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Biomedical subjects

H Tanabe

Publications and source records attributed to H Tanabe.

At least 379 records · Page 21Linked to original sources
PubMed1981

Inhibitory effect of adenosine 3',5'-phosphate on cell division of Escherichia coli K-12 mutant derivatives.

Cell division of Escherichia coli K-12 strain PA3092 was inhibited by the addition of adenosine 3',5'-phosphate (cAMP), and the cellular morphology was changed from rods into filaments. Nucleoids in the filaments were regularly distributed and septum formation was perfectly inhibited. This inhibition of cell division by cAMP was reversed by the addition of guanosine 3',5'-monophosphate. To examine whether the inhibitory effect of cAMP on cell division in E. coli PA3092 was specific, its effect in several parental strains was investigated. Induction of cell filamentation by cAMP was observed in E. coli PA309 and P678, but not in E. coli W505, W1, Y10, or the wild-type strain. This result suggests that filamentation by cAMP in E. coli PA3092, PA309, and P678 was due to the mutagenesis by which E. coli P678 was derived from E. coli W595.

Cell Division↗
PubMed1980

Changes in membrane potential and membrane fluidity in Tetrahymena pyriformis in association with chemoreception of hydrophobic stimuli: fluorescence studies.

The fluorescence intensity of rhodamine 6G (Rh6G) and 1,6-diphenyl-1,3,5-hexatriene (DPH) in the presence of Tetrahymena pyriformis was measured to monitor changes in the membrane potential and in the gross structure of the surface membrane in response to chemical stimuli. So-called "odorants" for higher vertebrates, which are usually uncharged and hydrophobic compounds, were chosen as chemical stimuli for a model study of the olfactory response. The fluorescence intensity of Rh6G started to increase at the chemotactic thresholds of the stimuli, indicating that negative chemotaxis of T. pyriformis to the hydrophobic stimuli is induced by depolarization of the cell. The fluorescence intensity of DPH increased in close association with chemoreception of the hydrophobic stimuli. The increase in the fluorescence intensity was ascribed mainly to uptake of DPH, suggesting that gross structural changes of the surface membrane occur with the reception of hydrophobic stimuli. The membrane fluidity determined by fluorescence polarization of DPH increased in close association with the chemoreception of the hydrophobic stimuli. Inorganic salts such as NcCl, KCl, and CaCl2 did not change the DPH fluorescence intensity or the fluorescence polarization, although these stimuli induced depolarization and negative chemotaxis in T. pyriformis.

Animals↗
PubMed1979

Osteomalacic myopathy.

Muscles from two cases of osteomalacia were studied histochemically and electron-microscopically. Histopathological finding were common in these two cases. There are (1) myopathic changes such as scattered muscle fiber atrophy, necrosis, and internal uuclei, (2) derangement of intermyofibrillar network. and (3) type II fiber atrophy. Electron-microscopical finding corresponded well with light microscopical findings. These are distinct pathological features and deserves to be called osteomalacic myopathy. As the pathogenetic mechanism of this myopathy, phosphate depletion in the muscle cells resulting in disturbed glycolysis, and decreased vitamin D effects on muscle cells resulting in diminished calcium uptake by sarcoplasmic reticulum, are considered to be the most important two factors.

Adolescent↗