• Journal of Oral Medicine and Pain
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• 제34권3호
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• pp.261-276
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• 2009

Lactacystin, a microbial natural product synthesized by Streptomyces, has been commonly used as a selective proteasome inhibitor in many studies. Proteasome inhibitors is known to be preventing the proliferation of cancer cells in vivo as well as in vitro. Furthermore, proteasome inhibitors, as single or combined with other anticancer agents, are suggested as a new class of potential anticancer agents. This study was undertaken to examine in vitro effects of cytotoxicity and growth inhibition, and the molecular mechanism underlying induction of apoptosis in SCC25 human tongue sqaumous cell carcinoma cell line treated with lactacystin. The viability of SCC25 cells, human normal keratinocytes (HaCaT cells) and human gingiva fibroblasts (HGF-1 cells), and the growth inhibition of SCC25 cells were assessed by MTT assay and clonogenic assay respectively. The hoechst staining, hemacolor staining and TUNEL staining were conducted to observe SCC25 cells undergoing apoptosis. SCC25 cells were treated with lactacystin, and Western blotting, immunocytochemistry, confocal microscopy, FAScan flow cytometry, MMP activity, and proteasome activity were performed. Lactacystin treatment of SCC25 cells resulted in a time- and does-dependent decrease of cell viability and a does-dependent inhibition of cell growth, and induced apoptotic cell death. Interestingly, lactacytin remarkably revealed cytotoxicity in SCC25 cells but not normal cells. And tested SCC25 cells showed several lines of apoptotic manifestation such as nuclear condensation, DNA fragmentation, the reduction of MMP and proteasome activity, the decrease of DNA contents, the release of cytochrome c into cytosol, the translocation of AIF and DFF40 (CAD) onto nuclei, the up-regulation of Bax, and the activation of caspase-7, caspase-3, PARP, lamin A/C and DFF45 (ICAD). Flow cytometric analysis revealed that lactacystin resulted in G1 arrest in cell cycle progression which was associated with up-regulation in the protein expression of CDK inhibitors, $p21^{WAF1/CIP1}$ and $p27^{KIP1}$. We presented data indicating that lactacystin induces G1 cell cycle arrest and apoptois via proteasome, mitochondria and caspase pathway in SCC25 cells. Therefore our data provide the possibility that lactacystin could be as a novel therapeutic strategy for human tongue squamous cell carcinoma.

• Journal of Oral Medicine and Pain
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• 제38권2호
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• pp.137-142
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• 2013

Oral Medicine includes temporomandibular disorder, orofacial pains such as neuropathic pain, soft tissue diseases, halitosis, laser treatment, snoring, sleep apnea and identification through forensic dentistry etc. Such diseases are relatively common and cause great inconvenience and pain to the patients, as well as incur fatal health scare at times. In terms of oral medicine, the number of orofacial patients is growing due to a change in the life style and an increased stress as time goes in contemporary society and the demand of areas requiring oral medical professionalism, such as soft tissue lesions, snoring and sleep apnea, forensic dentistry evaluation and others are rapidly ascending. Consequently, among the areas in dental science, the calls for the expertism in oral medicine and its role are mounting. Analyzing the distribution according to disease entity, symptoms, duration of disease, and the prehistory courses of new patients visiting the department of oral medicine in a year provides information of the role and the relative importance of oral medicine in prospect and enables effective diagnosis and treatments for the patients. Therefore, in the present study, by analyzing new patients visiting the oral medicine clinic in our dental hospital for a year and by evaluating the role and the professionalism in future oral medicine, the authors concluded the followings: 1. It was founded that new patients to oral medicine mainly had temporomandibular disorders, soft tissue diseases, and neuropathic pains. 2. The number of patients with temporomandibular disorder appeared to be the highest percentage and the order within this was the patients with combined disorders, muscle disorder, and internal derangement of joint disc. 3. The number of patients with xerostomia appeared to be the highest percentage within soft tissue disease, followed by lichen planus and recurrent apthous ulcers. 4. The number of patients with burning mouth syndrome appeared to be the highest percentage within neuropathic pain.

