研究者紹介システム

横山 俊史
ヨコヤマ トシフミ
大学院農学研究科 資源生命科学専攻
助教
獣医学畜産学関係
Last Updated :2021/05/12

研究者情報

所属

  • 【主配置】

    大学院農学研究科 資源生命科学専攻
  • 【配置】

    農学部 資源生命科学科

学位

  • 博士(農学), 神戸大学

授業科目

ジャンル

  • 環境・交通 / 農業

コメントテーマ

  • 生殖腺
  • 性分化
  • ネオニコチノイド系農薬
  • 環境ホルモン

研究活動

研究キーワード

  • 組織学
  • マウス
  • セルトリ細胞
  • 遺伝学
  • 性分化疾患
  • 性分化
  • Histology
  • 組織細胞生物学

研究分野

  • ライフサイエンス / 動物生命科学

受賞

  • 2010年07月 日本先天異常学会, 第50回日本先天異常学会学術集会 優秀ポスター賞, Sry 導入XXマウスにおける雄性生殖腺の形態学的解析

    横山 俊史

    国内学会・会議・シンポジウム等の賞

論文

  • Mizuki Maeda, Toshifumi Yokoyama, Sayaka Kitauchi, Tetsushi Hirano, Youhei Mantani, Yoshiaki Tabuchi, Nobuhiko Hoshi

    Fipronil (FPN) is a systemic insecticide that antagonizes the gamma-aminobutyric acid type A (GABAA) receptors in insects. Recently, adverse effects of FPN on mammals have been reported, but most of those were caused by high doses of FPN and additives in the products. We investigated the effects of low-dose pure FPN on the emotional behavior of mice. Nine-week-old male mice conducted behavioral tests 24 hr after FPN administration by gavage at doses of 0.05 or 5 mg/kg based on the no-observed-effect level (NOEL), showed a significant increase in locomotor activity and dose-dependent responses on the time they spent in the central zone in the open field test. Pure FPN below the NOEL dose may affect the emotional behavior of mice.

    2020年12月22日, The Journal of veterinary medical science, 英語, 国内誌

    研究論文(学術雑誌)

  • Masaya Arai, Youhei Mantani, Satoki Nakanishi, Tomohiro Haruta, Miho Nishida, Hideto Yuasa, Toshifumi Yokoyama, Nobuhiko Hoshi, Hiroshi Kitagawa

    Eosinophils are abundantly present in intestinal mucosa. However, the morphological characteristics of their cellular population are still largely unknown. In this study, we examine their characteristics in the rat ileal mucosa using histological and ultrastructural methods. The results indicated that ileal eosinophils could be distinguished into two main groups based on their nuclear shapes and distribution: eosinophils with spheric or reniform nuclei mainly localized in the villous region and eosinophils with annular or bacilliform nuclei as the major population around crypts. Immunohistochemical analysis revealed that all eosinophils in the lamina propria (LP) were immunopositive for CD11b, whereas eosinophils in LP of the intestinal villus but not those in LP around the crypt, were immunopositive for CD11c. Three-dimensional ultrastructural analysis using serial block-face scanning electron microscopy showed that the eosinophils with spheric or reniform nuclei were abundant in the upper portions of the intestinal villus, whereas those with annular nuclei were abundant in the lower portions of the intestinal villus and around crypts. The eosinophils with spheric or reniform nuclei possessed broader cellular bodies with greater abundance of surface projections compared with those with annular nuclei. Eosinophils in the upper portions of intestinal villus frequently extended their cellular bodies into the intraepithelial space. The number of total and eosinophil-specific granules was positively correlated with the minor axis of the nuclear holes in the annular nuclei. These data suggest that ileal eosinophils exhibit not homogenous but rather diverse characteristics, possible due to the mixture of eosinophils at different maturation and/or activation stages.

    2020年09月, Cell and tissue research, 381 (3), 439 - 450, 英語, 国際誌

    研究論文(学術雑誌)

  • Satoki Nakanishi, Youhei Mantani, Tomohiro Haruta, Toshifumi Yokoyama, Nobuhiko Hoshi

    The comprehensive targets of innervation in the intestinal mucosa are unknown, partly because of the diversity of cell types and the complexity of the neural circuits. Herein, we investigated the comprehensive targets of neural connectivity and analyzed the precise characteristics of their contact structures in the mucosa of rat ileum. We examined target cells of neural connections and the characteristics of their contact structures by serial block-face scanning electron microscopy at four portions of the rat ileal mucosa: the apical and basal portions in the villi, and the lateral and basal portions around/in the crypts. Nerve fibers were in contact with several types of fibroblast-like cells (FBLCs), macrophage-like cells, eosinophils, lymphocyte-like cells, and other types of cells. The nerve fibers almost always ran more inside of lamina propria than subepithelial FBLC, and thus contacts with epithelial cells were very scarce. The contact structures of the nerve fibers were usually contained synaptic vesicle-like structures, and we classified them into patterns based on the number of nerve fiber contacting the target cells at one site, the maximum diameter of the contact structures, and the relationship between nerve fibers and nerve bundles. The contact structures for each type of cells occasionally dug into the cellular bodies of the target cells. We revealed the comprehensive targets of neural connectivity based on the characteristics of contact structures, and identified FBLCs, immunocompetent cells, and eosinophils as the candidate targets for innervation in the rat ileal mucosa.

    2020年07月31日, The Journal of veterinary medical science, 82 (7), 990 - 999, 英語, 国内誌

    研究論文(学術雑誌)

  • Chinatsu Hasegawa, Toshifumi Yokoyama, Yuria Umemura, Kohei Kawanishi, Yuuka Miura, Nanako Takada, Shuji Ohno, Kanoko Onaru, Takuya Omotehara, Tetsushi Hirano, Yohei Mantani, Takanori Miki, Nobuhiko Hoshi

    Organ culture systems are useful for elucidating the process of testicular differentiation from mammalian undifferentiated genetically male gonads, as they permit various experiments, including experiments involving the control of gene expression. However, without addition of testicular differentiation-related factors, it is difficult to induce the formation of testis cord from immature gonads by a time point earlier 12 tail somites (ts) that corresponding to 11.0 days post coitum (dpc). In this study, we attempted to establish an organ culture system that induces testis formation from immature gonads (around 8 ts: 10.5 dpc) just before Sry (sex-determining region of the Y chromosome) expression. A paired gonad-mesonephros complex of around 8 ts was placed in the groove of an agarose gel block and put the semi-cylindrical piece of agarose gel to maintain the gonad morphology. The gonads were cultured in the gas phase for 96 hr. As a result, testis cord-like structures appeared in many genetically male gonads. Cells expressing the Sertoli cell markers Sox9 (SRY-box 9) and Amh (anti-Müllerian hormone) were observed, while granulosa cell marker Foxl2 (forkhead box L2) was not detected. In addition, Sox9- and Amh-expressing cells were observed throughout the entire gonad in many individuals. Amh mRNA expression was also upregulated. Surprisingly, formation of a partial testicular structure was observed from more immature gonads (6 ts). These results show that our gonadal organ culture system is useful for elucidating the regulation mechanism of Sry expression in undifferentiated bipotential gonads.

    2020年04月09日, The Journal of veterinary medical science, 82 (4), 414 - 421, 英語, 国内誌

    [査読有り]

    研究論文(学術雑誌)

  • Shuji Ohno, Yoshinori Ikenaka, Kanoko Onaru, Shizuka Kubo, Nanami Sakata, Tetsushi Hirano, Youhei Mantani, Toshifumi Yokoyama, Keisuke Takahashi, Keisuke Kato, Koji Arizono, Takahiro Ichise, Shouta M M Nakayama, Mayumi Ishizuka, Nobuhiko Hoshi

    Neonicotinoids (NNs), a widely used class of systemic pesticides, are regarded as exhibiting selective toxicity in insects. However, NNs are suspected of exerting adverse effects on mammals as well, including humans. To date, only adult male animal models have been subjected to general toxicity studies of NNs; fetuses have yet to be considered in this context. Here, we focused on the NN clothianidin (CLO) for the first quantitative LC-MS/MS analysis of maternal-to-fetal transfer and residual property of once-daily (single or multiple days), orally administered CLO and its metabolites in mice. The results revealed the presence of CLO and its five metabolites at approximately the same respective blood levels in both dams and fetuses. In the dams, CLO showed a peak value 1 h after administration, after which levels rapidly decreased at 3 and 6 h. In the fetuses of each group, levels of CLO were almost the same as those observed in the corresponding dams. The present results clearly demonstrated rapid passage of CLO through the placental barrier. However, metabolite-dependent differences observed in blood pharmacokinetics and residual levels. This is the first quantitative demonstration of the presence of CLO and its metabolites in fetal mouse blood.

    Elsevier BV, 2020年04月01日, Toxicology letters, 322, 32 - 38, 英語, 国際誌

    [査読有り]

    研究論文(学術雑誌)

  • Tadashi Takada, Naoki Yoneda, Tetsushi Hirano, Kanoko Onaru, Youhei Mantani, Toshifumi Yokoyama, Hiroshi Kitagawa, Yoshiaki Tabuchi, Collins Nimako, Mayumi Ishizuka, Yoshinori Ikenaka, Nobuhiko Hoshi

    Dinotefuran (DIN) belongs to the neonicotinoids (NNs), a class of globally applied pesticides originally developed to exhibit selective toxicity in insects. However, several reports have suggested that NNs also exert neurotoxic effects in mammals. We previously demonstrated neurobehavioral effects of DIN on mice under non-stressful conditions. For further toxicity assessments in the present study, we investigated the effects of DIN on mice exposed to stressful conditions. After subacutely administering a no-observed-effect-level (NOEL) dose of DIN and/or chronic unpredictable mild stress (CUMS) to mice, we conducted three behavioral tests (i.e., open field test [OFT], tail suspension test [TST] and forced swimming test [FST]). In addition, serotonin (5-HT) and tryptophan hydroxylase 2 (TPH2) of the dorsal raphe nuclei (DRN) and median raphe nuclei (MRN) and tyrosine hydroxylase (TH) of the ventral tegmental area and substantia nigra (SN) were evaluated immunohistochemically. A NOEL dose of DIN or CUMS alone increased of the total distance in OFT, decreased or increased the immobility time in TST or FST, respectively, and increased the positive intensity of 5-HT and TPH2 in the DRN/MRN, and TH in the SN. These changes were suppressed under the conditions of combined exposure to DIN and CUMS, though the blood corticosterone level was increased depending on the blood DIN values and the presence of CUMS. The present study suggests the multifaceted toxicity of the neurotoxin DIN.

    2020年03月24日, The Journal of veterinary medical science, 82 (3), 350 - 359, 英語, 国内誌

    [査読有り]

    研究論文(学術雑誌)

  • Kanoko Onaru, Shuji Ohno, Shizuka Kubo, Satoki Nakanishi, Tetsushi Hirano, Youhei Mantani, Toshifumi Yokoyama, Nobuhiko Hoshi

    Neonicotinoid pesticides (NNs) act as agonists on nicotinic acetylcholine receptors (nAChRs) of insects, and there have been concerns about the effects of NNs on the health of mammals. Since nAChRs are expressed in immune cells, it is possible that NNs disturb the immune system. However, few reports have examined the immunotoxicity of clothianidin (CLO), a widely-used NN. Here, we report the effects of CLO on immune organs and type IV allergic reactions in ear auricles. We orally administered CLO at 0, 30 and 300 mg/kg/day (CLO-0, 30 and 300) to Sprague-Dawley rats for 28 days. The effects were evaluated by organ and body weights, histopathology, and immunohistochemistry (TCRαβ, CD4, CD8, CD11b, CD68, CD103). In addition, some cecal contents were subjected to preliminary gut microbiota analysis, because microbiota contribute to host homeostasis, including the immunity. Our results showed loose stool, suppression of body weight gain, significant changes in organ weights (thymus: decreased; liver: increased) and changes of the gut microbiota in the CLO-300 group. There were no obvious histopathological changes in immune organs. Granulomas of the ear auricles were found in one rat of each of the CLO-30 and 300 groups, but CLO had no apparent effect on the thickness or immunohistochemistry in the ear auricles. We present new evidence that CLO affects the thymus and intestine, and might enhance the local inflammatory response. These findings should contribute to the appropriate evaluation of the safety of NNs in the future.

    2020年03月24日, The Journal of veterinary medical science, 82 (3), 360 - 372, 英語, 国内誌

    [査読有り]

    研究論文(学術雑誌)

  • Tetsushi Hirano, Satsuki Minagawa, Yukihiro Furusawa, Tatsuya Yunoki, Yoshinori Ikenaka, Toshifumi Yokoyama, Nobuhiko Hoshi, Yoshiaki Tabuchi

    Neonicotinoids are one of most widely used pesticides targeting nicotinic acetylcholine receptors (nAChRs) of insects. Recent epidemiological evidence revealed increasing amounts of neonicotinoids detected in human samples, raising the critical question of whether neonicotinoids affect human health. We investigated the effects of a neonicotinoid pesticide clothianidin (CTD) on human neuroblastoma SH-SY5Y cells as in vitro models of human neuronal cells. Cellular and functional effects of micromolar doses of CTD were evaluated by changes in cell growth, intracellular signaling activities and gene expression profiles. We examined further the effects of CTD on neuronal differentiation by measuring neurite outgrowth. Exposure to CTD (1-100 μM) significantly increased the number of cells within 24 h of culture. The nAChRs antagonists, mecamylamine and SR16584, inhibited this effect, suggesting human α3β4 nAChRs could be targets of neonicotinoids. We observed a transient intracellular calcium influx and increased phosphorylation of extracellular signal-regulated kinase 1/2 shortly after exposure to CTD. Transcriptome analysis revealed that CTD down-regulated genes involved in neuronal function (e.g., formation of filopodia and calcium ion influx) and morphology (e.g., axon guidance signaling and cytoskeleton signaling); these changes were reflected by a finding of increased neurite length during neuronal differentiation. These findings provide novel insight into the potential risks of neonicotinoids to the human nervous system.

    2019年11月15日, Toxicology and applied pharmacology, 383, 114777 - 114777, 英語, 国際誌

    [査読有り]

  • Kim SM, Yokoyama T, Ng D, Ulu F, Yamazaki Y

    2019年11月, PLoS One., 14 (11), e0224628

    [査読有り]

  • Toshifumi Yokoyama, Yuuka Miura, Anzu Yamamoto, Chinatsu Hasegawa, Kohei Kawanishi, Nanako Takada, Takuya Omotehara, Tetsushi Hirano, Yohei Mantani, Takanori Miki, Nobuhiko Hoshi

    C57BL/6J-XYPOS (B6J-XYPOS) mice, which have the Y chromosome derived from Mus musculus poschiavinus on a B6J genetic background, form ovotestes or ovaries. Previously, we replaced the genetic background of B6J-XYPOS mice with B6N and found that individuals with testes also appeared in addition to those with ovaries or ovotestes. To investigate the effect of the B6J genetic sequence on the testis differentiation, the genetic background of B6N-XYPOS mice was replaced with B6J again. The recovery of the B6J genetic background significantly decreased the incidence of testes; only ovaries developed. These results indicate that the testicular differentiation process tends to be perturbed especially in the B6J substrain. This shows the importance of substrain differences in mice usually treated as B6 collectively.

    2019年04月27日, The Journal of veterinary medical science, 81 (4), 608 - 611, 英語, 国内誌

    [査読有り]

    研究論文(学術雑誌)

  • MANTANI YOUHEI, HARUTA TOMOHIRO, NISHIDA MIHO, YOKOYAMA TOSHIFUMI, HOSHI NOBUHIKO, KITAGAWA HIROSHI

    2019年, The Journal of Veterinary Medical Science, 81 (3), 454 - 465, 英語

    [査読有り]

    研究論文(学術雑誌)

  • YUASA HIDETO, MANTANI YOUHEI, MIYAMOTO KAZUKI, NISHIDA MIHO, ARAI MASAYA, TSURUTA HIROKI, YOKOYAMA TOSHIFUMI, HOSHI NOBUHIKO, KITAGAWA HIROSHI

    2019年, The Journal of Veterinary Medical Science, 81 (4), 555 - 566, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Toshifumi Yokoyama, Takuya Omotehara, Tetsushi Hirano, Naoto Kubota, Shogo Yanai, Chinatsu Hasegawa, Tadashi Takada, Yohei Mantani, Nobuhiko Hoshi

    Stable reference genes are important for gene expression analyses such as quantitative PCR. The stability of 15 candidate reference genes that can be used to developing mouse gonads was thoroughly verified using combinations of multiple algorithms. The expression of these genes fluctuated greatly depending on the analysis period and/or gender. Peptidylprolyl isomerase A (Ppia) and polymerase (RNA) II (DNA directed) polypeptide A (Polr2a) were the reference genes that were used stably for a wide analysis period in developing mouse gonads. Furthermore, the stable reference genes corresponding to the analysis period and/or gender were ranked. These results are useful for the selection of the optimal reference gene required for high-precision measurements.

    2018年11月01日, The Journal of veterinary medical science, 80 (10), 1534 - 1539, 英語, 国内誌

    [査読有り]

    研究論文(学術雑誌)

  • Youhei Mantani, Miho Nishida, Kyouji Yamamoto, Kazuki Miyamoto, Hideto Yuasa, Natsumi Masuda, Takuya Omotehara, Hiroki Tsuruta, Toshifumi Yokoyama, Nobuhiko Hoshi, Hiroshi Kitagawa

    Paneth cells secrete bactericidal substances in response to bacterial proliferation on the mucosal surface without directly contacting bacteria. However, the induction mechanism of this transient secretion has not been clarified, although nervous system and/or immunocompetent cells in the lamina propria (LP) might be involved. In this study, we ultrastructurally and immunohistochemically investigated which LP cells are localized beneath Paneth cells and examined the relationship between the Paneth cell-derived cellular processes which extended into the LP and the LP cells. The results showed that various cells-including blood capillary, subepithelial stromal cell, and nerve fiber-were present in the LP beneath Paneth cells. Endothelial cells of blood capillary were the cells most frequently found in this location; they were situated within 1 μm of the Paneth cells and possessed fenestration on the surfaces adjacent to Paneth cells. The Paneth cells rarely extended the cellular processes toward the LP across the basal lamina. Most of the cellular processes of Paneth cells contacted the subepithelial stromal cells. Immunohistochemistry revealed that the CD34+ CD31- αSMA- stromal cells preferentially localized in the LP beneath the intestinal crypt base, while PDGFRαhi αSMA+ stromal cells mainly localized around the lateral portions of the intestinal crypt and PDGFRαhi αSMA- stromal cells localized in the intestinal villus. From these findings, the existence of blood capillaries beneath Paneth cells might reflect the active exocrine function of Paneth cells. Furthermore, subepithelial stromal cells, probably with a CD34+ CD31- αSMA- PDGFRα-/lo phenotype, beneath the crypt base might affect Paneth cell activity by interacting with their cellular processes. Anat Rec, 301:1074-1085, 2018. © 2018 Wiley Periodicals, Inc.

    2018年06月, Anatomical record (Hoboken, N.J. : 2007), 301 (6), 1074 - 1085, 英語, 国際誌

    [査読有り]

    研究論文(学術雑誌)

  • YAMAMOTO ANZU, OMOTEHARA TAKUYA, MIURA YUUKA, TAKADA TADASHI, YONEDA NAOKI, HIRANO TETSUSHI, MANTANI YOUHEI, KITAGAWA HIROSHI, YOKOYAMA TOSHIFUMI, HOSHI NOBUHIKO

    Anti-Müllerian hormone (AMH) produced in the developing testis induces the regression of the Müllerian duct, which develops into the oviducts, uterus and upper vagina. In our true hermaphrodite mouse with an ovary on one side and a testis on the other (O/T), the oviduct and uterus are present only on the ovary side, and nothing derived from the Müllerian duct is present on the testis side. Here, we investigate the mechanism underlying the unilateral Müllerian duct regression and the mode of AMH signaling, by performing immunohistology, Western blotting, and organ culture analyses. The histological analysis revealed that during the start of the Müllerian duct regression, the duct in the O/T mice was clearly regressed on the AMH-positive testis side compared to the AMH-negative ovary side. The immunohistochemistry showed a diffuse immunoreaction of AMH in the interstitium surrounding the testis cord and boundary region between the testis and mesonephros, especially in the cranial portion. Western blotting revealed that the amount of AMH in the cranial half of the mesonephros was larger than that in the caudal half. AMH injected into the gonads in organ culture induced the regression of the Müllerian duct via the interstitium of the organ. These results suggest that AMH acts on the Müllerian duct in male mice by exuding into the interstitium surrounding the testis cord and infiltrating through the cranial region from the testis to the mesonephros.

    2018年04月18日, The Journal of Veterinary Medical Science, 80 (4), 557 - 567, 英語, 国内誌

    [査読有り]

    研究論文(学術雑誌)

  • Tadashi Takada, Naoki Yoneda, Tetsushi Hirano, Shogo Yanai, Anzu Yamamoto, Youhei Mantani, Toshifumi Yokoyama, Hiroshi Kitagawa, Yoshiaki Tabuchi, Nobuhiko Hoshi

    It has been suggested that an increase in the use of pesticides affects neurodevelopment, but there has been no animal experiment showing a causal relation between neonicotinoid pesticides (NNs) and depression. We examined whether dinotefuran (DIN), the most widely used NN in Japan, induces depression. Male mice were administered DIN between 3 and 8 weeks of age, referring to the no-observed-effect level (NOEL). The mice were then subjected to a tail suspension test (TST) and a forced swimming test (FST). After these tests, their brains were dissected for immunohistochemical analyses of serotonin (5-HT). Antidepressant activity in TST and no decrease in 5-HT-positive cells were observed. The subchronic exposure to DIN alone in juvenile male mice may not cause depression-like indication.

    Japanese Society of Veterinary Science, 2018年04月01日, Journal of Veterinary Medical Science, 80 (4), 720 - 724, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Naoki Yoneda, Tadashi Takada, Tetsushi Hirano, Shogo Yanai, Anzu Yamamoto, Youhei Mantani, Toshifumi Yokoyama, Hiroshi Kitagawa, Yoshiaki Tabuchi, Nobuhiko Hoshi

    Although neonicotinoid pesticides are expected to have harmful influence on mammals, there is little animal experimental data to support the effect and mechanisms. Since acetylcholine causes the release of dopamine, neonicotinoids may confer a risk of developmental disorders via a disturbance in the monoamine systems. Male mice were peripubertally administered dinotefuran (DIN) referring to no observed effect level (NOEL) and performed behavioral and immunohistological analyses. In an open field test, the total locomotor activity was increased in a dose-dependent manner. The immunoreactivity of tyrosine hydroxylase in the substantia nigra was increased in DIN-exposed mice. These results suggest that exposure to DIN in peripubertal male mice causes hyperactivity and a disturbance of dopaminergic signaling.

    Japanese Society of Veterinary Science, 2018年04月01日, Journal of Veterinary Medical Science, 80 (4), 634 - 637, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Natsumi Masuda, Youhei Mantani, Chiaki Yoshitomi, Hideto Yuasa, Miho Nishida, Masaya Arai, Junichi Kawano, Toshifumi Yokoyama, Nobuhiko Hoshi, Hiroshi Kitagawa

    The host defense system with lysozyme and secretory phospholipase A2 (sPLA2) was immunohistochemically investigated in rat respiratory tract under healthy conditions. In the nasal epithelium, a large number of non-ciliated and non-microvillous cells (NC) and a small number of goblet cells (GC) were immunopositive for lysozyme and sPLA2. A few acinar cells and almost all epithelial cells of intercalated ducts were immunopositive for both bactericidal substances in the nasal glands. In the laryngeal and tracheal epithelia, few NC and GC were immunopositive for both bactericidal substances. In the laryngeal and tracheal glands, a few acinar cells and most ductal epithelial cells were immunopositive for both bactericidal substances. In extra-pulmonary bronchus, small numbers of NC and GC were immunopositive for lysozyme and sPLA2, whereas few NC and no GC were immunopositive in the intra-pulmonary bronchus. No secretory source of either bactericidal substance was located in the bronchioles. In the alveolus, many glandular epithelial cells and alveolar macrophages were immunopositive for lysozyme but immunonegative for sPLA2. Moreover, lysozyme and sPLA2 were detected in the mucus layer and in the periciliary layer from the nose to the extra-pulmonary bronchus. These findings suggest that secretory sources of lysozyme and sPLA2 are distributed in almost all the respiratory tract. Their secretory products are probably transported to the pharynx and contribute to form the first line of defense against inhaled bacteria throughout the respiratory tract.

    Japanese Society of Veterinary Science, 2018年02月01日, Journal of Veterinary Medical Science, 80 (2), 323 - 332, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Naoto Kubota, Toshifumi Yokoyama, Nobuhiko Hoshi, Mikita Suyama

    Cerebral palsy (CP) is a major neuronal disease and the most common movement disorder in children. Although environmental factors leading to CP have been greatly investigated, the genetic mechanism underlying CP is not well understood. Here we focused on two clinical reports that characterized a deletion involving the KANK1 gene locus in the 9p24.3 region. One report shows spastic CP and the other shows no spastic CP phenotype. Based on the epigenetic status and evolutionary conservation, we first found a functional genomic element at the noncoding region that was deleted only in patients with spastic CP. This element contains the retinoic acid receptor/retinoid X receptor (RAR/RXR) complex-binding motif that is widely conserved among placental mammals. RAR/RXR ChIP-seq data from mouse F9 embryonal carcinoma cells that were treated with trans-retinoic acids showed that the element has a binding ability. In addition, data regarding chromosome conformation capture from mouse neural progenitor and ES cells suggested that the element spatially interacts with the Doublesex and mab-3 related transcription factor 3 (Dmrt3) gene promoter that is located approximately 120 kb downstream of the RAR/RXR-binding site. Dmrt3 is detected in the developing mouse forebrain and in some interneurons in the spinal cord, and it works as a locomotion coordinator in horses and mice. Thus, the deletion of the cis-regulatory element for DMRT3 in humans may cause impaired development of the forebrain and gait abnormalities, resulting in spastic CP. In conclusion, this study provides new mechanistic insights into the genetic basis of CP.

    Elsevier B.V., 2018年01月29日, Biochemical and Biophysical Research Communications, 496 (1), 133 - 139, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Tetsushi Hirano, Shogo Yanai, Tadashi Takada, Naoki Yoneda, Takuya Omotehara, Naoto Kubota, Kiichi Minami, Anzu Yamamoto, Youhei Mantani, Toshifumi Yokoyama, Hiroshi Kitagawa, Nobuhiko Hoshi

    Neonicotinoids are novel systemic pesticides acting as agonists on the nicotinic acetylcholine receptors (nAChRs) of insects. Experimental studies have revealed that neonicotinoids pose potential risks for the nervous systems of non-target species, but the brain regions responsible for their behavioral effects remain incompletely understood. This study aimed to assess the neurobehavioral effects of clothianidin (CTD), a later neonicotinoid developed in 2001 and widely used worldwide, and to explore the target regions of neonicotinoids in the mammalian brain. A single-administration of 5 or 50 mg/kg CTD to male C57BL/6N mice at or below the no-observed-adverse-effect level (NOAEL) induced an acute increase in anxiety during the elevated plus-maze test. In addition, mice in the CTD-administered group spontaneously emitted human-audible vocalizations (4-16 kHz), which are behavioral signs of aversive emotions, and showed increased numbers of c-fos immunoreactive cells in the paraventricular thalamic nucleus and dentate gyrus of the hippocampus. In conclusion, mice exposed to NOAEL-dose CTD would be rendered vulnerable to a novel environment via the activation of thalamic and hippocampal regions related to stress responses. These findings should provide critical insight into the neurobehavioral effects of neonicotinoids on mammals.

    ELSEVIER IRELAND LTD, 2018年01月, TOXICOLOGY LETTERS, 282, 57 - 63, 英語

    [査読有り]

    研究論文(学術雑誌)

  • MASUDA NATSUMI, MANTANI YOUHEI, YUASA HIDETO, YOSHITOMI CHIAKI, ARAI MASAYA, NISHIDA MIHO, Qi WANG-MEI, KAWANO JUNICHI, YOKOYAMA TOSHIFUMI, HOSHI NOBUHIKO, KITAGAWA HIROSHI

    The distributions of β-defensin 1 and 2 in secretory host defense system throughout respiratory tract of healthy rats were immunohistochemically investigated. In the nasal epithelium, a large number of non-ciliated and non-microvillous cells (NCs) were immunopositive for both β-defensin 1 and 2, whereas a small number of goblet cells (GCs) were immunopositive only for β-defensin 1. Beta-defensin 2-immunopositive GCs were few. In the nasal glands, a small number of acinar cells and a large number of ductal epithelial cells were immunopositive for both β-defensins. In the laryngeal and tracheal epithelia, a very few NCs and GCs were immunopositive for both β-defensins. In laryngeal and tracheal glands, a very few acinar cells and a large number of ductal epithelial cells were immunopositive for both β-defensins. In the extra-pulmonary bronchus, a small number of NCs were immunopositive for both β-defensins. A small number of GCs were immunopositive for β-defensin 1, whereas few GCs were immunopositive for β-defensin 2. From the intra-pulmonary bronchus to alveoli, a very few or no epithelial cells were immunopositive for both β-defensins. In the mucus and periciliary layers, β-defensin 1 was detected from the nose to the extra-pulmonary bronchus, whereas β-defensin 2 was weakly detected only in the nose and the larynx. These findings suggest that the secretory sources of β-defensin 1 and 2 are mainly distributed in the nasal mucosa and gradually decrease toward the caudal airway in healthy rats.

