• Clinical and Experimental Pediatrics
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• v.48 no.7
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• pp.772-778
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• 2005

Purpose : Kawasaki disease(KD) is a systemic panvasculitis that causes coronary artery lesions. KD is accompanied by immunoregulatory abnormalities. Nitric oxide(NO) can induce relaxation of blood vessels by activating guanylate cyclase in smooth muscle cells and high levels of NO may result in coronary artery lesions. We investigated tumor necrosis factor$(TNF)-{\alpha}$ and NO production before and after intravenous immunoglobulin(IVIG) therapy to study the roles of NO and $TNF-{\alpha}$ in KD with coronary artery lesions. Methods : Serum levels of NO and $TNF-{\alpha}$ were measured in 24 patients with KD(group I, eight patients with normal coronary artery; group II, 16 patients with coronary artery lesions) and 23 controls(group III, 13 afebrile controls; group IV, 10 febrile controls). Blood samples from each subject were drawn before and after IVIG therapy and in the convalescent stage. Serum concentrations of NO and $TNF-{\alpha}$ were measured by enzyme linked immuno sorbent assay. Results : The NO levels before IVIG therapy were significantly higher in group II than in group I, group III and group IV. After IVIG therapy the levels of NO were significantly higher in group I and group II than in group III. The $TNF-{\alpha}$ levels before IVIG therapy were significantly higher in group I and group II than in group III. The serum $TNF-{\alpha}$ and NO levels were higher before IVIG therapy and decreased through the convalescent stage in KD patients. In the acute stage of KD patients with coronary artery lesions, serum NO levels significantly correlated with white blood cells (r=0.43, P<0.05). Conclusion : The serum concentration levels of $TNF-{\alpha}$ and NO were abnormally high in KD patients and NO concentrations were statistically higher in the KD patients with coronary artery abnormalities than those without coronary abnormality during the early stage of the KD. These results suggest NO may be involved in the development of coronary artery lesions.

• Clinical and Experimental Pediatrics
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• v.49 no.10
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• pp.1093-1099
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• 2006

Purpose : Homocysteine is a strong and independent risk factor for cardiovascular disease. The deleterious effects of homocysteine included endothelial dysfunction, arterial intimal-medial thickening, wall stiffness and procoagulant activity. However, the precise mechanism responsible for homocysteine release in children with coronary artery disease is still unknown. The purpose of this study was to investigate serum homocysteine and tumor necrosis $factor(TNF)-{\alpha}$ levels and identify whether these levels had any association with the development of coronary artery lesions in Kawasaki disease(KD). Methods : Serum homocysteine and $TNF-{\alpha}$ levels were measured in 24 KD patients(group 1, eight patients with normal coronary artery; group 2, 16 patients with coronary artery lesions) and 21 controls(group 3, 10 afebrile controls; group 4, 11 febrile controls). Blood samples were drawn from each study group before and after intravenous immunoglobulin(IVIG) therapy and in the convalescent stage. Results : The homocysteine levels before IVIG therapy were significantly higher in group 1 than in group 3, and in group 2 than in group 3 and 4. The $TNF-{\alpha}$ levels before IVIG therapy were significantly higher in group 2 than group 3 and 4. Serum homocysteine and $TNF-{\alpha}$ levels were highest in group 2 before IVIG therapy. In the acute KD patients, serum homocysteine levels correlated significantly with $TNF-{\alpha}$ levels. Conclusion : The increased serum homocysteine levels in the acute stage increase the susceptibility to coronary arterial lesions in KD. $TNF-{\alpha}$ may also play an important role in the formation of coronary arterial lesions in KD.

• Clinical and Experimental Pediatrics
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• v.51 no.4
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• pp.396-400
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• 2008

Purpose : The study was performed to assess the distribution of the diseases associated with nonspecific reactive hepatitis (NRH) for the past 10 years and to evaluate the change in the level of AST and ALT, and the difference by several variable factors. Methods : From January 1997 to December 2006, 646 patients had elevated liver enzymes among 22,763 patients admitted to the Holy Family Hospital. We analyzed the difference in the age distribution, the period of elevated levels of AST and ALT, the resolution period, the peak value, the daily resolution value of AST and ALT, the sexual differences and the difference in several disease entities. One hundred and ninety-seven patients not confirmed as NRH or lost during follow-up were excluded. Results : The prevalence rate of NRH was 2.84%. When compared to AST, ALT showed longer period of morbidity and resolution and the peak value was also higher in ALT. The male and female ratio showed significant value of 1.63:1. The morbid and resolution periods of AST and ALT between males and females were longer periods in males. The most prevalent disease entities were respiratory and gastrointestinal infections. Between the respiratory and the gastrointestinal diseases, the highest level of AST and ALT was observed in the respiratory disease. Conclusion : NRH is a common disease that occurs in 2.84% of the admitted pediatric patients. However, the pathogenesis and the progress of the disease have not been well known due to the lack of generalized information. Further research is necessary in the future.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.9
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• pp.1035-1043
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• 2007

