• Journal of Genetic Medicine
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• 제13권2호
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• pp.65-71
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• 2016

Cell-free nucleic acids (cf-NAs) originate in trophoblasts and are detected in the maternal plasma. Using innovative bioinformatic technologies such as next-generation sequencing, cf-NAs in the maternal plasma have been rapidly applied in prenatal genetic screening for fetal aneuploidy. Amniotic fluid is a complex and dynamic fluid that provides growth factors and protection to the fetus. In 2001, the presence of cf-NA in amniotic fluid was reported. Amniotic fluid is in direct contact with the fetus and is derived from fetal urine and maternal and fetal plasma. Therefore, these genetic materials have been suggested to reflect fetal health and provide real-time genetic information regarding fetal development. Recently, several studies evaluated the global gene expression changes of amniotic fluid cell-free RNA according to gestational age. In addition, by analyzing the transcriptome in the amniotic fluid of fetal aneuploidy, potential key pathways and novel biomarkers for fetal chromosomal aneuploidy were identified. Here, we review the current knowledge of cell-free RNA in amniotic fluid and suggest future research directions.

• 한국발생생물학회지:발생과생식
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• 제1권2호
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• pp.189-202
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• 1997

The hypothalamic peptide GnRH plays a central role in the regulation of the mammalian reproductive axis. Recent studies suggested that GnRH stimulates or inhibits the ovarian steroidogenesis and gametogenesis directly. Our previous report indicated that GnRH gene is expressed in adult rat ovary as well as in hypothalamus and that the expressed GnRH may induce the follicular atresia and apoptosis of ovarian granulosa cells in rat. Therfore, we studied whether GnRH gene is expressed in the mouse fetal ovary, when the germ cells are degenerating by apoptosis during gonad diffeerentiation. Mouse fetal gonads were obtained on the 12, 15,18 and 20th day of gestation from the mother mice superovulated (10 IU PMSG and 10 IU hCG) and mated. The morphological changes of fetal ovaries were examined histochemically by hematoxylin-eosin staining. The fetal sex was confirmed by PCR methods for sexing. RT-PCR methods were used to examine the expression of GnRH gene and the sex steroid hormones were determined by conventional radioimmunoassays. The levels of estradiol (E) and progesterone (P) were increaseduntil 18th day of gestation and then E was decreased just before parturition. The morphological changes of fetal gonadal tissue sections showed the ovarian development and coincided with the result of PCR analysis for sexing using ovary- or testis- specific oligonucleotide primers. Immunoreactive GnRH in placenta was decreased gradually until the end of gestation but fetal brain and ovarian GnRH were increased. The level of GnRH gene expression was increased during fetal ovarian development from 12 till 18th day and decreased suddenly on 20th day just before birth. From these results, it is suggested that ovarian GnRh may play a regulatory role on the germ cell differentiation of fetal ovary.

• 한국발생생물학회지:발생과생식
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• 제22권3호
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• pp.263-273
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• 2018

Aquaporin (AQP) 3, a facilitated transporter of water and glycerol, expresses in placenta and fetal membranes, but the detailed localization and function of AQP3 in placenta remain unclear. To elucidate a role of AQP3 in placenta, we defined the expression and cellular localization of AQP3 in placenta and fetal membranes, and investigated the structural and functional differences between wild-type and AQP3 null mice. Gestational sacs were removed during mid-gestational period and amniotic fluid was aspirated for measurements of volume and composition. Fetuses with attached placenta and fetal membranes were weighed and processed for histological assessment. AQP3 strongly expressed in basolateral membrane of visceral yolk sac cells of fetal membrane, the syncytiotrophoblasts of the labyrinthine placenta and fetal nucleated red blood cell membrane. Mice lacking AQP3 did not exhibit a significant defect in differentiation of trophoblast stem cells and normal placentation. However, AQP3 null fetuses were smaller than their control litter mates in spite of a decrease in litter size. The total amniotic fluid volume per gestational sac was reduced, but the amniotic fluid-to-fetal weight ratio was increased in AQP3 null mice compared with wild-type mice. Glycerol, free fatty acid and triglyceride levels in amniotic fluid of AQP3 null mice were significantly reduced, whereas lactate level increased when compared to those of wild-type mice. These results suggest a role for AQP3 in supplying nutrients from yolk sac and maternal blood to developing fetus by facilitating transport of glycerol in addition to water, and its implication for the fetal growth in utero.