    Japanese Society of Veterinary Science, 2018年, The Journal of Veterinary Medical Science, 80 (3), 395 - 404, 英語

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    研究論文(学術雑誌)

  • YUASA HIDETO, MANTANI YOUHEI, MASUDA NATSUMI, NISHIDA MIHO, ARAI MASAYA, YOKOYAMA TOSHIFUMI, TSURUTA HIROKI, HOSHI NOBUHIKO, KITAGAWA HIROSHI

    The mechanism by which indigenous bacteria on the follicle-associated epithelium (FAE) of lymphatic follicles (LFs) accelerate the differentiation of microvillous columnar epithelial cells (MV) into M-cells was immunohistochemically investigated in rat Peyer's patches. The results showed that the number of Toll-like receptor (TLR) -4(+) M-cells was greater in the FAE with expansion of bacterial colonies (LFs with bacterial colonies on the FAE: b-LF) than the FAE without expansion of bacterial colonies (nb-LF). TLR-4 was also expressed in the striated borders of MV upstream next to M-cells in the FAE of the b-LF. TLR-4(+) vesicles were frequently detected in the cytoplasms of MV with TLR-4(+) striated borders upstream next to TLR-4(+) M-cells in the FAE of b-LF. These findings suggest that TLR-4(+) MV take up TLR-4 ligands and differentiate into M-cells in the b-LF. Neither the distribution of RANK nor that of RANKL was coincident with that of M-cells in the b-LF. Moreover, RANK, but not RANKL, was expressed in intestinal villi, whereas cleaved caspase-3 was immunonegative in the MV and M-cells of the FAE, unlike in villous epithelial cells. Therefore, RANK/RANKL signaling in the LF might contribute to the down-regulation of epithelial apoptosis to facilitate the differentiation of MV into M-cells in rat Peyer's patches.

    JAPAN SOC VET SCI, 2017年11月, The Journal of Veterinary Medical Science, 79 (11), 1826 - 1835, 英語

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    研究論文(学術雑誌)

  • Shogo Yanai, Tetsushi Hirano, Takuya Omotehara, Tadashi Takada, Naoki Yoneda, Naoto Kubota, Anzu Yamamoto, Youhei Mantani, Toshifumi Yokoyama, Hiroshi Kitagawa, Nobuhiko Hoshi

    Neonicotinoids are pesticides used worldwide. They bind to insect nicotinic acetylcholine receptors (nAChRs) with high affinity. We previously reported that clothianidin (CTD), one of the latest neonicotinoids, reduced antioxidant expression and induced germ cell death in the adult testis of vertebrates. Here, we investigated the male reproductive toxicity of prenatal and early postnatal exposure to CTD, because it is likely that developmental exposure more severely affects the testis compared to adults due to the absence of the blood-testis barrier. Pregnant C57BL/6 mice were given water gel blended with CTD (0, 10 or 50 mg/kg/day; noobserved- adverse-effect-level [NOAEL for mice]: 47.2 mg/kg/day) between gestational day 1 and 14 days post-partum. We then examined the testes of male offspring at postnatal day 14. The testis weights and the numbers of germ cells per seminiferous tubule were decreased in the CTD-50 group, and abnormal tubules containing no germ cells appeared. Nevertheless, the apoptotic cell number and proliferative activity were not significantly different between the control and CTD-exposed groups. There were no significant differences in the androgen-related parameters, such as the Leydig cell volume per testis, the Sertoli cell number and the tubule diameter. The present study is the first demonstration that in utero and lactational exposures to CTD at around the NOAEL for mice reduce the germ cell number, but our findings suggest that these exposures do not affect steroidogenesis in Leydig cells during prenatal or early postnatal life.

    JAPAN SOC VET SCI, 2017年07月, JOURNAL OF VETERINARY MEDICAL SCIENCE, 79 (7), 1196 - 1203, 英語

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    研究論文(学術雑誌)

  • Takuya Omotehara, Kiichi Minami, Youhei Mantani, Yuria Umemura, Miho Nishida, Tetsushi Hirano, Hidefumi Yoshioka, Hiroshi Kitagawa, Toshifumi Yokoyama, Nobuhiko Hoshi

    Background: The left male gonad in the chicken embryo has a thickened cortical layer, but it eventually becomes flattened after the onset of testicular development. Because the destination of the cortical cells migrating from the left gonad remains unclear, we examined this issue herein. Results: The testis-inducing gene doublesex-and mab-3-related transcription factor 1 (DMRT1) was detected in a proportion of the columnar and cubic epithelial cells in the cortex of the left testis as well as Sertoli cells in both testes. Interestingly, some of the DMRT1-expressing cortical cells were contiguous with Sertoli cells in the testis cord. Some cortical cells exhibited a vimentin-positive cytoplasm that was elongated all the way to the medulla. In addition, a desmosome-like structure was observed between the elongated cytoplasm in these cells and the adjacent Sertoli cell. After the organ culture, a few cells labeled with a fluorescent dye that stained only the cortical cells at the beginning of the culture were located in the testis cord of the left testis. Conclusions: Some cortical cells expressing DMRT1 were suggested to contribute to the Sertoli cells in the testis cord only after the onset of testicular development and only in the left testis. (C) 2016 Wiley Periodicals, Inc.

    WILEY, 2017年02月, DEVELOPMENTAL DYNAMICS, 246 (2), 148 - 156, 英語

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    研究論文(学術雑誌)

  • Ferhat Ulu, Sung-Min Kim, Toshifumi Yokoyama, Yukiko Yamazaki

    Male differentiation of primordial germ cells (PGCs) is initiated by the inhibition of entry into meiosis and exposure to male-inducing factor(s), which are regulated by somatic elements of the developing gonad. Fibroblast growth factor 9 (FGF9) produced by pre-Sertoli cells is essential for male gonadal differentiation and also contributes to survival and male differentiation of XY PGCs. However, it is not clear how FGF9 regulates PGC fate. Using a PGC culture system, we identified dose-dependent, fate-determining functions of FGF9 in XY PGCs. Treatment with low levels of FGF9 (0.2 ng/ml) increased expression of male-specific Dnmt3L and Nanos2 in XY PGCs. Conversely, treatment with high levels of FGF9 (25 ng/ml) suppressed male-specific gene expression and stimulated proliferation of XY PGCs. Western blotting showed that low FGF9 treatment enhanced p38 MAPK (mitogen-activated protein kinase) phosphorylation in the same cells. In contrast, high FGF9 treatment significantly stimulated the ERK (extracellular signal-regulated kinase) 1/2 signaling pathway in XY PGCs. We investigated the relationship between the ERK1/2 signaling pathway stimulated by high FGF9 and regulation of PGC proliferation. An ERK1/2 inhibitor (U0126) suppressed the PGC proliferation that would otherwise be stimulated by high FGF9 treatment, and increased Nanos2 expression in XY PGCs. Conversely, a p38 MAPK inhibitor (SB202190) significantly suppressed Nanos2 expression that would otherwise be stimulated by low FGF9 in XY PGCs. Taken together, our results suggest that stage-specific expression of FGF9 in XY gonads regulates the balance between proliferation and differentiation of XY PGCs in a dose-dependent manner. Summary Sentence FGF9 directly regulates different fates of XY PGCs in a dose-dependent manner: low FGF9 treatment promotes p38 signaling pathway to induce PGC male differentiation, whereas high FGF9 treatment enhances ERK1/2 signaling pathway to proliferate PGCs.

    SOC STUDY REPRODUCTION, 2017年01月, BIOLOGY OF REPRODUCTION, 96 (1), 122 - 133, 英語

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    研究論文(学術雑誌)

  • Hideto Yuasa, Youhei Mantani, Natsumi Masuda, Miho Nishida, Junichi Kawano, Toshifumi Yokoyama, Nobuhiko Hoshi, Hiroshi Kitagawa

    The expressions of Toll-like receptor (TLR) -2, -4 and -9 were immunohistochemically investigated in the follicle-associated epithelium (FAE), and epithelia of the follicle-associated intestinal villus (FAIV) and ordinary intestinal villus (IV) in rat Peyer's patch regions with no bacterial colonies on the mucous membranes. TLR-2 was expressed in the striated borders of microvillous columnar epithelial cells (MV) in both FAIV and IV except in the apices. However, TLR-2 expression in the striated borders was weaker in the epithelium of the follicular side of FAIV (f-FAIV) than in epithelia of IV and the anti-follicular side of FAIV. TLR-4 and-9 were not expressed in the FAIV and IV. In the FAE, TLR-2,-4 and-9 were not expressed in the striated borders of MV, but the roofs of some typical M-cells were immunopositive for all TLRs. Especially, no TLR-positive MV were found at the FAE sites where M-cells appeared most frequently. In the follicle-associated intestinal crypt (FAIC), immunopositivity for all TLRs was observed in the striated borders of MV and the luminal substances. In conclusion, the lower levels of TLR-2 in both FAE and the epithelium of f-FAIV probably reduce recognition of indigenous bacteria. TLR-2,-4 and-9 appear not to participate directly in differentiation of MV into M-cells, because TLRs were not expressed in any MV in the upstream region of M-cells in FAE with no settlement of indigenous bacteria in the rat Peyer's patches.

    JAPAN SOC VET SCI, 2016年12月, JOURNAL OF VETERINARY MEDICAL SCIENCE, 78 (12), 1797 - 1804, 英語

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    研究論文(学術雑誌)

  • Yuria Umemura, Ryosuke Miyamoto, Rie Hashimoto, Kyoko Kinoshita, Takuya Omotehara, Daichi Nagahara, Tetsushi Hirano, Naoto Kubota, Kiichi Minami, Shogo Yanai, Natsumi Masuda, Hideto Yuasa, Youhei Mantani, Eiko Matsuo, Toshifumi Yokoyama, Hiroshi Kitagawa, Nobuhiko Hoshi

    Mammalian sexual fate is determined by the presence or absence of sex determining region of the Y chromosome (Sly) in the "bipotential" gonads. Recent studies have demonstrated that both male and female sexual development are induced by distinct and active genetic pathways. Breeding the Y chromosome from Mus m. domesticus poschiavinus (POS) strains into C57BL/6J (B6J) mice (B6J-XYPOS) has been shown to induce sex reversal (75%: bilateral ovary, 25%: true hermaphrodites). However, our B6N-XYPOS mice, which were generated by backcrossing of B6J-XYPOS on an inbred B6N-XX, develop as males (36%: bilateral testis with fertility as well as bilateral ovary (34%), and the remainder develop as true hermaphrodites. Here, we investigated in detail the expressions of essential sex-related genes and histological features in B6N-XYPOS mice from the fetal period to adulthood. The onsets of both Sry and SRY-box 9 (Sox9) expressions as determined spatiotemporally by whole-mount immunohistochemistry in the B6N-XYPOS gonads occurred 2-3 tail somites later than those in B6N-XYB6 gonads, but earlier than those in B6J-XYPOS, respectively. It is possible that such a small difference in timing of the Sry expression underlies testicular development in our B6N-XYPOS. Our study is the first to histologically show the expression and ectopic localization of a female-related gene in the XYPOS testes and a male -related gene in the XYPOS ovaries. The results from these and previous experiments indicate that the interplay between genome variants, epigenetics and developmental gene regulation is crucial for testis development.

    JAPAN SOC VET SCI, 2015年12月, JOURNAL OF VETERINARY MEDICAL SCIENCE, 77 (12), 1587 - 1597, 英語

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    研究論文(学術雑誌)

  • Yoshihiro Kobayashi, Tetsushi Hirano, Takuya Omotehara, Rie Hashimoto, Yuria Umemura, Hideto Yuasa, Natsumi Masuda, Naoto Kubota, Kiichi Minami, Shogo Yanai, Mitsuko Ishihara-Sugano, Youhei Mantani, Toshifumi Yokoyama, Hiroshi Kitagawa, Nobuhiko Hoshi

    Dioxins are widespread persistent environmental contaminants with adverse impacts on humans and experimental animals. Behavioral and cognitive functions are impaired by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) exposure. TCDD exerts its toxicity via the aryl hydrocarbon receptor (AhR), a ligand-activated transcription factor. The hippocampus, which plays important roles in episodic memory and spatial function, is considered vulnerable to TCDD-induced neurotoxicity, because it contains the AhR. We herein investigated the effects of TCDD toxicity on hippocampal development in embryonic mice. TCDD was administered to dams at 8.5 days postcoitum with a single dose of 20, 200, 2,000 and 5,000 ng/kg body weight (groups T20, T200, T2000 and T5000, respectively), and the brains were dissected from their pups at embryonic day 18.5. Immunohistochemical analysis demonstrated that the Glial Fibrillary Acidic Protein (GFAP) immunoreactivities in the dentate gyrus (DG) were reduced in the T5000 group. Granular GFAP immunoreactivity was observed in the hippocampal fimbria, and the number of immunoreactive fimbria was significantly decreased in the T5000 group. The number of Proliferating Cell Nuclear Antigen (PCNA)-positive cells was decreased in all TCDD-exposed groups and significantly reduced in the T20, T200 and T5000 groups. Together, these results demonstrate that maternal TCDD exposure has adverse impacts on neural stem cells (NSCs), neural precursor cells (NPCs) and granular cells in the DG and disrupts the NSC maintenance and timing of differentiation in the hippocampal fimbria, which in turn interrupt neuronal development in future generations of mice.

    JAPAN SOC VET SCI, 2015年11月, JOURNAL OF VETERINARY MEDICAL SCIENCE, 77 (11), 1355 - 1361, 英語

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    研究論文(学術雑誌)

  • Tetsushi Hirano, Shogo Yanai, Takuya Omotehara, Rie Hashimoto, Yuria Umemura, Naoto Kubota, Kiichi Minami, Daichi Nagahara, Eiko Matsuo, Yoshiko Aihara, Ryota Shinohara, Tomoyuki Furuyashiki, Youhei Mantani, Toshifumi Yokoyama, Hiroshi Kitagawa, Nobuhiko Hoshi

    Neonicotinoids, some of the most widely used pesticides in the world, act as agonists to the nicotinic acetylcholine receptors (nAChRs) of insects, resulting in death from abnormal excitability. Neonicotinoids unexpectedly became a major topic as a compelling cause of honeybee colony collapse disorder, which is damaging crop production that requires pollination worldwide. Mammal nAChRs appear to have a certain affinity for neonicotinoids with lower levels than those of insects; there is thus rising concern about unpredictable adverse effects of neonicotinoids on vertebrates. We hypothesized that the effects of neonicotinoids would be enhanced under a chronic stressed condition, which is known to alter the expression of targets of neonicotinoids, i.e., neuronal nAChRs. We performed immunohistochemical and behavioral analyses in male mice actively administered a neonicotinoid, clothianidin (CTD; 0, 10, 50 and 250 mg/kg/day), for 4 weeks under an unpredictable chronic stress procedure. Vacuolated seminiferous epithelia and a decrease in the immunoreactivity of the antioxidant enzyme glutathione peroxidase 4 were observed in the testes of the CTD+stress mice. In an open field test, although the locomotor activities were not affected, the anxiety-like behaviors of the mice were elevated by both CTD and stress. The present study demonstrates that the behavioral and reproductive effects of CTD become more serious in combination with environmental stress, which may reflect our actual situation of multiple exposure.

    JAPAN SOC VET SCI, 2015年10月, JOURNAL OF VETERINARY MEDICAL SCIENCE, 77 (10), 1207 - 1215, 英語

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    研究論文(学術雑誌)

  • Youhei Mantani, Eri Ito, Miho Nishida, Hideto Yuasa, Natsumi Masuda, Wang-Mei Qi, Junichi Kawano, Toshifumi Yokoyama, Nobuhiko Hoshi, Hiroshi Kitagawa

    Indigenous bacteria in the alimentary tract are exposed to various bactericidal peptides and digestive enzymes, but the viability status and morphological changes of indigenous bacteria are unclear. Therefore, the present study aimed to ultrastructurally clarify the degeneration and viability status of indigenous bacteria in the rat intestine. The majority of indigenous bacteria in the ileal mucous layer possessed intact cytoplasm, but the cytoplasm of a few bacteria contained vacuoles. The vacuoles were more frequently found in bacteria of ileal chyme than in those of ileal mucous layer and were found in a large majority of bacteria in both the mucous layer and chyme throughout the large intestine. In the dividing bacteria of the mucous layer and chyme throughout the intestine, the ratio of area occupied by vacuoles was almost always less than 10%. Lysis or detachment of the cell wall in the indigenous bacteria was more frequently found in the large intestine than in the ileum, whereas bacterial remnants, such as cell walls, were distributed almost evenly throughout the intestine. In an experimental control of long-time-cultured Staphylococcus epidermidis on agar, similar vacuoles were also found, but cell-wall degeneration was never observed. From these findings, indigenous bacteria in the mucous layer were ultrastructurally confirmed to be the source of indigenous bacteria in the chyme. Furthermore, the results suggested that indigenous bacteria were more severely degenerated toward the large intestine and were probably degraded in the intestine.

    JAPAN SOC VET SCI, 2015年09月, JOURNAL OF VETERINARY MEDICAL SCIENCE, 77 (9), 1121 - 1128, 英語

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    研究論文(学術雑誌)

  • Ei-ichirou Takahara, Hideto Yuasa, Miho Nishida, Youhei Mantani, Kankanam Gamage Sanath Udayanga, Wang-Mei Qi, Takashi Takeuchi, Toshifumi Yokoyama, Nobuhiko Hoshi, Hiroshi Kitagawa

    A portion of the minute chylomicrons less than 75 nm in diameter are transcytosed from the extravascular tissue into the subepithelial blood capillaries (sBC) in the villous apices of the rat jejunum. However, the details of the transportation mechanism have not been clarified. In this study, the endothelial receptor involved in the transportation of minute chylomicrons into the sBC's lumina was immunohistochemically and histoplanimetrically examined in intestinal villi of the rat jejunum. Immunopositivity for very low density lipoprotein (VLDL) receptor was detected on the luminal and basal surfaces of the endothelial cells of sBC in approximately 68% of those apices of jejunal villi that possessed numerous chylomicrons in the lamina propria, while VLDL receptor was detected on the endothelial cells of sBC in only approximately 8% of intestinal villi that possessed few or no chylomicrons in the lamina propria. No immunopositivity for VLDL receptor was detected in the sBC of all intestinal villi. These findings suggest that VLDL receptor is expressed by the endothelial cells of the sBC in conjunction with the filling of the lamina propria of jejunal villi with many chylomicrons produced by the villous columnar epithelial cells and that the VLDL receptor mediates the transportation of minute chylomicrons, maybe VLDL, into the subepithelial portal blood from the extravascular tissue of the rat jejunal villi.

    JAPAN SOC VET SCI, 2015年04月, JOURNAL OF VETERINARY MEDICAL SCIENCE, 77 (4), 387 - 393, 英語

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    研究論文(学術雑誌)

  • Tetsushi Hirano, Yoshihiro Kobayashi, Takuya Omotehara, Atsutoshi Tatsumi, Rie Hashimoto, Yuria Umemura, Daichi Nagahara, Youhei Mantani, Toshifumi Yokoyama, Hiroshi Kitagawa, Nobuhiko Hoshi

    Environmental stress affects various parts of mammals typically through the circulation of stress hormones. It has been identified as one of the possible reasons for male reproductive difficulties, but the complex mechanisms responsible for stress-induced reproductive suppression are poorly understood. Here, we examined the relationship between chronic environmental stress and hypothalamic kisspeptin, a recently discovered upstream regulator of the reproductive endocrine feedback system. We studied male mice under an unpredictable chronic stress procedure to replicate the situation of animals under chronic stress. Histological and immunohistochemical analyses were performed focusing on kisspeptin neurons in the arcuate hypothalamic nucleus (ARC) and DNA fragmented cells in seminiferous tubules. Although the ARC was not morphologically altered in either the stressed or non-stressed group, granular kisspeptin immunoreactivities decreased slightly in the stress group. In the testes of the stress group, several signs of testicular degeneration were observed, including increased numbers of ssDNA-positive cells per seminiferous tubule, thinning, vacuoled seminiferous epithelia and multinucleated giant cells. The decreases in kisspeptin in the stress group might be due to other hypothalamic peptides, such as corticotropin-releasing hormone and leptin, whose receptors are known to coexpress in the ARC. In addition, environmental stress directly and indirectly affects testicular function through stress hormones and gonadotropins. In summary, our findings enhance the understanding of stress-induced reproductive suppression possibly mediated by kisspeptin in the ARC.

    JAPAN SOC VET SCI, 2014年09月, JOURNAL OF VETERINARY MEDICAL SCIENCE, 76 (9), 1201 - 1208, 英語

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    研究論文(学術雑誌)

  • Insight into the Mechanism of Reproductive Dysfunction Caused by Neonicotinoid Pesticides

    Nobuhiko Hoshi, Tetsushi Hirano, Takuya Omotehara, Junko Tokumoto, Yuria Umemura, Youhei Mantani, Takashi Tanida, Katsuhiko Warita, Yoshiaki Tabuchi, Toshifumi Yokoyama, Hiroshi Kitagawa

    Neonicotinoids, which were developed in the 1990s as an insecticide having selective toxicity, were later found to cause reproductive abnormalities in experimental animals. In Japan there is an attempt to preserve endangered animals, including the Japanese crested ibis, and there is a question of whether neonicotinoids affect the reproduction of this bird, since they are used in its habitat. Hence, we investigated whether the daily oral administration of the neonicotinoid clothianidin (CTD) has any deleterious effects on the reproductive function of mature male only or both young male and female quails as experimental animals. Vacuolization and the number of germ cells having fragmented DNA in seminiferous tubules, as well as the number and size of vacuoles in hepatocytes, increased dose-dependently. The ovaries showed abnormal histology in the granulosa cells, which produce progesterone. There were significant differences in egg-laying rates and embryo weights between the groups. Glutathione Peroxidase 4 (GPx4) and Manganese Superoxide Dismutase (Mn-SOD), which protect the organism from oxidative damage, showed a dose-dependent decrease. Thus, it is possible neonicotinoids affect the bird's reproductive system through oxidative stress, reflecting an imbalance between the production of reactive oxygen species (ROS) and a biological system's ability to readily detoxify the reactive intermediates or easily repair the resulting damage. Responding to our study, Sado Island has since succeeded in breeding Japanese crested ibis in the wild without the use of neonicotinoids.

    PHARMACEUTICAL SOC JAPAN, 2014年09月, BIOLOGICAL & PHARMACEUTICAL BULLETIN, 37 (9), 1439 - 1443, 英語

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    研究論文(学術雑誌)

  • ネオニコチノイド系農薬クロチアニジンの低用量曝露とストレスの複合影響

    平野 哲史, 表原 拓也, 橋本 理恵, 梅村 ゆりあ, 久保田 直人, 南 貴一, 柳井 翔吾, 長原 大知, 湯浅 秀人, 万谷 洋平, 横山 俊史, 北川 浩, 星 信彦

    (公社)日本獣医学会, 2014年08月, 日本獣医学会学術集会講演要旨集, 157回, 331 - 331, 日本語

    [査読有り]

  • Youhei Mantani, Miho Nishida, Hideto Yuasa, Kyouji Yamamoto, Ei-Ichirou Takahara, Takuya Omotehara, Kankanam Gamage Sanath Udayanga, Junichi Kawano, Toshifumi Yokoyama, Nobuhiko Hoshi, Hiroshi Kitagawa

    Paneth cells (PCs) contribute to the host defense against indigenous bacteria in the small intestine. We found Paneth cell-like cells (PLCs) in the rat ascending colon, but the nature of PLCs is never clarified. Therefore, the present study aimed to clarify the cytological characteristics of PLCs and discuss their cellular differentiation. PLCs were localized in the bases of intestinal crypts, especially follicle-associated intestinal crypts in proximal colonic lymphoid tissue, but were very seldom found in the ordinary intestinal crypts of the ascending colon. PLCs possessed specific granules with highly electron-dense cores and haloes, as well as PCs in the small intestine. The secretory granules of PLCs were positive for PAS reaction, lysozyme and soluble phospholipase A2, but negative for Alcian blue staining, β-defensin-1 and -2, as well as the ones of PCs. Furthermore, intermediate cells possessing both the PLC-specific granules and the mucus granules similar to those of goblet cells (GCs) were occasionally found in the vicinity of PLCs. Intermediate cells ranged from goblet cell-like cells rich in mucus granules to PLC-like cells with few mucus granules. The cellular condensation and fragmentation were exclusively found in PLCs but never seen in intermediate cells or GCs. The PLCs, which were identified as PC, were suggested to be transformed from GCs through intermediate cells and finally to die by apoptosis in intestinal crypts of proximal colonic lymphoid tissue in the rat ascending colon.

    2014年08月, Anatomical record (Hoboken, N.J. : 2007), 297 (8), 1462 - 71, 英語, 国際誌

    [査読有り]

    研究論文(学術雑誌)

  • MANTANI YOUHEI, YUASA HIDETO, NISHIDA MIHO, TAKAHARA EI-ICHIROU, OMOTEHARA TAKUYA, UDAYANGA K. G. S, KAWANO JUNICHI, YOKOYAMA TOSHIFUMI, HOSHI NOBUHIKO, KITAGAWA HIROSHI

    The epithelial cell composition was investigated in the follicle-associated intestinal crypt (FAIC) of rat Peyer's patches. The epithelium of the FAIC mainly consisted of columnar epithelial cells, goblet cells and Paneth cells. The characteristics of secretory granules in Paneth cells and goblet cells of both the FAIC and ordinary intestinal crypts (IC) were almost the same in periodic acid-Schiff (PAS) reaction, Alcian blue (AB) staining and the immunohistochemical detection of lysozymes and soluble phospholipase A2. Both goblet cells and Paneth cells were markedly less frequent on the follicular sides than on the anti-follicular sides of the FAIC. Goblet cells were also markedly less frequent in the follicle-associated epithelium (FAR) than in the ordinary intestinal villi (IV). Indigenous bacteria were more frequently adhered to FAR than to follicle-associated intestinal villi or IV. These findings suggest that the host defense against indigenous bacteria is inhibited on the follicular sides of FAIC, which might contribute to the preferential settlement of indigenous bacteria on the FAE; they also suggest that differentiation into secretory cells is inhibited in the epithelium of the follicular sides of FAIC, so that differentiation into M cells might be admitted in the FAR of rat Peyer's patches. Furthermore, intermediate cells possessing characteristics of both Paneth cells and goblet cells were rarely found in the FAIC, but not in the IC. This finding suggests that the manner of differentiation into Paneth cells in the FAIC differs from that in the IC.

    JAPAN SOC VET SCI, 2014年06月, The Journal of Veterinary Medical Science, 76 (6), 833 - 838, 英語

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    研究論文(学術雑誌)

  • T. Omotehara, C. A. Smith, Y. Mantani, Y. Kobayashi, A. Tatsumi, D. Nagahara, R. Hashimoto, T. Hirano, Y. Umemura, T. Yokoyama, H. Kitagawa, N. Hoshi

    Sex of birds is genetically determined by the inheritance of sex chromosomes (ZZ for male and ZW for female), and the Z-linked gene named doublesex and mab-3 related transcription factor 1 (DMRT1) is a candidate sex- determining gene in avian species. However, the mechanisms underlying sex determination in birds are not yet understood, and the expression patterns of the DMRT1 protein in urogenital tissues have not been identified. In the current study, we used immunohistochemistry to investigate the detailed expression patterns of the DMRT1 protein in the urogenital systems (including Mullerian ducts) in male and female chicken embryos throughout embryonic development. Gonadal somatic cells in the male indifferent gonads showed stronger expressions of DMRT1 compared with those in the female indifferent gonads well before the presumptive period of the sex determination, and Sertoli cells forming testicular cords expressed DMRT1 in the testes after sex determination. Germ cells expressed DMRT1 equally in males and females after sex determination. The expression was continuous in males, but in females it gradually disappeared from the germ cells in the central part of the cortex of the left ovary toward both edges. The DMRT1 was also detected in the tubal ridge, which is a precursor of the Mullerian duct, and at the mesenchyme and outermost coelomic epithelium of the Mullerian duct in both sexes. Strong expression was observed in the males, but it was restricted to coelomic epithelium after the regression of the duct started. Thus, we observed the detailed spatiotemporal expression patterns of DMRT1 in the developing chicken urogenital systems throughout embryonic development, suggesting its various roles in the development of urogenital tissues in the chicken embryo.

    OXFORD UNIV PRESS, 2014年04月, POULTRY SCIENCE, 93 (4), 953 - 958, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Takanori Miki, Takashi Kusaka, Toshifumi Yokoyama, Ken-ichi Ohta, Shingo Suzuki, Katsuhiko Warita, Mostofa Jamal, Zhi-Yu Wang, Masaaki Ueki, Jun-Qian Liu, Tomiko Yakura, Motoki Tamai, Kazunori Sumitani, Naohisa Hosomi, Yoshiki Takeuchi

    Alcohol ingestion affects both motor and cognitive functions. One brain system that is influenced by ethanol is the basal forebrain (BF) cholinergic projection system, which projects to diverse neocortical and limbic areas. The BF is associated with memory and cognitive function. Our primary interest is the examination of how regions that receive BF cholinergic projections are influenced by short-term ethanol exposure through alterations in the mRNA levels of neurotrophic factors [nerve growth factor/TrkA, brain-derived neurotrophic factor/TrkB, and glial-derived neurotrophic factor (GDNF)/GDNF family receptor α1]. Male BALB/C mice were fed a liquid diet containing 5 % (v/v) ethanol. Pair-fed control mice were maintained on an identical liquid diet, except that the ethanol was isocalorically substituted with sucrose. Mice exhibiting signs of ethanol intoxication (stages 1-2) were used for real-time reverse transcription-polymerase chain reaction analyses. Among the BF cholinergic projection regions, decreased levels of GDNF mRNA and increased levels of TrkB mRNA were observed in the basal nucleus, and increased levels of TrkB mRNA were observed in the cerebral cortex. There were no significant alterations in the levels of expression of relevant neurotrophic factors in the septal nucleus and hippocampus. Given that neurotrophic factors function in retrograde/anterograde or autocrine/paracrine mechanisms and that BF cholinergic projection regions are neuroanatomically connected, these findings suggested that an imbalanced allocation of neurotrophic factor ligands and receptors is an initial phenomenon in alcohol addiction. The exact mechanisms underlying this phenomenon in the BF cholinergic system are unknown. However, our results provide a novel notion for the understanding of the initial processes in alcohol addiction.

