大橋 篤

Abstract Introduction Indoxyl sulfate (IS) is a protein‐bound uremic toxin that causes uremic sarcopenia. IS has poor dialysis clearance; however, the addition of a binding competitor improves its removal efficiency. Methods Dialysis experiments were performed using N‐acetyl‐l‐tryptophan (L‐NAT) instead of l‐tryptophan (Trp) using pooled sera obtained from dialysis patients. The molecular structures of L‐NAT and Trp were similar to that of IS. Therefore, we examined whether Trp and L‐NAT were involved in muscle atrophy in the same manner as IS by performing culture experiments using a human myotube cell line. Results The removal efficiency of L‐NAT was the same as that of Trp. However, L‐NAT concentrations in the pooled sera increased at the end of the experiment. Trp (1 mM) decreased the area of human myocytes, similar to IS, whereas L‐NAT did not. Conclusion L‐NAT is a binding competitor with the ability to remove protein‐bound IS while preventing sarcopenia.

Cell-free and concentrated ascites reinfusion therapy (CART) is performed by collecting the ascites from the patient, followed by filtration and concentration. Thereafter, concentrated cell-free ascites is reinfused into the patient intravenously. The new type of machine, Plasauto μ, for managing the process of CART was launched onto the market. We have evaluated the machine through postmarketing clinical study in 17 patients with malignant ascites. The amounts of original and concentrated ascites were 3673 ± 1920 g and 439 ± 228 g, respectively. Recovery rates were acceptable regarding values of total protein, albumin, and IgG that were 55.6% ± 17.3%, 60.2% ± 20.8%, and 58.2% ± 20.5%, respectively. Recovery rates were positively associated with amounts of original ascites and negatively associated with total protein concentration. No adverse events related to the machine were observed. The new type of machine showed preferable performance in processing malignant ascites.

Cell-free and concentrated ascites reinfusion therapy (CART) by internal filtration pressure method (internal method) and external filtration pressure method (external method) using the same cancerous ascites was performed. The rate of rise in circuit pressure and recovered components were compared between the two methods. The factors related to circuit pressure rise were also researched. In both methods, circuit pressure rose in 50% of cases. The recovery rates of IgG, IgA, IgM, and haptoglobin were significantly higher for the internal method than for the external method, whereas the recovery rate of α1 -antitrypsin was significantly lower in the internal method than in the external method. The levels of IL-6, haptoglobin, α1 -antitrypsin, and fibrinogen/fibrindegradation products (FDP) in the original ascites were significantly higher in the group wherein circuit pressure rose than in that without circuit pressure rise. These proteins might be related to the rise in circuit pressure.

Scaffolds, growth factors, and cells are three essential components in regenerative medicine. Nonwoven filters, which capture cells, provide a scaffold that localizes and concentrates cells near injured tissues. Further, the cells captured on the filters are expected to serve as a local supply of growth factors. In this study, we investigated the growth factors produced by cells captured on nonwoven filters. Nonwoven filters made of polyethylene terephthalate (PET), biodegradable polylactic acid (PLA), or chitin (1.2-22 mu m fiber diameter) were cut out as 13 mm disks and placed into cell-capturing devices. Human mesenchymal stem cells derived from adipose tissues (h-ASCs) and peripheral blood cells (h-PBCs) were captured on the filter and cultured to evaluate growth factor production. The cell-capture rates strongly depended on the fiber diameter and the number of filter disks. Nonwoven filter disks were composed of PET or PLA fibers with fiber diameters of 1.2-1.8 mu m captured over 70 % of leukocytes or 90 % of h-ASCs added. The production of vascular endothelial growth factor (VEGF), transforming growth factor beta 1, and platelet-derived growth factor AB were significantly enhanced by the h-PBCs captured on PET or PLA filters. h-ASCs on PLA filters showed significantly enhanced production of VEGF. These enhancements varied with the combination of the nonwoven filter and cells. Because of the enhanced growth factor production, the proliferation of human fibroblasts increased in conditioned medium from h-PBCs on PET filters. This device consisting of nonwoven filters and cells should be investigated further for possible use in the regeneration of impaired tissues.

