Brucella abortus invasion of osteocytes modulates connexin 43 and integrin expression and induces osteoclastogenesis via receptor activator of NF-κB ligand and tumor necrosis factor alpha secretion

Osteoarticular brucellosis is the most common localization of human active disease. Osteocytes are the most abundant cells of bone. They secrete factors that regulate the differentiation of both osteoblasts and osteoclasts during bone remodeling. The aim of this study is to determine if Brucella abortus infection modifies osteocyte function. Our results indicate that B. abortus infection induced matrix metalloproteinase 2 (MMP-2), receptor activator for NF-κB ligand (RANKL), proinflammatory cytokines, and keratinocyte chemoattractant (KC) secretion by osteocytes. In addition, supernatants from B. abortus-infected osteocytes induced bone marrow-derived monocytes (BMM) to undergo osteoclastogenesis. Using neutralizing antibodies against tumor necrosis factor alpha (TNF-α) or osteoprotegerin (OPG), RANKL's decoy receptor, we determined that TNF-α and RANKL are involved in osteoclastogenesis induced by supernatants from B. abortus-infected osteocytes. Connexin 43 (Cx43) and the integrins E11/gp38, integrin-α, integrin-β, and CD44 are involved in cell-cell interactions necessary for osteocyte survival. B. abortus infection inhibited the expression of Cx43 but did not modify the expression of integrins. Yet the expression of both Cx43 and integrins was inhibited by supernatants from B. abortus-infected macrophages. B. abortus infection was not capable of inducing osteocyte apoptosis. However, supernatants from B. abortus-infected macrophages induced osteocyte apoptosis in a dose-dependent manner. Taken together, our results indicate that B. abortus infection could alter osteocyte function, contributing to bone damage.Fil: Pesce Viglietti, Ayelén Ivana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Inmunología, Genética y Metabolismo. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Inmunología, Genética y Metabolismo; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Arriola Benitez, Paula Constanza. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Inmunología, Genética y Metabolismo. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Inmunología, Genética y Metabolismo; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Gentilini, Maria Virginia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Inmunología, Genética y Metabolismo. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Inmunología, Genética y Metabolismo; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Velasquez, Lis Noelia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; ArgentinaFil: Fossati, Carlos Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Estudios Inmunológicos y Fisiopatológicos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Estudios Inmunológicos y Fisiopatológicos; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Ciencias Biológicas; ArgentinaFil: Giambartolomei, Guillermo Hernan. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Inmunología, Genética y Metabolismo. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Inmunología, Genética y Metabolismo; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; ArgentinaFil: Delpino, María Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Inmunología, Genética y Metabolismo. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Inmunología, Genética y Metabolismo; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; Argentin

Effect of pacifier use on exclusive and any breastfeeding: a meta-analysis

The objective of this meta-analysis was to determine with cross-sectional and cohort trails whether the use of pacifier increases the risk of early weaning from exclusive breastfeeding before six months of age or cessation of breastfeeding from any breastfeeding before 24 months of age. Additionally, the effect of the age for starting pacifier use on breastfeeding duration was analyzed in the cohort trails. The Medline database was searched (1980 to 2006) with "breastfeed, breastfeeding, or breast feed" and "pacifier, dummy, or soother" as individual keywords. Only human studies published in English were included. Unpublished data were not sought. Twelve trials with weaning from exclusive breastfeeding and 19 trials with cessation of any breastfeeding were included in the meta-analysis. The meta-analysis was performed with Stata 6.0 statistical package. Summary risk ratio for early weaning before six months of age in exclusive breastfeeding trails was 2.016 (95% CI: 1.619-2.511) for pacifier users compared with nonusers in studies with univariate analysis and 1.792 (95% CI: 1.452-2.212) in studies with multivariate analysis. Similarly, pacifier usage compared with nonusers reduced the duration of any breastfeeding in both univariate (2.760, 95% CI: 2.083-3.657) and multivariate trials (1.952, 95% CI: 1.662-2.293). The use of pacifiers was associated with shortened duration of exclusive and of any breastfeeding. Given the increase in the benefits with duration of breastfeeding, parents should be informed of the link between pacifier use and shortened breastfeeding duration in order to help them make informed decisions about their children's care

