• Radiation Oncology Journal
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• v.4 no.2
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• pp.99-105
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• 1986

Optimal balance between control probability and risk of complication is emphasized even in present time, Although certain incidence of intestinal injury is accepted as an inevitable consequence after abdominopelvic irradiation, these complications still remain as problems. 60 mice were irradiated with 250 kVp orthovoltage x-ray machine and $200rad{\times}5/wk$ regimen. Histpathologic findings of colorectum and the relationship with occult blood test were analyzed and possible tolerable dose which would be safe from permanent complication was also estimated. Followings are the results: Mild mucosal and submucosal edema were observed in 1,000 rad irradiated group. Congestion of small vessels was prominent in 2,000 rad irradiated group and infiltration of inflammatory cells was observed in 3,000 rad irradiated group. Denuded mucosa was observed in 3,000 rad irradiated group. Occult blood test is not a proper indicator for rectal denuding or rectal ulcer, but our results suggest the possibility of using this as a relative scale of intestinal damage. Mitotic figures of crypt cells were observed even in 5,000 rad irradiated group, these suggest that the repair capacity of crypt cells are still functioning.

• Polymer(Korea)
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• v.32 no.1
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• pp.26-30
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• 2008

This study was designed to investigate the effect of hybridization of synthetic/natural materials for annulus fibrosus (AF) tissue regeneration in vitro and in vivo. The synthetic/natural hybrid scaffolds were prepared using PLGA (poly (lactic-co-glycolic) acid), SIS (small intestinal submucosa) and DBP (demineralized bone particles). PLGA, PLGA/SIS(20%), PLGA/DBP(20%) and PLGA/SIS (10%)/DBP (10%) scaffold were manufactured by solvent casting/salt leaching method. Compressive strength was measured. Rabbit AF cells were isolated, cultured and seeded into experimental groups. Hydroxyproline production and DNA quantity of AP cells on each scaffold was measured at 2, 4 and 6 weeks after in vitro culture. Cell-scaffold composites were implanted subcutaneously into athymic mice. After 1,4 and 6 weeks postoperatively, specimens were taken and H&E, Safranin-O and type I collagen staining were carried out concerning formation of cartilagenous tissue. In vitro PLGA/SIS scaffold was evaluated for total collagen content (bydroryproline/DNA content) and PLGA scaffold was evaluated for compressive strength.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.8
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• pp.1190-1195
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• 2007

This study was conducted to improve efficiency of a follicle culture system without reducing developmental competence of intrafollicular oocytes. Preantral follicles (100 to $125{\mu}m$ in diameter) of F1 hybrid (B6CBAF1) mice were cultured singly for 216 h in modified ${\alpha}$-MEM-glutamax medium, to which 2.5 IU/ml hCG and epidermal growth factor was added 16 h prior to the end of culture. Medium change was either performed three times (54 h interval), twice (72 h interval), once (108 h interval), or not at all (216 h interval). Maturation (progression to the metaphase II stage) of intrafollicular oocytes was detected from 4 days after culture in the three-times change treatment, while all treatments yielded mature oocytes from day 5 of culture. Compared with the three-times change, decreasing the change frequency to once did not reduce the capacity to begin maturation (germinal vesicle breakdown of 82 to 86%), to mature (78 to 79%) and to develop into blastocysts after parthenogenetic activation (29 to 32%). Morphological parameters were similar among these treatments. Except for the no medium change treatment, similar colony-forming activity of inner cell mass cells after culturing of blastocysts in leukemia inhibitory factor-containing medium was detected, while the morphology of the colony-forming cells deteriorated in the change-once treatment compared with the change twice or three-times. In conclusion, the efficiency of the preantral follicle culture system could be improved by reducing frequency of medium change up to a 72 h interval (three times in total 216 h culture) without decreasing developmental competence of oocytes.

• Clinical and Experimental Reproductive Medicine
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• v.20 no.1
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• pp.9-17
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• 1993

This study was carried out investigate the effect of water quality and the kind of media on the in vitro development of 1-cell and stage mouse embryos. $F_1$ hybrid mice were superovulated and timely mated. 1-cell stage and 2-cell stage mouse embryos were recruited and taken into Ham's F-10 or m-KRB media which was made of two of two kinds of water having different quality, highly purified water and tap water. 2-cell stage embryos grew up well in vitro to blastocyst or hatching blastocyst regardless of the composition of culture media, but 1-cell stage mouse embryo didn't develop well to blastocyst or hatching blastocyst in simple media like m-KRB. These results meant in vitro devleopment of 1-cell stage mouse embryo neded complex media like Ham's F-10 which contained abundant protein components. In case of quality control for water, in vitro fertilization program. observation of in vitro development of 2-cell mouse embryos up to blastocyst or hatching blastocyst media such as m-KRB would be efficatious in detecting the difference of water quality.

