Osteoarticular amyloidosis associated with haemodialysis: an immunoultrastructural study.

Osteoarticular amyloidosis occurred in a patient receiving long term haemodialysis. Histological examination showed that the amyloid deposit was surrounded by inflammatory cells and macrophages filled with haemosiderin. Electron microscopy showed that the amyloid fibrils were in close contact with cytoplasmic expansions, or located in intracytoplasmic pockets of the infiltrating cells. Immunohistological and immunoultrastructural observations confirmed that beta 2-microglobulin was a major constituent of amyloidosis associated with dialysis. Amyloid P component was also detected within the amyloid deposits. These findings suggest that amyloid P component, iron overload, or macrophage derived factors could have a role in the polymerisation of beta 2-microglobulin into amyloid deposit.

Low somatomedin-C (Sm-C) concentrations measured by direct radioimmunoassay in patients with chronic renal failure.

Ten patients suffering from chronic renal failure and undergoing regular hemodialysis were tested immediately before and immediately after a 3-hour dialysis. Serum levels of immunoreactive Sm-C, estimated on unextracted non acidified serum at non equilibrium, were significantly lower than in normal controls and no consistent modifications were observed after dialysis.

Effect of chronic oral testosterone undecanoate administration on the pituitary-testicular axes of hemodialyzed male patients.

Testosterone undecanoate (TU) or placebo was administered orally (for 12 weeks) in a double blind study, to 19 patients with chronic renal insufficiency on hemodialysis in a daily dose of 240 mg. Effect on plasma testosterone (T), dihydrotestosterone (DHT), androstenedione (A), 110H androstenedione (110A), FSH, LH and PRL concentration and the pituitary responsiveness to LH-RH/TRH stimulation was studied. These hormone levels were determined before the study and after 6 and 12 weeks of treatment. There was a rise in plasma androgen concentration in all treated patients. Mean plasma DHT, A and 110A increased at 12 weeks from 0.3, 0.85 and 1.13 ng/ml to 1.13 (p less than 0.05), 1.4 (p less than 0.05) and 1.44 (p less than 0.05) respectively. There was no change in plasma T or free testosterone. However, basal LH, FSH fell progressively from 5.51 and 5.51 ng/ml to 2.13 and 1.84 ng/ml (p less than 0.05). The level of significance of these changes was confirmed when the response to LH-RH was considered. Basal plasma PRL also decreased from 376 microU/nl to 306 (p less than 0.05), but PRL response to TRH remained unchanged. In contrast, none of these modifications were observed in placebo-treated patients. We conclude that oral TU restored to normal the pituitary-testicular axis. This form of treatment should be preferentially chosen instead of intramuscular injections in these frequently heparinized patients on hemodialysis.

Contribution of kidney basement membranes and collagen to the urinary excretion of hydroxylysyl glycosides.

Glucosyl-galactosyl-hydroxylysine and galactosyl-hydroxylysine are two substances present only in collagen and in basement membranes. The purpose of this study is to estimate to what extent the kidney contributes to urinary hydroxylysyl glycoside excretion. "In vitro" perfusion of isolated kidneys allows the measurement of hydroxylysyl glycosides independently of the important amount of interstitial collagen present in the whole body. It is shown that the kidney parenchyma contributes no more than 10 percent of the glycosylated hydroxylysine excreted in urine. GBM is not the only renal source of glucosyl-galactosyl-hydroxylysine in urine. Tubular basement membrane and intersitial collagen of kidney may contribute to the excretion by the isolated organ.