Stenosis and Aneurysm of Coronary Arteries in A Patient with Behcet’s Disease

Coronary artery disease is extremely rare in patients with Behçet’s disease. We report the case of a patient with a history of Behçet’s disease who was admitted in our hospital with instable angina pectoris. The patient’s electrocardiogram was normal. Coronary angiography revealed aneurysm of the distal right coronary artery with a tight stenosis of the proximal part of the posterolateral branch. These two conditions were initially treated with immunosuppressive treatment. Three years later coronary angiography showed a total occlusion of the right coronary artery treated with medical therapy. More than fourteen cases of coronary involvement were reported in the literature but the etiopathogeny and the treatment are yet unknow

Possible Brucellosis in an Early Hominin Skeleton from Sterkfontein, South Africa

We report on the paleopathological analysis of the partial skeleton of the late Pliocene hominin species Australopithecus africanus Stw 431 from Sterkfontein, South Africa. A previous study noted the presence of lesions on vertebral bodies diagnosed as spondylosis deformans due to trauma. Instead, we suggest that these lesions are pathological changes due to the initial phases of an infectious disease, brucellosis. The macroscopic, microscopic and radiological appearance of the lytic lesions of the lumbar vertebrae is consistent with brucellosis. The hypothesis of brucellosis (most often associated with the consumption of animal proteins) in a 2.4 to 2.8 million year old hominid has a host of important implications for human evolution. The consumption of meat has been regarded an important factor in supporting, directing or altering human evolution. Perhaps the earliest (up to 2.5 million years ago) paleontological evidence for meat eating consists of cut marks on animal remains and stone tools that could have made these marks. Now with the hypothesis of brucellosis in A. africanus, we may have evidence of occasional meat eating directly linked to a fossil hominin

Accuracy versus precision in boosted top tagging with the ATLAS detector

The identification of top quark decays where the top quark has a large momentum transverse to the beam axis, known as top tagging, is a crucial component in many measurements of Standard Model processes and searches for beyond the Standard Model physics at the Large Hadron Collider. Machine learning techniques have improved the performance of top tagging algorithms, but the size of the systematic uncertainties for all proposed algorithms has not been systematically studied. This paper presents the performance of several machine learning based top tagging algorithms on a dataset constructed from simulated proton-proton collision events measured with the ATLAS detector at √s = 13 TeV. The systematic uncertainties associated with these algorithms are estimated through an approximate procedure that is not meant to be used in a physics analysis, but is appropriate for the level of precision required for this study. The most performant algorithms are found to have the largest uncertainties, motivating the development of methods to reduce these uncertainties without compromising performance. To enable such efforts in the wider scientific community, the datasets used in this paper are made publicly available

Search for non-resonant Higgs boson pair production in the 2b+2l+ETmiss final state in pp collisions at s = 13 TeV with the ATLAS detector

A search for non-resonant Higgs boson pair (HH) production is presented, in which one of the Higgs bosons decays to a b-quark pair (bb ̄) and the other decays to WW*, ZZ*, or τ+τ−, with in each case a final state with l+l−+ neutrinos (l = e, μ). The analysis targets separately the gluon-gluon fusion and vector boson fusion production modes. Data recorded by the ATLAS detector in proton-proton collisions at a centre-of-mass energy of 13 TeV at the Large Hadron Collider, corresponding to an integrated luminosity of 140 fb−1, are used in this analysis. Events are selected to have exactly two b-tagged jets and two leptons with opposite electric charge and missing transverse momentum in the final state. These events are classified using multivariate analysis algorithms to separate the HH events from other Standard Model processes. No evidence of the signal is found. The observed (expected) upper limit on the cross-section for non-resonant Higgs boson pair production is determined to be 9.7 (16.2) times the Standard Model prediction at 95% confidence level. The Higgs boson self-interaction coupling parameter κλ and the quadrilinear coupling parameter κ2V are each separately constrained by this analysis to be within the ranges [−6.2, 13.3] and [−0.17, 2.4], respectively, at 95% confidence level, when all other parameters are fixed

