Hyang-Ok Woo

Changes in the Age-Specific Prevalence of Hepatitis A Virus Antibodies: A 10-Year Cohort Study in Jinju, South Korea

The changing patterns in seroprevalence rates of hepatitis A virus antibodies among children and adolescents from 1988 to 1997 reflect the cohort effects that occurred over 10 years in South Korea. Our results suggest that the majority of adolescents and young adults are at risk of symptomatic hepatitis A virus infection and morbidity.

Comparison of Helicobacter pylori infection between Fukuoka, Japan and Chinju, Korea.

Helicobacter pylori is the causative agent of type B chronic gastritis, and plays a major role in the pathogenesis of gastroduodenal ulcer and gastric cancer. Because gastric cancer has been the leading cause of cancer mortality in Japan and Korea, we conducted a seroepidemiological study to estimate the prevalence of H. pylori infection in Japan and Korea in order to explain the current change in the gastric cancer incidences between two countries.

Distinctive pattern of white matter injury in neonates with rotavirus infection

Objective: To report a consecutive series of neonates with seizures or apnea and displaying white matter injuries with distinctive magnetic resonance diffusion-weighted imaging (DWI) pattern, and to discuss the high positive rate of rotavirus infection seen in these patients. Methods: In a retrospective review of neonates who were admitted to a tertiary referral center with seizures or apnea, we found a distinctive pattern of white matter injury (symmetrical restricted diffusion in the periventricular white matter and white matter tracts including the corpus callosum) in 18 patients. We describe the clinical and laboratory features of these 18 neonates. Additional PCR analyses for rotaviruses and parechoviruses were performed on banked frozen samples of CSF of 4 patients and blood of 15 patients. Results: All 18 patients were born at term and healthy until symptoms occurred 4–7 days after birth. No history of asphyxia was observed. Only 1 patient presented with fever, and no patient showed a rash. All patients except 1 (94.4%) were rotavirus-positive in stool samples. However, neither rotaviruses nor enteroviruses/parechoviruses were detected in the CSF and blood. Tissue loss was observed in 5 of 8 subjects on repeat MRI scans. Conclusions: Neonates with this distinctive DWI pattern had a high positive rate of rotavirus infection, without evidence of other pathogens, and were characterized as term newborns with neurologic symptoms arising approximately the fifth day after birth. Although the specificity of this pattern is unclear, rotavirus testing should be considered for neonates presenting with this DWI pattern.

Role of Ca2+ homeostasis disruption in rotavirus-associated seizures.

Rotavirus infection disturbs cellular Ca2+ homeostasis by triggering an increase in Ca2+ permeation. A theoretical link between Ca2+ dysregulation and seizures in patients with rotavirus gastroenteritis has been suggested, but no prior studies have investigated this relationship. To test our hypothesis that patients with rotavirus-associated seizures have greater Ca2+ homeostasis disruption than those without seizures, we compared clinical and laboratory data—including corrected total serum Ca2+ levels—between the 2 groups. Age, gender, maximum body temperature, day of admission, levels of electrolytes except Ca2+, blood pH, and urine ketone levels were not related to seizure occurrence. Significantly lower Ca2+ levels were found among the seizure (+) group (9.22 ± 0.50 vs 9.66 ± 0.46 mg/dL, P = .01). Although Ca2+ levels were within normal ranges and did not directly cause the seizures, our results provide preliminary evidence for a relationship between Ca2+ homeostasis disruption and seizures in rotavirus patients.

Changing trend of neonatal infection: Experience at a newly established regional medical center in Korea.

Background: The purpose of the present paper was to study the natural history of neonatal sepsis in a newly established neonatal intensive care center that started in 1988 at Gyeongsang National University Hospital 9 (GNUH) in Chinju city, Korea.

Influencing Factors to Results of the Urease Test: Age, Sampling Site, Histopathologic Findings, and Density of Helicobacter pylori.

