bluuebunny/crossref_metadata_2025_split huggingface dataset:
Signal-Averaged Electrocardiography as a Noninvasive Tool for Evaluating the Outcomes After Radiofrequency Catheter Ablation of Ventricular Tachycardia in Patients With Ischemic Heart Disease
Authors: Dinov Borislav , Bode Kerstin , Koenig Sebastian , Oebel Sabrina , Sommer Philipp , Bollmann Andreas , Hindricks Gerhard , Arya Arash 
Published: September 2016

Background—
Inducibility of ventricular tachycardia (VT) has limited ability to predict recurrent VT after catheter ablation (CA). We sought to correlate the signal-averaged ECG (SAECG) with the endocardial scar characteristics in patients with ischemic VTs. We suggest that successful CA can result in normalization of the SAECG.

Methods and Results—

Fifty patients (42 male; aged 67±10 years, ejection fraction 34±12%) with ischemic VTs were prospectively enrolled. SAECG was performed before and after CA. Patients with at least 2 abnormal criteria (filtered QRS ≥114 ms; root mean square 40 <20 μV, and low-amplitude potentials 40 >38 ms) were defined as having positive SAECG. There was a linear correlation between endocardial scar area (<1.5 mV) and filtered QRS (
r
=0.414;
P
=0.003). CA resulted in normalization of the SAECG in 6 patients. In patients with filtered QRS ≤120 ms, 13 (40.6%) patients had normal SAECG after CA compared with 7 (21.9%) before ablation (
P
=0.034). Patients with normal or normalized SAECG after CA had better VT-free survival compared with those whose SAECG remained abnormal. Abnormal SAECG after CA was a predictor for VT recurrence: hazard ratio=3.64;
P
=0.039 for the overall population, and hazard ratio=5.80;
P
=0.022 for patients having QRS ≤120 ms.

Conclusions—
There is a significant correlation between the surface SAECG and endocardial scar size in patients with ischemic VTs. A successful CA can result in normalization of SAECG that is associated with more favorable long-term outcomes. SAECG can be useful to assess the procedural success of VT ablation.
Thoracic Epidural Anesthesia Reduces Right Ventricular Systolic Function With Maintained Ventricular-Pulmonary Coupling
Authors: Wink Jeroen , de Wilde Rob B. P. , Wouters Patrick F. , van Dorp Eveline L. A. , Veering Bernadette Th. , Versteegh Michel I. M. , Aarts Leon P. H. J. , Steendijk Paul 
Published: September 2016

Background:
Blockade of cardiac sympathetic fibers by thoracic epidural anesthesia may affect right ventricular function and interfere with the coupling between right ventricular function and right ventricular afterload. Our main objectives were to study the effects of thoracic epidural anesthesia on right ventricular function and ventricular-pulmonary coupling.

Methods:
In 10 patients scheduled for lung resection, right ventricular function and its response to increased afterload, induced by temporary, unilateral clamping of the pulmonary artery, was tested before and after induction of thoracic epidural anesthesia using combined pressure-conductance catheters.

Results:

Thoracic epidural anesthesia resulted in a significant decrease in right ventricular contractility (ΔESV
25
: +25.5 mL,
P
=0.0003; ΔEes: -0.025 mm Hg/mL,
P
=0.04). Stroke work, dP/dt
MAX
, and ejection fraction showed a similar decrease in systolic function (all
P
<0.05). A concomitant decrease in effective arterial elastance (ΔEa: -0.094 mm Hg/mL,
P
=0.004) yielded unchanged ventricular-pulmonary coupling. Cardiac output, systemic vascular resistance, and mean arterial blood pressure were unchanged. Clamping of the pulmonary artery significantly increased afterload (ΔEa: +0.226 mm Hg/mL,
P
<0.001). In response, right ventricular contractility increased (ΔESV
25
: -26.6 mL,
P
=0.0002; ΔEes: +0.034 mm Hg/mL,
P
=0.008), but ventricular-pulmonary coupling decreased (Δ(Ees/Ea) = -0.153,
P
<0.0001). None of the measured indices showed significant interactive effects, indicating that the effects of increased afterload were the same before and after thoracic epidural anesthesia.

