Prepubertal Period Research Articles

THE EFFECT OF THE AC-D-MPRG PEPTIDE BASED ON THE C-TERMINAL FRAGMENT OF ARGININE-VASOPRESSIN(6-9) ON THE CHARACTER OF RATS OF DIFFERENT AGES

RuIn this work, it was found that Ac-D-MPRG, a tetrapeptide synthesized on the basis of the C-terminal fragment of arginine-vasopressin(6-9), upon chronic neonatal administration, a ects anxiety and exploratory behavior in rats of three age groups. The most signi cant effect of the peptide was manifested under more stressful conditions. The rats of the experimental group showed less anxiety. They did less grooming in the Elevated Plus Maze test and increased time in light in the Light-Dark Chamber test. Motor activity changed from passive holding in the prepubertal period to active avoidance in puberty and adulthood. Based on the data obtained, we conclude that the effects of the peptide are manifested only when exposed to a biologically signi cant stimulus.

Prepubertal oral exposure to relevant doses of acrylamide impairs the testicular antioxidant system in adulthood, increasing protein carbonylation and lipid peroxidation

The increased prevalence of human infertility due to male reproductive disorders has been linked to extensive exposure to chemical endocrine disruptors. Acrylamide (AA) is a compound formed spontaneously during the thermal processing of some foods that are mainly consumed by children and adolescents. We previously found that prepubertal exposure to AA causes reduced sperm production and functionality. Oxidative stress is recognized as the main cause of reduced sperm quality and quantity. In this sense, our objective was to evaluate the expression and activity of genes related to enzymatic antioxidant defense, nonprotein thiols, lipid peroxidation (LPO), protein carbonylation (PC) and DNA damage in the testes of rats exposed to acrylamide (2.5 or 5 mg/kg) from weaning to adult life by gavage. For the AA2.5 and AA5 groups, there were no alterations in the transcript expression of genes related to enzymatic antioxidant defense. The enzymatic activities and metabolic parameters were also not affected in the AA2.5 group. For the AA5 group, the enzymatic activities of G6PDH and GPX were reduced, SOD was increased, and protein carbonylation (PC) was increased. Data were also evaluated by Integrate Biomarker Response (IBRv2), a method to analyze and summarize the effects on biomarkers between doses. The IBRv2 index was calculated as 8.9 and 18.71 for AA2.5 and AA5, respectively. The following biomarkers were affected by AA2.5: decreased enzymatic activities of G6PDH, SOD, and GPX, increased GST and GSH, increased LPO and PC, and decreased DNA damage. For AA5, decreased enzymatic activities of G6PDH, GST, CAT and GPX, increased SOD and GSH, increased PC, and decreased LPO and DNA damage were observed. In conclusion, AA exposure during the prepubertal period causes imbalances in the testicular enzymatic antioxidant defense, contributing to the altered spermatic scenario in the testes of these rats.

Determination of the ovine ovarian reserve during the prenatal and neonatal periods

Objective: To determine the ovine ovarian histomorphology and follicular staging at various age periods in Awassi breed. Methods: Ovaries were collected from prenatal fetuses [gestational age (95±5) days], neonatal (day 0), and prepubertal ewe lambs (two and four months of age); each age group included six animals. Ovaries (n=12, each group) were dissected and processed for hematoxylin and eosin staining. Stained sections (n=24, each group) were imaged and utilized for histomorphology assessment, follicle measurement, and classification. Results: Prenatal ovaries were mainly enriched with primordial follicles accompanied by a lower proportion of primary follicles. In addition to primordial and primary follicles, neonatal ovaries demonstrated a proportion of centrally located multilayered and antral follicles. In comparison with neonatal ovaries, the proportion of multilayered and antral follicles was significantly higher in the ovaries of two-month-old lambs; conversely, the proportion of peripherally situated primordial follicles dramatically declined compared to that of earlier age of lamb. Although there was no statistical variation in the sizes of primordial follicles across groups, the mean diameter of the primary follicle in the prenatal ovaries was substantially smaller than in postnatal ovaries. Compared to the neonatal ovaries, the size of the multilayered and antral follicles in the prepubertal ovaries was substantially larger. Conclusions: The earliest follicular developmental stages were established prenatally whereas the advanced growth stages started in the neonatal period and greatly increased in the prepubertal period.

