文献一覧: Kazuhiko OCHIAI (著者)

3 0 0 0 OA Examining multiple paternity in the raccoon dog (Nyctereutes procyonoides) in Japan using microsatellite analysis

著者: Natsuko SUGIURA Kazuhiko OCHIAI Toshiaki YAMAMOTO Takuya KATO Yoshi KAWAMOTO Toshinori OMI Shin-ichi HAYAMA
出版者: JAPANESE SOCIETY OF VETERINARY SCIENCE
雑誌: Journal of Veterinary Medical Science (ISSN:09167250)
巻号頁・発行日: vol.82, no.4, pp.479-482, 2020 (Released:2020-04-09)
参考文献数: 29
被引用文献数: 1

We analyzed the genotypes of three pregnant females and their litters to investigate the phenomenon of multiple paternity in wild raccoon dogs (Nyctereutes procyonoides) using 17 microsatellite markers. If a female has mated with only one male during estrus, then the maximum number of paternal alleles will not exceed two among littermates with the same father. The results revealed two out of three litters had three or four paternal alleles at one or five microsatellite loci. Therefore, the female had mated with more than one male during estrus. To the best of our knowledge, the present study is the first to report the possibility of multiple paternity in wild raccoon dogs.

2021-12-14 01:35:15
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3 0 0 0 OA Identification of the core motif of the BRCA2 C-terminal RAD51-binding domain by comparing canine and human BRCA2

著者: Yasunaga YOSHIKAWA Masami MORIMATSU Kazuhiko OCHIAI Toshina ISHIGURO-OONUMA Ryo MORIOKA Kento OKUDA Koichi ORINO
出版者: JAPANESE SOCIETY OF VETERINARY SCIENCE
雑誌: Journal of Veterinary Medical Science (ISSN:09167250)
巻号頁・発行日: pp.21-0006, (Released:2021-03-16)
被引用文献数: 2

Mammary tumors are the most common tumors in women and non-spayed female dogs. One of the reasons for mammary tumors is mutations of the tumor suppressor gene, BRCA2. BRCA2 participates in homologous recombination repair by interacting with the RAD51 recombinase. BRCA2 has two RAD51-binding domains, consisting of BRC repeats and the C-terminal RAD51-binding domain, respectively. Although several studies have addressed the function of the C-terminal RAD51-binding domain of human BRCA2, the amino acid sequences required for the RAD51-interaction activity remain unclear. In this study, the C-terminal RAD51-binding domains of canine and human BRCA2 were compared; the canine domain displayed a weaker interaction with RAD51. This difference was attributed to the C-terminal portion of the domain via a comparison between canine and human domains. Furthermore, peptides shorter than those previously reported displayed RAD51-interacting activity, and a core motif of this domain consisting of 25 amino acids was identified. Since a mutation (S3323N) was reported in the core motif of this domain, the effect of this mutation was evaluated. The mutant exhibited similar RAD51-binding activity as that of the wild-type protein, suggesting that the mutation was functionally neutral. These data suggested that the C-terminal portion of the BRCA2 C-terminal RAD51-binding domain influenced its RAD51-interaction activity, and a minimum core motif of 25 amino acids was identified in this domain. These data may help clarify BRCA2 function, as well as the tumorigenic effects of BRCA2 mutation.

2021-03-25 08:08:49
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3 0 0 0 OA Metabolite profiling in sphere-forming cells from canine mammary adenocarcinoma cell lines using gas chromatography-mass spectrometry

著者: Masaki MICHISHITA Namika SAITO Satoshi NOZAWA Rina FURUMOTO Takayuki NAKAGAWA Touko SATO Kazuhiko OCHIAI Daigo AZAKAMI Kinya KATAYAMA Rei NAKAHIRA Hiroyuki TAZAKI Yukino MACHIDA Toshiyuki ISHIWATA
出版者: JAPANESE SOCIETY OF VETERINARY SCIENCE
雑誌: Journal of Veterinary Medical Science (ISSN:09167250)
巻号頁・発行日: pp.19-0194, (Released:2019-07-15)
被引用文献数: 8

