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Biomedical subjects

M Kojima

Publications and source records attributed to M Kojima.

At least 919 records · Page 51Linked to original sources

Synthesis of iodine-131 labeled 6 beta-iodomethyl-19-norsitost-5(10)-en-3 beta-ol and 19-iodositost-5-en-3 beta-ol for adrenal imaging.

6 BETA-Iodomethyl-19-norsitost-5(10)-en-3 beta-ol (V) was synthesized by homoallylic rearrangement of 19-iodositost-5-en-3 beta-ol (IV), which was obtained by the hydrolysis of 19-iodositost-5-en-3 beta-ol acetate (III) derived from the displacement of sitost-5-ene-3 beta, 19-diol 3-acetate 19-p-toluenesulfonate (I) with sodium iodide in isopropanol. The radioiodinated IV and V were prepared by isotope exchange with sodium iodide-I-131.

Adrenal Glands↗

Tissue Distributions of Dhurrin and of Enzymes Involved in Its Metabolism in Leaves of Sorghum bicolor.

The tissue distributions of dhurrin [p-hydroxy-(S)-mandelonitrile-beta-d-glucoside] and of enzymes involved in its metabolism have been investigated in leaf blades of light-grown Sorghum bicolor seedlings. Enzymic digestion of these leaves using cellulase has enabled preparations of epidermal and mesophyll protoplasts and bundle sheath strands to be isolated with only minor cross-contamination. Dhurrin was located entirely in the epidermal layers of the leaf blade, whereas the two enzymes responsible for its catabolism, namely dhurrin beta-glucosidase and hydroxynitrile lyase, resided almost exclusively in the mesophyll tissue. The final enzyme of dhurrin biosynthesis, uridine diphosphate glucose:p-hydroxymandelonitrile glucosyltransferase, was found in both mesophyll (32% of the total activity of the leaf blade) and epidermal (68%) tissues. The bundle sheath strands did not contain significant amounts of dhurrin or of these enzymes. It was concluded that the separation of dhurrin and its catabolic enzymes in different tissues prevents its large scale hydrolysis under normal physiological conditions. The well documented production of HCN (cyanogenesis), which occurs rapidly on crushing Sorghum leaves, would be expected to proceed when the contents of the ruptured epidermal and mesophyll cells are allowed to mix.

Journal Article↗

Study of malignant lymphomas from the aspect of immunoglobulin production.

Intracytoplasmic localization of immunoglobulins in neoplastic cells of malignant lymphomas was studied by both light and electron microscopic immunoperoxidase methods. This was demonstrated in 17 out of 71 cases submitted to light or electron microscopic immunoperoxidase methods. Out of 19 cases examined by the electron microscopic immunoperoxidase method, immunoglobulins were intracellularly identified in 10 cases; 3 out of 6 cases which were diagnosed as follicular lymphoma, 3 out of 5 cases of reticulosarcoma, 2 out of 6 cases of lymphosarcoma and 2 cases of immunoblastic sarcoma. Out of the above 10 cases, IgM was demonstrated in 9 cases except one of immunoblastic sarcoma in which IgA, IgG and IgM were identified intracellularly. In addition to these findings, our ultracytological and pathological studies have indicated that immunoglobulin-producing tumors can be classified into the following three major groups according to their cellular origin; germinal centers (group 1), primary follicles (group 2) and extrafollicular (group 3). Group 1 is comprised of follicular lymphoma and reticulosarcoma, group 2 lymphosarcoma, and group 3 immunoblastic sarcoma.

Adolescent↗

Syndrome of the sea-blue histiocyte--the first case report in Japan and review of the literature--.

A case of the syndrome of sea-blue histiocyte is presented in a 53-year-old Japanese woman, which is the first recorded case in Japan. The patient had hepatosplenomegaly, bleeding manifestations, mild thrombocytopenia, fatty metamorphosis and cirrhosis of the liver, as well as abnormal serum lipid profiles. Her parents were consanguineous and her maternal grandmother with hepatomegaly died of hepatic failure. Histologically, peculiar histiocytes containing numerous, intracytoplasmic sea-blue stained granules on May-Giemsa stain were demonstrated in biopsy materials of the bone marrow, lymph node and liver. The sea-blue granules in these histiocytes proved to have histochemical staining characteristics of lipogenic ceroid-like pigment. Ultrastructurally, these granules showed membrane-bound, pleomorphic inclusions of heterogeneous nature, including electron-dense amorphous or variegatedly osmiophilic, frequently laminated materials. Enzyme cytochemically, localization of acid phosphatase activity was demonstrated in and around the intracytoplasmic inclusions. With regard to the pathogenesis of the sea-blue histiocytes in this case, it may be suggested that the existence of the abnormality in lipid metabolism plays an important role in intralysosomal ceroidogenesis in these histiocytes.

