• Journal of Embryo Transfer
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• v.15 no.1
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• pp.15-21
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• 2000

These studies were undertaken to evaluate morphological normality and development competence in vitro of hyman oocytes following vitrificatioin using ethylene glycol and electron microscopic grid. Human immature oocytes retrieved from natural and stimulated cycles was vitrified at 0 or 48 h and 0, 8 to 15 or 24 to 28 h after maturation culture, respectively. In oocytes retrieved from unstimulated cycle, no signifciant differences were found in morphological normality (56 to 63%) and fertilization (31 to 37%) rates between the times of vitrification. In stimulated patients, however, more oocytes were morphologically normal when vitrified at 24 to 28 h than when vitrified at 0 or 8 to 15 h after maturation culture. Regardlesss of the hormonal stimulation, high cleavage rates(83 to 100%) were obtained in all treatment groups but did not differ significantly. Twenty to 43% of cleaved oocytes developed to the blastocyst stage at 6 days after IVF. These results suggest that vitrified oocytes from unstimulated and stimulated cycles could develop to the blastocyst stage, regardless of the stages of vitrification.

• Journal of Embryo Transfer
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• v.16 no.1
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• pp.1-5
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• 2001

A total of 92 unfertilized human oocytes were treated with ethanol (EtOH), calcium ionophore A23187 (CI) or electric pulse (EP) for activating pronuclear formation and subsequent development. In Experiment 1, there was a significant (P=0.0001) treatment effect on the activation of unfertilized oocytes. No spontaneous activation was occurred in the control, but activation treatments induced PN formation with various efficacy. More unfertilized oocytes (UFOs) were activated after EtOH or EP treatment than after CI treatment. EP was as effective (63.6 %) as EtOH, but fragmentation was observed in 43% of UFOs activated by EP. Proportion of UFOs that formed presumptive haploid PN (2 PNs+1 PB or 1 PN +2 PBs) was 33.3, 0 and 28.6% after EtOH, CI and EP treatments, respectively. In Experiment 2, a significant (P=0.0362) effect of immature oocytes (IOs) status on activation was fecund. IOs at the GVBD-MI oocytes had higher potential to form PN than those at the GV stage or with abnormal morphology (25 vs. 77.8%). The results of this study clearly demonstrated that the treatment of 10% ethanol for 5 min effectively induced the activation of UFOs. IOs could form pronucleus with high efficacy by ethanol treatment, as long as they grew beyond the GVBD stage.

• Reproductive and Developmental Biology
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• v.28 no.4
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• pp.235-240
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• 2004

In vitro maturation of denuded porcine immature oocytes can be enhanced by co-incubation with spermatozoa even before fertilization. This study was to determine whether the addition of spermatozoa into the culture medium could influence the nuclear maturation of porcine cumulus-enclosed germinal vesicle (GV) oocytes. Cumulus-oocyte complexes (COCs) were collected from follicles of 3- to 5-mm diameter. Porcine COCs were cultured in tissue culture medium containing spermatozoa. After 48 h culture, oocytes were examined for evidence of GV breakdown, metaphase I, anaphase-telophase I, and metaphase II. The proportion of oocytes reaching at metaphase II was significantly (P < 0.05) increased in the oocytes cultured in media containing spermatozoa compared to those in media without spermatozoa (52.3% vs 12.5%). No difference in the percentage of metaphase II was observed among the different periods of spermatozoa exposure and among the spermatozoa from different species. The proportion of oocytes reaching metaphase II was significantly different between high and low concentrations of spermatozoa. The present study suggests that manunalian spermatozoa contain a substance(s) that improves nuclear in vitro maturation of porcine cumulus-enclosed GV oocytes. Enhancing effect of spermatozoa for in vitro maturation of oocytes is a highly dose-dependent.

• Reproductive and Developmental Biology
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• v.29 no.4
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• pp.207-212
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• 2005

In the present study, we investigated the effects of genotypes on in vitro maturation and fertilization in porcine fresh/frozen-thawed oocytes. The porcine cumulus-oocyte complexes (COCs) were divided into four groups according to whether they were: (1) in vitro matured; (2) cryopreserved and in vitro matured; (3) in vitro fertilized and (4) cryopreserved, and in vitro fertilized. Maturation of porcine COCs was accomplished by incubation in NCSU23 medium. Immature oocytes were cryopreserved by Open Pulled Straws (OPS) method according to Vajta et al., (1998). Oocytes stained by Acetic-Orcein method were observed under the microscope. DNA extracted from the ovaries was analyzed by RAPD (random amplified polymorphic DNA) and SSCP (single strand conformational polymorphisrrt) method. The rates of oocytes maturation and fertilization were significantly high in AA genotype. The results indicated that in vitro maturation and fertilization in porcine fresh/frozen-thawed oocytes may be affected by genotypes in pigs.

