Non-anticoagulant hemodialysis with EVAL (ethylene-vinyl alcohol copolymer) HF dialyzer (KF101) has been successfully performed with totally 466 treatments for patients with high bleeding risk and regular HD patients.
In this report the S EM study was made for blood-contact surface of EVAL HF membranes used in non-anticoagulant hemodialysis with KF101 (pretreated with gabexate mesilate). The deposition of blood cellular components on the inner surface of the membrane was minimal, as compared to the membrane subjected to regular heparinization hemodialysis, and thin layer of micro-granules and small amounts of platelet-like particles was observed. The initially blood-contacted surface of EVAL membrane (<2-3 mins) also showed layer of micro-granules (<100Åthick), which seemed a kind of protein layer, while cellulosic membrane surface showed thick layer of 700Å with different-size granules.
From these results, it is considered that non-anticoagulant dialysis with KF101 may be due to blood compatibility of EVAN itself and antithrombogenecity arising from surface heterogeneity of unique microporous structure of EVAL membrane.

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We previously reported that with scanning electron microscopy (SEM), the quantity and distribution in adherence of WBC and platelet onto the membrane surface of dialyser differs according to the membrane materials, sterilization methods and the design of dialyser. We also recognized the absence of correlation between WBC adhesion and hemodialysis leucopenia.
In the present study, we evaluated the adhesion of these blood components onto the membrane surface of hemofielter and activated charcoal, and also the effects of anticoagulation (heparin or prostaglandin D₂).
Furthermore, we developed the new evaluating method of blood adhesion using microdensitometry.
Even if the same kind of membrane is utilized, adherence onto the hemofilter membrane was less than that onto the dialyser. Estimated with microdensitometry patterns, the distribution of WBC adhesion onto the cellulose membrane was altered with the application of PGD₂ as an anticoagulant.
Platelet and WBC adhered mainly to the sutures of charcoal surface and there were no differences in adhesion between polyalcohol and polyHEMA coated ones. The adhesion was reduced with the increase of heparin dosage or the use of PGD₂.
These results indicate that WBC and platelet adhesion to the surface of artificial kidney differs according to materials, modes of treatment and the anticoagulation. The SEM and microdensitometry analysis were shown to be excellent evaluating methods for blood compatibility of artificial kidney.

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This report describes the mass transfer models for the water flux change during hemofiltration.
In the case of hemofiltration, plasma proteins will reduce water flux(J_V) since the proteins remain in membrane pores and/or accumulate on a membrane. Therefore, J_V may be determined by protein layer resistance(Rp).
Meanwhile, Rp is expressed as a function of total filtrate volume(V) or weight of accumulated protein on the membrane(M). The relationship between Rp and V is derived experimentally and the concentration polarization model gives the relationship between Rp and M. Through these relationships, J_V can be expressed as a function of time in two ways.
Compared with the experimental results, these two water flux models can sufficiently simulate JV change during hemofiltration.

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This report describes the quantitative analysis for solute permeability under the existance of plasma proteins.
In this filtration experiments, Cytochrome C and Inulin are chosen as a solute and dissolved with bovine albumin. The relationship between water flux and reflection coefficient is analyzed by the solute transfer model which considers concentration polarization layer, protein layer and membrane. In this model, the resistance in the protein layer is defined as the resistance excepting the membrane resistance.
From the theoretical calculations, the decrease of overall solute permeability results from increase of the reflection coefficient and decrease of the local permeability in the protein layer. The reflection coefficient and the local permeability are influenced by the plasma proteins and required to estimate the overall solute permeability.
When plasma protein concentration and water flux are fixed, the sieving coefficient of an interest solute can be calculated by this model.

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The hydraulic permeability (Lp) of a hemofiltration (HF) membrane is highly influenced by the proteins in plasma. It is always observed to decrease ultrafiltration rate (UFR) or increase transmembrane pressure (IMP) during HF therapy on chronic renal failure patients. For such a patient, the blood usually tends to be chyliform. The effect of Lipids to Lp of the HF membrane, therefore, was experimentally investigated in this paper.
The correlation coefficient between triglycerol (TG) and in vitro Lp (Lp(G)) was fairly high, that is, 0.9531, and the correlation equation was as follows;
Lp(G)=-0.01916*(TG)+8.7989
The chyliform plasma of HD patients gives higher TG concentration than the normal plasma of HD patients (p<0.01). However, total protein (TP) has more effect on Lp(G) than TG.
Lp(G) may be altered especially by the high TG concentration in plasma.

