• Korean Journal of Cognitive Science
• /
• v.28 no.1
• /
• pp.1-26
• /
• 2017

This study investigated the cortical generators of P300 in college students with schizotypal traits by using an auditory oddball paradigm, event-related potentials (ERPs) and standardized low resolution brain electromagnetic tomography (sLORETA) model. We also investigated the relationship between the current density of P300 and the clinical symptoms of schizophrenia. Based on the scores of Schizotypal Personality Questionnaire(SPQ), schizotypal trait (n=37) and control (n=42) groups were selected. For the measurement of P300, an auditory oddball paradigm, in which frequent standard tones (1000Hz) and rare target tones (1500Hz) were presented randomly, was used. Participants were required to count the number of the target tones during the task and report this at the end of the experiment. The two groups did not differ significantly in the accuracy of the oddball task. The schizotypal trait group showed significantly smaller P300 amplitudes than control group. In terms of source localization, both groups showed the P300 current density over bilateral frontal, parietal, temporal and occipital lobes. However, the schizotypal trait group showed significantly reduced activations in the left superior temporal gyrus and the right middle temporal gyrus, but increased activations in both left inferior frontal gyrus and right superior frontal gyrus compared to the control group. Furthermore, a negative correlation between the current density of the right superior frontal gyrus and SPQ disorganization score was found in the schizotypal trait group. These findings indicate that the individuals with schizotypal traits have dysfunctions of frontal and temporal areas, which are known to be the source of P300, as observed in patients with schizophrenia. In addition, the present results indicate that the disorganization score, rather than total score, of the SPQ is useful in predicting the risk of future schizophrenia.

• Clinical and Experimental Pediatrics
• /
• v.45 no.11
• /
• pp.1389-1396
• /
• 2002

Purpose : This study was done to analyze the changes in the clinical conditions and the diagnosis of hypertrophic pyloric stenosis. Methods : We report a retrospective clinical analysis of 39 patients with hypertrophic pyloric stenosis from Jan. 1992 to Aug. 2001. The age and sex distribution, family and birth history, clinical symptoms, the ultrasonographic and the operative sizes of pyloric canals were compared. Results : The body weight was below the 3 percentile at admission in eight cases(20.5%). "Olive like mass" in right upper quadrant was palpated during physical examination in 23 cases(59%) and gastric peristaltic wave observed in six cases(15%). The ultrasonographic measurements showed that the pyloric muscle thickness to be $4.95{\pm}0.99mm$($mean{\pm}SD$), pyloric diameter $14.42{\pm}2.64mm$, and pyloric length $20.17{\pm}3.92mm$. Fredet-Ramstedt pyloromyotomy was employed in all cases. The operative measurements of the pyloric muscle thickness was $5.11{\pm}1.01mm$, pyloric diameter $15.01{\pm}2.47mm$, and pyloric length $22.32{\pm}3.43mm$. Conclusion : There was no significant difference between the ultrasonographic and operative measurements. Currently, the hypertrophic pyloric stenosis patients showed lesser clinical hallmarks of the disease. The earlier diagnosis using imaging studies before development of significant metabolic abnormalities is becoming an important factor that change the future outcomes of hypertrophic pyloric stenosis.

• Clinical and Experimental Pediatrics
• /
• v.45 no.11
• /
• pp.1332-1339
• /
• 2002

Purpose : Through a survey undertaken among doctors practicing pediatric patients in primary medical facilities on nutrition during infancy, the present study was done to determine whether these doctors were giving appropriate advice on infant nutrition. Methods : We visited pediatric specialists(group one) and non-pediatric specialists or general practitioners(group two) who were practicing in Daegu to ask them to fill out a questionaire on infant nutrition. Results : When 10 points were given to each question for a total of 100 points, the results of the evaluation showed that the score in group one was $73.0{\pm}15.8$ points and $45.1{\pm}18.4$ points in group two, showing a significant difference. No statistical difference was seen in the scores between non-pediatric specialists and general practitioners. Each answer to each question on the feeding period of breast milk, on loose stools during breast milk feeding, methods to deal with jaundice during breast milk feeding, choice of commercial baby food, criteria on directing soy milk, and criteria of guiding infant cereal was different between group one and two. Conclusion : The results of the present investigation showed that specialists in other fields or general practitioners were giving inappropriate advice on nutrition during the infant stage compared with pediatric specialists; thus, we need to confirm methods to prevent inappropriate consultations by specialists of other fields, together with continued education of pediatric specialists.

