Management of an incidental finding of right internal jugular vein agenesis

published_or_final_versio

Remifentanil reduces the release of biochemical markers of myocardial damage after coronary artery bypass surgery: A randomized trial

Objective: Opioids, including remifentanil, have been demonstrated to confer cardiac protection against ischemia reperfusion injury in animals. This study evaluated whether remifentanil preconditioning is protective in first-time elective on-pump coronary artery bypass surgery patients receiving a standardized fentanyl (25 μg/kg in total) and propofol anesthetic. Design: A prospective, double blind, randomized, controlled study. Setting: University hospital; single institution. Participants: Forty patients scheduled for first-time elective, on-pump coronary artery bypass surgery for at least 3 diseased vessels. Interventions: Patients randomized to the remifentanil group (n = 20) received a 1 μg/kg bolus followed by a 0.5 μg/kg/min infusion for 30 minutes after induction but before sternotomy, while the control group (n = 20) received normal saline. Serial samples for measurement of creatine kinase (CK-MB), cardiac troponin I (cTnI), ischemia-modified albumin (IMA) and heart-type fatty-acid-binding protein (hFABP) were taken at baseline, prebypass, T = 10 minutes, 2, 6, 12, and 24 hours after cross-clamp release, to assess the degree of myocardial damage. Measurements and Main Results: Patients in the remifentanil group had lower levels of CK-MB from T = 2 hours to 24 hours, cTnI from T = 10 minutes to T = 12 hours, IMA from T = 10 minutes to T = 2 hours and h-FABP from T = 10 minutes to T = 12 hours (p < 0.05). The time to tracheal extubation was shorter in patients in the remifentanil group. The overall lengths of ICU and hospital stays were not different. Conclusions: The addition of remifentanil to the anesthesia regimen reduced the degree of myocardial damage. This incremental benefit may be attributable either to remifentanil itself or to an overall increased opioid dose, the latter may be necessary to trigger cardiac protection. © 2010 Elsevier Inc. All rights reserved.postprin

Isoflurane And Propofol Synergy In Reducing Heart-type Fatty Acid Binding Protein In Patients Undergoing Coronary Artery Bypass Graft Surgery

Conference Theme: Emerging Therapies for an Aging Populationpublished_or_final_versio

Elemental Abundances in the X-Ray Gas of Early-Type Galaxies with XMM and Chandra Observations

The source of hot gas in elliptical galaxies is thought to be due to stellar mass loss, with contributions from supernova events and possibly from infall from a surrounding environment. This picture predicts supersolar values for the metallicity of the gas toward the inner part of the galaxy, which can be tested by measuring the gas phase abundances. We use high-quality data for 10 nearby early-type galaxy from XMM-Newton, featuring both the EPIC and the Reflection Grating Spectrometer, where the strongest emission lines are detected with little blending; some Chandra data are also used. We find excellent consistency in the elemental abundances between the different XMM instruments and good consistency with Chandra. Differences in abundances with aperture size and model complexity are examined, but large differences rarely occur. For a two-temperature thermal model plus a point source contribution, the median Fe and O abundances are 0.86 and 0.44 of the Solar value, while Si and Mg abundances are similar to that for Fe. This is similar to stellar abundances for these galaxies but supernovae were expected to enhance the gas phase abundances considerably, which is not observed.Comment: 35 pages, 10 figures, accepted for publication in Astrophysical Journa

A Two Hour Quasi-Period in an Ultra-luminous X-Ray source in NGC628

Quasi-periodic oscillations and X-ray spectroscopy are powerful probes of black hole masses and accretion disks, and here we apply these diagnostics to an ultraluminous X-ray source (ULX) in the spiral galaxy NGC628 (M74). This object was observed four times over two years with the Chandra X-ray Observatory and XMM-Newton, with three long observations showing dramatic variability, distinguished by a series of outbursts with a quasi-period (QPO) of 4,000-7,000 seconds. This is unique behavior among both ULXs and Galactic X-ray binaries due to the combination of its burst-like peaks and deep troughs, its long quasi-periods, its high variation amplitudes of $>90$%, and its substantial variability between observations. The X-ray spectra is fitted by an absorbed accretion disk plus a power-law component, suggesting the ULX was in a spectral state analogous to the Low Hard state or the Very High state of Galactic black hole X-ray binaries. A black hole mass of $\sim2$--$20\times10^3 M_\odot$ is estimated from the $f_b$--$M_\bullet$ scaling relation found in the Galactic X-ray binaries and active galactic nuclei.Comment: 12 pages, 3 figures. accepted for publication in ApJ Lette

