Letter to the Editor

PEDIATRICS ◽  
1974 ◽  
Vol 54 (4) ◽  
pp. 519-519

Dr. Stevenson's observations concerning the association of amniotic fluid aspiration and hyaline membrane disease is quite interesting. Very little work, that we are aware of, has been done since these articles were published (1955 to 1958) to follow tip this theory. However, much work has been done to clarify the etiology of hyaline membrane disease. It is now well accepted that this clinical entity is directly related to the degree of immaturity of the lungs and the presence or absence of surface active material.

1984 ◽  
Vol 18 ◽  
pp. 394A-394A
Author(s):  
J C Jackson ◽  
S Palmer ◽  
T A Standaert ◽  
J Murphy ◽  
W E Truog ◽  
...  

1975 ◽  
Vol 39 (5) ◽  
pp. 735-741 ◽  
Author(s):  
R. J. King ◽  
J. Ruch ◽  
E. G. Gikas ◽  
A. C. Platzker ◽  
R. K. Creasy

We have isolated and partially characterized the protein found in surface-active material from adult human lungs, and have determined the time of appearance of this protein in amniotic fluid. Fluids were drawn at gestational ages from 12 to 44 wk, and were assayed for their concentration of apoprotein by an agglutination immunoassay. Surfactant apoprotein ((defined as that protein which is reproducibly found in purified preparations of surface active material) was usually first detected from 30 to 32 wk gestation, and its concentration increased almost fivefold to a maximum at 37 wk. The change in apoprotein concentration was approximately paralleled by the change in phospholipid concentration. At all gestational ages there was wide variability in both phospholipid and apoprotein concentrations, and the time of appearance of the apoprotein in amniotic fluid differed among fetuses. The results suggest that the presence of surfactant apoprotein in amniotic fluid is coincident with the biochemical and morphological maturation of the fetal lung, and are additional evidence that this apoprotein is cosecreted with the lipids of surface-active material.


1946 ◽  
Vol 14 (3) ◽  
pp. 316-329 ◽  
Author(s):  
R. Aschaffenburg

As moderate dilution causes little change in the surface tension of milk, it is shown to be advantageous to use σ-dilution curves in place of the σ-values of the undiluted fluid as a characteristic of the surface properties of milk. The complications arising from the presence of the milk fat are described, and it is suggested that the influence of the fat is of a physical rather than of a chemical nature. A study of the role of the various milk proteins shows the casein to be of great importance, whilst the heat-coagulable proteins have little influence. The serum obtained after removal of the casein and heat-coagulable proteins contains a residual fraction of protein-like material which is markedly surface active though constituting only about 3% of the total milk proteins. The surface-active material (σ-proteose) has been concentrated and isolated, and its properties are described in some detail.


1964 ◽  
Vol 207 (2) ◽  
pp. 402-406 ◽  
Author(s):  
Elwyn S. Brown

Lung extracts were obtained by either mincing the lungs in saline or by washing the lung with saline through the trachea. The surface tensions of the extracts on compression to 10% of the original area in a surface balance decreased to 7.5 ± 2.1 dynes/cm for rabbits, 10.0 ± 1.8 dynes/cm for dogs, and 6.8 ± 3.8 dynes/cm for man. The surface-active material in the extracts was completely precipitated with trichloroacetic acid. Ethyl or methyl alcohol extracted the activity from the precipitate. By concentrating and chilling the alcohol extract, a very surface-active white precipitate was obtained which was identified as dipalmityl phosphatidyl choline by melting point, chemical analysis, and paper chromatography. Cadmium chloride also precipitated a surface-active complex from the alcohol extract which was identified chemically as dipalmityl phosphatidyl choline. The quantity of hydrolecithin extracted from the lungs was 0.09–0.18% on a wet weight basis. No evidence of the presence of sphingomyelin or other surface-active phospholipid was obtained.


