when patients in the subgroups ( n = 73 ) that included all the patients with elevated nh3 were separated into one group ( n = 47 ) with normal nh3 ( less than or equal to 0.70 micrograms/ml ) and one group ( n = 26 ) with elevated nh3 ( greater than or equal to 0.71 micrograms/ml ) , student 's t tests for equality of means showed that the group with elevated nh3 had a significantly higher mean plasma concentration for vpa , pb , sum of vpa-pb , and sum of vpa-pb-pht ( all at p less than 0.001 ) when compared with the normal group .
C0031412
pb
C1875648
pb-pht