Precocious Puberty: Causes, Consequences, Daily Environmental Factors, and the need for Community/Societal Support

Precocious puberty, otherwise described as a group of medical conditions that cause early puberty onset, such as a pre-adolescent boy presenting with adult pattern of penile and testicular enlargement or a pre-adolescent girl presenting with mature breast development and onset of menses. Although the sexual and physical characteristics for this condition are well-described in medical literature, the causes are very rarely known. Nevertheless, it has substantial impacts on children’s lives. This is a review on sexual development, premature sexual development, the social complications children suffer from due to early onset puberty, and the associations with daily environmental exposures as possible influences for developing precocious puberty.

The testosterone barrier in sport

World Athletics (formerly known as IAAF) has recently published the eligibility regulations for female classification that apply to running events from 400 meters up to the mile. The regulations have prevented some elite women athletes with DSD (Difference of Sexual Development) to compete or have made some of them to change their preferred running event in the 2020 Tokyo Olympics. According to World Athletics, female hyperandrogenism (a biological anomaly that naturally produces a high level of testosterone) must be in some way “compensated” to respect the fair play of the competition. Nonetheless, such argument rests upon a problematic assumption: hyperandrogenic women are not “natural” women —at least when it comes to compete in sports— so their “not-normal” condition must be fixed to meet the standards. Norbert Elias’s process-sociology helps to place the case of hyperandrogenic sportswomen within a broader context of power relations. In this fashion, we see that the case becomes problematic because these women athletes are perceived as a threat/disruption of one of the vertebral categories of sport: sex/gender. The testosterone barrier is to sex/gender what the colour barrier was to race in sports: a disciplinary strategy to maintain what is considered the “natural” sports categories of a certain era.

The Gβ-like Protein AfCpcB Affects Sexual Development, Response to Oxidative Stress and Phagocytosis by Alveolar Macrophages in Aspergillus fumigatus

G-protein signaling is important for signal transduction, allowing various stimuli that are external to a cell to affect its internal molecules. In Aspergillus fumigatus, the roles of Gβ-like protein CpcB on growth, asexual development, drug sensitivity, and virulence in a mouse model have been previously reported. To gain a deeper insight into Aspergillus fumigatus sexual development, the ΔAfcpcB strain was generated using the supermater AFB62 strain and crossed with AFIR928. This cross yields a decreased number of cleistothecia, including few ascospores. The sexual reproductive organ-specific transcriptional analysis using RNAs from the cleistothecia (sexual fruiting bodies) indicated that the CpcB is essential for the completion of sexual development by regulating the transcription of sexual genes, such as veA, steA, and vosA. The ΔAfcpcB strain revealed increased resistance to oxidative stress by regulating genes for catalase, peroxiredoxin, and ergosterol biosynthesis. The ΔAfcpcB strain showed decreased uptake by alveolar macrophages in vitro, decreased sensitivity to Congo red, decreased expression of cell wall genes, and increased expression of the hydrophobin genes. Taken together, these findings indicate that AfCpcB plays important roles in sexual development, phagocytosis by alveolar macrophages, biosynthesis of the cell wall, and oxidative stress response.

Prevalence of endocrine pathology in childhood and adolescence

All over the world, the endocrine system diseases in children attract the attention of researchers of various specialties, since this pathology is characterized by the duration of the course and subsequent often developing complications that worsen the quality of life and the prognosis of the health status of children and adolescents. The prevalence and structure of endocrine pathology in childhood and adolescence differ significantly from those in adults. Due to the fact that children make up a significant share in the structure of medical care requests for osteopathy in medical institutions, osteopathic doctors need to know the basics of diagnosis and prevention of endocrine diseases in children and adolescents. The peculiarity of endocrine diseases with onset in childhood is the beginning of their development against the background of physiologically significant for the development of the body processes of growth and sexual development, which determines the need for a multidisciplinary clinical approach to differential diagnosis between the endocrine pathology and the constitutional features of physical and sexual development of a healthy child.