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Deterioration of membrane permeability in dialysis treatment is measured by the impulse response method. A small quantity of sodium chloride solution is injected as a tracer into the blood inlet of test dialyser. Then the residence time distribution of tracer is measured at the dialysate outlet. The declining part of response data is analyzed by a counter current plug flow model, and gives the axial length distribution of overall mass transfer coefficient. Thereby the variation of membrane permeability in dialysis treatment can be measured.
Results of impulse response experiments for 3 types of dialysers having different membrane materials and structures, are summarized as follows. After a dialysis treatment for 5 hours, the permeability of (saponified) cellulose hollow fiber membrane is nearly invariable except remarkable decrease in the arterial side, whereas uniform permeability deterioration is measured for PMMA hollow fiber and (regenerated) cellulose plate membranes. These results are closely correlated to the fidings of scanning electron microscopy for the white blood cell adsorption pattern on the membrane surface.

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Since 1970 author and his coworkers have studied a simple ultrafiltration type artificial kidney(AK), leading to the conclusion that the straight-porous polymeric membrane having an avegare pore size of 900 A is very suitable for hemoperfusion, but the removing rate of water is not balanced with those of various metabolites including creatinine and urea. In order to overcome the above shortcomings, author has proposed an ultrafiltration/dialysis type AK, on which some experiments have been carried out. In this article, as an extension we propose a new AK, whose basic principal as follows: (1) to filter the blood of patient with membrane having an average pore size of 10³A, (2) to filter and dialyze the filtrate thus isolated, coccurrently with membrane having an average pore size of 10²A in order to remove water and waste materials, (3) to combine the blood after the filtration in (1) with the filtrand in (2) and to return the mixture to patients' body. The validity of the idea of step (2) was experimentally confirmed. The usage of this AK will resolve the following problems: (a) the difficulty in removing the socalled middle molecules, encountered in dialysis type AK and (b)the loss of valuable proteins and needs of transfusion in ultrafiltration type AK.

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A hybrid artificial Kidney (HAK) made in trial is of quite a new type setting HFAK with 1m² of dialysis area and charcoal(50g) coated with collodion in one container in series.
This HAK is characteristic being much better effective for treatment of chemical introxications as well as short time dialysis and long term treatment of complications by combining both of them instead of single use of charcoal and HFAK respectively. The clearances of each substance in vitro using a test solution of this HAK are as follows: Clearance at 15 minutes after starting of perfusion (Q_B: 200ml/min, Q_D: 500ml/min): Urea N: 150±15ml/min.
Creatinine: 185±12ml/min.
Uric Acid: 173±14ml/min.
V. B 12: 160±11ml/min.

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Phosphate (P) retention is well recognized in chronic renal failure (CRF). Although P restriction and use of P binder such as aluminum are widely recommended to prevent its accumulation, the former causes mal-nutrition due to the deficiency of protein intake, furthermore in the latter, aluminum may be one of the etiological substances for dialysis encephalopathy or osteomalacia in hemodialysed patients. Hemodialysis or hemofiltration can remove P, but in compact artificial kidney system without using dialysate or substitution fluid, it is necessary to develope new methods for P removal. As zirconium (Zr) is able to adsorb P and has been utilized in dialysate recovery system, we examined adsorptive capacity of ZrO₂, and ZrO(OH)₂for P and applied them for direct hemoperfus ion (DHP).
Gram of powdered Zr adsorbed about 5.5mg of P, which was similar as powdered aluminum did. Zr beads encapsulated with gelatin and glutaraldehyde represented 30-60% reduced P adsorptive capacity. However, the smaller beads showed the better adsorptive capacity and Zr beads in size of 9 mesh adsorbed about 4.5mg of P/g of Zr.
On DHP with 60g of Zr microcapsule, serum P decreased significantly in P loaded acute renal failure dogs. Serum calcium was also reduced mildly but insignificantly.
These results indicate that DHP with Zr microcapsule is useful to treat hyperphosphatemia in CRF patients, and further investigations such as application of Zr for the oral adsorbent may be required.

