• Restorative Dentistry and Endodontics
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• v.48 no.1
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• pp.1.1-1.11
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• 2023

Objectives: This study evaluated the dentinal penetration depth of 2.5% sodium hypochlorite (NaOCl) in root canals with and without preparation and different irrigant activation protocols. Materials and Methods: Sixty-three bovine mandibular incisors were randomly allocated to 6 groups (n = 10): G1, preparation + conventional needle irrigation (CNI); G2, preparation + passive ultrasonic irrigation (PUI); G3, preparation + Odous Clean (OC); G4, no preparation + CNI; G5, no preparation + PUI; G6, no preparation + OC; and CG (negative control; n = 3). Samples were filled with crystal violet for 72 hours. Irrigant activation was performed. Samples were sectioned perpendicularly along the long axis, 3 mm and 7 mm from the apex. Images of the root thirds of each block were captured with a stereomicroscope and analyzed with an image analysis software. One-way analysis of variance, followed by the Tukey post hoc test, and the Student's t-test were used for data analysis, with a significance level of 5%. Results: The NaOCl penetration depth was similar when preparation was performed, regardless of the method of irrigation activation (p > 0.05). In the groups without preparation, G6 showed greater NaOCl penetration depth (p < 0.05). The groups without preparation had a greater NaOCl penetration depth than those with preparation (p = 0.0019). Conclusions: The NaOCl penetration depth was similar in groups with root canal preparation. Without root canal preparation, OC allowed deeper NaOCl penetration. The groups without preparation had greater NaOCl penetration than those undergoing root canal preparation.

• 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.32 no.3
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• pp.261-268
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• 2005

Objective: To compare the clinical results and pregnancy outcomes of in vitro fertilization (IVF) between GnRH antagonist cycles and GnRH agonist (GnRH-a) cycles including flare-up and long protocol in women with advanced age. Materials and Methods: Retrospective clinical study. From January 2001 to September 2003, IVF cycles of female patient 37 years over were included in this study. GnRH-a long protocol (62 cycles, 61 patients) and GnRH antagonist multi-dose flexible protocol (66 cycles, 51 patients) were compared with the control group of GnRH-a flare-up protocol (151 cycles, 138 patients). IVF cycles for non-obstructive azoospermia (NOA), endometriosis III, IV and polycystic ovarian syndrome (PCOS) were excluded in this study. Clinical results such as total gonadotropin dose, serum E2 on hCG administration, the number of retrieved oocytes and the pregnancy outcomes - clinical pregnancy rate (CPR), implantation rate (IR) and live birth rate (LBR) per embryo transfer - were compared. Results: There were significant differences in the total dose of gonadotropin (GnRH-a flare-up vs. GnRH-a long vs. GnRH-antagonist; 41.8 vs. 54.7 vs. 24.8), serum E2 on hCG administration (1787.2 vs. 1881.6 vs. 788.0), the numbers of retrieved oocytes (8.1 vs. 11.1 vs. 4.5) and endometrial thickness (9.1 vs. 10.4 vs. 8.0) which were significantly lower in GnRH-antagonist cycles. But pregnancy outcomes shows no significant differenced in CPR (25.0% vs. 35.8% vs. 24.5%), IR (11.7% vs. 12.3% vs. 10.1%) and LBR (15.8% vs. 28.3% vs. 15.1%) Conclusion: In women with advanced age, GnRH-antagonist cycles can result in comparable pregnancy outcomes to GnRH-a cycles including flare-up and long protocol. GnRH-a long protocol show higher CPR, IR and LBR than GnRH antagonist multi-dose flexible protocol and flare-up protocol without significant differences.