Modern aspects of biological modeling of sexual development disorders

Введение. Изучение механизмов развития репродуктивных нарушений в условиях эксперимента на крысах является одним из важных направлений современной патофизиологии. Крыса имеет функционирующий эстральный цикл, трехнедельную гестацию и гемохориальный тип плацентации. На циклических изменениях в яичниках и эпителии влагалища крысы базируется биологическое моделирование эндокринной гинекологической патологии. В настоящее время интерес представляет разработка экспериментальной модели нарушения полового созревания в периоде детства. Нарушение полового созревания может приводить к различным патологическим изменениям в сфере репродуктивного здоровья в будущем, актуальность данной проблемы очевидна. Цель работы - изучение современных аспектов моделирования преждевременного полового созревания у девочек. Методика. Анализ современных отечественных и зарубежных работ, касающихся механизмов преждевременного полового созревания и исследований в области моделирования данной патологии в экспериментах на крысах. Результаты. Преждевременное половое созревание у девочек - нарушение, проявляющееся развитием одного или комплекса признаков половой зрелости до 7 летнего возраста. Детерминация полового развития связана с особенностью генетических и эпигенетических факторов. К последним традиционно относят характер питания, стресс как адаптационную реакцию, интегрированную с активацией гормонопоэза. Фактор питания связан с функционированием гормонов жировой ткани, включая лептин, грелин, эффектами инсулиноподобного фактора роста. В ряде экспериментальных исследований, связанных с воздействием факторов питания, стресса и световой дезадаптации на репродуктивную систему животного, доказано значимое влияние последней на нейромедиаторные системы мозга. Наименее изученными в механизме преждевременного полового созревания остаются вопросы нейроэндокринной регуляции гонадной оси системой KISS/KISS1R. Продолжение изучения ассоциации изменения профиля нейромедиаторов моноаминового ряда и динамики кисспептина в эксперименте на крысах способно расширить представление о механизмах половой дифференцировки мозга и транслировать полученные данные в клиническую практику, связанную с обследованием девочек с преждевременным половым созреванием. Заключение. В связи с малой распространенностью и ограниченностью представлений о патогенезе преждевременного полового созревания, данная проблема требует детального изучения. Необходимо дальнейшее изучение патогенетических основ данной патологии в условиях биологического моделирования на самках крыс раннего возраста. Introduction. Studying pathogenetic mechanisms responsible for development of reproductive disorders in rat models is an important direction of modern pathophysiology. The rat has a functioning estrous cycle, a three-week gestation, and a hemochorial placentation. Biological modeling of endocrine gynecological pathology is based on cyclic changes in the ovaries and in the epithelium of the rat vagina. Currently, the development of an experimental model of puberty disorders in childhood is of interest. Premature puberty can lead to various pathological changes in future reproductive health. The relevance of this problem is obvious. The aim of this work was to study modern aspects of modeling premature puberty in girls. Method. Modern domestic and foreign reviews on the mechanism of premature puberty and studies of modeling this pathology in experiments on rats were analyzed. Results. Premature puberty in girls is a disorder manifested by the development of one or all signs of puberty as early as before the age of 7 yrs. Sexual development is associated with characteristic roles of genetic and epigenetic factors. The latter traditionally include nutrition and stress as an adaptive reaction integrated with the activation of hormone synthesis. The nutrition factor is related with the functioning of adipose tissue hormones, including leptin, ghrelin, and the effects of insulin-like growth factor. A number of experimental studies on rats addressing effects of nutrition, stress, and light maladaptation on the reproductive system have demonstrated its significant effect on brain neurotransmitter systems. Regarding the mechanism of premature puberty, the least studied issue is the neuroendocrine regulation of the gonadal axis by the KISS/KISS1R system. Continuing study of the association between changes in the profile of monoamine neurotransmitters and the dynamics of kisspeptin in experiments on rats can expand understanding of sexual differentiation mechanisms in the brain. The obtained data can be translated into clinical practice for the management of premature puberty in girls. Conclusion. Due to the rare prevalence of premature puberty and insufficient data on its pathogenesis, this problem requires detailed study. It is necessary to further study the mechanism of this pathology by biological modeling on female rats at an early age.

