Low-dosage ibopamine treatment in progressive renal failure: a long-term multicentre trial.

A multicentre trial (11 nephrology centres) was carried out to test the effects of ibopamine, an orally active dopamine-like drug, on the progression of chronic renal failure. For a 2-year period 189 chronic renal failure patients (serum creatinine level 1.5-4.0 mg/dl) were observed. They were homogeneous for basic nephropathy, degree of residual renal function, blood pressure, and proteinuria. The patients were randomly divided into two groups: 96 took ibopamine at a dosage of 100 mg/day (group A) and 93 served as controls (group B). All were on a low-protein diet (mean 0.8 g/kg body weight). By the end of the observation period, the rate of decrease of the renal function indexes in time proved significantly slower (1.8 times) in group A than in group B. The survival curves for renal function (pre-established end points were creatinine level increases equal to or > 20% and equal to or > 40% of the basal values) proved significantly better (p < 0.02 and p < 0.002 respectively) in group A than in group B. The mean plasma creatinine values rose by 17% in group A and by 36% in group B. The creatinine clearance decreased by 5% in treated patients and by 14% in the controls. Statistical analysis ruled out any possible centre effect. The trial suggests that low-dosage ibopamine administration may be used as a valid and safe pharmacological adjunct for retarding the progression of renal failure in patients with mild or moderate chronic renal impairment.

Insulin therapy in uremic diabetic patients on continuous ambulatory peritoneal dialysis; comparison of intraperitoneal and subcutaneous administration.

OBJECTIVE: To compare, in diabetic uremic patients on continuous ambulatory peritoneal dialysis (CAPD), the effects of two patterns of insulin administration, four times daily subcutaneous (SC) injections and intraperitoneal (IP) route, on blood glucose, insulin, lactate, beta-hydroxybutyrate and glycerol levels. PATIENTS AND METHODS: We examined 6 uremic insulin-dependent diabetic patients on CAPD. The two insulin regimens, SC and IP, were tested successively in randomized sequence in each patient. At the end of each treatment period we determined the 24-hour profiles of blood glucose, free insulin, lactate, beta-hydroxybutyrate, and glycerol. RESULTS: Mean blood glucose over 24 hours (SC 7.21 +/- 0.61 mmol/L, IP 7.49 +/- 0.93 mmol/L), Schlichtkrull's M value, an index of glycemic control and stability (SC 10 +/- 3, IP 10 +/- 5), and the blood intermediate metabolites beta-hydroxybutyrate, lactate, and glycerol were similar in both groups. Mean serum free insulin was significantly higher during subcutaneous treatment (SC 257.4 +/- 127.2 pmol/L, IP 170.4 +/- 83.4 pmol/L, p < 0.001). Insulin requirements were 2.5 times greater for the intraperitoneal route (SC 51 +/- 4 U/24 hours, IP 130 +/- 43 U/24 hours). CONCLUSIONS: In uremic diabetic patients on CAPD, good glycemic control may be achieved either with subcutaneous intensive insulin therapy or with intraperitoneal insulin administration. The latter method allows reduction of circulating free insulin levels, but requires a higher dose of insulin per day.

Aging of silastic peritoneal catheters.

Increasing the survival of patients on CAPD is related to the long-term reliability of the peritoneal access. Six silicone Tenckhoff catheters (with strip or diffuse barium sulphate inclusion) removed after 39-69 months because of the appearance of external segment fissures, were analysed by scanning electron microscopy (SEM) and infra-red spectroscopy with attenuated total refractance (ATR). The extracorporeal portion of the catheters showed (by ATR) a more prominent oxidation peak on the external than the internal surface; SEM showed marks and cracks on the external surface and exfoliation and flattening of the silastic reticle on the intraluminal surface. No evidence of oxidation was found in the intra-abdominal portion of the catheters but biofilm was found. We suggest that barium sulphate may render the silastic brittle and physiological and environmental long-term factors (such as uv-rays, temperature, sweat and disinfectants) could cause oxidation and loss of physico-chemical properties, with critical aging of the silastic and loss of catheter resistance to mechanical injury.

A multicenter, selection-adjusted comparison of patient and technique survivals on CAPD and hemodialysis.

Four hundred and eighty CAPD and 373 HD patients started regular dialysis treatment between 1981 and 1987 in 6 dialysis centers. The CAPD patients were 6 years older, on average, than the HD patients and had more complicating conditions (43.3% with 3 or more coexisting risk factors versus 28.9% with coexisting complications). The 7-year patient survival rate was not significantly different. Cox's proportional hazards regression showed that age, cardiovascular disease, cerebrovascular disease, peripheral vascular disease, diabetes, malignancy and multisystem disease had significant adverse effects on patient survival. After correcting for the influence of these factors, no significant differences in patient survival were seen. However, after 53.5 years of age, the increase in the risk of death was significantly higher in HD than in CAPD patients. Technique survival was significantly different in the 6 centers and was better for HD than for CAPD. There was no statistically significant difference between CAPD and HD technique survival when peritonitis was eliminated as a cause of failure. Based on this 7 year analysis, CAPD would appear to be an excellent alternative to HD.

Dextran deposits in tissues of patients undergoing haemodialysis.

Recently the possible storage of dextran-related material in patients undergoing regular haemodialysis has been suggested. We examined biopsy and autopsy specimens of 32 patients treated with regular haemodialysis for 61 +/- 34 months. All patients received dextran-40 as a plasma expander because of hypotension during haemodialysis. The same study was carried out in a control group of 11 haemodialysed patients who were given other plasma expanders. In the 11 patients who received larger doses of dextran-40 (0.38 g/kg body weight per week) we found particles in the cytoplasm of macrophages in various organs, which proved PAS positive and diastase resistant on light microscopy, and birefringent on polarisation. Electron microscopy revealed a fibrillar structure, but ionic analysis by electronic sampler on scanning electron microscopy excluded the presence of silicon. No intracellular inclusions were observed in the control group, nor in the patients given dextran-40 in doses lower than 0.08 g/kg body weight per week. As we also found a linear relationship between the number of particles and the dextran-40 doses given, we hypothesise that the material demonstrated in the macrophages is a structurally modified dextran.

Renal lesions in familial lecithin-cholesterol acyltransferase deficiency. Ultrastructural heterogeneity of glomerular changes.

Renal lesions of a new case of lecithin-cholesterol acyltransferase deficiency in an 18-year-old male are described. Large mesangial deposits and a sieve-like transformation of the peripheral basement membrane were the main glomerular lesions. Immunofluorescence identified C3 deposits in the mesangium. A heterogeneous pattern of ultrastructural findings was observed by electron microscopy. Thread-like structures with faint cross-striation and irregular tubular structures embedded in an amorphous material were found in mesangial and subepithelial sites. Mesangial areas and peripheral basement membranes showed irregular holes sometimes containing highly osmiophilic lamellar bodies. It is suggested that many mechanisms may be involved in the production of renal lesions induced by the lipoprotein abnormalities characteristic of the disease.