So far, echo-Doppler studies of the renal arteries have only been performed in adult subjects. They dealt with qualitative parameters of blood flow, but absolute velocity values could not be determined. This paper presents a method for measurement of absolute values of renal artery blood flow velocity in infancy with a well-defined steep angle of insonation of less than 25 degrees by using a range-gated Doppler system with Duplex-scan. The renal blood flow patterns were studied at specified sites by placement of the transducer below the costal arches on the right flank and left flank, respectively. Thus, a reference collective of 65 infants (26-40 weeks of gestational age, 650-3990 g body weight and 1-145 days of postnatal age at the time of examination) were studied. The time mean of maximum velocity significantly increased with the body weight from 17 cm/s below 1000 g to 29 cm/s above 3000 g of body weight. Whereas the pulsatility indices were independent of body weight. The reproducibility of the method, coefficient of variation (CV) 3%-9%, is comparable with the studies of cerebral vessels.

Blood flow velocities and pulsatory indices in both renal arteries (RAs) and in the internal carotid artery (CAI) were measured by pulsed Doppler ultrasonography in ten preterm infants with patent ductus arteriosus (PDA), before and after surgical ligation. The results obtained in the RAs were compared to those found in a reference group of 22 stable preterm infants. In the RAs the diastolic steal volume of the PDA led to a marked decrease in diastolic blood flow velocity (range 3 to -23 cm/s). Seven infants showed retrograde diastolic flow, whereas only three infants had these flow patterns in the CAI. In the RAs, the peak systolic blood flow velocities (range 56 to 135 cm/s) exceeded the values found in the reference group by 85% on average. The pulsatility indices reached values of above 1,00. In spite of the increase in systolic flow velocities before surgery, the time mean of maximum velocities was significantly lower than those measured after surgery and in the reference group. After PDA ligation, blood flow velocities normalized. The present study shows that a large PDA may induce abnormal flow patterns even in the RAs. These flow patterns may predispose to renal hypoperfusion and subsequent impairment of renal function.

The incidence of aseptic osteonecroses in the therapy of acute leukaemias in children has been studied. Out of 551 children treated at the Children's Hospital in Münster from 1971 to 1985, 6 developed osteonecrosis, an incidence of 1.09%. Of these children, 5 showed unilateral or bilateral necrosis of the femoral head. The osteonecroses occurred 8-109 months after initiation of the primary therapy or of the relapse treatment. The corticoid doses did not differ from those administered to other leukaemia patients without necrosis. Only 1 patient had received prednisone continuously for 1 year, at a total dose of 20.5 g/m2 of body surface area. Of these 6 children, 4 had been immobilized for several weeks before or during therapy. Two children had presented with pain-related relieving posture of the joints in which subsequently the osteonecrosis developed. Inactivity associated with the cortisone therapy seems to be an important factor in the development of aseptic osteonecroses.

In an infant with typical pyridoxine-dependent seizures, CSF GABA level, was determined before treatment with pyridoxine. Before onset of treatment, level of GABA in CSF was highly lowered (16 pmol/ml), pyridoxine level in serum was within normal range. Immediately after application of 80 mg pyridoxine fits stopped and the EEG was without seizure activity. The data substantiate previous findings in brain tissue from a patient with pyridoxine-dependent seizures. They are proof of a disturbed GABA metabolism in pyridoxine dependent seizures.