High level of recovery of fungi from water and dialysate in haemodialysis units.

The counts of yeasts and filamentous fungi were investigated in the municipal water supplies of haemodialysis centres, in the treated water and the dialysate from all 85 haemodialysis units in Greece, in order to estimate their occurrence, their correlation with contamination indicator bacteria and other influencing factors. Filamentous fungi and yeasts were isolated from 69 (81.2%) and from three (3.5%) feed water samples, from 74 (87.1%) and seven (8.2%) treated water samples and from 66 (77.7%) and 11 (12.9%) dialysate samples respectively. Aspergillus spp and Penicillium spp were the most frequent moulds, while Candida spp were the prevailing yeasts. The occurrence of yeasts was significantly higher in dialysate than in tap water samples. Counts of filamentous fungi in all 255 samples were significantly correlated with the counts of total heterotrophic bacteria and enterococci, whereas the counts of yeasts were correlated with faecal coliforms, total heterotrophic bacteria, as well as enterococci, Pseudomonas spp and total coliforms, while no correlation was detected with the age of either haemodialysis units, the age of water treatment system, the number of artificial kidney machines or the components of the water purification system. High recovery of fungi from haemodialysis aqueous environments implies a potential risk for haemodialysis patients and indicates the need for continuous maintenance and monitoring.

Effect of short-term rHuEPO treatment on insulin resistance in haemodialysis patients.

BACKGROUND/AIM: Decreased sensitivity to the hypoglycaemic action of insulin is an almost universal phenomenon in uraemic patients, and it is attributed either to uraemic toxins or to anaemia or even to secondary hyperparathyroidism. Considering the conflicting data of few existing studies, we examined the influence of erythropoietin (EPO) treatment on insulin resistance and tested the probable correlation of this influence with sympathetic nervous system (SNS) activity. METHODS: We studied 8 non-obese, non-diabetic, stable dialysis patients using the euglycaemic insulin clamp technique before administration of EPO (phase A), 10 days after (phase B), and after the correction of the haematocrit level, at least 8 weeks later (phase C). We estimated the indices (glucose infusion rate, mg/kg/min), M/G (glucose clearance), and M/I (tissue sensitivity to insulin), and we measured haematocrit, haemoglobin, triglyceride, ferritin, EPO, and fasting insulin levels in each phase. During each phase, we tested the SNS activity using the response of blood pressure to persistent handgrip and the response of blood pressure to the standing position. RESULTS: Our patients appeared to have an increased insulin resistance in phase A (M(A) = 6.24 +/- 1.01) which was significantly improved 10 days after the beginning of EPO treatment and before the rise of haematocrit (M(B) = 7.71 +/- 1.54, p < 0.05). There was no further improvement in phase C. Indices M/G and M/I behaved similarly. The serum triglyceride levels decreased in response to the increased insulin sensitivity. The patients studied did not demonstrate fasting hyperinsulinaemia, while the SNS activity was abnormal and remained unchanged throughout the study period in spite of some individual improvement. CONCLUSIONS: Our study proves the beneficial effect of EPO treatment on insulin resistance in dialysis patients which could be attributed to the EPO itself and not to the correction of anaemia and is accompanied by improvement in triglyceride levels. Amelioration of insulin resistance did not influence the SNS activity, making the association between EPO treatment and SNS-derived changes in blood pressure quite improbable.

Effect of pyrazinamide and probenecid on peritoneal urate transport kinetics during continuous ambulatory peritoneal dialysis.

OBJECTIVE: We administered pyrazinamide (PZA) and probenecid (PB) --two well-known modulators of urate transport via the proximal tubules - to evaluate their impact on urate transport through the peritoneal membrane and to clarify mechanisms affecting peritoneal transport. SETTING: A continuous ambulatory peritoneal dialysis (CAPD) unit in 2nd Hospital of IKA (Social Services Institute), Greece. PATIENTS: In 20 stable CAPD patients, on the study day, a 4-hour, 2-L, 1.36% glucose exchange was performed (control exchange). Pyrazinamide 3 g was given orally and another identical exchange was performed (study exchange). The same protocol was repeated with 2 g PB. KtN, peritoneal clearances of urea, creatinine, and urate for each exchange, and mass transfer area coefficients (MTAC) for the three solutes and their dialysate-to-plasma concentration (D/P) ratios were used to estimate peritoneal transport. RESULTS: Administration of PZA resulted in decreased clearances and MTAC values for the three solutes. The D/P ratio decreased significantly only for urate, indicating a more intense influence of PZA on urate. After PB administration, clearances of urea, creatinine, and urate were increased. MTAC and DIP ratio increased significantly only for urate (p < 0.05), demonstrating an action similar to that exerted on renal tubules. CONCLUSIONS: These findings provide evidence that unrestricted diffusion is not the only transport mechanism in the case of urate, and demonstrate the existence of an active mechanism in peritoneal urate transport with a reabsorptive and, probably, a secretive component that resembles that of renal tubule urate transport. Attention should be given in the case of CAPD patients undergoing antituberculous (PZA) treatment: it might have a negative impact on urea, creatinine, and urate peritoneal transport rates.

Endotoxin concentration in treated water of all hemodialysis units in Greece and inquisition of influencing factors.

