Feasibility of the modified sequential organ function assessment score in a resource-constrained setting: a prospective observational study.

BackgroundSub-Saharan Africa has a great burden of critical illness with limited health care resources. We evaluated the feasibility and utility of the modified Sequential Organ Function Assessment (mSOFA) score in assessing morbidity and mortality in the National Referral Hospital's intensive care unit (ICU) for one year.MethodsWe conducted a prospective, observational cohort study on patients above 12 years of age admitted to the ICU at Mulago Hospital (Kampala, Uganda). All SOFA scores were determined at admission and at 48 h. We modified the SOFA score by replacing the PaO2/FiO2 ratio with SPO2/FiO2. The primary outcome was ICU mortality.ResultsThis ICU cohort of 118 patients had a mean age of 37 years and an ICU mortality rate of 46.6%. Non-survivors had higher initial (7.7 SD 3.8 vs. 5.5 SD 3.3; p = 0.007), mean (8.1 SD 3.9 vs 4.7 SD 2.6; p < 0.001) and highest mSOFA scores (9.4 SD 4.2 vs. 5.8 SD 3.2; p < 0.001), with an increase of 1.0 (SD 3.1) mSOFA on average after 48 h when compared to survivors (p < 0.001). The area under the receiver operating characteristic curves for each mSOFA category was: initial-0.68, mean-0.76, highest-0.76 and delta mSOFA-0.74. Multivariate logistic regression analysis showed no significant association between mSOFA scores and mortality.ConclusionOur results confirm that calculation of the mSOFA score is feasible for an ICU population in a resource-limited country. More data are needed to test for an association between mSOFA and mortality

Self-Consistent Dynamic Models of Steady Ionization Fronts I. Weak-D and Weak-R Fronts

We present a method for including steady-state gas flows in the plasma physics code Cloudy, which was previously restricted to modeling static configurations. The numerical algorithms are described in detail, together with an example application to plane-parallel ionization-bounded HII regions. As well as providing the foundation for future applications to more complex flows, we find the following specific results regarding the effect of advection upon ionization fronts in HII regions: 1. Significant direct effects of advection on the global emission properties occur only when the ionization parameter is lower than is typical for HII regions. 2. The overheating of partially ionized gas in the front is not large, even for supersonic (R-type) fronts. 3. The most significant morphological signature of advective fronts is an electron density spike that occurs at the ionization front. Observational evidence for such a spike is found in images of the Orion bar. 4. Plane-parallel, weak-D fronts are found to show at best a shallow correlation between mean velocity and ionization potential for optical emission lines even when the flow velocity closely approaches the ionized sound speed.Comment: ApJ, main journal, in press 1 March 2005, v621 (22 pages, 3 appendices, 21 figures) PDF version with high-res figures available from http://www.astrosmo.unam.mx/~w.henney/astro-ph/0501034

Cost-Effectiveness Model Shows Superiority of Wireless Spinal Cord Stimulation Implantation Without a Separate Trial.

OBJECTIVE: We evaluated the cost-effectiveness of wireless spinal cord stimulation (Wireless SCS) with single stage direct to permanent implantation vs. screening with temporary electrodes and an external pulse generator followed by implantation of a system for long-term use (IPG SCS). MATERIALS AND METHODS: We created a cost model that takes a 2019 United States (U.S.) payer perspective and is based on IPG SCS cost models for subjects with chronic back and/or leg pain. Our six-month decision tree includes the screening trial period (success ≥50% relief) and leads to various levels of pain relief with or without complications for IPG SCS and Wireless SCS and without complications for conventional medical management (CMM). Every three months in the follow-on 15-year Markov model (with costs and quality-adjusted life years discounted 3.5% annually), subjects remain stable or transition to deteriorated health or death. Subjects who fail SCS receive CMM. After 60 Markov cycles, a 100,000-sample simulation reveals the impact of maximum willingness-to-pay (WTP) from $10,000 to$100,000 per quality-adjusted life year on net monetary benefit (NMB). Sensitivity analyses considered the impact of the Wireless SCS screening success rate, Wireless SCS device cost, and IPG SCS device longevity. RESULTS: Compared with IPG SCS, Wireless SCS offers higher clinical effectiveness at a lower cost and a higher NMB for our WTP thresholds and is, thus, dominant. Wireless SCS is also cost-effective compared with CMM. Results remain robust with 1) Wireless SCS screening success rates as low as 85% (dominant), 2) the cost of the Wireless SCS devices as high as $55,000 (cost-effective), and 3) IPG SCS devices lasting 12 years (dominant). CONCLUSIONS: In this model, compared with IPG SCS or with CMM, Wireless SCS is a superior strategy

New annelids from Florida

3 p. : ill. ; 24 cm

From Ultracompact to Extended HII Regions. II: Cloud Gravity and Stellar Motion

The dynamical evolution of HII regions with and without stellar motion in dense, structured molecular clouds is studied. Clouds are modeled in hydrostatic equilibrium, with gaussian central cores and external halos that obey r**-2 and r**-3 density power laws. The cloud gravity is included as a time-independent, external force. Stellar velocities of 0, 2, 8, and 12 km/s are considered. When stellar motion is included, stars move from the central core to the edge of the cloud, producing transitions from ultracompact to extended HII regions as the stars move into lower density regions. The opposite behavior occurs when stars move toward the cloud cores. The main conclusion of our study is that ultracompact HII regions are pressure-confined entities while they remain embedded within dense cores. The confinement comes from ram and/or ambient pressures. The survival of ultracompact regions depends on the position of the star with respect to the core, the stellar life-time, and the core crossing time. Stars with velocities less than the cloud dispersion velocity can produce cometary shapes smaller than 0.1 pc at times of 20,000 yr or more. The sequence Ultracompact to Compact to Extended HII region shows a variety of unpredictable structures due to ionization-shock front instability. Some ultracompact HII regions with a core-halo morphology might be explained by self-blocking effects, when stars overtake and ionize leading, piled-up clumps of neutral gas. We use thermal energy to support the cloud against gravity; the results remain the same if other types of isotropic cloud support are used.Comment: 27 pages, 7 ps figures, 5 png figures; submitted to Astrophysical Journa

