• Journal of the korean academy of Pediatric Dentistry
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• v.33 no.2
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• pp.181-191
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• 2006

NFI-C null mice demonstrated aberrant odontoblast differentiation and thus abnormal dentin formation while other tissues/organs in the body, including ameloblasts, appear to be unaffected and normal. However little is known about the mechanism of NFI-C function in odontoblast differentiation and dentin formation. Odontoblasts are tall, highly polarized cells that are responsible for formation and maintenance of the predentin and dentin. An indication of their polarity is the acquisition of specialized intercellular junctions. As preodontoblasts differentiate into odontoblasts, they are Joined and attached at the apical end by well developed terminal webs of cytoskeletal actins, and associated tight as well as adherent njunctions. In this study, in order to investigate if disruption of the NFI-C gene interferes with formation of a specific or other structural proteins of the intercellular junctions, we examined morphological characteristic of the aberrant odontoblast in NFI-C null mice using light and electron microscope. In addition, we determined the expression of major structural proteins of intercellular junctions, ZO-1 and occludin, during the differentiation of odontoblasts using immunohitochemistry. The results were as follows : 1. In light microscopy, abnormal odontoblasts of incisors of the NFI-C null mice were round in shape, lost their polarity, and trapped in osteodentin-like mineralized tissue. Mutant molars have relatively normal crowns, but short and abnormal differentiating adontoblasts in root formation area. 2. Electron microscopy of abnormal odontoblasts revealed the dissociation of the round osteoblast-like cells, the loss of their cellular polarity, and the absence of an intercellular junctional complex known as the tight junctions. 3. A mutant incisor showed labeling for ZO-1 at the proximal and distal ends of secreting ameloblasts, while staining for ZO-1 was not observed in the abnormal odontoblasts. 4. A normal incisor showed immunoreactivity for occludin in the differentiating odontoblasts. However, staining for occludin was not observed in the abnormal odontoblasts of mutant incisor. These results suggest that NFI-C gene causes dissociation of odontoblast and thus abberant odontoblast differentiation and abnormal dentin formation by interfering with the formation of intercellular junctions.

• Advances in pediatric surgery
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• v.16 no.2
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• pp.126-133
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• 2010

Malrotation is a congenital anomaly that becomes symptomatic more frequently during infancy. The indication for surgical treatment at that age is straightforward. In older children, the diagnosis may be more difficult because of chronic and vague complaint. The aim of this study is to compare the symptoms, rate of volvulus and surgical findings in children younger and older than one year. A retrospective study of 40 patients in a a single medical center diagnosed with malrotation from April 1996 to May 2010 was performed. There were 20 (50 %) boys and 20 (50 %) girls. At the time of operation, 27 (67.5 %) patients were younger and 13 (32.5 %) were older than 1 year. Vomiting was seen in 20 cases (74.1 %) of the younger group compared to 2 cases (15.4 %) of the older group. Abdominal sonography and upper gastrointestinal series showed a sensitivity of 100%. Operative findings: 12 (44.4 %) of the younger group presented with volvulus compared to none of the older group. The Ladd's procedure was routinely performed with appendectomy in all cases and bowel resection was requires when volvulus included bowel necrosis or other anomalies were found. After definite procedures, surgical correction for adhesive obstruction was necessary in 5 menbers (18.5 %) of the younger group and 1 patient (7.7 %) in the older group. There was 1 death due to respiratory failure and pneumonia. Abdominal pain was more frequent symptom and bilious vomiting was less frequent. Volvulus did not occur in the older group. Malrotation should be diagnosed promptly in children over 1 year of age by upper gastrointestinal series and abdominal ultrasonography even though symptoms are not as clear cut as in infants.