Mains and purified water samples from all hemodialysis centers in Greece were surveyed to assess hemodialysis water quality and the potential consequences on the dialysis population of any microbial and endotoxin contamination. Total heterotrophic bacteria counts were estimated employing the pour-plate method, the membrane filter technique, for total coliforms, fecal coliforms, enterococci and Pseudomonas spp., and the most probable number method for sulfite-reducing clostridia. Overall 170 paired samples were tested. Endotoxin concentrations were assayed in treated water samples, by the Limulus Amebocyte Lysate method, employing a chromogenic substrate. Endotoxin concentration varied from 0-30 EU/ml and exceeded 5 EU/ml in 30.6% of the centers. Endotoxin contaminated samples showed higher counts of total heterotrophic bacteria, fecal coliforms, enterococci and Pseudomonas spp. than the rest of the samples, though the difference was significant only for total heterotrophic bacteria and enterococci. Additionally, samples with endotoxin contamination derived from the mains water had significantly higher counts of fecal coliforms, enterococci and Pseudomonas spp. Endotoxin concentration was correlated with the presence of a deionization system, counts of fecal coliforms in supply water and counts of total coliforms, fecal coliforms and enterococci in treated water. These results demonstrate that hemodialysis centers in Greece need to monitor and preventively maintain the entire hemodialysis system, in order to ensure renal replacement therapy of good quality.

Microbiological quality of water and dialysate in all haemodialysis centres of Greece.

BACKGROUND: Bacterial contamination of treated water and dialysate comprises an important problem for patients undergoing haemodialysis. Both the progressive reduction of the thickness of cellulose membranes and the expanding use of high-flux membranes probably enhance the risk of pyrogenic reactions, therefore increasing the need for atoxic water and non-pyrogenic dialysis fluid. METHODS: Samples of tap water, treated water, and effluent dialysate in all 85 haemodialysis centres in Greece were examined for total heterotrophic bacteria counts employing the pour plate method, total and faecal coliforms, faecal streptococci and pseudomonas spp. using the membrane filter technique, and sulphite-reducing clostridia applying the most probable number method. Overall 255 paired samples were tested from January to March 1997. RESULTS: For total heterotrophic bacteria, the overall compliance of treated water and dialysate to the American Association of Medical Instrumentation standards (<200 c.f.u./ml for water and <2000 c.f.u./ml for dialysate) was 92.6 and 63.7% respectively, whereas the compliance of tap water samples to our national standards (total heterotrophic bacteria < 10 c.f.u./ml and absence of the other indicator bacteria) was 80.7%. The most commonly isolated bacteria were pseudomonas spp., found in 22.2% of treated water and 59.5% of dialysate samples, whereas the respective frequencies were 12.3 and 36.2% for total coliforms, 8.6 and 30.0% for faecal coliforms, 14.8 and 28.7% for faecal streptococci, and sulphite-reducing clostridia were isolated in 5.8% of dialysate samples only. Haemodialysis centres equipped with storage tanks for treated water experienced lower levels of total heterotrophic bacteria, but higher counts of total and faecal coliforms, faecal streptococci, and pseudomonas spp., although the difference was statistically significant only for faecal streptococci counts, (P<0.05). Sixty-seven haemodialysis centres were equipped with bacterial filters, but mean values of all the examined microorganisms were not statistically different from those of the other centres. Faecal streptococci counts in treated water samples were positively correlated with ageing of both haemodialysis centres (P<0.005) and purification system (P<0.05), whereas pseudomonas counts were significantly correlated with ageing of the purification system (P<0.05).

Variability of peritoneal protein loss in diabetic and nondiabetic patients on continuous ambulatory peritoneal dialysis.

In order to evaluate the influence of diabetes mellitus on peritoneal membrane permeability, we studied the peritoneal protein loss in two groups of patients. Group A consisted of 16 patients (9 nondiabetics and 7 diabetics) who were in the first month of treatment on continuous ambulatory peritoneal dialysis (CAPD). Group B consisted of 13 patients (7 nondiabetics and 6 diabetics) who had been on CAPD for approximately 15 months. In both groups we measured the body weight, serum total protein, albumin, and total protein, urea, and glucose in the peritoneal fluid. We did not find any difference in groups A and B between diabetics and nondiabetics as far as the estimated parameters were concerned. Age, body weight, serum biochemistry, and protein and urea content in peritoneal fluid were similar, when group A was compared to group B. Patients of group B had on average higher protein losses than those who had been on the method for a short period (mean 7.9 g/dL, vs 6.09 g/dL). Six patients were followed for over 15 months and were found to have significantly increased protein losses (p = 0.02). Glucose levels in peritoneal fluid were significantly lower in patients in group B, p < 0.05 (mean 51.8 g/dL vs 37.1 g/dL). Peritoneal protein loss does not seem to differ between diabetic and nondiabetic patients with end-stage renal disease treated with CAPD, at any given time of the treatment. We observed an increase in protein loss in some patients and a tendency to increase the protein loss in others.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of uremic serum on sperm motility: evaluation by multiple exposure photography.

The effect of serum from patients with severe chronic renal failure on the motility of ejaculated spermatozoa was objectively evaluated by the multiple exposure photography method. Uremic serum was not found to have a deleterious effect on the motility of ejaculated spermatozoa. On the contrary it caused a significant increase of spermatozoal velocity and a slighter increase in the percentage motility. These effects cannot be only attributed to the lowering of seminal viscosity and to the reduction of sperm concentration, but to various substances contained in blood serum.