67 research outputs found
Spontaneous Autologous Graft-versus-Host Disease in Plasma Cell Myeloma Autograft Recipients: Flow Cytometric Analysis of Hematopoietic Progenitor Cell Grafts
Nine plasma cell myeloma patients spontaneously developed histologically proven autologous graft-versus-host disease (GVHD) limited predominantly to the gastrointestinal tract within 1 month of initial autologous hematopoietic cell transplantation (AHCT) using high-dose melphalan conditioning. All recipients responded promptly to systemic and nonabsorbable oral corticosteroid therapy. All patients previously received systemic therapy with thalidomide, lenalidomide, or bortezomib before AHCT. Using enzymatic amplification staining-enhanced flow cytometry, we evaluated expression of selected transcription regulators, pathway molecules, and surface receptors on samples of the infused hematopoietic cell grafts. We demonstrated significantly enhanced expression of GATA-2, CD130, and CXCR4 on CD34+ hematopoietic progenitor cells of affected patients compared with 42 unaffected AHCT controls. These 3 overexpressed markers have not been previously implicated in autologous GVHD. Although we did not specifically evaluate T cells, we postulate that exposure over time to the various immunomodulating therapies used for induction treatment affected not only the CD34+ cells but also T cells or relevant T cell subpopulations capable of mediating GVHD. After infusion, the affected hematopoietic progenitor cells then encounter a host that has been further altered by the high-dose melphalan preparative regimen; such a situation leads to the syndrome. These surface markers could be used to develop a model to predict development of this syndrome. Autologous GVHD potentially is a serious complication of AHCT and should be considered in plasma cell myeloma patients with otherwise unexplained gastrointestinal symptoms in the immediate post-AHCT period. Prompt recognition of this condition and protracted treatment with nonabsorbable or systemic corticosteroids or the combination may lead to resolution
Efficacy of Maternal Choline Supplementation During Pregnancy in Mitigating Adverse Effects of Prenatal Alcohol Exposure on Growth and Cognitive Function: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial
Background: We recently demonstrated the acceptability and feasibility of a randomized, double-blind choline supplementation intervention for heavy drinking women during pregnancy. In this study, we report our results relating to the efficacy of this intervention in mitigating adverse effects of prenatal alcohol exposure (PAE) on infant growth and cognitive function. Methods: Sixty-nine Cape Coloured (mixed ancestry) heavy drinkers in Cape Town, South Africa, recruited in mid-pregnancy, were randomly assigned to receive a daily oral dose of either 2 g of choline or placebo from time of enrollment until delivery. Each dose consisted of an individually wrapped packet of powder that, when mixed with water, produced a sweet tasting grape-flavored drink. The primary outcome, eyeblink conditioning (EBC), was assessed at 6.5 months. Somatic growth was measured at birth, 6.5, and 12 months, recognition memory and processing speed on the Fagan Test of Infant Intelligence, at 6.5 and 12 months. Results: Infants born to choline-treated mothers were more likely to meet criterion for conditioning on EBC than the placebo group. Moreover, within the choline arm, degree of maternal adherence to the supplementation protocol strongly predicted EBC performance. Both groups were small at birth, but choline-treated infants showed considerable catch-up growth in weight and head circumference at 6.5 and 12 months. At 12 months, the infants in the choline treatment arm had higher novelty preference scores, indicating better visual recognition memory. Conclusions: This exploratory study is the first to provide evidence that a high dose of choline administered early in pregnancy can mitigate adverse effects of heavy PAE on EBC, postnatal growth, and cognition in human infants. These findings are consistent with studies of alcohol-exposed animals that have demonstrated beneficial effects of choline supplementation on classical conditioning, learning, and memory
Observation of Pseudoscalar and Axial Vector Resonances in pi- p -> K+ K- pi0 n at 18 GeV
A new measurement of the reaction pi- p -> K+ K- pi0 n has been made at a
beam energy of 18 GeV. A partial wave analysis of the K+ K- pi0 system shows
evidence for three pseudoscalar resonances, eta(1295), eta(1416), and
eta(1485), as well as two axial vectors, f1(1285), and f1(1420). Their observed
masses, widths and decay properties are reported. No signal was observed for
C(1480), an IG J{PC} = 1+ 1{--} state previously reported in phi pi0 decay.Comment: 7 pages, 6 figs, to be submitted to Phys. Let