Ex vivo effects of bisphenol A or zearalenone on the prepubertal rat testis

Bisphenol A (BPA) and zearalenone (ZEA) are two widespread xenoestrogens involved in male reproductive disorders. Few studies investigated the effects of these compounds on the prepubertal testis, which is highly sensitive to endocrine disruptors such as xenoestrogens. An ex vivo approach was performed to evaluate the effects of BPA or ZEA (10−11, 10−9, 10−6 M) on the testes of 20 and 25 dpp rats. To investigate the involvement of classical nuclear ER-mediated estrogen signaling in these effects, pre-incubation with an antagonist (ICI 182.780 10−6 M) was performed. BPA and ZEA have similar effects on spermatogenesis- and steroidogenesis-related endpoints in the immature testis, but our study highlights different age-dependent patterns of sensitivity to each compound during the prepubertal period. Moreover, our results indicate that the effects of BPA are likely to be induced by nuclear ER, whereas those of ZEA appear to involve other mechanisms.

Skeletal maturity as a biomarker for determining indications for regenerative interventional technologies in adolescent patients with hip and knee diseases

Skeletal maturity as a biomarker for determining indications for regenerative interventional technologies in adolescent patients with hip and knee diseases

The dopaminergic D1 receptor modulates the hyperactivity of Bapa mutant mice

The mutant bate-palmas (“claps”; symbol - bapa) mice induced by the mutagenic chemical ENU present motor incoordination and postural alterations. A previous study showed that bapa mice present increased motor/exploratory behaviors during the prepubertal period due to increased striatal tyrosine hydroxylase expression, suggesting striatal dopaminergic system hyperactivity. This study aimed to evaluate the involvement of striatal dopaminergic receptors in the hyperactivity of bapa mice. Male bapa mice and their wild strain (WT) were used. Spontaneous motor behavior was observed in the open-field test, and stereotypy was evaluated after apomorphine administration. The effects of DR1 and DR2 dopaminergic antagonists (SCH-23,390; sulpiride) and the striatal DR1 and D2 receptor gene expression were evaluated. Relative to WT, bapa mice showed: 1) increased general activity for four days; 2) increased rearing and sniffing behavior and decreased immobility after apomorphine; 3) blockage of rearing behavior after the DR2 antagonist but no effect after DR1 antagonist; 4) blockage of sniffing behavior after the DR1 antagonist in bapa and WT mice but no effect after the DR2 antagonist; 5) increased immobility after the DR1 antagonist but no effect after the DR2 antagonist; 6) increased expression of striatal DR1 receptor gene and reduced the DR2 expression gene after apomorphine administration. Bapa mice showed increased activity in open field behavior. The increased rearing behavior induced by apomorphine of bapa mice resulted from the increased gene expression of the DR1 receptor.

Short-term clinical and hormonal effects of a deslorelin implant on late-prepubertal bitches – Based on flare-up signs