Dynamical HII Region Evolution in Turbulent Molecular Clouds

We present numerical radiation-hydrodynamic simulations of the evolution of HII regions formed in an inhomogeneous medium resulting from turbulence simulations. We find that the filamentary structure of the underlying density distribution produces a highly irregular shape for the ionized region, in which the ionization front escapes to large distances in some directions within 80,000 years. In other directions, on the other hand, neutral gas in the form of dense globules persists within 1 parsec of the central star for the full duration of our simulation (400,000 years). Divergent photoablation flows from these globules maintain a root-mean-squared velocity in the ionized gas that is close to the ionized sound speed. Simulated images in optical emission lines show morphologies that are in strikingly detailed agreement with those observed in real HII regions.Comment: Minor changes to sync with accepted version. 7 pages, ApJ in press. Accompanying video available at http://ifront.org/wiki/Turbulent_Hii_Regions/Paper

Hydrodynamics of Cometary Compact HII Regions

We present numerical radiation-hydrodynamic simulations of cometary HII regions for a number of champagne flow and bowshock models. For the champagne flow models we study smooth density distributions with both steep and shallow gradients. We also consider cases where the ionizing star has a strong stellar wind, and cases in which the star additionally has a proper motion within the ambient density gradient. We present simulated emission-measure maps and long-slit spectra of our results. Our numerical models are not tailored to any particular object but comparison with observations from the literature shows that, in particular, the models combining density gradients and stellar winds are able to account for both the morphology and radial velocity behavior of several observed cometary HII regions, such as the well-studied object G29.96-0.02.Comment: Astrophysical Journal Supplement Series in press. 25 pages in emulate ApJ style. Revised to correspond to accepted pape

Evidence that links loss of cyclooxygenase-2 with increased asymmetric dimethylarginine : novel explanation of cardiovascular side effects associated with anti-inflammatory drugs

© 2014 The Authors. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution, and reproduction in any medium, provided that the original work is properly cited.BACKGROUND: Cardiovascular side effects associated with cyclooxygenase-2 inhibitor drugs dominate clinical concern. Cyclooxygenase-2 is expressed in the renal medulla where inhibition causes fluid retention and increased blood pressure. However, the mechanisms linking cyclooxygenase-2 inhibition and cardiovascular events are unknown and no biomarkers have been identified.METHODS AND RESULTS: Transcriptome analysis of wild-type and cyclooxygenase-2(-/-) mouse tissues revealed 1 gene altered in the heart and aorta, but >1000 genes altered in the renal medulla, including those regulating the endogenous nitric oxide synthase inhibitors asymmetrical dimethylarginine (ADMA) and monomethyl-l-arginine. Cyclo-oxygenase-2(-/-) mice had increased plasma levels of ADMA and monomethyl-l-arginine and reduced endothelial nitric oxide responses. These genes and methylarginines were not similarly altered in mice lacking prostacyclin receptors. Wild-type mice or human volunteers taking cyclooxygenase-2 inhibitors also showed increased plasma ADMA. Endothelial nitric oxide is cardio-protective, reducing thrombosis and atherosclerosis. Consequently, increased ADMA is associated with cardiovascular disease. Thus, our study identifies ADMA as a biomarker and mechanistic bridge between renal cyclooxygenase-2 inhibition and systemic vascular dysfunction with nonsteroidal anti-inflammatory drug usage.CONCLUSIONS: We identify the endogenous endothelial nitric oxide synthase inhibitor ADMA as a biomarker and mechanistic bridge between renal cyclooxygenase-2 inhibition and systemic vascular dysfunction.Peer reviewedFinal Published versio

Teleost Growth Factor Independence (Gfi) Genes Differentially Regulate Successive Waves of Hematopoiesis

Growth Factor Independence (Gfi) transcription factors play essential roles in hematopoiesis, differentially activating and repressing transcriptional programs required for hematopoietic stem/progenitor cell (HSPC) development and lineage specification. In mammals, Gfi1a regulates hematopoietic stem cells (HSC), myeloid and lymphoid populations, while its paralog, Gfi1b, regulates HSC, megakaryocyte and erythroid development. In zebrafish, gfi1aa is essential for primitive hematopoiesis; however, little is known about the role of gfi1aa in definitive hematopoiesis or about additional gfi factors in zebrafish. Here, we report the isolation and characterization of an additional hematopoietic gfi factor, gfi1b. We show that gfi1aa and gfi1b are expressed in the primitive and definitive sites of hematopoiesis in zebrafish. Our functional analyses demonstrate that gfi1aa and gfi1b have distinct roles in regulating primitive and definitive hematopoietic progenitors, respectively. Loss of gfi1aa silences markers of early primitive progenitors, scl and gata1. Conversely, loss of gfi1b silences runx-1, c-myb, ikaros and cd41, indicating that gfi1b is required for definitive hematopoiesis. We determine the epistatic relationships between the gfi factors and key hematopoietic transcription factors, demonstrating that gfi1aa and gfi1b join lmo2, scl, runx-1 and c-myb as critical regulators of teleost HSPC. Our studies establish a comparative paradigm for the regulation of hematopoietic lineages by gfi transcription factors.Stem Cell and Regenerative Biolog