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Background:Several reports indicate that extracellular volume predicted by bioimpedance analysis method is associated with hydration status of hemodialysis patients.Theory:Fundamentally, uric acid does not cross cell membranes by simple diffusion, either by facilitated diffusion or by active transport. In addition, uric acid cannot move through cell membranes in most tissues other than those involved in uric acid excretion. These facts support the interpretation that uric acid distribution volume would therefore correlate with extracellular volume.Methods:We examined correlation between uric acid distribution volume calculated by uric acid mass-balance modeling from regular blood test results and extracellular volume predicted by bioimpedance analysis predicted by BCM (Fresenius Medical Care) in 53 patients.Results:There was a significant correlation between uric acid distribution volume ( x) and extracellular volume predicted by bioimpedance analysis ( y): y = 0.69 x + 3.39, r2 = 0.61, p Conclusion:Uric acid distribution volume calculated by uric acid mass-balance modeling from regular blood test results may be an alternative marker of extracellular volume predicted by bioimpedance analysis.

The creatinine (Cr) generation rate reflects the muscle mass, a possible indicator of protein nutritional status. Thus, in this study, we developed equations for calculating the Cr generation rate. Depner and Daugirdas recently developed a method for determining the protein catabolic rate (PCR) from the pre- and postdialysis blood urea nitrogen concentrations. We modified their method to develop equations for calculating the total Cr generation rate from the measured predialysis Cr concentration and estimated postrebound concentration. The total Cr generation rate is defined as the sum of the intrinsic Cr generation rate and the extrinsic Cr generation rate (i.e., the generation rate of Cr derived from food). In the present study, the postrebound Cr concentration was estimated on the basis of postdialysis Cr concentration and the K/V for Cr. The intrinsic Cr generation rate was obtained by subtracting the extrinsic Cr generation rate, which was estimated on the basis of the PCR, from the total Cr generation rate calculated. The intrinsic Cr generation rate determined with this method was virtually the same as that obtained using the postrebound Cr concentration, the concentration immediately before the next hemodialysis (HD) session, and the PCR. The intrinsic Cr generation rate determined with the present method did not vary with changes in the HD prescription (i.e., with an increase in blood flow rate, a prolongation of the HD duration time, or a change in dialyzer membrane area). The present study also indicated that the intrinsic Cr generation rate decreased with age in both males and females.

Reports to date have indicated no strong relationship between hemodialysis (HD) prescription and health-related quality of life (HRQOL). However, none of these reports addressed the effect of protein-energy nutritional status on the relationship between HD prescription and HRQOL. Thus, taking the creatinine (Cr) generation rate as a marker of protein-energy nutritional status, we divided maintenance HD patients into two groups with high and low Cr generation rates compared with the average rate. We then investigated the relationship between HD prescription and HRQOL in the two groups. The subjects were 1887 patients receiving HD three times weekly. Together with conducting an HRQOL survey using SF-36 on these patients, we surveyed Kt/V, K/V, and Cr generation rate. In the present study, K/V (the marker of HD efficiency) was obtained by dividing Kt/V by the duration of the HD session. Lower HRQOL scores tended to be associated with higher Kt/V only in patients with a low Cr generation rate; in patients with a high Cr generation rate, almost no association was found between Kt/V and HRQOL scores. In patients with a low Cr generation rate, lower HRQOL scores were associated with higher K/V, whereas in those with a high Cr generation rate, there was almost no association between K/V and HRQOL scores. In terms of duration of the HD session, almost no relationship was found between HD prescription and HRQOL scores in other patient group. These results suggest that a high HD efficiency lowers HRQOL among patients with poor protein-energy nutritional status. In such patients, HRQOL could be improved by extending the duration of the HD session with lowering of the HD efficiency.

It is unclear at present which mathematical modeling Kt/Vurea is valid for assessment of both long mild hemodialysis (HD) and short intensive HD, the single-pool modeling Kt/V (Kt/Vsp) based on the pre- and postdialysis serum urea concentrations, double-pool modeling Kt/V (Kt/Vdp) based on the predialysis concentration and the estimated postdialysis equilibrated concentration, or Kt/V calculated on the basis of dialyzer urea clearance, HD session duration and urea distribution volume (Kt/Vdl). Thus, the respective Kt/V during a short intensive HD was compared with its counterpart Kt/V during a long mild HD, where the same amount of urea is removed during both HD treatments. It was found that the Kt/Vsp and Kt/Vdl during short intensive HD were significantly greater than the respective Kt/V during the long mild HD. On the other hand, there was no significant difference in the Kt/Vdp between the long mild and short intensive HDs. In conclusion, Kt/Vdp may be more valid for assessment of both long mild and short intensive HDs.