Isoflurane and propofol synergy in reducing myocardial ischemia-reperfusion injury in patients

Abstract no. A285postprin

Ultra-luminous X-ray Sources in nearby galaxies from ROSAT HRI observations II. statistical properties

The statistical properties of the ultra-luminous X-ray source (ULX) populations extracted from the ROSAT HRI survey of X-ray point sources in nearby galaxies in Paper I are studied to reveal connections between the ULX phenomenon and survey galaxy properties. The $logN$--$logS$ relation is used to calculate and remove the influence of false ULXs from the background and/or foreground objects. Study of the luminosity functions shows that the regular ULXs below $10^{40}$ erg/sec are an extension of the ordinary HMXB/LMXB population below $10^{39}$ erg/sec in the late-type galaxies, and that the extreme ULXs above $10^{40}$ erg/sec might be a different population from the regular ULXs. This survey confirms statistically that the ULX phenomenon is closely connected to star formation activities, since ULXs preferentially occur in late-type galaxies rather than in early-typTwo ULX populations, the HMXB-like ULXs as an extension of the ordinary HMXB population associated with the young stellar population and the LMXB-like ULXs as an extension of the ordinary LMXB population associated with the old stellar population, are both required to account for the total ULX population. It is found that the LMXB-like ULXs dominate the ULX population at low star formation rates, while HMXB-like ULXs dominate at high star formation rates. However, an accurate quantitative description of the relative fractions of HMXB-like ULXs and LMXB-like ULXs is impossible in the current HRI survey due to the source blending effects, and a Chandra survey of the X-ray point sources in nearby galaxies would be required for this purpose. e galaxies, and ULXs in late-type galaxies tend to trace the spiral arms.Comment: 45 pages, 14 figures, 5 tables. submitted to Ap

The diverse hot gas content and dynamics of optically similar low-mass elliptical galaxies

The presence of hot X-ray emitting gas is ubiquitous in massive early-type galaxies. However, much less is known about the content and physical status of the hot X-ray gas in low-mass ellipticals. In the present paper we study the X-ray gas content of four low-mass elliptical galaxies using archival Chandra X-ray observations. The sample galaxies, NGC821, NGC3379, NGC4278, and NGC4697, have approximately identical K-band luminosities, and hence stellar masses, yet their X-ray appearance is strikingly different. We conclude that the unresolved emission in NGC821 and NGC3379 is built up from a multitude of faint compact objects, such as coronally active binaries and cataclysmic variables. Despite the non-detection of X-ray gas, these galaxies may host low density, and hence low luminosity, X-ray gas components, which undergo a Type Ia supernova (SN Ia) driven outflow. We detect hot X-ray gas with a temperature of kT ~ 0.35 keV in NGC4278, the component of which has a steeper surface brightness distribution than the stellar light. Within the central 50 arcsec (~3.9 kpc) the estimated gas mass is ~3 x 10^7 M_sun, implying a gas mass fraction of ~0.06%. We demonstrate that the X-ray gas exhibits a bipolar morphology in the northeast-southwest direction, indicating that it may be outflowing from the galaxy. The mass and energy budget of the outflow can be maintained by evolved stars and SNe Ia, respectively. The X-ray gas in NGC4697 has an average temperature of kT ~ 0.3 keV, and a significantly broader distribution than the stellar light. The total gas mass within 90 arcsec (~5.1 kpc) is ~2.1 x 10^8 M_sun, hence the gas mass fraction is ~0.4%. Based on the distribution and physical parameters of the X-ray gas, we conclude that it is most likely in hydrostatic equilibrium, although a subsonic outflow may be present.Comment: 14 pages, 8 figures, 3 tables, accepted for publication in Ap