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Biomedical subjects

H Yamabayashi

Publications and source records attributed to H Yamabayashi.

At least 73 records · Page 4Linked to original sources
PubMed1978

Contact angle and surface tension in studies of lung surfactant.

The contact angle (theta) was determined in combination with surface tension measured in a Langmuiur-Willhelmy surface tension balance. Correction of the surface tension by the contact angle factor (1/cos theta) was tried on the monolayer curve of dipalmitoyl phosphatidyl choline (DPPC) and total lipid extracts from the bovine lung surfactant material (TLE). The contact angle was observed with an optical apparatus called a Contangulometer and pictures taken discontinuously, and was determined by drawing tangents at the peak of a junction between the water mensicus and a glass plate. The contact angle was about 15 degrees, and had a narrow range of variation until the surface tension became very low, less than 5 dynes/cm, and then the contact angle jumped to almost 90 degrees both in DPPC and in TLE. It is concluded that the directly recorded surface tension curve underestimates the value by about 3-4% and that when the surface tension becomes very low, less than 5 dynes/cm, the value is no longer valid because the contact angle becomes nearly 90 degrees.

Methods↗
PubMed1977

Isolation of apoprotein from bovine lung surfactant material by sodium deoxycholate.

Aqueous solutions of bovine lung surfactant material were solubilized with a high concentration of sodium deoxycholate and the protein moiety could then be separated from the mixed lipid-sodium deoxycholate micelles by gel filtration in the presence of a micellar concentration of sodium deoxycholate of 10 mM. The lipid-free protein showed only one detectable peak in the gel filtrate and the sedimentation rate of this protein was 12.1 S. Sodium dodecyl sulfate disc gel electrophoresis showed essentially the same pattern as did the protein extracted directly from the bovine lung surfactant material with organic solvents, of which the major component has a molecular weight of 36 000. This protein should be the main apoprotein of lung surfactant material, and the main band in the sodium dodecyl sulfate disc gel electrophoresis, with a molecular weight of 36 000, would constitute the major protein subunit.

Animals↗