• Toxicological Research
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• v.29 no.4
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• pp.221-227
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• 2013

Embryonic stem (ES) cells have potential for use in evaluation of developmental toxicity because they are generated in large numbers and differentiate into three germ layers following formation of embryoid bodies (EBs). In earlier study, embryonic stem cell test (EST) was established for assessment of the embryotoxic potential of compounds. Using EBs indicating the onset of differentiation of mouse ES cells, many toxicologists have refined the developmental toxicity of a variety of compounds. However, due to some limitation of the EST method resulting from species-specific differences between humans and mouse, it is an incomplete approach. In this regard, we examined the effects of several developmental toxic chemicals on formation of EBs using human ES cells. Although human ES cells are fastidious in culture and differentiation, we concluded that the relevancy of our experimental method is more accurate than that of EST using mouse ES cells. These types of studies could extend our understanding of how human ES cells could be used for monitoring developmental toxicity and its relevance in relation to its differentiation progress. In addition, this concept will be used as a model system for screening for developmental toxicity of various chemicals. This article might update new information about the usage of embryonic stem cells in the context of their possible ability in the toxicological fields.

• Journal of Animal Science and Technology
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• v.47 no.2
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• pp.187-194
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• 2005

Telomeres locate at the end of chromosomes and consist of a tandem repeat sequence of $(TIAGGG)^{n}$ and associated proteins. Telomerase is a ribonucleoprotein which act as a template for the synthesis of telomeric DNA. Telomeres are essential for chromosome stability and are related with cell senescence, apoptosis and cancer. This study was carried out to analyze the amount of telomeres and telomerase activity of chicken cells during embryonic and developmental stages. The whole embryos and prenatal tissues such as brain, heart, liver, kidney and testis at different developmental stages were obtained from Korean Native Chicken. The amount of telomeres on embryonic cells was analyzed by quantitative fluorescence in situ hybridization (Q-FISH) techniques using the chicken telomeric DNA probe. Telomerase activity was measured by telomeric repeat amplification protocol (TRAP) assay. Results indicated that the amounts of telomeric DNA on the most embryonic cells were gradually decreased during ontogenesis. Furthermore, the quantity of telomeres was quite different among embryonic tissues according to developmental origin. The relative amount of telomeres has more in regenerative cells such as embryonic disc and testicular cells than in non-regenerative cells such as liver, brain, heart and kidney cells. Telomerase activity was also highly detectable in most chicken cells at early embryonic stages. After 9 days of incubation, however, the telomerase activitie W

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.111-111
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• 2003

Telomeres are the end of chromosomes and consist of a tandem repeat sequence of (TTAGGG)n and associated proteins. Telomerase is a ribonucleoprotein which act as a template for the synthesis of telomeric DNA. Telomeres are essential for chromosome stability and are related with cell senescence, apoptosis and cancer. Even though telomeres and telomerase have been studied extensively, very little is known about telomere dynamics in embryonic cells. This study was carried out to analyze the telomeres distribution and telomerase activity of chicken cells during embryonic and developmental stages. The target cells for analysing were sperms, ovulated ova, early embryonic cells and the cells from brain, heart, liver, kidney and germinal tissue in fetus. Telomeres distribution on target cells was analyzed by Q-FISH (Quantitation-Fluorescence in situ Hybridization) techniques using a chicken telomere repeat probe. Telomerase activity was performed by TRAP assay (Telomeric repeat Amplification Protocol) with target DNA. In results, the telomeres of chicken were found at the ends of all chromosomes. In addition, chicken had interstitial telomeres on chromosomes 1, 2 and 3. Telomerase activity was highly detectable in early embryonic cells, germinal tissues and kidney cells. Whereas telomerase activity was gradually down-regulated when the organs, including brain, heart, and liver, were developed from embryos. In the distribution of telomeric DNA on the embryonic and developmental stages, most of the cells was gradually decreased in telomere quantity during ontogenesis.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2007.07a
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• pp.3-3
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• 2007

• Proceedings of the Korean Society of Toxicology Conference
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• 2005.05a
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• pp.159-159
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• 2005

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.2
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• pp.160-168
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• 2017

Optimizing the conditions for stem cell culture is an essential prerequisite for the efficient utilization of stem cells. In the culture of fish embryonic stem cells (ESCs) or ESC-like cells, embryo extracts are important for stable growth, but there is no rule for determining the developmental stage of the embryos used to obtain extracts. Therefore, this study investigated the effects of the developmental stage of extract donor embryos on the culture of Oryzias dancena ESC-like cells. O. dancena ESC-like cells were cultured in different media containing each of four types of embryo extract depending on the developmental stage of the extract donor embryos. Growth, morphology, colony-forming ability, alkaline phosphatase (AP) activity, and embryoid body (EB) formation of the cells were investigated. While the developmental stage of the extract donor embryos did not influence the growth, morphology, AP activity, or EB formation of ESC-like cells, colony-forming ability was affected and the pattern of the effects differed completely between the two ESC-like cells investigated. These results suggest that the developmental stage of extract donor embryos should be selected carefully for the culture of ESC-like cells, according to the research purpose and type of cell line.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.9
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• pp.1152-1158
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• 2010

