• Journal of Embryo Transfer
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• v.17 no.3
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• pp.179-185
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• 2002

This study was performed to investigate the effect of different cryoprotectants and superoxide dismutase(SOD) on viability of frozen-thawed oocytes by vitrification method in the pig. The proportions of oocytes matured to metaphase-I stage were higher in medium with ethylene glycol and DMSO(19.9%) than in medium with glycerol and DMSO(6.5%). When the oocytes were exposed in medium containing ethylene glycol, oocyte matured to prophase-I were not observed. On the other hand. significant differences were not observed between in medium with and without SOD( 1 unit/$m\ell$) during IVM of vitrified and thawed immature oocytes. However, the maturation rate from metaphase-I to metaphase-II were higher in medium with that than without SOD. The penetration rates after IVF of oocytes frozen-thawed were also higher in medium with that than without SOD. These results indicate that frozen-thawed oocytes treated with ethylene glycol and DMSO was more protective against freezing effect and that addition of 1 unit/$m\ell$ SOD in medium fur prevent of lipid peroxidation may play a positive role in improving of viability of frozen-thawed oocytes.

• Journal of Embryo Transfer
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• v.17 no.1
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• pp.55-59
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• 2002

The objective of this study is to determine the developmental competence of in vitro matured bovine oocytes after intracytoplasmic sperm injection(ICSI) with frozen-thawed epididymal spermatozoa. The ovaries were obtained from slaughtered Korean native cows. Oocytes matured in vitro for 24 hrs were fertilized by ICSI with frozen-thawed epididymal spermatozoa. After ICSI, a group of oocytes was activated with 7% ethanol fur 5 min, and the other group was not activated. The oocytes were cultured in TCM-199 medium containing hormones and 10% FCS for 24~30 hrs in a incubator with 5% $CO_2$ in air at 38.5$^{\circ}C$. The percentage of oocytes reaching M II after 24 hrs and 30 hrs of incubation were significantly higher(p<0.05) after culture with TCM-199 media(80.0% and 88.3%) than M I(8.3% and 6.7%). The rate of cleavaged embryos to blastocyst obtained by ICSI treated activation oocytes was significantly higher(p<0.05) than that of nonactivation oocytes(22/46, 47.8% vs 10/39, 25.6%). The rates of embryos development to blastocyst obtained by ICSI treated sperm of flesh, epididymal and frozen-thawed epididymal were 24/45(53.3%), 15/40(37.5%), 11/43(25.6%), respectively and these values of fresh sperm injection were higher than frozen-thawed epididymal sperm. We also concluded that embryos can be produced with ICSI of in vitro matured oocytes by ICSI using frozen-thawed epididymal semen.

• Clinical and Experimental Reproductive Medicine
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• v.27 no.1
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• pp.59-65
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• 2000

Objective: The purpose of this study was to determine the important factors affecting survival and pregnancy rate in frozen-thawed embryo transfer cycles. Methods: we performed retrospective analysis in 738 cycles of frozen-thawed embryo transfers, in relation to the insemination methods, the freezing stage of embryo, patient's age, infertility factors and the origin of injected sperm in ICSI cycles. After conventional IVF or ICSI, the supernumerary PN stage zygotes or multicellular embryos were cryopreserved by slow freezing protocol with 1,2-propanediol (PROH) as a cryoprotectant. Results: The survival rates of thawed embryos were 69.3% (1585/2287) in conventional IVF group and 71.7% (1645/2295) in ICSI group. After frozen-thawed embryo transfers, 27.0% (92/341) and 32.0% (109/341) of pregnancy rates were achieved in conventional IVF and ICSI group, respectively. There were no significant difference in the survival and pregnancy rates according to the insemination methods, the freezing stage and patient's age. However, the pregnancy rate (36.2%) of male factor infertility was significantly higher than the tubal (27.2%) and other female factor infertility (22.9%). In ICSI group, the origin of injected sperm did not affect the outcome of frozen-thawed embryo transfer cycles. Conclusion: The present study demonstrates that acceptable clinical outcomes can be achieved after the transfer of frozen-thawed embryos regardless of the stage of embryos for freezing, the patient's age and the origin of injected sperm.

