22 research outputs found
The Space Interferometry Mission Astrometric Grid Giant-Star Survey. I. Stellar Parameters and Radial Velocity Variability
We present results from a campaign of multiple epoch echelle spectroscopy of
relatively faint (V = 9.5-13.5 mag) red giants observed as potential
astrometric grid stars for the Space Interferometry Mission (SIM PlanetQuest).
Data are analyzed for 775 stars selected from the Grid Giant Star Survey
spanning a wide range of effective temperatures (Teff), gravities and
metallicities. The spectra are used to determine these stellar parameters and
to monitor radial velocity (RV) variability at the 100 m/s level. The degree of
RV variation measured for 489 stars observed two or more times is explored as a
function of the inferred stellar parameters. The percentage of radial velocity
unstable stars is found to be very high -- about 2/3 of our sample. It is found
that the fraction of RV-stable red giants (at the 100 m/s level) is higher
among stars with Teff \sim 4500 K, corresponding to the calibration-independent
range of infrared colors 0.59 < (J-K_s)_0 < 0.73. A higher percentage of
RV-stable stars is found if the additional constraints of surface gravity and
metallicity ranges 2.3< log g < 3.2 and -0.5 < [Fe/H] < -0.1, respectively, are
applied. Selection of stars based on only photometric values of effective
temperature (4300 K < Teff < 4700 K) is a simple and effective way to increase
the fraction of RV-stable stars. The optimal selection of RV-stable stars,
especially in the case when the Washington photometry is unavailable, can rely
effectively on 2MASS colors constraint 0.59 < (J-K_s)_0 < 0.73. These results
have important ramifications for the use of giant stars as astrometric
references for the SIM PlanetQuest.Comment: Astronomical Journal, in press, 22 pages, 11 Postscript figures, uses
aastex.cl
Lymphocyte Modulation with FTY720 Improves Hemorrhagic Shock Survival in Swine
The inflammatory response to severe traumatic injury results in significant morbidity and mortality. Lymphocytes have recently been identified as critical mediators of the early innate immune response to ischemia-reperfusion injury. Experimental manipulation of lymphocytes following hemorrhagic shock may prevent secondary immunologic injury in surgical and trauma patients. The objective of this study is to evaluate the lymphocyte sequestration agent FTY720 as an immunomodulator following experimental hemorrhagic shock in a swine liver injury model. Yorkshire swine were anesthetized and underwent a grade III liver injury with uncontrolled hemorrhage to induce hemorrhagic shock. Experimental groups were treated with a lymphocyte sequestration agent, FTY720, (n = 9) and compared to a vehicle control group (n = 9). Animals were observed over a 3 day survival period after hemorrhage. Circulating total leukocyte and neutrophil counts were measured. Central lymphocytes were evaluated with mesenteric lymph node and spleen immunohistochemistry (IHC) staining for CD3. Lung tissue infiltrating neutrophils were analyzed with myeloperoxidase (MPO) IHC staining. Relevant immune-related gene expression from liver tissue was quantified using RT-PCR. The overall survival was 22.2% in the vehicle control and 66.7% in the FTY720 groups (p = 0.081), and reperfusion survival (period after hemorrhage) was 25% in the vehicle control and 75% in the FTY720 groups (p = 0.047). CD3+ lymphocytes were significantly increased in mesenteric lymph nodes and spleen in the FTY720 group compared to vehicle control, indicating central lymphocyte sequestration. Lymphocyte disruption significantly decreased circulating and lung tissue infiltrating neutrophils, and decreased expression of liver immune-related gene expression in the FTY720 treated group. There were no observed infectious or wound healing complications. Lymphocyte sequestration with FTY720 improves survival in experimental hemorrhagic shock using a porcine liver injury model. These results support a novel and clinically relevant lymphocyte immunomodulation strategy to ameliorate secondary immune injury in hemorrhagic shock
