108 research outputs found

    Non-severe aortic regurgitation increases short-term mortality in acute heart failure with preserved ejection fraction.

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    Mild or moderate aortic regurgitation (AR) has only little effect on cardiovascular outcome in people with normal left ventricular ejection fraction (EF); therefore, it is not perceived as a major clinical problem. This study investigates whether mild or moderate AR is associated with increased short-term mortality in patients hospitalized for treatment of acute heart failure (AHF) and whether mild or moderate AR impacts differently on short-term mortality in AHF patients with reduced EF (AHFrEF), mid-range EF (AHFmrEF), or preserved EF (AHFpEF). This mono-centric study included 505 consecutive adult patients hospitalized for de novo or worsening chronic HF not related to acute ischaemia or severe valvular pathology in the echocardiogram at index hospitalization. Cox regression analysis studied the impact of AR on all-cause mortality (ACM) over the 150 days' study period. Mild or moderate AR was associated with increased ACM (HR 1.75 [95% CI: 1.1-2.7]; P = 0.009). The prevalence of mild or moderate AR in the study population was 42% and not significantly different between AHFpEF (n = 227), AHFmrEF (n = 86), and AHFrEF (n = 192) study participants (37.9% vs. 50.0% vs. 42.7%; P = 0.144). In AHFpEF patients, the age-adjusted hazard for ACM was increased in patients with AR compared with patients without AR (HR 2.17 [95% CI: 1.1-4.2]; P = 0.002). The age-adjusted hazard for ACM was increased by a trend in AHFmrEF with AR (HR 7.11, [95% CI: 0.9-57.8]; P = 0.067) and not different between the AHFrEF groups (HR 0.95 [95% CI: 0.5-1.8]; P = 0.875). Mild or moderate AR increased ACM only in AHFpEF patients, highlighting a distinct clinical relevance

    Already low drug dose antagonism of the renin-angiotensin aldosterone system decreases 1-year mortality and rehospitalization in old heart failure patients

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    Hospitalization for heart failure treatment (HHF) is an incisive event in the course of HF. Today, the large majority of HHF patients is ≥ 65 years and discharge HF drugs are most often not applied at dose levels acknowledged to provide prognostic benefit. This study therefore aims to investigate the treatment effect size of discharge HF drugs in old HHF patients. Drugs are analyzed according to pharmacological class. Individual discharge HF drug dose is reported as percentage of guidelines-recommended target dose. Primary endpoint was 1-year all-cause mortality (ACM) after discharge; the secondary endpoint combined 1-year ACM and first cardiovascular hospitalization within 1 year after discharge. Comparison between 65-80 years and > 80 years old study participants tested the relative treatment effect size as a function of respective age group. The 875 consecutive HHF patients had a median age of 82 years [76-87 years]; 48.6 % were females. Betablocker and diuretic treatment did not change the incidence of endpoints. Inhibition of the renin-angiotensin system (RASi), when compared to no treatment, decreased the incidence of endpoints both at the 1-25 % and the > 25 % target dose level. Antagonists of the mineralocorticoid receptor (MRA), when compared to no treatment, decreased the secondary endpoint at the 1-25 % target dose level but not at the > 25 % target dose level. The relative treatment effect size of RASi or MRA corresponded between the age strata for both endpoints. Low-dose RASi and MRA had beneficial effects in these old HHF patients

    Decongestion improving right heart function ameliorates prognosis after an acute heart failure episode.

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    The prognostic role of decongestion-related change of cardiac morphology and in particular right heart function has not been investigated comprehensively in AHF patients. This prospective observational single-centre study included consecutive patients hospitalized for treatment of AHF with reduced, mildly-reduced or preserved left ventricular ejection fraction (LVEF). Comprehensive transthoracic echocardiography at admission and discharge assessed decongestion-related change of cardiac function and morphology. The combined endpoint of 1 year all-cause mortality and cardiovascular rehospitalization explored the prognostic importance of decongestion-related change. The 176 study participants were 83 years old [74-87] and 54% were men. Fifty one (29%) had rLVEF, 65 (37%) mrLVEF, and 60 (34%) pLVEF. The proportion of de novo or worsening chronic HF was not different between LVEF groups. HF aetiology and cardiovascular risk factors were equally distributed across all groups except for a higher BMI in the pLVEF group. Decongestion equally reduced body weight, heart rate, systolic and diastolic blood pressure, tricuspid regurgitation gradient, and inferior vena cava diameter across all groups (P < 0.004 for all). Decongestion-related increase in TAPSE independent of the LVEF was associated with improvement of right-ventricular-pulmonary artery coupling and a lower incidence of the combined outcome in the Cox proportional hazard risk analysis (unadjusted HR 0.50 95% CI 0.33-0.78, P = 0.002; adjusted HR 0.46 95% CI: 0.33-0.78, P = 0.001). Decongestion-related increase in TAPSE and recovery of RV/pulmonary artery coupling was observed across all LVEF groups and associated with a risk reduction for the combined endpoint highlighting the important prognostic role of right heart recovery after an AHF episode

