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Dive into the research topics where Naoyuki Danbara is active.

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Featured researches published by Naoyuki Danbara.


Journal of Cutaneous Pathology | 2003

p63 expression in normal human epidermis and epidermal appendages and their tumors.

Miki Tsujita-Kyutoku; Katsuji Kiuchi; Naoyuki Danbara; Takashi Yuri; Hideto Senzaki; Airo Tsubura

Background:  p63, a member of the p53 gene family, is expressed in basal cells of several different organs.


Breast Cancer Research and Treatment | 2004

Perillyl Alcohol Inhibits Human Breast Cancer Cell Growth in vitro and in vivo

Takashi Yuri; Naoyuki Danbara; Miki Tsujita-Kyutoku; Yasuhiko Kiyozuka; Hideto Senzaki; Nobuaki Shikata; Hideharu Kanzaki; Airo Tsubura

The effect of monoterpene perillyl alcohol (POH) on cell growth, cell cycle progression, and expression of cell cycle-regulatory proteins in estrogen receptor (ER)-positive (KPL-1 and MCF-7) and ER-negative (MKL-F and MDA-MB-231) human breast cancer cell lines was examined. POH inhibited cell proliferation in a dose-dependent manner in all cell lines tested. POH at a dose of 500 µM had a cytostatic effect, in which growth inhibition was due to accumulation of cells in G1-phase. Cell cycle progression was preceded by a decrease in G1 cyclins (cyclin D1 and E), followed by an increase in p21Cip1/Waf1 and a decrease in proliferating cell nuclear antigen level. Levels of p53 and cyclin A were unchanged. POH at a dose of 75 mg/kg administered intraperitoneally three times a week throughout the entire 6-week experimental period suppressed orthotopically transplanted KPL-1 tumor cell growth and regional lymph node metastasis in a nude mouse system. POH inhibited both ER-positive and -negative human breast cancer cell growth in vitro, and suppressed growth and metastasis in vivo.


Nutrition and Cancer | 2004

Conjugated Docosahexaenoic Acid Is a Potent Inducer of Cell Cycle Arrest and Apoptosis and Inhibits Growth of Colo 201 Human Colon Cancer Cells

Naoyuki Danbara; Takashi Yuri; Miki Tsujita-Kyutoku; Mutsuya Sato; Hideto Senzaki; Hideho Takada; Takahiko Hada; Teruo Miyazawa; Kazuichi Okazaki; Airo Tsubura

Abstract: The effect of conjugated docosahexaenoic acid (CDHA) on the inhibition of colon cancer cell growth was examined in the colo 201 human colon cancer cell line, and the effect was compared with docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). CDHA was a more potent tumor cell growth inhibitor than DHA and EPA by colorimetric 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay (IC50 for 72 h: 31.6 μM, 46.8 μM, and 56.6 μM, respectively). CDHA inhibited cell cycle progression, due to accumulation of cells in G1 phase, which involved increased p21Cip1/Waf1 and decreased cyclin D1, cyclin E, and proliferating cell nuclear antigen expression; the p53 and cyclin A levels were unchanged. Induction of apoptosis was confirmed by the appearance of sub-G1 populations, and apoptosis cascade involved upregulation of the apoptosis-enhancing proteins (Bak and Bcl-ϰS) and downregulation of the apoptosis-suppressing proteins (Bcl-ϰL and Bcl-2). CDHA modulated cell cycle regulatory proteins and apoptosis-related proteins, similar to the effects of DHA. CDHA at a dietary dose of 1.0% significantly inhibited growth of colo 201 cells transplanted in nude mice.


