• Clinical and Experimental Reproductive Medicine
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• v.42 no.1
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• pp.22-29
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• 2015

Objective: Sperm must be properly prepared in in vitro fertilization (IVF)-embryo transfer (ET) programs in order to control the fertilization rate and ensure that embryos are of high quality and have appropriate developmental abilities. The objective of this study was to determine the most optimal sperm preparation method for IVF. Methods: Patients less than 40 years of age who participated in a fresh IVF-ET cycle from November 2012 to March 2013 were included in this study. Poor responders with less than three mature oocytes were excluded. Ham's F-10 medium or sperm-washing medium (SWM) was used in combination with the density-gradient centrifugation/swim-up (DGC-SUP) or SUP methods for sperm preparation. A total of 429 fresh IVF-ET cycles were grouped according to the media and methods used for sperm preparation and retrospectively analyzed (DGC-SUP/Ham's F-10, n=82; DGC-SUP/SWM, n=43; SUP/Ham's F-10, n=181; SUP/SWM, n=123). Results: There were no significant differences among these four groups with respect to the mean age of the female partners, duration of infertility, number of previous IVF cycles, and retrieved oocytes. We determined that both the DGC-SUP and SUP methods for sperm preparation from whole semen, using either Ham's F-10 or SWM media, result in comparable clinical outcomes, including fertilization and pregnancy rates. Conclusion: We suggest that both media and both methods for sperm preparation can be used for selecting high-quality sperm for assistive reproductive technology programs.

• Clinical and Experimental Reproductive Medicine
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• v.38 no.3
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• pp.142-147
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• 2011

Objective: This study was performed to evaluate testicular sperm chromatin condensation using aniline blue-eosin (AB-E) staining and its effects on IVF-ET. Methods: Chromatin condensation was analyzed using AB-E staining in 27 cases of testicular sperm extraction. There were 19 cases of obstructive azoospermia (OA) and 8 cases of non-obstructive azoospermia (NOA) in IVF-ET. Mature sperm heads were stained red-pink whereas immature sperm heads were stained dark blue. The percentage of sperm chromatin condensation was calculated from the ratio of the number of red-pink sperm to the total number of sperm analyzed. Results: The overall percentages of chromatin condensation in OA and NOA were $31.1{\pm}11.2%$ and $26.3{\pm}14.4%$, respectively. The fertilization rate was significant higher in OA than NOA ($p$ <0.05); however, the rates of good embryos and clinical pregnancy did not show statistical differences. In OA and NOA, statistical differences were not observed in the rate of chromatin condensation, fertilization, good embryos, and clinical pregnancy between the pregnant group and non-pregnant group. Conclusion: Chromatin condensation is less stable than OA and showed a low fertilization rate in NOA. While there were no significant differences in chromatin condensation results between NOA and OA, we propose that a pattern of decreased chromatin condensation in NOA is one of the factors of low fertilization results requiring further study.

• Clinical and Experimental Reproductive Medicine
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• v.51 no.1
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• pp.75-84
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• 2024

Objective: The purpose of this study was to evaluate the impact of preimplantation genetic testing for aneuploidy (PGT-A) on clinical outcomes among high-risk patients. Methods: This retrospective study involved 1,368 patients and the same number of cycles, including 520 cycles with PGT-A and 848 cycles without PGT-A. The study participants comprised women of advanced maternal age (AMA) and those affected by recurrent implantation failure (RIF), recurrent pregnancy loss (RPL), or severe male factor infertility (SMF). Results: PGT-A was associated with significant improvements in the implantation rate (IR) and the ongoing pregnancy rate/live birth rate (OPR/LBR) per embryo transfer cycle in the AMA (39.3% vs. 16.2% [p<0.001] and 42.0% vs. 21.8% [p<0.001], respectively), RIF (41.7% vs. 22.0% [p<0.001] and 47.0% vs. 28.6% [p<0.001], respectively), and RPL (45.6% vs. 19.5% [p<0.001] and 49.1% vs. 24.2% [p<0.001], respectively) groups, as well as the IR in the SMF group (43.3% vs. 26.5%, p=0.011). Additionally, PGT-A was associated with lower overall incidence rates of early pregnancy loss in the AMA (16.7% vs. 34.3%, p=0.001) and RPL (16.7% vs. 50.0%, p<0.001) groups. However, the OPR/LBR per total cycle across all PGT-A groups did not significantly exceed that for the non-PGT-A groups. Conclusion: PGT-A demonstrated beneficial effects in high-risk patients. However, our findings indicate that these benefits are more pronounced in carefully selected candidates than in the entire high-risk patient population.