Knowledge, attitudes, practices of teenagers on sexual health in the district of Ambohidratrimo

Background: Talking about sex, sexuality, sexual health in many countries, including Madagascar, is very difficult because of the sacred and taboos that surround these questions but especially because of certain puritanism. The objective of this study was to assess the knowledge, attitudes and practices of adolescents in matters of sexual health.Methods: A retrospective, descriptive cross-sectional study was carried out in adolescents aged 10 to 19 seen in Ambohidratrimo district. The data were collected during the month of June and July 2019 and relate to data for the twelve months before the survey.Results: A total of 210 adolescents were recruited whose average age was 15.82±2.75 years and the sex ratio was 1:04. Eighty-six percent of the adolescents surveyed had heard of sexual health. Nine out of 10 adolescents would go to a health worker if they contract an STI. Almost a quarter or 23.8% of respondents declared having already had sexual intercourse.Conclusions: At the end of this study on the knowledge, attitudes and practices of adolescents on sexual health, they certainly have knowledge but considered average. Therefore, there is a need for sexuality education, seeking to improve knowledge and understanding of sexual development, human procreation, healthy and adapted sexual behavior and different means of contraception, on the part of adolescents, but also with the aim of improving communications between adolescents and their parent.

"Heat waves" experienced during larval life have species-specific consequences on life-history traits and sexual development in anuran amphibians

Extreme temperatures during heat waves can induce mass-mortality events, but can also exert sublethal negative effects by compromising life-history traits and derailing sexual development. Ectothermic animals may, however, also benefit from increased temperatures via enhanced physiological performance and the suppression of cold-adapted pathogens. Therefore, it is crucial to address how the intensity and timing of naturally occurring or human-induced heat waves affect life-history traits and sexual development in amphibians, to predict future effects of climate change and to minimise risks arising from the application of elevated temperature in disease mitigation. We raised agile frog (Rana dalmatina) and common toad (Bufo bufo) tadpoles at 19 °C and exposed them to a simulated heat wave of 28 or 30 °C for six days during one of three ontogenetic periods (early, mid or late larval development). In agile frogs, exposure to 30 °C during early larval development increased mortality. Regardless of timing, all heat-treatments delayed metamorphosis, and exposure to 30 °C decreased body mass at metamorphosis. Furthermore, exposure to 30 °C during any period and to 28 °C late in development caused female-to-male sex reversal, skewing sex ratios strongly towards males. In common toads, high temperature only slightly decreased survival and did not influence phenotypic sex ratio, while it reduced metamorph mass and length of larval development. Juvenile body mass measured two months after metamorphosis was not adversely affected by temperature treatments in either species. Our results indicate that heat waves may have devastating effects on amphibian populations, and the severity of these negative consequences, and sensitivity can vary greatly between species and with the timing and intensity of heat. Finally, thermal treatments against cold-adapted pathogens have to be executed with caution, taking into account the thermo-sensitivity of the species and the life stage of animals to be treated.

Sexual Development Dysgenesis in Interspecific Hybrids of Rice Fish

Fish are amongst vertebrates the group with the highest diversity of known sex-determining genes. Particularly, the genus Oryzias is a suitable taxon to understand how different sex determination genetic networks evolved in closely related species. Two closely related species, O. latipes and O. curvinotus, do not only share the same XX/XY sex chromosome system, but also the same male sex-determining gene, dmrt1bY. We performed whole mRNA transcriptomes and morphology analyses of the gonads of hybrids resulting from reciprocal crosses between O. latipes and O. curvinotus. XY male hybrids, presenting meiotic arrest and no production of sperm were sterile, and about 30% of the XY hybrids underwent male-to-female sex reversal. Both XX and XY hybrid females exhibited reduced fertility and developed ovotestis while aging. Transcriptome data showed that male-related genes are upregulated in the XX and XY female hybrids. The transcriptomes of both types of female and of the male gonads are characterized by upregulation of meiosis and germ cell differentiation genes. Differences in the parental species in the downstream pathways of sexual development could explain sex reversal, sterility, and the development of intersex gonads in the hybrids. Our results provide molecular clues for the proximate mechanisms of hybrid incompatibility and Haldane’s rule.

Multiple Functions of the Dmrt Genes in the Development of the Central Nervous System

The Dmrt genes encode the transcription factor containing the DM (doublesex and mab-3) domain, an intertwined zinc finger-like DNA binding module. While Dmrt genes are mainly involved in the sexual development of various species, recent studies have revealed that Dmrt genes, which belong to the DmrtA subfamily, are differentially expressed in the embryonic brain and spinal cord and are essential for the development of the central nervous system. Herein, we summarize recent studies that reveal the multiple functions of the Dmrt genes in various aspects of vertebrate neural development, including brain patterning, neurogenesis, and the specification of neurons.