• Reproductive and Developmental Biology
• /
• 제32권2호
• /
• pp.135-140
• /
• 2008

Recent studies on nuclear transfer and induced pluripotent stem cells have demonstrated that differentiated somatic cells can be returned to the undifferentiated state by reversing their developmental process. These epigenetically reprogrammed somatic cells may again be differentiated into various cell types, and used for cell replacement therapies through autologous transplantation to treat many degenerative diseases. To date, however, reprogramming of somatic cells into undifferentiated cells has been extremely inefficient. Hence, reliable markers to identify the event of reprogramming would assist effective selection of reprogrammed cells. In this study, a transgene construct encoding enhanced green fluorescent protein (EGFP) under the regulation of human Oct4 promoter was developed as a reporter for the reprogramming of somatic cells. Microinjection of the transgene construct into pronuclei of fertilized mouse eggs resulted in the emission of green fluorescence, suggesting that the undifferentiated cytoplasmic environment provided by fertilized eggs induces the expression of EGFP. Next, the transgene construct was introduced into human embryonic fibroblasts, and the nuclei from these cells were transferred into enucleated porcine oocytes. Along with their in vitro development, nuclear transfer embryos emitted green fluorescence, suggesting the reprogramming of donor nuclei in nuclear transfer embryos. The results of the present study demonstrate that expression of the transgene under the regulation of human Oct4 promoter coincides with epigenetic reprogramming, and may be used as a convenient marker that non-invasively reflects reprogramming of somatic cells.

• 한국초지조사료학회지
• /
• 제14권2호
• /
• pp.76-81
• /
• 1994

대관령 지역에서 Tall fescue 9개 품종을 공시하여 가을철 예취시기에 따른 2번초의 수량구성 요소와 개체중의 변화를 검토하여 이 지역의 환경조건에 적응성이 높은 품종을 선발하여고 하였으며, 얻어진 결과를 요약하면 다음과 같다. 1. 2번초에서 개체당 경수가 많은 품종(Barcel, Forager)이 개체중도 무거워서 이지역의 환경조건에 적응성이 높은 품종이라고 생각되었다. 2. 가을철 예취시기에 따른 2번초의 개체당 경수는 개체중과 0.1%의 유의한 정상관을 나타냈으나 1경중은 유의한 상관이 인정되지 않았다. 3. 2번초의 편균 개체중이 최대에 도달하는 가을철 예취시기는 $C_3$(10월28일)으로 추정되었다. 4. 2번초의 평균 개체중은 1번초의 평균 개체중과 반비례적인 관계를 나타내었다.

• Journal of Genetic Medicine
• /
• 제12권1호
• /
• pp.31-37
• /
• 2015

Purpose: We investigated the neurogenic potentials of amniotic fluid-derived stem cells (AFSCs) according to the expression levels of stem cell markers and ingredients in the neural induction media. Materials and Methods: Four samples of AFSCs with different levels of Oct-4 and c-kit expression were differentiated neurally, using three kinds of induction media containing retinoic acid (RA) and/or a mixture of 3-isobutyl-1-methylxanthine/indomethacin/insulin (neuromix), and examined by immunofluorescence and reverse transcription-polymerase chain reaction (RT-PCR) for their expression of neurospecific markers. Results: The cells in neuromix-containing media displayed small nuclei and long processes that were characteristic of neural cells. RT-PCR analysis revealed that the number of neural markers showing upregulation was greater in cells cultured in the neuromix-containing media than in those cultured in RA-only medium. Neurospecific gene expression was also higher in Oct-4 and c-kit double-positive cells than in c-kit-low or -negative cells. Conclusion: The stem cell marker c-kit (rather than Oct-4) and the ingredient neuromix (rather than RA) exert greater effects on neurogenesis of AFSCs.

