• Korean Journal of Soil Science and Fertilizer
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• v.28 no.2
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• pp.154-159
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• 1995

In order to find out the effects of shading and nitrogen fertilizer on $NO_3^-$ accumulation in the edible parts of chinese cabbage, Cutivar, "Seoul", was cultivated in the pots under glasshouse condition with different rates of shading(0, 15, 30, 50, 75%) and nitrogen fertilization(recommended level, and double rate of recommended level). Leaf length, leaf width, yield (leaf weight), root width and root weight in the 15% shading rate showed the highest value, but decreased in the over 30% shading rates. The highest yield showed in the plot of the 15% shading rate with double rate application of recommended N level. High rate of shading increased the $NO_3^-$ accumulation, especially in midrib and outer leaf compared to leaf blade and inner leaf, respectively. The average $NO_3^-$ accumulation of edible parts of chinese cabbage are $4,872mg\;kg^{-1}$(outer midrib), $2,363mg\;kg^{-1}$(inner midrib), $1,405mg\;kg^{-1}$(outer leaf blade) and $727mg\;kg^{-1}$(inner leaf blade). $NO_3^-$ accumulation of outer midrib in the plots of double application of recommended N level were no difference between shading rate containing $5,000{\sim}6,000mg\;kg^{-1}$ $NO_3^-$, while in the plots of recommended N level it was increased by elevating shading rate. It was concluded that overuse of nitrogen fertiliration for chinese cabbage in glasshouse condition might lead to increase $NO_3^-$ accumulation. It could be advisable to cut out both the out leaf blade and outer midrib which might accumulate the high concentration of $NO_3^-$ before consumption.

• Korean Journal of Animal Reproduction
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• v.26 no.3
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• pp.275-289
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• 2002

The objective of this study was to develop an in vitro assessment of sperm fertilizing capacity of bulls and investigate the factors influencing sperm function and characteristics of frozen-thawed bovine spermatozoa. in vitro fertilization (IVF), the evaluation of motility and normal morphology, HOST (hypoosmotic swelling test), Ca-ionophore induced acrosome reaction, luminol and lucigenin-dependent chemiluminescence for the measurement of reactive oxygen species (ROS), the measurement of malondialdehyde formation for the analysis of lipid peroxidation (LPO), and the evaluation of DNA fragmentation using the method of 747-mediated nick end labelling (TUNEL) by flow cytometry were performed in frozen-thawed bovine spermatozoa. Correlations between the rates of fertilization, blastocyst formation after IVF and the values of respective assays were investigated. 1. IVF rate and blastocyst formation rate averaged 64.4% and 34.3% for spermatozoa from high -fertility bull group and averaged 18.5% and 6.2% for spermatozoa from low-fertility bull group, respectively. There were significantly different between two bull groups. Sperm motility and percentage acrosome reaction averaged 79.0% and 66.2% for spermatozoa from high-fertility bull group and averaged 40.7% and 22.9% for spermatozoa from low-fertility bull group, respectivitely. There were not different between two bull groups. 2. Luminol depenent chemiluminescence, LPO and DNA fragementation averaged 6.4, 2.0 nmol and 2.6% from spermatozoa from high-fertility bull group and averaged 6.5, 3.1 nmol and 7.4% for spermatozoa from low-fertility bull group, respectively. There were significantly different between two bull groups. There was no significant difference in lucigenin dependent chemiluminescence between two bull groups. 3. Fertilization rate was positively correlated with motility and the rate of Ca-ionophore induced acrosome reaction, but negatively correlated with the frequency of luminol-dependent chemiluminescence, the rate of LPO, and the percentage of sperm with DNA fragmentation. There was no correlation between fertilization rate and the percentage of swollen spermatozoa, normal morphology, and the frequency of lucigenin-dependent chemiluminescence. 4. Blastocyst formation rate was positively correlated with the rate of Ca-ionophore induced acrosome reaction, but negatively correlated with the frequency of luminol-dependent chemiluminescence, the rate of LPO, and the percentage of sperm with DNA fragmentation. There was no correlation between blastocyst formation rate and motility, the percentage of swollen spermatozoa, normal morphology, and the frequency of lucigenin-dependent chemiluminescence. In conclusion, these data suggest that ROS significantly impact semen quality. The assays of this study may provide a basis fur improving in vitro assessment of sperm fertilizing capacity.