Measurement of single top-quark production in association with a W boson in pp collisions at root s = 13 TeV with the ATLAS detector

The inclusive cross section for the production of a single top quark in association with a W boson is measured using 140 fb-1 of proton-proton collision data collected with the ATLAS detector at root s = 13 TeV. Events containing two charged leptons and at least one jet identified as originating from a b-quark are selected. A multivariate discriminant is constructed to separate the tW signal from the t⁢ tbar background. The cross section is extracted using a profile likelihood fit to the signal and control regions and it is measured to be sigma t W = 7⁢5 + 15 - 14 pb, in good agreement with the Standard Model prediction. The measured cross section is used to extract a value for the left-handed form factor at the Wtb vertex times the Cabibbo-Kobayashi-Maskawa matrix element mod(fLV Vtb) of 0.97 +- 0.10

Measurement of the polarisation of W bosons produced in top-quark decays using dilepton events at root s=13 TeV with the ATLAS experiment

A measurement of the polarisation of $W$ bosons produced in top-quark decays is presented, using proton-proton collision data at a centre-of-mass energy of $\sqrt{s} = 13$ TeV. The data were collected by the ATLAS detector at the Large Hadron Collider and correspond to an integrated luminosity of 139 fb$^{-1}$. The measurement is performed selecting $t\bar{t}$ events decaying into final states with two charged leptons (electrons or muons) and at least two $b$-tagged jets. The polarisation is extracted from the differential cross-section distribution of the $\cos{\theta^{*}}$ variable, where $\theta^{*}$ is the angle between the momentum direction of the charged lepton from the $W$ boson decay and the reversed momentum direction of the $b$-quark from the top-quark decay, both calculated in the $W$ boson rest frame. Parton-level results, corrected for the detector acceptance and resolution, are presented for the $\cos{\theta^{*}}$ angle. The measured fractions of longitudinal, left- and right-handed polarisation states are found to be $f_{0} = 0.684 \pm 0.005\,\mathrm{(stat.)} \pm 0.014\,\mathrm{(syst.)}$, $f_{\mathrm{L}} = 0.318 \pm 0.003\,\mathrm{(stat.)} \pm 0.008\,\mathrm{(syst.)}$ and $f_{\mathrm{R}} = -0.002 \pm 0.002\,\mathrm{(stat.)} \pm 0.014\,\mathrm{(syst.)}$, in agreement with the Standard Model prediction

Search for top-philic heavy resonances in pp collisions at √s = 13 TeV with the ATLAS detector

A search for the associated production of a heavy resonance with a top-quark or a top-antitop-quark pair, and decaying into a tt ̄ pair is presented. The search uses the data recorded by the ATLAS detector in pp collisions at √s = 13 TeV at the Large Hadron Collider during the years 2015–2018, corresponding to an integrated luminosity of 139 fb−1. Events containing exactly one electron or muon are selected. The two hadronically decaying top quarks from the resonance decay are reconstructed using jets clustered with a large radius parameter of R = 1. The invariant mass spectrum of the two top quark candidates is used to search for a resonance signal in the range of 1.0 TeV to 3.2 TeV. The presence of a signal is examined using an approach with minimal model dependence followed by a model-dependent interpretation. No significant excess is observed over the background expectation. Upper limits on the production cross section times branching ratio at 95% confidence level are provided for a heavy Z boson based on a simplified model, for Z mass between 1.0 TeV and 3.0 TeV. The observed (expected) limits range from 21 (14) fb to 119 (86) fb depending on the choice of model parameter