Gonadotropin-releasing hormone (GnRH) agonists offer an alternative to surgical sterilization in prepubertal dogs, preserving ovarian and uterine functions. However, the clinical and hormonal effects of GnRH agonist application during the late-prepubertal stage remain insufficiently understood. This study aimed to investigate the clinical effect (flare-up) and hormonal changes, specifically serum progesterone (P4) and estradiol (E2) levels, in bitches treated with 4.7 mg deslorelin acetate (DA) implants (Suprelorin®, Virbac, F) during the late prepubertal period. Sixteen clinically healthy kangal cross-breed bitches, aged 7–8 months, with a mean body weight of 20.5 ± 0.8 kg, were implanted with DA. Estrus signs were monitored daily, and blood and vaginal cytological samples were collected every other day for four weeks. Cytological changes were analyzed for overall and superficial cell index. Six out of sixteen DA-treated bitches (EST group; n = 6) exhibited clinical proestrus 8.6 ± 0.6 days after implant insertion. The mean serum concentrations of P4 and E2 at the onset of estrus were 1.38 ± 0.32 ng/ml and 37.38 ± 10.07 pg/ml, respectively. Notably, all non-estrus (N-EST group; n = 10) bitches demonstrated an increase in superficial cell index, in addition to expected cytological changes observed in the EST group. On the 18th day post-implantation, the EST group exhibited a significantly higher number of superficial cells compared to the N-EST group (p < 0.001). DA implantation resulted in cytological profile alterations accompanied by a slight increase in estrogen concentrations in all dogs. However, the flare-up response exhibited significant variability, differing from that observed in adult dogs. This study highlights the importance of meticulous timing and breed-specific considerations when utilizing DA for puberty manipulation in late-prepubertal bitches. The observed cytological and hormonal changes in response to DA implants provide valuable insights, but the variability in flare-up responses warrants further investigation.

Effects of Androgen Treatment on Growth in Patients with 5-α-Reductase Type 2 Deficiency.

Patients with 5-α-reductase type 2 deficiency (5αRD2) require androgen treatment for the growth of normal male external genitalia. Since limited research has been conducted on the effects of androgen treatment on height in individuals with 5αRD2, we investigated the effect of androgen treatment on bone age (BA) and the height status in children with 5αRD2. Of the 19 participants who were followed up for an average of 10.6 years, 12 received androgen treatment. BA and height standard deviation scores (SDS) were compared between the treatment and non-treatment groups, as well as between the dihydrotestosterone (DHT) and testosterone enanthate (TE) treatment groups. Despite the above-average height of the 19 patients with 5αRD2, the height SDS relative to BA (htSDS-BA) was below average, particularly in the androgen treatment group. DHT treatment did not lead to an increase in BA or htSDS-BA, whereas TE treatment resulted in BA advancement and decreased htSDS-BA, especially in the prepubertal period. DHT treatment is more favorable for height than TE treatment in patients with 5αRD2, particularly during the prepubertal period. Therefore, age and the type of androgen used should be carefully considered to minimize the risk of height reduction in these patient groups.

A Determination of p97/VCP (Valosin Containing Protein) and SVIP (Small VCP Interacting Protein) Expression Patterns in Human Testis.

Background and Objectives: The ubiquitin proteosome system (UPS) is a non-lysosomal pathway that functions in all eukaryotes. The transport of polyubiquitinated proteins to proteosomes takes place via the p97/Valosin-containing protein (VCP) chaperone protein. The p97/VCP binds to polyubiquitinated proteins, allowing these proteins to reach the proteasome and, thus, their destruction. In the case of p97/VCP deficiency, ubiquitinated proteins accumulate in the cell cytoplasm, and their subsequent failure to break down produces various pathological conditions. Small VCP interacting protein (SVIP) and p97/VCP proteins have not been studied in human testicular tissues from different postnatal periods. Therefore, in our study, we aimed to examine the expression of SVIP and p97/VCP in postnatal human testicular tissues. Our study aimed to contribute to further studies on the use of these proteins as testicular cell biomarkers in cases of unexplained male infertility. Materials and Methods: Immunohistochemical studies with the aim of determining the expression of p97/VCP and SVIP proteins in neonatal, prepubertal, pubertal, adult, and geriatric human testis tissues were performed. Results: In testicular sections obtained from a neonatal group, p97/VCP and SVIP were localized in different testicular and interstitial cells, and the lowest expression was observed in this group. While the expressions of these proteins were low in the neonatal period, they increased gradually in the prepubertal, pubertal and adult periods. The expression of p97/VCP and SVIP, which peaked in adulthood, showed a significant decrease in the geriatric period. Conclusions: As a result, the expression of p97/VCP and SVIP correlated with the increase in age, but it decreased significantly in older groups.