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Two kinds of newly designed dialdehyde starch (DAS; oxystarch) whose surface aldehydes were treated with either albumin or gelatin, were evaluated about their adsorptive capacity for urea and guanidino compounds in vitro, and their effects on serum concentration of nitrogen wastes in vivo. In in vitro studies, they adsorbed two times of urea compared with non-treated DAS, but showed no significant differences in adsorption of guanidino compounds. When administered 20g/day of the treated DAS orally for ten days to a stable anuric chronic renal failure patient on regular hemofiltration, BUN was reduced about 20% from control value without any adverse reactions. Serum concentration of creatinine and uric acid remained to be unchanged.
These results indicate that newly designed DAS is useful too treat uremia, especially as a supplemental therapy for compact artificial kidney systems.

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A filtration-adsorption method with continuous low filtrate flow has been found suitable for the realization of a wearable artificial kidney. This artificial kidney system operates in two stages, a filtration stage and a filtrate treatment stage. (Fig. 1)
In the filtration stage, a plasma separator appears to be superior to an ultrafilter from the viewpoint of miniaturization. In the filtrate treatment stage, this system consists of ultrafilter, immobilized urease, cation exchanger, activated charcoal and electrodialyzer.
Each component necessary for the constraction of the total system was manufactured and its fundamental properties were examined. Subsequently, the total system constructed from these components was tested in vitro to verify its operational capability.

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Despite many improvements of wearable artificial kidneys (WAK), their clinical use has been limited. Major problems rest on their size and weight, the source of power and the capacity of NH₃ adsorbent.
We developed a small blood pump measuring 8.6 × 6 × 14.8cm and weighing 625g. A max. flux was 250ml/min. It lasts 17 hours with a battery (12V, 1.9A). The concentration of NH₃ in both blood and dialysate using this WAK for 6 hours was well below the normal value, 250-300μg/dl.
Although our WAK system was improved from the last presentation, we feel more to be accomplished before its clinical application.

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Experimental plasmapheresis was performed using dogs in which the separated plasma was returned to the circuit at the outlet of PF-02.
Ht, PT, APTT and eugl. lysis time were not changed at all through the experiments, but slight decreases were found in platelet count, and activities of α₂-plasmin inhibitor, F. VIII and F. XII. The slight increases in platelet aggregations were found using ADP or collagen. However, prekallikrein (PK) and fibrinogen (Fbg) were decreased by 35% and 30% respectively at the first 15min. of plasmapheresis.
Coagulation/fibrinolysis in the separated plasma were compared with those of the circulating blood. No difference in any of the parameters was noted between these two specimens all through the experiment, except Fbg. Fbg in the separated plasma was reduced by half of that in the circulating blood, particularly at the first 15min. of plasmapheresis.
It was concluded that decrease of PK was due to the consumption, probably by activation within the circuit, while the decrease of Fbg was due to its adsorption onto PF-02, particularly at the early stage of the plasmapheresis.

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For the purpose of observing the alterations of the coagulo-fibrinolytic factors in the blood influenced by plasma exchange (PE) with Plasmanate (5%albumin/natrium solution), or with fresh frozen plasma (FFP), we performed two comparative studies in 3 cases PE and in vitro PE experiment by Plasmaflo Hi-05.
The conventional blood coagulation tests and the coagulo-fibrinolytic factors in the separated blood and the filtrates weve measured before and after each PE.
In the clinical study, the higher decrease in fibrinopen and plasminogen in the blood. after PE with FFP was coincided with the elevation of FDP concentration in the blood and the filtrates.
The results of in vitro PE experiment showed similar alterations of the coagulo-fibrinolytic factors in the bloods and the filtrates as observed in the clinical study.
The activation of the clotting and fibrinolytic factors must be more increased at the blood separation by PE with FFP, than with plasmanate.

