passages.id: split_8_test_1003_passage
passages.type: progene_text
passages.text: In the present study ( Pediatric Oncology Group study no. 9457 ) , we measured the levels of WR-2721 , its active metabolites , as well as cysteine and glutathione in whole blood , plasma , and blood cells in patients receiving high - dose alkylating agents with mesna .