    2014年02月, Journal of neural transmission (Vienna, Austria : 1996), 121 (2), 201 - 10, 英語, 国際誌

    [査読有り]

    研究論文(学術雑誌)

  • Takashi Tanida, Ken Tasaka, Eiichi Akahoshi, Mitsuko Ishihara-Sugano, Michiko Saito, Shigehisa Kawata, Megumi Danjo, Junko Tokumoto, Youhei Mantani, Daichi Nagahara, Yoshiaki Tabuchi, Toshifumi Yokoyama, Hiroshi Kitagawa, Mitsuhiro Kawata, Nobuhiko Hoshi

    Fetal exposure to dioxins and related compounds is known to disrupt normal development of the midbrain dopaminergic system, which regulates behavior, cognition and emotion. The toxicity of these chemicals is mediated mainly by aryl hydrocarbon receptor (AhR) signaling. Previously, we identified a novel binding motif of AhR, the AhR-responsive element III (AHRE-III), in vitro. This motif is located upstream from the gene encoding tyrosine hydroxylase (TH), the rate-limiting enzyme of dopamine biosynthesis. To provide in vivo evidence, we investigated whether 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) could regulate AHRE-III transcriptional activity in midbrain dopaminergic neurons. We produced transgenic mice with inserted constructs of the AHRE-III enhancers, TH gene promoter and the c-myc-tagged luciferase gene. Single oral administrations of TCDD (0-2000ngkg(-1) body weight) to the transgenic dams markedly enhanced TH-immunoreactive (ir) intensity in the A9, A10 and A8 areas of their offspring at 3days and 8weeks of age. The offspring of dams treated with 200ngkg(-1) TCDD exhibited significant increases in the numbers of TH- and double (TH and c-myc)-ir neurons in area A9 compared with controls at 8weeks. These results show that fetal exposure to TCDD upregulates TH expression and increases TH-ir neurons in the midbrain. Moreover, the results suggest that TCDD directly transactivates the TH promoter via the AhR-AHRE-III-mediated pathway in area A9. Fetal exposure to TCDD caused stable upregulation of TH via the AhR-AHRE-III signaling pathway and overgrowth of TH-ir neurons in the midbrain, implying possible involvement in the etiology of neurodevelopmental disorders such as attention-deficit/hyperactivity disorder (ADHD). Copyright (c) 2013 John Wiley & Sons, Ltd.

    WILEY, 2014年02月, JOURNAL OF APPLIED TOXICOLOGY, 34 (2), 117 - 126, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Takanori Miki, Toshifumi Yokoyama, Takashi Kusaka, Shingo Suzuki, Ken-ichi Ohta, Katsuhiko Warita, Zhi-Yu Wang, Masaaki Ueki, Kazunori Sumitani, Frederick P. Bellinger, Motoki Tamai, Jun-Qian Liu, Tomiko Yakura, Yoshiki Takeuchi

    Repetitive maternal deprivation (MD) of neonatal rats during early life is known as one of the strongest stressors to pre-weaned animals. There is increasing evidence that the cerebellum is involved in cognition and emotion. In the present study, we examined how neurotrophic factors and myelin-associated molecules and their receptors (NGF, BDNF, OMgp, TrIcA, TrkB, p75 NTR, and NgR) in the cerebellum are affected by early postnatal maternal separation. Rat pups were separated from their mothers for 3 h/day during postnatal days (PND) 10-15. At PND 16 and 30, the levels of mRNA and protein in the cerebellum were determined using real-time PCR and Western blot analysis. Cerebellar mRNA and protein levels of BDNF, TrkB, and OMgp were significantly increased in MD rats at PND 16. However, by PND 30 these variables normalized to control levels. In contrast, the levels of mRNA and protein for NGF, TrkA, p75 NTR, and NgR were unchanged at both ages examined. Transient enhancement of neurotrophic system and myelin-associated molecule expression may cause interference of normal development of the cerebellum such as precocious myelination, which may lead to functional and cognitive deficits later in life. (C) 2013 Elsevier B.V. All rights reserved.

    ELSEVIER SCIENCE BV, 2014年01月, JOURNAL OF THE NEUROLOGICAL SCIENCES, 336 (1-2), 62 - 67, 英語

    [査読有り]

    研究論文(学術雑誌)

  • MIKI TAKANORI, LIU JUN-QIAN, OHTA KEN-ICHI, SUZUKI SHINGO, KUSAKA TAKASHI, WARITA KATSUHIKO, YOKOYAMA TOSHIFUMI, JAMAL MOSTOFA, UEKI MASAAKI, YAKURA TOMIKO, TAMAI MOTOKI, SUMITANI KAZUNORI, HOSOMI NAOHISA, TAKEUCHI YOSHIKI

    The effects of early postnatal maternal deprivation on the biological characteristics of the adipose tissue later in life were investigated in the present study. Sprague-Dawley rats were classified as either maternal deprivation (MD) or mother-reared control (MRC) groups. MD was achieved by separating the rat pups from their mothers for 3h each day during the 10-15 postnatal days. mRNA levels of mitochondrial uncoupling protein 1 (UCP-1), β3-adrenergic receptor (β3-AR), and prohibitin (PHB) in the brown and white adipose tissue were determined using real-time RT-PCR analysis. UCP-1, which is mediated through β3-AR, is closely involved in the energy metabolism and expenditure. PHB is highly expressed in the proliferating tissues/cells. At 10 weeks of age, the body weight of the MRC and MD rats was similar. However, the levels of the key molecules in the adipose tissue were substantially altered. There was a significant increase in the expression of PHB mRNA in the white adipose tissue, while the β3-AR mRNA expression decreased significantly, and the UCP-1 mRNA expression remained unchanged in the brown adipose tissue. Given that these molecules influence the mitochondrial metabolism, our study indicates that early postnatal maternal deprivation can influence the fate of adipose tissue proliferation, presumably leading to obesity later in life.

    2013年12月06日, Biochemical and biophysical research communications, 442 (1-2), 68 - 71, 英語, 国際誌

    [査読有り]

    研究論文(学術雑誌)

  • Ei-ichirou Takahara, Youhei Mantani, Kankanam Gamage Sanath Udayanga, Wang-Mei Qi, Takashi Tanida, Takashi Takeuchi, Toshifumi Yokoyama, Nobuhiko Hoshi, Hiroshi Kitagawa

    Chylomicrons from villous columnar epithelial cells are generally known to be transported only by central lymph vessels (CLV), whereas antigenic particulates derived from the intestinal lumen can also be transported by subepithelial blood capillaries (sBCs) in rat intestinal villi. The possibility of chylomicron absorption by sBCs was histoplanimetrically studied in the rat jejunum under a transmission electron microscope. The chylomicrons more abundantly presented in villous venules than in arterioles. The most frequent size (MFS) of chylomicrons was 75 to 90 nm in diameter in the areas near sBCs, while it was 45 to 60 nm in the epithelial intercellular spaces just above sBCs or the intermediate areas between sBCs. The MFS of chylomicrons was 45 to 60 nm in the intermediate areas between sBCs and in the epithelial intercellular spaces just above these areas. The MFS of chylomicrons in CLV was intermediate between that in the area adjacent to sBCs and that in the intermediate areas between sBCs. Chylomicrons were found in small vesicles in the endothelial cytoplasms of sBCs. No chylomicrons larger than 600 nm were observed in the lamina propria. These findings suggest that some of the chylomicrons smaller than 75 nm, which are probable intestinal very low-density lipoproteins (VLDL), are directly transported to the liver by hepatic portal blood in addition to CLV and that epithelial fat droplets larger than 600 nm are not discharged into lamina propria in rat jejunum under physiological conditions.

    JAPAN SOC VET SCI, 2013年12月, JOURNAL OF VETERINARY MEDICAL SCIENCE, 75 (12), 1563 - 1569, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Youhei Mantani, Ei-ichirou Takahara, Takashi Takeuchi, Junichi Kawano, Toshifumi Yokoyama, Nobuhiko Hoshi, Hiroshi Kitagawa

    The relationship between the invasion of indigenous bacteria into intestinal crypts and the proliferation of epithelial cells was histoplanimetrically investigated in the rat ascending colon. Indigenous bacteria preferentially adhered to the intestinal superficial epithelial cells in the mesenterium-attached mucosa (MAM) compared to those in the mesenterium-non-attached mucosa (MNM). Intestinal crypts with indigenous bacteria were also significantly more frequently found in MAM than in MNM. Total epithelial cells, columnar epithelial cells and goblet cells were significantly more abundant in the intestinal crypts with no-indigenous bacteria in MAM (MAM-C) than those in MNM (MNM-C), whereas the columnar epithelial cells were less abundant in MAM-C than in the intestinal crypts with indigenous bacteria in MAM (MAM-C-B). Columnar epithelial cells and goblet cells immuno-positive for proliferating cell nuclear antigen (PCNA) in MAM-C were more abundant than those in MNM-C, but less abundant than those in MAM-C-B. Toll-like receptor (TLR)-2, -4 and -9 were immuno-positive in the striated borders of the intestinal superficial epithelial cells, but their positive intensities were weaker in MAM than in MNM. From these findings, indigenous bacteria were confirmed to preferentially settle on the intestinal superficial epithelium of MAM in the rat ascending colon, and low TLRs-expression might contribute to the preferential settlement of indigenous bacteria in MAM. The increase of proliferating epithelial cells is probably induced by the invasion of indigenous bacteria into the intestinal crypts of MAM.

    JAPAN SOC VET SCI, 2013年07月, JOURNAL OF VETERINARY MEDICAL SCIENCE, 75 (7), 939 - 947, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Histoplanimetrical study on the relationship between invasion of indigenous bacteria into intestinal crypts and proliferation of epithelial cells in rat ascending colon.

    MANTANI YOUHEI, TAKAHARA EI-ICHIRO, TAKEUCHI TAKASHI, KAWANO JUNICHI, YOKOYAMA TOSHIFUMI, HOSHI NOBUHIKO, KITAGAWA HIROSHI

    2013年07月, The Journal of Veterinary Medical Science, 75 (5), 939 - 947, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Junko Tokumoto, Megumi Danjo, Yoshihiro Kobayashi, Kyoko Kinoshita, Takuya Omotehara, Atsutoshi Tatsumi, Mineo Hashiguchi, Tsuneo Sekijima, Hiroshi Kamisoyama, Toshifumi Yokoyama, Hiroshi Kitagawa, Nobuhiko Hoshi

    Clothianidin (CTD) is a neonicotinoid developed in the 1990s as an insecticide having selective toxicity, but it was later found to cause reproductive abnormalities in rats through oxidative stress. There is an attempt to preserve endangered animals, including the Japanese crested ibis, in Japan. However, there is a concern that neonicotinoid affects the reproduction of this bird, since it is used in its habitat. CTD toxicity in the birds is poorly understood, so we investigated whether or not the daily oral administration of CTD has any deleterious effects on the reproductive functions of mature male quails as experimental animals. The animals were randomly divided into four groups of 6 or 7 quails each, treated orally with 0, 0.02, 1 or 50 mg CTD/kg body weight (Control, CTD0.02, CTD1 and CTD50). After that the males bred with untreated females to estimate the egg weights, and rates of fertilization and normal development, the testes, liver and spleen were examined histologically. Vacuolization and the number of germ cells having fragmented DNA in seminiferous tubules, and the number and size of vacuoles in hepatocytes increased dose-dependently. There were no significant differences in egg weights and fertilization rates between the groups, but some eggs of the CTD1 and CTD50 groups failed to develop, and embryonic length decreased dose-dependently. Thus, it was found that CTD affected the reproduction of the male quail through the fragmentation of germ cells and the inhibition or delay of embryonic development.

    JAPAN SOC VET SCI, 2013年06月, JOURNAL OF VETERINARY MEDICAL SCIENCE, 75 (6), 755 - 760, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Immunohistochemical analysis of steroidogenic acute regulatory protein (StAR) and StAR-binding protein (SBP) expressions in the testes of mice during fetal development

    Warita K, Mitsuhashi T, Fukui S, Ohta K, Suzuki S, Miki T, Takeuchi Y, YOKOYAMA TOSHIFUMI, KITAGAWA HIROSHI, Sugawara T, HOSHI NOBUHIKO

    2013年05月, Reproductive Biology, 13 (1), 92 - 95, 英語

    [査読有り][招待有り]

    研究論文(学術雑誌)

  • Katsuhiko Warita, Tomoko Mitsuhashi, Shiho Fukui, Ken-ichi Ohta, Shingo Suzuki, Takanori Miki, Yoshiki Takeuchi, Toshifumi Yokoyama, Hiroshi Kitagawa, Teruo Sugawara, Nobuhiko Hoshi

    The expression patterns of steroidogenic acute regulatory protein (StAR) and StAR-binding protein (SSP) in fetal Leydig cells were compared by using immunohistochemistry. While StAR immunoreactivity was detected during the first steps of testis differentiation, SBP expression was detected slightly later. The timing of SBP expression closely correlated with that of the testosterone surge, an event which is known to induce masculinization. Our results suggest that SBP plays an important role in male sexual development via interactions with StAR. (C) 2013 Society for Biology of Reproduction & the Institute of Animal Reproduction and Food Research of Polish Academy of Sciences in Olsztyn. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

    INST ANIMAL REPRODUCTION FOOD RESEARCH, 2013年03月, REPRODUCTIVE BIOLOGY, 13 (1), 92 - 95, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Differential effects of neonatal maternal separation on the expression of neurotrophic factors in rat brain. II: Regional differences in the cerebellum versus the cerebral cortex.

    Takanori Miki, Kyoung-Youl Lee, Toshifumi Yokoyama, Jun-Qian Liu, Takashi Kusaka, Shingo Suzuki, Ken-ichi Ohta, Katsuhiko Warita, Mostofa Jamal, Masaaki Ueki, Tomiko Yakura, Naohisa Hosomi, Yoshiki Takeuchi

    This study was conducted in order to examine the effects of early postnatal maternal separation stress on the age-dependent fluctuations in the expression levels of neurotrophic factor ligands and receptors in the developing cerebellum. Wistar rats were separated from their mothers for 3 h each day during postnatal days (PND) 10 to 15. The expression level of mRNA for brain-derived neurotrophic factor (BDNF), tyrosine kinase receptor B (TrkB), insulin-like growth factor-1 (IGF-1), and type-1 IGF receptor (IGF-1R) were evaluated in the cerebellum on PND16, 20, 30, and 60 with real-time RT-PCR. The mRNA levels of cerebellar BDNF in maternally separated rats were increased on PND16, while the other variables showed no significant alterations at any of the time points examined. However, the effects of an identical maternal separation on the cerebral cortex were previously reported to be completely different. These results indicate regional differences in the responses of neurotrophic factor ligands/receptors between the cerebellum and cerebral cortex. Given that neurotrophic factors play important roles in brain development, alterations in these factors may interrupt normal brain development and ultimately, lead to functional disruptions.

    2013年, Okajimas folia anatomica Japonica, 90 (3), 53 - 8, 英語, 国内誌

    研究論文(学術雑誌)

  • Midori Yuji, Masato Fujimoto, Wang-Mei Qi, Ei-ichirou Takahara, Youhei Mantani, Kankanam Gamage Sanath Udayanga, Takashi Takeuchi, Katsuhiko Warita, Toshifumi Yokoyama, Nobuhiko Hoshi, Hiroshi Kitagawa

    Previously, the specific antibody-mediated persorption of antigenic molecules and particulates from the small-intestinal lumen into the peripheral blood was clarified in rats, but the intermediation of the receptor for the specific antibodies was not. In this study, the existence of receptor for the specific antibody was experimentally examined in the rat small intestine. Glutaraldehyde-fixed sheep erythrocytes (SEs) coated by Fc-fragments of IgG (IgG-Fc), (Fab')(2)-fragments of IgG (IgG-Fab) or bovine serum albumin (BSA), were injected into 3 jejunal loops each 2 cm in length in non-orally pre-immunized rats, respectively. Thirty minutes after the injection, IgG-Fc-coated SEs were significantly more engulfed by villous columnar epithelial cells than Fab- or BSA-coated SEs. The most frequent absorption sites were the intestinal villous apices. The IgG-Fc-coated SEs were adhered to the striated borders and were engulfed by villous columnar epithelial cells. IgG-Fc-coated SEs passing through the epithelial cells were also detected in the subepithelial blood capillaries just beneath the villous epithelium, but not in the connective tissue and the lymph vessels. These findings suggest that the absorption of luminal antigenic particulates is probably mediated by the Fc-receptor, and that the absorbed antigenic particulates are directly transferred to the hepatic portal blood by passing through the endothelium of the subepithelial blood capillaries.

    JAPAN SOC VET SCI, 2012年11月, JOURNAL OF VETERINARY MEDICAL SCIENCE, 74 (11), 1447 - 1452, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Youhei Mantani, Yuh Yokoo, Aosa Kamezaki, Kankanam Gamage Sanath Udayanga, Ei-ichirou Takahara, Takashi Takeuchi, Junichi Kawano, Toshifumi Yokoyama, Nobuhiko Hoshi, Hiroshi Kitagawa

    Localization of Toll-like receptors (TLRs) in the exocrine glands associated with the rat alimentary tract was immunohistochemically studied using anti-TLR antibodies. TLR-2, -4 and -9 were detected in the secretory granules of acinar cells or the luminal substances of the gustatory gland, extraorbital lacrimal gland, Harderian gland, proper gastric gland and pancreas. TLR-2 and -9 were also detected in the mucous acinar cells of the sublingual gland. Positivity for all TLRs was found in the striated borders of columnar epithelial cells and the luminal substances of the intestinal crypts throughout the small intestine, and also in the goblet cells throughout the large intestine. Only TLR-4 was detected in the secretory granules of Paneth cells. A reduction of TLR-4-positive secretory granules and the formation of TLR-4-positive vacuoles were found in the ileal Paneth cells under the hyper-proliferation of indigenous bacteria. In the apical to middle intervillous portions of the ileum, Gram-positive bacterial colonies were significantly more abundant than Gram-negative bacterial colonies, whereas this difference disappeared in the basal intervillous portions. These findings suggest that there are distribution differences in the secretory sources of soluble TLRs that possibly neutralize their luminal ligands, in the rat alimentary tract. Therefore, the bacterial ligand-recognition system composed of the membranous TLRs of villous columnar epithelial cells and soluble TLRs from crypt epithelial cells might contribute to host defense mechanisms for the selective elimination of Gram-positive bacteria rather than Gram-negative bacteria in the rat small intestine.

    JAPAN SOC VET SCI, 2012年11月, JOURNAL OF VETERINARY MEDICAL SCIENCE, 74 (11), 1429 - 1438, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Kankanam Gamage Sanath Udayanga, Kyoji Yamamoto, Hidenori Miyata, Yuh Yokoo, Youhei Mantani, Ei-ichrou Takahara, Junichi Kawano, Toshifumi Yokoyama, Nobuhiko Hoshi, Hiroshi Kitagawa

    The apoptosis process in rat esophageal epithelium was investigated using enzyme-immunohistochemistry and transmission electron microscopy. As a result, Fas and Fas-L were expressed in the epithelial cell membrane and cytoplasm from the stratum spinosum (SS) to the stratum granulosum (SG). No TNF-R1 show immunopositivity in the cell membranes. TNF-alpha and caspase-8 were not observed in any layer. Caspase-10, cleaved caspase-3, XIAP and DNase-1 were found in the epithelial cytoplasm from the SS to the SG, whereas Bid, Apaf-1 and cleaved caspase-9 were detected only in the SG. Cytochrome c was observed as cytoplasmic granular positivity from the stratum basale (SB) and altered into homogeneous immunopositivity in the SG. Bcl-2 and Bcl-X immunopositivity was detected in cytoplasm from the SB to the SG. Immunoreactions of Bak in the cytoplasm and Bax beneath the cell membrane were observed from the upper portion of the SS with increasing intensity toward the SG. In the sites with the hyperproliferation of indigenous bacteria, TNF-R1, TNF-alpha and caspase-8 were detected in the SG and the immunopositive intensities of Bid, Apaf-1 and cleaved caspase-9 were altered to be strong. Prominently swollen cells and decreased mitochondria were ultrastructurally confirmed in the uppermost layers of stratum corneum. These findings suggest that the Fas-Fas-L-interaction initially induces apoptosis through a mitochondria-independent pathway and secondarily through a mitochondria-dependent pathway, leading to eventual epithelial cell death in the rat esophageal epithelium. The bacterial stimuli probably enhance the mitochondria-dependent pathway through the TNF-R1-TNF-alpha interaction.

    JAPAN SOC VET SCI, 2012年05月, JOURNAL OF VETERINARY MEDICAL SCIENCE, 74 (5), 597 - 605, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Kyoung-Youl Lee, Takanori Miki, Toshifumi Yokoyama, Masaaki Ueki, Katsuhiko Warita, Shingo Suzuki, Ken-Ichi Ohta, Zhi-Yu Wang, Mostofa Jamal, Tomiko Yakura, Jun-Qian Liu, Naohisa Hosomi, Yoshiki Takeuchi

    Aims: This study was carried out to examine the effects of early postnatal maternal separation stress on the development of the cerebral cortex with respect to time-dependent fluctuations of neurotrophic factor ligand and receptor expression. Main methods: Wistar rats were separated from their mothers for 3 h per day during postnatal days (PND) 10 to 15. The cerebral cortex was analyzed by real-time RT-PCR for the evaluation of the expression of mRNA for brain-derived neurotrophic factor (BDNF), TrkB, insulin-like growth factor-1 (IGF-1), and type 1 IGF receptor (IGF-1R) on PND16, 20, 30, and 60. Key findings: The expression of these neurotrophic factor ligands and receptors in the cerebral cortex was enhanced on PND16 and PND20, and then it returned to baseline levels on PND30. By PND60, however, the expression levels were attenuated. Significance: The important implication of this study is the persistent abnormal fluctuation of neurotrophic factor expression for a prolonged period, triggered even after the brain growth spurt. Given that neurotrophic factors play important roles in brain development, it can be speculated that the altered expression of these factors induced by maternal separation may interrupt normal brain development and ultimately lead to functional disruption. However, the possibility of such changes leading to various functional disruptions and the underlying mechanisms involved require further study. (c) 2012 Elsevier Inc. All rights reserved.

    PERGAMON-ELSEVIER SCIENCE LTD, 2012年04月, LIFE SCIENCES, 90 (15-16), 578 - 584, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Hiroko Ishiniwa, Kazuhiro Sogawa, Ken-ichi Yasumoto, Nobuhiko Hoshi, Toshifumi Yokoyama, Ken Tasaka, Tsuneo Sekijim

    InTech, 2012年02月, Immunosuppression - Role in Health and Diseases

    [査読有り]

  • Site differences of Toll-like receptor expression in the mucous epithelium of rat small intestine

    Youhei Mantani, Aosa Kamezaki, Kankanam Gamage Sanath Udayanga, Ei-ichirou Takahara, Wang-Mei Qi, Junichi Kawano, Toshifumi Yokoyama, Nobuhiko Hoshi, Hiroshi Kitagawa

    Toll-like receptors (TLRs) are known to recognize pathogen-associated molecular patterns and might function as receptors to detect microbes. In this study, the distribution of TLR-2, -4 and -9 were immunohistochemically investigated in the rat small intestine. As a result, TLR-2 was detected in the striated borders of villous columnar epithelial cells throughout the small intestine, except for the apices of a small number of intestinal villi. TLR-4 and -9 were detected in the striated borders of the villous columnar epithelial cells only in the duodenum. TLR-4-immunopositive minute granules were found in the apical cytoplasms of epithelial cells, subepithelial spaces and blood capillary lumina. TLR-2 and -4 were detected in the striated borders of undifferentiated epithelial cells and in the luminal substances of the intestinal crypts throughout the small intestine, but TLR-9 was not detected in the crypts throughout the small intestine. Only TLR-4 was detected in the secretory granules of Paneth cells in both the jejunal and ileal intestinal crypts. These findings suggest that duodenal TLRs might monitor indigenous bacteria proliferation in the upper alimentary tract, that TLR-2 might also monitor the proliferation of colonized indigenous bacteria throughout the small intestine, that the lack of TLR-2 at the villous apices might contribute to the settlement of indigenous bacteria, and that TLR-2 and -4 are secreted from intestinal crypts.

    F HERNANDEZ, 2011年10月, HISTOLOGY AND HISTOPATHOLOGY, 26 (10), 1295 - 1303, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Zhi-Yu Wang, Takanori Miki, Yan Ding, Shi-Jie Wang, Yu-Huan Gao, Xiao-Ling Wang, Yu-Hua Wang, Toshifumi Yokoyama, Katsuhiko Warita, Ken-ichi Ohta, Shingo Suzuki, Taira Ohnishi, Takashi Obama, Kuldip S. Bedi, Yoshiki Takeuchi, Bao-En Shan

    Apolipoprotein E (apoE) is one of the major transporters of cholesterol in the body and is essential for maintaining various neural functions in the brain. Given that hypercholesterolemia is a risk factor in Alzheimer's disease (AD), it has been suggested that altered cholesterol metabolism may be involved in the development of the pathogenesis, including neural degeneration, commonly observed in AD patients. Neurotrophic factors and their receptors, which are known to regulate various neural functions, are also known to be altered in various neurodegenerative diseases. We therefore hypothesized that cholesterol metabolism may itself influence the neurotrophin system within the brain. We decided to investigate this possibility by modulating the amount of dietary cholesterol given to apoE-knockout (apoE-KO) and wild-type (WT) mice, and examining the mRNA expression of various neurotrophin ligands and receptors in their hippocampal formations. Groups of eight-week-old apoE-KO and WT mice were fed a diet containing either "high" (HCD) or "normal" (ND) levels of cholesterol for a period of 12 weeks. We found that high dietary cholesterol intake elevated BDNF mRNA expression in both apoE-KO and WT mice and TrkB mRNA expression in apoE-KO animals. On the other hand, NGF and TrkA mRNA levels remained unchanged irrespective of both diet and mouse type. These findings indicate that altered cholesterol metabolism induced by HCD ingestion combined with apoE deficiency can elicit a differential response in the various neurotrophin ligand/receptor systems in the mouse hippocampus. Whether such changes can lead to neural degeneration, and the mechanisms that may be involved in this, awaits further research.

    SPRINGER/PLENUM PUBLISHERS, 2011年09月, METABOLIC BRAIN DISEASE, 26 (3), 185 - 194, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Immunohistochemical and Histoplanimetrical Study on the Spatial Relationship between the Settlement of Indigenous Bacteria and the Secretion of Bactericidal Peptides in Rat Alimentary Tract

    Yuh Yokoo, Hidenori Miyata, Kankanam Gamage Sanath Udayanga, Wang-Mei Qi, Ei-ichirou Takahara, Youhei Mantani, Toshifumi Yokoyama, Junichi Kawano, Nobuhiko Hoshi, Hiroshi Kitagawa

    To clarify the regulatory mechanism by bactericidal peptides secretion, the secretion of bactericidal peptides was immunohistochemically and histoplanimetrically compared with the degree of Gram-positive/negative bacterial colonization throughout the rat alimentary tract. In the associated exocrine glands from the oral cavity to the stomach, no comparable differences were observed under the changes of development of indigenous bacterial colonies. In the small intestine, immunopositive granules for lysozyme and secretory phospholipase A2 (sPLA2) were markedly decreased, whereas immunopositive vacuoles in the Paneth cells were more increased at sites with hyper-development of indigenous bacterial colonies in the intervillous spaces than at sites with no or less development. No changes in exocrine glands were observed in the large intestine because of the constant existence of large quantities of bacteria. Gram-positive bacterial colonies on the mucosal surfaces were dominant from the oral cavity to the stomach. Gram-negative bacteria were dominant in the large intestine, and the distributions of both Gram-positive and negative bacteria were intermediate in the small intestine. These findings suggest that lysozyme and sPLA2 secreted from the Paneth cells contribute to the regulation of the proliferation of indigenous bacteria in the intervillous spaces of the small intestine, and that the inversion of distributions of Gram-positive and -negative bacteria in the alimentary tract might be caused by the secretion of lysozyme and sPLA2 in the small intestine.

    JAPAN SOC VET SCI, 2011年08月, JOURNAL OF VETERINARY MEDICAL SCIENCE, 73 (8), 1043 - 1050, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Immunohistochemical study of the apoptosis process in epidermal epithelial cells of rats under a physiological condition

    K. G. S. Udayanga, H. Miyata, Y. Yokoo, W. -M. Qi, E. Takahara, Y. Mantani, T. Yokoyama, N. Hoshi, H. Kitagawa

    Epidermal homeostasis is maintained by both epithelial proliferation in the stratum basale (SB) and the apoptosis of epithelial cells under physiological conditions. In this study, the induction and regulation mechanisms of epidermal apoptosis were immunohistochemically investigated in the epidermis from Wistar rat's palm and foot pad by using several apoptotic related proteins under a physiological condition. The results showed that Fas and Fas-L were expressed in cellular membranes of the stratum spinosum (SS), whereas TNF-R1 did not show any membranous expression in any epidermal layers. TNF-alpha was not observed in the epidermis. Caspase-10, cleaved caspase-3 and DNase-1 were found in the epithelial cytoplasms from the SS to stratum granulosum (SG), whereas caspase-8 was not detected in the epidermis. XIAP and Bak were found in the cytoplasm from the SS to SG, and the intensity of Bak-positivity was stronger in the SG than the SS, whereas Bid, Apaf-1 and cleaved caspase-9 were restricted in the SG. Homogenous cytoplasmic immunoreactivity of Bcl-2 was found in the SB and the intensity was gradually decreased from the SB to the SG. The granular-cytoplasmic immuno-positivity of cytochrome C gradually altered into homogenous cytoplasmic expression in the upper half of the SG. Single-stranded DNA was rarely detected in the upper portion of the SG. These results suggest that epidermal apoptosis is induced by the interaction between Fas and Fas-L and the activation of caspase-10, and might initially proceed through a mitochondrial-independent pathway, and that a mitochondrial-dependent pathway finally accelerated under physiological conditions.