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Plasmapheresis was used for immune-complex medicated disease.
There are two methods; cell centrifuge and membrane separation, we have demonstrated the difference in the membrane between four degrees centigrade and room temperature. In comparison with membrane srcond filter we examined four kinds of pore sizes that are 0.4, 0.2, 0.02 and 0.08 micro.
The only significant difference in the removal ratio we were able to find between room temperature and four degrees centigrade was the pattern of 8ephacryl S 300.

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The authors conducted a study with the objective of obtaining an adsorbent selective for rheumatoid factor which would be practical and effective in treatment of rheumatoid arthritis.
Several methods were used for denaturation of hum an -γ-globulin and its in vitro binding activity for rheumatoid factor was shudied. In this research, human-γ-globulin denatured by organic solvent showed far stronger binding activities for rheumatoid factor than human-γ-globulin denatured by heat. The adsorbent of aggregated human-γ-globulin immobilized on sepharose-4B unexpectedly showed strong binding activities for immune complexes. The adsorption of rheumatoid factor and immune complexes was particularly effective and selective with the adsorbent containing aggregated human-γ-globulin obtained through dimethyl sulfoxide treatment.

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The effect of the Plasma Exchange in eliminating blood AFP was evaluated in the patients with hepatoma.
The blood AFP was decreased by 68%-90% (mean ± SD=75.1 ± 10.3, n=6 in 3 cases) with the membrane plasma separater and by 35%-72% (mean ± SD) =58 ± 12.3, n=3 in 1 case) with the centrifuge plasma separater.
In all cases, the symptoms were improved by the plasma exchange. Mild side effects (eruptions and fever) appeared in 22% of the trials. Tsukada et al. reported that anti-AFP-antibodies had cytotoxity to hepatoma cells. We expect that plasma exchange may prevent the formation of Ag-Ab complexes in the blood and may potentiate the effect of anti-AFP-antibodies against hepatoma cells.

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We examined the effects of hemodialysis and plasmapheresis on experimentally induced digitalis (digoxin) intoxication. Both methods were effective in reducing the elevated plasma digoxin level, with the latter being more effective than the former. The efficacy of plasmapheresis depended on the rate of plasma exchange. Since digoxin is partially bound to plasma protein, the latter method appears to have a further advantage in eliminating the accumulated digoxin. However, in all experiments with either hemodialysis or plasmapheresis plasma digoxin level elevated again to some extent after cessation of the dialyses, which probably was caused by the release of the drug from tissue storage sites. Thus, for the effective elimination of the drug, it might be necessary to perform repetitive plasmapheresis for a certain period of time.

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A newly developed plasma separator “PLASMAX”, made of PMMA (polymethylmethacrylate) hollow fiber, was evaluated, for its efficiency to filtrate plasma and its blood compatibility in 20 dog experiments.
The results are summarized below; 1. The optimal transmembrane pressure was under 30mmHg.
2. Plasma flux was mainly dependent on blood flow rate (QB) and was nearly proportional to QB. It was about 2L/hour at QB=6L/hour.
3. Sieving coefficients for various proteins were almost unity and remained so throughout the experiment which extended for up to 3 hours.
4. WBC platelets, fibrinogen and coagulation factors decreased during the early stage of plasma separation but seemed to be within acceptable ranges.

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Separation of plasma from whole blood using either cell centrifuge or membrane filtration has had an increasing application for treatment of various disease states. Separation rate and the quality of separated plasma during a limited time period are of primary importance for clinical applications. Plasma separation by means of membrane filters is a process during which membrane properties are changing. This is caused by a) deposition of formed blood particles at the surface of the membrane as a result of a dragging force created by filtration; b) entrapment and possible sorption of proteins, lipoproteins and other macromolecules within the structure of the membrane pores; c) gelation on the surface of the membrane of proteins and other substances for which sieving coefficient is less than one, and d) clotting mechanisms. Considering these factors, various plasma separators has been evaluated in in vitro, ex vivo and clinically, showing that membrane plasma separation is promising and can be best operated at the lowest possible transmembrane pressure to prevent serious deterioration of filtration properties.

