• The Korean Journal of Zoology
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• v.23 no.1
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• pp.13-24
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• 1980

The germarium contains the apical complex consisting of a multinucleated syncytium. Apical complex has a nutritive role for the early spermatogonia. Trophocytes are irregularly shaped and are distributed throughout the space from spermatogonial cysts to sperm bundles, and they increase in size by endopolyploidization. As meiotic divisions are not complete until the final moult, spermatogenesis continues even in the adult. Chromosome number is 2n=24. Spermiogenesis is divided into seven stages in terms of chromatin concentration, cytoplasmic granules, and the nuclear size and shape. These stages could be grouped into the spherical, the elongating and the rodform spermatids in shape.

• Applied Microscopy
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• v.26 no.3
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• pp.267-275
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• 1996

The internal ultrastructural changes of germ cells and external morphology of spermatozoon during the spermatogenesis in the rockfish, Sebastes inermis were studied using transmission and scanning electron microscope. The testis is seminiferous tubule type in internal structure. Seminiferous tubule consist of many cyst which contain numerous germ cells in same developmental stage. Spermatogonium contained a large nucleus with single nucleolus in interphase. Primary spermatocyte identified by the presence of synaptonemal complex in nucleus and the contained a number of mitochondria, endoplasmic reticula and Golgi bodies in cytoplasm. The nucleoplasm of secondary spermatocyte was more concentrated than that of the previous phase. Spermatids were more condensed in nucleus and cytoplasm, and show the long-spherical shape. In the cytoplasm of spermatid mitochondria located to lower portion of the nucleus and Golgi bodies located to upper portion, but proacrosomal granule is not appeared. The spermatozoon consist of the head and tail. No acrosome could be found in the head. The cytoplasmic collar of posterior part in sperm head contained mitochondria which surrounded axial filament. The well developed axonemal lateral fins were identified in sperm flagellum, and the axial filament of the flagellum consist of nine pairs of peripheral microtubules and one pair of central microtubules.

• Clinical and Experimental Reproductive Medicine
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• v.34 no.1
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• pp.41-48
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• 2007

Objective: To determine whether the presence of Y-chromosome microdeletion affects the outcome of in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) program. Methods: Fourteen couples with microdeletion in azoospermic factor (AZF)c region who attempted IVF/ICSI or cryopreserved and thawed embryo transfer cycles were enrolled. All of the men showed severe oligoasthenoteratoazoospermia (OATS) or azoospermia. As a control, 12 couples with OATS or azoospermia and having normal Y-chromosome were included. Both groups were divided into two subgroups by sperm source used in ICSI such as those who underwent testicular sperm extraction (TESE) and those used ejaculate sperm. We retrospectively analyzed our database in respect to the IVF outcomes. The outcome measures were mean number of good quality embryos, fertilization rates, implantation rates, $\beta$-hCG positive rates, early pregnancy loss and live birth rates. Results: Mean number of good quality embryos, implantation rates, $\beta$-hCG positive rates, early pregnancy loss rates and live birth rates were not significantly different between Y-chromosome microdeletion and control groups. But, fertilization rates in the Y-chromosome microdeletion group (61.1%) was significantly lower than that of control group (79.8%, p=0.003). Also, the subgroup underwent TESE and having AZFc microdeletion showed significantly lower fertilization rates (52.9%) than the subgroup underwent TESE and having normal Y-chromosome (79.5%, p=0.008). Otherwise, in the subgroups used ejaculate sperm, fertilization rates were showed tendency toward lower in couples having Y-chromosome microdeletion than couples with normal Y-chromosome. (65.5% versus 79.9%, p=0.082). But, there was no significance statistically. Conclusions: In IVF/ICSI cycles using TESE sperm, presence of V-chromosome microdeletion may adversely affect to fertilization ability of injected sperm. But, in cases of ejaculate sperm available for ICSI, IVF outcome was not affected by presence of Y-chromosome AZFc microdeletion. However, more larger scaled prospective study was needed to support our results.