• Korean Journal of Animal Reproduction
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• v.21 no.4
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• pp.355-362
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• 1997

This study was undertaken in an effort to product embryos through in vitro maturation(IVM), in vitro fertilization(IVF) and in vitro culture(IVC) after cryopreservation of immature and mature porcine oocytes. The experiments were conducted to investigate IVM rate of oocytes frozen with 3 different cryoprotectants and to examine IVF and IVC of frozen-thawed oocytes. The CEI(cumulus cells expansion index) after IVM of frozen-thawed immature oocytes was higher in oocytes frozen with PG＋PEG(propylene glycol plus polyethylene glycol) than those frozen with single cryoprotectant and this index was almost 90% of unfrozen oocyte's index(2.39 vs. 2.66). The IVF rate of all frozen oocytes was very low(68% of unfrozen oocytes) and the IVF rate of frozen immature oocytes was slightly higher than that of frozen mature oocytes(39.0% vs. 34.4%), but polyspermic penetration was higher in frozen immature oocytes(21.9% vs. 19.1%). The cleavage rate after IVF of frozen-thawed oocytes was 9.3% for frozen mature oocytes and 11.3% for frozen immature oocytes and this rate was significantly lower(P<0.05) than that of control(60.7%). The development to 8-cell stage was greatly lower in frozen mature oocytes than in frozen immature oocytes. The results indicate that the use of PG plus PEG as cryoprotectant may be very effective for vitrification of porcine oocytes and the frozen-thawed immature porcine oocytes can be used fro in vitro embryo production based on IVM, IVF and IVC system.

• Korean Journal of Animal Reproduction
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• v.19 no.1
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• pp.49-54
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• 1995

This experiments were carried out to investigate the viabilities and the pregnancy rate of frozen-thawed IVF bovine embryos in various media, cryoprotectants and age of embryos produced. Hanwoo oocyte were collected in size of 2~7mm follicles, matured for 20~22hrs at 38.5$^{\circ}C$ in 5% CO2 incubator and then in vitro fertilized with Hanwoo semen. Blastocysts or more developed embryos at Day 7, 8 and 9 were frozen in 1.5 or 1.8M ethylene glycol. Viability of frozen thawed IVF embryos were identified the reformation of blastocoele after thawing and culture for 24~48 hours at 38.5$^{\circ}C$ in 5% CO2 incubator. Production rate of Hanwoo IVF embryos in TCM 199 and CR1aa ws 21.3%(39/183) and 28.1%(41/146), respectively. The viability of frozen thawed IVF embryos was higher rate in 1.8M ethylene glycol and Day 7 embryos than that in 1.5M and Day 8.53 cows out of 100 Hanwoo receipients transfered IVF embryos were pregnant and twin production rate was 26.3%.

• Korean Journal of Animal Reproduction
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• v.15 no.2
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• pp.97-101
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• 1991

This study was carried out to investigate the survival rate of in vitro culture after frozenthawed, to used DMSO(dimethyl sulfoxide), glycerol and ethylene glycol of cryorpotective agents at the zona pellucida removed and intact on the morulae and blastocysts. The results obtained from this study were as follows : 1. The survival rate of in vitro culture after frozen-thawed to used cryoprotective agents of three kinds at the morulae was 86.0%, 87.1% and 83.3%, total or mean were 85.5%, respectively. 2. The survival rate of in vitro culture after frozen-thawed to used cryoprotective agents of three kinds at the zona pellucida removed morulae was 53.2%, 42.3% and 37.5%, total or mean were 44.3%, respectively. 3. The survival rate of in vitro cultrue after frozen-thawed to used cryoprotective agents of three kinds at the blastocysts was 89.4%, 86.2%, total or mean were 86.7%, respectively. 4. The survival rate of in vitro culture after frozen-thawed to used cryoprotective agents of three kinds at the zona pellucida removed blastocysts was 55.8%, 51.6% and 40.6%, total or mean were 49.3%, respectively.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.4
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• pp.500-503
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• 2002

