• The Journal of Korean Academy of Prosthodontics
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• v.43 no.2
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• pp.158-175
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• 2005

Statement of problem. Every effort has been continually made to obtain objectivity in measuring the longevity of fixed restorations, such as by establishing unified judgement standard for deciding success and adopting statistical method that analyzes the data of successful and failed cases at the same time. In Korea, however desired level of development has not to be made in this field yet. Purpose. This study, adopting California Dental Association (CDA) quality evaluation system, established objective standard for deciding success, and inferred the longevity of fixed restorations and their failure analysis through adopting Kaplan-Meier survival analysis. Material and method. In order to assess the longevity of flxed restorations serviced in Korea and causes of failure, a total of 1109 individuals (aged 15-74, 716 women and 393 men loaded with 2551 unit fixed restorations, and 1934 abutments) who lived in Kyung-In Province were examined and the findings were as follows : Results. 1. Length of service of fixed restorations serviced in Korea was 6.86$\pm$0.15 yr (mean), 5.5 yr (median), and the rate of success was 65.82% in 5 year survival, and 21.15% in 10 year survival. 2. When there was patient's need for replacing old prosthetics, longevity of fixed restorations was 7.51$\pm$0.27 yr (mean), 7 yr (median), and the rate of success was 61.08% in 5 year survival, and 17.57% in 10 year survival. 3. Longevity of fixed restorations was longest in the over-sixty age group(9.21$\pm$0.66) and that of the teen age group(3.39$\pm$0.28) was shortest (p<0.05). 4. Longevity of fixed restorations of women (7.38$\pm$0.18 years) was longer than that of men (6.00$\pm$0.26) (p<0.05). 5. As for the provider factor (such as unlicensed performers, university hospitals, and private clinic), there was no statistically significant difference in longevity of fixed restorations. 6. Defective margin (34.78%). periodontal disease (12.15%), periapical involvement (11.73%), was the most frequent causes of failure and poor esthetics group showed the longest life above all (p<0.05). Actual frequent causes of failure after removing old prosthetics were defective margin, periapical involvement, periodontal disease and uncemented restoration. In 75.67% of the cases, abutment state after removing old prosthetics was good enough for loading another prosthetics. 7. There was found to have statistically significant influence between longevity of single crown (6.35$\pm$0.20 yr) and that of 3 unit fixed restorations (7.60$\pm$0.30 y) (p<0.05). In each case the most frequent cause of failure was defective margin. 8. The number of cantilever pontic, pontic/abutment ratio, oral hygiene status were found to have no statistically significant influence on longevity of fixed restorations in all groups (p>0.05). 9. Longevity of fixed restorations made of non precious metal was longest (9.60$\pm$0.40 yr) semi precious and precious trailing behind(p<0.05). 10. Group function group (37.04%) and partial group function group (44.62%) were predominant in frequency but showed no correlation between them and among different types of occlusal plane and different types of occlusal surface (p>0.05). 11. Longevity of fixed restorations was longest in the centric interference group(9.35$\pm$0.62) (p<0.05) among different types of occlusal interference. Conclusion. We found that longevity of fixed restorations serviced in Korea is affected by age, gender and type of material, and that most frequent cause of failure is defective margin. In order to assess the accurate longevity of axed restorations, unified research design. overcoming inter-observer difference and establishing the objective research items are needed. Furthermore, it is thought that prospective approach through thorough study and regular follow-ups is needed just from the start of research. Nationwide detailed studies on length of service of fixed restorations manufactured in Korea are hoped to be conducted hereafter.

