Post-pubertal Stage Research Articles

Alternative Splicing Dynamics of the Hypothalamus-Pituitary-Ovary Axis During Pubertal Transition in Gilts.

The timing of puberty in mammals marks the point at which reproduction becomes possible. Abnormalities in the timing of puberty may exert a series of negative effects on subsequent health outcomes. Alternative splicing (AS) has not only emerged as a significant factor in the transcription of genes but it is also reported to play a role in the timing of puberty. However, to date, the changes and dynamics of AS during the onset of puberty is extremely seldom explored. In the present study, we used gilts as a research model to investigated the dynamics of AS and differentially expressed AS (DEAS) events within the hypothalamus–pituitary–ovary (HPO) axis across pre-, in-, and post-puberty. We detected 3,390, 6,098, and 9,085 DEAS events in the hypothalamus, pituitary, and ovary when compared across pre-, in-, and post-pubertal stages, respectively. Within the entire HPO axis, we also identified 22,889, 22,857, and 21,055 DEAS events in the pre-, in-, and post-pubertal stages, respectively. Further analysis revealed that the differentially spliced genes (DSGs) associated with staged DEAS events were likely to be enriched in the oxytocin signaling pathway, thyroid hormone signaling pathway, GnRH signaling pathway, and oocyte meiosis signaling pathway. The DSGs associated with DEAS events across the entire HPO axis were enriched in endocytosis signaling pathway, the MAPK signaling pathway, and the Rap1 signaling pathway. Moreover. the ASs of TAC1, TACR3, CYP19A1, ESR1, ESRRA, and FSHR were likely to regulate the functions of the certain HPO tissues during the onset of puberty. Collectively, the AS dynamics and DEAS events were comprehensively profiled in hypothalamus, pituitary, and ovary across the pre-, in-, and post-pubertal stages in pigs. These findings may enhance our knowledge of how puberty is regulated by AS and shed new light on the molecular mechanisms underlying the timing of puberty in mammals.

Data for: Cervical vertebral maturation: Are post-pubertal stages attained in all subjects?

Data for: Cervical vertebral maturation: Are post-pubertal stages attained in all subjects?

Effects of estrogen deficiency during puberty on maxillary and mandibular growth and associated gene expression \u2013 an \u03bcCT study on rats

BackgroundEstrogen is a well-known and important hormone involved in skeletal homeostasis, which regulates genes involved in bone biology. Some studies support that estrogen is important for craniofacial growth and development. Therefore this in vivo animal study aimed to investigate, whether and in which way low estrogen levels in the prepubertal period affect craniofacial development in the postpubertal stage and to quantify the gene expression of RANK, RANKL and OPG in cranial growth sites in ovariectomized estrogen-deficient rats during puberty.MethodsControl (sham-operated, n = 18) and ovariectomy (OVX, n = 18) surgeries were performed on 21-days-old female Wistar rats. Animals euthanized at an age of 45 days (pubertal stage) were used for gene expression analyses (n = 6 per group) and immunohistochemistry of RANK, RANKL and OPG. Animals euthanized at 63 days of age (post-pubertal stage) were used for craniofacial two-dimensional and three-dimensional craniofacial measurements using μCT imaging (n = 12 per group).ResultsIn the μCT analysis of the mandible and maxilla many statistically significant differences between sham-operated and OVX groups were observed, such as increased maxillary and mandibular bone length in OVX animals (p < 0.05). Condylar volume was also significantly different between groups (p < 0.05). The sham-operated group showed a higher level of RANK expression in the midpalatal suture (p = 0.036) and the RANKL:OPG ratio levels were higher in the OVX group (p = 0.015).ConclusionsOur results suggest that estrogen deficiency during the prepubertal period is associated with alterations in the maxillary and mandibular bone length and condylar growth.

