A new blood purification method of “Double filtration plasmapheresis” has been devised in an attempt to solve she problems persisting in current plasmapheresis.
Two filters with different membrane pore size are utilized in an extracorporeal circulation line. The first filter with larger pores is used as a plasma separator which permits only plasma to filtrate. Filtrated plasma is subsequently lead to the second filter. The second filter with smaller pores is used as a plasma filter which permits smaller molecular components of plasma to pass through. Larger molecular components of plasma are concentrated and selectively removed from whole blood by this new technic.
Eighteen procedures of “Double filtration plasmapheresis” have been performed in 5 patients with original diseases of SLF, RA, end-stage carcinoma, arteriosclerosis and Bürger's syndrome. Clinical effects have been observed in all patients with no unfavorable signs.

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Thirty-three patients with urinary tract anomalies detected by IVP or VCG followed at Pediatric Nephrology clinic in Kitasato University Hospital were studied. Urinary tract infection was the commonest reason for the radiological investigation and was associated with VUR frequently. Impairment of renal function was observed in those who have unilateral renal anomaly with chronic glomerulonephritis and one with unilateral UPJ obstruction and agenesis of another kidney. The importantroles of the pediatritian in prevention of renal failure among children are early recognition of patients with congenital obstruction of urinary tract, the referral of these patients to the urologist and prevention of the urinary tract infections which damage the renal function in them. Chronological deterioration of the renal function was not shown in these patients but failure of growth of the kidneys in patients with VUR and recurrent urinarytract infection was observed. On the other hand the normal growth of the kidneys were observed in a patient with severe UVJ obstruction whose urinary tract infections had been successfully treated medically. Screening of proteinuria and hypertension in asymptomatic children in also useful in detecting these patients with urinary tract anomalies and the control of hypertension is essential for the prevention of the development of chronic renal failure. Chronic glomerulonephritis is the commonest cause of the end stage renal diseases but there is no definitive therapy for it. Various treatments have been attempted but controlled studies are necessarry for thire evaluation.

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Pre and Post operative nutrition in renal failure patients is a key point in the success of their gastrointestinal surgery. In general, such nutrition is made intravenously or enterally. The latter technigue includes elemental diet, tube feeding and oral intake.
The control of fluid, calory and electrolytes must be paid special attention in dialysis patients. In the past 44 months, 12 gastrointestinal operations were performed in which 5 patients showed improvement in the diseases, although the remaining 7 patients died. When the causes of the deaths were evaluated, most of the diseases were malignant, and the admission to the hospital, as well as the operation was of the emergency, and pre-operatively, the patients were at poor risk. In addition, we consider that post-operatively, there was absolute lack of the volume of the food and high calory fluid intake. Furthermore, we have had little experience of such big surgery in dialysis patients and it seems we put too much limitation to dialysis frequency and fluid intake.
In the 5 succeeded patients, the factors such as that the large percentage of the total calory, post-operatively, was taken orally and that pre-operatively adequate calory (45cal/Kg) was ingested orally, must have led to the good results.
Post-operative peritoneal dialysis is becoming unnecessary in our hospital and an increase in supplement fluid can be inhibited by conducting ECUM (Extracorporeal Ultrafiltration Method). We believe that the technique of post-operative clinical care has been established to a considerable degree by our experience. Furthermore, the nutrition control will become perfect, if we can give adequate volume of low residue fluid diet to patients at the earliest moment after the recovery of the function of the gastrointestine was seen. We are encouraged to make further effort to increase the success rate of the surgery by inclusing in the reevaluation the starting period of feeding fluid diet, food taste of the patients and the volume of the foods eaten by them.

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The pulse-input method is proposed to evaluate the performance of dialyzer more precisely. This method gives not only the value of dialysance but many other informations such as flow characteristics of blood and dialysate.
The experimental procedure is very simple. A small quantity of indicator is injected into the inlet of the blood flow of a test dialyzer in the steady state, where the blood and dialysate flow rates, the transmembrane pressure and the temperature are controlled to be constant. The concentration of indicator is measured in the outlet of the dialysate and is recorded continuously. The parameters about the efficacy of dialyzer cited above can be calculated from this response curve by the countercurrent plug flow model.
We studied 4 kinds of hollow fiber typed artificial kidneys with different inner structures in vitro. As an indicator, 5ml of 10% NaCl was injected and the change of concentration was measured by the electric conductivity. The experimental results are summarized as follows;
1) The blood flow velocity is nearly uniform for each type of dialyzer.
2) The flow velocity distribution of dialysate depends strongly on the inner structure. The dialyzers with modified inner structure exhibit more uniform flows.
3) More uniform dialysate flows result in higher mass removal rates.
4) The dialysate flow patterns of dialyzers with modified inner structure is unstable in the lower flow rate region (Q_D 200-300ml/min).
These results show the close relation between the flow characteristics in dialyzers and the mass removal efficiency. The pulse-input method can be effectively applied to the evaluation of the blood and dialysate flow characteristics. It is expected that this technique is useful for evaluating the performance of artificial kidneys and contributes to the planning for more desirable dialyzers.

