Risk factors for recurrent wheezing in infants: a case-control study

ABSTRACT OBJECTIVE To evaluate the association between recurrent wheezing and atopy, the Asthma Predictive Index, exposure to risk factors, and total serum IgE levels as potential factors to predict recurrent wheezing. METHODS A case-control study with infants aged 6-24 months treated at a specialized outpatient clinic from November 2011 to March 2013. Evaluations included sensitivity to inhalant and food antigens, positive Asthma Predictive Index, and other risk factors for recurrent wheezing (smoking during pregnancy, presence of indoor smoke, viral infections, and total serum IgE levels). RESULTS We evaluated 113 children: 65 infants with recurrent wheezing (63.0% male) with a mean age of 14.8 (SD = 5.2) months and 48 healthy infants (44.0% male) with a mean age of 15.2 (SD = 5.1) months. In the multiple analysis model, antigen sensitivity (OR = 12.45; 95%CI 1.28–19.11), positive Asthma Predictive Index (OR = 5.57; 95%CI 2.23–7.96), and exposure to environmental smoke (OR = 2.63; 95%CI 1.09–6.30) remained as risk factors for wheezing. Eosinophilia ≥ 4.0% e total IgE ≥ 100 UI/mL were more prevalent in the wheezing group, but failed to remain in the model. Smoking during pregnancy was identified in a small number of mothers, and secondhand smoke at home was higher in the control group. CONCLUSIONS Presence of atopy, positive Asthma Predictive Index and exposure to environmental smoke are associated to recurrent wheezing. Identifying these factors enables the adoption of preventive measures, especially for children susceptible to persistent wheezing and future asthma onset

Live Leishmania promastigotes can directly activate primary human natural killer cells to produce interferon-gamma.

Natural killer (NK) cells have been implicated in the natural protection and healing of leishmaniasis by their ability to secrete the macrophage activating cytokine interferon (IFN)gamma. Previous studies have demonstrated that early production of interleukin (IL)-12 triggers IFN gamma secretion by NK cells. Here we report that live Leishmania promastigotes (the form that is injected by the vector) can directly induce human peripheral blood NK cells from healthy donors to IFN gamma secretion in the absence of IL-12 and professional antigen presenting cells. Killing of promastigotes abolishes this property. This novel mechanism of activation of the innate immune response may be relevant for establishment of infection and thus also the design of vaccines against leishmaniasis

Live Leishmania promastigotes can directly activate primary human natural killer cells to produce interferon-gamma.

Natural killer (NK) cells have been implicated in the natural protection and healing of leishmaniasis by their ability to secrete the macrophage activating cytokine interferon (IFN)gamma. Previous studies have demonstrated that early production of interleukin (IL)-12 triggers IFN gamma secretion by NK cells. Here we report that live Leishmania promastigotes (the form that is injected by the vector) can directly induce human peripheral blood NK cells from healthy donors to IFN gamma secretion in the absence of IL-12 and professional antigen presenting cells. Killing of promastigotes abolishes this property. This novel mechanism of activation of the innate immune response may be relevant for establishment of infection and thus also the design of vaccines against leishmaniasis

Peroxisome proliferator-activated receptors and retinoic acid receptors differentially control the interactions of retinoid X receptor heterodimers with ligands, coactivators, and corepressors.

As the obligate member of most nuclear receptor heterodimers, retinoid X receptors (RXRs) can potentially perform two functions: cooperative binding to hormone response elements and coordinate regulation of target genes by RXR ligands. In this paper we describe allosteric interactions between RXR and two heterodimeric partners, retinoic acid receptors (RARs) and peroxisome proliferator-activated receptors (PPARs); RARs and PPARs prevent and permit activation by RXR-specific ligands, respectively. By competing for dimerization with RXR on response elements consisting of direct-repeat half-sites spaced by 1 bp (DR1 elements), the relative abundance of RAR and PPAR determines whether the RXR signaling pathway will be functional. In contrast to RAR, which prevents the binding of RXR ligands and recruits the nuclear receptor corepressor N-CoR, PPAR permits the binding of SRC-1 in response to both RXR and PPAR ligands. Overexpression of SRC-1 markedly potentiates ligand-dependent transcription by PPARgamma, suggesting that SRC-1 serves as a coactivator in vivo. Remarkably, the ability of RAR to both block the binding of ligands to RXR and interact with corepressors requires the CoR box, a structural motif residing in the N-terminal region of the RAR ligand binding domain. Mutations in the CoR box convert RAR from a nonpermissive to a permissive partner of RXR signaling on DR1 elements. We suggest that the differential recruitment of coactivators and corepressors by RAR-RXR and PPAR-RXR heterodimers provides the basis for a transcriptional switch that may be important in controlling complex programs of gene expression, such as adipocyte differentiation

Laboratory-frame electron angular distributions: Probing the chemical environment through intramolecular electron scattering

Carbon 1s photoelectron asymmetry parameters β for the chlorinated and the methyl carbon atom of CH₃CH₂Cl, CH₃CHCl₂, and CH₃CCl₃ have been measured using synchrotron radiation in the 340-600 eV energy range. We provide experimental evidence that the intramolecular scattering strongly affects beta values, even far from the ionization threshold. The results are in agreement with B-spline density functional theory calculations, making it possible to single out the behavior of the various continuum partial waves. We conclude that the intramolecular scattering makes electron angular distributions sensitive to the chemical environment, even in isolated gas phase molecules.Keywords: Molecular orbital methods, Edge, Gaussian basis sets, Absorption fine structure, Row atoms, Photoemission, Wave functions, Potentials, 1s photoelectron spectroscopy, Photoionizatio

Nonstoichiometric Intensities in Core Photoelectron Spectroscopy

X-ray photoemission spectroscopy is used in a great variety of research fields; one observable is the sample's stoichiometry. The stoichiometry can be deduced based on the expectation that the ionization cross sections for innershell orbitals are independent of the molecular composition. Here we used chlorine-substituted ethanes in the gas phase to investigate the apparent carbon stoichiometry. We observe a nonstoichiometric ratio for a wide range of photon energies, the ratio exhibits x-ray-absorption fine structure spectroscopy (EXAFS)-like oscillations and hundreds of eV above the C1s ionization approaches a value far from 1. These effects can be accounted for by considering the scattering of the outgoing photoelectron, which we model by multiple-scattering EXAFS calculations, and by considering the effects of losses due to monopole shakeup and shakeoff and to intramolecular inelastic scattering processes.This is the publisher’s final pdf. The published article is copyrighted by American Physical Society and can be found at: http://prl.aps.org/Keywords: Absorption fine structure, Photoemissio