• Journal of Chest Surgery
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• v.43 no.4
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• pp.356-363
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• 2010

Background: Connexin 43-mediated gap junctional communication plays an important role in atherosclerosis. Numerous studies have demonstrated a correlation between mitral valve annular calcification and atherosclerotic disease. However, the relevance of connexin 43 to mitral valve disease remains unclear. We hypothesized that the mechanism contributing to mitral valve disease is associated with alterations in cell-to-cell communication mediated by changes in Connexin 43 expression. Material and Method: Twenty male New Zealand rabbits were divided into two groups: animals in group 1 (n=10) were fed a normal chow diet, whilst those in group 2 (n=10) received a diet containing 1% cholesterol for 12 weeks. After sacrificing the animals, the mitral valves were excised and analyzed with immunohistochemical staining and Real-time Reverse Transcriptase polymerase chain reaction (real time RT-PCR). Result: Myofibroblasts and macrophages were found concentrated within the endothelial layer on the ventricular side of the leaflet in the cholesterol diet group. Immunohistochemial staining showed elevated expression of connexin43 in the cholesterol diet group. Real-time RT-PCR revealed increased connexin43 mRNA levels in mitral valves from hypercholesterolemic animals. Conclusion: Our finding that connexin43 expression is increased in mitral valves of hypercholesterolemic rabbits suggests that alterations in cell-to-cell communication via connexin43 containing gap junctions play a role in the development of mitral valve disease in hypercholesterolemia.

• The Journal of Korean Academy of Prosthodontics
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• v.44 no.6
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• pp.699-711
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• 2006

Statement of problem. Elastomeric impression materials have been widely used to obtain an accurate impression. However there have not been enough studies on the influence of the thickness of the tray adhesives on the bonding strength between the trays and the elastomeric impression materials. Purpose. In order to understand the relationship between the thickness of the tray adhesive and the tensile bond strength and to suggest the thickness at which the bonding strength is strongest, tensile bond strength related to the thickness of adhesives of 3 different elastomeric impression materials were tested. Materials and methods. 3 impression materials, $Permlastic^{(R)}$. Regular Set(Kerr Corp., Romulus, Michigan, U.S.A.), $Impregum^{TM}$ $Penta^{TM}$(3M ESPE, Seefeld, Germany), and Aquasil Ultra Monophase Regular Set Smart Wetting.(Dentsply Caulk, Milford, Delaware, U.S.A.), were used in this study, and tray adhesives from the same manufacturers of the impression materials were used, which were Rubber Base Adhesive, Polyether Adhesive, and Silfix, respectively. The tray specimens were prepared by autopolymerizing the tray material(Instant Tray Mix, Lang, Wheeling, Illinois, U.S.A.), and a PVC pipe was used to house the impression material. In group A, tray adhesives were applied in multiple thin layers of 1 to 5 and in group B, adhesives were applied only once, in the thickness equivalent to several applications. Lightness($L^*$) of the adhesion surface was measured with a spectrophotometer(CM-3500d, Konica Minolta, Sakai, Osaka, Japan). The tensile bond strength of the elastomeric impression material and the tray resin was measured with universal materials testing machines(Instron, Model 3366, Instron Corp, Nowood, Massachusetts, U.S.A.). A formula between the number of adhesive application layers and the lightness of the adhesion surface was deduced in group A, and the number of adhesive layers in group B was estimated by applying the lightness($L^*$) to the deduced formula. Results. 1. In group A, a statistically significant increase in tensile bond strength appeared when the number of application layers increased from 1 to 2 and from 4 to 5, and no significant difference was present between 2, 3, and 4 layers in Permlastic. In Impregum, the tensile bond strength was significantly increased when the number of adhesive layers increased from 1 to 3, but no significant difference after 3 layers. In Aquasil, the tensile bond strength significantly increased as the number of application layers increased up to 4 but showed no significant difference between 4 and 5. 2. In group B, the tensile bond strength was decreased when the thickness of the adhesive increased in Permlastic. Impregum showed an increased tensile bond strength when the thickness of the adhesive was increased. In Aquasil, the tensile bond strength increased as the number of adhesive application layers increased up to approximately 2.5 layers but it sharply decreased after approximately 4.5. Conclusion. From the study, the common idea that it is better to apply a thin and single coat of tray adhesive needs correction in more detailed ways, and instructions on some of the tray adhesives should be reconsidered since there were several cases in which the tensile bond strength increased according to the increase in the thickness of the adhesives.

