• The korean journal of orthodontics
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• v.34 no.1 s.102
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• pp.71-81
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• 2004

In this study, we attempt to investigate the mechanisms by which PDL cells regulate osteoclast formation and also tc know whether PDL retained their characteristic phenotype during tooth eruption and interdental separation. Rats were prepared at developmental days 21 (pre-root formation), 27(toot development), 34(advanced root formation/eruption) and at later times(adult rats). To induce severe resorption state of alveolar bone and tooth root, interdental separation with brass wire was performed between the lower first and second molars for 2 weeks in adult rats. Rat mandibles were demineralized and embedded in paraffin, and horizontal and frontal section were prepared for immuno-histochemical analysis using PDL-specific protein 22 (PDLs22), receptor activator of NFKB ligand (RANKL) and osteoprotegerin (OPG) antibodies. 1. Root formation and eruption stage of tooth development. 1) PDLs22 immunolocalization was observed in tooth follicle/PDL cells and osteoblasts throught out the root formation and eruption stages of tooth development. 2) RANKL expression became stronger at eruption stage than root formation stage of tooth development. 3) Strong expression of OPG was detected in follice/PDL cells of toot formation stage but it was decreased with tooth eruption. 2. Interdental separation between lower first and second molar 1) Comparared to normal animal, multinucleated osteoclasts and odontoclasts were markedly induced in the alveolar bone and tooth root with PDL remodeling in hematoxylin-eosin section. 2) PDLs22 expression was decreased with interdental separation. 3) RANKL expression was Increased with interdental separation in PDL fibroblasts, osteoblasts, odontoclasts and it lacunae, resorting dentin, cementum and bone matrix. 4) OPG expression was slightly decreased in the PDL cells adjacent to the alveolar bone and root surface with interdental separation. These results suggested that during tooth eruption and tooth movement, RANKL and OPG in the periodontal tissues are important determinants regulating balanced alveolar bone and tooth root resorption. And it is also suggested that PDL cells retained their characteristic phenotype during tooth eruption and interdental separation except for the short period of PDL remodeling.

• Journal of dental hygiene science
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• v.16 no.6
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• pp.488-494
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• 2016

The purpose of the present study was to examine dental hygienists' perception of the current national practical examination. This research was performed using 199 self-reported surveys answered by professors of dental hygiene studies and clinical dental hygienist. Frequency analysis, chi-square tests, and analysis of variance were performed by using IBM SPSS Statistics ver. 20.0. The results revealed that many of the respondents consider the current national practical examination to be neutral. They did not think that the current national practical examination questions are useful for assessing occupation-centric integrated clinical practice ability and counseling techniques for patient intervention. The professors of dental hygiene studies believed that among the research tasks required as mentioned in the national practical examination questions, dental polishing and tooth brushing education are of paramount importance, whereas clinical dental hygienists believed that ultrasonic scaling is the most important (p<0.05). Most of the professors of dental hygiene studies reported that they conducted skills education for dental polishing and tooth brushing education, while most of the clinical dental hygienists reported that tasks actually performed in the clinic included impression taking, model fabrication, ultrasonic scaling, and explaining treatment precautions (p<0.05). Therefore, these tasks can be effectively carried out with the improvement of the national dental hygienist practical examination.

• Journal of Life Science
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• v.25 no.10
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• pp.1091-1097
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• 2015

We have isolated and characterized an ascorbate peroxidase (APx) gene, OsAPx1 from rice. Northern and Western blot analyses indicated that at young seedling stage, OsAPx1 mRNA was expressed highly in root, shoot apical meristem (SAM) and leaf sheath than leaf. In mature plant, OsAPx1 gene expressed highly in root, stem and flower but weakly in leaf. OsAPx1 gene and protein expression level was induced in leaves inoculated with Magnaporthe oryzae (M. oryzae) and Xanthomonas oryzae pv. oryzae (Xoo). Phytohormones treatment showed that OsAPx1 was up-regulated by jasmonic acid (JA), but was down regulated by ABA and SA co-treatments with JA, resulting that they have antagonistic effect on pathogen responsive OsAPx1 expression. Phylogenetic analysis illustrated that Arabidopsis AtAPx1 has a close relationship with OsAPx1. In AtAPx1 knock out lines, the accumulation of O₂^- and H₂O₂ are all highly detected than wild type, revealing that the high concentration of exogenous H₂O₂ cause the intercellular superoxide anion and hydrogen peroxide accumulation in AtAPx1 knockout plant. These results suggested that OsAPx1 gene may be associated with the pathogen defense cascades as the mediator for balancing redox state by acting ROS scavenger and is associated with response to the pathogen defense via Jasmonic acid signaling pathway.

