• Journal of Embryo Transfer
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• v.26 no.4
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• pp.223-227
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• 2011

The objective of this study was to compare of different isolation method of mouse preantral follicles, and to examine in vitro development of mouse preantral follicles isolated by different method. Preantral follicles were mechanically or enzymatically extracted from mouse ovaries. Mechanical isolation method used fine gauge needles and enzymatic method of isolating follicles used collagenase. The recovered preantral follicles were cultured for 10 days in alpha-minimal essential medium (${\alpha}$-MEM) + 5% FBS + Insulin-Transferrin-Selenium (ITS) + 100 mIU/ml FSH. The collected primary follicles by enzymatic treatment were higher than mechanical method. Others stage preantral follicle by mechanical isolation were higher than enzymatic method. After 10 days of culture, no statistical differences were shown in survival rates of preantral follicle among the 2 culture groups. The metaphase II rates of the oocytes were significantly higher (p<0.05) in mechanical method (17.8%) than in enzymatic method (5.1%). These results suggest that the isolation method of choice depends on the target stage preantral follicles and mechanical isolation is an optimal method of preantral folliclesin a culture of mouse preantral follicle.

• Proceedings of the KSAR Conference
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• 2003.06a
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• pp.29-29
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• 2003

The objective of this study is to examine an effective cryopreservation method and various vitrification containers on the survival vates of embroys. For the vitrification, in vitro produced embryos at blastocyst stage were exposed to ethylene glycol 5.5 M freezing solution (EG5.5) for 20 sec, loaded on containers such as grid, straw and paper and then immediately plunged into - 196$^{\circ}C$ L$N_2$. The blastocysts were thawed serially in 0.5, 0.25 and 0.125%; P < 0.05). Therefore, this study suggests that bovine embryos can be easily, effectively and successfully cryopreserved by grid, straw, and paper in the presence of freezing solution. Furthermore, vitrification using paper may be used as a no M sucrose in CR1aa, each for 1 min, and cultured in CR1 an medium supplemented with 10% FBS. After thawing, there were not significant differences in recovery rates of EM grid, straw and paper as 84.6, 88.3, and 93.7%, respectively (Table 1). However, survival rates of EM grid (78.1%) and paper (77.1%) showed significantly higher than straw (52. 1w method for bovine embryos.

• Atmosphere
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• v.27 no.4
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• pp.467-481
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• 2017

A correction method of reflectivity in partial beam blockage (PBB) area is suggested, which is based on the combination of digital terrain information and self-consistency principle between polarimetric observation. First, the reflectivity was corrected by adding the radar energy loss estimated from beam blockage simulation using digital elevation model (DEM) and beam propagation geometry in standard atmosphere. The additional energy loss by unexpected obstacles and non-standard beam propagation was estimated by using the coefficient between accumulated reflectivity ($Z_H$) and differences of differential phase shift (${\Phi}_{DP}$) along radial direction. The proposed method was applied to operational S-band dual-polarization radar at Jindo and its performance was compared with those of simulation method and self-consistency method for six rainfall cases. When the accumulated reflectivity and increment of ${\Phi}_{DP}$ along radial direction are too small, the self-consistency method has failed to correct the reflectivity while the combined method has corrected the reflectivity bias reasonably. The correction based on beam simulation showed the underestimation. For evaluation of rainfall estimation, the FBs (FRMSEs) of simulation method and self-consistency principle were -0.32 (0.59) and -0.30 (0.57), respectively. The proposed method showed the lowest FB (-0.24) and FRMSE (0.50). The FB and FMSE were improved by about 18% and by 19% in comparison to those before correction (-0.42 and 0.70). We can conclude that the proposed method can improve the accuracy of rainfall estimation in PBB area.

