1,414 research outputs found
Mineralocorticoid receptor antagonism in acutely decompensated chronic heart failure
Spironolactone was likely to provide faster congestion relief.
--------------------------------------------------------------------------------
Abstract
Background/objectives
Mineralocorticoid receptor antagonist (MRA) use in acutely decompensated chronic heart failure (ADCHF) may improve congestion through diuretic effect and prevent neurohormonal activation. We aimed to evaluate the clinical effect and safety of spironolactone in ADCHF.
Methods
Prospective, experimental, single-center, and single-blinded trial. Patients were treated with: standard ADCHF therapy or oral spironolactone 50–100 mg/d plus standard ADCHF therapy.
Results
During a 1 year period, 100 patients were enrolled, 50 included in the treatment group. Mean (SD) spironolactone dose (mg) at day 1 was 94.5 ± 23.3 and at day 3 was 62.7 ± 24.3. Worsening renal function (increase in pCr ≥ 0.3 mg/dL from day 1 to day 3) was more likely to occur in control group (20% vs. 4%; p = 0.038), serum potassium did not differ between groups, and plasma NTproBNP had a significant decrease in spironolactone group at day 3 (median [IQR], 2488 [4579] vs. 1555 [1832]; p = 0.05). Furthermore, a greater proportion of patients in the treatment group were free of congestion at day 3: less edema, rales, jugular venous pressure (JVP) and orthopnea (all, p < 0.05). In addition, a significantly higher proportion of patients were on oral furosemide at day 3 (44% vs. 82%; p < 0.001).
Conclusions
Our study supports the safety of high dose spironolactone in ADCHF and suggests a positive impact in the resolution of congestion. The important findings of our pilot study need to be confirmed in larger trials
IL-6 and TNF-alpha polymorphisms in portuguese psoriatic patients
Introduction: Cytokines regulate the growth, function and differentiation of cells and help to steer immune response and inflammation. In this study we focused our attention in two proinflammatory cytokines: IL-6 and TNFa. It is known that their overexpression is responsible for initiation, maintenance and recurrence of skin lesions in psoriatic patients. Therefore, it is important to investigate genetic biomarkers with functional effects in the genes of those cytokines that could help to predict the severity of Psoriasis.
Objectives: To investigate the hypothesis that allelic variants in IL-6 and TNF-a genes are a risk factor for the developing of severe Psoriasis.
Materials and Methods: A cohort of 178 (74 females, 104 males) psoriatic patients with severe plaque type psoriasis [according to the Psoriasis Area and Severity Index (PASI)] and 206 healthy individuals were selected. Several polymorphisms in the IL-6 gene (rs1800795, rs1800796, rs2069827, rs2069840) and TNF-a (rs361525, rs1799964, rs1800629) promoter region were genotyped. SNP genotyping was performed using Mass Spectrometry (MassARRAY iPLEX–Sequenom).
Results: We observed a lower frequency in the minor allele (C) of the TNFa rs1799964 SNP in psoriatic patients, compared with controls [(21.9% vs. 29.4%), p = 0.02, OR = 0.675 (0.49–0.94)]. The frequency of the CC genotype in patients was 3.93% while in the healthy control group it was 9.22% [(p = 0.04, OR = 0.403 (0.17–0.98)]. No statistical significant differences were found in the other polymorphisms.
Conclusion: Our data suggest that the rs1799964 C allele could be a protective factor for developing severe psoriasis. These results were similar to the findings of Gallo et al (2012) in a Spanish population. The mechanism to explain this association remains elusive, given the lack of evidence of a functional association
The Tensor to Scalar Ratio of Phantom Dark Energy Models
We investigate the anisotropies in the cosmic microwave background in a class
of models which possess a positive cosmic energy density but negative pressure,
with a constant equation of state w = p/rho < -1. We calculate the temperature
and polarization anisotropy spectra for both scalar and tensor perturbations by
modifying the publicly available code CMBfast. For a constant initial curvature
perturbation or tensor normalization, we have calculated the final anisotropy
spectra as a function of the dark energy density and equation of state w and of
the scalar and tensor spectral indices. This allows us to calculate the
dependence of the tensor-to-scalar ratio on w in a model with phantom dark
energy, which may be important for interpreting any future detection of
long-wavelength gravitational waves.Comment: 5 pages, 4 figure
Qualitative Properties of Magnetic Fields in Scalar Field Cosmology
We study the qualitative properties of the class of spatially homogeneous
Bianchi VI_o cosmological models containing a perfect fluid with a linear
equation of state, a scalar field with an exponential potential and a uniform
cosmic magnetic field, using dynamical systems techniques. We find that all
models evolve away from an expanding massless scalar field model in which the
matter and the magnetic field are negligible dynamically. We also find that for
a particular range of parameter values the models evolve towards the usual
power-law inflationary model (with no magnetic field) and, furthermore, we
conclude that inflation is not fundamentally affected by the presence of a
uniform primordial magnetic field. We investigate the physical properties of
the Bianchi I magnetic field models in some detail.Comment: 12 pages, 2 figures in REVTeX format. to appear in Phys. Rev.
