A partial obstruction of the left ureter was created in six-week-old rats. The effects on renal function were studied after three, nine and 15 weeks, first in normal hydration, and then after extracellular volume expansion. Moderate hydronephrosis without parenchymal weight reduction developed within three weeks. The hydronephrotic kidney i) excreted during normal hydration less urine and sodium than the intact one, because of increased reabsorption, ii) was capable of reacting fully on volume expansion and iii) had, after volume expansion, a higher renal blood flow and GFR but also a higher reabsorption of water, sodium, potassium and osmoles, resulting in excretions similar to those on the intact side. The differences noted were small (less than 20%) except for sodium excretion. The hydronephrotic kidney seemed to tolerate an increase in ureteral resistance better than the intact one would do. There were no significant differences between the three, nine and 15-week groups, with regard to the effects on the hydronephrotic kidney. Thus, except for a tendency to sodium retention, the effects of partial ureteric obstruction in young rats seem to be relatively harmless and do not increase with time.

To study lung development after repair of congenital diaphragmatic hernia 20 patients operated on between 1960 and 1976 were followed-up at 6-22 years of age. All had had an uneventful postoperative course, had no concomitant disease and were subjectively well with an ordinary physiological performance. The investigation showed a mean increase of residual volume by one third of predicted normal values. Fractional perfusion and ventilation were reduced by 20% on the hernia side compared with the contralateral side. Functional impairment owing to pulmonary hypoplasia was ruled out by the existence of a normal working capacity and maintenance of a normal alveolar gas exchange during exercise on a high work load.

The bioavailability of flucloxacillin (Heracillin@) following oral administration was determined in infants and children. After a dose of 12.5 mg/kg, peak concentrations were achieved at 60 min. which declined rapidly and were low in older children only 4 hours afterwards. Infants below 6 months of age showed a better absorption when given the mixture than older children. Older children achieved higher plasma concentrations when given tablets than when given equal doses of the mixture. There was no difference in the concentration when the dose was given to the subject when fasting, or with breakfast.