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Biomedical subjects

M Kusamichi

Publications and source records attributed to M Kusamichi.

6 recordsLinked to original sources
PubMed1993

Water molecules bound to fibrils by hydrogen bonds play an important role on the surface fibrillar structure of Candida albicans cells.

Influence of surrounding media on the appearance of surface structure of Candida albicans was further investigated by rapid-freezing and freeze-fracturing techniques with a scanning electron microscope. Fibrillar structure was observed on the surface of the cells treated with water, chloroform, trichloroethane, toluene or isoamyl alcohol, but not on that of the cells treated with methanol, ethanol, isopropanol, n-butanol, acetic acid or acetone. The appearance of the fibrillar structure is proposed to be discussed in a viewpoint of the chemical interactions among the constituent molecules of a fibril, water molecules bound to the fibril molecules and the molecules of surrounding medium, especially a role of water molecules bound to the fibril molecules by hydrogen bonds.

Candida albicans↗
PubMed1990

Initial attachment of Candida albicans cells to buccal epithelial cells. Demonstration of ultrastructure with the rapid-freezing technique.

The rapid-freezing technique was applied in association with scanning and transmission electron microscopy to observe the initial attachment (or contact) of Candida albicans cells to exfoliated human buccal epithelial cells. Low temperature scanning electron microscopy provided detailed three-dimensional morphological features of the yeast-epithelial cell association; adhesion of C. albicans cells to host cells was primarily owing to an interaction between fibrillar layer of the yeast cell wall and the membrane interdigitations of the epithelial cells. Such a particular interconnection between the two cells was confirmed by the freeze-substitution fixation for transmission electron microscopy. These results clearly demonstrate the outermost fibrillar cell wall layer of C. albicans responsible for adhesion to host cells.

Candida albicans↗
PubMed1990

Influence of surrounding media on preservation of cell wall ultrastructure of Candida albicans revealed by low temperature scanning electron microscopy.

Influence of surrounding media on the surface structures of the cell wall of Candida albicans was discussed with respect to the preservation of ultrastructure during the specimen preparation for scanning electron microscopy. The fibrillar structure of the cell surface was distinctly identified by the rapid-freezing technique. It was difficult, however, to observe this structure by the conventional specimen preparation technique. The reason for the difference between these two preparation techniques was studied using a low temperature SEM. Through investigating the influence of each step of the conventional technique on the fibrillar structure, it was found that the fibrils were drastically deformed and disappeared during the dehydration step in ethanol above 80% in concentration. In order to study which physicochemical properties participated in this disappearance phenomenon, yeast cells were treated with various media: solutions in different pH ranges and at different salt concentrations, ionic solutions, surfactants, formamide, dimethyl sulfoxide, acetone and Fehling's solution. As a result, the fibrillar structure was found well preserved when the medium had an affinity for the constituent molecules of the fibrils. When without affinity, the fibrils suffered a remarkable deformation. The mechanism of this deformation is discussed in terms of molecular interaction of solute and solvent.

Candida albicans↗
PubMed1989

Cell surface of Micrococcus luteus: chemical treatment of the cells and teichuronic acids on the surface.

Micrococcus luteus IFO 3333 cells, both treated with chemical reagents and non-treated, were observed with a scanning electron microscope (SEM). The agglutinability of the cells with antiserum containing anti-teichuronic acid antibody was examined. The binding of protein A-gold particles to the cells, mediated with the antiserum, was also observed with SEM. The surface of a M. luteus cell consisted of two or three areas with borders--the rough and the smooth areas, or the rough, the slightly rough, and the smooth areas; fluffy materials were clearly seen in the rough area. Gold particles were observed uniformly and densely on the whole cell surface. However, either mild acid treatment or mild Smith degradation of the cells altered the fluffy rough area to a rough one, and extremely decreased the agglutinability and the binding of protein A-gold particles. Teichuronic acids appeared to be distributed uniformly on the whole cell surface of M. luteus IFO 3333.

Agglutination Tests↗