• Journal of The Korean Association For Science Education
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• v.18 no.4
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• pp.601-615
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• 1998

Establishing and evaluating science education policies and revising and monitoring the effectiveness of science curriculum should be based upon the results of systematic and scientific research studies. Advanced nations have already been administering and developing national level science assessments for these purposes. The science assessments administered in Korea have been reported having many limitations and problems, and not succeeded in providing data for science education policy making and curriculum reform. The major purpose of the study is developing national level science knowledge assessment system in order to identify longitudinal trends of elementary and secondary school students science knowledge achievements. The research team consisted of science education experts and teachers from various school levels, decided the directions and major elements of national level science knowledge assessment with the consultation of educational evaluation experts. Item developing ability of the researchers was improved by seminars? and workshops on national assessment in advanced nations and developing skills of writing science items. Nearly 500 items were developed and revised. Pilot test was administered with 958 students at various school levels. 380 items were selected and tested with 8766 students, and the characteristics were analyzed in terms of item response theory. The target populations for national level science knowledge assessment are 5th-grade of elementary school, 2nd-grade of middle school, 1st and 2nd-grade of high school students. The proper period for the assessment is February every year. Multi-stage clustered sampling method is desirable and rotated forms are recommendable for the test format. Bridge items should be introduced to compare the results of multiple tests, and various grades. Anchor items should also be used for longitudinal interpretations of the results. The items for elementary school require low to medium abilities, for middle school and first grade of high school require medium to high abilities and for 2nd-grade of high school high abilities. The discrimination ability of the items developed is high.

• Culinary science and hospitality research
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• v.21 no.4
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• pp.16-28
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• 2015

The purpose of this study, as a part of developing a new french dressing, was to present the best conditions to make improved kiwi dressing, suitable for the tastes of modern people, the processing and cooking methods of different ratios of green kiwi and gold kiwi have been sought to develop a new type of dressing, then its antioxidant have been defined, and used for producing kiwi dressing. Each 150g of different Kiwi purees, made based on the most preferable combinations from the pre-test were used for kiwi dressing, and thereafter its quality characteristics, and physical properties were investigated, as well as a sensory test was conducted. The highest viscosity of kiwi dressing was test sample GD2, and in general that of combining both types of kiwis were higher than that of either single kiwi. The sugar content was decreased by changing the Gold kiwi portion(p<0.05). The chromaticity in general increased with increases in the Gold kiwi portion, and a-value(brightness) and b-value(redness) of sample GD1 were the highest by -2.75 and 17.50(p<0.05). From the acceptability test, the highest overall acceptability was the dressing sample combining Gold kiwi and Green kiwi at a ratio of 1:1. Based on the study results, it is expected that the dressing, made of kiwi puree, mixing Green kiwi and Gold kiwi by 1:1 ratio, and adding 130g of edible oil, 50g of onion, 40g of sugar, and 5g of salt, would improve the quality and overall acceptability of the dressing.

• Sleep Medicine and Psychophysiology
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• v.4 no.1
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• pp.57-65
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• 1997

As jet lag of modern travel continues to spread, there has been an exponential growth in popular explanations of jet lag and recommendations for curing it. Some of this attention are misdirected, and many of those suggested solutions are misinformed. The author reviewed the basic science of jet lag and its practical outcome. The jet lag symptoms stemed from several factors, including high-altitude flying, lag effect, and sleep loss before departure and on the aircraft, especially during night flight. Jet lag has three major components; including external de synchronization, internal desynchronization, and sleep loss. Although external de synchronization is the major culprit, it is not at all uncommon for travelers to experience difficulty falling asleep or remaining asleep because of gastrointestinal distress, uncooperative bladders, or nagging headaches. Such unwanted intrusions most likely to reflect the general influence of internal desynchronization. From the free-running subjects, the data has revealed that sleep tendency, sleepiness, the spontaneous duration of sleep, and REM sleep propensity, each varied markedly with the endogenous circadian phase of the temperature cycle, despite the facts that the average period of the sleep-wake cycle is different from that of the temperature cycle under these conditions. However, whereas the first ocurrence of slow wave sleep is usually associated with a fall in temperature, the amount of SWS is determined primarily by the length of prior wakefulness and not by circadian phase. Another factor to be considered for flight in either direction is the amount of prior sleep loss or time awake. An increase in sleep loss or time awake would be expected to reduce initial sleep latency and enhance the amount of SWS. By combining what we now know about the circadian characteristics of sleep and homeostatic process, many of the diverse findings about sleep after transmeridian flight can be explained. The severity of jet lag is directly related to two major variables that determine the reaction of the circadian system to any transmeridian flight, eg., the direction of flight, and the number of time zones crossed. Remaining factor is individual differences in resynchmization. After a long flight, the circadian timing system and homeostatic process can combine with each other to produce a considerable reduction in well-being. The author suggested that by being exposed to local zeit-gebers and by being awake sufficient to get sleep until the night, sleep improves rapidly with resynchronization following time zone change.

