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A Shimura

Publications and source records attributed to A Shimura.

29 records · Page 2Linked to original sources
PubMed1981

[The influence of whole body 60Co-irradiation on distribution of 67Ga in tumor-bearing mice (author's transl)].

Since the initial findings that 67Ga has a preferential affinity of soft tissue tumors, in humans numerous suggestions have been advanced for the basic mechanism involved. The effects produced by whole-body X-irradiation on the excretion and tissue distribution of 67Ga have been reported by Swartzendruber and others. Bradley and coworkers have shown that these irradiation effects were associated with an increase in serum iron. The present investigation was undertaken in order to study the relationships between the change in the serum iron concentration and 67Ga accumulation in the tumor and soft tissues in mice bearing Ehrlich's ascites tumor. The following results were obtained. (1) The serum iron concentration was significantly decreased between 3 and 6 hours after 10 Gy (1,000 rad) dose whole-body 60Co-irradiation. Subsequently, the serum iron levels were slowly elevated. (2) The uptake of 67GA in the tumor and soft tissues increased if the serum iron concentration was decreased by whole-body 60Co-irradiation during the early phase. On the contrary, if the serum iron concentration was high, the uptake of 67Ga in the tumor was decreased. (3) The excretion of 67Ga from the body was delayed if the serum iron concentration was decreased by whole-body 60Co-irradiation. However, if the serum iron concentration was high, the excretion of 67Ga from the body significantly increased.

Animals↗
PubMed1981

[The influence of iron on 67Ga distribution in tumor-bearing mice--effect of iron administered before 67Ga injection (author's transl)].

Following its discovery by Edwards and Hayes (1969), the propensity of 67Ga to accumulate preferentially in malignant tissues has been studied at diverse levels, not only for its importance in diagnostic imaging but also for its fundamental biological interest. The biodistribution of 67Ga citrate seems to be strongly influenced by the concentration of serum iron and the unsaturated iron-binding capacity (UIBC). Recently, it was found that the clearance of 67Ga from blood and the attainment of high tumor to normal soft-tissue concentration ratios are accelerated if the serum iron concentration is high. The present investigation was undertaken in order to study the relationships between the change of the concentration of serum iron and 67Ga accumulation in the tumor and soft-tissues in mice bearing Ehrlich's ascited tumor. The following results were obtained. (1) The uptake of 67Ga in the tumor and soft-tissues except bone was decreased compared with controls if the concentration of serum iron was elevated by Fesin (saccharated ferric oxide) administered prior the injection of 67Ga. (2) The urinary excretion of 67Ga was considerably increased if the concentration of serum iron was elevated by Fesin administered prior the injection of 67Ga. The results are consistent with the hypothesis that binding 67Ga to transferrin is very important to the accumulation of 67Ga in tumor and soft tissues.

Animals↗
PubMed1981

[The influence of iron on 67Ga distribution in tumor-bearing mice--effect of iron administered after 67Ga injection (author's transl)].

Gallium-67 concentrates in a variety of soft-tissue and tumor, however the accumulation is not specific for malignant tumor. The increase the tumor to non-tumor ratio is important to improve the quality of the tumor image. It has been recently found that the clearance of 67Ga from blood and the attainment of high ratios of the tumor to normal soft-tissue concentrations are accelerated, if the serum iron concentration is high. The present investigation was, therefore, undertaken in order to study the effect of administered iron after injection of 67Ga on the accumulation of 67Ga in the tumor tissue of mice bearing Ehrlich's ascited tumor. The following results were obtained. The accumulations of 67Ga in the tumor and soft-tissues were slightly decreased compared with controls after ferric acid saccharated (Fesin) administration 3, 6 and 24 hours after injection of 67Ga. However, the tumor to blood ratio (T/B) in each group treated with Fesin was considerably increased because the clearance of 67Ga from the blood is accelerated. The large tumor to blood ratio (T/B) would be advantageous for tumor scanning.

Animals↗
PubMed1980

Computed tomography and bone scintigraphy is polyostotic fibrous dysplasia. Report of a case.

A case of polyostotic fibrous dysplasia is presented in which the extent of bony lesions was defined on the results of the CT scan and bone scan with 99m Tc polyphosphate in addition to conventional radiography. These diagnostic procedures appear to be of considerable value in defining the extent of a variety of oral-maxillofacial bony lesions. This report describes the comparative findings from 99m Tc polyphosphate bone imaging and computed tomography (CT) in one patient with polyostotic fibrous dysplasia.

Adult↗
PubMed1980

Quantitative gallium-67 scanning for predictive value in primary lung carcinoma.

Gallium-67 scintigraphy was performed on 87 patients with a variety of histological types of untreated primary lung carcinoma. Gallium-67 uptake was determined, allowing for differences in tumor size. Differential uptakes were found for the various tumor types, with anaplastic small-cell carcinoma having the greatest average uptake, and adenocarcinoma and anaplastic large-cell carcinoma the smallest. Gallium-67 uptake was compared with response to radiation therapy, incidence of metastasis, and host survival in 58 of the patients. From these results it is suggested that the greater the Ga-67 accumulation in the tumor, the more effective is radiation therapy in reducing tumor size. Gallium-67 scintigraphy appears to be a valuable tool in estimating the sensitivity of the tumor before radiation therapy and in indicating the prognosis following radiation therapy in patients with primary lung carcinoma.

Adenocarcinoma↗
PubMed1979

Technetium 99m bone imaging in the evaluation of cancer of the maxillofacial region.

Technetium 99m bone images were obtained from five patients with mandibular gingival carcinoma and six patients with maxillary sinus carcinoma. Ten to 15 mCi of 99mTc-polyphosphate was administered intravenously, and imaging was performed three hours after injection. The anterior and lateral views of the maxillofacial skeleton were obtained with a gamma camera. Resultant gamma camera images were compared with the radiographic skeletal survey. 99mTc bone survey is a safe and simple diagnostic technique that can demonstrate abnormality of the bone with greater sensitivity than routine radiographs.

Adult↗