Cyclophosphamide and the bladder.

with advanced chronic renal failure and not on haemodialysis became positive when phosphate as well as calcium was administered.They gave 15 or 20 g of calcium carbonate in the morning and 5.6 or 8X4 g of calcium phosphate in the evening.When calcium phosphate was given alone the plasma concentration of phosphate rose, but when calcium carbonate was given as well it fell.Calcium and phosphate were retained in the proportion of 4 to 1, a ratio similar to that found in normal bone.These changes were of a similar magnitude to those found in normal persons, and they cast doubt on the "vitamin D resistance" hypothesis.That calcium and phosphate supplements may be of clinical value in maintenance haemodialysis is suggested by J. R. Curtis and his colleagues.9They report that they observed improvement in radiological appearances and a reduction in serum alkaline phosphatase in a small number of patients whom they treated.Though metastatic calcifica- tion did not occur in these patients, the safety of this treat- ment needs to be confirmed, and plasma concentrations of calcium and phosphate should be watched carefully when it is given.If their product exceeds 7010 the risk of calcification in arteries, eyes, and joints is high.