• Clinical and Experimental Reproductive Medicine
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• v.11 no.2
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• pp.59-67
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• 1984

In vitro fertilization have been performed to know whether the frozen semen has fertilizing ability and can be used clinically. The results of cultured and developed embryos obtained are as follows: 1. The semen was frozen in three media for the good viability. The viability was more than 50% and the motility was also moderate (grade III), 2. As the 33 oocytes were collected from 45 follicles, the oocyte recovery rate was 73.3%. Among them, mature and immature ova were 5% each, and premature ova were 69.7%, When the first polar body was appeared, above ova were inseminated after adequate incubation with activated sperms. 3. The main components of three freezing medium containing egg yolk, glycerol and pyruvate respectively were the best for sperm viability, and Ham's F-10 medium was used for the fertilization and culture of eggs. 4. The results of in vitro fertilization of 33 ova, showed the second polar body developed in 12%, polyspermia in 24%, 1-cell embryo in 21% and 2-cell embryo in 9%. One mature ova developed to blastocyst via 16-cell to 32-cell embryo. The fertilization rate was 66%. 5. Above mentioned results represent that the frozen semen has fertilizing ability and can be used practically in the clinic.

• Toxicological Research
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• v.21 no.4
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• pp.271-278
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• 2005

Reproductive and developmental toxicology is concerned with various physical or chemical agents interfering with fertility in both gender or normal growth of offsprings. Reproductive and developmental toxicology is rather a complex science, with many fields, i.e., various endpoints are involved and many different mechanisms of action. For that reason, diverse aspects must be considered when attempting to assess possible adverse health effects in the area of reproductive and developmental toxicology. The thalidomide tragedy made it clear to regulatory authorities around the world that systematic, comprehensive evaluation of the reproductive cycle was needed to adequately evaluate the potential of medicinal drugs to impair the process of reproduction or the development of embryos, fetuses, and children. International Conference on Harmonization of Technical Requirements for the Registration of Pharmaceuticals for Human Use (ICH) and U.S. Food and Drug Administration (FDA) developed a guideline to assess the reproductive and developmental toxicity. Also these guidelines have since been applied to the detection and regulation of environmental toxicants, food additives, and so on. Although it was hoped that testing procedures of guideline would be updated constantly to reflect the current state of the science in reproductive and developmental toxicology, it was not until this decade that regulatory guidelines and testing methods have been altered in a significant way. In this paper, we would like to present the recommended approaches and recent trends for improvement of testing guidelines or experimental methods in reproductive and developmental toxicology.

• Korean Journal of Animal Reproduction
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• v.7 no.1
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• pp.15-18
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• 1983

As a preliminary experiment to establish the process of embryo transfer in rabbit, present sutdies were carried out with 75 mature Japanese of ovary to pregnant mare's serum gonadotropin(PMSG) and human chorionic gonadotropin(hCG) and collection rate of embryos at various times after hCG injection. Female rabbits were superovulated using 50∼100IU hCG or 75∼100IU PMSG and 50∼751IU hCG injected 83hrs apart. The results obtained were as follows: 1. The average number of growth follicles obtained from all of rabbits treated with hCG or PMSG-hCG was 28.1. PMSG-hCG treatment group (30.9) was clearly increased more than hCG treatment group (16.7). 2. In ovulation score, PMSG-hCG treatment group (21.0) was increased more than hCG treatment group (7.9), showing the same trends in the growth of follicles. 3. The ovulation rate per follicles developed was higher in the rabbits treated with 100 IU PMSG and 75 IU hCG (18.9%) than that from the other groups. 4. The oviduct score (72.9%) was inclined to higher than that from uteri (57.1%) in score of embryo collection.

• Korean Journal of Animal Reproduction
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• v.18 no.3
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• pp.183-189
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• 1994

We examined early development in loach(Misgurnus mizolepis) embryos with parthenogenetic agents well-known in mammals. Female loach was superovulated with an intraperitoneal injection of 15 IU human chorionic gonadotrophin (hCG) per gram body weight. After 13 h of hCG injection, the oocytes were obtained from the abdomen. The oocytes were activated with 10% ethanol in tap water or fish Ringer's solution for 5, 10 and 15 minutes(eTW5, 10, 15 and eFRS5, 10, 15), respectively. The activation rates were 29% and 10% in eFRS10 and eFRS15, 5% and 6% in eTW10 and eTW15 by judging the cleaved blastomeres. Whereas, no parthenogenetic embryo was produced by tap water or fish Ringer's solution alone. The activation rate with the fish Ringer's solution was higher than that of tap water. No embryonic development was observed by calcium ionophore, A23187, at concentrations of 10, 20, 40 and 100$\mu$M when treated for 1, 2.5 and 5 minutes, respectively. The activation agents did not cause early development as in mammalian eggs. Therefore, the results suggest that fresh water fish may have a different egg activation pathway from that of mammals.

• Clinical and Experimental Reproductive Medicine
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• v.25 no.2
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• pp.233-237
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• 1998

We demonstrated that the normal pregnancy and delivery by round spermatid injection (ROSI) into oocytes was achieved from nonobstructive azoospermia patient. In this case, the normal fertilization rate was 50%. All of the two pronuclear stage embryos cleaved and were transferred to the patient's uterus. A singleton pregnancy was achieved and resulted in the birth of normal female infant. This resuJt show that intracytoplasraic injection of round spermatid seems to be new treatment of nonobstmctive azoospermia male infertility. Further research is needed to evaluate the required culture conditions to induce progression of the round spermatid into a more elongated stage.

