The number of mast cells in the skin was evaluated in 25 patients with end-stage renal failure on different treatment modality (conservative, hemodialysis and peritoneal dialysis). According to the presence of pruritus, uremic patients were divided into two groups: group A, 13 patients with diffuse pruritus, and group B, 12 patients without pruritus. Controls were 6 age- and sex-matched healthy subjects. In comparison with patients without pruritus, patients with pruritus had mainly degranulated, diffusely spread and more numerous mast cells in the skin; significantly higher levels of plasma middle molecular weight substances, serum histamine and PTH and significantly lower serum iron levels. However, no differences were noted in observed parameters between groups on different treatment modalities. Favorable therapeutic effects in patients with pruritus were achieved either with iron supplementation in those with hypoferremia or with antihistamines, mast cell membrane stabilizers and high-permeability membranes.

Previous studies demonstrated a high incidence of local thrombosis in patients in whom external arteriovenous shunts were used for vascular access. This procedure provides, therefore, a useful model for the evaluation of potential antithrombotic agents. The effect of the hemorheologically and hemostasiologically active drug Pentoxifylline on the incidence of thrombosis of arteriovenous shunts (Ramires shunt) was investigated in a long-term, double-blind, placebo-controlled study in 51 patients on chronic hemodialysis. The two treatment groups were comparable in age, sex, concomitant medication, and dialysis program (three times per week for four hours). Drugs known to affect platelet function or coagulation were excluded, with the exception of heparin, during the dialysis procedure. All shunts were placed in the forearm and inserted into the distal part of the radial artery and basilic antebrachial vein. Simultaneously, for medical reasons, in all patients an arteriovenous fistula was performed (proximal part of radial artery and cephalic antebrachial vein). Shunt thrombosis was assumed when the flow in the shunt discontinued under visual and auscultatory control. Thrombi were documented by physical removal from the arterial part of the shunt by use of gentle suction or by complete shunt thrombosis (both arterial and venous part of the shunt). Thereafter, the patients' trial period terminated. The total number of thrombi during the observation period was 44 in the pentoxifylline group (26 patients), compared with 82 in the placebo group (25 patients). The mean number of thrombi per patient was 1.69 +/- 1.29 in the pentoxifylline group, significantly lower than that in the placebo group (3.28 +/- 1.99/p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Cytogenetic analyses were performed on dividing cells from the peritoneal effluent of 26 patients undergoing chronic peritoneal dialysis (CPD). Numerical and structural abnormalities of karyotype served as the diagnostic criteria for “atypical cells.” The following cytogenetic abnormalities were observed in 7 patients: hyperdiploidy (in 6 patients), hypodiploidy (in 2 patients), and marker chromosomes (in 2 patients). In 3 patients more than one chromosome abnormality was present. Dividing cells with normal mitoses were observed in 11 patients, while in the remaining 8 patients no dividing cells could be found. There were no differences in age, sex, duration of dialysis, and peritonitis incidence between patients with pathological mitoses and those without it. The question whether this unexpected finding is a consequence of immunosuppressed uremic status, dialysis procedure, or some other factor remains to be elucidated.

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