Background/Aim: Employment of treated dialysate as replacement fluid raises concerns about exposure of patients to pyrogenic substances. This study was undertaken to evaluate the safety of treated dialysate as the replacement fluid for push/pull hemodiafiltration. Methods: In the present study, changes in the expressions of Mac-1 and CD14 on monocytes, which are upregulated by monocyte activation, were analyzed by flow cytometry, and the serum level of sCD14 which elevates by monocyte activation was measured by enzyme-linked immunosorbent assay (ELISA) during treatment in 7 patients on hemodialysis with regenerated cellulose (RC) membrane, polysulfone (PS) membranes and by push/pull hemodiafiltration (HDF) with PS membranes in a cross-over fashion. Results: During hemodialysis with RC, hemodialysis with PS or push/pull hemodiafiltration with PS, both Mac-1 and CD14 expressions on monocytes significantly increased by passing through the artificial kidneys, and, accordingly, the respective values downstream of the artificial kidneys were significantly higher than the predialysis values, even when the lipopolysaccharide level in dialysate was not detectable by Limulus assay. There was no significant variation in serum sCD14 levels during any of the hemodialysis with RC, hemodialysis with PS or push/pull hemodiafiltration. However, during hemodialysis with PS or push/pull hemodiafiltration with PS, changes in Mac-1 and CD14 expression on monocytes were significantly smaller than those during hemodialysis with RC. Conclusion: Monocytes are activated to a greater extent during hemodialysis with RC membranes than during push/pull HDF with PS membranes. We consider that push/pull HDF may be safer than hemodialysis with RC membrane and that it is as safe as hemodialysis with the PS membrane in terms of monocyte activation, when pyrogen-free dialysate is employed.

Effectiveness of various therapeutic modalities was analyzed among 1,196 patients entered in the registry of the Japanese Society for Dialysis Therapy who were on hemopurification therapy as of the end of 1998 and developed dialysis-related amyloidosis during 1999. In the investigation, the effectiveness of various hemopurification modalities on the dialysis-related amyloidosis was ranked as exacerbation, unchanged, or alleviation, so as to analyze the possible relationship between the hemopurification modality and its effectiveness. The analysis was performed using a logistic regression approach, and the results were shown as ″he risk of a worse therapeutic ranking" among the hemopurification modalities. The smaller ″the risk of a worse therapeutic effect" was, the more effective the treatment modality. When the risk of a worse therapeutic effect for the hemodialysis patients treated by a regular membrane was put at 1.0, the risk for hemodialysis patients using high-flux membrane was 0.489, the off-line hemodiafiltration risk was 0.117, the on-line hemodiafiltration risk was 0.013, and the risk of push/pull hemodiafiltration was 0.017. For hemodialysis with a β2-microglobulin adsorption column, a low risk of 0.054 was found. The results indicated that hemodiafiltration therapy and simultaneous hemodialysis with β2-microglobulin adsorption therapy were more effective treatment for dialysis-related amyloidosis. © 2001 by the National Kidney Foundation, Inc.

Background/Aim: CD31 on leukocytes is the adhesion molecule involved in the leukocyte extravasation in inflammatory conditions. During hemodialysis with cellulosic membranes, it is considered that activated leukocytes adhere to endothelium, but do not show extravasation. However, it is not elucidated why activated leukocytes do not show endothelial transmigration during hemodialysis with cellulosic membranes. Methods: In the present study, changes in the expressions of Mac-1 and CD31 on granulocytes and monocytes were analyzed by flow cytometry during hemodialysis in 7 patients treated with regenerated-cellulose (RC) membranes and next with polysulfone (PS) membranes. Results: During dialysis with RC, Mac-1 expressions on granulocytes and monocytes both significantly increased as compared with predialysis values and across the dialyzer. During dialysis with RC, the CD31 expression on granulocytes and monocytes significantly decreased as compared with predialysis values. During dialysis with PS, changes in Mac-1 and CD31 expressions on granulocytes and monocytes were smaller than those during dialysis with RC. Conclusions: Decreased CD31 expression on leukocytes may affect leukocyte function more in patients chronically hemodialyzed with RC than in those hemodialyzed with PS, since CD31 is important in leukocyte transendothelial migration in inflammatory conditions.

Push/pull hemodiafiltration (HDF) is characterized by alternate repetition of filtration and backfiltration during hemodialysis with high-flux membrane. In the pressure-controlled push/pull (PC P/P) HDF system, which is the newest push/pull HDF system, there are about 25 repetitions of dilution and concentration of the blood while it passes through the hemodiafilter. Hence, the PC P/P is functionally close to the predilution mode of on-line HDF. In the PC P/P, body fluid is replaced usually by more than 120 L of dialysate during the 4 h treatment. In selecting a hemodiafilter for PC P/P, one must be certain that the blood flow channels in the hemodiafilter do not collapse by the positive pressure on the dialysate side in the backfiltration phase. Thus, the polyacrylonitrile hollow-fiber hemodiafilter and polysulfon hollow-fiber hemodiafilter are suitable for PC P/P. In the short term, PC P/P has been reported to be effective against joint pain, itchiness, insomnia, irritability, and restless leg syndrome experienced by hemodialysis patients. Midterm clinical effectiveness of PC P/P includes the requisite lowering of the erythropoietin dose and improvement in skin pigmentation. The albumin loss per treatment with the PC P/P was significantly lower than that with the conventional HDF approach when a protein-permeable membrane is used. In terms of the removal rate of prolactin, no significant difference was found between PC P/P and conventional HDF. On the other hand, the removal rates of myoglobin and beta2M, where molecular size was smaller than prolactin, was significantly greater with the PC P/P than with conventional HDF.

