Antineoplastic Agents/therapeutic use; Neoplasms/drug therapy; Sulfhydryl Compounds/antagonists & inhibitors; Adenocarcinoma/drug therapy; Adenocarcinoma/metabolism; Adult; Agar; Animals; Anus Neoplasms/drug therapy; Anus Neoplasms/metabolism; Breast Neoplasms/drug therapy; Breast Neoplasms/metabolism; Carcinoma, Squamous Cell/drug therapy; Carcinoma, Squamous Cell/metabolism; DNA/metabolism; Dogs; Humans; Leucine; Leukocytes/metabolism; Liver/metabolism; Mice; Middle Aged; Neoplasms, Experimental/drug therapy; Neoplasms, Experimental/metabolism; Parotid Neoplasms/drug therapy; Parotid Neoplasms/metabolism; Proteins/metabolism; RNA/metabolism; Radioisotopes; Rectal Neoplasms/drug therapy; Rectal Neoplasms/metabolism; Thoracic Neoplasms/drug therapy; Thoracic Neoplasms/metabolism; Thymidine; Uridine