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Biomedical subjects

S Fukunaga

Publications and source records attributed to S Fukunaga.

103 records · Page 6Linked to original sources
PubMed1979

Some problems on the histopathological diagnosis of non-Hodgkin's malignant lymphoma -- a proposal of a new type.

A new classification for non-Hodgkin's malignant lymphoma is proposed as the one suited for the Lymphomas in Japan, which is to provide a new subtype "pleomorphic" for those more or less rapid-growing lymphomas of peripheral T-cell nature, along with another subtype lymphoblastic, after Nathwani et al. for those of central T-cell nature. The proposal is based on the result of the investigation by the Study Group for Histopathological Diagnosis on Malignant Lymphoma that (1) the presence of a significant number of T-cell lymphomas with peculiar "pleomorphism" is responsible for the very low reproducibility rate of histopathological diagnosis on the diffuse, mixed L&H type of Rappaport classification, and (2) the relative incidence of lymphoms as peripheral T-cell nature including the so-called adult T-cell leukemia is much higher in Japan than in the Western countries.

B-Lymphocytes↗
PubMedDate not supplied

Development of an outside flow membrane oxygenator using a silicone hollow fiber.

A new membrane oxygenator was devised and assessed for performance in animal experiments. A silicone fiber membrane oxygenator, heat exchanger, and arterial blood reservoir are the components. The oxygenator is an outside flow type with minimum intrapulmonary resistance and, consequently, gas transfer is by gravity venous drainage. This device was used to conduct normothermic cardiopulmonary bypass (CPB) in 10 sheep over a period of 8 hrs (high flow group: 6 sheep, mean flow, 4.7 + 0.5 L/min; low flow group: 4 sheep, mean flow, 1 L/min). Performance was evaluated with gas transfer capacity, hematologic examination during CPB, and scanning electromicroscopic (SEM) appearance of the membrane after CPB. Blood gas was maintained with high PO2 and acceptable PCO2 levels throughout CPB. Plasma free hemoglobin was significantly low and fibrinogen was also maintained within physiologic levels. Scanning electron microscopy showed no thrombus formation on the membranes of either group. These results indicate this oxygenator to be quite adequate for gas exchange and prevention of blood cell trauma; it is also applicable to pulsatile or separating CPB because of the arterial blood reservoir.

Animals↗
PubMedDate not supplied

Evaluation of two new liquid-liquid oxygenators.

The authors devised two liquid oxygenator units in which blood is directly oxygenated with oxygenated perfluorocarbon (PFC), a substance harmless to the blood that has a high specific gravity. 1) The droplet-type oxygenator unit is composed of a blood oxygenating chamber and a PFC oxygenating chamber. Blood is oxygenated by the infusion of PFC droplets into the blood oxygenating chamber; PFC is then spontaneously separated from the blood because of a difference in specific gravity, and reoxygenated in the PFC oxygenating chamber. Experimental results obtained using mongrel dogs indicated this oxygenator to have a high efficacy of oxygenation (Qp/Qt = 0.63-0.78 with blood flow of 450-300 ml, O2 Transfer Rate = 64 ml/min with blood flow of 300 ml), and high carbon dioxide discharge (delta CO2/PaCO2 = 0.07-0.13, CO2 Transfer Rate = 11 ml/min with blood flow of 300 ml). Pathology examination showed microthrombi containing PFC in the lung and liver. 2) The disk type oxygenator unit is composed of a cylinder and 18 rotors connected to an axle. Oxygenated PFC enters into the lower part of the oxygenator and mixes with venous blood flowing above the PFC layer. The rotation of the disk in the oxygenator causes the blood and PFC to mix. Experimental results obtained using mongrel dogs showed excellent O2 exchange (Qp/Qt = 0.48-0.83, O2 Transfer Rate = 52 ml/min with blood flow of 300 ml) and CO2 removal capacity (delta CO2/PaCO2 = 0.05-0.10, CO2 Transfer Rate = 9 ml/min at blood flow rate of 300 ml/min) for 2 hours.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMedDate not supplied

A pulsatile cardiopulmonary bypass system that prevents negative pressure at the membrane oxygenator.

Negative pressure is a problem in pulsatile cardiopulmonary bypass (CPB). To avoid this, the authors designed a pulsatile CPB system containing a Sarns centrifugal pump (CP) and a Univox membrane oxygenator, in which the inertial flow is not obstructed by the CP. In both an in vitro study and a clinical study, negative pressure was not observed in the arterial line of the CPB circuit when this system was used. When a roller pump (RP) was used, however, instead of a CP, negative pressure did occur. In a clinical study using this system, mean pulse pressure was 36 mmHg and hemolysis, expressed as the rate of rise in plasma free hemoglobin from 10 to 70 min of CPB, was 26.2 mg/dl/hr, which did not exceed that seen with a pulsatile CPB using an RP instead of a CP. The hemolysis seen in the study caused no clinical problems. Thus, pulsatile CPB using a CP and Univox membrane oxygenator should be considered for clinical use to prevent the occurrence of negative pressure.

Cardiopulmonary Bypass↗
PubMedDate not supplied

Development of an air lift pump oxygenator.

The authors devised an air lift pump oxygenator, comprised of double cylinders connected together and filled with perfluorocarbon (FC-75, 3M) as an oxygen carrier. While the oxygen enters the FC-75 through the lower inlet of one cylinder, the oxygenated FC-75 is lifted by an air lift pump and circulates in the two cylinders. FC-75 adds oxygen to the blood that infuses from the lower inlet of the other cylinder. The oxygenated blood is separated from the FC-75 by gravity and infused into the subject. The size of the cylinder is 2.2 cm in internal diameter and 17 cm in effective oxygenation height. The capacity of the oxygenator is 160 ml. PO2 went from 62 mmHg to 96 mmHg and PCO2 decreased from 31 mmHg to 25 mmHg at a blood flow of 50 ml/min and an oxygen flow of 2 L/min. Maximum blood flow was 60 ml/min and the blood reserve capacity was 20 ml/min. The air lift pump oxygenator has advantages, such as simple structure, no motor, and a small priming volume.

Blood Flow Velocity↗