We investigated a portable bioartificial renal tubule device (BRTD) consisting of renal tubule cells and hollow fibers, to improve the quality of life of patients. It is necessary for a BRTD system to be compact. A compact portable BRTB requires transfection of an appropriate water channel or electrical pump genes in tubular epithelial cells, which should be based on physiological similarities to human kidney function. LLC-PK 1 cells, into which rat kidney aquaporin 1 (AQP1) cDNA was stably transfected, were evaluated for water transport ability. The expression and localization of water AQP1 were examined by Western blotting, RT-PCR, and immunofluorescence. To measure transcellular water permeation, a simple method was applied, using phenol red as a cell-impermeant marker of concentration. In contrast to wild-type LLC-PK1 cells, rat AQP1-transfected cells had high transcellular osmotic water permeability. The expression of rat AQP1 mRNA (ratio of AQP1 to β-actin mRNA) and protein bands (a 28-kDa band and a broad, 35- to 45-kDa band) was confirmed to be stably maintained until a population doubling level of 24. In AQP1-transfected LLCPK1 cells, the protein was localized mainly to the basolateral side, but also the apical side, of the plasma membrane. Wild-type LLC-PK1 cells were not stained at the plasma membrane. It is possible that enough AQP1–transfected tubule epithelial cells were supplied for a bioartificial renal tubule device.

Transcellular

Aquaporin 1

Paracellular transport

Aquaporin 3

10.1089/1076327041348383

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Citations (22)

Purification of rat prolactin releasing factor by gel filtration.

The Tohoku Journal of Experimental Medicine (1978)

Katsuyuki Takahashi Teiko WAKAI N Furuhashi Hiroshi Hoshiai Yuichi Wada

Pregnant rat hypothalamic fragments were extracted with 30mM Tris-HCl buffer at pH 7.8, subjected to enzymatic digestion, and applied to gel filtration on Sephadex G-25 for purification of the prolactin releasing factor. Effect of the eluted fractions on the release of prolactin were tested by the determination of serum and pituitary prolactin after the injection in lactating rats. Prolactin was estimated by radioimmunoassay. One fraction (tube number 61-73) eluted later than synthetic ACTH enhanced release of prolactin 30min after injection, but other fractions had no effect on the release of prolactin. Prolactin releasing factor would be quantitatively predominant over prolactin inhibiting factor in pregnant rat.

Sephadex

10.1620/tjem.126.77

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Citations (2)

Cardiovascular and Stroke Risk in Japanese Hemodialysis Patients With Atrial Fibrillation

Therapeutic Apheresis and Dialysis (2016)

Jumpei Hasegawa Brian Bieber Maria Larkina Bruce Robinson Sachiko Wakai

Atrial fibrillation is one of the most common arrhythmias in hemodialysis patients. We evaluated its clinical outcomes among hemodialysis patients with atrial fibrillation in Japan. Using data derived from the Japanese Dialysis Outcomes and Practice Patterns Study, we analyzed backgrounds and outcomes among hemodialysis patients with and without atrial fibrillation in Japan. Among 7002 hemodialysis patients, the prevalence of atrial fibrillation was 5.7% and the incidence was 0.2 per 100 patient-years. Atrial fibrillation was independently associated with all-cause mortality (hazard ratio, 1.32; 95% confidence interval, 1.02-1.71) and cardiovascular events (hazard ratio, 1.39; 95% confidence interval, 1.15-1.68), but not with stroke events (hazard ratio, 0.77; 95% confidence interval, 0.55-1.06) after adjustment for other variables. We conclude that patients with atrial fibrillation experienced higher mortality and more cardiovascular events than did patients without atrial fibrillation, although the risk of stroke was lower than expected.