This study was carried out to investigate the effects of season influencing semen characteristics, frozen-thawed sperm viability and testosterone concentration in Duroc boars. There were no significant differences in the semen volume and sperm concentration of Duroc boars among spring, summer, autumn and winter. However, the pH of sperm-rich and sperm-poor fractions in autumn and winter season was higher than in spring and summer season in Duroc boars. Sperm motility and normal acrosome of raw semen in Duroc boars did not differ significantly among spring, summer, autumn and winter. However, motility and normal acrosome of frozen-thawed sperm were higher in spring season than in summer, autumn and winter. Serum testosterone concentrations in Duroc were higher in spring than summer, autumn and winter. In conclusion, when serum testosterone concentrations were higher in seasons, frozen-thawed sperm viability in Duroc boars were higher.

• Food Science of Animal Resources
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• v.18 no.2
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• pp.142-148
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• 1998

This study was conducted to investigate the quality change of beef muscle, which was thawed by different thawing rate in order to utilize it as fundamental data for establishing optimal and thawing condition. Chilled beef round which was purchased at a commercial market was used. The samples were frozen for 30min(time required to pas through the maximal ice forming zone, -1$^{\circ}C$∼-7$^{\circ}C$) and the thawing conditions were 3.9cm/hr, 0.21cm/hr, 0.13cm/hr. Thawing losses of rapidly thawed meat(3.9cm/hr) were significantly(p＜0.05) lower(6.10%), but cooking and total losses were the highest as 48.17% and 56.44%, respectively(p＜0.05). Characteristics such as color, flavor, texture and overall quality at different the thawing rates showed similar scores, but slightly increased after storage for 24hr. Juiciness of rapidly thawed meat was significantly(p＜0.05) higher than that compared to the other thawing rates.

• Clinical and Experimental Reproductive Medicine
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• v.17 no.2
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• pp.129-135
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• 1990

This study was done to verify factors affecting viability after cryopreservation and pregnancy rate after frozen-thawed embryo transfer into uterus. Embryos were cryopreserved slow freezing and slow thawing and used DMSO as cryoprotectant. The results were to follows. 1. Viability of frozen-thawed embryos were 75.5% (94/105), which compared with viability of embryos according to cell stage, $2{\sim}5$ cell was 68.4% and $6{\sim}16$ cell 80.4% were significant differences (p<0.05). 2. No significant difference in duration of cryopreservation on effects affecting pregnancy rate was observed. 3. Number of embryo transfered into uterus was significant differences (p<0.05). 4. Four pregnancies resulted following replacement of 35 frozen-thawed.

• Journal of Embryo Transfer
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• v.14 no.3
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• pp.163-169
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• 1999

This study was carried out to investigate the effect of co-culture system(bovine oviduct epithelial cells; BOEC) and defined culture system(modified TALP ; mTALP) on the development of IVM-IVF embryos, and survival of in vitro produced blastocysts after freezing and thawing. Occytes from the slaugheterhous ovaries were matured and fertilized using general protocol. The results obtained were as the following: 1. Survival rates of frozen-thawed blastocysts using 10% glycerol as cryoprotectant was higher in day 7 blastocysts than in Day 8 and 9 blastocysts from co-cultrue system, but survival rate of frozen-thawed blastocysts was higher in Day 10 blastocysts than in day 8 and 9 blastocysts from defined culture system. Regardless of their age, survival rate of frozen-thawed blastocysts was significantly higher (p<0.05) in co-culture system than in defined culture system. 2. The cell number of blastocysts was significanlty higher (p<0.05) in Day 7 blasotcysts than in Day 8 and 9 blastocysts from co-cultures, but the cell number of blsstocysts was significantly higher (p<0.05) in Day 10 blastocysts than in Day 8 and 9 blastocysts from defined culture system. Regardless of the culture system, blastocysts with higher cell number showed higher survival rates after freezing and thawing.