High intensity exercise induced alteration of hematological profile in sedentary post-pubertal boys and girls: A comparative study

Objectives: High-intensity exercise induces intensity dependent leukocytosis due to increased trafficking of white blood cells in circulation and also causes red blood cell (RBC) damage and hemolysis due to osmotic and mechanical stress. The present study was aimed to investigate the high-intensity exercise-induced perturbations of hematological profile in sedentary post-pubertal boys and girls. Materials and Methods: Blood samples were collected from sedentary post-pubertal boys (n = 22, age = 16.10 ± 0.74 years) and girls (n = 22, age = 16.04 ± 0.63 years) before and immediately after exercise to assess hematological parameters such as RBC Count, hematocrit, hemoglobin concentration (Hb), total leukocyte counts, and differential count. Results: Pre- and post-exercise RBC count, Hb and hematocrit had no significant inter-group variation. Pre- and post-exercise hematocrit and Hb were significantly (P &lt; 0.001) higher in post-pubertal boys. Leukocyte count had insignificant intergroup variation before the exercise but it increased significantly (P &lt; 0.001) following exercise in both the groups. Monocytosis and neutrophilia were significantly (P &lt; 0.01) higher in post-pubertal boys. Percentage change in monocyte, eosinophil and basophil did not depict significant inter-group variation while percentage increase in neutrophil was significantly (P &lt; 0.01) higher in boys as compared to girls. Post-exercise absolute lymphocyte count as well as percentage increase in this variable was significantly (P &lt; 0.001) higher in girls as compared to boys. Absolute eosinophil count increased significantly in both the groups but its relative count declined substantially probably due to higher rate of mobilization of lymphocyte and neutrophil. Basophil count was also perturbed following exercise. Conclusion: Gender appeared to have insignificant impact on exercise-induced perturbation in hematological profile at post-pubertal stage except for neutrophil and lymphocyte.

Stage-Dependent Expression of Protein Gene Product 9.5 in Donkey Testes.

Simple SummarySpermatogenesis and steroidogenesis are key functions of the testes. Molecular markers that identify each stage of germ cells and Leydig cells can identify and isolate specific germ or Leydig cells. Protein gene product (PGP)9.5 is observed in neuroendocrine cells and tumors; it is also used for the immunohistochemical detection of spermatogonial stem cells (SSCs) in various species of animals. It was found that the immunolabeling of PGP9.5 in testicular tissue was not observed in the seminiferous tubules in the pre-pubertal stage. However, in the post-pubertal stage, spermatogonia were immunolabeled with PGP9.5. Interestingly, some Leydig cells were immunolabeled with PGP9.5 in both pre- and post-pubertal stages. This study reflects that the PGP9.5 antibody can be used as a tool to identify and isolate spermatogonia from seminiferous tubules in the post-pubertal stage of donkey testes.Molecular markers can be used to identify and isolate specific developmental stages of germ cells and Leydig cells. Protein gene product (PGP)9.5 expression in spermatogonia and Leydig cells has been reported in several species. The stages of spermatogonia and Leydig cells expressing PGP9.5 vary depending on the species and reproductive stages. Thus, the objectives of this study were (1) to identify the localization of PGP9.5 in donkey testicular cells, and (2) to compare the expression patterns of PGP9.5 in donkey testicular cells between pre- and post-pubertal stages. Testes samples were collected following the routine field castration of six donkeys. Western blotting was performed to verify the cross-reactivity of the rabbit anti-human PGP9.5 antibody to donkey testes. Immunofluorescence was performed to investigate the expression pattern of PGP9.5 in testicular tissues at different reproductive stages. In Western blotting, the protein band of the PGP9.5 antibody appeared at approximately 27 kDa, whereas the band was not observed in the negative control treated with normal mouse IgG. In the pre-pubertal stage, the expression of deleted in azoospermia-like (DAZL) was found in some spermatogonia in pre-pubertal testicular tissues. However, the immunolabeling of PGP9.5 in testicular tissue was not observed in the seminiferous tubules. In stages 1 and 2, spermatogonia were immunolabeled with either PGP9.5 or DAZL. In contrast, PGP9.5 and DAZL were co-immunolabeled in some of the spermatogonia in stages 3 to 8. Interestingly, some Leydig cells were immunolabeled with PGP9.5 in both pre- and post-pubertal stages. In conclusion, the PGP9.5 antibody can be used as a tool to identify and isolate spermatogonia from seminiferous tubules.

