• Journal of Nutrition and Health
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• 제40권1호
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• pp.58-68
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• 2007

The associations between dietary, body composition and sexual maturation were investigated among Korean girls of pubertal age in this study. Dietary intakes were collected by 3 day food records, body compositions were measured by bio-impedence analyzer and sexual maturation stages were determined with a self-administrated questionnaire using Tanner stages in 1,114 girls 9-13 years of age. Girls were divided into early maturation (EM) and late maturation (LM), based on the comparative maturation stages of breast and pubic hair among the same age groups by months. Subjects were excluded if their stage of maturation could not be divided into early and late groups. EM and LM groups consisted of 42.8% and 38.9% of subjects by breast stage and 67.4% and 22.8% by pubic hair stage. Girls in LM group had significantly lower in height, weight and bone mineral contents (p < 0.05). When nutrient densities of average daily intake of the two groups were compared, folate density was significantly higher among the LM group of breast stages (p < 0.01), and Ca, P, K, Vit. $B_1$, Vit. $B_2$ and folate densities were significantly higher among the LM group of pubic hair stages (p < 0.05). These results show that intakes of some micronutrients differ between children with faster and slower sexual maturation velocities at early pubertal stages. More longitudinal studies are needed to confirm whether such differences are consistent throughout the pubertal period.

• Asian-Australasian Journal of Animal Sciences
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• 제20권1호
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• pp.19-24
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• 2007

Covariance components and genetic parameters of weekly live body weight from hatching to six weeks of age and age of sexual maturation were estimated in a laying type Japanese quail line. The univariate and bivariate animal model analysis included hatching group and sex as fixed effects. Each trait was analysed with animal as random effect to fit the additive direct effect. Additional random effects incorporated in the models were changed according to the trait examined. The best model for a trait was chosen based on a likelihood ratio test, comparing the models with and without maternal additive genetic and maternal permanent environmental effects. Heritability estimates of live-weight at hatch and one to six weeks of age with their standard errors were 0.22${\pm}$0.088, 0.39${\pm}$0.099, 0.31${\pm}$0.086, 0.38${\pm}$0.056, 0.46${\pm}$0.055, 0.50${\pm}$0.059, and 0.56${\pm}$0.062, respectively. Direct heritability value of age of sexual maturation was moderate (0.24${\pm}$0.055). The variances due to permanent environmental effect of dam after one week of age and maternal genetic effect after two weeks of age were not important sources of variation. The correlations between direct and maternal genetic effects were negative and ranged from high to moderate values (-0.21 to -0.83). Among the weekly live weights, genetic correlations were generally high between not only successive but also early and late weightings. It suggests that selection for final weight may be based on early weight records. Genetic correlations between age of sexual maturation and live weights were low, favourable but had high standard errors. These results indicate that selection for high weight will potentially result in lower age of sexual maturation only with accurate determination of breeding values.

• 동아시아식생활학회지
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• 제23권5호
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• pp.519-532
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• 2013

The purpose of this study was to make a comparative analysis of dietary habits, snacks, eating out and fast-food intake between students with a relatively early sexual maturity and others with a relatively late sexual maturity in a bid to grasp the impact of dietary behaviors on sexual maturity. The subjects in this study were 565 boys and girls who resided in Seoul and Gyeonggi province. They included fifth- and sixth-grade school children and seventh-grade middle school students. To classify the selected students according to the level of sexual maturity, the students of the same month age were divided into two groups in consideration of the stage of their sexual maturity and that of the other age groups. The early mature group was significantly taller and weighed more than the late mature group irrespective of gender. According to Tanner stages, the boys of the early mature group reached a 3.03 stage of sexual maturity when the sexual organs were taken into account, and those of the late mature group reached a 1.50 stage of sexual maturity. The girls of the early mature group reached a 3.43 stage of sexual maturity on the basis of breast, and those of the late mature group reached a 2.73 stage of sexual maturity. Concerning eating out, the early mature group ate out more frequently than the late mature group. In regard to snacks, the early mature group had a snack more often. The findings of the study indicated that there were differences in physical development and some dietary behaviors according to sexual maturity. The early mature group had a snack and ate out relatively more often than the late mature group, which showed that some dietary behaviors had an impact on the sexual maturity of the teens who arrived at the age of puberty.

