Objective This paper aims to study the relationship between body fat and sexual development in Chinese girls with different waist circumference.Methods Six thousand one hundred and fifty six girls aged 6-19 were sampl...Objective This paper aims to study the relationship between body fat and sexual development in Chinese girls with different waist circumference.Methods Six thousand one hundred and fifty six girls aged 6-19 were sampled.Their body weight,height,waist circumference,percentage of body fat and secondary sex characteristics were measured.All the subjects were divided into three groups：low class waist circumference,moderate class waist circumference and high class waist circumference.The menarche percentages were analyzed by using the status method.The menarche ages were analyzed by using the retrospective method.Estimates for mean age at entry into a pubertal stage and menarche were calculated by a probit analysis.Results The incidences of moderate class and high class waist circumstance were 20.94% and 25.27%,respectively.The sexual development of the former was earlier than that of the latter.The percentages of the menarche were detected as high classmoderate classlow class.The menarche ages were expressed as high classmoderate classlow class.Conclusion A close association is found between the waist circumference and sexual development,especially the menarche age.Girls with high class waist circumference are more vulnerable to earlier menarche and excess body fat.It is important to control the occurrence of central obesity through monitoring the change of waist circumference in puberty for girls＇ health.展开更多
Products of Chicken Embryo (PCE) such as Ji-Pei-Jing is a kind of food for Chinese children prepard from chicken embryo. Female rats on 21 days were administered with aqueous solutions of Ji-Pei-Jing (1. 2 %, 3 %, 12%...Products of Chicken Embryo (PCE) such as Ji-Pei-Jing is a kind of food for Chinese children prepard from chicken embryo. Female rats on 21 days were administered with aqueous solutions of Ji-Pei-Jing (1. 2 %, 3 %, 12%, and 48%, respectively) by gavage up to their onsets of puberty.The rats in the control group were treated with distilled water. However, Ji-Pei-Jing treatment exerted some effects on sexual mauration in the immature female rats. Essentially, the effects showed a dose-response tendency with an inverted 'U' shape.The age of vopnal opening for gnup treated with Ji-Pei-Jing was significantly earier than that to the control. Its uterus weight/b. w. ratio also significantly increased on day 30 and at the first estrus. There were significantly increases in the adrenal weight/b. w. raio of 30-day-old rats that were treated with 3%, 12%, and 48% Ji-Pei-Jing. The rats treated with 48% Ji-Pei-Jing had significantly lesser ovary weight.b.w. radio on day 30, too. The rats treated with Ji-Pei-Jing could normally ovulate at the first estrus, and no significant differences were observed during estrous cycles.The effects of PCE on serum levels of K, P, LH in 30-day-old nds and FSH in 28-day-old ras were elevated significantly by 3 % Ji-Pei-Jing treatment. It appeare that the effects of PCE result from interaction of contained complex physiologically active substances. Steriods, especially estradio-17β,possibly Play a key role, and polpeptide hormones may also exert important effects.展开更多
Although the child masturbation is recognized as not uncommon behavior, our understanding of normative sexual development in humans is fairly limited. To investigate the possible relationship between early childhood m...Although the child masturbation is recognized as not uncommon behavior, our understanding of normative sexual development in humans is fairly limited. To investigate the possible relationship between early childhood masturbation and subsequent sexual cognition, we retrospectively researched three adolescents who had been reared male and who masturbated in early childhood in similar ways, but had different subsequent sexual cognition. The three young people all recalled primary sexual pleasure from masturbation at age 4 or 5. Their distinctive sexual attitudes could be discerned at age 15 to 20. One was transgender, one was homosexual, and one was heterosexual. Combining recent findings of the neural mechanisms of sexual pleasure and cognition, it can be inferred that the early sexual pleasure in preschoolers might have little significance for the development of sexual cognition in adolescence.展开更多
