• Clinical and Experimental Reproductive Medicine
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• v.35 no.1
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• pp.39-48
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• 2008

Objective: The aim of this study was to investigate whether multipotent germline stem cells (MGSCs) can be established from neonatal mouse testis. Methods: Various cells containing MGSCs were collected from neonatal testis of ICR mice and allocated to plates for in vitro culture. After 7 days in culture, the cells were passed to a fresh culture plate and continuously cultured. From the third or fourth passage, the presumed MGSCs were cultured and maintained on mitomycin C-inactivated STO feeder cells. The MGSCs were cultured in a condition where mouse embryonic stem cells (ESCs) are cultured. Characteristics of the MGSCs were evaluated by RT-PCR, immunocytochemistry, alkaline phosphatase activity, karyotyping, and transmission electron microscopy. Results: Two MGSCs lines were established from 9 pooled sets of neonatal testicular cells. MGSCs colonies were morphologically undistinguishable from ESCs colonies and both MGSC lines as well as ESCs expressed undifferentiated stem cell markers, such as Thy-1, Oct-4, Nanog, Sox2 and alkaline phosphatase. Fine structure of undifferentiated MGSCs were similar to those of ESCs and 60% of MGSCs (12/20) had normal karyotype at passage 10. They were able to form embryoid bodies (EBs) and MGSC-derived EBs expressed marker genes of three germ layers. Conclusion: We could establish the MGSCs from neonatal mouse testis and they were differentiated to multipotent lineages of three germ layers. Molecular characteristics of MGSCs were similar to those of ESCs. Our results suggest a possibility that multipotent stem cells derived from testis, the MGSCs, could replace the ESCs in biotechnology and regenerative medicine.

• Journal of Embryo Transfer
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• v.24 no.3
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• pp.189-197
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• 2009

Two-pore domain $K^+(K_{2P})$ channels contribute to setting the resting membrane potential in excitable and nonexcitable cells. However, the cellular or tissue distribution and function of $K_{2P}$ channels expressed in mammalian germ cells and reproductive organs have not yet been reviewed by researchers. In this review, we focus on expression, localization and expected properties of $K_{2P}$ channels in germ cells and reproductive organs. The $K_{2P}$ channels are expressed in human cytotrophoblast cells, myometrium, placental vascular system, uterine smooth muscle, and pregnant term tissue, suggesting that $K_{2P}$ channels might be involved in the processes of pregnance. The $K_{2P}$ channels are also expressed in mouse zygotes, monkey sperm, ovary, testis, germ cells, and embryos of Korean cattle. Interestingly, $K_{2P}$ channels are modulated by changes in temperature and oxygen concentration which play an important role in embryonic development. Also, $K_{2P}$ channels are responsible for $K^+$ efflux during apoptotic volume decreases in mouse zygotes. These expression patterns and properties of the $K_{2P}$ channels in reproductive organs and germ cells are likely to help the understanding of ion channel-related function in reproductive physiology.

• Clinical and Experimental Reproductive Medicine
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• v.25 no.3
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• pp.299-304
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• 1998

Despite the rapid development of assisted reproductive technologies (ART) in recent years, implantation rates after replacement of embryos into the uterine cavity remains low. Several techniques such as culture conditions based on formulations of human tubal fluid and various ART techniques as GIFT, ZIFT, TET have been adopted in recent years to improve embryo viability in vitro and implantation rates. Also, coculture of human IVF-derived embryos have been used in an effort to increase the number of viable embryos following IVF and to improve synchrony between the developing embryo and the uterine environment. The aim of this study was to evaluate whether the use of co culture with autologous cumulus cells has a significant beneficial effect on the development of embryos in vitro and its relation to the pregnancy rates in 120 patients with previous failed IVF-ET from September, 1995 to January 1998. We obtained the results from which significant improvement in the quality of viable embryos were observed using a coculture system with autologous cumulus cells, but pregnancy rates in this group of patients did not differ from the rate in the standard IVF group during the same period. Our study shows that a simplified short-term coculture system with autologous cumulus cells may help rescue moderate quality embryos to cleave regularly.