• Progress in Medical Physics
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• v.8 no.2
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• pp.67-76
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• 1997

We studied optical behavior of scintillation light generated in NaI(TI) crystal using Monte Carlo simulation method. The simulation was performed for the model of NaI(TI) scintillator (size: 60 mm ${\times}$ 60 mm ${\times}$ 6 mm) using an optical tracking code. The sensitivity as a function of surface treatment (Ground, Polished, Metal-0.95RC, Polished-0.98RC, Painted- 0.98RC) of the incident surface of the scintillator was compared. The effects of NaI(TI) scintillator thickness and the refractive index of light guide optically coupling between the NaI(TI) scintillator and photomultiplier tube (PMT) were simulated. We also evaluated intrinsic position resolution of the system by calculating the spread of scintillation light generated. The sensitivities of the system having the surface treatment of Ground, Polished, Metal-0.95RC, Polished-0.98RC and Painted-0.98RC were 70.9％, 73.9％, 78.6％, 80.1％ and 85.2％, respectively, and the surface treatment of Painted-0.98RC allowed the highest sensitivity. As increasing the thickness of scintillation crystal and light guide, the sensitivity of the system was decreased. As the refractive index of light guide increases, the sensitivity was increased. The intrinsic position resolution of the system was estimated to be 1.2 mm in horizontal and vertical directions. In this study, the performance of NaI(TI)-PMT detector system was evaluated using Monte Carlo simulation. Based on the results, we concluded that the NaI(TI)-PMT detector array is a favorable configuration for small gamma camera imaging breast tumor using Tc-99m labeled radiopharmaceuticals.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.27 no.5
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• pp.404-416
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• 2001

Purpose : Traditionally, the treatement of choice has been a bone grafting procedure to increase the length of bone in case of actual length discrepancy. But, bone grafting procedure has many disadvantages, for example, graft resorption, donor site morbidity, and so on. So, many trials have been performed to avert the use of autogenous bone graft via introducing new materials or methods. And, one of those trials has been realized by the development of a technique inducing bone lengthening by osteotomy (or corticotomy) and slow gradual distraction of the osteotomized segments. This new technique of bone lengthening dates back to the early 20th century. But, the majority of information concerning the biology of new bone formation during bone lengthening and technical details of the procedure were produced by extensive clinical and experimental studies performed by Ilizarov, a Russian surgeon. According to Ilizarov, with adequate blood supply, preservation of periosteum, rigid fixation of the osteotomized segments, and proper rate and rhythm of distraction, intramembranous bone rapidly develops within the distraction gap in the limb lengthening procedure. In the limb lengthening, many orthopedic surgeons try to observe the biologic and clinical principles recommended by Ilizarov. In the oral and maxillofacial region, however, not a few studies must be performed to apply this surgical technique in the clinical cases. Besides, the mechanism of bone formation in the distraction gap is not clear, yet. The purpose of this experiment was to scrutinize serially the histological changes in the elongated bone affected by osteodistraction of the mandibular body in an adult canine model. In addition, it was performed to confirm the presence of specific region(s) which was important in the bone formation in the gap through the observation of the expression pattern of osteocalcin and osteonectin with the immunohistochemical examination. Materials and Methods : The experimental and control specimens were obtained from seven adult male mongrel dogs weighing over 20kg. The distractors were custom-made linear extraoral devices and bicortical fixation screws were 2.3mm in diameter, 50mm in total length, 15mm in screw length. The distractors were devised to produce a linear gap of 0.75mm between two bony segments every $360^{\circ}$ turn of the rotation rod of the device. The mandibular body of the right side of each animal was corticotomized perpendicular to the occlusal plane and then two bony segments were separated completely by careful manipulation of the segments with bone forceps. The left side of each animal was left intact. This side was served as control. At sixth day after osteotomy and fixation of the segments were performed, distraction of the segments was commenced with a rate of 1.1mm/day and a rhythm of two/day for ensuing 7 days. The animals were euthanized at the 16th. 29th, and 44th day after the osteotomy. The bony specimens were decalcified, embedded in paraffin, sectioned $5{\mu}m$ thick and stained with H&E. The prepared specimens were examined under the light microscope. And, immunohistochemical examinations using anti-osteocalcin antibody (OC1, Biodesign, USA) and anti-osteonectin antibody (Haematologic Technologies Inc., Essex, VT) to locate the expressions of osteocalcin and osteonectin, respectively, were performed. Results : 1. New bone was observed already at the 16th. day after osteotomy. This suggests that new bone formation in osteodistraction was commenced at an early stage of the regenerative process. But, radiologically and microscopically, bony union was not completed in the distraction gap at the 44th. day after osteotomy. Therefore, rigid fixation must be maintained between the bony fragments till the complete bony union is confirmed clinically rather than one month or so after the completion of distraction.