Treatment to suppression of focal lesions on positron emission tomography-computed tomography is a therapeutic goal in newly diagnosed multiple myeloma
Fluorine-18 fluorodeoxyglucose positron emission tomography with computed tomography attenuation correction (PET-CT) in myeloma can detect and enumerate focal lesions by the quantitative characterization of metabolic activity. The aim of this study was to determine the prognostic significance of the suppression of PET-CT activity at a number of time points post therapy initiation: day 7, post induction, post transplant, and at maintenance therapy. As part of the TT4-6 trial series, 596 patients underwent baseline PET-CT and were evaluated serially during their disease course using peak standardized uptake values above background red marrow signal. We demonstrate that the presence of more than 3 focal lesions at presentation identifies a group of patients with an adverse progression-free survival and overall survival. At day 7 of therapy, patients with complete focal lesion signal suppression revert to the same prognosis as those with no lesions at diagnosis. At later time points, the continued suppression of signal remains prognostically important. We conclude that for newly diagnosed patients with focal lesions, treatment until these lesions are suppressed is an important therapeutic goal as the prognosis of these patients is the same as those without lesions at diagnosis. (clinicaltrials.gov identifiers: 00734877, 02128230, 00869232, 00871013)
Systems genetics identifies a role for Cacna2d1 regulation in elevated intraocular pressure and glaucoma susceptibility
Glaucoma is a multi-factorial blinding disease in which genetic factors play an important role. Elevated intraocular pressure is a highly heritable risk factor for primary open angle glaucoma and currently the only target for glaucoma therapy. Our study helps to better understand underlying genetic and molecular mechanisms that regulate intraocular pressure, and identifies a new candidate gene, Cacna2d1, that modulates intraocular pressure and a promising therapeutic, pregabalin, which binds to CACNA2D1 protein and lowers intraocular pressure significantly. Because our study utilizes a genetically diverse population of mice with kno
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Analysis combining correlated glaucoma traits identifies five new risk loci for open-angle glaucoma
Open-angle glaucoma (OAG) is a major cause of blindness worldwide. To identify new risk loci for OAG, we performed a genome-wide association study in 3,071 OAG cases and 6,750 unscreened controls, and meta-analysed the results with GWAS data for intraocular pressure (IOP) and optic disc parameters (the overall meta-analysis sample size varying between 32,000 to 48,000 participants), which are glaucoma-related traits. We identified and independently validated four novel genome-wide significant associations within or near MYOF and CYP26A1, LINC02052 and CRYGS, LMX1B, and LMO7 using single variant tests, one additional locus (C9) using gene-based tests, and two genetic pathways - “response to fluid shear stress” and “abnormal retina morphology” - in pathway-based tests. Interestingly, some of the new risk loci contribute to risk of other genetically-correlated eye diseases including myopia and age-related macular degeneration. To our knowledge, this study is the first integrative study to combine genetic data from OAG and its correlated traits to identify new risk variants and genetic pathways, highlighting the future potential of combining genetic data from genetically-correlated eye traits for the purpose of gene discovery and mapping
Multi-trait genome-wide association study identifies new loci associated with optic disc parameters.