Cancer consists of heterogeneous cells that contain a small population of cells that possess stem cell properties; these cells, referred to as cancer stem cells (CSCs) or tumor-initiating cells, are involved in tumor progression and metastasis. Using a sphere-forming assay, canine mammary CSCs were found to be similar to human breast CSCs. Metabolic reprogramming has been recognized as a hallmark of various cancers. However, the significance of cellular metabolism in CSCs remains unclear. The aim of this study was to define the metabolic characteristics of CSCs derived from canine mammary tumors and gain an understanding of the maintenance of stemness. We identified metabolite profiles of canine mammary adenocarcinoma cell lines using gas chromatography-mass spectrometry. Metabolites were extracted from both adherent and sphere-forming cells derived from three cell lines. Sphere-forming cells were separated from adherent cells using an orthogonal, partial least squares discriminant analysis. Sphere-forming cells were found to contain high levels of the amino acids alanine, glycine and proline compared with adherent cells. They also had high levels of palmitoleate, palmitate and dihomo-gamma-linolenic acid compared with adherent cells. In a sphere-forming assay, palmitate increased the number of spheres for all cell lines. These results indicate that the sphere-forming cells derived from canine mammary adenocarcinoma cell lines have specific metabolic profiles that may be useful for the development of CSC-specific therapies targeting metabolic pathways and potential stemness biomarkers; these results also clarify the maintenance of stemness in canine mammary CSCs.

2019-07-18 06:43:00
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3 0 0 0 OA Leydig cell tumor in an Amur tiger (Panthera tigris altaica)

著者: Risako KAWATA Tatsuhito II Tatsuya HORI Yukino MACHIDA Kazuhiko OCHIAI Daigo AZAKAMI Toshiyuki ISHIWATA Masaki MICHISHITA
出版者: JAPANESE SOCIETY OF VETERINARY SCIENCE
雑誌: Journal of Veterinary Medical Science (ISSN:09167250)
巻号頁・発行日: vol.81, no.2, pp.186-189, 2019 (Released:2019-02-09)
参考文献数: 17
被引用文献数: 1

A 14-year and 8-month-old intact male Amur tiger presented with an enlarged left testis, measuring 5.7 × 5.5 × 4.5 cm. The cut surface was mottled dark red to reddish brown in color. Microscopically, the enlarged left testis comprised round or polygonal neoplastic cells arranged in a diffuse sheet pattern. These neoplastic cells had a hyperchromatic nucleus and an abundant eosinophilic cytoplasm. Immunohistochemically, these neoplastic cells were positive for vimentin, chromogranin A, synaptophysin, melan-A, inhibin-α, and S100 and negative for desmin and WT-1. Based on these morphological and immunohistochemical findings, the tumor was diagnosed as a Leydig cell tumor.

2019-03-21 04:41:26
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3 0 0 0 OA MicroRNA expression profiling in canine prostate cancer

著者: Masanori KOBAYASHI Akiko SAITO Yoshikazu TANAKA Masaki MICHISHITA Masato KOBAYASHI Mami IRIMAJIRI Takeharu KANEDA Kazuhiko OCHIAI Makoto BONKOBARA Kimimasa TAKAHASHI Tatsuya HORI Eiichi KAWAKAMI
出版者: 公益社団法人日本獣医学会
雑誌: Journal of Veterinary Medical Science (ISSN:09167250)
巻号頁・発行日: vol.79, no.4, pp.719-725, 2017 (Released:2017-04-05)
参考文献数: 32
被引用文献数: 23

Canine prostate cancer (cPCa) is an untreatable malignant neoplasm resulting in local tissue invasion and distant metastasis. MicroRNAs (miRs) are small non-coding RNAs that function as oncogenes or tumor suppressors. The purpose of this study was to characterize the expression of miRs that are altered in cPCa tissue. The expression levels of 277 mature miRs in prostatic tissue (n=5, respectively) were compared between the non-tumor and tumor groups using real-time PCR. Five miRs (miR-18a, 95, 221, 222 and 330) were up-regulated, but 14 miRs (miR-127, 148a, 205, 299, 329b, 335, 376a, 376c, 379, 380, 381, 411, 487b and 495) were down-regulated specifically in cPCa (P<0.05). These miRs have potential use as early diagnosis markers for cPCa and in miR-based therapy.