• Korean Journal of Animal Reproduction
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• v.26 no.3
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• pp.263-273
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• 2002

This study was undertaken to evaluate the effects of $\beta$-mercaptoethanol ($\beta$-ME) on lipid peroxidation and fertilization ability in vitro by xanthine (X) - xanthine oxidase (XO) system in boar spermatozoa frozen-thawed. The boar spermatozoa were treated with X and/or XO, and the spermatozoa viability were measured by the eosin-nigrosin stain method. In control group, level of vitality in boar spermatozoa were higher than in medium with X, XO and X+XO groups. No significant differences, however, were observed under the all conditions. The percentage of spermatozoa that reached acrosome reaction were significantly (P<0.05) higher in sperm treated without that than with $\beta$-ME under the all conditions. On the other hand, when spermatozoa were inseminated in medium with X and/or XO, the penetration rates in all conditions were higher in medium with that than without $\beta$-ME. However, significant differences were not observed between medium with and without $\beta$-ME. The lipid peroxidation of sperm was evaluated on the basis of malondialdehyde (MDA) production. The MDA were higher in sperm treated without that than with $\beta$-ME under the above all conditions. However, significant differences were not observed between medium with and without $\beta$-ME. Sperm-SH group were higher detected in medium with that than without $\beta$-ME under the all conditions. The activity of sperm binding to Bona pellucida was also evaluated through binding to salt-stored porcine oocytes. In control group, sperm binding to zona pellucida were significantly (P<0.05) higher than in medium with X+XO groups. The sperm binding in all conditions were higher in medium with that than without $\beta$-ME. However, significant differences were not observed between medium with and without $\beta$-ME. These results suggest that addition of $\beta$-ME in X-XO system may play a positive role in improving of fertilization ability in vitro.

• Journal of Embryo Transfer
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• v.16 no.3
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• pp.203-211
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• 2001

This study was carried out to determine sex of porcine embryos produced by in vitro fertilization. Porcine oocyte-cumulus complexes were cultured in BSA-free North Carolina State University (NCSU) 23 medium containing porcine follicular fluid (10%), cystein (0.1 mg/ml) and hormonal supplement (10 IU eCG and 10 IU hCG per ml) for 20~22 hrs. They were then cultured in the same medium but without hormonal supplement for additional 20~22 hrs. After culture, cumulus cells were removed and oocytes were co-incubated for 6 hrs with four different concentrations (5$\times$10$^4$, 2.5$\times$ 10$^{5}$ , 5.0$\times$10$^{5}$ and l0$\times$10$^{5}$ ) of porcine sperm. After fertilization, oocytes were transferred into NCSU 23 with 0.4% BSA medium. The cleavage and blastocyst formation rates were evaluated at 48 and 144 hrs, respectively. In this study, the polymerase chain reaction (PCR) was used to determine the sex of porcine embryos in the stage of blastocyst. The PCR was performed using a set of oligonucleotide primers (5‘-TCATGGACCAGGTAGGGAAT-3', 5’-GAAAGACACGTCCTTGGA GA-3') for 491 bp fragment of porcine male-specific DNA sequence. In the flour different sperm concentration (5$\times$10$^4$, 2.5$\times$10$^{5}$ , 5.0$\times$10$^{5}$ and l0$\times$10$^{5}$ ) for fertilization condition, the cleavage rate was 55.95, 67.88, 60.18 and 47.60%, respectivety, and the development rate of blastocysts was 16.03, 20.40, 21.41 and 12.37%, respectively. At 5.0$\times$10$^4$and 2.5$\times$10$^{5}$ of sperm concentrations per ml cleavage rate and development rate of blastocyst were higher than those of 5.0$\times$10$^4$and l0$\times$10$^{5}$ of sperm concentration (P<0.01). The male of porcine embryos was detected at 491 bp by PCR, and 18 of the 31 porcine blastocysts were the male (58.1%) and the rest 13 were the female(41.9%).

