4,733 research outputs found
Oxytocin and oxytocinase in the obese and nonobese parturients during induction and augmentation of labor
Abstract
ObjectiveâTo investigate differences in oxytocin (OXT) biodistribution between nonobese and obese parturients during labor.
Study DesignâPatients with body mass index (BMI) of eitherââĽâ18ââ¤â24.9 kg/m2 (ânonobeseâ) orââĽâ30 kg/m2 (âobeseâ) undergoing elective induction of labor were included (Nâ=â25 each). Blood samples were collected at baseline (T0), and 20 minutes after maximal OXT augmentation or adequate uterine contractions (T1) for OXT and oxytocinase assays. A mixed-model repeated-measures analysis of variance was used to test for group versus time interaction and analysis of covariance to detect a difference in OXT level at T1. Data presented as meanâÂąâstandard deviation or median (interquartile range), with pâ<â0.05 considered significant.
ResultsâThe mean BMIs (kg/m2) were 22.1âÂąâ1.6 and 35.9âÂąâ5.1 in the nonobese and obese groups, respectively. No differences were observed in either the duration of OXT infusion, total dose of OXT, or plasma OXT (pg/mL) either at T0 or T1. However, plasma oxytocinase (ng/mL) was significantly lower at T0 (1.41 [0.67, 3.51] vs. 0.40 [0.29, 1.12]; pâ=â0.03) in the obese group.
ConclusionâWe provide preliminary evidence that the disposition of OXT may not be different between obese and nonobese women during labor
Three-Dimensional Relativistic Magnetohydrodynamic Simulations of Current-Driven Instability with A Sub-Alfvenic Jet: Temporal Properties
We have investigated the influence of a velocity shear surface on the linear
and non-linear development of the CD kink instability of force-free helical
magnetic equilibria in 3D. In this study we follow the temporal development
within a periodic computational box and concentrate on flows that are
sub-Alfvenic on the cylindrical jet's axis. Displacement of the initial
force-free helical magnetic field leads to the growth of CD kink instability.
We find that helically distorted density structure propagates along the jet
with speed and flow structure dependent on the radius of the velocity shear
surface relative to the characteristic radius of the helically twisted
force-free magnetic field. At small velocity shear surface radius the plasma
flows through the kink with minimal kink propagation speed. The kink
propagation speed increases as the velocity shear radius increases and the kink
becomes more embedded in the plasma flow. A decreasing magnetic pitch profile
and faster flow enhance the influence of velocity shear. Simulations show
continuous transverse growth in the nonlinear phase of the instability. The
growth rate of the CD kink instability and the nonlinear behavior also depend
on the velocity shear surface radius and flow speed, and the magnetic pitch
radial profile. Larger velocity shear radius leads to slower linear growth,
makes a later transition to the nonlinear stage, and with larger maximum
amplitude than occur for a static plasma column. However, when the velocity
shear radius is much greater than the characteristic radius of the helical
magnetic field, linear and non-linear development can be similar to the
development of a static plasma column.Comment: 38 pages, 18 figures, accepted for publication in Ap
A FcÎłRIII-engaging bispecific antibody expands the range of HER2-expressing breast tumors eligible to antibody therapy
International audienceTrastuzumab is established as treatment of HER2high metastatic breast cancers but many limitations impair its efficacy. Here, we report the design of a Fab-like bispecific antibody (HER2bsFab) that displays a moderate affinity for HER2 and a unique, specific and high affinity for FcÎłRIII. In vitro characterization showed that ADCC was the major mechanism of action of HER2bsFab as no significant HER2-driven effect was observed. HER2bsFab mediated ADCC at picomolar concentration against HER2high, HER2low as well as trastuzumab-refractive cell lines. In vivo HER2bsFab potently inhibited HER2high tumor growth by recruitment of mouse FcÎłRIII and IV-positive resident effector cells and more importantly, exhibited a net superiority over trastuzumab at inhibiting HER2low tumor growth. Moreover, FcÎłRIIIA-engagement by HER2bsFab was independent of V/F158 polymorphism and induced a stronger NK cells activation in response to target cell recognition. Thus, taking advantage of its epitope specificity and affinity for HER2 and FcÎłRIIIA, HER2bsFab exhibits potent anti-tumor activity against HER2low tumors while evading most of trastuzumab Fc-linked limitations thereby potentially enlarging the number of patients eligible for breast cancer immunotherapy
Deterministically Driven Avalanche Models of Solar Flares
We develop and discuss the properties of a new class of lattice-based
avalanche models of solar flares. These models are readily amenable to a
relatively unambiguous physical interpretation in terms of slow twisting of a