• Clinical and Experimental Pediatrics
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• v.48 no.12
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• pp.1310-1316
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• 2005

Mechanical ventilation in children has some differences compared to in neonates or in adults. The indication of mechanical ventilation can be classified into two groups, hypercapnic respiratory failure and hypoxemic respiratory failure. The strategies of mechanical ventilation should be different in these two groups. In hypercapnic respiratory failure, volume target ventilation with constant flow is favorable and pressure target ventilation with constant pressure is preferred in hypoxemic respiratory failure. For oxygenation, fraction of inspired oxygen($FiO_2$) and mean airway pressure(MAP) can be adjusted. MAP is more important than FiO2. Positive end expiratory pressure(PEEP) is the most potent determinant of MAP. The optimal relationship of $FiO_2$ and PEEP is PEEP≒$FiO_2{\times}20$. For ventilation, minute volume of ventilation(MV) product of tidal volume(TV) and ventilation frequency is the most important factor. TV has an maximum value up to 15 mL/kg to avoid the volutrauma, so ventilation frequency is more important. The time constant(TC) in children is usually 0.15-0.2. Adequate inspiratory time is 3TC, and expiratory time should be more than 5TC. In some severe respiratory failure, to get 8TC for one cycle is impossible because of higher frequency. In such case, permissive hypercapnia can be considered. The strategy of mechanical ventilation should be adjusted gradually even in the same patient according to the status of the patient. Mechanical ventilators and ventilation modes are progressing with advances in engineering. But the most important thing in mechanical ventilation is profound understanding about the basic pulmonary mechanics and classic ventilation modes.

• Korean Journal of Bronchoesophagology
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• v.13 no.1
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• pp.29-32
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• 2007

Background and Objectives: Improvements in the fields of neonatology and surgical subspecialities make tracheotomy possible to the younger population. But complication rates for infantile tracheotomy are significantly higher than that for the other pediatric tracheotomy. This study was designed to present our 9-year experiences of infantile tracheotomy and to evaluate the effect of several factors of complications. Materials and Methods: From 1996 through 2004, 60 tracheotomies were performed. Charts were reviewed with respect to indications for tracheotomy, underlying diseases, success rate in decannulation and length of support time until decannulation, complication and mortality rate. Results: There were 41 male patients and 19 female patients. Ventilatory support for neurological impairment(38.3%) was the leading indication for tracheotomy, followed by subglottic stenosis(36.7%), laryngomalacia(13.3%). Decannulation was accomplished in 60.0% of infants with an average of 56.5momths with tracheotomy. Complications occurred in 43.3%. There was one tracheotomy-related mortality in case of tracheal atresia. Most common complication was subglottic stenosis. Conclusion: Infantile tracheotomy had significant morbidities and its outcomes are thought to be usually related to the underlying disease and age. To prevent complication, early decannulation is advisable, and for long-term tracheotomy patients, regulation of reflux and infection may be necessary.

• YAKHAK HOEJI
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• v.56 no.5
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• pp.333-345
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• 2012

A product labelling is one of key tools in ensuring that a patient uses drugs safely and effectively in self-care without professional support. This study aimed to explore the readability and comprehensibility of the information contained on two package inserts of medicines. Two package inserts were tested with first year college students. Fifty-one potential consumers underlined words they could not understand and answered 10 scenario questions. Any differences among groups with different characteristics were statistically tested. Secondly, the readability of two package inserts was assessed with comparison to the level of the 6th grade Korean textbooks. As results, more than 80% of participants properly replied to straightforward questions concerning indication, dosage, duplication, use in pregnancy and contraindication, and 73% about formulation. Less than half answered correctly in multiple choice questions about pediatric use (41%) and side effects (35%). Little discrepancy was observed in the comprehensibility between participants' characteristics. Drug inserts contained about 20% more professional-level words than 6th grade textbooks. In conclusion, Korean consumers may face challenges to understand drug information due to professional terminology and outdated expressions in the current package inserts. To secure safe and effective use of over-the-counter agents, greater efforts should be made to develop more consumer friendly labels. In the other hand, educational supports are required to prepare consumers in a proper level of knowledge for the safe use of drugs.

