• 한국동물번식학회:학술대회논문집
• /
• 한국동물번식학회 2003년도 학술발표대회 발표논문초록집
• /
• pp.75-75
• /
• 2003

Since the establishment of embryonic stem cell, pluripotency of the cells was known to allow differentiation of the cells into various cell types consisting whole body. Several protocols have been developed to induce expression of specific genes.. However, no precise protocol that will generate a single type of the cells from stem cells has been reported. In order to produce cells suitable for transplantion into brain of PD animal model, which arouse due to a progressive degeneration of dopaminergic neurons in midbrain, human embryonic stem cell (hESC, MB03) was transfected with cDNAs cording for tyrosine hydroxylase (TH). Successful transfection was confirmed by western immunoblotting. Newly transfected cell line (TH#2/MB03) was induced to differentiate by the two neurogenic factors retinoic acid (RA) and b-FGF. Exp. I) Upon differentiation using RA/ascorbic acid (AA), embryoid bodies (EB, for 4days) derived from hES cells were exposed to RA (10$^{-6}$ M)/AA (50 mM) for 4 days, and were allowed to differentiate in N2 medium for 7, 14, 21, or 28 days. Exp. II) When bFGF was used, neuronal precursor cells were selected for 8 days in N2 medium after EB formation. After selection, cells were expanded at the presence of bFGF (20 ng/ml) for another 6 days followed by a final differentiation in N2 medium for 7, 14, 21 or 28 days. By indirect immunocytochemical studies, proportion of cells expressing NF200 increased rapidly from 20% at 7 days to 70 % at 28 days in RA/AA-treated group, while those cells expressing NF160 decreased from 80% at 7 days to 10% at 28 days upon differentiation in N2 medium. However, in differentiation by RA/AA treatment system, there was a significant increase in proportion of neuron maturity (73%) at day 14 after N2 medium. TH#2/MB03 cells expressing TH are >90% when matured at the absence of either bDNF or TGF-$\alpha$. These results suggested that TH#2/MB03 cells could be differentiated in vitro into mature neurons by RA/AA.

• 디지털융복합연구
• /
• 제18권2호
• /
• pp.95-101
• /
• 2020

본 연구의 목적은 대학교육을 위해 입학 단계에서 다른 지역으로 이동하는 학생들의 특징을 살펴보는 것이다. 이러한 목적을 달성하기 위하여 2018년 학부교육 실태조사(K-NSSE) 자료를 분석하였다. 교차 분석(카이제곱 검정)과 이항 로지스틱 회귀분석을 하였다. 분석 결과, 서울 지역 학생들은 서울, 경인, 지방 등 다양한 지역으로 이동하는 비율이 상대적으로 높았지만, 지방 출신 학생의 경우 낮은 비율의 학생들이 서울 지역 대학으로 이동하고 있었다. 또한, 대학교육을 위해 서울에서 지방으로, 지방에서 서울 지역으로 이동하는 학생 집단이 사회경제적 배경, 고교 유형과 성취 수준, 진로 성숙 수준, 대학몰입 정도에 있어서 차이가 있음을 확인하였다. 본 연구는 서울 중심의 대학 서열화 구조를 극복하고 학생 구성의 다양성을 확보하여 교육의 질을 높이고 지역 발전에도 기여할 수 있도록 정부가 체계적인 지원을 할 필요가 있음을 제언한다.

• 한국발생생물학회지:발생과생식
• /
• 제20권4호
• /
• pp.305-314
• /
• 2016

The marine medaka, Oryzias dancena is a suitable sample as a laboratory animal because it has a small size and clearly distinguishes between female and male. Data on the growth and maturity of the diploid and triploid sea cucurbit species suitable for laboratory animals are very useful for studying other species. Triploidy was induced in the marine medaka by cold shock treatment ($0^{\circ}C$) of fertilized eggs for 45 min, applied two minutes after fertilization. The diploid and triploid male fish were larger than their female counterparts (P<0.05), and the concentrations of thyroid stimulating hormone (TSH) and thyroxine (T4) were higher in the induced triploids over 1 year (P<0.05). In both the diploid and tri-ploid groups the concentrations of TSH and T4 were higher in the male fish than in the females (P<0.05), while the testo-sterone and estradiol-$17{\beta}$ concentrations in the induced triploids were lower than in the diploids (P<0.05). The gonadosomatic index (GSI) of the triploid fish was lower than that for the diploids, and the GSI for females in each ploidy group were higher than that for the males. For both groups the GSI was highest at 4 months of age, and decreased thereafter to 12 months. Analysis of the gonads of one-year-old triploid fish suggested that the induction of triploidy probably causes sterility in this species; this effect was more apparent in females than in males.