Comparison of skeletal maxillary transverse deficiency treated by microimplant-assisted rapid palatal expansion and tooth-borne expansion during the post-pubertal growth spurt stage:

To investigate the efficacy of microimplant-assisted rapid palatal expansion (MARPE) to treat skeletal maxillary discrepancies during the post-pubertal growth spurt stage. Sixty patients with skeletal maxillary transverse deficiency during the post-pubertal growth spurt stage were randomly divided into MARPE and Hyrax groups. Thirty patients (mean age: 15.1 ± 1.6 years) were treated using the four-point MARPE appliance; 30 patients (mean age, 14.8 ± 1.5 years) were treated using the Hyrax expander. Cone beam computed tomography scans and dental casts were obtained before and after expansion. The data were analyzed using paired t-tests and independent t-tests. The success rates of midpalatal suture separation were 100% and 86.7% for MARPE and Hyrax groups, respectively. Palatal expansion and skeletal to dental ratio at the first molar level were greater in the MARPE group (3.82 mm and 61.4%, respectively) than in the Hyrax group (2.20 mm and 32.3%, respectively) (P < .01). Reductions in buccal alveolar bone height and buccal tipping of the first molars were less in the MARPE group than in the Hyrax group (P < .01). MARPE enabled more predictable and greater skeletal expansion, as well as less buccal tipping and alveolar height loss on anchorage teeth. Thus, MARPE is a better alternative for patients with skeletal maxillary deficiency during the post-pubertal growth spurt stage.

The role of postnatal estrogen deficiency on cranium dimensions.

The aim of this study was investigate the cranium dimensions of adult female rats, who suffered estrogen deficiency during the prepubertal stage, to assess the impact of estrogen deficiency on craniofacial morphology. Twenty-two female Wistar rats were divided into ovariectomy (OVX) (n = 11) and sham-operated control (n = 11) groups. Bilateral ovariectomy were performed in both groups at 21 days old (prepubertal stage), and rats were euthanized at an age of 63 days (post-pubertal stage). Micro-CT scans were performed with rat skulls, and the cranium morphometric landmark measurements were taken in the dorsal, lateral, and ventral view positions. Differences in measurements between the OVX and sham control groups were assessed using t test with an established alpha error of 5%. The measures of the rats' skull showed that the inter-zygomatic arch width and anterior cranial base length were significantly larger in OVX group (p = 0.020 and p = 0.050, respectively), whereas the length of parietal bone was significantly higher in the sham group (p = 0.026). For the remaining measurements no significant differences between groups were detected (p > 0.05). This study provides evidence that ovariectomized rats had alterations in cranial bone dimensions, demonstrating that estrogens during puberty are important for skull morphology. To understand the role of estrogen on the postnatal cranium development will impact the clinical diagnose and therapy during childhood and adolescence.

Diagnostic assessment of tooth maturation of the mandibular second molars as a skeletal maturation indicator: A retrospective longitudinal study

Our aim was to analyze the correlation between growth status in height and chronological age, carpal maturation, cervical maturation, and dental maturation, and assess the diagnostic performance of Demirjian's dental maturation as an indicator of the pubertal growth spurt, through a retrospective longitudinal study. Records of 60 Canadian patients obtained from the Burlington Growth Centre, which included height and weight charts and a set of x-rays at 6 points in time, were analyzed. The images at each point in time included 1 hand and wrist radiograph, a lateral cephalometric x-ray, and one 45° oblique cephalometric radiograph of each side, which were analyzed using the methods of Fishman, Baccetti, and Demirjian on the mandibular left and right secondmolars, respectively. The onset of the pubertal growth peak in height (distance to growth peak [DGP]) was identified, and the correlation between methods with DGP was assessed. High levels of correlation were obtained between the methods of Fishman, Baccetti, and Demirjian with DGP. The cutoff point between prepubertal and postpubertal stages was F stage for women and G stage for men, with statistically significant levels of sensitivity and specificity for the test. The use of the method of Demirjian applied to mandibular secondmolars is plausible as a predictor of the occurrence of the DGP for the studied population.

Postnatal differentiation and regional histological variations in the ductus epididymidis of the Congjiang Xiang pig