    F HERNANDEZ, 2011年07月, HISTOLOGY AND HISTOPATHOLOGY, 26 (7), 811 - 820, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Toshifumi Yokoyama, Takahiko Etoh, Kankanam Gamage Sanath Udayanga, Eiichiro Takahara, Wang-Mei Qi, Katsuhiko Warita, Yoshiki Matsumoto, Takanori Miki, Yoshiki Takeuchi, Nobuhiko Hoshi, Hiroshi Kitagawa

    The hypothesis that apoptotic factors play some roles in the denucleation of erythroblasts has been confirmed by the immunohistological detection of both phosphatidylserine and thrombospondin as phagocytosis-inducing factors in general apoptotic events. Both phosphatidylserine and thrombospondin were detected on the surface of cell membrane of mature erythroblasts, while thrombospondin was also detected in more immature erythroblasts. The intensities of their immune reactions increased as the erythroids matured. During denucleation, the positivities of both phosphatidylserine and thrombospondin were restricted on the surface of the cell membrane surrounding the protruding nuclei. Thus, the apoptotic process involves denucleation of erythroblasts and phosphatidylserine, and thrombospondin acts as phagocytosis-inducing factors in the denucleation event.

    JAPAN SOC VET SCI, 2011年07月, JOURNAL OF VETERINARY MEDICAL SCIENCE, 73 (7), 949 - 952, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Yuh Yokoo, Hidenori Miyata, Kankanam Gamage Sanath Udayanga, Wang-Me Qi, Ei-ichioru Takahara, Toshifumi Yokoyama, Junichi Kawano, Nobuhiko Hoshi, Hiroshi Kitagawa

    To clarify the fundamental regulation mechanism against indigenous bacterial proliferation in the alimentary tract, we immunohistochemically examined the localization of 4 bactericidal peptides (BP) in the rat digestive exocrine glands. In the upper alimentary tract, lysozyme was detected in the gustatory, extraorbital lacrimal and parotid glands. Secretory phospholipase A2 (sPLA2) was detected in the extraorbital lacrimal glands. β -defensin1 was detected in the gustatory and extraorbital lacrimal glands. β -defensin2 was detected in the Harderian glands. In the stomach, β -defensins were detected in the gastric superficial epithelial cells. In the small and large intestines, only lysozyme and sPLA2 were detected in the Paneth cells. In the cecum, all 4 BP were detected in the middle to apical portions of the crypts, and only sPLA2 was detected in the basal portion. No BP were localized in other exocrine glands associated with the alimentary tract. In addition, all 4 BP were also detected in the columnar epithelial cells of the apical portions of intestinal villi. In the intestinal superficial epithelial cells, lysozyme and β -defensins were detected in the ascending colon, whereas only β -defensin1 was detected in the descending colon and rectum. These results suggest that BP are mainly secreted from exocrine tissues in the initial portion of the digestive tract and play a role in host defense against indigenous bacteria throughout the digestive tract. Part of the BP in the chyme might be absorbed by the epithelium at the most inner sites of mucosae in the small and large intestines.

    2011年02月, Journal of Veterinary Medical Science, 73 (2), 217 - 225, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Lectin Histochemical Detection of Special Sugars on the Mucosal Surfaces of the Rat Alimentary Tract

    Kenkichi Yamamoto, Wang-Mei Qi, Yuh Yokoo, Hidenori Miyata, Kankanam Gamage Sanath Udayanga, Junichi Kawano, Toshifumi Yokoyama, Nobuhiko Hoshi, Hiroshi Kitagawa

    Surfaces of the most luminal positions of mucosae are fundamental settlement sites of indigenous bacteria throughout the rat alimentary tract. In these positions, also epithelial cell-shedding sites, the special sugar expression in the glycocalyx is very important as it provides possible ligands of bacterial lectins for attachment to epithelial cells. Therefore, the sugar expression in glycocalyx of epithelial cells was lectin-histochemically surveyed using 21 lectins throughout the rat alimentary tract. From the tongue to the nonglandular part of the stomach, alpha-D-Man, alpha-D-Glc and alpha-D-GalNAc were detected on the surface of the keratinized stratified squamous epithelium. In the glandular part of the stomach, alpha-D-Man, beta-D-Gal-4GlcNAc, D-Gal, D-GalNAc, D-GlcNAc, alpha-L-Fuc-alpha-D-Gal-beta(1-4)GlcNAc and bisected triantennary N-glycans were detected on the surface of gastric superficial epithelial cells. From the duodenum to the ileum, (GlcNAc)(2-4) was expressed exclusively on the epithelial cells in the apical portions of the intestinal villi. From the cecum to the rectum, alpha-D-Man, beta-D-Gal-4GlcNAc, D-Gal, D-GalNAc, alpha-D-Gal(1-3)D-GalNAc, (GalNAc)(n) and NeuNAc were expressed on the intestinal superficial epithelial cells. These results suggest that special sugars are expressed on the most luminal portions of mucosae as exclusive epithelial cell-shedding sites, and that sugar expression differs among the various segments of the alimentary tract. These site differences might reflect differences in resident bacterial species in the rat alimentary tract.

    JAPAN SOC VET SCI, 2010年09月, JOURNAL OF VETERINARY MEDICAL SCIENCE, 72 (9), 1119 - 1127, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Katsuhiko Warita, Tomoko Mitsuhashi, Teruo Sugawara, Yoshiaki Tabuchi, Takashi Tanida, Zhi-Yu Wang, Yoshiki Matsumoto, Toshifumi Yokoyama, Hiroshi Kitagawa, Takanori Miki, Yoshiki Takeuchi, Nobuhiko Hoshi

    Aims: To investigate the precise mechanisms underlying the action of estrogenic endocrine disruptors, we evaluated the direct effects of synthetic estrogen diethylstilbestrol (DES) on steroidogenesis in Leydig cells, with particular emphasis on the expression of the cholesterol side-chain cleavage enzyme P450scc. Furthermore, the mechanism underlying the action of DES was compared with that of endogenous estrogen 17 beta-estradiol (E2), which has a potency equivalent to that of DES.Main methods: TTE1 Leydig cells were treated with 5 x 10(-8) mu M to 5 mu M DES or E2 for 24 h, and P450scc gene expression and the histone modifications underlying their transcriptional activation were examined using reverse transcription-polymerase chain reaction (RT-PCR) and chromatin immunoprecipitation (ChIP), respectively.Key findings: P450scc mRNA expression in the DES-treated and E2-treated cells reduced in inverse proportion to the dose of DES and E2, respectively; however, cAMP stimulation induced a recovery in the expression to a level approximately equal to those in the controls. In the DES-treated cells, ChIP assay revealed histone deacetylation in the P450scc promoter region. Interestingly, E2 did not cause histone deacetylation.Significance: In the early stages of steroidogenesis, DES and E2 directly induced a reduction in P450scc mRNA expression in inverse proportion to their doses, and treatment with CAMP restored the decreased P450scc mRNA expression. Furthermore, DES can induce alterations in the histone modification of the P450scc gene, and natural estrogen and synthetic estrogenic compounds such as DES may induce reproductive disorders through different molecular mechanisms. (C) 2010 Elsevier Inc. All rights reserved.

    PERGAMON-ELSEVIER SCIENCE LTD, 2010年08月, LIFE SCIENCES, 87 (9-10), 281 - 285, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Tomoko Mitsuhashi, Katsuhiko Warita, Teruo Sugawara, Yoshiaki Tabuchi, Ichiro Takasaki, Takashi Kondo, Fumio Hayashi, Zhi-Yu Wang, Yoshiki Matsumoto, Takanori Miki, Yoshiki Takeuchi, Yasuhiko Ebina, Hideto Yamada, Noriaki Sakuragi, Toshifumi Yokoyama, Takashi Nanmori, Hiroshi Kitagawa, Jeffrey A. Kant, Nobuhiko Hoshi

    In normal ontogenetic development, the expression of the sex-determining region of the Y chromosome (SRY) gene, involved in the first step of male sex differentiation, is spatiotemporally regulated in an elaborate fashion. SRY is expressed in germ cells and Sertoli cells in adult testes. However, only few reports have focused on the expressions of SRY and the other sex-determining genes in both the classical organ developing through these genes (gonad) and the peripheral tissue (skin) of adult XY females. In this study, we examined the gonadal tissue and fibroblasts of a 17-year-old woman suspected of having disorders of sexual differentiation by cytogenetic, histological, and molecular analyses. The patient was found to have the 46,X,inv(Y)(p11.2q11.2) karyotype and streak gonads with abnormally prolonged SRY expression. The sex-determining gene expressions in the patient-derived fibroblasts were significantly changed relative to those from a normal male. Further, the acetylated histone H3 levels in the SRY region were significantly high relative to those of the normal male. As SRY is epistatic in the sex-determination pathway, the prolonged SRY expression possibly induced a destabilizing effect on the expressions of the downstream sex-determining genes. Collectively, alterations in the sex-determining gene expressions persisted in association with disorders of sexual differentiation not only in the streak gonads but also in the skin of the patient. The findings suggest that correct regulation of SRY expression is crucial for normal male sex differentiation, even if SRY is translated normally.

    WILEY, 2010年06月, CONGENITAL ANOMALIES, 50 (2), 85 - 94, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Tomoko Mitsuhashi, Katsuhiko Warita, Yoshiaki Tabuchi, Ichiro Takasaki, Takashi Kondo, Teruo Sugawara, Fumio Hayashi, Zhi-Yu Wang, Yoshiki Matsumoto, Takanori Miki, Yoshiki Takeuchi, Yasuhiko Ebina, Hideto Yamada, Noriaki Sakuragi, Toshifumi Yokoyama, Takashi Nanmori, Hiroshi Kitagawa, Jeffrey A. Kant, Nobuhiko Hoshi

    XY females are rare individuals who carry a Y chromosome but are phenotypically female. In approximately 80-90% of these cases, there are no mutations in the SRY gene, a testis-determining gene on the short arm of the Y chromosome, and the pathophysiology of XY females without SRY mutation remains unclear. In the present study, we used a molecular data mining technique to analyze the pathophysiology of an XY female with functional SRY and pericentric inversion of the Y chromosome, and compared the results with those of a normal male. Interestingly, upregulations of numerous genes included in the development category of the Biological Process ontology, including genes associated with sex determination and organ morphogenesis, were seen in the patient. Additionally, the transforming growth factor-beta (TGF-beta) signaling pathway and Wnt signaling pathway, in which most cell-cell interactions during embryonic development are involved, were altered. Alterations in the expression of numerous genes at the developmental stage, including alterations at both the gene and pathway levels, may persist as a vestige of anomalies of sex differentiation that presumably began in the fetal period. The present study indicates that a data mining technique using bioinformatics contributes to identification of not only genes responsible for birth defects, but also disorders of sex development (DSD)-specific pathways, and that this kind of analysis is an important tool for clarifying the pathophysiology of human idiopathic XY gonadal dysgenesis. Our findings could serve as one of the basic datasets which will be used for future follow-up investigations.

    WILEY, 2010年03月, CONGENITAL ANOMALIES, 50 (1), 40 - 51, 英語

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    研究論文(学術雑誌)

  • Z. Y. Wang, T. Miki, K. Y. Lee, T. Yokoyama, T. Kusaka, K. Sumitani, K. Warita, Y. Matsumoto, T. Yakura, N. Hosomi, K. Ameno, K. S. Bedi, Y. Takeuchi

    Alcohol ingestion affects both neuropsychological and motor functions. We hypothesized that one of the key factors involved in such functions are neurotrophins and their receptors. We have therefore examined the effects of short-term ethanol exposure on the mRNA expression and protein levels of neurotrophin ligands and receptors in the cerebellum using real-time RT-PCR and Western blotting techniques. Male BALB/C mice were fed a liquid diet containing 5% (v/v) ethanol. The pair-fed control mice were fed an identical liquid diet except that sucrose was substituted isocalorically for ethanol. The cerebellum of mice exhibiting intoxication signs of stage I or 2 were used in the present study. We found that exposure to ethanol resulted in elevated levels of nerve growth factor (NGF) and TrkA mRNA expression but a decreased level of brain-derived neurotrophic factor (BDNF) mRNA expression. The expression of TrkB and p73 mRNA was unchanged. Changes in the level of these proteins were found to mirror these mRNA expression levels. We conclude that exposure to ethanol for a short period can cause a differential responsive in the various neurotrophin ligand/receptor systems. The functional consequences of these changes are unknown at present. (C) 2010 IBRO. Published by Elsevier Ltd. All rights reserved.

    PERGAMON-ELSEVIER SCIENCE LTD, 2010年01月, NEUROSCIENCE, 165 (2), 485 - 491, 英語

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    研究論文(学術雑誌)

  • GABA expression in c-Fos immunoreactive neurons of the rat periaqueductal gray induced by electroacupuncture at the point of Zusanli

    FUSUMADA Kazutoshi, YOKOYAMA Toshifumi, MIKI Takanori, MATSUMOTO Yoshiki, WARITA Katsuhiko, WANG Zhiyu, YAKURA Tomiko, LIU JQ, TAKEUCHI Yoshiki

    2010年, Current Neurobiology, 1, pp.10-13 (1), 10 - 13, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Effectts of short-term ethanol ingestion on the expression of neurotrophins and their receptors: No changes in the expression of the glial-derived neurotrophic factor in the mouse hippocampus

    UENO Masaki, MIKI Takanori, WANG Zhiyu, YOKOYAMA Toshifumi, LEE Kyong-Youl, KUSAKA Takashi, WARITA Katsuhiko, SUMITANI Kazunori, MATSUMOTO Yoshiki, YAKURA Tomiko, LIU JQ, BEDI Kuldip S, TAKEUCHI Yoshiki

    2010年, Current Neurobiology, 1, pp.40-45 (1), 40 - 45, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Kana Ishihara, Seiichiroh Ohsako, Ken Tasaka, Hiroshi Harayama, Masashi Miyake, Katsuhiko Warita, Takashi Tanida, Tomoko Mitsuhashi, Takashi Nanmori, Yoshiaki Tabuchi, Toshifumi Yokoyama, Hiroshi Kitagawa, Nobuhiko Hoshi

    Recent animal experiments confirmed that paternal 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) exposure decreases the sex ratio of offspring at birth without altering litter size. However, the timing of this decrease remained unclear. Male mice were administered TCDD at 7-12 weeks of age and mated with non-treated females. The Y-bearing/X-bearing sperm ratio was examined by real-time PCR and FISH methods, and the sex ratio of the 2-cell embryos collected from non-treated females that had been mated with TCDD-exposed males were investigated by nested PCR. The Y-bearing/X-bearing sperm ratio was not significantly decreased in the TCDD group. However, the sex ratio of the 2-cell embryos of the TCDD group was significantly lower than that of the control group. These results may have resulted from a decrease in fertility of Y-bearing sperm. Thus, the results of this study suggested that the sex ratio of the offspring was decreased at fertilization and not during the spermatozoa stage. (C) 2009 Elsevier Inc. All rights reserved.

    PERGAMON-ELSEVIER SCIENCE LTD, 2010年01月, REPRODUCTIVE TOXICOLOGY, 29 (1), 68 - 73, 英語

    [査読有り]

    研究論文(学術雑誌)

  • TANIDA TAKASHI, WARITA KATSUHIKO, ISHIHARA KANA, FUKUI SHIHO, MITSUHASHI TOMOKO, SUGAWARA TERUO, TABUSHI YOSHIAKI, NANMORI TAKASHI, QI WANG-MEI, INAMOTO TETSUROU, YOKOYAMA TOSHIFUMI, KITAGAWA HIROSHI, HOSHI NOBUHIKO

    A major question is whether exposure to mixtures of low-dose endocrine disruptors (EDs) having different action mechanisms affects neurodevelopment differently than exposure to EDs individually. We therefore investigated the effects of fetal and neonatal exposure to three typical EDs - bisphenol A (BPA), di-(2-ethylhexyl)-phthalate (DEHP), and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) - on the midbrain dopaminergic system associated with functions - including motor activity, emotion, and cognition affected by neuropsychiatric diseases such as attention-deficit/hyperactivity disorder. ICR mouse dams and their pups were orally treated with BPA (5 mg/(kgday)), DEHP (1 mg/(kgday)), or TCDD (8ng/kg) individually, or with mixtures thereof, to compare the effects between sole and mixed administration. We analyzed tyrosine hydroxylase (TH)- and Fos-immunoreactive (it) neurons as markers of dopamine and neuronal activation, respectively. The numbers of TH- and/or Fos-ir neurons and the intensity of TH-immunoreactivity within midbrain dopaminergic nuclei (A9, A10, and A8) of each sole administration group significantly differed from controls at 2, 4, and 6 weeks of age. In contrast, no significant differences were detected in the mixture groups, suggesting counteractions among those chemicals. These results indicate that ED mixtures as pollution have unique and elusive effects. Thyroid hormones and/or aryl hydrocarbon receptor-related mechanisms may be responsible for this counteraction. (C) 2009 Published by Elsevier Ireland Ltd.

    ELSEVIER IRELAND LTD, 2009年08月, Toxicology Letters, 189 (1), 40 - 47, 英語

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    研究論文(学術雑誌)

  • Morphological Analyses of Sex Differences and Age-Related Changes in C3H Mouse Midbrain

    Takashi Tanida, Katsuhiko Warita, Tomoko Mitsuhashi, Kana Ishihara, Toshifumi Yokoyama, Hiroshi Kitagawa, Nobuhiko Hoshi

    While it is commonly hypothesized that sexual differentiation in the mammalian brain is initiated mainly by gonadal sex steroids, recent evidence has suggested that dopaminergic (DA) neurons within the rodent midbrain have sex differences independent of gonadal secretions. More recently, it has been reported that Sty (the sex-determining region of the Y chromosome) is directly involved in this difference. The possibility of sexual dimorphism in the mouse midbrain needs to be elucidated. In the present Study, the midbrain of C3H mice, which is little understood, was investigated histologically and immuno-histoplanimetrically to reveal sexual and developmental differences. The female ventral tegmental area appeared to contain higher immunoreactivity to tyrosine hydroxylase (TH) than that of males at 11 weeks of age, whereas general histological differences between the sexes were not clearly found. The TH-immunoreactive (TH-ir) neurons within the A8, A9, and A10 mesencephalic areas were examined separately. There was the sex difference in the time period when TH-ir cell numbers significantly increased, indicating that the growth rate of midbrain DA nuclei also differs and that the midbrain DA system may trace different processes of sexual maturation between the sexes. These differences between female and male may reflect the direct regulation by Sry or the multiple effects of both Sty and sex steroids. Further experiments are needed to determine which factor forms this difference in the growth pattern in the numbers of TH-ir neurons.

    JAPAN SOC VET SCI, 2009年07月, JOURNAL OF VETERINARY MEDICAL SCIENCE, 71 (7), 855 - 863, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Histoplanimetrical Study on the Relationship between Cellular Kinetics of Epithelial Cells and Proliferation of Indigenous Bacteria in the Rat Colon

    Wang-Mei Qi, Kenkichi Yamamoto, Yuh Yokoo, Hidenori Miyata, Kankanam Gamage Sanath Udayanga, Junichi Kawano, Toshifumi Yokoyama, Nobuhiko Hoshi, Hiroshi Kitagawa

    The aim of this study was to clarify the regulatory effects of epithelial kinetics on indigenous bacterial proliferation in the large intestine. The lifespan, migration speed and proliferation rate of crypt epithelial cells in the initial 20% of the colon (proximal colon) and the 50% of the colon (middle colon) in bromodeoxyuridine-administrated rats were histoplanimetrically and chronologically compared. The proximal colon possessed well-developed mucosal folds and a large amount of indigenous bacteria which filled the crypt lumen, whereas no folds or bacteria were found to occupy the crypt lumen in the middle colon. The cell lifespans were 32.2, 42.5 and 33.6 hr in the apical and the basal parts of the mucosal folds of the proximal colon, and in the middle colon, respectively. The migration speeds were 4.2, 2.1 and 3.3 mu m/hr, respectively, while the appearance frequencies of proliferating cell nuclear antigen (PCNA)-positive crypt epithelial cells were 35.0, 24.6 and 33.8%. These findings suggest that the lifespan was shortened and the migration speed increased in the most luminal mucosa of colon, contributing to the elimination of the adhered bacteria from the most luminal mucosa. By contrast, the elongation of the lifespan and deceleration of the migration of epithelial cells in the basal parts of the mucosal folds might contribute to reliable settlement of indigenous bacteria, resulting in the maintenance of a large amount of indigenous bacteria in the lumen of the proximal colon.

    JAPAN SOC VET SCI, 2009年06月, JOURNAL OF VETERINARY MEDICAL SCIENCE, 71 (6), 745 - 752, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Anterografe synaptic transport of neuronal tracer enzyme (WGA-HRP): Futher studies with Rab3A-siRNA in rats.

    TAKEUCHI YOSHIKI, MATSUMOTO YOSHIKI, MIKI TAKANORI, YOKOYAMA TOSHIFUMI, WARITA KATSUHIKO, WANG ZHI-YU, UENO TAKASHI, YAKURA TOMIKO, FUJITA MAMORU

    2009年05月, Journal of Biomedical Research, 20 (3), 149 - 154, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Histoplanimetrical Study on the Spatial Relationship of Distribution of Indigenous Bacteria with Mucosal Lymphatic Follicles in Alimentary Tract of Rat

    Kenkichi Yamamoto, Wang-Mei Qi, Yuh Yokoo, Hidenori Miyata, Kankanam Gamage Sanath Udayanga, Junichi Kawano, Toshifumi Yokoyama, Nobuhiko Hoshi, Hiroshi Kitagawa

    The spatial relationship between the distribution of indigenous bacteria (IB) and the Situation of mucosal lymphatic follicles (LF) is histoplanimetrically studied in the rat alimentary tract. From the oral cavity to the nonglandular part of the stomach, IB adhered to the corneal layer of the most luminal mucosa. In the glandular part of the stomach, IB adhered only to the most luminal mucosa but not in the gastric pits. In the small intestine, IB consistently adhered around the apices of both intestinal villi and the doilies, and their amounts decreased toward their basal portions. No IB entered the intestinal crypts. In the large intestine, IB consistently adhered to the most luminal mucosa. Numerous IB were Suspended in the intestinal crypts of both the cecum and the proximal colon, whereas there were no IB in the crypts of the distal colon and the rectum. When IB spread over the basal portions of the intestinal villi, IB with the same morphology were detected on the neighboring LF, whereas no bacteria were detected on the neighboring LF, when IB were located in the apical to middle portions of the intestinal villi. This close relationship between the distribution of IB and mucosal LF was also observed in the large intestine. These results Suggest that the most luminal mucosae are a fundamental settlement site of IB throughout the alimentary tract and that the hyperproliferation of IB's colonies might be detected by neighboring LF in the rat intestine.

    JAPAN SOC VET SCI, 2009年05月, JOURNAL OF VETERINARY MEDICAL SCIENCE, 71 (5), 621 - 630, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Histoplanimetrical Study on the Relationship between the Cell Kinetics of Villous Columnar Epithelial Cells and the Proliferation of Indigenous Bacteria in Rat Small Intestine

    Wang-Mei Qi, Kenkichi Yamamoto, Yuh Yokoo, Hidenori Miyata, Tetsurou Inamoto, Kankanam Gamage Sanath Udayanga, Junichi Kawano, Toshifumi Yokoyama, Nobuhiko Hoshi, Hiroshi Kitagawa

    The relationship between the kinetics of villous columnar epithelial cells and the expansion of colonies of indigenous bacteria from the narrow apical portions of intestinal villi was immunohistochemically and histoplanimetrically investigated in the small intestine of bromodeoxyuridine administred Wistar rats. As a result, the lifespan Of villous columnar epithelial cells was slightly shorter in the distal ileum than in other portions of small intestine, accompanying the minimum height of the intestinal villi of the distal ileum in the small intestine. The migration speed of villous columnar epithelial cells was significantly decreased toward the distal small intestine. The migration speed in the distal ileum was about one-fourth of that in the duodenum. The migration speed of the villous columnar epithelial cells was greater and their lifespans were shorter in the sites with Wide expansion of the indigenous bacterial colony from the narrow apical portions of the intestinal villi than that in sites with no or less expansion. Additionally, the expansion of the indigenous bacterial colony from narrow villous apices also immediately shortened the heights of the intestinal villi. These findings suggest that the migration speed of villous columnar epithelial cells might contribute to the regulation of the settlement of bacteria at the villous apices and the inevitable proliferation of indigenous bacteria at the intervillous spaces in the rat small intestine.

    JAPAN SOC VET SCI, 2009年04月, JOURNAL OF VETERINARY MEDICAL SCIENCE, 71 (4), 463 - 470, 英語

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    研究論文(学術雑誌)

  • Yoshiki Takeuchi, Yoshiki Matsumoto, Takanori Miki, Toshifumi Yokoyama, Katsuhiko Warita, Zhi-Yu Wang, Tomiko Yakura, Mamoru Fujita

    Elsevier BV, 2009年01月, Neuroscience Research, 65, S80 - S81

    [査読有り]

    研究論文(学術雑誌)

  • Tetsurou Inamoto, Makiko Namba, Wang-Mei Qi, Kenkichi Yamamoto, Yuh Yokoo, Hidenori Miyata, Junichi Kawano, Toshifumi Yokoyama, Nobuhiko Hoshi, Hiroshi Kitagawa

    The mechanism of physical elimination of indigenous bacteria was ultrastructurally and immunohistochemically investigated in microvillous columnar epithelial cells of Peyer's patches and intestinal villi of the rat jejunoileum. From ultrastructural observation, the microfilaments accumulated to form several electron-dense layers beneath the bacteria adhering to the cell membrane, which was slightly invaginated in the epithelial cells of Peyer's patches and intestinal villi. As the microfilamentous layers were forming, the end portions of invaginations were deformed into a cone-shape and were finally collapsed. At the same time, the end portions of the adhered bacteria were also deformed into cone-shapes. The bacterial cells were moved back toward the invagination orifices with no morphological change in their inner structure. From immunohistochemical observation, beta-actin and nonmuscle-type myosin were detected at the thin layer just beneath the invaginated cell membrane. These findings suggest that indigenous bacteria which adhere to epithelia] cells are removed by only a physical action of actin and myosin filaments, but are not killed. This bacterial cell removal system might lead to the establishment of a settlement of indigenous bacteria on host cells.

    JAPAN SOC VET SCI, 2008年11月, JOURNAL OF VETERINARY MEDICAL SCIENCE, 70 (11), 1153 - 1158, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Takanori Miki, Toshifumi Yokoyama, Kazunori Sumitani, Takashi Kusaka, Katsuhiko Warita, Yoshiki Matsumoto, Zhi-Yu Wang, Peter A Wilce, Kuldip S Bedi, Susumu Itoh, Yoshiki Takeuchi

    Maternal alcohol ingestion during pregnancy adversely affects the developing fetus, often leading to fetal alcohol syndrome (FAS). One of the most severe consequences of FAS is brain damage that is manifested as cognitive, learning, and behavioral deficits. The hippocampus plays a crucial role in such abilities; it is also known as one of the brain regions most vulnerable to ethanol-induced neurotoxicity. Our recent studies using morphometric techniques have further shown that ethanol neurotoxicity appears to affect the development of the dentate gyrus in a region-specific manner; it was found that early postnatal ethanol exposure causes a transitory deficit in the hilus volume of the dentate gyrus. It is strongly speculated that such structural modifications, even transitory ones, appear to result in developmental abnormalities in the brain circuitry and lead to the learning disabilities observed in FAS children. Based on reports on possible factors deciding ethanol neurotoxicity to the brain, we review developmental neurotoxicity to the dentate gyrus of the hippocampal formation.

    3, 2008年09月, Congenital anomalies, 48 (3), 110 - 7, 英語, 国際誌

    [査読有り]

    研究論文(学術雑誌)

  • Tetsurou Inamoto, Yuko Kawata, Wang-Mei Qi, Kenkichi Yamamoto, Katsuhiko Warita, Junichi Kawano, Toshifumi Yokoyama, Nobuhiko Hoshi, Hiroshi Kitagawa

    The ultrastructure of epithelial responses against the membrane adhesion of indigenous bacteria was investigated in the follicle-associated epithelium (FAE) of rat small intestine. The most frequent adherence of the various morphological types of bacteria to the epithelial membranes was found at the apex of the FAE. The attachment sites were deeply invaginated, and their bottoms were deformed into a sharp cone shape. Four layers with different electron densities were formed just beneath the apical membranes by microfilaments which surrounded the invaginations. The electron density of each layer was gradually decreased as being apart from the invaginations. The extremities of some bacteria in the invaginations were deformed into sharpened shapes. The cell walls of the extremities of the bacteria were occasionally dissolved in the invaginations, and their cytoplasms were slightly swollen with low electron densities. In some invaginations, the attached bacteria were eliminated to leave their fragments such as filamentous debris and a part of cell walls. Finally these remnants disappeared completely. When the bacterial colonies existed in the middle region of the FAE, the attachment of bacteria resulted in the engulfment of bacteria by M cells. The degenerated bacteria whose cytoplasmic matrices were separated into high electron dense materials and cleared materials were occasionally engulfed by ordinary microvillous columnar epithelial cells or goblet cells throughout the FAE. These findings suggest that the epithelial cells reject the attachment of live indigenous bacteria and that the M cells absorb indigenous bacteria in rat Peyer's patches.