A leachate containing an elevated concentration of organic and inorganic compounds has the potential to contaminate adjacent soils and groundwater as well as downgradient areas of the watershed. Moreover high-strength ammonium concentrations in leachate can be toxic to aquatic ecological systems as well as consuming dissolved oxygen, due to ammonium oxidation, and thereby causing eutrophication of the watershed. In response to these concerns landfill stabilization and leachate treatment are required to reduce contaminant loading sand minimize effects on the environment. Compared with other treatment technologies, leachate recirculation technology is most effective for the pre-treatment of leachate and the acceleration of waste stabilization processes in a landfill. However, leachate recirculation that accelerates the decomposition of readily degradable organic matter might also be generating high-strength ammonium in the leachate. Since most landfill leachate having high concentrations of nitrogen also contain insufficient quantities of the organic carbon required for complete denitrification, we combined a shortcut biological nitrogen removal (SBNR) technology in order to solve the problem associated with the inability to denitrify the oxidized ammonium due to the lack of carbon sources. The accumulation of nitrite was successfully achieved at a 0.8 ratio of $NO_2^{-}-N/NO_x-N$ in an on-site reactor of the sequencing batch reactor (SBR) type that had operated for six hours in an aeration phase. The $NO_x$-N ratio in leachate produced following SBR treatment was reduced in the landfill and the denitrification mechanism is implied sulfur-based autotrophic denitrification and/or heterotrophic denitrification. The combined leachate recirculation with SBNR proved an effective technology for landfill stabilization and nitrogen removal in leachate.

• Journal of Chest Surgery
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• v.30 no.7
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• pp.677-685
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• 1997

Thromboelastography(TEG) is the unique measure that gives rapid information about the whole clotting process. Simplifying the diagnosis of coagulopathy during operations, TEG can provide an adequate therapy for postoperative bleeding. Remarkable improvement in hemostasis after cardiopulmonary bypass(CPB) has been achieved by the treatment with proteinase inhibitor aprotinin, but the hemostatic mechanism of aprotinin during CPB is still unclear. This study was designed to evaluate the effects of aprotinin on coagulation system during CPB by using TEG. Forty patients who underwent CPB were divided into two groups: aprotinin(2u 106 kallikrein inhibition units, as a single dose into the cardiopulmonary bypass priming solution) treatment group(male 14, female 8, mean age=50.Byears) and no aprotinin treatment(control) group(male 10, female 8, mean age=53.4 years). TEG, activated clotting time, prothrombin time, activated partial thromboplastin time, platelet counts, fibrinogen an (ibrinogen degradation product(FDP) concentrations were checked before and after CPB(30 minutes after neutralization of heparin effect by protamine sulfate). There was no significant difference in other conventional coagulation tests of two groups except postcardiopulmonary bypass FDP concentration in control group, which was significantly increased compared to that in aprotinin group(p<0.05). In TEG variables of both groups, clot formation time(K) and alpha $angle(\alpha^{\circ})$ were significantly increased and decreased, respectively, after CPB(p<0.05), but fibrinolytic index(LYS60) was not changed during CPB. In aprotinin group, reaction time(R) was decreased significantly after CPB(p<0.05) but maximum amplitude(MA) was not changed(p>0.05). On the contrary, R was not changed markedly but MA was decreased significantly in control group after CPB(p<0.05). This result shows that main change in coagulation system during CPB is not hyperfibrinolysis but cecrease in clot strength by platelet dys unction, and the main effect of aprotinin during cardiopulmonary bypass is the maintenance of clot strength to the pre-CPB level by the preservation of platelet function.

