Ryohei Ichimura

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To elucidate the role of metal-related molecules in hepatocarcinogenesis, we examined immunolocalization of transferrin receptor (Tfrc), ceruloplasmin (Cp) and metallothionein (MT)-1/2 in relation to liver cell foci positive for glutathione-S-transferase placental form (GST-P) in the early stage of tumor promotion by fenbendazole (FB), phenobarbital,(More)
Wy-14,643 (WY), a peroxisome proliferator-activated receptor-alpha agonist, and piperonyl butoxide (PBO), a pesticide synergist, induce oxidative stress and promote hepatocarcinogenesis in the liver of rodents. These chemicals belong to a class of non-genotoxic carcinogens, but DNA damage secondary to the oxidative stress resulting from reactive oxygen(More)
To clarify the involvement of signaling of transforming growth factor (TGF)-β during the hepatocarcinogenesis, the immunohistochemical distribution of related molecules was analyzed in relation with liver cell lesions expressing glutathione S-transferase placental form (GST-P) during liver tumor promotion by fenbendazole, phenobarbital, piperonyl butoxide,(More)
To investigate the modifying effect of enzymatically modified isoquercitrin (EMIQ) on hepatocellular tumor promotion induced by beta-naphthoflavone (BNF) treatment, male rats were administered a single intraperitoneal injection of N-diethylnitrosamine (DEN) and were fed a diet containing BNF (0.5%) for 6 weeks with or without EMIQ (0.2%) in the drinking(More)
The topographic organization of cerebellar cortical efferent fibers from the posterior lobe of the albino rat was studied by silver impregnation methods. The corticonuclear fibers from the vermis of the posterior lobe project to the caudomedial and middle parts of the medial cerebellar nucleus (MN) with medio-lateral localization; fibers from the medial(More)
We report a rare case of benign sex cord-stromal tumor consisted largely of luteoma with minor portion of Sertoli cell tumor located at the position of the left ovary excision in an 11-year-old ovariectomized bitch. Granulosa cell component was lacking, and both luteal and Sertoli cell portions were entirely positive for inhibin alpha and neuron-specific(More)
To investigate liver tumor promotion mechanisms of copper (Cu)- and iron (Fe)-overloading, immunolocalization of metal-related biomolecules and lipid peroxidation end products was examined in preneoplastic liver cell foci that expressed glutathione S-transferase placental form (GST-P) in early-stage tumor promotion over 6 weeks in a rat two-stage(More)
Neonatal exposure to 17alpha-ethynylestradiol (EE) at relatively low doses leads to delayed effects characterized by the early onset of age-related anovulation. Kisspeptin neurons in the anteroventral periventricular nucleus (AVPV), located at the anterior hypothalamus, are proposed to play key roles in appearance of these delayed effects after maturation.(More)
The National Toxicology Program study of Ginkgo biloba extract (GBE), a herbal supplement, reported concerns regarding genotoxicity and clear evidence of hepatocarcinogenicity and liver hypertrophy in mice. To clarify the genotoxicity of GBE in vivo, we performed reporter gene mutation assay using gpt delta mice. We also used a combined liver comet assay(More)
Acifluorfen (ACI), a protoporphyrinogen oxidase (PROTOX) inhibitor herbicide, promotes the accumulation of protoporphyrin IX (PPIX), and induces tumors in the rodent liver. Porphyria is a risk factor for liver tumors in humans; however, the specific mechanisms through which ACI induces hepatocarcinogenesis in rodents are unclear. Here, we investigated the(More)