• Journal of the korean academy of Pediatric Dentistry
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• 제26권4호
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• pp.677-687
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• 1999

This study was performed to evaluate the effect of aging and thermal cycling on the tensile strength of six commercially available glass-ionomer materials: two chemically set glass-ionomer materials(Fuji II, Fuji IX), two resin-modified glass-ionomer materials(Fuji II LC, Vitremer), and two polyacid-modified composite resins(Compoglass, Dyract). Rectangular tension test specimens were fabricated in a teflon mold giving 5mm in gauge length and 2mm in thickness. All samples were divided into 3 groups. Group 1 was immersed in a $37^{\circ}C$ distilled water for 1 hour. Group 2 was immersed in a $37^{\circ}C$ distilled water for 30 days. Group 3 was subjected to 10,000 thermal cycles between $5^{\circ}C$ and $55^{\circ}C$, and the immersion time in each bath was 15 seconds per cycle. Tensile testing was carried out at a cross-head speed of 0.5mm/min and fracture surfaces were examined with scanning electron microscope. The results obtained were summarized as follows; 1. The polyacid-modified composite resins were stronger than the resin-modified glass-ionomer materials, which were much stronger than the conventional glass-ionomer materials. 2. Tensile strengths were slightly increased after aging treatments for 30days. 3. Tensile strengths of conventional glass ionomers were significantly increased after thermal cycling treatment(p<0.01). 4. The highest tensile strength value of 45.4MPa was observed in the Dyract group and the lowest value of 13.3MPa was observed in the Fuji II LC group after the thermal cycling test, and the strengths of polyacid-modified composite groups were significantly higher than those of other groups. 5. The highest characteristic strength value of 48.6MPa was obtained in the Dyract group, however the highest Weibull modulus value of 8.9MPa was obtained in the Compoglass group after thermal cycling test.

• Journal of Dental Rehabilitation and Applied Science
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• 제16권1호
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• pp.51-60
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• 2000

The purpose of this study was to compare the microleakage at the interface of cast post and tooth according to the type of cement. Forty anterior teeth with single root were used. The teeth were cut 2 mm coronal from the cementoeamel junction and chamfer finish line was made on 1 mm coronal from the cementoeamel junction. After the routine endodontic treatment, post space was prepared using #5.5 Parapost drill to a depth of 7 mm. After the pick up impression, core building was made to 3 mm of clinical crown with burnout wax, then post and core was cast with nonprecious metal. The teeth were divided into four groups of ten each. In Group I, post and core were cemented with Fleck's(Zinc phosphate cement) In Group II, post and core were cemented with Fuji I(Glass ionomer cement) In Group III, post and core were cemented with Superbond C & B(Composite resin cement) In Group IV, post and core were cemented with Panavia 21(Composite resin cement) All cemented teeth were stored in normal saline at $37^{\circ}C$ for 7 days and thermocycled from $5^{\circ}C$ to $55^{\circ}C$ for 500 cycles with a dwell time of 30 seconds. After thermocycling, teeth were immersed in 1% Basic fuchsin dye for 48 hours. All 40 teeth were then embedded in the epoxy resin and cut buccolingually with a cutting instrument. The degree of penetration of dye at interface was graded on a scale of 0 to 4 using a stereomicroscope at 25 to 40 times magnification. Through the findings of this study, the following conclusion were obtained. 1. All the groups showed the microleakage at the interface of cast post core and tooth. 2. Group I showed the highest microleakage score among the groups with a significant difference(p<0.05). 3. Group II showed higher microleakage score than Group III and Group IV with a significant difference(p<0.05). 4. Group IV showed the lowest microleakage score but there were no significant difference with Group III(p>0.05).

• Journal of Dental Rehabilitation and Applied Science
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• 제25권2호
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• pp.139-155
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• 2009

Objective : To assess the biological stability of immediate transmucosal placement of tapered implants into tooth extraction sockets. Material and methods : Following tooth extraction, tapered implants were immediately placed into the sockets. Teeth with evidence of acute periapical pathology were excluded. After implant placement, sutured allowing a non-submerged, transmucosal healing. Standardized radiographs were obtained every visiting from baseline to 32 weeks after implant placment. Changes in depth of the distance from the implant shoulder (IS) and from the alveolar crest (AC) to the bottom of the defect (BD) were assessed. Results : Thirteen patients (10 males and 3 females) were enrolled and followed. They contributed with 15 tapered implants. extraction iste displayed sufficient residual bone volume to allow primary stability of all implants. The mean surgery time was $41{\pm}10.0$ mins. All implants healed uneventfully yielding a survival rate of 100%. Mean ISQ values were relatively stable. Interproximal crestal bone decreased $1.69{\pm}1.2mm$ (mesial), $1.65{\pm}1.2mm$ (distal) from baseline to 32-week follow-up. No statistically significant changes with respect to FMPS, FMBS, PPD and width of KG were observed. Conclusions: Immediate transmucosal implant placement represented a predictable treatment option for the replacement of teeth lost due to reasons including fractures, endodontic failures and caries.