Conclusions:
Thoracic epidural anesthesia impairs right ventricular contractility but does not inhibit the native positive inotropic response of the right ventricle to increased afterload. Right ventricular-pulmonary arterial coupling was decreased with increased afterload but not affected by the induction of thoracic epidural anesthesia.

Clinical Trial Registration:

URL:
http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=2844
. Unique identifier: NTR2844.
Quantifying the Association Between Physical Activity and Cardiovascular Disease and Diabetes: A Systematic Review and Meta‐Analysis
Authors: Wahid Ahad , Manek Nishma , Nichols Melanie , Kelly Paul , Foster Charlie , Webster Premila , Kaur Asha , Friedemann Smith Claire , Wilkins Elizabeth , Rayner Mike , Roberts Nia , Scarborough Peter 
Published: September 2016

Background

The relationships between physical activity (
PA
) and both cardiovascular disease (
CVD
) and type 2 diabetes mellitus (T2
DM
) have predominantly been estimated using categorical measures of
PA
, masking the shape of the dose‐response relationship. In this systematic review and meta‐analysis, for the very first time we are able to derive a single continuous
PA
metric to compare the association between
PA
and
CVD
/T2
DM
, both before and after adjustment for a measure of body weight.

Methods and Results

The search was applied to
MEDLINE
and
EMBASE
electronic databases for all studies published from January 1981 to March 2014. A total of 36 studies (3 439 874 participants and 179 393 events, during an average follow‐up period of 12.3 years) were included in the analysis (33 pertaining to
CVD
and 3 to T2
DM
). An increase from being inactive to achieving recommended
PA
levels (150 minutes of moderate‐intensity aerobic activity per week) was associated with lower risk of
CVD
mortality by 23%,
CVD
incidence by 17%, and T2
DM
incidence by 26% (relative risk [
RR
], 0.77 [0.71–0.84]), (
RR
, 0.83 [0.77–0.89]), and (
RR
, 0.74 [0.72–0.77]), respectively, after adjustment for body weight.

Conclusions

By using a single continuous metric for
PA
levels, we were able to make a comparison of the effect of PA on
CVD
incidence and mortality including myocardial infarct (
MI
), stroke, and heart failure, as well as T2DM. Effect sizes were generally similar for
CVD
and T2DM, and suggested that the greatest gain in health is associated with moving from inactivity to small amounts of
PA
.
Alcohol Consumption, Left Atrial Diameter, and Atrial Fibrillation
Authors: McManus David D. , Yin Xiaoyan , Gladstone Rachel , Vittinghoff Eric , Vasan Ramachandran S. , Larson Martin G. , Benjamin Emelia J. , Marcus Gregory M. 
Published: September 2016

Background

Alcohol consumption has been associated with atrial fibrillation (
AF
) in several epidemiologic studies, but the underlying mechanisms remain unknown. We sought to test the hypothesis that an atrial myopathy, manifested by echocardiographic left atrial enlargement, explains the association between chronic alcohol use and
AF
.

Methods and Results

We evaluated the relationship between cumulative alcohol consumption and risk of incident
AF
in 5220 Offspring and Original Framingham Heart Study participants (mean age 56.3 years, 54% women) with echocardiographic left atrial size measurements. The incidence of
AF
was 8.4 per 1000 person‐years, with 1088 incident
AF
cases occurring over a median 6.0 years (25th–75th percentiles 4.0–8.7 years) of follow‐up. After multivariable adjustment for potential confounders, every additional 10 g of alcohol per day (just under 1 drink per day) was associated with a 0.16 mm (95%
CI
, 0.10–0.21 mm) larger left atrial dimension. Also in multivariable adjusted analysis, every 10 g per day of alcohol consumed was associated with a 5% higher risk of developing new‐onset
AF
(hazard ratio, 1.05; 95%
CI
, 1.01–1.09). An estimated 24% (95%
CI
, 8–75) of the association between alcohol and
AF
risk was explained by left atrial enlargement.