Purpose We investigated the positivity rate and the time period to the positive color change of the urease test in children and adults and assessed the correlation of the urease test to histopathologic findings. Methods From 1995 to 2000, endoscopic biopsies of the antrum and body were collected from 811 children and 224 adults and subjected to urease tests and histopathology. Results The positivity rate of the urease test was 49.4% for 0-4 years, 48.4% for 5-9 years, 47.3% for 10-15 years, and 62.5% for 20-29 years in the antrum. The positivity rate was 85.1% in 0-4 years, 82.3% in 5-9 years, 74.7% in 10-15 years, and 74.1% in 20-29 years for the body. In the antrum, the highest positivity rate was <1 hour for the group aged 10-29 years and 6-24 hours in the group <10 years old (p<0.0001). In the body, the highest positivity rate was <1 hour in adults and 6-24 hours in children (p<0.0001). The proportions of the positive reactions within 1 hour were similar for the antrum and the body. In the cases of more severe chronic gastritis, active gastritis, and Helicobacter pylori infiltration, a positive urease test reaction occurred more quickly (p<0.0001). Conclusion There were significant differences in urease tests according to age and sampling site. The discrepancy between the antrum and the body was greater in younger children. These results might be related to the low density and patchy distribution of bacteria in children and in the body.

Relationship between headache and mucosal mast cells in pediatric Helicobacter pylori-negative functional dyspepsia

Background Although many patients with functional dyspepsia experience headache concurrently with dyspeptic symptoms, studies suggesting mechanisms underlying this phenomenon are limited. Herein, we explore the relationship between gastrointestinal inflammatory cells and presence of headache associated with dyspeptic symptoms in children with Helicobacter pylori-negative functional dyspepsia. Methods Fifty-six patients with H. pylori-negative functional dyspepsia underwent upper endoscopy with biopsy to investigate recurrent epigastric pain or discomfort. Patients were divided into two groups according to self-reported presence of headache associated with dyspeptic symptoms. Inflammatory cells including mast cells, and enteroendocrine cells in the gastroduodenal mucosa were evaluated. Associations between headache presence and cellular changes in the gastroduodenal mucosa were examined. Results Headache was not associated with the grade of lymphocytes, neutrophil infiltration, or enteroendocrine cell density in the gastroduedenal mucosa. However, headache was significantly associated with high mast cell density in the body (27.81 ± 8.71 vs. 20.30 ± 8.16, p < 0.01) and duodenum (23.16 ± 10.40 vs. 14.84 ± 5.88, p < 0.01). Conclusions Presence of headache associated with dyspeptic symptoms is strongly related to mucosal mast cell density in pediatric patients with H. pylori-negative functional dyspepsia. Thus, our results may help clinicians understand and treat headache during dyspeptic symptoms in such pediatric patients.

Kawasaki Disease Presenting as Parotitis in a 3-Month-Old Infant

A male infant aged 3 months and 1 week had persistently high fever with parotitis that was unresponsive to antibiotics. Mumps was identified by serologic study, but he was finally diagnosed by clinical features as having Kawasaki disease and echocardiographic findings on the 9th day of fever. Parotitis, which is unresponsive to antibiotics, should be considered Kawasaki disease even though typical symptoms are not present.

Immunohistochemical Expressions of MUC2, MUC5AC, and MUC6 in Normal, Helicobacter pylori Infected and Metaplastic Gastric Mucosa of Children and Adolescents

The aim of this study was to investigate expression of gastric mucins in children and adolescents and to assess their relations with age and Helicobacter pylori (H. pylori) infection.

Development of an ELISA for Quantitative Detection of Immunoglobulin G (IgG) and IgA Antibodies to Helicobacter pylori for Use in Korean Patients with H. pylori-Associated Diseases

Background/Aims We aimed to develop a quantitative enzyme-linked immunosorbent assay (ELISA) using whole-cell lysates of Helicobacter pylori 51 and to investigate its validity. Methods Data from 300 plates were obtained by two different operators. Standard sera were used to make a standard curve to analyze the quantity of anti-H. pylori immunoglobulin G (IgG) and IgA antibody. We obtained reproducible data with fewer dilutions of samples by the addition of serially diluted standard serum to each ELISA plate. To evaluate the validity of this ELISA, the 114 H. pylori-positive and -negative subjects were stratified into four age groups, i.e., 0 to 4, 5 to 9, 10 to 15, and 20 to 29 years, before testing. Results The mean IgG-antibody titers in H. pylori-positive and -negative subjects were 1,766.4 IU/mL and 654.3 IU/mL (p<0.001). The mean IgA-antibody titers in H. pylori-positive and -negative subjects were 350.1 IU/mL and 193.5 IU/mL (p<0.001). Anti-H. pylori IgG and IgA titers in the four age groups were higher in H. pylori-positive subjects than in H. pylori-negative subjects (p<0.05). Conclusions Using the current ELISA based on whole-cell lysates of H. pylori 51, reliable anti-H. pylori antibody titers were obtained regardless of the subjects age.