Acid Phosphatase↗

Gaucher-like cells in juvenile GM1-gangliosidosis and in beta-thalassemia -- A histochemical and ultrastructural observation.

Peculiar storage cells appearing in bone marrow aspirates from a patient with juvenile GM1-gangliosidosis and from one with beta-thalassemia were examined light microscopically, histochemically and electron microscopically. Light microscopically, most of the storage cells closely resembled Gaucher cells pathognomonic for Gaucher's disease. The cytoplasm of the Gaucher-like cells contained numerous variable-shaped membrane-bound inclusions mostly arranged in a mosaic pattern and filled with fibrillar materials. Intermingled tubular structures were usually narrow as compared to those of the Gaucher cells. These ultrastructural differences of the stored materials between the Gaucher-like cells and Gaucher cells were more clearly substantiated by the high resolution electron microscopy with negative staining technique. Enzyme cytochemically, acid phosphatase activity was proved in or around the storage inclusions, suggesting their lysosomal origin. Histochemically, it might be suggested that the stored materials of the Gaucher-like cells in juvenile GMI-gangliosidosis were non-sulfated acid mucopolysaccharides and glycopeptides, whereas glycoproteins were the major component of the storage cells in beta-thalassemia. Possible mechanisms of storage in the Gaucher-like cells were discussed in both disorders.

Child↗

[On renal excretion of sodium 4-iodo-5-methylpyrazole-3-carboxylate-131I (author's transl)].

Sodium 4-iodo-5-methylpyrazole-3-carboxylate-131I(IMPC-131I) was synthesized by isotope exchange with Na 131I in the molten state to evaluate its potential usefulness as a renal function and/or imaging agent. Tissue distribution and clearance characteristics of IMPC-131I are described. Tissue distribution experiments in rats indicated a very high renal concentration of radioactivity following intravenous administration. At 5 min the kidney took up 27.8% of the injected dose (16.1% dose per gram) and the total activity in the kidney still accounted for 9.8% of the injected dose at 30 min, with only 1.2% localizing in the liver. The ratios for kidney-to-liver in the concentration of IMPC-131I were always higher than those of hippuran -131I throughout the period of the experiment. Within 24 hr, 78.6% of the injected dose were excreted in the urine. The autoradiographic and the scannographic studies were also performed. The present results suggest that IMPC-131I has potential as a new agent for both funciton and imaging studies of the kidney.

Animals↗

Studies on Actinomycetales producing antibiotics only on agar culture. I. Screening, taxonomy and morphology-productivity relationship of Streptomyces halstedii, strain SF-1993.

Soil Actinomycetales that produce antibiotics during growth on agar but not in submerged culture were searched for and about 25 strains were obtained. One of these, Streptomyces halstedii, strain SF-1993, which produces an antibiotic designated SF-1993 was studied taxonomically and morphologically. The antibiotic-productivity of strain SF-1993 was correlated with mycelial morphology. The vegetative mycelium was filamentous in antibiotic-producing agar cultures, but fragmented in non-producing submerged cultures. By maintaining submerged cells filamentous, production of antibiotic in the submerged fermentations was accomplished. Filamentation was maintained by the use of diluted media or non-fragmented mutant substrains.

Agar↗

Off-components in response to brief light flashes in the oscillatory potential of the human electroretinogram.

Amplitudes and implicit times of the several oscillatory potentials (OP's) in the human electroretinogram have been studied in relation to temporal, adaptive and spectral stimulus variables. The last of the OP-wavelets responds differently from the preceding ones; its implicit time shortens with increase in stimulus frequency or adaptive illumination, whereas that of the preceding OP's is prolonged or stays constant. Moreover, the last OP-wavelet is time locked with the stimulus offset, whereas the others are not. This can be confirmed by linear subtraction of responses to an isolated stimulus onset from responses to stimuli of variable durations. These results indicate, that the last oscillatory potential is related to the light offset and is presumably generated by the retinal off-elements described in single cell recordings.

Adaptation, Physiological↗

Isolation and Characterization of Factors in Sweet Potato Root Which Agglutinate Germinated Spores of Ceratocystis fimbriata, Black Rot Fungus.

A factor which agglutinates the germinated spores of Ceratocystis fimbriata was isolated from the sweet potato root. The factor is a glycoprotein with a molecular weight of 1.6 x 10(6) daltons and required divalent cations such as Ca(2+), Mn(2+), Ni(2+), and Mg(2+) for activity. The activity of the factor was pH-dependent. The factor also agglutinated rabbit erythrocytes and is classified as a phytohemagglutinin or lectin. The factor agglutinated germinated spores of seven strains of C. fimbriata to almost the same degree. The factor showed differential agglutinating activity toward the strains in the presence of unidentified low molecular weight factor(s) in the sweet potato root. These results support our earlier suggestion that the spore-agglutinating factors in host plants function as the determinants of specificity in some host-parasite interactions.

Journal Article↗