Heritability of testosterone levels in 12-year-old twins and its relation to pubertal development

The aim of this study was to estimate the heritability of variation in testosterone levels in 12-year-old children, and to explore the overlap in genetic and environmental influences on circulating testosterone levels and androgen dependent pubertal development. Midday salivary testosterone samples were collected on two consecutive days in a sample of 183 unselected twin pairs. Androgen induced pubertal development was assessed using self report Tanner scales of pubic hair development (boys and girls) and genital development (boys). A significant contribution of genetic effects to the variance in testosterone levels was found. Heritability was approximately 50% in both boys and girls. The remaining proportion of the variance in testosterone levels could be explained by non-shared environmental influences. The relatively high correlation between testosterone levels of opposite sex dizygotic twins suggests that sex differences in genes influencing variation in testosterone levels have not yet developed in pre- and early puberty. Variance in pubertal development was explained by a large genetic component, moderate shared environmental influences, and a small non-shared environmental effect. Testosterone levels correlated moderately (r = .31) with pubertal development; the covariance between testosterone levels and pubertal development was entirely accounted for by genetic influences

Endocrine Aspects of Duchenne Muscular Dystrophy

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Bio-Banding in Youth Sports::Background, Concept and Application

Inter-individual differences in size, maturity status, function, and behavior among youth of the same chronological age (CA) have long been a concern in grouping for sport. Bio-banding is a recent attempt to accommodate maturity-associated variation among youth in sport. The historical basis of the concept of maturity-matching and its relevance to youth sport, and bio-banding as currently applied are reviewed. Maturity matching in sport has often been noted but has not been systematically applied. Bio-banding is a recent iteration of maturity matching for grouping youth athletes into ‘bands’ or groups based on characteristic(s) other than CA. The percentage of predicted young adult height at the time of observation is the estimate of maturity status of choice. Several applications of bio-banding in youth soccer have indicated positive responses from players and coaches. Bio-banding reduces, but does not eliminate, maturity-associated variation. The potential utility of bio-banding for appropriate training loads, injury prevention, and fitness assessment merits closer attention, specifically during the interval of pubertal growth. The currently used height prediction equation requires further evaluation

Role of Coronin 1B in PDGF-Induced Migration of Vascular Smooth Muscle Cells

The type I subclass of Coronins, a family of actin binding proteins, regulates various actin dependent cellular processes including migration. However, the existence and role of coronins in vascular smooth muscle cell (VSMC) migration has yet to be determined

Effect of local cold-pack application on systemic anabolic and inflammatory response to sprint-interval training: a prospective comparative trial

We evaluated the effect of cold ice-pack application following a brief sprint-interval training on the balance between anabolic mediators [growth hormone (GH), insulin-like growth factor-I (IGF-I), testosterone], catabolic markers (cortisol, IGFBP-1), and circulating pro [Interlukin-6 (IL-6) and IL-1β]- and anti-inflammatory cytokines [IL-1 receptor antagonist (IL-1ra)]. Twelve males, elite junior handball players performed 4 × 250 m treadmill run, at 80% of each individual’s maximal speed, followed by a rest period with and without local cold-pack application. Pre, immediately post, and 60-min post-exercise blood samples were drawn. Exercise was associated with a significant increase in IL-6, GH, IGFBP-3, and testosterone levels. Local cold-pack application was associated with significant decreases in IL-1β, IL-1ra, IGF-I, and IGFBP-3 and a greater increase of IGFBP-1 during recovery. Local ice therapy immediately following sprint-interval training was associated with greater decreases in both pro- and anti-inflammatory cytokines and anabolic hormones supporting some clinical evidence for possible negative effects on athletic performance

Índice de Massa Corporal, Idade, Maturação Sexual e a Incidência de Hiperlordose Lombar em crianças e adolescentes

