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Characterizing genetic influences on DNA methylation (DNAm) provides an opportunity to understand mechanisms underpinning gene regulation and disease. In the present study, we describe results of DNAm quantitative trait locus (mQTL) analyses on 32,851 participants, identifying genetic variants associated with DNAm at 420,509 DNAm sites in blood. We present a database of >270,000 independent mQTLs, of which 8.5% comprise long-range (trans) associations. Identified mQTL associations explain 15-17% of the additive genetic variance of DNAm. We show that the genetic architecture of DNAm levels is highly polygenic. Using shared genetic control between distal DNAm sites, we constructed networks, identifying 405 discrete genomic communities enriched for genomic annotations and complex traits. Shared genetic variants are associated with both DNAm levels and complex diseases, but only in a minority of cases do these associations reflect causal relationships from DNAm to trait or vice versa, indicating a more complex genotype-phenotype map than previously anticipated., (© 2021. The Author(s), under exclusive licence to Springer Nature America, Inc.)

Introduction: Salivary cortisol is a useful tool as a biomarker of stress in pediatrics because it allows for non-invasive sampling. There is little information about its use in children, and no reference values for healthy infants have been reported in Argentina. Reference values should be established at each site as the basis for subsequent tests in infants, for whom salivary cortisol appears to be the most relevant objective tool to assess stress at present., Objective: To determine reference values for salivary cortisol in healthy infants aged 0-12 months., Methods: Descriptive, cross-sectional study that assessed morning salivary cortisol levels in healthy male and female infants aged 0-12 months that attended Hospital Pirovano for a health checkup between March 2017 and March 2018. Fasting saliva samples were collected between 8 and 9 a.m. and were processed using electrochemiluminescence. Results were reported as mean and standard deviation., Results: A total of 140 infants were included, and 96 samples were collected. Mean morning salivary cortisol levels were 5.46 nmol/L (95 % confidence interval: 4.66-6.38), standard deviation: 2.15. No correlation to age was observed, so it was not necessary to divide the reference range into age groups. No significant differences were observed in terms of sex, gestational age, birth weight, type of delivery or type of feeding., Conclusion: The reference range of morning salivary cortisol levels in healthy infants aged 0-12 months was reported., Competing Interests: The authors report no conflicts of interest in this work., (Sociedad Argentina de Pediatría.)

Despite common notion that the correlation of socioeconomic status with child cognitive performance may be driven by both environmentally- and genetically-mediated transactional pathways, there is a lack of longitudinal and genetically informed research that examines these postulated associations. The present study addresses whether family income predicts associative memory growth and hippocampal development in middle childhood and tests whether these associations persist when controlling for DNA-based polygenic scores of educational attainment. Participants were 142 6-to-7-year-old children, of which 127 returned when they were 8-to-9 years old. Longitudinal analyses indicated that the association of family income with children's memory performance and hippocampal volume remained stable over this age range and did not predict change. On average, children from economically disadvantaged background showed lower memory performance and had a smaller hippocampal volume. There was no evidence to suggest that differences in memory performance were mediated by differences in hippocampal volume. Further exploratory results suggested that the relationship of income with hippocampal volume and memory in middle childhood is not primarily driven by genetic variance captured by polygenic scores of educational attainment, despite the fact that polygenic scores significantly predicted family income., (Copyright © 2019 The Authors. Published by Elsevier Ltd.. All rights reserved.)

The objective of this collaborative work carried out in the Fundación Favaloro and the Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia, was to determine optimal conditions for incubation (time and atmosphere) of quantitative cultures of catheters processed according to the technique of vortex agitation (Brun Buisson method). From 689 processed catheters, 551 yielded negative cultures. From the 138 positive cultures, 125 yielded monomicrobial cultures and 13 polimicrobial cultures (total number of microorganisms was 151). In the last situation each micoorganism was considered on an individual basis. A total of 58 episodes of catheter related bacteremias occurred, being 52 monomicrobial and 6 polimicrobial (total number of microorganisms was 64). When colony counts were compared in aerobic and in 5-10% CO2 atmospheres, a very good correlation was obtained (p = 0.27; r2 = 0.9268). No advantage was observed by incubating plates for more than 48 hours. Colony counts performed at the second versus the third day, and at the second day versus the seventh, gave very good correlation (p = 0.10 and r2 = 0.9996; p = 0.31 and r2 = 0.9995, respectively).