• Fisheries and Aquatic Sciences
• /
• 제10권1호
• /
• pp.30-36
• /
• 2007

We present age and growth data for Ilisha elongata, based on 363 specimens caught in 1999 and 2000 around Jeju Island and the southwest coast of Korea. Scale and ring radii of each ring group showed a direct one-to-one relationship, with ring radius increasing as scale radius increased. The relationship between fork length and scale radius was FL=39.553SR+60.935 for females, FL=39.474SR+54.026 for males, and FL=39.608SR+57.547 for both sexes. Monthly changes in the marginal index indicated that a new ring appears once each year (in July). Maximum age, mean age and mean fork length of fish were 10 years, 5.0 years, and 349mm, respectively. Von Bertalanffy's growth equations were $FL_t=495.4{\times}[1-\exp(-0.2586(t+0.6487))]$ for fork length (mm) and $W_t=1,112.5{\times}[1-\exp(-0.2586(t+0.6487))]^{2.874}$ for body weight (g) for both sexes. Monthly changes in the gonadosomatic index (GSI) indicated that the spawning period was in June and July, which corresponded closely with ring formation time. Differences in monthly GSI changes in 1999 and 2000 may be related to water temperature variation. Fecundity ranged from 5,664 to 176,290 eggs per individual (n=43, fork length 264-470mm). The relationship between fecundity(F) and fork length was $F=7.7{\times}10^{-7}{\times}FL^{4.9269}$.

• Animal cells and systems
• /
• 제13권4호
• /
• pp.439-445
• /
• 2009

Cytochrome P450 aromatase (P450arom) catalyzes the conversion of androgens to estrogens and plays an important role in reproduction and development in vertebrates. We investigated the expression patterns of ovarian P450arom (P450aromA) and brain P450arom (P450aromB) mRNA during sex change in black porgy. Maturity was divided into seven stages from male to female (immature testis, mature testis, testicular portion of mostly testis, ovarian portion of mostly testis, testicular portion of mostly ovary, ovarian portion of mostly ovary, and mature ovary). P450aromA expression was significantly higher in the ovarian portion of mostly-ovarian stage fish, and P450aromB expression was highest in the brain of black porgy with mostly-ovarian gonads. Histology showed that testicular tissues were disintegrated with the development of ovarian tissue associated with an increase in the expression of the two P450arom mRNAs during sex change. Interestingly, among various tissues, P450aromA was only expressed in the ovary, and P450aromB was only expressed in the brain. To understand the role of gonadotropin-releasing hormone (GnRH) and estradiol ($E_2$), we injected exogenous hormone (GnRH analogue [GnRHa] and $E_2$) into immature black porgy. In the GnRHa group, expression of the two P450arom genes decreased 12 h after injection, and expression of the two P450arom genes were significantly higher at 6 dafter $E_2$ injection. These results provide useful baseline knowledge on the mechanism of natural sex change in black porgy.

• 대한의생명과학회지
• /
• 제15권1호
• /
• pp.9-15
• /
• 2009

Early age at menarche, which is indicator of early biological maturity, has been shown to be associated with increased adult body mass index. Early menarche has also been associated with many cardiovascular disease risk factors and metabolic syndrome. To evaluate the impact of menarche to cardiovascular risk factor, we assessed by age at menarche, brachial-ankle pulse wave velocity (baPWV), which represents arterial stiffness, in women with or without metabolic syndrome. The subjects recruited for this study were three hundred one women. Relatively early menarche and relatively late menarche were classified according to less than $50^{th}$ percentile for relatively early menarche, and great than the $50^{th}$ percentile for relatively late menarche. Subject were divided four group, 1) women who had not adulthood metabolic syndrome and relatively early menarche, 2) women who had not adulthood metabolic syndrome and relatively late menarche, 3) women who had adulthood metabolic syndrome and relatively early menarche, 4) women who had adulthood metabolic syndrome and relatively late menarche. Women who had a relatively early menarche with adulthood metabolic syndrome had significantly high levels of blood pressure, triglyceride, fasting insulin and homeostatic model assessment of insulin resistance (HOMA-IR) levels than women with late menarche with adulthood metabolic syndrome, and had significantly lower HDL-cholesterol levels. And also, women who underwent a relatively early menarche with metabolic syndrome had highest level of baPWV in adult. In this study we found effect of age at menarche on adulthood metabolic risk factors for cardiovascular disease (e.g., baPWV, insulin resistance, hyperlipidemia) in Korean women.

• Journal of Animal Science and Technology
• /
• 제52권6호
• /
• pp.499-504
• /
• 2010

This study was conducted to determine the effects of ruminally protected amino acid-enriched fatty acids (RPAAFA) on body weight gain, feed intake and carcass characteristics of fattening Hanwoo cows. Twenty eight Hanwoo cows, $6.0{\pm}1.7$ years old and weighing an average of $463.2{\pm}77.6\;kg$, were used for 4 months. Animals were fed a basal diet supplemented with RPAAFA at 0 g (control) and 100 g (treatment), respectively. Average daily gain, dry matter intake and feed conversion ratio were not different among the control and treatment. The supplementation of RPAAFA did not affect carcass weight and rib eye areas. Quality grade score ($1^{++}$, $1^+$ and 1) for treatment was higher in RPAAFA supplemented group compared with the control, whereas no differences appeared in meat color, fat color, texture and maturity. Thus present results indicate that supplementation of RPAAFA may be recommended for producing high quality beef from fattening Hanwoo cows.