Background/Objective: Toll-like receptors (TLR) mediate the recognition of microbial constituents and stress-induced endogenous ligands by the immune system. They may also be involved in the maintenance or break down of tolerance against autologous antigens. The aim of our investigation was to study the consequence of TLR4 deficiency on the development of insulin-deficient diabetes in the NOD mouse. Methods: The TLR4 defect of the C57BL/10ScN mouse was backcrossed onto the NOD background and the effect of TLR4 deficiency on diabetes development was analysed by in vivo and in vitro studies. Results: Compared to animals with wildtype TLR4 expression (TLR4(+/+)), female NOD mice carrying a homozygous TLR4 defect (TLR4(-/-)), showed significant acceleration of diabetes development, with a younger age at diabetes onset (TLR4(+/+) 177 +/- 22 d, TLR-/- : 118 +/- 21 d; p < 0.01). Pancreata of 120 d old TLR4(-/-) NOD mice revealed increased proportions of islets with advanced stages of immune cell infiltration compared to TLR4(+/+) mice (p < 0.05). TLR4 deficiency did not affect the susceptibility of islet cells to the beta cell damaging mediators nitric oxide or the inflammatory cytokines tumor necrosis factor alpha, interleukin-1 beta and interferon gamma. The lack of TLR4 further had no effect on the frequency of regulatory T-cells but reduced their capacity to inhibit T-cell proliferation. Conclusions: Our findings demonstrate that TLR4 deficiency results in an acceleration of diabetes development and immune cell infiltration of islets in NOD mice. We conclude that TLR4 is involved in the progression of the insulitis process thereby controlling the development of insulin-deficient diabetes in NOD mice.

Amyloid beta proteins (Aβ) in the brain are the main cause of Alzheimer's disease. Peripheral administration of Aβ-binding substances, which may act as a sink for Aβ from the brain, has been reported to reduce brain Aβ. We previously found C16-cellulose beads had high Aβ-removal activity in vitro. In this study, we investigated the optimum surface properties of adsorbents for removal of Aβ in vitro and in humans. Batch analysis was performed with porous cellulose beads or silica beads with or without 2-22 methylene groups. Aβ-removal activity of C16-cellulose beads increased with increasing alkyl chain length. In contrast, with cellulose the amount of Aβ removed by the silica beads decreased with increasing alkyl chain length. Cellulose beads with 16 or 22 methylene groups were best (over 99 % removal) among all the beads tested (p ≤ 0.01). The adsorbent surfaces were analyzed by near-infrared spectroscopy, which revealed that the optimum beads had a sufficiently hydrophobic surface with an appropriate amount of adsorbed water accessible on the surface. Aβ removal efficiency by C16-cellulose beads was investigated for 5 renal failure patients on hemodialysis, resulting in 51.1 ± 6.6 % for Aβ1-40 and 43.8 ± 4.5 % for Aβ1-42 (p ≤ 0.01). In conclusion, cellulose beads with 16 or 22 methylene groups and an appropriate amount of adsorbed water were the optimum Aβ adsorbents. The device with C16-cellulose beads had high Aβ removal activity in humans. These adsorbents might be useful for Alzheimer's disease therapy. © 2012 The Japanese Society for Artificial Organs.

The pathological changes of Alzheimer's disease include the deposition of amyloid beta protein (A beta) as senile plaques in the brain. We hypothesized that the rapid removal of A beta s from the blood may act as a peripheral A beta drainage sink from the brain. In this study, the plasma A beta concentrations and the cognitive functions were investigated for in 57 patients on hemodailysis (69.4 +/- A 3.8 years), 26 renal-failure patients without hemodialysis (66.6 +/- 14.7 years), and 17 age-matched healthy controls (66.6 +/- 4.1 years). The concentrations of plasma A beta s increased along with the decline of renal functions. Moreover, the renal-failure patients without hemodialysis and with poorer renal functions showed lower cognitive functions. The plasma concentrations of A beta(1-42) correlated with serum creatinine (P < 0.001) and Mini-Mental-State Examination scores (P = 0.017). The dialyzers effectively removed A beta s in the blood during hemodialysis sessions. The plasma A beta concentrations showed steady or slightly decreasing along with duration of hemodialysis. The total amount of A beta s removed during a hemodialysis session was calculated to be comparable to the A beta s dissolved in the blood and the cerebrospinal fluid. The MMSE scores of the hemodialysis patients showed no clear decrease in longer hemodialysis duration. Therefore, the therapeutic approach for Alzheimer's disease by removing A beta s from the blood is worthy of further investigation, including whether or not A beta s in the brain decrease.

