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Biomedical subjects

M Takano

Publications and source records attributed to M Takano.

At least 433 records · Page 24Linked to original sources

Computed radiography utilizing scanning laser stimulated luminescence.

A new system of computed radiography that is based on new concepts and the latest computer technologies has been developed. This system eliminates the drawbacks of conventional screen-film radiography. The basic principle of the system is the conversion of the x-ray energy pattern into digital signals utilizing scanning laser stimulated luminescence (SLSL).

Computers↗

Auricular chromomycosis.

Chromomycosis, a relatively uncommon infection caused by a variety of dematiaceous fungi, eg, Phialophora verrucosa, Fonsecaea pedrosoi, Fonsecaea compacta, Cladosporium carrionii, Rhinocladiella aquaspersa, and Cladophialophora ajelloi, reflects a spectrum of disease ranging from an usually localized cutaneous form to rare visceral involvement. The cutaneous form has been reported to involve almost any site on the body surface. However, the lesions are usually confined to the extremities, face, or buttocks; other parts of the body are rarely affected. We report a case of chromomycosis that involved the auricle.

Adult↗

Mechanisms of p-aminohippurate transport by brush-border and basolateral membrane vesicles isolated from rat kidney cortex.

The uptake of [3H]-labeled p-aminohippurate by brush-border and basolateral membrane vesicles isolated from rat renal cortex has been studied by a rapid filtration technique. Some characteristics of carrier-mediated transport for p-aminohippurate were demonstrated in basolateral membrane vesicles: the uptake was inhibited by probenecid or 4,4'-diisothiocyano-2,2'-disulfonic stilbene (DIDS), was saturable, was stimulated by the countertransport effect, and showed discontinuity in the Arrhenius plot. In contrast, brush-border membrane vesicles failed to display saturability of p-aminohippurate uptake and stimulation by the countertransport effect, although probenecid and DIDS reduced the uptake. Furthermore, p-aminohippurate uptake by brush-border membrane vesicles was influenced more sensitively by alteration in the membrane potential compared with that by basolateral membrane vesicles.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗

The interaction of cephalosporin antibiotics with renal cortex of rats: accumulation to cortical slices and binding to purified plasma membranes.

The interaction of cephalosporin antibiotics with renal cortex of rats has been examined in vitro by means of cortical slice uptake and binding assay to plasma membranes and other subcellular fractions, including the comparative study with p-aminohippurate. The uptakes of cephalexin and cephaloridine by cortical slices were concentrative, and were strongly inhibited in the presence of 2,4-dinitrophenol, ouabain, nitrogen gas and probenecid. In the case of cefazolin, the degree of concentrative uptake and influence of inhibitors were low. Cephalexin, cephaloridine and p-aminohippurate specifically bound to the basolateral membranes, compared to brush border membranes and other subcellular fractions. Cefazolin binding to basolateral membranes was relatively small. These results suggest that the specificity of cephalexin and cephaloridine bindings to the basolateral membranes could be related to the interaction with the organic acid transport system at the antiluminal side. Thus, an examination of cephalosporin interaction with plasma membranes from renal cortex could offer an appropriate in vitro model system to study the renal transport of these antibiotics.

Animals↗

Comparative studies on the distribution mode of orthomyxo-virus and paramyxo-virus receptor possessing cells in mice and birds.

Many experimental studies have shown that orthomyxo- and para-myxoviruses may be pneumotropic, but not enterotropic in mammals. On the other hand, these viruses are both pneumotropic and enterotropic in avian species. We have devised a new method for detecting virus receptor possessing cells (VRPC) in tissue sections. VRPC could be detected in the cells lining the airways of both mice and birds. The mode of distribution of VRPC in mouse digestive system differed remarkedly from that in avian digestive system. VRPC were not found in the epithelium of mouse digestive systems whereas the epithelium of bird digestive system were abundant in VRPC. When the large intestines from mice or duck undergoing laparotomy and inoculated directly into intestine with influenza virus were examined, viral antigen was detected in the epithelial cell of duck colon, but not in mouse intestines. From the study utilizing the new method, it could be concluded that the distribution mode of VRPC is one of the most important factors determining the virus tissue specificity.

Animals↗

Heat-induced blebbing and vesiculation of the outer membrane of Escherichia coli.

