An automatic method for the determination of anionic surface-active material in water

The Analyst ◽  
1966 ◽  
Vol 91 (1079) ◽  
pp. 113-118 ◽  
Author(s):  
A. Södergren
Keyword(s):  
Active Material ◽  
Automatic Method ◽  
Surface Active ◽  
Surface Active Material ◽  
Anionic Surface

Rapid alveolar liquid removal by a novel convective mechanism

2001 ◽  
Vol 281 (6) ◽  
pp. L1327-L1334 ◽  
Author(s):  
P. M. Wang ◽  
Y. Ashino ◽  
H. Ichimura ◽  
J. Bhattacharya
Keyword(s):  
Active Material ◽  
Ringer Solution ◽  
Surface Active Properties ◽  
Intracellular Ca ◽  
Surface Active ◽  
Surface Active Material ◽  
Liquid Removal ◽  
Air Liquid Interface ◽  
Alveolar Surface

Although alveoli clear liquid by active transport, the presence of surface-active material on the alveolar surface suggests that convective mechanisms for rapid liquid removal may exist. To determine such mechanisms, we held the isolated blood-perfused rat lung at a constant alveolar pressure (Pa). Under videomicroscopy, we micropunctured a single alveolus to infuse saline or Ringer solution in ∼10 adjacent alveoli. Infused alveoli were lost from view. However, as the infused liquid cleared, the alveoli reappeared and their diameters could be quantified. Hence the time-dependent determination of alveolar diameter provided a means for quantifying the time to complete liquid removal (C t ) in single alveoli. All determinations were obtained at an Pa of 5 cmH2O. C t , which related inversely to alveolar diameter, averaged 4.5 s in alveoli with the fastest liquid removal. Injections of dye-stained liquid revealed that the liquid flowed from the injected alveoli to adjacent air-filled alveoli. Lung hyperinflations instituted by cycling Pa between 5 and 15 cmH2O decreased C t by 50%. Chelation of intracellular Ca2+ prolonged C t and abolished the inflation-induced enhancement of liquid removal. We conclude that when liquid is injected in a few alveoli, it rapidly flows to adjacent air-filled alveoli. The removal mechanisms are dependent on alveolar size, inflation, and intracellular Ca2+. We speculate that removal of liquid from the alveolar surface is determined by the curvature and surface-active properties of the air-liquid interface.

Letter to the Editor

PEDIATRICS ◽  
1974 ◽  
Vol 54 (4) ◽  
pp. 519-519
Keyword(s):  
Amniotic Fluid ◽  
Active Material ◽  
Hyaline Membrane Disease ◽  
Clinical Entity ◽  
Letter To The Editor ◽  
Hyaline Membrane ◽  
Surface Active ◽  
Surface Active Material

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.

336. Surface activity and proteins of milk

1946 ◽  
Vol 14 (3) ◽  
pp. 316-329 ◽  
Author(s):  
R. Aschaffenburg
Keyword(s):  
Milk Fat ◽  
Chemical Nature ◽  
Active Material ◽  
Milk Proteins ◽  
Residual Fraction ◽  
Total Milk ◽  
Surface Active ◽  
Surface Active Material ◽  
Dilution Curves

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.

Isolation and assay of dipalmityl lecithin in lung extracts

1964 ◽  
Vol 207 (2) ◽  
pp. 402-406 ◽  
Author(s):  
Elwyn S. Brown
Keyword(s):  
Phosphatidyl Choline ◽  
Trichloroacetic Acid ◽  
Cadmium Chloride ◽  
Active Material ◽  
Weight Basis ◽  
Alcohol Extract ◽  
Wet Weight ◽  
Surface Active ◽  
Surface Active Material ◽  
Surface Balance

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.

Beta-receptors and surface active material flux in fetal lamb lung: female advantage

1987 ◽  
Vol 63 (2) ◽  
pp. 828-833 ◽  
Author(s):  
D. Warburton ◽  
L. Parton ◽  
S. Buckley ◽  
L. Cosico ◽  
T. Saluna
Keyword(s):  
Pulmonary Surfactant ◽  
Binding Capacity ◽  
Active Material ◽  
Degree Polynomial ◽  
Beta Adrenergic ◽  
Female Advantage ◽  
Beta Agonists ◽  
Beta Receptors ◽  
Surface Active ◽  
Surface Active Material

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.

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