52 research outputs found

    Circumstellar chemistry

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    The study of the outer envelopes of cool evolved stars has become an active area of research. The physical properties of CS envelopes are presented. Observations of many wavelengths bands are relevant. A summary of observations and a discussion of theoretical considerations concerning the chemistry are summarized. Recent theoretical considerations show that the thermal equilibrium model is of limited use for understanding the chemistry of the outer CS envelopes. The theoretical modeling of the chemistry of CS envelopes provides a quantitive test of chemical concepts which have a broader interest than the envelopes themselves

    Jet Power in Pre-Planetary Nebulae: Observations vs. Theory

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    High velocity jets are among the most prominent features of a wide class of planetary nebulae, but their origins are not understood. Several different types of physical model have been suggested to power the jets, but there is no consensus or preferred scenario. We compare current theoretical ideas on jet formation with observations, using the best studied pre-planetary nebulae in millimeter CO, where the dynamical properties are best defined. In addition to the mass, velocity, momentum, and energy of the jets, the mass and energetics of the equatorial mass-loss that typically accompanies jet formation prove to be important diagnostics. Our integrated approach provides estimates for some key physical quantities - such as the binding energy of the envelope when the jets are launched - and allows testing of model features using correlations between parameters. Even with a relatively small sample of well-observed objects, we find that some specific scenarios for powering jets can be ruled out or rendered implausible, and others are promising at a quantitative level.Comment: 4 pages, 1 figure, to appear in "Planetary Nebulae: an Eye to the Future", IAU Symposium 283, eds. A Manchado, L. Stanghellini, D. Schoenberne

    Dietary Plant Sterol Esters Must Be Hydrolyzed to Reduce Intestinal Cholesterol Absorption in Hamsters

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    Background: Elevated concentrations of LDL cholesterol are associated with the development of atherosclerosis and therefore are considered an important target for intervention to prevent cardiovascular diseases. The inhibition of cholesterol absorption in the small intestine is an attractive approach to lowering plasma cholesterol, one that is addressed by drug therapy as well as dietary supplementation with plant sterols and plant sterol esters (PSEs). Objective: This study was conducted to test the hypothesis that the cholesterol-lowering effects of PSE require hydrolysis to free sterols (FSs). Methods: Male Syrian hamsters were fed atherogenic diets (AIN-93M purified diet containing 0.12% cholesterol and 8% coconut oil) to which one of the following was added: no PSEs or ethers (control), 5% sterol stearate esters, 5% sterol palmitate esters (PEs), 5% sterol oleate esters (OEs), 5% sterol stearate ethers (STs; to mimic nonhydrolyzable PSE), or 3% FSs plus 2% sunflower oil. The treatments effectively created a spectrum of PSE hydrolysis across which cholesterol metabolism could be compared. Metabolic measurements included cholesterol absorption, plasma and liver lipid concentration, and fecal neutral sterol and bile acid excretion. Results: The STs and the PEs and SEs were poorly hydrolyzed (1.69–4.12%). In contrast,OEs were 88.3% hydrolyzed. The percent hydrolysis was negatively correlated with cholesterol absorption (r=20.85; P \u3c 0.0001) and positively correlated with fecal cholesterol excretion (r = 0.92; P \u3c 0.0001), suggesting that PSE hydrolysis plays a central role in the cholesterol-lowering properties of PSE. Conclusions: Our data on hamsters suggest that PSE hydrolysis and the presence of FSs is necessary to induce an optimum cholesterol-lowering effect and that poorly hydrolyzed PSEs may lower cholesterol through an alternative mechanism than that of competition with cholesterol for micelle incorporation

    The Children's Respiratory and Environmental Workgroup (CREW) birth cohort consortium: design, methods, and study population

