Bacterial endotoxin testing is performed for quality monitoring of dialysis fluid at many dialysis units. We measured bacterial activity using LAL assay twice a week for 3 years and three months, and investigated causes of variances in measured values. We found that sporadic increase or decrease by 0.5log occurred with a frequency of 1.79%. The actual rate of bacterial contamination at sampling confirmed by intermediate precision was only 0.45% and technical problems with the assay showed a rate of 0.36% by intra-assay precision. These findings suggested that over half of the variances in data were not caused by contamination, facilitating the development of a strategy for bacterial control. To determine whether the variance was caused by contamination, we should (1) re-confirm the data as soon as possible, (2) at the same sampling site showing the un-expected data as well as (3) at another sampling site simultaneously in order to confirm equal fluid quality.

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Members of the hemodialysis staff are continuously trying to improve his or her puncture skills, for example, aiming at maintaining vascular access for extended periods. It is also of great importance that patients are satisfied with the overall process of puncture and there may be contributing factors not only the staff's technical skill level but also his/her interaction with the patient. However, the components of puncture skills may be unclear, and we need to establish a construct of their evaluating factors from both technical and patient perspectives. For this purpose, we conducted a questionnaire-based survey in which 37 and 116 responses were collected from hemodialysis staff members and patients, respectively. Similar but slightly different constructs of seven factors evaluating staff skills were elicited with 60.8% and 65.5% of cumulative variance accounted for by applying factor analysis independently to both the patient and staff samples. Common factors shared by both samples were overall skills and performance stability ; ease of contact from patients ; sincere attitudes ; skill-directed attitudes ; attention to infection avoidance ; and patient-centered attitudes. We also applied factor analysis to the staff sample which included responses to additional statements related to individual skills that may be required by hemodialysis staff. This analysis yielded factors of component skills such as decision performance ; thoughtful observation ; leadership ; and positive attitudes to skill seeking. To identify factors contributing to patients' evaluation of overall staff skills, multiple regression analysis was applied to the patient sample with a score of “overall skill evaluation” as the objective variable and scores for seven factors identified from the patient sample as independent variables. As a result, only the factor,“overall skills and performance stability” yielded a significant effect on the objective variable (t=15.9, p<0.001 ; R²=0.928). From these results, it is suggested that patients are most likely to be satisfied with hemodialysis staff based on the high quality of his/her overall skills and stable performance of puncture.

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In patients with end-stage renal disease, renal anemia develops as a result of erythropoietin deficiency. Recombinant human erythropoietin (rHuEPO) has been widely prescribed to treat renal anemia. Darbepoetin, which is an analogue of rHuEPO with an increased terminal half-life, has been approved in Japan since July 2007. We performed a prospective study to compare Hb-maintenance dose and cost effectiveness between darbepoetin and rHuEPO in hemodialysis patients for 18 weeks. Our cohort comprised 77 patients who were undergoing maintenance hemodialysis 3 times per week in Suzuki-Nephro Clinic. The patients were divided into two groups. Thirty-nine patients were assigned to receive rHuEPO 750IU/HD and 39 patients were assigned darbepoetin 15μg/week as Hb-maintenance dose to maintain a target Hb level of 10.0 to 11.4g/dL, respectively. At 18 weeks, the mean Hb level of darbepoetin group was significantly higher than that of rHuEPO group. The proportion of patients whose Hb level exceeded target Hb level was significantly higher in the darbepoetin group than rHuEPO group. Although final Hb level was higher in darbepoetin group than that of rHuEPO group, the cost was lower in the darbepoetin group than in the rHuEPO group, indicating that darbepoetin was definitely superior to rHuEPO in cost effectiveness. The present results suggests that the dose of darbepoetin 15μg/week is high as a regular dose to maintain the target Hb level in hemodialysis patients and it may be necessary to reduce the dose to less than 15μg/week.

