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Biomedical subjects

H Imamura

Publications and source records attributed to H Imamura.

At least 379 records · Page 21Linked to original sources

[Therapeutic embolization in the external carotid artery region (author's transl)].

UNLABELLED: This paper reports our experience of therapeutic embolization in the external carotid artery region. Therapeutic embolization was done for the purpose of decreasing hemorrhage during operation. MATERIAL AND METHOD: Therapeutic embolization was done in 6 cases of meningioma, 1 case of capillary hemangioma of the cheek and one case of olfactory neuroblastoma. Catheterization was done through the common carotid artery in adults and done through the femoral artery in an infant. Small pieces of Gelfoam were used as emboli. Emboli, 1 X 1 X 0.5 mm in size, were instilled with normal saline. One embolus was used in one instillation as a rule. A larger embolus was used for occlusion of a larger artery. Heparin was not used through entire procedure. Four illustrative cases are presented. when a feeder of a tumor is occluded by artificial emboli, two kinds of effect can be resulted. when emboli lodge within the tumor or in a feeding artery distal to arterial anastomoses, blood is no longer supplied to the tumor (embolization effect). On the other hand, when a feeding artery is occluded by emboli at the point proximal to arterial anastomoses, blood supply to the tumor is transiently reduced but it is soon restored through arterial anastomoses (ligation effect). To minimize bleeding during surgery it is very important to gain embolization effect. For this purpose small emboli should be instilled repeatedly until embolization effect is established. Then ligation effect should be obtained, if necessary, by injection lower emboli. Operation was performed on the day following embolization in cases of meningioma. In a case of capillary hemangioma of the cheek operation was performed three days after embolization and in a case of olfactory neuroblastoma surgery was performed two days after embolization. In all cases the primary purpose to minimize bleeding during operation was achieved. No untoward side effects were encountered in this series. The ophthalmic artery may arise from the middle meningeal artery. The vertebral artery might be visualized through the collateral from the occipital artery. We should pay attention to these vascular anomalies before embolization to prevent possible catastrophe.

Aged↗

Right-sided cervical aortic arch associated with tetralogy of Fallot and peculiar tortuosity of the descending aorta.

A right-sided cervical aortic arch, tetralogy of Fallot, and a peculiar tortuosity of the descending aorta in which the aorta formed triple loops were diagnosed by angiocardiography in a 12-year-old girl. Histologic examination of the biopsied wall of the left subclavian artery, taken at the time of a Blalock-Taussig anastomosis, revealed no elastic-tissue defect.

Angiocardiography↗

Effects of 2-[4-(2-imidazo[1,2-a]pyridyl)phenyl] propionic acid (Y-9213) on in vivo release of lysosomal enzymes from rat polymorphonuclear leukocytes during phagocytosis of particles.

Intraperitoneal administration of carrageenin-zymosan suspension into rats induced an increment of the free activity and its ratio of aryl sulfatase in the exudate and such was accompanied by protein exudation and polymorphonuclear leukocyte emigration. Each test solution was orally administered twice, 1 hr before and 2 hr after, or once 2 hr after injection of the irritant. The peritoneal fluid was withdrawn 5 hr after the injection. 2-[4-(2-imidazo[1,2-a]pyridyl)phenyl] propionic acid (Y-9213) and other anti-inflammatory drugs tested inhibited the increment of the ratio of the free activity (aryl sulfatase) in the peritoneal fluid at the same dose which showed anti-inflammatory activities such as prevention of protein exudation. These results suggest that Y-9213 inhibits the phagocytic secretion in vivo of lysosomal constituents from leukocytes.

Animals↗

New surgical method for repair of anomalous left coronary artery from pulmonary artery.

A new surgical method for repair of anomalous origin of the left coronary artery from the pulmonary trunk is described. The principle of the proposed technique is to transmit the oxygenated blood to the anomalous left coronary artery through surgically created aortopulmonary window and the internal tunnel created in the main pulmonary trunk. A 2-year-old boy in whom this anomaly was associated with mitral regurgitation caused by papillary muscle dysfunction was successfully treated by this new surgical method, and the deformed mitral valve was concomitantly replaced by a Hancock porcine xenograft.

Angiocardiography↗

Biocompatibility tests of components of an implantable cardiac assist device.

A permanently implantable in-series left ventricular assist device, the dynamic aortic patch (DAP), has been tested in chronic animal experiments. The DAP replaces a section of the intrathoracic aortic wall. Hemothorax and hematocele at the implantation site have been complications in recent experiments. Primary postoperative hemorrhage was ruled out, and the biocompatibility of all components was therefore examined. Dacron velour, Teflon felt, conductive polyurethane, segmented polyether polyurethane, and Teflon-coated polyester fiber sutures were implanted in the pleural cavities of dogs and tested in vitro by culturing canine saphenous vein explants on them. In vivo experiments demonstrated that all components elicited mild to moderate inflammatory reactions, but hematocele occurred only when the components were implanted in the aorta with direct blood contact and exposed to arterial blood pressures. In vitro, cells were cultured on all components with no signs of toxic reactions. These results indicated that the host tolerated all implant components without major inflammatory responses. However, histological data indicated that chronic slow bleeding into or through the Dacron velour in contact with the arterial blood serum could account for hemothorax or hematocele formation. Therefore, a configuration of the assist device using materials impermeable to blood may obviate these difficulties.

Animals↗

Effects of 2-(4-(2-imidazo[1,2-a]pyridyl)phenyl) propionic acid (Y-9213) and anti-inflammatory drugs on erythrocytes, polymorphonuclear leukocytes and lysosomes in vitro.

2-(4-(2-Imidazo[1,2-a]pyridyl)phenyl)propionic acid (Y-9213) with analgesic, antipyretic and anti-inflammatory activities significantly inhibited hemolysis of rat erythrocytes. Activity of Y-9213 (100--500 micrometer) on hemolysis was more potent than that of phenylbutazone, and less potent than that of indomethacin. The spontaneous release of enzymes from rat liver lysosomes by incubation alone was significantly inhibited by Y-9213 (1--100 micrometer) to the same degrees as phenylbutazone or tinoridine hydrochloride. Release of enzymes from the lysosomes by addition of phospholipase C (PLC, 0.03 units/ml) was slightly inhibited by Y-9213 (10--100 micrometer) and phenylbutazone (100 micrometer). Dexamethasone, prednisolone, hydrocortisone and tinoridine hydrochloride (1--10 micrometer) inhibited more potently the PLC-induced release than the spontaneous release. Y-9213 (1--100 micrometer) inhibited considerably the release of enzymes from intact lysosomes of rabbit polymorphonuclear (PMN) leukocytes. The release of enzymes from the PMN leukocyte lysosomes preincubated at 37 degrees C for 15 min was strongly inhibited by dexamethasone, prednisolone and hydrocortisone (1--100 micrometer), but not by Y-9213, phenylbutazone and indomethacin (100 micrometer). Y-9213 (0.1--10 micrometer) also inhibited significantly the phagocytic secretion of lysosomal enzymes from PMN leukocytes without affecting phagocytosis of the particles. Activity of this agent was similar to that of phenylbutazone, and less active than that of indomethacin, dexamethasone or prednisolone. Our results suggest that Y-9213 may stabilize membranes of erythrocytes and lysosomes and inhibit phagocytic secretion of lysosomal constitutents from PMN leukocytes.

Animals↗