• Clinical and Experimental Reproductive Medicine
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• 제43권2호
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• pp.133-138
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• 2016

Objective: To determine the incidence of embryo retention (ER) in the transfer catheter following embryo transfer (ET) in blastocyst transfer and investigate whether retransferring retained embryos has an impact on reproductive outcomes in patients undergoing in vitro fertilization-ET. Methods: We retrospectively analyzed the records of 1,131 blastocyst transfers, which comprised 223 single blastocyst transfer (SBT) and 908 double blastocyst transfer (DBT) cycles. Each SBT and DBT group was classified depending on whether ET was performed without retained embryos in the catheter during the first attempt (without-ER group) or whether any retained embryos were found following ET (ER group) for the purpose of comparing reproductive outcomes in a homogenous population. Results: The overall incidence of finding retained embryos was 2.8% (32/1,131). There were no retained embryos in SBT cycles. In DBT cycles, implantation rates (30.0% vs. 26.6%), positive ${\beta}-hCG$ rates (57.2% vs. 56.2%), clinical pregnancy rates (45.3% vs. 46.9%), and live birth rates (38.9% vs. 43.8%) were not significantly different between the without-ER and ER groups. There were no significant differences in the mean birth weight (g) $2,928.4{\pm}631.8$ vs. $2,948.7{\pm}497.8$ and the mean gestational age at birth ($269.3{\pm}17.2days$ vs. $264.2{\pm}25.7days$). A total of nine cases of congenital birth defects were found in this study population. Eight were observed in the without-ER group and one in the ER group. Conclusion: Our results suggest that retransfer of retained embryos does not have any adverse impact on reproductive outcomes in blastocyst transfer cycles. Furthermore, our results support finding that SBT might be advantageous for decreasing the incidence of retained embryos in catheters.

• Asian-Australasian Journal of Animal Sciences
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• 제22권7호
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• pp.962-968
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• 2009

The aim of this study was to compare the effects of oviductal fluid, porcine zygote medium (PZM)-3, PZM-4 and PZM-5, and modified PZM-5 culture media, and determine the effects of zona pellucida (ZP) removal on the development of nuclear transfer (NT) embryos. There were no significant differences in the rates of fusion and cleavage among the five different oviductal fluid concentrations. However, the rates of blastocyst formation and the cell numbers per blastocyst were high in the embryos at the 14 and 28 $\mu{g}$/ml concentrations of oviductal fluid compared to the 0, 56 and 100 $\mu{g}$/ml concentrations. The rates of cleavage and blastocyst formation, and the cell numbers per blastocyst were higher in the PZM-3, PZM-5 and modified PZM-5 media than in the PZM-4 medium. However, there were no significant differences in the fusion rates of oocytes among the four culture media. The cell numbers per blastocyst in the embryos without ZP were significantly greater than those with ZP. However, there were no significant differences in the rates of fusion, cleavage and blastocyst formation between the embryos with and without ZP. In conclusion, we improved blastocyst development and the quality of NT embryos by replacing PVA with 3 mg/ml of BSA in PZM-5 medium and supplementing the PZM-5 medium with 14 $\mu{g}$/ml oviductal fluid. The NT embryos produced by the zona-free NT method had a high rate of blastocyst formation in the modified PZM-5 medium.

• Clinical and Experimental Reproductive Medicine
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• 제39권3호
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• pp.114-117
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• 2012

Objective: It is well known that fresh blastocyst transfer results in better pregnancy outcomes with a smaller number of transferred embryos compared with cleavage stage embryo transfer. However, in terms of frozen-thawed blastocyst transfer, only a few studies are available. We aimed to evaluate clinical outcomes of frozen-thawed embryo transfer (FET) with blastocysts. Methods: Retrospective analysis of FET cycles with blastocysts (B-FET) between Jan 2007 and June 2009 was performed. Age-matched FET cycles with cleavage stage embryos (C-FET) during the same period were collected as controls. A total of 58 B-FET cycles were compared with 172 C-FET cycles and also compared with those of post-thaw extended culture blastocysts from frozen pronuclear stage embryos (22 cycles). Results: There was no difference in the patient characteristics of each group. The embryos' survival rates after thawing were comparable (>90%) and there was no difference in the implantation rate or clinical and ongoing pregnancy rate among the three groups. Conclusion: In FET, blastocyst transfers may not present better pregnancy outcomes than cleavage stage embryo transfers. A further large-scale prospective study is needed.