• 생명과학회지
• /
• 제18권9호
• /
• pp.1249-1256
• /
• 2008

본 연구에서는 안동호의 수질이 수심에 따른 식물플랑크톤 군집에 어떠한 변화를 미치는가에 대해 이해하는 연구의 일환으로 안동호의 2개 지점(서부리, 댐축)에서 6회 시료 채취 및 조사를 한 결과는 다음과 같다. 안동호의 수질의 경우 수온은 수심 1 m와 수심 4 m는 계절에 따라 다소 변화가 나타나고 있지만, 수심 7 m의 경우에는 계절의 변화와는 크게 관계없이 일정한 범위 내에서 유지되고 있다. DO는 수심 1 m와 수심 4 m는 비슷한 수치를 나타내고 있지만, 수심 7 m는 수온이 낮아지면서 DO는 증가하였다. pH와 탁도는 모든 수심(수심 1 m, 수심 4 m, 수심 7 m)에서 일정한 수치를 나타내고 있고, SiO2-Si는 수심과는 커다란 연관성 없었으며, Chl-a는 수심이 깊어질수록 그 수치가 낮아지고 있다. 따라서 수심이 깊어질수록 DO, pH, SiO2-Si, Chl-a의 수치가 수심 1 m에 비해 조금씩 낮아지고 있으며, 변화의 폭도 크게 나타났다. 안동호에서 출현한 식물플랑크톤은 모두 59종류였고, 녹조강이 25종류(43%), 남조강이 17종류(29%), 규조강이 10종류(17%), 은편모조강이 3종류(5%), 시누라조강과 와편모조강이 각각 2종류(3%)가 출현하였다. 우점종은 녹조강의 Elakatothrix gelatinosa (8월 23일), Eutetramorus fottii (8월 23일 및 9월 28일) 남조강의 Aphanizomenon cf. flos-aquae (8월 16일), Microcystis aeruginosa (모든 조사기간), Aphanocapsa delicatissima (10월 27일), 규조강의 Cyclotella stelligera (10월 13일), Cyclotella sp. (10월 13일 및 10월 27일), Synedra acus (8월 16일)였다.

• Clinical and Experimental Reproductive Medicine
• /
• 제28권1호
• /
• pp.33-40
• /
• 2001

Objective: This study was to establish the human embryonic stem (ES) cells derived from frozen-thawed blastocyst stage embryo that were destined to be discarded after five years in routine human IVF-ET program. Methods: Frozen-thawed and survived human blastocysts were treated by immunosurgery, and recovered ICM cells were cultured onto STO feeder cell layer and ICM colony was subcultured by mechanical dissociation into clumps. To identify ES cell, alkaline phosphatase staining and expression of Oct4 in replated ICM colonies were examined. Also, to examine the possibility of ES cell differentiation, retinoic acid (RA), basic fibroblast growth factor (b-FGF), nerve growth factor (NGF) were added in culture medium. In addition, to classify the specific cell type, differentiated cells were stained by indirect immunocytochemistry. Results: One ICM colony recovered from frozen-thawed six blastocysts was subcultured, continuously replated during 40 passage culture duration without differentiation. Subcultured colonies were strong positively stained by alkaline phophatase. When the expression of Oct4 in cultured ES colony was examined, Oct4b type is more clearly indicated than Oct4a one although there was not detected in embryoid body or differentiated cells. In differentiated cardiomyocytes from ES colony, cells were beaten regularly (60 times/min). In differentiated neural cells from ES colony, neurofilament (NF) 200 kDa protein, microtubule associated protein (MAP) 2 and ${\beta}$-tubulin of specific marker in neurons, glial fibrillary acidic protein (GFAP) of specific marker in astrocytes and galactocelebrocide (GalC) of specific marker in oligodendrocytes were confirmed by indirect immunocytochemistry. Also, muscle cells were detected by indirect immunocytochemistry. In addition, ES colonies can be successfully cryopreserved. Conclusion: This study suggested that establishment of human ES cells can be successfully derived from frozen-thawed blastocysts that were destined to be discarded, and obtained specific cell types (cardiomyocytes, neurons and muscle cells) through the in vitro differentiation procedures of ES cells.

• 기본간호학회지
• /
• 제9권3호
• /
• pp.473-483
• /
• 2002

The purpose of this study was to explore the attitude of student nurses to euthanasia. The convenient sample for this study consisted of 293 nursing students at a nursing college in Kyeongi Province. The data were collected from Oct. 15, 2002 to Oct. 30, 2002 and were analyzed using frequency, percentage, and $X^2$-test with the SAS package. The results of this study are as follow : 77.1% of students agreed to passive euthanasia and 70.6% subjects agreed to legalization of passive euthanasia. 78.5% of students can given an exact explanation of the concept of hospice. They obtained information about hospice from the mass media (1.1%), books (30.0%), friends and neighbors (3.4%), and religious groups (2.4%). The preferred place for death was reported to be home (75.4%), hospital (9.4%) or a peaceful place (6.3%). Fears of facing death were suffering in death (23.4%), grief of remaining family (21.2%), unknown about the other world (10.0%), separation from people who are loved (9.7%), forgotten from the people's memory(6.3%). In conclusion, the attitude of student nurses toward passive euthanasia approached a positive direction. But euthanasia was seen as dangerous and having multiple problems. Therefore the training for student nurses as health professionals should include content on dealing with hospice care and euthanasia.