Sex development anomalies represent a group of congenital pathologies in which chromosomal, gonadal and anatomical sex differentiation is atypical. The aim of our study was to use molecular biology techniques to eluci...Sex development anomalies represent a group of congenital pathologies in which chromosomal, gonadal and anatomical sex differentiation is atypical. The aim of our study was to use molecular biology techniques to elucidate sex in cases of anomalies of sexual differentiation in Burkina Faso. This cross-sectional study took place from March 2023 to June 2023. Oral and blood samples were collected respectively using sterile swabs and stored on Swab Kits and NUCLEIcardTM (https://www.copangroup.com/product-ranges/nucleic-card/) were used to determine gonosome profiles. Extraction was carried out using the DNA Swap solution Kit and the DNA IQ System Kit, and a PowerPlex? 21 kit (Promega) for amplification. The Applied Biosystems 9700 thermal cycler was used for PCR followed by 36 cm capillary electrophoresis in the Applied Biosystems 3130 prism sequencer. Sequence files were analyzed using GeneMapper IDX v. 3.2 software. Seven (07) patients were registered during the study period. There were 4 cases of XX DSD or 46, XX DSD and 3 cases of XY DSD or 46, XY DSD. The median age of our patients was 16 years. Civilian sex was male in 4 cases and female in 3. The most frequent reason for consultation was micropenis in 3 cases, followed by primary amenorrhea and sex ambiguity. There were 03 cases of discrepancy between genetic sex and civil sex. The accessibility of molecular diagnosis is little known to clinicians. XX DSDs or 46, XX DSDs were the most frequent (4/7) in our study. The problem facing this situation is early diagnosis to help prevent complications in Burkina Faso.展开更多
Background and Aims: Younger age at first sexual intercourse is associated with a variety of adverse health outcomes. We aimed to gain a clearer understanding of a wide range of individual, family and social factors t...Background and Aims: Younger age at first sexual intercourse is associated with a variety of adverse health outcomes. We aimed to gain a clearer understanding of a wide range of individual, family and social factors that may influence sexual behavior of children and adolescents. Specifically, we examined the relationships of developmental assets with age of first sexual intercourse among a large sample (n = 1061) of adolescent African American males living in low-income neighborhoods in Mobile, Alabama. Methods: Using the Developmental Asset Model as a theoretical guide, we selected variables from adolescent survey data and conducted logistic regression analysis to determine predictors of early age of first sexual intercourse. Results: Nearly one half (49%) of the male survey participants reported that they first had sexual intercourse at the age of 12 or younger. The total number of assets was the strongest predictor of later age (13 years old or later) of first sexual intercourse (OR 1.49, 95% CI = 1.09, 2.04), followed by decision-making skills (OR 1.40, 95% CI = 1.04, 1.86), and positive view of the future (OR 1.36, 95% CI = 1.02, 1.74). Conclusion: There are several developmental assets related to the age of first sexual intercourse. This study found support for the Developmental Asset Model as a framework for promoting sexual and overall adolescent health. Recommendations for asset-building among this population are discussed.展开更多
Growth and differentiation factor-11 (GDF-11) is a secreted protein that is closely related to myostatin, a known inhibitor of skeletal muscle development. The role of GDF-11 in regulating skeletal muscle growth remai...Growth and differentiation factor-11 (GDF-11) is a secreted protein that is closely related to myostatin, a known inhibitor of skeletal muscle development. The role of GDF-11 in regulating skeletal muscle growth remains unclear and the pattern of expression during post-natal growth has not been reported. Therefore, we sought to determine the expression of GDF-11 during post-natal growth and its effect on myoblast proliferation and differentiation. We collected gastrocnemius muscles from male and female mice at 2, 3, 4, 6, 12, 20 and 32 weeks of age (n = 6 per sex and age). In addition, gastrocnemius muscles were col- lected from male wild-type and myostatin knockout mice at 4, 6, 12 and 20 weeks of age (n = 6 per age and genotype). RNA was extracted and reverse tran- scribed. Northern analysis identified an expected 4.4 kb mRNA transcript for GDF-11 in gastrocnemius muscles of mice. The concentration of GDF-11 mRNA, as determined by quantitative PCR, was increased in gastrocnemius muscles from 2 to 6 weeks—a period of rapid postnatal muscle growth—and remained higher in male than female mice from 4 to 20 weeks of age (P gastrocnemius muscles of myostatin knockout compared with wild-type mice (P < 0.05), which may suggest a compensatory mecha- nism for the lack of myostatin. In support, recombi- nant GDF-11 inhibited differentiation of C2C12 mur- ine myoblasts and those isolated from myostatin knockout and wild-type mice (P < 0.05). Inhibited dif-ferentiation of C2C12 myoblasts was associated with decreased mRNA expression of early and late mo- lecular markers of differentiation (MyoD, myogenin, IGF-II, desmin and MyHC, P < 0.05). Our results suggest that GDF-11 regulates growth of skeletal muscles by inhibiting myoblast differentiation in an autocrine/paracrine manner and, perhaps, also plays a role in regulating sexually dimorphic growth.展开更多