• Molecules and Cells
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• v.25 no.3
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• pp.358-367
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• 2008

The embryonic germ cell (EGCs) of mice is a kind of pluripotent stem cell that can be generated from pre- and post-migratory primordial germ cells (PGCs). Most previous studies on DNA methylation of EGCs were restricted to 12.5 days post coitum (dpc). This study was designed to establish and characterize murine EGC lines from migrated PGCs as late as 13.5 dpc and to estimate the degrees of methylation of their imprinted genes as well as of the non-imprinted locus, Oct4, using an accurate and quantitative method of measurement. We established five independent EGC lines from post migratory PGCs of 11.5-13.5 dpc from C57BL/6 ${\times}$ DBA/2 F1 hybrid mouse fetuses. All the EGCs exhibited the typical features of pluripotent cells including hypomethylation of the Oct4 regulatory region. We examined the methylation status of three imprinted genes; Igf2, Igf2r and H19 in the five EGC lines using bisulfite genomic sequencing analysis. Igf2r was almost unmethylated in all the EGC lines irrespective of the their sex and stage of isolation; Igf2 and H19 were more methylated than Igf2r, especially in male EGCs. Moreover, EGCs derived at 13.5 dpc exhibited higher levels of DNA methylation than those from earlier stages. These results suggest that in vitro derived EGCs acquire different epigenotypes from their parental in vivo migratory PGCs, and that sex-specific de novo methylation occurs in the Igf2 and H19 genes of EGCs.

• Korean Journal of Food Science and Technology
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• v.49 no.6
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• pp.649-658
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• 2017

The potential of the ethyl acetate fraction from Pteridium aquilinum (EFPA) to improve the cognitive function in high-fat diet (HFD)-induced diabetic mice was investigated. EFPA-treatment resulted in a significant improvement in the spatial, learning, and memory abilities compared to the HFD group in behavioral tests, including the Y-maze, passive avoidance, and Morris water maze. The diabetic symptoms of the EFPA-treated groups, such as fasting glucose and glucose tolerance, were alleviated. The administration of EFPA reduced the acetylcholinesterase (AChE) activity and malondialdehyde (MDA) content in mice brains, but increased the acetylcholine (ACh) and superoxide dismutase (SOD) levels. Finally, kaempferol-3-o-glucoside, a major physiological component of EFPA, was identified by using high-performance liquid chromatography coupled with a hybrid triple quadrupole-linear ion trap mass spectrometer (QTRAP LC-MS/MS).

• Clinical and Experimental Reproductive Medicine
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• v.28 no.1
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• pp.55-63
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• 2001

Objectives: This study was carried out to evaluate the effects of embryonic stage, cryoprotectant, and freezing-thawing method on the rates of survival and development of the cryopreserved mouse early embryo and finally to establish the cryopreservation method of surplus embryos obtained during assisted reproductive technology (ART). Materials and Methods: Two to eight cell embryos were obtained from oviducts of mated $F_1$ hybrid female mice superovulated by pregnant mare's serum gonadotropin (PMSG) and human chorionic gonadotropin (hCG). Two-step 1,2-propanediol (PROH), dimethylsulfoxide (DMSO) and 4-step PROH DMSO were used as cryoprotectant and dehydration and rehydration method of embryos, and slow-cooling or rapid-cooling method was used as frozen program. The survival rates of embryos were measured after thawing and rehydration, and the developmental rates of embryos were compared and observed during culturing embryos for 24, 48, 72, 96 hrs. Results: As for the survival and development rates of embryos according to embryonic stage, the survival rate of 2 cell stage in PROH and DMSO was significantly higher than 4-8 cell (64.5% versus 62.1 %,79.7% versus 73.2%) (p<0.01, p<0.01), but the development rates of 4-8 cell embryos in PROH and DMSO were significantly higher than 2 cell embryos for whole culture period (p<0.01) and the development rates of 4-8 cell embryos in PROH were significantly higher than 2 cell embryos in DMSO (p<0.01). As for the survival and development rates of embryos according to cryoprotectant, the survival rate of 2 cell embryo in DMSO was significantly higher than that in PROH (74.4% versus 64.5%) (p<0.01), whereas the development rate of embryos was not differ till 24 hrs. The developmen1 rate from morular to hatching blastocyst, however, was significantly higher in PROH than in DMSO during 48 hr (p<0.01). The survival rate of 4-8 cell embryo was 62.1% in PROH and 73.2% in DMSO. The development rates of embryo in PROH were significantly higher for whole culture periods (p<0.01, 0.05). In respect to the effect of freezing and thawing program on the survival and development rates of embryos, method of slow cooling and rapid thawing was more effective than that of rapid cooling and rapid thawing. Conclusions: The survival rate of embryo in 2 cell stage was higher than in 4-8 cell stage, and PROH appears more effective cryoprotectant than DMSO because PROH showed better development rates of embryos in 2 and 4-8 cell stage. Moreover, slow cooling and rapid thawing method was considered as the best cryopreservation program.