PEDIATRICS ◽  
1962 ◽  
Vol 30 (2) ◽  
pp. 324-330
Author(s):  
Mary Ellen Avery

The alveoli of the normal lung are lined by a substance which exerts surface tension at the air-liquid interface. In the expanded lung the tension is high and operates to increase the elastic recoil of the lung. In the lung at low volumes the surface tension becomes extremely low. This confers stability on the airspaces and thus prevents atelectasis. This lining layer is a lipoprotein film, which is not found where alveoli are still lined by cuboidal epithelium. Its time of appearance coincides with the appearance of alveolar lining cells. Electron microscopic evidence of secretory activity in alveolar cells suggests that they may be the source of the surface-active film. The normal alveolar lining layer is not present in lungs of infants who die from profound atelectasis and hyaline membrane disease. Whether its absence is a failure of development or due to inactivation is not established.


PEDIATRICS ◽  
1980 ◽  
Vol 65 (6) ◽  
pp. 1176-1177
Author(s):  
Mary Ellen Avery

Ever since it was realized that hyaline membrane disease was the consequence of surfactant deficiency, replacing the missing surface-active alveolar lining layer has been a tantalizing prospect. The report of Fujiwara et al1 is the first demonstration in the human of consistent and dramatic success after a single instillation of an artificial surfactant by way of an endotracheal tube. The prompt restoration of a stable alveolar lining layer and the impressive improvement in blood gases are well documented. The problem of the widely patent ductus producing difficulties in the subsequent days is expected and of course could be approached by other interventions.


1987 ◽  
Vol 63 (2) ◽  
pp. 828-833 ◽  
Author(s):  
D. Warburton ◽  
L. Parton ◽  
S. Buckley ◽  
L. Cosico ◽  
T. Saluna

We correlated the ontogeny of pulmonary beta-adrenergic receptors with the onset of surface active material (SAM) flux into tracheal fluid of male and female chronically catheterized fetal lambs. SAM flux began between 0.82 and 0.85 gestation in the females and between 0.85 and 0.89 gestation in the males and matured more rapidly thereafter in the females than in the males (P less than 0.01). beta-Adrenergic receptor binding, using [3H]dihydroalprenolol as the ligand, was saturable, linear, and stereospecific. The order of potency of competitive beta-agonists was isoproterenol greater than norepinephrine greater than epinephrine. The maximal binding capacity (Bmax) of pulmonary beta-receptors approximately doubled between 0.84 and 0.89 gestation, coinciding with the onset of SAM flux. Bmax matured as a third degree polynomial function of gestational age in females (r = 0.9, P less than 0.001) but as a linear function in males (r = 0.8, P less than 0.005). Between 0.86 and 0.93 gestation, Bmax was 1.45-fold greater in females than males (P less than 0.001). The dissociation constant of beta-receptors was not influenced significantly by gender or gestation. We conclude that maturation of pulmonary beta-receptors coincides with the onset of SAM flux in fetal lambs and that both mature more rapidly in females. We speculate that pulmonary beta-receptor maturation and SAM flux are coregulated by hormonal factors. More rapid maturation of pulmonary beta-receptors and SAM flux in females may be a factor in the female advantage with regard to pulmonary surfactant maturation and the survival of premature neonates.


1980 ◽  
Vol 26 (6) ◽  
pp. 766-769 ◽  
Author(s):  
C G Duck-Chong ◽  
J M Gupta ◽  
G N Storey ◽  
C R Houghton

Abstract A micro-method has been devised for isolating a lung-derived membranous fraction from human amniotic fluid. The phospholipid content of this fraction, known as lamellar body phospholipid, provides an indication of fetal lung maturity (Ann. Clin. Biochem 16: 191, 1979). This method has now been applied to 479 samples of amniotic fluid from 330 pregnancies. The lecithin/sphingomyelin ratio has also been determined for each of the samples by the routine method currently in use in the hospitals providing the samples. Hyaline membrane disease was associated with a low concentration of lamellar body phospholipid (< 35 mg/L) in all eight cases encountered in this study. In contrast, in 182 of the 185 cases where the lamellar body content of the amniotic fluid, collected within two days of delivery, exceeded 35 mg/L, the infants were free from serious respiratory problems. Data are presented which suggests that the lecithin/sphingomyelin ratio falsely indicated lung immaturity in many cases, amounting to 44% or more of all values indicating immaturity that were reported.


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