• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.5 no.1
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• pp.39-50
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• 2002

Hepatitis B viral infection which affect about 10% of Korean population manifests asymptomatic carrier, chronic hepatitis and liver cirrhosis and even associates with hepatocellular carcinoma. Clinical manifestations induced by hepatitis B virus vary depending on the degree of immune response by cytotoxic T cells against viral epitope-presenting liver cells. Since hepatitis B virus presents high rate of mutaton that might change the presented epitope and eventually alter immune response, viral mutations, especially in promoters and enhancers, have an important implication in hepatic inflammation and viral replication. To identify mutations related to the hepatic inflammation, we investigated sequence variations of hepatitis B viral promotor regions in the presence or absence of symptoms in hepatitis B carriers. For this, sera from persistently hepatitis B virus-infected mother-child pairs were collected. After PCR amplifiation of all hepatitis B viral promoters (C promoter, S1 promoter, S2/S promoter, X promoter) using serum DNA from each pair, viral promotors were sequenced by automatic sequencer and then sequence data were analyzed by ClustalW. In most cases, the dominant type of maternal virus was transmitted to the child. However, in some children, some new host specific viral variants could be observed in Cp, S1p and S2/Sp. The mutations in C promoter did not seem to be vertically transmitted but arose in new host independently after the wild type had been transmitted. Enhancer I containing X promoter revealed high host specific variations as has been reported before. Two S promoters, S1p and S2/Sp, have shown some point mutations in children, but no deletion mutations were detected as in chronic hepatitis patients in whom deletion mutations are frequently found. In conclusion, the children with the vertically transmitted hepatitis B virus mostly retain the dominant type virus that had been transmitted. However, host specific variants tended to accumulate over time, possibly as clinical symptoms develop.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.5 no.2
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• pp.166-173
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• 2002

Purpose: Recurrent abdominal pain (RAP) is common, affecting between 7% and 25% of school-aged children and young adult. This study was designed to assess the relationship between RAP and depressive trends in school-aged children. Methods: In 1999, We surveyed 1,181 elementary school children (566 boys and 615 girls) whose ages ranged from 9 to 12 years. The degree of depression was compared between the group with RAP and normal control group without RAP according to Korean Children's Depression Inventory (CDI) of Kovacs and Beck. Results: The number of the group with RAP was significantly higher in female (25.7%) than in male (18.9%). The most common site of abdominal pain was periumbilical. The mean depression score in the group with RAP was higher than that of the control group. The depression score was significantly higher in the group with RAP who has frequently pain and additional symptoms. The depression score was significantly higher in the group with RAP who prefered to play alone, did not enjoy going to school and had few friends than in the group with RAP who had a lot of friends, had active and meticulous characters. The depression scores were not significantly different according to the duration of abdominal pain, the onset time of pain, and the day of pain in the group with RAP. Conclusion: The depression score of the group with RAP was higher than that of normal group. So, there is relatively a specific association between childhood RAP and depression in school aged children. It is good for physicians to consider psychological support in the treatment of childhood RAP.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.2 no.2
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• pp.185-193
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• 1999

Purpose: Proliferation of bile duct-like structures and fibrosis is a hepatic cellular reaction observed in most forms of human liver disease and in a variety of experimental conditions associated with liver injury. The aim of this study was to investigate the activation of Ito cells and bile duct proliferation in the rat after common bile duct ligation (CBDL). Methods: Hepatic morphological abnormalities were examined in rats whose bile ducts had been irreversibly ligated for 15, 21, 24 and 28 days. The liver was examined by immunohistochemical staining for ${\alpha}$-smooth muscle actin, the known marker of activated Ito cells, and light and electron microscopes. Results: After CBDL, the bile canalicular proliferation and interstitial fibrosis were gradually increased in the periportal areas extended to hepatic sinusoids. Ito cells positive for ${\alpha}$-smooth muscle actin were frequently observed in the periductular space and in perisinusoidal space of Disse. Ito cells and myofibroblasts were gradually increased in the interstitial fibrosis until the 28th day after CBDL. Ito cells and myofibroblasts had microfilaments with dense body at the periphery of the cell. Conclusions: Our results suggest that Ito cells may be fibroblastic or myogenic. It has also been postulated that during the development of hepatic fibrosis, Ito cells become myofibroblasts or fibroblast like cells.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.2 no.2
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• pp.178-184
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• 1999

