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Basal plasma prolactin (PRL) has been measured in 6 patients with chronic renal failure 3 months before and at monthly intervals during a 3 months 1,25-dihydroxyvitamin D3 [1,25 (OH)2-D] treatment. Plasma PRL decreased rapidly during, 1,25 (OH)2-D treatment, while it remained unchanged during the 3-months control period. There was no correlation between PRL and parathyroid hormone (PTH; measured either with carboxy- or amino-terminal assays) and several other parameters. A direct effect of 1,25 (OH)2-D on PRL secretion may exist.

Microcytic, hypochromic anaemia is a feature of aluminium toxicity. To detect the possible influence of aluminium on erythropoiesis in a general haemodialysis population we studied the evolution of red blood cell parameters and aluminium status in 30 patients (27 without aluminium toxicity symptoms). Aluminium status was assessed by serum aluminium measurements before (BAl) and after (PAl) a desferrioxamine infusion. The evolution with time (delta) of PAl and DAl (= PAl - BAl) during the prospective study inversely correlated with delta mean corpuscular volume (2 alpha less than 0.01) and delta mean corpuscular haemoglobin (2 alpha less than 0.001). Patients with DAl greater than 180 micrograms/L had lower mean corpuscular haemoglobin values (p less than 0.05). These findings suggest that aluminium inhibits haemoglobin synthesis even in haemodialysis patients free of aluminium toxicity symptoms.

Vancomycin is widely used for the treatment of infections with Gram-positive bacteria in patients with end-stage renal disease. The concentration of vancomycin in serum, in ultrafiltrate, and in dialysate was measured during nine haemofiltration and seven haemodialysis procedures with high-permeability membranes. The t1/2 of vancomycin was 101 +/- 19 h in the interdialytic and interhaemofiltration period. There was no significant difference between the haemodialysis clearance (55.2 +/- 18.5 ml/min) and the haemofiltration clearance (66.8 +/- 13.6 ml/min). The redistribution phenomenon was about 25% in the post haemofiltration period and only 10% in the post haemodialysis period. Approximately 270 mg of vancomycin was recovered in dialysate or ultrafiltrate. With high-permeability membranes more commonly used in patients with end-stage renal disease, continuous monitoring of vancomycin therapy is recommended.

In developing this method for determination of Al in bone we paid special attention to the homogenization of bone samples, which presents great difficulties for trace-element analysis. To minimize the risk of contamination, we preferred low-temperature ashing over classical wet-digestion techniques for destruction of the organic material. Graphite-furnace atomic absorption spectroscopy is used for measurement of Al. For Al concentrations exceeding 15 micrograms/g, direct standardization against a calibration line can be used (between-run CV, 5.9%). For Al concentrations within the normal range (less than 15 micrograms/g) the standard-addition technique should be applied. Comparison of results by the method with those by a procedure based on extraction of Al with a saturated solution of EDTA revealed that, although the latter method gave considerably lower results for three of 13 samples, there was no statistical difference between results by the two methods.

As microcytic anemia is a feature of aluminium intoxication, we prospectively studied the hematologic effects of deferoxamine in 10 hemodialysis patients with aluminum-induced bone disease. Comparing the mean monthly results of a 4 month period before and during deferoxamine therapy, we observed an important decrease of the transfusion needs (alpha less than 0.025) and an increase of hematocrit (p less than 0.02), hemoglobin (p less than 0.02), MCV (p less than 0.02) and MCH (p less than 0.05); the number of red blood cells remained unchanged. Our results show that deferoxamine treatment of dialysis patients with aluminum bone disease can markedly improve their anemia, even in the absence of recent aggravation, microcytosis and hypochromia. They also suggest that aluminum could participate in the anemia of dialysis patients even if it is normocytic.

In order to classify the underlying disorder in four patients with biopsy-proven amyloidosis without overt monoclonal gammopathy, the cytoplasmic immunoglobulin (Ig) distribution of bone marrow plasma cells was evaluated using direct immunofluorescence microscopy. This procedure revealed the presence of a monoclonal proliferation of light chain containing plasma cells, and thus led to the diagnosis of immunoglobulin-related amyloidosis.

An 87-year-old woman presented with the nephrotic syndrome 12 months after administration of ketoprofen, 100 mg daily for osteoarthritis. Clinical course and laboratory data were consistent with drug-induced nephropathy. Kidney biopsy showed membranous glomerulonephritis. Evolution was favorable with resolution of proteinuria after drug withdrawal and steroid administration. A review of the literature on nephrotic syndrome associated with NSAID reveals membranous glomerulonephritis to be an unusual complication.

Acceptability and plasma concentrations of rilmenidine, a new antihypertensive agent mainly eliminated via the kidney, were evaluated in 17 hypertensive patients (supine diastolic blood pressure, 104 +/- 3 mmHg) with renal insufficiency (creatinine clearance, 35 +/- 4 ml.minute-1/1.73 m2; range, 12 to 58). Patients were treated for six months with rilmenidine at the dose of 1 mg in the morning or 1 mg twice daily as single-drug therapy in untreated patients, or in combination or as substitution in patients already treated. Plasma concentrations of rilmenidine were measured by gas chromatography combined with mass spectrometry at Days 0, 1, 5, 7, 9, and 11, and Months 1.5, 3, 4.5, and 6 before administration. Supine and erect blood pressure (sphygmomanometer) measurements and side effects were noted at the same times. Laboratory and electrocardiographic parameters were evaluated at Days 0 and 11, and Months 1.5 and 6. Blood pressure was effectively controlled during the trial in 12 patients (mean decrease in systolic/diastolic blood pressure of 12/8 mmHg). Five patients were removed from the trial after Month 1.5 because of a rise in blood pressure (three cases) or noncompliance (two cases). Side effects were moderate and transient (dry mouth, constipation, daytime drowsiness, mood disturbances, insomnia) never requiring treatment withdrawal. Surveillance of renal function revealed no significant mean variation. Rilmenidine plasma concentrations reached steady state the fifth day at the latest and were related to the degree of renal insufficiency. When renal function was stable (13 cases), plasma concentrations did not vary until the end of the trial. When renal function was progressive (four cases), plasma concentrations increased in parallel in two patients, without the onset of side effects, and remained stable in the other two patients. In conclusion, this study confirmed the good acceptability of rilmenidine in hypertensive patients with chronic renal insufficiency. It showed stable plasma concentrations of rilmenidine during a six-month treatment in hypertensive patients with renal insufficiency, reflecting the absence of accumulation of the drug.

The influence of hyperparathyroidism and aluminium toxicity on bone scan scores (FS = Fogelman's score) was studied in 37 haemodialysis patients (group 1), of whom 24 had aluminium toxicity (group 2). FS, parathormone (iPTH) and aluminium status were assessed simultaneously, the latter by measuring serum aluminium before (BAl) and 48 hours after (PAl) a desferrioxamine infusion. FS correlated directly with iPTH in all groups, inversely with PAl and DAl (= PAl - BAl) in group 1; FS less than or equal to 2 was found in group 2 only (2 alpha less than 0.05). The time course of FS and aluminium concentration was also studied in 24 patients: a PAl increase was significantly associated with a FS decrease (2 alpha less than 0.001). In conclusion, hyperparathyroidism increases and aluminium toxicity decreases FS; FS less than or equal to 2 is very suggestive of aluminium toxicity.