• Food Science and Preservation
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• v.11 no.2
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• pp.195-200
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• 2004

Microbial lethal value and nutrient retention of sous vide processed spinach were evaluated with mathematical model prediction and experimental trial for different package sizes and pasteurization temperatures. The package size covers 500 g, 1 kg and 2 kg, while the pasteurization temperature includes 80, 90 and 97$^{\circ}C$. The basic process scheme consists of filling blanched spinach into barrier plastic film pouch, sealing under vacuum, pasteurization in hot water with over pressure and final cooling to 3$^{\circ}C$. Pasteurization condition was designed based on attainment of 6 decimal inactivation of Listeria monocytogenes at geometric center of the pouch package by heating cycle, which was determined by general method. Heat penetration property of the package and thermal destruction kinetics were combined to estimate the retention of ascorbic acid and chlorophyll. Smaller packages with shorter pasteurization time gave better nutrient retention, physical and chemical qualities. Larger package size was estimated and confirmed experimentally to give higher pasteurization value at center, lower ascorbic acid and chlorophyll contents caused by longer heat process time. Lower pasteurization temperature with longer process time was predicted to give lower pasteurization value at center and lower ascorbic acid, while chlorophyll content was affected little by the temperature. Experimental trial showed better retention of ascorbic acid and chlorophyll for smaller package and higher pasteurization temperature with shorter heating time. The beneficial effect of smaller package and higher pasteurization temperature was also observed in texture, color retention and drip production.

• Radiation Oncology Journal
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• v.20 no.3
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• pp.221-227
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• 2002

Purpose : To evaluate the role of postoperative chemoradiotherapy in locally advanced rectal cancer, we retrospectively analyzed the treatment results of patients treated by curative surgical resection and postoperative chemoradiotherapy. Materials and Methods : From April 1989 through December 1998, 119 patients were treated with curative surgery and postoperative chemoradiotherapy for rectal carcinoma in Gyeongsang National University Hospital. Patient age ranged from 32 to 73 years, with a median age of 56 years. Low anterior resection was peformed in 59 patients, and abdominoperineal resection in 60. Forty-three patients were AJCC stage II and 76 were stage III. Radiation was delivered with 6 MV X rays using either AP-PA two fields, AP-PA both lateral four fields, or PA both lateral three fields. Total radiation dose ranged from 40 Gy to 56 Gy. In 73 patients, bolus infusions of 5-FU $(400\;mg/m^2)$ were given during the first and fourth weeks of radiotherapy. After completion of radiotherapy, an additional four to six cycles of 5-FU were given. Oral 5-FU (Furtulone) was given for nine months in 46 patients. Results : Forty $(33.7\%)$ of the 119 patients showed treatment failure. Local failure occurred in 16 $(13.5\%)$ patients, 1 $(2.3\%)$ of 43 stage II patients and 15 $(19.7\%)$ of 76 stage III patients. Distant failure occurred in 31 $(26.1\%)$ patients, among whom 5 $(11.6\%)$ were stage II and 26 $(34.2\%)$ were stage III. Five-year actuarial survival was $56.2\%$ overall, $71.1\%$ in stage II patients and $49.1\%$ in stage III patients (p=0.0008). Five-year disease free survival was $53.3\%$ overall, $68.1\%$ in stage II and $45.8\%$ in stage III (p=0.0006). Multivariate analysis showed that T stage and N stage were significant prognostic factors for five year survival, and that T stage, N stage, and preoperative CEA value were significant prognostic factors for five year disease free survival. Bowel complication occurred in 22 patients, and was treated surgically in 15 $(12.6\%)$, and conservatively in 7 $(5.9\%)$. Conclusion : Postoperative chemoradiotherapy was confirmed to be an effective modality for local control of rectal cancer, but the distant failure rate remained high. More effective modalities should be investigated to lower the distant failure rate.