Nutrition and Cancer | 2003

Dietary Docosahexaenoic Acid Suppresses N-Methyl-N-Nitrosourea-Induced Mammary Carcinogenesis in Rats More Effectively Than Eicosapentaenoic Acid

Takashi Yuri; Naoyuki Danbara; Miki Tsujita-Kyutoku; Kenji Fukunaga; Hideho Takada; Yoshikazu Inoue; Takahiko Hada; Airo Tsubura

We comparedthe effects of identical amounts but different proportions of dietary n-3 polyunsaturated fatty acids (PUFAs) on N-methyl-N-nitrosourea (MNU)-induced mammary cancer in a rat model. The ability of dietary docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) to suppress mammary cancer was evaluated. Female Sprague-Dawley rats were randomly assigned to three groups and maintained on diets containing 10% fatty acid consisting of EPA, a 1:1 mixture of EPA-plus-DHA, or DHA. The experimental diet was started after administration of MNU at 49 days of age, and the rats were maintained on the respective diets until the largest mammary tumor reached ≷ 1 cmin diameter or until the end of the study period (20 wk after MNU). All histologically detected mammarycarcinomas were evaluated, irrespective of size. The DHAdiet was associated with significant suppression of the carcinogenic effect of MNU compared with the EPA and EPA-plus-DHA diets: tumor incidence decreased to 23% (3/13) compared with 73% (11/15) and 65% (12/17) (P<0.01 andP<0.05, respectively); tumor multiplicity decreased to 0.23 compared with 1.67 and 1.59 (P < 0.01 and P < 0.05, respectively). There was no significant difference in tumor latency among the DHA, EPA, and EPA-plus-DHA groups (119, 105, and 117 days, respectively). Over 20 wk, the fatty acid composition of serum and mammary fat tissue reflected differences in the dietary n-3 PUFAs. Although DHA suppressed MNU-induced mammary carcinogenesis more effectively than EPA, generalized steatosis including mammary fat tissue appeared in all three groups.


Pathology International | 2004

Malignant rhabdoid tumor of the liver: case report and literature review.

Takashi Yuri; Naoyuki Danbara; Nobuaki Shikata; Sachiko Fujimoto; Takahide Nakano; Noriko Sakaida; Yoshiko Uemura; Airo Tsubura

A case of malignant rhabdoid tumor (MRT) occurring as a primary hepatic neoplasm in a 12‐month‐old Japanese female infant is presented. The patient had a slight fever for 2 weeks and presented with a palpable mass in her left hypochondrial region. After admission, the hepatic artery was embolized due to intra‐abdominal hemorrhage arising from the tumor. The patient received chemotherapy with cisplatin, cyclophosphamide and adriacin. Despite treatment, the patient developed dyspnea, pancytopenia and disseminated intravascular coagulation. Rupture of the tumor resulted in death within 3 weeks. A limited abdominal autopsy revealed that the liver weighed 1240 g and was occupied by multiple hemorrhagic and/or necrotic tumor nodules. Histologically, neoplastic cells had an abundant eosinophilic cytoplasm containing paranuclear inclusions, and vesicular nuclei with a centrally located prominent nucleolus. Ultrastructurally, the cytoplasmic inclusions were composed of whorled filaments measuring 10 nm. Immunohistochemically, almost all of the neoplastic cells were positive for vimentin and cytokeratins (CK) 8 and 18, some were positive for CK 7 and 19, while none were positive for CK 1, 10, 13–17 and 20. The tumor cells did not express desmin, myoglobin, and α‐fetoprotein. We found 18 cases of MRT of the liver published in English language literature and then, adding the present case, we summarized the 19 cases. Hepatic MRT is an uncommon neoplasm. However, it should be considered in the differential diagnosis of an aggressive liver neoplasm in childhood.


Breast Cancer Research | 2004

Conjugated docosahexaenoic acid suppresses KPL-1 human breast cancer cell growth in vitro and in vivo: potential mechanisms of action

Miki Tsujita-Kyutoku; Takashi Yuri; Naoyuki Danbara; Hideto Senzaki; Yasuhiko Kiyozuka; Norihisa Uehara; Hideho Takada; Takahiko Hada; Teruo Miyazawa; Yutaka Ogawa; Airo Tsubura

