2,025 research outputs found
Associations of PON1 and genetic ancestry with obesity in early childhood.
Get PDFObesity in children has become an epidemic in the U.S. and is particularly prominent in minority populations such as Mexican-Americans. In addition to physical activity and diet, genetics also plays a role in obesity etiology. A few studies in adults and adolescents suggest a link between obesity and paraoxonase 1 (PON1), a multifunctional enzyme that can metabolize organophosphate pesticides and also has antioxidant properties. We determined PON1192 genotype and arylesterase levels (ARYase, measure of PON1 enzyme quantity), to characterize the relationship between PON1 and obesity in young Mexican-American children (n = 373) living in an agricultural community in California. Since PON1 polymorphisms and obesity both vary between ethnic groups, we estimated proportional genetic ancestry using 106 ancestral informative markers (AIMs). Among children, PON1192 allele frequencies were 0.5 for both alleles, and the prevalence of obesity was high (15% and 33% at ages two and five, respectively). The average proportion of European, African, and Native American ancestry was 0.40, 0.09, and 0.51, yet there was wide inter-individual variation. We found a significantly higher odds of obesity (9.3 and 2.5- fold) in PON1192QQ children compared to PON1192RR children at ages two and five, respectively. Similar relationships were seen with BMI Z-scores at age two and waist circumference at age five. After adjusting for genetic ancestry in models of PON1 and BMI Z-score, effect estimates for PON1192 genotype changed 15% and 9% among two and five year old children, respectively, providing evidence of genetic confounding by population stratification. However even after adjustment for genetic ancestry, the trend of increased BMI Z-scores with increased number of PON1192 Q alleles remained. Our findings suggest that PON1 may play a role in obesity independent of genetic ancestry and that studies of PON1 and health outcomes, especially in admixed populations, should account for differences due to population stratification
Recommended from our members
The Effect of Salsalate Therapy on Endothelial Function in a Broad Range of Subjects
Get PDFBackground: Inflammation is fundamental to the development of atherosclerosis. We examined the effect of antiâinflammatory doses of salicylate on endotheliumâdependent vasodilation, a biomarker of cardiovascular risk, in a broad range of subjects. Methods and Results: We performed a randomized, doubleâblind, placeboâcontrolled crossover trial evaluating the effects of 4 weeks of highâdose salsalate (disalicylate) therapy on endotheliumâdependent flowâmediated and endotheliumâindependent vasodilation. Fiftyâeight subjects, including 17 with metabolic syndrome, 13 with atherosclerosis, and 28 healthy controls, were studied. Among all subjects, endotheliumâdependent flowâmediated vasodilation decreased after salsalate compared with placebo therapy (P=0.01), whereas nitroglycerinâmediated, endotheliumâindependent vasodilation was unchanged (P=0.97). Endotheliumâdependent flowâmediated vasodilation after salsalate therapy was impaired compared with placebo therapy in subjects with therapeutic salicylate levels (n=31, P0.2). Conclusions: Salsalate therapy, particularly when therapeutic salicylate levels are achieved, impairs endotheliumâdependent vasodilation in a broad range of subjects. These data raise concern about the possible deleterious effects of antiâinflammatory doses of salsalate on cardiovascular risk. Clinical Trial Registration URL: www.clinicaltrials.gov. Unique Identifiers: NCT00760019 and NCT00762827
The Mini Astrophysical MEV Background Observatory (MAMBO): A CubeSat Mission for Gamma-ray Astronomy
Get PDFH-alpha kinematics of S4G spiral galaxies-II. Data description and non-circular motions
Get PDFWe present a kinematical study of 29 spiral galaxies included in the Spitzer
Survey of Stellar Structure in Galaxies, using Halpha Fabry-Perot data obtained
with the Galaxy Halpha Fabry-Perot System instrument at the William Herschel
Telescope in La Palma, complemented with images in the R-band and in Halpha.
The primary goal is to study the evolution and properties of the main
structural components of galaxies through the kinematical analysis of the FP
data, complemented with studies of morphology, star formation and mass
distribution. In this paper we describe how the FP data have been obtained,
processed and analysed. We present the resulting moment maps, rotation curves,
velocity model maps and residual maps. Images are available in FITS format
through the NASA/IPAC Extragalactic Database and the Centre de Donn\'ees
Stellaires. With these data products we study the non-circular motions, in
particular those found along the bars and spiral arms. The data indicate that
the amplitude of the non-circular motions created by the bar does not correlate
with the bar strength indicators. The amplitude of those non-circular motions
in the spiral arms does not correlate with either arm class or star formation
rate along the spiral arms. This implies that the presence and the magnitude of
the streaming motions in the arms is a local phenomenon.Comment: 23 pages, 14 figures, without appendices, accepted to be published in
MNRA
An Evolutionary Sequence of Expanding Hydrogen Shells in Galaxy Discs
Get PDFLarge HI shells, with diameters of hundreds of pc and expansion velocities of
10-20kms-1 are well observed features of local gas rich galaxies. These shells
could well be predicted as a result of the impact of OB associations on the
ISM, but doubt has been cast on this scenario by the apparent absence of OB
stars close to the centres of a large fraction of these shells in recent
observations of the SMC. Using Fabry-Perot scanned Halpha emission line mapping
of nearby galaxy discs we have detected, in all the HII regions where the
observations yield sufficient angular resolution and S:N ratio, dominant Halpha
shells with radii a few tens of pc, expanding at velocities of 50-100kms-1. We
have applied a simple dynamically consistent framework in which we can
extrapolate the properties of the observed Halpha shells to a few 10^7yr after
the formation of the OB stars. The framework includes the dynamical inputs of
both winds and SNe on the surrounding ISM. The results give quantitative
statistical support to the hypothesis that the Halpha emitting shells are
generic progenitors of the HI shells. During the time taken for an expanding
shell to reach the size of a typical HI shell, the OB association may well lose
its most luminous stars so the absence of such stars near the centres of many
of the HI shells is well explained in this scenario.Comment: 8 pages, 4 figures, accepted for publication in Astronomy and
Astrophysic
- âŠ
