An in vitro intact globe expansion method for evaluation of cross-linking treatments.

Purpose: To measure the tissue mechanical response to elevated intraocular pressure (IOP) using intact globe expansion of rabbit eyes. This method examined rabbit kit (2-3 weeks old) eyes as a model for weakened tissue and evaluated riboflavin/UVA and glyceraldehyde cross-linking treatments.

Methods: The ocular shape of enucleated eyes was photographed during a 24-hour period while a controlled IOP was imposed (either low IOP = 22 mm Hg or high IOP = 85 mm Hg).

Water dynamics and salt-activation of enzymes in organic media: mechanistic implications revealed by NMR spectroscopy.

Deuterium spin relaxation was used to examine the motion of enzyme-bound water on subtilisin Carlsberg co-lyophilized with inorganic salts for activation in different organic solvents. Spectral editing was used to ensure that the relaxation times were associated with relatively mobile deuterons, which were contributed almost entirely by D(2)O rather than hydrogen-deuteron exchange on the protein. The results indicate that the timescale of motion for residual water molecules on the biocatalyst, (tau(c))(D(2)O), in hexane decreased from 65 ns (salt-free) to 0.