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[in Japanese]
1992 Volume 21 Issue 1 Pages
1
Published: February 15, 1992
Released on J-STAGE: October 07, 2011
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Kiyotaka SAKAI
1992 Volume 21 Issue 1 Pages
3-6
Published: February 15, 1992
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An artificial organ is a great boon to medical cares produced by the collaboration of medicine and engineering. Practical use of artificial organs actually contributes to variety of medical cares and prolongation of the life of patients, and further introduction of new concepts of medical cares to medicine. The switchover of idea often causes a great discovery. Medicine is no exception to this rule. Medicine is deeply indebted to medical technology for remarkable progress in modern medical cares. Collaboration of medicine and engineering surely develops the medical technology, but unfortunately does not necessarily meet our ideal to date. It is an urgent necessity for further development of artificial organs to establish fresh collaboration of medicine and engineering.
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[in Japanese], [in Japanese]
1992 Volume 21 Issue 1 Pages
7-10
Published: February 15, 1992
Released on J-STAGE: October 07, 2011
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[in Japanese], [in Japanese]
1992 Volume 21 Issue 1 Pages
11-12
Published: February 15, 1992
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T. TANI, K. NUMA, H. ABE, T. YOSHIOKA, H. AOKI, K. MATSUDA, Y. ENDO, K ...
1992 Volume 21 Issue 1 Pages
13-15
Published: February 15, 1992
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We have experienced the coworks between medical and engineering side during Polymyxin-B immobilized fiber had been developed. Based on our experiences, the encounter of both side is the essential point for the creating new idea. Actually, almost all animal experiments have been done by engineering side (company), medical field in public institute or university can automatically attend to the study after clinical study. If it is the ideal way that public institutes participate in or proceed study by themselfs from the idea, huge man power and financial support are requaired. For the completion of new material, aggressive leaders who believe the success of material and can decide mass production are essential in both side.
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PROBLEMS EXPERI-ENCED IN THE NATIONAL PROJECT FOR A NEW TYPE OF HYBRID ARTIFICIAL LIVER SUPPORT SYSTEM, AND SUGGESTIONS FOR THE FUTURE.
S. KASAI, M. MITO
1992 Volume 21 Issue 1 Pages
16-19
Published: February 15, 1992
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The liver is an organ with very complicated functions, and therefore the prognosis of its functional failure has not so improved. In 1914, Abel made the first experimental attempt to support the damaged liver functions by artificial methods such as hemodialysis or plasmaseparation. Since the end of 1950's, we have also studied biological artificial liver using freezed-dried liver granules. In 1970's the remarkable development in biotechnology, enabled us to study artificial liver support systems. The national project for artificial liver support systems was initiated in 1979, and we engaged in the part of metabolic support system using isolated hepatocytes. In this paper, our progress in the 6-year research will be summarized and the problems in the cooperative work for artificial organs will be discussed.
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Tohru MORIOKA
1992 Volume 21 Issue 1 Pages
20-25
Published: February 15, 1992
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As the ground for discussion on ECMO in this symposium, the past history, present status of ECMO, terminology of acronyms, methods, results, and indications based on our past experienecs are presented. Though the acronym of ECMO has been replaced, on many occasions, by such as ECLA, ECLHA, ECCO
2R, ELS, AREC, etc. ECMO is still used in general. Neonatal ECMO has been increasing explossively in the U.S.A. in the past several years. Both neonatal and adult ECMO have begun to increase in European countries and Japan. ECMO will become one of the most powerful means of life support for patients with cardiopulmonary failure provided that the problem of blood compatibility of the circuit is solved. A veno-arterial ECMO is also effective for cerebral resuscitation. Therefore, a portable and manually operated ELS circuit, with a self inflating blood reservoir as a pump, has been made for an emergency. By squeezing the reservoir, blood is infused into an artery through an artificial lung.
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Hiroaki KITAGAWA, James B. ATKINSON, Tadanori KAWADA, Sigeki FUNAKI, T ...
1992 Volume 21 Issue 1 Pages
26-31
Published: February 15, 1992
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A Hundred and sixty cases From January 1987 through June 1990, 160 newborn infants in whom maximal ventilator therapy failed were treated with extracorporeal membrane oxygenation (ECMO). The indications for going on ECMO were an oxygenation index score (OI) greater than 40, and failed to respond to maximum treatment. Entry diagnoses and aggregate survival were: meconium aspiration syndrome (MAS) 76 (97%), respiratory distress syndrome (RDS) 24 (92%), congenital diaphragmatic hernia (CDH) 21(67%), pneumonia or sepsis 31 (68%) and others. The overall long-term survival rate was 84%. Ninety-two percent of these patients developed persistent pulmonary hypertension of the newborn (PPHN) prior to ECMO. ECMO has been used as rescue therapy in all infants with PPHN when conventional management failed. We conclude that ECMO is a remarkably effective modality to reverse severe neonatal failure with PPHN and that excellent survival can be achieved, despite the critical condition of these patients.
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T SEO, T ITO, K HO, J KATO, H. TAKAGI
1992 Volume 21 Issue 1 Pages
32-37
Published: February 15, 1992
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To confirm the safety and reliability of the neonatal and infantile ECMO management, we developed the automatically-controlled ECMO system using modified Takagi's double chambered alternate pumping blood pumps.
A sack type blood chamber was placed in the cylinder filled with saline solution and compressed indirectly with positive air pressure. The modified blood pump prevented air embolism in rare cases of rupture of the blood chambers. The new regulating machine would automatically set the best timing of alternate pumping of blood chambers. It also equipped the delay system which changed the ECMO flow continuously. The modified ECMO system produced flow of 750ml/min under automatic control of the flow depending on pre- and afterload. Serum free hemoglobin was less than a third of a roller pump after 48 hours of pumping. On the effects of VA-ECMO on hemodynamics of puppies, the left ventricular enddiastolic pressure and the disparity between the left ventricular systolic pressure and the peripheral arterial pressure increased, and the cardiac output and coronary flow decreased as the bypass flow increased. These findings indicated the strain on the heart causing by the VA-ECMO system.
