title: Density determinations of human parathyroid glands by density gradients.
abstract: The densities of human parathyroid glands were measured in density gradient columns of various media. Percoll (an aqueous colloidal solution of polyvinylpyrrolidone-coated silica), equilibrated to 300 mOsm with sodium chloride, was found to be the ideal gradient medium for density measurements of tissues with a density greater than 1.0 g/ml. which includes most parathyroid glands. The densities of the glands varied between 0.96 and 1.06 g/ml. Density measurements in gradients of Percoll were simple and reproducible and were made with an accuracy of approximately 0.001 g/ml. In other gradient media (aqueous solutions of sucrose and Ficoll, and organic solvents) there was a drift in density caused by osmotic or lipid-solving effects of the media. For measurements of densities less than 1.0 g/ml no ideal gradient medium was found, but a silicon oil or carbon tetrachloride/kerosone gradient could be used with somewhat reduced accuracy. It is concluded that the density gradient technique with the use of Percoll is potentially useful as a complement to routine histopathological parathyroid diagnosis, as glandular density is a good indicator of the relative proportions of parenchymal and fat tissue.
mesh_terms: D000273:Adipose Tissue / Q000032:analysis*; D002251:Carbon Tetrachloride; D003102:Colloids; D005362:Ficoll; D006801:Humans; D007648:Kerosene; D008722:Methods; D009994:Osmolar Concentration; D009997:Osmotic Pressure; D010280:Parathyroid Glands / Q000032:analysis*; D011205:Povidone; D012822:Silicon Dioxide; D012828:Silicones; D012965:Sodium Chloride; D012997:Solvents; D013395:Sucrose
chemical_list: D003102:Colloids; D007648:Kerosene; D012828:Silicones; D012997:Solvents; D005362:Ficoll; D012965:Sodium Chloride; D013395:Sucrose; D012822:Silicon Dioxide; D002251:Carbon Tetrachloride; D011205:Povidone