Sexual size dimorphism （SSD） is widespread among diverse animal taxa and has attracted the attention of evolutionary biologists for over a century. SSD is likely to be adaptive and the result of divergent selection ...Sexual size dimorphism （SSD） is widespread among diverse animal taxa and has attracted the attention of evolutionary biologists for over a century. SSD is likely to be adaptive and the result of divergent selection on different size optima for males and females, given their different roles in reproduction. The developmental trajectory leading to SSD may help us to understand how selection acts on male and female size. Here, we describe the growth and development of two Australian praying mantids, Pseudomantis albofimbriata and Hierodula majuscula including the number of moults, time to adulthood, size at each moult, and the degree of SSD. While both species exhibit the common pattern of female-biased SSD, the number of moults required for individuals to reach adulthood differed between males and females and between species. Despite their larger adult size, P. albofimbriata females require fewer moults and less time than males to reach adulthood, but are significantly larger than males from the second instar onwards. In contrast, H. majuscula males reached adulthood in fewer moults, and less time than females, however males and females did not differ in size until females went through their final moult into adulthood. H. majuscula also required more time and more moults to reach adulthood than 17. albofimbriata. We discuss these different developmental pathways in light of the existing knowledge of reproductive biology for each species. We also suggest that these differences may relate to the different phenologies that occur in strongly seasonal temperate environments compared with those in the tropics. This study provides evidence that SSD can result from two different patterns of growth and development in closely related species.展开更多
Background Menarche is a substantial milestone of female puberty.Timing of age at menarche is considered the key to understanding the potential linkages with women’s health outcomes later in life.This study aimed to ...Background Menarche is a substantial milestone of female puberty.Timing of age at menarche is considered the key to understanding the potential linkages with women’s health outcomes later in life.This study aimed to explore the secular trends and urban‒rural disparities in the median age at menarche among Chinese Han girls from 1985 to 2019.Methods Data were extracted from the 1985,1995,2005,2014,and 2019 Chinese National Surveys on Students’Constitution and Health,which were nationally representative cross-sectional studies,and a total of 173,535 Han girls aged 9–18 years were examined.Girls were asked whether menarche had occurred.The median age at menarche was estimated by probit analysis.Z tests were used to compare the differences between survey years and between urban and rural areas.Results The median age at menarche among Chinese Han girls decreased from 13.37 years in 1985 to 12.00 years in 2019,and the overall decrease was more significant in rural areas(1.77 years)than in urban areas(0.99 years).The average five-year change in the decrease in the median age at menarche showed an accelerating and then slowing pace;and it was observed similarly in both urban and rural areas.The urban‒rural disparities shrank from 0.64 years in 1985 to 0.44 years in 1995,then to 0.27 years in 2005,0.24 years in 2014,and finally to−0.14 years in 2019.Conclusions The median age at menarche among Chinese Han girls continued to decline from 1985 to 2019 but at a slowing pace in the last five years.Urban‒rural disparities gradually narrowed.Sexual and reproductive health education and interventions to prevent the decline in the age of menarche are needed,especially in rural areas.展开更多
基金supported by the Research Fund from the Natural Science Foundation of China (30972495)
文摘Objective This paper aims to study the relationship between body fat and sexual development in Chinese girls with different waist circumference.Methods Six thousand one hundred and fifty six girls aged 6-19 were sampled.Their body weight,height,waist circumference,percentage of body fat and secondary sex characteristics were measured.All the subjects were divided into three groups：low class waist circumference,moderate class waist circumference and high class waist circumference.The menarche percentages were analyzed by using the status method.The menarche ages were analyzed by using the retrospective method.Estimates for mean age at entry into a pubertal stage and menarche were calculated by a probit analysis.Results The incidences of moderate class and high class waist circumstance were 20.94% and 25.27%,respectively.The sexual development of the former was earlier than that of the latter.The percentages of the menarche were detected as high classmoderate classlow class.The menarche ages were expressed as high classmoderate classlow class.Conclusion A close association is found between the waist circumference and sexual development,especially the menarche age.Girls with high class waist circumference are more vulnerable to earlier menarche and excess body fat.It is important to control the occurrence of central obesity through monitoring the change of waist circumference in puberty for girls＇ health.
