Efeitos da aerossolterapia nas propriedades fisico-quimicas do muco bronquico / Effect of aerossolterapia in the physical-chemical properties of the mucus bronquico

A aerossolterapia e utilizada com frequencia no tratamento das alteracoes do aparelho mucociliar, entretanto, ate hoje nao ha provas significativas de seus efeitos. Este estudo analisou amostras de muco bronquicoexpectorado por 12 bronquiectasicos submetidos a inaloterapia com N-acetilcisteina (NAC 10 por cento), salina hipertonica (SH 1,5 por cento), salina isotonica (SI 0,9 por cento) e agua destilada (AD). Para analisar as propriedades do muco bronquico foram realizadasa mensuracao do angulo de adesao do deslocamento do muco na maquina simuladora da tosse e a celocidade de transporte em palato isolado de ra, alem da quantidade de muco expectorado, pela analise do peso umido e pela relacao peso seco/peso umido. Nao foram verificadas diferencas significativas (p<0,05) quando comparadas as substancias estudadas para as variaveis espirometria, relacao peso seco/peso umido, angulo e adesao e medida de deslocamento do mucona maquina simuladora da tosse. Porem, ao serem analisadas cada uma separadamente em relacao aos periodos antes, apos e 60 minutos do termino da sessao foram encontradas diferencas para as variaveis peso umido, na maquina simuladora da tosse e transporte palato ra. A solucao salina hipertonica (1,5 por cento), determinou reducao significativa (p<0,05) na quantidade de muco expectorado apos 60 minutos de inalacao (80), porem de melhor transportabilidade. A N-acetilcisteina (NAC 10 por cento) promoveu aumento significativo (p<0,05) na quantidade de muco expectorado, associado a tendencia de pior transportabilidade"""''as

Effects of formaldehyde on the frog's mucociliary epithelium as a surrogate to evaluate air pollution effects on the respiratory epithelium

The increasing use of alcohol as an alternative fuel to gasoline or diesel can increase emission of formaldehyde, an organic gas that is irritant to the mucous membranes. The respiratory system is the major target of air pollutants and its major defense mechanism depends on the continuous activity of the cilia and the resulting constant transportation of mucous secretion. The present study was designed to evaluate the effects of formaldehyde on the ciliated epithelium through a relative large dose range around the threshold limit value adopted by the Brazilian legislation, namely 1.6 ppm (1.25 to 5 ppm). For this purpose, the isolated frog palate preparation was used as the target of toxic injury. Four groups of frog palates were exposed to diluted Ringer solution (control, N = 8) and formaldehyde diluted in Ringer solution at three different concentrations (1.25, 2.5 and 5.0 ppm, N = 10 for each group). Mucociliary clearance and ciliary beat frequency decreased significantly in contact with formaldehyde at the concentrations of 2.5 and 5.0 ppm after 60 min of exposure (P<0.05). We conclude that relatively low concentrations of formaldehyde, which is even below the Brazilian threshold limit value, are sufficient to cause short-term mucociliary impairment

Methods for studying respiratory mucus and mucus clearance

We describe some basic procedures for studying the properties of mucus. These techniques can be applied in both clinical and physiological studies to improve the understanding of the mechanisms related to epithelial defense in health and disease. Mucus collection - A major difficulty is the lack of simple and noninvasive methods for collecting normal mucus in sufficient quantity for later analysis. Physical properties of mucus - A. Rheology: Mucus exhibits both solid and liquid properties and the important factor governing the actual behavior is time. The magnetic microrheometer provides an elegant method for measuring rheological properties of microsamples. B. Adhesivity: It characterizes the forces of attraction between an adherent surface and an adhesive system and can be calculated by measuring the contact angle between a mucus drop and a surface. Mucus Transport - A. Mucus transport by cilia: Mucus is primarily cleared by the continuous ciliary beating, which can be studied using techniques such as the frog palate preparation as well as direct measurement. i.e., in situ mucus clearance. B. Cough clearance: It is essential for elimination of secretions in diseases leading to hypersecretory states. The cough machine simulates the flow-time profile of human coughing. Transepithelial potential difference - A potential difference exists between the epithelial surface and the submucosa and is the net result of the activity of the ion-transport system of the pulmonary epithelium. The potential can be measured using appropriate microelectrodes. Quantitative morphology - Methods may be used to characterize the epithelial surface condition that continuously changes during aggressive conditions.