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Biomedical subjects

K Inamura

Publications and source records attributed to K Inamura.

At least 73 records · Page 4Linked to original sources
PubMed1986

Arachidonic acid-induced brain ischaemia: different severity between stroke-resistant spontaneously hypertensive rats and Wistar-Kyoto rats.

A thrombo-embolic stroke model was produced by the internal carotid artery (ICA) infusion of arachidonic acid (AA). The differences in responses to AA ICA infusion were investigated in stroke-resistant spontaneously hypertensive rats (SHRSR) and Wistar-Kyoto (WKY) rats. The SHRSR showed a higher mortality, more severe brain oedema and brain metabolic impairment, more prominent elevation of TXB2 and 6-keto-PGF1 alpha. Electron microscopic observation revealed more severe endothelial damage, mitochondrial swelling and perivascular oedema and earlier thrombus formation in SHRSR than in WKY rats.

6-Ketoprostaglandin F1 alpha↗
PubMed1986

[Effect of bilateral common carotid artery ligation on prostaglandin levels (TXA2, PGI2) in spontaneously hypertensive rats (SHRSP, SHRSR) and normotensive rats (WKY)].

Three different levels of global forebrain ischemia were induced in rats and their plasma levels of Thromboxane B2 (TXB2) and 6 Keto PGF1 alpha were determined to investigate the relation between severity of ischemia and eicosanoid production. Ischemia stimulates the activity of cellular lipase whose actions cause deacylation of brain phospholipids and release of free fatty acids. Arachidonic acid (A.A.) is one of the predominant fatty acids which is liberated in brain after ischemia. A.A. is the primary substrate for the synthesis of prostaglandins (PGs), Thromboxane A2 (TXA2) and Prostacyclin (PGI2), which play an important role in regulation of platelet aggregation and vasotonus. Thromboxane is a potent platelet aggregator and vasoconstrictor. On the other hand, PGI2 has the opposite nature. Therefore it can be considered that PGs and moreover, the balance of TXA2 and PGI2 may have an intimate relation to the development of cerebral ischemia. Three different levels of ischemia were produced by bilateral carotid artery ligation (BLCL) using three kinds of rats with different blood pressure ranges, namely, SHRSP (Stroke-prone spontaneously hypertensive rats), SHRSR (Stroke-resistant spontaneously hypertensive rats) and WKY (Wistar kyoto rats). It is known that higher pressure groups suffer severe ischemia by BLCL procedure. Hypertensive rats (SHRSP, SHRSR) were originally produced from WKY. The experimental animals used were about 300 gr and 16 weeks old male rats. The plasma and brain TXB2 and 6 Keto-PGF1 alpha, stable metabolites of TXA2 and PGI2 were measured by radioimmunoassay. The chronological changes of brain and plasma PGs levels after ischemia using SHRSR were also investigated.(ABSTRACT TRUNCATED AT 250 WORDS)

6-Ketoprostaglandin F1 alpha↗
PubMed1985

Cyclic guanidines. 17. Novel (N-substituted amino)imidazo[2,1-b]quinazolin-2 ones: water-soluble platelet aggregation inhibitors.

A series of novel 1,2,3,5-tetrahydroimidazo[2,1-b]quinazolin-2-one derivatives substituted with a secondary amino group has been prepared and tested for the activities of inhibiting platelet aggregation in rats in vitro and ex vivo. Most of the compounds were found to be the potent inhibitors of platelet aggregation. Some of the active compounds were soluble in water and effective via iv infusion in rats. Structure-activity relationships have indicated that a lipophilic secondary amino group located at position 6 or 7 contributed to retention of potent activity. Among the compounds studied, 7-piperidino-1,2,3,5-tetrahydroimidazo[2,1-b]quinazolin-2- one (13 g,DN-9693) was the most favorable compound.

Animals↗
PubMed1985

[Effects of S-adenosyl-L-methionine on experimental cerebral ischemia].

