1,297 research outputs found
Peripheral venous blood gases and pulse-oximetry in acute cardiogenic pulmonary oedema
Background: The role of venous blood gases as an alternative to arterial blood gases in patients with severe acute heart failure has not been established. Objective: To assess the correlation between arterial and peripheral venous blood gases together with pulse-oximetry (SpO2), as well as to estimate arterial values from venous samples in the first hours upon admission of patients with acute cardiogenic pulmonary oedema. Methods: Simultaneous venous and arterial blood samples were extracted on admission and over the next 1, 2, 3, 4, and 10 hours. SpO2 was also registered at the same intervals. Results: A total of 178 pairs of samples were obtained from 34 consecutive patients with acute cardiogenic pulmonary oedema. Arterial and venous blood gases followed a parallel course in the first hours, showing high correlation rates at all time intervals. Venous samples underestimated pH (mean difference −0.028) and overestimated CO2 (+5.1 mmHg) and bicarbonate (+1 mEq/l). Conversely, SpO2 tended to underestimate SaO2 (mean±SD: 93.1±9.1 vs. 94.2±8.4). Applying simple mathematical formulae based on these differences, arterial values were empirically calculated from venous samples, showing acceptable agreement in the Bland−Altman test. Likewise, a venous pH 51.3 mmHg, and bicarbonate <22.8 mEq/l could fairly identify arterial acidosis, either respiratory or metabolic, with a test accuracy of 92, 68, and 91%, respectively. Conclusions: In patients with cardiogenic pulmonary oedema, arterial blood gas disturbances may be estimated from peripheral venous samples. By monitoring SpO2 simultaneously, arterial punctures could often be avoide
Stellar Population gradients in galaxy discs from the CALIFA survey
While studies of gas-phase metallicity gradients in disc galaxies are common,
very little has been done in the acquisition of stellar abundance gradients in
the same regions. We present here a comparative study of the stellar
metallicity and age distributions in a sample of 62 nearly face-on, spiral
galaxies with and without bars, using data from the CALIFA survey. We measure
the slopes of the gradients and study their relation with other properties of
the galaxies. We find that the mean stellar age and metallicity gradients in
the disc are shallow and negative. Furthermore, when normalized to the
effective radius of the disc, the slope of the stellar population gradients
does not correlate with the mass or with the morphological type of the
galaxies. Contrary to this, the values of both age and metallicity at 2.5
scale-lengths correlate with the central velocity dispersion in a similar
manner to the central values of the bulges, although bulges show, on average,
older ages and higher metallicities than the discs. One of the goals of the
present paper is to test the theoretical prediction that non-linear coupling
between the bar and the spiral arms is an efficient mechanism for producing
radial migrations across significant distances within discs. The process of
radial migration should flatten the stellar metallicity gradient with time and,
therefore, we would expect flatter stellar metallicity gradients in barred
galaxies. However, we do not find any difference in the metallicity or age
gradients in galaxies with without bars. We discuss possible scenarios that can
lead to this absence of difference.Comment: 24 pages, 17 figures, accepted for publication in A&
Compromised Hippocampal Neuroplasticity in the Interferon-α and Toll-like Receptor-3 Activation-Induced Mouse Depression Model.
