• Clinical and Experimental Reproductive Medicine
• /
• v.24 no.1
• /
• pp.83-93
• /
• 1997

Although IVF-ET is widely applied in the treatment of couples with male factor infertility, it may fail in many infertile couples with normal semen parameters, and certain couples cannot be accepted for standard IVF-ET due to unfertilization or extremely low fertilization rate of oocytes. Recently, several procedures of microassisted fertilization (MAF) using micromanipulation have been introduced, and pregnancies and births have been obtained after partial zona dissection (PZD), subzonal insertion (SUZI), and intracytoplasmic sperm injection (ICSI). This clinical study was performed to develop and establish ICSI as an effective procedure of MAF in infertile couples who could not undergo standard IVF-ET repetitively because of failure in fertilization or extremely low fertilization rate of oocytes with the conventional fertilization technique in the previous IVF-ET cycles. From March, 1995 to May, 1996, 27 cycles of IVF-ET with ICSI in 19 infertile patients were included in study group, and the outcomes of ICSI were analyzed according to fertilization rate, cumulative embryo score (CES), and pregnancy rate. The number of oocytes retrieved after controlled ovarian hyperstimulation (COH) was $10.50{\pm}6.13$ in 30 previous cycles, and $10.57{\pm}5.53$ in 27 ICSI cycles. In ICSI cycles, the number of oocytes optimal for ICSI procedure was $7.89{\pm}4.30$, and the fertilization rate of $67.9{\pm}20.2%$ could be obtained after ICSI. The number of embryos transferred was $1.43{\pm}2.40$ in previous cycles, and $4.36{\pm}1.77$ with the mean CES of $41.8{\pm}27.4$ in ICSI cycles. In ICSI cycles, the overall pregnancy rate was 29.6% (8/27) per cycle and 42.1% (8/19) per patient with the clinical pregnancy rate of 22.2% (6/27) per cycle and 31.6% (6/19) per patient. In conclusion, MAF of human oocytes with ICSI is a promising fertilization method for IVF-ET patients, especially with the past history of failure in fertilization or low fertilization rate of oocytes in the previous IVF-ET cycles, and ICSI using micromanipulation procedures applied to human oocytes will provide a range of novel techniques which may dramatically improve the pregnancy rate in IVF-ET program and contribute much to effective management of infertile couples.

• Korean Journal of Animal Reproduction
• /
• v.18 no.1
• /
• pp.25-29
• /
• 1994

This study was carried out to investigate the in-vitro fertilization rate survival rate of rapidly frozen porcine immature embryos. The porcine embryos following dehydration by cryoprotectants containing sucrose were directly plunged into liquid nitrogen and thawed in 3$0^{\circ}C$ water bath. Survival rate was defined as development rate on vitro culture or FDA test. The results are summarized as follows : 1. The in vitro fertilization rate of all frozen immature oocytes(6.7~26.7%) was very low, 35.0% of unfrozen oocytes and the rate of immature oocytes was very higher than that of mature oocytes. 2. The survival rate of all frozen immature oocytes(10.3~25.0%, 13.3~30.0%) was very low, 45% of unfrozen oocytes and the rate of immature oocytes was slightly higher than that of mature oocytes.

• Journal of Embryo Transfer
• /
• v.5 no.2
• /
• pp.45-55
• /
• 1990

The in-vitro fertilization in human clinic and animal reproduction is a very important technique but the rate of success is still low. When the in-vitro fertilization and culture of gametes or embryos were done under the condition which Hema hydrogel chamber were implanted into the peritoneal cavity of mouse, the in-vitro fertilization and development of embryos could be significantly improved and the cell-block under in-vitro culture could be overcome. Also, the Rema hydrogel chamber was very useful for the protection of isolated blastomeres. It is concluded that the polymerized Hema (pHema) hydrogel chamber may be effectively used in the fields of embryo transfer and in vitro fertilization.

• Journal of Climate Change Research
• /
• v.6 no.3
• /
• pp.249-256
• /
• 2015

This study was conducted to investigate the effects of different levels and types of nitrogen fertilizer on seedlings and soil chemical properties in a semi-arid area, Mongolia. 2-year-old Populus sibirica and 4-year-old Ulmus pumila seedlings were planted in May 2014. Six treatments with three levels of nitrogen (low-level: urea $5g\;tree^{-1}$; medium-level: urea $15g\;tree^{-1}$, ammonium sulfate $33g\;tree^{-1}$, urea $15g\;tree^{-1}$ with potassium phosphate $10g\;tree^{-1}$; high-level: urea $30g\;tree^{-1}$) were applied and for the medium-level of nitrogen, different types of fertilizer were treated. Survival rate, root collar diameter (RCD) growth rate, leaf nitrogen concentration of seedlings, and soil chemical properties were determined in August 2014. The seedling survival rate of both species decreased as the level of nitrogen increased. This result can be explained by water stress caused by nitrogen fertilization in arid regions. The RCD growth rate of P. sibirica was significantly decreased by the treatment of high-level of nitrogen due to excessive nitrogen fertilization, and was increased by the treatment of ammonium sulfate due to sulfur which might promote nitrogen uptake. The leaf nitrogen concentration of P. sibirica did not change by the treatment of low-level of nitrogen, and was increased by the treatment of medium-level of nitrogen. There were no significant differences in the RCD growth rate and the leaf nitrogen concentration of U. pumila among the six treatments. None of soil chemical properties was affected by nitrogen fertilization. Overall, the low-level of nitrogen showed no effect on seedlings and soil chemical properties, except on survival rate of U. pumila and the high-level of nitrogen was considered excessive fertilization. Continuous monitoring of medium-level nitrogen fertilization including the ammonium sulfate, which increased early growth of seedlings, would be needed to elucidate the effect of fertilization on seedling growth and soil properties in a semi-arid region.