In differentiating human embryonic stem (d-hES) cells there are a number of types of cells which may secrete various nutrients and helpful materials for pre-implantation embryonic development. This study examined whether the d-hES could function as a feeder cell in vitro to support mouse embryonic development. By RT-PCR analysis, the d-hES cells revealed high expression of three germ-layered differentiation markers while having markedly reduced expression of stem cell markers. Also, in d-hES cells, LIF expression in embryo implantation-related material was confirmed at a similar level to undifferentiated ES cells. When mouse 2PN embryos were cultured in control M16 medium, co-culture control CR1aa medium or co-cultured with d-hES cells, their blastocyst development rate at embryonic day 4 (83.9%) were significantly better in the d-hES cell group than in the CR1aa group (66.0%), while not better than in the M16 group (90.7%)(p<0.05). However, at embryonic days 5 and 6, embryo hatching and hatched-out rates of the dhES cell group (53.6 and 48.2%, respectively) were superior to those of the M16 group (40.7 and 40.7%, respectively). At embryonic day 4, blastocysts of the d-hES cell group were transferred into pseudo-pregnant recipients, and pregnancy rate (75.0%) was very high compared to the other groups (M16, 57.1%; CR1aa, 37.5%). In addition, embryo implantation (55.9%) and live fetus rate (38.2%) of the d-hES cell group were also better than those of the other groups (M16, 36.7 and 18.3%, respectively; CR1aa, 23.2 and 8.7%, respectively). These results demonstrated that d-hES cells can be used as a feeder cell for enhancing in vitro and in vivo developmental potential of mouse pre-implantation embryos.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.02a
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• pp.4-4
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• 2003

No Abstract, See Full Text

• Journal of dental hygiene science
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• v.20 no.2
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• pp.74-81
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• 2020

Background: In the early stages of development, teeth and lingual papillae are induced and developed through special and complex epithelial-mesenchymal interactions. Tooth completion indicates the beginning of the weaning phase, and accordingly, many oral tissues and organs are completed, and it is thought that their developmental completion times are related to each other. The purpose of this study was to clarify the embryonic and neonatal development of the filiform papillae and mandibular molar tooth, and discuss the developmental relationship between these organs by comparing the developmental completion times. Methods: Embryos at embryonic day 15 (EM15), 17 (EM17), and 21 (EM21) and mice at neonatal day 1 (NE1), 5 (NE5), 10 (NE10), and 21 (NE21) were used for experimentation. Tissues dissected from embryos and mice were fixed, and processed for histological analysis. Sections from the tissues were stained with hematoxylin and eosin for observation under a light microscope. Results: Based on the histological analysis results, the developmental process of the lingual epithelium covering the dorsal surface of the tongue was classified into three stages: initiation, morphogenesis, and functional. The development of the filiform papillae begins at EM17; undergoes rapid morphological changes in epithelial cells at EM21, PN1 and PN5, and reaches the functional stage at PN10, which is the sucking phase. Tooth development begins at EM13 or 15 and is completed at NE21 through prenatal and postnatal development. Conclusion: The development of the filiform papillae was initiated late and completed quickly through embryonic and neonatal development in comparison with the mandibular molar tooth. The filiform papillae are considered to play an important role in sucking rather than mastication as it is completed in the sucking phase.

• Journal of Ginseng Research
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• v.43 no.2
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• pp.242-251
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• 2019

Background: Korean Red Ginseng has been widely used in traditional oriental medicine for a prolonged period, and its pharmacological effects have been extensively investigated. In addition, Angelica gigas and deer antlers were also used as a tonic medicine with Korean Red Ginseng as the oriental herbal therapy. Methods: This study was conducted to evaluate the potential toxicological effect of KGC-HJ3, Korean Red Ginseng with angelica gigas and deer antlers, on reproductive and developmental functions including fertility, early embryonic development, maternal function, and embryo-fetal development. KGC-HJ3 was administered by oral gavage to Sprague-Dawley rats (22 animals per sex per group) at dose levels of 0 mg/kg (control), 500 mg/kg, 1000 mg/kg, and 2000 mg/kg to evaluate the potential toxicological effect on fertility and early embryonic development. In addition, KGC-HJ3 was also administered by oral gavage to mating-proven Sprague-Dawley rats (22 females per group) during the major organogenesis period at dose levels of 0 mg/kg (control), 500 mg/kg, 1000 mg/kg, and 2000 mg/kg to evaluate the potential toxicological effect on maternal function and embryo-fetal development. Results and conclusion: No test item-related changes in parameters for fertility, early embryonic development, maternal function, and embryo-fetal development were observed during the study period. On the basis of these results, it was concluded that KGC-HJ3 did not have toxicological potential on developmental and reproductive functions. Therefore, no observed adverse effect levels of KGC-HJ3 for fertility, early embryonic development, maternal function, and embryo-fetal development is considered to be at least 2000 mg/kg/day.