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    Background: Single birth cohort studies have been the basis for many discoveries about early life risk factors for childhood asthma but are limited in scope by sample size and characteristics of the local environment and population. The Children’s Respiratory and Environmental Workgroup (CREW) was established to integrate multiple established asthma birth cohorts and to investigate asthma phenotypes and associated causal pathways (endotypes), focusing on how they are influenced by interactions between genetics, lifestyle, and environmental exposures during the prenatal period and early childhood. Methods and results: CREW is funded by the NIH Environmental influences on Child Health Outcomes (ECHO) program, and consists of 12 individual cohorts and three additional scientific centers. The CREW study population is diverse in terms of race, ethnicity, geographical distribution, and year of recruitment. We hypothesize that there are phenotypes in childhood asthma that differ based on clinical characteristics and underlying molecular mechanisms. Furthermore, we propose that asthma endotypes and their defining biomarkers can be identified based on personal and early life environmental risk factors. CREW has three phases: 1) to pool and harmonize existing data from each cohort, 2) to collect new data using standardized procedures, and 3) to enroll new families during the prenatal period to supplement and enrich extant data and enable unified systems approaches for identifying asthma phenotypes and endotypes. Conclusions: The overall goal of CREW program is to develop a better understanding of how early life environmental exposures and host factors interact to promote the development of specific asthma endotypes.HHS/NIH [5UG3OD023282]; Columbia University [P01ES09600, R01 ES008977, P30ES09089, R01 ES013163, R827027]; Tucson Children's Respiratory Study (TCRS) [NHLBI 132523]; Infant Immune Study (IIS) [HL-56177]; Childhood Origins of Asthma Study (COAST) [P01 HL070831, U10 HL064305, R01 HL061879]; Wayne County Health, Environment, Allergy and Asthma Longitudinal Study (WHEALS) [R01 AI050681, R56 AI050681, R01 AI061774, R21 AI059415, K01 AI070606, R21 AI069271, R01 HL113010, R21 ES022321, P01 AI089473, R21 AI080066, R01 AI110450, R01 HD082147]; Fund for Henry Ford Health System; Childhood Allergy Study (CAS) [R01 AI024156, R03 HL067427, R01 AI051598]; Blue Cross Foundation Johnson; Fund for Henry Ford Hospital; Microbes, Allergy, Asthma and Pets (MAAP) [P01 AI089473]; Infant Susceptibility to Pulmonary Infections and Asthma following RSV Exposure (INSPIRE) [NIH/NIAID U19 AI 095227, NIH/NCATS UL1 TR 002243, NIH/NIAID K24 AI 077930, NIH/NHLBI R21 HD 087864, NIH/NHLBI X01 HL 134583]; Wisconsin Infant Study Cohort (WISC) [U19 AI104317, NCATS UL1TR000427]; Upper Midwest Agricultural Safety and Health Center (UMASH) [U54 OH010170]; RTI International, Research Triangle Park, North Carolina, USA; NIH [U24OD023382]; Urban Environment and Childhood Asthma Study (URECA) [NO1-AI-25482, HHSN272200900052C, HHSN272201000052I, NCRR/NIH RR00052, M01RR00533, 1UL1RR025771, M01RR00071, 1UL1RR024156, UL1TR001079, 5UL1RR024992-02, NCATS/NIH UL1TR000040]; Cincinnati Childhood Allergy and Air Pollution Study (CCAAPS) [R01 ES11170, R01 ES019890]; Epidemiology of Home Allergens and Asthma Study (EHAAS) [R01 AI035786]Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

    A signalome screening approach in the autoinflammatory disease TNF Receptor Associated Periodic Syndrome (TRAPS) highlights the anti-inflammatory properties of drugs for repurposing