• Clinical and Experimental Reproductive Medicine
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• v.13 no.1
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• pp.11-19
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• 1986

Follicular flxid (FF) and their matched oocytes were obtained from 58 follicles of 27 women who underwent an in vitro fertilization (IVF) procedure with ovarian hyperstimulation by clomiphene citrate(n=8), hMG(n=9),FSH/hMG(n=10). Follicular aspiration was performed 36 hours after human chorionic gonadotropin administration. The concentcation of androstendione (ADD), testosterone (T) was correlated with hyperstimulation regimens, the morphology of the oocyte-corona-cumulus complex (OCCC), oocyte fertilization, and the incidence of pregnancy after embryo transfer. The results were as follows. 1. According to hyperstimulation regimens, there was no significant differance in FF ADD and T concentrations of the similar morphology of OCCC. 2. In clomiphene-treated and FSH/hMG-treated cycles, FF ADD concentrations of preovulatory oocytes were 43.09${\pm}$9.53 ng/ml and 59.46${\pm}$9.09 ng/ml, those of immature occytes were 96.98${\pm}$16.55 ng/ml and 116.13${\pm}$36.81 ng/ml, those of atretic oocytes were 246.5 ${\pm}$9.25 ng/ml and 634.25${\pm}$9.25 ng/ml respectively, reflecting the significant relationship between FF ADD level and morphologic maturity of OCCC (p<0.05). But in hMG-treated cycles, such relationship was not found (p>0.1). In clomiphene-treated and FSH/hMG-treated cycles, FF T concentrations of preovulatory oocytes were 11.37${\pm}$2.38 ng/ml and 11.68${\pm}$1.73 ng/ml respectively which were significantly lower than those of atretic oocytes (25.1${\pm}$7.50 ng/ml and 23.25${\pm}$0.95 ng/ml respectively) (p<0.05). But in all cycles, FF T concentrations of immature oocytes were not significantly different from those of preovulatory oocytes, artetic oocytes (p>0.1). 3. In hMG-treated and FSH/hMG-treated cycles, FF ADD concentrations of fertilized oocytes were 32.43${\pm}$4.09 ng/ml and 42.61${\pm}$4.82 ng/ml respectively which were significantly lower than those of non-fertilized oocytes (72.18${\pm}$17.31 ng/ml and 108.09${\pm}$17.32 ng/ml respectively) (p<0.05), but in clomiphene-treated cycles there was no significant difference (p>0.1). In FSH/hMG-treated cycles, FF T concentration of fertilized oocytes was 7.33${\pm}$1.06 ng/ml which was significantly lower than that of non-fertilized oocytes (20.3${\pm}$6.21 ng/ml) (p>0.02), but in clomiphne-treated and hMG-treated cycles there was no significant difference (p>0.1). 4. In all cycles FF ADD and T concentrations did not correlated with the success of pregnancy after embryo transfer. Above results suggested that FF ADD and T may play an important role in oocyte maturation and fertilization, but their relationship with the success of psegnancy was not found.

• Clinical and Experimental Reproductive Medicine
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• v.36 no.3
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• pp.175-186
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• 2009

Objective: We examined the effect of different culture media on oocyte maturation. Methods: Four groups of media, (1) 0.3% BSA mBASAL-XI-HTF, (2) 0.3% BSA mBASAL-XI-HTF with FSH, (3) 10% FBS mBASAL-XI-HTF and (4) 10% FBS mBASAL-XI-HTF with FSH were prepared. Mouse cumulus enclosed oocytes (CEOs) were incubated in each group of medium. Hypoxanthine (Hx) was mixed to each group of medium in increasing concentrations of 1 mM, 2 mM and 4 mM. CEOs were incubated and assessed for GVBD and MII development at 3, 6, 18 hours. Results: CEOs maturation to GVBD was seen in all four groups during 3 hours of culture, however MII stage of oocytes was seen after 6 hours. Complete arrest of GV stage in 4 mM Hx media without FSH and partial arrest in 2 mM Hx media without FSH were seen during 18 hours of culture but development was not suppressed in 1 mM Hx media without FSH. More prominent GVBD suppression was noted at early 3, 6 hours culture in 1 mM, 2 mM Hx media with FSH compared to media without FSH. But the suppression was recovered at 18 hours. This result suggests that low concentrated Hx and FSH supplemented media can suppress CEOs maturation during early culture period but recovery is resumed or even stimulated at late period. 1 mM, 2 mM Hx 10% FBS medium with FSH had significantly higher rates of MII development (71.7%, 66.7%) at 18 hours compared to other media. Conclusion: Our results show that low concentrated Hx and FSH supplemented 10% FBS media may stimulate MII development after an initial inhibitory effect.