• Tuberculosis and Respiratory Diseases
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• v.45 no.4
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• pp.754-759
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• 1998

Background : Lung cancer is an important public health problem because of rapidly increasing malignancy in both sexes in relation with high smoking rate in Korea. Despite advances in therapeutic modalities and supportive cares, 5-year survival rate has improved only marginally during the past 2 decades. Therefore, the early detection of lung cancer is strongly needed for better prognosis and we conducted this study to review the clinical factors resulting in delayed diagnosis of lung cancer. Method: The clinical data such as presenting symptoms, duration for diagnosis, disease entities causing misdiagnosis or delayed diagnosis, were analyzed retrospectively in 154 patients with primary lung cancer diagnosed at Chungnam National university hospital from January to December in 1995. Results : 63 patients(40.9%) out of 154 patients were delayed diagnosed with the duration of 6.3 months compared with 3.6 months in patients diagnosed without delay. In delayed diagnosed group, Cough & sputum and dyspnea as presenting symptom were more critical than hemoptysis and chest pain, and doctor's delay was more critical than patient's delay. Tuberculosis(30/63) was most frequent disease entity causing delayed diagnosis, followed by pneumorua(9/63), COPD(6/63), heart diseases(5/63), etc.. Conclusion: It should be emphasized that any respiratory symptom be checked with chest X-ray to differentiate lung cancer and periodic check of chest X-ray be also needed for the longterm patients with any disease, especially with high risk group.

• Tuberculosis and Respiratory Diseases
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• v.43 no.3
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• pp.410-419
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• 1996

Background : Spontaneous pneumothorax have been managed with a variety of methods. The technique most frequently used is chest tube drainage. Small caliber catheters were first used in the management of pneumothorax complicating the percutaneous needle aspiration lung biopsy, and the try to treat spontaneous pneumothorax also has been reported. However, the value of small caliber catheters in spontaneous pneumothorax has not been fully evaluated. So, we tried to elucidate the efficacy of 8 French catheter in the management of spontaneous pneumothorax. Method : From January, 1990, to April, 1994, 44 patients with spontaneous pneumothorax treated at Chung-Ang university hospital were reviewed. The patients were sub-divide into 8 French catheter insertion group (n=21) and chest tube insertion group (n=23). We compared the presence of underlying lung disease, the extent of the collapse, the duration of indwelling catheter and complication between two groups. Results : 1) The duration of indwelling showed no significant difference between 8 French catheter group and chest tube. But, complication after insertion as subcutaneous emphysema was developed in only chest tube group. (p<0.05) 2) In the primary spontaneous pneumothorax, all case of the pneumothorax of which size was less than 50% showed complete healing with 8 French catheter insertion. Whereas the success rate in patients with large pneumothorax (more than 50%) was tended to be dependent on the age. 3) In the patients with secondary spontaneous pneumothorax who were managed with 8 French catheter, the success rate was trended to be high if the underlying disease of pneumothorax was not COPD and if the patient was young. Conclusion : These results show that 8 French catheter insertion probably was effective in the pneumothorax less than 50%, the primary spontaneous pneumothorax, young age or secondary pneumothorax not associated with COPD.

