As a basic study with the aim of its application to biomaterials, fluoridated CO₃apatite was synthesized by supplying F^--containing solution initially, followed by F^--free solution. This heterogeneously synthesized fluoridated CO₃apatite had half of the maximum fluoride content of fluorapatite. The (300) reflection peak of the apatite was split. However, it was not a mechanical mixture of CO₃ apatite and fluorCO₃apatite. SEM observation revealed that it had many small crystals, similar to those of homogeneous CO₃apatite, adhering to the larger hexagonal crystals which were also similar to those of homogeneous fluorCO₃apatite. Spectroscopy attached to the SEM showed a lower fluoride intensity in its spectrum than that of fluorCO₃apatite. After solubility experiment, the small crystals adhered to the surface almost disappeared. When magnesium ions were added to the source solution for synthesis, a similar tendency was noted. These results suggested that heterogeneous fluoridated CO₃ apatite, fluor CO₃apatite covered with CO₃apatite, was formed. The simple two-step supply system used in this study is expected to be applicable in the synthesis of hybrid-type apatites with multilayers.

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In an attempt to remove the related substances in the plasma with fulminant hepatitis, in vitro study has been made to examine the effect of photo irradiation (at 376, 392 and 423nm) and adsorption with adsorbent. i. e. active carbon, anionic exchange resin or hydroxyapatite. The analysis with HPLC technique has clarified that the combination of photo-irradiation and adsorption was much more effective for the removal than the photo-irradiation or adsorption alone, as previously observed in our study for bilirubin removal. The light at wave length of 423nm was the most effective and caused less damage on plasma proteins. The effect of photo-irradiation may be explained by the detachment of albumin-bound substances. Thereby, the substances being converted to polar low molecular weight, then could easily be removed by adsorbents such as poly-HEMA coated active carbon.

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Knitted Dacron prostheses impregnated with gelatin to confer zero porosity (Gelseal Triaxial®) were implanted in 30 patients with thoracic or abdominal aneurysm, or atherosclerosis obliterance. The accumulation of effusion occurred postoperatively around the grafts at the same time when gelatin absorption might happen in two patients with DeBakey's type II and III b dissecting thoracic aortic aneurysm, resulting in mediastinitis and cardiac tamponade respectively, and in one with atherosclerosis obliterance. The graft is handy because of no requirement of preclotting, but the accumulation of effusion around the graft may occur. Therefore, the use of Gelseal Triaxial^® should be prudent particularly in patients with thoracic aortic aneurysm.

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The plasma level of the EDA(+)fibronectin (EDA(+)FN), one of the cellular fibronectin, elevates temporarily during cryofiltration in patients with rheumatoid arthritis and SLE. Therefore its plasma level is not so reduced after cryofiltration, in spite of a large amount of reduction in cryogel. The purpose of this study is to calculate the clearance of EDA(+)FN, plasma fibronectin (pFN), fibrinogen (Fbg) and albumin (Alb) in cryofiltration and to study the relationship between the clearance and the reduction index. The clearance was calculated in 3 patients with rheumatoid arthritis, 2 with SLE, 1 with polymyositis and 3 for antibody reduction. The clearances were not different between rheumatoid arthritis and SLE group. In all patients, the clearance of EDA(+)FN, pFN, Fbg and Alb was 23.3±6.4ml/min, 16.5±4.1ml/min, 22.9±5.7ml/min, and 11.4±2.4ml/min, respectively. EDA(+)FN clearance and Fbg clearance were same level, which were significantly higher than that of pFN. There was a statistical correlation between the clearance and the reduction index, but no correlation between the clearance and the plasma concentration before cry-ofiltration. As plasma flow in cryofiltration was 30ml/min, the clearance of EDA(+)FN and Fbg, approximately 23ml/min, was obviously high. EDA(+)FN and Fbg were reduced efficiently by cryofiltration.

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New hemofilter (Amicon Ireland Minifilter Plus) was employed in 30 pediatric open heart surgeries as extracorporeal ultrafiltration method (ECUM). Blood was drained from the arterial side of CPB and returned to the venous side and ECUM was performed continuously during CPB. Total filtration volume and removal rate of water by ECUM were 343±142ml and 5.1±2.4ml/min, respectively. Average ECUM-to-urine excretion ratio of water was 4.6±5.6. Hemoconcentration seemed effective, because hemoglobin level was significantly increased from 6.3±1.6g/dl to 7.4±2.4g/dl (p<0.05) after termination of ECUM. Total protein, albumin, and serum electrolytes values did not significantly change before and after ECUM. The small hemofilter (Amicon Ireland Minifilter Plus) was effective and safe as an equipment of ECUM in pediatric open heart surgery.