The Congjiang Xiang pig is a rare Chinese miniature breed whose epididymal histologic features through the postnatal development are poorly understood. To clarify the histomorphological differences between each region of epididymis during postnatal development, 24 male Congjiang Xiang pigs aged from neonatal (15 d), peri-puberty (30 d), puberty (60 d) to adult (180 d) stages, were examined. Postnatal differentiation of the different regions (I–V) of the epididymis started from birth and continued until maturity that showed regional variations. Developmental progression was disto-proximal. At the neonatal stage, Wolffian duct differentiation starts in the distal region, then ascends to the middle region which forms regions V, IV and III, respectively. A simple lined cuboidal in the epidydimal epithelial, which gradually differentiated into a pseudostratified columnar with stereocilia from neonatal to post-pubertal. After puberty cell rearrangement occurred in the epithelium, differentiation accelerated, and spermatozoon seen in the lumen, especially the lumen of region II. In region III, both halo and apical cells were frequently observed. At the post-pubertal stage, clear cells were frequently observed in Region IV-V, and the epididymal duct was markedly increased in size and fully packed with spermatozoa. The information presented in this study will be helpful for future evaluations of Congjiang Xiang pig fertility. After puberty cell rearrangement occurred in the epithelium, differentiation accelerated, and spermatozoon seen in the lumen, especially the lumen of region II. In region III, both halo and apical cells were frequently observed. At the post-pubertal stage, clear cells were frequently observed in Region IV–V, and the epididymal duct was markedly increased in size and fully packed with spermatozoa. The information presented in this study will be helpful for future evaluations of Congjiang Xiang pig fertility.

Insulin sensitivity in male sheep born to ewes treated with testosterone during pregnancy.

In animal models, exposure to excess testosterone during gestation induces polycystic ovary syndrome (PCOS)-like reproductive and metabolic traits in female offspring, suggesting that the hyperandrogenemic intrauterine environment may have a role in the etiology of PCOS. Additionally, few studies have also addressed metabolic and reproductive outcomes in male offspring. In the present study, the intravenous glucose tolerance test (IGTT) was used to assess the insulin-glucose homeostasis at various ages during sexual development in male sheep born to testosterone-treated ewes. To further analyze the programming effect of testosterone on insulin-glucose homeostasis, indexes of insulin sensitivity were assessed in orchidectomized post-pubertal males born to testosterone-treated ewes (Torq-males) and orchidectomized post-puberal controls (Corq-males) before and 48 h after a testosterone injection. There was no difference in insulin sensitivity indexes between males born to testosterone-treated ewes (T-males) and control males born to control ewes (C-males) at 5, 10, 20 and 30 weeks of age, representing the infantile, early and late pre-pubertal, and early post-pubertal stage of sexual development, respectively. In orchidectomized males, basal levels of insulin and glucose were not different between both groups before and after the testosterone injection; however, Torq-males released more insulin before and after T challenge during the first 20 min of the test. Despite this, plasma glucose concentrations were not different in both groups during IVGTT, resulting in an insulin sensitivity index composite similar between groups. We concluded that the effect of prenatal exposure to excess testosterone may reprogram the pancreatic β-cells insulin release in ovine males, with effects more evident in castrated males versus intact males.

Insufficient physical activity levels and high screen time among adolescents: impact of associated factors

The scope of this study was to verify the impact of associated factors with insufficient physical activity levels and high screen time among adolescents. A cross-sectional and representative study was conducted with 899 public high school adolescents from São José dos Pinhais, Paraná, Brazil. It involved measurement of physical activity levels and screen time and classification according to the norms of the World Health Organization and the American Academy of Pediatrics. The factors associated with insufficient physical activity levels and high screen time were gender, sexual maturation, social support and self-efficacy in terms of physical activity. Poisson regression was applied to test the associations. Population attributable fraction (PAF) and relative risk reduction (RRR) calculated the impact of associated factors with insufficient physical activity levels and high screen time among adolescents. In the combined presence of insufficient physical activity levels with high screen time, the female sex presented PAF = 13.04, a post-pubertal stage PAF = 9.91 and social support presented RRR = 31.00. The findings suggest that being female and post-pubescent are risk factors, while social support is a protective factor, for combined insufficient physical activity levels and high screen time among adolescents.

Assessment of Relationship Between Insulin-Like Growth Factor- 1 Levels And Mp3 Radiographs in Determining Skeletal Maturity