• Tuberculosis and Respiratory Diseases
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• v.48 no.6
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• pp.898-908
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• 2000

Background : Eotaxin a CC chemokine specific for eosinophils, is implicated in the pathogenesis of asthma by recruiting eosinophils into the airways. Theophylline has been used for the treatment of asthma and recently was proposed to have an anti-inflammatory action. The aim of this study is to examine whether theophylline may inhibit the eosinophilic airway inflammation by reducing the expression of eotaxin. Methods : The expression of eotaxin mRNA was assessed by Northern analysis in A549 cells 4 h after stimulation with TNF-$\alpha$ or IL-1$\beta$. And then, theophylline was added to A549 cells stimulated with 0.1 ng/mL IL-1$\beta$. Results : Eotaxin mRNA expression rates induced by 0.1, 1, 10 ng/mL TNF-$\alpha$ as compared with $\beta$-actin, were 7%, 22%. 28%, respectively. Eotaxin mRNA expression rates induced by 0.01, 0.1, 1, 10 ng/mL IL-1$\beta$, as compared with $\beta$-actin, were 10%, 42%, 63%, 72%, respectively. Eotaxin mRNA expression rates after the addition of 0, 0.001, 0.01, 0.1 ${\mu}M$ dexamethasone induced by 10 ng/mL TNF-$\alpha$ as compared with $\beta$-actin, were 27%, 18%, 8%, respectively. Eotaxin mRNA expression rate after the addition of 0, 0.001, 0.01, 0.1 ${\mu}M$ dexamethasone induced by 0.1 ng/mL IL-1$\beta$ as compared with $\beta$-actin, were 43%, 47%, 12%, 8%, respectively. Eotaxin mRNA expression rates after the addition of 0, 0.001, 0.01, 0.1, 1, 10 mM theophylline induced by 0.1 ng/mL IL-1$\beta$, as compared with $\beta$-actin, were 48%, 40%, 33%, 22%, 16%, 14%, respectively. Conclusion : These results suggest that theophylline may reduce eosinophil infiltration of the airway at least in part by reducing the expression of eotaxin under the conditions of these experiments.

• Tuberculosis and Respiratory Diseases
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• v.49 no.2
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• pp.189-197
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• 2000

Background : Tissue inhibitor of metalloproteinase is a natural inhibitor that counteracts pro teolytic enzymes essential to the invasion of cancer cell. Whether or not TIMP-2 gene transfer via adenovirus could inhibit the invasion of lung cancer cell iη vitro was evaluated for the future purpose of gene therapy against lung cancer. Methods : Recombinant adenovirus-TIMP-2(Ad-TIMP-2) was generated by homologous recombination after pACCMV-TIMP-2 and pJM17 were cotransfected into 293 cell by standard calcium phosphate coprecipitate method. Calu-6, one of the most invasive lung cancer cells, was transduced with Ad-TIMP-2 or Ad-$\beta$gal. Anchorage-independent growth and invasiveness were assessed by soft agar clonogenicity assay and invasion assay using two-chamber, well divided by matrigel. Results : Ad-TIMP-2 transduced calu-6 cells produced biologically active TIMP-2 more than 50 times more than parental calu-6. TIMP-2 gene transfer did not suppress the in vitro tumorigenicity. However, two chamber well assay revealed that Ad-TIMP-2 transduction reduced the invasiveness of calu-6 efficiently (12% compared with parental cell) even at low 10moi. Conclusion : Even though TIMP-2 gene transfer did not inhibit in vitro tumorigenicity, it did inhibit invasion of lung cancer cell in vitro. The inhibition of invasion by Ad-TIMP-2 may be a useful strategy for the treatment of lung cancer.

