Pulmonary Ultrastructure in Neonatal Hyaline
نویسنده
چکیده
of lungs obtained at necropsy from 44 children at or above the 50th centile dying from non-pulmonary causes were described. In the present paper some results from the analysis of 92 further pressure-volume curves are described. These were compared with the theoretically normal values according to total body length, by dividing the observed value by the theoretically normal one. This was done for both the maximum inflation volume and the low pressure air retention index. These indices were then plotted against each other to look for 'clusters'. One cluster showed low maximum volume, but, in contrast to the IRDS group, an above normal low pressure air retention index. The deflation curve characteristics of this group closely resembled the normal curves of premature infants rather than those of the growthmatched controls. Histological examination of these lungs fixed distended at a pressure of + 5 cm. H20 showed only alveolar ducts and collapsed alveoli, whereas the controls showed alveolar ducts lined with open alveoli. Stains for elastic tissues showed that the alveoli were normally developed, but collapsed against the duct walls. At low pressures, alveolar morphology is almost certainly controlled by surfactant. From these findings, it is suggested that, (1) the finding in an older child's lung of a deflation curve profile similar to that of a premature lung but with a severely diminished maximum inflation volume is characteristic of alveolar closure with surfactant malfunction in a more mature lung; (2) the reason for the different deflation profiles of surfactant malfunction in the newborn and the older child is that in the older child the elastic tissues around the alveolar ducts are sufficiently rigid to hold them open against the increased surface tension (due to surfactant malfunction); and (3) the similarity of deflation curve profile between the premature lung and abnormal older child's lung is because both are respiring with simple alveolar ducts without functioning definitive alveoli.
منابع مشابه
Lipid peroxidation and pulmonary hyaline membranes of the newborn: a histochemical, fluorescent microscopic and ultrastructural study.
Representative portions of lung from 17 newborn infants with hyaline membrane disease were studied. The consistent findings in the hyaline membranes of Schiff's positivity requiring periodic acid pretreatment, their autofluorescence between 350 and 400 nm, and the granular ultrastructure of the membrane matrix provided morphologic evidence for lipid peroxidation's having occurred in association...
متن کاملLocalization of plasminogen activator in neonatal lung in the presence of hyaline membrane disease.
A case is described in which Todd's method (1959) for the histological localization of plasminogen activator was applied to neonatal lung tissue obtained at (unsuccessful) open cardiac massage. This was localized around small pulmonary veins, usually at some distance from the hyaline membrane.
متن کاملPulmonary structural changes in neonatal hyaline membrane disease treated with high pressure artificial respiration.
متن کامل
Hyaline membrane disease. II. Lung lecithin.
Boughton, K., Gandy, G., and Gairdner, D. (1970). Archives of Disease in Childhood, 45, 311. Hyaline membrane disease. H: Lung lecithin. The lecithin content of lung, together with its surface tension properties, were determined in 34 stillbirths, and 61 neonatal deaths. Lecithin content ranged widely from 1-5 to 18 6% of dry lung tissue. In 24 cases the 'palmitic-lecithin' was also measured; i...
متن کاملUltrastructure of hyaline, border, and vacuole cells in chick inner ear.
The sense organ for hearing in birds, the basilar papilla, is capable of replacing lost or damaged hair cells and supporting cells through regeneration. Potential candidates for precursor-cell populations include cells within the auditory receptor epithelium and nonsensory cells inferior to the sensory epithelium. Ultrastructural characteristics of hyaline cells, border cells, and vacuole cells...
متن کاملLung function and airway responsiveness in children and adolescents after hyaline membrane disease: a matched cohort study.
Some investigators consider prematurity to be responsible for the lung function abnormalities found in prematurely born children and adolescents who had neonatal respiratory diseases. This study attempts to measure the effect of neonatal respiratory disease on lung function during school age and adolescence, by controlling the confounding effect due to prematurity. Lung volumes, airway resistan...
متن کامل