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    TNF Receptor Associated Periodic Syndrome (TRAPS) is an autoinflammatory disease caused by mutations in TNF Receptor 1 (TNFR1). Current therapies for TRAPS are limited and do not target the pro-inflammatory signalling pathways that are central to the disease mechanism. Our aim was to identify drugs for repurposing as anti-inflammatories based on their ability to down-regulate molecules associated with inflammatory signalling pathways that are activated in TRAPS. This was achieved using rigorously optimised, high through- put cell culture and reverse phase protein microarray systems to screen compounds for their effects on the TRAPS-associated inflammatory signalome. 1360 approved, publically available, pharmacologically active substances were investigated for their effects on 40 signalling molecules associated with pro-inflammatory signalling pathways that are constitutively upregulated in TRAPS. The drugs were screened at four ten-fold concentrations on cell lines expressing both wild-type (WT) TNFR1 and TRAPS-associated C33Y mutant TNFR1, or WT TNFR1 alone; signalling molecule levels were then determined in cell lysates by the reverse phase protein microarray. A novel mathematical methodology was developed to rank the compounds for their ability to reduce the expression of signalling molecules in the C33Y-TNFR1 transfectants towards the level seen in the WT-TNFR1 transfectants. Seven high-ranking drugs were selected and tested by RPPA for effects on the same 40 signalling molecules in lysates of peripheral blood mononuclear cells (PBMCs) from C33Y-TRAPS patients compared to PBMCs from normal controls. The fluoroquinolone antibiotic lomefloxacin, as well as others from this class of compounds, showed the most significant effects on multiple pro-inflammatory signalling pathways that are constitutively activated in TRAPS; lomefloxacin dose-dependently significantly reduced expression of 7/40 signalling molecules across the Jak/Stat, MAPK, NF-kB and PI3K/AKT pathways. This study demonstrates the power of signalome screening for identifying candidates for drug repurposing

    The role of gonadotrophin-releasing hormone antagonists in the treatment of patients with advanced hormone-dependent prostate cancer in the UK.

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    PURPOSE: Comparing gonadotrophin-releasing hormone (GnRH) antagonists and agonists as androgen deprivation therapy for advanced prostate cancer (PC). METHODS: This article stems from a round-table meeting in December 2014 to compare the properties of GnRH agonists and antagonists in the published literature in order to identify the patient groups most likely to benefit from GnRH antagonist therapy. A broad PubMed and congress abstract search was carried out in preparation for the meeting to ensure that the latest data and opinion were available for the discussions. RESULTS: In randomised, controlled trials, GnRH antagonist therapy provides more rapid suppression of luteinising hormone, follicle-stimulating hormone and testosterone than GnRH agonist treatment. Compared with the GnRH agonist, there is evidence of improved disease control by a GnRH antagonist, with longer interval to prostate-specific antigen progression and greater reduction of serum alkaline phosphatase. In a post hoc analysis of six randomised trials, the risk of cardiac events within 1 year of initiating therapy was significantly lower among men receiving GnRH antagonist than agonist. Pre-clinical laboratory data suggest a number of mechanisms whereby GnRH antagonist therapy may benefit men with pre-existing cardiovascular disease (CVD), the most plausible hypothesis being that, unlike GnRH agonists, GnRH antagonists do not activate T lymphocytes, which act to increase atherosclerotic plaque rupture. CONCLUSION: When making treatment decisions, clinicians should consider comorbidities, particularly CVD, in addition to effects on PC. GnRH antagonists may be appropriate in patients with significant CV risk, existing osteopenia, lower urinary tract symptoms and significant metastatic disease

    Transancestral mapping and genetic load in systemic lupus erythematosus

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    Systemic lupus erythematosus (SLE) is an autoimmune disease with marked gender and ethnic disparities. We report a large transancestral association study of SLE using Immunochip genotype data from 27,574 individuals of European (EA), African (AA) and Hispanic Amerindian (HA) ancestry. We identify 58 distinct non-HLA regions in EA, 9 in AA and 16 in HA (B50% of these regions have multiple independent associations); these include 24 novel SLE regions (Po5 10 8), refined association signals in established regions, extended associations to additional ancestries, and a disentangled complex HLA multigenic effect. The risk allele count (genetic load) exhibits an accelerating pattern of SLE risk, leading us to posit a cumulative hit hypothesis for autoimmune disease. Comparing results across the three ancestries identifies both ancestry-dependent and ancestry-independent contributions to SLE risk. Our results are consistent with the unique and complex histories of the populations sampled, and collectively help clarify the genetic architecture and ethnic disparities in SL

    Patient and stakeholder engagement learnings: PREP-IT as a case study

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    Correction to: Cluster identification, selection, and description in Cluster randomized crossover trials: the PREP-IT trials

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    An amendment to this paper has been published and can be accessed via the original article
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