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H TERASAKI, T OTSU, T OKAMOTO, H AKASU, T MORIOKA
1992 Volume 21 Issue 1 Pages
38-42
Published: February 15, 1992
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We present the results of our fundamental animal studies and clinical experiences in extracorporeal life support (ELS) with the artificial membrane lung. A new type of heparin-bonded dense membrane lung reduced the systemic requirement of heparin to less than half of the conventional dose in ELS on goats. This heparin-bonded circuit was applied in ELS on patients with active bleeding sites, and could save them from severe cardio-pulmonary failure refractory to conventional treatments. As another approach to prevent bleeding attributable to impaired blood coagulation with heparin, we administered Nafamostat mesilate (FUT) as a substitute for heparin during ELS on dogs. A large amount of FUT, 7.3±0.8mg/kg/hr (mean±SD, n=7), enabled safer ELS. To simplify the ELS maneuver in emergencies, we devised a pre-primed ELS circuit which was manually driven without using electric power. A preprimed lung, stored for one year, provided a good function of gas exchange. The total number of ELS patients in Kumamoto University Hospital has been 43 up to October, 1991. Of the 43 patients who underwent ELS, 26 patients underwent respiratory support, and 17 patients circulatory support. The survival rate was 46%. ELS will become a new promising method in critical care medicine.
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Y TAENAKA, T NAKATANI, H AKAGI, T MASUZAWA, H. TAKANO
1992 Volume 21 Issue 1 Pages
43-46
Published: February 15, 1992
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Mechanical circulatory support systems were developed and improved to have better clinical therapeutic results of profound heart failure. A percutaneous insertion system of the inflow cannula and an noninvasive monitoring method of the natural heart output were employed into our paracorporeal temporary ventricular assist system (VAS). As a bridging device to cardiac transplantation, a pneumatic VAS with an inflow conduit for apical cannulation and a pneumatic total artificial heart system were developed. A totally implantable artificial heart was also built and in vitro performances were evaluated. In the system, an electrohydraulic actuator is placed in the abdominal wall separately from intrathoracic blood pumps. A compact centrifugal pump was also being developed so as to have better antithrombogenicity and longer durability.
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Y. NARUSE, Y. KANEKO, T. TAKAHAMA, H. MAKUUCHI, H. MATSUNAGA, A. FURUS ...
1992 Volume 21 Issue 1 Pages
47-51
Published: February 15, 1992
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The efficacy of dynamic cardiomyoplasty was investigated in acute experimental studies. Synchronous contraction of the sutured skeletal muscle increased stroke volume of the left ventricle and maximum elastance (Emax), which showed that dynamic cardiomyoplasty is able to assist the cardiac function of the native heart. No adverse effect on the diastolic function was observed during the contraction of the skeletal muscle. After wrapping the latissimus dorsi muscle around each heart of the animals, chronic experimental models were prepared with “single pulse stimulation” of the skeletal muscle for more than 3 months. In the chronic experimental models, synchronous contraction of the skeletal muscle produced systolic augmentation in the hemodynamic study. Only minimal degeneration of the skeletal muscle was observed after a 3-month period. As long as the patient is properly selected, dynamic cardiomyoplasty can be an effective surgical procedure for patients with severe heart failure.
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K. KOKAJI, R. YOZU, Y. SOMA, S. TAGUCHI, Y. SOMA, M. KUDOU, I. KISO, T ...
1992 Volume 21 Issue 1 Pages
52-58
Published: February 15, 1992
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In the last 7 years, we applied ventricular assist system (VAS) to 22 cases of cardiac or aortic surgery. In this series, there were two long term survivors. VAS was applied to 7 of 22 cases for more than 3 days, six of whom were complicated with renal failure, finally became MOF and died. Our results suggest that VAS should be applied in an earlier period to increase survival rate and also to act as a bridge for heart transplantation. Recently, we have been developing a new type of artificial heart called the Valvo-pump. This is a axial nonpulsatile blood pump implanted in the heart valve position. Our experimental study using a mock circulation demonstrated that this pump can generate a flow of 5l/min with 138mmHg. We believe VAS can be applied to a donor heart as a bridge for heart transplantation. Because our experimental study using a dog brain death model confirmed that cardiac function was maintained by using LVAS, which otherwise deteriorated in a few hours.
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Kiyoyuki EISHI, Robert L KORMOS, Hitoshi KOYANAGI, Bartley P GRIFFITH
1992 Volume 21 Issue 1 Pages
59-67
Published: February 15, 1992
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To better understand the clinical implication of left ventricular assist system (LVAS) on right ventricular (RV) function, RV pressure-cross sectional area data were obtained in five patients undergoing Novacor LVAS implantation. RV pressure was acquired simultaneously with digitized RV cross sectional area obtained through transesophageal echocardiograms. While altering loading conditions, maximum area elastance (aEmax), end diastolic pressure-area relation (EDPAR) and stroke work-end diastolic area relation (PRaSW) were assessed before and one hour after LVAS implantation. Three patients (Group A) required minimal inotropic support for the RV, while two patients (Group B) required temporary mechanical support for RV failure. The slope of PRaSW in group A increased from 10.7mmHg (mean) to 18.8 but, in Group B, the slope decreased from 11.5 to 3.8. The intensity of the curvature indicative in EDPAR decreased in both groups (Group A; K1: from 0.17 to 0.09, Group B; from 0.03 to 0.01, where K1 is a parameter described in EDP=e (K1*EDA+K2)). In all patients, peak RV pressure (afterload) decreased dramatically (Group a; from 38.4mmHg to 27.9, group B; from 42.3 to 29.3) contributing to an increase in RV stroke work. In Group A, aEmax increased from 2.53mmHg/cm
2 to 3.70, however in Group B, there was no change. These results suggest that the improvement of RV performance was achieved by 1) increasing diastolic function (EDPAR) 2) increasing mechanical efficiency by abrupt afterload reduction and 3) improving contractility (aEmax). Deterioration of performance is related to a decrease in systolic function.
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Y. MIYAMOTO, S. NAKANO, R. SHIRAKURA, S. NAKATA, M. KANEKO, M. NISHIMU ...
1992 Volume 21 Issue 1 Pages
68-72
Published: February 15, 1992
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Twenty patients have been evaluated regarding their suitability for cardiac transplantation at Osaka University Medical School since August, 1990. Seventeen patients had dilated cardiomyopathy and three had others. Among the 20 patients, 6 patients died while awaiting transplantation after the evaluation. To predict deterioration of the patients awaiting transplantation, these six patients (group D) were compared with others. There were no significant differences between the groups in terms of ejection fraction, cardiac index or left ventricular size at the timing of the evaluation. All patients (6/6) in group D needed catecholamine before the evaluation, whereas only 2 of the 14 patients in the other group needed it (p<0.01). The doses of dopamine and dobutamine were 1-5μg/kg/min and 2-8μg/kg/min, respectively. Therefore we think that ventricular support system should be considered if a patient starts to need even a small amount of catecholamine.