Thermal damage to the outer membrane of Escherichia coli W3110 was studied. When E. coli cells were heated at 55 degrees C in 50 mM Tris-hydrochloride buffer at pH 8.0, surface blebs were formed on the cell envelope, mainly at the septa of dividing cells. Membrane lipids were released from the cells during the heating period, and part of the released lipids formed vesicle-like structures from the membrane. This vesicle fraction had a lipopolysaccharide to phospholipid ratio similar to that of the outer membrane of intact cells, whereas it had a lower content of protein than the isolated outer membrane. After heating bacterial cells at 55 degrees C for 30 min, the resulting leakage from the cells of a periplasmic enzyme, alkaline phosphatase, amounted to 52% of the total activity, whereas no release of a cytoplasmic enzyme, glucose-6-phosphate dehydrogenase, was detected. The results obtained suggest that surface blebs formed by heat treatment almost completely consist of the outer membrane and that the blebs may be gradually released from the cell surface into the heating menstruum to partially form vesicles.

Alkaline Phosphatase↗

[Behavioral effects of flutoprazepam (KB-509) and its metabolites].

The behavioral effects of KB-509 and its metabolites were investigated and compared with those of diazepam in mice and rats. The locomotor activity of mice measured by an Animex test was decreased with relatively large doses of KB-509 and diazepam. The anticonflict effect of KB-509 in rats was approximately as potent as that of diazepam. The lever pressing responses in the unpunished period were reduced by diazepam at a dose of 50 mg/kg p.o., while they were not affected by KB-509 even at a large dose such as 100 mg/kg p.o. KB-509 inhibited conditioned avoidance responses of the rat in a shuttle box at an extremely large dose such as 1000 mg/kg p.o. This effect of KB-509 was much less potent than that of diazepam. KB-509 was more potent than diazepam in inhibiting footshock-induced fighting behavior in mice. KB-509 and diazepam prevented maximal electroshock, pentetrazol, and strychnine induced convulsions in mice. KB-509 was more potent than diazepam in potentiating barbital anesthesia, in impairing rotarod performance, and in muscle relaxant activity measured by a traction test in mice. The pharmacological activity of desalkyl-KB-509 was more potent than that of KB-509 and that of desalkyl-3-OH-KB-509 was approximately as potent as that of KB-509. These results indicate that KB-509 possesses pharmacological properties similar to that of diazepam, and it is slightly greater in potency and is much longer in duration of action than diazepam.

Aggression↗

A simple method for the isolation of basolateral plasma membrane vesicles from rat kidney cortex. Enzyme activities and some properties of glucose transport.

A procedure for preparing basolateral membrane vesicles from rat renal cortex was developed by differential centrifugation and Percoll density gradient centrifugation, and the uptake of D-[3H] glucose into these vesicles was studied by a rapid filtration technique. (Na+ + K+)-ATPase, the marker enzyme for basolateral membranes, was enriched 22-fold compared with that found in the homogenate. The rate of D-glucose uptake was almost unaffected by Na+ gradient (no overshoot).

Alkaline Phosphatase↗

Tris-induced cross-linking of thylakoid peptides; thiol oxidation catalyzed by Tris-Cu2+ complexes as a possible mechanism.

After Tris(hydroxymethyl)aminomethane[Tris buffer]-treatment cross-linking of the chloroplast thylakoid peptides of 11, 13, 18, 43, 55, and 87 kdaltons was observed on SDS-polyacrylamide gel electrophoresis. Tris-induced disulfide formation was suggested by the decrease of thiol groups of the chloroplast thylakoids in Tris medium at pHs above 8. In addition to the finding that Tris coordinates to Cu2+ in the forms of Tris-Cu2+ and Tris2-Cu2+ whose successive stability constants are 5.78 x 10(3) M-1 and 4.46 x 10(6) M-2, respectively, it was observed that Tris-Cu2+ complexes catalyze cysteine oxidation. Sinc release of copper from the chloroplast thylakoids is enhanced by increasing the concentration of Tris, oxidation of thiols by Tris-Cu2+ complexes formed in chloroplast thylakoids is a possible mechanism for the cross-linking of chloroplast thylakoid peptides.

Chloroplasts↗