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Cerebral oxygenation levels during deep hypothermic selective cerebral perfusion were measured with near infrared spectro-scopy (NIRS) as a cerebral monitoring system for 4 patients with thoracic aortic aneurysm. The levels monitored with NIRS were almost stable in 3 of 4 patients. In the other 1 patient, the oxyhe-moglobin level which decreased at the onset of selective cerebral perfusion from right axillar artery increased with additional cerebral perfusion from left carotid artery. The relationship between oxy-hemoglobin level and cerebral perfusion rate had a good correlation in each patient. Cerebral oxy-genation monitoring with NIRS may be useful to establish optimal method of cerebral perfusion for patients with thoracic aortic aneurysm.

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This paper reports a quantitative assessment of enhanced neutrophil adherence on venular endothelium which was induced by the infusion of a potent anaphilatoxin C 5 a and complement-activated serum. In vivo microscopy, equipped with a TV monitor and a videorecorder, was used to determine the numbers of rolling and adhering neutrophils in venules of exteriorized rat mesentery. Experiments run at the duration from the first one hour after exteriorization to following one hour when external disturbances induced by surgical procedures on hemodynamics and numbers of circulating neutrophils were minimized. The results showed; irrespective of infusion of C5a or activated serum, little difference in number of rolling neutrophils before and after infusion was observed, whereas the number of adhering neutrophils was significantly increased especially 10-30 min after infusion, followed by a gradual decrease. A dose-dependent increase was observed for C5a infusion. These resemble well leukostasis which was clinically observed during extracorporeal circulation using potent complement activation-inducing artificial dialyzers and artificial oxygenators. Enhanced adherence was discussed in conjunction with associative interactions between adhesive molecules expressed in both cell types.

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We describe a 72-year-old man who could be weaned from left ventricular assist system (LVAS) to IABP using alternate synchronous driving method (ASDM), which was newly devised for smooth and safe weaning from LVAS. ASDM could drive IABP and LVAS alternately with electrocardiogram synchronization. During the weaning stage, ASDM increased IABP pumping ratio while decreasing LVAS pumping ratio according to recovery of the natural heart function. The patient had an episode of ventricular fibrillation caused by coronary spasm on the way to the ICU after coronary bypass grafting. Defibrillation was successful but acute myocardial infarction occurred. Extracorporeal circulation (ECC) was initiated again to maintain systemic circulation, but repeated attempts to wean from EGO failed even with IABP support. LVAS was then initiated with gradual increase in cardiac function during LVAS support. The patient however developed infection as well as renal and respiratory failure. In order to wean safely from LVAS, ASDM was actuated. The patient was weaned from LVAS to IABP without deterioration in systemic perfusion, and his organ function did not deteriorate during weaning process. ASDM proved to be useful and safe in weaning from LVAS without hemo-dynamic instability, and to evaluate cardiac function of the natural heart before removal of LVAS.

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Gelatin impregnated knitted Dacron graft was used for the replacement of thoracic aorta in 22 cases. These cases were followed at the out-patient clinic and the size of implanted graft was measured by CT scanning. No complication related to the graft was observed in all cases. Only one patient died due to pneumonia. Other 21 patients are alive and well. Im planted graft dilated 25-30% in diameter 4.5 months after operation by the measurement of CT scanning. Intensive follow up is necessary in the patient who used the knitted Dacron graft in the thoracic aorta.

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The left ventricular assist system (LVAS, Toyobo Co. Ltd., Japan) was used for 190 days in a 44-year-old male patient with endstage dilated cardiomyopathy (DCM) as a life-saving procedure. The patient had been hospitalized several times for congestive heart failure due to DCM until December, 1992 when he was emergently readmitted for cardiogenic shock. The LVAS was implanted because of progressively worsening heart failure inspite of the use of catecholamines, IABP, mechanical ventilatory support and continuous hemofiltration for water reduction. Before the LVAS implantion, the cardiac output index, mean pulmonary artery pressure, pulmonary capillary wedge pressure and the pulmonary vascular resistance was 1.89 l/min/m², 52mmHg, 38mmHg and 4.4 Wood units, respectively. Followng the instrumentation of the LVAS, these hemodynamic variable returned to normal; 2.88 l/min/m², 17mmHg, 5mmHg and 2.5 Wood units, respectively. Also, the patient had marked hepatic and renal dysfunctions (total bilirubin 6.1, BUN 73 and serum creatinine 3.1mg/dl) prior to the use of LVAS. These functions returned to normal as well (total bilirubin 1.2, BUN 11 and serum creatinine 0.6mg/dl) within a month after the implantion. At this point, the patient considered as a good candidate for heart transplantation. However, the patient was complicated by multiple cerebral embolisms of various grades on the 9th, 57th and 175th postoperative days despite the continuous use of heparin, and died on the 190th day. Hemodynamic normalization and improvements of multi-organ dysfunction were successfully obtained by means of the LVAS support. However, the long-term use of LVAS in our patient was complicated by multiple thromboembolic episodes. Although our experience with the long-term use of this equipment is very limitted, improvements of the pump surface material and development of the left ventricular apical drainagee cannulation system are required for a bridge LVAS to heart transplantation.

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