• Korean Journal of Animal Reproduction
• /
• v.14 no.4
• /
• pp.245-252
• /
• 1990

This study was carried out to investigate the factors affecting fertilization in vitro of follicular oocytes with frozen-thawed spermatozoa in Korean Native Cattle. The bovine ovaries were obtained at a slaughter house and the follicular oocytes were recovered by aspirating the follicular fluid from the visible follicles of 3~6mm. The bovine oocytes were matured in vitro for 20~24 hours in TCM-199 containing FCS and hormones. The matured oocytes were fertilized in vitro using Percoll-separated frozen-thawed spermatozoa in BO solution. The effects of dilution and fertilization media, capacitating method, concentration of inseminated sperm and time after insemination of fertilization, were observed. The results obtained are summarized as follows : 1. The fertilization rate of frozen-thawed sperm inseminated in BO solution with caffeine and heparin together(56.4%) was higher than that of sperm inseminated in BO solution with either caffeine(10.5%) or heparin(8.9%) and without both caffeine and heparin(0%)(P<0.05). 2. The fertilization rate(56.3%) of frozen-thawed sperm inseminated in BO solution with both caffeine and heparin without preincubation was higher than that of sperm preincubated(2.9%)(P<0.05). 3. The fertilization with high concentration of frozen-thawed sperm(1.4~1.8$\times$107cells/ml) in BO solution containing caffeine and heparin resulted in higher fertilization rate, 76.7%, than the low concentration of sperm(0.8~1.0$\times$107cells/ml), 32.7%(P<0.01). 4. When the oocytes were inseminated with frozen-thawed sperm in BO solution containing caffeine and heparin without preincubation, fertilization rate increased by time and the rates were 5.9, 46.0 and 59.4% at 8, 16 and 24 hours, respectively.

• Journal of Embryo Transfer
• /
• v.17 no.2
• /
• pp.117-121
• /
• 2002

This study was carried out to investigate the in vitro fertilization rate of canine immature oocytes cryopreserved by vitrification freezing. The vitrification solutions of EPS and EDS were consisted of 40％ ethylene glycol 18％ Ficoll and 0.3M sucrose, and 20％ ethylene glycol, 16.5％ DMSO and 0.5M sucrose in TCM-199 medium supplemented with 10％ FCS, respectively. The oocytes were exposed The developmental rate of in vitro cultured oocytes recovered from ovaries collected at different stages of the reproductive cycle were 3.8％, 10.7％, 46％, respectively. to EFS or EDS at $25^{\circ}C$ and loaded into straw fer 30 sec. The straws was slowly immersed into L$N_2$. Fertilization and survival rate was defined as development rate on in vitro culture or FDA-test. 1. The fertilization rate after vitrification freezing of immature oocytes at 1, 6, 12 and 24 hrs after collection from ovaries was very low(5.3％～31.4％) than the unfrozen oocyte(60.0％). And the fertilization rate after vitrification freezing of immature oocytes was very higher than that of mature oocytes. 2. The survival rate after vitrification freezing of immature oocytes at 1, 6, 12 and 24 hrs after collection from ovaries was 55.0％, 40.0％, 28.6％ and 17.1％, respectively. And the survival rate after vitrification freezing of immature oocytes was slightly higher than that of mature oocytes.

• Clinical and Experimental Reproductive Medicine
• /
• v.44 no.2
• /
• pp.96-104
• /
• 2017