• Journal of Periodontal and Implant Science
• /
• v.32 no.3
• /
• pp.445-456
• /
• 2002

The purpose of this study were to determine that dexamethasone(Dex) induces differentiation of periodontal ligament(PDL) cells to osteoblastic cells and to investigate expression of matrix Gla protein(MGP), which is one of bone matrix protein. The isolated human PDL cells and gingival fibroblasts were prepared and cultured. The fourth or sixth sub-passage cells were used in this experiments. control group, ascorbic acid and ${\beta}$-glycerophosphate treated group, ascorbic acid, ${\beta}$-glycerophosphate and l00nM Dex treated group, ascorbic acid, ${\beta}$-glycerophosphate, and 5 ${\mu}M$ Dex treated group were made for study. The results were as follows: Cellular morphological change of PDL cells according to time was investigated. At first, the cells exhibited confluent monolayer of spindle or polygonal appearance. The multilayer of cells were seen after 7 days of treatment. After 14 days, the cells lost polarity and were densely packed. The mineralized nodule formation was seen at 21 days in the only Dex treated PDL cell groups. In the gingival fibroblast groups and no Dex treated PDL cell groups, the mineralized nodule was not seen. The mineralized nodule formation of 5 ${\mu}M$ Dex treated group was higher than 100 nM Dex treated group. Alkaline phosphatase(ALP) activity was higher in the Dex treated PDL cell groups of 14 and 21 days than 0 and 7 days. MGP was expressed in the control and all experimental groups and the expression was constant at 0,7,14,21 day. The above results confirm that Dex is affected to differentiation of the PDL cells to osteoblastic or cementoblastic cells and has dose-dependent effect for mineralization. And, MGP is expressed in the PDL cells and is not affected to mineralization of PDL cells.

• Journal of Biomedical Engineering Research
• /
• v.23 no.2
• /
• pp.147-153
• /
• 2002

The purpose of this study was to evacuate the effect of different types of Poly(lactic-co-glycolic acid) (PLGA) scaffolds on the formation of human auricular and septal cartilages. All of the scaffolds were formed in a tubular shape for potential application for artificial trachea or esophagus with either 110,000 g/mol PLGA. 220,000 g/mol PLGA. or a combination of both. In order to maintain the tubular shape in vivo, two methods were used. One method was inserting polyethylene tube at the center of scaffolds made of 110,000 g/mol PLGA. The other method involved combination of the two different molecular weight PLGA's. The inner surface of tubular shaped scaffold made with 110,000 g/mol PLGA was coated with 220,000 9/mol PLGA to give more mechanical rigidity. Elastic cartilage was taken from the ear of a patient aged under 20 nears old and hyaline cartilage was taken from the nasal septum. The chondrocytes were then isolated. After second passage, the chondrocytes were seeded on the PLGA scaffolds followed by in vitro culture for one week. The cells-PLGA scaffold complex were implanted subcutaneously on the back of nude mice for 8 weeks. The tissue engineered cartilages were separated from nude mice and examined histologically after staining with the Hematoxylin Eosin. The morphology of the scaffolds were examined by scanning electron microscopy. The pores were well formed and uniformly distributed in the various PLGA scaffolds. After 8 weeks in vivo culture, cartilage was well formed with 110,000 g/mol PLGA. however lumen had collapsed. In contrast. a minimal amount of neocartilage was formed with 220,000 g/mol PLGA, while the architecture of scaffold and lumen were well preserved. Elastic cartilage formed more neocartilage than hyaline. Hyaline and elastic neocartilage were well formed on 110,000 g/mol PLGA with the polyethylene tube, exhibiting mature chondrocytes and preservation of the tubular shape. It was found that 110,000 g/mol PLGA was more appropriate for cartilage formation but higher molecular weight polymer was necessary to maintain the three dimensional shape of the scaffold.