• Journal of Embryo Transfer
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• v.19 no.2
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• pp.155-163
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• 2004

The aims of this study are 1) to test oocytes and embryos collected from in-vitro to achieving the valuable protocol by culturing, vitrifying and thawing of oocytes/embryos, and 2) to transfer them to recipient, and finally have resulted in pregnancies from recipient females after surgical or nonsurgical transfer. In vitro maturation and fertilization were performed according to Funahashi et al (1994). Glucose-free NCSU 23 supplemented with 5 mM sodium pyruvate, 0.5 mM sodium lactate and 4 mg/ml bovine serum albumin for 2 days at $39^{\circ}C$, and 10% fetal bovine serum albumin was added to the culture medium thereafter. Embryos were treated with 7.5 ${\mu}g/ml$ cytochalasin-B for 30 min, centrifuged at 13,000 rpm for 13 min and then exposed sequentially to an ethylene glycol(EG) vitrification solution, aspirated into OPS, and plunged/thawed into/from liquid nitrogen. In vivo embryos were surgically collected from three dornors after AI for control group. Forty-nine embryos were washed 3 times in mPBS + 10% FBS, followed treatments : cultured, centrifuged, vitrified, recovered and transferred to recipients as in vitro prepared embryos. Three recipients were transferred individually with 100, 100 frozen embryos derived from abattoir and 34 fresh embryos by surgically, and another three recipients were transferred individually with 150, 150 frozen embryos and 100 fresh embryos by nonsurgically, respectively. all recipient sows exhibited delayed returns to estrus. To our knowledge, theses results suggest that required an improved techniques, more vigorous embryos preparation and substitute to gilt with cleaner uterous condition.

• Clinical and Experimental Reproductive Medicine
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• v.36 no.4
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• pp.265-274
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• 2009

Objective: MicroRNAs (miR) are known to repress target genes at post-transcriptional level and play important roles in development and maturation of cell. However, the expression profiles of miR during ovarian follicle maturation have not been fully elucidated. Here, we designed this study to investigate the expression profiles of miR in oocytes and granulose cells (G-cells) after in vitro culture according to gonadotropins and adding hCG. Methods: Ovaries from 12-day-old mice (C57BL6) were removed and preantral follicles were isolated and cultured in $20\;{\mu}L$-drop of culture media with supplementation of either rFSH, rLH, or rFSH+rLH. After their full maturation, follicles were incubated with rhCG and rEGF. RNA was isolated from oocytes and G-cells, and real-time PCR were performed with primers of miR known to be expressed in the mouse ovary (mmu-miR-16, -miR-27a, -miR-126, -miR-721). Results: FSH+LH group showed the highest ovulation and MII rates among gonadotropin groups. The profiles of miRs in oocytes and G-cells differed according to gonadotropin groups and adding hCG. The profiles of miRs showed divergent changes between oocytes and G-cells. Conclusion: miR expression profiles are altered by gonadotropins and supplementation of hCG during in vitro maturation of murine follicles. Target gene study must be necessary to validate these findings.

• Clinical and Experimental Reproductive Medicine
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• v.36 no.4
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• pp.275-281
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• 2009