Renal failure is a frequent complication in patients with multiple myeloma. Immunoglobulin free light chains (FLCs) form casts in the distal tubules, resulting in renal obstruction, and are also directly toxic to proximal renal tubules. Removal of FLCs contributes to renal recovery. High cut-off (HCO) membrane Theralite2100, protein leaking dialyzer PES210D alpha, plasma separator Evacure1A20 and beta(2) microglobulin adsorption column LixelleS-35 were compared in their FLC removal rate. Dialysis using Theralite2100 or Evacure1A20, diafiltration using PES210D alpha and adsorption using LixelleS-35 were performed in an in vitro circuit. The highest removal rate was obtained by Theralite2100 dialysis among the four blood purification methods. Albumin loss was also the greatest in Theralite2100 dialysis. The removal content of FLCs per 1 g albumin loss was better in PES210D alpha diafiltration. The removal rate of FLCs by Evacure EC1A-20 dialysis was the third highest. Adsorption of FLCs by the beta(2) microglobulin adsorption column Lixelle S-35 was confirmed. In conclusion, Theralite2100 dialysis was the best in removal of FLCs. PES210D alpha diafiltration can remove FLCs with smaller loss of albumin.

Background/Aims: Rapid removal of plasma amyloid-beta (A beta) by blood purification may serve as a peripheral A beta sink from the brain for Alzheimer's disease therapy. We investigated the reduction of plasma A beta during hemodialysis and cognitive states. Methods: A beta concentrations and Mini-Mental State Examinations (MMSE) were investigated in 37 hemodialysis patients (68.9 +/- 4.1 years). Results: The dialyzers effectively removed A beta(1-40) and A beta(1-42), 63.9 +/- 14.4 and 51.6 +/- 17.0% at 4 h dialysis, resulting in the reduction of A beta s in whole-body circulation by 51.1 +/- 8.9 and 32.7 +/- 12.0%, respectively. Although the plasma A beta s before dialysis (750.8 +/- 171.3 pg/ml for A beta(1-40)) were higher than those reported for Alzheimer's disease patients, the cognitive states of hemodialysis patients were relatively normal, especially of longer dialysis vintages. Conclusions: Dialyzers effectively reduced A beta s in whole-body circulation. Repeated rapid decrease of plasma A beta s might maintain cognitive state. Copyright (C) 2011 S. Karger AG, Basel

血液透析療法における透析膜材質の違いによるC型肝炎ウイルス(HCV)吸着について検討した。対象は慢性維持血液透析中のHCV抗原陽性男性患者5名(平均年齢60.5歳、平均透析歴9.5年)で、原疾患は糖尿病性腎症、慢性糸球体腎炎各2名、腎硬化症1名であった。1)4種類の透析膜を用いて透析前・後のHCV抗原濃度とトランスアミナーゼ(AST、ALT)を測定したところ、各透析膜のHCV抗原濃度減少率はF-70S:32.7%、BK-1.6P:19.0%、FB-150E:10.4%、AM-FP1.3:8.8%といずれでも有意な減少が認められた。だが、翌週にはほぼ前値に復していた。2)AST、ALT値は全例が正常範囲で推移し、週変動は認めなかった。3)in vitroのHCV抗原吸着実験による各透析膜での減少率は、F-60S:25.8%、BK-1.3P:20.5%、FB-130U:16.0%、AM-FP1.3:10.5%で、HCV抗原の回収実験では各透析膜とも吸着実験で減少したHCV抗原量にほぼ同等の量であった。以上、血中のHCV抗原は透析膜で吸着除去されると考えられた。

Background/Aims: To clarify the clinical significance of tumor necrosis factor (TNF) receptors in patients with myeloperoxidase (MPO)-anti-neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis, we evaluated the cell surface expression of TNF receptor 1 (TNFR1) and TNF receptor 2 (TNFR2). Patients and Methods: 43 patients with MPO-ANCA-associated vasculitis, 16 patients with chronic renal failure, 10 patients with sepsis, 15 patients with systemic lupus erythematosus, and 18 healthy controls were enrolled in this study, and the surface expression levels of TNFR1, TNFR2, CD63, and CD64 on granulocytes were assessed. In 21 patients with MPO-ANCA-associated vasculitis, soluble TNFR1 (sTNFR1), soluble TNFR2 (sTNFR2), and TNF-alpha in the serum were also measured. Results: The surface expression levels of TNFR1 and TNFR2 on granulocytes were significantly higher in patients with MPO-ANCA-associated vasculitis than in the healthy controls, and positively correlated with the Birmingham Vasculitis Activity Score (BVAS). The levels of sTNFR1, sTNFR2, and TNF-alpha in the serum were also significantly higher in patients with MPO-ANCA-associated vasculitis than in the healthy controls. Serum levels of sTNFR1 and sTNFR2 correlated with serum creatinine, while the surface expression of TNFR1 and TNFR2 on the granulocytes did not. There was no significant correlation between the BVAS and CD63 or BVAS and CD64. Conclusion: The surface expression levels of TNFR1 and TNFR2 on granulocytes were upregulated in patients with MPO-ANCA-associated vasculitis and reflected disease activity. Copyright (C) 2009 S. Karger AG, Basel