• The Journal of Korean Society for Radiation Therapy
• /
• v.18 no.1
• /
• pp.21-28
• /
• 2006

Purpose: The purpose of this study is to find a optimal beam spoiler condition on the dose distribution near the surface, when treating a squamous cell carcinoma of the head and neck and a lymphatic region with 10 MV photon beam. The use of a optimal spoiler allows elivering high dose to a superficial tumor volume, while maintaining the skin-sparing effect in the area between the surface to the depth of 0.4 cm. Materials and Methods: The lucite beam spoiler, which were a tissue equivalent, were made and placed between the surface and the photon collimators of linear accelerator. The surface-dose, the dose at the depth of 0.4 cm, and the maximum dose at the dmax were measured with a parallel-plate ionization chamber for $5{\times}5cm\;to\;30{\times}30cm^2$ field sizes using lucite spoilers with different thicknesses at varying skin-to-spoiler separation (SSS). In the same condition, the dose was measured with bolus and compared with beam spoiler. Results: The spoiler increased the surface and build-up dose and shifted the depth of maximum dose toward the surface. With a 10 MV x-ray beam and a optimal beam spoiler when treating a patient, a similer build-up dose with a 6 MV photon beam could be achieved, while maintaining a certain amount of skin spring. But it was provided higher surface dose under SSS of less than 5 cm, the spoiler thickness of more than 1.8 cm or more, and larger field size than $20{\times}20cm^2$ provided higher surface dose like bolus and obliterated the spin-sparing effect. the effects of the beam spoiler on beam profile was reduced with increasing depths. Conclusion: The lucite spoiler allowed using of a 10 MV photon beam for the radiation treatment of head and neck caner by yielding secondary scattered electron on the surface. The dose at superficial depth was increased and the depth of maximum dose was moved to near the skin surface. Spoiling the 10 MV x-ray beam resulted in treatment plans that maintained dose homogeneity without the consequence of increased skin reaction or treat volume underdose for regions near the skin surface. In this, the optimal spoiler thickeness of 1.2 cm and 1.8 cm were found at SSS of 7 cm for $10{\times}10cm^2$ field. The surface doses were measured 60% and 64% respectively. In addition, It showed so optimal that 94% and 94% at the depth of 0.4 cm and dmax respectively.

• Journal of Korean Orthopaedic Sports Medicine
• /
• v.2 no.2
• /
• pp.142-148
• /
• 2003

Purpose: This study was performed to evaluate the operative results of osteochondritis dissecans treated with autogenous osteochondral grafts. Materials and Methods: From May 1990 to May 2000, this study included 13 patients, 17 cases treated with autogenous osteochondral grafts. The mean age of patients at operation was 23.4 years (range,20 to 32 years), all cases were men, and the mean follow-up was for 24.2 months (range, 12 to 110 months). Treatment was done by open or arthroscopic method using with Osteochondral Autograft Transfer System (OATS, Arthrex, USA). Results: Trauma history existed in all cases, and major trauma history in 7 cases, and minor repetitive in 10 cases. The involved sites of lesion were medial femoral condyle in 11 cases, in which extended classic site was 9 cases, inferocentral site was 2 cases, and lateral femoral condyle in 6 cases, in which all cases were inferocentral site. Magnetic resonance imaging (MRI) staging was stage II in 1 case, stage III in 11 cases, stage IV in 5 cases, and arthroscopic staging was stage III in 12 cases, stage IV in 5 cases. The mean lesion size was 3.19$cm^2$ (range, 1 to 8$cm^2$). Clinical results evaluated with grading system by Aichroth, were excellent in 3 cases (18$\%$), good in 11 cases (65$\%$), moderate in 2 cases (12V), poor in 1 case (5$\%$), which revealed satisfactory results in 83$\%$. Congruent articular surface, satisfactory articular thickness, and no loosening or subsidence was evidenced by follow-up MRI or arthroscopic finding. Conclusion: Autogenous osteochondral grafts can be an alternative treatment in lesions larger than 1$cm^2$ in size, unstable lesion, and involvement of weight-bearing articular surface. Long term follow-up will be needed for the final efficacy of autogenous osteochondral grafts.