Funder: All funders per study are acknowledged in the Supplementary FileA new avenue of mining published genome-wide association studies includes the joint analysis of related traits. The power of this approach depends on the genetic correlation of traits, which reflects the number of pleiotropic loci, i.e. genetic loci influencing multiple traits. Here, we applied new meta-analyses of optic nerve head (ONH) related traits implicated in primary open-angle glaucoma (POAG); intraocular pressure and central corneal thickness using Haplotype reference consortium imputations. We performed a multi-trait analysis of ONH parameters cup area, disc area and vertical cup-disc ratio. We uncover new variants; rs11158547 in PPP1R36-PLEKHG3 and rs1028727 near SERPINE3 at genome-wide significance that replicate in independent Asian cohorts imputed to 1000 Genomes. At this point, validation of these variants in POAG cohorts is hampered by the high degree of heterogeneity. Our results show that multi-trait analysis is a valid approach to identify novel pleiotropic variants for ONH
Multi-trait genome-wide association study identifies new loci associated with optic disc parameters
A new avenue of mining published genome-wide association studies includes the joint analysis of related traits. The power of this approach depends on the genetic correlation of traits, which reflects the number of pleiotropic loci, i.e. genetic loci influencing multiple traits. Here, we applied new meta-analyses of optic nerve head (ONH) related traits implicated in primary open-angle glaucoma (POAG); intraocular pressure and central corneal thickness using Haplotype reference consortium imputations. We performed a multi-trait analysis of ONH parameters cup area, disc area and vertical cup-disc ratio. We uncover new variants; rs11158547 in PPP1R36-PLEKHG3 and rs1028727 near SERPINE3 at genome-wide significance that replicate in independent Asian cohorts imputed to 1000 Genomes. At this point, validation of these variants in POAG cohorts is hampered by the high degree of heterogeneity. Our results show that multi-trait analysis is a valid approach to identify novel pleiotropic variants for ONH
Efficacy and safety of tenofovir alafenamide versus tenofovir disoproxil fumarate given as fixed-dose combinations containing emtricitabine as backbones for treatment of HIV-1 infection in virologically suppressed adults: a randomised, double-blind, active-controlled phase 3 trial
Background Emtricitabine with tenofovir disoproxil fumarate is a standard-of-care nucleoside reverse transcriptase inhibitor (NRTI) backbone. However, tenofovir disoproxil fumarate is associated with renal and bone toxic effects; the novel prodrug tenofovir alafenamide achieves 90% lower plasma tenofovir concentrations. We aimed to further assess safety and efficacy of fixed-dose combination emtricitabine with tenofovir alafenamide in patients switched from emtricitabine with tenofovir disoproxil fumarate. Methods In this controlled, double-blind, multicentre phase 3 study, we recruited virologically suppressed (HIV RNA <50 copies per mL) patients with HIV aged 18 years and older receiving regimens containing fixed-dose combination emtricitabine with tenofovir disoproxil fumartate from 78 sites in North America and Europe. Patients were randomly assigned (1:1) to switch to fixed-dose 200 mg emtricitabine with 10 mg or 25 mg tenofovir alafenamide or to continue 200 mg emtricitabine with 200 mg or 300 mg tenofovir disoproxil fumarate, while remaining on the same third agent for 96 weeks. Randomisation was done by a computer-generated allocation sequence and was stratified by the third agent (boosted protease inhibitor vs other agent). Investigators, patients, and study staff giving treatment, assessing outcomes, and collecting data were masked to treatment group. The primary outcome was the proportion of patients with plasma HIV-1 RNA less than 50 copies per mL at week 48 as defined by the US Food and Drug Administration snapshot algorithm with a prespecified non-inferiority margin of 10%. The primary efficacy endpoint was analysed with the per-protocol analysis set, whereas the safety analysis included all randomly assigned patients who received at least one dose of study drug. This study is registered with ClinicalTrials.gov, number NCT02121795. Findings We recruited patients between May 6, 2011, and Sept 11, 2014; 780 were screened and 668 were randomly assigned to receive either tenofovir alafenamide (n=333) or tenofovir disoproxil fumarate (n=330). Through week 48, virological success (HIV-1 RNA <50 copies per mL) was maintained in 314 (94%) of patients in the tenofovir alafenamide group compared with 307 (93%) in the tenofovir disoproxil fumarate group (difference 1·3%, 95% CI −2·5 to 5·1), showing non-inferiority of tenofovir alafenamide to tenofovir disproxil fumarate. Seven patients in the tenofovir alafenamide (2%) and three (1%) in the tenofovir disoproxil fumarate group discontinued due to adverse events. There were no cases of proximal renal tubulopathy in either group. Interpretation In patients switching from emtricitabine with tenofovir disoproxil fumarate to emtricitabine with tenofovir alafenamide, high rates of virological suppression were maintained. With its safety advantages, fixed-dose emtricitabine with tenofovir alafenamide has the potential to become an important NRTI backbone. Funding Gilead Sciences.SCOPUS: ar.jinfo:eu-repo/semantics/publishe