Hemolytic-uremic syndrome (HUS) is a main cause of acute or chronic renal failure in childhood, but, its treatment has not been established. We treated 8 years old boy taking HUS with the plasma exchange (PE) used plasma separator MA 2500 (ASAHI) and fresh frozen plasma. After the PE therapy, plasma FDP decreased, gross hematuria ceased, thrombocytopenia improved gradually. But, the decrease of urine FDP and proteinuria was mild, the urine volume increased, a little, and he went to regular hemodialysis terminally. These results suspect the probability that the PE therapy prevents the formation of thrombi in the afferent arterioles and capillaries of the renal glomeruli, which would be the primary lesions of the HUS. The reason why he could not recover completely from his impaired kidney function with PE therapy is probably the delayed start of the PE therapy. Therefore, it needs further studies whether early PE therapy for the HUS will meet with better outcomes.

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Methemoglobinemia probably related to the ingestion of phenacetin and isosorbide dinitrate occurred in a 65-year old man who had been on chronic hemodialysis for four years. Although the withdrawal of the drugs and the administration of vitamin C lowered the concentration of methemoglobin from 22% to 2.6%, he died from heart failure soon after. The other hemodialyzed patients showed a normal concentration of methemoglobin (0.4-2.3%).
To examine whether the red blood cells of dialyzed patients are susceptible to the oxidant, the formation and reduction of methemoglobin were examined in vitro. Methemoglobin concentration was measured by the method described by Van Assendilft. When the washed cells from six normal and six dialyzed subjects were incubated in Krebs Ringer phosphate buffer containing 10mM glucose at 37°C in the presence of 0-6.75mM of NaNO₂, a dose-and time-dependent formation of methemoglobin was observed. There was no difference in the velocity and magnitude of the reaction between the two groups. The reducing power of the red blood cells was examined by further incubation of the cells pretreated for 30 minutes with 2.25mM NaNO₂ in the presence or absence of 10^-5M methylene blue. Both the slow NADH-dependent reduction and rapid NADPH-dependent reduction induced by methylene blue were demonstrated to the same extent in normal and dailyzed subjects.
Thus, in the present experiment, by which the reaction of red blood cells was examined in vitro, no evidence was obtained to indicate that the cells of dialyzed patients themselves were particularly susceptible to the exidant and had decreased ability to reduce the formed methemoglobin. It is assumed that, in addition to the change in pharmacokinetics common to patients on hemodialysis, individual tendencies such as that to form more oxidative metabolites or a decreased reducing power of the red blood cells contributed to the onset of methemoglobinemia in the present patient.

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A comparative study was made as to whether ECUM or high-sodium hemofiltration (Na-HF) would be clinically better in controlling the somatic fluid in severe edema.
In our investigations to identify suitable substances for the adjustment of the intracellular overflow and to determine their optimal concentration, frozen plasma was dialyzed with pure water, dialyzable substances, including electrolytes, were removed, and then NaCl, KCl, glucose, mannitol and glycerol were added at different concentrations to allow a fixed quantity of red cells to be suspended. Na and K in these red cells were estimated together with the hematocrit value before and after suspension. Simultaneously, the resistance of the osmotic pressure of the red cell membrane was also estimated using the Coil Planet Centrifuge Apparatus. Consequently, Na was found to be the most effective in correcting the intracellular overflow. Some effect was also seen with mannitol. Glycerol and K had to be added at a higher concentration, while glucose proved to have no effect. Na needed to be at a concentration of 145mEq/l or more to correct the intracellular overflow, but when the concentration exceeded the level of 180mEq/l, it tended to induce hemolysis.
Patients with severe systemic edema were treated with high Na-HF using a substitutional fluid containing-Na at a concentration of 150-160mEq/l, ECUM was also undertaken on the same patients for control of their somatic fluid in order to ascertain whether ECUM or high Na-HF would be more effective with respect to water removal, serum protein and hematocrit. Although there were no appreciable differences in these items of investigation, the patients complained of fatigue, weakness and muscular pain after ECUM, whereas they remained asymptomatic after high Na-HF.
High Na-HF using a substitutional fluid containing Na at 150-160mEq/l, if necessary, with transfusion of protein preparations induced no symptoms, but produced a somatic fluid control by reducing the body weight by 6kg/6 hours. when high Na-HF was applied to patients, it permitted them to return to work with a lower frequency of treatment, thereby convincing us of its usefulness.

