• The korean journal of orthodontics
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• v.26 no.5 s.58
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• pp.581-590
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• 1996

Bone resorptiion was predominate in compression site, bone formation in tension site of periodontal ligament during tooth movement. The biologic response at compressiion site was different from tension site. Thus the CGHP immuno-positive nerve fiber will respond differently to mechanical force according to the area( compression or tension site). The purpose of this study was to investigate this response of CGRP immune-positive nerve fiber in the periodontal ligament according to the duration of applied force and the area (compression or tension site) during experimental tooth movement. The experimental animals were 7 week old male rat (approximately 200 gm). The orthodontic force was applied mesially to the right maxillary molar using the Ni-Ti coil spring during 12hours, 1, 3, 7, and 120days. Immunohistochemical staining using antibody against CGRP was performed after sacrifice. The results were as follows. The CGRP immune-positive nerve bundle showed reduced immunoreactivity and nerve fibers reduced in density after application of orthodontic force for 12 hours and 1day. The CGRP immune-positive nerve fibers showed many thin branches at the apical periodontal ligament after application of force for 3 days as compared with normal. The tension site in the apical periodontal ligament showed more branches than the compression site. In 7 day group, the CGRP immune-positive nerve fibers increased in terms of the number and had many thin branches in the apical periodontal ligament. The tension site had more branches than the compression site. In 12 day group, the CGRP immune-positive nerve fibers showed similar distribution to normal control at compression site of apical periodontal ligament, but the fibers at the tension site increased in number. The CGRP immuno-positive nerve fibers showed more increased at tension site than compression site after application of orthodontic force. Therefore it seems to have some relation to the bone remodeling besides the local inflammatory process.

• Journal of Life Science
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• v.29 no.12
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• pp.1305-1313
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• 2019

Licochalcone (LC), isolated from the roots of Glycyrrhiza inflata has multiple pharmacological effects including anti-inflammatory and anti-tumor activities. To date, Licochalcone C (LCC) has induced apoptosis and inhibited cell proliferation in oral and bladder cancer cells, but lung cancer has not yet been studied. In addition, no study reported LCC-induced autophagy in cancer until now. The present study was designed to investigate the effect of LCC on gefitinib-sensitive and -resistant lung cancer cells and elucidate the mechanism of its action. The 3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assay data showed that LCC significantly inhibited cell viability in non-small cell lung cancer (NSCLC) HCC827 (gefitinib-sensitive) and HCC827GR (gefitinib-resistant) cell lines. Interestingly, Annexin V/7-aminoactinomycin D double staining and cell cycle analysis showed an apoptosis rate within about 20% at the highest concentration of LCC. LCC induced G2/M arrest by reducing the expression of the cell cycle G2/M related proteins cyclin B1 and cdc2 in NSCLC cell lines. Treatment of LCC also induced autophagy by increasing the expression of the autophagy marker protein microtubule-associated protein 1 light chain 3 (LC3) and the protein autophagy-related gene 5 involved in the autophagy process. In addition, LCC increased the production of reactive oxygen species (ROS), and the cell viability was partially restored by treatment with the ROS inhibitor N-acetyl-L-cysteine. In western blotting analysis, the expression of cdc2 was increased and LC3 was decreased by the simultaneous treatment of NAC and LCC. These results indicate that LCC may contribute to anti-tumor effects by inducing ROS-dependent G2/M arrest and autophagy in NSCLC. In conclusion, LCC treatment may be useful as a potential therapeutic agent against NSCLC.

• Journal of radiological science and technology
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• v.33 no.2
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• pp.127-132
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• 2010

The purpose of this study is to measure scattered ray which is occurred except for Z-axis range of the detector in MDCT's iso-center and present the basic data about the standard for reduction of scattered ray. The development of MDCT brings out the enlargement of beam thickness to the patient's Z-axis, which distributes to the increase in exposure dose according to the rise of scattered ray. Also MDCT brings out the increase of scattered ray about 4times more than SDCT. To evaluate scattered ray according to the change of beam thickness on MDCT, we measured scattered ray of MDCT's Z-axis beam thickness by using one 16-slice CTs and two 64-slice CTs. We used the ionization chamber 60ml 2026C as the equipment of measurement. In our results, we found out that the change of scattered ray according to the beam thickness in the same kVp has increase of scattered ray. Secondly we found out the increase of scattered ray according to the increase of kVp. Lastly we found out the decrease of scattered ray according to the increase of the distance from the ionization chamber.

