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Biomedical subjects

T Sasajima

Publications and source records attributed to T Sasajima.

117 records · Page 7Linked to original sources

Water movement between myocardial tissue and capillary blood during and after coronary reactive hyperemia as studied by continuous measurement of colloid osmotic pressure of cardiac venous blood.

Colloid osmotic pressure (COP) of blood from the great cardiac vein was continuously measured by the use of a membrane colloid osmometer during reactive hyperemia resulting from temporary occlusion of the anterior descending branch of left coronary artery. The COP increased sharply but transit was concluded that a measurable amount of water moved from the capillary blood into the myocardial tissue and then flowed back slowly into the capillary blood.

Animals↗

Directional non-uniformity of pulsatile intramyocardial pressure.

A method using piezoelectric ceramics was newly devised which permitted measurements of intramyocardial pressure. In open-chest dogs, a directional non-uniformity of the intramyocardial pressure was observed, which may be attributable to the variation in the myocardial fibre orientation.

Animals↗

Effects of coronary occlusion on myocardial oxygen and pulsatile intramyocardial pressure.

Local oxygen partial pressure in terms of O2-availability and pulsatile intramyocardial pressure of the left ventricular myocardium of anaesthetized open-chest dogs have been measured simultaneously by means of a piezoelectric ceramic and a platinum electrode. The tissue PO2 decreases more slowly than the pulsatile intramyocardial pressure during a transient acute occlusion of the anterior descending branch of the coronary artery. The slow decrease in the tissue PO2 seems to be explicable by the assumption that the local myocardial contractile force decreases quickly due to an unknown factor during the acute coronary occlusion and that the O2-consumption of the local myocardial tissue is reduced in accordance with the rapid decrease in the contractile force.

Animals↗

Intracranial plasma cell granuloma evaluated by positron emission tomography.

A 50-year-old farmer with plasma cell granuloma had PET scans showing marked accumulation of C-11 Met. The PET had superiority in imaging the existence and extent of the lesion and monitored therapeutic response as compared with CT and MR imaging. PET yields information on hemocirculatory and metabolic aspects of this rare disease.

Brain Diseases↗

Early delineation of cerebral glioma using amino acid positron tracers.

A 56-yr-old housewife with cerebral astrocytoma was reported with positron emission tomography findigns using 11C-methyl-L-methionine (11C-Met) and 18F-fluorophenylalanine (18F-Phe) tracers. 11C-Met and 18F-Phe accumulated intensely in tumor lesions, although CT scans showed only a foggy low-density area. Five years and one month after, an enhancing mass appeared on CT scans. Thus, amino acid tracers may play a important role in the early diagnosis of gliomas.

Astrocytoma↗

Demonstration of cerebral radiation injury with metabolic positron emission tomography images.

A 2-year-old girl with medulloblastoma who had postoperative radiotherapy and intrathecal administration of methotrexate is reported. Five months after radiation and chemotherapy, she developed involuntary movement. Positron emission tomography (PET) demonstrated that the metabolic rate of glucose was depressed markedly in the temporal and occipital lobes, indicative of metabolic depression induced by radiation. Prompt initiation of steroid therapy ameliorated the patient's neurological symptoms. Follow-up PET revealed an increase in 18F-fluorodeoxyglucose uptake in the entire brain, including temporal and occipital lesions. No areas with high accumulation of (11C-methyl)-L-methionine were detectable. We concluded that PET may be useful in establishing an early diagnosis of radiation injury of the brain and in monitoring metabolic changes following radiation in brain tumor patients.

Blood Glucose↗

Local pulsatile intramyocardial pressure (IMP) as a vector force: simultaneous measurements of IMP and tissue oxygen availability.

A directional nonuniformity of the intramyocardial pressure (IMP) was observed in anesthetized open-chest dogs using a piezoelectric pressure sensor implanted in the left ventricular myocardium. The nonuniformity seemed to be attributable to the variation in myocardial fiber orientation. The IMP, which developed in a direction parallel to the base-apex line, was measured in the deep portion of the myocardium, simultaneously with local O2 availability. In some cases, IMP decreased quickly as soon as a decrement in O2 availability had proceeded only slightly as a result of ligation of the anterior descending artery (LAD). In other cases, the once decreased IMP recovered gradually even when O2 availability remained lowered by continuation of the ligation. These observations indicated that IMP had no direct dependency on O2 availability in the case of acute LAD.

Animals↗

Early clinical results of the modified human umbilical cord vein homograft (Dardik Biograft).

Fifty-six reconstructions using Biograft were performed in 45 cases with peripheral arterial occlusion. These consisted of 11 femoro-popliteal bypasses above the knee, 19 femoro-popliteal below the knee, 10 femoro-tibial or peroneal and 16 other miscellaneous procedures including aorto-femoral and extra-anatomic bypasses. Overall patency rates for each type of procedure were 81.8%, 78.9%, 30.0%, and 93.8%, respectively. The cumulative patency rate (calculated by the life table method) for the total group was 70.5% at 56 months. Early failure was thought to relate to technical factors in most instances. The majority of late failures was due to intimal hyperplasia at the distal anastomotic site. One of 9 late failures was successfully treated by patch angioplasty at 23 months following initial operation. Therefore, in order to attain better late results, early discovery of developing stenosis by noninvasive examination techniques and arteriography is important.

Aged↗