Publications by authors named "Natsumi Kato"

The cellulolytic insect symbiont bacterium sp. strain SirexAA-E secretes a suite of arbohydrate-ctive enymes (CAZymes), which are involved in the degradation of various polysaccharides in the plant cell wall, in response to the available carbon sources. Here, we examined a poorly understood response of this bacterium to mannan, one of the major plant cell wall components.

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PICOT (PKC-interacting cousin of thioredoxin) consists of one thioredoxin homology domain in the N-terminal and two tandem PICOT homology domains in the C-terminal. PICOT specifically interacts with protein kinase C theta (PKC-theta) via its thioredoxin homology domain and acts as an important modulator of T cell receptor (TCR)-signaling. Using PICOT overexpressing rat basophilic leukemia cells (RBL-2H3), we evaluated the effect of PICOT overexpression on the FcepsilonRI-mediated signaling.

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Initiation activity of phenylethyl isothiocyanate (PEITC) was examined in a two-stage urinary bladder carcinogenesis model. Male 6-week-old Fischer 344 rats were fed diet containing 0.1% PEITC for 12 or 24 weeks, with or without subsequent administration of 5% sodium l-ascorbate (Na-AsA) in diet until week 48, or for the entire experimental period.

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To evaluate developmental toxicity of di-n-butyl phthalate (DBP) with exposure during the period from late gestation to following lactation, maternal rats were given DBP at dietary concentrations of 0, 20, 200, 2000 and 10,000 ppm from gestational day 15 to postnatal day (PND) 21. At 10,000 ppm, male offspring showed a decreased neonatal anogenital distance and retention of nipples (PND 14), while females showed a slight non-significant delay in the onset of puberty. At PND 21, reduction of testicular spermatocyte development was evident from 20 ppm, as well as mammary gland changes at low incidence in both sexes.

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To identify genes showing responses to estrogen exposure in the livers of animals in a repeated oral dose toxicity study, dose-dependent gene expression profiles were analyzed using high-density oligonucleotide microarrays in Sprague-Dawley rats of both sexes administered ethinylestradiol (EE) for 28 days at concentrations of 0, 0.01, 0.1, and 1.

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We have previously shown methacarn to be a versatile fixative for analysis of proteins, DNA, and RNA in paraffin-embedded tissues (PETs). In this study we analyzed its suitability for quantitative mRNA expression analysis of microdissected PET specimens using a real-time RT-PCR technique. Fidelity of expression in the methacarn-fixed PET sections, with reference to dose-dependent induction of cytochrome P450 2B1 in the phenobarbital-treated rat liver, was high in comparison with the unfixed frozen tissue case, even after hematoxylin staining.

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A subchronic toxicity study of N-acetylglucosamine (GlcNAc), a monomeric form of chitin, was conducted in groups of 10 male and 10 female F344 rats fed pelleted diets containing 0, 0.625, 1.25, 2.

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