• Journal of Korean Orthopaedic Sports Medicine
• /
• v.6 no.1
• /
• pp.38-44
• /
• 2007

Purpose: To evaluate status of reconstructed ACL and changes around graft through second-look arthroscopy after arthroscopic reconstruction of the ACL with autograft tendons. Material and Methods: Between Jun. 2003 and Feb. 2007, the second look arthroscopy was performed on 22 cases. Second-look arthroscopy was conducted on average 15.1 $(7\sim31)$ months after reconstruction. 15 cases received hamstring tendon autograft, 7 cases received bone-patellar tendonbone autograft. We measured graft tension using displacement by probing, synovial coverage by visual analysis at second-look arthroscopy The assay in Lysholm score, Lachmann test and KT-2000 arthrometer were evaluated status of reconstructed ACL. Results: The hamstring tendon group showed normal tension in 11 cases and lax tension in 4 cases. The patellar tendon group showed normal tension in 3 cases, lax tension in 2 cases and partial tear in 2 cases. In the hamstring tendon group, synovial coverage was good in 11 cases, half in 3 cases and pale in 1 case, and the bone-patellar tendon-bone group was good in 4 cases and half in 3 cases. The patellar tendon group was superior to the hamstring tendon group in Lysholm score (p<0.05), but insignificance difference in KT-2000 arthrometer results statistically. Conclusion: The hamstring tendon group was superior to the bone-patellar tendon-bone group in second-look arthroscopy after ACL reconstruction with autograft tendons results, but long term follow up will be necessary to further evaluated.

• Pediatric Gastroenterology, Hepatology & Nutrition
• /
• v.13 no.1
• /
• pp.58-65
• /
• 2010

Purpose: Since there are few studies involving acute pancreatitis in children, we reviewed our experience with this medical condition to describe the clinical features. Methods: A retrospective analysis was conducted by reviewing the medical records of 41 patients with AP who were admitted to the Department of Pediatrics of Pusan National University Hospital between January 1996 and June 2007. Results: Twenty males and 21 females (mean age, 8.7${\pm}$4.5 years) were included. In 22 patients (53.7%), no definitive causes were found. The most common etiologies were choledochal cysts (22.0%). Necrotizing pancreatitis was diagnosed in 5 patients (12.2%), and recurrent acute pancreatitis in 4 patients (9.8%). CT findings included pancreatic swelling (43.9%), peripancreatic fluid collection (29.3%), ascites (24.4%), and peripancreatic fat necrosis (12.2%). Serum amylase and lipase levels at diagnosis were 535.3${\pm}$553.2 and 766.2${\pm}$723.6 U/L, respectively, and were normalized within 1 week in 22 and 14 patients, respectively. On the basis of the Balthazar scale, 2 patients were diagnosed with severe AP. In 4 patients (9.8%), a surgical procedure was indicated. Major complications included ascites (32.3%), sepsis (16.1%), and pseudocyst and renal impairments (12.9%). Two patients died from multi-organ failure. Conclusion: The etiologies of AP in children are varied. Most children have a single episode and a self-limited course. However, AP of childhood still carries significant morbidity and mortality. Early diagnosis, appropriate treatment according to disease severity, and management of complications are important.

• Pediatric Gastroenterology, Hepatology & Nutrition
• /
• v.13 no.1
• /
• pp.51-57
• /
• 2010

Purpose: It has been reported that children with hypopituitarism have features of metabolic syndrome, including obesity, impaired glucose tolerance, and dyslipidemia. The aim of this study was to investigate the clinical features and liver histology of pediatric non-alcoholic fatty liver disease (NAFLD) associated with hypopituitarism. Methods: We reviewed the clinical data of 11 children diagnosed with NAFLD among patients with hypopituitarism. Results: The mean age at the time of diagnosis of hypopituitarism was 10.4${\pm}$3.2 years, and the mean age at the time of diagnosis of NAFLD was 13.1${\pm}$2.7 years. A craniopharyngioma was the most common cause of pituitary dysfunction. At the time of diagnosis of NAFLD, 9 patients (82%) had a body mass index greater than the 85th percentile, 5 patients (45%) had elevated fasting blood glucose levels, and 9 patients (82%) had hypertriglyceridemia. The mean height SD score was significantly lower at the time of diagnosis of NAFLD than at the time of diagnosis of hypopituitarism. Of the six patients who were biopsied, one had cirrhosis, two had non-alcoholic steatohepatitis (NASH) with bridging fibrosis, two had NASH with mild portal fibrosis, and one had simple steatosis. Conclusion: Children with hypopituitarism are at risk of short stature, obesity, dyslipidemia, and NAFLD. The early diagnosis of NAFLD is important in children with hypopituitarism because advanced fibrosis is common.