• Applied Microscopy
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• v.41 no.2
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• pp.109-116
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• 2011

Polycystic ovary syndrome (PCOS) is hormonal imbalance condition as the endocrine and metabolic disorder that induces the infertility and various complications in reproductive age women. Estradiol valerate (EV) is used hormone replacement therapy in menopausal women and is reported that excessive administration of EV induces the PCOS. Nerve growth factor (NGF) is the factor to regulate the survival and maturation of developing neuronal cell and is also synthesized in ovary. And NGF is overexpressed in EV-induced polycystic ovary (PCO) as previously reported. Therefore, this study examined the possibility of NGF as can be used the biological marker in diagnosis of PCOS, the hormonal imbalance condition, using PCO and CHO (chinese hamster ovarian) cell lines. The concentration of EV treatment is optimized a 1 mg as not influence on the proliferation of CHO cell but 2 mg and 3 mg of EV treatment have the inhibition effect at initial stage. The morphological change was not observed in CHO cell after dose dependent manner treatment of EV. Expression of NGF mRNA and protein is significantly increased at 30 min after EV treatment in CHO cells compared to that of control. And NGF protein expression is strongly increased in PCO tissue, which observed many follicular cysts compared to normal ovary tissue. Taken together, overexpression of NGF may be act as a molecule to induce an abnormal development of follicle, suggesting that NGF can be used as a biological marker in diagnosis of PCOS.

• The Journal of Korean Academy of Prosthodontics
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• v.50 no.2
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• pp.112-118
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• 2012

Purpose: The purpose of this study was to evaluate the difference in shear bonding strength between resin cements to dental materials when a universal primer (Monobond plus) was applied in place of a conventional primer. Materials and methods: Four groups of testing materials: gold alloy (Argedent Euro, n = 16), non precious metal (T-4, n = 20), zirconia (Cercon, n = 20) and glass ceramic (IPS e.max press, n = 20), were fabricated into discs, which were embedded in an acrylic resin matrix. The gold alloy specimens were airborne-particle abraded, 8 of the specimens were coated with Metal primer II, while the remaining 8 specimens were coated with Monobond plus. The non precious and zirconia specimen were airborne-particle abraded then, the control group received Alloy primer coating, while the other was coated with Monobond plus. Glass ceramic specimens were etched. 10 specimens were coated with Monobond-S and the remaining specimens were coated using Monobond plus. On top of the surface, Multilink N was polymerized in a disc shape. All of the specimens were thermal cycled before the shear bonding strength was measured. Statistical analysis was done with Two sample $t$-test or Mann-Whitney U test (${\alpha}$=.05). Results: There were no significant differences in bonding strength depending on the type of primer used in the gold alloy and glass ceramic groups ($P$>.05), however, the bonding strengths of resin cements to non precious metal and zirconia groups, were significantly higher when the alloy primer was used ($P$<.05). Conclusion: Within the limitations of this study, improvement of universal primers which can be applied to all types of restorations is recommended to precious metals and zirconia ceramics. But, the bond strengths of non precious metals and zirconia ceramics were significantly lower when compared to a 10-MDP primer. More research is needed to apply universal primers to all types of restorations.

• Journal of Dental Rehabilitation and Applied Science
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• v.30 no.2
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• pp.121-130
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• 2014

Purpose: To assess the surface profile of dentinal wall, dentin chips and smear layer during the canal shaping with rotary (ProTaper) and ProFile and reciprocating (WaveOne) nickel-titanium file. Materials and Methods: Sixty human extracted mandibular premolars and incisors with single canals were randomly selected. Three experimental groups (n = 20) were instrumented with ProTaper (F2), ProFile (25/.06), WaveOne (25/.08) with irrigation of 2.5% NaOCl. The dentin chips were collected from flute of file during each canal preparation. After canal preparation, roots were grinded and each group was divided into two subgroups (n = 10) for surface profile and smear layer of dentinal wall of shaped root canal. Each specimen was observed under scanning electron microscope for evaluating size of dentin chips, root canal surface recessions and smear layer. Scores of Smear layer were statistically analyzed using Kruskal Wallis test and Mann Whitney test at P = 0.05 level. Results: The size of dentin chips from ProFile, ProTaper and WaveOne was up to $7{\mu}m$, $6.5{\mu}m$, and$4{\mu}m$, respectively. In the surface profile, the width of surface irregularity was measured and Profile, ProTaper and WaveOne was up to $150{\mu}m$, $70{\mu}m$, and $80{\mu}m$, respectively. Completely cleaned root canals were not found. In the middle and apical third of the canals, WaveOne group showed higher smear layer score than ProFile and ProTaper groups (P < 0.05). Conclusion: Within limits of this study, reciprocating motion WaveOne group was not significant difference of shaping ability with the full-sequence ProFile and ProTaper systems except canal clearness of middle and apical third of root canal. When using WaveOne to shaping root canal, thorough root canal irrigation is recommended.