• 한국가축번식학회지
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• 제11권3호
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• pp.170-180
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• 1987

This study was undertaken to determine the effects of HCG and trout pitutary on sexual maturation and ovulation in the Korean loach, Misgurnus anguillicaudatus. Sexual maturation was observed in the fish treated with 250＋125 IU HCG within 2-4 days following injections. Total ovary weight and GSI were significantly greater in the hormone-treated fish than in the control fish. Furthermore, in the hormone-treated fish body weight increased by about 4-9 percent in 2 days. The water content of the ovulated eggs of the fish treated with 250＋125 IU HCG was also greater than that in the control. Changes in both macroscopic & microscopic appearnce of Korean loach ovaries are describled, as well as changes in the gonadosomatic index. Oocytes pass through seven cytologically changes in the relative stages. By examining these stages, it was found that oogenesis occures in two broad phases. The previtellogenic phasebegins as a new oogonia continues to arise following spawning. These rapidly develop into early perinucleolus oocytes, which in turn develop into resting stage oocytes. Most oocytes remain in this stage when they develop into late perinucleolus oocytes. The vitellogenic phase begins as these late perinucleolus oocytes become transformed into early maturing oocytes through the accumulation of yolk. The cytoplasm completely fills with yolk as oocytes reach the late maturing stage. Shortly before spawning the final hyaline stage of developing is reached. Changes in the microscopic appearances of the ovaries were well correlated with changes in both gonadosomatic index and macroscopic appearance.

• 한국수산과학회지
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• 제39권1호
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• pp.27-34
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• 2006

Sexual maturation and reproductive cycle of the bat star Asterina pectinifera were investigated by histological method. Specimens were collected monthly in Donghwari, Gosunggun, Korea from January 2004 to February 2005. The bat star was dioecious. The gonads are composed of a number of gametogenic follicles. The gonadosomatic index (GSI) of female and male were reached the maximum in July (5.72, 4.54) and the minimum in December (0.89) and January, February (0.51), and the gonad index (GI) of female and male were reached the maximum in July (3.53, 3.91) and the minimum in August (0.95) and October to December (1.0), respectively. The main spawning was from August to September. The reproductive cycle of the bat star could be divided into five stages: in the female, inactive (November-February), early active (January February), late active (March-June), ripe (July), spent and degenerative (August-November) and in the male, inactive (November-February), early active (January-March), late active (April-June), ripe (July), spent and degenerative (August-October), respectively.

• Fisheries and Aquatic Sciences
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• 제4권4호
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• pp.208-218
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• 2001

We have investigated the gonad index (GI), gonadal development, reproductive cycle, first sexual maturity, sex ratio, the number of spawned eggs and spawning frequency of the Manila clam, Ruditapes philippinarum. Samples were collected from the intertidal zone of Komso Bay, Korea from January to December in 1999. Monthly changes in the gonad index (GI) and condition index showed a similar pattern in the reproductive cycle. The spawning period was once a year between early June and early October, there was a spawning peak between July and August when seawater temperature was over $20^{\circ}C$. The reproductive cycle of this species can be categorized into five successive stages; early active (February to March), late active (April to May), ripe (April to August), partially spawned (June to October), and spent/inactive stage (August to March). Percentages of first sexual maturity of female and male clams of l5.1-20.0mm in shell length were $56.3\%$ and $60.0\%$, respectively, and $100\%$ for the clams >25. mm. The sex ratio of individuals >15.1 mm in shell length was about 1:1 $(\chi^2= 0.02,\;p>0.05)$. Number of the eggs released from each clam by the induction increased as the size of clam in terms of shell length increased. Mean number of the eggs from the second induction of the spawning was $75.35-84.30\%$ $(average\;79.81\%)$ of the number of the eggs released in the first spawning. Our data indicated that R. philippinarum in Komso Bay has one major spawning peak with over two minor spawning, and the interval of each spawning was estimated to be approximately 15-17 (average 16.5) days.

• 정신신체의학
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• 제6권2호
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• pp.97-103
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• 1998

A dolescence can be defined as the period between pubescence and physical maturity, and the passage through adolescence(age of 12-19) forms a critical period. Major developmental tasks of adolescence are construction of an emancipated identity, realistic ambitions, and reasonable ideals, and the further development of sexual and social identities. In early adolescence one struggles to adjust psychologically to the spurt in growth and tensions filled with sexual and aggressive impulses. There are reshuffling of peer groups due to differing rates of maturation, early adolescence crushes, sublimation of sexuality, and the resurgence of oedipal feelings. One reaches so-called period of formal operations in cognitive development. In mid-adolescence one struggles to overcome family attachments and controls, and it is a time marked by revolt and conformity. One has to overcome sexual repression while caught in reactivation of oedipal attachment. Peer groups gains in importance, and the peer group changes into a youth group that carries the youth culture. Late adolescence is a period of achieving an ego identity and capacities for intimacy. One has to prevent premature closure : Identity foreclosure limits both opportunity and the ability to guide one's own life. Gradually adolescent begins to have a loss self-centered and narcissistic orientation to one's sexual and affectional needs, and becomes involved in love relationship.

