Methods for Fractionation and Identification of Nonhistone Proteins of Rat Liver Chromatin

Combinations of methods were devised for fractionation and characterization of proteins obtained from rat liver chromatin. The chromosomal proteins were extracted from DNA by treatment with 3M NaCl, 7M urea, or by heating in 1% sodium dodecyl sulfate. The proteins dissociatdd by sodium dodecyl sulfate were fractionated by gel filtration in the presence of the detergent. A number of discrete components, each containing a population of polypeptides of limited heterogeneity with respect to molecular weight, were isolated by this method. Proteins obtained by urea-salt dissociation were initially subfractionated into histone and nonhistone components. The nonhistone proteins were examined by sodium dodecyl polyacrylamide gel electrophoresis and by analytical and preparative isoelectric focusing methods, in an effort to provide reproducible methods for identification of specific families of proteins

A Case of Retroperitoneal Malignant Mesenchymoma

A rare case of malignant mesenchymoma of a retroperitoneal lesion, com-posed of liposarcoma and osteosarcoma, is reported. For complete resection of the tumor, two surgical operations were performed. The first operative material showed a mass measuring 20 x 20 x 10 cm, weighing 1607g, arising from the soft tissue of the left retroperitoneum and the tumor had a smooth surface and elastic-hard consistency. The secondary operative materials exhi-bited a mass measuring 10 x 5 x 3 cm, weighing 268g. The tumor was com-posed of soft gelatinous tissues and adhered to the tail of the pancreas but was separate from the spleen. More than 3 years after the secondary operation, no recurrence has been observed. Immunohistochemical examinations showed that S-100 protein and non-specific enolase were present in the liposarcoma-tous area and that vimentin was positive in the osteosarcomatous area