The aetiology of destructive non-infectious spondylo-arthropathy has not been completely elucidated. Deposition of various crystals and of amyloid (beta-2-microglobulin) is a possible cause of this condition which has not been considered previously. The appearances of destructive non-infectious spondylo-arthropathy are illustrated by seven patients with renal insufficiency and on chronic haemodialysis; these were examined by conventional radiographs and by CT. It is possible to distinguish between the complete condition (five patients) and an early form (two patients). The differential diagnosis of the changes in the vertebral end-plates are discussed with reference to three further patients with chronic renal disease and on dialysis.

We have reported previously changes of plasma dehydroepiandrosterone (DHA) and plasma dehydroepiandrosterone sulphate (DHAS) before and during pregnancy (Nieschlag, Walk & Schindler, 1974). There are strong indications that labour represents a stressful stimulus to the endocrine system. This is reflected in a rise of maternal plasma corticotrophin (ACTH)DHAS concentrations in maternal blood during the course of labour are rare and do show a variety of results (Lefebvre et al. 1970;Gandy, 1971). Therefore, we have measured DHA by radioimmunoassay (Nieschlag et al. 1974) in 37 women and DHAS by a gas chromatographic method (Schindler, Gnad & Walk, 1975) in 30 women at the beginning of labour and at the time of delivery.The mean concentration of DHA increased from 979 ± 356 to 1429 ± 340 (S.D.) ng/100 ml. The mean level of DHAS rose from 40-9 ± 12-4 to 75-4 ± 52-5 Mg/100 ml. For DHA and DHAS the differences were highly significant (P<0001). An increase of DHA was found in all pregnancies studied and for DHAS 23 cases out of 30 revealed a rise in plasma DHAS concentration.This study clearly demonstrates an increase of DHA and DHAS in maternal plasma during labour. This is most likely due to increased secretion of these steroids by the maternal adrenal as a consequence of increased ACTH secretion. Influences of an altered utero-placental blood flow and changes in placental enzyme activity could be additional factors affecting the metabolism of these steroid precursors by the placenta. Furthermore, a transfer of DHA and DHAS from the foetal circulation has to be considered since the concentrations of these steroids are higher in cord blood (Simmer, Dignam, Easterling, Frankland & Naftolin, 1966).