Background This study had four goals: (1) to evaluate an index of health-related quality of life (HQOL) among renal-transplant recipients in Japan, (2) to compare HQOL of renal-transplant recipients with that of the Japanese population as a whole, and (3,4) to study associations of HQOL with renal function and with the time since transplantation. Methods Questionnaires were distributed to 570 subjects. All were outpatients, were 16 years old or older, and were studied at least 1 year after they had received their latest renal transplant. HQOL was assessed with the Short Form 36-item health survey. Subjects' physicians provided data on renal function. Associations of HQOL with serum creatinine concentration and with the time since transplantation were evaluated by logistic regression. Results The response rate was 83%. Data from patients with diabetes and from those who had had at least two renal transplants were excluded; data from 395 recipients were analyzed. On the physical functioning, general health perception, vitality, and social functioning scales, the patients' scores were significantly lower than the Japanese national-norm scores. General health perception was particularly low. Serum creatinine concentrations were associated with general health perception, vitality, and social functioning. Longer times since transplantation were associated with better social functioning. Conclusions Although social and physical functioning may improve after transplant surgery, a low self-rating of general health seemed to remain. The rarity of renal transplantation in Japan and other psychosocial factors may explain the low self-rating of general health in Japanese renal-transplant recipients.

Crescentic glomerulonephritis leads to a rapid loss of renal function. Although glomerular crescents are rich in extracellular matrix (ECM), the composition and genesis of the ECM are incompletely understood. Heparan sulfate (HS) is a major ECM molecule and has polymeric structure of great variability. Recent findings that alterations in HS epitopes are associated with renal pathology prompted us to hypothesize that specific HS epitopes might be expressed in the evolution of crescents. We reviewed clinical records of 724 patients who underwent renal biopsy and found 21 patients with rapidly progressive glomerulonephritis. Immunohistochemistry was performed using monoclonal antibodies (mAbs) against well-defined HS epitopes. One mAb was directed against unsaturated uronic acid residues generated during the selective removal of HS by heparitinase (a), and a further two different mAbs against N-sulfate-enriched and O-sulfate-poor portions of HS (b). Results showed that mAb (a) reacted to ECM of normal, sclerosed and crescentic glomeruli and that mAbs (b) reacted strongly to ECM of fibrocellular crescents but not to fibrous crescents, the periglomerular areas and noncrescentic intraglomerular areas. We concluded there are regional differences in HS epitope expression, although HS are ubiquitous components of glomerular ECM. N-sulfate-enriched and O-sulfate-poor portions of HS might play a role in crescent formation.

Many patients with end-stage renal disease have altered host defenses against infectious agents. We have demonstrated that T cells, which play an important role in the immunological response, may undergo apoptosis by the Fas system in uraemia. To elucidate whether gammadelta T cells, which function as a first defense against intracellular pathogens, are altered in number or characteristics in dialysis patients, surface expressions of TCR, LFA-1 and Fas antigen on peripheral T cells were examined by immunofluorescence analysis. We demonstrated that the proportions of peripheral gammadelta T cells are altered significantly in haemodialysis (HD) patients. Interestingly, there were marked differences in the levels of expression of LFA-1 and Fas antigen between the two types of T cells. Moreover, both the expression of LFA-1 and that of Fas antigen were enhanced significantly in HD patients compared with normal controls. These results suggest that circulating gammadelta T cells may be susceptible to activation-induced cell death in comparison with alphabeta T cells in uraemic environments.

SUMMARY: Advanced glycation end products (AGEs) have been found to accumulate in the amyloid deposits, skin and plasma of haemodialysis patients (HD), implicating the possible involvement of AGE-modified protein in pathogenesis in dialysis-related amyloidosis. Pentosidine, an AGE cross-link, is a specific marker for AGEs. Plasma pentosidine levels in HD patients were increased dramatically. In the present study, plasma pentosidine, fructoselysine, advanced oxidation protein products (AOPP) and glutathione peroxidase (GSHPx) levels were measured to elucidate the role of oxidative stress in pentosidine formation in nondiabetic HD patients. Plasma pentosidine did not correlate with fructoselysine; plasma AOPP levels were significantly higher than those in normal subjects (201.45 ± 57.93 vs. 55.91 ± 6.57 μmol/L, P

Background Whereas the creatinine generation rate may reflect only the protein nutritional status by way of muscle mass, the predialysis serum albumin concentration may well reflect a variety of aspects of a patient's pathophysiologic status, including the protein nutritional status. The aim of this study was to clarify whether or not serum albumin concentration and the creatinine generation rate reflect the same pathophysiologic status.

We estimated the number of patients with chronic renal failure (CRF) but not with end-stage renal disease (ESRD) in Japan by two methods: a nationwide survey and an estimation using incidence rates of ESRD among CRF patients as well as the number of incident ESRD. The former estimated the number of patients with CRF but not with ESRD as 154, 000 (95% confidence interval 139, 000-168, 000), while so did the latter as 142, 000 (133, 000-150, 000). It follows that the number of CRF patients including ESRD could amount to more than 300, 000, which would give a substantial impact on public health in Japan. Despite some own methodological issues in estimation, the two estimates were reasonably in good agreement: supporting their methodological validity in estimation, since sources of errors appeared to be quite independent of each other. J Epidemiol, 1998 ; 8 : 278-284.

