Intravenous immunoglobulin in septic shock: review of the mechanisms of action and meta-analysis of the clinical effectiveness

Sepsis is characterized by a complex immune response. In this study we aimed to provide a review of the mechanisms of action of immunoglobulin (Ig) related to sepsis and an updated meta-analysis of the clinical effectiveness of the Ig use in septic patients

Acute renal failure and renal replacement therapy in the postoperative period of orthotopic liver transplant patients versus nonelective abdominal surgery patients

Acute renal failure (ARF) often complicates the postoperative period of patients undergoing orthotopic liver transplantation (OLT); it is habitually associated with high mortality rates. Similarly, patients undergoing major nonelective abdominal surgery are prone to ARF because of their frequent preexistent morbidities, abdominal sepsis, and needed for extended surgical procedures. The aim of this study was to evaluate the incidence of ARF and use of renal replacement therapy (RRT) among OLT versus nonelective abdominal surgery patients and associations with clinical outcomes. We studied all the patients admitted to a surgical intensive care unit (ICU) from January 2008 to December 2009 after OLT or nonelective abdominal surgery. The inclusion criteria were an ICU stay of at least 48 hours and without prior end-stage renal failure. OLT patients (n = 84) were younger and less severly ill than surgery patients (n = 60). ARF occurrence was lower among the OLT (29%) than the surgery group (47%) requiring RRT in 71% and 53% of patients due to ARF, respectively. The ICU mortality of ARF patients in both groups (29% OLT and 51% surgery) were greater than among subjects without ARF (2% and 6%). The occurrence of ARF is common among these two patient groups, and associated with increased risk of death among in surgery (+45%) versus in OLT (+27%) patients. © 2011 Elsevier Inc. All rights reserved

Early therapy with IgM-enriched polyclonal immunoglobulin in patients with septic shock

To determine whether there was an association between adjunctive therapy with IgM-enriched immunoglobulin (IgM) and the 30-day mortality rate in patients with septic shock

The X-Ray Polarimetry View of the Accreting Pulsar Cen X-3

International audienceThe first X-ray pulsar, Cen X-3, was discovered 50 yr ago. Radiation from such objects is expected to be highly polarized due to birefringence of plasma and vacuum associated with propagation of photons in the presence of the strong magnetic field. Here we present results of the observations of Cen X-3 performed with the Imaging X-ray Polarimetry Explorer. The source exhibited significant flux variability and was observed in two states different by a factor of ~20 in flux. In the low-luminosity state, no significant polarization was found in either pulse phase-averaged (with a 3σ upper limit of 12%) or phase-resolved (the 3σ upper limits are 20%-30%) data. In the bright state, the polarization degree of 5.8% ± 0.3% and polarization angle of 49.°6 ± 1.°5 with a significance of about 20σ were measured from the spectropolarimetric analysis of the phase-averaged data. The phase-resolved analysis showed a significant anticorrelation between the flux and the polarization degree, as well as strong variations of the polarization angle. The fit with the rotating vector model indicates a position angle of the pulsar spin axis of about 49° and a magnetic obliquity of 17°. The detected relatively low polarization can be explained if the upper layers of the neutron star surface are overheated by the accreted matter and the conversion of the polarization modes occurs within the transition region between the upper hot layer and a cooler underlying atmosphere. A fraction of polarization signal can also be produced by reflection of radiation from the neutron star surface and the accretion curtain

Angling for x-ray pulsar geometry with polarimetry

Using observations of X-ray pulsar Her X-1 by the Imaging X-ray Polarimetry Explorer, we report on a highly significant detection of the polarization signal from an accreting neutron star. The observed degree of the polarization of $\sim10$% is found to be far below theoretical expectations for this object, and stays low throughout the spin cycle of the pulsar. Both the polarization degree and the angle exhibit variability with pulse phase, which allowed us to measure the pulsar spin position angle and magnetic obliquity of the neutron star, which is an essential step towards detailed modeling of intrinsic emission of X-ray pulsars. Combining our results with the optical polarimetric data, we find that the spin axis of the neutron star and the angular momentum of the binary orbit are misaligned by at least $\sim$20 deg, which is a strong argument in support of the models explaining stability of the observed super-orbital variability with the precession of the neutron star.Comment: Submitte

Polarized x-rays from a magnetar

We report on the first detection of linearly polarized x-ray emission from an ultra-magnetized neutron star with the Imaging X-ray Polarimetry Explorer (IXPE). The IXPE 35 observations of the anomalous x-ray pulsar 4U 0142+61 reveal a linear polarization degree of $(12\pm 1)\%$ throughout the IXPE 2--8 keV band. We detect a substantial variation of the polarization with energy: the degree is $(14\pm 1)\%$ at 2--4 keV and $(41\pm 7)\%$ at 5.5--8 keV, while it drops below the instrumental sensitivity around 4--5 keV, where the polarization angle swings by $\sim 90^\circ$. The IXPE observations give us completely new information about the properties of the neutron star surface and magnetosphere and lend further support to the presence of the quantum mechanical effect of vacuum birefringence.Comment: 32 pages, 9 figures, 3 table

The X-Ray Polarimetry View of the Accreting Pulsar Cen X-3

International audienceThe first X-ray pulsar, Cen X-3, was discovered 50 yr ago. Radiation from such objects is expected to be highly polarized due to birefringence of plasma and vacuum associated with propagation of photons in the presence of the strong magnetic field. Here we present results of the observations of Cen X-3 performed with the Imaging X-ray Polarimetry Explorer. The source exhibited significant flux variability and was observed in two states different by a factor of ~20 in flux. In the low-luminosity state, no significant polarization was found in either pulse phase-averaged (with a 3σ upper limit of 12%) or phase-resolved (the 3σ upper limits are 20%-30%) data. In the bright state, the polarization degree of 5.8% ± 0.3% and polarization angle of 49.°6 ± 1.°5 with a significance of about 20σ were measured from the spectropolarimetric analysis of the phase-averaged data. The phase-resolved analysis showed a significant anticorrelation between the flux and the polarization degree, as well as strong variations of the polarization angle. The fit with the rotating vector model indicates a position angle of the pulsar spin axis of about 49° and a magnetic obliquity of 17°. The detected relatively low polarization can be explained if the upper layers of the neutron star surface are overheated by the accreted matter and the conversion of the polarization modes occurs within the transition region between the upper hot layer and a cooler underlying atmosphere. A fraction of polarization signal can also be produced by reflection of radiation from the neutron star surface and the accretion curtain

Determination of X-ray pulsar geometry with IXPE polarimetry

International audienceUsing observations of X-ray pulsar Hercules X-1 by the Imaging X-ray Polarimetry Explorer we report a highly significant (>17σ) detection of the polarization signal from an accreting neutron star. The observed degree of linear polarization of ~10% is far below theoretical expectations for this object, and stays low throughout the spin cycle of the pulsar. Both the degree and angle of polarization exhibit variability with the pulse phase, allowing us to measure the pulsar spin position angle 57(2) deg and the magnetic obliquity 12(4) deg, which is an essential step towards detailed modelling of the intrinsic emission of X-ray pulsars. Combining our results with the optical polarimetric data, we find that the spin axis of the neutron star and the angular momentum of the binary orbit are misaligned by at least ~20 deg, which is a strong argument in support of the models explaining the stability of the observed superorbital variability with the precession of the neutron star