243 research outputs found
Quantification of gliadin levels to the picogram level by flow cytometry
Celiac disease is a widely prevalent enteropathy caused by intolerance to gliadin, one of the gluten proteins. We developed two methods for the analysis of gliadin levels. Both methods use flow cytometry and rat antibodies against a 16-residue peptide of gliadin. The peptide is common to the alpha-, beta-, gamma-, and omega-gliadins
The dark halo of the Hydra I galaxy cluster: core, cusp, cosmological? Dynamics of NGC 3311 and its globular cluster system
NGC 3311 is the central cD galaxy of the Hydra I cluster. We use globular
clusters around NGC 3311, combined with kinematical data of the galaxy itself,
to investigate the dark matter distribution in the central region of Hydra I.
Radial velocities of 118 bright globular clusters, based on VLT/VIMOS mask
spectroscopy, are used to calculate velocity dispersions which are well defined
out to 100 kpc. NGC 3311 is the most distant galaxy for which this kind of
study has been performed. We also determine velocity dispersions of the stellar
component from long slit spectroscopy out to 20 kpc. Moreover, we present a new
photometric model for NGC 3311 in the V-band. We search for a dark halo which
in the context of a spherical Jeans model. We also compare the radial velocity
distributions of globular clusters and planetary nebulae. The projected stellar
velocity dispersion rises from 185 km/s to 350 km/s at a radius of 20 kpc. The
globular cluster dispersion rises as well from 500 km/s at 10 kpc to about 800
km/s at 100 kpc, comparable to the velocity dispersion of the cluster galaxies.
A dark matter halo with a core reproduces well the velocity dispersions of
stars and globular clusters simultaneously under isotropy. The central stellar
velocity dispersions predicted by cosmological NFW halos are less good
representations, while the globular clusters allow a wide range of halo
parameters. A suspected radial anisotropy of the stellar population aggravates
the deviations. However, we find discrepancies with previous kinematical data,
which we cannot resolve and may indicate a more complicated velocity pattern.
Although one cannot conclusively demonstrate that the dark matter halo of NGC
3311 has a core rather than a cusp, a core seems to be preferred by the present
data. A more complete velocity field and an analysis of the anisotropy is
required to reach firm conclusions.Comment: 8 pages, 5 figures, abstract abridged, accepted for publication in
A&
Splenic B1 B Cells Acquire a Proliferative and Anti-Inflamatory Profile During Pregnancy in Mice
B cells are a heterogeneous cell population with differential ontogeny, anatomical location, and functions. B1 B cells are a distinct subpopulation characterized by their unique capacity of self-renewal, the production of large quantities of IL-10, and the ability to secrete protective, anti-inflammatory natural antibodies (NAbs), presumably upon down-regulation of CD1d expression. Although natural antibodies are thought to be protective, due to their polyreactivity, their participation in certain autoimmune diseases has been suggested. In the context of pregnancy, the role of B1 B cells has been discussed controversially. While in human pregnancies B1 B cells and natural/polyreactive antibodies they produce are involved in the development of preeclampsia, in mice they promote healthy gestation and fetal protection. In this work, we aimed to functionally characterize the splenic B1 B cell population during pregnancy in mice. Functional enrichment analysis using only up-regulated transcripts from a transcriptomic profile performed on total splenic B cells from pregnant compared to non-pregnant mice showed augmented cell cycle and DNA replication pathways. Proliferation studies by flow cytometry showed augmented Ki-67 proliferation marker expression and percentages of B1 B cells. Furthermore, B1 B cells produced higher levels of IL-10 and lower levels of TNF-α leading to an increased IL-10/TNF-α ratio and showing an immunoregulatory phenotype. Finally, we observed lower expression of CD1d on B1 B cells, suggesting a higher capacity to produce NAbs in the context of pregnancy. In summary, our results showed not only an expanded and proliferative splenic B1 B cell population during pregnancy but also the acquisition of immunomodulatory capacities suggesting its critical role in the intricate process of pregnancy tolerance
Diversity and technological potential of lactic acid bacteria of wheat flours
Lactic acid bacteria (LAB) were analysed from wheat flours used in traditional bread making throughout
Sicily (southern Italy). Plate counts, carried out in three different media commonly used to detect food
and sourdough LAB, revealed a maximal LAB concentration of approximately 4.75 Log CFU g 1. Colonies
representing various morphological appearances were isolated and differentiated based on phenotypic
characteristics and genetic analysis by randomly amplified polymorphic DNA (RAPD)-PCR. Fifty unique
strains were identified. Analysis by 16S rRNA gene sequencing grouped the strains into 11 LAB species,