Measurement of the p-pbar -> Wgamma + X cross section at sqrt(s) = 1.96 TeV and WWgamma anomalous coupling limits
The WWgamma triple gauge boson coupling parameters are studied using p-pbar
-> l nu gamma + X (l = e,mu) events at sqrt(s) = 1.96 TeV. The data were
collected with the DO detector from an integrated luminosity of 162 pb^{-1}
delivered by the Fermilab Tevatron Collider. The cross section times branching
fraction for p-pbar -> W(gamma) + X -> l nu gamma + X with E_T^{gamma} > 8 GeV
and Delta R_{l gamma} > 0.7 is 14.8 +/- 1.6 (stat) +/- 1.0 (syst) +/- 1.0 (lum)
pb. The one-dimensional 95% confidence level limits on anomalous couplings are
-0.88 < Delta kappa_{gamma} < 0.96 and -0.20 < lambda_{gamma} < 0.20.Comment: Submitted to Phys. Rev. D Rapid Communication
Measurement of the ttbar Production Cross Section in ppbar Collisions at sqrt{s} = 1.96 TeV using Kinematic Characteristics of Lepton + Jets Events
We present a measurement of the top quark pair ttbar production cross section
in ppbar collisions at a center-of-mass energy of 1.96 TeV using 230 pb**{-1}
of data collected by the DO detector at the Fermilab Tevatron Collider. We
select events with one charged lepton (electron or muon), large missing
transverse energy, and at least four jets, and extract the ttbar content of the
sample based on the kinematic characteristics of the events. For a top quark
mass of 175 GeV, we measure sigma(ttbar) = 6.7 {+1.4-1.3} (stat) {+1.6- 1.1}
(syst) +/-0.4 (lumi) pb, in good agreement with the standard model prediction.Comment: submitted to Phys.Rev.Let
Measurement of the ttbar Production Cross Section in ppbar Collisions at sqrt(s)=1.96 TeV using Lepton + Jets Events with Lifetime b-tagging
We present a measurement of the top quark pair () production cross
section () in collisions at TeV
using 230 pb of data collected by the D0 experiment at the Fermilab
Tevatron Collider. We select events with one charged lepton (electron or muon),
missing transverse energy, and jets in the final state. We employ
lifetime-based b-jet identification techniques to further enhance the
purity of the selected sample. For a top quark mass of 175 GeV, we
measure pb, in
agreement with the standard model expectation.Comment: 7 pages, 2 figures, 3 tables Submitted to Phys.Rev.Let
Search for single top quark production in ppbar collisions at sqrt(s)=1.96 TeV
We present a search for electroweak production of single top quarks in the
s-channel and t-channel using neural networks for signal-background separation.
We have analyzed 230 pb of data collected with the D0 detector at the
Fermilab Tevatron Collider at a center-of-mass energy of 1.96 TeV and find no
evidence for a single top quark signal. The resulting 95% confidence level
upper limits on the single top quark production cross sections are 6.4 pb in
the s-channel and 5.0 pb in the t-channel.Comment: 9 pages, 4 figure
Measurement of the Lambda^0_b lifetime in the decay Lambda^0_b -> J/psi Lambda^0 with the D0 Detector
We present measurements of the Lambda^0_b lifetime in the exclusive decay
channel Lambda^0_{b}->J/psi Lambda^0, with J/psi to mu+ mu- and Lambda^0 to p
pi-, the B^0 lifetime in the decay B^0 -> J/psi K^0_S with J/psi to mu+ mu- and
K^0_S to pi+ pi-, and the ratio of these lifetimes. The analysis is based on
approximately 250 pb^{-1} of data recorded with the D0 detector in pp(bar)
collisions at sqrt{s}=1.96 TeV. The Lambda^0_b lifetime is determined to be
tau(Lambda^0_b) = 1.22 +0.22/-0.18 (stat) +/- 0.04 (syst) ps, the B^0 lifetime
tau(B^0) = 1.40 +0.11/-0.10 (stat) +/- 0.03 (syst) ps, and the ratio
tau(Lambda^0_b)/tau(B^0) = 0.87 +0.17/-0.14 (stat) +/- 0.03 (syst). In contrast
with previous measurements using semileptonic decays, this is the first
determination of the Lambda^0_b lifetime based on a fully reconstructed decay
channel.Comment: 7 pages, 4 figures, Submitted to Physical Review Letters, v2: Added
FNAL Pub-numbe
Measurement of the WW production cross section in p anti-p collisions at s**(1/2) = 1.96 TeV
We present a measurement of the W boson pair-production cross section in p
anti-p collisions at a center-of-mass energy of sqrt{s}=1.96 TeV. The data,
collected with the Run II DO detector, correspond to an integrated luminosity
of 224-252 pb^-1 depending on the final state (ee, emu or mumu). We observe 25
candidates with a background expectation of
8.1+/-0.6(stat)+/-0.6(syst)+/-0.5(lum) events. The probability for an upward
fluctuation of the background to produce the observed signal is 2.3x10^-7,
equivalent to 5.2 standard deviations.The measurement yields a cross section of
13.8+4.3/-3.8(stat)+1.2/-0.9(syst)+/-0.9(lum) pb, in agreement with predictions
from the standard model.Comment: submitted to PR
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