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S. KASAI
1992 Volume 21 Issue 1 Pages
73-76
Published: February 15, 1992
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The idea has existed since the days of Hipocrates that diseases were resulted from toxic substances accumulated in the body, and thus depletion had been already attempted to prevent and treat them. In 1914, Abel attempted the first blood purification by centrifuging type plasma separation. Dialysis, diafiltration, adsorbtion, and plasma separation have been developed for blood purification, and today they are applied widely to remove toxic substances from the blood. However, toxic substances vary according to the types of the diseases, and some of them are not yet identified. In this paper, the history, present status, and problems of blood purification will be discussed.
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K KANAMORI, K SAKAI
1992 Volume 21 Issue 1 Pages
77-82
Published: February 15, 1992
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Most of blood purification methods are grouped among separation process according to chemical engineering. This paper describes separation principles used for blood purification methods on the basis of chemical engineering. Separation process consists of three basic operations, mechanical separation, transport separation and diffusion separation. Mechanical separation suited for immiscible phases is used for plasma separation and blood cell separation. Transport separation and diffusion separation are well suited for homogeneous phases. Hemofiltration and hemodialysis are typical of transfer separation and of diffusion separation respectively. Solute transport through dialysis membranes is not caused only by diffusion, but also by filtration. So it is impossible to distinguish between three different modalities of hemodialysis, hemodiafiltration and hemofiltration. Adsorption operation is one of diffusion separation and also a typical modality of blood purifications. Adsorption operation had little been used for blood purifications because of several reasons. Recently, excellent selectivity of adsorption, especially immunoadsorption, is noted again. Toxin removal characteristics by blood purification methods depend on combination of three basic phenomena, diffusion, filtration and adsorption. To elucidate specifications of blood purification, to enable selectivity separation through affinities like immunoadsorption and to increase biocompatibility of separation media are very indispensable for further development of blood purifications.
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M HIDA, J WATANABE, K TANAKA, K TSUNEMI, T IIDA, S HIRAGA, T SATOH
1992 Volume 21 Issue 1 Pages
83-87
Published: February 15, 1992
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Drug intoxication cases in the Dialysis Unit, Tokai University School of Medicine, were collected during a ten year period from 1981 to 1990, and therapeutic usefulness of blood purification for drug intoxication was investigated in 82 cases. Furthermore in five dialysis patients with malignancy treated with CDDP and one case of malignantmelanoma treated with high-dose melphelan blood purification was conducted and its clinical effects were investigated
1) Blood purification for acute drug intoxication cases was effective measures for improvement of vital signs including conciousness, respiration and blood pressure.
2) Direct hemoperfusion using activated charcoal (DHP) for acute pesticide intoxication cases was effective for reducing plasma pesticide level and for improvement of vital signs.
3) Continuous intestinal irrigation using golytely, kayexalate and Magcorol, and continuous blood purification including plasma exchange (PE), followed by continuous DHP for paraquat intoxication improved survival.
4) Blood purification for cases with anticancer agents was effective for protection of side effects of the drugs.
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T. YURA, S. YUASA, N. TAKAHASHI, K. UCHIDA, H. TANAKA, N. YAMAMOTO, M. ...
1992 Volume 21 Issue 1 Pages
88-93
Published: February 15, 1992
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Cis-diamminedichloroplatinum (II) (cisplatin) is widely used clinically in the treatment of malignant tumors in various fields. However, there are limitations on the dose which can be administered because of side effects such as nephrotoxicity. The blood levels of non-protein bound platinum, which can be removed by dialysis, play an important role in the antitumor effects and the appearance of the side effects of cisplatin. Therefore, intraarterial injection of cisplatin during concomitant hemodialysis (HD) was performed in patients with gynecological malignancies to reinforce the antitumor action and alleviate systemic side effects, and the efficacy of such treatment was studied. The area under the time-concentration curve of total platinum in the blood up to 5 hours after intraarterial injection was reduced by 46%. When doses of 200mg and 250mg/body were administered concomitantly with HD, the maximum blood levels were suppressed to about the same degree as when 100mg/body was administered without concomitant HD. At all doses, about three times the non-protein bound platinum excreted in the urine during the same period was removed by HD. A definite reduction in the incidence of side effects was seen, and reduction in the severity of nephrotoxicity was also observed. These results indicated that chemotherapy with local intraarterial injections of cisplatin using concomitant HD not only reduces systemic side effects, but also allows for increased doses at the tumor site.
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M ISHII, J KONDO, Y NOISHIKI, H KAJIWARA, M MO, Y ICHIKAWA, S SUZUKI, ...
1992 Volume 21 Issue 1 Pages
94-99
Published: February 15, 1992
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We previously showed the stable construction with rapid endothelialization of fabric vascular prosthesis by transplantation of autologous venous tissue fragments into the wall. But, because of thrombogenecity, grafts impregnated with venous tissue fragments are difficult to use as small caliber vascular prostheses. To overcome this problem, we combined venous tissue fragments with heparin ionically and applied it to small caliber vascular prostheses. The teated grafts of inner diameter 4mm using highly porous fabric prostheses impregnated with tissue fragments were implanted into canine bilateral carotid arteries. All grafts were patent at the time of grafts explantation. One hour after implamntation, a very thin layer of thrombus was observed on the luminar surface. The longest case of amngiography demonstrated patent garaft in both carotid arteries of one dog 244 days after implantation.
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Y TOMIZAWA, Y NOISHIKI, T OKOSHI, H KOYANAGI
1992 Volume 21 Issue 1 Pages
100-103
Published: February 15, 1992
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Antithrombogenicity is one of the essential characters for a small caliber vascular graft in low blood flow position. Slow heparin release method was introduced to give satisfactory antithrombogenicity to a biologic vascular graft. A small-caliber heparinized bovine graft was developed and evaluated its possibility for the clinical use. Fresh bovine artery was obtained and cross-linked with polyepoxy compound, and heparinized. The graft was white and soft. Percent Tanning (PT), Kink Resistance (KR) and Suture Retention Strength (SRS) were tested on HBG and Bioflow (BF) as a control. HBG had higher PT, better KR and SRS, compared to BF. Three month study in the canine model was performed using 4mm internal diameter HBG, BF and Gore-Tex (GT). Five HBG and 5 GT in carotid position, 5 HBG and 5 BF in femoral position were implanted end to end in 5 dogs. At implantation, no thrombus attachment at the inner surface was observed on HBG but on BF. Five HBG were patent in carotid position but only 2 GT patent. Three HBG and 3 BF were patent in femoral position. Explanted HBG had white and smooth inner surface without thrombus formation. From these observations, it was concluded that the developed HBG showed satisfactory biomechanical and handling characteristics. With more improvement, Better patency could be obtained compared to the commercially available small caliber vascular graft.