Conclusions

Our study of a large, community‐based sample identified alcohol consumption as a predictor of left atrial enlargement and subsequent incident
AF
. Left atrial enlargement may be an intermediate phenotype along the causal pathway linking long‐term alcohol consumption to
AF
.
Bayesian Optimization of the Community Land Model Simulated Biosphere–Atmosphere Exchange using CO2 Observations from a Dense Tower Network and Aircraft Campaigns over Oregon
Authors: Schmidt Andres , Law Beverly E. , Göckede Mathias , Hanson Chad , Yang Zhenlin , Conley Stephen 
Published: September 2016

Abstract
The vast forests and natural areas of the Pacific Northwest compose one of the most productive ecosystems in the Northern Hemisphere. The heterogeneous landscape of Oregon poses a particular challenge to ecosystem models. This study presents a framework using a scaling factor Bayesian inversion to improve the modeled atmosphere–biosphere exchange of CO2. Observations from five CO/CO2 towers, eddy covariance towers, and airborne campaigns were used to constrain the Community Land Model, version 4.5 (CLM4.5), simulated terrestrial CO2 exchange at a high spatial and temporal resolution (1/24°; 3 hourly). To balance aggregation errors and the degrees of freedom in the inverse modeling system, the authors applied an unsupervised clustering approach for the spatial structuring of the model domain. Data from flight campaigns were used to quantify the uncertainty introduced by the Lagrangian particle dispersion model that was applied for the inversions. The average annual statewide net ecosystem productivity (NEP) was increased by 32% to 29.7 TgC yr−1 by assimilating the tropospheric mixing ratio data. The associated uncertainty was decreased by 28.4%–29% on average over the entire Oregon model domain with the lowest uncertainties of 11% in western Oregon. The largest differences between posterior and prior CO2 fluxes were found for the Coast Range ecoregion of Oregon that also exhibits the highest availability of atmospheric observations and associated footprints. In this area, covered by highly productive Douglas fir forest, the differences between the prior and posterior estimate of NEP averaged 3.84 TgC yr−1 during the study period from 2012 through 2014.
Estimating Snow Water Storage in North America Using CLM4, DART, and Snow Radiance Data Assimilation
Authors: Kwon Yonghwan , Yang Zong-Liang , Zhao Long , Hoar Timothy J. , Toure Ally M. , Rodell Matthew 
Published: September 2016

Abstract
This paper addresses continental-scale snow estimates in North America using a recently developed snow radiance assimilation (RA) system. A series of RA experiments with the ensemble adjustment Kalman filter are conducted by assimilating the Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR-E) brightness temperature TB at 18.7- and 36.5-GHz vertical polarization channels. The overall RA performance in estimating snow depth for North America is improved by simultaneously updating the Community Land Model, version 4 (CLM4), snow/soil states and radiative transfer model (RTM) parameters involved in predicting TB based on their correlations with the prior TB (i.e., rule-based RA), although degradations are also observed. The RA system exhibits a more mixed performance for snow cover fraction estimates. Compared to the open-loop run (0.171 m RMSE), the overall snow depth estimates are improved by 1.6% (0.168 m RMSE) in the rule-based RA whereas the default RA (without a rule) results in a degradation of 3.6% (0.177 m RMSE). Significant improvement of the snow depth estimates in the rule-based RA is observed for tundra snow class (11.5%, p &lt; 0.05) and bare soil land-cover type (13.5%, p &lt; 0.05). However, the overall improvement is not significant (p = 0.135) because snow estimates are degraded or marginally improved for other snow classes and land covers, especially the taiga snow class and forest land cover (7.1% and 7.3% degradations, respectively). The current RA system needs to be further refined to enhance snow estimates for various snow types and forested regions.
Analysis of urinary human chorionic gonadotrophin concentrations in normal and failing pregnancies using longitudinal, Cox proportional hazards and two-stage modelling
Authors: Marriott Lorrae , Zinaman Michael , Abrams Keith R , Crowther Michael J , Johnson Sarah 
Published: September 2016

