Regulatory mechanisms of microRNAs involved in pubertal development / 国际儿科学杂志

The regulatory mechanisms of pubertal development are complex and affected by many factors.MicroRNAs, which major participants in epigenetics, are short single-stranded RNAs composed of 21-25 nucleotides.They can regulate the expression or translation of multiple target genes, playing an important role in complex biological phenomena.During pubertal development, microRNAs can regulate the expression of related genes on the hypothalamic-pituitary-gonadal axis(HPGA). Recently, studies have found that the lack or overexpression of some specific microRNAs can cause abnormal pubertal development(premature or delayed)and lead to reproductive disorders, providing a new direction for the diagnosis and treatment of puberty diseases.Here we mainly review the regulatory mechanisms that microRNAs participate in pubertal development.

Erythrocyte zinc and serum copper in male and female adolescents according to puberty stage at different growth phases

BACKGROUND: Considering that modification in body composition and growth velocity leads to alterations in zinc and copper nutritional status, the purpose of the study was to assess erythrocyte zinc and serum copper in adolescents of both genders, according to the stage of sexual maturity at different growth phases. METHODS: Two hundred and eighty-six adolescents were assessed, 157 were female, with body mass index Z-scorebetween−2 and +2. Clinical biochemical measurements were assessed using atomic absorption spectrophotometry. Student's t, Kruskal-Wallis, and Bonferroni tests were used. RESULTS Median serum copper was superior, and zinc was inferior to respective reference values in all groups. Serum copper presented significant reduction in the final stages of pubertal development in males; in turn, erythrocyte zinc values increased linearly with the evolution of puberty stages in both genders. Comparison between genders in each stage of growth showed significant difference in peak acceleration and in deceleration for erythrocyte zinc and serum copper, with both being higher in females. CONCLUSIONS: Serum copper is inversely influenced by modifications that occur with the evolution of puberty in males, whereas erythrocyte zinc is directly influenced in both genders, although always with deficient deposition. At peak acceleration and deceleration of growth, there is greater mobilization of erythrocyte zinc and serum copper in males, when compared with females, which does not occur at the onset of the acceleration of growth.

Desreguladores endócrinos e desenvolvimento puberal humano / Endocrine disruptors and human pubertal development

Múltiplos fatores genéticos e ambientais influenciam o início da puberdade. Acredita-se que a melhora das condições nutricionais e de saúde pública sejam os principais fatores relacionados ao declínio na idade de início da puberdade observado ao longo do último século. No entanto, a exposição a compostos desreguladores endócrinos pode apresentar um papel nesse processo. Os desreguladores endócrinos são definidos como compostos exógenos que podem interferir no funcionamento do sistema endócrino humano ou de qualquer animal. No presente artigo, as autoras fazem uma revisão sobre os desreguladores endócrinos e seu papel no desenvolvimento puberal humano.

Multiple genetic and environmental factors influence the onset of puberty. It is believed that better nutrition and public health are the main factors related to the earlier onset of puberty observed over the last century. Nonetheless, exposure to endocrine-disrupting compounds may also play a role in this process. Endocrine disruptors are defined as exogenous compounds that might interfere with the functioning of the animal and human endocrine systems. In this article, the authors review endocrine disruptors and their role in human pubertal development.

A Clinical Study of the Relationship between Obesity and Pubertal Development in Girls / 대한소아소화기영양학회지

PURPOSE: Recently, public interest in obesity and earlier pubertal development has been increasing. The purpose of this study was to analyze the relationship between obesity and pubertal development in girls. METHODS: A total of 158 girls presenting with earlier pubertal development from July 2008 to June 2010 were included in the study. Their mean age was 8.27+/-1.3 years and the mean bone age advancement was 1.86+/-0.3 years. RESULTS: Based on weight-for-height percentiles, their obesity rate was 9.2% and overweight rate was 15.8%. However, for body mass index (BMI), the result was a bit different; with an obesity rate of 13.2% and overweight rate of 24.3%. About 40% of the girls had a family history of early maturation. Among them, 25.7% had a maternal history, 4.6% paternal and 7.2% both. However, 60% of them had no family history. We then classified these girls into families with one son and one daughter, and those with two daughters. In one-son/one-daughter families, 69.3% were the first children and 30.7% were second. In two-daughter families, 65.3% were the first and 34.7% were second. We found that 67.5% had a history of taking herbal medicine. CONCLUSION: The obesity and overweight rates in girls with earlier pubertal development were higher than those of normal girls, but with a small discrepancy between weight-for-height percentile and BMI-based results. Furthermore, taking herbal medicine seems to be a potential factor for earlier pubertal development in Korea.

