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Biomedical subjects

M Mogi

Publications and source records attributed to M Mogi.

142 records · Page 8Linked to original sources
PubMed1982

[Studies on dental self-curing resins (22) - adhesion of 4-META/MMA-TBB resin to enamel (author's transl)].

Bovine enamels cleaned with citric acid and FeCl3 which had been brushed or ground were joined with PMMA rods with the 4-META/MMA-TBB cement. Their tensile adhesive strength was measured after post-treatments. Stable adhesive strength such as 6.2 MPa was obtained on an enamel which was brushed and washed with an aqueous solution of 10% citric acid-3% FeCl3 for 30 sec. even after a 60 times percolation test between 4 degrees C and 60 degrees C. It is adequate to clinics. The value increased to 16.1 MPa on ground enamel. These results suggest that phosphoric acid etching, essential nowadays, is not necessary for good adhesion to enamel. Monomers with both hydrophobic and hydrophilic groups like 4-META possess affinity with tooth substrates and promote the infiltration of cements into the enamel. The infiltrated monomers polymerized in situ and strong adhesion with the enamel took place. Comparison of the tag length formed in the enamel by cements, MMA-TBB, HNPM/MMA-TBB, Phenyl-P/MMA-TBB and 4-META/MMA-TBB supports this consideration.

Acrylic Resins↗
PubMedDate not supplied

Induction of chromosomal aberrations in cultured Chinese hamster cells by short-term treatment with cadmium chloride.

Inducibility of chromosomal aberrations and cytotoxicity in cultured Chinese hamster cells by cadmium chloride (CdCl2) was investigated under 3 different treatment conditions: (i) 2-h treatment in MEM medium supplemented with 10% fetal bovine serum (MEM + 10% FBS) or (ii) in HEPES-buffered Hanks' solution (HEPES-Hanks), and (iii) continuous treatment for 24 h in MEM + 10% FBS. Two-h treatment with CdCl2 in HEPES-Hanks or continuous treatment for 24 h in MEM + 10% FBS was respectively 2 or 3 times more cytotoxic than 2-h treatment with the metal in MEM + 10% FBS. Continuous treatment for 24 h with a CdCl2 concentration in excess of 5 X 10(-6) M was too toxic to the cells to allow chromosomal analysis, and moreover, only a slight increase in incidence of chromosomal aberrations was observed at a concentration of 5 X 10(-6) M CdCl2. In contrast, a marked and concentration-dependent increase in incidence of chromosomal aberrations was observed after post-treatment culture for 22 h follows 2-h treatment with 1 X 10(-6) M to 5 X 10(-5) M of CdCl2 in both MEM + 10% FBS and HEPES-Hanks. Two-h treatment with cadmium in HEPES-Hanks was approximately 3 times more potent for the induction of chromosomal aberrations than that in MEM + 10% FBS. Types of aberrations induced by CdCl2 mainly consisted of chromatid gaps and breaks, although a few exchanges, dicentrics and fragmentations were observed at high concentrations of cadmium. Increase in incidence of tetraploidy was also observed with a concentration dependency after 2-h treatment with CdCl2. Potency of CdCl2 to induce chromosomal aberrations after 2-h exposure was comparable to that of benzo[a]pyrene activated with S9 at equitoxic concentrations. Two-h treatment with cadmium markedly inhibited incorporation of [3H]thymidine, even at concentrations at which incorporation of [3H]uridine or [3H]leucine was less inhibited. However, the inhibition of [3H]thymidine incorporation by cadmium was reversible and the incorporation restored to the control level during 2-6 h of post-treatment incubation. These findings suggest that restoration of DNA synthesis after cadmium exposure is required for the efficient detection of chromosomal aberrations induced by the metal.

Animals↗