Cognitive performance at school age of very low birth weight infants with bronchopulmonary dysplasia.

The hypothesis was that bronchopulmonary dysplasia (BPD) adversely affects cognitive performance at school age. This prospective cohort study examined three groups of children at 8 to 10 years of age. Group 1 (n = 311) consisted of very low birth weight (VLBW) infants without BPD and Group 2 (n = 95) consisted of VLBW infants with BPD. Group 3 (n = 188) consisted of term infants without BPD. Regression analysis determined the effect of BPD on eight performance measures while controlling for possible confounding variables. Children in Group 3 had the best performance and children in Group 2 had the poorest performance on all measures. These differences were significant (p = .0001) for the Full Scale IQ, Performance IQ, and reading and math grades and ages. Children in Groups 3 and 1 performed better than children in Group 2 for the Verbal IQ (p = .0001) and the Developmental Test of Visual-Motor Integration (p = .0012), but for these two measures there was no significant difference between children in Groups 3 and 1. Thus, poorer performance was found in VLBW infants with a history of BPD.

Regional blood-to-tissue transport in an irradiated rat glioma model.

To assess vascular permeability in intracerebral grafts of the 36B-10, F-344 rat glioma following 20 Gy 137Cs whole brain irradiation, the blood-to-tissue transport constant, K, of [14C]-alpha-aminoisobutyric acid (AIB) was measured with quantitative autoradiography. Mean, 90th percentile, and 95th percentile values of K were determined in individual tumors and in treatment groups. In 15-day-old unirradiated control tumors, mean, 90th percentile, and 95th percentile values of K were, respectively, 11.3, 18.4, and 20.8 ml kg-1 min-1. In 15-day-old tumors irradiated on Day 14 (Day 1 postirradiation tumors) the K values were 5.9, 9.4, and 10.4, all of which were significantly less than the respective control values (P less than 0.01). In 16-day-old tumors irradiated on Day 14 (Day 2 postirradiation tumors), the K values were 10.8, 15.0, and 16.0, respectively, none of which was significantly different from control tumors. Mean K values for Day 2 vs Day 1 postirradiation tumors (10.8 vs 5.9) yielded P less than 0.05, but the 90th percentile and 95th percentile values for Day 2 vs Day 1 yielded 0.05 less than P less than 0.10. Separate experiments measured AIB and 86RbCl uptake in 36B-10 cells in vitro 1 and 2 days following 20 Gy irradiation to assess whether this radiation dose reduced the capacity of tumor cells to trap AIB or Rb+. Irradiation did not reduce the accumulation of either tracer, but rather was associated with an increased accumulation of AIB. Therefore, the AIB transport data suggest that vascular permeability and/or surface area decreases significantly in the day following 20 Gy irradiation and that this decrease reverses by the second day following irradiation.