    DNA topoisomerases participate in fragility of the oncogene RET

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    Fragile site breakage was previously shown to result in rearrangement of the RET oncogene, resembling the rearrangements found in thyroid cancer. Common fragile sites are specific regions of the genome with a high susceptibility to DNA breakage under conditions that partially inhibit DNA replication, and often coincide with genes deleted, amplified, or rearranged in cancer. While a substantial amount of work has been performed investigating DNA repair and cell cycle checkpoint proteins vital for maintaining stability at fragile sites, little is known about the initial events leading to DNA breakage at these sites. The purpose of this study was to investigate these initial events through the detection of aphidicolin (APH)-induced DNA breakage within the RET oncogene, in which 144 APHinduced DNA breakpoints were mapped on the nucleotide level in human thyroid cells within intron 11 of RET, the breakpoint cluster region found in patients. These breakpoints were located at or near DNA topoisomerase I and/or II predicted cleavage sites, as well as at DNA secondary structural features recognized and preferentially cleaved by DNA topoisomerases I and II. Co-treatment of thyroid cells with APH and the topoisomerase catalytic inhibitors, betulinic acid and merbarone, significantly decreased APH-induced fragile site breakage within RET intron 11 and within the common fragile site FRA3B. These data demonstrate that DNA topoisomerases I and II are involved in initiating APH-induced common fragile site breakage at RET, and may engage the recognition of DNA secondary structures formed during perturbed DNA replication

    The breakthrough listen search for intelligent life: a wideband data recorder system for the Robert C. Byrd green bank telescope

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    The Breakthrough Listen Initiative is undertaking a comprehensive search for radio and optical signatures from extraterrestrial civilizations. An integral component of the project is the design and implementation of wide-bandwidth data recorder and signal processing systems. The capabilities of these systems, particularly at radio frequencies, directly determine survey speed; further, given a fixed observing time and spectral coverage, they determine sensitivity as well. Here, we detail the Breakthrough Listen wide-bandwidth data recording system deployed at the 100-m aperture Robert C. Byrd Green Bank Telescope. The system digitizes up to 6 GHz of bandwidth at 8 bits for both polarizations, storing the resultant 24 GB/s of data to disk. This system is among the highest data rate baseband recording systems in use in radio astronomy. A future system expansion will double recording capacity, to achieve a total Nyquist bandwidth of 12 GHz in two polarizations. In this paper, we present details of the system architecture, along with salient configuration and disk-write optimizations used to achieve high-throughput data capture on commodity compute servers and consumer-class hard disk drives

    Interaction of the Retinoblastoma Protein with Orc1 and Its Recruitment to Human Origins of DNA Replication

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    Background: The retinoblastoma protein (Rb) is a crucial regulator of cell cycle progression by binding with E2F transcription factor and repressing the expression of a variety of genes required for the G1-S phase transition. Methodology/Principal Findings: Here we show that Rb and E2F1 directly participate in the control of initiation of DNA replication in human HeLa, U2OS and T98G cells by specifically binding to origins of DNA replication in a cell cycle regulated manner. We show that, both in vitro and inside the cells, the largest subunit of the origin recognition complex (Orc1) specifically binds hypo-phosphorylated Rb and that this interaction is competitive with the binding of Rb to E2F1. The displacement of Rb-bound Orc1 by E2F1 at origins of DNA replication marks the progression of the G1 phase of the cell cycle toward the G1-S border. Conclusions/Significance: The participation of Rb and E2F1 in the formation of the multiprotein complex that binds origins of DNA replication in mammalian cells appears to represent an effective mechanism to couple the expression of gene

    Optimizing sparse RFI prediction using deep learning

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    Radio frequency interference (RFI) is an ever-present limiting factor among radio telescopes even in the most remote observing locations. When looking to retain the maximum amount of sensitivity and reduce contamination for Epoch of Reionization studies, the identification and removal of RFI is especially important. In addition to improved RFI identification, we must also take into account computational efficiency of the RFI-Identification algorithm as radio interferometer arrays such as the Hydrogen Epoch of Reionization Array (HERA) grow larger in number of receivers. To address this, we present a deep fully convolutional neural network (DFCN) that is comprehensive in its use of interferometric data, where both amplitude and phase information are used jointly for identifying RFI. We train the network using simulated HERA visibilities containing mock RFI, yielding a known \u2018ground truth\u2019 data set for evaluating the accuracy of various RFI algorithms. Evaluation of the DFCN model is performed on observations from the 67 dish build-out, HERA-67, and achieves a data throughput of 1.6 7 105 HERA time-ordered 1024 channelled visibilities per hour per GPU. We determine that relative to an amplitude only network including visibility phase adds important adjacent time\u2013frequency context which increases discrimination between RFI and non-RFI. The inclusion of phase when predicting achieves a recall of 0.81, precision of 0.58, and F2 score of 0.75 as applied to our HERA-67 observations
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