To assess the value of exosomal miRNAs as biomarkers for Alzheimer disease (AD), the expression of microRNAs was measured in a plasma fraction enriched in exosomes by differential centrifugation, ...using Illumina deep sequencing. Samples from 35 persons with a clinical diagnosis of AD dementia were compared to 35 age and sex matched controls. Although these samples contained less than 0.1 microgram of total RNA, deep sequencing gave reliable and informative results. Twenty miRNAs showed significant differences in the AD group in initial screening (miR-23b-3p, miR-24-3p, miR-29b-3p, miR-125b-5p, miR-138-5p, miR-139-5p, miR-141-3p, miR-150-5p, miR-152-3p, miR-185-5p, miR-338-3p, miR-342-3p, miR-342-5p, miR-548at-5p, miR-659-5p, miR-3065-5p, miR-3613-3p, miR-3916, miR-4772-3p, miR-5001-3p), many of which satisfied additional biological and statistical criteria, and among which a panel of seven miRNAs were highly informative in a machine learning model for predicting AD status of individual samples with 83-89% accuracy. This performance is not due to over-fitting, because a) we used separate samples for training and testing, and b) similar performance was achieved when tested on technical replicate data. Perhaps the most interesting single miRNA was miR-342-3p, which was a) expressed in the AD group at about 60% of control levels, b) highly correlated with several of the other miRNAs that were significantly down-regulated in AD, and c) was also reported to be down-regulated in AD in two previous studies. The findings warrant replication and follow-up with a larger cohort of patients and controls who have been carefully characterized in terms of cognitive and imaging data, other biomarkers (e.g., CSF amyloid and tau levels) and risk factors (e.g., apoE4 status), and who are sampled repeatedly over time. Integrating miRNA expression data with other data is likely to provide informative and robust biomarkers in Alzheimer disease.
Objective
This narrative review examines six important non‐nutritive substances in breast milk, many of which were thought to have little to no biological significance. The overall objective is to ...provide background on key bioactive factors in breast milk believed to have an effect on infant outcomes (growth and body composition).
Methods
The evidence for the effects of the following six bioactive compounds in breast milk on infant growth outcomes are reviewed: insulin, leptin, adiponectin, ghrelin, interleukin‐6, and tumor necrosis factor‐α.
Results
The existing literature on the effects of breast milk insulin, ghrelin, interleukin‐6, and tumor necrosis factor‐α and their associations with infant growth and adiposity is sparse. Of the bioactive compounds reviewed, leptin and adiponectin are the most researched. Data reveal that breast milk adiponectin has negative associations with growth in infancy.
Conclusions
There is a need for innovative, well‐designed studies to improve causal inference and advance our understanding in the effects of breast milk and its components on offspring growth and body composition. The recommendations provided, along with careful consideration of both known and unknown factors that affect breast milk composition, will help improve, standardize, and ultimately advance this emergent field.
Body composition assessment in the infant Demerath, Ellen W; Fields, David A
American journal of human biology,
May/June 2014, Letnik:
26, Številka:
3
Journal Article
Recenzirano
Odprti dostop
Body composition assessment provides a sharper picture of the human biological response to genetic and environmental influences than measures of body size and weight. Infant body composition is ...particularly important as a marker of fetal adaptation and developmental programming of subsequent health and disease, but until recently, the range of options for measuring infant body composition was relatively narrow. The purpose of this Toolkit: Methods in Human Biology review is to provide a comprehensive overview of methods of body composition methods currently used in infants 0 to 2 years of age, including anthropometric prediction equations, air displacement plethysmography (ADP), dual energy X-ray absorptiometry (DXA), bioelectrical impedance analysis (BIA), isotope dilution, and magnetic resonance imaging (MRI). Information on the reliability, validity, and accuracy of the methods is provided. Unique aspects of infant physiology and behavior create challenges for body composition assessment, but this review provides guidance on suitable testing approaches and environments that may aid researchers in this important area of investigation.
Evidence linking breastfeeding to reduced risk of developing childhood obesity is inconclusive, yet previous studies have not considered variation in specific components of breast milk that may ...affect early development.
We examined whether differences in the composition of human milk oligosaccharides (HMOs) correlate with infant growth and body composition at 1 and 6 mo of age.
Twenty-five mother-infant dyads were recruited from the University Hospital at the University of Oklahoma Health Sciences Center. Infants were breastfed for 6 mo. Breast-milk and infant measures were obtained at 1 and 6 mo of infant age. HMO composition was analyzed by high-pressure liquid chromatography, and infant growth (length and weight) and body composition (percentage fat, total fat, lean mass) were measured by dual-energy X-ray absorptiometry. Relations between HMOs and infant growth and body composition were examined by using multiple linear regression. A priori covariates included maternal prepregnancy body mass index, pregnancy weight gain, and infant age and sex.