• Clinical and Experimental Reproductive Medicine
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• v.19 no.1
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• pp.31-39
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• 1992

By means of the results of In vitro fertilization(IVF) of supernumerary oocytes, the possibility of predicting a pregnancy outcome following gamete intrafallopian transfer(GIFT) and the prognostic implications for future pregnancy were evaluated in 46 GIFT cycles excluding simultaneous program of GIFT and IVF from February, 1989 to July, 1991. IVF of supernumerary oocytes were identified in 21 cycles, but not in remaining 25 cycles. There was no significant difference in age, duration and etiologic factors of infertility, and serum levels of FSH, LH and $E_2$ on MCD #3 and $E_2$ on the day of hCG injection between fertilized(N=21) and unfertilized group(N=25). The number of oocytes retrieved was similar in both groups. The number of supernumerary oocytes available for IVF after transfer was $5.43{pm}2.95$ ranging from 2 to 12. The prenancy rate in fertilized group, 33.3%(7/21), was higher without statistical significance, compared with 8.0%(2/25) in unfertilized group. Using IVF of supernumerary oocytes as a test of pregnancy following GIFT, sensitivity was 77.8 %; specificity, 61.2%; positive predictive value(PPV), 33.3%; negative predictive value(NPV), 92%. The fertilization rate of supernumerary oocytes in pregnant group, $86.4{\pm}22.8%$ was significantly higher compared with $56.1{\pm}20.2%$ in nonpregnant group. In cases with fertilization rate ${\geq}80%$, pregnancy was expected with PPV of 85.7%. In conclusion, IVF of supernumerary oocytes in GIFT program can be a profitable method as a prognostic indicator of pregnancy following GIFT. More aggressive diagnostic and therapeutic measures should be performed in cases with failure in IVF of supernumerary oocytes.

• Clinical and Experimental Reproductive Medicine
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• v.27 no.4
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• pp.359-366
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• 2000

The present studt was performed to investigate the effect of treatment and samples of human follicular fluid (hFF) on the development in vitro of mouse embryos. The two cell stage embryos collected at 40 h post-hCG injection were cultured in the modified human tubal fluid (m-RTF) containing 15% synthetic serum substitute (SSS) or human tubal fluid (hFF) for up to 3 days at $37^{\circ}C$ in 5% $CO_2$ incubator. Also the composition of hormone, total protein and protein pattern of hFF samples were analyzed. The developmental rate of mouse embryos developed to blastocyst were not significant difference in the m-RTF containing 15% hFF filtered with 0.22 or 0.8 ${\mu}m$ syringe filter, however, the embryos cultured in the m-RTF containing inactivated hFF were significantly (p<0.05) developed at the high rate to blastocyst than those containing fresh hFF and SSS. The in vitro developmental rate to blastocyst and hatched blastocyst in the m-RTF containing 15% hFF sample A (90.5 and 85.4%, respectively) and SSS (79.4 and 75.3, respectively) were significantly (p<0.05) increased, compared with hFF sample B (64.2 and 54.1 %, respectively). The hFF sample A tended to be higher concentration of LH, FSR, total protein and the ratio of progesterone/$E_2$ and lower concentration of $E_2$ and progesterone than the hFF sample B, but there were no differences in the protein pattern between the two hFF samples. The results of these study suggest that the addition of hFF to the culture medium enhances the development in vitro to blastocyst and hatched blastocyst, but the in vitro developmental rate of mouse embryos is different between hFF samples.

• Clinical and Experimental Reproductive Medicine
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• v.17 no.1
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• pp.29-44
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• 1990