銀は安全性が高いことと抗菌スペクトルが広いことからさまざまな分野で使用されている．今回，銀イオン（Ag⁺）水の殺菌性を次亜塩素酸ナトリウム（NaClO）と比較し，Ag⁺水の透析用消毒剤としての有用性を検討した．試験菌株としてPseudomonas aeruginosa，Escherichia coli，Staphylococcus aureusを用いて各消毒剤の最小殺菌濃度（MKC）を測定した．また，透析用水製造工程（原水，活性炭処理水，RO水），透析液ライン（Bタンク，透析液）から検出された細菌に対して各消毒剤の殺菌効果試験を行った．MKCの結果から，Ag⁺水はNaClOのような即効性は認められないが，長い時間作用させるとNaClOと同等の殺菌性を有することがわかった．特に透析用水製造工程で塩素消毒耐性の水棲菌の消毒についてはNaClOよりもAg⁺水は有効であると考えられる．また，Ag⁺水はグラム陰性菌以外にもグラム陽性菌に対しても殺菌力があり，NaClOに匹敵する透析用消毒剤として利用できる可能性がある．

Bisphenol A [BPA, 2,2-bis(4-hydoxyphenyl)propane], an industrial chemical used in the production of polycarbonate, epoxide resin, and polyarylate, is considered to be an endocrine-disrupting chemical. BPA may be present in some hollow-fiber dialyzers used in hemodialysis. In this study, we tested the amounts of BPA eluted from various hollow fibers. Furthermore, we measured the BPA concentration in the sera of 22 renal disease predialysis patients, as well as 15 patients who were receiving hemodialysis, to see if there is BPA accumulation in these patients. The elution test of BPA showed that a much larger amount of BPA was eluted from polysulfone (PS), and polyester-polymeralloy hollow fibers. Among renal disease patients who had not undergone hemodialysis, the serum BPA concentration increased as the renal function deteriorated, showing a significant negative association. In a crossover test between PS and cellulose (Ce) dialyzers, the predialysis serum BPA concentration of PS dialyzer users decreased after changing to a Ce dialyzer, and the serum BPA increased again after switching back to PS dialyzers. In patients who were using PS dialyzers, the BPA level significantly increased after a dialysis session. However, in the Ce dialyzer users, the BPA level decreased. Since accumulation of BPA could affect the endocrine or metabolic system of the human body, it is important to perform further investigations on dialysis patients. Copyright (c) 2007 S. Karger AG, Basel.

Twenty-one patients with myeloperoxidase-antineutrophil cytoplasmic autoantibody (MPO-ANCA)-associated vasculitis were treated using cytapheresis. Of these, 17 were treated for glomerulonephritis and four were treated for pulmonary hemorrhage. The overall survival rate was 85.7% with a follow-up duration of 24.0 ± 13.8 months. In the 17 patients with MPO-ANCA-associated glomerulonephritis, pretreatment creatinine was 3.2 ± 1.6 mg/dL, and renal function recovered in 76.5%. Pulmonary hemorrhage was ameliorated in all four patients. Abdominal pain occurred in three of the 21 patients but symptoms resolved soon after the cytapheresis procedure was completed. No other adverse effects occurred during cytapheresis. From these results, cytapheresis can be considered a safe and effective treatment for MPO-ANCA-associated vasculitis. As for the mechanism of its action, soluble tumor necrosis factor receptor 1 (sTNFR), sTNFR2 and interleukin 1 receptor antagonist were elevated soon after cytapheresis and those levels 2 h after the cytapheresis procedure were higher than before the procedure in some cases. These elevations might be related to the efficacy of cytapheresis. © 2006 International Society for Apheresis.

Polyvinyl chloride (PVC) tubing is an indispensable medical material for extracorporeal circulation therapy. However, di(2-ethylhexyl)phthalate (DEHP), a suspected endocrine disruptor, can be eluted from PVC, suggesting that an alternative material that does not contain DEHP is needed for clinical applications. First, we evaluated the endocrine disrupting risks of the plasticizers contained in PVC tubes by investigating their binding affinities for the human estrogen receptor alpha (ERα). Our results revealed that, while DEHP has some binding affinity for ERα, neither epoxidized soybean oil nor tris(2-ethylhexyl)trimellitate (an alternative to DEHP) has any affinity for ERα. Second, we evaluated the endocrine disrupting risks of a tube made of newly developed plasticizer-free (PF) materials. We confirmed the presence of DEHP and detected several unidentified substances in plasma stored within the PVC tube. This plasma's competitive binding affinity for ERα was significantly higher than that of control plasma (P &lt 0.01). In contrast, the profile of plasma stored in the PF tube was similar to that of the control, both in terms of high-performance liquid chromatography chromatograms and competitive binding capacity for ERα, suggesting that the PF tube is biocompatible and is useful for reducing the elution of substances capable of binding to ERα. © The Japanese Society for Artificial Organs 2005.