• The korean journal of orthodontics
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• v.28 no.4 s.69
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• pp.547-561
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• 1998

Obstructive sleep apnea (OSA) is a disorder characterized by repetitive episode of upper airway collapse during sleep. Recent studies showed that not only the anatomic factors but the physiologic factors of the upper airway also have effcts on the occurrence of apnea and that the genioglossus muscle also plays an important role in the maintenance of the upper airway. A variety of therapies were performed to treat OSA, and among them the use of mandibular repositioning appliances showed reasonable results. But there is still a lack of research on the structural and physiological mechanism upon the use of mandibular repositioning appliances. The author selected 26(male 17, female 9) OSA patients that came to the Yonsei University Dental Hospital, Department of Orthodontics, and 20 normal adults (male 10, female 10) and took cephalometric radiographs of them in a supine position before and after the placement of the mandibular repositioning appliance to see the structural changes of the upper airway and compare the therapeutic effects between the two groups. We also studied the waking genioglossus muscle activity in OSA patients and investigated the difference in the electromyogram of the genioglosssus muscle upon the change in body posture and the use of mandibular repositioning appliance. Following results were obtained. 1. Among the cephalometric measurements of the upper airway structure, the length of the soft palate, maximum thickness of the soft Palate and SPAS, MAS, VAL, H-H1, MP-H showed statistically significant differences between the normal and OSA groups, but the IAS and EAS showed no statistically significant differences between the two groups. 2. In both the normal and OSA groups, as the epiglottis moved forward on wearing the mandibular repositioning appliance, the epiglottis level of the upper airway increased and the maximum thickness of the soft palate changed and the hyoid bone also moved forward, but the IAS in both groups showed various results and the effect of the mandibular repositioning appliance on the structure of the upper airway was different in the two groups. 3. Upon changing the position, the electromyogram of the genioglossus muscle showed a increasing tendency but there was no statistically significant differences, and when the mandibular repositioning appliance were worn there was a statistically significant increase in the electromyogram of the genioglossus muscle in both the upright and supine positions. The mandibular repositioning appliances not only have an effect on the anatomical structure of the upper airway but also on the physiology of the upper airway. There are different responses to the use of mandibular repositioning appliance between the normal and OSA groups therefore it could be considered to have the different physiology of the upper airway between the two groups.

• Progress in Medical Physics
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• v.19 no.3
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• pp.157-163
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• 2008

Retinal prosthesis is regarded as the most feasible method for the blind caused by retinal diseases such as retinitis pigmentosa or age-related macular degeneration. One of the prerequisites for the success of retinal prosthesis is the optimization of the electrical stimuli applied through the prosthesis. Since electrical characteristics of degenerate retina are expected to differ from those of normal retina, we investigated differences of the retinal waveforms in normal and degenerate retina to provide a guideline for the optimization of electrical stimulation for the upcoming prosthesis. After isolation of retina, retinal patch was attached with the ganglion cell side facing the surface of microelectrode arrays (MEA). $8{\times}8$ grid layout MEA (electrode diameter: $30{\mu}m$, electrode spacing: $200{\mu}m$, and impedance: 50 $k{\Omega}$ at 1 kHz) was used to record in-vitro retinal ganglion cell activity. In normal mice (C57BL/6J strain) of postnatal day 28, only short duration (<2 ms) retinal spikes were recorded. In rd/rd mice (C3H/HeJ strain), besides normal spikes, waveform with longer duration (~100 ms), the slow wave component was recorded. We attempted to understand the mechanism of this slow wave component in degenerate retina using various synaptic blockers. We suggest that stronger glutamatergic input from bipolar cell to the ganglion cell in rd/rd mouse than normal mouse contributes the most to this slow wave component. Out of many degenerative changes, we favor elimination of the inhibitory horizontal input to bipolar cells as a main contributor for a relatively stronger input from bipolar cell to ganglion cell in rd/rd mouse.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.4
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• pp.750-756
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• 2008

Supernumerary teeth are frequently found in the anterior portion of the maxilla and develop as a result of abnormal proliferation of the dental lamina during tooth germ formation, caused by genetic or environmental factors. They may result in various complications, such as eruption interference, displacement, rotation of adjacent teeth, diastema, eruption into the nasal cavity, and development of dentigerous cyst. The optimal time for surgical extraction of supernumerary teeth has been a controversial issue. Someone prefer early surgical extraction because supernumerary teeth can cause eruption interference and displacement of adjacent teeth, eventually altering occlusion. Others prefer to delay surgical extraction until $8{\sim}10$ years of age in consideration of root maturation of the adjacent teeth and also patient's behavior. When surgical extraction of supernumerary teeth is postponed, there is possibility that impacted supernumerary teeth in the inverted or horizontal position move toward the nasal cavity, hard palate, or premolar area. When such intraosseous tooth migration is combined with the vertical growth of the maxilla, surgical approach becomes even harder. Therefore, possibility of intraosseous tooth migration should be considered as an important factor when deciding appropriate time for surgical extraction. We are presenting cases of mesiodens which showed intraosseous migration during $6{\sim}7$ years of follow-up period since the first diagnosis had been made at the $2{\sim}3$ years of age.