• Journal of Embryo Transfer
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• v.18 no.1
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• pp.1-14
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• 2003

This study was conducted to investigate that the immature and mature oocytes of porcine can be cryopreserved by vitrification. Oocytes were centrifuged to polarize the cytoplasmic lipid droplets. The lipids were removed from cytoplasm by micromanipulation. Delipated oocytes were centrifuged after being preincubated with cytochalasin B(CB) fer 10 min, and lipid droplets were removed. Centrifuged oocytes were treated with CB and centrifuged to polorize lipid droplets but not delipated and control oocytes is not-treatment. Oocytes of three types were vitrified in electron microscope(EM) grids. The results of survival, maturation and cleavage rates were as follows. 1 The survival rates of immature oocytes were 15.1%, 0% and 0% in the Delipated, Centrifuged and Control after vitrification, respectively, and its rate of Delipated wassignificantly higher than Centrifuged and Control(P<.01). 2. The survival rates of mature oocytes were 12.21%, 0% and 0% in the Delipated, Centrifuged and Control after vitrification, respectively, and its rate of Delipated was significantly higher than Centrifuged and Control(P<.01). 3 The maturation rates of immature oocytes were 37.5% and 68.9% for metaphase II in the Delipated after vitrification and Non-vitrification, respectively, and its rate of Non-vitrification was significantly higher than Delipated after vitrification(P<.01). 4. The cleavage rates of immature oocytes were 12.5%, 0%, 0% and 56.1% in the Delipated, Centrifuged, Control after vitrification and Non-vitrification, respectively. It's rate of Delipated was higher than Centrifuged and Control, but there were no significant difference, and its rate of Non-vitrification was significantly higher than Delipated, Centrifuged and Control(P<.05). 5 The cleavage rates of mature oocytes were 25.0%, 0%, 0% and 67.9% in the Delipated, Centrifuged, Control after vitrification and Non-vitrification, respectively. It's rate of Delipated was higher than Centrifuged and Control, but there were no significant difference, and its rate of Non-vitrification was significantly higher than Delipated, Centrifuged and Control(P<.05).

• Clinical and Experimental Reproductive Medicine
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• v.39 no.4
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• pp.166-171
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• 2012

Objective: We compared the assisted reproductive technology (ART) outcomes among infertile women with polycystic ovary syndrome (PCOS) treated with IVM, conventional IVF, GnRH agonist, and GnRH antagonist cycles. Methods: The prospective study included a total of 67 cycles in 61 infertile women with PCOS. The women with PCOS were randomized into three IVF protocols: IVM/IVF with FSH and hCG priming with immature oocyte retrieval 38 hours later (group A, 14 cycles), GnRH agonist long protocol (group B, 14 cycles), and GnRH antagonist multi-dose flexible protocol (group C, 39 cycles). IVF outcomes, such as clinical pregnancy rate (CPR), implantation rate (IR), miscarriage rate (MR), and live birth rate (LBR), were compared among the three groups. Results: Age, BMI, and basal FSH and LH levels did not differ among the three groups. The number of retrieved oocytes and 2 pronucleus embryos was significantly lower in group A compared with groups B and C. The CPR, IR, MR, and LBR per embryo transfer showed no differences among the three groups. There was no incidence of ovarian hyperstimulation syndrome in group A. Conclusion: The IR, MR, and LBR in the IVM cycles were comparable to those of the GnRH agonist and GnRH antagonist cycles. The IVM protocol, FSH and hCG priming with oocyte retrieval 38 hours later, is an effective ART option that is comparable with conventional IVF for infertile women with PCOS.

