In September 1982, I (BSK) wrote to Dr. Conrad Gasser to inform him of my intention to dedicate this contribution to him. He died a month before my letter reached his office. Conrad Gasser not only separated haemolytic uraemic syndrome (HUS) from thrombotic thrombocytopenic purpura (TTP) but also defined its cardinal features (Gasser et al. 1955) and recognised that there could be familial occurrences, recurrences and the possibility of a favourable long-term prognosis. In paying tribute to Dr. Gasser, it is also fitting to mention the important contributions of Dr. Renée Habib and Dr. Carlos Gianantonio and their respective colleagues. Dr. Habib has made the most important contributions to our understanding of the renal histopathology of HUS (Habib et al. 1967, 1982), while Dr. Gianantonio’s descriptions of the clinical features of the “classical” form of HUS are unequalled, and he has led the way in the treatment of HUS by peritoneal dialysis (Gianantonio et al. 1964, 1967, 1973).

A dynamic estimation of the complement system was obtained by immunochemical estimation of C3, C4, C5, C1q, C3b + C3c, C3d, Ba in children with hemolytic-uremic syndrome. The presence of increased breakdown products of C3 (C3b + C3c, C3d) and of factor B (Ba) suggests an activation of the complement system possibly by the alternative pathway. No definite explanation for these complement abnormalities can be given.

The effects of the infusion in four different dosages (0.001, 0.005, 0.02 and 0.2 mg/kg/min during 60 min) of cyclic 3',5'-adenosine monophosphate and of its dibutyryl derivative on plasma growth hormone and on glucose, immunoreactive insulin and cortisol were studied in 38 normal subjects and in 10 patients with idiopathic hypopituitarism. In normal subjects cyclic 3',5'-adenosine monophosphate provokes an increase in plasma growth hormone levels (only when a dosage of 0.2 mg/kg/min is used) without any changes in plasma glucose, insulin and cortisol. The maximal value of the means is observed 75 min after starting the infusion. Dibutyryl cyclic 3',5'-adenosine monophosphate (0.2 and 0.02 mg/kg/min) provokes a dose-related rise in plasma growth hormone levels which is always preceded by hyperglycaemia and hyperinsulinaemia. The peak of the mean growth hormone levels occurs at 135 min after initiation of the infusion. In all but one hypopituitary patients the nucleotides do not promote growth hormone secretion. It is concluded that exogenous cyclic 3',5'-adenosine monophosphate and its dibutyryl derivative may not be considered as analogous and that both compounds may contribute to study growth hormone release in normal subjects and in patients with growth abnormalities.

The administration of c-AMP and DB c-AMP to six children with NDI has failed to yield an antidiuretic effect. From the present study it may be concluded that, at the doses used, neither c-AMP nor its dibutyryl derivative can mimic the action of ADH in NDI as they do in normal subjects. On the contrary, DB c-AMP increased urine volume and Cosm in a very marked way, without changing the creatinine excretion.

Abstract. Vanderschueren‐Lodeweyckx, M., Van den Berghe, G., Proesmans, W., Corbeel, L., Eggermont, E. and Eeckels, R. (Department of Paediatrics, Katholieke Universiteit Leuven, Belgium). Dibutyryl cyclic 3':5'‐adenosine monophosphate in hypopituitarism and Silver‐Russel syndrome. Acta Paediatr Scand 63: 364, 1974.–The effect of the infusion of dibutyryl cyclic 3':5'‐adenosine monophosphate (0.2 mg/kg/min during 1 hour) on plasma growth hormone and on glucose, immunoreactive insulin and cortisol was studied in 3 control children, in 2 Silver‐Russell patients and in 8 patients with idiopathic hypopituitarism. Upon the infusion of the cyclic nucleotide, plasma glucose and immunoreactive insulin increased markedly. An increased level of plasma cortisol was also observed in all cases except in one hypopituitary patient with associated ACTH deficiency. In contrast to what has been reported in normal subjects and observed in the 3 normal children and the 2 Silver‐Russell patients, dibutyryl cyclic 3':5'‐adenosine monophosphate failed to increase the level of plasma growth hormone above 1 ng per ml in 7 out of the 8 hypopituitary patients. Exogenous dibutyryl c‐AMP may be considered as an alternative test for the study of growth hormone release.

Cyclic adenosine 3′,5′-monophosphate(c-AMP) and its dibutyryl derivative (DBc-AMP) were given intravenously, either as a single shot in two different dosages (c-AMP: 6 and 10 mg/kg, DBc-AMP 5 mg/kg) or as an infusion for 45 to 60 minutes (c-AMP: 0.5 mg/kg/min, DBc-AMP: 0.2 mg/kg/min) to six patients with nephrogenic diabetes insipidus (NDI), to one boy with cystinosis and to one girl with Bartter's syndrome. c-AMP as a single shot or as an infusion was unable to reduce, in a constant and reproducible manner, urine volume (V) and free water clearance (CH2O) in NDI patients and in the cystinosis patient. DBc-AMP given to the same patients regularly did increase these parameters. In contrast to this, in the patient with Bartter's syndrome, both c-AMP and DBc-AMP reduced V and CH2O significantly.

The urinary excretion of cyclic 3'-5'-adenosine monophosphate (c-AMP) was studied in 5 patients with idiopathic hypopituitarism during two -day periods before and during administration of 5 mg of human growth hormone (HGH) per day. In 4 out of these 5 patients the urinary excretion of c-AMP was normal and not modified by the administration of HGH. In one patient, however, urinary c-AMP was found to be absent during 2 consecutive days following an insulin tolerance test performed in the control period. The effect of dibutyryl c-AMP (0.2 mg/kg.min during 60 min) on plasma glucose, immunoreactive insulin (IRI), growth hormone (GH) and cortisol was investigated in 8 patients with idiopathic hypopituitarism and in 2 patients with the Silver-Russell syndrome. Plasma glucose and IRI increased markedly in all patients. An increased level of cortisol was also observed except in 1 hypopituitary patient presumably having ACTH deficiency. Although the 2 Silver-Russell patients showed a net increase of plasma GH at 120 min., 7 out of the 8 hypopituitary patients failed to increase the level of plasma GH above 1 ng/ml. In 1 patient, however, the cyclic nucleotide provoked an increase of plasma GH up to 5 ng/ml. The significance of these findings for the investigation of GH-deflciency is discussed.

Two unrelated male infants with pseudohypoaldosteronism are reported. Their main clinical symptom was failure to thrive. Renal and adrenal function were normal. Sodium balance studies showed an abnormal urinary salt loss in the presence of very high aldosterone secretion rates. A daily oral administration of salt supplement resulted in a complete therapeutic success. A brief review of the literature on this rare condition is given and the pathophysiology is discussed.