• Journal of Chest Surgery
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• v.30 no.5
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• pp.471-478
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• 1997

Introduction: The use of rabbits as a cardiopulmonary bypass(CPB) animal model is extremely dif%cult mainly due to technical problems. On the other hand, deep hypothermic circulatory arrest(CA) is used to facilitate surgical repair in a variety of cardiac diseases. Although steroids are generally known to be effective in the treatment of cerebral edema, the protective effects of steroids on the brain during CA are not conclusively established. Objectives of this study are twofold: the establishment of CPB technique in rabbits and the evaluation of preventive effect of steroid on the development of brain edema during CA. Material '||'&'||' Methods: Fifteen New Zealan white rabbits(average body weight 3.5kg) were divided into three experimental groups; control CA group(n=5), CA with Trendelenberg position group(n=5), and CA with Trendelenberg position + steroid(methylprednisolone 30 mglkg) administration group(n=5). After anesthetic induction and tracheostomy, a median sternotomy was performed. An aortic cannula(3.3mm) and a venous ncannula(14 Fr) were inserted, respectively in the ascending aorta and the right atrium. The CPB circuit consisted of a roller pump and a bubble oxygenator. Priming volume of the circuit was approximately 450m1 with 120" 150ml of blood. CPB was initiated at a flow rate of 80~85ml/kg/min, Ten min after the start of CPB, CA was established with duration of 40min at $20^{\circ}C$ of rectal temperature. After CA, CPB was restarted with 20min period of rewarming. Ten min after weaning, the animal was sacrif;cod. One-to-2g portions of the following tissues were rapidly d:ssected and water contents were examined and compared among gr ups: brain, cervical spinal cord, kidney, duodenum, lung, heart, liver, spleen, pancreas. stomach. Statistical significances were analyzed by Kruskal-Wallis nonparametric test. Results: CPB with CA was successfully performed in all cases. Flow rate of 60-100 mlfkgfmin was able to be maintained throughout CPB. During CPB, no significant metabolic acidosis was detected and aortic pressure ranged between 35-55 mmHg. After weaning from CPB, all hearts resumed normal beating spontaneously. There were no statistically significant differences in the water contents of tissues including brain among the three experimental groups. Conclusion: These results indicate (1) CPB can be reliably administered in rabbits if proper technique is used, (2) the effect of steroid on the protection of brain edema related to Trendelenburg position during CA is not established within the scope of this experiment.

• Health Policy and Management
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• v.15 no.1
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• pp.97-117
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• 2005

This study was designed to compare the differences m results of supervisor and subordinate rating. Data was collected from personnel evaluation and subordinate rating results for middle managers(n=68) in hospital from 3rd January to 20th March in 2004. Supervisor rating consisted of performance, ability and attitude evaluation. Subordinate rating consisted of leadership, ability and attitude evaluation. Collected data included sociodemographic characteristics, work department, work level, years of work, years at present level and whether working in a patient serving department. The difference of standardized supervisor and subordinate rating score was used to define groups as 'higher in supervisor rating group'. Groups were defined in total score, ability score and attitude score. Main results were as follows: 1. In total score, sectional chiefs were apt to be 'higher in subordinate rating group' while chief clerks were apt to be 'similar group' or 'higher in supervisor rating group'. Staffs in patient serving department were likely to be 'higher in supervisor rating group' and staffs in non-patient serving department were likely to be 'higher in subordinate rating group'. All these results were statistically significant. 2. In ability score, there were no statistically significant differences in age, sex, years of education, work department, work level, years of work and whether working in a patient serving department among 'higher in supervisor rating group', 'similar group' and 'higher in subordinate rating group'. 3. In attitude score, staffs in the department of medical affairs and the department of administration were apt to be 'higher in subordinate rating group'. Staffs in the department of nursing were apt to be 'higher in supervisor rating group'. Staffs in a patient serving department were likely to be 'higher in supervisor rating group' and staffs in a non-patient serving department were likely to be 'higher in subordinate rating group'. All these results were statistically significant. 4. Logistic analysis about total score showed that sectional chiefs had higher Odds Ratio(OR) to be in 'higher in subordinate rating group'. Staffs in a non-patient serving department had higher OR to be in 'higher in subordinate rating group'. Both these results were statistically significant. 5. Logistic analysis about ability score showed that sectional chiefs had higher OR to be in 'higher in subordinate rating group'. Staffs in a non-patient serving department had higher OR to be in 'higher in subordinate rating group'. These results were not statistically significant. 6. Logistic analysis about total score showed that sectional chiefs had higher OR to be in 'higher in subordinate rating group', but the difference was not statistically significant. Staffs in a non-patient serving department had significantly higher OR to be in 'higher in subordinate rating group'. In conclusion, there is no clear superiority between supervisor and subordinate rating in personnel evaluation. It would be better to use a mixed model. It's also suggested to use an intervening rate of application or scores considering work levels and work department in personnel evaluation. These results would be helpful for hospitals planning a supervisor and subordinate rating system for personnel evaluation.

