Koji Sano

Ultrapure Dialysate Reduces Plasma Levels of β2-Microglobulin and Pentosidine in Hemodialysis Patients

Background: β2-Microglobulin (β2MG) and carbonyl stress are reported to contribute to the development of dialysis-related amyloidosis. The aim of this study was to determine whether the purity of dialysate affects plasma levels of β2MG and pentosidine (a surrogate marker of carbonyl stress) in hemodialysis patients. Methods: Sixteen patients on hemodialysis with a polysulfone membrane participated in this study. We switched the dialysate from conventional dialysate (endotoxin level 0.055–0.066 endotoxin units (EU)/ml) to ultrapure dialysate (endotoxin level <0.001 EU/ml), followed patients for 6 months, and then switched back to conventional dialysate once again. Plasma levels of β2MG, pentosidine, CRP and interleukin-6 (IL-6) were determined before the switch to ultrapure dialysate, 1 and 6 months after the switch to ultrapure dialysate, and 1 month after the switch back to conventional dialysate. Results: The switch from conventional to ultrapure dialysate significantly decreased plasma levels of β2MG, from 30.1 ± 1.4 to 27.1 ± 1.4 mg/dl (p < 0.05) and pentosidine, from 1,535.8 ± 107.5 to 1,267.6 ± 102.9 nmol/l (p < 0.01) after 1 month of use. The change of dialysate also significantly decreased plasma levels of CRP, from 0.28 ± 0.09 to 0.14 ± 0.05 mg/dl (p < 0.05) and IL-6, from 9.4 ± 2.7 to 3.5 ± 0.8 pg/ml (p < 0.01) over the 1-month period. These changes in plasma levels of β2MG, pentosidine, CRP and IL-6 were maintained over 6 months after switching to ultrapure dialysate and returned to basal levels by switching back to a conventional dialysate. Conclusions: Ultrapure dialysate decreases plasma levels of β2MG, pentosidine and inflammatory markers in hemodialysis patients. The use of ultrapure dialysate might be useful in preventing and/or treating complications of dialysis, such as dialysis-related amyloidosis, atherosclerosis and malnutrition.

Attenuation of cisplatin-induced acute renal failure is associated with less apoptotic cell death

To clarify the pathophysiologic role of apoptosis in acute renal failure (ARF), we examined whether the attenuation of cisplatin-induced ARF is associated with the change in the degree of apoptotic cell death. The administration of cisplatin (CDDP) (6 mg/kg body weight) in rats induced ARF at day 5, as manifested by a significant increase in serum creatinine (Scr) and tubular damage. CDDP-induced apoptotic cell death was confirmed by electron microscopic examination, agarose gel electrophoresis, and increased cells positive for TaT-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) in the outer medulla of the kidney. Treatment with dimethylthiourea (DMTU)--a scavenger of hydroxyl radicals--or glycine abrogated CDDP-induced increases in Scr, the tubular damage score, and the number of TUNEL-positive cells. Pretreatment with uranyl acetate (UA) induced a significant expression of Bcl-2 in the kidney and ameliorated CDDP-induced increases in Scr, the tubular damage score, and TUNEL-positive cells in the outer stripe of the outer medulla. Our findings indicate (1) that the attenuation of CDDP-induced ARF was associated with less apoptotic cell death and (2) that the induction of the anti-apoptotic protein Bcl-2 attenuated apoptosis and tubular damage. Our results suggest that apoptotic cell death may play an important role in the development of cisplatin-induced ARF.

A CASE WITH ACUTE RENAL FAILURE COMPLICATED BY WALDENSTRÖM'S MACROGLOBULINEMIA AND CRYOGLOBULINEMIA

We encountered a 53-year-old man associated with acute renal failure caused by Waldenströms macroglobulinemia and type I cryoglobulinemia. Treatment with prednisolone and cyclophosphamide induced a rapid recovery from acute renal failure. Renal histology revealed endocapillary proliferation and lobular formation with scattered subendothelial, amorphous and periodic acid-Schiff (PAS)-positive materials in the glomerular capillaries which were positive for IgM on immunofluorescence study. Although the exact mechanism for pathophysiology of acute renal failure remains unknown, treatment with prednisolone and cyclophosphamide could induce a rapid recovery from acute renal failure accompanied by Waldenströms macroglobulinemia and type I cryoglobulinemia.

