Earlier Menarche Can Be an Indicator of More Body Fat:Study of Sexual Development and Waist Circumference in Chinese Girls

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.

Effects of "Products of Chicken Embryo" on Growth and Sexual Development in Rats

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.

Common Childhood Masturbation, But Different Sexual Attitudes in Three Male-at-Birth Adolescents: Possible Implications for Sexual Development

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.

Molecular Diagnosis of Sexual Differentiation Disorders in Burkina Faso

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.

Developmental assets and age of first sexual intercourse among adolescent African American males in Mobile, Alabama

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.

Growth and differentiation factor-11 is developmentally regulated in skeletal muscle and inhibits myoblast differentiation

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.

Male sex determination： insights into molecular mechanisms

Disorders of sex development often arise from anomalies in the molecular or cellular networks that guide the differentiation of the embryonic gonad into either a testis or an ovary, two functionally distinct organs. The activation of the Y-linked gene Sry （sex- determining region Y） and its downstream target Sox9 （Sry box-containing gene 9） triggers testis differentiation by stimulating the differentiation of Sertoli cells, which then direct testis morphogenesis. Once engaged, a genetic pathway promotes the testis development while actively suppressing genes involved in ovarian development. This review focuses on the events of testis determination and the struggle to maintain male fate in the face of antagonistic pressure from the underlying female programme.

皖南花猪11种血液生化指标的发育性变化及性别差异

随机选择出生30、45、90、180日龄的皖南花猪公母各5头,测定了11项血清生化指标.结果显示:血糖(GLU)、总胆固醇(TC)、高密度脂蛋白胆固醇(HDL-C)、游离脂肪酸(FFA)、脂联素(ADP)、瘦素(leptin)和IgG有极显著的发育性变化(P<0.01);而甘油三酯(TG)、低密度脂蛋白胆固醇(LDL-C)、IgA和IgM等没有明显的发育性变化.母猪的TG、TC、HDL-C和IgM极显著或显著大于公猪(P<0.01或P<0.05),其他血清生化指标虽在总体上没有性别差异,但在有些日龄差异明显,大多表现为母猪在90或180日龄大于公猪.结果表明:皖南花猪血液生化指标有特定的发育性模式,并存在不同程度的性别差异.

孕期非那雄胺暴露致子代雄性小鼠生殖器官发育异常

目的:探讨孕期非那雄胺暴露对子代雄性小鼠生殖器官发育的影响。方法:CD-1小鼠在受孕后0~17 d给予非那雄胺处理,通过宏观观察、解剖分析与组织形态学染色观察子代雄性小鼠生殖器官的发育情况;通过免疫荧光染色分析子代雄性小鼠精子发生情况。结果:宏观观察结果显示,孕期非那雄胺暴露可导致子代雄性小鼠外生殖器官畸形,表现为阴囊未完全融合及阴茎畸形;此外,还观察到小鼠肛门与生殖器的距离显著缩短(P<0.01)。解剖分析结果显示,孕期非那雄胺暴露可导致子代雄性小鼠睾丸不同程度的不完全下降及长度显著缩短(P<0.01)。组织形态学结果显示,各阶段阴茎长度均显著缩短(P<0.01);睾丸生精小管密度和生精小管管腔成熟精子数均显著降低(P<0.01),生精小管管腔和睾丸间质间隙均显著增大(P<0.01)。免疫荧光染色结果显示,睾丸中支持细胞、睾丸间质细胞和精原细胞的密度均显著降低(P<0.01);生精小管细胞的caspase-3荧光强度显著增加(P<0.01),Ki67与沙漠刺猬因子(desert hedgehog,Dhh)荧光强度均显著降低(P<0.01)。结论:孕期非那雄胺暴露可导致子代小鼠生殖器官发育异常并影响精子发生。

大学生性行为及性道德观发展研究

目的了解当代大学生性行为及性道德观念的发展变化。方法自制问卷,对全国9所高校的2000余名大学生进行调查,并用SPSS10.0对结果进行统计处理。结果大学生性交行为发生率呈逐年上升趋势,且随年级上升而增加;大学生认可性交行为道德观的5个维度,但各年级之间有差异;大学生边缘性行为和独自性行为发生率随年级显著上升,认可度也随年级增加而上升;大学生对同性性接触基本持排斥态度,但排斥态度则趋于下降。结论大学生性行为和性道德随年级上升而明显变化,应加强学校教育和引导。

油棕象甲室内生物学特性及形态观察

在室内对油棕象甲Elaeidobius kamerunicus Faust生物学特性及其形态进行系统观察。在温度为24-28℃,RH 75%-95%,光照12 h的条件下用油棕Elaeis guineensis雄花饲养油棕象甲各虫态,每4 h观察记录各虫态的形态学特征及其发育情况,测量各虫态体长、体宽、体重等重要发育指标。结果表明油棕象甲卵的发育历期平均为16.00±0.71 h,整个幼虫期的历期平均为2.63±0.05 d,预蛹和蛹的平均发育历期分别为3.21±0.37 d和2.21±0.41 d,油棕象甲完成一个世代平均需要13.67±0.75 d。1龄幼虫体长1.70±0.08 mm,体重0.0006±0.0001 g,之后随龄期迅速增加,至3龄时,体长为2.88±0.06 mm,体重增加到0.0021±0.0001 g。蛹期体长为2.17-3.05 mm,蛹重0.0015-0.0028 g。油棕象甲成虫具有雌雄二型现象,子代性比(雌∶雄)为1.65∶1。油棕象甲是油棕最高效、最安全的授粉昆虫,其基础生物学和形态学研究是该虫室内扩繁技术研究的基础,本研究结果旨在为油棕象甲的保护利用提供理论依据。

