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PubMedDate not supplied

[Ostéomalacia following uretero sigmoidostomies (author's transl)].

Surgical anastomosis of the ureter in the sigmoid could lead to osteomalacia. The pathogenesis of this disease is rather complicated and involves several factors, the most important of which is hyerchloremic acidosis associated with modifications of transport across the intestinal lining, and in particular, the elimination of bicarbonates and the reabsorption of H+ ions. This systemic acidosis makes the calcium balance negative by mobilizing calcium bicarbonate from bone and possibly by inhibiting alkaline phosphatase activity. The role of PTH and vitamin D has yet to be satisfactorily explained. The authors present cases of osteomalacia following two uretero-sigmoidostomies, one for bladder exstrophy and the other after bladder removel for tumour. The physiopathological mechanisms of osteomalacia are briefly recalled together with indications of treatment.

Acidosis↗

PubMedDate not supplied

[Study of circulating 25 hydroxyvitamin D].

The levels of circulating 25 OH-D were determined by a direct radio-competition methods both in normal subjects and in subjects with various pathological conditions. In normal subjects, the average level of 25 OH-D was higher in summer (42.3 ng/ml) than in winter (29.1 ng/ml), P less than 0.005. Monthly variations in the 25 HO-D levels were found in relation to insolation The level of 25 OH-D was practically normal in osteoporosis (28.9 ng/ml), clearly lower in the mixed forms called "osteoporomalacia" (13.5 ng/ml, P less than 0.005) and very low in osteomalacia (5.8 ng/ml, P less than 0.001). In cases of cortisone osteopathy the average level was 22.8 ng/ml (NS). The level of 25 OH-D was also found to be lower in hepatic cirrhosis (11.7 ng/ml, P less than 0.01), in subjects treated with anticonvulsants (P less than 0.01), and in the course of hyperparathyroidism (P less than 0.002). There was no corelation between the level of 25 OH-D and calcaemia, phosphoraemia, circulating immunoreactive parathyroid hormone, or the relative osteoid volume. In contrast, there seemed to be a good correlation with the level of alkaline phosphatasaemia. The level of 25 OH-D was also determined in 4 subjects with vitamin-resistant osteomalacia: in 3 cases hepatic hydroxylation seemed normal, indicating the possibility of a subsequent disorder of vitamin D metabolism; in one case the absence of hepatic hydroxylation was noted.

Alkaline Phosphatase↗