• Journal of Embryo Transfer
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• v.10 no.2
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• pp.105-113
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• 1995

This study was conducted to examine the efficiency of enucleation and blastomere isolation from recipient oocytes and donor embryos, respectively and to determine the effect of oocyte age and electric voltage on the fusion rate and in vitro development of the fused oocytes in rabbit nuclear transplantation. Immature oocytes collected from ovarian follicles were matured in vivo for 12 h in TCM-199 containing FCS and hormones and in vivo matured oocytes were collected 17 to 18 h post-HCG. The fresh and frozen donor embryos of 8- to 16-cell stage were collected from the oviduct of superovulated does. The proportion of successfully enucleated oocytes was greatly lower in in vitro matured oocytes (42.3%) than that (62.7%) in in vivo matured oocytes The level of cytochalasin B for in vivo matured oocytes did not affect the efficiency of enuleation, but 7.5 $\mu$g /mL cytochalasin B for in vitro matured oocytes showed a high enucleation rate significantly. The isolation efficiency of a single blastomere nucleus did not differ between 8- and 16-cell stage embryos. The percentage of single blastomeres isolated from 16-cell stage fresh embryos after 0.5% pronase treatment was greatly higher at 16-min treatment (94.4%) than at 8-min(78. 1%) and the blastomeres(61.5%) isolated from frozen-thawed embryos after 16-min pronase were significantly fewer than those of fresh embryos. The age of recipient oocytes affected nuclear fusion rate. The reconstituted oocytes fused at 24-h age showed slightly higher fusion rate (77.8%) than those (65.0%)fused at 18-h age. The fusion rate of in vitro and in vivo matured oocytes inserted with fresh blastomere did not differ among electric voltages, but the cleavage rate and development to morula-blastocysts of in vitro matured oocytes was more higher under 0.6 kV/cm than under 0.8 to 1.2 kV/cm, while the cleavage rate and development of in vivo matured oocytes was higher under 0.8 to 1.0 kV/cm than under 1.2 kV/cm. The fusion and cleavage rate fol1owing insertion with frozen-thawed blastomere was not different between the in vitro and in vivo matured oocytes and was similar to those from fresh blastomere insertion.

• Journal of Embryo Transfer
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• v.12 no.3
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• pp.293-300
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• 1997

Supplementation of maturation medium with additional granulosa cells has beneficial effect on in vitro maturation of bovine follicular oocytes and their subsequent cleavage and development in vitro. However, maturation system using granulosa cells have some disadvantages that collection of granulosa cells is cumbersome and metabolic activity of the cells is variable according to ovarian cycle or follicular size. We hypothesized that bovine immsture oocytes matured without granulosa cell coculture can fertilize and develop normally if the medium volume per oocyte is reduced during in vitro maturation. Immature oocytes were matured for 24 hours in a TCM199 containing 10% fetal calf serum, anterior pitultary hormone (0.02 AU /ml Antrinⓡ) and estradiol with or without granulosa cells in vitro. In Group 1, 35 to 40 oocytes were matured in a well of 4-well plastic dish containing 500 $\mu$l of maturation medium and granulosa cells, and 9 to 10 oocytes were matured in a 50-$\mu$l drop of maturation medium without granulosa cells in Group 2. After maturation, oocytes were coincubated with sperm for 30 hours in a modified Tyrode's medium (IVF). Inseminated oocytes were cultured in a microdrop (30 $\mu$l) of a synthetic oviduct fluld medium (SOFM) containing BSA, Minimum Essential Medium essential and non-essential amino acids for 9 days. As a preliminary experiment, we investigated the beneficial effect of granulosa cells during maturation on subsequent cleavage and development using the same type of culturedishes (4-well dish). Granulosa cells could not increase embryo cleavage after fertilization but significantly improved (p<0.05) embryo development to expanding blastocyst (Table1 and 2). In Group 1, 68 and 80% of inseminated oocytes have cleaved at 30 hours and 2 days after IVF, respectively, which is similar (p>0.05) to the result of Group 2 (69% at 30 hours and 78% at 2 days after IVF). The oocytes in Group 2 showed 21 and 11% of developmental rates to expanding and hatching blastocysts, respectively, which was not significantly different (p>0.05) from those (20 and 10%, respectively) of oocytes in Group 1. In conclusion, it has been clarified that a microdrop culture system without granulosa cells for in vitro maturation can support bovine embryonic development to blastocyst in vitro as readily as a granulosa cell coculture system.