The hemopurification therapy is operated at present based merely upon the medical staff's judgement. The purpose of this study is to establish the automatic control of hemodialysis therapy by using desk-top computer.
The removal of uremic toxins in the body and in a module was analyzed both with a pool model and a mass transfer model. As a result of this analysis, the logarithmic concentration of blood and dialysate was found to change linearly with time. From the linear line of dialysate concentration, it was found that the slope had depended upon C_L or D_B. The intercept at the start of hemodialysis therapy depends upon pre-dialysis concentration [C_B(O)].
The change of the blood concentration can then be estimated simply from the dialysate concentration. Using more than two dialysate concentration data, the concentration profile of dialysate will be determined. C_L (or D_B) and C_B(O) can be obtained from the slope and the intercept of the profile. The blood concentration at any time is then derived from the following equation: C_B(t)=C_B(O)exp(C_L/V_B)
The calcurated values of blood concentration were found to agree with the experimental values.
A continuous analysis method of urea was devised through the use of ammonia electrode and unease column. This column was packed with the immobilized urease on a porous glass to reduce urease loss.

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It has become possible to diagnose amyloidosis with the advent of biopsy during life. We undertook clinico-pathological investigations of 11 cases of chronic renal failure with amiloidosis, of which eight showed dysfunction of many organs, involving fatigue, arrythmia, anorexia, nausea, vomiting, generalized edema, itching, pigmentation, and enlargement of the liver. The more evident the clinical signs, the worse was the prognosis. Cases which revealed a low voltage and frequent appearance of arrythmia on E. C. G., had a poor prognosis. They were presumed to have cardiac amyloidosis. Comparison of the times of entering hemodialysis between cases of chronic renal failure from chronic glomerulonephritis and these from amyloidosis, revealed that the latter was faster. Most of them had rather to start hemodialysis in order to improve and overcome cardiac failure and symptoms of the gastroenteric tract, especially anorexia. Many cases of amyloidosis were difficult to the sustain because of difficulty in maintaining the shunt due to vulnerability of the vessels, hypotension and a poor general conditions There were four cases of primary generlaied amyloidosis, six cases of secondary amyloidosis, and one suggesting multiple myeloma. We examined tissues from autopsy which exhibited amyloid deposition throughout the body in both the primary and secondary disease, and there were no appreciable differences in deposition between the two. As precursors of amyloid fibrils, the proteins of AL (primary amyloidosis) and AA (secondary amyloidosis) have been maintained. The molecular weight of the former is 5, 000-25, 000, and that of the latter is 8, 500. Such protein including the precursor should be eliminated by means of specific hemodialysis including plasmapheresis.
Cases without cardiac amyloidosis are expected to have a good prognosis following hemodialysis. It is to be hoped therefore that effective agents like DMSO, etc. for amyloidosis will be found. Early diagnosis and treatment should be borne in mind.

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Recently, hemodialysis (HD) for children with chronic renal failure (CRF) has made remarkable progress in Japan, and the numbers of surviving children are gradually increasing. The ultimate purpose of the treatment of children with CRF is not only to save their lives but also to help them grow up.
One of the causes for the reduced growth found in CRF chiliren appears to be insufficient nutrition resulting from an inadequate diet. Although amino acid analysis on such patients has been performed to evaluate their nutritional condition, the results have tended to be rather controversial due to insufficient numbers of patients.
The present report deals with amino acid analysis performed in 19 children on maintenance HD, and the results are compared with those in adults to clarify the abnormal metabolism of amino acids in children with CRF.
Results:
1) The total amino acid concentrations were significantly low in the HD group compared to normal controls.
2) The concentrations of essential amino acids, eskecially of valine, were decreased.
3) The concentrations of histidine, interpreted as an essential amino acid in CRF, were similar in the HD group and controls.
4) The concentrations of non-essential amino acids such as 1-methyl histidine, 3-methyl histidine, o-phosphoserine, cystine, and β-amino isobutyric acid were increased, whereas those of arginine, serine, alanine, and tyrosine were significantly decreased.
5) The ratios of tyrosine/phenylalanine, arginine/citrulline and serine/o-phosphoserine were decreased.
Discussion:
Some differences in serum amino acid concentrations were observed between the patients on maintenance HD and normal children. The low concentrations of total amino acids in the patients may have been due to insufficient nutrition. The decrease in ratio of certain amino acids suggests that the activity of amino acid transferase was reduced in the CRF children.
Recently, amino acid infusion therapy has been attempted. However, appropriate management of the dies would seem to be of paramount importance in children on maintenance HD.