• Korean Journal of Poultry Science
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• v.41 no.4
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• pp.249-259
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• 2014

Cryopreserving cells which are maintaining their viability are the very complex process. This study has been carried out in order to find the effects of cryopreservation steps and freezing media on the rates of viability of cryopreserved chicken primordial germ cells (PGCs). PGCs obtained from the germinal gonade of 5.5~6 day (stage 28) chick embryos of Korean Ogye (KO) and Commercial breeds (C), using the MACS method were suspended in a freezing medium containing a freezing and protecting agents (e.g. dimethyl sulfoxide (DMSO), ethylene glycol (EG) and propylene glycol (PG)). Gonads were harvested from stage 28 chick embryos and pooled in groups of 5, 10, 15, 20E embryos, contributing gonads to the cell suspension. The gonadal cells, including PGCs, were then frozen in 1 of the following cryoprotectant treatments : 2.5%, 5%, 10%, 15% and 0% cryoprotectant (DMSO, EG, PG) as a control. Effects of exposure to slow freezing and vitrification, with different concentrations of the cryoprotectant solution, were examined. After vitrification and slow freezing, survival rates of the frozen-thawed PGCs from the 10% EG plus FBS treatment were 85.63%, and 66.14% (p<0.05), respectively. The viability of PGCs after freeze-thawing was significantly higher for 10% EG plus FBS treatment than for 10% PG + FBS treatment (p<0.05) (85.63% vs 66.81%) by vitrification. This study established a method for preserving chicken PGCs that enables systematic storage and labeling of cryopreserved PGCs in liquid ($LN_2$) at a germplasm repository and ease of entry into a data base. In the future, the importance for this new technology is that poultry lines can be conserved while work is being conducted on improving the production of germline chimeras.

• Clinical and Experimental Reproductive Medicine
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• v.28 no.2
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• pp.79-86
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• 2001

Objective: Mouse pre-antral follicles require the addition of gonadotropins (Gns) to complete maturation and ovulation of oocyte and antrum formation in vitro. However, we tried examination of in vitro growth of mouse pre-antral follicles in medium without Gns and/or phygiological factors. And also, pre-antral follicles were isolated from ovaries by mechanical method. Our present studies were conducted to evaluate on the growth of follicles and intra-follicular oocytes and antrum formation in vitro of mouse pre-antral follicles in two different media. Methods: Pre-antral follicles ($91{\sim}120{\mu}m$) were isolated mechanically by fine 30G needles not using enzymes from ovaries of 3-6 week-old female ICR mice. Isolated pre-antral follicles were cultured in $20{\mu}l$ droplets of TCM (n=17; follicles: $107.8{\pm}1.58{\mu}m$; oocytes: $57.9{\pm}1.2{\mu}m$) or MEM (n=12; follicles: $109.3{\pm}2.53{\mu}m$; oocytes: $55.4{\pm}1.6{\mu}m$) under mineral oil on the 60 mm culture dish. All experimental media was supplemented with 10% FBS without Gns and/or physiological factors. Pre antral follicles were individually cultured for 8 days. Antram formation and growth of pre-antral follicles and intra-follicular oocytes were evaluated using precalibrated ocular micrometer at X200 magnifications during in vitro culture. Results were analyzed using combination of Student's t-test and Chi-square, and considered statistically significant when p<0.05. Results: Antrum formation had started in two culture media on day 2. On day 8, antrum formation had occurred in 58.3% of pre-antral follicles cultured in DMEM, but only in 23.5% of those cultured in TCM (p=0.0364). Growth of pre-antral follicles and intra-follicular oocytes were observed on day 4 and 8. On day 4, follicular diameter was similar (p=0.1338) in TCM ($119.4{\pm}2.58{\mu}m$) and MEM ($125.4{\pm}4.52{\mu}m$). However, on day 8, diameters of pre-antral follicles cultured in MEM ($168.9{\pm}17.29{\mu}m$) were significantly bigger (p=0.0248) than that in TCM ($126.7{\pm}4.28{\mu}m$). On day 4 and 8, diameters of intra-follicular oocytes were similar in TCM ($67.1{\pm}1.3$ and $72.4{\pm}0.9{\mu}m$) and MEM ($65.2{\pm}1.7$ and $73.3{\pm}1.5{\mu}m$), respectively. Conclusion: We can conform that medium without Gns and/or physiological factors can be used for in vitro antrum formation and growth of pre-antral follicles and intra-follicular oocytes in mouse. In conclusion, MEM supplemented with FBS can be used for growth in vitro of mouse pre-antral follicles isolated mechanically.

