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Biomedical subjects

T Sanaka

Publications and source records attributed to T Sanaka.

83 records · Page 5Linked to original sources
PubMed1980

Influence of uremic middle molecules on blood cells.

Uremic middle molecular weight substances are obtained from the ultrafiltrate of plasma of uremic patients. Seven subfractions are isolated by chromatography using Sephadex G-15 and DEAE 25 A columns. Each subfraction is tested for its inhibitory effect upon lymphocyte blastogenesis and influence upon osmotic fragility of red blood cells. Consequently, subfractions c and d exert notable effects on both lymphocytes and red blood cells. The main constituents of subfraction d are aspartic acid, glycine, glutamine, and cysteine. It is concluded that uremic middle molecular substances have a deleterious effect upon blood cells. Therefore, hemofiltration, which is advantageous for the removal of middle molecular weight substances, is considered to be a method of choice for uremic patients.

Amino Acids↗
PubMedDate not supplied

Analysis of the clinical course of 130 Japanese non-insulin-dependent diabetic patients undergoing dialysis.

To clarify the characteristics of diabetic nephropathy (DN) in Japanese patients with non-insulin-dependent diabetes (NIDDM), we analyzed the clinical course of 130 such patients who began dialysis treatment due to DN between 1978 and 1988 at the Diabetes Center of Tokyo Women's Medical College. Analysis of the clinical course prior to attending the Diabetes Center revealed that 64 (49.2%) of the patients neglected or discontinued their initial treatment for diabetes until the development of diabetic complications because of the lack of symptoms. The average duration of untreated diabetes in these patients was 10.7 +/- 4.6 years. The biggest problem for NIDDM patients was the absence of symptoms until the development of diabetic complications.

Diabetes Mellitus, Type 2↗
PubMedDate not supplied

Extracorporeal hybridization of proximal renal tubular cells and an artificial membrane for the purpose of beta 2 microglobulin removal.

The present study was designed to develop a bioartificial kidney hybridized with LLC-PK1 cells for the purpose of beta 2microglobulin (B2M) removal. Cells were prepared in polystyrene culture wells; the bottom of each was covered with collagen fiber and the cells grown as monolayer cultures. Each well was inoculated with 1 ml cell suspensions with 0.0, 1.0 X 10(6), 2.0 X 10(6), or 4.0 X 10(6) cells/well. B2M was added to the culture system at a concentration of 80 micrograms/dl. Results were as follows: 1) Concentration of B2M in the supernatant of 4 X 10(6) cultivated LLC-PK1 cells was decreased from 79.32 +/- 2.41 micrograms/dl to 67.02 +/- 3.00 micrograms/dl (n = 6, p less than 0.01) at 2 hr; 2) Concentration of B2M in the supernatant of 1 X 10(6), 2 X 10(6), and 4 X 10(6) cultivated LLC-PK1 cells was 75.06 +/- 2.31 micrograms/dl (n = 6, p less than 0.05); 67.27 +/- 11.41 micrograms/dl (n = 6, p less than 0.001); and 67.02 +/- 3.00 micrograms/dl (n = 6, p less than 0.001), respectively, vs. 79.32 +/- 2.41 micrograms/dl in controls at 2 hr; 3) There was a significant positive correlation between the efficacy of B2M removal and cell number; and 4) These results suggested that it is possible to develop an artificial kidney hybridized with proximal tubular cells that possesses a high affinity for B2M removal.

Animals↗
PubMedDate not supplied

Continuous monitoring of blood volume in double filtration plasmapheresis.