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We have developed a new hollow fiber for plasma separator which is made of the polymer alloy consisting of cellulose acetate-acrylic polymer-cellulose nitrate.
Experimental plasma separation was carried out in rabbits with a carotid-to-jugular external shunt and has shown that the polymer alloy hollow fiber has a good compatibility.
Further, it has been discussed a relation between the fine structure of the membrane and the plasma separation efficiency such as plasma flux, hemolysis and sieving coefficient of total protein.

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Two types of modules, in which planer blood channels and sorbent layers were stacked alternately, were constructed for ex vivo experiments of plasma separation and perfusion. Type I comprised five channels and six sorbent layers, both 200mm long and 50mm wide. Four of the sorbent layers, respectively between two channels, were 10mm thick, and the other two, between a channel and an end plate were 5mm thick. The total packing volume of sorbent was 500ml. The inner surface of a channel was porous polymeric membrane, Nudepore Membrane Filter, supported by a pair of 35% perforated metal sheets from the outside. The total effective area of the membrane was 0.035m². In this kind of modules, the blood plasma is, along the channels, infiltrated through the membrane into the sorbent layers and, near by the outlets, returned to the channels: in other words, separation, perfusion and return of plasma are successively practiced from the upper reaches to the lower. Type II had the almost same constructions to those of Type I, but the sorbent layers were bisected perpendicularly to the blood stream direction. This is equivalent to the series connected two modules of half length of Type I. The experiments were carried out on creatininized dogs. The tested membrane pore size were 0.8 and 2μm. The set thickness of the channels were 0.15 and 0.2mm. In every case, the blood compatibility was sufficient. The plasma separation efficiency was examined by the ratio of creatinine removal from the blood stream. The 2μm pored membrane showed poor permeability. The highest removal ratio, obtained with the 0.8μm pored membrane, was nearly 30%.

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Double filtration plasmapheresis was devised in an attempt to reduce an amount of replacement fluid and consequently to save human blood products. Clinical effectiveness and conservation of human blood.
However, as balancing manipulation of three pumps for an extracorporeal circulation, plasma separation and plasma filtration was cumbersome, an automatic control system which automatically regulates a plasma separation rate has been devised.
With this new system double filtration plasmapheresis has become performed very easily with less hemolysis.

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We have presently designed the method to collect plasma from the donor and simultaneously exchange that of the patient with it. This method has been experimentaly evaluated for its safety and efficiency.
In both a healthy dog and the dog with induced acute hepatic failure by galactosamine, simultaneous extracorporeal circulation was carried out. The blood from the healthy dog is led into Plasmaflo, where plasma is separated from the blood and then stored in collection chamber. The same amount of substitute fluid as that of the separated plasma, is introduced into the venous side chamber in the extracorporeal blood circuit of the healthy dog by double channel roller pump, maintaining the balance of circulating plasma volume constant. The plasma separated from the dog with acute hepatic failure, using the above mentioned technique, is discarded and the same amount of plasma separated from the donor is sent into the venous side chamber in the blood circuit of the diseased dog by double channel roller pump. Thus the plasma of the dog with hepatic failure is simultaneously exchanged with the collected plasma.
This plasma exchange therapy was safely and easily performed in the experimental dogs and was considered to be the best way because the fresh and warm plasma from the donor was instantly given to the recipient, without any delay and any loss, which otherwise could have been introduced by the preservation of the plasma.

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In order to adjudge and evaluate the limit of control ability of SMEC IABP system, which ECG R-wave trigger system is applied to set the deflation start and end, so the inflation duration is set automatically, using a mocked up circuits. in-vitro tests were run.
Under conditions of heart rate 200/min, deflation start after R-wave trigger 70msec and deflation duration 230msec, driving with helium gas, the timing setting ability of the control system was perfect.
IABP was employed for the failing heart with atrial fibrillation after cardiac surgery of severe valvular disease. In all cases, positive left ventricle assist effects were obtained for such severe patients with arrhythmia.

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We measured colloid osmotic pressure-pulmonary artery wedge pressure gradient (COP-PAWP gradient) and left ventricular stroke work index (LVSWI) before and after intraaortic balloon pumping (IABP). The following results are obtained.
1) The IABP is indicated in patients of LOS after cardiac surgery who have criteria 1. and 2.
1. COP-PAWP≤OmmHg
2. LVSWI≤25gm.m/m²
2) The change of COP-PAWP gradient is useful for prognostic indicator of IABP.
3) The reduction in COP-PAWP gradient may follow the onset of pulmonary edema.

