The timing of adrenarche in Maya girls, Merida, Mexico

BackgroundAdrenarche involves maturation of the hypothalamic‐pituitary‐adrenal axis and increased production of dehydroepiandrosterone and its sulfate ester, dehydroepiandrosterone‐sulfate (DHEA‐S). It occurs at ages 6 to 8 in industrialized populations, marking the transition from childhood to juvenility and cognitive development at middle childhood. Studies in subsistence level populations indicate a later age (8‐9) for adrenarche, but only two such studies currently exist for comparison.AimsTo investigate adrenarcheal age among Maya girls and its association with body composition and dietary variables. We hypothesized adrenarche would occur earlier given the current dual burden of nutrition in Mexico.Materials and Methods25 Maya girls aged 7 to 9 from Merida, Mexico using ELISAs to measure salivary DHEA‐S, standard anthropometry for height, weight, and skinfolds, bioelectrical impedance for body composition variables, as well as a food frequency questionnaire for dietary information.ResultsOur hypothesis was rejected—adrenarche occurred close to 9 years. While no measures of body composition were significantly associated with adrenarcheal status, girls eating meat and dairy products more frequently had significantly higher DHEA‐S levels.DiscussionLike other populations living in ecologically challenging environments, adrenarche occurred relatively late among Maya girls. Adrenarche has been linked to measures of body composition, particularly, the adiposity or body mass index rebound, but no relevant anthropometric measures were associated, possibly because of the small sample.ConclusionFurther studies are required to illuminate how adrenarcheal variation relates to developmental plasticity, body composition, pubertal progression, and animal product consumption in other transitional populations.</div

Iron overdose epidemiology, clinical features and iron concentration-effect relationships: the UK experience 2008–2017

<p><b>Background:</b> Iron poisoning is potentially serious, but mortality has fallen worldwide since implementation of pack size and packaging restrictions, and changes in iron use during pregnancy. The management of individual cases of overdose remains problematic due to uncertainty about indications for antidote. We examine the epidemiology of iron overdose in hospital cases referred to the UK National Poisons Information Service (NPIS) and evaluate the toxicokinetics of iron in patients ingesting only iron preparations.</p> <p><b>Methods:</b> Anonymized hospital referral patient data from the NPIS database were collated for the period 1 January 2008 to 31 July 2017. Information was extracted, where recorded, on type of ingestion [iron alone (single), or combined with other agents (mixed)], reported dose, iron salt, timed iron concentrations and symptoms. In single-agent ingestions, the relationships between reported elemental iron dose, early concentrations (4–6 h), and symptoms were evaluated in teenagers and adults (≥13 years) and children (≤12 years) using standard statistical techniques (correlation and unpaired nonparametric comparisons). In those patients with sufficient sample points (three or more), a simple kinetic analysis was conducted.</p> <p><b>Results:</b> Of 2708 patients with iron overdoses referred by UK hospitals for advice during the 9.7 years study period, 1839 were single-agent ingestions. There were two peaks in age incidence in single-agent exposures; 539/1839 (28.4%) were <6 years (54.1% males) while 675/1839 (36.7%) were between 13 and 20 years (91% females), the latter a substantial excess over the proportion in the totality of hospital referrals to the NPIS in the same period (13–20 years: 23,776/144,268 16.5%; 67.5% female) (<i>p</i> < .0001 overall and for female %). In 475 teenagers and adults and 86 children, with at least one-timed iron concentration available, there was no correlation between stated dose and iron concentration measured 4–6 h post-ingestion. Observed peak iron concentrations were not related to reported symptoms in adults. Initial iron concentrations were significantly higher in 30 patients (25 adults, 5 children) who received desferrioxamine (DFO) compared to those that did not [no DFO: mean 63.8 μmol/L (95% CI 62.1–65.6), median 64; DFO: mean 78.5 μmol/L (95% CI 69.2–87.7), median 78.1; Mann–Whitney <i>p</i> < .0018). No significant differences in symptoms were observed pre-treatment between DFO-treated and untreated groups. No patients died in this cohort.</p> <p><b>Conclusion:</b> Single-agent iron exposures reported from UK hospitals were most common in children <5 years and young people aged 13–20 years. Poisoning with organ failure was not identified and there were no fatalities. No correlations were observed between reported iron doses and early concentrations, or between iron concentrations and symptoms in this cohort of mild-to-moderate poisoning.</p

Multiple replication kinetics of infections in PER.C6 cells with a cell density of 10⁷ cells/ml at an MOI of 1–2, at 30°C and 37°C, harvested at 0–48 hours post infection.