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Y. MATSUI, K. GOH, T. GOHDA, K. SAKAI, K. YASUDA, M. SAKURAI
1992 Volume 21 Issue 1 Pages
104-108
Published: February 15, 1992
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We experienced three cases of implantation of automatic implantable cardioverter defibrillator in patients with ventricular tachyarrhythmias. (VT; 1, VT+VF; 1, idiopathic VF; 1) One patient suffered from broad anterior myocardial infarction and another dilated cardiomyopathy. Implantation of AICD was indicated for patients who survived circulatory arrest or with life-threatening VT. In all cases median sternotomy was performed. Myocardial electrodes for sensory and large patch-small patch electrodes for defibrillation were selected. One case of moderate cardiac failure which needs intensive care and one case of pericarditis occurred as perioperative complication. In the follow-up period, AICD worked effectively in a patient of spontaneous VF 6 months after implantation. It is concluded that AICD system is effective for the life-threatening ventricular tachyarrhythmias although the estimation in longer follow-up period should be warrented.
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Y. SOMA, R. YOZU, R. TAKAHASHI, K. KOKAJI, S. TAGUCHI, M. KUDO, H. ODA ...
1992 Volume 21 Issue 1 Pages
109-112
Published: February 15, 1992
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Our clinical experiences of AICD was reported. There were 4 patients of VT and 2 patients of VF with basic diseases such as myocardial infarction in 2 patients, left ventricular aneurysm in 1, aortic regurgitation in 1 and primary electrical disease in 2, all of whom were sudden cardiac death survivors. Antiarrhythmic drug resistance was confirmed in all of the VT patients, but it was undecided in VF patients because tachyarrhythmias were not inducible. Spontaneous discharge for VT occured in only one patient. Postoperative complications were necrosis of the skin, fracture of the electrode, pleuritis, spontaneous inactivation of the generator, one patients each, and incorrect discharge 2 patients. Although there was no operative death, two patients died of cerebrovascular accident 26 and 40 months postoperatively. One patients was reoperated due to device exhaustion and fracture of electrode. AICD was easily implantable and considered to be effective for the treatment of life threatening ventricular tachyarrhythmias.
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M KITAMURA, VA STARNES, EB STINSON
1992 Volume 21 Issue 1 Pages
113-115
Published: February 15, 1992
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The ICD was implanted as bridge to cardiac transplantation in six patients with lethal ventricular arrhythmia and progressive heart failure at Stanford University. Three patients had ischemic heart disease and the others were idiopathic cardiomyopathy. Subxyphoidal or left thoracotomy approach was applied. Duration of bridge was 5-39 (mean 20) months after ICD implantation. All six patients were successfully bridged to cardiac transplantation. Two patients with chronic amiodarone therapy had severe respiratory failure after transplantation. The remaining four patients were doing well and discharged a couple of weeks after heart transplantation. In conclusion, the ICD implantation as bridge to heart transplantation can be a treatment of choice for fatal ventricular arrhythmia with irreversible cardiac failure. Intensive respiratory care was needed after heart transplantation of the patients with amiodarone therapy and ICD implantation.
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K. KUDOH, Y. HOSODA, M. WATANABE, M. NUKARIYA, M. TAHARA, T. SATOH, M. ...
1992 Volume 21 Issue 1 Pages
116-122
Published: February 15, 1992
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The possible damaging effects of speed of revolution, generated heat, volume of flow and pressure in the circuit to the cellular element of blood when using centrifugal pump (Bio-pump) was investigated by in vitro experiment. The amount of hemolysis possibly caused by the heat generated by the high speed of revolution and temperature gradient in the circuit was measured. The clinical experience in 405 BP-80 was analyzed and compared with the roller pump in regard to their hemolytic effect. The speed of revolution and the temperature of blood was found to be highly related to the degree of hemolysis when using the centrifugal pump, rather than the volume of flow and pressure. Since the centrifugal pump generates a completely nonpulsatile and steady flow, it could be less traumatic to the severely arteriosclerotic arteries seen in elderly coronary artery disease patients. The operation of the centrifugal pump is somewhat easier and safer than that of the roller pump, but no difference was observed in the effect to the cellular element of blood in comparison to the roller pump.
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R. YOZU, K. KOKAJI, K. ONOGUCHI, S. TAGUCHI, Y. SOMA, I. KISO, T. MAEH ...
1992 Volume 21 Issue 1 Pages
123-129
Published: February 15, 1992
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We applied various centrifugal blood pumps for assisted circuration in 21 cases who had undergone cardiac or aortic surgery during last seven years. Eight out of 21 cases had left heart assist. One case out of 21 had right heart assist. Remaining 13 casses had both left and right heart assist. In this series three could be weaned from the all assist blood pumps and two of these three were survived. Centrifugal blood pumps are very effective in hemodynamics. Compare to the pulsatile blood pump, centrifugal blood pump is easy to use as a pump for circuratory assist from the applicavility, availability and economical view points. Its efficacy is comparable with pulsatile assist blood pump especially when applied with IABP.
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M. ANDO, N. NAKAJIMA, S. ADACHI, M. NAKAYA, Y. KAWASHIMA
1992 Volume 21 Issue 1 Pages
130-135
Published: February 15, 1992
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Bio-Medicus centrifugal pump was used as an adjunct in operation for 56 cases of thoracic aortic aneurysm. Types of aneurysms were descending thoracic aneurysm in 18 patients, thoracoabdomimal aneurysm in 18 patients and others were aortic dissections. There were 37 men and 19 women whose ages ranged from 17 to 80 years with an average age of 59. We made left heart bypass in 40 patients and direct arterial bypass in 16 patients using Bio-pump with limited systemic heparinization. Operative method was graft replacement in all patients. Mean bypass flow was 2.1l/min and the pressure of femoral artery was maintained at 70% of radial artery during bypass, by which urinary volume could be satisfactorily obtained. Our intraoperative autotransfusion system was used at the same time. 11 cases of renal failure and 5 cases of paraplegia as postoperative complications were encountered. There were 6 hospital deaths. Neither were considered due to the use of Bio-pump. These results have led us to believe that Bio-pump is safe and useful as an adjunct in operation for thoracic aortic aneurysm.
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T. KOYAMA, T. SOME, T. ITOH, A. TAKASU, M. MURASE, H. SASSA, K. MINAKU ...
