270 research outputs found
Safety and efficacy of dexpramipexole in eosinophilic asthma (EXHALE): aĀ randomized controlled trial
BACKGROUND: There is a need for new and effective oral asthma therapies. Dexpramipexole, an oral eosinophil-lowering drug, has not previously been studied in asthma. OBJECTIVE: We sought to evaluate the safety and efficacy of dexpramipexole in lowering blood and airway eosinophilia in subjects with eosinophilic asthma. METHODS: We performed a randomized, double-blind, placebo-controlled proof-of-concept trial in adults with inadequately controlled moderate to severe asthma and blood absolute eosinophil count (AEC) greater than or equal to 300/Ī¼L. Subjects were randomly assigned (1:1:1:1) to dexpramipexole 37.5, 75, or 150 mg BID (twice-daily) or placebo. The primary end point was the relative change in AEC from baseline to week 12. Prebronchodilator FEV1 week-12 change from baseline was a key secondary end point. Nasal eosinophil peroxidase was an exploratory end point. RESULTS: A total of 103 subjects were randomly assigned to dexpramipexole 37.5 mg BID (NĀ = 22), 75 mg BID (NĀ = 26), 150 mg BID (NĀ = 28), or placebo (NĀ = 27). Dexpramipexole significantly reduced placebo-corrected AEC week-12 ratio to baseline, in both the 150-mg BID (ratio, 0.23; 95% CI, 0.12-0.43; PĀ < .0001) and the 75-mg BID (ratio, 0.34; 95% CI, 0.18-0.65; PĀ = .0014) dose groups, corresponding to 77% and 66% reductions, respectively. Dexpramipexole reduced the exploratory end point of nasal eosinophil peroxidase week-12 ratio to baseline in the 150-mg BID (median, 0.11; PĀ = .020) and the 75-mg BID (median, 0.17; PĀ = .021) groups. Placebo-corrected FEV1 increases were observed starting at week 4 (nonsignificant). Dexpramipexole displayed a favorable safety profile. CONCLUSIONS: Dexpramipexole demonstrated effective eosinophil lowering and was well tolerated. Additional larger clinical trials are needed to understand the clinical efficacy of dexpramipexole in asthma
Coordinated Sampling of Microorganisms Over Freshwater and Saltwater Environments Using an Unmanned Surface Vehicle (USV) and a Small Unmanned Aircraft System (sUAS)
Biological aerosols (bioaerosols) are ubiquitous in terrestrial and aquatic environments and may influence cloud formation and precipitation processes. Little is known about the aerosolization and transport of bioaerosols from aquatic environments. We designed and deployed a bioaerosol-sampling system onboard an unmanned surface vehicle (USV; a remotely operated boat) to collect microbes and monitor particle sizes in the atmosphere above a salt pond in Falmouth, MA, United States and a freshwater lake in Dublin, VA, United States. The bioaerosol-sampling system included a series of 3D-printed impingers, two different optical particle counters, and a weather station. A small unmanned aircraft system (sUAS; a remotely operated airplane) was used in a coordinated effort with the USV to collect microorganisms on agar media 50 m above the surface of the water. Samples from the USV and sUAS were cultured on selective media to estimate concentrations of culturable microorganisms (bacteria and fungi). Concentrations of microbes from the sUAS ranged from 6 to 9 CFU/m3 over saltwater, and 12 to 16 CFU/m3 over freshwater (over 10-min sampling intervals) at 50 m above ground level (AGL). Concentrations from the USV ranged from 0 (LOD) to 42,411 CFU/m3 over saltwater, and 0 (LOD) to 56,809 CFU/m3 over freshwater (over 30-min sampling intervals) in air near the water surface. Particle concentrations recorded onboard the USV ranged from 0 (LOD) to 288 Ī¼g/m3 for PM1, 1 to 290 Ī¼g/m3 for PM2.5, and 1 to 290 Ī¼g/m3 for PM10. A general trend of increasing concentration with an increase in particle size was recorded by each sensor. Through laboratory testing, the collection efficiency of the 3D-printed impingers was determined to be 75% for 1 Ī¼m beads and 99% for 3 Ī¼m beads. Additional laboratory tests were conducted to determine the accuracy of the miniaturized optical particle counters used onboard the USV. Future work aims to understand the distribution of bioaerosols above aquatic environments and their potential association with cloud formation and precipitation processes
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Spent fuel waste form characteristics: Grain and fragment size statistical dependence for dissolution response
The Yucca Mountain Project of the US Department of Energy is investigating the suitability of the unsaturated zone at Yucca Mountain, NV, for a high-level nuclear waste repository. All of the nuclear waste will be enclosed in a container package. Most of the nuclear waste will be in the form of fractured UO{sub 2} spent fuel pellets in Zircaloy-clad rods from electric power reactors. If failure of both the container and its enclosed clad rods occurs, then the fragments of the fractured UO{sub 2} spent fuel will be exposed to their surroundings. Even though the surroundings are an unsaturated zone, a possibility of water transport exists, and consequently, UO{sub 2} spent fuel dissolution may occur. A repository requirement imposes a limit on the nuclide release per year during a 10,000 year period; thus the short term dissolution response from fragmented fuel pellet surfaces in any given year must be understood. This requirement necessitates that both experimental and analytical activities be directed toward predicting the relatively short term dissolution response of UO{sub 2} spent fuel. The short term dissolution response involves gap nuclides, grain boundary nuclides, and grain volume nuclides. Analytical expressions are developed that describe the combined geometrical influences of grain boundary nuclides and grain volume nuclides on the dissolution rate of spent fuel. 7 refs., 1 fig
