The development of the 'newly high sensitive biological evaluation method for dental organic materials

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The simply simultaneous method to analyze in the high sensitivity to identify the leached substances from the dental organic materials immersed in saliva and its metabolites was developed using HPLC. It could be clarified the possibility that bisphenol A was immigrated from the polycarbonate orthodontic bracket into the oral cavity and that dibutyl phthalate did also from the temporary filling materials. It became obvious with a child that the daily intake of these substances was the quantity which could not be ignored. The HeLa cell that was introduced genes encoding estrogen responsive element (ERE) and eGFP by retrovirus expression vector, expressed fluorescence when they were stimulated with estradiol-l7β. The lowest concentration of estrogen was 1 ng/mL by which the cells expressed GFP protein 12 hr after the stimulation. RSa-derived cells with up-regulation of human estrogen receptor (hERα) and down-regulation of 78-kDa glucose regulated protein (GRP78) could be established. The … More hERα overproducing cells showed the similar sensitivity to the mutagenic effects of BPA with vector control cells in mutation analysis using ouabain resistance test. However, GRP78-down-regulated cells showed higher sensitivity to BPA mutagenicity than the control cells: the mutagenicity was detected at concentrations over 1 x 10^<-9>〜10^<-8> M in GRP78-down-regulated cells. Thus, GRP78-down-regulated cells may be useful for evaluating mutagenicity of environmental chemicals at very low concentrations. A gene construct Choriogenin L 1.5Kb/GFP to another construct emgb/RFP was linked, injected the double fusion gene construct into 1-or 2-cell-stage embryos, and selected embryos expressing RFP in erythroid cells. When exposed to estradiol-17β, adult fish raised from the embryos showed the liver-specific expression of GFP, suggesting that the 1.5Kb 5'-upstream region promotes estrogen-dependent liver-specific expression of the chg-L gene. This transgenic medaka may be useful as one of test animals for detecting environmental estrogens. BPA alone didn't induce the transcriptional activation of the CYP1A1 gene, but BPA together with 3-methylcholanthrene (MC), superinduced the human CYP1A1 gene. In addition, BPA enhanced the transcriptional activation of the CYP1A1 gene through the AhR/Arnt complex. These results suggested that the superinduction of the human CYP1A1 gene transcription by BPA together with 3-MC is involved in the increasing concentration of intracellular Ca^<2+> to the inhibition of the sarco-endoplasmic reticulum Ca2+-ATPases. From these results, each evaluation developed by this present research can be thought to be the high new sensitive biological evaluation method which can be applied to the basic biological test of the organic material for the dentistry. Less