2017-04-05 22:05:13
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3 0 0 0 OA MicroRNA expression profiling in canine prostate cancer

著者: Masanori KOBAYASHI Akiko SAITO Yoshikazu TANAKA Masaki MICHISHITA Masato KOBAYASHI Mami IRIMAJIRI Takeharu KANEDA Kazuhiko OCHIAI Makoto BONKOBARA Kimimasa TAKAHASHI Tatsuya HORI Eiichi KAWAKAMI
出版者: 公益社団法人日本獣医学会
雑誌: Journal of Veterinary Medical Science (ISSN:09167250)
巻号頁・発行日: pp.16-0279, (Released:2017-02-27)
被引用文献数: 23

2017-02-27 23:56:53
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2 0 0 0 OA Functional alteration of canine isocitrate dehydrogenase 2 (IDH2) via an R174K mutation

著者: Shota KAWAKAMI Kazuhiko OCHIAI Yuiko KATO Masaki MICHISHITA Hinako HIRAMA Ryo OBARA Daigo AZAKAMI Masami WATANABE Toshinori OMI
出版者: 公益社団法人日本獣医学会
雑誌: Journal of Veterinary Medical Science (ISSN:09167250)
巻号頁・発行日: pp.17-0362, (Released:2017-11-21)

Gliomas are common intracranial neoplasias in dogs. However, the underlying pathogenic mechanisms remain unclear. In humans, isocitrate dehydrogenase 2 (IDH2) is often mutated in gliomas. Although almost human IDH2 mutations have been identified at the Arg172 codon, few studies have reported structural, functional, or mutational information for canine IDH2. In this study, we cloned the full-length canine IDH2 (cIDH2) cDNA and substituted wild type Arg174 (cIDH2 WT: corresponding to R172 of human IDH2) with Lys (cIDH2 R174K). The cIDH2 WT and R174K proteins were overexpressed in HeLa cells, and their presence was confirmed using an anti-human IDH2-WT mAb (clone: KrMab-3) and an anti-IDH2-R172K mAb (clone: KMab-1). The IDH2 activity between cIDH2 WT and cIDH2 R174K transfectants was compared by measuring the production of NADH and NADPH. NADPH production was lower for cIDH2 R174K than that for cIDH2 WT transfectants. Finally, we detected increased expression of hypoxia inducible factor-1 alpha (HIF-1α) in cIDH2 R174K transfectants. This indicates that mutations at R174 can potentially induce carcinogenesis in canine somatic cells.

2017-11-26 01:24:59
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2 0 0 0 OA Identification of tumor-initiating cells derived from two canine rhabdomyosarcoma cell lines

著者: Takuya Evan KISHIMOTO Shoko YASHIMA Rei NAKAHIRA Eri ONOZAWA Daigo AZAKAMI Makoto UJIKE Kazuhiko OCHIAI Toshiyuki ISHIWATA Kimimasa TAKAHASHI Masaki MICHISHITA
出版者: 公益社団法人日本獣医学会
雑誌: Journal of Veterinary Medical Science (ISSN:09167250)
巻号頁・発行日: pp.16-0412, (Released:2017-05-21)
被引用文献数: 7

Cancer stem cells or tumor-initiating cells (TICs) are a small subpopulation of cells that have the capacity to self-renew, differentiate and initiate tumors. These cells may function in tumor initiation, aggression and recurrence. Whether spheres derived from canine rhabdomyosarcoma cells have stem cell-like properties is unclear. We induced sphere formation in the canine rhabdomyosarcoma cell lines, CMS-C and CMS-J, and characterized the spheres in vitro and in vivo. Sphere-forming cells were more resistant to vincristine, mitoxantrone and doxorubicin than adherent cells. Xenograft transplantation demonstrated that 1 × 103 sphere-forming cells derived from CMS-C were sufficient for tumor formation. The sphere assay showed that the sphere-forming cells were present in these tumors. These results suggest that the spheres derived from canine rhabdomyosarcoma cells may possess characteristics of TICs. This study provides the foundation for elucidating the contribution of TICs to rhabdomyosarcoma tumorigenesis.

