Typescript. / Thesis (Ph. D.)--University of Hawaii at Manoa, 1985. / Bibliography: leaves 103-111. / Photocopy. / Microfilm. / x, 111 leaves, bound ill. 29 cm

Infants with bronchopulmonary dysplasia (BPD), showed impaired body growth when compared to control infants. In terms of changes in the biochemical composition of the lung, BPD infants had higher DNA, soluble protein, collagen and desmosine contents as well as increased concentrations of DNA, collagen and desmosine in their lungs when compared to the growth patterns obtained for the lungs of control infants. Pathologically BPD was classified into 4 grades. Grade I BPD, was a phase of acute lung injury, grades II and III were proliferative phases. In grade IV BPD, lung structure returned towards normal. Evidence of fibrosis was seen by a significant increase in collagen concentration in grades II and III while desmosine concentration was seen to increase in grades III and IV suggesting that the increase in collagen and desmosine contents in the lungs of BPD infants may be controlled by two different mechanisms. Collagen type I/III ratio was seen to decrease progressively from grade II to grade IV BPD in comparison to age matched controls, indicating a higher proportion of type III collagen in the lungs of infants with BPD. From the clinical analysis and the results obtained from discriminant analysis procedure, it was seen that there was a high degree of correlation between the continuation of the disease and collagen accumulation in the lungs suggesting that pulmonary fibrosis with excessive collagen accumulation is an integral part of BPD. This fibrotic process seemed to correlate significantly with assisted ventilation and high oxygen supplementation received by the infants, but it was difficult to assess the individual contribution of the two treatments in the pathogenesis of BPD. Other variables such as severity of the initial disease and the length of survival of the infants, made the assessment of individual contribution much more difficult. / Medicine, Faculty of / Pathology and Laboratory Medicine, Department of / Graduate

This study was designed to examine the hypothesis that the amount of amniotic fluid present during gestation is critical to normal lung growth and maturation. On day 16 of gestation the amniotic sacs of the right or left uterine horns of timed pregnant Sprague-Dawley rats were punctured with a 20 gauge needle. The fetuses of the opposite horn served as controls. On day 21 of gestation (one day prior to natural delivery) the fetuses were delivered by Cesarean section. An unbalanced, mixed model analysis of variance was performed on the data collected from each fetus. Probability values of less than 0.05 between control and experimental animals were considered significant. Amniotic sac puncture resulted in a significant loss of amniotic fluid as indicated by reduced amniotic fluid volume on day 21. Experimental body weight was significantly reduced indicating fetal growth retardation. Lung growth was also retarded as indicated by significantly reduced lung weight to body weight ratios and lung volume to body weight ratios following amniotic sac puncture. There was a reduction in the amount of fluid present within the experimental lungs. There appeared to be no significant effect on the structural units of the lung as indicated by no significant difference between control and experimental fetal lungs in terms of cell number, cell size, total protein to body weight ratio, maturation of type II cells, volume fraction of saccular air, saccular wall, conducting air and nonparenchyma, airspace size, saccular surface area to body weight ratio and surface to volume ratio. Thus, loss of amniotic fluid significantly affected lung growth, more than it affected overall body growth, without having an effect on lung maturation. / Medicine, Faculty of / Pathology and Laboratory Medicine, Department of / Graduate

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Abstract not available