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This study was designed to decrease the mortality rate in the patients with cardiogenic shock following acute myocardial infarction (AMI). The effects of IABP and left heart bypass (LHB by using roller pump or artificial heart device) were compared from the standpoints of hemodynamics and myocardial metabolism (lactate extraction) in dogs with AMI produced by multiple legations of the coronary artery. Besides, in addision to AMI complete A-V block was produced by electric coagulation of the A-V node or Formalin injection into this node.
By this procedure, the infarcted area of the myocardium reached to 25-550 (average 30%) of free wall of the left ventricle. This area was clearly confirmed by postmortem coronary angiogram and NBT staining. Subsequently, the effects of diastolic augmentation and systolic unloading by IABP were clearly recognized and pacemaking was useful procedure to maintain IABP at the time of complete A-V block. Changes of hemodynamics and lactate extraction due to changing of heart rate were observed between 80 and 160/min during IABP and LHB.
These procedures were favorable methodes to improve hemodynamics and ryocardial metabolism which were remarkably disturbed by coronary ligations and complete A-V block. In this study, hemodynamics and myocardial metabolism were more greatly improved by IABP and LHB, in which the bypass flow was about 30% of the total circulating blood volume. Especially, the favorable effects could be obtained under heart rate of 120/min in the group of with application of artificial heart device.

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Recently, we have developed a, new method for assisted circulation. This circuit system consists basically of Pulsatile Assist Device (PAD) with two ball valves at its inlet and outlet. Thereby, the PAD was used as a tubular type pulsatile pump. In this method, we can obtain not only pulsatile bypass flow but also counterpulsation effects without insertion of intra-aortic balloon. We have already reported the hemodynamic effects of VAB and LHB using this device. In the former studies, we used silastic ball valve at the outlet and the prosthetic metalic ball valve at the inlet. But, in this study, we improved the valve mechanisms. That is to say, we changed the inlet valve to Bjork-Sheiley disc valve and the outlet valve to Star-Edwards ball valve. Then, we applied this device to in vitro mock circulation. In conclusion, this device was able to produce more than 3L/min bypass flow. But the ventricular pressure raised upto 400mmHg. So, we considered the appropriate bypass flow was less than 2L/min in which the ventricular pressure was less than 250mmHg. We consider this method will be a useful assisted circulation in future.

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An evaluation was made on quantitative left heart failure model experimentally produced in mogrel dogs by injection of 5N-NaOH and the effect of assisted circulation was examined with this model. In 5 mongrel dogs with quantitative left heart failure produced by injection of 5N-NaOH, transapical left ventricular bypass (TALVB) was applied in order to evaluate the effect of assisted circulation. The following results were obtained in these studies.
Injection of 0.3ml/kg of 5N-NaOH into the myocardium of the left ventricular free wall produced quantitative left heart failure model having a necrotic size of about 33%, respectively. In examining the hemodynamic changes, it was found that cardiac output was remarkably decreased and LAP and LVEDP were significantly elevated, demonstrating acute left heart failure.
Systolic left ventricular pressure, max LV dp/dt, and tension time index were decreased by TALVB, but aortic pressure was elevated during TALVB in both the normal heart group and acute left heart failure group. In acute left heart failure group, systolic aortic pressure and cardiac output which were reduced to the shock level were restored to the normal level by TALVB. Elevated mean left atrial pressure and mean pulmonary arterial pressure were decreased to the normal level during TALVB. Such effects of TALVB as maintenance of systemic circulation, decrease of myocardial oxygen consumption and reduction of left ventricular preload were observed in the left heart failure group, confirming the effectiveness of TALVB in power failure.

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A left ventricular bypass (LVB) system with a roller pump, which was able to deliver pulsatile flow, has been employed in canine experiments. This system was attached, between left atrium and descending aorta, to mongrel dogs weighing 15 to 22kg. During LVB, it was sometimes observed that pulmonary arterial pressure increased with the start of pumping and lead to pulmonary congestion. As this pulmonary hypertension was suspected to be referred to excess negative pressure on venous line of LVB, in which blood was drained from left atrium by gravity, a device was developed to cancel this excess negative pressure, that is, a reservoir, being connected suction system, was inserted into the venous line. This device excerted low negative pressure upon the inside of the reservoir as a damper of the venous line and realized better LVB without the collapse of pulmonary vessels or the elevation of pulmonary arterial pressure.