    JAPAN SOC VET SCI, 2008年03月, JOURNAL OF VETERINARY MEDICAL SCIENCE, 70 (3), 235 - 241, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Ippei Yamaoka, Mitsuo Nakayama, Takanori Miki, Toshifumi Yokoyama, Yoshiki Takeuchi

    e assessed the contribution of dietary protein to circadian changes in core body temperature (T-b) and metabolic rate in freely moving rats. Daily changes in rat intraperitoneal temperature, locomotor activity (LMA), whole-body oxygen consumption (VO2), and carbon dioxide production (VCO2) were measured before and during 4 days of consuming a 20% protein diet (20% P), a protein-free diet (0% P), or a pair-fed 20% P diet (20% P-R). Changes in T-b did not significantly differ between the 20% P and 20% P-R groups throughout the study. The T-b in the 0% P group remained elevated during the dark (D) phase throughout the study, but VO2, VCO2, and LMA increased late in the study when compared with the 20% P-R group almost in accordance with elevated T-b. By contrast, during the light (L) phase in the 0% P group, T-b became elevated early in the study and thereafter declined with a tendency to accompany significantly lower VO2 and VCO2 when compared with the 20% P group, but not the 20% P-R group. The respiratory quotient (RQ) in the 0% P group declined, throughout the D phase and during the early L phase. By contrast, RQ in the 20% P-R group consistently decreased from the late D phase to the end of the L phase. Our findings suggest that dietary protein contributes to the maintenance of daily oscillations in T-b with modulating metabolic rates during the D phase. However, the underlying mechanisms of T-b control during the L phase remain obscure.

    PHYSIOLOGICAL SOC JAPAN, 2008年02月, JOURNAL OF PHYSIOLOGICAL SCIENCES, 58 (1), 75 - 81, 英語

    研究論文(学術雑誌)

  • Katsuhiko Warita, Kazutaka Okamoto, Ken-ichiro Mutoh, Yoshihisa Hasegawa, Zhan-Peng Yue, Toshifumi Yokoyama, Yoshiki Matsumoto, Takanori Miki, Yoshiki Takeuchi, Hiroshi Kitagawa, Teruo Sugawara, Nobuhiko Hoshi

    Oxford University Press (OUP), 2008年01月01日, Biology of Reproduction, 78 (1), 59 - 67

    [査読有り]

    研究論文(学術雑誌)

  • Early postnatal ethanol exposure induces fluctuation in the expression of BDNF mRNA in the developing rat hippocampus

    Takanori Miki, Hiromi Kuma, Toshifumi Yokoyama, Kazunori Sumitani, Yoshiki Matsumoto, Takashi Kusaka, Katsuhiko Warita, Hi-Yu Wang, Naohisa Hosomi, Tomohiro Imagawa, Kuldip S. Bedi, Susumu Itoh, Yu Nakamura, Yoshiki Takeuchi

    Effects of early postnatal ethanol exposure on brain-derived neurotrophic factor (BDNF) mRNA expression in the rat hippocampus were investigated. Wistar rats were assigned to either ethanol treatment (ET), separation control (SC) or mother-reared control (MRC) groups. Ethanol exposure was achieved by a vapor inhalation method for 3 hours a day between postnatal days (PND) 10-15. On PND 16, 20, 30, and 60, the expression of BDNF mRN. A in the hippocampus was determined using real-time RT-PCR analysis. There was a significant age-related increase in the BDNF mRNA expression between PND 30-60 in MRC animals. The BDNF mRNA expression in ET rats was increased at both PND 16 and 20 and thereafter decreased at PND 60 compared to SC animals. Such age-related fluctuation in the expression of BDNF mRNA differed from that of MRC animals. The exact functional implications, if any, of these ethanol-induced changes in BDNF mRNA expression remain unknown although it can be speculated that they may have an effect on the behaviors known to be influenced by the hippocampal formation.

    NENCKI INST EXPERIMENTAL BIOLOGY, 2008年, ACTA NEUROBIOLOGIAE EXPERIMENTALIS, 68 (4), 484 - 493, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Sachiko Onishi, Hidenori Miyata, Tetsurou Inamoto, Wang-Mei Qi, Kenkichi Yamamoto, Toshifumi Yokoyama, Katsuhiko Warita, Nobuhiko Hoshi, Hiroshi Kitagawa

    It is well known that some caspases in apoptosis is involved in determinant of terminal differentiation and maturation of various cells. Our previous study ultrastructurally clarified the differentiation into M cells from immature microvillous epithelial cells and the redifferentiation from M cells to microvillous epithelial cells in the follicle-associated epithelium (FAE) of rat Peyer's patch. In this study, the difference of epithelial apoptosis between the FAE of Peyer's patch and intestinal villi was immunohistochemically investigated in rat jejunoileum. As a result, cleaved caspase-3 was limited to several epithelial cells at the tip of FAE, whereas almost all of the epithelial cells were cleaved caspase-3 positive in intestinal villi. Cleaved caspase-9 was detected only in a few exfoliating or exfoliated epithelial cells of both FAE and intestinal villi. Nuclear DNA-fragmentation was detected only in several epithelial cells of the tip of FAE, while it was expressed from the middle regions in the intestinal villi. The DNase I expression of the epithelial cytoplasm was much weaker in FAE than in intestinal villi. Bcl-x expression was restricted in the apical cytoplasms of epithelial cells in the FAE, whereas it was restricted in whole cytoplasms in villous epithelial cells. These findings suggest that the progression of the apoptotic process in the epithelial cells of FAE is later than in the intestinal villi, so that the possibility of epithelial differentiation might be remained in the FAE, unlike in the intestinal villi.

    JAPAN SOC VET SCI, 2007年11月, JOURNAL OF VETERINARY MEDICAL SCIENCE, 69 (11), 1123 - 1129, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Takanori Miki, Toshifumi Yokoyama, Kazunori Sumitani, Zhi-Yu Wang, Weiwen Yang, Takashi Kusaka, Yoshiki Matsumoto, Katsuhiko Warita, Nam-Seob Lee, Yoshihiro Fukui, Yoshiki Takeuchi

    The developing central nervous system is known to be highly vulnerable to X-irradiation. Although glial cells are involved in various brain functions, knowledge on the effects of X-irradiation on glial cells is limited. Therefore, the purpose of the present study was to evaluate the effects of prenatal X-irradiation on glial cells. Pregnant Wistar rats were exposed to X-irradiation at a dose of 1.0 Gy on day 15 of gestation. Their offspring were examined at 7 weeks of age. The forebrain weight of X-irradiated rats was significantly lower than that of the age-matched controls. Histological quantification with stereology of the somatosensory cortex (SC) revealed no significant difference in the numerical density of glial cells between the X-irradiated and control rats. However, the glial cells in the X-irradiated animals had significantly larger nuclear size. We had previously reported that a similar X-irradiation paradigm resulted in no significant change in the numerical density of neurons in the SC. According to the results of the present study, there were no significant differences in the glial cell-to-neuron ratios between the X-irradiated and control animals. Taken together, it is speculated that prenatal X-irradiation has an equal effects on the numerical densities of glial cells and neurons. (C) 2007 ISDN. Published by Elsevier Ltd. All rights reserved.

    PERGAMON-ELSEVIER SCIENCE LTD, 2007年08月, INTERNATIONAL JOURNAL OF DEVELOPMENTAL NEUROSCIENCE, 25 (5), 293 - 297, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Kazutoshi Fusumada, Toshifumi Yokoyama, Takanori Miki, Zhi-Yu Wang, Weiwen Yang, Nam-Seob Lee, Yoko Endo, Yoshiki Takeuchi

    Electroacupuncture (EA) delivered to the acupoint (AP) called Zusanli (ST36) was administered on the bilateral hindlimb. This experiment resulted in strong expression of c-Fos immunoreactivity in the ventrolateral to lateral subdivision throughout the periaqueductal gray (PAG) compared to the non-AP and sham cases. On the other hand, it was of particular interest in the experiment of the AP that strong expression of gamma aminobutylic acid (GABA) frequently showed similar pattern of distribution to that of c-Fos in the PAG. This overlapped pattern of distribution, demonstrated in the present study, suggests that the PAG neurons activated by EA at the AP might play an important role in the descending pain control system involving the GABA since the PAG has special reference to the dorsal horn of the spinal cord and function of pain control.

    2007年05月, Okajimas Folia Anatomica Japonica, 84 (1), 1 - 10, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Sachiko Onishi, Toshifumi Yokoyama, Keigi Chin, Midori Yuji, Tetsurou Inamoto, Wang-Mei Qi, Katsuhiko Warita, Nobuhiko Hoshi, Hiroshi Kitagawa

    The differentiation process of immature microvillous epithelial cells to M cells and the fate of M cells in the follicle-associated epithelium (FAE) of the mucosa-associated lymphoid tissues are still unclear. In this study, the differentiation process and the fate of M cells were clarified in rat Peyer's patches under a transmission electron microscope. Almost all immature epithelial cells were found to possess long, slender microvilli, which gradually shortened, thickened and dispersed as the immature epithelial cells migrated away from the crypt orifices. These morphological changes started in the centers and moved to the peripheries of the apical surfaces of epithelial cells, accompanied by the protrusion of apical cytoplasm out of the terminal web. During these changes, the bundles of microfilaments of microvilli never shortened, and both small vesicles in the apical cytoplasm and tiny invaginations of the apical membranes were found. The intraepithelial migrating cells gradually accumulated to form typical intraepithelial pockets. In all FAE, there was no morphological sign of cell death in M cells. The rearrangement of microfilament bundles, the reconstruction of microvilli and the disappearance of pockets resulted in the transformation of M cells into microvillous epithelial cells. These serial ultrastructural changes suggest that M cells are a temporal and transitional cell type caused by the active engulfment of luminal substances and that when the engulfment ceases, the M cells transform into mature microvillous epithelial cells.

    JAPAN SOC VET SCI, 2007年05月, JOURNAL OF VETERINARY MEDICAL SCIENCE, 69 (5), 501 - 508, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Midori Yuji, Masato Fujimoto, Hidenori Miyata, Tetsurou Inamoto, Wang-Mei Qi, Kenkichi Yamamoto, Katsuhiko Warita, Toshifumi Yokoyama, Nobuhiko Hoshi, Hiroshi Kitagawa

    The possibility of persorption of prefixed bovine serum albumin-coated sheep erythrocytes (BSA-SEs) from mucous epithelial cells and its mechanisms were investigated in rats orally immunized by BSA for 14 consecutive days. On the day after the final oral immunization, the rats were duodenally perfused by BSA-SEs or non-coated SEs. BSA-SEs were also duodenally perfused in nonimmunized rats. Thirty min after perfusion, BSA-SEs were significantly more engulfed by late-apoptotic-stage villous columnar epithelial cells in the orally immunized rats than those in other experiments. The specific antibody (SpAb) was detected on the surfaces of BSA-SEs in rats with oral immunization. In Peyer's patches of all animals, no SEs reached the follicle-associated epithelium, because of the close attachment of follicle-associated intestinal villi and the thick mucous layer. BSA-SEs were more frequently persorbed into portal blood in the orally immunized rats than in other rats. Small numbers of BSA-SEs or SEs were detected in the systemic blood of all animals. BSA-SEs were also histologically found in the blood vessels of the liver, but not in mesenteric lymph nodes. These findings suggest that sensitized antigenic particulates are taken up by late-apoptotic-stage villous columnar epithelial cells in the small intestine and are finally persorbed into the systemic blood circulation. The uptake of antigenic particulates might be mediated by its luminal SpAb.

    JAPAN SOC VET SCI, 2007年04月, JOURNAL OF VETERINARY MEDICAL SCIENCE, 69 (4), 339 - 346, 英語

    [査読有り]

    研究論文(学術雑誌)

  • 嗅球における発達中の神経系に対するイソフルレン吸入麻酔の影響

    横山 俊史, 三木 崇範, 汪 治宇, 楊 衛文, 李 京烈, 植木 正明, 竹内 義喜

    (一社)日本解剖学会, 2007年03月, 解剖学雑誌, 82 (Suppl.), 219 - 219, 日本語

    [査読有り]

  • Keigi Chin, Sachiko Onishi, Midori Yuji, Tetsurou Inamoto, Wang-Mei Qi, Kenkichi Yamamoto, Katsuhiko Warita, Toshifumi Yokoyama, Nobuhiko Hoshi, Hiroshi Kitagawa

    Our previous study clarified that the apical regions of both the follicle-associated epithelium (FAE) of Peyer's patches and the intestinal villi are the only adhesion sites of indigenous bacteria in rat jejuno-ileum. To survey the ligands against bacterial lectins, sugar expression patterns on epithelial cells were lectin-histochemically investigated using 21 lectins in the jejuno-ileal Peyer's patches of rats. As a result, (D-glcNAc)(2-4), detected by Solanum tuberosum (STL) and by Lycopersicon esculentum (LEL), and beta-D-gal(1-3)-D-galNAc detected by Peanut agglutinin (PNA), were strongly expressed on the brush borders of the apical regions of the FAE and the intestinal villi. On the other hand, neither sugar was expressed on the brush borders of the basal regions of both FAE and intestinal villi. The positive intensities for the lectins correlated with the progression of epithelial apoptosis in the FAE and in the intestinal villi. Moreover, the double staining with lectin histochemical method and the in situ nick end-labeling method could simultaneously detect the strong expression of both sugars and nuclear DNA fragmentation in epithelial cells at the late apoptotic stage. Other sugar expression patterns in the intestinal villi were similar with those in the FAE. There were no lectins specific for M cells in the FAE. From these findings, the possible sugars of ligands against some indigenous bacterial lectins, expressing specially on the apoptotic epithelial cells, might be narrowed down in rat jejuno-ileum.

    JAPAN SOC VET SCI, 2007年02月, JOURNAL OF VETERINARY MEDICAL SCIENCE, 69 (2), 193 - 199, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Matsumoto Yoshiki, Tsukamoto Yasuhiro, Miki Takanori, Ogawa Kazushige, Lee Kyoung-Youl, Yokoyama Toshifumi, Satriotomo Irawan, Li Hong-Peng, Gu He, Wang Zhi-Yu, Karasawa Shigeru, Ueda Susumu, Sasaki Fumihiko, Takeuchi Yoshiki

    Wiley, 2006年12月01日, Congenital Anomalies, 46 (4), 188 - 193

  • Persorption of luminal antigenic molecules and its specific antibody via apoptotic epithelial cells of intestinal villi and Peyer’s patches into peripheral blood in rats

    YUJI Midori, TSUBATA Masahito, CHIN Keigi, ONISHI Sachiko, INAMOTO tetsurou, QI Wang-Mei, WARITA Katsuhiko, YOKOYAMA Toshifumi, HOSHI Nobuhiko, 北川 浩

    The possibility of persorption of bovine serum albumin (BSA) molecules from mucous epithelial cells and its mechanism were investigated in rats orally pre-immunized by BSA for 14 consecutive days. In the small and large intestines, both the BSA antigen (BSA-Ag) and its specific antibody (SpAb) were absorbed by the epithelial cells at the late apoptotic stage (ApoEp), and were subsequently transcytosed by membranes of the small vesicles. The basal cytoplasms containing highly-concentrated BSA-Ag and SpAb were occasionally fragmented into small cytoplasmic droplets that were secreted into the lamina propria. In Peyer's patches, both BSA-Ag and SpAb were more actively absorbed and transcytosed toward the dome area by the ApoEp of the dome apex than by the M cells. BSA-Ag and SpAb were finally persorbed into the portal blood and lymph, but were never secreted into the bile. They were also engulfed by macrophage-like cells in the villous lamina propria, mesenteric lymph node and spleen, and by hepatocytes in the liver. These findings suggest that sensitized soluble luminal antigens are taken up by ApoEp in the small intestine and are finally persorbed into the peripheral blood. The uptake of luminal antigen might be mediated by its luminal SpAb.

    JAPAN SOC VET SCI, 2006年12月, The Journal of Veterinary Medical Science, 68 (12), 1297 - 1305, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Hanayo Okamoto, Takanori Miki, Kyoung-Youl Lee, Toshifumi Yokoyama, Hiromi Kuma, Zhi-Yu Wang, He Gu, Hong-Peng Li, Yoshiki Matsumoto, Satriotomo Irawan, Kuldip S. Bedi, Yu Nakamura, Yoshiki Takeuchi

    The hippocampal formation has been shown to be particularly vulnerable to the neurotoxic effects of chronic ethanol consumption. It was hypothesized that this damage was due to the disruption of the expression of neurotrophic factors and certain other proteins within the hippocampus. By using real-time reverse transcription-polymerase chain reaction (RT-PCR) techniques, this study aimed to determine whether chronic ethanol consumption could alter the mRNA expression level of brain-derived neurotrophic factor (BDNF), glial-derived neurotrophic factor (GDNF), and oligodendrocyte myelin glycoprotein (OMgp) in the hippocampus. Wistar male rats received an unrestricted access to a liquid diet containing 5% (v/v) ethanol as the sole source of fluid from 10 to 29 weeks of age. Control rats had unlimited access to a liquid diet containing an isocaloric amount of sucrose. We found that chronic ethanol consumption did not cause significant changes in the levels of mRNA for BDNF and GDNF. However, OMgp mRNA showed a significant deficit in ethanol-treated animals. It is suggested that this deficit may be related to the demyelination that is commonly observed in human alcoholics and that this may contribute to the functional and cognitive deficits. (c) 2006 Elsevier Ireland Ltd. All rights reserved.

    ELSEVIER IRELAND LTD, 2006年10月, NEUROSCIENCE LETTERS, 406 (1-2), 76 - 80, 英語

    研究論文(学術雑誌)

  • Differentiation of epithelial cells to M cells in response to bacterial colonization on the follicle-associated epithelium of Peyer's patch in rat small intestine

    Keigi Chin, Sachiko Onishi, Midori Yuji, Tetsurou Inamoto, Wang-Mei Qi, Katsuhiko Warita, Toshifumi Yokoyama, Nobuhiko Hoshi, Hiroshi Kitagawa

    To clarify the relationship between M cells and intestinal microflora, histoplanimetrical investigation into the bacterial colonization and the differentiation to M cells was carried out in rat Peyer's patch under physiological conditions. The follicle-associated epithelium (FAE), except for the narrow area of apical region, was closely covered with both neighboring intestinal villi and a thick mucous layer, the latter of which also filled the intervillous spaces as well as the space between the FAE and the neighboring intestinal villi. Indigenous bacteria adhered almost constantly to the narrow areas of apical regions of both intestinal villi and the FAE. Bacterial colonies were occasionally located on the basal to middle region of FAE, where M cells also appeared, forming large pockets. When bacterial colonies were located on the basal to middle region of FAE, bacteria with the same morphological characteristics also proliferated in the intervillous spaces neighboring the Peyer's patch. In cases with no bacterial colonies on the basal to middle region of FAE, however, M cells were rare in the FAE. Histoplanimetrical analysis showed the similar distribution pattern of bacterial colonies on the FAE and M cells in the FAE. M cells ultrastructurally engulfed indigenous bacteria, which were then transported to the pockets. These results suggest that indigenous bacterial colonization on the FAE stimulates the differentiation of M cells in the FAE under physiological conditions. The uptake of bacteria by M cells might contribute the regulation of the development of indigenous bacterial colonies in the small intestine.

    JAPAN SOC VET SCI, 2006年10月, JOURNAL OF VETERINARY MEDICAL SCIENCE, 68 (10), 1023 - 1028, 英語

    [査読有り]

    研究論文(学術雑誌)

  • HP Li, T Miki, T Yokoyama, KY Lee, H Gu, Y Matsumoto, ZY Wang, H Kawano, Y Takeuchi

    The purpose of the present study was to elucidate regional differences in the vulnerability of cerebellar foliations of rats exposed to X-irradiation. Effects of X-irradiation on foliations were examined with respect to histological changes in Purkinje cells and Bergmann glial fibers by calbindin-D28k (CB) and glial fibrillary acidic protein (GFAP) immunohistochemistry, respectively. Wistar rats were exposed to X-irradiation (1.5 Gy) on postnatal day (PND) 1. At 3 weeks of age, the cerebellum was examined. The cerebella of rats exposed to X-irradiation showed smaller and abnormal foliations compared with controls. Fewer cerebellar foliations due to fusion with neighboring folia were observed in folia I-III and VIa-VII. Moreover, the extent of such abnormalities was more severe in the latter folia. CB-immunoreactive (IR) Purkinje cells exhibited thin, short, disoriented dendrites that had invaded the granular layer or white matter. On the other hand, GFAP-IR Bergmann glial fibers had not extended their processes into the molecular layer perpendicular to the pial surface, and they appeared thin and disoriented. Accordingly, the above cerebellar abnormalities were more severe in folia I-III, VIa-VII and X than in other regions. In contrast to the histological alterations in these folia, there were no apparent qualitative differences in folia IV-V between X-irradiated and controls. These findings indicate regional difference in the vulnerability of cerebellar folia to X-irradiation. Such differences might be attributed to the cerebellar neurogenetic gradient. (c) 2006 Elsevier Ireland Ltd. All rights reserved.

    ELSEVIER IRELAND LTD, 2006年07月, NEUROSCIENCE LETTERS, 402 (1-2), 86 - 91, 英語

    研究論文(学術雑誌)

  • D Gonzalez, Satriotomo, I, T Miki, KY Lee, T Yokoyama, T Touge, Y Matsumoto, A Li, S Kuriyama, Y Takeuchi

    The expression of calcium binding proteins (CaBPs) has been linked to protection of neurons. The present study investigated the effects of monocular enucleation on the distribution of parvalbumin immunoreactive (PV-IR) neurons and glial fibrillary acidic protein immunoreactive (GFAP-IR) astrocytes in both the dorsal (dLGN) and ventral (vLGN) regions of the lateral geniculate nucleus (LGN). Our results demonstrated an increase in PV-IR neuronal density on the contralateral vLGN at 1-week post-enucleation (PE), which was maintained without significant change for 12 weeks. By contrast, PV-IR neurons in dLGN decreased significantly at all time point examined. The number of GFAP-IR astrocytes showed an initial increase from 1 to 4 weeks PE and then gradually decreased until 48 weeks in both regions of the LGN with contralateral side predominance. The present results suggest that monocular enucleation results in variable expression of PV-IR neurons and GFAP-IR astrocytes in the LGN complex, which may play an important role in neuronal degeneration and neuroplasticity of the rat visual system. (c) 2005 Elsevier Ireland Ltd. All rights reserved.

    ELSEVIER IRELAND LTD, 2006年03月, NEUROSCIENCE LETTERS, 395 (2), 149 - 154, 英語

    研究論文(学術雑誌)

  • OKAMOTO Hanayo, FUSUMADA Kazutoshi, IMAGAWA Tomohiro, WANG Zhi-Yu, NAKAMURA Yu, TAKEUCHI Yoshiki, MIKI Takanori, LEE Kyoung-Youl, YOKOYAMA Toshifumi, KUMA Hiromi, GU He, LI Hong-Peng, MATSUMOTO Yoshiki, YAMAOKA Ippei

    Chronic ethanol consumption has adverse effects on the central nervous system. Hippocampus is one of the target sites of ethanol neurotoxicity. Hippocampal damage is known to result in impairment of learning and memory. This study was aimed to determine whether chronic ethanol consumption could alter the expression levels of brain-derived neurotrophic factor (BDNF) and glial-derived neurotrophic factor (GDNF) mRNAs in the hippocampus. Male Wistar rats were given unrestricted access to a liquid diet containing 5% (v/v) ethanol as the sole fluid source for 19 weeks beginning at 10 weeks of age. The expression levels of BDNF and GDNF mRNAs in the hippocampus were analyzed by real-time reverse transcription-polymerase chain reaction (RT-PCR) analysis. The present study revealed that chronic ethanol consumption did not result in significant changes in the expression levels of BDNF and GDNF mRNAs. Our present results showed no significant alteration in the expression of these neurotrophic factors; these results will lead to further studies to examine the possible alterations in the gene expression of various neurotrophins that are related to hippocampal functions including learning and memory.

    オカジマ・フォリア・アナトミカ・ヤポニカ編集部, 2006年, Okajimas Folia Anatomica Japonica, 83 (1), 1 - 6, 英語

  • Application of the physical disector to the central nervous system: Estimation of the total number of neurons in subdivisions of the rat hippocampus

    Takanori Miki, Irawan Satriotomo, Hong-Peng Li, Yoshiki Matsumoto, He Gu, Toshifumi Yokoyama, Kyoung-Youl Lee, Kuldip S. Bedi, Yoshiki Takeuchi

    Stereology is a group of mathematical and statistical methods that allows the extrapolation of three-dimensional structural information from two-dimensional sections (or slices). This allows researchers to derive important quantitative structural information, such as the volume, surface area or numbers of particular particles (e.g. cells) within defined regional boundaries. The need for such quantitative information in biology is of particular importance when evaluating the influence of various experimental treatments on specific organs, tissues and cells in the body. Knowledge of such changes has given important insights into the neural substrates that may be responsible for the functional and behavioral consequences of a disparate range of experimental treatments. Here, we describe some of these methods as applied to quantifying the total numbers of cells in defined regions of the hippocampal formation. The methods used for this evaluation were, first, the Cavalieri principle, which was used to determine the volumes of the various subdivisions of the rat hippocampus, and, second, the 'physical disector' method, which was used to estimate the numerical density of neurons within each subdivision. Once these values were derived, it was but a simple task to multiply them together to obtain estimates for the total numbers of cells in the given hippocampal region. We found that 16- and 30-day-old normal male rats had 176 800 and 152 700 pyramidal cells in the CA1 region, respectively. This decrease in the neuronal number was statistically significant. However, in the CA2 + CA3 region, there were approximately 169 300 and 149 600 pyramidal cells in 16- and 30-day-old normal male rats, respectively, which was not significantly different. In the dentate gyrus, there were approximately 36 700 neurons in the hilus region and 483 000 granule cells in the granule cell layer, irrespective of the age of the rats. There were no significant differences between these estimates of hilus neurons and granule cells.

    2005年09月, Anatomical Science International, 80 (3), 153 - 162, 英語

  • GONZALEZ Daniel, TAKEUCHI Yoshiki, SATRIOTOMO Irawan, MIKI Takanori, LEE Kyoung-Youl, YOKOYAMA Toshifumi, TOUGE Tetsuo, MATSUMOTO Yoshiki, LI Hong-Peng, KURIYAMA Shigeki

    The present study was undertaken to evaluate the effects of monocular enucleation on the calbindin-D 28k (CB) and c-Fos immunoreactive (IR) neurons in the lateral geniculate nucleus (LGN) complex of adult rats. The enucleation resulted in neuronal degeneration and decrease of neurons in the LGN complex. Our study demonstrated a decrease of CB-IR neuronal density on the contralateral side of the ventral (vLGN) and dorsal LGN (dLGN) until 12 weeks post-enucleation (PE). On the ipsilateral side, CB-IR neuronal density in the dLGN and vLGN showed significant and continuous decrease until 48 and 12 weeks PE, respectively. In an additional experiment, c-Fos-IR neurons were increased at 2 days PE in the vLGN with ipsilateral predominance. At 7 days, c-Fos-IR neurons on the ipsilateral vLGN were still higher than those of pre-enucleated rats. The present results suggest that monocular enucleation affects the expression of the CB and c-Fos in the LGN complex. It is indicated that these may play an important role in the neuronal degeneration and neuroplasticity of the subvisual system in rats.

    オカジマ・フォリア・アナトミカ・ヤポニカ編集部, 2005年, Okajimas Folia Anatomica Japonica, 82 (1), 9 - 18, 英語

  • H Kuma, T Miki, Y Matsumoto, H Gu, HP Li, T Kusaka, Satriotomo, I, H Okamoto, T Yokoyama, KS Bedi, S Onishi, H Suwaki, Y Takeuchi

    The effects of maternal deprivation (MD) during early postnatal life on the brain-derived neurotrophic factor (BDNF) level were investigated in the present study. Wistar rats were assigned to either maternal deprivation or mother-reared control (MRC) groups. MD manipulation was achieved by separating rat pups from their mothers for 3 h a day during postnatal days (PND) 10-15. At 16, 20, 30, and 60 days of age, the level of BDNF mRNA in the hippocampal formation of each group was determined using real-time PCR analysis. Early postnatal maternal deprivation of rat pups resulted in a significant increase in body weight at 60 days of age. The expression of BDNF mRNA in the hippocampus was significantly decreased at 16 days of age, and increased at 30 and 60 days of age. These data indicate that even a brief period of maternal deprivation during early postnatal life can affect hippocampal BDNF expression. (C) 2004 Elsevier Ireland Ltd. All rights reserved.

    ELSEVIER SCI IRELAND LTD, 2004年11月, NEUROSCIENCE LETTERS, 372 (1-2), 68 - 73, 英語

    研究論文(学術雑誌)

  • S Tsukahara, K Inami, F Maekawa, M Kakeyama, T Yokoyama, M Yuji, H Kitagawa, Y Kannan, K Yamanouchi

    To determine whether apoptosis is involved in the formation of the structure and morphological sex difference of the lateral septum (LS), the postnatal developmental changes in the number of apoptotic cells were examined in the LS on postnatal day 1 (PD1 = birth day), 4, 6, 8, 11, 16, and 31 in male and female rats. Apoptotic cells were imimmohistochemically detected by antibody against single-stranded DNA (ssDNA) or active caspase-3. The volume of the LS was also measured and was found to increase with age. The number of apoptotic cells detected by anti-ssDNA in the LS increased from PD1 to PD8 but decreased after PD11. Also, the LS was divided into dorsal, intermediate, and ventral parts (LSd, LSi, and LSv), and the volume and number of ssDNA-immunoreactive cells in each part were measured on PD6, 8, 11, 16, and 31. In both sexes, a large number of ssDNA-immunoreactive cells was found in the LSd and LSi on PD8 (but not on PD6) and in the LSv on PD6 and PD8. On PD6, the number of active caspase-3-immunoreactive cells was significantly greater in the LSv than in the LSd or LSi, in both sexes. Only the LSi of males had a high number of ssDNA-immunoreacitve cells on PD16; the number was significantly greater than that of females of the same age. However, there was no significant sex difference in the number of active caspase-3-immunoreacitve cells in the LSi on PD16. On PD31, the volume of the LSi was significantly greater in females than in males. There was no sex difference in volume or number of apoptotic cells in the LSd or LSv. These findings indicate that loss of cells due to apoptosis, which is partially caused by activation of caspase-3, occurs in the LS during postnatal development, with regional differences. They also indicate that sex difference in caspase-3-independent apoptosis contributes to morphological sexual differentiation of the LSi. (C) 2004 Wiley-Liss, Tue.