Disrupted neuronal plasticity due to subtle inflammation is considered to play a fundamental role in the pathogenesis of major depressive disorder. Interferon-α (IFN-α) potentiates immune responses against viral pathogens that induce toll-like receptor-3 (TLR3) activation but evokes severe major depressive disorder in humans by mechanisms that remain insufficiently described. By using a previously established mouse model of depression induced by combined delivery of IFN-α and polyinosinic:polycytidylic acid (poly(I:C)), a TLR3 agonist, we provide evidence that IFN-α and poly(I:C) reduce apical dendritic spine density in the hippocampal CA1 area ex vivo via mechanisms involving decreased TrkB signaling. In vitro, IFN-α and poly(I:C) treatments required neuronal activity to reduce dendritic spine density and TrkB signaling. The levels of presynaptic protein vesicular glutamate transporter (VGLUT)-1 and postsynaptic protein postsynaptic density-95 (PSD95) were specifically decreased, whereas the expression of both synaptic and extrasynaptic α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor 1 (AMPAR1) was increased by IFN-α and poly(I:C) delivery. Patch clamp recordings in primary hippocampal neurons revealed that morphological changes at the synapse induced by IFN-α and poly(I:C) costimulation were accompanied by an increased action potential threshold and action potential frequency, indicative of impaired neuronal excitability. Taken together, IFN-α and poly(I:C) delivery leads to structural and functional alterations at the synapse indicating that compromised neuroplasticity may play an integral role in the pathogenesis of immune response-induced depression
Boolean network model predicts cell cycle sequence of fission yeast
A Boolean network model of the cell-cycle regulatory network of fission yeast
(Schizosaccharomyces Pombe) is constructed solely on the basis of the known
biochemical interaction topology. Simulating the model in the computer,
faithfully reproduces the known sequence of regulatory activity patterns along
the cell cycle of the living cell. Contrary to existing differential equation
models, no parameters enter the model except the structure of the regulatory
circuitry. The dynamical properties of the model indicate that the biological
dynamical sequence is robustly implemented in the regulatory network, with the
biological stationary state G1 corresponding to the dominant attractor in state
space, and with the biological regulatory sequence being a strongly attractive
trajectory. Comparing the fission yeast cell-cycle model to a similar model of
the corresponding network in S. cerevisiae, a remarkable difference in
circuitry, as well as dynamics is observed. While the latter operates in a
strongly damped mode, driven by external excitation, the S. pombe network
represents an auto-excited system with external damping.Comment: 10 pages, 3 figure
New 1-aryl-3-substituted propanol derivatives as antimalarial agents
This paper describes the synthesis and in vitro antimalarial activity against a P.
falciparum 3D7 strain of some new 1-aryl-3-substituted propanol derivatives. Twelve of
the tested compounds showed an IC50 lower than 1 μM. These compounds were also tested
for cytotoxicity in murine J774 macrophages. The most active compounds were evaluated
for in vivo activity against P. berghei in a 4-day suppressive test. Compound 12 inhibited
more than 50% of parasite growth at a dose of 50 mg/kg/day. In addition, an FBIT test was
performed to measure the ability to inhibit ferriprotoporphyrin biocrystallization. This data
indicates that 1-aryl-3-substituted propanol derivatives hold promise as a new therapeutic
option for the treatment of malaria
Genomic adaptations to aquatic and aerial life in mayflies and the origin of insect wings
The evolution of winged insects revolutionized terrestrial ecosystems and led to the largest animal radiation on Earth. However, we still have an incomplete picture of the genomic changes that underlay this diversification. Mayflies, as one of the sister groups of all other winged insects, are key to understanding this radiation. Here, we describe the genome of the mayfly Cloeon dipterum and its gene expression throughout its aquatic and aerial life cycle and specific organs. We discover an expansion of odorant-binding-protein genes, some expressed specifically in breathing gills of aquatic nymphs, suggesting a novel sensory role for this organ. In contrast, flying adults use an enlarged opsin set in a sexually dimorphic manner, with some expressed only in males. Finally, we identify a set of wing-associated genes deeply conserved in the pterygote insects and find transcriptomic similarities between gills and wings, suggesting a common genetic program. Globally, this comprehensive genomic and transcriptomic study uncovers the genetic basis of key evolutionary adaptations in mayflies and winged insects
Mediterranean diet and psychological well-being intervention to reverse metabolic syndrome in Chile (CHILEMED trial)
