to determine the most sensitive early indicator of toxicity from exposure to o2 , we measured respiratory clearance of 99mtc-diethylenetriamine pentaacetate ( tc-dtpa ) , pulmonary function , serum factor viii antigen , and plasma fibronectin values and monitored symptoms in six normal volunteers who breathed 21 , 40 , and 100 % o2 , administered in random order , for 17 h at least 1 wk apart .
C0229671
serum
C0032105
plasma