<p>Panel A) Average and standard deviation of two (n = 2) replication kinetic curves of the Brunenders strain versus 3 selected clones (clone A, B and C) derived after passage with impaired growth at 37°C. Panel B) Average and standard deviation of three (n = 3) independent infections of Brunenders and the CAVA backbone, which contained all mutations from Clones A, B and C combined. Panel C) Average and standard deviation of three (n = 3) independent infections of the Brunenders strain versus the CAVA vaccine strains (CAVA-1 Mahoney, CAVA-2 MEF-1 and CAVA-3 Saukett).</p

Reversion of the temperature sensitive phenotype by stepwise increase of the infection temperature.

<p>Serial passage was performed using CAVA-1 Mahoney in suspension PER.C6 cells infected at a cell density of 10⁷ cells/ml at low MOI (0.01) and harvested at 3–4 days post infection. Temperature was gradually increased (33–37°C) or temperature was kept constant at 30°C for the control viruses. Panel A depicts the viral titers at each passage when titrated and incubated at 30°C or 37°C for the two independent experiments (n = 2). Panel B lists the reverting CAVA mutations of the viruses at passage number 6 where the nucleotide number refers to the position from the start of the viral genome.</p

Secondary RNA structure prediction of Domain II and Domain VI of the IRES in Brunenders and CAVA using the MFOLD program developed by M. Zuker.

<p>Circled nucleotides (at positions 133, 142, 146, and 163 in domain II and at positions 597, 609 in domain VI) represent nucleotide changes between CAVA and Brunenders. The last remaining CAVA IRES mutation (nt579) lies outside of any IRES domains and in the spacer region between Domains V and VI. After serial passage at increasing temperature (<a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1005483#ppat.1005483.g006" target="_blank">Fig 6</a>) nucleotide 127 (indicated by square box) mutated in both passaging experiments (n = 2) from U to C, forming a C–G base pair with CAVA mutation nt 163. The CAVA mutations induce a change in predicted secondary structure and increased free energy (ΔG) for domain II, whilst for domain VI only the free energy is affected.</p

<i>In vivo</i> immunogenicity of the CAVA vaccine strains as compared to cIPV.

<p>Groups of ten (n = 10) rats were immunized with a full dose (FD: 100% 40:8:32 DU/dose or 150% 60:12:48 DU/dose) or a 1:2, 1:4 or 1:16 dilution of the full dose. Poliovirus type 1, 2 and 3-specific neutralizing antibody titers were determined by Sabin Virus Neutralizing Assay at day 21 post immunization. Each dot represents one individual animal; the connected line represents the geometric mean at each dose. Relative potency estimates and 95% confidence intervals of the difference between the CAVA vaccine strain and cIPV reference based on the number of seroconverting animals are depicted in the table, horizontal dotted line represents the seroconversion limit for each assay.</p

Schematic overview of the viruses described here and their incorporated mutations.

<p>Black vertical lines represent the synonymous CAVA mutations whilst red vertical lines represent non-synonymous CAVA mutations, dispersed over the poliovirus genome; a detailed description of the individual mutations is given in <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1005483#ppat.1005483.s005" target="_blank">S1 Table</a>. 5’UTR = 5’ Untranslated Region, 3’UTR = 3’Untranslated Region.</p

Electron micrographs of two representative cells per panel after infection of suspension PER.C6 cells with a cell density of 10⁷ cells/ml at an MOI of 1, harvested between 24–48 hours post infection.

<p>Panel A) PBS (Mock) infected cells, Panel B) Mahoney infection at 37°C, Panel C) CAVA-1 Mahoney at 37°C, Panel D) CAVA-1 Mahoney at 30°C.</p

Quantification of poliovirus infectious units (by infectious titer determination, Panel A), viral RNA levels (by RTqPCR, Panel B) and viral proteins (by Western blot, Panel C) after infection of suspension PER.C6 cells with a cell density of 10⁷ cells/ml at an MOI of 1 at 30°C and 37°C, harvested between 0–48 hours post infection.

<p>Viruses used were Brunenders (WT), Brunenders with the CAVA mutations in the IRES (IRES), Brunenders with the CAVA mutations in the Non-Structural proteins (NS), the CAVA-1 Mahoney (C1) vaccine strain and the CAVA backbone virus (CBB); Control (Ctrl) is an uninfected control. Data depict one representative infection (n = 1) measured once for infectivity and (n = 3) times for viral RNA and protein levels. Error bars represent standard deviation from the mean and one representative of three independent western blots is shown.</p