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In the automatically controled pulsatile extracorporeal circulation system designed in our clinic, pulsatile flow was generated by the following method; the pump used in this system was roller pump. Rapid rotation was added periodically to the fixed rotation. Tolerance to the pulsatile roller pump was compared between four kinds of pump chamber by the longevity and by the change of systolic pressure and pulse pressure during the pump run. Bentley tube and Tygon tube were superior to Silicone tube and Latex tube.
In order to investigate blood damage by this pulsatile pump, GOT, GPT, LDH, and plasma free hemoglobin were measured during 24 hours of pump run. These values were elevated after 10 hours of pump run with statistical significance.

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In a purpose to evaluate the effects of left atrium to aorta (LA-Ao) bypass, pressure-volume curves obtained by UCG and manometry, were analyzed. Bypass system was composed of roller pump and pulsatile assist device inserted between aorta and roller pump. Eight mongrel dogs weighing 17 to 21Kg were used in this study. Pressure-volume curves were drawn according to the changes in bypass flow of every 25ml/Kg/min. Decreases in left ventricular net work and left ventricular output (PA flowbypass flow), according to the increases in bypass flow of every 25ml/Kg/min were 18% of control. Left ventricular pressure (LVP) was maintained despite increase in bypass flow till 100ml/Kg/min. Decrease in LVP was observed finally when bypass flow increased to 125ml/Kg/min. In this condition left atrial pressure decreased to -10 to -15mmHg simultaneously and maintenance of LA-Ao bypass became difficult because of arrhythmias. From this study, it was concluded that decrease in LV net work can be achieved adequately by LA-Ao bypass and effects of left heart bypass could be evaluated quantitatively by this method.

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This study compares the effect of pulsatile and non-pulsatile flow upon the plasma catecholamine concentration. Nine dogs weighning between 16 and 25Kg were anesthetized with pentobarbital and mechanically ventilated with pure oxygen. Bypass system was constructed according to modified Litwak's technique. Aortic root was cross clamped during bypass, so that left ventricle supplies only to coronary system (so called hybrid type of left heart bypass). After non-pulsatile left heart bypass of 40 min, adrenaline and noradrenaline increased significantly up to 2 or 3 times of control lebel. After pulsatile left heart bypass, Increase in plasma catecholamine concentration was much less than in non-pulsatile bypass. It is conculuded from this study, that pulsatile flow perfusion is superior to non-pulsatile perfusion to maintain physiological circulation.

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The most adequate perfusion site and flow rate in the case of V-A bypass was studied in mongrel dogs with acute cardiopulmonary failure by endotoxin.
Per carotid aortic perfusion (CA) gave the best mixing and equal distribution of oxygenated blood. CA with bypass rate of above 60% could elevate the arterial blood pressure, whereas femoral perfusion (FA) in vain even with high bypass rate. The right and the left ventricular works were reduced only by bypass rate of 80%, but total pulmonary vascular resistance and total systemic peripheral vascular resistance elevated markedly by this rate. Coronary blood oxygen saturation was elevated more significantly by flow rate of above 60%, and myocardial oxygen extraction rate was reduced by those rates.
CA with bypass rate of 60% was proposed.

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TR-7 (Recirculating dialysis system using 70 1 dialysate in tank and remodeling TM101 in the system without sorbent column) is more beneficial equipment to achieve dialysis with prescribed dialysate. The dialysate prescribed is bicarbonate dialysate with high chloride (114mEq/1) and lower buffer base concentration. The dialysis using this dialysate has been undergone intermittently during regular dialysis schedule, that is, one of three times and the incidence of dialysis symptoms were assessed. It was confirmed that this method of dialysis contributed to asymptomatic dialysis and more smooth restoration of acid-base balance. However, one would not expect patient's well-control with this method of dialysis alone.