Purpose: The aims of this study were to evaluate the clinical manifestations and prognosis of the syndromic and nonsyndromic intrahepatic bile duct paucity (IHBDP). Methods: We studied histology of 42 infants with neonatal cholestasis. Fourteen patients were diagnosed as IHBDP. We evaluated the clinical manifestations, courses and prognosis retrospectively. Results: Underlying disease of the 42 infants with neonatal cholestasis were biliary atresia in 23, intrahepatic bile duct paucity in 14 (Alagille syndrome in 4 and nonsyndromic IHBDP in 10), neonatal hepatitis in 5 infants. The mean ratio of the bile ducts per portal tract was 0.087 (range: 0~0.5). The manifestations in 4 patients with Alagille syndrome demonstrated as follows: characteristic face in 3, chronic cholestasis in 4, posterior embryotoxon in 2, vertebral anomalies in 2, peripheral pulmonary stenosis in 2. One of 4 patients of Alagille syndrome improved cholestasis and the other 3 patients were remained their cholestasis and growth retardation. All patients of the nonsyndromic IHBDP were idiopathic. Seven out of 8 patients of nonsyndromic IHBDP showed improvement of cholestasis, and one patient received liver transplantation due to cirrhosis. Conclusion: This study suggested that IHBDP should be considered in the differential diagnosis of neonatal cholestasis. The outcome of idiopathic IHBDP was better than predicted.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.2 no.2
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• pp.147-152
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• 1999

Purpose: The aim of this study was to evaluate the prevalence of H. pylori infection in normal preschool children. Methods: Study population consisted of 220 preschool children aged 2 to 5 years in Seoul, Korea. We measured H. pylori specific IgG antibody using the GAP test IgG kit, and samples with concentrations greater than 20 U/ml were considered positive. Results: Of the 220 children, 5 (2.3%) were positive, and thirteen (5.9%) of 220 were equivocally probable positive. Conclusion: The positive rate of H. pylori infection detected by specific IgG antibody in normal preschool children aged 2 to 5 years was approximately 2.3% to 8.2%. This prevalence rate is still high, compared to that of the West. A better knowledge of the transmission of H. pylori is crucial to formulate recommendations for lowering the rate.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.18 no.1
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• pp.48-54
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• 2015

Purpose: Metabolic liver disease (MLD) often progresses to life-threatening conditions. This study intends to describe the outcomes of liver transplantation (LTx) for MLD at a living donor-dominant transplantation center where potentially heterozygous carrier grafts are employed. Methods: We retrospectively evaluated the medical records of 54 patients with MLD who underwent LTx between November 1995 and February 2012 at Asan Medical Center in Seoul, Korea. The cumulative graft and patient survival rates were analyzed according to patient age, and living or deceased donor LTx. Recurrence of the original disease was also investigated. Results: The post-transplant cumulative patient survival rates at one, five, and 10 years were 90.7%, 87.5% and 87.5%, and the graft survival rates were 88.8%, 85.5%, and 85.5%, respectively. There were no differences in the patient survival rates according to the recipient age, human leukocyte antigen matching, and living or deceased donor LTx. There were also no differences in the patient survival rates between the MLD and the non-MLD groups for children. Recurrence of the original metabolic disease was not observed in any patient during the follow-up period. Conclusion: Our results suggest that the living donor-dominant transplantation program is well-tolerated in MLD without recurrence of the original MLD using all types of transplantation.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.18 no.1
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• pp.17-22
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• 2015

Purpose: This study aims to investigate Saccharomyces boulardii CNCM I-745 during Helicobacter pylori eradication in children. Methods: One hundred ninety-four H. pylori positive children were randomized in two groups. Therapy (omeprazole+ clarithromycin+amoxicillin or omeprazole+clarithromycin+metronidazole in case of penicillin allergy) was given to both groups during two weeks. In the treatment group (n: 102) S. boulardii was added to the triple therapy, while the control group (n: 92) only received triple therapy. The incidence, onset, duration and severity of diarrhea and compliance to the eradication treatment were compared. A $^{13}C$ urea breath test was done 4 weeks after the end of eradication therapy in two groups of 21 patients aged 12 years and older to test the H. pylori eradication rate. Results: In the treatment group, diarrhea occurred in 12 cases (11.76%), starting after $6.25{\pm}1.24days$, lasting $3.17{\pm}1.08days$, and compliance to eradication treatment was 100%. In the control group, diarrhea occurred in 26 cases (28.26%), starting after $4.05{\pm}1.11days$, lasting $4.02{\pm}0.87days$, and in six cases eradication treatment was stopped prematurely (p<0.05). The $^{13}C$ urea breath test showed successful H. pylori eradication in 71.4% of the patients in the treatment and in 61.9 % in the control group (not significant). Conclusion: S. boulardii has a beneficial effect on the prevention and treatment of diarrhea during H. pylori eradication in children. Although S. boulardii did only slightly increase H. pylori eradication rate, compliance to eradication treatment was improved.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.18 no.1
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• pp.10-16
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• 2015