• Journal of Life Science
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• v.28 no.10
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• pp.1201-1211
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• 2018

The study compared the anti-aging, anti-adipogenesis, and anti-tumor effects of epigallocatechin-3- gallate (EGCG) in various cancer cell lines (SNU-601, MKN74, AGS, MCF-7, U87-MG, and A-549) and normal cell lines (MRC-5 fibroblasts, dental tissue-derived mesenchymal stem cells [DSC], and 3T3-L1 pro-adipocytes). Half inhibitory concentration ($IC_{50}$) values were significantly (p<0.05) higher in normal cell lines (~50 uM), when compared to that in cancer cell lines (~10 uM). For anti-aging effects, MRC-5 and DSC were exposed to 10 uM EGCG for up to five passages that did not display any growth arrest. Population doubling time and senescence-related ${\beta}-galactosidase$ ($SA-{\beta}-gal$) activity in treated cells were similar to untreated cells. For anti-adipogenic effects, mouse 3T3-L1 pre-adipocytes were induced to adipocytes in an adipogenic differentiation medium containing 10 uM EGCG, but adipogenesis in 3T3-L1 cells was not inhibited by EGCG treatment. For anti-tumor effects, the cancer cell lines were treated with 10 uM EGCG. PDT was significantly (p<0.05) increased in EGCG-treated SNU-601, AGS, MCF-7, and U87-MG cancer cell lines, except in MKN74 and A-549. The level of telomerase activity and cell migration capacity were significantly (p<0.05) reduced, while $SA-{\beta}-gal$ activity was highly up-regulated in EGCG treated-cancer cell lines, when compared to that in untreated cancer cell lines. Our results have demonstrated that EGCG treatment induces anti-tumor effects more efficiently as noted by decreased cell proliferation, cell migration, telomerase activity, and increased $SA-{\beta}-gal$ activity than inducing anti-aging and anti-adipogenesis. Therefore, EGCG at a specific concentration can be considered for a potential anti-tumor drug.

• Journal of Oral Medicine and Pain
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• v.31 no.4
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• pp.347-354
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• 2006

Most patients suffering from TMD appear to have unsatisfactory masticatory function and compromised values of bite force. The purposes of this study were to investigate and compare bite force between affected and unaffected sides of patients with unilateral TMD and to evaluate its relation with duration of TMD. 42 patients with unilateral TMD, from Department of Oral Medicine, Dankook University Dental Hospital, were selected for this study. The ratio of men to women was 9:33 and their mean age of $27.2{\pm}10.4$ years. The bite forces were measured over both canines (for anterior bite force) and $1^{st}$ molars (for posterior bite force) using a bite force recorder while all the subjects were asked to clench successively for 3 seconds not until pain was felt. They were compared with those measured from bilateral TMD patients(N=6, M:F=1:5, mean age: $23.0{\pm}27.3$ years). The unilateral TMD patients were divided into time groups according to duration of TMD on the basis of 1 and 6 months, respectively. Paired and unpaired t-tests were used for statistical analysis. Unilateral TMD patients in this study showed that the affected sides had significantly lower bite force than the unaffected sides(force difference of about 7-8 kgf, p<0.05) while there was no significant sides difference in the bilateral patients. Nor did bite force on the affected sides reveal significant difference between unilateral and bilateral TMD patients. With regards to TMD duration, there was significant difference between the patients with TMD < 6 months and $\geq$ 6 months (p<0.05) while no significant difference existed between < 1 month and $\geq$ 1 month. The results of this study indicated that unilateral TMD patients can exhibit more reduced bite force on the affected sides compared with that on the unaffected sides and that bite force on the unaffected sides might be deteriorated more as longer did TMD last.