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2002.11a
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• pp.113-113
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• 2002

The stimulatory effect of EGF and FSH on oocyte maturation have been reported in various mammalian species. And some reports presented FSH enhanced the effect of EGF on oocyte maturation. But, the interaction between EGF and FSH on nuclear maturation of mammalian oocytes is not fully understood. We observed the effect of EGF and FSH on nuclear maturation during in vitro maturation of mouse oocytes. Also, we examined the interaction between EGF and FSH on nuclear maturation of mouse oocytes using the EGFR inhibitor or FSH inhibitor. Germinal vesicle (GV) stage oocytes were obtained from 3-4weeks PMSG primed BCFI hybrid mice and cultured in TCM-199 medium with 0.4%PVP supplemented with/without EGF (1ng/ml), FSH (1ug/ml), EGFR specific tyrosine kinase inhibitors: Tyrphostin AG 1478 (500nM), MAP kinase kinase inhibitor : U0126 (20uM) or PD 98059 (100uM) for 14-l5hr. Rapid staining method were used for the assessment of nuclear maturation. Nuclear maturation rates of EGF indjor FSH-treated group were significantly higher than those of control group. Treatment of EGFR inhibitor significantly block the nuclear maturation of GV oocyte in EGF-treated group, but it did not block those of GV oocyte in FSH-treated or FSH and EGF-treated group. Treatment of FSH inhibitor(U0126, PD98059) significantly block the nuclear maturation of EGF-treated group, FSH-treated and FSH and EGF-treated group. These results show that EGF has a stimulatory effect as well as different action pathway with FSH on in-vitro maturation of mouse oocyte in vitro. Therefore, further studies will be needed to find the signaling pathway of EGF associated with nuclear maturation.

• Clinical and Experimental Reproductive Medicine
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• v.25 no.1
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• pp.59-64
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• 1998

This study was designed to evaluate the influence of pronuclear age on the survival and post-thawing development after cryopreservation of mouse embryos. Freezing and thawing were performed in the different pronuclear stages of mouse embryos after IVF. Embryos were obtained from $F_1$ hybrid mice and classified into 4 groups according to the pronuclear stage (6hr, 9hr, 12hr and 15hr after insemination). Pronuclear ova were slowly cooled in a biological freezer using 1.5M 1,2-propanediol and 0.1M sucrose as cryoprotectant. Thawing was done at room temperature and 1,2-propanediol was removed by multi-step dilutions. Both frozen-thawed embryos and control fresh embryos were cultured in vitro in Ham's F-10 medium supplemented with 4mg/ml BSA. In control group, the development rate after 48hr was 99.3%, and the complete hatching rate after 144hr was 61.3%. In experimental groups, the survival rate after thawing was 95.4% in 6hr, 88.7% in 9hr, 75.2% in 12hr and 62.4% in 15hr after insemination, the development rate after 48hr was 61.1, 77.0, 67.0 and 79.6%, respectively, and the complete hatching rate after 144hr was 25.7, 43.7, 42.2 and 60.0%, respectively. The survival rate in 15hr was significantly lower (p<0.05) compared with other groups. In vitro development rates after 48hr were similar in all groups, but complement hatching rate was significantly lower (p<0.05) in 6hr group. In conclusion, cryopreservation of mouse pronuclear ova with 2 distinct pronuclei (9hr and 12hr groups) showed better results after thawing compared with early (6hr group) or late pronuclear ova just prior to cleavage (15hr group).

• Journal of Embryo Transfer
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• v.30 no.3
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• pp.195-200
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• 2015

The objective of this study was to evaluate the toxicities of permeable cryoprotectants and finally to establish the cryopreservation method of surplus embryos obtained during assisted reproductive technology (ART). Toxicities of permeable cryoprotectants, dimethyl sulfoxide (DMSO), ethylene glycol (EG), Glycerol, and 1,2-PROH were investigated using a murine embryo model. Female $F-{_1}$ mice were stimulated with gonadotropin, induced ovulation with hCG and mated. Two cell embryos were collected and cultured after exposure to among DMSO, EG, Glycerol, and 1,2-PROH. Embryo development was evaluated up to the blastocyst stage. The total cell count of blastocysts that were treated with DMSO and Glycerol at the 2-cell stage was significantly lower than that were treated with EG ($81.1{\pm}15.1$), 1,2-PROH ($88.0{\pm}21.1$) or the control ($99.9{\pm}21.3$) (p<0.001). On comparison of four cryoprotectant treated groups, the DMSO and Glycerol treated group showed a decreased cell count compared with the EG and 1,2-PROH treated group (p<0.05). Both DMSO ($14.7{\pm}1.3$), EG ($12.1{\pm}1.1$), Glycerol ($15.2{\pm}1.8$), and 1,2-PROH ($11.5{\pm}1.3$) treated groups showed higher apoptosis rates of cells in the blastocyst compared with the control ($6.5{\pm}0.7$, p<0.0001). In addition, the DMSO or Glycerol treated group showed more apoptotic cells than the EG or 1,2-PROH treated group (p<0.001). The potential toxicity of cryoprotectants was uncovered by prolonged exposure of murine embryos to among DMSO, EG, Glycerol, and 1,2-PROH at room temperature. When comparing four permeable cryoprotective agents, EG and 1,2-PROH appeared to be less toxic than DMSO and Glycerol at least in a murine embryo model.