文摘Products of Chicken Embryo (PCE) such as Ji-Pei-Jing is a kind of food for Chinese children prepard from chicken embryo. Female rats on 21 days were administered with aqueous solutions of Ji-Pei-Jing (1. 2 %, 3 %, 12%, and 48%, respectively) by gavage up to their onsets of puberty.The rats in the control group were treated with distilled water. However, Ji-Pei-Jing treatment exerted some effects on sexual mauration in the immature female rats. Essentially, the effects showed a dose-response tendency with an inverted 'U' shape.The age of vopnal opening for gnup treated with Ji-Pei-Jing was significantly earier than that to the control. Its uterus weight/b. w. ratio also significantly increased on day 30 and at the first estrus. There were significantly increases in the adrenal weight/b. w. raio of 30-day-old rats that were treated with 3%, 12%, and 48% Ji-Pei-Jing. The rats treated with 48% Ji-Pei-Jing had significantly lesser ovary weight.b.w. radio on day 30, too. The rats treated with Ji-Pei-Jing could normally ovulate at the first estrus, and no significant differences were observed during estrous cycles.The effects of PCE on serum levels of K, P, LH in 30-day-old nds and FSH in 28-day-old ras were elevated significantly by 3 % Ji-Pei-Jing treatment. It appeare that the effects of PCE result from interaction of contained complex physiologically active substances. Steriods, especially estradio-17β,possibly Play a key role, and polpeptide hormones may also exert important effects.
文摘Although the child masturbation is recognized as not uncommon behavior, our understanding of normative sexual development in humans is fairly limited. To investigate the possible relationship between early childhood masturbation and subsequent sexual cognition, we retrospectively researched three adolescents who had been reared male and who masturbated in early childhood in similar ways, but had different subsequent sexual cognition. The three young people all recalled primary sexual pleasure from masturbation at age 4 or 5. Their distinctive sexual attitudes could be discerned at age 15 to 20. One was transgender, one was homosexual, and one was heterosexual. Combining recent findings of the neural mechanisms of sexual pleasure and cognition, it can be inferred that the early sexual pleasure in preschoolers might have little significance for the development of sexual cognition in adolescence.
文摘Sex development anomalies represent a group of congenital pathologies in which chromosomal, gonadal and anatomical sex differentiation is atypical. The aim of our study was to use molecular biology techniques to elucidate sex in cases of anomalies of sexual differentiation in Burkina Faso. This cross-sectional study took place from March 2023 to June 2023. Oral and blood samples were collected respectively using sterile swabs and stored on Swab Kits and NUCLEIcardTM (https://www.copangroup.com/product-ranges/nucleic-card/) were used to determine gonosome profiles. Extraction was carried out using the DNA Swap solution Kit and the DNA IQ System Kit, and a PowerPlex? 21 kit (Promega) for amplification. The Applied Biosystems 9700 thermal cycler was used for PCR followed by 36 cm capillary electrophoresis in the Applied Biosystems 3130 prism sequencer. Sequence files were analyzed using GeneMapper IDX v. 3.2 software. Seven (07) patients were registered during the study period. There were 4 cases of XX DSD or 46, XX DSD and 3 cases of XY DSD or 46, XY DSD. The median age of our patients was 16 years. Civilian sex was male in 4 cases and female in 3. The most frequent reason for consultation was micropenis in 3 cases, followed by primary amenorrhea and sex ambiguity. There were 03 cases of discrepancy between genetic sex and civil sex. The accessibility of molecular diagnosis is little known to clinicians. XX DSDs or 46, XX DSDs were the most frequent (4/7) in our study. The problem facing this situation is early diagnosis to help prevent complications in Burkina Faso.
文摘Background and Aims: Younger age at first sexual intercourse is associated with a variety of adverse health outcomes. We aimed to gain a clearer understanding of a wide range of individual, family and social factors that may influence sexual behavior of children and adolescents. Specifically, we examined the relationships of developmental assets with age of first sexual intercourse among a large sample (n = 1061) of adolescent African American males living in low-income neighborhoods in Mobile, Alabama. Methods: Using the Developmental Asset Model as a theoretical guide, we selected variables from adolescent survey data and conducted logistic regression analysis to determine predictors of early age of first sexual intercourse. Results: Nearly one half (49%) of the male survey participants reported that they first had sexual intercourse at the age of 12 or younger. The total number of assets was the strongest predictor of later age (13 years old or later) of first sexual intercourse (OR 1.49, 95% CI = 1.09, 2.04), followed by decision-making skills (OR 1.40, 95% CI = 1.04, 1.86), and positive view of the future (OR 1.36, 95% CI = 1.02, 1.74). Conclusion: There are several developmental assets related to the age of first sexual intercourse. This study found support for the Developmental Asset Model as a framework for promoting sexual and overall adolescent health. Recommendations for asset-building among this population are discussed.
