PubMed Health⌕ Search

Biomedical subjects

F A Bettelheim

Publications and source records attributed to F A Bettelheim.

At least 73 records · Page 4Linked to original sources
PubMed1977

Small-angle light-scattering patterns of corneas of different species.

Light-scattering patterns of corneas of different species have been obtained. The different small-angle light-scattering (SALS) patterns were classified into four groups on the basis of the angular dependence of the intensity of light scattered in the I+ and I modes. At present, only two types of patterns can be explained on the basis of theoretical models. The need to develop a general model that can account for all four types of SALS patterns is discussed.

Animals↗
PubMed1977

An interpretation of small-angle light-scattering patterns of human cornea.

Small-angle light-scattering patterns of human cornea in I. and I modes were compared to theoretical scattering patterns generated in the computer on the basis of a cornea model. This model is a nonrandom assembly of optically anistropic rods. The best match of theoretical and experimental patterns yielded the following parameters describing the ultrastructure of human cornea: length of the rod (fiber)=12 mu; angle between optic and geometric axis of the rod=60 degrees; most probable orientation of the rod=150 degree; the width of the distribution function of rod orientation (omega0)=2.5; intrinsic birefringence of the rod=7 X 10(-6); form birefringence=1.3 X 10(-5).

Birefringence↗
PubMed1976

Distribution of hexosamines in bovine cornea.

Excised bovine cornea were sectioned from epithelium to endothelium into 6 to 8 fractions. The glucosamine/galactosamine ratio steadily increases from epithelium to endothelium in all bovine corneas investigated. The glucosamine/galactosamine ratio reflects the keratan sulfate/chondroitin-4-sulfate ratio in the cornea. The significance of this topographic distribution is discussed in terms of the different hydration properties of proteoglycans containing predominantly keartan sulfate or chondroitin-4-sulfate chains.

Animals↗
PubMed1975

Water vapor sorption of keratan sulfate.

Keratan sulfate was isolated from bovine cornea. The water vapor sorption isotherms were obtained on both sodium and calcium salts of keratan sulfate at different temperatures. Deuterated water sorption isotherms were obtained on sodium keratan sulfates. The infrared spectra of the keratan-sulfate was monitored as a function of water and D2O uptake. The results are discussed in terms of an open polymer matrix that exists in the solid state of keratan sulfate.

Animals↗
PubMed1975

The hydration of proteoglycans of bovine cornea.

The water sorptive and retentive capacities of three corneal proteoglycans with different keratan sulfate/chondroitin-4-sulfate compositions were investigated. The calcium salt of a predominantly keratan sulfate containing proteoglycan had hydration properties similar to that of calcium keratan sulfate. The proteoglycan containing predominantly calcium chondroitin-4-sulfate side chains sorbed water to a greater extent than pure calcium chondroitin-4-sulfate but its retentive power was somewhat less. The proteoglycan containing about twice as much keratan sulfate as chondroitin-4-sulfate, on a dissaccharidic molar basis and had hydration properties which were closer to the behavior of chondroitin-4-sulfate than keratan sulfate. The results are discussed in terms of structure and polymer interaction in the proteoglycan matrices.

Amino Acids↗