• Journal of Embryo Transfer
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• v.20 no.2
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• pp.123-128
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• 2005

This study examines the effects of kinds and concentrations of cryoprotectants on the survival rate of vitrification-thawed porcine oocytes, together with the effects on survival, in vitro fertilization and development of immature oocytes. 1. The developmental rate of oocytes to MII and diploid stage when the vitrification-thawed of recovered immature oocytes cultured for 0, 15, 30 and 40h were cultured for 0, 15, 30 and 40h were $56.7\%,\;53.3\%,\;63.3\%,\;65.0\%\;and\;23.3\%,\;18.3\%,\;10.0\%,\; 3.3\%$, respectively. The in vitro development to MII stage were lower than the control group $(78.2\%)$, but higher fo. diploid stage $(5.5\%)$. 2. When the vitrification of immature oocytes after being culture for 0, 15, 30 and 40 hours, the survival rate were $34.0\%,\;26.0\%,\;18.0\%\;and\;10.0\%$ respectively. This result was lower than that of the control group $(60.0\%)$. 3. When the fertilization of the vitrified immature oocytes after being culture for 0, 15, 30 and 40 hours, the in vitro fertilization rate were $60.0\%,\;54.0\%,\;48.0\%,\;38.0\%$, and developmental rates were $26.0\%,\;18.0\%,\;8.0\%,\;4.0\%$, respectively. This results were lower than the control group $(78.0\%\;and\;38.0\%)$. 4. When the fertilization of the immature oocytes after being culture for $0\~15$ hours vitrified with EDS and ETS, the fertilization and developmental rates were $50.0\%,\; 22.0\%$ and $46.0\%,\;18.0\%$, respectively. This results were lower than the control group $(74.0\%\;and\;38.0\%)$.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.2
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• pp.136-141
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• 2013

Lowering tree height has been a key practice for efficient management of persimmon orchards. This experiment was conducted to assess whether fertilization rates could be reduced after lowering the tree height by heavy pruning. Twelve-year-old 'Uenishiwase' persimmon trees were lowered to 2 m from over 3 m by severe dormant pruning, and then conventional fertilization rate was applied to some trees in April (N 224 g, $P_2O_5$ 172 g, and $K_2O$ 172 g per tree), June (N 112 g and $K_2O$ 99 g per tree), and October (N 112 g and $K_2O$ 99 g per tree). At the same time, 1/3 or 2/3 of the conventional rate and none were applied to other trees, respectively. Non-application decreased shoot length and reduced number of unnecessary secondary shoots by 39% compared with the conventional rate, not affecting yield and weight, color, firmness, and soluble solids of fruits. No significant difference was also found in the yield and the fruit characteristics among the trees fertilized with different rates. Concentrations of soluble sugars, starch, N, and K of dormant shoots in March of the following year were not significantly changed by the different treatments of the previous year. There was no significant difference of shoot growth and yield among the treatments the following year when the same fertilization rate was supplied to all the trees. Results indicated that fertilization rate could be reduced to less than 1/3 of conventional rate to save the cost and stabilize shoot vigor when tree height is lowered by severe pruning.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.1
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• pp.101-108
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• 2014