Objective: This study was performed to evaluate the effect of oxytocin antagonist on the outcome of IVF/ICSI cycles in infertile patients with repeated failure of IVF/ICSI treatment. Method: Forty patients who had experienced two or more failures of IVF/ICSI treatment without low ovarian reserve, were recruited for this prospective randomized study. All patients received controlled ovarian stimulation (COS) using GnRH antagonist multidose protocol (MDP). For the intervention group, intravenous administration of atosiban (mixed vasopressin $V_{1A}$/oxytocin antagonist) started with a bolus dose 6.75 mg one hour before embryo transfer (ET) and continued at an infusion rate of 18 mg/hour. After ET, administered atosiban was reduced to 6 mg/hour and continued for 2 hours. The main efficacy endpoints were clinical pregnancy rate and implantation rate. Results: Patients' characteristics were comparable in the intervention and control groups. COS parameters and IVF results were also similar. The number of uterine contractions for 3 minutes measured just before ET was significantly lower in the intervention group than control group ($3.5{\pm}1.4$ vs $8.7{\pm}2.2$, p<0.001). While there was no statistically significant difference in the clinical pregnancy rate between control group and intervention group (20.0% and 40.0%, p=0.168), the implantation rate was significantly higher in the intervention group, with 16.9% (11/65) compared with 6.0% (4/67) in the control group (p=0.047). There were no differences in ectopic pregnancy rate and miscarriage rate between the two groups. Conclusion: This study demonstrates that administration of oxytocin antagonist during ET can improve the implantation rate probably by decreasing the frequency of uterine contractions in infertile patients undergoing IVF/ICSI treatment.

• Korean Journal of Animal Reproduction
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• v.23 no.2
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• pp.105-111
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• 1999

The effects of exogenous spleen cells on the progesterone and insulin like-growth factor-I (IGF-I) secretions in luteal cells were studied by using in vitro luteal cell culture system in the Hanwoo luteal cells. The corpora lutea(CL) were collected and pooled from the Korean native cattle(Hanwoo) ovaries from a local slaughter house. After enzymatic dissociation, combined large and small luteal cells(LLC and SLC)(1.0$\times$10$^{6}$ cells/$m\ell$) were incubated in D-MEM media containing antibiotics and 10% FCS. Spleen cells (1.0$\times$10$^{6}$ cells/$m\ell$) obtained from castrated adult male Hanwoo were added to luteal cells and co-cultured for 24 h in the absence or presence of luteinizing hormone (LH) (100 ng). Progesterone contents from luteal tissues were increased at CL-3 stage during each stage of estrous cycle. Progesterone secretion from luteal cell culture by the presence of LH (100 ng/$m\ell$) was positively stimulated compared with control. However, progesterone secretion was not changed by the addition of 5, 10 and 20% of spleen cells in the absence of LH. Co-culture of luteal cells with 10% of spleen cells in the presence of LH(l00ng/$m\ell$) significantly. enhanced after 24 h of culture. IGF-Isecretion from in vitro luteal cells co-culture by the addition of spleen cells (5%, 10% and 20%) was not significantly effected. Besides, in the presence of LH (100ng/$m\ell$), IGF-Isecretions from luteal cells by addition of spleen cells were higher than control media. However, LH alone significantly increased IGF-I secretion at 24 h of culture. These data provide the demonstrate that spleen cells can enhance LH action so as to stimulate progesterone secretion from Hanwoo luteal cells but have no effect to stimulate IGF-I secretion.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.3
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• pp.391-405
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• 2003

Craniosynostosis, known as a premature fusion of cranial sutures, is a developmental disorder characterized by precocious differentiation and mineralization of osteoblasts in the calvarial sutures. Recent genetic studies have demonstrated that mutation in the homeobox gene Msx2 causes Boston-type human craniosynostosis. Additionally, the phenotype of Dlx5 homozygote mutant mouse presents craniofacial abnormalities including a delayed ossification of calvarial bone. Furthermore transcription of osteocalcin, a mature osteoblast marker, is reciprocally regulated by the homeodomain proteins Msx2 and Dlx5. These facts suggest important roles of osteocalcin, Msx2 and Dlx5 genes in the calvarial bone growth and suture morphogenesis. To elucidate the function of these molecules in the early morphogenesis of mouse cranial sutures, we have first analyzed by in situ hybridization the expression of osteocalcin, Msx2 and Dlx5 genes in the developing parietal bone and sagittal suture of mouse calvaria during the embryonic (E15-E18) stage. Osteocalcin mRNA was found in the periosteum of parietal bones from E15, and gradually more highly expressed with aging. Msx2 mRNA was intensely expressed in the sutural mesenchyme, osteogenic fronts and mildly expressed in the dura mater during the embryonic stage. Dlx5 mRNA was intensely expressed osteogenic fronts and the periostem of parietal bones. To further examine the upstream signaling molecules of transcription factor Msx2 and Dlx5, we have done in vitro experiments in E15.5 mouse calvarial explants. Interestingly, implantation of BMP2-, BMP4-soaked beads onto the osteogenic fronts after 48 hours organ culture induced etopic expressions of Msx2 and Dlx5 genes. On the other hand, overexpression of $TGF{\beta}1$, GDF-6, -7, FGF-2, -4 and Shh did not induce the expression of Msx2 and Dlx5. Taken together. these data indicate that transcription factor Msx2 and Dlx5 play critical roles in the calvarial bone and suture development, and that BMP siganling is involved in the osteogenesis of calvarial bones and the maintenance of cranial sutures through regulating these two transcriotpn factors. Furthermore, different expression patterns between Msx2 and Dlx5 suggest their specific functions in the osteoblast differentiation.