In 105 patients with the past history of poor response to the previous controlled ovarian hyperstimulation(COH) due to poor follicular growth or premature LH surge, the effectiveness of pituitary suppression with gonadotropin-releasing hormone agonist(GnRH agonist) in IVF/GIFT program was evaluated in 112 cycles of COH using a combination regimen of Leuprolide acetate (Lupron TAP Pharmaceuticals, USA) and FSH/hMG or pure FSH from May to December, 1989 at SNUH. Starting on day 21 of the menstrual cycle(MCD #21, Day 1), Lupron (1.0mg/day, subcutaneous) was administered once a day till next MCD #3(suppression phase). After the confirmation of pituitary suppression, ovarian follicular growth was stimulated with FSH/hMG or pure FSH from MCD #3(Day + 1), and Lupron was continued with hMG or FSH until hCG administration (D 0) (stimulation phase). After suppression phase, serum E2 level decreased from 183.7${\pm}$95.1(Day 1) to 17.4${\pm}$12.3pg/ml (Day +1), and serum progesterone level from 19.17${\pm}$8.67 to 0.12${\pm}$0.05ng/ml. But there was no decresas in serum LH and FSH levels; LH from 12.74${\pm}$6.21 to 15.49${\pm}$4.93mIU/ml,FSH from 7.60${\pm}$3.84 to 8.58${\pm}$3.15 rnlU/ml. There was no occurrence of premature LH surge during COH. Eleven cycles(9.8%) were cancelled due to poor follicular growth during stimulation phase, and 3 cycles (3.0%) failed in the transvaginal oocytes fretrieval. Serum E2 level was 1366.8${\pm}$642.4 on D 0 and 1492.3${\pm}$906.9pg/ml on D+1. 7.00${\pm}$3.32 follicles(FD${\geq}$12mm) were observed on D 0, and 6.11${\pm}$4.15 oocytes were retrieved, with the oocyte retrieval rate per follicle of 95.0%. 3.59${\pm}$2.57 oocytes were fertilized and cleaved with the oocyte cleavage rate of 55.7%. In 83 IVF patients, 4.08${\pm}$2.39 embryos were transferred, and 16 pregnancies were obtained with the pregnancy rate per ET 2.39 mebryos were transferred, and 16 pregnancies were obtained with the pregnancy rate per ET of 19.3%. In 6 GIFT patients, 7.83${\pm}$3.31 oocytes were retrieved and transferred with maximum number of 6, but no pregnancy was obtained. When compared with the previous 108 cycles of COH using FSH/hMG or pure FSH regimen, the cancellation rate during COH was significantly decreased, and all the parameters of the outcome of COH including the pregnancy rate were increased. These data suggest that GnRH agonist therapy for pituitary suppression is an effective adjunct to the current gonadotropin regimens for COH in IVF/GIFT and can increase the probability of oocytes retrieval and pregnancy, especially in the previous poor responders.

• Journal of Veterinary Clinics
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• v.19 no.4
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• pp.391-396
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• 2002

cows, in order to suggest a means for the improvement of milk production. A total of 30 Holstein cows (3rd to 5th of parity) were used and assigned to two groups according This study investigated blood biochemical values between high and low yielding dairy to milk production levels at 15, 30, 60 and 90 days postpartum. Milk production of group A was less than an average of 27 kg/day and that of group B was an average of 30 kg/day. Blood samples were collected by jugular venipuncture from each cow six times at 15 days before the anticipated calving date, within 12 hours postpartum (0 days) and at 15, 30, 60 and 90 days after calving. In serum mineral concentrations, group B was consistently higher than group A in both Mg and Ca. Inorganic phosphorus concentrations showed a little fluctuation between the groups at antepartum and at postpartum, but group B was significantly higher than group A at 15 and 30 days after calving (p < 0.05). In serum biochemical values cholesterol concentrations were consistently higher in group B except at 0 days. BUN and glucose concentrations did not differ between the groups. The concentration of vitamin A of group B was significantly higher than group A at 15 days before the anticipated calving date and at 15 days postpartum (p < 0.01), but at 30, 60 and 90 days postpartum vitamin A concentration of both groups were similar. Vitamin E concentration did not differ between the groups during the experimental period. Results of this study suggest that raising the levels of Mg, Ca, Pi and vitamin A in serum would be effective in increasing milk production of low producing cows.

• Korean Journal of Applied Biomechanics
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• v.33 no.3
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• pp.110-117
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• 2023

Objective: The purpose of this study was to find out kinematic and kinetic differences the lower extremity joint according to the landing type during vertical jump movement after jump landing, and to present an efficient landing method to reduce the incidence of injury in youth players. Method: Total of 24 Youth players under Korean Sport and Olympic Committee, who used either heel contact landing (HCG) or toe contact landing (TCG) participated in this study (HCG (12): CG height: 168.7 ± 9.7 cm, weight: 60.9 ± 11.6 kg, age: 14.1 ± 0.9 yrs., career: 4.3 ± 2.9 yrs., TCG height: 174.8 ± 4.9 cm, weight: 66.9 ± 9.9 kg, age 13.9 ± 0.8 yrs., career: 4.7 ± 2.0 yrs.). Participants were asked to perform jump landing consecutively followed by vertical jump. A 3-dimensional motion analysis with 19 infrared cameras and 2 force plates was performed in this study. To find out the significance between two landing styles independent t-test was performed and significance level was set at .05. Results: HCG showed a significantly higher dorsi flexion, extension and flexion angle at ankle, knee and hip joints, respectively compared with those of TCG (p<.05). Also, HCG revealed reduced RoM at ankle joint while it showed increased RoM at knee joint compared to TCG (p<.05). In addition, HGC showed greater peak force, a loading rate, and impulse than those of TCG (p<.05). Finally, greater planta flexion moment was revealed in TCG compared to HCG at ankle joint. For the knee joint HCG showed extension and flexion moment in E1 and E2, respectively, while TCG showed opposite results. Conclusion: Compared to toe contact landing, the heel contact landing is not expected to have an advantage in terms of absorbing and dispersing the impact of contact with the ground to the joint. If these movements continuously used, performance may deteriorate, including injuries, so it is believed that education on safe landing methods is needed for young athletes whose musculoskeletal growth is not fully mature.