• Clinical and Experimental Reproductive Medicine
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• v.33 no.4
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• pp.219-227
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• 2006

Objective: To evaluate the impact of endometriosis on IVF-ET cycles and to compare IVF outcomes between stage I/II and stage III/IV endometriosis. Methods: We analyzed 697 patients (1,199 cycles) with endometriosis (stage I-II:638 cycles, stage III-IV: 561 cycles) and 325 pts (459 cycles) with tubal factor as controls between January 1994 and April 2004. Pts with endometriosis were diagnosed by laparoscopy and medical and surgical treatment were done in 353 cycles (55.3%) and 466 cycles (83.1%) of stage I-ll/stage III-IV endometriosis. Cycles with age>35 years or FSH>20 miU/mL or severe male factor infertility were excluded. Results: The number of retrieved oocytes ($9.97{\pm}7.2$ vs. $13.4{\pm}7.9$ (p<0.0001 )), total number of embryos ($6.5{\pm}4.8$ vs. $9.1{\pm}5.6$ (p<0.0001)), and good quality embryos ($2.43{\pm}1.6$ vs. $2.74{\pm}1.7$ (p=0.013)) significantly decreased in stage III-IV endometriosis than in control. But pregnancy rate of stage III-IV endometriosis was comparable with control (35.7% vs. 36.8%). Fertilization rate and number of total embryos were lower in stage I-II endometriosis than in control ($64.8{\pm}22.9$ vs. $70.8{\pm}20.8$ (p<0.0001), $7.6{\pm}5.0$ vs. $9.1{\pm}5.6$ (p<0.0001)). In patients with medical and surgical treatment of endometriosis, pregnancy rate and live birth rate was significantly lower in stage I-II than in stage III-IV endometriosis (29.2 vs. 36.2 (%), p=0.045, 23.9 vs. 31.5 (%), p=0.043). There was no difference in the mean age, but the duration of infertility was significantly longer ($56.5{\pm}26.3$ vs. $46.9{\pm}25.8$ (mon), p<0.0001) and fertilization rate was lower ($64.7{\pm}23.3$ vs. $70.5{\pm}22.7$ (%), p=0.001) in stage I-II than stage III-IV endometriosis. Conclusion: We suggest that IVF should be considered earlier in patients with minimal to mild endometriosis because of significantly decreased fertilization rates.

• Journal of Embryo Transfer
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• v.22 no.1
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• pp.1-7
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• 2007

This study was conducted to examine the role of intact cumulus cells during in vitro fertilization (IVF) on sperm penetration, male pronuclear (MPN) formation and subsequent embryo development of oocytes matured and fertilized in vitro. Cumulus-oocyte complexes obtained from the slaughtered gilt ovaries were matured for 44 h in TCM199 containing 10% porcine follicular fluid, epidermal growth factor and hormones. After maturation culture, denuded oocytes or oocytes with intact cumulus cells were coincubated with frozen-thawed boar semen for 8h in a modified tris-buffered medium containing 5mM caffeine and 10mM calcium chloride. Putative zygotes were fixed and examined for sperm penetration and MPN formation (Experiments $1{\sim}3$), or cultured in North Carolina State University-23 medium fo. 156 h (Experiment 3). In Experiment 1, sperm penetration was examined after insemination of denuded oocytes and oocytes with intact cumulus cells at the concentration of $7.5{\times}10^5$ sperm/ml. Optimal sperm concentration for IVF of cumulus-intact oocytes was determined in Experiment 2 by inseminating intact oocytes with $2{\sim}5{\times}10^6$ sperm/ml. In Experiment 3, denuded or intact oocytes were inseminated at the concentrations of $7.5{\times}10^5$ and $4.0{\times}10^6$ sperm/ml, respectively, and in vitro embryo development was compared. Sperm penetration was significantly (p<0.01) decreased in cumulus-intact oocytes compared to denuded oocytes (35.2% vs. 77.4%). Based on the rates of sperm penetration and normal fertilization, the concentration of $4.0{\times}10^6$ sperm/ml was optimal for the IVF of intact oocytes compared to other sperm concentrations. The presence of intact cumulus cells during IVF significantly (p<0.05) improved embryo cleavage (48.8% vs. 58.9%), blastocyst (BL) formation (11.0% vs. 22.8%) and embryo cell number $(22{\pm}2\;vs.\;29{\pm}2\;cells)$ compared to denuded oocytes. In conclusion, these results suggest that intact cumulus cells during IVF inhibit sperm penetration but improve embryo cleavage, BL formation and embryo cell number of porcine embryos produced in vitro.

