Previous studies from several laboratories have established that adenovirus is a common cause of severe childhood bronchiolitis. The observation that children with an established history of bronchiolitis subsequently developed unremitting airways obstruction even after adequate steroid therapy led us to postulate that this bronchial obstruction might be due to persistence of an adenoviral infection. This hypothesis was tested by performing bronchoalveolar lavage (BAL) on a group of 34 children with a mean age of 5 yr (range, 14 mo to 14 yr) who showed an unfavorable response to standard corticosteroid and bronchodilator therapy. Analysis of cytospin preparations of BAL fluid at the light-microscopic level, using a monoclonal antibody to detect adenoviral antigens, demonstrated that capsid protein was present in 31 of 34 (94%) of the children examined. Limited repeat studies within 1 yr showed 6 of 8 (75%) were positive twice when tested on two occasions, and that three were positive in all occasions when sampled three times. Cultures of the BAL fluid were also positive for adenovirus in six of six cultures performed, indicating that the virus was in some cases replicating. Similar studies of control patients without persistent asthma showed no evidence of adenovirus. We conclude that persistent and/or latent adenoviral infection may contribute to the pathogenesis of childhood asthma in which there is an unfavorable response to steroid and bronchodilatation therapy.
The persistent presence of viruses in the upper respiratory tract of asthmatic children shows a possible connection between viral infections and asthma.
The action of halothane on the pulmonary vasoconstrictor response to unilateral alveolar hypoxia was studied in two groups of dogs. In the first group the redistribution of blood flow between the two lungs was studied with a radioactive isotope method, which provided intermittent measurements, whilst in the second group the distribution of blood flow was observed continuously. In both groups there was no significant alteration of the hypoxic vasoconstrictor response with inspired halothane concentrations varying from 0.5 to 1.5%.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.