• Toxicological Research
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• v.16 no.2
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• pp.163-172
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• 2000

Recently, there is a worldwide concern that a great number of man-made chemicals have a hormone-like action both in humans and in animals. DECD is developing screening programs using validated test systems to determine whether certain substances may have an effect in humans. In the present study. the establishment oj repeated-dose toxicity test method was tried. Flutamide. an anti-androgenic agent. was administered by gavage to Sprague-Dawley rats for 28 days at dose levels of 0. 0.5. 3 and 18 mg/kg body weight (10-15 rats/sex/group) to examine the effects on general findings. especially reproductive and endocrine parameters. Clinical signs. body weights, food consumption, and sexual cycle were checked and measured. For the gross and microscopic examinations. 10 rats/sex/group were sacrificed at the end of dosing period and the remaining animals of control and high dose groups (5 each) were sacrificed after 14 days recovery. Examinations for hematology and clinical chemistry were carried out at necropsy. There were no treatment-related changes in clinical signs. body weights, food consumption. gross necropsy. hematology and clinical chemistry at all doses of both sexes. The period and regularity of sexual cycle were not adversely affected at all doses by the test agent. At 18 mg/kg. both decreased weights of prostate, seminal vesicle and epididymis in males and increased weights of spleen and thymus in females were observed. In addition, decreased number of spermatids and sperms. increased serum testosterone concentration and increased incidence (100%) of interstitial cell hyperplasia were seen in males. At 18 mg/kg of the recovery group. decreased prostate weight. reduced sperm count and increased incidence (20%) of interstitial cell hyperplasia in males and increased thymus weight in females were observed. At 3 mg/kg. reduced sperm count was found. There were no adverse effects on parameters examined at 0.5 mg/kg of both sexes. The results suggested that the potential target organs of flutamide may be accessory sexual glands including testes for males and spleen and thymus for females. Taken together. this test method was found to be a useful screening test system for endocrine disrupting chemicals.

• Journal of Embryo Transfer
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• v.25 no.1
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• pp.51-55
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• 2010

The relationships of scrotal circumference (SC) to semen characteristics and the conception rate (70 days-nonreturn rate) of artificial insemination in farm were studied with 137 heads of bull in Hanwoo. The average and range of SC were $38.27{\pm}3.90$ cm and 26.0~52.5 cm, respectively. Hanwoo bulls were classified with SC, divided into 34 cm below group, 34~39 cm group, and 39 cm over group. The 5,487 semen records of 43 heads of bull from July. 1. 2007 to June. 30. 2008. were used to determine the relationships between SC and semen characteristics. The semen concentration and total sperm number of each group were 11.18, 16.68, and $17.4{\times}10^8/ml$, and 69.83, 101.64 and $114.40{\times}10^8$/ejaculate. The bulls with 34 cm or more SC were higher than the bulls with 34 cm below in semen concentration and total sperm number (p<0.01). But between SC and semen volume have no significant relationship (p>0.05). The 9,862 mating records of 44 farm with 137 heads of bull were used to determine the relationships between SC and conception rate. The conception rate of 1st artificial insemination were 73.31, 74.16, and 77.33 % in each group. Also SC was positively correlated with pregnancy rate (r=0.12, p=0.17). These results indicate that SC correlates positively with semen characteristics, and maybe with pregnancy rate in Hanwoo.

• Clinical and Experimental Reproductive Medicine
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• v.44 no.1
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• pp.47-51
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• 2017

Objective: This study was designed to report the status of assisted reproductive technology (ART) therapy in South Korea between January 1, 2012 and December 31, 2012. Methods: A localized online survey, originally developed by the International Committee Monitoring Assisted Reproductive Technologies, was first launched and provided to all available ART centers via email in 2015. Fresh embryo transfer (FET) cases were categorized as standard in vitro fertilization, intracytoplasmic sperm injection (ICSI), or half-ICSI. Thawed embryo transfer (TET) and other related procedures, including surgical sperm retrieval, were surveyed. Results: Data from 33,956 ovum pick-up procedures were provided by 75 clinics in 2012. Of the 33,088 cycles in which ovums were retrieved, a complete transfer was performed in 90.5% (29,932 cycles). In addition, 10,079 FET cycles were confirmed to have resulted in clinical pregnancy, representing a pregnancy rate of 30.5% per ovum pick-up and 33.7% per ET. The most common number of embryos transferred in FET was 2 (41.6%), followed by 3 (34.0%), and non-elective single ETs (10.0%). Of the 10,404 TET cycles in which transfer was completed, 3,760 clinical pregnancies (36.1%) were confirmed by ultrasonography. Conclusion: The overall clinical pregnancy rate for FET and TET cycles in 2012 was higher than in 2011 (33.7% vs. 33.2% and 36.1% vs. 31.1%, respectively). The most common number of embryos transferred in FET cycles was 2, unlike in 2011.

