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Biomedical subjects

H Orii

Publications and source records attributed to H Orii.

53 records · Page 3Linked to original sources

Chemical properties and tumor affinity of separated isomers of cobalt-bleomycin.

Co-57 bleomycin is a chemically stable and diagnostically useful radiopharmaceutical. Stoichiometric preparation of Co-bleomycin causes two chemically different complexes. Four kinds of chelates (A2- type I, A2-type II, B2-type I and B2-type II) are easily separated by silicagel then-layer chromatography. Circular dicroism study of these chelates indicate that two types of complexes are conformational isomers. This chemical difference is assumed to cause the difference in the biological behavior. The biodistribution study of each type of complex, using tumor-bearing mice, showed higher tumor-to-blood ratios and tumor-to muscle ratios as compared with the clinical grade Co-bleomycin mixture. But the difference between the two types was not as large as expected. The similarity in biologic bahavior suggests that the groups on the bleomycin molecule, which are concerned with chelate formation, do not take part in its binding to DNA.

Animals↗

In vivo localization of Ga-citrate in rat liver as determined by cell fractionation with isopycnic rate-zonal ultracentrifugation.

The in vivo behaviour of Ga-67 citrate was studied, using a rat liver model, and the mechanisms of cellular uptake were investigated by observing the time course of the radionuclide in subcellular liver cell fractions. Modified continuous ultracentrifugation was used to successively fractionate the homogenates according to isopycnic and rate-zonal principles. To collect the cell nuclei, a special technique, which consisted of supplementing the outer sucrose layer with cesium chloride to increase density, was applied to trap nuclei with isopycnic equilibrium. We isolated nuclei, mitchondria, lysosomes and peroxysomes, microsomes, and the cell supernatant in a sufficiently purified state. By this method, the in vivo localization of Ga-67 was studied. At 30 min after intravenous injection, radioactivity was found mainly in the cell supernatant, the radioactivity peak corresponded to 5 S. However, after 24 h, the radioactivity was localized in the heavier fraction containing lysosomes and heavy endoplasmic reticulum. No intranuclear localization was observed. In spite of the difficulty in completely separating the lysosomal fraction from heavy endoplasmic reticulum, our results suggest the participation of heavy endoplasmic reticulum in gallium localization.

Animals↗

Partition behaviour of a cultured mouse mammary cancer cell line in aqueous two-phase polymer systems.

Cell surface-associated changes in behaviour of cultured cells on partition in an aqueous two-phase polymer system were studied using FM3A cell line (a cultured mammary cancer of mouse) with respect to aging. The aqueous polymer system consisted of dextran, polyethyleneglycol and sodium phosphate, equilibrated at 6 degrees C to separate into two phases. Enzyme treatment of cells with neuraminidase reduced cell electrophoretic mobility, as well as the cell partition ratio. Hyaluronidase produced no observable effects on partition and cell electrophoretic mobility, suggesting that the partition is related to culture time was similar for both cell electrophoretic mobility and cell partition, showing a rise and fall of charge-associated cell surface change during cell growth, the maxium occurring at the beginning of exponential growth. This change was reflected in the pattern of countercurrent distribution of the cells in respective stages of growth. Countercurrent distribution with our two-phase system is expected to be capable of fractionating cell populations according to cell surface properties.

Animals↗

Determination of the cross-points of rat liver peroxisomes, peroxisomal core and the core components by cross-partition.

The cross-points of rat liver peroxisomes, peroxisomal core and the core components were determined by means of cross-partition in two phase systems. The partitions were carried out in the systems containing 6% (w/w) Dextran T 500 and 6% (w/w) polyethyleneglycol 4000 in sodium salts. The same cross-point, pH 5.6, was obtained in peroxisomal marker enzymes in light mitochondrial fraction of liver homogenate, such as catalase, D-amino acid oxidase and urate oxidase. The cross-point as determined by cross-partition of purified peroxisomal core was 6.7. The cross-points of urate oxidase and framework protein fractions obtained by alkali treatment on the purified core were 7.8 and 4.2, respectively, and the ratio of the proteins of urate oxidase to framework protein was 2 : 1. The theoretical value of cross-point of the core calculated from from the relationship between the cross-point and protein ratio of each component of the core coincided with the experimental value obtained by this method.

Animals↗

Whole body bone scintigram and stage classification of the patients with adenocarcinoma of lung.

One hundred and six patients having adenocarcinoma of the lung were studied by whole body bone scanning with 99mTc-phosphates in connection with their clinical stages. Abnormal accumulation was found in 64 patients (60%). There were 64 patients who received surgical treatment. Among these 64 patients, 38 underwent bone scanning within 3 months after the establishment of their clinical stages. Twenty-two of them were classified as Stage I clinically. Pathological stage classification after the surgery revealed these 22 to be classified into 3 groups; 6 for Pathological Stage I, 4 for Pathological Stage II and 12 for Pathological Stage III. None of these 6 in Stage I showed abnormal accumulations. However, 1 of 4 in Stage II and 6 of 12 in Stage III were found to have abnormal accumulations. Therefore, if bone scintigrams had been taken into consideration for clinical stage classification, 7 patients would have never been placed into Clinical Stage I and could be expected more precise treatment. The authors recommend application of the results of whole body bone scanning to stage classification of adenocarcinoma of the lung. Needle biopsy is also recommended to confirm the metastasis at the site of radioisotope accumulation in the rib.

Adenocarcinoma↗

Bone scanning with 99m-Tc-phosphates: a comparison and problems in the detection of tumor metastasis.

A comparative study on 99m-Tc-phosphate compounds (TcPP) in detecting tumor metastasis to bone and problems accompanying it are reported. TcPP revealed metastatic foci which are unrecognized by conventional bone survey. To recognize these foci, exclusion of following problems is necessary: Accumulation at front of neck, asymmetrical image of joint, increased bone density of the aged, Tc-photon absorption and radiotherapy effect. The mechanism of TcPP accumulation is discussed.

Absorption↗