• Clinical and Experimental Reproductive Medicine
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• v.24 no.3
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• pp.347-353
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• 1997

This study was to test whether in vitro/in vivo survival of vitrified mouse blastocysts was influenced by culture conditions and ET method. Mouse blastocysts were obtained from in vitro fertilization and cultured for 4 days in M16 medium, and they were vitrified in EFS40 which contained 40% ethlyene glycol, 18% Ficoll and 0.5 mol sucrose in PBS. In experiment I, in vitro and in vivo survival rate of these embryos were evaluated in different culture condition after thawing. When thawed embryos were cultured in M16 medium as a control, m-CR1 medium contained 20 amino acids (2% BME amino acis and 1% MEM non-essential amino acids solution) and 4 mg/ml BSA and cumulus monolayer cell co-cultured condition in mCR1 medium (10% FBS), their in vitro survival at 24 hr after thawing was not affected by culture condition (75.6, 83.1, 82.4%). However, in vivo survival rates of implantation in m-CR1 medium (80.4%) were significantly higher than those of M16 medium (51.2%), co-culture (57.1%) condition, although there was no difference in live fetuses rates on day 15 gestation (39.0, 49.0, 38.1%). In experiment II, the in vivo development potential of embryos by ET methods was examined. When blastocysts were transferred to the day 2, 3 pseudopregnant recipient without culture soon after thawing, no pregnant recipient was obtained on the day 2 pseudopregnancy, and 50% of pregnancy rates and 15.4% of live fetus rates were obtained on the day 3 pseudopregnant recipients. These results were significantly lower than those of transferred group (day 3 pseudopregnant recipients) after culture for 16 hr post thawing (73.5, 57.1%) (p<0.05). In experiment III, to elevate usability of delayed embryos in vitro/in vivo survival of vitrified embryos (day 4 early, day 5 early and expanding blastocyst) were examined. in vivo survival rates (live fetus, total implantation) were higher in day 4 early blastocysts (33.3, 66.7%) than in day 5 expanding blastocysts (29.0, 38.7%), although the highest in vitro survival rates were obtained in the day 5 expanding brastocysts (78.3%). Therefore, these results suggest that the in vitro/in vivo survival rates of vitrified embryos could be improve by the culture condition and ET method and that the in vivo development rates of delayed embryos were decreased with longer culture duration in vitro. It means that more effective cryopreservation was obtained in day 4 early blastocysts than in day 5 expanding blastocysts.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.52 no.1
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• pp.104-111
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• 2007