Sorogrupos e genes de virulĂŞncia em Escherichia coli isoladas de psitacĂdeos
Escherichia coli isolates from 24 sick psittacine birds were serogrouped and investigated for the presence of genes encoding the following virulence factors: attaching and effacing (eae), enteropathogenic E. coli EAF plasmid (EAF), pili associated with pyelonephritis (pap), S fimbriae (sfa), afimbrial adhesin (afa), capsule K1 (neu), curli (crl, csgA), temperature-sensitive hemagglutinin (tsh), enteroaggregative heat-stable enterotoxin-1 (astA), heat-stable enterotoxin -1 heat labile (LT) and heat stable (STa and STb) enterotoxins, Shiga-like toxins (stx1 and stx2), cytotoxic necrotizing factor 1 (cnf1), haemolysin (hly), aerobactin production (iuc) and serum resistance (iss). The results showed that the isolates belonged to 12 serogroups: O7; O15; O21; O23; O54; O64; O76; O84; O88; O128; O152 and O166. The virulence genes found were: crl in all isolates, pap in 10 isolates, iss in seven isolates, csgA in five isolates, iuc and tsh in three isolates and eae in two isolates. The combination of virulence genes revealed 11 different genotypic patterns. All strains were negative for genes encoding for EAF, EAEC, K1, sfa, afa, hly, cnf, LT, STa, STb, stx1 and stx2. Our findings showed that some E. coli isolated from psittacine birds present the same virulence factors as avian pathogenic E. coli (APEC), uropathogenic E. coli (UPEC) and Enteropathogenic E. coli (EPEC) pathotypes.Amostras de Escherichia coli isoladas de 24 psitacĂdeos doentes foram sorogrupadas e investigadas para a presença de genes que codificam os seguintes fatores de virulĂŞncia: attaching e effacing (eae), plasmĂdeo EAF (EAF), pili associado Ă pielonefrite (pap), fĂmbria S (sfa), adesina afimbrial (afa), cápsula K1 (neu), curli (crl, csgA), hemaglutinina termosensĂvel (tsh), enterotoxina termo-estável 1 de E. coli enteroagregativa (astA), toxina termolábil (LT) e toxina termoestável (STa e STb), Shiga-like toxinas (stx1 e stx2), fator citotĂłxico necrotizante 1 (cnf1), hemolisina (hly), produção de aerobactina (iuc) e resistĂŞncia sĂ©rica (iss). Os resultados mostraram que os isolados pertenciam a 12 sorogrupos: O7; O15; O21; O23; O54; O64; O76; O84; O88; O128; O152 e O166. Os genes de virulĂŞncia encontrados foram: crl em todos os isolados, pap em 10 isolados, iss em sete isolados, csgA em cinco isolados, iuc e tsh em trĂŞs isolados e eae em dois isolados. A combinação dos genes de virulĂŞncia revelou 11 perfis genotĂpicos distintos. Todas as amostras foram negativas para os genes que codificam EAF, EAEC, K1, sfa, afa, hly, cnf, LT, STa, STb, stx1 e stx2. Estes resultados demonstraram que algumas amostras de E. coli isoladas de psitacĂdeos apresentam os mesmos fatores de virulĂŞncia presentes nos patotipos de E. coli patogĂŞnicas para aves (APEC), uropatogĂŞnicas (UPEC) e E. coli enteropatogĂŞnicas (EPEC).916921Fundação de Amparo Ă Pesquisa do Estado de SĂŁo Paulo (FAPESP
Interatomic potentials for atomistic simulations of the Ti-Al system
Semi-empirical interatomic potentials have been developed for Al, alpha-Ti,
and gamma-TiAl within the embedded atomic method (EAM) by fitting to a large
database of experimental as well as ab-initio data. The ab-initio calculations
were performed by the linear augmented plane wave (LAPW) method within the
density functional theory to obtain the equations of state for a number of
crystal structures of the Ti-Al system. Some of the calculated LAPW energies
were used for fitting the potentials while others for examining their quality.
