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Background: Circulating concentrations of biomarkers that are related to vitamin status vary by factors such as diet, fortification, and supplement use. Published biomarker concentrations have also been influenced by the variation across laboratories, which complicates a comparison of results from different studies. Objective: We robustly and comprehensively assessed differences in biomarkers that are related to vitamin status across geographic regions. Design: The trial was a cross-sectional study in which we investigated 38 biomarkers that are related to vitamin status and one-carbon and tryptophan metabolism in serum and plasma from 5314 healthy control subjects representing 20 cohorts recruited from the United States, Nordic countries, Asia, and Australia, participating in the Lung Cancer Cohort Consortium. All samples were analyzed in a centralized laboratory. Results: Circulating concentrations of riboflavin, pyridoxal 5'-phosphate, folate, vitamin B-12, all-trans retinol, 25-hydroxyvitamin D, and α-tocopherol as well as combined vitamin scores that were based on these nutrients showed that the general B-vitamin concentration was highest in the United States and that the B vitamins and lipid soluble vitamins were low in Asians. Conversely, circulating concentrations of metabolites that are inversely related to B vitamins involved in the one-carbon and kynurenine pathways were high in Asians. The high B-vitamin concentration in the United States appears to be driven mainly by multivitamin-supplement users. Conclusions: The observed differences likely reflect the variation in intake of vitamins and, in particular, the widespread multivitamin-supplement use in the United States. The results provide valuable information about the differences in biomarker concentrations in populations across continents. [ABSTRACT FROM AUTHOR]

Background: Most of the genetic variants identified from genome-wide association studies of breast cancer have not been validated in Asian women. No risk assessment model that incorporates both genetic and clinical predictors is currently available to predict breast cancer risk in this population. [ABSTRACT FROM PUBLISHER]

Heat stress is one of the major environmental stressors challenging the global poultry industry. Identifying the genes responsible for heat tolerance is fundamentally important for direct breeding programs. To uncover the genetic basis underlying the ambient temperature adaptation of chickens, we analyzed a total of 59 whole genomes from indigenous chickens that inhabit South Asian tropical regions and temperate regions from Northern China. We applied F ST and π-ratio to scan selective sweeps and identified 34 genes with a signature of positive selection in chickens from tropical regions. Several of these genes are functionally implicated in metabolism (FABP2, RAMP3, SUGCT , and TSHR) and vascular smooth muscle contractility ( CAMK2 ), and they may be associated with adaptation to tropical regions. In particular, we found a missense mutation in thyroid-stimulating hormone receptor (41020238:G>A) that shows significant differences in allele frequency between the chicken populations of the two regions. To evaluate whether the missense mutation in TSHR could enhance the heat tolerance of chickens, we constructed segregated chicken populations and conducted heat stress experiments using homozygous mutations (AA) and wild-type (GG) chickens. We found that GG chickens exhibited significantly higher concentrations of alanine aminotransferase, lactate dehydrogenase, and creatine kinase than AA chickens under heat stress (35 ± 1°C) conditions (P < 0.05). These results suggest that TSHR (41020238:G>A) can facilitate heat tolerance and adaptation to higher ambient temperature conditions in tropical climates. Overall, our results provide potential candidate genes for molecular breeding of heat-tolerant chickens. [ABSTRACT FROM AUTHOR]