Objective: This study aimed to compare the clinical outcomes between in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) in sibling oocytes. Additionally, we evaluated whether the implementation of split insemination contributed to an increase in the number of ICSI procedures. Methods: A total of 571 cycles in 555 couples undergoing split insemination cycles were included in this study. Among them, 512 cycles (89.7%) were a couple's first IVF cycle. The patients were under 40 years of age and at least 10 oocytes were retrieved in all cycles. Sibling oocytes were randomly allocated to IVF or ICSI. Results: Total fertilization failure was significantly more common in IVF cycles than in ICSI cycles (4.0% vs. 1.4%, p<0.05), but the low fertilization rate among retrieved oocytes (as defined by fertilization rates greater than 0% but < 30%) was significantly higher in ICSI cycles than in IVF cycles (17.2% vs. 11.4%, p<0.05). The fertilization rate of ICSI among injected oocytes was significantly higher than for IVF ($72.3%{\pm}24.3%$ vs. $59.2%{\pm}25.9%$, p<0.001), but the fertilization rate among retrieved oocytes was significantly higher in IVF than in ICSI ($59.2%{\pm}25.9%$ vs. $52.1%{\pm}22.5%$, p<0.001). Embryo quality before embryo transfer was not different between IVF and ICSI. Although the sperm parameters were not different between the first cycle and the second cycle, split insemination or ICSI was performed in 18 of the 95 cycles in which a second IVF cycle was performed. Conclusion: The clinical outcomes did not differ between IVF and ICSI in split insemination cycles. Split insemination can decrease the risk of total fertilization failure. However, unnecessary ICSI is carried out in most split insemination cycles and the use of split insemination might make ICSI more common.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.48 no.3
• /
• pp.97-106
• /
• 2006

The pollutant concentrations at experimental paddy plots with three (excessive, standard, reduced) different fertilization rates were investigated during 2001-2002 irrigation seasons. Mean concentrations of pollutants in ponded water were not significantly different among three experimental plots, but the T-N concentrations in percolated water significantly depended on fertilization rates. The T-N, T-P and $COD_{Cr}$, concentrations in ponded water during early irrigation season (late May to mid-June) were much higher than those during later irrigation season likely due to fertilization and low uptake by young rice crops. The T-N concentrations decreased but the concentrations of T-P and $COD_{Cr}$, increased three days after tillering fertilization. The removal rates of T-N by paddy plots were $0.13-0.16g/m^2{\cdot}d$ for an excessive fertilization plot, $0.08-0.25g/m^2{\cdot}d$ for a standard fertilization plot, and $0.03-0.34g/m^2{\cdot}d$ for a reduced fertilization plot three days after tillering fertilization. On the other hand, T-P and $COD_{Cr}$, were released three days after tillering fertilization.

• Ocean and Polar Research
• /
• v.37 no.1
• /
• pp.37-47
• /
• 2015

The effects of low salinity (fertilization success and larval survival) on the limpet Cellana grata were studied at early stages of development using the marine bioassay technique. It was shown that, under normal conditions for development from fertilization to the post veliger stage, the salinity must be not less than 20.0~35.0 psu. However, the fertilization rate and larval survival of C. grata was obviously reduced at 5.0 psu and 10.0 psu, respectively. Mass mortality was estimated to occur at <20.0 psu (48-h $EC_{50}=19.54psu$) and the survival rate of normal veliger larvae decreased with experimental time during exposure. No observed effective concentration (NOEC) and lowest observed effect concentration (LOEC) of post veliger were estimated at 30.0 psu and 25.0 psu, respectively, during 48-h exposure. The tolerance limits of the test species to salinity revealed various concentration ranges of salinity, which may reflect the physiology and ecology of the initial development stages of C. grata. These results demonstrate that reduced salinity is detrimental to the reproductive success and larval survival of C. grata, and if salinity is lowered by natural or anthropogenic sources during spawning, this would lead to decreased reproductive success and larval settlement.

• Clinical and Experimental Reproductive Medicine
• /
• v.42 no.2
• /
• pp.45-50
• /
• 2015

Objective: Artificial oocyte activation (AOA) is an effective method to avoid total fertilization failure in human in vitro fertilization-embryo transfer (IVF-ET) cycles. AOA performed using a calcium ionophore can induce calcium oscillation in oocytes and initiate the fertilization process. We evaluated the usefulness of AOA with a calcium ionophore in cases of total fertilization failure in previous cycles and in cases of severe male factor infertility patients with non-motile spermatozoa after pentoxifylline (PF) treatment. Methods: The present study describes 29 intracytoplasmic sperm injection (ICSI)-AOA cycles involving male factor infertility at Cheil General Hospital from January 2006 to June 2013. Patients were divided into two groups (control, n=480; AOA, n=29) depending on whether or not AOA using a calcium ionophore (A23187) was performed after testicular sperm extraction-ICSI (TESE-ICSI). The AOA group was further split into subgroups according to sperm motility after PF treatment: i.e., motile sperm-injected (n=12) and non-motile sperm-injected (n=17) groups (total n=29 cycles). Results: The good embryo rate (52.3% vs. 66.9%), pregnancy rate (20.7% vs. 52.1%), and delivery rate (10.3% vs. 40.8%) were lower in the PF/AOA group than in the control group. When evaluating the effects of restoration of sperm motility after PF treatment on clinical outcomes there was no difference in fertilization rate (66.6% vs. 64.7% in non-motile and motile sperm, respectively), pregnancy rate (17.6% vs. 33.3%), or delivery rate (5.9% vs. 16.7%) between the two groups. Conclusion: We suggest that oocyte activation is a useful method to ensure fertilization in TESE-ICSI cycles regardless of restoration of sperm motility after PF treatment. AOA may be useful in selected patients who have a low fertilization rate or total fertilization failure.