• The korean journal of orthodontics
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• v.27 no.5 s.64
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• pp.771-779
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• 1997

The purpose of this in vitro study was to evaluate the effects of different acid etching times on the enamel surface morphology, shear bond strength and debonding failure mode of orthodontic attachment. Ninety six extracted human mandibular premolars were divided into eight groups of twelve teeth. The buccal surfaces were etched with $37\%$, phosphoric acid for 5, 10, 15, 30, 45, 60, 90 and 120 seconds, respectively. Two teeth from each group were used for scanning electron microscope examination. On the etched buccal surfaces of remaining teeth, orthodontic attachments(lingual buttons) were bonded with light cured orthodontic adhesive. Twenty foot hours after bonding, a Instron universal testing machine was used to determine shear bond strength of orthodontic attachment to enamel. After debonding, bases of orthodontic attachments and enamel surfaces were examined under stereoscopic microscope to determine failure mode. Statistical analysis of the data was carried out with one nay ANOVA and Duncan's multiple range test The results were as follows; 1. There was no statistically significant difference in shear bond strengths between the various etching times(p<0.05). 2. The failure modes of orthodontic attachments had some differences. In 5, 10 and 15 seconds etching groups, the percentage of adhesive/enamel interface failure was higher than that of adhesive/attachment interface failure. On the contrary, in 30, 45, 60, 90 and 120 seconds etching groups, the results were reversed. 3. The etching patterns of enamel surfaces had a great variation. So, we could not find any correlation between etching pattern and bond strength. 4. The findings in this study indicate that in vitro reduction of the etching me to 5 seconds maintains clinically acceptable bond strength. However, further study is required to determine the cause of failure mode in 5, 10 and 15 seconds groups.

• Clinical and Experimental Reproductive Medicine
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• v.33 no.3
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• pp.199-205
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• 2006

Objective: The aim of this study was to evaluate the correlation between severity of endometriosis and the incidence of endometrial polyp. Methods: The study population consisted of six hundred thirty-one women who had undergone laparoscopic operation due to infertility, severe dysmenorrhea or ovarian tumors. We divided two groups: 434 women with endometriosis (study group) and 197 women without the disease (control group). The presence of endometriosis was documented by diagnostic or therapeutic laparoscopic operation and the disease severity was scored according to revised The American Fertility Society classification. We confirmed the endometrial polyps by pathologic examination after hysteroscopic polypectomy, and compared endometrial polyp incidence according to severity of endometriosis. Results: There was no significant difference between groups with regard to age, mean duration of infertility. Endometrial polyps were found in 274 women (63.0%) with endometriosis and in 58 controls (29.8%, p=0.0000). The incidence of endometrial polyps differed significantly according to stage of endometriosis. The incidence of endometrial polyps were 77/142 (54.2%), 58/90 (64.4%), 73/108 (67.6%, p<0.05), 66/94 (70.2%, p<0.05) in endometriosis stage I, II, III, and IV. There was a linear correlation between stage of endometriosis and endometrial polyps incidence (p=0.008). Conclusion: Endometriosis is accompanied by endometrial polyps. This results showed positive correlation between severity of the endometriosis and incidence of endometrial polyps. It is the possible mechanism for low pregnancy rate in the severe endometriosis.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.4 no.2
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• pp.181-190
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• 2001