• Clinical and Experimental Reproductive Medicine
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• 제43권1호
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• pp.31-37
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• 2016

Objective: The aim of this study was to investigate associations between the morphology score of blastocysts and blastocoele re-expansion speed after warming with clinical outcomes, which could assist in making correct and cost-effective decisions regarding the appropriate time to vitrify blastocysts and to transfer vitrified-warmed blastocysts. Methods: A total of 327 vitrified-warmed two-blastocyst transfer cycles in women 38 years old and younger were included in this retrospective study. Results: The clinical pregnancy rate (CPR) and implantation rate (IR) of transfers of two good-morphology grade 4 blastocysts vitrified on day 5 (64.1% and 46.8%, respectively) were significantly higher than the CPR and IR associated with the transfers of two good-morphology grade 3 blastocysts vitrified on day 5 (46.7% and 32.2%, respectively). No significant differences were found in the CPR and IR among the transfers of two good-morphology grade 4 blastocysts regardless of the day of cryopreservation. Logistic regression analysis showed that blastocoele reexpansion speed after warming was associated with the CPR. Conclusion: The selection of a good-morphology grade 4 blastocyst to be vitrified could be superior to the choice of a grade 3 blastocyst. Extending the culture of grade 3 blastocysts and freezing grade 4 or higher blastocysts on day 6 could lead to a greater likelihood of pregnancy. Since re-expansion was shown to be a morphological marker of superior blastocyst viability, blastocysts that quickly re-expand after warming should be prioritized for transfer.

• 한국수정란이식학회지
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• 제5권2호
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• pp.38-44
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• 1990

This study was carried out to produce superior dairy cattle by embryo transfer. Seven dairy cows were superovulated with divided injection of FSH 4Omg for 5 days started on day 9 to 14 of the estrus cycle and injection of PGF$_2$$\alpha$ 45mg on day 4 of FSH injection. Donor cows were flushed to collect embryos on day 7 or 8 of the estrus cycle. Fresh embryos collected were transferred to synchronized dairy recipients or frozen using glycerol 3 step method to he equilibrated. And 35 embryos which were frozen using glycerol 6 step method were imported from U.S.A. After glycerol dilution of frozen embryos was done by reverse density during freezing. frozen-thawed embryos were transferred to synchronized dairy or beef recipients. The results obtained were as follows; 1. Total of 24 embryos were collected from 7 donor cows flushed and transferable embryos were 18 (75.0%). 2. Among 24 embryos. morula, early blastocyst, blastocyst, expanded blastocyst and unfertilized ova were 3 (12.5%), 1 (4.2%), 10 (41.6%), 4 (16.7%) and 6 (25.0%), respectively. 3. Heat inducing rate after 1st and 2nd injections of PGF$_2$$\alpha$ in Holstein and beef cattle was 83.3% and 71.4% and 62.5% and 69.2%, respectively. 4. Among 56 recipients, 23 head were pregnant (41.1%). The pregnancy rate of fresh embryos was 50.0% (1/2 heads) and the pregnancy rate of frozen embryos which were frozen using glycerol 3 step and using glycerol 6 step imported from U.S.A. was 52.6%(l0/19 heads) and 34.3%(12/35 heads), respectively. 5. The pregnancy rate of blastocyst (60.0%) was higher than that of morula (39.0%), early blastocyst (25.0%) and expanded blastocyst (0%). 6. The pregnancy rate of grade I embryos (52.2%) was higher than that of grade 2 (34.6%) and grade 3 (28.6%). 7. The pregnancy rate according to synchrony of recipient with donor was higher in simultaneous recipient (55.0%) and +l2hrs' (53.8%) than -24hrs' (23.5%), -l2hrs' (20.0%) and +24hrs' (0%).