1992 Volume 21 Issue 1 Pages
136-141
Published: February 15, 1992
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Problems of centrifugal pump were studied in 28 cases in which centrifugal pump were used as a postoperative left heart assist or percutaneous cardiopulmonary support (PCPS). One of 3 cases which required left heart assist postoperatively was weaned but could not be salvaged. Eight of 17 cases (47%) which underwent emergency PCPS were weaned and 7 of them (41%) survived. Emergency PCPS was used in 10 cases as a cardiopulmonary resuscitation. Four of them showed complete recovery of consciousness 10 minutes to 17 hours later. Duration of cardiopulmonary resuscitation was 15 to 43 minutes (mean 30 minutes) in cases with complete recovery of consciousness. Elective PCPS was adopted in 8 cases during supported percutaneous transluminal angioplasty. In 6 of them, good results and symptomatic improvement were obtained. Centrifugal pump is easy for setting of the cardiopulmonary bypass circuit and can make it small-sized. Such a pressure control as a roller pump is not necessary. Centrifugal pump is very useful and safe in clinical use.
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M NISHIMURA, S NAKANO, M KANEKO, Y MIYAMOTO, K KADOBA, H TAKANO, A AME ...
1992 Volume 21 Issue 1 Pages
142-146
Published: February 15, 1992
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Twenty-eight patients (pts) who received ventricular or cardiopulmonary support or ECMO using centrifugal pump were analyzed. Among the 28 pts, 16 pts received left and/or right heart bypass (LHB-RHB), another 9 pts received cardiopulmonary support (CPS) and the remaining 3 pts, ECMO. Out of 16 LHB-RHB pts, twelve (75%) could be weaned from bypass and 6 (38%) discharged, while, in 9 CPS pts, two (22%) could be weaned and 2 (22%) discharged. The incidence of the pts that could be weaned from circulatory support was significantly lower in CPS than LHB-RHB. In 3 ECMO pts, two (66%) could be weaned and 2 (66%) discharged. Concerning the pump-related complications, three LHB-RHB pts had cerebral infarction and one ECMO pt had a crack in the centrifugal pump. Although the centrifugal pump has some limitations in durability and antithrombogenesity, it seems useful for temporary circulatory support.
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Ichiro SUZUKI
1992 Volume 21 Issue 1 Pages
147-150
Published: February 15, 1992
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Centrifugal pump (Bio-pump) as a continuous-flow pump was used in 68 patients who underwent open heart surgery to evaluate the change of hemodynamics and the influence on the hematology. Most of the adult patients whose perfusion time was about 3 hours; 43 of ischemic heart disease. 20 of heart valve disease and 5 of congenital heart disease.
Membrane oxygenators were used in all cases. Perfusion time was 185±98 min, and aortic clamp time was 98±40 min.
Right after the perfusion, plasma free Hb was 64±23mg/dl, and haptoglobin value was 72±36mg/dl. Decrease of flowrate during the centrifugal pump operation is observed when the resistance in the peripheral veins is increased, and the circulatory dynamics during the perfusion can be easily and precisely evaluated. In addition, the destruction is small. Based on this result, we believe that the centrifugal pump is effective as a continuous-flow pump during the perfusion.
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Hitoshi MIYAKE
1992 Volume 21 Issue 1 Pages
151-155
Published: February 15, 1992
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For the future-coming advanced old aged society, this paper describes the new developing method, designing with the dynamic analysis, of the internally frameworked (intra-skelton) manipulator, which works softly by the artificial muscle. The contraction characteristics of the Shape Memory Alloy artificial muscle, which is made as like as the living muscle, is also resembled by the "contraction equation" as same as this. And this has non-linear motion. Then the motion control of the manipulator with this artificial SMA muscle is difficult, especially, when unknown outer force comes. So this newly developed method consists firstly of a computer model of the manipulator, secondly of the dynamic analysis of the dynamic equation substituted the artificial muscle contraction characteristics equation. thirdly of the solutions, which are displayed on the CRT as animations, and finally of the easily changeable construction, which are recalculated and redisplayed.
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Y SHIMIZU, E MAKINO, A TASHIRO, S YOSHIDA, T KUNITOMO
1992 Volume 21 Issue 1 Pages
156-161
Published: February 15, 1992
Released on J-STAGE: October 07, 2011
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Glucose sensors were fabricated for in vivo measurement of glucose by using microhole array electrode (1000 microholes of 7μm diameter and 50μm depth over carbon fiber microdisk electrodes). Enzyme and electron mediator were immobilized on the surface of the micro-disk electodes in microholes. The glucose sensors were coated with non-thrombogenetic membrane. Three sensors were inserted into venous blood vessel, subcutaneous tissue and abdominal cavity simultaneously. Two sensors except for inserted into abdominal cavity showed good response. We concluded that this is a feasible technology for further development as an implantable glucose sensor.
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K. ABE, T. OKANO, K. SUZUKI, Y. SAKURAI, M. SUGAWARA, T. HORIE
1992 Volume 21 Issue 1 Pages
162-168
Published: February 15, 1992
Released on J-STAGE: October 07, 2011
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In order to clarify an inhibitory mechanism of platelet activation on HEMA-St block copolymer surface synthesized by means of anionic living polymerization, the morphological changes of platelets after contact with and/or platelets adhered for 3 hours to the block copolymer surfaces were analyzed by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Polystyren (PSt), HEMA-St random copolymer and HEMA-St block copolymer with an alternate lamellae structure of approximately 160Å in width were examined. The microsphere column method (column length 10cm; inner diameter 3mm) was used as experimental equipment to evaluate the interaction between the polymer beads (φ150μm) and the platelets suspended in Hanks' balanced salt solution (Ca
++, Mg
++ free). The flow rate was examined at both 0.1ml/min×15min and 0.5ml/min×3min. The platelets were treated in the routine procedure and were analyzed by TEM and SEM. As a result, the morphological changes of platelets on the block copolymer surfaces were inhibited significantly compared to that on PSt and the random copolymer surfaces without regard to the different flow rates. This result suggests that the block copolymer surfaces inhibit the platelet activation by the mechanism which inhibits the reorganization of platelet cytoskeletal contents such as actin polymerization and actomyosin contraction.