Purpose: The aim of this study is to investigate the usefulness of intestinal ultrasonography (US) and upper gastrointestinal endoscopy in the early diagnosis of Henoch-Sch$\"{o}$nlein purpura (HSP) with the gastrointestinal (GI) symptoms preceding the emergence of the skin lesion. Methods: The clinical, intestinal US and upper gastrointestinal endoscopic records of 85 patients (88 cases) with GI symptoms relating to HSP presenting between January 1999 and April 2001 were reviewed. Results: 1) GI symptoms were observed in 52 cases (59%) and skin, joint, renal and scrotal manifestations were observed in 88 (100%), 64 (73%), 15 (17%), 3 cases (3%) respectively. 2) Out of 52 cases with GI symptoms, abdominal pain was observed in all cases (100%). Positive stool occult blood, nausea and vomiting, abdominal tenderness, melena or tarry stool, diarrhea, hematemesis, rebound tenderness and rigidity were observed in 28 (50%), 17 (33%), 17 (33%), 12 (23%), 6 (12%), 4 (8%), 1 (2%) and 1 case (2%) respectively in order of frequency. 3) Intestinal US examination was performed in 27 cases with HSP and GI symptoms (52 cases). Out of 27 sonographic examinations 22 showed abnormal findings. Thickening of the duodeno-jejunal wall was observed in 16 cases (73%). Free peritoneal fluid, enlarged mesenteric lymph node, ileus and abnormal gall bladder were seen in 8 (36%), 8 (36%), 4 (18%) and 1 case (5%) respectively. In three cases of HSP without GI symptoms, those changes were absent. 4) In all of five cases with HSP and GI symptoms, endoscopic study showed mucosal edema and multiple hemorrhagic erosions especially at the second portion of the duodenum. Biopsy specimens from the duodenum of 2 cases out of 5 endoscopic examinations showed acute inflammatory infiltrates in the mucosa with hemorrhage. 5) Both intestinal US and endoscopic studies were performed in 4 cases with HSP and GI symptoms simultaneously. Out of 4 those cases, 3 cases showed the thickened duodeno-jejunal wall on the intestinal US, which suggested erosive hemorrhagic duodenitis by endoscopic findings. Conclusion: The typical but nonpathognomonic intestinal US findings including the thickening of the duodeno-jejunal wall and upper gastrointestinal endoscopic findings including hemorrhagicerosive duodenitis, in children with GI symptoms, should be considered a manifestation of HSP, even in the absence of skin lesion.

• Nuclear Medicine and Molecular Imaging
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• v.41 no.2
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• pp.172-180
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• 2007

Among the nuclear medicine imaging methods available today, $H_2^{15}O-PET$ is most widely used by cognitive neuroscientists to examine regional brain function via the measurement of regional cerebral blood flow (rCBF). The short half-life of the radioactively labeled probe, $^{15}O$, often allows repeated measures from the same subjects in many different task conditions. $H_2^{15}O-$ PET, however, has technical limitations relative to other methods of functional neuroimaging, e.g., fMRI, including relatively poor time and spatial resolutions, and, frequently, insufficient statistical power for analysis of individual subjects. However, recent technical developments, such as the 3-D acquisition method provide relatively good image quality with a smaller radioactive dosage, which in turn results in more PET scans from each individual, thus providing sufficient statistical power for the analysis of individual subject's data. Furthermore, the noise free scanner environment $H_2^{15}O$ PET, along with discrete acquisition of data for each task condition, are important advantages of PET over other functional imaging methods regarding studying state-dependent changes in brain activity. This review presents both the limitations and advantages of $^{15}O-PET$, and outlines the design of efficient PET protocols, using examples of recent PET studies both in the normal healthy population, and in the clinical population.

• Clinical and Experimental Pediatrics
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• v.52 no.10
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• pp.1127-1135
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• 2009

Purpose : To observe the abnormal white matter findings on the magnetic resonance imaging (MRI) scans of very-low- birth-weight (VLBW) infant brains at term-equivalent age and to determine the clinical risk factors for the development of periventricular leukomalacia (PVL). Methods : In all, MRI was performed in 98 VLBW infants and the white matter abnormalities were observed. Clinical risk factors for cystic and noncystic PVL were determined. Results : MRI scans of 74 infants (75.5%) showed diffuse excessive high signal intensity (DEHSI) in the periventricular white matter, 17 (17.3%) lateral ventricle dilation, 5 (5.1%) and 11 (11.2%) focal punctate lesions and cystic changes in the periventricular white matter, respectively, 9 (9.1%), germinal layer hemorrhage (GLH) or subependymal cysts 3 (3.1%) intraventricular hemorrhage (>grade 2) 2 (2.0%) posthemorrhagic hydrocephalus and 2 (2.0%) periventricular hemorrhagic infarct. Gestational age (GA), 1-minute Apgar score, Clinical Risk Index for Babies-II (CRIB-II) score, and inotrope use, and GA, CRIB-II score, postnatal steroid administration, inotrope use, and abnormal white blood cell (WBC) count at admission were related to cystic PVL and noncystic PVL development, respectively (P<0.05). However, in logistic regression analysis, CRIB-II (odds ratio, 1.63, 295% confidence interval, 1.15-2.30 P=0.006) for cystic PVL, and GA (odds ratio 0.90, 95% confidence interval, 0.82-0.99 P=0.036) for noncystic PVL were only significant independently. Conclusion : White matter abnormalities could be observed on MRI scans of the VLBW infant brains at term-equivalent age, and CRIB-II and GA were only independently significant for cystic and noncystic PVL development, respectively.