• Journal of Life Science
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• v.15 no.5 s.72
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• pp.840-846
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• 2005

This study was carried out to investigate the effect of electron beam irradiation and cooking temperature on physico-chemical characteristics and lipid oxidation of beef. A total of six beef carcasses ($280\∼300 kg$) that were quality grade $1^{+}$(marbling score No.7, meat color No.4, maturity No.1, texture No.1) was purchased at the commercial slaughter house. The carcasses were transported and washed using high pressure water, and pasteulized with $ 50\% $ ethyl alcohol in the laboratory. After the carcasses were deboned and trimmed, loin and round were taken out to make steak (1.5cm thickness) or ground beef respectively. Samples were wrap or vacuum packaged and irradiated with 0, 3, 4.5, 6 and 7.5 kGy using electron-beam accelerator at Samsung Heavy Industries Ltd. Co. (in Taejun). Irradiated samples were cooked with different methods(electronic pan and gas oven) and temperatures ($ 60^{\circ}C, 70^{\circ}C and 80^{\circ}C$) and used to measure fatty acid composition, TBARS, cholesterol oxide products and panel test scores. The content of saturated fatty acids increased by increasing heating temperature in oven boiling steak (OBS) and pan boiling steak (PBS), and there was no difference by electron-beam irradiation. Both irradiated and non-irradiated treatment were high as the heating temperature increased in TBARS by heating temperature in PBS (p < 0.05) and the amount of Malonaldehyde (MA), standard of fat deterioration, was increased in OBS (p < 0.05). Non-irradiated and 3, 6 kGy treatment produced about 2 fold amount of MA at $ 60^{\circ}C $ compared with $ 80^{\circ}C $. In comparison with PBS, OBS produced much amount of MA and a bit different from non-irradiated treatment but did not show no tendency. As irradiation levels and heating temperature increased, the amount of cholesterol oxides products was increased and also pan-heating method, direct heating method, significantly increased the degree of oxidation compared with oven-heating method, indirect heating method (p < 0.05).

• Korean Journal of Environmental Biology
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• v.29 no.4
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• pp.251-257
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• 2011

Cobalt is a naturally occurring element found in rocks, soil, water and/or is among the harmful pollutants as generated by industrialized. In the environment, cobalt has two oxidation states, cobalt (II) (Co (II)) and cobalt (III) (Co (III)). If coastal water is contaminated by cobalt, it through the food chain can have an impact on marine ecosystems. Therefore, we examined the gametotoxic and embryotoxic effects of Co (II) at various concentrations (10, 100, 500, 1000, 2500 ppb) in the sea urchin $Hemicentrotus$ $pulcherrimus$. Spawning was induced by injecting 1 mL of 0.5 M KCl into coelomic cavity. Males released white or cream-colored sperms and females released yellow or orange-colored eggs. Experiment was begun within 30 min the collection of both gametes. The fertilization and embryo development rates test were performed for 10 min and 64 h after fertilization, respectively. The fertilization rates in the control condition (not including Co (II)) and experimental group were not significantly changed. The embryo development rates in the control condition were greater than 90% and were significantly decreased with concentration dependent manner. The normal embryogenesis rate was significantly inhibited in exposed to cobalt (II) ($EC_{50}$=71.84 ppb, 95% Cl=16.71-203.36 ppb). The NOEC and LOEC of normal embryogenesis rate were <10 ppb and 10 ppb, respectively. These results suggest that the early embryo stages of $H.$ $pulcherrimus$ have toxic effect at greater than 10 ppb of Co (II) concentration.