Effects of S-adenosyl-L-methionine (SAMe) on experimental cerebral ischemia were investigated using two different ischemic models. Cerebral energy metabolites (ATP, lactate, c-AMP) and brain water content were measured. It is reported that SAMe accelerates synthesis of phosphatidyl choline and increases erythrocyte membrane fluidity. Complete ischemia was produced by heart excision using wistar kyoto rats. SAMe (100 mg/kg, I.P.) was administered twice at one hour and immediately before inducing ischemia. The brain of rats were irradiated by microwave to stop the enzyme activity exactly 60 seconds after inducing ischemia and brain energy metabolites were measured. Recirculation model was produced by one hour recirculation following two hours ischemia induced by clipping of bilateral common carotid arteries using stroke-prone spontaneously hypertensive rats. SAMe (100 mg/kg, I.V.) was administered twice one hour after clipping and ten minutes after recirculation. The brain metabolites and water content were measured one hour after recirculation. In the complete ischemia, ATP and c-AMP levels were statistically high in the SAMe treated group compared to the untreated group (vehicle). But there was no statistical difference in lactate between the treated group and the untreated group. In the recirculation model, lactate elevation was suppressed in the SAMe treated group compared to the vehicle group with statistical difference, but there was no difference in ATP and c-AMP. Also, there was no difference in water content between the treated and the untreated group. SAMe protected energy failure in ischemia and accelerated recovery from ischemia. It is indicated that this agent is beneficial for treatment of cerebral ischemia in the acute stage.

Acute Disease↗
PubMed1984

[Experimental cerebral ischemia after bilateral common carotid artery ligation in SHRSP, SHRSR and Wistar rats: correlation between blood pressure and degree of ischemia].

Three different pressure groups of rats, stroke-prone spontaneously hypertensive rats (SHRSP, 200-270 mmHg), stroke-resistant SHR (SHRSR, 160-240 mmHg), and Wistar rats (WR, 120-160 mmHg) were used to investigate the effect of prior existing hypertension on the severity of brain damage induced by ischemia. The cerebral ischemia was induced by bilateral common carotid artery ligation (BLCL) and the survival rate, cerebral blood flow, cerebral energy metabolites (ATP, lactate c-AMP) and water content were measured. Colloidal carbon perfusion was also performed. Sixteen-week-old male rats were used. The survival rate was observed until 24 hours after BLCL. Cerebral blood flow was measured in parietal cortex by hydrogen clearance method. ATP was measured by luciferin-luciferase method, and lactate by enzymatic method using LDH. c-AMP was measured by radioimmunoassay. Brain water content was measured by freeze-dry method. These measurements were done for animals surviving 6 hours of BLCL. Colloidal carbon perfusion was done according to Ames' Method. The survival rate was lower in the hypertension group. The survival of SHRSP and SHRSR were 20% compared to 71% in WR after 24 hours of BLCL. The cerebral circulation of SHRSP fell abruptly and was near to zero after one hour of BLCL. In SHRSR this fall of cerebral blood flow was prominent in the rats of higher blood pressure. On the other hand there was no apparent fall of cerebral blood flow in WR after BLCL. The cerebral energy metabolites. ATP and c-AMP showed the lowest level in SHRSP which had the negative correlation to blood pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Triphosphate↗
PubMed1978

Design and development of a comprehensive computer system for radiotherapy departments.

An analysis of computer requirements in radiation therapy departments is presented. The performance and structure of an effective computer system designed for large or small radiotherapy departments are described. The system is composed of two or three sets of minicomputer-based subsystems of which can be operated alone or connected to other subsystems. The size of the system can be adjusted to the size of the radiotherapy department. The system covers treatment planning, automatic control, and record processing.

Computers↗
PubMedDate not supplied

Planning for PACS at Osaka University Hospital.

We have a plan to adopt PACS as a medical image information system in the new hospital. In order to construct PACS suitable for our hospital, a preliminary survey was carried out to determine how PACS should be introduced and what are the physicians requirements for a new medical image system. The most important requirement of the physicians was a good quality workstation. Our plan of a new medical image information system is as follows. A primary database will be constructed according to each of modalities in the Department of Radiology. In the Department of Medical Information Science, we will make a secondary database according to the patient. Although it may be difficult for us to obtain a sufficient budget digitalizing all medical images by our move to the new hospital, our goal is to establish total PACS throughout the new hospital in 1995.

Computer Communication Networks↗
PubMedDate not supplied

HIS/RIS contribution to image diagnosis and maximization of efficacy of PACS when coupled with HIS/RIS.

To maximize the efficacy of the PACS coupled with the HIS/RIS and to clarify the effectiveness of the PACS itself, the amount of contribution of the HIS/NS to image diagnosis was measured beforehand. Video-tape recorders were used to record the CRT display of the HIS/RIS terminals and the simultaneous conversation between a patient and his physician in the clinics of our hospital. Consultation time and entry time for image examination order were measured for each case by replay of the tape. Consultation time was approximately 10 min, while order time was 2-3.5 min depending on whether the physician was an internist or an orthopedist. Detailed description on an order was closely related to detailed reports. The HIS/RIS contributed to image diagnosis even before the PACS was coupled. Concrete methods of efficacy maximization of the PACS were pointed out by internists and orthopedists in terms of modalities, outpatient clinics and wards.

Ambulatory Care Facilities↗