This study was conducted to investigate the effect of nitrogen rates on the growth characteristics and yield of maize in agricultural fields with the stream. This indicates the necessity and optimal level of nitrous fertilization to examine the possibilities of quantity enhancement. Plant height and ear height of maize were not significantly different among the nitrogen rates. Stem diameter and leaf area index increased in the nitrogen treatment compared to untreated control. Changes of photosynthetic rate in maize leaves depending on nitrogen treatments increased as much as nitrogen rates were increased up to the highest level, 36 kg per 10a. NDF and ADF content levels of maize were investigated with different nitrogen rates regardless of treatments. In the case of NDF, it showed a tendency to decrease after 8 days of tasseling date. ADF had also decreased after 15 days of tasseling date. Nitrogen uptake of maize leaves with different nitrogen rates showed the highest level, $4.9g\;kg^{-1}$ with 36 kg per 10a on the tasseling date. Ear length and 100-kernel weight, there were no significant differences according to yield and the components with different nitrogen rates. Ear diameter and kernel number, nitrogen rates of 18 kg and 36 kg were increased compared to nitrogen rate of 9 kg per 10a and untreated control. The pericarps in 9 kg nitrogen rate and control were thicker than those of 18 kg and 36 kg treatment. The yield, 18 kg, 36 kg, and 9 kg treatments were increased by 10.96%, 9.27%, and 3.31%, compared to control. The component analysis on maize kernel with different nitrogen rates, starch showed no significant differences among treatments. Total sugar in 18 kg nitrogen treatment represented the highest content level, 6.37%. In addition, Amylopectin in 18 kg treatment showed the highest content level of 90.38%. However, amylose in 18 kg treatment showed the lowest level, 9.62% which drew a conclusion that waxy of 18 kg treatment is considered to be the strongest one. From the results described above, nitrous fertilization is essential to grow maize in agricultural fields with the stream. The optimum level of nitrous fertilization is considered 18 kg per 10a.

• Clinical and Experimental Reproductive Medicine
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• v.26 no.1
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• pp.75-81
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• 1999

The beneficial effect of glucose and phosphate ions in culture medium on the development of human embryos in vitro has not been fully elucidated. The purpose of this study was to evaluate the influence of fertilization and culture of embryos in glucose/phosphate-free m-TALP medium on pregnancy rates in IVF-ET program. The patients in 244 IVF-ET cycles received GnRH agonist + HMG regimens. A does of 10,000 IU HCG was administered when two or more dominent follicles reached 18mm in diameter. Thirty-six hours after HCG, oocytes were recovered transvaginally using ultrasound guidance. Aspirated oocytes were matured for 4 to 6 h in TCM-199 supplemented with 10% follicular fluid (FF). Insemination was carried out with 50,000 motile spermatozoa in TCM-199 + 10% FF or m-TALP + 5% FF + 5% fetal cord serum (FCS) according to experimental design. After 6 h, oocytes were washed 3 to 4 times and cultured in each fresh medium. After 20 h, oocytes were freed from cumulus/corona cells and examined for the presence of pronuclei. Fertilized oocytes were transferred into each co-culture drops and cultured for further incubation. On day 3, embryo transfer was performed with grade 1 and 2 embryos. Monolayers for co-culture of embryos were prepared by plating $1{\times}10^5$ cumulus cells/ml in 10ul drop of TCM-199 + 10% FF or m-TALP + 5% FF + 5% FCS media 24 h prior to the onset of co-culture. Development to 4 to 16 cell stage was observed at 70x magnification following two days of incubation. Pregnancy was confirmed by detecting increasing serum ${\beta}$-hCG concentrations for 11 days following embryo transfer. Data were analyzed by ${\chi}^2$-test. Oocytes from 244 IVF-ET cycles were randomized. The number of cycles and mean age of patients were 97 and 147, 31.3 yrs and 31.2 yrs for TCM-199 (control) and m-TALP groups, respectively. The mean number of retrieved oocytes/cycle, fertilization rates, number of embryos transferred/ET and pregnancy rates were 11.1 and 10.3, 65.1% and 67.3%, 4.1 and 4.7, 28.9% and 43.8% for TCM-199 and m-TALP groups, respectively. Differences in the pregnancy rates were found between control and m-TALP groups (p<0.05). The pregnancy rate of patients divided according to maternal age groups of ${\leq}30$, 31-35, $36{\leq}$ were 44.4% and 49.0%, 26.1% and 41.3%, 29.2% and 41.2% for control and m-TALP groups, respectively. These data indicate that culture of human embryos in glucose/phosphate-free m-TALP medium improves pregnancy rates.