    WILEY-LISS, 2004年07月, JOURNAL OF COMPARATIVE NEUROLOGY, 475 (2), 177 - 187, 英語

    [査読有り]

    研究論文(学術雑誌)

  • H Kitagawa, Y Yoshizawa, T Yokoyama, T Takeuchi, MJR Talukder, H Shimizu, K Ando, E Harada

    The absorption and the transportation of intestinally administrated bovine lactoferrin (LF) were immunohistochemically and physiochemically investigated in the small intestine of growing pigs. At the apical halves of the small intestinal villi, bovine LF was absorbed by transcytosis as small vesicles through villous columnar epithelial cells. The presence of bovine LF-positive membranes of transcytotic vesicles suggests that the absorption was mediated by LF-binding factors on the epithelial cell membranes. Almost all of the absorbed bovine LF was demonstrated to be transported via the lymphatics and the portal vein into the systemic circulation. The LF-concentration in systemic circulation was significantly higher at 1 hr following intestinal administration of bovine LF. Bovine LF-positive lymphocytes also were transferred into the systemic circulation from intestine via the lymphatics and the portal vein.

    JAPAN SOC VET SCI, 2003年05月, JOURNAL OF VETERINARY MEDICAL SCIENCE, 65 (5), 567 - 572, 英語

    研究論文(学術雑誌)

  • T Yokoyama, T Etoh, H Kitagawa, S Tsukahara, Y Kannan

    It has been hitherto considered that mature erythroblasts migrate toward the sinusoid along the cytoplasmic processes of macrophages of erythroblastic islands in bone marrow. Our previous report, however, has demonstrated the morphological features of a mature erythroblastic island passing through the sinusoidal endothelium. In this study, the possibility of migration of erythroblastic islands toward the sinusoid was examined in rat bone marrow by light microscopical histoplanimetry. As a result, the more mature erythroblasts were not regularly arranged in the peripheral direction of the erythroblastic islands. Immature erythroblasts were populated more in the erythroblastic islands away from the sinusoid than in those islands neighboring the sinusoid, whereas mature erythroblasts were more in erythroblastic islands neighboring the sinusoid. These findings suggest that the formation of erythroblastic islands occurs in a region away from the sinusoid, and that erythroblastic islands migrate towards the sinusoids as erythroid maturation proceeds.

    JAPAN SOC VET SCI, 2003年04月, JOURNAL OF VETERINARY MEDICAL SCIENCE, 65 (4), 449 - 452, 英語

    [査読有り]

    研究論文(学術雑誌)

  • Hiroshi Kitagawa, Masashi Hosokawa, Takashi Takeuchi, Toshifumi Yokoyama, Tomohiro Imagawa, Masato Uehara

    To clarify the cellular origin and the fate of M cells, detailed distributions of the epithelial cells were investigated scanning electron microscopically on the follicle-associated epithelia (FAE) of chicken cecal tonsils. The distribution of M cells was closely related with the situation of the crypt orifices in chicken cecal tonsils. In undeveloped cecal tonsils, the intestinal crypts were localized at the periphery of the FAE. In these tonsils, M cells without microvilli (M0) were predominantly populated in the basal region of the FAE, whereas goblet cells and microvillous epithelial cells (MV) were more distributed in the middle to the apical region of the FAE. A few M cells with short microvilli were dispersed throughout the FAE. Significantly shrunk MV (MVs) clustered together in transitional portions from the lateral face to the roof of the FAE. In well-developed cecal tonsils, the crypts also opened at the lateral surface in addition to the periphery of the FAE. In these tonsils, the M0 accumulated densely in the small areas around the crypt orifices exclusively. No sign of exfoliation of apoptotic epithelial cells was found in the M0-accumulated areas and at their peripheral boundaries. The MVs were often clustered in the central regions among the crypt orifices in addition to the roof of the FAE. These findings suggest that M cells are directly derived from the undifferentiated crypt epithelial cells, not fall into apoptotic cell death and further differentiate into MV in the FAE of chicken cecal tonsils.

    Maruzen Co. Ltd., 2003年, Journal of Veterinary Medical Science, 65 (2), 171 - 178, 英語

    [査読有り]

    研究論文(学術雑誌)

  • YOKOYAMA Toshifumi, ETOH Takao, KITAGAWA Hiroshi, TSUKAHARA Shinji, KANNAN Yasuyuki

    A possibility of apoptotic cell death in erythropoietic regulation was examined by means of detailed light microscopical histoplanimetry, electron microscopy, the in situ nick-end labeling method, and an immunohistological method in the rat bone marrow. Serum erythropoietin concentrations were shown at normal levels. The erythroid series on a mature process presented several morphological features of apoptosis, i.e. the shrinkage of both nuclei and cytoplasm and the chromatin condensation. In the light microscopical histoplanimetry, however, morphological signs of final apoptotic cell death were never found in any erythroid cell within the erythroblastic islands. This finding was also supported by detailed ultrastructural observation: No erythroid cell bodies were trapped and degraded by the central macrophages of the erythroblastic islands, while the denucleated nuclei with small amount of cytoplasm of late erythroblasts were often trapped and degraded in the macrophages. Nuclear DNA fragmentation was not detected in any erythroblasts, but was detected in the lysosomes of the central macrophages. These findings suggest that erythropoiesis is regulated by other regulatory mechanisms than apoptotic cell death. An additional ultrastructural finding shows that the reticulocytes anchored to the central macrophages are transported into the peripheral blood circulation.

    JAPAN SOC VET SCI, 2003年, The Journal of Veterinary Medical Science, 64 (10), 913 - 919, 英語

    [査読有り]

    研究論文(学術雑誌)

書籍等出版物

  • 獣医組織学 改訂第8版-第19章 家禽の組織学(1.血液,2.骨髄)

    学窓社, 2020年03月

  • 獣医組織学 改訂第8版-第4章 血液及び骨髄(骨髄)

    学窓社, 2020年03月

  • 獣医組織学 改訂第7版-第4章 血液及び骨髄(骨髄)

    横山 俊史

    その他, 学窓社, 2017年03月, 日本語

    教科書・概説・概論

  • 獣医組織学 改訂第6版-第4章 血液及び骨髄(骨髄)

    横山 俊史

    その他, 学窓社, 2014年03月, 日本語

    教科書・概説・概論

講演・口頭発表等

  • 性分化撹乱マウス系統(B6J-XYPOS)における性腺原基の卵巣化に関する免疫組織化学的研究

    中村大河,横山俊史,三浦由佳,加藤栞,奥西宣祐,成田大翔,万谷洋平,星信彦

    第96回日本解剖学会近畿支部学術集会, 2020年11月, 日本語, 国内会議

  • ラット消化管粘膜上皮表面における常在細菌の定着程度の概日リズムに関する定量組織学的解析

    坂田奈那美,万谷洋平,中西怜稀,横山俊史,星 信彦

    第96回日本解剖学会近畿支部学術集会, 2020年11月, 日本語, 国内会議

  • ラット大腸粘膜における線維芽細胞様細胞の部位差に関する組織学的研究

    万谷洋平, 田村彩貴, 大野伸彦, 横山俊史, 星 信彦.

    第163回日本獣医学会学術集会, 2020年09月, 日本語, 国内会議

  • 無毒性量ネオニコチノイド系農薬がマウスの継世代雌性生殖器に及ぼす影響

    北内 佐也可,前田 瑞稀,西 美咲,正田 明日香,村田 碧,平野 哲史,万谷 洋平,横山 俊史,星 信彦

    第163回日本獣医学会学術集会, 2020年09月, 日本語, 国内会議

  • 性分化撹乱マウス系統(B6J-XYPOS)における精巣化破綻機構に関する免疫組織化学的研究

    中村大河,横山俊史,三浦由佳,加藤栞,奥西宣祐,成田大翔,万谷洋平,星信彦

    第163回日本獣医学会学術集会, 2020年09月, 日本語, 国内会議

  • ラット消化管各部位の粘膜上皮表面における常在細菌の定着程度の日内変動に関する組織学的解析

    坂田奈那美,万谷洋平,中西怜稀,横山俊史,星 信彦

    第163回日本獣医学会学術集会, 2020年09月, 日本語, 国内会議

  • 腸管各部位の集合リンパ小節における細網細胞の部位差に関する免疫組織化学的研究

    土居萌花,万谷洋平,中西怜稀,坂田奈那美,横山俊史,星 信彦

    第163回日本獣医学会学術集会, 2020年09月, 日本語, 国内会議

  • 無毒性量ネオニコチノイド系農薬が次世代のマウス雌性生殖機能に及ぼす影響

    北内 佐也可,前田 瑞稀,平野 哲史,万谷 洋平,横山 俊史,星 信彦

    第60回日本先天異常学会学術集会, 2020年07月, 日本語, 国内会議

  • 無毒性量の浸透性農薬のマウス胎子・授乳期曝露による神経行動学的影響

    前田瑞稀,北内佐也加,平野哲史,万谷洋平,横山俊史,星 信彦

    第60回日本先天異常学会学術集会, 2020年07月, 日本語, 国内会議

  • ネオニコチノイド系農薬における野生哺乳動物の曝露状況と都道府県別の出荷量との関連.

    杉田晄佑, 高田 匡, 万谷洋平, 横山俊史, 石塚真由美, 池中良徳, 星 信彦.

    環境ホルモン学会第22回研究発表会, 2019年12月, 日本語, 国内会議

    ポスター発表

  • ネオニコチノイド系農薬クロチアニジンが次世代雌性生殖器に及ぼす影響.

    北内佐也可, 前田瑞稀, 久保静花, 大成果乃子, 宮田結佳, 平野哲史, 万谷洋平, 横山俊史, 星 信彦.

    環境ホルモン学会第22回研究発表会, 2019年12月, 日本語, 国内会議

    ポスター発表

  • クロチアニジンおよびその代謝産物の母子間移行における組織分布・蓄積性の定量的解明.

    大野周嗣, 大成果乃子, 久保静花, 平野哲史, 万谷洋平, 横山俊史, 石塚真由美, 池中良徳, 星 信彦.

    環境ホルモン学会第22回研究発表会, 2019年12月, 日本語, 国内会議

    ポスター発表

  • 低用量クロチアニジンの胎子・授乳期曝露による神経行動学的影響.

    前田瑞稀, 北内佐也可, 宮田結佳, 久保静花, 平野哲史, 万谷洋平, 横山俊史, 星 信彦

    環境ホルモン学会第22回研究発表会, 2019年12月, 日本語, 国内会議

    ポスター発表

  • 低用量クロチアニジンによる情動変容への加齢の影響評価.

    宮田結佳, 久保静花, 大野周嗣, 大成果乃子, 前田瑞稀, 中西怜稀, 平野哲史, 万谷洋平, 横山俊史, 石塚真由美, 池中良徳, 星 信彦

    環境ホルモン学会第22回研究発表会, 2019年12月, 日本語, 国内会議

    ポスター発表

  • クロチアニジンの亜急性摂取はラット腸内細菌叢を変化させる.

    大成果乃子, 大野周嗣, 久保静花, 中西怜稀, 平野哲史, 万谷洋平, 横山俊史, 星 信彦

    環境ホルモン学会第22回研究発表会, 2019年12月, 日本語, 国内会議

    ポスター発表

  • 低用量クロチアニジンによるマウスの物体認識・空間学習記憶障害とその性差.

    久保静花, 宮田結佳, 大成果乃子, 大野周嗣, 平野哲史, 万谷洋平, 横山俊史, 星 信彦.

    環境ホルモン学会第22回研究発表会, 2019年12月, 日本語, 国内会議

    ポスター発表

  • Left-right asymmetry of Sry expression in the developing gonad of C57BL/6N mouse.

    Kohei KAWANISHI, Chinatsu HASEGAWA, Taiga NAKAMURA, Shiori KATOH, Yohei MANTANI, Toshifumi YOKOYAMA, Nobuhiko HOSHI

    The 42nd Annual Meeting of the Molecular Biology Society of Japan, 2019年12月, 英語, Fukuoka, 国際会議

    ポスター発表

  • Testis differentiation process of YPOS mice with fragile Sry is affected by genetic differences in C57BL/6 substrains.

    Toshifumi YOKOYAMA, Yuuka MIURA, Anzu YAMAMOTO, Chinatsu HASEGAWA, Kohei KAWANISHI, Nanako TAKADA, Takuya OMOTEHARA, Tetsushi HIRANO, Yohei MANTANI, Takanori MIKI, Nobuhiko HOSHI

    The 42nd Annual Meeting of the Molecular Biology Society of Japan, 2019年12月, 英語, Fukuoka, 国際会議

    ポスター発表

  • マウス健常雄個体の性腺におけるSry 発現の左右差に関する定量組織学的研究

    川西 航平, 長谷川 千夏, 中村 大河, 加藤 栞, 万谷 洋平, 横山 俊史, 星 信彦

    第95回日本解剖学会近畿支部学術集会, 2019年11月, 日本語, 大阪市, 国内会議

    口頭発表(一般)

  • Serial block-face 走査型電子顕微鏡を用いたラット回腸粘膜における神経接続の三次元解析

    中西 怜稀, 万谷 洋平, 春田 知洋, 横山 俊史, 星 信彦

    第95回日本解剖学会近畿支部学術集会, 2019年11月, 日本語, 大阪市, 国内会議

    口頭発表(一般)

  • ラット小腸粘膜における好酸球の多様性に関する組織学的研究

    荒井真也, 万谷洋平, 中西怜稀, 春田知洋, 西田美穂, 湯浅秀人, 横山俊史, 星信彦, 北川浩

    第95回日本解剖学会近畿支部学術集会, 2019年11月, 日本語, 大阪市, 国内会議

    口頭発表(一般)

  • GABA撹乱物質フィプロニルがマウスの情動行動に及ぼす影響

    前田 瑞稀, 大成 果乃子, 大野 周嗣, 久保 静花, 杉田 晄佑, 宮田 結佳, 北内 佐也加, 西 美咲, 高田 匡, 平野 哲史, 万谷 洋平, 横山 俊史, 池中 良徳, 星 信彦

    第162回日本獣医学会学術集会, 2019年09月, 日本語, つくば市, 国内会議

    口頭発表(一般)

  • 性決定期のマウス性腺におけるSry発現の時空間的解析-健常雄個体におけるSry発現の左右差

    川西 航平, 長谷川 千夏, 中村 大河, 加藤 栞, 万谷 洋平, 横山 俊史, 星 信彦

    第162回日本獣医学会学術集会, 2019年09月, 日本語, つくば市, 国内会議

    口頭発表(一般)

  • 性決定前のマウス未分化XY性腺の精巣化を誘導する器官培養法の確立とその組織学的評価

    長谷川 千夏, 梅村 ゆりあ, 川西 航平, 中村 大河, 加藤 栞, 万谷 洋平, 横山 俊史, 星 信彦

    第162回日本獣医学会学術集会, 2019年09月, 日本語, つくば市, 国内会議

    口頭発表(一般)

  • Serial block-face走査型電子顕微鏡(SBF-SEM)を用いたラット回腸の粘膜固有層における 神経投射対象の解明

    中西怜稀, 万谷洋平, 春田知洋, 横山俊史, 星信彦

    第162回日本獣医学会学術集会, 2019年09月, 日本語, つくば市, 国内会議

    口頭発表(一般)

  • Serial block-face走査型電子顕微鏡を用いたラット回腸における単核食細胞系列の細胞と上皮 内リンハ?球の相互作用に関する研究

    万谷洋平, 春田知洋, 中西怜稀, 片田裕亮, 横山俊史, 星信彦, 北川浩

    第162回日本獣医学会学術集会, 2019年09月, 日本語, つくば市, 国内会議

    口頭発表(一般)

  • Three-Dimensional Observation of Mononuclear Phagocyte Lineages in the Rat Ileum using Serial Block-Face Scanning Electron Microscopy

    Youhei MANTANI, Tomohiro HARUTA, Satoki NAKANISHI, Yusuke KATADA, Toshifumi YOKOYAMA, Nobuhiko HOSHI, Hiroshi KITAGAWA

    19th International Congress of Mucosal Immunology, 2019年07月, 英語, Brisbane, 国際会議

    ポスター発表

  • In vivo and in vitro effects of a neonicotinoid pesticide, clothianidin, on mammalian nervous function

    Tetsushi Hirano, Satsuki Minagawa, Yukihiro Furusawa, Tatsuya Yunoki, Toshifumi Yokoyama, Nobuhiko Hoshi, Yoshiaki Tabuchi

    IUTOX 15th International Congress of Toxicology, 2019年06月, 英語, Honolulu, 国際会議

    ポスター発表

  • ネオニコチノイド系農薬がヒト神経芽細胞腫に及ぼすシグナル毒性的影響に関するメカニズム解析

    平野 哲史, 皆川 沙月, 古澤 之裕, 柚木 達也, 池中 良徳, 横山 俊史, 星 信彦, 田渕 圭章

    第46回日本毒性学会, 2019年06月, 日本語, 徳島市, 国内会議

    口頭発表(一般)

  • C57BL/6マウスの亜系統差による生殖腺表現型の変化

    三浦由佳, 横山 俊史, 山本杏, 川西航平, 長谷川千夏, 高田菜々子, 万谷洋平, 星 信彦

    第32回モロシヌス研究会, 2019年06月, 日本語, 千葉市, 国内会議

    口頭発表(一般)

  • Serial Block face走査型電子顕微鏡を用いたラット回腸粘膜における単核食細胞系列の細胞の三次元的観察

    万谷洋平, 春田知洋, 中西怜稀, 横山 俊史, 星 信彦, 北川 浩

    第124回日本解剖学会総会全国学術集会, 2019年03月, 日本語, 新潟市, 国内会議

    ポスター発表

  • Adverse effects on cognitive-emotional behavior and immune system function in experimental animals administered a NOAEL-dose of neonicotinoids.

    星 信彦, 池中良徳, 大野周嗣, 大成果乃子, 久保静花, 前田瑞稀, 宮田結佳, 杉田晄佑, 石塚真由美, 万谷洋平, 横山 俊史

    Chemical Hazard Symposium in Hokkaido, 2019年03月, 英語, Sapporo, 国際会議

    [招待有り]

    シンポジウム・ワークショップパネル(指名)

  • 無毒性量のネオニコチノイド系農薬曝露による行動影響の性差

    久保静花, 宮田結佳, 大成果乃子, 大野周嗣, 高田匡, 平野哲史, 横山 俊史, 星 信彦

    環境ホルモン学会第21回研究発表会, 2018年12月, 日本語, 東京都文京区, 国内会議

    ポスター発表

  • 母子間移行における浸透性農薬およびその代謝産物の定量的な解明

    大野周嗣, 大成果乃子, 久保静花, 坂田奈那美, 平野哲史, 万谷洋平, 横山 俊史, 石塚真由美, 池中良徳, 星 信彦

    環境ホルモン学会第21回研究発表会, 2018年12月, 日本語, 東京都文京区, 国内会議

    ポスター発表

  • 兵庫県における野生哺乳動物のネオニコチノイド系農薬への曝露実態調査

    杉田晄佑, 高田匡, 万谷洋平, 横山 俊史, 石塚真由美, 池中良徳, 星 信彦

    環境ホルモン学会第21回研究発表会, 2018年12月, 日本語, 東京都文京区, 国内会議

    ポスター発表

  • 性決定遺伝子発現前のマウス未分化XY性腺の精巣化を誘導する器官培養法

    長谷川千夏, 梅村ゆりあ, 三浦由佳, 川西航平, 高田菜々子, 大野周嗣, 万谷洋平, 横山 俊史, 星 信彦

    関西実験動物研究会第140回研究会, 2018年12月, 日本語, 京都市, 国内会議

    口頭発表(一般)

  • ラットにおけるネオニコチノイド系農薬の亜急性曝露による免疫毒性の検証

    大成果乃子, 大野周嗣, 久保静花, 中西怜稀, 荒井真也, 横山 俊史, 星 信彦

    環境ホルモン学会第21回研究発表会, 2018年12月, 日本語, 東京都文京区, 国内会議

    ポスター発表

  • ネオニコチノイド系農薬が老年動物に及ぼす影響

    宮田結佳, 久保静花, 大野周嗣, 前田瑞稀, 荒井真也, 中西怜稀, 高田匡, 平野哲史, 横山 俊史, 星 信彦

    環境ホルモン学会第21回研究発表会, 2018年12月, 日本語, 東京都文京区, 国内会議

    ポスター発表

  • 性決定前のマウス未分化 XY 性腺の精巣化を誘導する器官培養法の確立とその組織学的評価

    長谷川千夏, 梅村ゆりあ, 三浦由佳, 川西航平, 高田菜々子, 大野周嗣, 万谷洋平, 横山 俊史, 星 信彦

    第94回日本解剖学会近畿支部学術集会, 2018年11月, 日本語, 神戸市, 国内会議

    口頭発表(一般)

  • ラット回腸粘膜における好酸球系列の細胞の組織学的研究

    荒井真也, 万谷洋平, 西田美穂, 湯浅秀人, 横山 俊史, 星 信彦, 北川 浩

    第94回日本解剖学会近畿支部学術集会, 2018年11月, 日本語, 神戸市, 国内会議

    口頭発表(一般)

  • ラット回腸の上皮下線維芽細胞様細胞を制御し得る神経伝達物質の同定

    中西怜稀, 万谷洋平, 田村彩貴, 荒井真也, 横山 俊史, 星 信彦, 北川 浩

    第94回日本解剖学会近畿支部学術集会, 2018年11月, 日本語, 神戸市, 国内会議

    口頭発表(一般)

  • 生殖腺の表現型に及ぼすマウス亜系統差の影響に関する遺伝学的研究

    三浦由佳, 山本杏, 川西航平, 長谷川千夏, 高田菜々子, 高田匡, 万谷洋平, 横山 俊史, 星 信彦

    第161回日本獣医学会学術集会, 2018年09月, 日本語, つくば市, 国内会議

    口頭発表(一般)

  • 浸透性農薬の行動影響の性差

    久保静花, 宮田結佳, 大成果乃子, 大野周嗣, 杉田晄佑, 前田瑞稀, 高田匡, 平野哲史, 万谷洋平, 横山 俊史, 星 信彦

    第161回日本獣医学会学術集会, 2018年09月, 日本語, つくば市, 国内会議

    口頭発表(一般)

  • 浸透性農薬とその代謝産物の胎子移行量の解明

    大野周嗣, 大成果乃子, 久保静花, 坂田奈那美, 杉田晄佑, 宮田結佳, 高田匡, 平野哲史, 万谷洋平, 横山 俊史, 石塚真由美, 池中良徳, 星 信彦

    第161回日本獣医学会学術集会, 2018年09月, 日本語, つくば市, 国内会議

    口頭発表(一般)

  • ラット小腸粘膜におけるCD11b陽性細胞を中心とした各種免疫担当細胞の組織内配置に関する免疫組織化学的研究

    荒井真也, 万谷洋平, 西田美穂, 湯浅秀人, 横山 俊史, 星 信彦, 北川 浩

    第161回日本獣医学会学術集会, 2018年09月, 日本語, つくば市, 国内会議

    口頭発表(一般)

  • ラット呼吸器系粘膜におけるSP-AおよびSP-D分泌細胞の分布

    斉旺梅, 増田なつみ, 万谷洋平, 横山 俊史, 星 信彦, 北川 浩

    第161回日本獣医学会学術集会, 2018年09月, 日本語, つくば市, 国内会議

    口頭発表(一般)

  • ラット回腸腸絨毛における上皮下および非上皮下線維芽細胞様細胞の三次元的解析

    万谷洋平, 春田知洋, 西田美穂, 横山 俊史, 星 信彦, 北川 浩

    第161回日本獣医学会学術集会, 2018年09月, 日本語, つくば市, 国内会議

    口頭発表(一般)

  • ラット回腸の上皮直下における線維芽細胞様細胞への神経投射に関する免疫組織化学的研究

    中西怜稀, 万谷洋平, 田村彩貴, 荒井真也, 横山 俊史, 星 信彦, 北川 浩

    第161回日本獣医学会学術集会, 2018年09月, 日本語, つくば市, 国内会議

    口頭発表(一般)

  • ネオニコチノイド系農薬における哺乳動物への免疫毒性の検証

    大成果乃子, 大野周嗣, 久保静花, 中西怜稀, 荒井真也, 杉田晄佑, 宮田結佳, 高田匡, 平野哲史, 万谷洋平, 横山 俊史, 星 信彦

    第161回日本獣医学会学術集会, 2018年09月, 日本語, つくば市, 国内会議

    口頭発表(一般)

  • ネオニコチノイド系農薬が老齢動物に及ぼす影響

    宮田結佳, 大成果乃子, 大野周嗣, 久保静花, 杉田晄佑, 高田匡, 前田瑞稀, 中西怜稀, 平野哲史, 万谷洋平, 横山 俊史, 星 信彦

    第161回日本獣医学会学術集会, 2018年09月, 日本語, つくば市, 国内会議

    口頭発表(一般)

  • 発達期におけるネオニコチノイド系農薬曝露により引き起こされたドーパミン神経系の攪乱を伴う多動

    米田直起, 高田 匡, 大成果乃子, 大野周嗣, 久保静花, 杉田晄佑, 宮田結佳, 平野哲史, 万谷洋平, 横山 俊史, 北川 浩, 星 信彦

    環境ホルモン学会第20回研究発表会, 2017年12月, 日本語, 神戸市, 国内会議

    ポスター発表

  • 環境ストレスおよびネオニコチノイド系農薬ジノテフランの複合影響評価

    高田 匡, 米田直起, 大成果乃子, 大野周嗣, 久保静花, 杉田晄佑, 宮田結佳, 平野哲史, 万谷洋平, 横山 俊史, 北川 浩, 星 信彦

    環境ホルモン学会第20回研究発表会, 2017年12月, 日本語, 神戸市, 国内会議

    ポスター発表

  • マウスの亜系統差が生殖腺に及ぼす影響の遺伝学的研究

    三浦由佳, 山本 杏, 川西航平, 長谷川千夏, 横山 俊史, 星 信彦

    第136回関西実験動物研究会, 2017年12月, 日本語, 京都市, 国内会議

    口頭発表(一般)

  • ラット大腸の上皮直下における間質細胞の部位差に関する免疫組織化学的研究

    田村彩貴, 万谷洋平, 西田美穂, 湯浅秀人, 増田なつみ, 横山 俊史, 星 信彦, 北川 浩

    第93回日本解剖学会近畿支部学術集会, 2017年11月, 日本語, 大津市, 国内会議

    口頭発表(一般)

  • ラット回腸における間質細胞を介した細胞間ネットワーク解析へのSerial Block Face走査型電子顕微鏡の有用性

    万谷洋平, 春田知洋, 西田美穂, 湯浅秀人, 増田なつみ, 横山 俊史, 星 信彦, 北川 浩

    第93回日本解剖学会近畿支部学術集会, 2017年11月, 日本語, 大津市, 国内会議

    口頭発表(一般)

  • マウスのミュラー管退行におけるAMH作用様式

    山本杏, 表原拓也, 三浦由佳, 川西航平, 長谷川千夏, 万谷洋平, 北川 浩, 横山 俊史, 星 信彦

    第93回日本解剖学会近畿支部学術集会, 2017年11月, 日本語, 大津市, 国内会議

    口頭発表(一般)

  • 生理的条件下のラット呼吸器系粘膜における補体成分C3と補体受容体C3aRおよびCD11bの局在に関する免疫組織化学的研究

    吉冨千晶, 増田なつみ, 湯浅秀人, 西田美穂, 万谷洋平, 河野潤一, 横山 俊史, 星 信彦, 北川 浩

    第160回日本獣医学会学術集会, 2017年09月, 日本語, 鹿児島市, 国内会議

    口頭発表(一般)

  • ラットパイエル板におけるlysozyme陽性細胞を介する生体防御機構に関する免疫組織化学的研究

    宮本和樹, 万谷洋平, 湯浅秀人, 西田美穂, 増田なつみ, 横山 俊史, 星 信彦, 北川 浩

    第160回日本獣医学会学術集会, 2017年09月, 日本語, 鹿児島市, 国内会議

    口頭発表(一般)

  • Serial block face-走査型電子顕微鏡を用いたラット回腸腸陰窩周囲の間質細胞に関する3次元超微形態学的解析

    万谷洋平, 春田知洋, 西田美穂, 湯浅秀人, 増田なつみ, 横山 俊史, 星 信彦, 北川 浩

    第160回日本獣医学会学術集会, 2017年09月, 日本語, 鹿児島市, 国内会議

    口頭発表(一般)

  • ニワトリの発生過程に特徴的な生殖腺の左右差

    表原拓也, 南貴一, 万谷 洋平, 朝克吉楽, 梅村ゆりあ, 西田美穂, 平野哲史, 青山裕彦, 吉岡秀文, 北川 浩, 横山 俊史, 星 信彦

    第122回日本解剖学会総会・全国学術集会, 2017年03月, 日本語, 長崎市, 国内会議

    [招待有り]

    口頭発表(招待・特別)

  • 胎子期および発達期におけるネオニコチノイド系農薬曝露がドーパミン神経系および行動に及ぼす影響

    米田直起, 平野哲史, 柳井翔吾, 高田匡, 岩本遥, 表原拓也, 片田裕亮, 万谷 洋平, 横山 俊史, 北川 浩, 星 信彦

    第19回環境ホルモン学会研究発表会, 2016年12月, 日本語, つくば市, 国内会議

    ポスター発表

  • マウス胎子性腺における性分化関連遺伝子転写調節領域のDNAメチル化状態

    久保田直人, 表原拓也, 山本杏, 三浦由佳, 平野哲史, 南貴一, 柳井翔吾, 高田匡, 米田直起, 岩本遥, 万谷 洋平, 横山 俊史, 北川 浩, 星 信彦

    第39回日本分子生物学会年会, 2016年12月, 日本語, 横浜市, 国内会議

    ポスター発表

  • ネオニコチノイド系農薬曝露によりみられた神経行動学的異常および標的脳領域の探索

    平野哲史, 柳井翔吾, 高田匡, 米田直起, 表原拓也, 南貴一, 久保田直人, 万谷 洋平, 横山 俊史, 北川 浩, 星 信彦

    第19回環境ホルモン学会研究発表会, 2016年12月, 日本語, つくば市, 国内会議

    口頭発表(一般)

  • ネオニコチノイド系農薬ジノテフラン曝露はうつ様行動を引き起こすか?