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Y. SUZUKI, M. KUSAKABE, S. SATO, H. IWAKI, K. AKIBA, K. KUSAKABE
1992 Volume 21 Issue 1 Pages
169-175
Published: February 15, 1992
Released on J-STAGE: October 07, 2011
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Ion implantations into silicone rods were performed at 150 keV with doses ranging from 1×10
17 to 3×10
17 ions/cm
2. The non-thrombogenicity was tested by the superior vena cava (SVC) indwelling method for two days in rats with In-111-tropolone-platelets, and by the inferior vena cava (IVC) indwelling method. Results of the SVC indwelling method showed that platelet accumulation on ion implanted specimens decreased. Macroscopic views of the ion-implanted IVC specimens in dogs revealed little thrombus formation. In particular, SVC indwelling method revealed that O
2+, K
+, and Kr
+ (1×10
17 ions/cm
2) implantation was most effective in reducing platelet accumulation.
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K. TAMURA, S. HITOMI, T. NATSUME, T. KOBAYASHI, O. KUWABARA, T. OHONIS ...
1992 Volume 21 Issue 1 Pages
176-180
Published: February 15, 1992
Released on J-STAGE: October 07, 2011
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We have prepared new hydrogel from Polyvinyl alcohol (PVA) which has rubber-like-elasticity. Its water content is 80-90 wt% resembling organic tissue. The purpose of this examination was to confirm the possibility of applying this PVA gel as an implantable medical material. It was implanted in a rabbit peritoneal cavity and in a dog pericardial cavity. After the excision, tensil elongation testing, dynamic Young's modules evaluation and stress relaxtion study were measured. Electrolytes were measured by the ionochromatography method. As the result of implantation during 3 to 18 months, the mechanical strength changed little and the elasticity was not lost. And the values of Mg2+ and Ca2+ were greater for gels in the rabbit than dogs, but they were extremely low. By these aspects, this new hydrogel can be used implantable biomaterial.
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S. ECHIGO, T. MATSUDA, T. KAMIYA, K. KUROE, S. FUSE, H. OZASA, R. YODA
1992 Volume 21 Issue 1 Pages
181-185
Published: February 15, 1992
Released on J-STAGE: October 07, 2011
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We developed a new transvenous patent ductus arteriosus (PDA) occlusion technique driven by thermo-expandable mechanics. In this experimental series, a new radio-opaque occluder device was made of shape memory polymer compounded barium sulphate. The aorto-pulmonary shunt was performed in five dogs using a e-PTFE graft. A barlike occluder device processed by hot press was pushed out transvenously into the graft by a pushing catheter through a long sheath with fluoloscopy. After dashed with 45°C normal saline solution through catheters, the device was expanded fully and stayed in the graft without any support. The aortogram after the procedure revealed three complete and two partial occlusions.
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T. SUGAWARA, T. MATSUDA
1992 Volume 21 Issue 1 Pages
186-190
Published: February 15, 1992
Released on J-STAGE: December 02, 2011
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This paper addresses novel surface process technologies aiming at chemical fixation of proteins on substrate surfaces. The essential feature of newly developed process is based on surface photochemical reactions. Two different approaches were explored. One was azidophenyl-derivatized proteins, which underwent chemical bonding with a polymeric substrate via adsorption and subsequent UV-irradiation. The other was photochemical generation of surface carboxyl groups and subsequent condensation with a protein. This was achieved by photodegradation of o-nitrobenzyl ester of a side chain of copolymers, which were precoated on substrates. Irrespective of approaches, proteins were chemically fixed on polymeric substrates. These were evidenced with ESCA measurement and colorimetric staining using corresponding antibodies. IN principle, these photo-induced protein fixation methods allow us to fix proteins on polymeric substrates with dimensional precise of micron-order. This was verified with atomic force microscopic observation. Photochemical protein fixation technologies developed here may find versatile applications to artificial organs, biosensors and cellular engineering.
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A. KISHIDA, T. MATSUDA, M. TAKATSUKA
1992 Volume 21 Issue 1 Pages
191-195
Published: February 15, 1992
Released on J-STAGE: October 07, 2011
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RGD (Arg-Gly-Asp) peptide was identified as the minimal active core peptide sequence common to adhesive proteins. In this paper, we report preparation of RGD-albumin conjugate (RGD-ALB) and its cellular adhesive functions in vitro. RGD-ALB was prepared via coupling reaction of albumin with pentapeptide (GRGDS; Gly-RGD-Ser) by water soluble carbodiimide. Bovine endothelial cells (ECs) adhered and spread on surface coated with RGD-ALB, whereas few EC adhered on surfaces coated with GRGESP-albumin conjugate (GRGESP peptide with little cell-attachment activity; false control) and albumin. Cellular behaviors, such as adhesion, spreading, growth and migration, on surfaces coated with RGD-ALB, fibronectin (FN) and vitronectin (VN) were examined. Adhered cell number on RGD-ALB coated surface was larger than those of FN and VN. Cell morphology on RGD-ALB coated surface was similar to that on FN. The cell growth and migration activity on RGD-ALB coated surface were almost equal to those on FN and VN. Thus, RGD-ALB was found to promote cell adhesion, migration and growth as effective as fibronectin.
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A. KISHIDA, M. TADATSUKA, T. MATSUDA
1992 Volume 21 Issue 1 Pages
196-200
Published: February 15, 1992
Released on J-STAGE: October 07, 2011
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The cell adhesion, migration and growth are fundamental processed controlling wound healing and tissue regeneration. We have reported that albumin conjugated with Arg-Gly-Asp (RGD) peptide, which has cell-adhesion promoting activity, has cellular adhesive activity comparable to fibronectin. In this study, we examined whether RGD-albumin conjugate (RGD-ALB) can promote the soft tissue ingrowth into porous matrix in vivo. Polyurethane sponge with 150-500 um pore size was prepared and used as a matrix. RGD-ALB, fibronectin (FN), albumin (ALB) were coated onto sponge surface, respectively. These sponges implanted in the subcutaneous tissue of rats were examined histologically. The inflammatory cells such as polymorphonuclear leukocyte (PMN) invaded into the deep inside of the RGD-ALB and FN coated sponge within 1 day after implantation. Both sponges exhibited rapid tissue ingrowth at 7th day postimplantation. On the other hand, the inflammatory cell invasion and the tissue ingrowth were markedly retarded for non-coated and ALB coated sponges. As RGD-ALB and FN were found to have little PMN chemotactic activity, the enhanced tissue ingrowth was mainly due to the cell adhesion activity. It was concluded that RGD-ALB can promote tissue activity at the initial stage of wound healing.
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H KAJIWARA, Y NOISHIKI, M ISHII, M ISHII, S SUZUKI, T KOSUGE, M MO, K ...