• Journal of Preventive Medicine and Public Health
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• v.27 no.2 s.46
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• pp.200-216
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• 1994

In present study, the authors investigated the possible effect of coffee consumption on serum cholesterol level in 1017 men between the ages of 40 and 59 years, who were randomly selected from the members of Seoul Cohort Study. Serum total cholesterol data was collected with other serologic indices (e.g. systolic blood pressure, diastolic blood pressure, hight, weight, etc.) through the program of biennial health check-up offered by Korean Medical Insurance Corporation (KMIC). The amount of coffee consumption was assessed by a self-administered questionnaire through mailing. Other confounding factors, such as age, body mass index, cigarette smoking, alcohol consumption, physical activity, and other dietary intake pattern were also determined by the questionnaire. The differences in means of serum total cholesterol in compared to non consumers were $-0.4{\pm}3.56mg/dl$ for those drinking less than 1 cup a day, $-0.6{\pm}3.60mg/dl$ for those drinking 1 cup a day, and $7.1{\pm}3.41mg/dl$ for those drinking more than 2 cups a day. Since smoking interacted the relationship between coffee consumption and serum total choleaterol, we re-analyzed those relationship in smokers and non-smokers separately Other atherogenic behaviors were well correlated with total cholesterol, so we adjusted the mean values of serum total cholesterol through multivariate model selection with age(r=0.12), total cigarette index (cigarette-years; r=0.10), Quetelet's index ($Kg/m^2$, r=0.16), daily calory expenditure (kcal/day, r=0.06), weekly meat and poultry consumption(g/week, r=0.05), weekly fish consumption (g/week, r=0.08), other caffeinated beverage intake (cups/week), and the amount of sugar and prim added to the coffee. Among those variables only age, Quetelet's index, fish consumption, and total cigarette index (in smokers) were remained in the models. After adjustment, the corresponing differences of total cholesterol in smokers were changed to $0.4{\pm}5.24mg/dl,\;-0.5{\pm}4.97mg/dl,\;and\;8.9{\pm}4.78mg/dl$, which were significantly different among themselves (P=0.011). In non-smokers, however, the differences were not statistically significant (P=0.76). Adjusted mean values of systolic blood pressure and diastolic blood pressure were also determined to evaluate the direct effect of coffee to cardiovascular system, but their means were not significantly different by coffee consumption(p=0.18 for SBP, p=0.48 for DBP). Asuming instant coffee in the most popular type of coffee in Korea, the association observed in our study between coffee and serum total cholesterol, especially in smokers, is very interesting finding for the connection between coffee and serum total cholesterol, because only 'boiled coffee' tend to show significant lipid raising effect rather than to other types of coffee, like filtered or espresso, in most of the western countries. We concluded that people who drink coffee more than 2 cups a day have significantly higher serum total cholesterol level than those who never drink coffee, especially in smokers.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.5
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• pp.537-544
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• 2017

In this study, the anti-inflammatory effect of Polyopes affinis ethanol extract (PAEE) was investigated using LPS-stimulated RAW 264.7 cells and a croton oil-induced ICR mice model. Treatment with PAEE significantly reduced production of nitric oxide (NO) and pro-inflammatory cytokines [interleukin (IL)-6, tumor necrosis factor $(TNF)-{\alpha}$, and $IL-1{\beta}$] in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. PAEE treatment also reduced expression of inducible NO synthase, cyclooxygenase-2, nuclear $factor-{\kappa}B$, and mitogen-activated protein kinases in LPS-stimulated RAW 264.7 cells. In the croton oil-induced ear edema test, application of PAEE (10~250 mg/kg body weight) reduced ear edema in a dose-dependent manner, and PAEE treatment at 50 mg/kg body weight showed similar inhibitory effects compared with prednisolone (10 mg/kg body weight). Histological analysis revealed reduced dermal thickness and lower number of infiltrated mast cells. These results suggest that PAEE might be used as a promising anti-inflammatory agent for inhibition of LPS-induced inflammation and ear edema formation.