• Clinical and Experimental Pediatrics
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• 제49권7호
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• pp.718-725
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• 2006

The pubertal activation of gonadotrophin releasing hormone(GnRH) requires coordinated changes in excitatory or inhibitory amino acids, growth factors, and a group of transcriptional regulators. The age of onset of puberty is progressing to younger age. Factors affecting early puberty include genetic traits, nutrition(body fat) and exposure to endocrine disrupting chemicals. In rapidly progressing central precocious puberty, gonadotrophin releasing hormone(GnRH) agonists(GnRHa) appear to increase final height if treated early stage. Further large scaled long-term follow-up study of the effects of GnRHa on final height is needed.

• 디지털융복합연구
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• 제12권9호
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• pp.283-290
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• 2014

본 연구는 조기 2차 성징을 주호소로 내원하여 특발성 성조숙증으로 진단받은 여아의 진단 유형에 따른 신체발육, 성호르몬 분비의 특성을 파악하고자 시도하었다. 2차 조기성숙을 주호소로 내원한 여아 중 기질적 원인으로 인한 경우를 제외한 성조숙증 여아들을 진성 성조숙증과 가성 성조숙증으로 분류하여, 내원 당시 연령, 출생 시 체중, 2차 성징 발현 나이, 부모 및 조부모 키, 키, 체중, 골연령, 체질량지수 등을 조사하였다. 또한 성호르몬 분비정도를 비교분석하였다. 수집된 자료는 SPSS 20.0 통계프로그램을 이용하여, 평균과 표준편차 그리고 Student t-test로 분석하였다. 본 연구결과 진성 성조숙증이 47명(38.9%), 가성 성조숙증이 66(61.1%)였다. 진성 성조숙증집단에서는 신장 및 체중 표준편차점수가 유의한 수준으로 증가되어 있었으며(p<.05), 성호르몬 검사 상 황체형성호르몬(LH), 난포자극호르몬(FSH) 그리고 에스트라디올(Estradiol)의 기저치가 가성 성조숙증에 비해 유의하게 높았다(p<.05).

• Animal Bioscience
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• 제35권7호
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• pp.955-963
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• 2022

Objective: The aim of this study was to estimate genetic parameters for 305-day cumulative milk yield and components, growth, and reproductive traits in Guzerá cattle. Methods: The evaluated traits were 305-day first-lactation cumulative yields (kg) of milk (MY305), fat (FY305), protein (PY305), lactose (LY305), and total solids (SY305); age at first calving (AFC) in days; adjusted scrotal perimeter (cm) at the ages of 365 (SP365) and 450 (SP450) days; and adjusted body weight (kg) at the ages of 210 (W210), 365 (W365), and 450 (W450) days. The (co)variance components were estimated using the restricted maximum likelihood method for single-trait, bi-trait and tri-trait analyses. Contemporary groups and additive genetic effects were included in the general mixed model. Maternal genetic and permanent environmental effects were also included for W210. Results: The direct heritability estimates ranged from 0.16 (W210) to 0.32 (MY305). The maternal heritability estimate for W210 was 0.03. Genetic correlation estimates among milk production traits and growth traits ranged from 0.92 to 0.99 and from 0.92 to 0.99, respectively. For milk production and growth traits, the genetic correlations ranged from 0.33 to 0.56. The genetic correlations among AFC and all other traits were negative (-0.43 to -0.27). Scrotal perimeter traits and body weights showed genetic correlations ranging from 0.41 to 0.46, and scrotal perimeter and milk production traits showed genetic correlations ranging from 0.11 to 0.30. The phenotypic correlations were similar in direction (same sign) and lower than the corresponding genetic correlations. Conclusion: These results suggest the viability and potential of joint selection for dairy and beef traits in Guzerá cattle, taking into account reproductive traits.