• 한국잠사곤충학회지
• /
• 제43권2호
• /
• pp.99-103
• /
• 2001

오디용 뽕품종으로 대성뽕, 대붕뽕 및 대옥뽕을 육성하였으며 큰누에용 장려품종중에서 신광뽕을 선발하였는 바 주요 특성은 다음과 같다. 1. 대성뽕, 대붕뽕 및 대옥뽕은 염색체수가 2n=56인 4배체이고, 신광뽕은 2n=42인 3배체이다. 2. 오디의 종자형성률은 대성뽕, 대붕뽕 및 대옥뽕은 58%이상이였으며 신광뽕은 6.7%로 매우 낮았다. 3.오디의 과중은 대성뽕이 4.05g,대옥뽕이 3.38g,대붕뿐이 2.99g로서 대과형이고 신광뽕은 2.28g로 중과형이다 4. 오디과즙의 당도는 신광뽕은 14.8% , 대옥뽕은 13.7% , 대붕뽕은 13.1% , 대성뽕은 12.7%이며 당산비는 모든 품종이 21이상이다. 5. 오디의 숙기는 신광뽕은 조숙계, 대붕뽕, 대옥뽕은 중숙계 , 대성봉은 만숙계 이다. 6. 오디의 수량성은 대붕뽕은 다수성이고 대성뽕과 신광뽕은 비교적 높은편이며 대옥뽕은 보통 수준이다. 7. 내동(한)성은 신광뽕, 대옥뽕, 대붕뽕은 보통이고 대성뽕은 다소 약하다.

• 한국융합학회논문지
• /
• 제12권6호
• /
• pp.39-47
• /
• 2021

이 연구는 치아발육단계에서 성장호르몬 결핍의 영향을 알아보기 위해서 성장호르몬 결핍이나 특발성 저신장 소아와 정상 소아 간의 차이를 분석하는 것을 목적으로 한다. 영남대학교 의과대학 부속병원 소아청소년과에서 저신장으로 진단받은 소아들을 성장호르몬 결핍인 대상자와 특발성 저신장 소아로 분류하였다. 구강 파노라마와 신체지수를 계측하여 치아발육과의 관계를 분석하였다. 성장호르몬 결핍성 저신장 소아와 특발성 저신장 소아 간의 유의한 차이는 측절치에서만 나타났다. 성장호르몬 결핍성 저신장 소아와 정상 소아 간에는 모든 치아에서 성장호르몬 결핍성 저신장 소아의 발육이 유의하게 늦은 것으로 나타났다. 결론적으로 저신장 소아에서 성장호르몬 결핍성 저신장 소아나 특발성 저신장 소아 모두 신장뿐만 아니라 치아 발육 역시 영향을 받은 것으로 나타났다. 이 연구는 향후 저신장 소아의 교정치료 프로토콜의 기초자료를 제시할 수 있을 것으로 기대한다.

• Journal of Oral Medicine and Pain
• /
• 제46권4호
• /
• pp.125-130
• /
• 2021

Purpose: The dental age estimation of children is performed using dental maturity. Postmortem missing of the anterior teeth or the distortion of image of the anterior teeth in panoramic radiographs can make it difficult to analyze the development of the anterior teeth. This pilot study was conducted to derive a new age estimation method based only on the developmental stage of mandibular posterior teeth. Methods: This study was conducted using panoramic radiographs of 650 subjects aged 3 to 15 years old. The dental developmental stages of the lower left first premolar, second premolar, first molar and second molar were evaluated according to the Demirjian's criteria. The intra-/inter-observer reliability was evaluated, and multiple linear regression analyses were performed including the developmental stage of each tooth as an independent variable. Results: The intra-/inter-observer reliability was 0.9626 and 0.8877, respectively, and showed very high reproducibility. Multiple linear regression analyses were performed for males and females, and the age calculation table was derived by obtaining the intercept and the coefficient according to the development stage of each tooth. The coefficient of determination (r²) of the age calculation method was 0.9634 for male and 0.9570 for female subjects, and the mean difference between chronological age and estimated dental age was -0.42 and -0.21, respectively. Conclusions: This pilot study evaluated the developmental stages of four lower posterior teeth in the Korean group according to Demirjian's criteria, and derived age estimation method. The accuracy was lower than when more teeth were used, but it will be useful to estimate age of children when the anterior teeth are difficult to accurately analyze.