ABSTRACT
BACKGROUND: Exercise is one of the most common precipitants of acute asthma encountered in clinical practice. The development of airflow limitation that occurs several minutes after vigorous exercise, i. g. exercise-induced bronchoconstriction(EIB), has been shown to be closely correlated with the nonspecific bronchial hyperresponsiveness, which is the hallmark of bronchial asthma. All previous reports that assessed the correlation of EIB to nonspecific bronchial hyperresponsiveness have focused on airway sensitivity(PC20) to inhaled bronchoconstrictor such as methacholine or histamine. However, maximal airway narrowing(MAN), reflecting the extent to which the airways can narrow, when being exposed to high dose of inhaled stimuli, has not been studied in relation to the degree of EIB. METHODS: Fifty-six children with mild asthma(41 boys and 15 girls), aged 6 to 15 years(mean +/- SD, 9.9 +/- 2.5 years) completed this study. Subjects attended the laboratory on two consecutive days. Each subject performed the high-dose methacholine inhalation test at 4 p.m. on the first day. The dose-response curves were characterized by their position(PC20) and MAN, which was defined as maximal response plateau(MRP: when two or three data points of the highest concentrations fell within a 5% response range) or the last of the data points(when a plateau could not be measured). On the next day, exercise challenge, free running outdoors for ten minutes, was performed at 9 a.m.. FEV1 was measured at graduated intervals, 3 to 10 minutes apart, until 60 minutes after exercise. Response(the maximal DeltaFEV1 from the pre-exercise value) was classified arbitrarily into three groups; no response ((-) EIB: DeltaFEV1 20%). RESULTS: 1) When geometric mean PC20 of the three groups were compared, PC20 of (+) EIB group was significantly lower than that of (-)EIB group. 2) There was a close correlation between PC20 and the severity of EIB in the whole group(r= -0.568, p<0.01). 3) Of the total 56 subjects, MRP could be measured in 36 subjects, and the MRP of these subjects correlated fairly with the severity of EIB(r= 0.355, p<0.05) 4) The MAN of (+) EIB group was significantly higher than that of (-)EIB group(p<0.01). 5) The MAN correlated well with the severity of EIB in the whole group(r=0.546, p<0.01). CONCLUSION: The degree of MAN as well as bronchial sensitivity (PC2o) to methacholine is correlated well with the severity of EIB. The results suggest that the two main components of airway hyperresponsiveness may be equally important determinants of exercise reactivity, although the mechanism may be different from each other. The present study also provides further evidence that EIB is a manifestation of the increased airway reactivity characteristic of bronchial asthma.
Subject(s)
Child , Humans , Asthma , Bronchoconstriction , Histamine , Inhalation , Methacholine Chloride , RunningABSTRACT
In recent years pulmonary function teste have had a wide application in clinical pulmonary diseases. By combining a number of different pulmonary function tests, abnormality present in a particular pa tient can be defined. This narrows the list of possible diagnosis and allows to determine accurately the degree of impairment and assess the pesponse to therapy. To assess the pulmonary function in a patient and label as abnormal, it becomes important to define the range of expected values for a normal population. These normal'predicted values'vary according to sex and prowth, i.e., age, height, and weight, particularly in children. In addition, race and geography have been consistently shown to bc an important determinant of lung function. In order to obtain normal perdicted values of pulmonary function tests in Korean school-aged children, we performed spirometry-based pulmonary function tests on the normal healthy 2022 children, age from 6 through 15, and analyzed the data, with the parameters such as sex, age, height, weight, and body surface area. We calculated each of their simple and complex linear and logarithmic regression equations setting the predicted values. The results are as follows: 1) Predicted values of pulmonary function test items were generally higher in boys than those of girls. 2) A correlation coefficient to the parameters examined was the highest in FEV1, then those of FVC, FEF25,PEFR, FEF50, MMEF, AND FEF75 follow in order. 3) Of the parameters examined, height had the highest correlation coefficient consistently in all pulmonary function test items. 4) As compared with the inland and overseas data, some differences were observed.
Subject(s)
Child , Female , Humans , Body Surface Area , Racial Groups , Diagnosis , Geography , Lung , Lung Diseases , Respiratory Function TestsABSTRACT
A total of 197 cases of fungal infections in biopsy specimens obtained from the pathology file of the Department of Pathology, Seoul National University Hospital, for a period of 28 years from 1960 to 1987 were studied by histopathologic investigations with analysis of clinical records. The following results are obtained; 1) While most fungal infections increased in number, annual relative frequency of them were between 0.1% and 0.2%. 2) Among 197 cases of fungal infections, deep-seated mycosis was 175 cases (88.8%). Aspergillosis was the most common mycosis, accounting for 29.4 percent. 3) The age and sex distribution of fungal infection was even throughout the ages, but it was more common in age group over fifty, and the male was more frequently affected than the female. 4) Aspergillosis was encountered in 58 cases (29.4%) and the preferred localization was the lung. The candidiasis was seen in 48 cases (24.4%) and the preferred localization of cryptococcosis was lymph node and skin.