1992 Volume 21 Issue 1 Pages
201-205
Published: February 15, 1992
Released on J-STAGE: October 07, 2011
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A cardiovascular wall substitute which did not show any bleeding through the wall under fibrinolysis condition was developed. A piece of adipose connective tissue was minced with scissors and then stirred into saline to create a tissue suspension. This suspension was enmeshed into the wall of a highly porous fabric vascular prosthesis by repeated pressurized injections using a syrings. A non-meshed area of the same prosthesis was preclotted and used as the control. Tissue plasminogen activator was injected intravenously 1 hour after complete stop bleeding from the graft area. However, no bleeding at area of the tissue fragments enmeshing. This method enable to easily produce the graft with any size and shape in the surgery room. Such a graft is expected to have a high healing ability of the neointima of the graft surface.
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N. YAMADA, H. SAKAI, T. OKANO, Y. SAKURAI
1992 Volume 21 Issue 1 Pages
206-211
Published: February 15, 1992
Released on J-STAGE: October 07, 2011
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Recovery of cultured cells from substratum requires the treatment of proteolytic enzymes. The enzymes hydrolyze membrane protein molecules, resulting in the impairment of cell functions. We have developed poly (isopropylacrylamide) (PIPAAm) grafted surfaces as a novel cell culture substrata based on new concept. PIPAAm could be grafted uniformly onto a tissue culture polystyrene dishes by irradiation using an electron beam. The PIPAAm grafted surface reversibly change from hydrophilic to hydrophobic state by controlling temperature. Rat hepatocytes sensitive to enzymatic treatment were cultured on PIPAAm grafted surface. The cell adhesion and cell growth on both PIPAAm grafted and control dishes were identical. Nearly 100% of cells were detached and recovered from PIPAAm grafted dishes by low temperature treatment (10°C, 30min). Hepatocytes recovered by low temperature and trypsin treatment were subcultured on new control dishes. The percents of cell adhesion after 24h of cultivation were 80% of the cells recovered by low temperature and 25% of the trypsin-treated cells. Hepatocytes recovered from PIPAAm grafted dishes had remained the same activity of albumin secretion as primary cells, but that of cells by trypsin treatment was 1/5 of primary cells. We demonstrated that the attachment and detachment of rat hepatoccytes on PIPAAm grafted dishes can be easily controlled thermally. Moreover rat hepatocytes were recovered without the loss of liver-specific functions from PIPAAm grafted dishes.
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K. FUJIMOTO, Y. KONDO, Y. TAKEI, S. TOBE, T. AKAIKE
1992 Volume 21 Issue 1 Pages
212-216
Published: February 15, 1992
Released on J-STAGE: October 07, 2011
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In order to develop a hybrid artificial liver and a hepatic biosimulator for the analysis of drug metabolism, it is important to design some attachment substratum to maintain its differentiated function and longevity. It is considered that the peptide bond, conformation, balance of electric charge play important roles in the specific interactions for the stability of bonding and the selectivity. So we imitated them, and synthesized polypeptides containing different compositions of lysine, glutamic acid, leucine. Then we studied the attachment of hepatocytes to these polypeptides to make clear the interactions between hepatocytes and these polypeptides. Hepatocytes showed high adhesion to the polypeptides containing much lysine residue (Cation rich polypeptides). Hepatocytes on cation rich polypeptides exhibit better maintenance of liver specific functions as well as on collagen. Furthermore, hepatocytes cultured under the hormone supplemented medium formed remarkably multicellular spheroid within 3 days, then multicellular spheroid floated gradually from the surface of the dishes. It was interesting phenomenon that hepatocytes cultured on synthetic polypeptide formed floating multicellular spheroid by the stimulation of suppremented hormones. Polypeptides which have the activity of the forming spheroid in culture are very useful materials for the reconstruction of the liver tissue. Further studies using cultured system described here may be carried out to clarify the mechanism of spheroid formation in hepatocytes culture.
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APPLICATION OF SYNTHETIC EXTRACELLULAR MATRIX TO ORGAN ENGINEERING
S TOBE, Y TAKEI, T KUGUMIYA, A KOBAYASHI, T AKAIKE
1992 Volume 21 Issue 1 Pages
217-221
Published: February 15, 1992
Released on J-STAGE: October 07, 2011
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Liver tissue consists hepatocytes and nonparenchymal liver cells (NPC) and hepatocytes in vivo are surrounded by NPC, and the differentiation and growth of hepatocytes are regulated by their interactions with NPC. Therefore, it is important to coculture hepatocytes with NPC for establishing hepatocyte culture system which has structural organization similar to liver in order to develop hepatic module system. In this study, our attempt to culture hepatocytes with NPC on PVLA (poly-N-p-vinyl benzyl-D-lactonamide) as a polymer model of asialoglycoprotein for establishing hepatocyte culture system is described. Attached hepatocytes on PVLA remarkably formed anchored multilayer aggregations resembling micro-liver without supplemented growth factors, when cocultured with NPC. Hepatocytes in multilayer aggregations which were induced by NPC, retained enhanced expression of differentiated functions such as the secretion of albumin, and also survived for a long time. It seems likely that hepatocytes cultured with NPC experienced the stable environment of liver tissue in vivo, and as a result exhibited enhanced expression of differentiated functions and long-term survivability. Therefore, PVLA as a synthetic substratum is an efficacious substratum for the coculture of hepatocytes and NPC which results in a culturing system similar to liver tissue in vivo. The culture system described here has useful potentials for the development of hybrid artificial liver and the study of the process in liver regeneration.
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N. YUI, K. SUZUKI, T. OKANO, Y. SAKURAI
1992 Volume 21 Issue 1 Pages
222-227
Published: February 15, 1992
Released on J-STAGE: October 07, 2011
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An elevation of cytoplasmic free calcium levels ([Ca
2+]i) in platelets in contact with polystyrene latex particles was examined in comparison with those by thrombin and calcium ionophore (A23187). Benzyl alcohol-treated platelets showed much higher [Ca
2+]i by A23187 but lower by thrombin and polystyrene, which suggests that elevation of [Ca
2+]i by polystyrene surface is not due to an increase in membrane fluidity. Serratia protease-treated plateletes showed a steep increase in [Ca
2+]i by polystyrene but gradual increase by thrombin, which suggests that polystyrene surface can initiate platelet activation independent of glycocalicin of GPIb. Dibucaine-treated platelets showed few increase in [Ca
2+]i by polystyrene, which indicates that microfilament assembly including the binding of GPIb with actin binding protein should be required for platelet activation by polystyrene surface. Thus, a change in membrane glycoproteins-cytoskeleton networks can be dominant in initiating platelet activation by polymer surfaces.