Background Human chorionic gonadotrophin is a marker of early pregnancy. This study sought to determine the possibility of being able to distinguish between healthy and failing pregnancies by utilizing patient-associated risk factors and daily urinary human chorionic gonadotrophin concentrations. Methods Data were from a study that collected daily early morning urine samples from women trying to conceive (n = 1505); 250 of whom became pregnant. Data from 129 women who became pregnant (including 44 miscarriages) were included in these analyses. A longitudinal model was used to profile human chorionic gonadotrophin, a Cox proportional hazards model to assess demographic/menstrual history data on the time to failed pregnancy, and a two-stage model to combine these two models. Results The profile for log human chorionic gonadotrophin concentrations in women suffering miscarriage differs to that of viable pregnancies; rate of human chorionic gonadotrophin rise is slower in those suffering a biochemical loss (loss before six weeks, recognized by a rise and fall of human chorionic gonadotrophin) and tends to plateau at a lower log human chorionic gonadotrophin in women suffering an early miscarriage (loss six weeks or later), compared with viable pregnancies. Maternal age, longest cycle length and time from luteinizing hormone surge to human chorionic gonadotrophin reaching 25 mIU/mL were found to be significantly associated with miscarriage risk. The two-stage model found that for an increase of one day in the time from luteinizing hormone surge to human chorionic gonadotrophin reaching 25 mIU/mL, there is a 30% increase in miscarriage risk (hazard ratio: 1.30; 95% confidence interval: 1.04, 1.62). Conclusion Rise of human chorionic gonadotrophin in early pregnancy could be useful to predict pregnancy viability. Daily tracking of urinary human chorionic gonadotrophin may enable early identification of some pregnancies at risk of miscarriage.
Influence of sample preparation on MX-80 bentonite microstructure
Authors: Matusewicz M. , Pulkkanen V.-M. , Olin M. 
Published: September 2016

AbstractCompacted bentonite is to be used as a buffer material between waste canisters and the bedrock in the deep geological disposal of high-level nuclear waste in several countries. In spite of the fact that such large bentonite systems have long equilibration times, estimation of the material properties and performance in repository conditions is often based on short-term, laboratory-scale experiments. Sample-preparation procedures in these experiments may differ from the natural evolution of the bentonite in the repository, however, affecting the bentonite properties. The present study reports the influence on the structure of clay tactoids of four different preparation procedures of water-saturated, compacted MX-80 bentonite samples using four target dry bulk densities. Small-angle X-ray scattering was used to illustrate the differences between the samples. The different treatments of the bentonite samples may lead to different structural features. Clear differences between low-density samples prepared using different procedures were observed. The influence of the preparation methods was less, but still noticeable, for the high-density samples.
Anticoagulants in children and adolescents
Authors: Young Guy 
Published: September 2016

Abstract
Thrombotic complications are increasing at a steady and significant rate in children, resulting in the more widespread use of anticoagulation in this population. Anticoagulant drugs in children can be divided into the older multitargeted agents (heparin, low-molecular-weight heparin, and warfarin) and the newer targeted agents (argatroban, bivalirudin, and fondaparinux). This review will compare and contrast the multitargeted and targeted anticoagulants and suggest situations in which it may be appropriate to use argatroban, bivalirudin, and fondaparinux. The various agents differ in their pharmacokinetics, requirements for therapeutic drug monitoring, frequency of administration, efficacy, and adverse effects. The targeted anticoagulants have properties that may make them more attractive for use in specific clinical situations. Prospective clinical trial data are presented supporting the current and future use of these agents in children.
Hemolytic disease of the fetus and newborn: managing the mother, fetus, and newborn
Authors: Delaney Meghan , Matthews Dana C. 
Published: September 2016

AbstractHemolytic disease of the fetus and newborn (HDFN) affects 3/100 000 to 80/100 000 patients per year. It is due to maternal blood group antibodies that cause fetal red cell destruction and in some cases, marrow suppression. This process leads to fetal anemia, and in severe cases can progress to edema, ascites, heart failure, and death. Infants affected with HDFN can have hyperbilirubinemia in the acute phase and hyporegenerative anemia for weeks to months after birth. The diagnosis and management of pregnant women with HDFN is based on laboratory and radiographic monitoring. Fetuses with marked anemia may require intervention with intrauterine transfusion. HDFN due to RhD can be prevented by RhIg administration. Prevention for other causal blood group specificities is less studied.
Using genetic diagnostics in hemophilia and von Willebrand disease
Authors: Swystun Laura L. , James Paula 
Published: September 2016