coronal loop. They share similarities with other avalanche models, such as the
classical stick--slip self-organized critical model of earthquakes, in that
they are driven globally by a fully deterministic energy loading process. The
model design leads to a systematic deficit of small scale avalanches. In some
portions of model space, mid-size and large avalanching behavior is scale-free,
being characterized by event size distributions that have the form of
power-laws with index values, which, in some parameter regimes, compare
favorably to those inferred from solar EUV and X-ray flare data. For models
using conservative or near-conservative redistribution rules, a population of
large, quasiperiodic avalanches can also appear. Although without direct
counterparts in the observational global statistics of flare energy release,
this latter behavior may be relevant to recurrent flaring in individual coronal
loops. This class of models could provide a basis for the prediction of large
solar flares.Comment: 24 pages, 11 figures, 2 tables, accepted for publication in Solar
Physic
3D Relativistic Magnetohydrodynamic Simulations of Current-Driven Instability. I. Instability of a static column
We have investigated the development of current-driven (CD) kink instability
through three-dimensional relativistic MHD simulations. A static force-free
equilibrium helical magnetic configuration is considered in order to study the
influence of the initial configuration on the linear and nonlinear evolution of
the instability. We found that the initial configuration is strongly distorted
but not disrupted by the kink instability. The instability develops as
predicted by linear theory. In the non-linear regime the kink amplitude
continues to increase up to the terminal simulation time, albeit at different
rates, for all but one simulation. The growth rate and nonlinear evolution of
the CD kink instability depends moderately on the density profile and strongly
on the magnetic pitch profile. The growth rate of the kink mode is reduced in
the linear regime by an increase in the magnetic pitch with radius and the
non-linear regime is reached at a later time than for constant helical pitch.
On the other hand, the growth rate of the kink mode is increased in the linear
regime by a decrease in the magnetic pitch with radius and reaches the
non-linear regime sooner than the case with constant magnetic pitch. Kink
amplitude growth in the non-linear regime for decreasing magnetic pitch leads
to a slender helically twisted column wrapped by magnetic field. On the other
hand, kink amplitude growth in the non-linear regime nearly ceases for
increasing magnetic pitch.Comment: 24 pages, 10 figures, and 1 table, submitted to Ap
Effect of a 14-day course of systemic corticosteroids on the hypothalamic-pituitary-adrenal-axis in patients with acute exacerbation of chronic obstructive pulmonary disease
<p/> <p>Background</p> <p>As supra-physiological intake of corticosteroids is a well known risk factor for the development of adrenal insufficiency, we investigated the function of the hypothalamic-pituitary-adrenal (HPA) axis during a 14-day course of systemic corticosteroids in patients with acute exacerbation of chronic obstructive pulmonary disease using clinical and laboratory measures.</p> <p>Methods</p> <p>A systematic clinical and laboratory assessment including measurement of basal cortisol levels and the response to low dose (1 Îźg) ACTH stimulation was performed in nine patients before, on the first and the last day of treatment, as well as 2, 7 and 21 days after corticosteroid withdrawal.</p> <p>Results</p> <p>At baseline, all nine patients had normal responses to 1 Îźg ACTH. On the first day of steroid treatment, 78% had a blunted peak cortisol response. This percentage increased to 89% after 14 days of steroid treatment. 78%, 33% and 33% of the patients had a blunted cortisol response to ACTH 2, 7, and 21 days after corticosteroid withdrawal, respectively. ROC curve analysis revealed that only basal cortisol concentrations (AUC 0.89), but not ACTH concentrations (AUC 0.49) or clinical signs (AUC 0.47) were predictive of an impaired function of the HPA axis. Basal cortisol levels of > 400 and < 150 nmol/l were 96% and 100% sensitive for a normal or pathological response to the ACTH stimulation test, respectively.</p> <p>Conclusion</p> <p>Immediate and prolonged suppression of the HPA axis is a common finding in otherwise asymptomatic patients undergoing systemic steroid treatment for acute exacerbation of chronic obstructive pulmonary disease and can reliably be assessed with the low-dose ACTH test.</p
Intercalibration of the barrel electromagnetic calorimeter of the CMS experiment at start-up