As protein content of milled rice, generally used as a benchmark for rice eating quality, is greatly affected by N fertilization and nutrition status of rice plant, understanding its response to nitrogen rate and plant nitrogen status at different growth stage is important for recommending N fertilizer management for high quality rice production. The responses of milled-rice protein content were compared and quantified under various combinations of basal+tillering and panicle N application levels in 2001 and 2002. Protein content of milled rice was ranged from 6 to 9%, increasing significantly with increasing basal+tillering and panicle N rates. However, milled rice protein content was raised much greater by panicle N than by basal+tillering N fertilization. Even though basal+tillering N increased up to 20 kg/ha, protein content of milled rice was observed less than 7% in case that panicle N was applied below 1.8 kg/10a. Regression analysis revealed that nitrogen accumulated until harvest was partitioned with almost constant rates of 58.3% and 46.5% to panicle and milled rice, respectively. The partitioning rates was slightly but not significantly different between experimental years. Protein content of milled rice showed linear and quadratic responses to the shoot N accumulation until panicle initiation stage (PIS) ant shoot nitrogen accumulation from PIS to harvest, respectively. The increment of milled-rice protein content per unit N increase was much greater in shoot N accumulation from PIS to harvest than in that until PIS. Regardless of shoot N accumulation until PIS upto 8 kg/10a, protein content of milled rice was lower than 7% and ranged from 6.5 to 7.5% in case that shoot N accumulation from PIS to harvest was below 3.0 kg/10a and below 6.0 kg/10a respectively. It would be concluded that even under the same N accumulation until harvest milled rice protein content could be different according to the N fertilizer management and weather condition especially during ripening, providing rooms for controlling protein content by N fertilizer management without damage to grain yield.

• Reproductive and Developmental Biology
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• v.29 no.3
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• pp.201-205
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• 2005

The objective of this study was to investigative the effects of amino acids supplementation on maturation, fertilization and embryo development of pig oocytes. Essential amino acids (EA), non-essential amino acids (NA) or both amino acids (EA + NA) were supple-mented to North Carolina State University (NCSU) 23 medium containing porcine follicular fluid (pFF). When the amino acids were supplemented to the maturation medium, the maturation rates were higher (p<0.05) in the NA group than control ($83.3{\pm}0.04\%\;versus\;70.0{\pm}0.05\%$, but the subsequent cleavage rates and development to morula and blstocyst stage between aminoacid supplement groups and control were not different. The developmental rates to morula and blastocysts stage were not significantly different regardless of amino acid supplementation to culture medium. In addition, supplementation of amino acids did not significantly affect the rate of fertilization and polyspermy. When the amino acids were supplement to culture medium, the number of trophectodermal (TE) cells was significantly (p<0.05) higher in amino acid supplement group than that of control ($18.6{\pm}0.5\;versus\;16.1{\pm}0.6$), whereas the numbers of inner cell mass (ICM) cells were not different among the treaonent groups and control ($29.0{\pm}0.9\~31.5{\pm}1.2$). Total cell number was also significantly (p<0.05) higher in EANA group ($50.0{\pm}1.0$) than that of control group ($44.2{\pm}1.1$). These results indicate that the amino acid supplementation to maturation and culture medium may not significantly stimulate early embryo development, but may improve the TE cell number of blastocyst stage in the pig.

• Clinical and Experimental Reproductive Medicine
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• v.37 no.4
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• pp.339-348
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• 2010

Objective: To investigate the beneficial effect of fragment removal on the subsequent cell division and clinical outcome of the fragmented human embryos. Methods: A prospective study was performed in Hanna Women's Clinic and Mizmedi Hospital. Sixty couples undergoing In vitro fertilization-embryo transfer (IVF-ET) program were participated in the present study. The microsurgical fragment removal was performed in 106 fragmented embryos of 29 patients before the transfer. As a control group, 122 fragmented embryos of 31 patients were transferred without the fragment removal. Effects of fragment removal on morphological changes and clinical outcomes of fragmented embryos were investigated. Results: Mean morphological grade (G2.79) of fragmented embryos was significantly improved after the fragment removal(G1.63, p<0.001). Most of the fragmented embryos did not show a regeneration of fragments after the fragment removal during the subsequent development, and a beneficial effect of fragment removal on the development of the fragment removed embryos was observed. Implantation and pregnancy rates of fragment removed embryos were 12.3% and 31.3%, whereas the rates of control group embryos were 6.6% and 22.5%, respectively. There was no statistical significance in the rates between the two groups because of the low number of trials. Conclusion: Microsurgical fragment removal improved the subsequent development as well as the morphological grade of fragmented embryos. The fragment removal may be beneficial for neighboring blastomeres by repairing the intercellular communication and removing the secretion of the potential toxic materials by fragments.