MORPHOFUNCTIONAL CHARACTERISTICS THYROID GLAND OF WHITE-BREASTED MALE HEDGEHOG IN THE PERIOD OF PUBERTY

The issue of the morphofunctional characteristics of the thyroid gland of male white-breasted hedgehogs during puberty on the territory of Belarus was studied. Material for the study was taken from 15 males, who were divided into three stages of studying the sexual maturation of hedgehogs: stage I - prepubertal period, stage II - the beginning of puberty, and stage III - activation of the gonads and the end of puberty. The results obtained characterize the morphological state of the thyroid gland of male white-breasted hedgehogs during puberty, and thus makes it possible to use morphometric indicators of structures as indicators of the environment and physiological states (for assessing puberty).

Assessment of heart rate variability and tone of the autonomic nervous system in puberty-aged children with undifferentiated connective tissue dysplasia

Within the framework of the research into pathological conditions and syndromes associated with undifferentiated connective tissue dysplasia (UCTD), an emphasis needs to be placed on the changes in heart rhythm. In puberty, the severity of neurovegetative disorders caused by the presence of UCTD might increase manifold. The features of heart rate variability (HRV) in pubertal children against the background of UCTD have been studied insufficiently and require more detailed analysis. This study aims to assess heart rate variability and tone of the autonomic nervous system (ANS) in puberty-aged children with UCTD. Two groups of children were examined, with methods including electrocardiography and cardiointervalography. The main group consisted of 36 puberty-aged children with UCTD, the control group consisted of 30 healthy children. ANS tone was assessed based on the HRV. In the control group of children aged 11, the value of variation range (VR) was 0.18±0.4, mode amplitude (MA) 35.2±2.4, stress index (IN) 72.8±4.3, which corresponds to the state of vegetative balance. As the puberty progresses, the state of eutonia is replaced by the activation of the sympathetic division of the ANS, which becomes most pronounced at the age of 13 years. In the control group of children aged 13, the value of VR was 0.08±0.02, MA 61.7±2.1, SI 210.6±8.6, which corresponds to moderate sympathicotonia. By the end of puberty, in healthy children, the severity of sympathetic activation begins to decrease, and at the age of 15 years, vegetative balance is again observed. However, this pattern is violated in children with UCTD. Upon entering puberty, moderate activation of the sympathetic division of the ANS is already observed in children with UCTD. At the age of 11 years in this group, the value of VR is 0.06±0.02, MA 72.4±3.1, SI 211.2±8.6. At the age of 13, pronounced sympathicotonia is observed, which is confirmed by the values of VR - 0.04±0.01, MA 80.2±4.3 and SI 34.3±14.7. By the end of puberty in children with UCTD, in contrast to the control group, the analyzed parameters indicate not an equilibrium of the ANS, but the predominance of parasympathetic activation. The research provides an insight into heart rate variability in puberty-aged children with UCTD. It was established that healthy children enter puberty in a state of equilibrium of the autonomic nervous system, which in the middle of puberty is replaced by moderate sympathicotonia, and then returns to its original values. Children with the presence of UCTD enter puberty with moderately pronounced sympathicotonia, which gradually increases to pronounced values and is replaced by moderate vagotonia. FUNDunding Acknowledgement Type of funding sources: None.

Normal Sexual Development and Puberty

Puberty is the hormonally mediated process of physical changes that occur during the transition of childhood to adulthood. Activation of the hypothalamic-pituitary-gonadal axis triggers the onset of puberty. Gonadotropin hormone-releasing hormone (GnRH) is the major regulator of the reproductive axis. GnRH stimulates the anterior pituitary gland to release luteinizing hormone (LH) and follicle-stimulating hormone (FSH), which in turn activate the gonads to produce sex steroids. Thelarche is stimulated by estrogen and is usually the first sign of puberty in girls. Adrenarche, although associated temporally with puberty, is mediated by the adrenal cortex and is unrelated to pubertal maturation. A growth spurt occurs mid-puberty. Menarche, usually occurring 2-3 years after thelarche, is considered the end of puberty. After menarche, only about 1-2 additional inches of height are accrued. Understanding what is considered the normal timeline of sexual development allows better recognition of precocious or delayed puberty, both of which may be associated with serious underlying health issues This review contains 4 tables, 5 figures, and 29 references. Keywords: puberty, pubertal development, hypothalamic-pituitary-gonadal axis, thelarche, menarche, normal sexual development