Higher HMO diversity and evenness at 1 mo were associated with lower total and percentage fat mass at 1 mo. At 1 mo, each 1-μg/mL increase in lacto-N-fucopentaose (LNFP) I was associated with a 0.40-kg lower infant weight (P = 0.03). At 6 mo, each 1-μg/mL increase in LNFPI was associated with a 1.11-kg lower weight (P = 0.03) and a 0.85-g lower lean mass (P = 0.01). At 6 mo, each 1-μg/mL increase in LNFPI was associated with a 0.79-g lower fat mass (P = 0.02), whereas disialyl-lacto-N-tetraose and LNFPII were associated with a 1.92-g (P = 0.02) and 0.42-g (P = 0.02) greater fat mass, respectively. At 6 mo, each 1-μg/mL increase in fucosyl-disialyl-lacto-N-hexaose and lacto-N-neotetraose was associated with 0.04% higher (P = 0.03) and 0.03% lower (P < 0.01) body fat, respectively.
These findings support the hypothesis that differences in HMO composition in mother's milk are associated with infant growth and body composition. This trial was registered at clinicaltrials.gov as NCT02535637.
Maternal obesity is a risk factor for childhood obesity; this is a major public health concern given that ∼40% of pregnant women are either overweight or obese. Whether differences in milk ...composition in lean compared with obese women contribute to childhood obesity is unclear.
We aimed to analyze relationships between maternal obesity and human milk metabolites, infant body composition, and postnatal weight gain.
This was a prospective study in which mothers intending to breastfeed exclusively, and their newborn infants, were enrolled at delivery (n = 35 mother–infant pairs). We excluded mothers with diabetes, other medical conditions, or pregnancy complications. Participants were grouped by maternal prepregnancy BMI <25 (lean) or ≥25 kg/m2 (overweight/obese). We analyzed infant body composition by dual-energy X-ray absorptiometry and used untargeted liquid chromatography–gas chromatography–mass spectrometry to measure the milk content of 275 metabolites at 1 and 6 mo postpartum.
At 1 mo postpartum, 10 metabolites differed between overweight/obese and lean groups with nominal P < 0.05, but none was altered with a false discovery rate <0.25. Many differentially abundant metabolites belonged to the same chemical class; e.g., 4/10 metabolites were nucleotide derivatives, and 3/10 were human milk oligosaccharides. Milk adenine correlated positively with both continuously distributed maternal BMI and with infant adiposity and fat accrual. Analysis of milk composition at 6 mo postpartum revealed 20 differentially abundant metabolites (P < 0.05) in overweight/obese compared with lean women, including 6 metabolites with a false discovery rate of <0.25. At both 1 and 6 mo, human milk abundance of 1,5-anhydroglucitol, which has not previously been described in milk, was positively associated with maternal BMI.
Maternal obesity is associated with changes in the human milk metabolome. While only a subset of metabolites correlated with both maternal and infant weight, these point to potential milk-dependent mechanisms for mother–child transmission of obesity. This trial was registered at www.clinicaltrials.gov as NCT02535637.
Historically SARS-CoV-2 secondary attack rates (SAR) have been based on PCR positivity on screening symptomatic contacts; this misses transmission events and identifies only symptomatic contacts who ...are PCR positive at the time of sampling. We used serology to detect the relative transmissibility of Alpha Variant of Concern (VOC) to non-VOC SARS-CoV-2 to calculate household secondary attack rates. We identified index patients diagnosed with Alpha and non-VOC SARS-CoV-2 across two London Hospitals between November 2020 and January 2021 during a prolonged and well adhered national lockdown. We completed a household seroprevalence survey and found that 61.8% of non-VOC exposed household contacts were seropositive compared to 82.1% of Alpha exposed household contacts. The odds of infection doubled with exposure to an index diagnosed with Alpha. There was evidence of transmission events in almost all households. Our data strongly support that estimates of SAR should include serological data to improve accuracy and understanding.
Objective The purpose of this study was to compare bodyweight and composition (percent fat, fat mass, and fat-free mass) in neonates born to mothers with a normal pregravid body mass index (BMI; < 25 ...kg/m2 ) vs neonates born to mothers with an overweight/obese pregravid BMI (≥ 25 kg/m2 ). Study Design Seventy-two neonates (33 from normal mothers and 39 from overweight/obese mothers) of singleton pregnancies with normal glucose tolerance had their bodyweight and body composition assessed by air-displacement plethysmography. Results After controlling for neonate age at time of testing, significant differences were found between groups for percent fat (12.5 ± 4.2% vs 13.6 ± 4.3%; P ≤ .0001), fat mass (414.1 ± 264.2 vs 448.3 ± 262.2 g; P ≤ .05), and fat-free mass (3310.5 ± 344.6 vs 3162.2 ± 343.4 g; P ≤ .05), with no significant differences between birth length (50.7 ± 2.6 vs 49.6 ± 2.6 cm; P = .08) or birthweight (3433.0 ± 396.3 vs 3368.0 ± 399.6 g; P = .44). Conclusion Neonates born to mothers who have a normal BMI have significantly less total and relative fat and more fat-free mass than neonates born to overweight/obese mothers. Although preliminary, these data suggest that the antecedents of future disease risk (eg, cardiovascular disease, diabetes, and obesity) occur early in life.
