George E. Digenis

Continuous Ambulatory Peritoneal Dialysis in Diabetics with End-Stage Renal Disease

Twenty diabetics with end-stage renal disease who had never previously received dialysis treatment were treated with continuous ambulatory peritoneal dialysis for periods of two to 36 months (average, 14.5). Intraperitoneal administration of insulin achieved good control of blood sugar. Even though creatinine clearance decreased significantly (P = 0.001), control of blood urea nitrogen and serum creatinine was adequate. Hemoglobin and serum albumin levels increased significantly (P = 0.005 and 0.04, respectively). Similarly, there was a significant increase in serum triglycerides and alkaline phosphatase (P = 0.02 and 0.05). Blood pressure became normal without medications in all but one of the patients. Retinopathy, neuropathy, and osteodystrophy remained unchanged. Peritonitis developed once in every 20.6 patient-months--a rate similar to that observed in nondiabetics. The calculated survival rate was 93 per cent at one year; the calculated rate of continuation on ambulatory peritoneal dialysis was 87 per cent. We conclude that continuous ambulatory dialysis with intraperitoneal administration of insulin is a good alternative treatment for diabetics with end-stage renal disease.

Ultrastructure of Normal Rabbit Mesentery

The ultrastructure of the mesentery was examined by electron microscope (EM) after in vivo fixation in 7 normal rabbits. In 1, the fixation was performed after intravenous injection of an electron-dense tracer (iron dextran) and intraperitoneal infusion of dialysate 4.25% for 1 h. We studied morphometric data of what is considered to be the active peritoneal dialysis membrane, i.e. capillary endothelial cells, interstitium and mesothelial cells. The mesothelial cells are flattened and overlapping with tight junctions between them. They lie on a continuous basement membrane and they contain numerous intracytoplasmic vesicles, separated or in clusters. The mesenteric microvessels were mainly true capillaries of continuous type and postcapillary venules. Capillary lymphatics and larger lymphatic channels (lacunae) seem to be more extensive than the blood capillaries and venules. The endothelial cells contain many vesicles. The interstitium consists of bundles of collagen, fibroblasts and occasional macrophages. The electron-dense tracer was found in the vesicles of the mesothelial cells suggesting that vesicular transport may play an important part in the transportation of at least molecules of a certain size.

On the usefulness of glycylglycine in hemodialysis and peritoneal dialysis solutions

&NA; This article reviews current knowledge on the usefulness of glycylglycine in preparing single stable hemodialysis (HD) and peritoneal dialysis (PD) solutions containing bicarbonate. The coexistence of bicarbonate and glycylglycine in a dialysis solution renders it a potent, stable buffer in which the well known reactions between bicarbonate and calcium and magnesium, and the subsequent formation of insoluble neutral calcium and magnesium carbonate salts, are avoided. Single stable bicarbonate‐glycylglycine (BiGG) solutions for HD and PD have been successfully prepared and studied, both experimentally and clinically. These studies have demonstrated the advantages of BiGG solutions in terms of simplicity, stability, convenience, tolerance, biocompatibility, protection of the peritoneum, and higher ultrafiltration, compared to standard acetate or lactate solutions, and on‐line prepared bicarbonate solutions. Progressive accumulation of glycylglycine or glycine, even after prolonged use, side effects, or signs of toxicity were not observed. In conclusion, BiGG solutions ensure a physiologic dialysis both from the theoretic and practical points of view. ASAIO Journal 1996;42:984‐992.

Recent developments in peritoneal dialysis

Significant developments over the past 10 years have established continuous ambulatory peritoneal dialysis as a successful kidney-replacement treatment. Peritonitis rates have fallen, and investigators are attempting to establish objective criteria for adequacy of dialysis. Malnutrition is a serious concern, but short-term experience with intraperitoneal amino acids promises success in the management of this complication, A significant improvement in the well-being of patients with end-stage renal disease was produced by recombinant human erythropoietin, and use of recombinant human growth hormone promises catch-up growth for children receiving long-term peritoneal dialysis treatment. As increasing numbers of patients are maintained on continuous ambulatory peritoneal dialysis over longer periods, we will begin to encounter β2-microglobulin-related amyloidosis possibly at the same rate in these patients as in those receiving long-term hemodialysis treatment.

Kidney Stones in Chronic Dialysis Patients

While the kidneys of patients undergoing hemodialysis or peritoneal dialysis function poorly, they are not inert and may develop certain complications such as cysts, neoplasms (1, 2) and spontaneous hemorrhage (3). Nephrolithiasis also may be seen in dialysis patients and, in fact, happens frequently. Symptoms occur in a way similar to that seen in the general population with ureteric colic or as the passage of stones or stone-like particles. In 1974, Oreopoulos and Silverberg (4) first reported stones in two dialysis patients; one had been on hemodialysis for 18 months and the other had been on peritoneal dialysis for 9 months. Both were men who had no history of stone disease but developed renal colic and passed multiple urinary calculi, Chemical analysis and infrared spectroscopy showed that these stones were composed of calcium oxalate. Both patients had hypercalcemia (1 1.3 and 10.7 mg/ dL, respectively). Their daily urinary output was 100120 mL with a very low daily calcium excretion. In contrast, urinary oxalate concentration was high. These authors speculated that, in the presence of high oxalate concentration, hypercalcemia might increase the tendency for calcium oxalate precipitation thus forming the initial nucleus, which eventually may lead to stone formation. Later, in 1979, Caralps et al. ( 5 ) reported that 7.5% of their hemodialysis patients (12 out of 160) who had no history of renal calculi, passed at least one stone after the initiation of dialysis. This figure is significantly higher than the 2%-3% prevalence of kidney stones in the general population of Western countries (6). In their series, 6 more patients (3.7%) complained of renal colic without passing stones. All these patients were on hemodialysis for at least 6 months. The examination of some of these calculi by infrared spectroscopy revealed calcium oxalate crystals. These investigators measured the daily excretion of calcium, uric acid, and oxalic acid in the urine of 17 pre-dialysis chronic renal failure patients with creatinine clearances of 10-30 mL/min and no history of urinary lithiasis. Urinary calcium and uric acid values were lower than normal (mean urinary calcium, 86 mg and uric acid 4 13 mg per 24 h) while