Calibration of the relative response of the individual channels of the barrel electromagnetic calorimeter of the CMS detector was accomplished, before installation, with cosmic ray muons and test beams. One fourth of the calorimeter was exposed to a beam of high energy electrons and the relative calibration of the channels, the intercalibration, was found to be reproducible to a precision of about 0.3%. Additionally, data were collected with cosmic rays for the entire ECAL barrel during the commissioning phase. By comparing the intercalibration constants obtained with the electron beam data with those from the cosmic ray data, it is demonstrated that the latter provide an intercalibration precision of 1.5% over most of the barrel ECAL. The best intercalibration precision is expected to come from the analysis of events collected in situ during the LHC operation. Using data collected with both electrons and pion beams, several aspects of the intercalibration procedures based on electrons or neutral pions were investigated
Salvage Stereotactic Reirradiation for Local Recurrence in the Prostatic Bed After Prostatectomy: A Retrospective Multicenter Study
Background: Management of local recurrence of prostate cancer (PCa) in the prostatic bed after radical prostatectomy (RP) and radiotherapy remains challenging. Objective: To assess the efficacy and safety of salvage stereotactic body radiotherapy (SBRT) reirradiation in this setting and evaluate prognostic factors. Design, setting, and participants: We conducted a large multicenter retrospective series that included 117 patients who were treated with salvage SBRT for local recurrence in the prostatic bed after RP and radiotherapy in 11 centers across three countries. Outcome measurements and statistical analysis: Progression-free survival (PFS; biochemical, clinical, or both) was estimated using the Kaplan-Meier method. Biochemical recurrence was defined as prostate-specific antigen nadir +0.2 ng/ml, confirmed by a second increasing measure. The cumulative incidence of late toxicities was estimated using the Kalbfleisch-Prentice method by considering recurrence or death as a competing event. Results and limitations: The median follow-up was 19.5 mo. The median SBRT dose was 35 Gy. The median PFS was 23.5 mo (95% confidence interval [95% CI], 17.6-33.2). In the multivariable models, the volume of the recurrence and its contact with the urethrovesical anastomosis were significantly associated with PFS (hazard ratio [HR]/10 cm3 = 1.46; 95% CI, 1.08-1.96; p = 0.01 and HR = 3.35; 95% CI, 1.38-8.16; p = 0.008, respectively). The 3-yr cumulative incidence of grade âĽ2 late GU or GI toxicity was 18% (95% CI, 10-26). In the multivariable analysis, a recurrence in contact with the urethrovesical anastomosis and D2% of the bladder were significantly associated with late toxicities of any grade (HR = 3.65; 95% CI, 1.61-8.24; p = 0.002 and HR/10 Gy = 1.88; 95% CI, 1.12-3.16; p = 0.02, respectively). Conclusions: Salvage SBRT for local recurrence in the prostate bed may offer encouraging control and acceptable toxicity. Therefore, further prospective studies are warranted. Patient summary: We found that salvage stereotactic body radiotherapy after surgery and radiotherapy allows for encouraging control and acceptable toxicity in locally relapsed prostate cancer
Radiation hardness qualification of PbWO4 scintillation crystals for the CMS Electromagnetic Calorimeter
This is the Pre-print version of the Article. The official published version can be accessed from the link below - Copyright @ 2010 IOPEnsuring the radiation hardness of PbWO4 crystals was one of the main priorities during the construction of the electromagnetic calorimeter of the CMS experiment at CERN. The production on an industrial scale of radiation hard crystals and their certification over a period of several years represented a difficult challenge both for CMS and for the crystal suppliers. The present article reviews the related scientific and technological problems encountered
Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV
The performance of muon reconstruction, identification, and triggering in CMS
has been studied using 40 inverse picobarns of data collected in pp collisions
at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection
criteria covering a wide range of physics analysis needs have been examined.
For all considered selections, the efficiency to reconstruct and identify a
muon with a transverse momentum pT larger than a few GeV is above 95% over the
whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4,
while the probability to misidentify a hadron as a muon is well below 1%. The
efficiency to trigger on single muons with pT above a few GeV is higher than
90% over the full eta range, and typically substantially better. The overall
momentum scale is measured to a precision of 0.2% with muons from Z decays. The
transverse momentum resolution varies from 1% to 6% depending on pseudorapidity
for muons with pT below 100 GeV and, using cosmic rays, it is shown to be
better than 10% in the central region up to pT = 1 TeV. Observed distributions
of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO
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