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Biomedical subjects

M Abe

Publications and source records attributed to M Abe.

At least 1,225 records · Page 68Linked to original sources
PubMed1986

Boron distribution analysis by alpha-autoradiography.

The distribution of the boron-10 compound, Na2 10B12H11SH, which is now in clinical use for boron neutron capture therapy for brain tumors, was studied topographically and quantitatively in rats using neutron-induced alpha-autoradiography. Transplanted intracerebral tumors in Sprague-Dawley rats were used. In the normal brain, only a minute amount of 10B (less than 1 microgram 10B/cm3) was found in the brain parenchyma, except for the infundibulum and area postrema. Boron-10 accumulated in the brain tumors. The tumor-to-blood concentration ratio of 10B increased with time after injection and reached unity 12 hr after injection. The tumor concentration calculated at that time was 18 micrograms 10B/cm3. This study clearly shows that this 10B compound accumulates in the transplanted rat tumors in the brain and that tumor concentration and tumor-to-blood ratio of 10B can provide a sufficient condition for brain tumor treatment.

Animals↗
PubMed1986

[Clinical evaluation of thermoradiotherapy for deep-seated tumors].

Between October 1981 and February 1985, RF capacitive heating with frequencies of 8 and 13.56 MHz was combined with radiotherapy in the treatment of 28 deep-seated tumors that were previously considered incurable by conventional radiotherapy alone. Intra-tumor temperatures of higher than 42 degrees C were achieved in 69% of overall heat sessions. Clinical evaluation was made by calculating the percentage of tumor regression from pre- and post-treatment CT films. As for the criteria of clinical evaluation, complete regression (CR) was defined as clinical disappearance of any measurable tumor, partial regression a and b (PRa and PRb) as regressions of 80% or more and 50 to less than 80%, respectively, and no response (NR) as less than 50% regression. Of 28 deep-seated tumors, 4 (14%) achieved CR, 5 (18%) PRa, 11 (39%) PRb and 8 (29%) NR. In some NR and PRb tumors, however, CT scan revealed remarkable increases in low density areas that suggested necrosis of tumor tissues. This was proved by subsequent histological examination. Clinical tumor response appeared to decrease as the initial size of the tumor increased and to be independent of any TDF factor for radiotherapy and the number of heat sessions.

Combined Modality Therapy↗
PubMed1986

Intra-operative radiotherapy for carcinoma of the stomach.

Intra-operative radiotherapy (IOR) was performed for the treatment of 101 patients with gastric cancer. Doses of 28 to 35 Gy with electron beams were delivered during the surgical procedure to tumour beds, high risk lymphnodes and/or remaining cancer nests after gastrectomy. Five-year survival rates were 87.2% for patients with Stage I disease, 83.5% for Stage II, 62.3% for Stage III and 14.7% for Stage IV. Compared with the data on 110 patients treated by surgery alone, IOR has yielded better results in patients with locally advanced disease. Based on these results, indications of IOR for gastric cancer were discussed.

Electrons↗
PubMed1986

[Clinical results of radiofrequency capacitive hyperthermia in deep-seated tumors].

The advantages of deep radiofrequency (RF) capacitive heating are its applicability to various anatomical sites and negligible systemic effects. The disadvantages are on the other hand, that its primary usefulness is limited to patients with thin subcutaneous fat and with large or hypovascular tumors. Clinical benefits of RF hyperthermia combined with radiotherapy are strongly suggested for deep-seated tumors. Intratumor low density areas on post-treatment CT and histopathological examinations are considered important parameters to assess the tumor response to thermoradiotherapy.

Abdominal Neoplasms↗
PubMed1986

Noradrenergic and non-noradrenergic relaxation at basal and high tone levels in the guinea-pig tracheal smooth muscle.

Responses to the beta-adrenoceptor agonist, 1-isoprenaline, and to transmural (electrical) stimulation of the guinea-pig tracheal muscle were evaluated at basal and high levels of carbachol or potassium-induced (K+) tone. The sensitivity of guinea-pig tracheal preparations to 1-isoprenaline was reduced by approximately 7-fold when high level tone was induced by carbachol or K+. Propranolol also shifted the dose-response curves to the right, but was apparently more potent in preparations with basal tone than in tissues where high tone was induced by carbachol or K+. Transmural (electrical) stimulation of tracheal strips produced an initial contraction followed by a longer lasting relaxation. At high level of tone produced by carbachol or K+, the contractile component was almost abolished while the relaxant response was unaltered. Relaxation induced by transmural stimulation was decreased to similar extents by propranolol at both basal and high tone levels. These results suggest that the potency of 1-isoprenaline and propranolol is affected by tonic conditions of tracheal muscle but the proportion of noradrenergic to non-noradrenergic components in the relaxation induced by neural stimulation may be unaltered at basal and elevated tone levels.

Animals↗