• Molecules and Cells
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• v.20 no.2
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• pp.228-234
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• 2005

Caenorhabditis elegans him-6 mutants, which show a high incidence of males and partial embryonic lethality, are defective in the orthologue of human Bloom's syndrome protein (BLM). When strain him-6(e1104) containing a missense him-6 mutation was irradiated with ${\gamma}$-rays during germ cell development or embryogenesis, embryonic lethality was higher than in the wild type, suggesting a critical function of the wild type gene in mitotic and pachytene stage germ cells as well as in early embryos. Even in the absence of ${\gamma}$-irradiation, apoptosis was elevated in the germ cells of the him-6 strain and this increase was dependent on a functional p53 homologue (CEP-1), suggesting that spontaneous DNA damage accumulates due to him-6 deficiency. However, induction of germline apoptosis by ionizing radiation was not significantly affected by the deficiency, indicating that HIM-6 has no role in the induction of apoptosis by exogenous DNA damage. We conclude that the C. elegans BLM orthologue is involved in DNA repair in promeiotic cells undergoing homologous recombination, as well as in actively dividing germline and somatic cells.

• Korean Journal of Agricultural Science
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• v.44 no.3
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• pp.309-317
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• 2017

Melatonin (N-acetyl-5-methoxytryptamine) is an indole synthesized from tryptophan by the pineal gland in animal. The major function of melatonin is to modulate circadian and circannual rhythms in photoperiodic mammals. Importantly, however, melatonin is also a free radical scavenger, anti-oxidant, and anti-apoptotic agent. Recently, the beneficial effects of melatonin on oocyte maturation and embryonic development in vitro have been reported in many species such as pig, cattle, sheep, mouse, and human. In this review, we will discuss recent studies about the role of melatonin in the production of porcine and bovine oocytes and embryos in vitro in order to provide useful information of melatonin in oocyte maturation and embryo culture in vitro.

• The Journal of Korean Obstetrics and Gynecology
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• v.18 no.1
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• pp.192-206
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• 2005

Objective : To know about ovarian hyperstimulation syndrome pathophysiology, risk factors and clinical features and to research the trend of the study related to OHSS. Methods : We referred a PubMed site by using searching word of "ovarian hyperstimulation syndrome"(Limits: 1 Year, only items with abstracts, Human). Results : 28 journals with 49 papers were searched. Conclusion 1. The study of OHSS subjects on pathophysiology, prevention and medical treatment. 2. As OHSS is an exaggerated response to ovulation induction therapy, it's emphasized that aspect of prevention OHSS. 3. Preventing OHSS are the following. The first is to give a GnRH agonist or antagonist in substitute for hCG. The second is to screen out prevalence of thrombophilia. The third is to monitor $E_2$ levels. The forth is to aspirate of Mediculous follicle. The fifth is cryopreservation of all embryos. The sixth is that administration of albumin for treatment of OHSS. But, it's not useful to administration of albumin for prevention of OHSS. 4. There's no therapy of OHSS. But, there's only symptomatic treatment of OHSS.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.97-97
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• 2003

Embryonic stem (ES) cells, derived from preimplantation embryos, are able to differentiate into various types of cells consisting the whole body, or pluripotency. In addition to the plasticity, ES cells are expected to be different from terminally differentiated cells in very many ways, such as patterns of gene expressions, ability and response of the cells in confronting environmental stimulations, metabolism, and growth rate. As a model system to differentiate these two types of cells, human ES (hES, MB03) cells and terminally differentiated cells (HeLa), we examined the ability of these two types of cells in confronting a severe oxidative insult, that is $H_2 O_2$. Ratio of dying cells as determined by the relative amount of dye neutral red entrapped within the cells after the exposures. Cell death rates were not significantly different when either MB03 or HeLa were exposed up to 0.4 mM $H_2 O_2$. However, relative amount of dye entrapped within the cells sharply decreased down to 0.12% in HeLa cells when the cells were exposed to 0.8 mM $H_2 O_2$, while it was approximately 54% in MB03. Pretreatment of cells with BSO (GSH chelator) and measurement of GSH content results suggest that cellular GSH is the major defensive mechanism of hES cells. Induction of apoptosis in hES cell was confirmed by DNA laddering, induction of Bax, and chromatin condensation. In summary, hES cells 1) are extremely resistant to oxidative stress, 2) utilize GSH as a major defensive mechanism. and 3) experience apoptosis upon exposure to oxidative stress.

• Applied Microscopy
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• v.23 no.1
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• pp.109-124
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• 1993

The prenatal development of thoracic spinal cord was studied by electron microscope in human embryos and fetuses ranging from 9mm to 260mm crown-rump length (5-30 weeks of gestational age). Ependymal cells in all fetal ages had conspicuous junctional complexes close to the lumen of the central canal into which microvilli and cilia projected. The ependymal cells contained numerous longitudinally arranged mitochondria, flattened cisternae of endoplasmic reticulum and Golgi complex. At 20 mm embryo, the floor and roof plates were composed of ependymoglial cells and undifferentiated neuroepithelial cells. The neuroepithelia of the sacral spinal cord were delineated from central medullary cord. By 100 mm fetus few undifferentiated neuroepithelial cells remained in the floor and roof plates. At 150 mm fetus, the whole central canal was formed by ciliated columnar epithelial cells containing cilia with basal bodies. The microvilli became tangled and club-shaped and formed a matted surface. The canal was filled with areas of dark and pale amorphous materials bounded by membrane-like structure. These two types of material were found throughout the whole central canal from 100 mm fetus onwards. By 260 mm fetus, microfibrils were first observed in the ependymal cells. In conclusion, it seems that early development and differentiation of central canal ependyma are simlar to that in other part of the brain ventricular system although ependymoglial cells are more prominent.