Marked Bradycardia Associated with Profound Hyperkalemia in Patients with End-Stage Renal Disease

Accessible online at: http://BioMedNet.com/karger Dear Sir, Since profound hyperkalemia induces fatal arrhythmias, the recognition of its electrocardiographic manifestations is very important. The changes on the ECG correlate roughly with the severity of hyperkalemia [1]. It has been, however, less recognized that severe hyperkalemia is associated with bradycardia [2]. We herein present 7 patients with end-stage renal disease manifesting marked bradycardia in the presence of hyperkalemia. The ECGs of 7 patients with severe hyperkalemia were analyzed and compared with those obtained before admission. The clinical and laboratory data are shown in table 1. The electrocardiographic manifestations are shown in table 2. No abnormality was observed in the ECGs before admission except for 2 patients (Y.U. and S.T.), in whom left bundle branch block and first-degree AV block were found, respectively. The signs of ischemic heart disease on ECG before admission were found in 4 patients. The exact causes of end-stage renal disease were unknown, but the complicated disorders were as follows: diabetes mellitus in 5, hypothyroidism in 2 which was not so severe, and rheumatoid arthritis in 1. When marked bradycardia was observed, the serum potassium concentration was between 6.6 and 8.1 mEq/l, except for 1 patient (S.T.), in whom marked bradycardia was observed on mild hyperkalemia (5.6 mEq/l), had been given diltiazem (200 mg twice a day). The electrocardiographic maniTable 1. Clinical and laboratory data

Glycine attenuates apoptotic cell death in uranyl acetate-induced acute renal failure in rats

AbstractBackground. Although uranyl acetate (UA) is known to induce apoptosis in renal tubular cells, the pathophysiological role of apoptotic cell death in UA-induced acute renal failure (ARF) is not clear. In this study, we examined whether glycine, which is known to provide protection against nephrotoxic acute renal failure, attenuated tubular damage in UA-induced ARF in rats, and, if so, whether the attenuation of tubular damage was associated with reduced apoptotic cell death. Methods. Sprague-Dawley rats were allocated to three groups; normal controls, UA-treated, and UA plus glycine-treated. Acute renal failure was induced by the intravenous injection of UA (5 mg/kg). UA plus glycine-treated rats were given glycine at 1 g/kg, i.v. over 3 min at the same time as the UA injection. Serum creatinine concentration (Scr) and tubular damage score were examined 5 days after UA administration. Apoptosis was evaluated by counting the number of terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL)-positive cells in the outer stripe of the outer medulla. Results. Glycine significantly decreased the UA-induced increases in Scr (3.73 ± 0.31 vs 2.74 ± 0.11 mg/dl; P < 0.05) and the tubular damage score (3.83 ± 0.13 vs 2.58 ± 0.01; P < 0.01). UA significantly increased the number of TUNEL-positive cells in the outer stripe of the outer medulla (0.16 ± 0.04 vs 7.45 ± 0.46/high power field at ×400 magnification; P < 0.01 vs normal control value). Glycine infusion significantly lessened the number of TUNEL-positive cells (5.84 ± 0.31/ high power field at ×400 magnification; P < 0.01 vs UA-treated rats). A significant correlation was found between the number of TUNEL-positive cells and the tubular damage score (r = 0.93; P < 0.01). Conclusion. Glycine ameliorated the severity of UA-induced ARF and the degree of apoptotic cell death. This finding suggested that the protective effect of glycine in UA-induced ARF may be mediated, at least in part, through a reduction of apoptosis.

Eradication therapy for Helicobacter pylori infection improves nutrition status in Japanese hemodialysis patients: a pilot study

Plasma ghrelin level is influenced by Helicobacter pylori (H. pylori) status and the severity of gastric mucosal atrophy, and the ghrelin level is associated with nutrition status in hemodialysis patients. Here, we investigated the efficacy of H. pylori eradication therapy in improving nutrition status in relation to the ghrelin level in H. pylori-positive hemodialysis patients. Of H. pylori-positive patients receiving hemodialysis at 8 dialysis center, 21 patients underwent gastroduodenoscopy for evaluation of the severity of gastric atrophy, and nutrition markers and plasma ghrelin levels before and 1 year after H. pylori eradication therapy were evaluated. Serum cholinesterase level was significantly increased after H. pylori eradication compared with the level before eradication (303.2 ± 76.0 vs 287.3 ± 68.1 IU/L, p = 0.029). In particular, cholesterol (before, 196.6 ± 23.2 mg/dl; after, 206.1 ± 25.9 mg/dl, p = 0.042) and cholinesterase levels (before, 296.9 ± 70.8 IU/L; after, 316.4 ± 73.8 IU/L, p = 0.049) increased more strongly in patients with mild–moderate atrophy than those with severe atrophy, irrespective of improvement of plasma acyl-ghrelin and desacyl-ghrelin levels after eradication therapy. In conclusion, H. pylori eradication may improve nutrition status by increasing serum cholinesterase and cholesterol levels in hemodialysis patients, especially those with mild and moderate gastric mucosal atrophy.