Context: The clinical importance of evaluating skeletal maturation has long been recognized by the health professions. Skeletal maturation is an integral part of individual patterns of growth and development.With many orthodontic patients, pubertal growth needs to be factored into the diagnostic equation.Accurate prediction of the timing of the pubertal growth spurt and the amount of remaining growth affects the treatment decisions in orthodontics, orthognathic surgery and dental implantology.IGF-1 mirrors growth hormone levels. Thus, IGF-I might be a good indicator of residual mandibular growth. Aims: To establish a relationship between IGF-1 levels evaluated from blood samples and MP3 stages of skeletal maturity. To investigate the relationship between the IGF-1 and the skeletal age. Methods and Material: The sample size consisted of 40 subjects between the age group of 5 – 25 including both the sexes. The periapical radiographs for MP3 and blood sample for IGF-1 was collected. Sample was sent to the lab to determine IGF-1 values. Statistical analysis used: Descriptives, ONE way ANOVA, POST HOC test, Spearman coefficient. Results: Results showed that IGF-1 levels at the peak pubertal growth were statistically higher than the start of pubertal growth, acceleration, deceleration, maturation of growth spurt and on completion of growth. There was statistically significant positive correlation between IGF-1 and MP3 stages. Conclusions: From the present study it can be concluded that IGF-1 can be successfully used as a skeletal maturity indicator. Key-words: IGF-1, MP3, GH Key Messages:The results of this study shows that mean IGF-I levels at pubertal and post pubertal stages were significantly higher than at the other stages. From the present study it can be concluded that IGF-1 can be successfully used as a skeletal

Post-pubertal Difference in Nigral Dopaminergic Cells Firing in the Schizophrenia Model Prepared by Perinatal Challenges of a Cytokine, EGF

Schizophrenia in humans typically develops during and after adolescence; however, the biological underpinning for the specificity of this onset time window remains to be determined. In the present study, we investigated this knowledge gap using our own animal model for schizophrenia. Rodents and monkeys challenged with a cytokine, epidermal growth factor (EGF), as neonates are known to exhibit various behavioral and cognitive abnormalities at the post-pubertal stage. We used the EGF-challenged mice as an animal model for schizophrenia to evaluate the electrophysiological impact of this modeling on nigral dopamine neurons before and after puberty. In vivo single unit recording revealed that the burst firing of putative dopamine neurons in substantia nigra pars compacta was significantly higher in the post-pubertal stage of the EGF model than in that of control mice; in contrast, this difference was not observed in the pre-pubertal stage. The increase in burst firing was accompanied by a decline in Ca2+-activated K+ (ISK) currents, which influence the firing pattern of dopamine neurons. In vivo local application of the SK channel blocker apamin (80 μM) to the substantia nigra was less effective at increasing burst firing in the EGF model than in control mice, suggesting the pathologic role of the ISK decrease in this model. Thus, these results suggest that the aberrant post-pubertal hyperactivity of midbrain dopaminergic neurons is associated with the temporal specificity of the behavioral deficit of this model, and support the hypothesis that this dopaminergic aberration could be implicated in the adolescent onset of schizophrenia.

Effect of ovariectomy on maxilla and mandible dimensions of female rats.

The role of oestrogen in craniofacial growth still remains unclear. Therefore, the present study aimed to assess the effect of oestrogen deficiency on maxilla and mandible dimensions. The study was conducted at the Department of Pediatric Dentistry at the School of Dentistry of Ribeirão Preto, University of São Paulo, and used forty female Wistar rats. Ovariectomy (OVX) and placebo surgery (Sham) were performed when animals were twenty-one days old (prepubertal stage). Dimensions of the maxilla and mandible were assessed by craniometric analysis using radiographs, during and after puberty of the animals (45 and 63days old, respectively). Quantitative real-time PCR and immunohistochemical analyses were performed to determine the expression and localization, respectively, of oestrogen receptor alpha (ERα) and oestrogen receptor beta (ERβ) in different growth sites of the evaluated structures at puberty. The differences between the groups for each outcome were evaluated using the t test with an established alpha error of 5%. There were significant differences between the OVX and Sham groups for horizontal and vertical linear measurements in the maxilla and the mandible at both pubertal and post-pubertal stages (P<.05). The ovariectomized rats showed significantly greater measures for all dimensions assessed. No differences in gene expression of ERα and ERβ were identified at the different growth sites between the OVX and Sham groups (P>.05). Immunohistochemical analyses revealed the presence of both oestrogen receptors in osteoblasts and chondrocytes in the midpalatal suture and mandibular condyle, respectively, in the OVX and Sham groups. Our results suggest that oestrogen deficiency from the prepubertal stage might increase the growth of the maxilla and mandible in female rats.

Cervical vertebral maturation: Are postpubertal stages attained in all subjects?