• Child Health Nursing Research
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• v.4 no.2
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• pp.193-206
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• 1998

The purpose of this study was to examine the stressors and stress coping styles of 6th grade el ementary school children and to explore the relationship between stressful life events and health symptoms and the effects of coping style which is theoretically considered to mediate the relationship between stress and health symptoms. The study subjects consisted of 329 in 6th grade elementary school children in Cheong-Ju city. Of the 329 subjects, 171 were boys and 158 were girls. For this study, three kinds of questionnaires were adopted as follows ; 1) Feel Bad Scale (FBS) by Lewis et al., 2) lazarus-Folkman's Way of coping questionnaire 3) Hee Sun Shin's Health Symptom questionnaire (HSQ) The researcher visited the school and collected data in the class using the questionnaire method after an explanation of the purpose and procedures was given to the children. Data collection was done for 10 days (from 5th to 15th of July 1997) . The data were analyzed by descriptive statistics, correlation analysis, multiple regression analysis using the SAS statistical program. The results of this study were as follows : 1. The mean score for the FBS was 211.37(range : 77-427), The most severe stressors perceived by children were parental divorce and other's smash or steal of my things. The most frequently experienced stressful life events were conflict with siblings and being scolded for other's fault. 2. The most frequently used stress coping style was the active coping (M=17.85), followed by passive (M=13.64) and magical one (M=13.42). 3. The mean score for the HSQ was 23.30(range : 0-72) The most frequently complained health symptoms were headache and having much worry about everything. 4. There was a significant relationship between stressful life events and health symptoms (r=.60, p<.001). Also, stressful life events were positively related with passive coping(r=.27, p<.001) and magical coping (r=.38, p<.001). Health symptoms were positively correlated with passive coping(r=.33, p<.001) and magical coping (r=.41, p<.001). 5. Stepwise multiple regression analysis revealed that the most powerful predictor was the variable of stressful life events. Health concerns, magical coping style, passive coping style and active coping style accounted for 49.15% of the variance in health symptoms. This study revealed that stressful life events correlated with health symptoms in 6th grade elementary school children and passive coping and magical coping had mediating effects on this relationship. The implication for nursing is that there is a need to develop supportive interventions for high risk population to decrease health problems due to stress.

• Journal of Periodontal and Implant Science
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• v.26 no.4
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• pp.873-887
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• 1996

Platelet-derived growth factor(PDGF) is one of the polypeptide growth fators. PDGF has been reported as a biological mediator which regulates activities of wound healing process including the cell proliferation, migration and metabolism. Recent studies indicated that demineralized root surface as the primary site for growth factor application has advantages over other application method, especially due to binding capacity of growth factor for exposed matrix component of deminera1ized dentin surface. The purpose of this study is to evaluate optimal application time of PDGF-BB on proliferation of human gingival fibroblasts using deminera1ized dentin surface as primary application site. Human gingival fibroblasts and dentin slabs were prepared from the first premolar tooth extracted for the orthodontic treatment, cells were cultured in DMEM/I0% FBS at the $37^{\circ}C$, 5% CO2 incubator. All of the dentin slabs were preconditioned with Tetracycline HCI(100mg/ml) solution and rinsed in PBS. In the cell proliferation experiment, experimental group was immersed in DMEM containing 10% FBS, 50ng/rnl PDGF-BB during different time(30sec, 1, 2, 4, 8 minutes) and dried. Cells at concentration of $1{\times}10^5$cells/ml were seeded in each culture well which contained dentin slabs and incubated for 6 hours. Then, all of the dentin slabs were moved into new 24 well culture dish and incubated for 24, 48, 72 hours. The cell counting was done by hemocytometer with inverted phase contrast microscope after trypsinization. The results were as follows : The application of PDGF-BB for 1, 2 min slightly increased the number of gingival fibroblasts, and the application of PDGF-BB for 4, 8 min prominently increased the number of gingival fibroblasts. The application of PDGF-BB for 4 min showed maximum proliferation rate of gingival fibroblasts at 24, 48, 72 hours, and the application of PDGF-BB for 8 min showed less proliferation rate of gingival fibroblasts compared to the application of PDGF-BB for 4 min at 24, 48, 72 hours. In conclusion, the application of PDGF-BB for 4 min appeared to be optimal to obtain maximum proliferation of gingival fibroblasts using demineralized dentin surface as primary applicaton site of PDGF-BB.