• Pediatric Infection and Vaccine
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• v.18 no.2
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• pp.135-142
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• 2011

Purpose : Hospital associated infection (HAI) caused by multidrug-resistant (MDR) microorganisms has been recognized as an important issue in the world, especially in critically ill patients such as the patients admitted in the intensive care unit. There are fewer papers about MDR-HAI in pediatric patients compared to adult patients. In this study, we investigated the incidence and associated factors of MDR-HAI in children admitted to the intensive care unit (ICU) of a university hospital. Methods : We retrospectively evaluated 135 children who were admitted in ICU for at least 3 days between January 2009 and December 2010. HAI cases were divided into MDR-HAI group and non-MDR-HAI group. Clinical characteristics and various associated factors were compared between those groups. Results : In 39 patients, 45 cases of ICU-related HAI were developed. ICU-related HAI incidence was 47.7 per 1000 patientdays. Thirty-six cases (80.0%) were MDR-HAI. Acinetobacter baumannii was isolated more commonly in MDR-HAI group. And the followings were found more frequently in MDR-HAI group than non-MDR-HAI group: medical condition as an indication for ICU admission, mechanical ventilation, urinary catheterization and previous use of broad-spectrum antibiotics. Among the risk factors, previous use of broad-spectrum antibiotics was the independent risk factor for MDR-HAI. Conclusion : ICU-related HAI incidence was higher than previously reported. Previous use of broad-spectrum antibiotics was the independent risk factor for MDR-HAI. To investigate the characteristics of MDR-HAI in children admitted in ICU, further studies with a larger sample size over a longer period of time are warranted.

• Childhood Kidney Diseases
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• v.6 no.2
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• pp.218-226
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• 2002

Purpose: The purpose of this study is to assess the ability of power Doppler sonography in the detection of acute pyelonephritis. Materials and Methods: We performed gray scale sonography, power Doppler sonography, and $^{Tc-99m}DMSA$ scintigraphy of the kidney in 80 patients with symptoms suggesting upper urinary tract infection. All imaging studies were obtained within 4 days. On $^{Tc-99m}DMSA$ scintigraphy, decreased radioactivity or photopenic lesions were considered indicative of acute pyelonephritis. Triangular areas of decreased perfusion identified on power Doppler sonography were considered as parenchymal lesions of acute pyelonephritis. The results of gray scale sonography and power Doppler sonography were retrospectively analysed and compared with those of $^{Tc-99m}DMSA$ scintigraphy which was given as the standards of reference. Results: For 40(85%) of the 47 patients with scintigraphy-proven acute pyelonephritis, power Doppler sonography diagnosed this condition on the correct side. The acute pyelonephritis which was not revealed by power Doppler sonography was observed in seven patients. Also, in three patients, false-positive indication of pyelonephritis was given by power Doppler sonography. Gray scale sonography showed positive findings in 23(49%) of 47 patients with positive findings on scintigraphy. Conclusion: Power Doppler sonography seems to be less sensitive than $^{Tc-99m}DMSA$ DMSA scintigraphy but significantly more sensitive than gray scale sonography for the detection of acute pyelonephritis in children. Power Doppler sonography shows promise as a noninvasive means of assessing renal cortical perfusion in children with clinically suspected acute pyelonephritis.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.14 no.2
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• pp.141-147
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• 2011