• Korean Journal of Clinical Laboratory Science
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• v.47 no.4
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• pp.216-224
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• 2015

This study aims to identify the prevalence of sleep related disease in those who experienced car accidents caused by drowsy driving. To this end, a survey of usual sleep habits, polysomnography, and multiple sleep latency tests were conducted in 34 persons who experienced an accident after normal sleep (Group 1), 22 persons who experienced an accident after abnormal sleep (Group 2), and 17 persons who was proven to be normal as a result of polysomnography and had no accident (Group 3). In all, 192 persons responded to the preliminary survey and the results were compared and analyzed. Crossover analysis was conducted to test the homogeneity of statistical characteristics, and the physical characteristics by age were analyzed. In the survey of sleeping habits, there was a significance between groups in how often they woke up while asleep (p<0.01), how difficult it was to go back to sleep again after waking up from sleep (p<0.05), how early they woke up in the morning (p<0.05), how difficult it was to get up in the morning (p<0.05), how sleepy they felt in the daytime (p<0.01), and how tired they felt in the daytime (p<0.01). Furthermore, among 56 subjects who had an accident during drowsy driving, 94.6% (53 persons) were found to have sleep related diseases. This suggests that car accidents during drowsy driving is not simply caused by temporary lack of sleep but by sleep related diseases even when sleep is adequate, leading to car accidents. Therefore, this study is significant identifying the association between car accidents during drowsy driving and sleep related disorders. Furthermore, the data would be considered basic to prepare social measures against drowsy driving related to such sleep related disorders.

• Tuberculosis and Respiratory Diseases
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• v.65 no.3
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• pp.183-190
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• 2008

Background: The control of active pulmonary tuberculosis is still an issue in community medicine. But there are also considerable needs for supportive management of symptomatic patients with post-tuberculous destroyed lung. Few studies have evaluated clinical characteristics and health-related quality of life in patients with post-tuberculous destroyed lung. Methods: We evaluated lung function, exercise tolerance, HRCT and health-related quality of life measurements using the Korean version of St. George's Respiratory Questionnaire (SGRQ) in 22 patients with parenchymal damage to more than a half of one lung due to pulmonary tuberculosis. Results: In the pulmonary function test, mixed defects and obstructive defects were observed in 10 (45.0%) and 9 (40.9%) of patients, respectively. In the cardiopulmonary exercise test, the mean $VO_2max%$ predicted ($39.0%{\pm}10.9%$) and $O_2$ pulse% predicted ($61.3%{\pm}13.6%$) were markedly decreased. In the SGRQ, the impact score (mean $27.8{\pm}18.5$) was significantly lower than the symptom score (mean $53.9{\pm}20.9$) or activity score (mean $50.8{\pm}27.3$) (p<0.05, p<0.01). Cronbach's alpha coefficient value for reliability was more than 0.7 for each subscale and total score. The total score showed a significant negative correlation with $FEV_1%$ predicted (r=-0.46, p<0.05) and $SaO_2$ (r=-0.60, p<0.05). On HRCT, a median of 9 (range 5~15) bronchopulmonary segments were destroyed by less than half, which significantly correlated with SGRQ total score (r=-0.52, p=0.02). Conclusion: The reliability and validity of the Korean version of the SGRQ was acceptable for the measurement of health-related quality of life in patients with post-tuberculous destroyed lung.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.7 no.1
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• pp.92-109
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• 1996

The objectives of the present study were to provide comprehensive assessment of the impact of epilepsy on the psychological well-being of children with epilepsy and to identify the neurological factors associated with the psychopathology. The participant patients were recruited from the population of children and adolescent aged 7 to 16 attending the OPD of department of pediatric neurology in Seoul National University Hospital in Korea. We exclude mental retardation, pervasive developmental disorder and brain organic pathology. As control group, formal students were chosen and their sex, age, achievement, socioeconomic status were matched to patients. The first author interviewed the children and their family members and obtained the developmental history and family information. We used the following 10 scales for assessing psychological and behavioral problems in patients and their family member. The scales were standardized and their validity and reliability were confirmed before. Parent rating scales : Yale children's inventory, Disruptive behavior disorder scale, Parent's attitude to epilepsy questionnaire, Family environment scale, Symptom check-list-90 revision, Children behavior check-list. Children's self rating scales : Children's depression inventory, Spielberger's state-trait anxiety anxiety, Piers-Harris self-concept inventory and Self-administered Dependency questionnaire for Mother. The result showed the risk factors associated depression were early onset, complex partial seizure, lateralized temporal focal abnormality on EEG, Drug polypharmacy, high seizure frequency and sick factors associated anxiety were old age of patient, lateralized temporal focal abnormality EEG, Drug polypharmacy, high seizure frequency. Also the result of this present study indicated that risk factors associated oppositional defiant disorder, conduct disorder and attention deficit hyperactivity disorder were young age, male, early onset, lateral temporal EEG abnormality and high seizure frequency. According to these results, common risk factors associated psychological and behavioral problems were lateralized EEG temporal abnormality, high seizure frequency in neurological factors.