Beginning in 1966, the Patient Registration Committee of the Japanese Society for Dialysis Therapy has conducted a survey once a year on renal replacement therapy in Japan. As of 1983, the survey covered the life/death of patients in the survey years, as well as the case mix of individual patients. In 1990 several laboratory variables were added to the survey items. The present report summarizes the data from the 1993 and 1994 surveys. The Committee mailed out questionnaire forms at the end of the survey year to the heads of all dialysis facilities. Survey forms were returned from 99.6% of the dialysis facilities in the 1993 survey, and from 99.8% of the facilities in the 1994 survey. Some 143 709 patients were treated by renal replacement therapy in 1994 (7509 were treated by CAPD, and 131 016 by extracorporeal haemopuri- fication). The gross mortality rate was 9.5% in the same year. The mean values of the laboratory variables among 88 693 patients undergoing thrice weekly haemodialysis were as follows in 1993: Kt/V, 1.31 ±0.30; protein catabolic rate, 1.04 + 0.30 g/kg/ day; haemodialysis time, 4.12 + 0.50 h. In 1994, the variables were: predialysis serum creatinine concentra- tion, 11.54 + 2.85 mg/dl; predialysis serum albumin concentration, 3.91+0.55 g/dl; predialysis haemato- crit, 28.69+4.36%.

The prognosis for haemodialysis patients is reported to be more favourable in Japan than in Europe or North America. Consequently, evaluation of the death predictors for haemodialysis patients in Japan is of considerable interest outside Japan. The Patient Registration Committee of the Japanese Society for Dialysis Therapy annually surveys the individual patient case mix, laboratory data and important events occurring in the previous years. Thus, using case mix data and laboratory data (including Kt/V and protein catabolic rate) from the 1993 questionnaire survey and the individual patients' life/death statistics from the 1994 questionnaire survey, a logistic regression analysis was conducted on 53867 patients. The analysis indicated that important death risk predictors were: (i) advanced age, (ii) occurrence of diabetes mellitus, (iii) male sex, (iv) Kt/V lower than 1.8, (v) haemodialysis time less than 5 h, (vi) protein catabolic rate less than 0.9 g/kg/day, and (vii) percentage body weight decrease less than 4% and more than 8% during the first haemodialysis session of the week.

Injection of anti-Thy-1 antibody into a rat induces immediate glomerular cell death and subsequent development of glomerulonephritis. Whether the immediate cell death in this model is apoptotic has yet to be determined. Recent in vivo studies on thymocyte death have elucidated that the Thy-1 molecule can activate intracellular signaling for apoptosis. This observation prompted us to re-examine whether stimulation with anti-Thy-1 antibody can provoke apoptosis in the rat glomerulus. We found that anti-Thy-1 antibody could induce laddered DNA fragmentation of isolated glomeruli and mesangial cells in culture, definite biochemical evidence for random double-stranded breaks through apoptosis. Such DNA laddering was also demonstrated in the isolated glomeruli of rats that had been infused with anti-Thy-1 antibody several hours before. Furthermore, the terminal deoxynucleotidyl-transferase-mediated oligonucleotide nick end labeling technique stained a cell in the mesangium. Although apoptosis may be considered a candidate mechanism mediating resolution of hypercellularity in the anti-Thy-1 model, we propose that it is also involved in the immediate cell death in this model.

Chronic renal failure (CRF) is often complicated by lymphopenia, which may be partly responsible for immune deficiency. We hypothesized that lymphopenia in CRF might result from apoptosis of T cells in vivo. To elucidate the involvement of Fas antigen which mediates apoptosis, we analyzed Fas expression on peripheral blood T cells in uremic non-dialyzed (non-HD) patients and hemodialysis (HD) patients. T cells from both uremic groups expressed Fas with higher intensity than control T cells. When two uremic groups were compared, Fas intensity on T cells was significantly higher in non-HD patients than in patients on HD. Moreover, uremic T cells were shown to undergo accelerated apoptosis when cultured in vitro, in correlation with Fas expression. Our results suggest that T cells in CRF may undergo apoptosis by the Fas system and that hemodialysis treatment has beneficial effects in the light of the inhibition of T cell apoptosis.

Stimulation of T cells through the T cell receptor (TcR) initiate activation pathways, and paradoxically can also result in activation-induced cell death. Many factors influence a stimulated cell's decision to manifest one or the other. Here we show that co-stimulation with LFA-1 plays a key role in the choice between the two fates, differentiating between alpha beta and gamma delta T cells. Peripheral gamma delta. T cells but not alpha beta T cells undergo apoptosis upon co-cross-linking of TcR and LFA-1 in MRL lpr/lpr mice as well as +/+ mice. Our results suggest that apoptosis of gamma delta T cells is inducible by combined stimuli independent of the Fas-mediated pathway.