• Journal of Embryo Transfer
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• v.10 no.2
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• pp.121-129
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• 1995

To examine the critical effect of oxygen concentration on embryonic development, in vitro fertilized embryos were cultured in media(TCM199 vs. SOF) supplemented sera(1O% FCS vs. 10% HS) with and without bovine oviduct epithelial cells under two gas atmosphere (5% $CO_2$ in air vs. 5% $CO_2$, 5% $O_2$, 90% $N_2$). Oocytes, obtained from abattoir ovaries, were matured in EGF containing TCM199 medium co-cultured with BOEC for 24 hours, followed by exposure to frozen-thawed, heparin4reated spermatozoa in TALP for 30 hours. And then early embryos(1~2 cell) were cultured in both TCM199 and SOF supplemented with 10% FCS or 10% RS under 5% $CO_2$ in air or 5% COi, 5% $O_2$, 90% $N_2$. Development to morulae and blastocysts was recorded on days 7, after the start of in vitro fertilization. The developmental rates of in vitro fertilized embryos to morulae and blastocysts cultured in SOF with BOEC under 5% $CO_2$, 5% $O_2$, 90% $N_2$(24.4%) were significantly(p<0.05) higher than cultured in SOF with BOEC under 5% $CO_2$ in air(14.1%) at seven days after in vitro fertilization. When early bovine embryos were cultured in TCM 199 and SOF under two different gas atmosphere, there were no significant differences in the developmental rates to morulae and blastocysts between supplements of 10% FCS and 10% HS. The rates of development to morulae and blastocysts were significantly(p<0.01) higher in TCM 199 with BOEC(24.7%) than TCM199 without BOEC(10.9%) under 5% $CO_2$ in air, otherwise SOF without BOEC(36.4%) were significantly (p<0.05) higher than in SOF with BOEC (24.4%) under 5% $CO_2$, 5% $O_2$, 90% $N_2$. In summary, these experiments have proved that the culture system in SOF supplemented 10% ES is effective on in vitro development of early bovine embryos under 5% $CO_2$, 5% $O_2$, 90% $N_2$. In addition, it is effective to development of bovine embryos that TCM 199 should be co-cultured with BOEC and SOF should be cultured without somatic cells under two different gas atmosphere.

• Clinical and Experimental Reproductive Medicine
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• v.26 no.3
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• pp.339-344
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• 1999

Objective: To evaluate incidence of microbial growth from the tip of the embryo transfer catheter after embryo transfer in relation to clinical pregnancy rate following in-vitro fertilization and embryo transfer. Method: This study was performed prospectively at the time of transcervical embryo transfer following conventional in-vitro fertilization and intracytoplasmic sperm injection procedures. Sixty three patients were enrolled in this study. Microbiological cultures were performed on endocervical swabs and embryo transfer catheter tips. Results: Positive microbial growths were observed from endocervical swabs in 45 (71.4%) women and from catheter tips in 30 (47.6%) women. There was no statistically significant difference seen in the mean number of oocytes fertilized or number and grade of embryos transferred between the group of patients without growth and the group of patients with positive microbial growth from catheter tips. The clinical pregnancy rate were 30.3% in the group of patients without growth and 13.3% in the group with positive microbial growth from catheter tips. This difference in clinical pregnancy rates was statistically significant. Conclusion: Our finding is that microbial contamination at embryo transfer may influence implantation rates. The major questions arising from our finding are whether eradication of endocervical micro-organisms is possible and whether their eradication will improve implantation rates.

• Journal of Aquaculture
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• v.7 no.3
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• pp.159-164
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• 1994

All-female diploid Paralichtlrys olivaceus populations were produced by the artificial fertilization with the normal eggs and gynogenetic diploid males sperms. All-female triploids were also conducted to the fertilized eggs by cold shock. Floating, fertilization and hatching rates of the all-female diploid eggs were not significantly different from that of the diploid control eggs (P>0.05). All-female triploids were also not significantly different from their diploid controls or all-female diploid groups (P>0.05) in the floating and fertilization rates of eggs. However, hatching rates of all-female triploid groups were lower than that of the control (P<0.05). Induction of the triploids were confirmed by the measurement of erythrocyte sizes and by the chromosome counts. The volumes of erythrocytes and nucleus of triploid were larger than those of diploids, respectively. Percent incidences of triploid were $92.6\%$ in this experiment. The chromosome number of diploids and triploids showed 2n=48 and 3n=72, respectively, and their karyotypes were consisted of all acrocentric chromosomes. The gonads of 4-month-old triploids were histologically sterile.