title: A novel diagnostic method for pulmonary aspiration in a murine model. Immunocytochemical staining of milk proteins in alveolar macrophages.
abstract: Aspiration of foreign material into the lungs has been implicated in the etiology of a variety of pulmonary disorders. Although aspiration is a common clinical problem, its diagnosis represents a major challenge due to the lack of sensitive and/or specific tests. In this study, we evaluated the sensitivity and specificity of a novel diagnostic method in a murine model of milk aspiration. Under light anesthesia, BALB/c mice received either single or repeated intranasal instillation of milk. Control animals received sterile physiologic saline or were infected with respiratory pathogens in a similar manner. After isolation and cannulation of the trachea, mouse lungs were lavaged with PBS at various time points after the last aspiration event. Cells were recovered for Oil Red O (ORO) staining as well as immunocytochemistry for milk proteins: alpha-lactalbumin and beta-lactoglobulin. After single aspiration of milk, a large number of alveolar macrophages displayed a strong immunoreactivity for alpha-lactalbumin for 2-96 h. After single and repeated aspiration, the percentage of positive cells for alpha-lactalbumin was significantly higher when compared with ORO staining at 24, 48, and 72 h (p < 0.05). No immunoreactivity for milk proteins was found in alveolar macrophages obtained from our control groups. These findings demonstrate that immunocytochemical staining of milk proteins within alveolar macrophages represents a novel, sensitive, and specific test for the diagnosis of aspiration in a murine model.
authors.affiliation: Department of Pediatrics, Division of Pulmonary Medicine, Baylor College of Medicine, University of Texas-Houston Medical School, Houston, Texas 77030, USA.
authors.forename: O
authors.initials: O
authors.lastname: Elidemir
authors.forename: L L
authors.initials: LL
authors.lastname: Fan
authors.forename: G N
authors.initials: GN
authors.lastname: Colasurdo
mesh_terms: D000818:Animals; D003937:Diagnosis, Differential; D004195:Disease Models, Animal; D005260:Female; D007768:Lactalbumin / Q000032:analysis*; D007782:Lactoglobulins / Q000032:analysis*; D016676:Macrophages, Alveolar / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D011015:Pneumonia, Aspiration / Q000175:diagnosis* / Q000473:pathology; D011650:Pulmonary Alveoli / Q000473:pathology*
chemical_list: D007782:Lactoglobulins; D007768:Lactalbumin