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The side effects during dialysis are markedly reduced with bicarbonate dialysis as compared to acetate dialysis. However, a significantly larger amont of water is removed during bicarbonate dialysis, resulting in excessive Na removal, hyponatremia, a shift of extracellular water into the cells, hemoconcentration, and complaints secondary to hypotension. These symptoms can be prevented by limiting the fall of plasma volume to less than 80%. Water is efficiently pulled ouo of the cells into the plasma by raising the dialysate's Na concentration to more than 146mEq/l. The results from simulation using a three-pool model were compared with clinical symptoms in order to ascertain the optimum Na concentration. The cell wash method is effective to reduce thirst.

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Amount of small solute removal (M) is measured not only by actual survey, but by collecting a part of whole drainage (dialysate or filtrate). In haemofiltration (HF) therapy, we proposed two different methods of measuring ‘M’ except actual survey (storing whole drainage). Because these methods gave quite close value each other, they are capable enough to apply in vivo.
In haemodialysis (HD) or haemodiafiltration therapy, it is actual survey which is in fact the only method to adapt, but it is impossible to measure ‘M’ with no considerable errors. So the simple method, which is proposed in this paper (only net fluid removal volume and its solute concentration are needed, using ultrafiltration controller), can be useful to know ‘M’ less than ±7% errors.
Then ‘M’ is proved to be in proportion to serum solute concentration before the therapy (C(0)) in each treatment method. So we proposed new index M/C(0) in order to compare the essential difference of small solute removal capacity between HD and HF. We concluded that HD therapy is more valuable than HF to remove larger amount of small solute, because it is theoretically and experimentally confirmed that ‘M’ is mainly dependent upon artificial kidney clearance.
Amount of removed solute is easily measured, using our methods, and they made it simple to evaluate solute removal performance in blood purification therapy.

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Details of the time course change in the sieving coefficient (SC) of different molecular weights of protein during plasma exchange (PE) using membrane are not welk known. We studied the SC of several kinds of protein, including very-low-density lipoprotein (VLDL) and low-density lipoprotein (LDL), at the start and the end of PE in patients including a patient with hyperlipoproteinemia. The number of PE during the study period was 22 and PE was performed using the polyvinylalcohol (PVA) membrane. The exchange fluid was 5% albumin Ringer lactate solution and the exchange volume was 5% of body weight. The SC of seven different molecular weights of protein (MW 12000-100×10⁴) was measured in all five patients, including a case of familial hyperlipo-proteinemia (Case 1) and, in one of the other cases who had a normal lipoprotein level (Case 5), the SC of LDL (MW 200×10⁴) and VLDL (MW 1000×10⁴) were measured.
The SC of the above seven different molecular weights of protein were all more than 0.8 and did not change significantly during PE. There was no downward tendency in the SC in proportion to the increasing molecular weight.
In Cases 1 and 5, the SC of LDL and VLDL averaged more than 0.8 and did not change from the start to the end of PE. Even in Case 1 alone, there was no significant change of the SC from the start to the end. In this case, there was a significant decrease in serum total cholesterol, triglyceride, LDL and VLDL by PE.
By the electromicroscopic examination, there was no significant difference on the surface of the PVA membrane after PE between a case of hypercholesterolemia and a case with a normal cholesterol level.
Generally, solute permeability through membrane is influenced by multiple factors, such as molecular weight, molecular size, time course of filtration, number of types of solutes and density of solutes. In our study, it was apparent that the permeability of protein, including LDL and VLDL, was high and remained unchanged during the course of filtration in PE using the PVA membrane.
In conclusion, the PVA membrane in useful for PE in patients to remove different molecular weights of protein from 12000 to 1000×10⁴, including LDL and VLDL. it is suggested that PE using the PVA membrane is useful for patients with familial hyperlipoproteinemia.

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In many patients undergoing long-term hemodialysis, blood access problems, i.e., inadequate blood flow volume for dialysis have been seen periodically. A microscopic surgery technique was used to create adequate arteriovenous fistulae in order to eliminate these problems in 270 cases starting in 1975. Thus, blood access problems were reduced quite favorably.
The histopathological changes of arteries and veins were investigated in order to ascertain whether the failed blood access originated from the vascular area itself or not. Although arteries were considered changes of Arteriosclerosis, Hypertention and Diabetes, there was appreciated various hyalin degenerations in veins.
Cardiac pressure study was undertaken to estimate the effects of arteriovenous fistulae on circulatory function. There were no significant enanges, before and after surcery, with fistulae of 5-6mm in diameter.

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