Respiratory function at 18 months of age following in utero gene transfer at 16 days gestation. Respiratory function in 18 month old animals following treatment at 16 days gestation with replication deficient adenovirus containing eGFP, (control, solid bars), or anti-sense CFTR gene fragment, (ASCFTR, crossed bars). (A) static compliance. (B), conducting airway resistance, (Raw). (C) tissue damping. (D) elastance. (E) hysteresivity, (eta). Four animals are included in each data point. All data were obtained in triplicate for each animal. Error bars are ± standard error of mean. * p < 0.005; ** p < 0.004; # p < 0.02.