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Biomedical subjects

M Kumakura

Publications and source records attributed to M Kumakura.

59 records · Page 4Linked to original sources
PubMedDate not supplied

Odd mating-type substances may work as precursor molecules of even mating-type substances in Paramecium caudatum.

Mating-type substances are key molecules in the sexual recognition of the odd (O) and even (E) complementary mating-type cells in Paramecium caudatum. Indirect evidence suggested that the substances were proteins and were located on ventral surface cilia. Monoclonal antibodies inhibiting the mating reactivity of the O cells have been obtained. Using these antibodies, we tried to detect antigen molecules as dot-blot signals. Strong dot-blot signals of antigens were only detected from the mating reactive cells, but they were not detected from the well-fed and starved cells without mating reactivity. In addition to identifying the antigen on cilia and cytoplasm of the O cell, the antigen was detected from the cytoplasm of the E cells but never from their cilia. Furthermore, extracts of the E cells induced mating reaction with the living E cells but not with O cells. Thus, the O mating-type substances exist in the cytoplasm of the E mating-type cells, supporting strongly the hypothesis that O mating-type substances are precursor molecules of the E mating-type substances.

Animals↗
PubMedDate not supplied

Immobilization of E. coli cell as an antigen by radiation polymerization method.

E. coli NIJ cells were immobilized by radiation polymerization of 2-hydroxyethyl methacrylate at low temperatures. The immobilized E. coli cells as an antigen were reacted with peroxidase labeled anti-E. coli in competition with the free E. coli cells. It was found that E. coli cells can be assayed quantitatively with the immobilized E. coli cells in disc form. Microorganisms such as gram negative bacteria had no specific affinity to anti-E. coli. Cross reactivity of the immobilized E. coli cells with the E. coli cells from various strains was examined.

Antibodies, Bacterial↗
PubMedDate not supplied

Polymer cellulose sheets immobilizing antibody by radiation polymerization.

Antibody such as anti-alpha-fetoprotein was immobilized on cellulose fibril sheets by radiation polymerization of hydrophilic monomers. The nature of the immobilized anti-alpha-fetoprotein sheets was examined by measuring the enzyme activity in an antibody-antigen complex reaction. The relationship between the activity and the polymerization condition was studied. The degree of hydration of the polymer matrix giving a maximum activity appeared to be about 0.2. The activity varied with monomer concentration and with monomer composition in copolymerization of acrylate and diacrylate monomer. The activity was increased by the addition of polyethylene glycol diacrylate monomers, in which the activity increased with increasing length of the oxyethylene unit chain.

Antibodies↗