We studied the bronchial hyperreactivity in neonates and early infants by measuring transcutaneous oxygen pressure (tcPO₂) during histamine inhalation challenge tests.
The subjects were 157 infants (74 boys and 83 girls) who had been admitted to Neonatal Intensive Care Unit in Niigata City General Hospital. The mean age was 45 days (6-179 days) old and the mean birth weight was 2, 143g (665g-4, 440g). For the 41 of the subjects, the same tests were performed again after certain intervals to clarify the changes in bronchial hyperreactivity.
As a marker of bronchial responsiveness we used respiratory threshold of histamine (abbreviated as Th) defined as the minimal concentration of histamine solution needed to induce a more than 10% fall in tcPO₂. Histamine solution was prepared for inhalation challenge tents at serially doubling concentrations (39, 78, 156, 313, 625, 1, 250, 2, 500, 5, 000, and 10, 000 μg/ml), and we expressed each concentration as integral numbers 1 through 9 respectively from the lowest. To show the respiratory threshold, we used those numbers instead of absolute concentrations for statistical convenience. In case the tcPO₂ did not fall more than 10% even at 10, 000 μg/ml, the Th was expressed as 10.
The mean value of Th in all 157 infants was 5.8±2.2 (m±SD). There existed definite relationships between Th and the following factors; 1) presence of allergic disorders within a third degree family, 2) history of respiratory distress syndrome, and 3) oxygen and mechanical ventilation therapy in the newborn period.
About the 41 subjects who underwent the histamine inhalation challenge tests twice, the mean value of Th in the second tests was 7.7, which was significantly greater than that in the first tests, 5.3. Individually, most of the subjects who showed much smaller Th in the second tests compared to that in the first had a history of wheezing.

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We reported three children with uneven radiolucency in the both lungs on chest X-P. There was one with a granuloma in left main bronchus, one with a right pulmonary artery absence and the other with the Swyer-James-Macleod syndrome. The images of pulmonary ventilation-perfusion scintigraphy using Xe-133 showed a different pattern in the former two patients. In first patient with a granuloma, the images showed a decreased ventilation and perfusion distribution to the left lung with marked retention of gas on the later images. In second with PA absence, it showed a mild volume loss and a marked decreased perfusion distribution to the right lung. In third with Swyer-James-Macleod syndrome who examined only by perfusion scintigraphy using Tc-99m microspheres, it showed a decreased distribution to the left lung.
Pulmonary ventilation-perfusion scintigraphy seems to be benefit for diagnosis of children with uneven radiolucency in the both lungs on chest X-P.

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According to classic respiratory physiologoy, tracheal wall is expected to expand during inspiratory phase. However, in clinical cases under respiratory care, inspiratory dyspnea commonly seen in intrathoracic central airway obstruction. The direction of tracheal wall motion is dependent on the pressure difference in and outside of the trachea. Using intubated dogs connected to a mechanical ventilator, we measured intratracheal pressure, peritracheal pressure, and intrathoracic pressure simultaneously. The pressure difference was in the direction of tracheal constriction during the inpiratory phase. During the expiratory phase the pressure difference was in the direction of tracheal expansion. The peritracheal pressure changed in the same magnitude but at shifted levels with the intrathoracic pressure. The intratracheal pressure moved in phase with respiratory flow. These results show pressure relationships that are opposite from the classic physiology. The results from the present study support our clinical report that peak inspiratory flow rate is specifically reduced in intrathoracic central airway obstruction.

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We studied the sizes of Tuberculin reaction (TR) of 296 children who admitted to Tokyo Metropolitan Children's Hospital for active tuberculosis. The patients were classified into 4 groups; BCG group with or without some history of contact with a tuberculous patient, no BCG group with or without the history. About 30% of the total children showed the sizes of TR below the criteria established by the Ministry of Health and Welfare in 1989 for INH prophylaxis. The rate of the children whose TR were below the criteria were 4.3% of no BCG group with the history, 29.3% of no BCG group without the history, 50% of BCG group with the history and 92.9% of BCG group without the history.

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