• Clinical and Experimental Reproductive Medicine
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• 제27권1호
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• pp.75-81
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• 2000

Objective: The objective of this study is to influence of sequential embryo transfers in an invitro fertilization was examined. Method: After in vitro fertilization, a maximum of 6 fertilized oocytes was enrolled in this study. At day 3 after an oocytes retrieval, embryos with good quality were transferred (mean 4.9), remaining embryos (mean 2.0/cycle) were cryopreserved at blastocyst stage (Group 1). At day 5 after oocytes collection, second a embryo transfer (mean 1.2/cycle) was performed, if one of these embryos had reached the blastocyst stage (Group 2) using P1 supplemented with 10 SSS and 30% Follicular fluid. No statistical difference in the pregnancy rate could be seen between the group without a second embryo transfer (n=21; 28.6%) and the group with a second transfer (n=52; 28.8%). Results: The incidence of multiple pregnancy rate per embryo transfer was not statistically different between both group and no high-rank multiple pregnancy (greater than triplete) were observed (0.9%, 15.4%, respectively, p=0.74, ${\chi}^2$). Out of 114 cycles (506 embryos) cultured embryos in group 2, 52 cycles (159 embryos, 29.8%) reached the blastocyst stage. Conclusion: The second transfer did not have a significant effect on the pregnancy rate. The most important factor for the pregnancy seems to be the quality of the embryos transferred on day 3 following oocyte retrieval. We recommend embryo transfer is performed only one, day $2{\sim}3$ or D5.

• 한국수정란이식학회지
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• 제11권3호
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• pp.217-223
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• 1996

This study was conducted to investigate the effects of co-culture for the development rate to morula /blastocyst stages of early porcine embryos, derived from oocytes matured and fertilized in vitro, with porcine endometrial cell monolayers(PEM) in the two different media, respectively. The rates of embryos developed to 2-, 4-, 8~16-cell and morula /blastocyst stage were 49.6, 40.5, 28.2 and 15.3% in Ham's F-10 with PEM, and 55.3, 45.9, 32.7, and 17.6% in TCM-HEPES with PEM, respectively. The above development rates to morula /blastocyst stages were significantly higher than those of the embryos cultured in the Ham's F-10 and TGM-HEPES without PEM(P<0.05). The in vitro development rates to the morula /blastocyst stage of 1-cell embryos cultured in Ham's F-10 and TCM-HEPES without PEM were 0~1.2%. Especially, most of embryos were observed to arrest the development beyond 4-cell stages. As shown in the above results, the co-culture of in vitro produced porcine embryos with PEM in the two different media enhanced the development of fertilized eggs to morula /blastocyst stages in vitro. However, we didn't find out any differences for the in vitro development to morula /blastocyst stages between Ham's F-10 and TcM-HEPES media.

• 한국수정란이식학회지
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• 제18권3호
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• pp.237-242
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• 2003

본 연구에서는 소에 있어서 수정란 이식을 다각적으로 분석하고 개선하기 위해 이식한 결과를 비교 검토하였고 그 결과는 다음과 같다. 1. 채란된 한우 난포란을 이용하여 생산된 체외수정란을 서로 다른 지역별로 이식한 바 B지역(경주)에서는 106의 수란우에 이식하여 51두(48.1％)가 수태하였고, A지역(김천) 수태율(33.8％)과 D 지역(경산) 수태율(35.3％)보다 유의하게 높았지만, C 지역(탑리)에서는 유의차가 존재하지 않았다. 따라서, 수정란이식에 있어서 이식 지역과 사육 환경, 시술자의 숙련도에 따라 수태율이 달라질 수 있다는 것을 알 수 있었다. 2. 수란우의 산차에 따른 수태율은, 미경산우 42.9％로서 경산우의 36.6％에 비해 다소 높은 수태율을 보였으나 유의적인 차이는 인정되지 않았다(P<0.05). 3. 이식 수정란의 발육단계는 중기 배반포 또는 후기 배반포로서 구분하여 수란우에 이식하였다. 중기 배반포가 45.5％, 후기 배반포 41.0％로서 중기 배반포가 후기 배반포보다 높은 수태율을 나타내었지만 유의한 차이는 인정되지 않았다. 배반포기가 생성된 날짜에 따른 수란우의 수태율은 7일째 생성된 배반포 이식시 수태율은 43.8％, 8일째 생성된 배반포 이식시 수태율은 32.9％, 9일째 생성된 배반포 이식시 수태율은 20.0％로서 7일째 배반포의 수태율 이 다른 두 처리군보다 수태율은 높았지만, 유의차는 인정되지 않았다.

