Article

Absence of Phosphatidylglycerol (PG) in Respiratory Distress Syndrome in the Newborn

Pediatric Research (Impact Factor: 2.67). 05/1977; 11(6):714-720. DOI: 10.1203/00006450-197706000-00003

ABSTRACT Phosphatidylglycerol (PG) was absent from lung effluent in 41 infants with respiratory distress syndrome of the newborn (RDS), whereas effluent from healthy control subjects of similar gestational age contained this phospholipid (4.9 ± 2.4% of lipid-phosphorus (P), n = 32). Control infants of 28 weeks of gestation or less with various respiratory disturbances other than RDS also had low PG (0.2 ± 0.2% of lipid-P, n = 5). In RDS surfactant complex often could be isolated from the airways using differential and density gradient centrifugation. The material thus obtained had prominent phosphatidylinositol (PI) (13.6 ± 2.8% of lipid-P, n = 6), but no PG. Of those 18 infants who had such surfactant even in the early stages of RDS, 13 were 35 weeks of gestation or more, 3 were offspring of diabetic mothers, and 2 had severe perinatal asphyxia. In healthy control subjects PG sometimes appeared first within an hour of birth, but in RDS PG did not appear until recovery from RDS.In RDS type II (transient tachypnea of the newborn) PG in lung effluent also was abnormally low (1.3 ± 0.6% of lipid-P, n = 5) and PI was correspondingly prominent (9.7 ± 3.6% of lipid-P, n = 5), indicating immaturity of surfactant similar to RDS.Surfactant with PG and PI has superior surface-active properties compared to that containing PI, but no PG. Surfactant without PG does not seem to stabilize the alveoli of the newborn as well as does surfactant with PG. The failure of PG appearance following birth therefore may precipitate RDS, especially beyond 35 weeks of gestation.Speculation: Pre- and postnatal monitoring of the acidic phospholipids, PG and PI, in lung effluent is useful in diagnosis and follow-up of RDS as well as in evaluation of various therapies.Keywords: Lecithin; phospholipids, acidic; pulmonary surfactant; respiratory distress syndrome

0 Bookmarks
 · 
67 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: Surfactant function using the stable microbubble test (SMT) was investigated in term or near term infants with respiratory distress. Newborn infants > or = 34 weeks gestation with an initial clinical hypothesis of transient tachypnoea of the newborn (TTN) needing supplemental oxygen and controls were included. Gastric aspirates were collected immediately after birth for SMT. The first chest X-ray films were examined by three independent radiologists and according to their interpretation the babies were divided into a TTN, a respiratory distress syndrome of the newborn (RDS), or a poorly-defined X-ray group. A total of 32 infants with respiratory distress and 32 controls with similar gestational age and birth weight were studied. The median and interquartile range (IQR) of the stable microbubble (SMB) count was significantly lower (P < 0.001) for the respiratory distress group than for the control group (17; range 6-33 versus 120; range 79-275). The proportion of babies with less than 35 stable microbubbles/mm2 (SMB/mm2) was significantly different for the whole respiratory distress group (24/32-75%) and for the TTN (9/13-69%), the RDS (5/5-100%), and the poorly-defined (10/12-83%) groups as compared with the controls (2/32-6%; P < 0.05). A total of 24/26 babies (92%) who needed oxygen for > or = 24 h but only 1/6 (17%) of them who needed < 24 h had a bubble count of less than 35 SMB/mm2 (P < 0.05). Conclusion: the results suggest that deficiency or dysfunction of the surfactant system is involved in the majority of cases of respiratory distress in near term and possibly term babies. The stable microbubble test can enable clinicians to take an earlier decision to give surfactant to term or near term infants with more severe and progressive respiratory distress.
    European Journal of Pediatrics 08/2004; 163(8):443-8. · 1.91 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: To determine the effect of various culture conditions on the maintenance of lipid synthesis and morphology in alveolar type II cells, we cultured isolated adult rat alveolar type II cells on either plastic or denuded human amnionic basement membrane (ABM) in medium supplemented with either fetal bovine, porcine, horse, rat, or human serum. Lipid synthesis was assessed by incubation with [1-14C]acetate and determination of the distribution of radiolabel into individual lipid classes. Cells cultured on ABM incorporated significantly higher percentages of acetate into either phosphatidylcholine (PC) or phosphatidylglycerol (PG), and retained lamellar inclusions and a more characteristic cuboidal shape for longer periods than did cells cultured on plastic. Compared to other sera, cells cultured in the presence of rat serum incorporated the highest percentages of acetate into PC and saturated PC, had the best preservation of lamellar-body ultrastructure, and also appeared to contain more multivesicular bodies. The percent composition of linoleic acid, an essential fatty acid, was found to vary widely among the different sera. Supplementing media with linoleic acid resulted in a marked increase in acetate incorporation into saturated PC and a decreased incorporation into PG. We conclude that for maintenance of differentiated function of adult rat alveolar type II cells in primary culture (1) ABM is preferable to plastic as a culture substratum, (2) rat serum is preferable to fetal bovine serum as a serum supplement, and (3) the regulation of lipid synthesis by linoleic acid causes disparate effects on PG and saturated PC synthesis.
    Experimental Lung Research 02/1987; 13(4):427-47. · 1.47 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Lung tissue explants from mid-trimester human abortuses were maintained for 8 days in organ culture in medium with or without serum. Before the start of culture the cells lining the pre-alveolar ducts were undifferentiated and contained no lamellar bodies, the intracellular organelle that contains surfactant. After 4 days in organ culture, the epithelium lining the pre-alveolar ducts was composed of differentiated type II cells containing numerous lamellar bodies. During the 8-day culture period there was increased incorporation of [3H]choline into phosphatidylcholine and disaturated phosphatidylcholine. In addition, the specific activity of phosphatidate phosphohydrolase, a regulatory enzyme in lung phospholipid synthesis, increased 4-fold during the culture period. Lamellar bodies isolated by differential centrifugation from explants maintained in culture for 7 days had the characteristic ultrastructure described for this organelle. Lamellar bodies were isolated from explants which had been incubated with [14C]glycerol. When the glycerophospholipid composition of lamellar bodies was analyzed it was found that the majority of the radiolabeled glycerol (74%) was incorporated into phosphatidylcholine and into the anionic phospholipids, phosphatidylglycerol (5%) and phosphatidylinositol (6%). Thus, human fetal lung explants maintained in organ culture contain differentiated type II cells which synthesize surfactant characteristic of human fetal lung at 36 to 38 weeks of gestation.
    Cell and Tissue Research 02/1981; 220(1):17-25. · 3.68 Impact Factor