    高田匡, 平野哲史, 柳井翔吾, 米田直起, 岩本遥, 表原拓也, 万谷 洋平, 横山 俊史, 北川 浩, 星 信彦

    第19回環境ホルモン学会研究発表会, 2016年12月, 日本語, つくば市, 国内会議

    口頭発表(一般)

  • ネオニコチノイド系農薬クロチアニジンは胎子型と成獣型,2種類のライディッヒ細胞にそれぞれ異なる影響を及ぼす

    柳井翔吾, 平野哲史, 表原拓也, 高田匡, 米田直起, 岩本遥, 万谷 洋平, 横山 俊史, 北川 浩, 星 信彦

    第19回環境ホルモン学会研究発表会, 2016年12月, 日本語, つくば市, 国内会議

    口頭発表(一般)

  • ラット呼吸器系粘膜を覆う粘液層における β-defensin 1 および β-defensin 2 の存在および分泌源の同定

    増田なつみ, 万谷 洋平, 西田美穂, 湯浅秀人, 河野潤一, 横山 俊史, 星 信彦, 北川 浩

    第92回日本解剖学会近畿支部学術集会, 2016年11月, 日本語, 東大阪市, 国内会議

    口頭発表(一般)

  • ラット回腸粘膜における各種間質細胞の局在

    万谷 洋平, 宮本和樹, 西田美穂, 湯浅秀人, 増田なつみ, 横山 俊史, 星 信彦, 北川 浩

    第92回日本解剖学会近畿支部学術集会, 2016年11月, 日本語, 東大阪市, 国内会議

    口頭発表(一般)

  • ラットパイエル板における濾胞被蓋上皮のアポトーシスとRANK/RANKLの発現との関係

    湯浅秀人, 万谷 洋平, 増田なつみ, 西田美穂, 河野潤一, 横山 俊史, 星 信彦, 北川 浩

    第92回日本解剖学会近畿支部学術集会, 2016年11月, 日本語, 東大阪市, 国内会議

    口頭発表(一般)

  • マウス真性半陰陽個体のミュラー管退行とAMHの作用様式

    山本杏, 表原拓也, 久保田直人, 南貴一, 平野哲史, 万谷 洋平, 北川 浩, 横山 俊史, 星 信彦

    第92回日本解剖学会近畿支部学術集会, 2016年11月, 日本語, 東大阪市, 国内会議

    口頭発表(一般)

  • ニワトリ雌右性腺退縮メカニズムの解明

    南貴一, 表原拓也, 田渕圭章, 平野哲史, 横山 俊史, 万谷 洋平, 北川 浩, 星 信彦

    第92回日本解剖学会近畿支部学術集会, 2016年11月, 日本語, 東大阪市, 国内会議

    口頭発表(一般)

  • 生理学的条件下のラットパイエル板におけるRANK/RANKLの発現および常在細菌の増殖による影響

    湯浅秀人, 増田なつみ, 西田美穂, 河野潤一, 横山 俊史, 万谷 洋平, 星 信彦, 北川 浩

    第159回日本獣医学会学術集会, 2016年09月, 日本語, 藤沢市, 国内会議

    口頭発表(一般)

  • ラット呼吸器におけるβ-defensin 1およびβ-defensin 2を介した分泌型の生体防御機構に関する免疫組織化学的研究

    増田なつみ, 万谷 洋平, 西田美穂, 湯浅秀人, 河野潤一, 横山 俊史, 星 信彦, 北川 浩

    第159回日本獣医学会学術集会, 2016年09月, 日本語, 藤沢市, 国内会議

    口頭発表(一般)

  • ラット回腸におけるtelocyteの免疫組織化学的同定

    万谷 洋平, 宮本和樹, 西田美穂, 湯浅秀人, 増田なつみ, 横山 俊史, 星 信彦, 北川 浩

    第159回日本獣医学会学術集会, 2016年09月, 日本語, 藤沢市, 国内会議

    口頭発表(一般)

  • マウス真性半陰陽個体におけるAMHの作用様式に関する組織学的解析

    山本杏, 表原拓也, 久保田直人, 南貴一, 広川千英, 平野哲史, 磯江美智子, 柳井翔吾, 高田匡, 米田直起, 三浦由佳, 岩本遥, 万谷 洋平, 北川 浩, 横山 俊史, 星 信彦

    第159回日本獣医学会学術集会, 2016年09月, 日本語, 藤沢市, 国内会議

    口頭発表(一般)

  • ネオニコチノイド系農薬曝露とうつ発症との関連性の検証

    高田匡, 平野哲史, 柳井翔吾, 米田直起, 表原拓也, 磯江美智子, 久保田直人, 南貴一, 山本杏, 岩本遥, 三浦由佳, 万谷 洋平, 横山 俊史, 北川 浩, 星 信彦

    第159回日本獣医学会学術集会, 2016年09月, 日本語, 藤沢市, 国内会議

    口頭発表(一般)

  • ネオニコチノイド系農薬ジノテフランによるドーパミン神経系の攪乱および多動性の誘発

    米田直起, 平野哲史, 柳井翔吾, 高田匡, 表原拓也, 久保田直人, 南貴一, 山本杏, 岩本遥, 三浦由佳, 磯江美智子, 万谷 洋平, 横山 俊史, 北川 浩, 星 信彦

    第159回日本獣医学会学術集会, 2016年09月, 日本語, 藤沢市, 国内会議

    口頭発表(一般)

  • ネオニコチノイド系農薬クロチアニジン急性投与が及ぼす行動学的影響とその作用点

    平野哲史, 柳井翔吾, 高田匡, 米田直起, 表原拓也, 久保田直人, 南貴一, 山本杏, 岩本遥, 三浦由佳, 磯江美智子, 万谷 洋平, 横山 俊史, 北川 浩, 星 信彦

    第159回日本獣医学会学術集会, 2016年09月, 日本語, 藤沢市, 国内会議

    口頭発表(一般)

  • 発達期におけるネオニコチノイド系農薬曝露により多動が引き起こされる

    米田直起, 平野哲史, 柳井翔吾, 高田匡, 表原拓也, 磯江美智子, 久保田直人, 南貴一, 広川千英, 山本杏, 岩本遥, 三浦由佳, 万谷 洋平, 横山 俊史, 北川 浩, 星 信彦

    第56回 先天異常学会学術集会, 2016年07月, 日本語, 姫路市, 国内会議

    ポスター発表

  • 発達期におけるネオニコチノイド系農薬ジノテフラン曝露とうつ病発症との関係

    高田匡, 平野哲史, 柳井翔吾, 米田直起, 表原拓也, 磯江美智子, 久保田直人, 南貴一, 広川千英, 山本杏, 岩本遥, 三浦由佳, 万谷 洋平, 横山 俊史, 北川 浩, 星 信彦

    第56回 先天異常学会学術集会, 2016年07月, 日本語, 姫路市, 国内会議

    ポスター発表

  • 胎子期から成獣期にかけてのネオニコチノイド系農薬クロチアニジン曝露が及ぼす行動学的影響

    平野哲史, 柳井翔吾, 高田匡, 米田直起, 表原拓也, 磯江美智子, 久保田直人, 南貴一, 広川千英, 山本杏, 岩本遥, 三浦由佳, 万谷 洋平, 横山 俊史, 北川 浩, 星 信彦

    第56回 先天異常学会学術集会, 2016年07月, 日本語, 姫路市, 国内会議

    ポスター発表

  • ネオニコチノイド系農薬クロチアニジン単回投与によりみられた異常啼鳴および神経行動学的影響

    平野哲史, 柳井翔吾, 高田匡, 米田直起, 表原拓也, 久保田直人, 南貴一, 広川千英, 山本杏, 万谷 洋平, 横山 俊史, 北川 浩, 星 信彦

    第43回日本毒性学会学術年会, 2016年06月, 日本語, 名古屋市, 国内会議

    ポスター発表

  • ニワトリ胚の性腺発生における左右差

    表原拓也, 南貴一, 万谷洋平, 梅村ゆりあ, 西田 美穂, 平野哲史, 吉岡 秀文, 北川浩, 横山俊史, 星信彦

    第121回日本解剖学会総会・全国学術集会, 2016年03月, 日本語, 郡山市, 国内会議

    口頭発表(一般)

  • 環境ストレス下においてネオニコチノイド系農薬クロチアニジンが与える神経行動学的影響

    平野哲史, 柳井翔吾, 表原拓也, 高田匡, 米田直起, 梅村ゆりあ, 久保田直人, 南貴一, 広川千英, 山本杏, 万谷洋平, 横山俊史, 北川浩, 星信彦

    環境ホルモン学会第18回研究発表会, 2015年12月, 日本語, 下野市, 国内会議

    ポスター発表

  • ネオニコチノイド系農薬クロチアニジンの妊娠期及び授乳期曝露がマウス産子の雄性生殖器に与える影響

    柳井翔吾, 平野哲史, 表原拓也, 高田匡, 米田直起, 梅村ゆりあ, 久保田直人, 南貴一, 広川千英, 山本杏, 万谷洋平, 横山俊史, 北川浩, 星信彦

    環境ホルモン学会第18回研究発表会, 2015年12月, 日本語, 下野市, 国内会議

    ポスター発表

  • ニワトリ胚の左精巣に特異的なセルトリ細胞の起源

    表原拓也, 万谷洋平, 南貴一, 梅村ゆりあ, 平野哲史, 横山俊史, 北川浩, 星信彦

    第38回日本分子生物学会年会・第88回日本生化学会大会合同大会, 2015年12月, 日本語, 神戸市, 国内会議

    口頭発表(一般)

  • 生理学的条件下におけるラットパイエル板濾胞被蓋上皮におけるToll-like receptor-4の発現とM細胞への分化との関係について

    湯浅秀人, 万谷洋平, 増田なつみ, 西田美穂, 河野潤一, 横山俊史, 星信彦, 北川浩

    第91回日本解剖学会・近畿支部学術集会, 2015年11月, 日本語, 京都市, 国内会議

    口頭発表(一般)

  • 性逆転系統(B6-XYPOS)マウスにおける性腺分化と遺伝的背景

    梅村ゆりあ, 表原拓也, 平野哲史, 久保田直人, 柳井翔吾, 増田なつみ, 湯浅秀人, 万谷洋平, 北川浩, 横山俊史, 星信彦

    第91回日本解剖学会・近畿支部学術集会, 2015年11月, 日本語, 京都市, 国内会議

    口頭発表(一般)

  • ラット呼吸器系粘膜を覆う液相に含まれるlysozymeおよびsPLA2の分泌源の特定

    増田なつみ, 万谷洋平, 西田美穂, 湯浅秀人, 河野潤一, 横山俊史, 星信彦, 北川浩

    第91回日本解剖学会・近畿支部学術集会, 2015年11月, 日本語, 京都市, 国内会議

    口頭発表(一般)

  • ラット回腸における間質細胞telocyteに関する超微形態学的研究

    万谷洋平, 西田美穂, 湯浅秀人, 増田なつみ, 横山俊史, 星信彦, 北川浩

    第91回日本解剖学会・近畿支部学術集会, 2015年11月, 日本語, 京都市, 国内会議

    口頭発表(一般)

  • ニワトリ胚の左性腺に特異的な細胞運命の追跡

    表原拓也, 南貴一, 万谷洋平, 梅村ゆりあ, 西田美穂, 平野哲史, 吉岡秀文, 横山俊史, 北川浩, 星信彦

    第91回日本解剖学会・近畿支部学術集会, 2015年11月, 日本語, 京都市, 国内会議

    口頭発表(一般)

  • ニワトリの性腺形態における左右差形成メカニズムの解明

    南 貴一, 表原拓也, 田渕圭章, 梅村ゆりあ, 平野哲史, 横山俊史, 北川 浩, 星 信彦

    第91回日本解剖学会・近畿支部学術集会, 2015年11月, 日本語, 京都市, 国内会議

    口頭発表(一般)

  • 環境ストレス下において浸透性農薬クロチアニジンが行動及び生殖機能に与える影響

    平野哲史, 柳井翔吾, 表原拓也, 梅村ゆりあ, 久保田直人, 南貴一, 高田匡, 米田直起, 広川千英, 山本杏, 万谷洋平, 横山俊史, 北川浩, 星信彦

    第158回日本獣医学会, 2015年09月, 日本語, 十和田市, 国内会議

    口頭発表(一般)

  • ラット小腸のPaneth細胞に連絡する粘膜固有層細胞の超微形態

    万谷洋平, 西田美穂, 湯浅秀人, 増田なつみ, 横山俊史, 星信彦, 北川浩

    第158回日本獣医学会, 2015年09月, 日本語, 十和田市, 国内会議

    口頭発表(一般)

  • ラット呼吸器系におけるlysozymeおよびsPLA2の分泌上皮細胞に関する免疫組織化学的研究

    増田なつみ, 万谷洋平, 西田美穂, 湯浅秀人, 河野潤一, 横山俊史, 星信彦, 北川浩

    第158回日本獣医学会, 2015年09月, 日本語, 十和田市, 国内会議

    口頭発表(一般)

  • ラットパイエル板濾胞被蓋上皮におけるToll-like receptor-2, -4および-9の発現に対する常在細菌増殖の影響

    湯浅秀人, 万谷洋平, 増田なつみ, 西田美穂, 河野潤一, 横山俊史, 星信彦, 北川浩

    第158回日本獣医学会, 2015年09月, 日本語, 十和田市, 国内会議

    口頭発表(一般)

  • ニワトリ胚における左精巣特異的な発生メカニズム

    表原拓也, 万谷洋平, 南貴一, 梅村ゆりあ, 平野哲史, 横山俊史, 北川浩, 星信彦

    日本家禽学会2015年度秋季大会, 2015年09月, 日本語, 江別市, 国内会議

    口頭発表(一般)

  • ニワトリ性腺の左右差形成メカニズムに関する網羅的遺伝子発現解析

    南 貴一, 表原拓也, 田渕圭章, 梅村ゆりあ, 平野哲史, 北川 浩, 横山俊史, 星 信彦

    日本家禽学会2015年度秋季大会, 2015年09月, 日本語, 江別市, 国内会議

    口頭発表(一般)

  • The short-term effect of peptidoglycan injected into the intestinal lumen against host defense responses.

    MANTANI YOUHEI, MIYAMOTO KAZUKI, MATSUMORI SEIKO, YUASA HIDETO, MASUDA NATSUMI, YOKOYAMA TOSHIFUMI, HOSHI NOBUHIKO, KITAGAWA HIROSHI

    17th International Congress of Mucosal Immunology, 2015年07月, 英語, Berlin, Germany, 国際会議

    ポスター発表

  • C57BL/6マウスの不可思議さ:その遺伝的背景に潜むSry-HMG box & Q-rich領域と性決定

    梅村ゆりあ, 橋本理恵, 表原拓也, 長原大知, 平野哲史, 久保田直人, 南貴一, 柳井翔吾, 万谷 洋平, 横山 俊史, 北川 浩, 星 信彦

    第62回日本実験動物学会, 2015年05月, 日本語, 京都市, 国内会議

    ポスター発表

  • Sex-related genes' asymmetric expression in early mouse gonads

    梅村 ゆりあ, 橋本 理恵, 表原 拓也, 平野 哲史, 長原 大知, 湯浅 秀人, 久保田 直人, 南 貴一, 柳井 翔吾, 万谷 洋平, 横山 俊史, 北川 浩, 星 信彦

    第120回 日本解剖学会総会・全国学術集会, 2015年03月, 日本語, 神戸市, 国内会議

    ポスター発表

  • Selection of stable reference genes for quantitative RT-PCR analyses in developing mouse gonads

    横山 俊史, 橋本 理恵, 梅村 ゆりあ, 表原 拓也, 平野 哲史, 長原 大知, 柳井 翔吾, 南 貴一, 久保田 直人, 万谷 洋平, 北川 浩, 星 信彦

    第120回 日本解剖学会総会・全国学術集会, 2015年03月, 日本語, 神戸市, 国内会議

    ポスター発表

  • Reproductive and behavioral effects of clothianidin in male mice in a chronically stressed condition

    平野 哲史, 柳井 翔吾, 表原 拓也, 橋本 理恵, 梅村 ゆりあ, 久保田 直人, 南 貴一, 万谷 洋平, 横山 俊史, 北川 浩, 星 信彦

    第120回 日本解剖学会総会・全国学術集会, 2015年03月, 日本語, 神戸市, 国内会議

    ポスター発表

  • Light and Electron Microscopical Study on the Particulate Bodies Found in Epithelium of Rat Airway.

    MANTANI YOUHEI, NISHIDA MIHO, YUASA HIDETO, MASUDA NATSUMI, TAKAHARA EIICHIROU, YOKOYAMA TOSHIFUMI, HOSHI NOBUHIKO, KITAGAWA HIROSHI

    第120回 日本解剖学会総会・全国学術集会, 2015年03月, 日本語, 神戸市, 国内会議

    ポスター発表

  • Left-right asymmetry of testicular formation in the chicken embryo

    表原 拓也, 橋本 理恵, 梅村 ゆりあ, 平野 哲史, 南 貴一, 長原 大知, 湯浅 秀人, 久保田 直人, 柳井 翔吾, 万谷 洋平, 横山 俊史, 北川 浩, 星 信彦

    第120回 日本解剖学会総会・全国学術集会, 2015年03月, 日本語, 神戸市, 国内会議

    ポスター発表

  • Differential Expression of Toll-like Receptor-2,-4 and -9 in the Various Type of Epithelia Associated with Rat Peyer’s Patches

    湯浅 秀人, 万谷 洋平, 西田 美穂, 高原 英一郎, 増田 なつみ, 河野 潤一, 横山 俊史, 星 信彦, 北川 浩

    第120回 日本解剖学会総会・全国学術集会, 2015年03月, 日本語, 神戸市, 国内会議

    ポスター発表

  • 消化管付属リンパ組織、パイエル板の上皮におけるToll-like receptor-2、-4および-9の発現に関する免疫組織化学的研究

    湯浅 秀人, 万谷 洋平, 横山 俊史, 星 信彦, 北川 浩

    神戸大学研究基盤センター若手フロンティア研究会2014, 2014年12月, 日本語, 神戸市, 国内会議

    ポスター発表

  • 環境ストレス下動物の生殖機能抑制機序に関する形態機能学的研究

    平野 哲史, 柳井 翔吾, 表原 拓也, 橋本 理恵, 梅村 ゆりあ, 久保田 直人, 南 貴一, 万谷 洋平, 横山 俊史, 北川 浩, 星 信彦

    環境ホルモン学会第17回研究発表会, 2014年12月, 日本語, 京都市, 国内会議

    口頭発表(一般)

  • 発生中のマウス胎子生殖腺における内部標準遺伝子の検討

    横山 俊史, 橋本 理恵, 梅村 ゆりあ, 表原 拓也, 長原 大知, 平野 哲史, 久保田 直人, 南 貴一, 湯浅 秀人, 柳井 翔吾, 万谷 洋平, 北川 浩, 星 信彦

    第157回日本獣医学会学術集会, 2014年09月, 日本語, 札幌市, 国内会議

    口頭発表(一般)

  • 通常飼育下のラットの呼吸器系に吸入された粒子状物の粘膜上皮への取り込みに関する組織学的研究

    万谷 洋平, 西田 美穂, 湯浅 秀人, 高原 英一郎, 河野 潤一, 横山 俊史, 星 信彦, 北川 浩

    第157回日本獣医学会学術集会, 2014年09月, 日本語, 札幌市, 国内会議

    口頭発表(一般)

  • ラット呼吸器系粘膜上皮におけるToll-like receptor -1-9の局在に関する網羅的解析

    池邊 正大, 万谷 洋平, 西田 美穂, 湯浅 秀人, 高原 英一郎, 河野 潤一, 横山 俊史, 星 信彦, 北川 浩

    第157回日本獣医学会学術集会, 2014年09月, 日本語, 札幌市, 国内会議

    口頭発表(一般)

  • ラットパイエル板濾胞被蓋上皮および濾胞付属腸絨毛の上皮におけるToll-like receptor-2,-4および-9の発現特性

    湯浅 秀人, 万谷 洋平, 西田 美穂, 高原 英一郎, 河野 潤一, 横山 俊史, 星 信彦, 北川 浩

    第157回日本獣医学会学術集会, 2014年09月, 日本語, 札幌市, 国内会議

    口頭発表(一般)

  • マウス胎子生殖腺における性分化関連遺伝子発現の左右差に関する分子形態学的研究

    橋本 理恵, 梅村 ゆりあ, 表原 拓也, 平野 哲史, 長原 大知, 湯浅 秀人, 久保田 直人, 南 貴一, 柳井 翔吾, 万谷 洋平, 横山 俊史, 北川 浩, 星 信彦

    第157回日本獣医学会学術集会, 2014年09月, 日本語, 札幌市, 国内会議

    口頭発表(一般)

  • ネオニコチノイド系農薬クロチアニジンの低用量曝露とストレスの複合影響

    平野 哲史, 表原 拓也, 橋本 理恵, 梅村 ゆりあ, 久保田 直人, 南 貴一, 柳井 翔吾, 長原 大知, 湯浅 秀人, 万谷 洋平, 横山 俊史, 北川 浩, 星 信彦

    第157回日本獣医学会学術集会, 2014年09月, 日本語, 札幌市, 国内会議

    口頭発表(一般)

  • ニワトリ胚における性腺の形成機構とその左右差

    表原 拓也, 橋本 理恵, 梅村 ゆりあ, 平野 哲史, 南 貴一, 長原 大知, 湯浅 秀人, 万谷 洋平, 横山 俊史, 北川 浩, 星 信彦

    日本家禽学会2014年度秋季大会, 2014年09月, 日本語, 鹿児島市, 国内会議

    口頭発表(一般)

  • ニワトリ胚における性腺の形成メカニズムと左右差

    表原 拓也, 橋本 理恵, 梅村 ゆりあ, 平野 哲史, 南 貴一, 長原 大知, 湯浅 秀人, 久保田 直人, 柳井 翔吾, 万谷 洋平, 横山 俊史, 北川 浩, 星 信彦

    第157回日本獣医学会学術集会, 2014年09月, 日本語, 札幌市, 国内会議

    口頭発表(一般)

  • ネオニコチノイド系農薬による生殖機能障害とそのメカニズム

    平野 哲史, 徳本 順子, 横山 俊史, 北川 浩, 星 信彦

    日本薬学会第134年会, 2014年03月, 日本語, 国内会議

    [招待有り]

    シンポジウム・ワークショップパネル(指名)

  • セルトリ細胞の成熟に対する細胞接着の影響

    横山 俊史, 金 聖民, Ferhat Ulu, 山崎 由起子

    第89回日本解剖学会近畿支部学術集会, 2013年11月, 日本語, 奈良市, 国内会議

    口頭発表(一般)

  • 性腺分化とその破綻メカニズムに関する分子形態学的研究

    表原 拓也, 木下 今日子, 長原 大知, 段上 めぐみ, 徳本 順子, 小林 泰丈, 辰巳 敬哉, 橋本 理恵, 平野 哲史, 梅村 ゆりあ, 横山 俊史, 北川 浩, 星 信彦

    第156回日本獣医学会学術集会, 2013年09月, 日本語, 岐阜市, 国内会議

    口頭発表(一般)

  • ラット上行結腸の集合リンパ小節近傍の腸陰窩に出現するパネート細胞様外分泌細胞に関する超微形態学的および組織化学的研究

    万谷 洋平, 高原 英一郎, 河野 潤一, 横山 俊史, 星 信彦, 北川 浩

    第156回日本獣医学会学術集会, 2013年09月, 日本語, 岐阜市, 国内会議

    口頭発表(一般)

  • ラット上行結腸における酸好性顆粒を有する腸陰窩上皮細胞に関する形態学的研究

    万谷 洋平, 高原 英一郎, 河野 潤一, 横山 俊史, 星 信彦, 北川 浩

    第89回日本解剖学会近畿支部学術集会, 2013年09月, 日本語, 岐阜市, 国内会議

    口頭発表(一般)

  • ラット空腸の腸絨毛における小型乳ビ球の門脈血への移行の仕組みに関する免疫組織化学的研究

    高原 英一郎, 万谷 洋平, 横山 俊史, 星 信彦, 北川 浩

    第156回日本獣医学会学術集会, 2013年09月, 日本語, 岐阜市, 国内会議

    口頭発表(一般)

  • ラットの消化器系における補体成分C3とC4の産生部位に関する免疫組織化学的研究

    又吉 緑, 万谷 洋平, 高原 英一郎, 横山 俊史, 河野 潤一, 星 信彦, 北川 浩

    第156回日本獣医学会学術集会, 2013年09月, 日本語, 岐阜市, 国内会議

    口頭発表(一般)

  • ネオニコチノイド系農薬クロチアニジンが鳥類の繁殖能力に及ぼす影響とその作用機序

    徳本 順子, 星 信彦, 橋口 峰雄, 表原 拓也, 小林 泰丈, 辰巳 敬哉, 平野 哲史, 橋本 理恵, 梅村 ゆりあ, 長原 大知, 関島 恒夫, 上曽山 博, 横山 俊史, 北川 浩

    第156回日本獣医学会学術集会, 2013年09月, 日本語, 岐阜市, 国内会議

    口頭発表(一般)

  • ウミガメの総排泄腔傍嚢の形態機能学的特徴

    辰巳 敬哉, 亀崎 直樹, 藍原 祥子, 山下 真路, 谷口 真理, 三根 佳奈子, 坂本 未来, 表原 拓也, 小林 泰丈, 横山 俊史, 北川 浩, 今川 智敬, 星 信彦

    第156回日本獣医学会学術集会, 2013年09月, 日本語, 岐阜市, 国内会議

    口頭発表(一般)

  • Effect of Cell-Cell contact on the maturation of Sertoli cells

    横山 俊史, 金 聖民, Ferhat Ulu, 山崎 由起子

    第156回日本獣医学会学術集会, 2013年09月, 日本語, 岐阜市, 国内会議

    口頭発表(一般)

  • 環境ストレス下動物の生殖機能抑制機序に関する形態機能学的研究

    平野 哲史, 小林 泰丈, 表原 拓也, 辰巳 敬哉, 橋本 理恵, 梅村 ゆりあ, 長原 大知, 横山 俊史, 北川 浩, 星 信彦

    第19回日本野生動物医学会大会, 2013年08月, 日本語, 京都市, 国内会議

    ポスター発表

  • カメ類における「膀胱」の形態機能学的定義

    辰巳 敬哉, 亀崎 直樹, 藍原 祥子, 山下 真路, 谷口 真理, 三根 佳奈子, 坂本 未来, 表原 拓也, 小林 泰丈, 横山 俊史, 北川 浩, 今川 智敬, 星 信彦

    第19回日本野生動物医学会大会, 2013年08月, 日本語, 京都市, 国内会議

    ポスター発表

  • Cell-Cell contact is essential for Sertoli cell maturation.