ИНДЕКСЫ СУРРОГАТНОЙ ОЦЕНКИ ИНСУЛИНОРЕЗИСТЕНТНОСТИ У ДЕТЕЙ И ПОДРОСТКОВ С ОЖИРЕНИЕМ

Obesity is the most common reason for the insulin resistance (IR) though obesity in children is not always associated with IR. The markers based on fasting glucose and/or insulin levels and alternative parameters with conventional lipid-based indexes are used in assessing the IR in clinical practice. The purpose of the research was to assess the relationship between alternative IR surrogate biomarkers as follows: triglycerides (TG) to high-density lipoprotein cholesterol (HDL-C), TG/HDL-C ratio; single-point insulin sensitivity estimator (SPISE) index; triglyceride-glucose index (TyG), with generally accepted indices based on the insulin/glucose ratios, such as HOMA-IR, QUICKI, Caro, in a cohort of obese children and adolescents. Materials and methods used: a single-stage multicenter comparative study was conducted involving 127 patients aged 6 to 17 y/o with simple obesity of varying degrees. The following indices were calculated: HOMA-IR = fasting insulin (mU/ml) x fasting plasma glucose (FPG) (mmol/L) / 22.5; QUICKI = 1/Log (Fasting Insulin, µU/ml) + Log (Fasting Glucose, mg/dl); Caro = fasting plasma glucose (mmol/l) / fasting insulin (μU/ml); TG/HDL-C = TG (mmol/L) / HDL-C (mmol/L); triglyceride-glucose index TyG = Ln [fasting TG (mg/dl) x fasting plasma glucose (mg/dl)/2], where Ln is the logarithm; SPISE = 600 × HDL-C0.185/(TG0.2 x BMI1.338). Results: 75 (59%) boys and 52 (41%) girls were included in the study; the median age was 12.9 [10.4; 14.9] y/o. Pre-pubertal development was recorded in 25 (19.7%), pubertal - in 102 (80.3%). The prevalence of impaired glucose tolerance (IGT) was 5.5%. In children with IGT, the SPISE index was lower than in children with normal glucose tolerance (3.69 [3.49; 4.37] vs. 4.8 [3.99; 5.55], p=0.021) with no statistically significant differences between these groups in other markers. In the IGT subgroup, a high negative correlation was found between SDS BMI and SPISE (R=-0.97). In the general SDS group, BMI correlated with insulin (R=+0.24), TG (R=+0.2), HOMA (R=+0.24), Caro (R=-0.26), TG/HDL-C (R=+0.28) and SPISE (R=-0.65). The SPISE index was lower in girls than in boys (4.94 [3.63; 5.73] vs. 4.07 [3.59; 5.16], p = 0.045). No statistically significant differences were recorded for other gender-related markers. A negative correlation was also found between the obesity degree and SPISE in the subgroups of girls (R=-0.49) and boys (R=-0.70) as well as among pre-pubertal children of both genders (R=-0.61). The maximum correlation between SDS BMI and SPISE was recorded in the subgroup of teenagers of both genders (R=-0.88). In the general group, TyG was weakly correlated with HOMA-IR (R=+0.26) and QUICKI (R=-0.24), while SPISE showed a weak association with all studied insulin indices; no statistically significant correlation between insulin indices and TG/HDL-C was found. In the subgroup of girls, no significant relationships between the evaluated markers were found, in the subgroup of boys, TyG weakly correlated with HOMA-IR (R=+0.29) and QUICKI (R=-0.32). Stronger correlations were recorded in boys between SPISE and all studied insulin indices. In the subgroup of prepubertal patients, a correlation was found between TyG and QUICKI (R=-0.44), SPISE and Caro (R=+0.56), SPISE and HOMA-IR (R=-0.50). The TG/HDL-C ratio did not statistically significantly correlate with traditional IR markers. TyG showed weak correlations with HOMA-IR and QUICKI in the general group and the boys’ subgroup. In the prepubertal period, TyG only weakly correlated with QUICKI and did not show strong associations with insulin-based indices in pubertal children. The SPISE index showed correlations with insulin markers both in the main group and in individual subgroups. Conclusion: the SPISE index can be considered as a relatively simple and accessible method for assessing IR in obese children and adolescents.