• Archives of Plastic Surgery
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• 제32권3호
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• pp.347-356
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• 2005

The wound healing process in fetus is quite different form that of adult. Regeneration plays an important role and scarless wound healing is possible in early gestational fetal period. Recently, the various effects of the hypoxia and reoxygenation in the wound healing process have been investigated by many researchers. The hypoxic state is known to alter protein synthesis and gene expression of TGF-${\beta}$, VEGF. The authors hypothesize there may be differences between fetal and adult fibroblast and this difference may play a possible role in the mechanism of scarless fetal wound healing. In this study, we investigated the growth of fibroblast, the amount of collagen deposition, the amount of protein synthesis and gene expression in TGF-${\beta}$(transforming growth factor-${\beta}$), VEGF(vascular endothelial growth factor) under the various hypoxic and reoxygenation conditions. Through these processes, we tried to determine the relationships between scarless fetal wound healing and hypoxic condition. In control group, fetal and adult fibroblasts were cultured under normoxic condition. The experimental groups were allocated into four different groups. The differences in TGF-beta, VEGF under 24, 48, 72 hours were statistically investigated. Compared to adult fibroblast group, there was a statistically significant increase (p<0.01) in the rates of protein synthesis in TGF-beta and VEGF of fetal fibroblast. In this study, these results may reflect the possibility that fetal fibroblast are more susceptible to change in oxygen and has a superior rate of angiogenesis through increased VEGF expression. The possible superiority of angiogenesis in fetal fibroblast may play an important role in scarless wound healing.

• 대한수의학회지
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• 제36권1호
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• pp.235-245
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• 1996

Serial ultrasonographic examinations were performed on 9 pregnant Korea Jin-do bitches that were the Korean native breed, from days 15 to 60 pregnancy to determine the time of first detection and ultrasonographic appearance of the fetal and extra-fetal structures of pregnancy. Gestational age was timed from the day of ovulation (Day 0), which was estimated to occur when plasma progesterone concentration was first increased above 4.0 ng/ml. Gestational ages at earliest detection of the following fetal and extra-fetal structures were; gestational sac at days 17 to 22; placental layers in the uterine wall at days 20 to 24; zonary placenta at days 25 to 28; yolk sac membrane at days 22 to 24; amnionic membrane at days 27 to 29; embryo initial detection at days 21 to 23; fetal heartbeat at days 21 m 25; bipolar shape embryo at days 25 to 26; fetal movement at days 28 to 31; limb buds at days 31 to 35; anechoic area in head at days 31 to 36; stomach at days 34 to 37; urinary bladder at days 34 to 37; skeleton at days 36 to 38; dorsal sagittal tubular structure in vertebrae at days 36 to 38; lung hyperechoic vs liver at days 37 to 39; liver hypoechoic vs abdomen at days 37 to 40 and kidney at days 43 to 48, respectively.

• 한국수산과학회지
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• 제28권1호
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• pp.114-122
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• 1995

B 세포가 다양화되어 가는 기작을 규명한다는 것은 면역 반응의 조절이 생체 내에서 어떻게 이루어지고 있는 가를 이해하는데 가장 기본이 되는 것이다. 본 연구는 기 확립한 in situ hybridization 기법을 이용하여 항체의 항원 결합 부위 유전자가 B 세포의 발달 과정 중 어떻게 조절이 되고 있으며 이것은 B 세포의 다양화라는 측면과 어떻게 연관이 되어 있는 지를 분석하였다. Gestation 시기가 16일, 18일, 19일, 20일 되었을 때간에 있는 B 세포는 $V_H7183$와 $V_HQ52$두개의 $V_H$ 유전자군을 가장 많이 이용하고 있었으며 이러한 경향은 gestation 기간 전체를 통하여 변화 없이 일정하게 나타났다. 간에 있는 fetal B 세포를 differentiation 단계별로 구분하기 위하여 표면 항체를 갖고 있는 집단과, 갖고 있지 않은 두 집단으로 나눈 후 각 집단이 발현하는 $V_H$ 유전자를 분석하였을 때 뚜렷한 차이를 나타냄이 없이 양쪽 집단 모두 fetus의 특징적 $V_H$ 이용양식을 보여주었다. 또 다른 조혈 기능 임파 기관인 fetal spleen에 있는 B 세포 또한 fetal liver의 B 세포와 동일한 양상의 $V_H$ 유전자 이용 양식을 보여 주어 각 임파 기관별 B 세포의 다양성 차이를 발견 할 수 없었다. 이와 같이 adult의 B 세포에 대비하여 독특한 $V_H$ 유전자 이용 양상을 보이는 fetal B 세포의 전구 세포를 4주 이상 미리 형성시킨 adult 골수 세포와 직접 접촉시키면서 발달, 성숙시킨 후 다시 나타난 B 세포를 분석하여도 여전히 fetal B 세포로서의 $V_H$ 유전자 이용 양상을 보이는 것은 fetal B세포의 전구 세포가 갖고 있는 유전적 잠재력에 의한 것이지 환경이나 B 세포의 differentiation 단계 또는 B 세포가 머무르고 있는 특수 임파 장기의 생리적 환경 등에 좌우되는 것이 아니라는 것이 확인되었다.