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The frequency of diabetic among all patients on regular dialysis treatment has increased in recent years. About 11% of new dialysis patients in 1979 in our dialysis center had diabetes.
We analysed the relation between complications at the start of dialysis treatment and prognosis in 51 diabetic patients on regular dialysis treatment. At the start of regular dialysis treatment, pulmonary congestion was observed in 73.7% of diabetic and in 15.0% of non-diabetic patients. Severe gastrointestinal symptoms were observed in 30.6% of diabetic and in 95% of non-diabetic patients. Mean serum creatinine concentration is 10.0±3.4mg/dl in diabetic and 15.6±5.0mg/dl in non-diabetic patients. Pleural effusion, ascites, and calcification of peripheral arteries were common complications in diabetic patients.
There were no significant differences between diabetic and non-diabetic groups in mean fall of serum osmolality and in diminution of circulating blood volume during hemodialysis. A low response of plasma renine activity during hemodialysis was common in diabetic patients. High histamin concentration in blood was observed in some diabetic patients, especially hypotensive cases. The rises of serum acetate concentration during hemodialysis in two groups were same extent.
The diabetic patients had more episodes of hypotension, nausea, and vomiting during hemodialysis than the nondiabetic one. Causes of these symptoms may result from multi-factors; such as arteriosclerosis, autonomic nervous disturbances, poor responsiveness of renin-angiotensin system, which cause poor adaptation to change of body fluids.
After begining of dialysis in diabetic patients, daily insulin requirements frequently decreased in good prognosis group and on the other hand marked fluctuation of blood sugar was common in poor prognosis group. Hyponatremia, pleural effusion, anorexia, and consciousness disturbance were commoner in poor prognosis group, but renal function at the first dialysis was rather better in this group. Thus, prognosis of diabetic patients was correlative with extrarenal complications at the early phases of dialysis treatment.
Main causes of death in diabetic patients at the early phase of dialysis treatment were infection and heart failure. A high incidence of tuberculosis in diabetic patients was observed and their prognosis was poor.
From our experiences, it is concluded that, in diabetic patients, dialysis using REDY system, dialysis using bicarbonate dialysate, and hemofiltration are effective to prevent uncomfortable sideeffects during hemodialysis.

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The hemodynamic assessment of blood access was performed by the estimation of shunt flow with ultrasonic Doppler flowmeter and cardiac output with dye-dilution technique.
(A) Subcutaneous A-V fistulae on the forearm (36 cases). Blood flow velocity of the brachial artery averaged 5 times larger on the fistula-side as compared to another side. Shunt flow was regarded as excellent when the flow velocity of the brachial artery on the fistula-side exceeded 20cm/sec and was at least twice as compared to another side. Blood flow rate of the brachial artery on the flstula-side was estimated as 517±258ml/min (m±SD) for the side-to-end anastomosis and 518±199ml/min for the side-to-side anastomosis, and was considered to be an approximation to the shunt flow. The former mode of anastomosis is preferred, because the anastomosis can be easily performed with less tension on blood vessels, and the venous distension of the hands and fingers (“sore thumb syndrome”) occurs less frequently. Though A-V fistula might increase cardiac output, the ratio of the flow rate of the brachial artery to the cardiac output was as little as 2.9-12.4% (av. 7.3%), suggesting the least possibility of the high output failure.
(B) E-PTFE grafts (9 cases). Grafts were implanted as loop-shaped on thighs or forearms. The flow rate of grafts of ID 8mm exceeded 1l/min in all patients with the occurrence of heart failure in a 77-year-old diabetics. Grafts of ID 5mm was sufficient for hemodialysis, but grafts of ID 6mm may be advised, when the possibility of the gradual occurrence of stenosis after the longterm use was taken into account.
It is concluded that the hemodynamic evaluation of blood access is useful from the clinical standpoint.

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Calcium balance study during hemofiltration was performed on four patients treated with chronic hemofiltration three times a week by the post-dilution technique. In each hemofiltration at least 18l of body fluid was replaced in addition to ultrafiltrate for intertreatment body weight gain. The group of 4 patients were treated with 3 kinds of substitution fluid having the calcium concentration of 3.0, 3.5 and 4.0mEq/l, each kind for 2 or weeks in sequence, which resulted in 3 different treatments according to the different Ca concentration.
Calcium balance during hemofiltration was affected positively by the calcium concentration of substitution fluid, and negatively by the amount of ultrafiltrate for body weight loss. The amount of phosphate removal, however, was not varied between the 3 treatments.
Although serum calcium concentration in each treatment increased during hemofiltration, the increase was not related to calcium balance. On the other hand, a decrease of serum phosphate concentration was correlated to the amount of phosphate removal during hemofiltration. An increase of serum non-ionized calcium concentration which was larger than that of serum ionized calcium concentration, showed a significant correlation with an increase of serum albumin concentration owing to hemoconcentration.
PTH level decreased after hemofiltration, which was more closely correlated to an increase in serum ionized calcium than to calcium balance.
Positive calcium balance might be obtained in ordinary hemofiltration procedure when calcium concentration of substitution fluid is above 3.5mEq/l.

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