• Tuberculosis and Respiratory Diseases
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• 제53권3호
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• pp.275-284
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• 2002

Background : Gemcitabine is a new anti-cancer agent for treating non-small cell lung cancer. Functioning as an antimetabolite, it induces anti-cancer effects by suppressing DNA synthesis after being incorporated into the DNA as a cytosine arabinoside analogue. When Gemcitabine is incorporated into the DNA, the p53 gene may be activated by induction of the DNA defect. However, there are a few studies on the molecular mechanisms of Gemcitabine-induced cell death. This study examined the role of p53 in Gemcitabine-induced cell death. Methods : A549 and NCl-H358 lung cancer cells were used in this study. The cell viability test was done using a MTT assay at Gemcitabine concentrations of 10nM, 100nM, 1uM, 10uM and 100uM. A FACScan analysis with propium iodide staining was used for the cell cycle analysis. Western blot analysis was done to investigate the extent of p53 activation. For the functional knock-out of p53, stable A549-E6 cells and H358-E6 cells were transfected pLXSN-16E6SD which is over expresses the human papilloma virus E6 protein that constantly degrades p53 protein. The functional knock out of p53 was confirmed by Western blot analysis after treatment with a DNA damaging agent, doxorubicine. Results : Gemcitabine exhibited cell toxicity in dose-dependent fashion. The cell cycle analysis resulted in an S phase arrest. Western blot analysis significant p53 activation in time-dependent manner. Gemcitabine-induced cytotoxicity was reduced by 20-30% in the A549-E6 cells and the 30-40% in H358-E6 cells when compared with the A549-neo and H358-neo control cells. Conclusion : Gemcitabine induces an S phase arrest, as expected for the anti-metabolite, and activates the p53 gene, Furthermore, p53 might play an important role in Gemcitabine-induced cell death. Further investigation into the molecular mechanisms on how Gemcitabine activates the p53 gene and its signaling pathway are recommended.

• Tuberculosis and Respiratory Diseases
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• 제63권6호
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• pp.491-496
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• 2007

Background: The best way of delivering drugs for the treatment of asthma and chronic obstructive pulmonary disease (COPD) is via the inhaled route of administration. However, many patients use inhaler devices incorrectly. To augment the proper use of inhalation medicine and to improve knowledge of the disease and compliance, we have developed a "Computerized Respiratory Service Program" and applied the use of this program to educate patients. Methods: Prospectively, this study was performed in 164 patients with asthma or COPD prescribed with inhaled medication. When inhalation medication was first prescribed, education using a drug model was conducted two times and thereafter every month. In addition, education using a drug model was conducted and the ability of the patient to use inhalation medicine properly was evaluated. Results: A total of 164 patients participated in the sessions more than two times and received education. Fifty-seven patients participated in three sesions. After the patients received education one time, the ability of these patients to use an inhaler had an average score of 20.6. After the patients received education two times, the average score was 21.9. After the patients received education three times, the average score was 22.3, a further increase. The compliance of using the inhaler was 70.1% at the second session and increased to 81.8% at the third session. Conclusion: Feedback education using the "Computerized Respiratory Service Program" will increase the ability of the patient to use an inhaler and consistent education can maintain patient compliance with inhaler use.

• Progress in Medical Physics
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• 제14권2호
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• pp.131-140
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• 2003

As the importance of accuracy in measurings of 3-D anatomical structures continues to be stressed, an objective and quantitative of assessing image quality and accuracy of 3-D volume-rendered images is required. The purpose of this study was to evaluate the quantitative accuracy of 3-D rendered images obtained with MDCT, scanned at various scanning parameters (scan modes, slice thicknesses and reconstruction slice thickness). Twelve clinically significant points that play an important role for the craniofacial bone in plastic surgery and dentistry were marked on the surface of a dry human skull. The direct distances between the reference points were defined as gold standards to assess the measuring errors of 3-D images. Then, we scanned the specimen with acquisition parameters of 300 mA, In kVp, and 1.0 sec scan time in axial and helical scan modes (pitch 3:1 and 6:1) at 1,25 mm, 2.50 mm, 3.75 mm and 5.00 mm slice thicknesses. We performed 3-D visualizations and distance measurements with volumetric analysis software and statistically evaluated the quantitative accuracy of distance measurements. The accuracy of distance measurements on the 3-D images acquired with 1.25, 2.50, 3,75 and 5.00 mm slice thickness were 48%, 33%, 23%, 14%, respectively, and those of the reconstructed 1.25 mm were 53%, 41%, 43%, 36% respectively. Meanwhile, there were insignificant statistical differences (P-value<0.05) in the accuracy of the distance measurements of 3-D images reconstructed with 1.25 mm thickness. In conclusion, slice thickness, rather than scan mode, influenced the quantitative accuracy of distance measurements in 3-D rendered images with MDCT. The quantitative analysis of distance measurements may be a useful tool for evaluating the accuracy of 3-D rendered images used in diagnosis, surgical planning, and radiotherapeutic treatment.