The newly defined superphylum Patescibacteria such as Parcubacteria (OD1) and Microgenomates (OP11) has been found to be prevalent in groundwater, sediment, lake, and other aquifer environments. ...Recently increasing attention has been paid to this diverse superphylum including > 20 candidate phyla (a large part of the candidate phylum radiation, CPR) because it refreshed our view of the tree of life. However, adaptive traits contributing to its prevalence are still not well known.
Here, we investigated the genomic features and metabolic pathways of Patescibacteria in groundwater through genome-resolved metagenomics analysis of > 600 Gbp sequence data. We observed that, while the members of Patescibacteria have reduced genomes (~ 1 Mbp) exclusively, functions essential to growth and reproduction such as genetic information processing were retained. Surprisingly, they have sharply reduced redundant and nonessential functions, including specific metabolic activities and stress response systems. The Patescibacteria have ultra-small cells and simplified membrane structures, including flagellar assembly, transporters, and two-component systems. Despite the lack of CRISPR viral defense, the bacteria may evade predation through deletion of common membrane phage receptors and other alternative strategies, which may explain the low representation of prophage proteins in their genomes and lack of CRISPR. By establishing the linkages between bacterial features and the groundwater environmental conditions, our results provide important insights into the functions and evolution of this CPR group.
We found that Patescibacteria has streamlined many functions while acquiring advantages such as avoiding phage invasion, to adapt to the groundwater environment. The unique features of small genome size, ultra-small cell size, and lacking CRISPR of this large lineage are bringing new understandings on life of Bacteria. Our results provide important insights into the mechanisms for adaptation of the superphylum in the groundwater environments, and demonstrate a case where less is more, and small is mighty.
The objective of this study was to determine the accuracy, precision, bias, and reliability of percent fat (%fat) determined by air‐displacement plethysmography (ADP) with the pediatric option ...against the four‐compartment model in 31 children (4.1 ± 1.2 years, 103.3 ± 10.2 cm, 17.5 ± 3.4 kg). %Fat was determined by (BOD POD Body Composition System; COSMED USA, Concord, CA) with the pediatric option. Total body water (TBW) was determined by isotope dilution (2H2O; 0.2 g/kg) while bone mineral was determined by dual‐energy X‐ray absorptiometry (DXA) (Lunar iDXA v13.31; GE, Fairfield, CT and analyzed using enCore 2010 software). The four‐compartment model by Lohman was used as the criterion measure of %fat. The regression for %fat by ADP vs. %fat by the four‐compartment model did not deviate from the line of identity where: y = 0.849(x) + 4.291. ADP explained 75.2% of the variance in %fat by the four‐compartment model while the standard error of the estimate (SEE) was 2.09 %fat. The Bland—Altman analysis showed %fat by ADP did not exhibit any bias across the range of fatness (r = 0.04; P = 0.81). The reliability of ADP was assessed by the coefficient of variation (CV), within‐subject SD, and Cronbach's α. The CV was 3.5%, within‐subject SD was 0.9%, and Cronbach's α was 0.95. In conclusion, ADP with the pediatric option is accurate, precise, reliable, and without bias in estimating %fat in children 2–6 years old.
Maternal pregnancy nutrition influences fetal growth. Evidence is limited, however, on the relationship of maternal diet during pregnancy and lactation on infant postnatal growth and adiposity. Our ...purpose was to examine associations between maternal diet quality during pregnancy and lactation with offspring growth and body composition from birth to six months. Maternal diet quality was serially assessed in pregnancy and at one and three months postpartum, using the Healthy Eating Index⁻2015 in a cohort of 354 fully breastfeeding mother⁻infant dyads. Infant length-for-age (LAZ), weight-for-age (WAZ), and weight-for-length (WLZ) Z-scores were assessed at birth, one, three, and six months. Infant body fat percent (BF%), fat mass (FM), and fat-free mass (FFM) were measured at six months using dual-energy X-ray absorptiometry. Higher maternal diet quality from pregnancy through three months postpartum was associated with lower infant WLZ from birth to six months (
= 0.02) and BF% at six months (
≤ 0.05). Higher maternal diet quality at one and three months postpartum was also associated with lower infant FM at six months (
< 0.01). In summary, maternal diet quality during pregnancy and lactation was inversely associated with infant relative weight and adiposity in early postnatal life. Additional research is needed to explore whether associations persist across the life course.
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