Browsing by Subject "Puberty"

Now showing 1 - 2 of 2
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    Sexual Maturation, social support and physical activity in adolescents
    (Murcia: Servicio de publicaciones de la Universidad de Murcia, 2019) Piola, Thiago Silva; Bacil, Eliane; Watanabe, Priscila; Camargo, Edina; Fermino, Rogerio; Campos, Wagner
    To analyze moderating maturation effect on association between social support and physical activity level in adolescents. Cross-sectional study conducted in 2014 with a representative sample of 855 adolescents (54% girls) enrolled in public school of São José dos Pinhais, Brazil. Adolescents reported weekly attendance who received different types of social support for physical activity, which was classified into three categories (“never," "sometimes," "always"). The social support score from each source was computed and classified in tertiles ("low", "intermediate", "high"). The moderate to vigorous leisure time physical activity was evaluated with a valid questionnaire and the score was classified as ≥300 min/wk. The maturation was self-assessed by pubic hairiness by photos and classified as "pubescent" and "post-pubescent". The associations were tested with Poisson regression in STATA 14. The fact that parents "sometimes" (PR: 2.51; 95% CI: 1.42-4.44) or "always" (PR: 4.60; 95% CI: 2.10-10.10) to attend the activities was positively associated with the physical activity of pubertal adolescents, whereas positive reinforcement for the activities ("always" commenting) was positively associated with the outcome in post-pubertal adolescents (PR: 2.60; 95% CI: 1.01-6.71). The fact that friends "always" watch activities (PR: 2.39; 95% CI: 1.01-5.76), the score "intermediate" (PR: 2.13; 95% CI: 1.28-3.58) and "high" (RP: 1.91; 95% CI: 1.11-3.28) were positively associated with the physical activity of pubertal adolescents. Maturation shows a moderating effect in the association between the social support and physical activity.
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    Steroid receptors in the testis: implications in the physiology of prenatal and postnatal development and translation to clinical application
    (Universidad de Murcia. Departamento de Biología Celular e Histología, 2023) Rey, Rodolfo A.
    The testes are the main source of sex steroids in the male, especially androgens and to a lesser extent estrogens. In target cells, steroid hormones typically signal after binding to intracellular receptors, which act as transcription factors. Androgens and estrogens have ubiquitous functions in peripheral organs, but also have paracrine actions within the gonads where they are far more concentrated. The levels of steroid production by the testes vary throughout fetal and postnatal development: they are high in intrauterine life and in the first months after birth, then they decline and are almost undetectable in childhood and increase again during puberty to attain adult levels. The expression of the androgen and estrogen receptors also depict specific ontogenies in the various testicular cell types. The combination of intratesticular steroid concentration with the pattern of expression of the steroid hormone receptors defines androgen and estrogen action on Sertoli, germ and Leydig cells. Here, we review the ontogeny of expression of the androgen and estrogen receptors in the testis, its impact on testicular physiology during prenatal and postnatal development, as well as its implication on the pathophysiology of different disorders affecting gonadal function throughout life.