• 한국수정란이식학회지
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• 제31권2호
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• pp.131-136
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• 2016

Since the first success of animal cloning, somatic cell nuclear transfer presented various ideas in many research areas such as regenerative medicine. However, SCNT embryos has poor survival rate. Therefore, numerous researches carried out to enhance the developmental capability of porcine nuclear transfer embryos. Cytochalasin B, demecolcine, latrunculin A, cycloheximide and 6-dimethylaminopurine are efficient chemicals treated in post-activation procedure to increase the efficiency of SCNT. This review study is aim to investigate the effects of these chemicals applied to post-activation in porcine SCNT. Cytochalasin B, demecolcine, latrunculin A are cytoskeletal manuplators inhibit extrusion of pseudo-polar body. Cytochalasin B and demecolcine showed considerably higher blastocyst formation proportion (26-28%) compared to when they are not treated (16%). And when latrunculin A was treated for postactivation, blastocyst formation proportion was increased in SCNT embryos exposed to LA (38%) than those in control (14%). On the other hand, cycloheximide and 6-dimethylaminopurine are protein synthesis and kinase inhibitors. And they help to maintain $Ca^{2+}$ fluctuation in oocytes. Cleavage and blastocyst rates of NT embryos were increased when they were exposed to CHX (16.9% and 5.4% with no CHX).And 6-DMAP also showed higher blastocyst formation (21.5% compared to 15.7%, control). Although all these chemicals have different mechanisms, they showed developmental competence enhancement in NT embryos. However, there are only few studies comparing each chemical's post-activation effect. Therefore, further research and study should be conducted to find optimal chemical for improving the efficiency of SCNT.

• 한국수정란이식학회지
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• 제20권2호
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• pp.89-95
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• 2005

본 연구에서는 한우 체외수정란의 이식에 있어서 수정란 측 요인들이 수란우의 임신과 유산에 미치는 영향을 검토하였다. 이식에 제공하는 배반포의 수량에 따른 임신율은 1개, 2개 및 3개 이식 군에서 각각 32, 44 및 $32\%$였고, 유산율은 $6.3\~13.6\%$로서 2개 이식군의 임신율과 유산율이 가장 높았으나 유의차는 인정되지 않았다. 배반포 등급에 따른 임신율은 $40.8\~44.2\%$, 유산율은 $9.4\~16.3\%$로서 유사한 경향이었다. 배반포의 발생 단계에 따른 임신율은 $39.1\%\~45.3\%$로서 비슷하였으나, 유산율은 HB군$(20.8\%)$이 LB군의 $9.0\%$에 비해서는 유의하게 높았다(p<0.05). 배반포의 발생일령에 따른 임신율은 배반포 $7\cdot7$일째와 $7\cdot8$일째가 각각 $47.1\%$와 $53.9\%$로서 $9\cdot9$일 및 $8\cdot9$일째(29.8 및 $R27.7\%$)에 비해 유의하게 높았다(p<0.05). 유산율은$8\cdot9$일령이 $30.8\%$로 가장 높았고 $7\cdot7$일령의 $10.1\%$와는 유의차가 인정되었다.