Psychosocial status and lifestyle are key risk factors of non-communicable diseases (NCDs), which, in turn, are main drivers of healthcare costs and morbimortality worldwide, including Chile. Mediterranean diet (MedDiet) is one of the healthiest dietary patterns under study. However, its impact on high-risk conditions, such as metabolic syndrome (MetS), and NCDs outside the Mediterranean Basin remains mostly unexplored. Even though Central Chile has an environment, food production, and culinary traditions comparable to those present in Mediterranean countries, few studies -some with significant methodological limitations- have evaluated the effect of MedDiet on health and/or disease in Chilean subjects. Importantly, a Mediterranean lifestyle is a modus vivendi that integrates physical health with mental and social well-being. Psychological well-being (PWB) is associated with healthy behaviors, positive health outcomes, and longevity, thereby emerging as a novel healthcare goal. We report here an ongoing randomized controlled clinical trial in Chilean patients with MetS seeking to test whether (1) a PWB theory-based intervention facilitates induction to and increases long-term adherence to a locally adapted MedDiet, and (2) a MedDiet intervention -implemented alone or combined with well-being promotion- is more effective at reversing MetS compared to individuals following a low-fat diet without psychological support. The CHILEan MEDiterranean (CHILEMED) diet intervention study is a 1-year trial including patients with MetS living in Chile. Participants will be assigned randomly by a computer-generated random number sequence to one of the three intervention arms: a) low-fat diet as control group, b) MedDiet alone, and c) MedDiet plus well-being support. Patients will be followed-up by individual and/or group online nutritional sessions or phone cal as well as 6- and 12-month in-person re-assessment of medical history, medication use, food intake, PWB, anthropometrics/physical exam, and blood collection for laboratory analysis. The primary outcome of the trial will be the effect of the MedDiet -with or without PWB intervention- on overall reversal of MetS compared to low-fat diet alone. Based on a statistical superiority trial, expected impact, and patient loss, the estimated study sample is 339 subjects (113 individuals per arm in 3 equal-sized groups). Currently, we have enrolled 179 patients, predominantly women, evenly distributed by age (group means ranging from 45.7 to 48,9 years-old), 3/4 are obese with almost all of them showing abdominal obesity, 70% are hypertensive, whereas <10% exhibit diabetes. If findings turn out as expected (e.g., MedDiet -with or without PWB intervention- is better than the low-fat diet for reversion of MetS at 1-year follow-up), CHILEMED will provide further beneficial evidence of the MedDiet on NCD risk conditions beyond the Mediterranean region
Boolean network simulations for life scientists
Modern life sciences research increasingly relies on computational solutions, from large scale data analyses to theoretical modeling. Within the theoretical models Boolean networks occupy an increasing role as they are eminently suited at mapping biological observations and hypotheses into a mathematical formalism. The conceptual underpinnings of Boolean modeling are very accessible even without a background in quantitative sciences, yet it allows life scientists to describe and explore a wide range of surprisingly complex phenomena. In this paper we provide a clear overview of the concepts used in Boolean simulations, present a software library that can perform these simulations based on simple text inputs and give three case studies. The large scale simulations in these case studies demonstrate the Boolean paradigms and their applicability as well as the advanced features and complex use cases that our software package allows. Our software is distributed via a liberal Open Source license and is freely accessible fro
Multiwavelength studies of MHD waves in the solar chromosphere: An overview of recent results
The chromosphere is a thin layer of the solar atmosphere that bridges the
relatively cool photosphere and the intensely heated transition region and
corona. Compressible and incompressible waves propagating through the
chromosphere can supply significant amounts of energy to the interface region
and corona. In recent years an abundance of high-resolution observations from
state-of-the-art facilities have provided new and exciting ways of
disentangling the characteristics of oscillatory phenomena propagating through
the dynamic chromosphere. Coupled with rapid advancements in
magnetohydrodynamic wave theory, we are now in an ideal position to thoroughly
investigate the role waves play in supplying energy to sustain chromospheric
and coronal heating. Here, we review the recent progress made in
characterising, categorising and interpreting oscillations manifesting in the
solar chromosphere, with an impetus placed on their intrinsic energetics.Comment: 48 pages, 25 figures, accepted into Space Science Review
- …