A continuous hematocrit (HCT) monitor, Crit-Line, was introduced to examine the change in patients' blood volume (BV) due to albumin loss during double filtration plasmapheresis (DFPP) treatments. Nine patients with autoimmune diseases or ABO incompatible renal transplantation received 15 DFPP treatments under Crit-Line monitoring. In these patients, plasma albumin concentration (C(P)) changed from 3.7 +/- 0.6 g/dl to 3.5 +/- 0.5 g/dl and HCT from 28.7% +/- 3.3% to 31.3% +/- 4.3% (change ratio [CR] of BV = -8.1%) during treatment with albumin concentrations (C(S)) of 9.5 +/- 1.0 g/dl and 500 ml volumes (V(S)) of supplementation fluid. Although the apparent CR value of C(P) was -5.3%, on average, the CR of albumin in the patients' plasma (M(P)) was -16.1%, which means a corrected CR value of C(P) by the HCT value to eliminate the influence of the patient's blood volume contraction during treatment. Albumin loss usually occurred in DFPP treatments. The decrease in BV was induced by an oncotic pressure drop due to albumin loss, and often resulted in a blood pressure drop. The amount of albumin loss during DFPP treatments strongly depends on sieving coefficients of the plasma separator (SC(PS)) and the plasma fractionator (SC(PF)), the filtration fraction of the plasma fractionator (FF(PF)), pretreatment C(P) value, and C(S) and V(S) values of the supplementation fluid. To determine the optimum C(S) and V(S) values for each patient, the authors introduced a variable blood volume model for albumin transport in DFPP. In this model, changes in C(P), HCT, and BV values could be estimated during treatment. For example, a patient with an HCT of 31.2%, body weight of 61.1 kg, and pretreatment C(P) of 4.4 g/dl received a DFPP treatment using a plasma separator, OP-05 (SC(PS) of 0.99), and a plasma fractionator, Evaflux 2A (SC(PF) of 0.40), under FF(PF) of 0.8 with a V(S) of 500 ml. A value for C(S) of about 10 g/dl is required for the patient to maintain a normal C(P) level during treatment by an estimation from the model. As a result of the treatment with a C(S) of 10 g/dl, the patient had no adverse reactions, such as a blood pressure decrease, during treatment under these conditions.

Blood Volume↗
PubMedDate not supplied

Non-heparin hemodialysis with oral administration of newly developed antiplatelet agent.

Non-heparin hemodialysis (HD) was successfully done in anuric dogs with the oral administration of a newly developed antiplatelet agent, 4-cyano-5,5-bis(4-methoxyphenyl)-4-pentenoic acid, (E5510, Eisai Pharmaceutical Co., Japan). In the current study, the antithrombotic effect of E5510 during HD was investigated. Eleven mongrel dogs with bilateral ureteral ligation were given 0.1 mg/kg of E5510 orally 1 hr before undergoing 4 hr HD using hollow fiber dialyzers, (PMMA 5, regenerated cellulose 6) without heparin and under general anesthesia. Blood samples were taken before the administration of E5510 and before and 1, 2, 3, and 4 hr after starting HD; blood counts, hematocrits, blood chemistries, and plasma thromboxane levels (TxB2) were examined. Platelet aggregation, activated clotting times (ACT), and activated partial thrombin times (APTT) were also measured, and sequential plasma E5510 concentrations were determined. In 10 of 11 anuric dogs, non-heparin HD was successfully done with minimal clotting in the dialyzer and drip chambers. The maximum aggregation rate was depressed to less than 20% of the initial value throughout HD. Plasma TxB2 concentration was depressed, and ACT and APTT were mildly, but not significantly prolonged. Neither hemorrhagic complications nor other side effects of E5510 were observed.

Administration, Oral↗
PubMedDate not supplied

Difference in beta 2-microglobulin removal between cellulosic and synthetic polymer membrane dialyzers.

Several kinds of dialyzers, with highly permeable membranes (HPM), have been designed to specifically remove beta 2-microglobulin (BMG). To clarify their solute transport characteristics, nine types of HPM dialyzers were evaluated during in vivo and in vitro studies using human plasma and aqueous solutions. No BMG membrane adsorption and/or plugging was seen with cellulosic membrane dialyzers during in vitro experiments using human plasma. On the other hand, all synthetic polymer membrane dialyzers had adsorptive properties, and in a dialyzer with a polymethylmethacrylate membrane, a large amount of BMG was removed by adsorption alone. Dialyzers with cellulose triacetate and polyacrylonitril membranes showed higher values of BMG diffusive dialysance (greater than 20 ml/min) and sieving coefficient (greater than 0.9). From in vitro experiments using an aqueous solution containing several solutes with relatively small or middle molecular weights, all HPM dialyzers had a higher overall mass transfer coefficient than any conventional membrane dialyzer.

Blood Flow Velocity↗