1,599 research outputs found
Alemtuzumab induced ST-segment elevation and acute myocardial dysfunction
AbstractCardiac toxicity as a side effect of chemotherapeutic agents has been well reported in the literature. Cardiac toxicity secondary to alemtuzumab has been reported, presenting as congestive heart failure and arrhythmias. Here we report a case of acute myocardial dysfunction after administration of a test dose of alemtuzumab. Our patient was a 66-year-old man with a history of small lymphocytic lymphoma/chronic lymphocytic lymphoma who received a test dose of alemtuzumab. Twenty minutes post administration, the patient developed nausea, vomiting, rigors, and tachycardia. Electrocardiography (ECG) showed acute ST-segment elevations in contiguous leads V2–V6, I, and AVL with no associated chest pain. Bedside echocardiogram showed akinesis of the anterior septum, apex, distal anterior wall, and decreased left ventricular ejection fraction. Cardiac catheterization showed non-critical occlusive disease and no intervention was undertaken. Post-catheterization ECG revealed resolution of ST segment elevations, TWI in V4–V6, and prolongation of corrected QT. Repeat echocardiogram 10 days after the event demonstrated no improvement in wall motion or ejection fraction. We discuss the possible mechanisms causing ST-elevations and acute myocardial dysfunction after treatment with alemtuzumab.<Learning objective: Alemtuzumab can cause acute myocardial dysfunction after administration of a test dose. Considering that this is a serious adverse effect, detailed cardiac evaluation and a high level of caution are recommended before administration of alemtuzumab. While no clear etiology could be identified for this side effect, excessive and acute cytokine release triggered by alemtuzumab administration is a possible explanation. This could be potentially attenuated by using anti-interleukin-6 or tumor necrosis factor inhibitors.
Recommended from our members
Emulating the impact of additional proton–proton interactions in the ATLAS simulation by presampling sets of inelastic Monte Carlo events
The accurate simulation of additional interactions at the ATLAS experiment for the analysis of proton–proton collisions delivered by the Large Hadron Collider presents a significant challenge to the computing resources. During the LHC Run 2 (2015–2018), there were up to 70 inelastic interactions per bunch crossing, which need to be accounted for in Monte Carlo (MC) production. In this document, a new method to account for these additional interactions in the simulation chain is described. Instead of sampling the inelastic interactions and adding their energy deposits to a hard-scatter interaction one-by-one, the inelastic interactions are presampled, independent of the hard scatter, and stored as combined events. Consequently, for each hard-scatter interaction, only one such presampled event needs to be added as part of the simulation chain. For the Run 2 simulation chain, with an average of 35 interactions per bunch crossing, this new method provides a substantial reduction in MC production CPU needs of around 20%, while reproducing the properties of the reconstructed quantities relevant for physics analyses with good accuracy
Recommended from our members
Differential cross-section measurements for the electroweak production of dijets in association with a Z boson in proton–proton collisions at ATLAS
ArtÃculo escrito por un elevado número de autores, solo se referencian el que aparece en primer lugar, el nombre del grupo de colaboración, si le hubiere, y los autores pertenecientes a la UA
Differential tt¯cross-section measurements using boosted top quarks in the all-hadronic final state with 139 fb−1 of ATLAS data
Measurements of single-, double-, and triple-differential cross-sections are presented for boosted top-quark pair-production in 13 TeV proton–proton collisions recorded by the ATLAS detector at the LHC. The top quarks are observed through their hadronic decay and reconstructed as large-radius jets with the leading jet having transverse momentum (pT) greater than 500 GeV. The observed data are unfolded to remove detector effects. The particle-level cross-section, multiplied by the tt¯ → WWbb¯ branching fraction and measured in a fiducial phase space defined by requiring the leading and second-leading jets to have pT> 500 GeV and pT> 350 GeV, respectively, is 331 ± 3(stat.) ± 39(syst.) fb. This is approximately 20% lower than the prediction of 398−49+48 fb by Powheg+Pythia 8 with next-to-leading-order (NLO) accuracy but consistent within the theoretical uncertainties. Results are also presented at the parton level, where the effects of top-quark decay, parton showering, and hadronization are removed such that they can be compared with fixed-order next-to-next-to-leading-order (NNLO) calculations. The parton-level cross-section, measured in a fiducial phase space similar to that at particle level, is 1.94 ± 0.02(stat.) ± 0.25(syst.) pb. This agrees with the NNLO prediction of 1.96−0.17+0.02 pb. Reasonable agreement with the differential cross-sections is found for most NLO models, while the NNLO calculations are generally in better agreement with the data. The differential cross-sections are interpreted using a Standard Model effective field-theory formalism and limits are set on Wilson coefficients of several four-fermion operators. [Figure not available: see fulltext.]
