Comparison of urinary oxalate excretion in urolithiasis patients with and without hypercalciuria.

The relationships between urinary oxalate, calcium and magnesium were investigated in 81 patients with idiopathic calcium oxalate urolithiasis on their regular diets. A significant relationship was established between calcium and oxalate excretion in the analysis of recurrent stone-formers (n = 44, P less than 0.01), though there was no significant difference between the two in the analysis of the patients overall or in single stone-formers. This suggests that recurrent stone-formers may have some abnormality of oxalate absorption in relation to calcium absorption. The role of calcium-oxalate interaction in the gut as a cause of mild hyperoxaluria is discussed.

The effects of vegetable and animal protein diets on calcium, urate and oxalate excretion.

A group of 30 meat eating normal subjects were compared with a second group of vegetarians matched for age and sex. Their diets and urinary excretion patterns were compared by statistical analysis. A link between protein intake, particularly animal protein, and urinary calcium excretion was demonstrated and also that dietary calcium was inversely related to urinary oxalate excretion. Urinary oxalate increases with the vegetable protein content of the diet, but within the limits of these diets, animal protein does not affect oxalate excretion though it does affect excretion of urinary urate.

Urinary bladder stones in aboriginal children.

Primary bladder stones are described as occurring in aboriginal children from native reserves. Here breast feeding is supplemented early in life with white flour and little else. A comparison is made between this diet and that of children in endemic bladder stone regions, and reasons are advanced for the formation of these stones, with biochemical evidence to support the thesis that ammonium acid urate precipitation is the initiating factor.

Renal transplantation. 12-Year experience.

The results of cadaveric renal transplantation in one centre over 12 years are reviewed. One hundred and sixty-eight grafts have been performed in 147 recipients. At one year after transplantation, patient survival rate was 86%, and graft survival rate was 63%. Analysis of factors influencing graft survival show that the age of recipients, the lack of blood transfusions, and the use of poorly matched grafts (three to four HLA mismatches against 0 to two mismatches), all had adverse effect on survival. Death was a significant cause of graft loss in patients over the age of 45 years. Patients who had not received blood transfusions, and who received grafts which were mismatched for three to four HLA antigens, did especially badly, graft survival rate at six months being only 24% compared with that of 70% in patients who received blood transfusions.

Macromolecular inhibitors of calcium oxalate crystal growth and aggregation.

Inhibitors of crystal growth and aggregation present in urine are largely pyrophosphate and glycosaminoglycans. The latter is a mixture of chondroitin sulphates A & C. The activity of glycosaminoglycans is enhanced by the presence of calcium and magnesium ions. The source of urinary glycosaminoglycans is probably not the urinary tract but the connective ground substances of the body.

The role of common urinary constituents in the precipitation of ammonium acid urate.

A high proportion of the inhibitory activity shown by urine toward precipitation of ammonium acid urate is ultrafilterable and most of this can be accounted for by the common, low molecular weight components of urine. The individual inhibitory effects of sodium chloride, sodium sulphate, potassium chloride, calcium chloride, magnesium sulphate, sodium dihydrogen phosphate, sodium pyrophosphate, citric acid, hippuric acid, creatinine and urea upon the precipitation of ammonium acid urate have been quantified in an aqueous test system.

Factors affecting the solubility of ammonium acid urate.

Evidence is presented that sodium acid urate exists in aqueous solution in a non-colloidal state. The levels of ammonium and urate ions required to precipitate ammonium acid urate have been established for some aqueous media. The effect of pH on the formation product of ammonium acid urate is described. Evidence is presented that there is no epitaxial relationship between this salt and calcium oxalate monohydrate.

Glycosaminoglycans as inhibitors of calcium oxalate crystal growth and aggregation.

Evidence is presented that the glycosaminoglycans, chondroitin 6-sulphate and chondroitin 4-sulphate, are the major inhibitors of calcium oxalate crystal growth and aggregation in dilute normal urine.

Orthopaedic problems of renal transplantation.

One in six patients receiving renal transplants has orthopaedic problems. Osteoporosis with accompanying fractures is common, as is avascular necrosis of the hips, knees, and other bones. Immunosuppressive therapy with steroids is implicated and its mode of action discussed. No means of prophylasix is known. If treated conservatively, aseptic necrosis of bone is much more disabling than is commonly believed as judged by the critical assessment technique of Charnley. The authors therefore recommend that a surgical approach should be adopted whenever possible.

The diagnosis and treatment of lymphocoeles associated with renal transplantation. A report of 6 cases and a review of the literature.

Six patients have developed a lymphocoele after renal transplantation, an incidence of 4%. A lymphocoele should be suspected in a patient who develops a rising creatinine with a pelvic mass or pressure effects on the pelvic veins 1 or more months after operation. The diagnosis is confirmed by intravenous urography, venography and ultrasonography: the use of the latter as a diagnostic measure is recommended. Treatment is by marsupialisation into the peritoneum or external drainage with breakdown of all loculi. Aspiration is unsatisfactory.

The endemic bladder stones of Indonesia---epidemiology and clinical features.

Bladder stone is a relatively common disease of childhood in West Sumatra with an incidence of 8.3/100,000 population per year. We have studied 87 cases with a peak age of onset of 2-4 years and a male/female ratio of 12:1. The majority of these are from poor families with a diet low in protein and phosphate. Diarrhoea is common. The composition of the stones is primarily ammonium acid urate. Patients with sterile urine have shown significantly higher levels of urinary ammonia than controls, and only approximately 50% of patients' urine were infected. This is consistent with excretion of a high acid load, due both to an acidogenic rice diet and diarrhoea, combined with a low level of phosphate. This condition was once endemic in Europe but is now confined to a belt of countries from the Balkans through Asia.

The management of urinary fistulae following cadaveric renal transplantation.

Vesicoureteric, ureteric and calyceal fistulae in cadaver transplants may be successfully treated by early exploration and nephrostomy splintage with silastic tubing for a period of not less than 6 weeks.