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Biomedical subjects

A Muranaka

Publications and source records attributed to A Muranaka.

At least 73 records · Page 4Linked to original sources
PubMed1980

Uptake and excretion of 67Ga-citrate in malignant tumors and normal cells.

Using in vivo and in vitro experimental models, the uptake and excretion of 67Ga-citrate in tumor cells and normal cells were studied. The time-lapse accumulation of 67Ga in the tumor of rats bearing Yoshida sarcoma reached its peak 24 h after the administration of 67Ga and gradually decreased thereafter. However, the excretion of 67Ga from the tumor was less than that from normal lung. For culture cells in vitro, the uptake of 67Ga increased with lapse of contact time between 67Ga and the cells, but there was no distinct difference between the results for tumor cells and normal skin fibroblasts. The excretion of 67Ga from the cells tended to decrease with prolongation of the contact time, the excretion from tumor cells being only about 10% after a contact time of 24 h. This indicated a significant delay in excretion in comparison with that of normal skin fibroblasts. This delay in the excretion of 67Ga may be an important factor in the tumor accumulation of 67Ga.

Animals↗
PubMed1980

99mTc-colloid kits from the view point of the accretion in the bone marrow--with special reference to comparison with 198Au-colloid.

With 9 kinds of available 99mTc-colloid kits for RES imaging, especially from the aspect of RES imaging of the bone marrow, observations were conducted on pH, the presence of free 99mTcO4(-), labelling efficiency, rabbit blood clearance, the uptake in RES, urinary excretion, as well as the scintigraphy with rabbits and clinical cases. Compared to 198Au-colloid, marrow to liver ratio was found to be about the same, but its uptake to the spleen and liver was greater. In particular its urinary excretion was much more marked than 198Au-colloid, and in clinical use the bladder was more often delineated. This fact seems to suggest that it is desirable to develope a 99mTc-colloid more suitabale for the bone marrow scintigraphy.

Anemia, Aplastic↗
PubMed1980

Experimental and clinical studies on differential diagnosis of bone diseases with nucleomedical procedures.

This report is a study of the differential diagnosis of bone diseases using nucleomedical procedures. Experimental and clinical studies on the accumulation of 201Tl and 67Ga in bone inflammation and bone tumors were performed. Also, the degree of deposition of 99mTc-phosphorous compounds represented as a color difference was evaluated for a differentiation between malignant and benign diseases of the spine and shoulder. Uptake of 201Tl in inflammation of the spine and in tumor of the pelvis of rabbits was very low, while that of 67Ga was high. Uptake of 67Ga decreased gradually with lapse of time after the onset of inflammation. These experimental results agreed with clinical studies. The detectability of malignant tumors with 201Tl was inferior to that with 99mTc-label and 67Ga, although osteolytic lesions were occasionally 201Tl-positive. In terms of color range, the difference was 2 or less in spines of normal subjects and 3 or more in the metastatic bone disease and compression fracture. This difference was not statistically significant. Since 67Ga scan was occasionally negative in compression fracture, a differentiation was considered to be possible in such a case. A combined study of bone imaging with 99mTc-phosphorous compound including color difference, 67Ga imaging, bone-marrow imaging and radiography are considered to be helpful for the differentiation.

Animals↗
PubMed1978

Experimental study on tumor affinity of 201T1-chloride.

The tumor affinity of 201T1 was studied with normal and VX-2 cancer-bearing rabbits. 201T1 distribution in normal rabbit tissues was greatest in the kidney and heart muscle, followed by thyroid gland small intestine, spleen, lung, liver, bone marrow, bone, skeletal muscle, and blood, respectively. Accumulation into the thyroid varied greatly according to individuals. Generally, the taller the height of follicular cells, the greater was the affinity. Accumulation of 201T1 into the tumor transplanted into femoral muscle reached its maximum within 1 h after administration, and thereafter decreased gradually. When the tumor affinity was compared with that of 67Ga, the ratio of 67Ga accumulation to tissues (except blood) was greater than that of 201T1. Accumulation of 201T1 is significantly correlated to that of 42K, and the mechanism of 201T1-tumor affinity seems to be triggered by the acceleration of the potassium metabolism of a tumor. Accumulation into the inflammatory focus was greater with 67Ga as a ratio to muscle, while the ratio to blood was greater with 201T1.

Animals↗
PubMed1978

Accumulation of radioisotopes with tumor affinity. I. Uptake and excretion of 67Ga-citrate in malignant tumors and normal cells.

Using in vivo and in vitro experimental models, the uptake and excretion of 67Ga-citrate in tumor cells and normal cells were studied. The time-lapse accumulation of 67Ga in the tumor of rats bearing Yoshida sarcoma reached its peak 24 h after the administration of 67Ga and gradually decreased thereafter. However, the excretion of 67Ga from the tumor was less than that from normal lung. For culture cells in vitro, the uptake of 67Ga increased with lapse of contact time between 67Ga and the cells, but there was no distinct difference between the results of tumor cells and normal skin fibroblasts. The excretion of 67Ga from the cells tended to decrease with prolongation of the contact time, the excretion from tumor cell being only about 10% after a contact time of 24 h. This indicated a significant delay in excretion in comparison with that of normal skin fibroblasts. This delay in the excretion of 67Ga may be an important factor in the tumor accumulation of 67Ga.

Animals↗
PubMed1976

[Experimental and clinical studies on the accuracy of geometry-independent counter].

For the purpose to conduct precise geometry-independent radioassay of large biological samples, the authors constructed an apparatus with the "peak+scatter" counting method slightly modified from that of Gibbs, et al. and studied its accuracy from the basic and clinical aspects. The apparatus, an opposed-head counter, consisted of two matched 2 x 2-in. NaI crystal detectors and photomultipliers that were connected in parallel to a pulse-height spectrometer. The crystal faces were separated by 54 cm. The detectors were enclosed in 5cm-thick shield built with lead and the sample chamber was a 15 cubic cm-box type of 3 mm-thick Lucite. A 13 cmphiX7.7 cm styrene topper container was used for the sample container. It was found that the relation of primary gamma energy of six radioisotopes and geometry-independent counting threshold turned out to be linear. The assay accuracy with 131I was about +/- 5% in fluid samples irrespective of its sizes (up to 500 ml) or homogeneity. In solid samples the accuracy approached that of fluid by the addition of water up to the height of it. The range, in which the activity could be measured within 5% error originating from statistical fluctuations or loss of counts due to instrument dead time, proved to be about 34 approximately .06 micronCi with 57Co in assay time of 10 min. On the basis of the basic investigations, the geometry-independent counting was used for the radioassay of stool and urine. Since the assay could be done simply up to a relatively large volume without need of material adjustment, it served well in the assay of urine and stool of clinical practice as well as in animal radioassay.

Evaluation Studies as Topic↗