which belonged to six genera: Enterococcus, Lactobacillus, Lactococcus, Leuconostoc, Pediococcus and
Weissella. Weissella cibaria, Lactobacillus plantarum, Leuconostoc pseudomesenteroides and Leuconostoc
citreum were the most prevalent species. The strains were not geographically related. Denaturing
gradient gel electrophoresis (DGGE) analysis of total DNA of flour was used to provide a more complete
understanding of the LAB population; it confirmed the presence of species identified with the culturedependent
approach, but did not reveal the presence of any additional LAB species. Finally, the technological
characteristics (acidifying capacity, antimicrobial production, proteolytic activity, organic acid,
and volatile organic compound generation) of the 50 LAB strains were investigated. Eleven strains were
selected for future in situ applications
Substructure and Scatter in the Mass-Temperature Relations of Simulated Clusters
Galaxy clusters exhibit regular scaling relations among their bulk
properties. These relations establish vital links between halo mass and cluster
observables. Precision cosmology studies that depend on these links benefit
from a better understanding of scatter in the mass-observable scaling
relations. Here we study the role of merger processes in introducing scatter
into the - relation, using a sample of 121 galaxy clusters
simulated with radiative cooling and supernova feedback, along with three
statistics previously proposed to measure X-ray surface brightness
substructure. These are the centroid variation (), the axial ratio (),
and the power ratios ( and ). We find that in this set of
simulated clusters, each substructure measure is correlated with a cluster's
departures and from the mean - relation, both for emission-weighted temperatures and for
spectroscopic-like temperatures , in the sense that clusters with
more substructure tend to be cooler at a given halo mass. In all cases, a
three-parameter fit to the - relation that includes substructure
information has less scatter than a two-parameter fit to the basic - relation.Comment: Accepted by ApJ, 10 pages, 10 figure
Redox regulation of cellular stress response in multiple sclerosis
Multiple sclerosis (MS) is an autoimmune-mediated neurodegenerative disease with characteristic foci of inflammatory demyelination in the brain, spinal cord, and optic nerves. Recent studies have demonstrated not only that axonal damage and neuronal loss are significant pathologic components of MS, but that this neuronal damage is thought to cause the permanent neurologic disability often seen in MS patients. Emerging finding suggests that altered redox homeostasis and increased oxidative stress, primarily implicated in the pathogenesis of MS, are a trigger for activation of a brain stress response. Relevant to maintenance of redox homeostasis, integrated mechanisms controlled by vitagenes operate in brain in preserving neuronal survival during stressful conditions. Vitagenes encode for heat shock proteins (Hsp) Hsp32, Hsp70, the thioredoxin and the sirtuin protein systems. In the present study we assess stress response mechanisms in the CSF, plasma and lymphocytes of control patients compared to MS patients. We found that the levels of vitagenes Hsp72, Hsc70, HO-1, as well as oxidative stress markers carbonyls and hydroxynonenals were significantly higher in the blood and CSF of MS patients than in control patients. In addition, an increased expression of Trx and sirtuin 1, together with a decrease in the expression of TrxR were observed. Our data strongly support a pivotal role for redox homeostasis disruption in the pathogenesis of MS and, consistently with the notion that new therapies that prevent neurodegeneration through nonimmunomodulatory mechanisms can have a tremendous potential to work synergistically with current MS therapies, unravel important targets for new cytoprotective strategies
A guanosine 5′-triphosphate-dependent protein kinase is localized in the outer envelope membrane of pea chloroplasts
A guanosine 5-triphosphate (GTP)-dependent protein kinase was detected in preparations of outer chloroplast envelope membranes of pea (Pisum sativum L.) chloroplasts. The protein-kinase activity was capable of phosphorylating several envelope-membrane proteins. The major phosphorylated products were 23- and 32.5-kilo-dalton proteins of the outer envelope membrane. Several other envelope proteins were labeled to a lesser extent. Following acid hydrolysis of the labeled proteins, most of the label was detected as phosphoserine with only minor amounts detected as phosphothreonine. Several criteria were used to distinguish the GTP-dependent protein kinase from an ATP-dependent kinase also present in the outer envelope membrane. The ATP-dependent kinase phosphorylated a very different set of envelope-membrane proteins. Heparin inhibited the GTP-dependent kinase but had little effect upon the ATP-dependent enzyme. The GTP-dependent enzyme accepted phosvitin as an external protein substrate whereas the ATP-dependent enzyme did not. The outer membrane of the chloroplast envelope also contained a phosphotransferase capable of transferring labeled phosphate from [-32P]GTP to ADP to yield (-32P]ATP. Consequently, addition of ADP to a GTP-dependent protein-kinase assay resulted in a switch in the pattern of labeled products from that seen with GTP to that typically seen with ATP
