Integration of In Vivo Genotoxicity and Short-term Carcinogenicity Assays Using F344 gpt Delta Transgenic Rats: In Vivo Mutagenicity of 2,4-Diaminotoluene and 2,6-Diaminotoluene Structural Isomers

An important trend in current toxicology is the replacement, reduction, and refinement of the use of experimental animals (the 3R principle). We propose a model in which in vivo genotoxicity and short-term carcinogenicity assays are integrated with F344 gpt delta transgenic rats. Using this model, the genotoxicity of chemicals can be identified in target organs using a shuttle vector λ EG10 that carries reporter genes for mutations; short-term carcinogenicity is determined by the formation of glutathione S-transferase placenta form (GST-P) foci in the liver. To begin validating this system, we examined the genotoxicity and hepatotoxicity of structural isomers of 2,4-diaminotoluene (2,4-DAT) and 2,6-diaminotoluene (2,6-DAT). Although both compounds are genotoxic in the Ames/Salmonella assay, only 2,4-DAT induces tumors in rat livers. Male F344 gpt delta rats were fed diet containing 2,4-DAT at doses of 125, 250, or 500 ppm for 13 weeks or 2,6-DAT at a dose of 500 ppm for the same period. The mutation frequencies of base substitutions, mainly at G:C base pairs, were significantly increased in the livers of 2,4-DAT–treated rats at all three doses. In contrast, virtually no induction of genotoxicity was identified in the kidneys of 2,4-DAT–treated rats or in the livers of 2,6-DAT–treated rats. GST-P–positive foci were detected in the livers of rats treated with 2,4-DAT at a dose of 500 ppm but not in those treated with 2,6-DAT. Integrated genotoxicity and short-term carcinogenicity assays may be useful for early identifying genotoxic and nongenotoxic carcinogens in a reduced number of experimental animals

シニクコウ シンシュツエキ チュウ ノ バイオマーカー オ モチイタ シシュウビョウ シンダン

Periodontal diseases cause an inflammation and degradation of periodontal tissues and missing of teeth. The incidence rate of periodontal diseases is high in middle-aged and elderly people. A reasonable diagnosis of periodontal diseases is very important to keep teeth, however, conventional examinations of periodontal diseases is not necessarily exact and objective. Gingival crevicular fluid (GCF) is an exudate secreted from periodontal tissues and contains many components including proteolytic enzymes, inflammatory cytokines, blood-associated proteins, cellular and bacterial fragments. Because some proteins in GCF are related to inflammation, tissue degradation and bone metabolism, those proteins have been studying as a diagnostic marker of periodontal diseases. GCF is noninvasively collected using a sterile paper strip and biomarkers are determined using enzyme-linked immunosorbent assay (ELISA) and enzyme activity assay. We identified calprotectin, an inflammationrelated protein, in GCF and calprotectin level in GCF from periodontitis sites was significantly higher than that of healthy control. Calprotectin level in GCF was positively correlated to gingival index and other biomarkers and decreased by periodontal treatments. Resistin is an adipocytokine and its level increases in some inflammatory diseases. Resistin level in GCF from periodontitis sites was high compared to the level of healthy control samples. Procollagen type I C-terminal peptide (PICP) is a biomarker for bone metabolism and its level was high in GCF collected from periodontitis sites. These results suggested that calprotectin, resistin and PICP are useful biomarkers for periodontal diseases. On the other hand, we showed that glycated albumin (GA), a marker of diabetes mellitus (DM), was contained in GCF and GA level in GCF from DM patients was significantly higher than that of non-DM individuals. Components in GCF may be biomarkers of systemic diseases as well as periodontal diseases and their determination will be useful diagnostic examination of some diseases. Recently, we have been studying the determining system of GCF calprotectin, including microchip ELISA, surface plasmon resonance assay and immuno-chromatography assay. When GCF biomarkers are determined using the determining systems, we will simply, exactly and objectively diagnose periodontal diseases at our dental offices

More than the “Wife Corps”: Female Tenant Farmer Struggle in 1920s Japan

AbstractStruggles over social reproduction intensified and took on new forms in Japan during the interwar period, as the state found it increasingly difficult to secure the foundations for the continued accumulation of capital. Landlord-tenant disputes that erupted nationwide in the midst of Japan's post-World War I agricultural recession was one concrete manifestation of these struggles. While the significance of tenant disputes has been analyzed in great detail by scholars, there has been a surprising lack of historical scholarship on the role that female tenant farmers played within them. This absence is a manifestation of two tendencies: First, gendered assumptions surrounding the figure of the tenant farmer have led scholars of agrarian social movements to work from a relatively limited understanding of what constitutes struggle and by extension, who its protagonists have been. Second, the conflation of waged work as productive work and by extension, non-waged work as unproductive has unwittingly relegated many forms of struggle that working women participated in to the realm of the pre-political. This paper contends that far from being mere supporters – the wife corps – of what was ultimately a male-driven movement, female participants in tenant disputes produced their own powerful critiques of the way that the Japanese state and capital undervalued their lives and labor. As such, they should be understood as one link in a rich history of proletarian feminist struggle both within and outside of the Japanese empire