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K. SUZUKI, N. YUI, T. OKANO, Y. SAKURAI
1992 Volume 21 Issue 1 Pages
228-233
Published: February 15, 1992
Released on J-STAGE: October 07, 2011
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We discuss the mechanism of prevented platelet activation on microdomain-structutured surface in terms of [Ca
2+]i On PSt, [Ca
2+]i in platelets increased rapidly to reach maximum within 2 min. The platelets on PHEMA, however, showed a gradual increase in [Ca
2+]i. On the other hand, the [Ca
2+]i showed few increase in the case of the HEMA-St block copolymer (Block). This result indicates that platelets activation is preventing when contacting with Block from early stage of activation. Then the platelets on polymer were activated by thrombin and calcium ionophore. Platelets on Block exhibited almost the same response in thrombin activation as those on homopolymer. This result indicates that the activation mechanism is different from receptor mediated one. By ionophore, [Ca
2+]i in the platelets on PHEMA showed higher level than any other polymrs. These results suggest that the membrane fluidity could be increased by contacting with PHEMA. Therefore, the platelet activation mechanism by contacting with PSt and PHEMA are different from each other. The Block prevent platelets activation by the formation of microdomain structures.
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T. SUGAWARA, T. MATSUDA
1992 Volume 21 Issue 1 Pages
234-238
Published: February 15, 1992
Released on J-STAGE: October 07, 2011
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Development of surface modification method providing biocompatibility is one of main subjects in the field of artificial organs. In this report, we present a novel graft polymerization method, which permits surface modification of complex-shaped devices. This method consists of three steps: i) photochemical fixation of poly (allylamine), ii) chemical fixation of radical polymerization initiator onto poly (allylamine), iii) surface graft polymerization. Poly (allylamine) was partially modified with p-azidobenzoyloxy succinimide. The resultant photoreactive polymer was chemically-fixed on substrates by UV-irradiation. The amino groups chemically-fixed on substrates were subsequently condensed with 4, 4'-azobis(4-cyanovaleric acid) by water-soluble carbodiimide. The graft polymerization was carried out at 60 C. Two examples of graft polymerization were demonstrated. One was styrene graft polymerization on poly (vinyl alcohol) surface, and the other was acrylamide graft polymerization on poly (ethylene terephthalate). ESCA analysis and water contact angle measurement evidenced that these surfaces were grafted on only irradiated portions. Nobel surface graft polymerization method could have potential versatility for surface modification of fabricated devices.
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T. OKANO, H. KATONO, N. OGATA, Y SAKURAI, K. SANUI
1992 Volume 21 Issue 1 Pages
239-243
Published: February 15, 1992
Released on J-STAGE: October 07, 2011
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Temperature responsive ON-OFF drug delivery systems have been investigated using interpenetrating polymer networked gels (IPN gels) composed of poly (acrylamide-co-butyl methacrylate) and poly (acrylic acid). Drug release from IPN was performed by fluctuating temperature at fixed times with various temperature gaps. The IPN demonstrated reversible release rate change with temperature fluctuations, showing higher release rate only at higher temperature. In some cases, rapid rate increase followed by rapid rate decrease was observed after cooling. The rate changes related to the shrinking mechanism of the IPN. At the beginning of the shrinking process, IPN formed a shrunken dense layer (DL) at the surface as the surface was first part cooled by temperature change. At the same time, shrinkage caused an internal pressure (IP) against the DL due to water flux. When IP overwhelmed DL barrier, water and drug flowed out by a squeezing effect, resulting in the drastic rate increase, this was followed by a steep rate decrease because of thick dense layer formation. When DL was strong enough to resist IP, drug release was restricted, resulting in a drastic rate decrease soon after cooling. In the "OFF" release mechanism, the release rate change was determined by DL/IP strength balance.
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R. YOSHIDA, K. SAKAI, T OKANO, Y SAKURAI
1992 Volume 21 Issue 1 Pages
244-248
Published: February 15, 1992
Released on J-STAGE: October 07, 2011
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Thermo-responsive copolymers of N-isopropyl acrylamide with alkyl methacrylate are capable of "on-off" regulation of drug release in response to external temperature change. To search the minimum temperature change achieving "on-off" regulation, dynamic process of "on-off" switching has been investigated by changing the chemical structure of polymer and the degree of temperature changes. In the switching process of drug release from the "on" state to the "off" state, large temperature changes lead to large volume changes at the gel surface and resulted in remarkable squeezing of drug from the gel surface. Squeezing was suppressed by small temperature changes, but in this case, sharp peaks appeared with a lag time due to the accumulation of internal pressure in the shrunken gel. Effects of the length of the copolymer alkyl side chain and the degree of temperature changes are discussed to achieve controlled pulsatile drug release pattern.
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H. ADACHI, R. OMOTO, Y. YOKOTE, S. KIMURA, S. KYO, H. NODA, K. HASEGAW ...
1992 Volume 21 Issue 1 Pages
249-253
Published: February 15, 1992
Released on J-STAGE: October 07, 2011
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Ringed intraluminal grafts were used for 16 patients with acute aortic dissection (type A: 13 cases, type B: 3 cases). Six of them died after surgery (cardiac arrest occurd two of them before surgery). In one patient, a new intimal tear was recognized at the site of the hard ring. Two of 10 survivers needed reoperation due to hemolysis and enlargement of the residual false lumen. Ringed graft is useful for poor risk cases. However, this graft is not suitable for aortic arch replacement. Further study is needed to evaluate the indication of ringed graft for acute aortic dissection.
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Keiichiro KATSUAIOTO, Tatsuru NIIBORI, Mohammed MINHAZUDDIN
1992 Volume 21 Issue 1 Pages
254-258
Published: February 15, 1992
Released on J-STAGE: October 07, 2011
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Glassy carbon stented intraluminal grafts were used for the treatment of thoracic aortic aneurysms. As a stent, glassy carbon tubes of 22 and 24mm in outer diameter were cut to a length of 25mm. The stents were prepared for use in the assembly of sutureless intraluminal grafts, using conventional artificial vascular prostheses. Five cases of thoracic aortic aneurysms were replaced with this method. The location of the stents were always at the distal end of the aorta but every proximal end-to-end anastomosis was performed using a conventional hand suture technique. The maximal follow-up term is 3 years in one case and the others over one year. No complications such as thromboenbolism, graft detachment or pseudoaneurysm have been observed to date. The results were quite satisfactory and our metod has proved to be a great advantage over commercially available intraluminal grafts.
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