• Current Optics and Photonics
• /
• 제3권4호
• /
• pp.351-351
• /
• 2019

• 한국초지조사료학회지
• /
• 제13권2호
• /
• pp.78-85
• /
• 1993

This experiment was carried out to select for the varieties with high environmental adaptability in mountainous pastures of Taekwalyong area, and the evaluation was based on the data of varietal differences of dry matter production and yield components in Tall fescue cutting at various developmental stages in growth period of autumn. The results were summarized as follows; 1. The varieties with high number of tillers per plant(NT) showed a high dry weight of plant(DW) in all autumn cuttings. These varieties(Barce1 and Fuego) may be more adaptable to mountainous pastures of Taekwalyon area than other varieties. 2. The number of tillers per plant(NT) was significantly positive correlated with dry weight of plant (DW), but dry weight of tiller(WT) was not significantly correlated with dry weight of plant(DW) in all autumn cuttings. 3. The multiple regression equations of autumn cutting stages with mean dry weight of plant(DW) and number of tillers per plant(NT) can be used to estimate the cutting time to obtain maximum mean dry weight of plant(DW) and the highest number of tillers per plant(NT). The maximum mean dry weight of plant(DW) and the highest number of tillers per plant(NT) was estimated at the time of 21 Oct. and 26 Oct, respectively. 4. Dead leaves tended to increase greatly after the 2nd cutting(l4 Oct.) in growth period of autumn. 5. The number of tillers per plant(NT) was an important yield component before tiller density achieved equilibrium, but dry weight of tiller(WT, including dead leaves) was of most significant as a yield determinant after maximum tiller density reached in growth period of autumn.

• 환경위생공학
• /
• 제5권2호
• /
• pp.89-99
• /
• 1990

Morphology, anatomy and diurnal acid fluctuations were investigated monthly for the succulent C4 dicot Portulaca grandiflora Hook. growing under natural environmental conditions. Modified Kranz-Type sturcture and typical CAM-like cells were shown in leaves and stems, respectively. Values of indices of mesophyll succulence inleaves stems were 5.62 and 16.68, respectively. The number of stomata were 1476$\textrm{cm}^{-2}$ in leaves while the stomata in stems were not observed through growing seasons from spring to summer. However, on Sep. 16, 1981 in defoliate autumn season, stomata were begun to be produced for the first time in stems and the number were increased gradually to 216$\textrm{cm}^{-2}$ on Oct. 29. This feature can be interpreted as a seasonal plant dimorphism. P. grandiflora exhibited a diurnal fluctuation of titratable acidity in leaves and stems. Seasonal amplitudes of acid fluctuation in stems were as follows: 27 $\mu$eq./g.f.wt. on Sep. 21; 57$\mu$eq/g.f.wt. on Oct. 3; 80$\mu$eq./g.f.wt. on Oct. 21. Such the results in seasonal amplitude were able to consider due to decrease of light period and cool night air temperature according to change of season. Also, the naturally defoliated stems which had already stomata exhibited usual diurnal acid fluctuation, on the other hand the treated stems which possessed artificially closed stomata showed a few of acid fluctuation. Especially, stomata in stems are developed by seasonal dimorphism and activated stomata participate in CAM behavior of stems.

• 한국약용작물학회지
• /
• 제8권1호
• /
• pp.58-63
• /
• 2000

작약 식재후(植載後) 1년생은 일반관리법으로 재배하고 2년생부터 4년생 까지 3년간은 지상부 병해(病害)에 약제(藥劑)를 전혀 살포하지 않고 조기고사된 작약과 1년에 4회씩 3년간 적용약제를 살포하여 정상생육한 작약을 7월 25일부터 10월 25일까지 한 달 간격으로 4회 수확하여 조사한 결과 약제무방제에 따른 조기고사의 경우 건근수량(乾根收量)이 7월 하순경에 일찍 수확한 것은 1,126kg/10a 로 10월 하순 수확 1,177kg/10a에 비해 차이가 없으면서 paeoniflorin 함량이 가장 높았고, 약제방제에 따른 정상생육의 경우 수확 시기를 조정하여 10월 하순에 늦게 수확하는 것이 paeoniflorin 함량은 7, 8월 수확보다 낮았지만 건근수량(乾根收量)은 1,650kg/10a로 7월 수확 1,242kg/10a 에 비해 33% 증수(增收)되었다. 따라서 고품질 다수확을 위해서 는 작약 지상부병해에 약제를 살포하지 않고 일찍 고사시킬 것이 아니라 약제방제를 철저히 하여 지상부 생육을 10월 하순까지 유지하는 것이 필수적이었다.