Search PubMed⌕ Search

Biomedical subjects

M Nakano

Publications and source records attributed to M Nakano.

At least 1,063 records · Page 59Linked to original sources
PubMed1985

Chemiluminescence in L-tyrosine-H2O2-horseradish peroxidase system: possible formation of tyrosine cation radical.

Tyrosine-H2O2-horseradish peroxidase system at pH 7.4 emitted light in visible region. Phenolic compounds other than tyrosine were also emissive, whereas methoxy phenylalanine and phenyl compounds were not, in H2O2-peroxidase systems. Chemiluminescence spectrum of tyrosine of tyrosine-H2O2-horseradish peroxidase system showed two prominent peaks at 478 nm and 500 nm (Luminescence 1) and additional two or three peaks near 550 and 610 nm (Luminescence 2). Luminescence 1 is quite similar to the phosphorescence originated from an excited tyrosine in triplet state, while Luminescence 2 is quite similar to the phosphorescence originated from an indole in triplet state. Possible formation of tyrosine cation radical (a precursor of the excited tyrosine) and indole cation radical in the enzyme protein (a precursor of the excited tryptophan residue) were discussed.

Free Radicals↗
PubMed1985

Age-related change in brush borders of rat kidney cortex.

Age-related change of rat renal brush borders was examined with electron microscopy and biochemical procedures. Total activity of renal brush border enzymes, such as alkaline phosphatase and leucine aminopeptidase in the homogenate, was significantly decreased with age. Acid phosphatase activity and protein content were not significantly changed with age. Specific activity of leucine aminopeptidase in brush border fraction was significantly decreased at a later stage of age. Protein content of brush border fraction was decreased significantly with age. On sodium dodecyl sulfate-polyacrylamide gel electrophoresis, some of the proteins disappeared during aging. Electron microscopic observations of kidney cortex showed that microvilli of renal brush borders from old rats were observed to be fewer than those from the young; epithelial cells in young rats have more densely packed brush border projections than those in old rats. From these results, it is suggested that during aging renal brush borders are degraded, and that protein components of the brush borders were different between old and young.

Acid Phosphatase↗
PubMed1985

Removing dowels in difficult teeth.

An improved method for removing dowels from endodontically treated teeth has been presented. It includes a cast supplementary device that supports the tooth while the dowel is being removed. Although the procedure requires more than one appointment, it provides a safe method for removing the dowel from the tooth.

Crowns↗
PubMed1985

Isolation and characterization of four forms of trehalase from rabbit kidney cortex.

Four forms of renal trehalase were isolated and purified to homogeneity. Hydrophobic interaction chromatography separated two forms; A-form and B-form. Both forms were subdivided further on Con A-Sepharose and were stained with periodic acid-Schiff reagent, indicating that they are glycoproteins. The four forms of renal trehalase showed no significant difference in Km values for trehalose and K1 values for various inhibitors. The optimum pH of the four forms was pH 6.0 in phosphate buffer. Apparent molecular weights on gel filtration of the four forms were the same, 175,000. Furthermore, the four forms showed the same antigenicity on double immunodiffusion. However, isoelectric point (pI), susceptibility to HgCl2, stability at -80 degrees C and Na+ activation behavior were different. Glycoprotein forms were more susceptible to HgCl2 and showed lower Na+ activation than nonglycoprotein forms. The pI of less hydrophobic forms (A1, A2) was more acidic than that of more hydrophobic forms (B1, B2). On the basis of these results, it is likely that four forms of renal trehalase are "isozymes."

Animals↗
PubMed1985

Role of interleukin 2 on enhancement of concanavalin A-induced human peripheral blood lymphocyte proliferation by murine B cell mitogens.

Murine B cell mitogens such as bacterial lipopolysaccharide (LPS), butanol-extracted water soluble adjuvant (Bu-WSA), dextran sulfate (DS), synthetic muramyl dipeptide (MDP), and its analog MDP-Lys (L18) do not show any mitogenic ability in vitro on human peripheral blood lymphocytes or mixed cell populations of purified T and B cells obtained from the lymphocytes in an ordinary culture system. However, these mitogens are capable of enhancing the mitogenic effect of concanavalin A (Con A) in the cultures. In the presence of one of these mitogens, the activity of interleukin 2 (IL 2), but not interleukin 1, in the supernatants obtained from cultures containing Con A-stimulated T cell and B cell populations was higher than that of control cultures. The role of the newly produced IL 2 in the synergistic effect of the mitogens in human lymphocyte cell cultures was discussed.

B-Lymphocytes↗
PubMed1985

Comparison of murine B cell clonal expansions by synthetic lipid A and muramyl dipeptide analogs.

Direct stimulations of murine B lymphocytes with synthetic lipid A analogs and synthetic muramyl dipeptide (MDP) derivatives were studied using a limiting dilution assay system. Synthetic lipid A analogs, GLA-27 and GLA-40, when conjugated with bovine serum albumin (BSA) had the ability to induce B cell clonal expansion of a single B cell from the spleen or bone-marrow. Their activities were almost the same as those of naturally obtained lipid A, but were lower than that of bacterial lipopolysaccharide (LPS). Addition of dextran sulfate (DXS) enhanced the effect of lipid A analogs. In contrast, synthetic MDP and its derivatives, although they had many biological and immunological activities in experimental animals, could not stimulate a single B cell to induce clonal expansion regardless of the presence or absence of DXS. These results suggested that lipid A analogs can directly cause the proliferation of B cells, but MDPs can not.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1985

Transport of theophylline from blood to the intestinal lumen following i.v. administration to rats.

The exsorption of theophylline into the small intestinal lumen after intravenous administration of aminophylline was studied by in situ single-pass perfusion technique. As the concentrations of the drug in the serum and the bile juice were decreased, the exsorption rate of the drug into the perfusate decreased obeying the apparent first-order kinetics. The half-lives of the drug concentrations in the serum and the bile juice were 2.13 and 2.58 h for pH 6.0 isotonic phosphate buffer, and were 2.71 and 2.32 h for pH 8.0 isotonic phosphate buffer, respectively. The amounts of theophylline excreted in the perfusate and the bile juice were 12.08% and 0.17% of dose for pH 6.0 isotonic phosphate buffer, and were 13.81% and 0.20% of dose for pH 8.0 isotonic phosphate buffer. These results demonstrated that a considerable amount of theophylline was exsorbed into the intestinal lumen. The mechanism by which oral activated charcoal enhanced clearance of theophylline administered intravenously may be adsorption of the drug transported into the gastrointestinal tract by the charcoal.

Animals↗