title: [Damage by gamma rays and heavy ions to superhelical structures of nuclear DNA].
abstract: Chinese hamster cells (V79-4), human lymphocytes and mouse ascites cell were exposed to gamma-rays and heavy ions (4He and 12C). Sedimentation of complexes containing DNA was studied after cell lysis by centrifugation in a neutral sucrose gradient. The distinctions noted after irradiation with gamma-rays and heavy ions are consistent with the idea of the superhelical organization of DNA into discrete and membrane-bound compact units. According to the estimates made the diameter of these complexes was approximately 0.2 micron and DNA content, about 2 X 10(9) dalton.
mesh_terms: D000818:Animals; D002244:Carbon; D002286:Carcinoma, Ehrlich Tumor / Q000473:pathology; D002460:Cell Line; D002588:Cesium Radioisotopes; D006224:Cricetinae; D003412:Cricetulus; D004273:DNA, Neoplasm / Q000528:radiation effects; D004278:DNA, Superhelical / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D005347:Fibroblasts / Q000528:radiation effects; D005720:Gamma Rays; D006371:Helium; D006801:Humans; D007477:Ions; D008214:Lymphocytes / Q000528:radiation effects; D051379:Mice
chemical_list: D002588:Cesium Radioisotopes; D004273:DNA, Neoplasm; D004278:DNA, Superhelical; D007477:Ions; D006371:Helium; D002244:Carbon
vernacular_title: Povrezhdenie gamma-luchami i tiazhelymi ionami superspiral'nykh struktur iadernoĭ DNK.