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Darbepoetin alfa is a new erythropoiesis stimulating protein with a three-fold longer terminal half-life than recombinant human erythropoietin (rHuEPO) in hemodialysis patients. This study investigated the safety and efficacy of darbepoetin alfa to treat anemia in hemodialysis patients when administered at a reduced dosing frequency. Dialysis patients (n=157) maintained on rHuEPO treatment (alfa or beta) were switched to darbepoetin alfa under the following doses : 10μg (n=35), 15μg (n=34), 20μg (n=38), 30μg (n=25), 40μg (n=25). Darbepoetin alfa administered intravenously once weekly during 10 weeks. Mean hemoglobin levels were elevated by 0.17±0.16 (SD) g/dL (10μg), 0.26±0.18g/dL (15μg), 0.20±0.20g/dL (20μg), 0.30±0.31g/dL(30μg), 0.44±0.51g/dL (40μg). The difference was significant(p<0.05). There was an increase in serum iron level, but decreases in serum ferritin and TSAT level after 10 weeks. It is suggested that darbepoetin therapy increases the rate of erythropoiesis and therefore the iron support should be considered. There were no major adverse events associated with darbepoetin alfa dosing during 10 weeks. However, two patients withdrew from the study due to adverse events(fatigue and flushing). These findings show that darbepoetin alfa increase hemoglobin concentrations effectively and safely in hemodialysis patients, but with a reduced dosing frequency.

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For the development of a bioartificial glomerulus, in which the inner surface of hollow fibers is lined by endothelial cells, it is essential to increase the permeability of the cells in order to achieve a sufficient ultrafiltrate. We tried to increase it using an actin-microfilament polymerization inhibitor, cytochalasin B (CyB), to enlarge fenestrae diameter of the endothelial cells. CyB was added for 2h at a final concentrations of 20, 30, 40 and 50μg/mL to culture medium of confluent rat glomerular endothelial cells (RGEC) and human umbilical vein endothelial cells (HUVEC). After CyB treatment cell viability was evaluated with Cell Counting Kit-8, and fenestrae diameter of the cells was measured by scanning electron microscopy (SEM), and ultrafiltrate rate through the cell-attached semipermeable membrane was detected under 130mmHg of hydrostatic pressure at days 1, 4, 7. After exposure of platelet-rich plasma, platelet adhesions on CyB-treated and nontreated cells were determined by SEM. Fifty μg/mL of CyB was the best concentration in terms of the cell viability and enhanced ultrafiltrate rate. Scanning electron microscopy demonstrated a larger average diameter of fenestrae on CyB-treated endothelial cells at 50μg/mL of CyB, compared with non-treated cells and CyB-treated cells at 20, 30, and 40μg/mL of CyB. This phenomenon also lasted for at least 7 days. Under 130mmHg hydrostatic pressure, the CyB-treated cells at 50μg/mL of CyB produced significantly more ultrafiltration than the non-treated control group and CyB-treated group at other CyB concentrations, and this increase was maintained for at least 7 days. Horseradish peroxidase (HRP) permeability acutely and reversibly increased in the CyB-treated group compared with that in the non-treated control group. The platelet adherence test showed that CyB did not deteriorate the antithrombogenic property of endothelial cells. These findings indicate that CyB is potentially applicable for the enhancement of endothelial cell permeability in a bioartificial glomerulus.

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This paper investigated nutrient intake and physical characteristics of 38 hemodialysis (HD) and 18 peritoneal dialysis (PD) patients and compared the findings with Guidelines of the Japan Society of Nephrology. The body mass index(BMI) for HD and PD patients were 19.8±3.2 and 20.8±2.7kg/m², respectively. These values were below the reference value(22kg/m²) recommended by the Guidelines for dialysis patients. In comparison with the Guideline (27~39kcal/kg), male HD patients were in the lower limit of the range (27.4±7.4kcal/kg). Female HD, male and female PD patients were well within the range. Protein intake for female HD patients was within the range ; however, those of the other 3 groups were below the Guidelines. Phosphorus intake for female HD patients was above the Guidelines ; however, those of the other 3 groups were within the range. Because the body mass index for HD and PD patients were below the reference value recommended by the Guidelines for dialysis patients, it is suggested that patients whose BMI is markedly lower than the reference value gradually increase their energy intake.

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