• 한국생활과학회지
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• 제21권2호
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• pp.213-223
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• 2012

The purpose of this study was to evaluate the relationship between stress, temperament and maternal-fetal attachment in pregnant women. The respondents in this research were 249 pregnant women who were participating in a Parent Education project. Data was collected by way of a questionnaire. A summary of the findings were as follows: Among the pregnant women in this study, total stress level was below the average and maternal fetal attachment level was above the average. The group demonstrating high levels of stress exhibited low level of maternal-fetal attachment when compared to those with low levels stress. Pregnant woman's stress and maternal temperament demonstrated a significant correlation with maternal-fetal attachment.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.181-184
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• 2004

There are reports showing that electromagnetic fields (EMFs) emitted at non-thermal levels may be associated with biological alterations in target cells. In this study it is objected to assess the potential influences of EMFs produced by cellular phones on fetal heart rate. Non Stress Test (NST) is a widely used method of fetal monitoring and assessing fetal health and well-being. Sixty volunteers with uncomplicated term pregnancies were studied by a Spacelabs AM-67 Doppler ultrasound monitor. Fetal Heart Rate recordings were obtained while there were no Cellular Phone around for 10 minutes. Afterwards, all patients were exposed to EMFs for 10 minutes. NST was performed while they were holding the CP on stand-by mode and then on dialing mode, each for 5 minutes. The recordings were analyzed with respect to baseline heart rate, accelerations and decelerations. The Wilcoxon matched-pairs signed-ranks test was used to compare these variables. The results indicate that EMFs emitted by CP do not cause any demonstrable effects on baseline FHR, acceleration or deceleration.

• 대한의용생체공학회:의공학회지
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• 제12권3호
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• pp.209-214
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• 1991

Digital fetal monitoring system based on the personal computer combined with the digital signal processing (DSP) board was implemented. The DSP board acquires and digitally processes ultra- sound fetal Doppler signal for digital signal conditioning, rectification, low -pass filtering, autocorrealtion function calculation and its peak detection. The personal computer interfaced with the DSP board is in charge of graphic display, hardcopy, data transmission and on -line analysis of fetal heart rate change including on - line warning system, base -line estmation, acceleration, deceleration and variability. It is one of the most suitable situation to apply the DSP chip for siganl conditioning, digital filtering of ultrasound fetal Dopier signal and fetal heart rate estimation using autocorrelation technique .

• Journal of Genetic Medicine
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• 제8권1호
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• pp.1-16
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• 2011

현재 사용되고 있는 침습적 산전진단법(양수천자, 융모막샘플링)은 1-2%의 태아 손실이 초래되어, 비침습적 산전진단법이 산전진단의 궁극적인 목표로 대두되어 왔다. 1997년 Dr. Lo에 의해서 임신부 혈장 내에 세포 유리 태아 DNA (cffDNA)의 존재가 발견된 후 비침습적 산전진단의 새로운 가능성이 열렸으며, 과거 10년간 이에 대한 연구의 많은 진전을 보여주고 있다. 최근에 cffDNA를 이용한 Hemophilia A와 듀센형 근이영양증 등 반성 유전병(X-linked disorders) 진단에 필수적인 산전태아의 성 판정과 RhD-음성 임신부에서 태아의 RhD유전자 핵형 분석 등이 이미 외국에서 임상적으로 적용되고 있으나, 한국에서는 아직 실용화되지 않고 있다. CffDNA의 임상 사용에는 여전히 많은 제약점이 있으며, 이는 임신부 혈장 내 cffDNA 양에 비해 많은 양의 모태 DNA가 존재하고, 종래에 사용되었던 특이적인 Y염색체 유전자(Y-specific gene)는 남아 태아 임신 시에만 적용된다는 것에 기인한 다. 따라서 모든 태아에 적용할 수 있는 태아 성과 무관한 마커(sex-independent universal fetal marker as internal positive controls)가 요구되며, 이를 이용하여 정확한 태아 DNA를 검출할 수 있다. 본 연구진은 국내 처음으로 임신부 혈장 내에 cffDNA를 이용하여 SRY 유전자, RhD-exon 7, 태아 성과 무관한 DNA마커(universal fetal DNA marker)로써 RASSF1A 유전자를 실시간 중합효소연쇄반응(RT- PCR)을 사용하여 뛰어난 결과를 얻었다. 이는 한국에서 처음으로 성공적으로 시도된 것이다. 연구결과에서 산전 태아 성 판별과 산후 태아의 성이 100% 일치하였으며, 임신 주기별 SRY 수치는 임신이 진행할수록 증가함을 확인할 수 있었다. 따라서 이러한 방법은 혈우병 A, 듀센형 근이영양증, 선천성 부신증식증과 연골 무형성증의 진단과 치료 상담에 이용할 수 있으며 50%에서 침습적인 방법을 줄일 수가 있다. 또한, RhD-음성 임신부 대상으로 태아의 성 판정과 RhD 태아 유전자형을 분석한 결과 RhD-음성 태아를 정확히 검출함으로써 앞으로 기존 양수천자 등 침습적 검사를 대체할 수 있을 것이다. 특히 이는 치료가 필요 없는 RhD-음성 태아에서 RhD-면역글로불린의 예방적 치료를 사전에 막을 수 있어, 임신부 건강을 보호하고 의료 비용을 줄일 수 있는 큰 장점을 가진다. 한국에서 최초로 시도된 임신부 혈장 내 cffDNA를 이용한 본 연구의 성공은 비침습적 산전진단 임상 적용의 새 길을 제시하였다. 따라서 이를 각 유전질환의 산전진단에 유용하게 활용하는 것은 태아와 임신부의 건강 증진과 의료비용 절약 등 개인과 국가에 많은 기여를 할 것으로 사료된다.