AbstractMost bleeding disorders encountered in clinical practice will be diagnosed, at least initially, by phenotypic assays. However, since the characterization of the genes that encode coagulation factors in the 1980s, significant progress has been made in translating this knowledge for diagnostic and therapeutic purposes. For hemophilia A and B, molecular genetic testing to determine carrier status, prenatal diagnosis, and likelihood of inhibitor development or anaphylaxis to infused coagulation factor concentrates is an established component of comprehensive clinical management. In contrast, although significant recent advances in our understanding of the molecular genetic basis of von Willebrand disease (VWD) have allowed for the development of rational approaches to genetic diagnostics, questions remain about this complex genetic disorder and how to incorporate emerging knowledge into diagnostic strategies. This article will review the state-of-the-art for molecular diagnostics for both hemophilia and VWD.
The unique aspects of presentation and diagnosis of hemophagocytic lymphohistiocytosis in adults
Authors: Nikiforow Sarah , Berliner Nancy 
Published: September 2016

Abstract
Hemophagocytic lymphohistiocytosis (HLH) was initially described as an inflammatory condition affecting young children but is increasingly diagnosed in adults. Presenting features such as fever, cytopenias, phagocytosis, elevated ferritin, and increased levels of soluble IL-2 receptor are common in both age groups, but the prevalence of several clinical and biochemical criteria differ between pediatric and adult patients. Specifically, an elevated ferritin level does not have the same specificity for HLH in adults, and many other inflammatory conditions need to be considered in the differential. In contrast to the high incidence of infectious triggers seen in pediatric HLH, HLH in adults is often precipitated by a hematologic malignancy. Malignancy-associated HLH has unique manifestations and a uniformly very poor prognosis. Given these differences, diagnostic scoring systems unique to adult HLH have been proposed, and additional prognostic clinical and immunologic parameters are being explored. Although a genetic predisposition is increasingly found to underlie cases of adult-onset HLH, the mutations are less likely to be bi-allelic and differ slightly from those seen in pediatric cases of familial HLH. The facilitating genetic and environmental factors governing presentation of HLH in adults remain elusive. Understanding the clinical aspects and pathophysiology specific to adults with HLH is necessary to tailor therapies derived in pediatric disease to this under-recognized population.
Diagnosis and treatment of sideroblastic anemias: from defective heme synthesis to abnormal RNA splicing
Authors: Cazzola Mario , Malcovati Luca 
Published: September 2016

AbstractThe sideroblastic anemias are a heterogeneous group of inherited and acquired disorders characterized by the presence of ring sideroblasts in the bone marrow. X-linked sideroblastic anemia (XLSA) is caused by germline mutations in ALAS2. Hemizygous males have a hypochromic microcytic anemia, which is generally mild to moderate and is caused by defective heme synthesis and ineffective erythropoiesis. XLSA is a typical iron-loading anemia; although most patients are responsive to pyridoxine, treatment of iron overload is also important in the management of these patients. Autosomal recessive sideroblastic anemia attributable to mutations in SLC25A38, a member of the mitochondrial carrier family, is a severe disease: patients present in infancy with microcytic anemia, which soon becomes transfusion dependent. Conservative therapy includes regular red cell transfusion and iron chelation, whereas allogenic stem cell transplantation represents the only curative treatment. Refractory anemia with ring sideroblasts (RARS) is a myelodysplastic syndrome characterized mainly by anemia attributable to ineffective erythropoiesis. The clinical course of RARS is generally indolent, but there is a tendency to worsening of anemia over time, so that most patients become transfusion dependent in the long run. More than 90% of these patients carry somatic mutations in SF3B1, a gene encoding a core component of the RNA splicing machinery. These mutations cause misrecognition of 3′ splice sites in downstream genes, resulting in truncated gene products and/or decreased expression attributable to nonsense-mediated RNA decay; this explains the multifactorial pathogenesis of RARS. Variants of RARS include refractory cytopenia with multilineage dysplasia and ring sideroblasts, and RARS associated with marked thrombocytosis; these variants involve additional genetic lesions. Inhibitors of molecules of the transforming growth factor-β superfamily have been shown recently to target ineffective erythropoiesis and ameliorate anemia both in animal models of myelodysplastic syndrome and in RARS patients.