To clarify biochemical characteristics of tumor growth and/or invasion, the energy status of oral squamous cell carcinomas was investigated by measuring adenine nucleotides and correlating with morphological features. For this purpose, tumors originating from human squamous cell carcinoma of the tongue that had been transplanted into nude mice, and surgically resected human oral squamous cell carcinomas were used as materials. Adenine nucleotides, ATP, ADP and AMP, were measured with HPLC, revealing differences in relative concentrations between active and inactive regions of tumor growth and/or invasion. Specifically, the relative concentration of ATP was found to be high in regions where tumor growth and/or invasion seemed most active. Energy charge ratio was also high in those regions. These results suggest that adenine nucleotide metabolism may play some role in growth and/or invasion of oral squamous cell carcinoma.
This report compares tissue irritation by a newly developed calcium-based root canal filling material with irritation by previously available materials and evaluates the toxicity of various components in the root canal filling material. Polyethylene tubes filled with root canal filling materials were implanted in rat subcutaneous tissue, enucleated after 2, 4, 8 and 12 weeks, and histopathologically evaluated for tissue reaction. The tissue inflammation was microscopically evaluated and divided into 4 grades. The new root canal filling material has good tissue affinity compared to prior material. Transmission electronic microscopy and X-ray analysis revealed : titanium in AH-26; barium and bismuth in. Canals, Tubli-seal and the newly developed root canal filling cement A; and zinc in the root canal filling cement B. Tissue was variously inflamed and, occasionally, necrosis was induced in the cells. The newly developed root canal filling cement A, showed better tissue affinity and no or slightly morphology change