The quantitative and qualitative characteristics of cells in the peritoneal dialysate from 12 patients were examined. The number of cells in each subsequent fraction of dialysate decreased, while the differential cell count remained relatively constant for each individual patient. Macrophages, lymphocytes, granulocytes and occasionally mesothelial cells were observed. In 1 patient, plasmocytes were also found. Evident differences in cellularity and cell composition were noticed in dialysate obtained from different patients, especially in 2 patients with bacterial peritonitis there was a rise in cellularity with neutrophilia. Cytochemical (peroxidase, nonspecific esterase activity) and functional (phagocytosis, receptor expression) tests revealed that macrophages form a heterogeneous population of cells.

No abstract

It was found that middle-sized molecules obtained from dialysate of uremic patients caused suppression of PHA-induced lymphocyte transformation. This was expressed by the lowering of labeled leucine incorporation and by the suppression of lymphocyte transformation as morphologically assessed. In view of the presented data middle-sized molecules seem to be biologically active substances.

No abstract

It was found that neutrophils in untreated uraemic patients as well as in subjects on regular dialysis treatment displayed higher activity of acid phosphatase, alkaline phosphatase and peroxidase. Spontaneous reduction of nitro blue tetrazolium (NBT) by granulocytes was also higher in both groups in comparison to controls. Stimulation with latex particles gave similar results of NBT reduction in investigated patients and controls. Lymphocytes also showed an increase in acid phosphatase activity if compared to healthy persons. It seems possible that granulocytes which take part in unspecific defense mechanisms are more active in uraemic patients due perhaps to subclinical infections.

To investigate further the biologic activity of solutes in the middle-molecular-weight range, we studied the influence of these compounds on the migration of unseparated white blood cells and separated granulocytes and lymphocytes. Middle molecules (MM) inhibit the migration of unseparated leukocytes, but this effect on lymphocytes was seldom observed. With scanning electron microscopy, unseparated leukocytes were shown to adhere to one another, forming cellular clumps. This phenomenon could not be seen when separated cells were used. These results give some insight into the mechanism of inhibition exerted by MM and into the changes, observed in earlier experiments, of cellular composition of skin exudate obtained from untreated patients with uremia.

No abstract

The number of circulating platelet aggregates determined according to the method of Wu and Hoak and the platelet morphology revealed by scanning electron microscopy were investigated in 10 patients (8 males, 2 females) age 28–58 years) with end-stage renal failure treated by repeated hemodialysis. The examination was carried out twice: during a 4-hour hemodialysis session with the use of heparin alone and 1 week later during the course of another dialysis in the presence of both heparin and prostacyclin. During each dialysis session the platelet system was examined three times: prior to, after 90 min, and at the end of the procedure. As compared with the situation prior to dialysis, the number of platelet aggregates assessed after 90 min of dialysis and after its termination insignificantly rose following the treatment with heparin, but significantly fell after the use of the prostacyclin/heparin combination. The differences were also significant when the effects of both treatment types were compared. As revealed by scanning electron microscopy, during the course of hemodialysis with the use of heparin alone, the platelets showed signs of activation manifested by increases in number and length of cytoplasmic processes and by a tendency to aggregate. When both prostacyclin and heparin were used during dialysis, platelet activation was minimal or absent. Thus, the combined treatment with prostacyclin and heparin protects platelets from activation induced by their contact with artificial surfaces and may lower the risk of microthrombosis, making thereby hemodialysis safer and more effective.