Serum proteins as mortality index in elderly patients.

ronmental condition (high temperature and high humidity) in which the blocks of plastic are stored. Deterioration of antigenicity or enzyme activity in glycol methacrylate blocks is not a problem we have encountered, possibly because Aberdeen, Scotland has a relatively low ambient temperature and low humidity. We would agree that low-acid glycol methacrylate is the resin of choice and we understand that the commercial formulation of glycol methacrylate resin that we use (JB4, Polysciences, Warrington, PA) contains low-acid glycol methacrylate monomer. Ice crystal damage is a problem when ultrastructural studies are being performed, but there is no ice crystal damage visible with light microscopy. There is no evidence that during the process of freeze substitution and plastic embedding that redistribution of tissue components occurs, and freeze-substituted plasticembedded tissue has been used for electron probe analysis of diffusible intracellular ions in different subcellular compartments. Electron probe of analysis freeze-substituted plastic-embedded tissue has demonstrated no diffusion of intracellular ions and the results from those studies would be considered critical evidence indicating that there is no redistribution of tissue components. Diffusion of tissue components is more likely to occur during room temperature dehydration.