    YOKOYAMA TOSHIFUMI, KIM SUNG-MIN, ULU FERHAT, YAMAZAKI YUKIKO

    Biomedical Sciences and Health Disparities Symposium, 2013年04月, 英語, Honolulu City, Hawaii,, 国際会議

    ポスター発表

  • 生後発達期におけるTCDDの神経発達障害の分子基盤

    段上 めぐみ, 田阪 健, 長原 大知, 木下 今日子, 徳本 順子, 表原 拓也, 小林 秦丈, 辰巳 敬哉, 谷田 任司, 横山 俊史, 菅野 美津子, 赤星 英一, 北川 浩, 星 信彦

    第88回日本解剖学会近畿支部学術集会, 2012年12月, 日本語, 神戸市, 国内会議

    口頭発表(一般)

  • 生後発達期におけるTCDDによる神経発達障害の分子基盤

    段上 めぐみ, 田阪 健, 木下 今日子, 徳本 順子, 表原 拓也, 小林 泰丈, 辰巳 敬哉, 谷田 任司, 赤星 英一, 菅野 美津子, 横山 俊史, 北川 浩, 星 信彦

    第15回環境ホルモン学会研究発表会, 2012年12月, 日本語, 東京,文京区, 国内会議

    口頭発表(一般)

  • 性腺分化と性分化カスケードに関する分子形態学的研究

    木下 今日子, 長原 大知, 段上 めぐみ, 徳本 順子, 表原 拓也, 小林 泰丈, 辰巳 敬哉, 横山 俊史, 北川 浩, 星 信彦

    第88回日本解剖学会近畿支部学術集会, 2012年12月, 日本語, 神戸市, 国内会議

    口頭発表(一般)

  • ラット上行結腸腸陰窩における常在細菌の増殖に対する生体防御に関する研究

    万谷 洋平, 高原 英一郎, 河野 潤一, 横山 俊史, 星 信彦, 北川 浩

    第88回日本解剖学会近畿支部学術集会, 2012年12月, 日本語, 神戸市, 国内会議

    口頭発表(一般)

  • ラット十二指腸粘膜上皮におけるMyeloid differentiation factor-2とToll-like receptor-2の発現に関する免疫組織化学的研究

    樅山 真丈, 万谷 洋平, 高原 英一郎, 河野 潤一, 横山 俊史, 星 信彦, 北川 浩

    第88回日本解剖学会近畿支部学術集会, 2012年12月, 日本語, 神戸市, 国内会議

    口頭発表(一般)

  • ラット空腸腸絨毛の毛細血管内皮における乳ビ球に対する受容体に関する免疫組織化学的研究

    高原 英一郎, 万谷 洋平, 樅山真丈, 又吉 緑, 横山 俊史, 星 信彦, 北川 浩

    第88回日本解剖学会近畿支部学術集会, 2012年12月, 日本語, 神戸市, 国内会議

    口頭発表(一般)

  • ラット肝臓における補体C3およびC4の産生に関する免疫組織化学的研究

    又吉 緑, 万谷 洋平, 高原 英一郎, 河野 潤一, 横山 俊史, 星 信彦, 北川 浩

    第88回日本解剖学会近畿支部学術集会, 2012年12月, 日本語, 神戸市, 国内会議

    口頭発表(一般)

  • マウス胎子海馬の神経発達に及ぼすTCDD毒性の基礎的評価

    小林 泰丈, 段上 めぐみ, 徳本 順子, 長原 大知, 木下 今日子, 表原 拓也, 辰巳 敬哉, 横山 俊史, 北川 浩, 星 信彦

    第15回環境ホルモン学会研究発表会, 2012年12月, 日本語, 東京,文京区, 国内会議

    口頭発表(一般)

  • ネオニコチノイド系農薬が鳥類の繁殖能力に及ぼす影響の分子形態学的研究

    徳本 順子, 段上 めぐみ, 小林 泰丈, 木下 今日子, 表原 拓也, 辰巳 敬哉, 橋口 峰雄, 関島 恒夫, 上曽山 博, 横山 俊史, 北川 浩, 星 信彦

    第15回環境ホルモン学会研究発表会, 2012年12月, 日本語, 東京,文京区, 国内会議

    口頭発表(一般)

  • ネオニコチノイド系農薬が鳥類の繁殖能力に及ぼす影響の基礎的評価

    徳本 順子, 長原 大知, 木下 今日子, 段上 めぐみ, 表原 拓也, 小林 泰丈, 辰巳 敬哉, 橋口 峰雄, 関島 恒夫, 上曽山 博, 横山 俊史, 北川 浩, 星 信彦

    第88回日本解剖学会近畿支部学術集会, 2012年12月, 日本語, 神戸市, 国内会議

    口頭発表(一般)

  • カメ類における「膀胱」の形態機能学的研究

    辰巳 敬哉, 亀崎 直樹, 藍原 祥子, 山下 真路, 谷口 真理, 三根 佳奈子, 坂本 未来, 木下 今日子, 横山 俊史, 北川 浩, 今川 智敬, 金沢 和樹, 星 信彦

    第51回日本爬虫類両棲類学会, 2012年11月, 日本語, 豊田市, 国内会議

    口頭発表(一般)

  • 遺伝子改変性転換マウス(Ypos)の真性半陰陽個体生殖腺における発生形態学的研究

    橋本 理恵, 長原 大知, 木下 今日子, 段上 めぐみ, 徳本 順子, 安田 玲子, 表原 拓也, 小林 泰丈, 辰巳 敬哉, 横山 俊史, 北川 浩, 星 信彦

    新学術領域研究「性差構築の分子基盤」若手研究会, 2012年10月, 日本語, 和歌山市, 国内会議

    口頭発表(一般)

  • ニワトリ胚における性分化関連遺伝子の時空間的発現に関する分子形態学的研究

    表原 拓也, 長原 大知, 木下 今日子, 段上 めぐみ, 徳本 順子, 安田 玲子, 小林 泰丈, 辰巳 敬哉, 横山 俊史, 北川 浩, 星 信彦

    新学術領域研究「性差構築の分子基盤」若手研究会, 2012年10月, 日本語, 和歌山市, 国内会議

    口頭発表(一般)

  • ターナーモザイク患者の性腺分化とその破綻機構の分子基盤の解明

    長原 大知, 森實 真由美, 蛯名 康彦, 木下 今日子, 段上 めぐみ, 徳本 順子, 安田 玲子, 表原 拓也, 小林 泰丈, 辰巳 敬哉, 横山 俊史, 北川 浩, 山田秀人, 星 信彦

    新学術領域研究「性差構築の分子基盤」若手研究会, 2012年10月, 日本語, 和歌山市, 国内会議

    口頭発表(一般)

  • Y染色体腕間逆位を有するXY女性におけるSRY遺伝⼦子のエピジェネティック異常

    星 信彦, 割田(三觜) 友子, 割田 克彦, 田渕 圭章, 横山 俊史, 北川 浩, 櫻木 範明

    新学術領域研究「性差構築の分子基盤」若手研究会, 2012年10月, 日本語, 和歌山市, 国内会議

    口頭発表(一般)

  • ラット小腸腸陰窩上皮細胞の細胞死に関する超微形態学的および免疫組織化学的研究

    山本 教司, 樅山 真丈, UDAYANGA KANKANAM, GAMAGE SANATH, 万谷 洋平, 高原 英一郎, 竹内 崇師, 横山 俊史, 河野 潤一, 星 信彦, 北川 浩

    第154回日本獣医学会学術集会, 2012年09月, 日本語, 盛岡市, 国内会議

    口頭発表(一般)

  • ラットの上行結腸における常在細菌の定着とその制御に関する定量組織学的研究

    万谷 洋平, 高原 英一郎, 竹内 崇師, 河野 潤一, 横山 俊史, 星 信彦, 北川 浩

    第154回日本獣医学会学術集会, 2012年09月, 日本語, 盛岡市, 国内会議

    口頭発表(一般)

  • マウス胎子の海馬におけるTCDDの神経発達毒性

    小林 泰丈, 長原 大知, 木下 今日子, 段上 めぐみ, 徳本 順子, 安田 玲子, 表原 拓也, 辰巳 敬哉, 横山 俊史, 北川 浩, 星 信彦

    第154回日本獣医学会学術集会, 2012年09月, 日本語, 盛岡市, 国内会議

    口頭発表(一般)

  • ネオニコチノイド系殺虫剤が鳥類の繁殖能力に及ぼす影響の基礎的評価

    徳本 順子, 谷口 和美, 竹中 亜紗実, 長原 大知, 木下 今日子, 段上 めぐみ, 安田 玲子, 表原 拓也, 小林 泰丈, 辰巳 敬哉, 橋口 峰雄, 関島 恒夫, 上曽山 博, 横山 俊史, 北川 浩, 星 信彦

    第154回日本獣医学会学術集会, 2012年09月, 日本語, 盛岡市, 国内会議

    口頭発表(一般)

  • ニワトリ胚における性分化関連遺伝子の時空間的発現に関する分子形態学的研究

    表原 拓也, 長原 大知, 木下 今日子, 段上 めぐみ, 徳本 順子, 安田 玲子, 小林 泰丈, 辰巳 敬哉, 横山 俊史, 北川 浩, 星 信彦

    第154回日本獣医学会学術集会, 2012年09月, 日本語, 盛岡市, 国内会議

    口頭発表(一般)

  • ターナーモザイク患者の性腺分化とその破綻機構の分子基盤の解明

    長原 大知, 森實 真由美, 蛯名 康彦, 木下 今日子, 段上 めぐみ, 徳本 順子, 安田 玲子, 表原 拓也, 小林 泰丈, 辰巳 敬哉, 横山 俊史, 北川 浩, 山田 秀人, 星 信彦

    第154回日本獣医学会学術集会, 2012年09月, 日本語, 盛岡市, 国内会議

    口頭発表(一般)

  • カメ類における「膀胱」の形態機能学的解析

    辰巳 敬哉, 亀崎 直樹, 山下 真路, 長原 大知, 木下 今日子, 段上 めぐみ, 徳本 順子, 安田 玲子, 表原 拓也, 小林 泰丈, 横山 俊史, 北川 浩, 今川 智敬, 星 信彦

    第154回日本獣医学会学術集会, 2012年09月, 日本語, 盛岡市, 国内会議

    口頭発表(一般)

  • 胎子・授乳期TCDD曝露による発達中のセロトニン神経系への影響とその作用機序

    段上 めぐみ, 須谷 真巳, 石川 恭子, 藤井 裕香, 木下 今日子, 安田 玲子, 谷田 任司, 横山 俊史, 北川 浩, 星 信彦

    第87回日本解剖学会近畿支部学術集会, 2011年12月, 日本語, 西宮市, 国内会議

    口頭発表(一般)

  • 胎子・授乳期TCDD曝露と胸腺微小環境の変化

    星 信彦, 石川 恭子, 須谷 真己, 藤井 裕香, 段上 めぐみ, 木下 今日子, 安田 玲子, 長原 大知, 谷田 任司, 横山 俊史, 北川 浩

    第87回日本解剖学会近畿支部学術集会, 2011年12月, 日本語, 西宮市, 国内会議

    口頭発表(一般)

  • ラットの大腸粘膜上皮におけるToll-like receptorの発現と分泌

    万谷 洋平, 亀崎 青沙, UDAYANGA KANKANAM, GAMAGE SANATH, 高原 英一郎, 谷田 任司, 河野 潤一, 横山 俊史, 星 信彦, 北川 浩

    第87回日本解剖学会近畿支部学術集会, 2011年12月, 日本語, 西宮市, 国内会議

    口頭発表(一般)

  • ラットの呼吸器粘膜におけるToll-like receptorの発現と分泌

    亀崎 青沙, 万谷 洋平, UDAYANGA KANKANAM, GAMAGE SANATH, 高原 英一郎, 谷田 任司, 河野 潤一, 横山 俊史, 星 信彦, 北川 浩

    第87回日本解剖学会近畿支部学術集会, 2011年12月, 日本語, 西宮市, 国内会議

    口頭発表(一般)

  • Acceleration of Epithelial Apoptosis through the Secondary Activation of Mitochondria-Dependent Pathway in the Indigenous Bacteria Settlement Sites of Rat Tongue

    UDAYANGA KANKANAM, GAMAGE SANATH, YAMAMOTO KYOJI, MANTANI YOUHEI, TAKAHARA EI-ICHIRO, KAMEZAKI AOSA, TANIDA TAKASHI, YOKOYAMA TOSHIFUMI, KAWANO JUNICHI, HOSHI NOBUHIKO, KITAGAWA HIROSHI

    第87回日本解剖学会近畿支部学術集会, 2011年12月, 日本語, 西宮市, 国内会議

    口頭発表(一般)

  • Mitochondria-Dependent Pathway as a Final Apoptosis Process Secondarily Induced in Rat Esophageal Epithelium under a Physiological Condition

    UDAYANGA KANKANAM, GAMAGE SANATH, MIYATA HIDENORI, YOKOO YUH, TAKAHARA EI-ICHIRO, MANTANI YOHEI, YOKOYAMA TOSHIFUMI, HOSHI NOBUHIKO, KITAGAWA HIROSHI

    2011 Mitochondria, Apoptosis and Cancer Conference, 2011年10月, 英語, Singapore, 国際会議

    ポスター発表

  • 胎子・授乳期TCDD曝露による発達中のセロトニン神経系への影響に関する分子形態学的研究

    段上 めぐみ, 須谷 真巳, 石川 恭子, 藤井 裕香, 木下 今日子, 安田 玲子, 谷田 任司, 横山 俊史, 北川 浩, 星 信彦

    第152回日本獣医学会学術集会, 2011年09月, 日本語, 堺市, 国内会議

    口頭発表(一般)

  • 胎子・授乳期TCDD曝露がマウス胸腺微小環境に及ぼす影響に関する分子形態学的研究

    横山 俊史, 石川 恭子, 須谷 真己, 藤井 裕香, 段上 めぐみ, 木下 今日子, 安田 玲子, 谷田 任司, 北川 浩, 星 信彦

    第152回日本獣医学会学術集会, 2011年09月, 日本語, 堺市, 国内会議

    口頭発表(一般)

  • ラット大腸におけるToll-like receptorの局在に関する免疫組織化学的研究

    万谷 洋平, UDAYANGA KANKANAM, GAMAGE SANATH, 高原 英一郎, 河野 潤一, 横山 俊史, 星 信彦, 北川 浩

    第152回日本獣医学会学術集会, 2011年09月, 日本語, 堺市, 国内会議

    口頭発表(一般)

  • ラット呼吸器系上皮におけるToll-like receptorの局在に関する免疫組織化学的研究

    亀崎 青沙, 万谷 洋平, UDAYANGA KANKANAM, GAMAGE SANATH, 高原 英一郎, 谷田 任司, 河野 潤一, 横山 俊史, 星 信彦, 北川 浩

    第152回日本獣医学会学術集会, 2011年09月, 日本語, 堺市, 国内会議

    口頭発表(一般)

  • Acceleration of epithelial apoptosis in anterior epithelial column of filiform papilla in rat tongue by indigenous bacterial settlement.

    UDAYANGA KANKANAM, GAMAGE SANATH, YAMAMOTO KYOUJI, MANTANI YOUHEI, TAKAHARA EI-ICHIRO, TANIDA TAKASHI, YOKOYAMA TOSHIFUMI, KAWANO JUNICHI, HOSHI NOBUHIKO, KITAGAWA HIROSHI

    第152回日本獣医学会学術集会, 2011年09月, 日本語, 堺市, 国内会議

    口頭発表(一般)

  • 中脳発達における環境中化学物質のAhR介在性分化制御機構の解明

    段上 めぐみ, 田阪 健, 須谷 真巳, 石川 恭子, 横山 俊史, 赤星 英一, 菅野 美津子, 北川 浩, 星 信彦

    環境ホルモン学会(日本内分泌攪乱化学物質学会)第13回研究発表会, 2010年12月, 日本語, 東京,文京区, 国内会議

    ポスター発表

  • 逆転症系統(Ypos)由来半陰陽マウスの生殖腺における発生形態学的研究

    横山 俊史, 宮本 良介, 土居 弘明, 田阪 健, 橋本 佳樹, 藤井 裕香, 石川 恭子, 須谷 真巳, 長原 大知, 三觜 友子, 北川 浩, 星 信彦

    第86回日本解剖学会近畿支部学術集会, 2010年11月, 日本語, 泉佐野市, 国内会議

    口頭発表(一般)

  • ラット消化管付属分泌腺からのToll-like receptorの分泌に関する免疫組織化学的研究

    万谷 洋平, UDAYANGA KANKANAM, GAMAGE SANATH, 高原 英一郎, 河野 潤一, 横山 俊史, 星 信彦, 北川 浩

    第86回日本解剖学会近畿支部学術集会, 2010年11月, 日本語, 泉佐野市, 国内会議

    口頭発表(一般)

  • Changes in apoptosis process of rat esophageal epithelium with hyperproliferation of the indigenous bacteria under a physiological condition

    UDAYANGA KANKANAM, GAMAGE SANATH, 山本教司, 宮田英典, 横尾 諭, 万谷 洋平, 高原 英一郎, 横山 俊史, 星 信彦, 北川 浩

    第86回日本解剖学会近畿支部学術集会, 2010年11月, 日本語, 泉佐野市, 国内会議

    口頭発表(一般)

  • 遺伝子改変性転換マウス(Ypos)の半陰陽個体生殖腺における発生形態学的研究

    横山 俊史, 宮本 良介, 土居 弘明, 田阪 健, 橋本 佳樹, 藤井 裕香, 石川 恭子, 須谷 真巳, 長原 大知, 三觜 友子, 北川 浩, 星 信彦

    第150回日本獣医学会学術集会, 2010年09月, 日本語, 帯広市, 国内会議

    口頭発表(一般)

  • ラット消化管附属分泌腺からのToll-like receptorの分泌に関する免疫組織化学的研究

    万谷 洋平, UDAYANGA KANKANAM, GAMAGE SANATH, 高原 英一郎, 河野 潤一, 横山 俊史, 星 信彦, 北川 浩

    第150回日本獣医学会学術集会, 2010年09月, 日本語, 帯広市, 国内会議

    口頭発表(一般)

  • Immunohistochemical study on the apoptotic process in normal esophageal epithelium under a physiological condition

    UDAYANGA KANKANAM, GAMAGE SANATH, 高原 英一郎, 河野 潤一, 横山 俊史, 星 信彦, 北川 浩

    第150回日本獣医学会学術集会, 2010年09月, 日本語, 帯広市, 国内会議

    口頭発表(一般)

  • 遺伝子改変-性逆転マウスYposの生殖腺における発生形態学的研究

    星 信彦, 宮本 良介, 横山 俊史, 土居 弘明, 田阪 健, 橋本 佳樹, 藤井 裕香, 石川 恭子, 須谷 真巳, 長原 大知, 三觜 友子, 北川 浩

    第50回日本先天異常学会学術集会, 2010年07月, 日本語, 淡路市, 国内会議

    ポスター発表

  • Sry 導入XXマウスにおける雄性生殖腺の形態学的解析

    横山 俊史, 土居 弘明, 宮本 良介, 田阪 健, 橋本 佳樹, 藤井 裕香, 石川 恭子, 須谷 真巳, 長原 大知, 三觜 友子, 北川 浩, 星 信彦

    第50回日本先天異常学会学術集会, 2010年07月, 日本語, 淡路市, 国内会議

    ポスター発表

  • Paternal exposure to 2,3,7,8-tetrachloro- dibenzo-p-dioxin (TCDD) affects the sex ratio of offspring at birth by change the sex ratio of fertilized egg

    ISHIHARA KANA, TASAKA KEN, TANIDA TAKASHI, WARITA KATSUHIKO, MITSUHASHI TOMOKO, MIYAKE MASASHI, HARAYAMA HIROSHI, YOKOYAMA TOSHIFUMI, KITAGAWA HIROSHI, HOSHI NOBUHIKO

    11th International Symposium on Spermatology, 2010年06月, 英語, 宜野湾市, 国際会議

    ポスター発表

  • ラット腸管の常在細菌と寒天平板培養細菌の超微形態学的比較検討

    伊藤 栄理, 浅田 千枝, 西田 美穂, UDAYANGA KANKANAM, GAMAGE SANATH, 河野 潤一, 横山 俊史, 星 信彦, 北川 浩

    第85回日本解剖学会近畿支部学術集会, 2009年11月, 日本語, 橿原市, 国内会議

    口頭発表(一般)

  • ラット腸管の上皮細胞における経時的形態学的変化とアポトーシスの進行に関する免疫組織化学的研究

    西田 美穂, 伊藤 栄理, 宮田 英典, 平野 晶子, 斉 旺梅, UDAYANGA KANKANAM, GAMAGE SANATH, 横山 俊史, 星 信彦, 北川 浩

    第85回日本解剖学会近畿支部学術集会, 2009年11月, 日本語, 橿原市, 国内会議

    口頭発表(一般)

  • ラット小腸腸絨毛におけるToll-like Receptorの発現

    万谷 洋平, UDAYANGA KANKANAM, GAMAGE SANATH, 横尾 諭, 宮田英典, 河野 潤一, 横山 俊史, 星 信彦, 北川 浩

    第85回日本解剖学会近畿支部学術集会, 2009年11月, 日本語, 橿原市, 国内会議

    口頭発表(一般)

  • ラット小腸および大腸の粘膜リンパ組織における上皮細胞の動態の特性

    宮田 英典, 平野 晶子, 斉 旺梅, 横尾 諭, UDAYANGA KANKANAM, GAMAGE SANATH, 横山 俊史, 星 信彦, 北川 浩

    第85回日本解剖学会近畿支部学術集会, 2009年11月, 日本語, 橿原市, 国内会議

    口頭発表(一般)

  • マウス胎子性ライディッヒ細胞に関する発生形態学的研究

    横山 俊史, 青木 香保里, 三觜 友子, 石原 可奈, 谷田 任司, 北川 浩, 星 信彦

    第85回日本解剖学会近畿支部学術集会, 2009年11月, 日本語, 橿原市, 国内会議

    口頭発表(一般)

  • アカネズミのAhR遺伝子多型におけるダイオキシン曝露の影響

    須谷 真巳, 石庭 寛子, 田阪 健, 藤井 裕香, 土居 弘明, 橋本 佳樹, 宮本 良介, 三觜 友子, 石原 可奈, 谷田 任司, 横山 俊史, 北川 浩, 関島 恒夫, 星 信彦

    第85回日本解剖学会近畿支部学術集会, 2009年11月, 日本語, 橿原市, 国内会議

    口頭発表(一般)

  • TCDDによる次世代出生前性比低下と感受性との関係

    田阪 健, 石原 可奈, 土居 弘明, 橋本 佳樹, 宮本 良介, 三觜 友子, 谷田 任司, 横山 俊史, 北川 浩, 星 信彦

    第85回日本解剖学会近畿支部学術集会, 2009年11月, 日本語, 橿原市, 国内会議

    口頭発表(一般)

  • Sry導入XXマウスにおける雄性生殖腺の生後変化

    土居 弘明, 宮本 良介, 田阪 健, 橋本 佳樹, 三觜 友子, 石原 可奈, 谷田 任司, 横山 俊史, 北川 浩, 星 信彦

    第85回日本解剖学会近畿支部学術集会, 2009年11月, 日本語, 橿原市, 国内会議

    口頭発表(一般)

  • Apoptosis Process in Epidermal Epithelial Cells of Rat under a physiological condition

    UDAYANGA KANKANAM, GAMAGE SANATH, MIYATA HIDENORI, YOKOO YUH, QI WANG-MEI, NISHIDA MIHO, YOKOYAMA TOSHIFUMI, HOSHI NOBUHIKO, KITAGAWA HIROSHI

    第85回日本解剖学会近畿支部学術集会, 2009年11月, 日本語, 橿原市, 国内会議

    口頭発表(一般)

  • 投与雄マウスにおける感受性と次世代出生前性比との関係

    田阪 健, 石原 可奈, 土居 弘明, 橋本 佳樹, 宮本 良介, 三觜 友子, 谷田 任司, 横山 俊史, 北川 浩, 星 信彦

    第148回日本獣医学会学術集会, 2009年09月, 日本語, 鳥取市, 国内会議

    口頭発表(一般)

  • 成獣雄マウスにおける性決定遺伝子Sry発現の分子学的解析

    藤井 裕香, 横山 俊史, 田阪 健, 須谷 真巳, 万谷 洋平, 三觜 友子, 石原 可奈, 谷田 任司, 北川 浩, 星 信彦

    第148回日本獣医学会学術集会, 2009年09月, 日本語, 鳥取市, 国内会議

    口頭発表(一般)

  • ラット腸管の濾胞被蓋上皮における上皮細胞の動態に関する計量免疫組織化学的研究

    宮田 英典, 平野 晶子, 斉 旺梅, 横尾 諭, UDAYANGA KANKANAM, GAMAGE SANATH, 横山 俊史, 星 信彦, 北川 浩

    第148回日本獣医学会学術集会, 2009年09月, 日本語, 鳥取市, 国内会議

    口頭発表(一般)

  • ラット小腸の粘膜上皮におけるToll-like receptorの発現に関する免疫組織化学的研究

    万谷 洋平, UDAYANGA KANKANAM, GAMAGE SANATH, 横尾 諭, 宮田 英典, 河野 潤一, 横山 俊史, 星 信彦, 北川 浩

    第148回日本獣医学会学術集会, 2009年09月, 日本語, 鳥取市, 国内会議

    口頭発表(一般)

  • ラットの腸管内腔に存在する常在細菌の超微形態学的観察

    伊藤 栄理, 浅田 千枝, 西田 美穂, UDAYANGA KANKANAM, GAMAGE SANATH, 河野 潤一, 横山 俊史, 星 信彦, 北川 浩

    第148回日本獣医学会学術集会, 2009年09月, 日本語, 鳥取市, 国内会議

    口頭発表(一般)

  • ラットの腸管上皮におけるアポトーシス発現に関する超微形態学的研究

    西田 美穂, 伊藤 栄理, 宮田 英典, 平野 晶子, 斉 旺梅, UDAYANGA KANKANAM, GAMAGE SANATH, 横山 俊史, 星 信彦, 北川 浩

    第148回日本獣医学会学術集会, 2009年09月, 日本語, 鳥取市, 国内会議

    口頭発表(一般)

  • マウスにおける胎子性ライディッヒ細胞の局在に関する発生形態学的研究

    横山 俊史, 青木 香保里, 三觜 友子, 石原 可奈, 谷田 任司, 北川 浩, 星 信彦

    第148回日本獣医学会学術集会, 2009年09月, 日本語, 鳥取市, 国内会議

    口頭発表(一般)

  • アカネズミのAhR遺伝子多型とダイオキシン曝露の影響に関する分子形態学的評価

    須谷 真巳, 石庭 寛子, 田阪 健, 藤井 裕香, 土居 弘明, 橋本 佳樹, 宮本 良介, 三觜 友子, 石原 可奈, 谷田 任司, 横山 俊史, 北川 浩, 関島 恒夫, 星 信彦

    第148回日本獣医学会学術集会, 2009年09月, 日本語, 鳥取市, 国内会議

    口頭発表(一般)

  • Ultrastructural Study on the Indigenous Bacteria in the Lumen of Rat Intestine.

    ITO ERI, ASADA CHIE, NISHIDA MIHO, YOKOO YUH, UDAYANGA KANKANAM, GAMAGE SANATH, QI WANG-MEI, KAWANO JUNICHI, YOKOYAMA TOSHIFUMI, HOSHI NOBUHIKO, KITAGAWA HIROSHI

    The 6th International Symposium on Electron Microscopy in Medicine and Biology, 2009年09月, 英語, 神戸市, 国際会議

    ポスター発表

  • Ultrastructural and immunohistochemical study on the apoptotic process of intestinal epithelial cells in rats.

    NISHIDA MIHO, ITO ERI, MIYATA HIDENORI, UDAYANGA KANKANAM, GAMAGE SANATH, YOKOO YUH, QI WANG-MEI, YOKOYAMA TOSHIFUMI, HOSHI NOBUHIKO, KITAGAWA HIROSHI

    The 6th International Symposium on Electron Microscopy in Medicine and Biology, 2009年09月, 英語, 神戸市, 国際会議

    ポスター発表

  • Ultrastructural and histoplanimetrical demonstration of direct transportation of chylomicrons via subepithelial blood capillaries in rat intestinal villi.

    TAKAHARA EI-ICHIRO, ONISHI SACHIKO, NISHIDA MIHO, QI WANG-MEI, UDAYANGA KANKANAM, GAMAGE SANATH, YOKOYAMA TOSHIFUMI, WARITA KATSUHIKO, HOSHI NOBUHIKO, KITAGAWA HIROSHI

    The 6th International Symposium on Electron Microscopy in Medicine and Biology, 2009年09月, 英語, 神戸市, 国際会議

    ポスター発表

  • Sry導入XXマウスにおける雄性生殖腺の形態学的解析

    土居 弘明, 宮本 良介, 田阪 健, 橋本 佳樹, 三觜 友子, 石原 可奈, 谷田 任司, 横山 俊史, 北川 浩, 星 信彦

    第148回日本獣医学会学術集会, 2009年09月, 日本語, 鳥取市, 国内会議

    口頭発表(一般)

  • Scanning electron microscopic study on the persorption mechanism of large antigenic particulates from small intestinal lumen in rats.

    FUKUI YOSHITOMO, YUJI MIDORI, ONISHI SACHIKO, NISHIDA MIHO, INAMOTO TETSUROU, WARITA KATSUHIKO, YOKOYAMA TOSHIFUMI, HOSHI NOBUHIKO, KITAGAWA HIROSHI

    The 6th International Symposium on Electron Microscopy in Medicine and Biology, 2009年09月, 英語, 神戸市, 国際会議

    ポスター発表

  • Localization and developmental fate of fetal Leydig cells in mouse testis

    YOKOYAMA TOSHIFUMI, AOKI KAHORI, ISHIHARA KANA, MITSUHASHI TOMOKO, WARITA KATSUHIKO, HIROSHI KITAGAWA, NOBUHIKO HOSHI

    The 6th International Symposium on Electron Microscopy in Medicine and Biology, 2009年09月, 英語, 神戸市, 国際会議

    ポスター発表

  • Immunohistochemical study on the Toll-like receptor expression in villous columnar epithelial cells of rat small intestine

    MANTANI YOUHEI, YOKOO YUH, UDAYANGA KANKANAM, GAMAGE SANATH, QI WANG-MEI, NAMBA MAKIKO, NISHIDA MIHO, KAWANO JUNICHI, YOKOYAMA TOSHIFUMI, HOSHI NOBUHIKO, KITAGAWA HIROSHI

    The 6th International Symposium on Electron Microscopy in Medicine and Biology, 2009年09月, 英語, 神戸市, 国際会議

    ポスター発表

  • Immunohistochemical study on the apoptosis process in rat epidermis

    UDAYANGA KANKANAM, GAMAGE SANATH, MIYATA HIDENORI, YOKOO YUH, QI WANG-MEI, NISHIDA MIHO, YOKOYAMA TOSHIFUMI, HOSHI NOBUHIKO, KITAGAWA HIROSHI

    第148回日本獣医学会学術集会, 2009年09月, 日本語, 鳥取市, 国内会議

    口頭発表(一般)

  • Activin A and eCG recover reproductive dysfunction induced by neonatal exposure to an estrogenic endocrine disruptor in adult male mice

    WARITA KATSUHIKO, MITSUHASHI TOMOKO, YOKOYAMA TOSHIFUMI, MATSUMOTO YOSHIKI, KITAGAWA HIROSHI, MIKI TAKANORI, TAKEUCHI YOSHIKI, HOSHI NOBUHIKO

    The 6th International Symposium on Electron Microscopy in Medicine and Biology, 2009年09月, 英語, 神戸市, 国際会議

    ポスター発表

共同研究・競争的資金等の研究課題