Surgical-Orthodontic Diagnosis and Treatment Planning in an Asymmetric Skeletal Class III Patient—A Case Report

The skeletal Class III pattern is characterized by a sagittal intermaxillary mesial discrepancy. This discrepancy may have an unfavorable impact on function and aesthetics, which can be aggravated by the presence of facial asymmetries. This case report describes the diagnosis and treatment planning of a 19-year-old male patient with a skeletal Class III, maxillary hypoplasia, anterior crossbite, and mandibular asymmetry. When the patient reached skeletal maturity at the end of puberty, the definitive diagnosis was skeletal Class III with hyperdivergent profile and mandibular asymmetry, and a surgical-orthodontic treatment was proposed. At the end of the treatment, bimaxillary surgical correction allowed a skeletal Class I with mandibular symmetry, improving the function of the stomatognathic system and facial aesthetics.

SKELETAL MATURATION IN THE CURRENT PEDIATRIC MEXICAN POPULATION

Objective: The most commonly used methods for bone age (BA) reading were described in the Caucasian population decades ago. However, there are secular trends in skeletal maturation and different BA patterns between ethnic groups. Automated BA reading makes updating references easier and more precise than human reading. The objective of the present study was to present automated BA reference curves according to chronological age and gender in the Mexican population and compare the maturation tempo with that of other populations. Methods: The study included 923 healthy participants aged 5 to 18 years between 2017 and 2018. A hand radio-graph was analyzed using BoneXpert software to obtain the automated BA reading according to Greulich and Pyle (G&P) and Tanner-Whitehouse 2 (TW2) references. We constructed reference curves using the average difference between the BA and chronological age according to sex and age. Results: The G&P and TW2 automated reference curves showed that Mexican boys exhibit delays in BA during middle childhood by 0.5 to 0.7 (95% confidence interval [CI], −0.9 to −0.2) years; however, they demonstrate an advanced BA of up to 1.1 (95% CI, 0.8 to 1.4) years at the end of puberty. Mexican girls exhibited a delay in BA by 0.3 to 0.6 (95% CI, −0.9 to −0.1) years before puberty and an advanced BA of up to 0.9 (95% CI, 0.7 to 1.2) years at the end of puberty. Conclusion: Mexican children aged <10 years exhibited a delay in skeletal maturity, followed by an advanced BA by approximately 1 year at the end of puberty. This may affect the estimation of growth potential in this population. Abbreviations: BA = bone age; CA = chronological age; G&P = Greulich and Pyle; TW2 = Tanner-Whitehouse 2

Should 45,X/46,XY boys with no or mild anomaly of external genitalia be investigated and followed up?

Objective Few studies of patients with a 45,X/46,XY mosaicism have considered those with normal male phenotype. The purpose of this study was to evaluate the clinical outcome of 45,X/46,XY boys born with normal or minor abnormalities of external genitalia, notably in terms of growth and pubertal development. Methods Retrospective longitudinal study of 40 patients followed between 1982 and 2017 in France. Results Twenty patients had a prenatal diagnosis, whereas 20 patients had a postnatal diagnosis, mainly for short stature. Most patients had stunted growth, with abnormal growth spurt during puberty and a mean adult height of 158 ± 7.6 cm, i.e. −2.3 DS with correction for target height. Seventy percent of patients presented Turner-like syndrome features including cardiac (6/23 patients investigated) and renal malformations (3/19 patients investigated). Twenty-two patients had minor abnormalities of external genitalia. One patient developed a testicular embryonic carcinoma, suggesting evidence of partial gonadal dysgenesis. Moreover, puberty occurred spontaneously in 93% of patients but 71% (n = 5) of those evaluated at the end of puberty presented signs of declined Sertoli cell function (low inhibin B levels and increased FSH levels). Conclusion This study emphasizes the need to identify and follow-up 45,X/46,XY patients born with normal male phenotype until adulthood, as they present similar prognosis than those born with severe genital anomalies. Currently, most patients are diagnosed in adulthood with azoospermia, consistent with our observations of decreased testicular function at the end of puberty. Early management of these patients may lead to fertility preservation strategies.

The Physiology of Childhood Growth: Hormonal Regulation

The growth patterns of a child changes from uterine life until the end of puberty. Height velocity is highest in utero and declines after birth until puberty when it rises again. Important hormonal regulators of childhood growth are growth hormone, insulin-like growth factor 1, sex steroids, and thyroid hormone. This review gives an overview of these hormonal regulators of growth and their interplay with nutrition and other key players such as inflammatory cytokines.