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In order to keep dialysate pH constant, CO2 bubbling method is utilized in bicarbonate dialysis with batch system. In this report, we tested pH stability in the closed circuit system with Rhodial 75 manufactured by Rhone-Poulenc.
As the system mixes two solutions in air tight tank, difference of Pco₂ according to the adding point of bicarbonate solution was anticipated. Accordingly, Pco₂ was determined in five kinds of mixing in which adding points were different.
Effect of three kinds of HCO^-3 concentration, namely, 20, 25 and 30mEq/l on final blood pH were evaluated.
Blood pH were changed from 7.315±0.017 to 7.393±0.009, pCO₂ from 50.68±2.61 to 43.3±1.04 and HCO₃ from 25.34±0.36 to 25.62±0.16, respectively.
Thus, it was observed that bicarbonate dialysis with Rhodial 75 could ameriolate excessive increase of pH and kept stable HCO^-3 concentration. Precipitation mf calclm and magnesium was not observed.

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A clinical comparison between the partial air parallel flow (PAPF)-, none air parallel flow (NAPF)- and none air counter flow (NACF)-hemodialysis was made for 8 patients suffering from severe disequilibrium symptom during hemodialysis. PAPF method is a new hemodialysis technic in which both blood and dialysis fluid run parallel (up to down) in a dialysis vessel with air part (upper side of the vessel) in the dialysis fluid side. The results are summarized as follows: 1) There was no significant difference in removability of blood constituents such as BUN, creatinine, CTR, Ht., Na₊ and K₊ between the above three methods. 2) In the removal of body fluid, PAPF is higher than the other two methods by 300g per one dialysis. 3) The frequency of occurence of disequilibrium symptom is greatly surpressed by PAPF method, compared with the other two methods.
The above results for PAPF method may be drived from its' principal functions that an effective ultra-filtration of blood is performed at the air part in the dialysis fluid side, which has negative pressure against the blood passing in the membrane and that the filtrates mixed with ordinary dialysis fluid works as a buffer dialysis fluid for the concentrated blood.
PAPF method could be further improved by adjusting air volume with counterparallel flow changing valve invented by authors, according to the physical conditions of each individual patient, in view of the hemodialysis with no disequilibrium symptom.

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Since the molecular weights of acetate, bicarbonate and urea are almost identical, the dialysance of these substances are expected to be same. To know if this hypothesis is correct, we determined the dialysances of these substances both in acetate and bicarbonate dialysis. Contribution of the difference of membrane quality and effective surface area was also evaluated Dialysis was performed at the conditions of Ob 200ml/min, Od 500ml/min, TMP 200mmHg and the dialysis temperature 37°C.
Dialysances of bicarbonate and acetate showed a difference according to membrane materials and effective surface area. Transfer rates of bicarbonate exceeded in Cuprophane, EVA and large surface area dialyzer than in otherss. Acetate dialysance was inferior to bicarbonate and urea dialysance. This difference was not accounted for in terms of molecular weight. The transfer co-efficient of acetate showed a tendency to be low in large surface area dialyzer.

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As the appearance of pre-carcinogen dimethyl nitrosamine (DMNA) in the dialysate water purification process has been suggested recently, we examined DMNA in dialysate water of four dialysis units. Water samples, which were collected after the water softener or deionizer and activated carbon filter (ACF) were analyzed for DMNA with gas chromatography technique.
In all samples, DMNA could not be detected. However, the possibility that DMNA is derived from the interaction between anion exchange resin in deionizer and tap water will still remain.
Therefore, it may be necessary to use at least the ACF in dialysate water purification system to eliminate the possible contamination of DMNA.

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The mathematical model of solute and water removal is devised in order to determine the optimum sodium concentration in dialysate and substitution fluid. This model involves the movement of water and solutes between each body compartment. The theoretical results agree well with the clinical data. The results indicate that the change of intracellular volume during hemopurification therapy is independent of the urea concentration gradients between the intracellular and extracellular compartments, and that the effective factors required to determine the optimum sodium concentration in dialysate and substitution fluid are pre-treatment plasma concentration, effective osmolarity, volume of body fluid and body fluid removal. The effects of solute and body fluid removal on the plasma volume changes are also analysed.

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