We developed a new urea kinetic method for simultaneous determination of the Kt/V and protein catabolic rate (PCR) only from blood urea nitrogen (BUN) concentrations before and after a single dialysis session. Using this method, the parameters were calculated within 1.5 s even when a hand-held computer with a low central processing capacity is used. The total amount of urea eliminated during three dialysis sessions in 1 week is assumed to be equal to urea volume (Gw) generated over a 1-week period (Tw): [formula: see text]. Here, G is the generation rate, K is the dialyzer urea clearance, T is the dialysis time and C1, C2 and C3 are BUN during the respective dialysis session. If this equation and the equation expressing the urea kinetics during a single dialysis session are solved together, we have a solution for Kt/V and G. The thus-obtained Kt/V and G are corrected using the change in body weight. The corrected Kt/V showed a good correspondence with the parameter calculated with the classical method, and the midweek PCR derived from G determined by the present method being equivalent to the PCR averaged for a 1-week period determined by the classical methods.

Push/pull hemodiafiltration is characterized by alternate filtration and backfiltration, while sterile pyrogen-free dialysate is flowing through a hemodiafilter. During the filtration phase, uremic substances are eliminated not only by diffusive, but also by convective transport. During the backfiltration phase, dialysate is quickly pushed to the blood side (i.e. backfiltration) so as to make up for the excessive reduction in body fluid that has developed during the immediately preceding filtration phase. In the most recently improved version of push/pull hemodiafiltration, the body fluid replacement volume is over 120 liters during a 4- hour treatment. This replacement of a large amount of body fluid may be due to the increased filtration rate in the hemodiafilter resulting from failure of the complete formation of a protein gel layer on the blood side surface. The filtration time in push/pull hemodiafiltration is so short that the also short backfiltration to follow may take over before the protein gel layer is completely formed on the membrane surface. Since the filtration and backfiltration times are much shorter in push/pull hemodiafiltration than the time for blood to pass through the hemodiafilter, it is concentrated and diluted many times (approx. 25 times) before it leaves the hemodiafilter. Therefore, push/pull hemodiafiltration is functionally similar to a predilution hemodiafiltration. The reduction rate of beta-microglobulin was greater by push/pull hemodiafiltration than by hemodialysis, when a high-flux polysulfone hemodiafilter was employed. However, the difference in the reduction rate was rather small between them, because of the improved hemodiafilters, which remove so much beta2-microglobulin only by dialysis. Nevertheless, restless legs syndrome, irritability, insomnia and pruritus were alleviated after switching the treatment modality from hemodialysis to push/pull hemodiafiltration. This may indicate that these symptoms are caused by the accumulation of uremic substances larger than beta2-microglobulin.

Push/pull hemodiafiltration is characterized by alternate filtration and backfiltration, while sterile pyrogen-free dialysate is flowing through a hemodiafilter. During the filtration phase, uremic substances are eliminated not only by diffusive, but also by convective transport. During the backfiltration phase, dialysate is quickly pushed to the blood side (i.e. backfiltration) so as to make up for the excessive reduction in body fluid that has developed during the immediately preceding filtration phase. In the most recently improved version of push/pull hemodiafiltration, the body fluid replacement volume is over 120 liters during a 4- hour treatment. This replacement of a large amount of body fluid may be due to the increased filtration rate in the hemodiafilter resulting from failure of the complete formation of a protein gel layer on the blood side surface. The filtration time in push/pull hemodiafiltration is so short that the also short backfiltration to follow may take over before the protein gel layer is completely formed on the membrane surface. Since the filtration and backfiltration times are much shorter in push/pull hemodiafiltration than the time for blood to pass through the hemodiafilter, it is concentrated and diluted many times (approx. 25 times) before it leaves the hemodiafilter. Therefore, push/pull hemodiafiltration is functionally similar to a predilution hemodiafiltration. The reduction rate of beta-microglobulin was greater by push/pull hemodiafiltration than by hemodialysis, when a high-flux polysulfone hemodiafilter was employed. However, the difference in the reduction rate was rather small between them, because of the improved hemodiafilters, which remove so much beta2-microglobulin only by dialysis. Nevertheless, restless legs syndrome, irritability, insomnia and pruritus were alleviated after switching the treatment modality from hemodialysis to push/pull hemodiafiltration. This may indicate that these symptoms are caused by the accumulation of uremic substances larger than beta2-microglobulin.

Background/Aim: During hemodialysis, platelets and leukocytes are activated and form platelet-leukocyte coaggregates in which GPIIb/IIIa (CD41/CD61) and CD62P (P-selectin) are involved. However, it is still controversial whether platelet activation and platelet-leukocyte coaggregate formation are dependent on the dialyzer membrane material. Method: We examined the appearance of activation-dependent antibody on platelets as an index of platelet activation, and the appearance of platelet-specific antigen on leukocytes as an index of platelet-leukocyte coaggregation, during hemodialysis in 7 patients treated using regenerated cellulose (RC) membrane and next using polysulfone (PS) membrane. In order to reduce the influence of factors other than dialyzer membrane material, this study was conducted in a prospective crossover fashion using a pyrogen-free bicarbonate dialysate. Moreover, flow cytometric techniques with whole blood were employed, which reduce artificial cell activation during the cell or plasma separation procedure. The platelet-specific monoclonal antibodies used in this study were anti-CD61, PAC-1 (which recognizes only the conformationally activated GPIIb/IIIa) and anti-CD62P. Results: Changes in the percentage of PAC-1-positive platelets were significantly greater during hemodialysis with RC than with PS. However, changes in the percentage of CD62P-positive platelets were not significantly different between hemodialysis with RC and PS. Changes in the percentage of CD61- or CD62P-positive leukocytes were significantly greater during hemodialysis with RC than with PS. Although changes in percentage of PAC-1-positive platelets did not parallel those of CD62P-positive platelets during hemodialysis, there was a significant positive correlation between the percentage of CD61-positive leukocytes and the percentage of CD62P-positive leukocytes. Conclusion: This study, conducted in a prospective crossover fashion using a pyrogen-free bicarbonate dialysate in order to reduce the influence of factors other than the dialyzer membrane material, demonstrated that both the degrees of GPIIb/IIIa activation and platelet-leukocyte coaggregation were greater during hemodialysis with RC than PS.