Introduction: Hyperlordosis can cause several degenerative spinal pathologies in children and adolescents. Objective: Determine whether body mass index, age and sexual maturation predict the occurrence of hyperlordosis in children and adolescents. Method: The study analyzed 380 students aged between 10 and 18 years. Body mass index was evaluated using the reference values suggested by the Fitnessgram test battery, and sexual maturation through Tanner’s scale of self-assessed pubic hair growth. Postural assessment was conducted using the DIPA photogrammetry method, version 3.1. (Digital Image Based Postural Assessment) The SPSS 24.0 program was used to analyze the data, and the following statistical tests were applied: chi squared, Mann-Whitney, Fisher’s exact and binary logistic regression. Results: There was statistical significance between hyperlordosis, girls’ age and puberty in boys (p 0.05). Conclusion: The girls’ age and boys’ stage of puberty were associated with the occurrence of hyperlordosis.Introdução: A Hiperlordose lombar pode ocasionar diversas patologias degenerativas na coluna vertebral de crianças e adolescentes. Objetivo: Identificar se o Índice de Massa Corporal, a Idade e a Maturação Sexual são previsores da ocorrência da hiperlordose lombar em crianças e adolescentes. Método: O estudo analisou 380 estudantes entre 10 e 18 anos. O Índice de Massa Corporal foi avaliado por meio dos valores de referência sugeridos pela bateria de testes Fitnessgram e a maturação sexual por meio da auto-avaliação da pilosidade pubiana de Tanner. A avaliação postural foi realizada pelo método de fotogrametria DIPA versão 3.1. (Avaliação Postural Baseada em Imagem Digital). Para análise dos dados foi utilizado o programa SPSS 24.0, tendo sido aplicados os testes estatísticos: Qui-Quadrado, Mann Whitney, Exato de Fisher e Regressão Logística Binária. Resultados: Observou-se que houve significância estatística entre a Hiperlordose lombar e a idade das meninas e a puberdade dos meninos (p0,05). Conclusão: A idade das meninas e a puberdade dos meninos foi associada à ocorrência da hiperlordose lombar.This study was funded by CIEC (Center for Investigations in Childhood Studies), Strategic Project UID/CED/00317/2013, via National FCT (Science and Technology Foundation) funds and co-funded by the European Regional Development Fund (FEDER), via COMPETE 2020 – Competitivity and Internalization Operational Program (POCI) under reference number POCI-01-0145-FEDER-007562

Diagnosis, Genetics, and Therapy of Short Stature in Children: A Growth Hormone Research Society International Perspective

The Growth Hormone Research Society (GRS) convened a Workshop in March 2019 to evaluate the diagnosis and therapy of short stature in children. Forty-six international experts participated at the invitation of GRS including clinicians, basic scientists, and representatives from regulatory agencies and the pharmaceutical industry. Following plenary presentations addressing the current diagnosis and therapy of short stature in children, breakout groups discussed questions produced in advance by the planning committee and reconvened to share the group reports. A writing team assembled one document that was subsequently discussed and revised by participants. Participants from regulatory agencies and pharmaceutical companies were not part of the writing process. Short stature is the most common reason for referral to the pediatric endocrinologist. History, physical examination, and auxology remain the most important methods for understanding the reasons for the short stature. While some long-standing topics of controversy continue to generate debate, including in whom, and how, to perform and interpret growth hormone stimulation tests, new research areas are changing the clinical landscape, such as the genetics of short stature, selection of patients for genetic testing, and interpretation of genetic tests in the clinical setting. What dose of growth hormone to start, how to adjust the dose, and how to identify and manage a suboptimal response are still topics to debate. Additional areas that are expected to transform the growth field include the development of long-acting growth hormone preparations and other new therapeutics and diagnostics that may increase adult height or aid in the diagnosis of growth hormone deficiency.info:eu-repo/semantics/publishedVersio

KsgA, a 16S rRNA adenine methyltransferase, has a novel DNA glycosylase/AP lyase activity to prevent mutations in Escherichia coli

The 5-formyluracil (5-foU), a major mutagenic oxidative damage of thymine, is removed from DNA by Nth, Nei and MutM in Escherichia coli. However, DNA polymerases can also replicate past the 5-foU by incorporating C and G opposite the lesion, although the mechanism of correction of the incorporated bases is still unknown. In this study, using a borohydride-trapping assay, we identified a protein trapped by a 5-foU/C-containing oligonucleotide in an extract from E. coli mutM nth nei mutant. The protein was subsequently purified from the E. coli mutM nth nei mutant and was identified as KsgA, a 16S rRNA adenine methyltransferase. Recombinant KsgA also formed the trapped complex with 5-foU/C- and thymine glycol (Tg)/C-containing oligonucleotides. Furthermore, KsgA excised C opposite 5-foU, Tg and 5-hydroxymethyluracil (5-hmU) from duplex oligonucleotides via a β-elimination reaction, whereas it could not remove the damaged base. In contrast, KsgA did not remove C opposite normal bases, 7,8-dihydro-8-oxoguanine and 2-hydroxyadenine. Finally, the introduction of the ksgA mutation increased spontaneous mutations in E. coli mutM mutY and nth nei mutants. These results demonstrate that KsgA has a novel DNA glycosylase/AP lyase activity for C mispaired with oxidized T that prevents the formation of mutations, which is in addition to its known rRNA adenine methyltransferase activity essential for ribosome biogenesis