2017-05-22 23:58:47
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2 0 0 0 OA Primary T-cell high-grade lymphoma of the feline uterus

著者: Daigo AZAKAMI Eri ONOZAWA Masahiro MIYABE Kazuhiko OCHIAI Masaki MICHISHITA Taichi HIRANO Yutaka MOMOTA Katsumi ISHIOKA Toshinori SAKO
出版者: 公益社団法人日本獣医学会
雑誌: Journal of Veterinary Medical Science (ISSN:09167250)
巻号頁・発行日: pp.15-0575, (Released:2016-02-09)
被引用文献数: 2

A 12-year-old female American shorthair cat presented with a one-month history of hematuria and general lethargy. Abdominal ultrasonography revealed complete thickening of the left uterine wall. At a diagnostic laparotomy, a large mass arising from the left uterine horn was discovered, and ovariohysterectomy was performed. Histological diagnosis revealed a T-cell high-grade lymphoma of the uterus. After the ovariohysterectomy, the patient achieved complete remission and maintained by combination chemotherapy from 14 days after surgery. However, relapse occurred in the urinary bladder wall on day 287, and the patient died of postrenal acute renal failure on day 310. This is the first report of a feline case of primary uterine lymphoma that was treated with ovariohysterectomy followed by systemic chemotherapy.

2016-02-09 22:06:35
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1 0 0 0 OA Hepatic neuroendocrine carcinoma with metastases to the lymph nodes in a sika deer (Cervus nippon yakushimae)

著者: Ritsu SHIBATA Yukino MACHIDA Hitoshi HATAKEYAMA Hisashi YOSHIMURA Masami YAMAMOTO Kazuhiko OCHIAI Kazuyoshi UEMATSU Masaki MICHISHITA
出版者: JAPANESE SOCIETY OF VETERINARY SCIENCE
雑誌: Journal of Veterinary Medical Science (ISSN:09167250)
巻号頁・発行日: pp.19-0472, (Released:2020-01-01)

A 26-year and 6-month-old male sika deer that was kept at the Showa Park, Tokyo, Japan, collapsed and died of severe disease wasting and severe tabefaction. Grossly, numerous masses, 0.3–1.0 cm diameter, were dispersed throughout the liver. The multiple masses were composed of tumor cells, which had hypochromatic nuclei and abundant faintly eosinophilic cytoplasm, arranged in nests of various sizes. Immunohistochemically, tumor cells were positive for cytokeratin, chromogranin A, synaptophysin and gastrin. Ultrastructurally, the cytoplasm of the tumor cells contained abundant membrane-bound electron-dense granules. A metastatic lesion was observed in the renal, hepatic and pancreatic lymph nodes. On the basis of these findings, this tumor was diagnosed as neuroendocrine carcinoma with metastases to the lymph nodes.

2021-07-25 23:02:55
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1 0 0 0 OA Functional alteration of canine isocitrate dehydrogenase 2 (IDH2) via an R174K mutation

著者: Shota KAWAKAMI Kazuhiko OCHIAI Yuiko KATO Masaki MICHISHITA Hinako HIRAMA Ryo OBARA Daigo AZAKAMI Masami WATANABE Toshinori OMI
出版者: JAPANESE SOCIETY OF VETERINARY SCIENCE
雑誌: Journal of Veterinary Medical Science (ISSN:09167250)
巻号頁・発行日: vol.80, no.1, pp.85-91, 2018 (Released:2018-01-27)
参考文献数: 23

Gliomas are common intracranial neoplasias in dogs. However, the underlying pathogenic mechanisms remain unclear. In humans, isocitrate dehydrogenase 2 (IDH2) is often mutated in gliomas. Although almost human IDH2 mutations have been identified at the Arg172 codon, few studies have reported structural, functional or mutational information for canine IDH2. In this study, we cloned the full-length canine IDH2 (cIDH2) cDNA and substituted wild type Arg174 (cIDH2 WT: corresponding to R172 of human IDH2) with Lys (cIDH2 R174K). The cIDH2 WT and R174K proteins were overexpressed in HeLa cells, and their presence was confirmed using an anti-human IDH2-WT mAb (clone: KrMab-3) and an anti-IDH2-R172K mAb (clone: KMab-1). The IDH2 activity between cIDH2 WT and cIDH2 R174K transfectants was compared by measuring the production of NADH and NADPH. NADPH production was lower for cIDH2 R174K than that for cIDH2 WT transfectants. Finally, we detected increased expression of hypoxia inducible factor-1 alpha (HIF-1α) in cIDH2 R174K transfectants. This indicates that mutations at R174 can potentially induce carcinogenesis in canine somatic cells.