• Clinical and Experimental Pediatrics
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• v.46 no.5
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• pp.454-458
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• 2003

Purpose : Rotavirus is the main cause of infantile diarrheal disease worldwide. The purpose of this study is to assess the difference between clinical manifestations and feeding or delivery methods in healthy full-term neonates and those with nosocomially-acquired rotaviral infection. Methods : The study was conducted on 348 babies who were delivered in Dongguk University Kyongju Hospital from Jan 1 to June 30 in 2001. Stool specimens were collected from clinically symptomatic neonates. We studied the rate of positive stool rotazyme ELISA tests and positive symptoms. We compared the frequency of clinical manifestations according to the feeding methods [breast feeding(BF) or formula feeding(FF)] and the delivery methods[normal vaginal delivery(NVD) or Cesarean section(C/sec)]. Results : Rotavirus was detected in 152 of 348 babies. The rate of positive rotazyme ELISA test was 43.7% in healthy full-term symptomatic neonates. The most common symptom of rotaviral enteritis was mild fever; the others were watery diarrhea, abdominal distension, vomiting, delayed weight gain, irritability, poor oral intake and dehydration. Compared with FF neonates, BF neonates have lower frequency of symptoms, especially watery diarrhea, delayed weight gain and poor oral intake. The symptomatic frequency was higher in FF and NVD neonates than BF and C/sec. Conclusion : The symptoms of rotaviral enteritis were less frequent in BF or C/sec delivered neonates. BF appeared to alleviate the rotaviral enteritis but further studies are needed. The cause of the lower frequency of symptoms in C/sec delivered neonates was unknown.

• Tuberculosis and Respiratory Diseases
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• v.43 no.2
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• pp.173-181
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• 1996

Background : Several studies have suggested that impaired mucociliary clearance plays a role in the pathophysiology of bronchial asthma. Cough productive of mucoid sputum is common, and mucous plugs in the airways are frequently observed. These clinical features are in keeping with the histologic lesions of asthma, which involve primarily the epithelial and mucous-producing structures of the conducting airways. Some studies have shown that the mucociliary clearance is impaired in adult asthma, but it has not been studied in childhood asthma. The objectives of this study were to examine whether the mucociliary clearance is impaired in childhood asthma and to estimate the degree of impairment in comparison with that of immotile cilia syndrome. Method : Thirteen children with mild stable asthma and eight patients with immotile cilia syndrome completed this study. Ten healthy children were recruited as a normal control group. The whole-lung mucociliary clearance was measured by the radioaerosol technique. Aerosols, tin colloid particles tagged with the radionuclide technetium-99m($^{99m}Tc$), were generated by means of nebulizer, and inhaled via a mouthpiece. The retention of radioactivity was measured at 30, 60, 90 and 120 minutes by gamma camera, and mucociliary clearance was calculated as percent retention at each time. Results: 1) In each subject, the percent retention decreased variably with the lapse of time. 2) The percent retention of radionuclide decreased at each time in order of normal control, bronchial asthma and immotile cilia syndrome and the percent retention of immotile cilia syndrome was significantly higher than that of normal control at each time(p<0.05). 3) At two hours, the percent retention of bronchial asthma($65.0{\pm}1.8$(SE)%) was significantly higher than that of the normal control($54.4{\pm}3.5%$, p<0.05), and significantly lower than that of immotile cilia syndrome($73.3{\pm}1.4%$, p<0.01). 4) When the percent retention was analyzed according to $PC_{20}$ in the children with bronchial asthma, they had no relationship with each other. Conclusion: Mucociliary clearance in the children with bronchial asthma was significantly lower than normal control. This finding indicates that impaired mucociliary clearance operates in childhood asthma as well, and suggests that it may be one contributing factor in the pathogenesis of asthma. The degree of impairment, however, was not so severe as immotile cilia syndrome.