Ultrastructural nasal pathology in children chronically and sequentially exposed to air pollutants

Calderón  Garcidueñas, Lilian

Por favor, use este identificador para citar o enlazar este ítem: http://repositorio.pediatria.gob.mx:8180/handle/20.500.12103/2934

Título :	Ultrastructural nasal pathology in children chronically and sequentially exposed to air pollutants
Creador:	Calderón Garcidueñas, Lilian
Nivel de acceso:	Open access
Palabras clave :	Contaminantes del aire - efectos adversos Niño México Mucosa nasal - efectos de drogas Mucosa nasal - ultraestructura Sistema respiratorio - efectos de drogas Sistema respiratorio - ultraestructura Air Pollutants - adverse effects Child Mexico Nasal Mucosa - drug effects Nasal Mucosa - ultrastructure Respiratory System - drug effects Respiratory System - ultrastructure
Descripción :	Southwest Metropolitan Mexico City (SWMMC) children are repeatedly exposed to a complex mixture of air pollutants, including ozone, particulate matter, and aldehydes. Nasal biopsies taken from these children exhibit a wide range of histopathologic alterations: marked changes in ciliated and goblet cell populations, basal cell hyperplasia, squamous metaplasia, and mild dysplasias. We studied the ultrastructural features of 15 nasal biopsies obtained from clinically healthy children 4 to 15 yr of age, growing up in SWMMC. The results were compared with nasal biopsies from 11 children growing up in Veracruz and exposed to low pollutant levels. Ultrathin sections of nasal biopsies revealed an unremarkable mucociliary epithelium in control children, whereas SWMMC children showed an epithelium comprised of variable numbers of basal, ciliated, goblet, and squamous metaplastic as well as intermediate cells. Nascent ciliated cells, as evidenced by the presence of migratory kinetosomes, were common, as were ciliary abnormalities, including absent central microtubules, supernumerary central and peripheral tubules, ciliary microtubular discontinuities, and compound cilia. Dyskinesia associated with these abnormal cilia was suggested by the altered orientation of the central microtubules in closely adjacent cilia. A transudate was evident between epithelial cells, suggesting potential deficiencies in epithelial junction integrity. Particulate matter was present in heterolysosomal bodies in epithelial cells and it was also deposited in intercellular spaces. The severe structural alteration of the nasal epithelium together with the prominent acquired ciliary defects are likely the result of chronic airway injury in which ozone, particulate matter, and aldehydes are thought to play a crucial role. The nasal epithelium in SWMMC children is fundamentally disordered, and their mucociliary defense mechanisms are no longer intact. A compromised nasal epithelium has less ability to protect the lower respiratory tract and may potentially leave the distal acinar airways more vulnerable to reactive gases. Impairment of mucociliary clearance has the potential to increase the contact time between deposited mutagenic particulate matter and the epithelial surface, thus increasing the risk for nasal carcinogenesis. Chronic exposures to air pollutants affect the whole respiratory tract; the nasal epithelium is an accessibl
Colaborador(es) u otros Autores:	Valencia Salazar Gildardo Rodríguez Alcaraz Antonio Gambling Todd M García Raquel Osnaya Norma Villarreal Calderón Anna Devlin Roberto B Carson Johnny L.
Fecha de publicación :	2001
Tipo de publicación:	Artículo
Formato:	pdf
Identificador del Recurso :	10.1165/ajrcmb.24.2.4157
Fuente:	Am J Respir Cell Mol Biol 24(2):132-138
URI :	http://repositorio.pediatria.gob.mx:8180/handle/20.500.12103/2934
Idioma:	eng
Aparece en las colecciones:	Artículos

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