We used the 36-item Short-Form Health Survey to compare health-related quality of life (HRQOL) between 104 dialysis patients in Seattle, WA, and 2,178 patients in Aichi, JAPAN: Compared with Aichi patients, Seattle patients had lower scores on three scales related to physical HRQOL: Physical Functioning (PF; P = 0.03), Role-Physical (RP; P = 0.004), and Vitality (VT; P0.001). However, scores related to mental HRQOL were higher for Seattle patients compared with those of Aichi patients, which included scores for Role-Emotional (RE; P = 0.005) and Mental Health (MH; P0.001). Scores for Bodily Pain, General Health Perception, and Social Functioning did not differ significantly between the two groups. These differences persisted even after potential confounding factors were controlled for. However, after taking into account national norm data for the United States and Japan, differences in PF and VT disappeared, whereas differences in RP, RE, and MH persisted. These results suggest that the higher scores for PF and VT in Aichi patients were partly explained by the higher physical HRQOL of the Japanese general population. Although these data may not be representative of the total dialysis populations in the United States and Japan, they suggest potential differences in HRQOL between patients in the two countries. Additional research is needed to confirm these results and understand the factors associated with these differences. The findings suggest the need for further attention to the physical limitations of US dialysis patients and the mental health of Japanese dialysis patients.

Human serum immunoglobulin IgA1 is produced in bone marrow and interacts with specific cellular receptors that mediate biological events. In this study, we have analyzed the detailed glycoform structure of the human serum IgA1 Fc O-glycosylated hinge region by electrospray ionization liquid mass spectrometry. The IgA1 fragments containing the hinge glycopeptide were separated from 4 IgA nephropathy patient (IgAN) pooled sera, 10 non-IgAN pooled sera with other primary glomerulonephritides, and 5 healthy control subject pooled sera by trypsin treatment and Jacalin affinity chromatography. The molecular weights of IgA1 hinge glycopeptide were estimated using mass spectrometry, and 13 sialo and 8 asialo glycopeptide groups were identified. The results obtained clearly showed a decrease of GalNAc, Gal, and sialic acid in IgAN compared with non-IgAN and normal controls, and those strongly suggested the possibility that the decreased galactosylation and sialylation of the IgA1 hinge result in its glomerular deposition in IgAN.

The Maillard reaction, initiated by the nonenzymatic reaction of reducing sugar with protein, is proposed to play a significant role in protein aging and the complications of aging and diabetes. In this study, we detected and quantified some advanced glycation endproducts (AGEs) in human serum proteins of control and uremic patients by a highly selective and specific assay, electrospray ionization liquid chromatography-mass spectrometry-mass spectrometry (ESI-LC-MS-MS). From our results, levels of each AGEs in serum of uremic patients were significantly elevated, compared to age-matched controls. These results provide the evidence for increased modifications of proteins by Maillard reaction in uremia.

Report on the annual statistical survey of the Japanese Society for Dialysis Therapy in 1996. Background Nearly 170,000 patients were treated by maintenance renal replacement therapy (RRT) in Japan in 1996. The current status of Japanese patients on RRT might, in some way, be suggestive for patients on RRT in other countries. Methods The Japanese Society for Dialysis Therapy conducts a questionnaire survey of virtually every dialysis facility in Japan at the end of each year. Here we present the results of our survey of patients undergoing RRT as of the end of 1996, as well as five-year trends (1992–1996) in some of the data. Results The response rate was 99.8%. At the end of 1996, there were 167,192 patients on maintenance RRT in Japan (1,328 persons per million population). The numbers of patients on maintenance RRT continued to increase during the five-year period. The gross mortality rate for that period ranged from 9.4% to 9.7%. Cuprammonium rayon was the most commonly used material (24.0%) for dialyzer membranes, followed by cellulose triacetate (18.7%). Approximately 5.0% of hemodialysis (HD) patients had a prior history of surgical release of carpal tunnel. The longer the years on HD therapy, the greater the proportion of patients with a history of such an operation. The predialysis plasma β2-microglobulin concentration was highest in patients aged 30 to 45years and declined slightly after the age of 45. There was no significant difference in the HbA1c level between continuous ambulatory peritoneal dialysis and HD patients, both in whom diabetes was the disease causing renal failure. Moreover, among HD patients with diabetes, there was a clear tendency for the HbA1c level to be higher when the normalized protein catabolic rate was higher. Conclusion This report summarizes the latest results of the survey on Japanese patients on RRT.