• Clinical and Experimental Reproductive Medicine
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• v.33 no.2
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• pp.115-123
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• 2006

Objective: To investigate new signal transduction cascade through integrin, FAK and ERK in the suppressed cell proliferation by GnRH-I and -II. Method: Human endometrial cancer cells (HEC1A) were cultured under the following condition: DMEM/F12 (10% FBS). GnRH-I and -II were treated time (0, 5, 10, 15, 20, 30 min; 100 nM) and dose (10 nM or 100 nM; 20 min) dependent manner according to experimental purposes. Cell proliferation was measured using [$^3H$] thymidine incorporation assay. Immunoblotting was utilized to detect proteins. Results: GnRH-I and -II inhibited proliferation of HEC1A cells and induced expression of integrin ${\beta}3$. Phosphorylation of FAK and ERK were induced by GnRH-I and -II. Conclusion: GnRH inhibited cell proliferation via the expression of integrin and FAK, ERK phosphorylation.

• Clinical and Experimental Reproductive Medicine
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• v.33 no.2
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• pp.105-113
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• 2006

Objective: To investigate the role of ERK and $PPAR{\gamma}$ on the $TGF-{\beta}1$ induced human endometrial stromal cell decidualization in vitro. Method: Endometrial stromal cells are cultured under the following condition: DMEM/F12 (10% FBS, 1 nM E2 and 100 nM P4). $TGF-{\beta}1$ (5 ng/ml), Rosiglitazone (50 nM), and PD98059 ($20{\mu}M$) were added according to experimental purposes. Trypan-Blue and hematocytometer were utilized to count cell number. Enzyme-linked immunosorbent assay (ELISA) and western blotting were utilized to detect proteins. Result: $TGF-{\beta}1$ inhibited proliferation of cultured human endometrial stromal cells and induced expression of PGE2 and prolactin. This effect was mediated by Smad and ERK activation. Administration of rosiglitazone, $PPAR{\gamma}$ agonist, prevented $TGF-{\beta}1$ effect on cell proliferation. Furthermore, Rosiglitazone inhibited $TGF-{\beta}1$ induced activation of ERK, consequently reduced PGE2 and prolactin production. Conclusion: $TGF-{\beta}1$ induced decidualization of endometrial stromal cell through Smad and ERK phosphorylation. $PPAR{\gamma}$ acts as a negative regulator of human ndometrial cell decidualization in vitro.

• Clinical and Experimental Reproductive Medicine
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• v.25 no.2
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• pp.129-134
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• 1998

The objective of this study was to test whether the developmental capacity of human multi-pronuclear (PN) zygotes after ultra-rapid freezing using EM grid can be maintained. For this experiment, multi-PN zygotes which produced in human IVF program were used as an alternatives of normal 2PN zygotes, and they were separated into 3PN or $\geq4PN$ zygotes to compare their in vitro development and cryoinjury according to PN number. As freezing solution, EFS30 which consisted of 30% ethylene glycol, 18% bcoll, 0.5 M sucrose and 10% FBS added D-PBS was used. The result obtained in this experiment was summarized as follows; When the multi..PN zygotes were ultrarapidly frozen and thawed, the high mean percentages (85.5%) were survived. Also when the cleavage rates between control and freezing group were compared with PN number, there were not significantly different in each group (3PN; 81.3% & 85.4% and $\geq4PN$; 90.0% & 95.7%). When the in vitro development rates after thawing were examined, freezing 3PN group (22.0%) was not differed to control 3PN group (38.5%), although the development result of freezing $\geq4PN$ group (45%) was significantly lower than that of control $\geq4PN$ group (44.4%) (p<0.05). These results demonstrate that developmental capacity of human zygote can be obtained by ultra-rapid freezing method using EM grid and EFS30.