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The clinical advantages of newly developed dialysate (Na-140-D) which was composed of 140mEq/l of Na, 2mEq/l of K, 3.3mEq/l of Ca, 1mEq/l of Mg, 109.3mEq/l of Cl, 37mEq/l of acetate and 100mg/dl of glucose were evaluated.
38 chronically hemodialysed patients were treated with Na-140-D for 6 months, the frequency of dialysis disequilibrium syndrome (DDS) and laboratory data were compared with those of previous 6 months when the patients had been treated with K-3 dialysate (Na 132, K 2, Ca 3.5, Mg 1.5, Cl 104, acetate 35mEq/l and glucose 200mg/dl).
The occurrence of DDS was reduced significantly in Na 140-D. The frequency of treatment for DDS such as saline infusion etc. also decreased significantly.
Predialysis serum Ca concentration was same in both dialysates. Though the elevation of Ca concentration after each treatment was less in Na-140-D, post-dialysis ionized Ca level was within physiological values and post-dialysis depressive effect on PTH was recognized in both dialysates.
Na-140-D reduced serum Mg concentration significantly.
Alteration in blood sugar of diabetic hemodialysis patients during treatment was less in Na-140-D than in K-3.
These results indicate that Na-140-D has several beneficial characteristics in the treatment of the cases who are easy to get DDS, who are administered with vitamin D metabolites and who are diabetic.

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A study was carried out to compare the effect of bicarbonate-containing dialysate (bicarbonate dialysis) with acetate-containing dialysate (acetate dialysis) on hemodialysis-induced morbidity and vascular instability. In this study, hemodialyses were performed using acetate-dialysate for the first one month and with bicarbonate-dialysate for the next one month, and thereafter with acetate-dialysate for the third month in 27 chronic hemodialysis patients who had been symptomatic on acetate dialysis. All details of bicarbonate dialysis including dialyzers, dialysate delivery systems, dialysate composition, dialysate flow, blood flow rate, ultrafiltration rate, dialysis time and dialysis frequency, were the same as during acetate dialysis except for the sort of dialysate-alkaline solution.
In the both dialyses, no significant differences were observed in pre-, post-dialysis levels of BUN, serum creatinine, serum electrolytes, plasma pH and bicarbonate of the patients. During dialysis therapy with acetate, hypotension, the feeling of discomfort and vomiting were noted in 49%, 35, 5% and 9.8%, respectively. While with bicarbonate dialyses, these occurrences were 35%, 23% and 2.5%, respectively. The incidence of muscle cramps was 2.1% with acetate dialysis and 4.8% with bicarbonate dialysis.
On the other hand, a significant decrease in the side effects was noted with bicarbonate dialysis in 2 patients who had had hyperacetatemia above 10mEq/l, during acetate dialysis.
It was concluded from this cross-over study that hemodialysis-induced morbidity and vascular instability observed during acetate dialysis could be reduced significantly by bicarbonate dialysis. Especially, marked improvement can be expected in the patients with acetate-intolerance.

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The routine dialysate delivery system (DDS) as a single patient unit, Centry 2^®, was reformed for bicarbonate (BC) hemodialysis. A new rotary pump to propel 6.8% BC fluid was attached to the axis of the mixing rotor. Appropriate BC dialysate (BC-D) was effected using a conductivity control potentiometer as a proportioning system. The BC and sodium concentration of the dialysate could be exchanged in the required proportions. Various elements in the dialysate were stable during the course of a six-hour test operation. Precipitation of calcium and magnesium salts in the tube of the DDS was observed just before mixing the electrolyte concentrate fluid and tap water containing BC, but could be excluded by ten min recirculation of 4% acetate solution once every two weeks. Such reformation was easy and cheap.
The reformed DDS was studied in three patients with dialysis problems, particularly cardiovascular instability, during the time of undergoing acetate hemodialysis. The diseases due to renal failure were diabetic nephropathy in two cases, and membranoproliferative glomerulonephritis in one case, who showed a very light body weight. Unexplained marked metabolic alkalosis with neuropsychiatric symptoms occurred in the patient with renal failure due to diabetic nephropathy during clinical practice with approximately 27mEq/l BC containing dialysate. One of the causes was thought to be an inadequately high BC concentration in the dialysate for improvement of the metabolic acidosis.
The optimum BC concentration of the dialysate for the reformed DDS was investigated. Tentative hemodialysis was performed using five different dialysates, containing mean values of above 27, 26, 24, 22, and 20mEq/l BC, respectively. The blood BC (B-BC) values reached above 27mEq/l after five hours using the former three dialysates. The remaining two dialysates were adequate for obtaining normal blood gas values. During hemodialysis using the 22 and 20mEq/l BC dialysates, the B-BC values in the inlet and outlet of dialyser were analyzed. BC was tansferred into the blood from the dialysate at the start and third hour of hemodialysis. At the fifth hour, the BC flux shifted from the blood to the dialysate. The 22mEq/l BC dialysate demonstrated more adequate recovery of B-BC and less B-BC flux at the fifth hour. Dialysis without problems has been performed following use of the 22mEq/l BC dialysate.
The above results suggest that the 22mEq/l BC dialysate was optimum for the reformed DDS in patients with renal failure due to diabetic nephropathy and having a light body weight.

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