Various muscle symptoms are well recognized among patients on maintenance hemodialysis. Carnitine deficiency may be an important factor of dialysis-associated muscle symptoms, whereas high-dose L-carnitine supplementation may result in unphysiologically high plasma levels of carnitine and carnitine esters. We studied the effect of low-dose L-carnitine treatment (500 mg/d) on muscle symptoms, plasma carnitine fractions, and lipid profiles in 30 periodically dialyzed patients with muscular weakness, fatigue, or cramps/aches. After 12 weeks of L-carnitine treatment, about two-thirds of patients had at least some improvement in muscular symptoms, whereas carnitine fractions were normal or slightly above normal ranges, but lipid profiles showed no demonstrable changes. This study also showed the correlation between plasma-free carnitine deficiency and months on dialysis. These results suggest that prolonged low-dose L-carnitine treatment can improve dialysis-associated muscle symptoms by restoring carnitine tissue levels and washing out acyl moieties.

Autoimmune-prone lpr mice develop lymphoproliferative disorders, whereas their lymphocytes show accelerated apoptosis in culture. To elucidate whether the bcl-2 protein, a repressor of apoptosis, is critical to the discrepancy between in vivo and in vitro survival, we examined bcl-2 expression in T cells from +/+ and lpr mice during culture. The expression levels of bcl-2 in cultured T cells from lpr mice were significantly down-modulated compared to those from +/+ mice and freshly obtained T cells. Besides, the reduction of bcl-2 protein levels was inhibited in T cells cultured in the presence of T cell receptor (TCR) signalling. These results suggest that lpr T cells might be susceptible to apoptosis in vitro due to down-modulation of bcl-2 by withdrawal of TCR signalling.

We found a new spot on the two-dimensional electrophoresis pattern of the urine protein from hemodialysis patients. In order to identify the protein forming this new spot, the protein was purified by five steps of chromatography. It was shown that the amino acid sequence of this new protein from the N-terminal to the 20th amino acid was identical with the sequence from the 4197th to 4216th amino acid of perlecan, which is the core protein of the proteoglycan localizing in the systemic capillary basement membranes. It was also found that the molecular weight (25 000 daltons) of this new protein was comparable to the calculated molecular weight of the molecular region of the perlecan from the 4197th amino acid to the C-terminal. Lastly, it was shown that the antibodies against this new protein reacted with the perlecan produced by human fibroblasts. All these findings indicated that the new protein is a perlecan fragment.

Lysozyme in the urine of a hemodialysis patient was purified in two steps: DEAE Sephadex chromatography followed by Sephacryl chromatography. The Sephacryl S-100 column chromatographed fraction showing lytic activity was proven to give one band on SDS-PAGE and to have a molecular mass of 14 500, in agreement with that of lysozyme. The N-terminal amino acid sequence of this purified protein was identical to that of lysozyme. These results indicate that the protein purified was indeed lysozyme. The specific affinity of lysozyme for Sephacryl S-100 may explain the greater purity of the same protein isolated by this method.

Pentosidine is an advanced glycation end product and its formation is shown to be closely related to oxidative processes. Recent studies have shown that pentosidine levels are increased not only in plasma and matrix proteins from diabetic patients, but also markedly in nondiabetic hemodialysis patients. Currently, the mechanism of accumulation and kinetics of pentosidine formation in hemodialysis patients remain unknown. Gel filtration of uremic plasma revealed that plasma pentosidine exists in the albumin fraction (approximately 90%) and, interestingly, in free form (approximately 5%) as well. Plasma free pentosidine was undetectable in subjects with normal renal function. There was a significant correlation between the plasma levels of albumin-linked and free pentosidine in hemodialysis patients. Kinetic studies indicated that dietary pentosidine was absorbed into the circulation and that, after either oral or intravenous administration of pentosidine to intact or nephrectomized rats, the plasma free pentosidine level was closely linked to the level of renal function. These findings demonstrate that: (1) Pentosidine accumulates as albumin-linked and in free form in the circulation of uremic patients; (2) dietary pentosidine can be absorbed into the circulation, thus being one possible origin of circulating free pentosidine; (3) free pentosidine may accumulate as a result of decreased glomerular filtration; and (4) the mechanism of accumulation of albumin-linked pentosidine is not related to high glucose levels. It suggests the simultaneous accumulation, during renal failure, of either unknown pentosidine precursor(s) or catalyst(s) of glycoxidation, independent of glucose.

Alternate repetition of short fore- and backfiltrations reduces convective albumin loss. An effective therapeutic means to remove relatively large polypeptide uremic toxins seems to be a hemofiltration (HF) or hemodiafiltration (HDF) employing a larger-pore membrane, that is, a protein-permeable membrane. With either method, however, a significant amount of albumin will be lost into the ultrafiltrate or dialysate. Now, repetition of alternate short fore- and backfiltrations may prevent the development of the ultrafiltration-induced higher albumin concentration on the membrane surface (protein concentration polarization), where a single forefiltration time is shorter than the time needed for completion of protein concentration polarization. Since the albumin concentration on the protein-permeable membrane surface will be one of the determinants of albumin loss by convection, such HDF treatment may reduce protein loss into the dialysate. To examine this assumption, we alternately repeated short and rapid fore- and backfiltrations (push/pull HDF) through a protein-permeable membrane, each less than 1 second in duration and at each filtration volume of 15 ml, where a pyrogen-free dialysate was supplied. The present results indicated that the albumin amount lost by push/pull HDF was approximately one-third of that by conventional HDF. Nevertheless, the reduction rates of β 2 -microglobulin and myoglobin were significantly greater by push/pull HDF than by conventional HDF.