• Tuberculosis and Respiratory Diseases
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• v.45 no.4
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• pp.776-784
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• 1998

Background: The cyclin D1 gene is one of the most frequently amplified chromosomal regions(11q13) in human carcinomas. In laryngeal and head and neck carcinomas, its overexpression has been shown to be associated with advanced local invasion and presence of lymph node metastases. Cyclin D1 may therefore playa key role in cell growth regulation and tumorigenesis. Lung cancer is a worldwide problem and in many contries it is the most lethal malignancy. As relapse is frequent after resection of early stage non-small cell lung cancer, there is an urgent need to define prognostic factors. Purpose: This study was undertaken to evaluate the prognostic value of the cyclin D1, that is one the G1 cyclins which control cell cycle progression by allowing G1 to S phase transition, on the patients in radically resected non-small cell lung cancer. Method: Total 81 cases of formalin-fixed paraffin-embedded blocks from resected primary non-small cell lung cancer from January 1, 1983 to July 31, 1995 at Hanyang University Hospital were available for both clinical follow-up and immunohistochemical staining using monoclonal antibodies for cyclin D1. Results : The histologic classification of the tumor was based on WHO criteria, and the specimens included 45 squamous cell carcinomas, 25 adenocarcinomas and 11 large cell carcinomas. Cyclin D1 overexpression was noted in 26 cases of 81 cases tested (30.9%). Cyclin D1 expression was not significantly associated with cell types of the tumor, pathological staging and the size of the tumor. But cyclin D1 overexpression was significantly correlated with positive lymph node metastasis(p=0.035). The mean survival duration was $22.76{\pm}3.50$ months in cyclin D1 positive group and $45.38{\pm}5.64$ months in eyclin D1 negative group. There was a nearly significant difference in overall survival between cyclin D1 positive and negative groups(p=0.0515) in radically resected non-small cell lung cancer. Conclusion: Based on this study, cyelin D1 overexpression appears an important poor prognostic indicator in non-small cell lung cancer and may have diagnostic and prognostic importance in the treatment of resectable non-small cell lung cancer.

• Tuberculosis and Respiratory Diseases
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• v.43 no.6
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• pp.925-935
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• 1996

Background : In order to elucidate one of the pathogenic mechanisms of ARDS associated with pulmonary surfactant and oxidant injury, acute lung injury was induced by N-nitroso N-methylurethane (NNNMU). In this model, the role of phospholipase $A_2$ ($PLA_2$), surfactant, gamma glutamyl transferase (GGT) and morphology were investigated to delineate one of the pathogenic mechanisms of ARDS by inhibition of $PLA_2$ with high dose of dexamethasone. Method: Acute lung injury was induced in Sprague-Dawley rats by NNNMU which is known to induce acute lung injury in experimental animals. To know the function of the alveolar type II cells, GGT activity in the lung and bronchoalveolar lavage was measured. Surfactant phospholipid was measured also. $PLA_2$ activity was measured to know the role of $PLA_2$ in ARDS. Morphological study was performed to know the effect of $PLA_2$ inhibition on the ultrastructure of the lung by high dose of dexamethasone. Results : Six days after NNNMU treatment (4 mg/kg), conspicuous pulmonary edema was induced and the secretion of pulmonary surfactant was decreased significantly. In the acutely injured rats' lung massive infiltration of leukocytes was observed. At the same time rats given NNNMU had increased $PLA_2$ and GGT activity tremendously. Morphological study revealed bizarre shaped alveolar type II cells and hypertrophied lamellar bodies in the cytoplasm of the alveolar type II cells. But after dexamethasone treatment (20 mg/kg, for six days) in NNNMU-treated rats, these changes were diminished i.e. there were decrease of pulmonary edema and increase of surfactant secretion from alveolar type D cells. Rats given dexamethasone and NNNMU had decreased $PLA_2$ and GGT activity in comparison to NNNMU induced ARDS rats. Conclusion : Inhibition of $PLA_2$ by high dose of dexamethasone decreased pathological findings caused by infiltration of leukocytes and respiratory burst. Based on these experimental results, it is suggested that an activation of $PLA_2$ is the one of the major factors to evoke the acute lung injury in NNNMU-induced ARDS rats.