• Clinical and Experimental Reproductive Medicine
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• v.48 no.3
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• pp.189-193
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• 2021

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel coronavirus found in China in 2019. The disease caused by SARS-CoV-2, coronavirus disease 2019 (COVID-19), has been found to be closely related to the cells that secrete angiotensin-converting enzyme 2 (ACE2). ACE2 is involved in the renin-angiotensin system and is widely secreted in several tissues, including the testis, which has raised concerns because organs with high expression of the ACE2 receptor are susceptible to infection. Analyses have shown that in testicular cells, such as spermatogonia, seminiferous duct cells, Sertoli cells, and Leydig cells, there is a high expression level of ACE2. Therefore, SARS-CoV-2 may damage male reproductive tissues and cause infertility. Since male infertility is an important problem, scientists are evaluating whether COVID-19 may influence male infertility through the ACE2 receptor.

• Toxicological Research
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• v.14 no.2
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• pp.193-203
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• 1998

The toxicity of DA-125. a new anthracycline anticancer agent, on the male reproductive system was studied in Sprague-Dawley rats. Forty male rats were rando$m\ell$y assigned to Jour groups with ten rats in each group and given single intraveneous doses of DA-125 at dose levels of 0. 12.5. 25. and 50 mg/kg body weight. On day 56 after treatment the animals were allowed to mate. and their male reproductive Junctions and organs were examined in detail. Copulated females were sacrificed on day 20 of gestation for examination of embryo-fetal development. One out of ten rats in the 50 mg/kg group died on day 12 after treatment. Clinical signs such as emaciation. sedation, anorexia. swelling. dark material around eye. alopecia. and diarrhea were observed in the 25 and/or 50 mg/kg groups. Reduction in the body weight gain. decrease in the absolute weights of testes. epididymis and seminal vesicles. and/or decrease in the number of testicular sperm heads were also found. Although histopathological changes such as atrophy of seminiferous tubules. loss or decrease of spermatogenic cells. exfoliation of spermatogenic cells. vacuolization of Sertoli cells. decrease of sperm. and/or increase of necrotic spermatogenic cells in epididymal ducts were observed. no adverse effects on the motility and morphology of epididymal sperm. copulation index. fertility index. and embryo-fetal development were detected in the 25 and 50 mg/kg groups. There were no evidences of male reproductive toxicity in the 12.5 mg/kg group. These results show that single intravenouse doses of DA-125 produce significant dose-related testicular atrophy. histopathological changes. and oligozoospermia in rats and $LD_{10}$ for DA-125 appears to be 50 mg/kg body weight.

• Clinical and Experimental Reproductive Medicine
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• v.34 no.1
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• pp.1-9
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• 2007

• Clinical and Experimental Reproductive Medicine
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• v.29 no.1
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• pp.13-20
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• 2002

Objective: This study was carried out to establish the effectiveness of the vitrification method and the optimal cryoprotectants in the cryopreservation of human embryonic stem cells (ESC). Materials and Methods: Human ESC clumps established at Seoul National University Hospital (SNUhES 1) were cryopreserved with the vitrification method using the EM grid. EDS and EFS40 were used as vitrification solutions. Results: Between the EDS and EFS40 groups, there was no significant difference in the recovery rate after cryopreservation of human ESC. The formation rates of ESC colonies in the vitrified groups were significantly lower than those in the control ESC group (p<0.05, p<0.05). In addition, the formation rate of ESC colonies in the EDS group was significantly higher than that in the EFS40 group (p<0.05). The ESC colonies in the vitrified groups were significantly smaller after culture duration of 2 and 4 days, respectively, compared with the control ESC group (p<0.1, p<0.05). However, these effects could be reduced to nonsignificant level by the additional culture of ESC colonies. The vitrified human ESC retained the properties of pluripotent cells, including the expression of cell surface. markers for the undifferentiated cells such as alkaline phosphatase and SSEA-4 (stage-specific embryonic antigen-4), and the expression of transcription factor Oct-4 (octamer-binding transcription factor-4), and the normal karyotype. Conclusion: The vitrification method using the EM grid and EDS solution was confirmed to be very effective for the cryopreservation of human ESC.

• 대한생식의학회:학술대회논문집
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• 2004.11a
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• pp.79-80
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• 2004

• 대한생식의학회:학술대회논문집
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• 2004.11a
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• pp.74-75
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• 2004

• 대한생식의학회:학술대회논문집
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• 1994.10a
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• pp.31.2-32
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• 1994