Chandra Cluster Cosmology Project II: Samples and X-ray Data Reduction
We discuss the measurements of the galaxy cluster mass functions at z=~0.05
and z=~0.5 using high-quality Chandra observations of samples derived from the
ROSAT PSPC All-Sky and 400deg^2 surveys. We provide a full reference for the
data analysis procedures, present updated calibration of relations between the
total cluster mass and its X-ray indicators (T_X, Mgas, and Y_X) based on a
subsample of low-z relaxed clusters, and present a first measurement of the
evolving L_X-Mtot relation (with Mtot estimated from Y_X) obtained from a
well-defined statistically complete cluster sample and with appropriate
corrections for the Malmquist bias applied. Finally, we present the derived
cluster mass functions, estimate the systematic uncertainties in this
measurement, and discuss the calculation of the likelihood function. We
confidently measure the evolution in the cluster comoving number density at a
fixed mass threshold, e.g., by a factor of 5.0 +- 1.2 at M_500=2.5e14 h^-1 Msun
between z=0 and 0.5. This evolution reflects the growth of density
perturbations and can be used for the cosmological constraints complementing
those from the distance-redshift relation.Comment: ApJ in press (Feb 10, 2009 issue); replacement to match accepted
version, includes revisions in response to referee's and community comment
Social distancing in chronic migraine during the covid-19 outbreak: Results from a multicenter observational study
Background: The restrictions taken to control the rapid spread of COVID-19 resulted in a sudden, unprecedented change in people’s lifestyle, leading to negative consequences on general health. This study aimed to estimate the impact of such changes on migraine severity during 2020 March–May lockdown. Methods: Patients affected by migraine with or without aura, diagnosed by expert physicians, completed a detailed interview comprehensive of: assessment of migraine characteristics; measure of physical activity (PA) levels; measure of the intake frequency of main Italian foods; the Insomnia Severity Index (ISI) questionnaire investigating sleep disorders. Results: We included 261 patients with a mean age of 44.5 ± 12.3 years. During social distancing, 72 patients (28%) reported a headache worsening, 86 (33%) an improvement, and 103 (39%) a stable headache frequency. A significant decrease of the PA levels during COVID-19 quarantine in the whole study sample was observed (median total metabolic equivalent task (METs) decreased from 1170 to 510; p < 0.001). Additionally, a significant difference was reported on median ISI scores (from 7 to 8; p < 0.001), which were increased in patients who presented a stable or worsening headache. Conclusions: Our study confirmed that the restrictions taken during the pandemic have affected the practice of PA levels and sleep quality in migraine. Hence, PA and sleep quality should be assessed to find strategies for an improvement in quality of life
The Planetary Nebula Luminosity Function at the Dawn of Gaia
The [O III] 5007 Planetary Nebula Luminosity Function (PNLF) is an excellent
extragalactic standard candle. In theory, the PNLF method should not work at
all, since the luminosities of the brightest planetary nebulae (PNe) should be
highly sensitive to the age of their host stellar population. Yet the method
appears robust, as it consistently produces < 10% distances to galaxies of all
Hubble types, from the earliest ellipticals to the latest-type spirals and
irregulars. It is therefore uniquely suited for cross-checking the results of
other techniques and finding small offsets between the Population I and
Population II distance ladders. We review the calibration of the method and
show that the zero points provided by Cepheids and the Tip of the Red Giant
Branch are in excellent agreement. We then compare the results of the PNLF with
those from Surface Brightness Fluctuation measurements, and show that, although
both techniques agree in a relative sense, the latter method yields distances
that are ~15% larger than those from the PNLF. We trace this discrepancy back
to the calibration galaxies and argue that, due to a small systematic error
associated with internal reddening, the true distance scale likely falls
between the extremes of the two methods. We also demonstrate how PNLF
measurements in the early-type galaxies that have hosted Type Ia supernovae can
help calibrate the SN Ia maximum magnitude-rate of decline relation. Finally,
we discuss how the results from space missions such as Kepler and Gaia can help
our understanding of the PNLF phenomenon and improve our knowledge of the
physics of local planetary nebulae.Comment: 12 pages, invited review at the conference "The Fundamental Cosmic
Distance Scale: State of the Art and Gaia Perspective", to appear in
Astrophysics and Space Scienc
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