Retrospective Cohort Analysis of the Impact of Puberty on Plexiform Neurofibroma Growth in Patients with Neurofibromatosis Type 1

To assess the hypothesis that plexiform neurofibroma (PN) growth rates increase during puberty. PN growth rates before and during puberty were compared in a retrospective cohort of children with neurofibromatosis type 1 with puberty defined by Tanner staging. Of 33 potentially eligible patients, 25 had adequate quality magnetic resonance imaging for volumetric analysis and were included in ≥1 anchor cohort. Volumetric analysis was performed for all available imaging studies within the 4years before and after puberty, and before and after 9- and 11-year-old anchor scans. Linear regression was performed to estimate the slope of change (PN growth rate); growth rates were compared with paired t test or Wilcoxon matched-pairs signed rank test. There were no significant difference in rates of PN growth in milliliters per month or milliliters per kilogram per month in the prepubertal vs pubertal periods (mean,1.33±1.67 vs 1.15±1.38 [P=.139] and -0.003±0.015 vs -0.002±0.02 [P=.568]). Percent increases of PN volumes from baseline per month were significantly higher prepubertally (1.8% vs 0.84%; P=.041) and seemed to be related inversely to advancing age. Puberty and its associated hormonal changes do not seem to influence PN growth rate. These findings support those previously reported, but from a typical population of children with neurofibromatosis type 1 with puberty confirmed by Tanner staging.

The effects of orchiectomy and steroid on fertility in experimental testicular atrophy.

Despite our understanding of Sertoli cell function and the state of spermatogenesis, the underlying mechanisms remain unclear. This study was conducted to compare the effects of orchiectomy and steroid treatment on fertility in testicular atrophy occurring after testicular torsion. Thirty-three rats were divided into four groups. The atrophy, orchiectomy, and atrophy-steroid groups each contained nine rats, while the control group contained six. The left testes were rotated 720º, and atrophy was observed. In the atrophy-steroid rats, orchiectomy was performed after atrophy, and 1 mg/kg steroid was injected. Each male rat was housed with five female rats for 6 days. The fertility of the male rats was evaluated based on the pregnancy of the female rats. Left and right orchiectomies were performed to determine the tissue Johnsen score (JS) and the serum inhibin B (IB) level. JS values were significantly lower in the atrophy, orchiectomy, and atrophy-steroid groups than in the control group (p<0.05), while no significant difference was observed in JS between the atrophy and orchiectomy groups (p>0.05). Similarly, no significant differences in IB level or fertility percentage were found between the atrophy and orchiectomy rats (p>0.05). In unilateral testicular atrophy, which can occur in the prepubertal period due to various causes, orchiectomy does not appear to benefit fertility, as indicated by IB, JS, and the fertility percentage.

The effects of oral supplementation of Japanese sake yeast on anxiety, depressive-like symptoms, oxidative stress, and BDNF changes in chronically stressed adolescent rats