Purpose: The aim of this study is to investigate the changing prevalence rate of Helicobacter pylori infection in children, of different age groups, with recurrent abdominal pain over a 10-year period. Methods: Children with recurrent abdominal pain who visited the pediatric outpatient clinic at university hospital were screened for H. pylori. Children were divided into 3 age categories of 4-5, 6-11, and 12-16 years. To study the changes in the annual prevalence rates of H. pylori infection, the study period was divided into 3 time periods: 2004-2007, 2008-2010, and 2011-2014. Urea breath test was performed for all children aged 4-16 years, with a cut-off value of 4.0‰ for children aged ${\geq}6$ years and 7‰ for children aged <6 years. Results: A total of 2,530 children (1,191 boys) with a mean age of $10.0{\pm}3.0years$ (range, 4.0-16.9 years) were included in the study. The total prevalence of H. pylori infection was 7.4% (187/2,530). The prevalence rate of H. pylori infection in children with recurrent abdominal pain was 8.0% (70/873) in 2004-2007, 7.7% (51/666) in 2008-2010, and 6.7% (66/991) in the 2011-2014. Nevertheless, a significant difference was observed in the prevalence rate between children <12 years old and ${\geq}12$ years of age (p=0.018). Conclusion: The prevalence of H. pylori infection in Korean children with recurrent abdominal pain was 7.4%, showing no significant decrease in the last 11 years; however, the prevalence rate in children <12 years old was significantly lower than that in those ${\geq}12$ years old.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.20 no.4
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• pp.227-235
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• 2017

Purpose: Crohn's disease (CD) can involve any site of the gastrointestinal tract (GIT). However, the characteristics of upper GIT involvement in CD are unclear, especially in the Eastern pediatric population. This study aimed to estimate the prevalence of upper GIT involvement and identify the clinical features of Korean children with CD. Methods: This was a retrospective multicenter cohort study that included 52 pediatric patients with CD who underwent esophagogastroduodenoscopy and biopsy. The clinical symptoms and endoscopic and histologic features of the upper GIT were identified according to the presence or absence of upper gastrointestinal symptoms. Results: Among the 52 patients, upper GIT involvement was noted in 50.0% (26/52). The mean age at CD diagnosis was $14.1{\pm}2.1$ years. Gastric ulcer was the most common lesion (19.2%) found on upper GIT endoscopy, followed by duodenal ulcers (15.4%). Chronic inflammation was the most common histopathologic feature (75.0%), followed by gastric erosion (17.3%). Granuloma was found in 9.6% of patients. Helicobacter pylori infection was identified in 5.8% of patients. Endoscopic and histologic findings were not significantly different, but the mean values of erythrocyte sedimentation rate ($60.7{\pm}27.1$ vs. $43.0{\pm}27.6mm/h$, p=0.037) and C-reactive protein ($16.5{\pm}28.2$ vs. $6.62{\pm}13.4mg/dL$, p=0.014) were significantly different between patients with and without upper gastrointestinal CD symptoms. Conclusion: Upper GIT involvement was relatively common in pediatric patients with CD irrespective of upper gastrointestinal symptoms, and H. pylori infection was relatively uncommon. The results of this study should aid the establishment of regional guidelines for upper GIT examination.

• Journal of Life Science
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• v.15 no.6 s.73
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• pp.955-960
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• 2005

Resistance to metronidazole, a key component of therapies against Helicobacter pylori, is common in clinical isolates. Resistance generally requires inactivation of rdxA (HP0954), and sometimes also frxA (HP0642), two related nitroreductase genes. Here we studied the effect of resistance to metronidazole on fitness of the gastric pathogen H. pylori. The effect of metronidazole resistance for H. pylori in culture was assessed first by looking at colonies formed by freshly constructed mutant derivatives of H. pylori strain 26695. Mutations resulting in metronidazole resistance caused premature death of H.pylori in stationary phase, but had no significant effect on early exponential growth. The effect of nitroreductase deficiencies on fitness in vivo was tested by infecting C57BL/6 mice with 1:1 mixtures of SS1 wild type and its isogenic metronidazole resistant derivatives. Inactivation of rdxA caused an inability to colonize mice in SS1 H. pylori strain. Derivatives of a metronidazole resistant strain that survived better in stationary phase, although remaining metronidazole resistant, could again colonize mice. In conclusion, metronidazole resistance diminishes H. pylori's fitness, but their costs can be suppressed by additional mutation.