The cervical vertebral maturation (CVM) method comprises 6 stages reported to be prepubertal (1 and 2), pubertal (3 and 4) and postpubertal (5 and 6), and its use has been recommended for planning treatment timing in orthodontics. Reliable use of the method implies that pubertal stages have to mature into postpubertal as soon as the growth peak is terminated. The present study was aimed at determining whether postpubertal CVM stages 5 or 6 are attained in all subjects. A total of 450 adult subjects (270 females and 180 males; mean age, 30.4±27.3years; range, 20-45years) seeking orthodontic treatment and having a lateral head film were included in the study. Customized cephalometric analysis was used, and each recording was converted into an individual CVM code according to the concavities of the C2 to C4 and shapes of C3 and C4. The retrieved CVM codes, either falling within the reported norms (regular cases) or not (exception cases), were also converted into the CVM stages and a newly introduced CVM score (0-9) capable of defining intermediate stage. The most frequent CVM stage was 5, while the CVM stage 6 was attained in only one third of the sample. Up to about 11% of adult subjects showed the pubertal CVM stage 4. Irrespective of the CVM stage or CVM score, no significant differences were seen between the sexes or across ages. The C4 showed a rectangular vertical shape in only 16.4% of the cases. The percentage of adult population maintaining a pubertal CVM stage 4 is not high, but still relevant from a clinical standpoint. In light of this finding, planning treatment timing-based only on CVM appears not fully reliable.

A cross-sectional survey of adrenal steroid hormones among overweight/obese boys according to puberty stage

BackgroundObesity is associated with many chronic diseases including cortisol rhythm disorder and low testosterone. Furthermore, studies on obese children are quite limited and no concordance results have been obtained, especially for boys in puberty. Moreover, the sample sizes of previous studies were small, and were not representative.MethodsWe conducted a cross-sectional survey including 1148 boys aged 6–14 years, they were divided into overweight/obesity (OW/OB) group and normal weight (NW) group. Puberty status was assessed according to Tanner scale and testicular volume. Serum levels of pregnenolone, 17-OH progesterone, corticosterone, dehydroepiandrosterone (DHEA), and androstenedione were detected by LC-MS. Serum free testosterone and sex hormone-binding globulin (SHBG) levels were measured by chemiluminescence immunoassay.ResultsThe 17-OH progesterone, DHEA, androstenedione and free testosterone levels of OW/OB boys at prepubertal stage or at the age 6 = < 10 years group were higher than those of the NW boys (all the P values were < 0.01). Furthermore, androstenedione and free testosterone levels were lower in OW/OB boys at late puberty, and the trend continued at the post pubertal stage for FT (P < 0.01–0.05). DHEA, androstenedione, and FT levels persisted to be higher at the 10~ < 12 years in OW/OB boys but not for 17-OH progesterone. FT level was lower in the OW/OB group at the 12~ < 15 years group. The SHBG levels in the OW/OB boys were lower than those in the NW ones at the 6~12 years group, and prepubertal to early pubertal stage.ConclusionsPremature adrenarche is more likely in OW/OB boys. More attention should be given to the lower androgen levels of OW/OB boys at late pubertal and post pubertal stages.

Diagnostic performance of eruption stages for identification of skeletal maturity.

Objectives:To investigated the diagnostic performance of circumpubertal eruption stages which identify skeletal maturity stages using the cervical vertebral maturation (CVM) method in a Saudi population.Methods:This is a retrospective cross-sectional study. Lateral cephalograms, panoramic radiographs, and intraoral pictures of 600 orthodontic patients (284 boys, 316 girls) who met inclusion criteria were assessed. Records were retrieved between January 2016 and April 2018. The diagnostic performance of eruption stages for identifying skeletal maturity was tested with positive likelihood ratios (LHR+).Results:Prevalence of each CVM stage in the eruption stages was reported. For every eruption stage, LHR+ was reported in order to identify every CVM stage. The majority of the LHR+ values were ≤3.5, with a significant value of ≥10 for the identification of the post-pubertal growth stage. The other eruptions stages did not strongly predict skeletal maturity.Conclusion:In treatment planning for cases that require identifying the growth peak, the use of eruption stages is not recommended as an indicator of skeletal maturity except for the early permanent dentition stage where strong diagnostic performance for identifying post-pubertal skeletal growth stage has been shown.

