Lung Function Reference Values in Healthy Korean Children / 소아알레르기및호흡기학회지

PURPOSE: Appropriate reference values are needed for assessment of pulmonary function during childhood. We performed pulmonary function test with simple computerized spirometry to establish reference values of air flow rates in healthy Korean children. METHODS: We examined 1,317 children aged 6 to 15 years at their schools by standardized method during May, 2001. The children with poor cooperation, respiratory symptom, and chronic disease were excluded. Regression analysis was applied for FVC, FEV1, PEF, FEF25-75% predicted from sex, age, standing height, weight, and body surface area. RESULTS: In 1,317 children(Male : 716, Female : 601), the distribution of height was from 106.7 cm to 173.5 cm, weight was from 16.5 kg to 75.5 kg. We could get regression equations and determinant coefficients between anthropometric parameters and air flow rates. In both sexes, height showed very close correlation with lung function variables, and FEV1 showed very close correlation with all anthropometric parameters. Reference values of pulmonary function test were generally higher in boys than in girls. CONCLUSION: After performing the pulmonary function test in healthy Korean children, we report their normal values of air flow rates and regression equations for the predicted values. Among anthropometric parameters, height showed most close correlation with lung function variables in both sexes.

Sequence Variations of Hepatitis B Virus Promotor Regions in Vertically Transmitted Mother-child Pairs / 대한소아소화기영양학회지

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.

Dexamethasone Induced Cardiac Hypertrophy in Preterm Infants hypertrophy, Hypertrophic Cardiomyopathy

PURPOSE: Dexamethasone is a well-known treatment for preterm infants with bronchopulmonary dysplasia. However, serious side effects have been identified, including hypertension, and cardiac hypertrophy. This study was undertaken to examine whether dexamethasone induced cardiac hypertrophy in preterm infants with bronchopulmonary dysplasia. METHODS: We retrospectively reviewed 12 infants with bronchopulmonary dysplasia treated with dexamethasone at Korea University Hospital from August 1995 to February 1999. Serial two-dimensional and M-mode echocardiographic measurements were taken before treatment and at 1,2,3,4,5 weeks after the start of dexamethasone therapy. RESULTS: Patients receiving dexamethasone had a significantly increase in interventricular septal thickness and left ventricular posterior wall thickness. These effects were transient, reached their maximal degree by the third week of treatment, and approached pretreatment conditions by the fifth week of treatment. Heart rate was increased but statistically not significant. The fractional shortening, systolic and diastolic arterial pressure were transiently increased during dexamethasone therapy. CONCLUSION: We conclude that a transient myocardial hypertrophy is associated with dexamethasone therapy in infants with bronchopulmonary dysplasia. Follow up of careful echocardiac monitoring should be considered in infants with dexamethasone therapy.