A Compton-vetoed germanium detector with increased sensitivity at low energies
The difficulty to directly detect plutonium in spent nuclear fuel due to the high Compton background of the fission products motivates the design of a Gamma detector with improved sensitivity at low energies. We have built such a detector by operating a thin high-purity Ge detector with a large scintillator Compton veto directly behind it. The Ge detector is thin to absorb just the low-energy Pu radiation of interest while minimizing Compton scattering of high energy radiation from the fission products. The subsequent scintillator is large so that forward scattered photons from the Ge detector interact in it at least once to provide an anti-coincidence veto for the Ge detector. For highest sensitivity, additional material in the line-of-sight is minimized, the radioactive sample is kept thin, and its radiation is collimated. We will discuss the instrument design, and demonstrate the feasibility of the approach with a prototype that employs two large CsI scintillator vetoes. Initial spectra of a thin Cs-137 calibration source show a background suppression of a factor of {approx}2.5 at {approx}100 keV, limited by an unexpectedly thick 4 mm dead layer in the Ge detector
Neuroinflammation, Mast Cells, and Glia: Dangerous Liaisons
The perspective of neuroinflammation as an epiphenomenon following neuron damage is being replaced by the awareness of glia and their importance in neural functions and disorders. Systemic inflammation generates signals that communicate with the brain and leads to changes in metabolism and behavior, with microglia assuming a pro-inflammatory phenotype. Identification of potential peripheral-to-central cellular links is thus a critical step in designing effective therapeutics. Mast cells may fulfill such a role. These resident immune cells are found close to and within peripheral nerves and in brain parenchyma/meninges, where they exercise a key role in orchestrating the inflammatory process from initiation through chronic activation. Mast cells and glia engage in crosstalk that contributes to accelerate disease progression; such interactions become exaggerated with aging and increased cell sensitivity to stress. Emerging evidence for oligodendrocytes, independent of myelin and support of axonal integrity, points to their having strong immune functions, innate immune receptor expression, and production/response to chemokines and cytokines that modulate immune responses in the central nervous system while engaging in crosstalk with microglia and astrocytes. In this review, we summarize the findings related to our understanding of the biology and cellular signaling mechanisms of neuroinflammation, with emphasis on mast cell-glia interactions
Influenza Virus Infectivity Is Retained in Aerosols and Droplets Independent of Relative Humidity
Pandemic and seasonal influenza viruses can be transmitted through aerosols and droplets, in which viruses must remain stable and infectious across a wide range of environmental conditions. Using humidity-controlled chambers, we studied the impact of relative humidity on the stability of 2009 pandemic influenza A(H1N1) virus in suspended aerosols and stationary droplets. Contrary to the prevailing paradigm that humidity modulates the stability of respiratory viruses in aerosols, we found that viruses supplemented with material from the apical surface of differentiated primary human airway epithelial cells remained equally infectious for 1 hour at all relative humidities tested. This sustained infectivity was observed in both fine aerosols and stationary droplets. Our data suggest, for the first time, that influenza viruses remain highly stable and infectious in aerosols across a wide range of relative humidities. These results have significant implications for understanding the mechanisms of transmission of influenza and its seasonality
Relationships between Levels of Serum IgE, Cell-Bound IgE, and IgE-Receptors on Peripheral Blood Cells in a Pediatric Population
Background: Elevated serum immunoglobulin (Ig) E is a diagnostic marker of immediate-type allergic reactions. We hypothesize that serum IgE does not necessarily reflect total body IgE because in vivo IgE can be bound to cell surface receptors such as FcĪµRI and FcĪµRII (CD23). The aim of this study was to analyze the relationships between levels of serum IgE, cell-bound IgE, and IgE-receptors on peripheral blood cells in a pediatric population. Methodology: Whole blood samples from 48 children (26 boys, 22 girls, mean age 10,3Ā±5,4 years) were analyzed by flow cytometry for FcĪµRI, CD23, and cell-bound IgE on dendritic cells (CD11c+MHC class II+), monocytes (CD14+), basophils (CD123+MHC class II-) and neutrophils (myeloperoxidase+). Total serum IgE was measured by ELISA and converted into z-units to account for age-dependent normal ranges. Correlations were calculated using Spearman rank correlation test. Principal Findings: Dendritic cells, monocytes, basophils, and neutrophils expressed the high affinity IgE-receptor FcĪµRI. Dendritic cells and monocytes also expressed the low affinity receptor CD23. The majority of IgE-receptor positive cells carried IgE on their surface. Expression of both IgE receptors was tightly correlated with cell-bound IgE. In general, cell-bound IgE on FcĪµRI+ cells correlated well with serum IgE. However, some patients carried high amounts of cell-bound IgE despite low total serum IgE levels. Conclusion/Significance: In pediatric patients, levels of age-adjusted serum IgE, cell-bound IgE, and FcĪµRI correlate. Even in the absence of elevated levels of serum IgE, cell-bound IgE can be detected on peripheral blood cells in a subgroup of patients
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