research outputs found

    Gender differences in advanced heart failure: insights from the BEST study

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    OBJECTIVES: The goal of this study was to determine the influence of gender on baseline characteristics, response to treatment, and prognosis in patients with heart failure (HF) and impaired left ventricular ejection fraction (LVEF). BACKGROUND: Under-representation of women in HF clinical trials has limited our understanding of gender-related differences in patients with HF. METHODS: The impact of gender was assessed in the Beta-Blocker Evaluation of Survival Trial (BEST) which randomized 2,708 patients with New York Heart Association class III/IV and LVEF < or =0.35 to bucindolol versus placebo. Women (n = 593) were compared with men (n = 2,115). Mean follow-up period was two years. RESULTS: Significant differences in baseline clinical and laboratory characteristics were found. Women were younger, more likely to be black, had a higher prevalence of nonischemic etiology, higher right and left ventricular ejection fraction, higher heart rate, greater cardiothoracic ratio, higher prevalence of left bundle branch block, lower prevalence of atrial fibrillation, and lower plasma norepinephrine level. Ischemic etiology and measures of severity of HF were found to be predictors of prognosis in women and men. However, differences in the predictive values of various variables were noted; most notably, coronary artery disease and LVEF appear to be stronger predictors of prognosis in women. In the nonischemic patients, women had a significantly better survival rate compared with men. CONCLUSIONS: In HF patients with impaired LVEF, significant gender differences are present, and the prognostic predictive values of some variables vary in magnitude between women and men. The survival advantage of women is confined to patients with nonischemic etiology

    In-hospital versus out-of-hospital presentation of life-threatening ventricular arrhythmias predicts survival Results from the AVID registry

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    AbstractOBJECTIVESThis study describes the outcomes of patients from the Antiarrhythmics Versus Implantable Defibrillators (AVID) Study Registry to determine how the location of ventricular arrhythmia presentation influences survival.BACKGROUNDMost studies of cardiac arrest report outcome following out-of-hospital resuscitation. In contrast, there are minimal data on long-term outcome following in-hospital cardiac arrest.METHODSThe AVID Study was a multicenter, randomized comparison of drug and defibrillator strategies to treat life-threatening ventricular arrhythmias. A Registry was maintained of all patients with sustained ventricular arrhythmias at each study site. The present study includes patients who had AVID-eligible arrhythmias, both randomized and not randomized. Patients with in-hospital and out-of-hospital presentations are compared. Data on long-term mortality were obtained through the National Death Index.RESULTSThe unadjusted mortality rates at one- and two-year follow-ups were 23% and 31.1% for patients with in-hospital presentations, and 10.5% and 16.8% for those with out-of-hospital presentations (p < 0.001), respectively. The adjusted mortality rates at one- and two-year follow-ups were 14.8% and 20.9% for patients with in-hospital presentations, and 8.4% and 14.1% for those with out-of-hospital presentations (p < 0.001), respectively. The adjusted long-term relative risk for in-hospital versus out-of-hospital presentation was 1.6 (95% confidence interval [CI] 1.3–1.9).CONCLUSIONSCompared with patients with out-of-hospital presentations of life-threatening ventricular arrhythmias not due to a reversible cause, patients with in-hospital presentations have a worse long-term prognosis. Because location of ventricular arrhythmia presentation is an independent predictor of long-term outcome, it should be considered as an element of risk stratification and when planning clinical trials

    Hormone replacement therapy is associated with improved survival in women with advanced heart failure

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    OBJECTIVES: We sought to determine whether hormone replacement therapy (HRT) is associated with an improved prognosis in women with advanced heart failure (HF) and systolic dysfunction. BACKGROUND: There are about two million postmenopausal women in the U.S. with HF. However, limited data are available to assess the effects of HRT on survival in this large group of patients. METHODS: A retrospective analysis of women age 50 years and over entered into the Beta-Blocker Evaluation of Survival Trial (BEST) was conducted using Cox regression analysis comparing survival in HRT users and non-users after correcting for baseline variables known to predict survival in women with HF and systolic dysfunction. RESULTS: In 493 women age 50 years and older, HRT was associated with a significant reduction in mortality-21% mortality in HRT users and 34% in non-users (p = 0.025). Multivariate analysis demonstrated a hazard ratio for mortality of 0.6 (95% confidence interval = 0.36 to 0.97) (p = 0.039) for HRT users. The benefits of HRT were noted only in women with a nonischemic etiology of HF (n = 237). CONCLUSIONS: Hormone replacement therapy is associated with a marked improvement in survival in postmenopausal women with advanced HF. A prospective, randomized trial of HRT should be performed in this large group of patients