Chronic stress during the pre-pubertal period has adverse effects in developing neuropsychiatric disorders such as depression and anxiety. The administration of supplements with antioxidant properties may alleviate depression and anxiety behavior. This study investigated the effects of oral supplementation of Japanese sake yeast on anxiety, depressive-like symptoms, oxidative stress, and changes in brain-derived neurotropic factor (BDNF) in adolescence rats subjected to chronic stress. In order to assess the effects of chronic stress, adolescent rats were grouped into one non-stressed control group (non-stress) and four different experimental groups. The other animals were subjected to stress and orally received normal saline (Control-stress), 15 mg/kg yeast (Stress-15), 30 mg/kg yeast (Stress-30) and 45 mg/kg yeast (Stress-45). Anxiety and depression-like behavior, BDNF levels, and oxidative stress markers were evaluated. The rats exposed to stress exhibited anxiogenic and depression-like behavior as well as lower levels of BDNF and higher levels of oxidative markers compared with non-stressed rats (P&lt;0.05). However, the oral supplementation of sake yeast decreased anxiogenic and depression-like behavior and oxidative indices, and also increased BDNF levels compared to stressed rats treated with saline in a dose-dependent manner (P&lt;0.05). In sum, stress caused anxiety and depression behavior, increased oxidative indices, and reduced BDNF levels while sake yeast alleviated adverse effects of stress on anxiety and depression behaviors, decreased oxidative markers, and increased BDNF levels.

Treatment of Class II Malocclusion in the Growing Patient: Early or Late?

The aim of this paper is to evaluate several factors that can improve the efficacy of Class II treatment in the growing patient with mandibular skeletal retrusion. Previous research has shown that functional appliances are most effective in altering short-and long-term mandibular growth and mandibular sagittal position if active treatment includes the pubertal growth spurt. If functional jaw orthopedic treatment is initiated in the prepubertal growth period, the positive occlusal changes are primarily dentoalveolar in nature. The staging of the maturation level of the cervical vertebrae (CVM method) has proven effective in differentiating the stages of maturation.The second factor, typically not considered routinely during the decision-making process, is the responsiveness of a specific patient to the prescribed treatment. Not all patients respond to the same treatment in the same manner. One way of predicting individual patient responsiveness is to evaluate mandibular morphology at puberty. Good responders to functional jaw orthopedics for Class II malocclusion with mandibular retrusion are characterized by a small mandibular angle (Co-Go-Me). Poor responders have larger mandibular angles.The third issue that is addressed is the question of whether an early phase of treatment is necessary in a Class II patient with mandibular skeletal retrusion. The most frequently seen deficiency in the early mixed dentition is narrowness of the maxilla. A measurement of transpalatal width between the closest points between the maxillary first permanent molars of 35-39 mm usually indicates that there is enough arch perimeter to accommodate teeth of normal size. If transpalatal width is constricted, an acrylic splint expander or a banded expander can be used to widen the maxilla. A removable lower Schwarz expander also can be used to gain a modest amount of lower arch perimeter while uprighting the lower posterior teeth. Rapid maxillary expansion in the early mixed dentition can help in improving Class II malocclusion as a side-effect, both skeletally and dentally.

Репродуктивное здоровье девочек и девушек Москвы. Развитие специализированной помощи

Due to a steady trend towards an increase in the incidence of various gynecological diseases, one of the most significant problems of modern society is the protection of the reproductive health of girls and adolescents. Diseases that are asymptomatic or with an erased clinical presentation but have a significant impact on the reproductive potential of the young population deserve close attention. Purpose. To reveal the prevalence of gynecological diseases among the female population of the neutral, prepubertal and pubertal period in Moscow and to determinate ways to reduce incidence of preventable diseases. Material and methods. An analysis of the data on gynecological morbidity of girls and adolescents in Moscow is presented based on the data of the annual report of the chief freelance specialist gynecologist of childhood and adolescence in Moscow in 2021 (n = 925 632). According to the report, the prevalence of gynecological pathologies during examinations in 2021 is (n = 82 517): delayed puberty (n = 182), premature thelarche (n = 779), menstrual disorders (n = 11 748), other endocrine disorders (n = 15), premenstrual tension syndrome (n = 353), dysmenorrhea (n = 5265), inflammatory diseases of vulva and vagina (n = 18 796), ovarian cysts (n = 2384), labial adhesion (labia minora) (n = 6261), disorders of breast (n = 1136), anogenital warts (n = 26), congenital disorders of female genital organs (n = 71), unspecified injury of external genitals (n = 223), sexual transmitted diseases (n = 39), Turner’s syndrome (n = 21), unspecified malignant primary neoplasms (n = 5). Results. An analysis of the prevalence of gynecological diseases in girls and adolescents in Moscow in 2021 (n = 925 632) has revealed that the highest incidence among all diseases of the reproductive system (n = 82 517) is: inflammatory diseases of the external and internal genital organs – 23% (n = 18 796), as well as menstrual disorders – 14% (n = 11 748), including dysmenorrhea – 6% (n = 5265), and labial adhesions – 8% (n = 6261). Reducing the incidence of gynecological diseases among girls and adolescents in Moscow can be achieved through regular full well-child examinations and improving the quality of specialized gynecological care. Conclusion. Providing regular preventive physical examinations and educational activities among adolescents and parents is one of the ways to timely detect various diseases of the reproductive system. The incidence of gynecological diseases among this age group can also be significantly reduced by increasing the coverage of the population with medical care and improving the quality of its provision

