Showing papers by "Norichika Tatematsu published in 1999"
TL;DR: The results indicate that morin acts as a chemopreventive agent against tongue carcinogenesis induced by 4‐NQO through modification of detoxifying enzyme activities and/or cell proliferation activities.
Abstract: The modifying effects of dietary exposure of the flavonoid morin on 4-nitroquinoline 1-oxide (4-NQO)-induced tongue tumorigenesis, the activities of phase II detoxifying enzymes glutathione S-transferase (GST) and quinone reductase (QR) in liver and tongue, and cell proliferation activity in tongue were investigated in male F344 rats. At 7 weeks of age, all animals except those treated with morin alone and control group were given 4-NQO (20 ppm) in drinking water for 8 weeks to induce oral neoplasms. Starting 7 days before 4-NQO exposure, experimental groups were fed experimental diets containing morin (100 and 500 ppm) for 10 weeks ("initiation feeding"). Starting 1 week after the cessation of exposure to 4-NQO, other experimental groups given 4-NQO and a basal diet were given experimental diets for 22 weeks ("post-initiation feeding"). At week 32 week, "initiation feeding" of morin caused a significant reduction in the incidence of tongue carcinoma (by 44-100%). "Post-initiation feeding" with morin also significantly decreased the frequency of tongue carcinoma (by 44%). Morin feeding elevated liver GST and QR activities and GST activity in the anterior portion of tongue. Feeding with morin significantly lowered QR activity of the posterior part of the tongue. Dietary exposure to morin significantly decreased the proliferating cell nuclear antigen-positive index in the posterior portion. Also, morin feeding lowered tongue polyamine levels, especially in the "post-initiation feeding" group. Our results indicate that morin acts as a chemopreventive agent against tongue carcinogenesis induced by 4-NQO through modification of detoxifying enzyme activities and/or cell proliferation activities.
97 citations
TL;DR: The results suggest that the combination of PCR ribotyping and AP-PCR fingerprinting is well suited for the epidemiological study of P. intermedia and P. nigrescens and that each family seems to carry a distinct subtype(s) of these species.
Abstract: We established a typing system for Prevotella intermedia and Prevotella nigrescens using the combination of PCR ribotyping and arbitrarily primed PCR (AP-PCR) fingerprinting and applied this system to the study of intrafamilial incidence of these species in the oral cavity. PCR ribotyping followed by subtyping by AP-PCR fingerprinting was applied to each type strain of P. intermedia and P. nigrescens and 54 isolates (32 isolates of P. intermedia and 24 isolates of P. nigrescens) from extraoral infections, resulting in an excellent discriminatory power (discrimination index, 0.99) for both species. A total of 18 subjects from six families, with the subjects from each family comprising the mother, the father, and a child who had subclinical early-stage to moderate adult periodontitis or simple gingivitis and who carried P. intermedia or P. nigrescens, or both, were enrolled in the study of intrafamilial carriage. When 20 colonies per specimen of subgingival plaque, if available, were picked from primary culture, 115 P. intermedia and 178 P. nigrescens isolates were recovered from the 18 subjects. Among the subjects studied, family members shared the same subtype strain(s) but non-family members did not. Multiple subtypes were found in 8 (57%) of the 14 P. nigrescens-positive subjects but in only 3 (27%) of the 11 P. intermedia-positive subjects; the difference was, however, not statistically significant (P = 0.14). These results suggest that the combination of PCR ribotyping and AP-PCR fingerprinting is well suited for the epidemiological study of P. intermedia and P. nigrescens and that each family seems to carry a distinct subtype(s) of these species.
32 citations