• Animal cells and systems
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• 제11권2호
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• pp.191-198
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• 2007

The ultrastructure of germ cells and follicle cells during oogenesis, oocyte degeneration, reproductive cycle, and first sexual maturity in female Cyclina sinensis were investigated for clams collected from Simpo, Jeollabuk-do, Korea, by cytological and histological observations. Vitellogenesis occured by way of endogeous autosynthesis and exogenous heterosynthesis: vitellogensis occurred through a process of autosynthesis, which involves a combined activities of the Golgi complex, mitochondria, and rough endoplasmic reticulum. The process of heterosynthesis involved endocytotic incorporation of extraovarian precursors into the basal region of the early vitellogenic oocytes prior to the formation of vitelline envelope. The follicle cells appear to play an integral role in vitellogenesis and oocyte degeneration, functioning in phagocytosis and digestion of products originating from the degenerated oocytes: these functions can permit the transfer of yolk precursors needed for vitellogenesis. Follicle cells might have a lysosomal system for breakdown and might also resorb phagosomes in the cytoplasm for nutrient storage during oocyte degeneration.

• 한국패류학회지
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• 제4권1호
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• pp.30-41
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• 1988

The gonadal development, the annual reproductive cycle and the first sexual maturity of surf clam, Mactra veneriformis Reeve were studied histologically. Speciemens were monthly collected at the intertidal zone of Naechodo, Chollabuk-do, Korea, for one year from March 1986 to February 1987. Sexuality of the clam is dioecious. The gonads were located between the subregion of mid-intestinal gland in the visceral cavity and the reticular connetive tissues of the foot, The ovary is composed of a number of ovarian sacs, and the testis comprise several testiculat lobules. The undifferentiated mesenchymal tissues and eosinophilic granular cells function as nutritive cells in the early stage. The ripe eggs were about 50-60${\mu}{\textrm}{m}$ in diameter, and they were wurroundedby the gelatinous membranes. The spawing period was from early June to September the main spawning occurred beetween July and August when the water temperature reached above 24$^{\circ}C$. The annual reproductive cycle of this species could be classified into five successive stages: multiplicative(January to March), growing(March to May), mature(April to August), spent(June to September), degenerative and resting(September to February). The monthly changes of fatness coefficient closely correlated with the annual reproductive cycle. Percentages of the first sexual maturity of female and male clams were over 50% among those individals ranging from 2.1 To 2.5cm, and 100% in those over 2.6cm in shell length.

• Clinical and Experimental Pediatrics
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• 제52권1호
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• pp.111-118
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• 2009

목 적 : 어린시기에 genistein과 같은 식물성 에스트로겐의 섭취가 사회적 관심사로 대두되고 있다. 본 연구에서는 어린 쥐에서 genistein에 노출이 사춘기 개시 및 생식기관에 미치는 영향을 알아 보았다. 방 법 : 이유기(3주령) 암컷 흰쥐를 저용량 genistein (10 mg/kg/day), 고용량 genistein (100 mg/kg/day), 대조군의 세 그룹 (각 그룹 당 n=6)으로 나누고 첫 번째 질구 개방이 확인되는 날까지 농도별로 각각 경구 투여하였다. 질구 개방일을 확인하고 생식 기관의 무게를 측정하며 난소와 자궁에서 $ER{\alpha}$, $ER{\beta}$, PR 유전자들의 발현양상을 RT-PCR을 이용해 비교하였고, 난소와 자궁의 구조적 이상을 확인하기 위해 조직학적 분석을 실시하였다. 결 과 : 고용량 genistein 투여군은 저용량군 및 대조군에 비해 질구 개방일이 유의하게 촉진되었다. RT-PCR결과, $ER{\alpha}$, $ER{\beta}$, PR의 전사활성은 genistein에 노출된 쥐들의 난소와 자궁에서 유의하게 증가하였다. 그라프 난포와 황체는 genistein 투여군의 난소에서만 발견되었고, 대조군의 난소에서는 1차, 2차 난포들과 작은 미성숙 난포들만이 관찰되었다. Genistein 처리군의 자궁에서도 내막층 근막층 및 상피층이 과다성장상태였으나 대조군에서는 모든 세포층과 분비선이 미약하게 발달하였다. 결 론 : 결론적으로, 사춘기 이전 시기에 비교적 단기간의 genistein 노출이라도 미성숙 암컷 흰쥐에서 생식 내분비 활성을 일으켜 조기 사춘기와 성 스테로이드 호르몬 수용체의 발현 양상 변화를 초래할 수 있으며, genistein의 노출이 아동기 성성숙에 미치는 영향에 대한 더욱 많은 연구가 필요할 것으로 사료된다.