Testicular volume in 268 children and adolescents followed-up for childhood obesity-a retrospective cross-sectional study.

Prevalence of obesity in childhood has increased over the past few decades. The impact of obesity and of obesity-related metabolic disorders on testicular growth is unknown. To evaluate the impact of obesity, hyperinsulinemia, and insulin resistance on testicular volume (TV) in pre-pubertal (<9 years), peri-pubertal (9-14 years), and post-pubertal (14-16 years) periods. We collected data on TV, age, standard deviation score (SDS) of the body mass index (BMI), insulin, and fasting glycemia in 268 children and adolescents followed-up for weight control. Peri-pubertal boys with normal weight had a significantly higher TV compared to those with overweight or obesity. No difference was found in the other age ranges when data were grouped according to BMI. Pre- and post-pubertal children/adolescents with normal insulin levels had significantly higher TV compared to those with hyperinsulinemia. Peri-pubertal boys with hyperinsulinemia had significantly higher TV compared to those with normal insulin levels. Post-pubertal adolescents with insulin resistance had lower TV and peri-pubertal boys had higher TV compared to those without insulin resistance. No difference was found in pre-puberty. Closer control of the body weight and the associated metabolic alterations in childhood and adolescence may maintain testicular function later in life.

Plant-Based Diet during the Prepubertal Period and Age at Menarche: A Systematic Review

This systematic review aimed to analyze the effect of a prepubertal plant-based diet, through dietary patterns and its nutritional components, on the age at menarche. Systematic searches through Medline (EBSCO), Embase, Health &amp; Medical Collection (Proquest), Scopus, and Google Scholar for articles published between January 2000 and September 2022 in English using the keywords of plant-based diet, age at menarche, and their synonyms identified 673 articles. Articles were screened through titles and abstracts, as well as full-text reviews based on inclusion/exclusion criteria and assessment of research quality using the JBI Critical Appraisal Tools with a JBI cut-off final score of &gt;50%, leaving 12 articles in this systematic review presented in the PRISMA 2020 flowchart. Data analysis was conducted descriptively by comparing findings between articles. Age at menarche/puberty was reported as an outcome of food intake through a vegetarian diet, Mediterranean diet, vegetable protein, phytoestrogens and isoflavones, and dietary fiber. Based on the analysis of each subgroup, the plant-based diet did not consistently influence the incidence of menarche. In conclusion, a plant-based diet does not significantly affect age at menarche when it is accompanied by a balanced intake of energy and macro-micronutrients. The principles of balanced nutrition and the assistance of nutritionists are needed in practicing a plant-based lifestyle, especially for children and adolescents who are still in the developmental stage.

