Biomedical subjects

Kazutami Sakamoto

Publications and source records attributed to Kazutami Sakamoto.

4 recordsLinked to original sources

PubMed2002

Intracellular redox regulation by a cystine derivative suppresses UV-induced NF-kappa B activation.

Nuclear factor (NF)-kappa B pathways are influenced by the intracellular reduction-oxidation (redox) balance. While NF-kappa B is activated through inhibitor (I)-kappa B degradation by oxidative stress, its DNA binding is accelerated in the reduced state. We found that N,N'-diacetyl-L-cystine dimethylester (DACDM) suppressed the UVB-induced NF-kappa B binding activity at a much lower concentration (50-100 microM) than N-acetyl-L-cysteine (NAC, 10-30 mM). While NAC suppressed the I-kappa B degradation but not the DNA binding, DACDM prevented the activated NF-kappa B from binding DNA, without influencing the I-kappa B degradation. These properties of DACDM make it possible to effectively regulate the intracellular redox balance.

Acetylcysteine↗

PubMed2001

Solubilization of Polar Oils in Surfactant Self-Organized Structures.

The cloud temperature of 2 wt% C(12)EO(8) aqueous solutions decreases upon addition of sarcosinate-lauroyl isopropyl (SLIP), 1-dodecanol, and m-xylene, whereas it increases in glycerol tris(2-ethylhexanoic) ester (TEH), isopropyl myristate (IPM), and saturated hydrocarbon systems. A three-phase microemulsion is formed at equal weights of water and oil in the IPM system, but a lamellar liquid crystal (L(alpha)) is present in the SLIP system at the balanced temperature. The effect of added oil on the phase transition of the hexagonal (H(1)) phase was also investigated by means of SAXS study. The H(1)-L(alpha) transition occurs upon addition of SLIP or 1-dodecanol whereas the H(1)-I(1) (discontinuous micellar cubic) phase transition takes place in TEH or IPM systems. These differences in phase behavior are attributed to the placement of solubilized oil in micelles: In the former systems, oil tends to penetrate in the surfactant palisade layer and induces the surfactant layer curvature in micelles to be less positive, while the penetration tendency is small and the opposite effect on the curvature is induced upon addition of the latter oils. Copyright 2001 Academic Press.

Journal Article↗

PubMed2000

Electron paramagnetic resonance: a new techniquein skin research.

BACKGROUND/AIM: Electron paramagnetic resonance (EPR) spectra of nitroxide spin probes have been used for studying biological membranes and chemical-membrane interaction. We have investigated the influence of surfactants on the intercellular lipid structure of cadaver stratum corneum and the possibility of EPR spectral measurements on the stripped stratum corneum utilizing cyanoacrylate resin, which might reflect the actual skin lipid conditions. CONCLUSION: EPR spectra are useful in evaluating the fluidity measurement of stratum corneum of cadaver skin and stripped stratum corneum.

Journal Article↗

PubMed2000

Electron paramagnetic resonance study utilizing stripping method on normal human stratum corneum.

BACKGROUND/AIM: Electron paramagnetic resonance (EPR) spectra of nitroxide spin probes are useful for studying biological membranes, and chemical-membrane interaction. The objective of this study was to assess the fluidity of stripped stratum corneum (SC) of normal human skin with EPR. METHODS: We quantified the fluidity of stripped SC (S-SC) by a single stripping with cyanoacrylate onto quartz glass, cover glass or transparent film. Spectra were compared with those of the SC of cadaver skin (C-SC). RESULTS: All S-SC spectra were similar to those of C-SC. There were no statistical differences in the order parameters S between C-SC and those on quartz cell and cover glass, but those of transparent film were significantly higher. Spectra after a month storage at room temperature at 5 degrees C and at -20 degrees C were unchanged. The order parameter S had decreased after a 3-month storage in all conditions. CONCLUSION: This method is useful for the evaluation of the fluidity measurement utilizing EPR spectra of S-SC.

Journal Article↗