To evaluate the efficacy of cytapheresis for the treatment of rapidly progressive glomerulonephritis (RPGN) caused by myeloperoxidase antineutrophil cytoplasmic antibody (MPO-ANCA)-associated vasculitis, the renal prognosis and the mortality rate at 1 year after treatment were compared between a Cytapheresis Group and a Steroid Pulse Group. The Cytapheresis Group included 10 patients who were treated with cytapheresis and oral corticosteroids. Five had granulocytapheresis with the Adacolumn (Japan Immuno Research Laboratories Co. Ltd, Takasaki, Japan) and the remaining five had leukocytapheresis with the leukocyte removal filter, Cellsorba (Asahi Medical Co. Ltd, Tokyo, Japan). The Steroid Pulse Group was comprised of 12 patients who were treated with methylprednisolone pulse therapy and oral corticosteroids. In the Cytapheresis Group, renal function recovered in 70% of the patients and the mortality rate was 10%. In the Steroid Pulse Group, renal function recovered in 66.7% and the mortality rate was 33.3%, with infection as the cause of death. Total doses of corticosteroids converted to prednisolone dose during a 1 month period, ranged from 280 mg to 1226 mg in the Cytapheresis Group. On the other hand, these dosages ranged from 2375 mg to 8380 mg in the Steroid Pulse Group. These results indicated that the mortality rate by infection could be reduced by adding cytapheresis therapy. Concerning the mechanism of cytapheresis, anti-inflammatory factors such as soluble tumor necrosis factor receptor, and interleukin-10 reduced after cytapheresis. These changes might be responsible for the efficacy of cytapheresis. In conclusion, cytapheresis is thought to be one of the effective treatments for RPGN caused by MPO-ANCA-associated vasculitis, reducing the levels of anti-inflammatory factors.

In this report, we describe 5 patients with cholesterol atheroembolic renal failure. In 3 of the 5 patients, combined therapy with corticosteroids and plasma exchange was performed. These 3 patients survived, with 2 showing an improvement in renal function. The 2 remaining patients died of multifactorial causes. The literature on therapy for cholesterol atheroembolic renal failure is reviewed and the efficacy of combined therapy by use of corticosteroids and plasma exchange is evaluated. Copyright (C) 2000 S. Karger AG, Basel.

血液透析の際にフタル酸ジエチルヘキシル量を測定し,ハイパフォーマンス膜(HPM)がDEHP除去に有用であった

出血性生病変を伴う慢性維持透析患者6名に再循環法による無抗凝固薬透析を試みたが, 血液回路特にドリップチェンバーを改良することにより支障なく施行できた. その際, 凝固線溶系に関する諸因子の変動を見たが, その成績に基づき各種膜材料の抗血栓性の評価も行った.<br>ヘパリンHD終了時のTAT値は, HD開始前に比し上昇しなかったが, 無抗凝固薬透析は前値に比し9.1倍の有意 (p<0.01) な上昇が見られた.<br>無抗凝固薬透析を行った場合, PC膜では, 透析によるTAT, 血小板減少率およびPF-4の変動が少なく, かつ, 透析終了時に全く残血を認めず, 最も抗血栓性に優れていると判定された.

エリスロポエチン (EPO) 投与による貧血の改善が, 投与前後の網赤血球 (RET) 率と赤血球 (RBC) 数の変動より予測可能かどうか検討した.<br>対象は, 血液透析 (HD) 歴が2年以上の安定期HD患者10人と, 導入期HD患者8人とした.<br>まず, EPO投与前後のRBC数, RET率を経時的に測定した著者の成績とこれまでの諸報告に基づきシュミレーションカーブを作成し, EPO投与4週以降14週までの期間のRBCの増加を予測する式を作成した.<br>この予測式に安定期HD患者6例のEPO投与後4週および8週目のRET数とRBC数を当てはめ, 8週および12週先のRBC数を予測したところ, 実測RBC数と近似した結果が得られ, 予測は可能と思われた, さらに, この予測式により導入期HD患者のEPO投与後のRBC数を算出し, 実測値と比較したが, 実測値がやや高値を示した. また, EPO投与後5週間の平均RBC増加数は, 導入期HD患者で82万個, 安定期HD患者では46万個であり, 導入期のRBC増加は, 安定期の約1.8倍であった.