• Clinical and Experimental Reproductive Medicine
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• v.35 no.2
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• pp.131-141
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• 2008

Objective: To compare the outcomes of intracytoplasmic sperm injection (ICSI) with fresh and cryopreserved-thawed testicular spermatozoa in patients with azoospermia. Methods: One hundred and nine cycles (66 couples) where ICSI was planned with fresh or cryopreserved-thawed testicular spermatozoa were included in this study; Ninety two cycles (61 couples) with fresh testicular spermatozoa (fresh group) and seventeen cycles (13 couples) with cryopreserved-thawed testicular spermatozoa (cryopreserved-thawed group). We compared ICSI outcomes such as fertilization rate, implantation rate, pregnancy rate and miscarriage rate, which were statistically analyzed using Mann-Whitney U test or Fisher's exact test, where appropriate. Results: In 9 out of the 92 cycles where ICSI was planned with fresh testicular spermatozoa, testicular spermatozoa could not be retrieved. Fertilization rate tended to be higher in the fresh group than in the cryopreserved-thawed group ($58.0{\pm}27.8%$ vs. $45.9{\pm}25.0%$, p=0.076). The number of high quality embryos was significantly higher in the fresh group ($0.9{\pm}1.2$ vs. $0.2{\pm}0.5$, p=0.002). However, there were no significant differences in clinical pregnancy rate, implantation rate and miscarriage rate between the two groups. Conclusion: The results of this study suggest that although the use of cryopreserved-thawed testicular sperm for ICSI in patients with azoospermia may reduce fertilization capacity and embryo quality, it may not affect pregnancy rate, implantation rate and miscarriage rate. If testicular sperm can be obtained before ICSI procedure, the use of cryopreserved-thawed testicular sperm may also avoid unnecessary controlled ovarian hyperstimulation and cancellation of oocyte retrieval when spermatozoa cannot be retrieved as well as damage on testicular function by repeated TESE.

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

• Korean Journal of Animal Reproduction
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• v.25 no.2
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• pp.181-189
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• 2001

The objective of this study was to evaluate the development of porcine follicular oocytes fertilized by intracytoplasmic sperm injection (ICSI). Cumulus-oocyte-complexes (COCs) were collected by aspiration from follicles of 2~7 mm in diameter from a local slaughterhouse. Oocytes were matured in vitro for 40~44 h, and spermatozoa were prepared by swim-up in the presence or absence of 5 mM dithiothreitol (DTT) and then M II stages of the oocyte were either centrifuged or not centrifuged for the following injection of ooplasm. Injected oocytes were cultured in NCSU 23 medium for 6 to 8 days. The results obtained were as follows: 1. The rates of cleavage and development rates into blastocyst by ICSI were not significantly different between the with (53.0% and 19.7%) or without (48.3% and 23.8%) centrifugation, respectively (P＜0.05). 2. The cleavage and developmental rates to blastocyst after ICSI with or without 5 mM DTT treated-sperm were not significantly different (60.4% vs 16.4% and 45.5% vs 22.2%), respectively (P＜0.05). 3. The cleavage and the developmental rates to btastocyst were not significantly different between the zygotes obtained by IVF (51.8% vs. 22.4%) and ICSI (51.4% vs. 21.6%) (P＜0.05). 4. The number of blastomere in blastocyst stages after IVF or ICSI was not significantly different (46.7$\pm$2.9 and 41.9$\pm$4.6).

• Korean Journal of Agricultural Science
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• v.28 no.2
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• pp.85-91
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• 2001

This study was carried out to investigate the effects of liquid boar semen on reproductive performance in swine artificial insemination. Many factors, which were breeds, time of insemination, breeding season, sperm per dose etc, have been tried to improve reproductive efficiency. Boars were raised at Swine Artificial Insemination Center in National Livestock Research Institute, Sunghwan, Chungnam, Korea. This experiment was carried out from 1995 to 2000. There were no differences in the fertility results compared with 3 breeds (Landrace, Yorkshire and Duroc), frequencies of artificial insemination (double and triple) per estrus cycle and different seasons by using liquid boar semen. There were no significant differences in conception rate, farrowing rate and litter size using 4 trials of 3.0, 2.5, 2.0 and $1.5{\times}10^9/80ml$ in liquid boar semen with 70% of motile sperm cells. We confirmed that the sperm number per dose of $1.5{\times}10^9/80ml$ could be used for commercial artificial insemination.