The potentials correctly predict the equilibrium crystal structures of the
phases and accurately reproduce their basic lattice properties. The potentials
are applied to calculate the energies of point defects, surfaces, planar faults
in the equilibrium structures. Unlike earlier EAM potentials for the Ti-Al
system, the proposed potentials provide reasonable description of the lattice
thermal expansion, demonstrating their usefulness in the molecular dynamics or
Monte Carlo studies at high temperatures. The energy along the tetragonal
deformation path (Bain transformation) in gamma-TiAl calculated with the EAM
potential is in a fairly good agreement with LAPW calculations. Equilibrium
point defect concentrations in gamma-TiAl are studied using the EAM potential.
It is found that antisite defects strongly dominate over vacancies at all
compositions around stoichiometry, indicating that gamm-TiAl is an antisite
disorder compound in agreement with experimental data.Comment: 46 pages, 6 figures (Physical Review B, in press
Perturbation evolution with a non-minimally coupled scalar field
We recently proposed a simple dilaton-derived quintessence model in which the
scalar field was non-minimally coupled to cold dark matter, but not to
`visible' matter. Such couplings can be attributed to the dilaton in the low
energy limit of string theory, beyond tree level. In this paper we discuss the
implications of such a model on structure formation, looking at its impact on
matter perturbations and CMB anisotropies. We find that the model only deviates
from CDM and minimally coupled theories at late times, and is well
fitted to current observational data. The signature left by the coupling, when
it breaks degeneracy at late times, presents a valuable opportunity to
constrain non-minimal couplings given the wealth of new observational data
promised in the near future.Comment: Version appearing in Physical Review D. 10 pages, 9 figs. Comparison
with SN1a and projected MAP results, and appendix adde
Insulator-Superfluid transition of spin-1 bosons in an optical lattice in magnetic field
We study the insulator-superfluid transition of spin-1 bosons in an optical
lattice in a uniform magnetic field. Based on a mean-field approximation we
obtained a zero-temperature phase diagram. We found that depending on the
particle number the transition for bosons with antiferromagnetic interaction
may occur into different superfluid phases with spins aligned along or opposite
to the field direction. This is qualitatively different from the field-free
transition for which the mean-field theory predicts a unique (polar) superfluid
state for any particle number.Comment: 10 pages, 2 eps figure
Accurate Atmospheric Parameters at Moderate Resolution Using Spectral Indices: Preliminary Application to the MARVELS Survey
Studies of Galactic chemical and dynamical evolution in the solar
neighborhood depend on the availability of precise atmospheric parameters
(Teff, [Fe/H] and log g) for solar-type stars. Many large-scale spectroscopic
surveys operate at low to moderate spectral resolution for efficiency in
observing large samples, which makes the stellar characterization difficult due
to the high degree of blending of spectral features. While most surveys use
spectral synthesis, in this work we employ an alternative method based on
spectral indices to determine the atmospheric parameters of a sample of nearby
FGK dwarfs and subgiants observed by the MARVELS survey at moderate resolving
power (R~12,000). We have developed three codes to automatically normalize the
observed spectra, measure the equivalent widths of the indices and, through the
comparison of those with values calculated with pre-determined calibrations,
derive the atmospheric parameters of the stars. The calibrations were built
using a sample of 309 stars with precise stellar parameters obtained from the
analysis of high-resolution FEROS spectra. A validation test of the method was
conducted with a sample of 30 MARVELS targets that also have reliable
atmospheric parameters from high-resolution spectroscopic analysis. Our
approach was able to recover the parameters within 80 K for Teff, 0.05 dex for
[Fe/H] and 0.15 dex for log g, values that are lower or equal to the typical
external uncertainties found between different high-resolution analyzes. An
additional test was performed with a subsample of 138 stars from the ELODIE
stellar library and the literature atmospheric parameters were recovered within
125 K for Teff, 0.10 dex for [Fe/H] and 0.29 dex for log g. These results show
that the spectral indices are a competitive tool to characterize stars with the
intermediate resolution spectra.Comment: Accepted for publication in AJ. Abstract edited to comply with arXiv
standards regarding the number of character
- …