皖南花猪部分屠宰性状的发育性变化及性别差异

为了研究皖南花猪部分屠宰性状的发育性变化及性别差异,试验采用0,30,45,90,180日龄的皖南花猪公、母各5头进行屠宰测定。结果表明:皖南花猪的各项屠宰指标都有不同程度的发育性变化,30日龄时,肾脏重有显著增长(P<0.05),其他指标都有极显著增长(P<0.01);在30～45日龄阶段,胴体斜长、膘厚、皮厚、肺脏重有显著增长(P<0.05),但眼肌面积、心脏重、肝脏重、脾脏重、肾脏重增长不显著(P>0.05);在45～180日龄阶段,所有指标都呈现快速的增长。出生和180日龄时,屠宰指标的性别差异均不显著(P>0.05);30日龄时母猪的膘厚显著大于公猪(P<0.05);45日龄时,母猪的胴体斜长和肝脏、脾脏、肾脏重显著小于公猪(P<0.05);90日龄时母猪的胴体斜长显著大于公猪(P<0.05);皖南花猪的肌内脂肪含量较高,且在背最长肌和半腱肌有不同的发育规律。

大猿叶虫生活史特性的地理变异

【目的】比较不同地理种群生活史特性的差异,是揭示生物体对环境适应机制的最有效方法之一。本研究旨在探明大猿叶虫Colaphellus bowringi不同地理种群生活史特性随纬度变异的特点。【方法】在室内恒温19℃、光周期16L∶8D条件下,观察测定了来自6个不同纬度的大猿叶虫种群从卵孵化到化蛹和化蛹到成虫羽化的时间,以及蛹和成虫体重。【结果】幼虫历期随纬度的升高逐渐延长,生长速率与纬度呈负相关,这两个生活史特性显示了顺梯度的变异。蛹历期在种群间没有显著差异。体重随纬度的升高逐渐减小,显示了反贝格曼法则。在所有的种群中,雌性蛹和成虫个体均显著大于雄虫,显示了雌性偏向的性体型二型性(SSD)。不同纬度的种群SSD指数存在差异,中纬度种群显示了最大的SSD指数。雄蛹在变态中比雌蛹丢失了更多的体重,导致成虫期的SSD指数大于蛹期。【结论】结果表明,大猿叶虫幼虫发育历期、生长速率和体重在不同纬度间呈现了显著变异。

同源四倍体水稻双受精过程的细胞学观察

同源四倍体水稻的双受精比较特殊.花粉粒在其柱头上萌发比较慢，花粉管在花柱内的伸长比较迟缓，双受精延迟，退化胚囊的频率比较高(36.0%)，极核和反足细胞的形态异常，存在着一定频率的胚自发现象.由此认为，同源四倍体水稻的有性生殖能力已经明显变弱。

Secular trends and urban–rural disparities in the median age at menarche among Chinese han girls from 1985 to 2019

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.

Different paths to sexual size dimorphism in two praying mantids, Pseudomantis albofimbriata and Hierodula majuscula

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.

花粉原生质体与配子原生质体操作的研究进展与前景

总结我们近十年来在高等植物两类重要的性细胞原生质体——花粉原生质体与配子原生质体操作方面的研究进展,简介国际上有关的研究动态与热点,提出今后研究的设想。

植物发育程序:基于有性生殖周期的“双环”

长期以来,人们一直认为植物具有"无限生长"的特点.可是,如果植物是"无限生长"的,那么被用于进行遗传研究的材料该如何划分上下代?因为遗传学研究是根据后代表型的变化来寻找决定表型的基因并研究其作用方式的;如果不是"无限生长",植物生活周期的起点和终点分别是什么?而且,对很多被子植物而言,不同器官类型的发生存在先后顺序.这种顺序是如何决定的?本文基于作者近年以植物雄蕊早期发育为对象的研究,在"植物发育单位"、"有性生殖周期"等概念的基础上,对"植物发育程序"的内涵进行了概要的探讨.为上述两个问题给出了自己的回答.

pyrG is required for maintaining stable cellular uracil level and normal sporulation pattern under excess uracil stress in Aspergillus nidulans

Tight control of the intracellular uracil level is believed to be important to reduce the occurrence of uracil incorporation into DNA. The pyrG gene ofAspergillus niduIans encodes orotidine 5＇-phosphate decarboxylase, which catalyzes the conversion of orotidine monophosphate （OMP） to uridine monophosphate （UMP）. In this study, we found that pyrG is critical for maintaining uracil at a low concentration in A. nidulans cells in the presence of exogenous uracil. Excess uracil and its derivatives had a stronger inhibitory effect on the growth of the pyrG89 mutant with defective OMP decarboxylase activity than on the growth of wild type, and induced sexual development in the pyrG89 mutant but not in wild type. Analysis of transcriptomic responses to excess uracil by digital gene expression profiling （DGE） revealed that genes related to sexual development were transcrip- tionally activated in the pyrG89 mutant but not in wild type. Quantitative analysis by HPLC showed that the cellular uracil level was 6.5 times higher in the pyrG89 mutant than in wild type in the presence of exogenous uracil. This study not only provides new information on uracil recycling and adaptation to excess uracil but also reveals the potential effects of OMP decarboxylase on fungal growth and development.