    The Next Frontier: Making Research More Reproducible

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    Science and engineering rest on the concept of reproducibility. An important question for any study is: are the results reproducible? Can the results be recreated independently by other researchers or professionals? Research results need to be independently reproduced and validated before they are accepted as fact or theory. Across numerous fields like psychology, computer systems, and water resources there are problems to reproduce research results (Aarts et al. 2015; Collberg et al. 2014; Hutton et al. 2016; Stagge et al. 2019; Stodden et al. 2018). This editorial examines the challenges to reproduce research results and suggests community practices to overcome these challenges. Coordination is needed among the authors, journals, funders and institutions that produce, publish, and report research. Making research more reproducible will allow researchers, professionals, and students to more quickly understand and apply research in follow-on efforts and advance the field

    Effect of Beta-Blocker Dose on Survival After Acute Myocardial Infarction

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    Beta-blocker therapy after acute myocardial infarction (MI) improves survival. Beta-blocker doses used in clinical practice are often substantially lower than those used in the randomized trials establishing their efficacy

    β-Blocker use following myocardial infarction: Low prevalence of evidence-based dosing

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    Quality improvement programs have shown increased use of beta-blockers post-myocardial infarction(MI), but there are no data on whether appropriate doses are administered

    Control of mitochondrial pH by uncoupling protein 4 in astrocytes promotes neuronal survival.

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    Brain activity is energetically costly and requires a steady and highly regulated flow of energy equivalents between neural cells. It is believed that a substantial share of cerebral glucose, the major source of energy of the brain, will preferentially be metabolized in astrocytes via aerobic glycolysis. The aim of this study was to evaluate whether uncoupling proteins (UCPs), located in the inner membrane of mitochondria, play a role in setting up the metabolic response pattern of astrocytes. UCPs are believed to mediate the transmembrane transfer of protons, resulting in the uncoupling of oxidative phosphorylation from ATP production. UCPs are therefore potentially important regulators of energy fluxes. The main UCP isoforms expressed in the brain are UCP2, UCP4, and UCP5. We examined in particular the role of UCP4 in neuron-astrocyte metabolic coupling and measured a range of functional metabolic parameters including mitochondrial electrical potential and pH, reactive oxygen species production, NAD/NADH ratio, ATP/ADP ratio, CO2 and lactate production, and oxygen consumption rate. In brief, we found that UCP4 regulates the intramitochondrial pH of astrocytes, which acidifies as a consequence of glutamate uptake, with the main consequence of reducing efficiency of mitochondrial ATP production. The diminished ATP production is effectively compensated by enhancement of glycolysis. This nonoxidative production of energy is not associated with deleterious H2O2 production. We show that astrocytes expressing more UCP4 produced more lactate, which is used as an energy source by neurons, and had the ability to enhance neuronal survival

    Advancing Research on the Complex Interrelations Between Atrial Fibrillation and Heart Failure A Report From a US National Heart, Lung, and Blood Institute Virtual Workshop

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    The interrelationships between atrial fibrillation (AF) and heart failure (HF) are complex and poorly understood, yet the number of patients with AF and HF continues to increase worldwide. Thus, there is a need for initiatives that prioritize research on the intersection between AF and HF. This article summarizes the proceedings of a virtual workshop convened by the US National Heart, Lung, and Blood Institute to identify important research opportunities in AF and HF. Key knowledge gaps were reviewed and research priorities were proposed for characterizing the pathophysiological overlap and deleterious interactions between AF and HF; preventing HF in people with AF; preventing AF in individuals with HF; and addressing symptom burden and health status outcomes in AF and HF. These research priorities will hopefully help inform, encourage, and stimulate innovative, cost-efficient, and transformative studies to enhance the outcomes of patients with AF and HF

    Dynamic trafficking of wheat γ-gliadin and of its structural domains in tobacco cells, studied with fluorescent protein fusions

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    Prolamins, the main storage proteins of wheat seeds, are synthesized and retained in the endoplasmic reticulum (ER) of the endosperm cells, where they accumulate in protein bodies (PBs) and are then exported to the storage vacuole. The mechanisms leading to these events are unresolved. To investigate this unconventional trafficking pathway, wheat γ-gliadin and its isolated repeated N-terminal and cysteine-rich C-terminal domains were fused to fluorescent proteins and expressed in tobacco leaf epidermal cells. The results indicated that γ-gliadin and both isolated domains were able to be retained and accumulated as protein body-like structures (PBLS) in the ER, suggesting that tandem repeats are not the only sequence involved in γ-gliadin ER retention and PBLS formation. The high actin-dependent mobility of γ-gliadin PBLS is also reported, and it is demonstrated that most of them do not co-localize with Golgi body or pre-vacuolar compartment markers. Both γ-gliadin domains are found in the same PBLS when co-expressed, which is most probably due to their ability to interact with each other, as indicated by the yeast two-hybrid and FRET-FLIM experiments. Moreover, when stably expressed in BY-2 cells, green fluorescent protein (GFP) fusions to γ-gliadin and its isolated domains were retained in the ER for several days before being exported to the vacuole in a Golgi-dependent manner, and degraded, leading to the release of the GFP ‘core’. Taken together, the results show that tobacco cells are a convenient model to study the atypical wheat prolamin trafficking with fluorescent protein fusions
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