Applicability of self-rated pubertal development scale among urban Chinese adolescents / 中华流行病学杂志

Objective To explore the applicability of pubertal development scale in estimating sexual maturation among urban Chinese adolescents.Methods A cross-sectional survey was conducted among 2562 students of 4th to 12th grade in Shanghai,selected by stratified cluster sampling method.Self-reported pubertal maturation level was obtained by Pubertal Development Scale (PDS).Meanwhile,visual depiction of Tanner stages of breast,genital and pubic hair development were rated by a trained rater of the same gender,Results In 2562 students,the correlation between self-reported PDS and assessment from the raters were substantial,both in boys and girls (Pearson' s correlation coefficients:0.822 and 0.814,respectively).The overall agreement of pubertal development stages based on PDS and the rater' s assessment were 35.24％ and 51.42％ for boys and girls,respectively,with Kendall' s correlation coefficients as 0.713 and 0.685,respectively.Adolescents who were older,had relatively higher level of pubertal stages or adolescents from the richer families,tended to underestimate their actual level of pubertal maturation while those male subjects and overweight or obese subjects were even more likely to be so.Conclusion Using the self-reported PDS,we could conveniently obtain the necessary information regarding sexual maturation among the urban adolescents.It seemed especially useful in the related epidemiological survey when physical examination was precluded by cost,privacy and other concerns.

Abnormal pubertal development in Korean adolescent girls / 대한산부인과학회지

Puberty is the period of first attaining capability of reproduction, and is signed by the appearance of secondary sex characteristics and the occurrence of menarche in females. The timing of puberty is ethnically, sexually and individually variable and is influenced by both genetic and environmental factors. The diagnosis of precocious or delayed puberty is considered when signs of puberty develop before or after 2 standard deviation of the mean age for the onset of puberty. Consequently, a comprehensive understanding of the normal progression of puberty is vital in the evaluation of abnormal pubertal development. In most western countries, the first signs of puberty occur between 8 and 13 years of age. Correspondingly, the recent Korean data have shown that puberty begins in most Korean girls with breast development at the age between 8.7 and 13.9 years. This article reviewed lately published literatures on normal and abnormal pubertal development in Korean adolescent females to delineate features of pubertal disorders in this population.

Bajo peso al nacer, desarrollo puberal y presión arterial en adolescentes del sexo femenino / Low weight at birth, pubertal development and blood pressure in female adolescents

Se estudió la presión arterial en una muestra de adolescentes del sexo femenino, sanas, con edades comprendidas entre doce y catorce años. Se determinó la condición de las muchachas con respecto a la menarquia. El objetivo de la investigación fue confirmar la conocida asociación inversa entre el peso al nacimiento y la presión arterial, estudiar la asociación entre el peso al nacimiento y la edad de la menarquia y poner a prueba una hipótesis sobre el tamaño relativo del riñón con respecto al volumen corporal y su asociación con las cifras de presión arterial. Se llevó a cabo un estudio descriptivo, observacional y transversal a dicha muestra. Los resultados evidenciaron que las adolescentes que tienen menarquia más temprana tienen cifras más altas de tensión arterial y mayor índice de masa corporal. Un indicador alométrico de la relación entre el volumen renal y el índice de masa corporal también se encuentra disminuido en este grupo de muchachas. En las adolescentes que nacieron con peso insuficiente, la menarquia ocurre, en promedio, casi un año antes que en las que nacieron con peso normal. Se concluye que el peso insuficiente al nacimiento favorece, bajo ciertas condiciones, un adelanto en los eventos puberales, lo cual se acompaña de reacciones adaptativas en el organismo, se determinó que existe correlación significativa entre estas variables con una p=0.014. Esta cadena de sucesos contribuye a un incremento en las cifras de prensión arterial.

Blood pressure was studied in a sample of 12-14-year-old healthy female adolescents, determining the condition of their menarche. The aim of the present research is to prove the known inverse association between the body weight at birth and blood pressure, to study the association between the body weight at birth and the age of the menarche and to prove a hypothesis on the relative size of the kidney with respect to the body volume and its association with the counts of the blood pressure. A descriptive observational and cross sectional study was performed in the sample. Results showed that adolescents with earlier menarche have higher counts of blood pressure as well as a greater body mass index. An alometric index in the relationship between the renal volume and the body mass index is also decreased in this group of adolescents. In those born with a low body weight, menarche appears almost a year before than in those born with a normal body weight. It is concluded that the low body weight at birth is in favour of , under some circumstances, an increase of the pubertal events, being accompanied by adaptative reactions in the economy, it was also determined that there is a significant correlation among these variables (p =0.014). This chain of events leads to an increase of blood pressure counts.