• Applied Microscopy
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• v.27 no.2
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• pp.189-196
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• 1997

The ultrastrucures of Xenopus otic vesicle from normal embryo (st. 43) and induced otic vesicle from animal cap assay with Activin A were compared. Activin A was applied to the presumptive ectoderm at various concentrations for three days at $20^{\circ}C$. The results were almost identical to the reference studies, but it was found that the otic vesicle was induced at the concentration of 10 ng/ml in to)v rate. This otic vesicle may be secondarily induced by the neural tissue showed commonly at the concentration of 10 ng/ml. Otoliths were observed as three or four-axis crystaline bodies in the lumen of otic vesicle. In electron micrograph of the normal embryo, two kinds of microvilli were observed on the apical position of hair cells. One was small and common, the other was large-sized and sparsely distributed. In both cell of otic vesicle, mitochondria, golgi apparatus and multivesicular body were rich, so, they showed a lot of similarities in ultrastructure. However, the otolith was not found and microvilli were overexpressed in the otic vesicle induced by Activin A.

• Journal of Animal Reproduction and Biotechnology
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• v.34 no.2
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• pp.117-122
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• 2019

The objective of this study was to establish an in vitro culture system for ovarian preantral follicles of B6D2F1. First, we optimized the in vitro preantral-follicle culture by culture duration, follicle stimulating hormone (FSH) type, and activin A concentration. Duration of in vitro culture for 9, 11, and 13 days was sufficient for the normal development of preantral follicles to antral follicles. Formation of cumulus cell-oocyte complex (COC) was induced by treatment with human chorionic gonadotropin (hCG; 2.5 IU/mL) and epidermal growth factor (EGF; 5 ng/mL). In addition, metaphase II (MII) oocytes formed during this in vitro culture of preantral follicles. In vitro preantralfollicle culture for 9 days showed higher rates of growth and maturation, thus yielding a greater number of antral follicles, and there were significant differences (p < 0.05) in the number of MII oocytes (that formed from these preantral follicles via differentiation) between the 9-day culture and 11-day or 13-day culture. The follicles cultured for 9 days contained a tightly packed well-defined COC, whereas in follicles cultured for 11 days, the COC was not well defined (spreading was observed in the culture dish); the follicles cultured for 13 days disintegrated and released the oocyte. Second, we compared the growth of the preantral follicles in vitro in the presence of various FSH types. There were no significant differences in the growth and maturation rates and in differentiation into MII oocytes during in vitro culture between preantral follicles supplemented with FSH from Merck and those supplemented with FSH from Sigma. To increase the efficiency of MII oocyte formation, the preantral follicles were cultured at different activin A concentrations (0 to 200 ng/mL). The control follicles, which were not treated with activin A, showed the highest rate of differentiation into antral follicles and into MII oocytes among all the groups (0 to 200 ng/mL). Therefore, activin A (50 to 200 ng/mL) had a negative effect on oocyte maturation. Thus, in this study, we propose an in vitro system of preantral-follicle culture that can serve as a therapeutic strategy for fertility preservation of human oocytes for assisted reproductive medicine, for conservation of endangered species, and for creation of superior breeds.

• Proceedings of the Zoological Society Korea Conference
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• 1997.10b
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• pp.195.1-195
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• 1997

No Abstract, See Full Text

• Proceedings of the KSAR Conference
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• 2003.06a
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• pp.31-31
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• 2003

The incidence of reproductive abnormalities in the male has been reported to have increased during the past 50 years. These changes may be attributable to the presence of chemical with oestrogenic activity in our environment. Present study was carried out to determine the effects of maternal exposure to xenoestrogens on the testicular development and on the transcriptional expression of the steroidogenic enzyme and subunits of inhibin/activin in testis of male offspring. Pregnant female mice were administrated with 4-tert-octylphenol (OP; 2, 20, 200mg/kg), Bisphenol A (BPA; 2, 20, 200$\mu\textrm{g}$/kg), $\beta$-estradiol 17-valerate (EV; 2$\mu\textrm{g}$/kg) or vehicle (CV; corn oil) during gestational days 11 to 17. Offsprings were sacrificed on gestational day 18 (fetal 18) and neonatal day 7. Body weights were significantly increased in groups treated with all doses of OP and BPA. Maximum seminiferous tubules diameter on gestational day 18 were not changed in any treatment group, however, they were significantly increased on the neonatal day 7 in the group treated with low-dose of OP (2 mg/kg) and BPA (2 $\mu\textrm{g}$/kg). Increased expression of the P450$_{17a}$-hydroxylase dehydrogenase (P450$_{17a}$), 3$\beta$-hydroxylase dehydrogenase (3$\beta$-HSD), and 17$\beta$-hydroxylase dehydrogenase (17$\beta$-HSD) on gestational day 18 were observed in the groups treated with 2 or 20 mg/kg of OP. However, expression of the steroidogenic enzymes were not changed in the groups treated with all the doses of BPA. In contrast with the results from fetal testis, no expressional changes of these enzymes was found in all the OP-treated group and increased expression of inhibin/activin $\beta$B subunit mRNA were obseued in the 200 $\mu\textrm{g}$/kg BPA-treated group in the neonatal day 7. These results suggest that gestational exposure to low level of xenoestrogen causes a stimulatory effects on the transcriptional expressions of steroidogenic enzymes and subunits of inhibin/activin and on the seminiferous tubule development by their estrogen-like actions.ons.