• Korean Journal of Plant Resources
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• 제27권4호
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• pp.380-391
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• 2014

Plants as well as crops are damaged by a combination of the hot and dry winds that has been a major factor in the reduction of crop production. A means to protect them from damaging conditions is to consider a coating material. In this study, we established laboratory screening methods to find a coating material to protect a crop from rapid transpiration caused by various factors. In a test measuring the weight loss of kidney bean seedlings for 6 days, Avion treatments decreased its weight loss (P=0.05). Owing to long-time spend in completing this assay, we performed a more simple method using a cobalt chloride paper strip, which changes from blue to red colors under water condition. Beewax, guagum, paraffin liquid, soybean oil, and PE-635 gave a waterproofing effect above 37 and 43% at 0.5 and 1 h after treatment, respectively. However, these tested materials did not show significant waterproofing results at 2 h. Although the methods produced reasonable results, a screening method to obtain more objective data is needed. An alternative is to use an instrument that can detect the transpiration of crop leaves. In a preliminary test using barley leaves, a portable photosynthesis system showed transpiration inhibition of 2% soybean oil and 10 times-diluted Avion under field conditions. In another test using the leaves of maize seedlings and apricot tree, 2% liquid paraffin and plant oils such as apricot oil, linseed oil, olive oil, and soybean oil showed significant transpiration inhibition (P=0.05). Especially, paraffin liquid and soybean oil selected from above tests gave good transpiration inhibitory effects against rice at 2%. In addition, the mixture of 2% soybean oil and a spreader showed more elevated inhibition results comparing with soybean oil or the spreader alone indicating that the spreader may be attributed to more uniform diffusion of the hydrophobic material onto the leaf surface of maize seedlings. The hydrophobic material coated physically the stomata and cuticle layers on leaf surfaces of rice. These hydrophobic materials screened in this study are expected to be used as plant coating materials.

• Journal of dental hygiene science
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• 제7권3호
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• pp.121-127
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• 2007

The purpose of this study was to analyze college students basic knowledge of oral health of a college student and compare with the knowledge of oral health between dental hygiene students and non-dental hygiene students. A survey was conducted on the residents in Gyeonggi-do and Gwangju from June 2006 to May 2007. The findings of the study were as follows: 1. Concerning the knowledge of oral health, dental hygiene students got the source of information most frequently from school work about oral health(80.0%) and non-dental hygiene students got from health programs of TV or radio(42.7%). Concerning the reason of keeping of oral hygiene, dental hygiene students were to preventive of dental caries(80.9%) and nondental hygiene students were to preventive of periodontal disease(52.4%). There were significant difference between dental hygiene students and non-dental hygiene students(p < 0.001). 2. The knowledge degree of dental caries, to the both groups, methods of preventing caries appeared regular brush and main cause of dental caries was not to brush. There were significant difference between dental hygiene students and non-dental hygiene students(p < 0.001). 3. Dental hygiene students answered about the knowledge of fluoride know fluoride(93.6%) and non-dental hygiene students answered (55.3%). Dental hygiene students thought that fluoride could preventive dental caries(85.5%) but non-dental hygiene students thought that fluoride couldn't preventive dental caries(51.0%). There was significant difference between dental hygiene students and non-dental hygiene students(p < 0.001). 4. In the knowledge of oral health state, both of groups, replied that their own tooth state is average but they concerned about their tooth health. There was significant difference between dental hygiene students and non-dental hygiene students(p < 0.001). About main cause of dental caries, students ranked that the first reason was the poor toothbrush and the second reason was the over intaking of sugared foods. 5. About knowledge of oral diagnosis, to both groups, students ranked that first could endure the pain and the second was in much pain. For both groups, students ranked that difficult of dental treatment was cost, fear and time. There was significant difference between dental hygiene students and non-dental hygiene students(p < 0.01). For both groups, when they visit dentist's office, they felt misgivings and fear.