• Journal of Life Science
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• v.18 no.8
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• pp.1132-1139
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• 2008

A CpG island is a short stretch of DNA in which the frequency of the CG dinucleotide is higher than other regions. CpG islands are present in the promoters and exonic regions of approximately $30{\sim}60$% of mammalian genes so they are useful markers for genes in organisms containing 5-methylcytosine in their genomes. Recent evidence supports the notion that the hypermethylation of CpG island, by silencing tumor suppressor genes, plays a major causal role in cancer, which has been described in almost every tumor types. In this respect, CpG island search by computational methods is very helpful for cancer research and computational promoter and gene predictions. I therefore developed a window program (called CpGi) on the basis of CpG island criteria defined by D. Takai and P. A. Jones. The program 'CpGi' was implemented in Visual C++ 6.0 and can determine the locations of CpG islands using diverse parameters (%GC, Obs (CpG)/Exp (CpG), window size, step size, gap value, # of CpG, length) specified by user. The analysis result of CpGi provides a graphical map of CpG islands and G+C% plot, where more detailed information on CpG island can be obtained through pop-up window. Two human contigs, i.e. AP00524 (from chromosome 22) and NT_029490.3 (from chromosome 21), were used to compare the performance of CpGi and two other public programs for the accuracy of search results. The two other programs used in the performance comparison are Emboss-CpGPlot and CpG Island Searcher that are web-based public CpG island search programs. The comparison result showed that CpGi is on a level with or outperforms Emboss-CpGPlot and CpG Island Searcher. Having a simple and easy-to-use user interface, CpGi would be a very useful tool for genome analysis and CpG island research. To obtain a copy of CpGi for academic use only, contact corresponding author.

• Journal of Embryo Transfer
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• v.21 no.1
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• pp.35-43
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• 2006

Ions play important roles in various cellular processes including fertilization and differentiation. However, it is little known whether how ions are regulated during early embryonic development in mammalian animals. In this study, we examined changes in $Ca^{2+}\;and\;K^+$ concentrations in embryos and oviduct during mouse early embryonic development using patch clamp technique and confocal laser scanning microscopy. The intracellular calcium concentration in each stage embryos did not markedly change. At 56h afier hCG injection when 8-cell embryos could be Isolated from oviduct, $K^+$ concentration in oviduct increased by 26% compared with that at 14h after injection of hCG During early embryonic development, membrane potential was depolarized (from -38 mV to -16 mV), and $Ca^{2+}$ currents decreased, indicating that some $K^+$ channel might control membrane potential in oocytes. To record the changes in membrane potential induced by influx of $Ca^{2+}$ in mouse oocytes, we applied 5 mM $Ca^{2+}$ to the bath solution. The membrane potential transiently hyperpolarized and then recovered. In order to classify $K^+$ channels that cause hyperpolarization, we first applied TEA and apamin, general $K^+$ channel blockers, to the bath solution. Interestingly, the hyperpolarization of membrane potential still appeared in oocytes pretreated with TEA and apamin. This result suggest that the $K^+$ channel that induces hyperpolarization could belong to another $K^+$ channel such as two-pore domain $K^+(K_{2P})$channel that a.e insensitive to TEA and apamin. From these results, we suggest that the changes in $Ca^{2+}\;and\;K^+$ concentrations play a critical role in cell proliferation, differentiation and reproduction as well as early embryonic development, and $K_{2P}$ channels could be involved in regulation of membrane potential in ovulated oocytes.