• Proceedings of the Zoological Society Korea Conference
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• 1998.10b
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• pp.219.1-219
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• 1998

No Abstract, See Full Text

• Proceedings of the Zoological Society Korea Conference
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• 1999.10b
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• pp.172.2-172
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• 1999

No Abstract, See Full Text

• Annals of dermatology
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• v.30 no.6
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• pp.755-757
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• 2018

• Proceedings of the Zoological Society Korea Conference
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• 2001.04a
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• pp.68-68
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• 2001

No Abstract, See Full Text

• Clinical and Experimental Reproductive Medicine
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• v.34 no.4
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• pp.239-252
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• 2007

Objectives: In the present study, we examined the differentiation potential of human adipose-(HAD) and human umbilical cord-derived mesenchymal like stem cells (HUC) into cardiomyocytes. Methods: Cells were initially exposed to 5-azacytidine for 24h cells and then were cultivated in the presence or absence of activin A, TGF-$\beta$1, or Wnt inhibitor with various combinations of BMP and FGF. Assessment of cardiomyogenic differentiation was made upon the expression of cardiomyocyte-specific genes using RT-PCR. Results: HAD that cultivated in control medium for 4 weeks after 5-azacytidine expose showed new expression of TnT gene and increased expression of Cmlc1 and kv4.3 genes. However, HAD cultivated in the presence of combinations of BMP-4/FGF-4 (B4/F4) and BMP-4/FGF-8 (B4/F8) showed new expression of $\beta$-MHC gene and more increased expression of Cmlc1, TnT, TnI, Kv4.3 genes. Significantly enhanced expression of Cmlc1, TnT, and Kv4.3 genes were also observed compared to that cultivated in the control medium. Treatment of HUC with either 5-azacytidine or combinations of BMP and FGF did not affect the expression profile of these genes. However, when activin A or TGF-$\beta$1 was present in addition to the BMP-2/FGF-8 (B2/F8) after 5-azacytidine exposure, HUC exhibited new expression of $\beta$-MHC gene and increased expression of $\alpha$-CA, TnT and Kv4.3 genes. When Wnt inhibitor was present in addition to BMP and FGF, HUC showed new expression of Cmlc1 gene and increased expression of $\alpha$-CA, TnT, TnI and Kv4.3 genes. Conclusions: Based on these observations, it is suggested that HAD and HUC could differentiate into cardiomyocytes which might be used as therapeutic cells for the heart diseases.

• Journal of Korean Neurosurgical Society
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• v.61 no.6
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• pp.669-679
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• 2018

Objective : To compare the spinal bone fusion properties of activin A/BMP2 chimera (AB204) with recombinant human bone morphogenetic protein (rhBMP2) using a rat posterolateral spinal fusion model. Methods : The study was designed to compare the effects and property at different dosages of AB204 and rhBMP2 on spinal bone fusion. Sixty-one male Sprague-Dawley rats underwent posterolateral lumbar spinal fusion using one of nine treatments during the study, that is, sham; osteon only; $3.0{\mu}g$, $6.0{\mu}g$, or $10.0{\mu}g$ of rhBMP2 with osteon; and $1.0{\mu}g$, $3.0{\mu}g$, $6.0{\mu}g$, or $10.0{\mu}g$ of AB204 with osteon. The effects and property on spinal bone fusion was calculated at 4 and 8 weeks after treatment using the scores of physical palpation, simple radiograph, micro-computed tomography, and immunohistochemistry. Results : Bone fusion scores were significantly higher for $10.0{\mu}g$ AB204 and $10.0{\mu}g$ rhBMP2 than for osteon only or $1.0{\mu}g$ AB204. AB204 exhibited more prolonged osteoblastic activity than rhBMP2. Bone fusion properties of AB204 were similar with the properties of rhBMP2 at doses of 6.0 and $10.0{\mu}g$, but, the properties of AB204 at doses of $3.0{\mu}g$ exhibited better than the properties of rhBMP2 at doses of $3.0{\mu}g$. Conclusion : AB204 chimeras could to be more potent for treating spinal bone fusion than rhBMP2 substitutes with increased osteoblastic activity for over a longer period.