title: [Studies on the mechanisms of resistance to methotrexate--with special emphasis on the change of nucleotide pools].
mesh_terms: D000818:Animals; D004351:Drug Resistance; D006824:Hybridization, Genetic; D007939:Leukemia L1210 / Q000188:drug therapy*; D008297:Male; D008727:Methotrexate / Q000627:therapeutic use*; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D009711:Nucleotides / Q000378:metabolism*
chemical_list: D009711:Nucleotides; D008727:Methotrexate