Stroke

10.1111/1744-9987.12460

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Citations (3)

Kidney tissue engineering

Elsevier eBooks (2007)

Akira Saitō

Glomerulus

Regenerative Medicine

Tubule

Artificial kidney

Intercalated Cell

Distal convoluted tubule

10.1533/9781845693817.2.421

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Citations (1)

Present status and future perspectives on the development of bioartificial kidneys for the treatment of acute and chronic renal failure patients

Hemodialysis International (2011)

Akira Saitō Kaichiro Sawada Satoshi Fujimura

A bioartificial renal tubule device (BTD) consisting of a hollow-fiber module and human proximal tubular epithelial cells has been completed technically by Humes and colleagues and a few other groups. Humes and colleagues developed BTD, treated acute kidney injury patients with multiorgan failure by continuous hemofiltration (CHF) in conjunction with BTD, and reported a significantly higher survival rate than that by CHF with BTD without cells in the Food and Drug Administration phase IIa trial. However, BTD has never been approved by the US Government, as the CHF+BTD treatment did not show a significant difference from the control group in the phase IIb trial. Human proximal tubular epithelial cells were confirmed to be overgrown on artificial membrane, which resulted in the inhibition of active transports and the metabolism of essential substances. Function of the BTD could be maintained in a U0126-contained medium, even if the BTD had to have been waited by a new acute kidney injury patient for several weeks. For wearable kidneys, heparin-covalently bound membrane or methacryloyloxyethyl phosphorylcholine (MPC) polymer-coated membranes are candidates for antithrombogenic hemofilters, while endothelial progenitor cells from a cord blood, CD133+ cells-attached hemofilter in which the permeability of the cells was enhanced by the enlarged diameter of fenestrae by treating with cytochalasin B are another candidate. The MPC blend membrane containing 1% of the MPC polymer in polysulfone was developed as a BTD module. MPC was 7 times larger at the sponge layer than at the skin layer of the membrane, resulting in hemocompatibility at the sponge layer and cytocompatibility at the skin layer.

Phosphorylcholine

10.1111/j.1542-4758.2011.00530.x

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Citations (27)

Kidney International (2003)

Donna Mapes Antônio Alberto Lopes Sudtida Satayathum Keith McCullough David A. Goodkin

10.1046/j.1523-1755.2003.00072.x

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Citations (821)

[The in vivo activity of tobramycin intravenous drip fusion (author's transl)].

PubMed (1980)

Akira Saitō

Source

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Citations (0)

The effect on the rate and amount of removal of various substances by changes in dialysis flow, dialysis time and blood flow.

Nihon Toseki Igakkai Zasshi (1996)

Hisashi Ichikawa Akira Saitō Hidetaka Yamazaki Yasutaka Hurukawa Kazuyoshi Hori

維持血液透析患者に, 透析液流量 (QD), 透析時間, 血流量 (QB) を変更し, その際小分子量物質として尿素窒素 (UN), クレアチニン (Cr), 尿酸 (UA), 無機リン (iP), 中分子量物質としてピーク2a, 低分子量蛋白としてβ2-MGの除去率, 除去量の比較検討を行った. また, QBを変更した時のUreaのKT/V, TACBUNを測定し比較検討した.結果は, (1) QDを500ml/minと400ml/min, (2) 透析時間を4時間と5時間で透析したときの各小分子量物質, ピーク2aおよびβ2-MGの除去率では有意差は認められなかったが, 除去量ではUN, Cr, UA, iP, ピーク2a, β2-MGそれぞれに有意な差が認められた. (3) KT/V, TACBUNは目標値とされている範囲内での変動であり, 除去率と同様KT/V値のみを指標とすることは慎重でなければならないと思われた. 今回の成績から, 透析条件としてQDは400ml/minよりは500ml/minが, 透析時間は4時間よりは5時間が望ましいと考えられた.

Kt/V

10.4009/jsdt.29.1043

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Citations (0)

CAPD and Protein-Permeating Hemodialysis: A Clinical Comparison

Springer eBooks (1986)

Akira Saitō Hiroshi Ogawa Tai Gi Chung Kenji Maeda

Beta-2 microglobulin

Serum Albumin

10.1007/978-3-662-11784-2_57

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Citations (6)