2018-01-27 19:26:31
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1 0 0 0 OA Disseminated histiocytic sarcoma with hemophagocytosis in a rabbit

著者: Mio ISHIMORI Masaki MICHISHITA Hisashi YOSHIMURA Daigo AZAKAMI Kazuhiko OCHIAI Toshiyuki ISHIWATA Kimimasa TAKAHASHI
出版者: 公益社団法人日本獣医学会
雑誌: Journal of Veterinary Medical Science (ISSN:09167250)
巻号頁・発行日: pp.17-0297, (Released:2017-07-21)
被引用文献数: 11

A 7-year-old female domestic rabbit suffered from labored respiration, poor appetite, mild anemia and thrombocytopenia. Radioscopic examination revealed masses in multiple locations including the intrapleural cavity and spleen. Forty-three days after the first visit to a private veterinary clinic, the rabbit died of severe respiratory distress. Microscopically, all of the masses were composed of round to polygonal neoplastic cells with distinct cell borders that were arranged in a sheet pattern. Multinucleated giant neoplastic cells were often observed. Some neoplastic cells had phagocytozed one or more erythrocytes. Immunohistochemical staining revealed that the neoplastic cells expressed vimentin, CD204, Iba-1 and lysozyme, but not CD163. Based on the morphological and immunohistochemical findings, this case was diagnosed as disseminated histiocytic sarcoma with hemophagocytosis.

2017-07-30 08:51:46
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1 0 0 0 OA Identification of tumor-initiating cells derived from two canine rhabdomyosarcoma cell lines

著者: Takuya Evan KISHIMOTO Shoko YASHIMA Rei NAKAHIRA Eri ONOZAWA Daigo AZAKAMI Makoto UJIKE Kazuhiko OCHIAI Toshiyuki ISHIWATA Kimimasa TAKAHASHI Masaki MICHISHITA
出版者: 公益社団法人日本獣医学会
雑誌: Journal of Veterinary Medical Science (ISSN:09167250)
巻号頁・発行日: vol.79, no.7, pp.1155-1162, 2017 (Released:2017-07-07)
参考文献数: 29
被引用文献数: 7

2017-07-07 23:03:33
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1 0 0 0 OA Polymorphisms of canine BRCA2 BRC repeats affecting interaction with RAD51

著者: Kazuhiko OCHIAI Toshina ISHIGURO-OONUMA Yasunaga YOSHIKAWA Chihiro UDAGAWA Yuiko KATO Masami WATANABE Makoto BONKOBARA Masami MORIMATSU Toshinori OMI
出版者: バイオメディカルリサーチプレス
雑誌: Biomedical Research (ISSN:03886107)
巻号頁・発行日: vol.36, no.2, pp.155-158, 2015-04-01 (Released:2015-04-16)
参考文献数: 21
被引用文献数: 2 13

Mutations in the breast cancer susceptibility gene BRCA2 leading to the failure of interactions with the recombinase RAD51 are associated with an increased risk of cancer in humans. This interaction depends on the eight BRC repeat (BRC1–8) sequences in BRCA2. We previously reported that canine BRC3 has two polymorphisms (T1425P and K1435R) influencing the interaction with RAD51, and 1435R was identified in mammary tumor dog samples. In this study, we investigated the sequence variations of BRC3 and 4 in 236 dogs of five breeds. Allele frequencies of 1425P and 1435R were 0.063 and 0.314, respectively, and there was no other polymorphism in the sequenced region. A mammalian two-hybrid assay using BRC3–4 sequences demonstrated that 1425P allele reduced the binding strength with RAD51 but 1435R had no effect. These results may provide an insight into the functions of not only individual but also multiple BRC repeats of BRCA2 in dogs.

2015-04-23 09:30:22
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