Monocyte/macrophage response to β2-microglobulin modified with advanced glycation end products. We recently found that acidic β2-microglobulin (β2m), a major isoform of β2m in amyloid fibrils of patients with dialysis-related amyloidosis (DRA), contained early Amadori products and advanced glycation end products (AGEs) formed nonenzymatically between sugar and protein. Further analysis revealed that acidic β2m induces monocyte chemotaxis and macrophage secretion of bone-resorbing cytokines, suggesting the involvement of acidic β2m in the pathogenesis of DRA. Acidic β2m, however, is a mixture of heterogeneous molecular adducts due to various types of modification. In the present study, we investigated the modification responsible for the biological activity of acidic β2m toward monocytes/macrophages. The presence of a fair amount of β2m species with deamidation was detected in acidic β2m isolated from urine of non-diabetic long-term hemodialysis patients, but deamidated β2m had no biological activity. In contrast, normal β2m acquired the activity upon incubation with glucose in vitro. Among the glycated β2m, the pigmented and fluorescent β2m that formed after a long incubation period, that is, AGE-modified β2m, exhibited biological activity, whereas β2m modified with Amadori products, major Maillard products in acidic β2m, had no such activity. These findings suggest that AGEs, although only a minor constituent of acidic β2m, are responsible for monocyte chemotaxis and macrophage secretion of cytokines, implicating the contribution of AGEs to bone and joint destruction in DRA.

A major constituent of the amyloid fibrils in dialysis-related amyloidosis is beta 2-microglobulin (beta 2-MG). Heparan sulphates (HS) co-localize with the amyloid fibrils and monocytes/macrophages are commonly found around amyloid deposits, but the role of HS in amyloidogenesis is not yet defined. HS have variable saccharide sequences and can interact specifically with basic fibroblast growth factor (bFGF), a potent chemotactic factor for the monocyte/macrophage. The present investigation was undertaken to look for a functional link between co-localized HS and the pathogenesis of dialysis-related amyloidosis. Using amyloid-enriched ligament, immunohistochemical localization was tested for beta 2-MG, endogenous bFGF, and bFGF-binding portions of HS. For the detection of bFGF-binding portions of HS, the ligament sections were incubated with exogenous bFGF and then with anti-bFGF antibody. The specificity of the interaction between bFGF and HS was established by confirming a concomitant loss of immunoreactivity during selective removal of HS with heparitinase. beta 2-MG, endogenous bFGF, and bFGF-binding portions of HS were detected between bundles of collagen. Endogenous bFGF and bFGF-binding portions of HS were not detected in more advanced amyloid lesions, whereas beta 2-MG and other portions of HS were detected. We propose that beta 2-MG, endogenous bFGF, and bFGF-binding portions of HS form a complex and localize in the early amyloid lesions of dialysis-related amyloidosis.

First, this investigation showed that plasma levels of inosine, hypoxanthine, and xanthine, which are metabolites of adenosine, rose sharply when blood pressure dropped suddenly along with symptoms during a hemodialysis session (sudden hypotension), but not when it decreased gradually with eventual symptoms (gradual hypotension). Because adenosine has an action to dilate vessels, this result indicates the possibility that the increased release of adenosine would be a cause of sudden hypotension. Second, it was found that the frequency of sudden hypotension decreases with the administration of caffeine, which is an adenosine-receptor antagonist, whereas the frequency of gradual hypotension did not change. This result supports the above-mentioned hypothesis that adenosine may well be a mediator of sudden hypotension, but not of gradual hypotension. Third, our investigation demonstrated no significant differences in plasma norepinephrine level, in plasma renin activity, or in mean blood pressure between the hemodialysis session in which caffeine was administered and the session in which a placebo was given. These findings suggest that the effect of caffeine administration to prevent sudden hypotension is not mediated by the stimulation of the sympathetic nervous system or activation of the renin-angiotensin system, but by the adenosine-receptor antagonism.

The authors investigated the influence of Kt/V and protein catabolic rate (PCR) on dialysis failure for 689 hemodialysis (HD) outpatients treated at the seven dialysis facilities in Aichi Prefecture, Japan. Dialysis failure was defined as death or hospitalization for reasons other than blood access, accident, wound, or mental disease. Patients were followed for 2 years. The rate of patients who developed dialysis failure during the observation period relative to the total patient population was defined as the dialysis failure rate. A total of 123 patients developed dialysis failure, which was fatal in 33 cases. In patients with Kt/V values of 1.6 or higher, the mean dialysis failure rate was significantly lower at 12.0% than that (19.2%) of patients with Kt/V values between 0.8 and 1.6 (p < 0.04). In patients that had PCR values under 0.8 g/kg/day, the dialysis failure rate was significantly higher at 32.5% than that (15.8%) of patients with PCR values between 0.8 and 1.4 g/kg/day (p < 0.0001).