Ex vivo effects of 17β-estradiol on the prepubertal rat testis

Although it is well established that testis produces estrogens, their precise effect is not fully documented, particularly during the prepubertal period. In a previous in vivo study, we demonstrated that an exposure of prepubertal rats (15–30 days post-partum (dpp)) to 17β-estradiol (E2) delays the establishment of spermatogenesis. In order to characterize the mechanisms of action and the direct targets of E2 on the immature testis, we developed an organotypic culture model of testicular explants obtained from prepubertal rats (15, 20 and 25 dpp). To determine the involvement of nuclear estrogen receptors (ERs) in the effect of E2, particularly that of ESR1 which is the major ER expressed in the prepubertal testis, a pre-treatment with the full antagonist of this type of ERs (ICI 182.780) was performed. Histological analyses, gene expression studies and hormonal assays were conducted to investigate the effects of E2 on steroidogenesis- and spermatogenesis-related endpoints. Testicular explants from 15 dpp rats were unresponsive to E2 exposure while E2 effects were observed in those obtained from 20 and 25 dpp rats. An E2 exposure of testicular explants obtained from 20 dpp rats seemed to accelerate the establishment of spermatogenesis, whereas an E2 exposure of 25 dpp testicular explants induced a delay of this process. These effects could be related to the E2-induced modulation of steroidogenesis, and involved both ESR1-dependent and -independent mechanisms of action. Overall, this ex vivo study demonstrated differential age- and concentration-related effects of E2 on the testis during the prepubertal period.

Changes in testicular histomorphometry and ultrastructure of Leydig cells in adult male Japanese quail exposed to di (n-butyl) phthalate (DBP) during the prepubertal period

Phthalate esters, such as di(n-butyl) phthalate, (DBP), are synthetic chemical pollutants commonly used as plasticizers in the manufacture of plastics. In the present study, we investigated the effects of DBP in the testes of adult male quails (Coturnix cortunix japonica) exposed by oral gavage to variable doses of DBP (0 [control], 1, 10, 50, 200, and 400 mg/kgbw−d), for 30 days during the prepubertal period, using histo-morphometric and ultrastructural techniques. Generally, significant decreases in seminiferous tubular diameter (STD) and epithelial height (SEH) were observed predominantly at the highest DBP doses (200 and 400 mg/kg), as compared to medium (50 mg/kg), and lowest doses (1 and 10 mg/kg) as well as the control group. Ultrastructurally, apparent dose-specific degenerative changes were observed in the Leydig cells. The lowest DBP doses (1 and 10 mg/kg) did not produce significant effects on Leydig cell ultrastructure, whereas, at the highest doses (200 and 400 mg/kg), the Leydig cells were remarkably conspicuous in the interstitium and appeared foamy. There was a preponderance of electron-lucent lipid droplets which crowded out the normal organelles of the cell, as well as increases in the number of dense bodies in the cytoplasm. The smooth endoplasmic reticulum (sER) was less obvious, compacted, and wedged between the abundant lipid droplets and mitochondria. Taken together, these findings indicate that pre-pubertal exposure of precocious quail birds to DBP, produced parameter-specific histometric tubular changes, as well as dose-dependent cyto-structural derangement of the Leydig cells; which consequently may lead to overt reproductive impairments in the adult bird in the environment.Graphical

Comparison of Commonly Used Methods to Predict the Final Height in Constitutional Tall Stature

To determine the accuracy of adult height prediction in children with constitutional tall stature. The medical records of 138 non-syndromatic prepubertal and early pubertal children (52 male, 86 female) with a height of ≥90th percentile born between the years 1975 and 1988 were included in this study. Using the Bayley-Pinneau (BP) and Tanner-Whitehouse I (TWI) prediction methods, their height standard deviation score (SDS) at referral was compared with their height SDS at age 17 years when measured at the IDF conscription center. While remaining tall, the height SDS at age 17 years was lower than that at referral decreasing from 2.13±1 to 1.65±1.21 in boys and from 2.48±1 to 2.15±1 in girls. The prediction by the BP and TWI methods can be useful for estimating adult height in constitutional tall stature even in the prepubertal and early pubertal period. However, the fallibility of these methods should be kept in mind during clinical practice. We think that this study will shed light on these issues.