RESUMO

The perimeter of the basement membrane (Pbm) of an airway viewed in cross section is used as a marker of airway size because in normal lungs it is relatively constant, despite variations in airway smooth muscle (ASM) shortening and airway collapse. In vitro studies (McParland BE, Pare PD, Johnson PR, Armour CL, Black JL. J Appl Physiol 97: 556-563, 2004; Noble PB, Sharma A, McFawn PK, Mitchell HW. J Appl Physiol 99: 2061-2066, 2005) have suggested that differential stretch of the Pbm between asthmatic and nonasthmatic airways fixed in inflation may occur and lead to an overestimation of ASM thickness in asthma. The relationships between the Pbm and the area of ASM were compared in transverse sections of airways from cases of fatal asthma (F) and from nonasthmatic control (C) cases where the lung tissue had been fixed inflated (Fi; Ci) or uninflated (Fu; Cu). When all available airways were used, the regression slopes were increased in Fu and Cu, compared with Fi and Ci, and increased in Fu and Fi, compared with Cu and Ci, suggesting effects of both inflation and asthma group, respectively. When analyses were limited to airway sizes that were available for all groups (Pbm < 15 mm), the slopes of Fi and Fu were similar, but both were greater than Ci and Cu, which were also similar. It was calculated that the effect of asthma group accounted for 80% and inflation for 20% of the differences between Fi and Ci. We conclude that the effects of inflation on the relationship between Pbm and ASM are small and do not account for the differences observed in ASM between cases of asthma and nonasthmatic controls.

Assuntos

Asma/fisiopatologia , Membrana Basal/fisiopatologia , Pulmão/fisiopatologia , Músculo Liso/fisiopatologia , Adolescente , Adulto , Idoso , Asma/mortalidade , Asma/patologia , Austrália , Membrana Basal/patologia , Brasil , Colúmbia Britânica , Estudos de Casos e Controles , Criança , Feminino , Humanos , Pulmão/patologia , Complacência Pulmonar , Masculino , Pessoa de Meia-Idade , Músculo Liso/patologia , Nova Zelândia

RESUMO

OBJECTIVES: To determine whether early treatment of cystic fibrosis made possible by diagnosis after newborn screening results in improved pulmonary outcomes in adolescence. STUDY DESIGN: Both screening (SG) and non-screening groups (NSG) comprised a cohort of children from Australia previously studied at 1, 5, and 10 years of age. The groups were compared on measures of clinical status obtained during their comprehensive annual review conducted at or near the 15th birthday of the subjects. RESULTS: Data were collected on 48 of 57 original subjects in the NSG (7 had died; 2 were lost to follow-up) and 52 of 60 original subjects in the SG (4 had died; 2 transferred out of the country; 2 were lost to follow-up). Those dying in the SG were significantly older (by 48 months, P < .05) than those in the NSG. No statistically significant differences were found between the groups in nutritional status. However, subjects in the SG displayed statistically better total Shwachman-Kulczycki scores (7.0, P

Assuntos

Fibrose Cística/diagnóstico , Triagem Neonatal/organização & administração , Adolescente , Fatores Etários , Estatura , Peso Corporal , Criança , Mortalidade da Criança , Transtornos da Nutrição Infantil/etiologia , Pré-Escolar , Fibrose Cística/complicações , Fibrose Cística/mortalidade , Fibrose Cística/terapia , Diagnóstico Precoce , Medicina Baseada em Evidências , Feminino , Seguimentos , Volume Expiratório Forçado , Humanos , Recém-Nascido , Masculino , New South Wales/epidemiologia , Estado Nutricional , Avaliação de Resultados em Cuidados de Saúde , Índice de Gravidade de Doença , Espirometria , Taxa de Sobrevida , Capacidade Vital