文摘Growth and differentiation factor-11 (GDF-11) is a secreted protein that is closely related to myostatin, a known inhibitor of skeletal muscle development. The role of GDF-11 in regulating skeletal muscle growth remains unclear and the pattern of expression during post-natal growth has not been reported. Therefore, we sought to determine the expression of GDF-11 during post-natal growth and its effect on myoblast proliferation and differentiation. We collected gastrocnemius muscles from male and female mice at 2, 3, 4, 6, 12, 20 and 32 weeks of age (n = 6 per sex and age). In addition, gastrocnemius muscles were col- lected from male wild-type and myostatin knockout mice at 4, 6, 12 and 20 weeks of age (n = 6 per age and genotype). RNA was extracted and reverse tran- scribed. Northern analysis identified an expected 4.4 kb mRNA transcript for GDF-11 in gastrocnemius muscles of mice. The concentration of GDF-11 mRNA, as determined by quantitative PCR, was increased in gastrocnemius muscles from 2 to 6 weeks—a period of rapid postnatal muscle growth—and remained higher in male than female mice from 4 to 20 weeks of age (P gastrocnemius muscles of myostatin knockout compared with wild-type mice (P < 0.05), which may suggest a compensatory mecha- nism for the lack of myostatin. In support, recombi- nant GDF-11 inhibited differentiation of C2C12 mur- ine myoblasts and those isolated from myostatin knockout and wild-type mice (P < 0.05). Inhibited dif-ferentiation of C2C12 myoblasts was associated with decreased mRNA expression of early and late mo- lecular markers of differentiation (MyoD, myogenin, IGF-II, desmin and MyHC, P < 0.05). Our results suggest that GDF-11 regulates growth of skeletal muscles by inhibiting myoblast differentiation in an autocrine/paracrine manner and, perhaps, also plays a role in regulating sexually dimorphic growth.
文摘Sexual size dimorphism （SSD） is widespread among diverse animal taxa and has attracted the attention of evolutionary biologists for over a century. SSD is likely to be adaptive and the result of divergent selection on different size optima for males and females, given their different roles in reproduction. The developmental trajectory leading to SSD may help us to understand how selection acts on male and female size. Here, we describe the growth and development of two Australian praying mantids, Pseudomantis albofimbriata and Hierodula majuscula including the number of moults, time to adulthood, size at each moult, and the degree of SSD. While both species exhibit the common pattern of female-biased SSD, the number of moults required for individuals to reach adulthood differed between males and females and between species. Despite their larger adult size, P. albofimbriata females require fewer moults and less time than males to reach adulthood, but are significantly larger than males from the second instar onwards. In contrast, H. majuscula males reached adulthood in fewer moults, and less time than females, however males and females did not differ in size until females went through their final moult into adulthood. H. majuscula also required more time and more moults to reach adulthood than 17. albofimbriata. We discuss these different developmental pathways in light of the existing knowledge of reproductive biology for each species. We also suggest that these differences may relate to the different phenologies that occur in strongly seasonal temperate environments compared with those in the tropics. This study provides evidence that SSD can result from two different patterns of growth and development in closely related species.
基金The present study was funded by National Natural Science Foundation(82273654 to Y.S.)。
文摘Background Menarche is a substantial milestone of female puberty.Timing of age at menarche is considered the key to understanding the potential linkages with women’s health outcomes later in life.This study aimed to explore the secular trends and urban‒rural disparities in the median age at menarche among Chinese Han girls from 1985 to 2019.Methods Data were extracted from the 1985,1995,2005,2014,and 2019 Chinese National Surveys on Students’Constitution and Health,which were nationally representative cross-sectional studies,and a total of 173,535 Han girls aged 9–18 years were examined.Girls were asked whether menarche had occurred.The median age at menarche was estimated by probit analysis.Z tests were used to compare the differences between survey years and between urban and rural areas.Results The median age at menarche among Chinese Han girls decreased from 13.37 years in 1985 to 12.00 years in 2019,and the overall decrease was more significant in rural areas(1.77 years)than in urban areas(0.99 years).The average five-year change in the decrease in the median age at menarche showed an accelerating and then slowing pace;and it was observed similarly in both urban and rural areas.The urban‒rural disparities shrank from 0.64 years in 1985 to 0.44 years in 1995,then to 0.27 years in 2005,0.24 years in 2014,and finally to−0.14 years in 2019.Conclusions The median age at menarche among Chinese Han girls continued to decline from 1985 to 2019 but at a slowing pace in the last five years.Urban‒rural disparities gradually narrowed.Sexual and reproductive health education and interventions to prevent the decline in the age of menarche are needed,especially in rural areas.