Effect of prepubertal and postpubertal long-term exposure to the mild dose of soybean seeds on the tissue and function of thyroid gland in albino rat

The aim of this study is to investigate the effect of long-term exposure to the mild dose of soybean seeds on the tissue and some physiological parameters of the thyroid gland in the prepubertal and postpubertal life stages. Twenty four Sprague-Dawley albino male rats were divided into four groups (n=6); control rats at the prepubertal life stage; prepubertal rats treated with 20% soybean seeds of daily diet for 40 days after the weaning; normal control rats, at the postpubertal stage; and postpubertal rats, were treated with 20% soybean seeds. Morphmetrical, histological and physiological changes were examined. Consumption of mild dose of soybean seeds along the prepubertal life stage showed significant decrease (P&lt;0.05) in the height of follicular cell, significant increase (P&lt;0.05) in the diameter of follicular lumen and ratio of cold follicles, slightly non-significant decline in (T3 and T4) hormones levels and significant increment (P&lt;0.05) in body weight, while at postpuberty, long-term exposure for the same dose of soybean seeds showed significant increase in the height of follicular cell (P&lt;0.05), significant decrease (P&lt;0.05) in the diameter of follicular lumen and ratio of cold follicles caused hyperactivity of the thyroid, significant decline (P&lt;0.05) in (T3 and T4) hormones levels and slightly non-significant increment (P&lt;0.05) in body weight. We concluded that the long-term exposure to the mild dose of the soybean affect adversely the tissue and function of the thyroid at both life stages, pre- and postpuberty.

Effect of prepubertal and postpubertal long-term exposure to the mild dose of soybean seeds on the tissue and function of thyroid gland in albino rat

The aim of this study is to investigate the effect of long-term exposure to the mild dose of soybean seeds on the tissue and some physiological parameters of the thyroid gland in the prepubertal and postpubertal life stages. Twenty four Sprague-Dawley albino male rats were divided into four groups (n=6); control rats at the prepubertal life stage; prepubertal rats treated with 20% soybean seeds of daily diet for 40 days after the weaning; normal control rats, at the postpubertal stage; and postpubertal rats, were treated with 20% soybean seeds. Morphmetrical, histological and physiological changes were examined. Consumption of mild dose of soybean seeds along the prepubertal life stage showed significant decrease (P&lt;0.05) in the height of follicular cell, significant increase (P&lt;0.05) in the diameter of follicular lumen and ratio of cold follicles, slightly non-significant decline in (T3 and T4) hormones levels and significant increment (P&lt;0.05) in body weight, while at postpuberty, long-term exposure for the same dose of soybean seeds showed significant increase in the height of follicular cell (P&lt;0.05), significant decrease (P&lt;0.05) in the diameter of follicular lumen and ratio of cold follicles caused hyperactivity of the thyroid, significant decline (P&lt;0.05) in (T3 and T4) hormones levels and slightly non-significant increment (P&lt;0.05) in body weight. We concluded that the long-term exposure to the mild dose of the soybean affect adversely the tissue and function of the thyroid at both life stages, pre- and postpuberty.

The Notch system during pubertal development of the bovine mammary gland

The development of the mammary gland of cows during pre-weaning and puberty will condition its future productive capacity and warrants special study. In this respect, Notch signaling regulates tissue development and fate by modifying cell proliferation and differentiation and has been involved in stem cell maintenance, but has not been extensively studied in the developing mammary glands in cows. We therefore investigated Notch receptor expression and localization, as well as the expression of Notch ligands and target genes in the mammary gland of Holstein heifers in pre- and post-pubertal stages. Notch receptors 1 to 4 were detected by immunohistochemistry in the parenchyma and stroma of the developing gland. The subcellular localization of the four receptors was predominantly cytoplasmic except for NOTCH4, which was mostly nuclear. The membrane and the active intracellular domains of NOTCH paralogues were identified by western blot. NOTCH1 and NOTCH2 active domains increased during pubertal stages while NOTCH3 and NOTCH4 active domains decreased, suggesting strikingly different involvement of NOTCH paralogues in bovine mammary gland development and differentiation. The mRNA expression levels of the target genes HEY1 and HEY2 increased during peri-puberty whereas no variation of HES1 mRNA levels was observed. The mRNA levels of the Notch ligands JAGGED1 and DELTA1 also increased gradually during development. In conclusion, Notch signaling system dynamically varies throughout the development of the mammary gland during puberty pointing to specific time involvement of each component.