IntroductionThe present study was conducted to examine the effect of conjugated docosahexaenoic acid (CDHA) on cell growth, cell cycle progression, mode of cell death, and expression of cell cycle regulatory and/or apoptosis-related proteins in KPL-1 human breast cancer cell line. This effect of CDHA was compared with that of docosahexaenoic acid (DHA).MethodsKPL-1 cell growth was assessed by colorimetric 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay; cell cycle progression and mode of cell death were examined by flow cytometry; and levels of expression of p53, p21Cip1/Waf1, cyclin D1, Bax, and Bcl-2 proteins were examined by Western blotting analysis. In vivo tumor growth was examined by injecting KPL-1 cells subcutaneously into the area of the right thoracic mammary fat pad of female athymic mice fed a CDHA diet.ResultsCDHA inhibited KPL-1 cells more effectively than did DHA (50% inhibitory concentration for 72 hours: 97 μmol/l and 270 μmol/l, respectively). With both CDHA and DHA growth inhibition was due to apoptosis, as indicated by the appearance of a sub-G1 fraction. The apoptosis cascade involved downregulation of Bcl-2 protein; Bax expression was unchanged. Cell cycle progression was due to G0/G1 arrest, which involved increased expression of p53 and p21Cip1/Waf1, and decreased expression of cyclin D1. CDHA modulated cell cycle regulatory proteins and apoptosis-related proteins in a manner similar to that of parent DHA. In the athymic mouse system 1.0% dietary CDHA, but not 0.2%, significantly suppressed growth of KPL-1 tumor cells; CDHA tended to decrease regional lymph node metastasis in a dose dependent manner.ConclusionCDHA inhibited growth of KPL-1 human breast cancer cells in vitro more effectively than did DHA. The mechanisms of action involved modulation of apoptosis cascade and cell cycle progression. Dietary CDHA at 1.0% suppressed KPL-1 cell growth in the athymic mouse system.


The American Journal of Gastroenterology | 2007

Total colonoscopy with a transparent hood for trainees.

Mitsunobu Matsushita; Naoyuki Danbara; Toshiro Fukui; Takayuki Matsumoto; Kazushige Uchida; Mika Omiya; Kazuichi Okazaki

TO THE EDITOR: The article by Sawhney et al. compares the prevalence of advanced colonic neoplasm in nonanemic patients and anemic patients with a variety of ferritin levels (1). While the use of odds ratios in Table 3 is correctly interpreted in the text, the likelihood ratios in Table 4 are not clearly discussed in the text. Guyatt et al. define an odds ratio as “a ratio of the odds of an event in an exposed group to the odds of the same event in a group that is not exposed” (2). Using the data from Table 3, Sawhney et al. correctly state patients with ferritin <50 ng/mL and ferritin 51–100 ng/mL are almost 5 times more likely to have advanced colonic neoplasia than those patients with ferritin >100 ng/mL or nonanemic controls. A likelihood ratio is defined by Guyatt et al. as the relative likelihood that a given test would be expected in a patient with as opposed to one without a disorder of interest (2). Fletcher and Wagner state likelihood ratios reflect the probability of that test result in people with the disease divided by the probability of the result in people without disease (3). Therefore, using the likelihood ratios in Table 4, the authors should have clarified in the text that a ferritin >100 ng/mL is 0.27 times as likely to occur in a patient with colonic neoplasm compared to a patient without colonic neoplasm. If a statement defining likelihood ratios was included, readers could more readily interpret the results. The likelihood ratio and the odds ratio could then be expressed to a patient in terms that the patient could understand and weigh the risks and benefits.


Medical Molecular Morphology | 2004

Immunohistochemical profiles of Mallory body by a panel of anti-cytokeratin antibodies.