Search for non-resonant Higgs boson pair production in the 2b+2â„“+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
Search for resonant production of dark quarks in the dijet final state with the ATLAS detector
This paper presents a search for a new Z′ resonance decaying into a pair of dark quarks which hadronise into dark hadrons before promptly decaying back as Standard Model particles. This analysis is based on proton-proton collision data recorded at s = 13 TeV with the ATLAS detector at the Large Hadron Collider between 2015 and 2018, corresponding to an integrated luminosity of 139 fb−1. After selecting events containing large-radius jets with high track multiplicity, the invariant mass distribution of the two highest-transverse-momentum jets is scanned to look for an excess above a data-driven estimate of the Standard Model multijet background. No significant excess of events is observed and the results are thus used to set 95% confidence-level upper limits on the production cross-section times branching ratio of the Z′ to dark quarks as a function of the Z′ mass for various dark-quark scenarios
Search for top-philic heavy resonances in pp collisions at s=13Â 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 parameters
A precise measurement of the Z-boson double-differential transverse momentum and rapidity distributions in the full phase space of the decay leptons with the ATLAS experiment at s=8 TeV
This paper presents for the first time a precise measurement of the production properties of the Z boson in the full phase space of the decay leptons. This is in contrast to the many previous precise unfolded measurements performed in the fiducial phase space of the decay leptons. The measurement is obtained from proton–proton collision data collected by the ATLAS experiment in 2012 at s=8 TeV at the LHC and corresponding to an integrated luminosity of 20.2 fb-1. The results, based on a total of 15.3 million Z-boson decays to electron and muon pairs, extend and improve a previous measurement of the full set of angular coefficients describing Z-boson decay. The double-differential cross-section distributions in Z-boson transverse momentum pT and rapidity y are measured in the pole region, defined as 80<mℓℓ<100 GeV, over the range |y|<3.6. The total uncertainty of the normalised cross-section measurements in the peak region of the pT distribution is dominated by statistical uncertainties over the full range and increases as a function of rapidity from 0.5–1.0% for |y|<2.0 to 2-7% at higher rapidities. The results for the rapidity-dependent transverse momentum distributions are compared to state-of-the-art QCD predictions, which combine in the best cases approximate N4LL resummation with N3LO fixed-order perturbative calculations. The differential rapidity distributions integrated over pT are even more precise, with accuracies from 0.2–0.3% for |y|<2.0 to 0.4–0.9% at higher rapidities, and are compared to fixed-order QCD predictions using the most recent parton distribution functions. The agreement between data and predictions is quite good in most cases
Combination of searches for invisible decays of the Higgs boson using 139 fb−1 of proton-proton collision data at √s = 13 TeV collected with the ATLAS experiment
Many extensions of the Standard Model predict the production of dark matter particles at the LHC.
Sufficiently light dark matter particles may be produced in decays of the Higgs boson that would
appear invisible to the detector. This Letter presents a statistical combination of searches for H →
invisible decays where multiple production modes of the Standard Model Higgs boson are considered.
These searches are performed with the ATLAS detector using 139 fb−1 of proton–proton collisions at a
centre–of–mass energy of √s = 13 TeV at the LHC. In combination with the results at √s = 7 TeV and
8 TeV, an upper limit on the H → invisible branching ratio of 0.107 (0.077) at the 95% confidence level
is observed (expected). These results are also interpreted in the context of models where the 125 GeV
Higgs boson acts as a portal to dark matter, and limits are set on the scattering cross-section of weakly
interacting massive particles and nucleons
Search for a CP-odd Higgs boson decaying into a heavy CP-even Higgs boson and a Z boson in the ℓ+ℓ−tt¯ and νν¯bb¯ final states using 140 fb<sup>−1</sup> of data collected with the ATLAS detector
A search for a heavy CP-odd Higgs boson, A, decaying into a Z boson and a heavy CP-even Higgs boson, H, is presented. It uses the full LHC Run 2 dataset of pp collisions at s = 13 TeV collected with the ATLAS detector, corresponding to an integrated luminosity of 140 fb−1. The search for A → ZH is performed in the ℓ+ℓ−tt¯ and νν¯bb¯ final states and surpasses the reach of previous searches in different final states in the region with mH > 350 GeV and mA > 800 GeV. No significant deviation from the Standard Model expectation is found. Upper limits are placed on the production cross-section times the decay branching ratios. Limits with less model dependence are also presented as functions of the reconstructed m(tt¯) and m(bb¯) distributions in the ℓ+ℓ−tt¯ and νν¯bb¯ channels, respectively. In addition, the results are interpreted in the context of two-Higgs-doublet models
- …