Induced sputum in children and adolescents with asthma:: safety, clinical applicability and inflammatory cells aspects in stable patients and during exacerbation - Palomina, Addy L. M.; Bussamra, Maria Helena C. F.; Saraiva-Romanholo, Beatriz Mangueira; Martins, Milton de Arruda; Nunes, Maria do Patrocinio Tenorio; Rodrigues, Joaquim Carlos (Jornal de Pediatria, 2005)