Ren-Jeng Pei; Naoyuki Danbara; Miki Tsujita-Kyutoku; Takashi Yuri; Airo Tsubura

Mallory bodies (MBs) are hyaline inclusions found in a variety of liver diseases. Because the major components of MBs are cytokeratins (CKs), CK profiles of MBs were examined immunohistochemically in 37 autopsied liver specimens (including a variety of nontumor pathological livers and hepatocellular carcinomas), using 13 antibodies against specific CKs: 34βB4 (CK 1), OV-TL12/30 (CK 7), 34βH11 (CK 8), LHP1 (CK 10), KS-1A3 (CK 13), LL002 (CK 14), LHK15 (CK 15), LL025 (CK 16), E3 (CK 17), DC10 (CK 18), b170 (CK 19), Ks20.8 (CK 20), and 34βE12 (CKs 1, 5, 10, and 11). Positive staining rates of MBs in 37 cases were as follows: CK 8, 100% (37/37); CK 18, 100% (37/37); CK 19, 57% (21/37). CK 7, 49% (18/37); CK 20, 35% (13/37); CK 1, CK 5, CK 10, CK 11, CK 13, CK 14, CK 15, CK 16, and CK 17 were all negative in MBs. CK expression patterns in MBs found in tumor or non-tumor hepatocytes was basically similar. Thus, all present MBs were composed of similar material with common antigenic determinants, regardless of underlying disease; in particular, they consistently contained CK 8 and CK 18, and frequently contained CK 7, CK 19, and CK 20.


Nutrition and Cancer | 2003

Prepubertal zearalenone exposure suppresses N-methyl-N-nitrosourea-induced mammary tumorigenesis but causes severe endocrine disruption in female Sprague-Dawley rats

Yasuyoshi Nikaido; Katsuhiko Yoshizawa; Ren-Jeng Pei; Takashi Yuri; Naoyuki Danbara; Takehiko Hatano; Airo Tsubura

The effect of prepubertal exposure to zearalenone, an estrogenic mycotoxin, on N-methyl-N-nitrosourea (MNU)-induced mammary tumorigenesis and its influence on reproductive organs were examined in female Sprague-Dawley rats. Prepubertal rats were treated daily with either 0.1 or 10 mg/kg body weight of zearalenone between 15 and 19 days of age and compared with zearalenone-untreated animals (30 rats in each group). Six rats in each group were autopsied at 28 days of age, and their growth was evaluated. All remaining rats were given 50 mg/kg body weight MNU at 28 days of age and followed by monitoring for occurrence of mammary tumors ≥1 cm in diameter. Zearalenone did not affect body weight increase, and mammary glands showed similar development at 28 days of age (time at carcinogen administration). Both low- and high-dose zearalenone treatment significantly reduced incidence of mammary tumors ≥1 cm in diameter but did not influence latency (time between MNU administration and harvest of mammary tumor ≥1 cm in diameter) compared with untreated controls. Zearalenone dose dependently suppressed the number of histologically detected tumors (carcinomas) and multiplicity; the suppression was significant with high-dose treatment. However, high-dose treatment caused significantly earlier vaginal opening, both low- and high-dose treatment significantly caused irregularity of estrous cycle (persistent estrus or prolonged diestrus) at 8 to 10 wk of age, and zearalenone dose dependently increased the number of anovulatory rats (ovaries without newly formed corpora lutea) at 37 wk of age. Thus, short-duration zearalenone treatment in the prepubertal period suppressed subsequent mammary cancer occurrence but also severely damaged ovarian functions. This suggests that ingestion of foods containing zearalenone in the infantile period can have dramatic effects in later life.


Medical Molecular Morphology | 2005

Basal cell carcinoma arising from a keratinous cyst of the skin: a case report and review of the literature.

Miki Tsujita-Kyutoku; Naoyuki Danbara; Takashi Yuri; Yasuyoshi Nikaido; Takahiko Hatano; Airo Tsubura

Although keratinous cysts of the skin are frequently seen, malignant transformation is a rare event. Here we report a case of basal cell carcinoma arising in the wall of the keratinous cyst, and we review 12 other such Japanese cases.

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Airo Tsubura

Kansai Medical University

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Takashi Yuri

Kansai Medical University

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Mika Omiya

Kansai Medical University

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Nobuaki Shikata

Kansai Medical University

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Norihisa Uehara

Kansai Medical University

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