Purpose: Ultrasonography (US) is widely used as a screening test in patients with abdominal pain (AP). We investigated the usefulness of US by a pediatrician in children with AP. Methods: We retrospectively analysed the medical records of children with AP who undertook US from December, 2008 to July, 2010. Results: A total of 628 patients (325 male, 303 female) were enrolled in this study. The mean age of patients was $8.08{\pm}4.61$ years. Duration of AP was acute in 427 and chronic in 201 patients. Localization of AP was diffuse (36.9%), periumbilical (24.4%), epigastric (21.0%), and right lower quadrant (8.1%). On the examination, there were no abnormal findings in 327 patients (52.1%). Abnormal ultrasonographic findings were mesenteric lymphadenitis (27.1%), intestinal mural thickening (10.0%), intussusception (3.0%), appendicitis (2.6%), choledochal cyst (1.6%), and pancreatitis (0.3%). We performed additional imaging studies such as computed tomography (CT) or magnetic resonance imaging (MRI) in 39 patients who showed obscure findings on the US. In 33 patients (84.6%), the same results were obtained from CT or MRI. Two cases of appendicitis, one case of pancreatitis and one case of Henoch-Sh$\ddot{o}$nlein purpura were diagnosed by the CT examination. However, there were two cases of appendicitis diagnosed by US thathad no evidence of appendicitis on the CT. Diagnostic accuracy of initial US in children with abdominal pain was 99.4%. Conclusion: US by a pediatrician as a screening test in children with AP provides a rapid and accurate diagnostic indication and has non-invasive and radiation-free advantages.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.5 no.2
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• pp.136-142
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• 2002

Purpose: Foreign body swallowing is common in children. Most of foreign bodies passed upper esophagus are removed spontaneously. But recently, therapeutic endoscopy in children is widely used. In this study, we reviewed gastric foreign bodies regarding types, location, interval from swallowing, complications, and treatment or method of removal. Methods: We reviewed medical records of 96 cases with foreign bodies in gastrointestinal tract at Department of Pediatrics in Gyeongsang National University Hospital (GNUH) from Feb 1987 to Feb 2002. Results: The peak age of patients (male=60, female=36) with foreign bodies in gastrointestinal tract was 2 to 5 years of age. Sixty two patients (64.5%) were asymptomatic. The location of foreign bodies in gastrointestinal tract were detected by simple X-ray in eighty one patients (86.0%), barium study (1 case), and gastroduodenoscopy in 37 cases. The most common location was stomach (63.5%). The most common foreign body was coin (41.7%). In thirty seven cases (38.5%), foreign bodies were removed with flexible gastroduodenoscopy. Fifty four patients (56.3%) visited GNUH in 24 hours after swallowing foreign bodies. The long interval (over 24 hours) of swallowing of foreign bodies is related with high frequency of endoscopic removal. Conclusion: The flexible gastroduodenoscopy was effective in diagnosis and removal of foreign bodies. Further studies for indication and validity of endoscopic removal of foreign bodies in upper gastrointestinal tract are needed.

• Childhood Kidney Diseases
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• v.5 no.2
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• pp.196-205
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• 2001

Purpose : Membranous glomerulopathy is a glomerular disease characterized by the presence of subepithelial immune deposits with thickening of the capillary wall of the glomerulus without inflammatory change. The pathogenesis of membranous glomerulopathy is still unknown. Its incidence is higher in males, and it is rarely found in infants and adolescents. Among the clinical manifestations proteinuria is most common, while edema and hematuria are present. According to reports from other countries, among few patients diagnosed with membranous glomerulopathy by renal biopsy, show isolated microscopic hematuria without the clinical manifestations. Little research in this area has been performed in Korea, and so we conducted retrograde studies on membranous glomerulopathy associated with isolated microscopic hematuria. Materials and Methods : We analyzed retrogradely 109 cases of asymptomatic isolated microscopic hematuria that were diagnosed as membranous glomerulopathy by renal biopsy at Yonsei University Severance hospital from January, 1992 to July, 2001. Results : In 87 of the 109 cases patients were over 15 years old while in 22 cases patients were under 15 at the time of dignosis. Only three patients showed isolated microscopic hematuria without the clinical manifestations and abnormal laboratory findings and they were all male patients under 15 years old. Conclusion : Few cases of the membranous glomerulopathy show only asymptomatic isolated microscopic hematuria However, since membranous glomerulopathy can be found in patients who present with asymptomatic isolated microscopic hematuria only, if adequate indication for renal biopsy is present, we conclude that renal biopsy must be aggresively pursued in order to find the underlying disease. (J Korean Soc Pediatr Nephrol 2001 ; 5 : 196-205)