• Tuberculosis and Respiratory Diseases
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• v.42 no.2
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• pp.165-174
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• 1995

Background: Exercise is one of the most common precipitants of acute asthma encountered in clinical practice. The development of airflow limitation that occurs several minutes after vigorous exercise, i. g. exercise-induced bronchoconstriction(EIB), has been shown to be closely correlated with the nonspecific bronchial hyperresponsiveness, which is the hallmark of bronchial asthma. All previous reports that assessed the correlation of EIB to nonspecific bronchial hyperresponsiveness have focused on airway sensitivity($PC_{20}$) to inhaled bronchoconstrictor such as methacholine or histamine. However, maximal airway narrowing(MAN), reflecting the extent to which the airways can narrow, when being exposed to high dose of inhaled stimuli, has not been studied in relation to the degree of EIB. Methods: Fifty-six children with mild asthma(41 boys and 15 girls), aged 6 to 15 years(mean${\pm}$SD, $9.9{\pm}2.5$ years) completed this study. Subjects attended the laboratory on two consecutive days. Each subject performed the high-dose methacholine inhalation test at 4 p.m. on the first day. The dose-response curves were characterized by their position($PC_{20}$) and MAN, which was defined as maximal response plateau(MRP: when two or three data points of the highest concentrations fell within a 5% response range) or the last of the data points(when a plateau could not be measured). On the next day, exercise challenge, free running outdoors for ten minutes, was performed at 9 a.m.. $FEV_1$ was measured at graduated intervals, 3 to 10 minutes apart, until 60 minutes after exercise. Response(the maximal ${\triangle}FEV_1$ from the pre-exercise value) was classified arbitrarily into three groups; no response((-) EIB: ${\triangle}FEV_1$<10%), equivocal response ($({\pm})$EIB:10%<${\triangle}FEV_1$<20%) and definite response($({\pm})$EIB:${\triangle}FEV_1$>20%). Results: 1) When geometric mean $PC_{20}$ of the three groups were compared, $PC_{20}$ of (+) EIB group was significantly lower than that of (-)EIB group. 2) There was a close correlation between $PC_{20}$ and the severity of EIB in the whole group(r=-0.568, p<0.01). 3) Of the total 56 subjects, MRP could be measured in 36 subjects, and the MRP of these subjects correlated fairly with the severity of EIB(r=0.355, p<0.05) 4) The MAN of (+) EIB group was significantly higher than that of (-)EIB group(p<0.01). 5) The MAN correlated well with the severity of EIB in the whole group(r=0.546, p<0.01). Conclusion: The degree of MAN as well as bronchial sensitivity($PC_{20}$) to methacholine is correlated well with the severity of EIB. The results suggest that the two main components of airway hyperresponsiveness may be equally important determinants of exercise reactivity, although the mechanism may be different from each other. The present study also provides further evidence that EIB is a manifestation of the increased airway reactivity characteristic of bronchial asthma.

• Tuberculosis and Respiratory Diseases
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• v.60 no.3
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• pp.297-303
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• 2006

Background : Pulmonary tuberculosis is frequently accompanied with complications such as bronchiectasis, cavities, fibrosis and a deterioration of the lung function. However, there is little information available on the pathogenesis of these complications in pulmonary tuberculosis. Among the many factors involving in tissue remodeling, transforming growth factor-${\beta}1$ ($TGF-{\beta}1$) is a potent stimulus of the extracellular matrix fomation and a mediator of potential relevance for airway wall remodeling. Therefore, this study examined the relationship between the radiological changes and the $TGF-{\beta}1$ level in patients with pulmonary tuberculosis. Methods : Serum and bronchoalveolar lavage fluid (BALF) were collected from total of 35 patients before treating them for active pulmonary tuberculosis, and the $TGF-{\beta}1$ levels were measured using an enzyme-linked immunosorbent assay (ELISA). The BALF levels were recalculated as the epithelial lining fluid (ELF) levels using the albumin method. pulmonary function test (PFT) and high resolution computed tomography (HRCT) were performed before and after treatment. Results : There was a strong correlation between the serum $TGF-{\beta}1$ level and the presence of cavities (r=0.404, p=0.006), even though the BAL $TGF-{\beta}1$ level showed a weak correlation with complications. In addition, there was no correlation between the $TGF-{\beta}1$ levels before treatment and the changes in the PFT and HRCT during treatment. Conclusion : There is a correlation between the serum $TGF-{\beta}1$ level and cavity formation in pulmonary tuberculosis before treatment. However, further study will be needed to confirm this.