Brown University

About: Brown University is a education organization based out in Providence, Rhode Island, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 35778 authors who have published 90896 publications receiving 4471489 citations. The organization is also known as: brown.edu & Brown.

Effect of eritoran, an antagonist of MD2-TLR4, on mortality in patients with severe sepsis: the ACCESS randomized trial.

Abstract: Importance Eritoran is a synthetic lipid A antagonist that blocks lipopolysaccharide (LPS) from binding at the cell surface MD2-TLR4 receptor. LPS is a major component of the outer membrane of gram-negative bacteria and is a potent activator of the acute inflammatory response. Objective To determine if eritoran, a TLR4 antagonist, would significantly reduce sepsis-induced mortality. Design, Setting, and Participants We performed a randomized, double-blind, placebo-controlled, multinational phase 3 trial in 197 intensive care units. Patients were enrolled from June 2006 to September 2010 and final follow-up was completed in September 2011. Interventions Patients with severe sepsis (n = 1961) were randomized and treated within 12 hours of onset of first organ dysfunction in a 2:1 ratio with a 6-day course of either eritoran tetrasodium (105 mg total) or placebo, with n = 1304 and n = 657 patients, respectively. Main Outcome Measures The primary end point was 28-day all-cause mortality. The secondary end points were all-cause mortality at 3, 6, and 12 months after beginning treatment. Results Baseline characteristics of the 2 study groups were similar. In the modified intent-to-treat analysis (randomized patients who received at least 1 dose) there was no significant difference in the primary end point of 28-day all-cause mortality with 28.1% (366/1304) in the eritoran group vs 26.9% (177/657) in the placebo group (P = .59; hazard ratio, 1.05; 95% CI, 0.88-1.26; difference in mortality rate, −1.1; 95% CI, −5.3 to 3.1) or in the key secondary end point of 1-year all-cause mortality with 44.1% (290/657) in the eritoran group vs 43.3% (565/1304) in the placebo group, Kaplan-Meier analysis of time to death by 1 year, P = .79 (hazard ratio, 0.98; 0.85-1.13). No significant differences were observed in any of the prespecified subgroups. Adverse events, including secondary infection rates, did not differ between study groups. Conclusions and Relevance Among patients with severe sepsis, the use of eritoran, compared with placebo, did not result in reduced 28-day mortality. Trial Registration clinicaltrials.gov Identifier: NCT00334828

Oleylamine-mediated synthesis of Pd nanoparticles for catalytic formic acid oxidation.

Abstract: We report a facile synthesis of monodisperse Pd nanoparticles by the reduction of Pd(acac)2 with oleylamine and borane tributylamine complex. The oleylamine-coated Pd nanoparticles are readily “cleaned” with a 99% acetic acid wash, and the Pd particles supported on Ketjen carbon are catalytically active for formic acid oxidation in HClO4 solution. The catalyst shows no obvious activity degradation after 1500 cyclic voltammetry cycles under ambient conditions. These Pd particles hold promise as a highly active non-Pt catalyst for fuel cell applications.

Accounting for the Effect Of Health on Economic Growth

Abstract: I use microeconomic estimates of the effect of health on individual outcomes to construct macroeconomic estimates of the proximate effect of health on GDP per capita. I employ a variety of methods to construct estimates of the return to health, which I combine with cross-country and historical data on height, adult survival rates, and age at menarche. Using my preferred estimate, eliminating health differences among countries would reduce the variance of log GDP per worker by 9.9 percent and reduce the ratio of GDP per worker at the 90th percentile to GDP per worker at the lOth percentile from 20.5 to 17.9. While this effect is economically significant, it is also substantially smaller than estimates of the effect of health on economic growth that are derived from cross-country regressions.

Liver regeneration. 2. Role of growth factors and cytokines in hepatic regeneration.

Abstract: During liver regeneration quiescent hepatocytes undergo one or two rounds of replication and then return to a nonproliferative state. Growth factors regulate this process by providing both stimulatory and inhibitory signals for cell proliferation. EGF, TGF alpha, and HGF stimulate DNA synthesis in hepatocytes in vivo and in culture but the sensitivity of cultured hepatocytes to the mitogenic effects of these factors is much higher than that of quiescent hepatocytes in intact livers. We have proposed that after partial hepatectomy, hepatocytes enter a state of replicative competence ("priming") before they can fully respond to growth factors. The priming step is an initiating event in liver regeneration that involves the activation and DNA binding of NF-kappa B and other transcription factors, which could be induced by TNF or other cytokines. EGF, TGF alpha, and HGF have major effects on liver growth. TGF alpha expression correlates with hepatocyte DNA synthesis during liver development and growth and the constitutive expression of the factor confers proliferative activity to adult hepatocytes in vivo and in culture. The data indicate that the activity of stimulatory and inhibitory growth factors such as TGF beta 1 and activin is low in normal livers but that the expression of both types of factors increase during liver regeneration.

Graphene microsheets enter cells through spontaneous membrane penetration at edge asperities and corner sites

Abstract: Understanding and controlling the interaction of graphene-based materials with cell membranes is key to the development of graphene-enabled biomedical technologies and to the management of graphene health and safety issues. Very little is known about the fundamental behavior of cell membranes exposed to ultrathin 2D synthetic materials. Here we investigate the interactions of graphene and few-layer graphene (FLG) microsheets with three cell types and with model lipid bilayers by combining coarse-grained molecular dynamics (MD), all-atom MD, analytical modeling, confocal fluorescence imaging, and electron microscopic imaging. The imaging experiments show edge-first uptake and complete internalization for a range of FLG samples of 0.5- to 10-μm lateral dimension. In contrast, the simulations show large energy barriers relative to kBT for membrane penetration by model graphene or FLG microsheets of similar size. More detailed simulations resolve this paradox by showing that entry is initiated at corners or asperities that are abundant along the irregular edges of fabricated graphene materials. Local piercing by these sharp protrusions initiates membrane propagation along the extended graphene edge and thus avoids the high energy barrier calculated in simple idealized MD simulations. We propose that this mechanism allows cellular uptake of even large multilayer sheets of micrometer-scale lateral dimension, which is consistent with our multimodal bioimaging results for primary human keratinocytes, human lung epithelial cells, and murine macrophages.