• Journal of Oral Medicine and Pain
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• v.34 no.4
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• pp.379-385
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• 2009

The purpose of this study was to present basic data that is needed in comprehension of dysesthesia after mandibular nerve injury and grasp meaning. We analyzed medical records of 59 patients who were diagnosed as dysesthesia after mandibular nerve injury from January 2007 to July 2009. The results are summarized as follows. 1. The most frequent cause was implant surgery (59%) and the most frequent injured branch of mandibular nerve was inferior alveolar nerve(81%). 2. The period passed after nerve injury showed significant interrelationship with level of pain. Visual Analogue Scale(VAS) increased from 4.82 to 6.91 after 6 month. 3. The period passed after nerve injury did not show significant interrelationship with recovery of dysesthesia. But, when conservative treatment was offered at earlier stage, ratio of patients who showed recovery of symptom tended to increase. 4. In computed tomography, level of invasion into inferior alveolar nerve canal did not show significant interrelationship with level of pain and recovery of dysesthesia. Conclusively, in the patients with dysesthesia of mandibular nerve, inferior alveolar nerve injury by dental implant surgery dominated most significant problem. Although level of invasion into inferior alveolar nerve is the most important factor to initiation of dysesthesia, there are other various factors exert more influence on the level of pain or recovery of dysesthesia. Therefore, begining conservative therapy at earlier stage is encouraged. Also, because nerve injuries can occur without direct invasion into nerve canal, so leaving enough safe space from nerve canal is needed for prevention of indirect nerve injury.

• The Journal of Korean Academy of Prosthodontics
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• v.43 no.2
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• pp.232-247
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• 2005

Purpose. The purposes of this investigation were to discover the possibility of clinical application in the areas of dental implants and bone grafts by investigating the bone formation histologically around specimen which was depending on the intensity of magnetic field of neodymium magnet inside of the specimens. Material and method. 1. Measurement of magnetic intensity - placed the magnet inside of the specimen, and measured the intensity of magnetic field around the 1st thread and 3rd thread of specimen 20 times by using a Gaussmeter(Kanetec Co., Japan). 2. Surgical Procedure - Male rabbit was anesthetised by constant amount of Ketamine (0.25ml/kg) and Rompun (0.25ml/kg). After incising the flat part of tibia, and planted the specimens of titanium implant, control group was stitched without magnet, while experimental groups were placed a magnedisc 500(Aichi Steel Co., Japan) or magnedisc 800(Aichi Steel Co., Japan) into it, fixed by pattern resin and stitched. 3. Management after the surgery - In order to prevent it from the infection of bacteria and for antiinflammation, Gentamycin and Ketopro were injected during 1 week from operation day, and dressed with potadine. 4. Preparation of histomorphometric analysis - At 2, 4 and 8 weeks after the surgery, the animals were sacrificed by excessed Ketamine, and then, specimens were obtained including the operated part and some parts of tibia, and fixed it to 10% of PBS buffer solution. After embedding specimens in Technovit 1200 and B.P solution, made a H-E stain. Samples width was 75$\mu$m . In histological findings through the optical microscope and using Kappa image base program(Olympus Co. Japan), the bone contact ratio and bone area ratio of each parts of specimens were measured and analyzed. 5. Statistical analysis - Statistical analysis was accomplished with Mann Whitney U-test. Results and conclusion. 1. In histomorphometric findings, increased new bone formation was shown in both control & experimental groups through the experiment performed for 2, 4 & 8 weeks. After 4 weeks, more osteoblasts and osteoclasts with significant bone remodeling were shown in experimental groups. 2. In histomorphometric analysis, the bone contact ratios were 38.5% for experimental group 1, 29.5% for experimental group 2 and 11.9% for control group. Experimental groups were higher than control group(p<0.05) (Fig. 6, Table IV). The bone area ratios were 60.9% for experimental group 2, 46.4% for experimental group 1 and 36.0% for control group. There was no significantly statistical difference between experimental groups and control group(p<0.05) (Fig. 8, Table VII) 3. In comparision of the bone contact ratios at each measurement sites according to magnetic intensity, experimental group 2(5.6mT) was higher than control group at the 1st thread (p<0.05) and experimental group 1 (1.8mT) was higher than control group at the 3rd thread(p<0.05) (Fig. 7, Table V, VI). 4. In comparision of the bone area ratios at each measurement sites according to magnetic intensity, experimental group 2(5.6mT) was higher than control group and experimental group 1 (4.0mT) at the 1st thread(p<0.1) and experimental group 2(4.4mT) was higher than experimental group 1 (1.8mT) at the 3rd thread(p<0.1) (Fig. 9, Table IX, X). Experiment group 2 was largest, followed by experiment group l and control group at the 3rd thread of implant. There was a significant difference at the 1st thread of control group & experiment group 2, and at 1st thread & 3rd thread of experiment group 1 & 2, and not at control group experiment group 1.(p<0.1)