2021/07/12 更新

写真a

ヤマモト ミチオ
山本 倫生
YAMAMOTO Michio
所属
環境生命科学学域 准教授
職名
准教授
外部リンク

研究分野

  • 自然科学一般 / 応用数学、統計数学

経歴

 

論文

  • Effect of herbal medicine daikenchuto on oral and enteral caloric intake after liver transplantation: A multicenter, randomized controlled trial. 査読 国際誌

    Toshimi Kaido, Masahiro Shinoda, Yukihiro Inomata, Takahito Yagi, Nobuhisa Akamatsu, Yasutsugu Takada, Hideki Ohdan, Tsuyoshi Shimamura, Yasuhiro Ogura, Susumu Eguchi, Hidetoshi Eguchi, Satoshi Ogata, Tomoharu Yoshizumi, Toshihiko Ikegami, Michio Yamamoto, Satoshi Morita, Shinji Uemoto

    Nutrition (Burbank, Los Angeles County, Calif.)   54   68 - 75   2018年10月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    OBJECTIVE: Postoperative early oral or enteral intake is a crucial element of the Enhanced Recovery After Surgery (ERAS) protocol. However, normal food intake or enteral feeding cannot be started early in the presence of coexisting bowel dysfunction in patients undergoing liver transplantation (LT). The aim of this multicenter, randomized, double-blinded, placebo-controlled trial was to determine the enhancement effects of the Japanese herbal medicine Daikenchuto (DKT) on oral/enteral caloric intake in patients undergoing LT. METHODS: A total of 112 adult patients undergoing LT at 14 Japanese centers were enrolled. The patients were randomly assigned to receive either DKT or placebo from postoperative day (POD) 1 to 14. The primary endpoints were total oral/enteral caloric intake, abdominal distension, and pain on POD 7. The secondary endpoints included sequential changes in total oral/enteral caloric intake after LT, and portal venous flow volume and velocity in the graft. RESULTS: A total of 104 patients (DKT, n = 55; placebo, n = 49) were included in the analyses. There were no significant differences between the two groups in terms of primary endpoints. However, postoperative total oral/enteral caloric intake was significantly accelerated in the DKT group compared with the placebo group (P = 0.023). Moreover, portal venous flow volume (POD 10, 14) and velocity (POD 14) were significantly higher in the DKT group than in the placebo group (P = 0.047, P = 0.025, P = 0.014, respectively). CONCLUSIONS: Postoperative administration of DKT may enhance total oral/enteral caloric intake and portal venous flow volume and velocity after LT and favorably contribute to the performance of the ERAS protocol.

    DOI: 10.1016/j.nut.2018.02.022

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  • A clinical trial for Kienböck disease by cultured autologous multipotent mesenchymal stromal cells augmented with vascularized bone grafts: A report of five cases 査読

    Ryosuke Ikeguchi, Tomoki Aoyama, Ryosuke Kakinoki, Michiko Ueda, Yasuaki Kasai, Taira Maekawa, Harue Tada, Michio Yamamoto, Shuichi Matsuda, Takashi Nakamura, Junya Toguchida

    Journal of Orthopaedic Science   2018年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:Elsevier  

    DOI: 10.1016/j.jos.2017.02.002

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  • Local control of sphincter-preserving procedures and abdominoperineal resection for locally advanced low rectal cancer: Propensity score matched analysis. 査読

    Ryosuke Okamura, Koya Hida, Tomohiro Yamaguchi, Tomonori Akagi, Tsuyoshi Konishi, Michio Yamamoto, Mitsuyoshi Ota, Shuichiro Matoba, Hiroyuki Bando, Saori Goto, Yoshiharu Sakai, Masahiko Watanabe, Kazuteru Watanabe, Koki Otsuka, Ichiro Takemasa, Keitaro Tanaka, Masataka Ikeda, Chu Matsuda, Meiki Fukuda, Junichi Hasegawa, Shintaro Akamoto, Manabu Shiozawa, Atsushi Tsuruta, Takashi Akiyoshi, Takeshi Kato, Shunsuke Tsukamoto, Masaaki Ito, Masaki Naito, Akiyoshi Kanazawa, Takao Takahashi, Takashi Ueki, Yuri Hayashi, Satoshi Morita, Takashi Yamaguchi, Masayoshi Nakanishi, Hirotoshi Hasegawa, Ken Okamoto, Fuminori Teraishi, Yasuo Sumi, Jo Tashiro, Toshimasa Yatsuoka, Yoji Nishimura, Kenji Okita, Takaya Kobatake, Hisanaga Horie, Yasuyuki Miyakura, Hisashi Ro, Kunihiko Nagakari, Eiji Hidaka, Takehiro Umemoto, Hideaki Nishigori, Kohei Murata, Fuminori Wakayama, Ryoji Makizumi, Shoichi Fujii, Eiji Sunami, Hirotoshi Kobayashi, Ryosuke Nakagawa, Toshiyuki Enomoto, Shinobu Ohnuma, Jun Higashijima, Heita Ozawa, Keigo Ashida, Fumihiko Fujita, Keisuke Uehara, Satoshi Maruyama, Masato Ohyama, Seiichiro Yamamoto, Takao Hinoi, Masanori Yoshimitsu, Masazumi Okajima, Shu Tanimura, Masayasu Kawasaki, Yoshihito Ide, Shoichi Hazama, Jun Watanabe, Daisuke Inagaki, Akihiro Toyokawa

    Annals of gastroenterological surgery   1 ( 3 )   199 - 207   2017年9月

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    記述言語:英語  

    Sphincter-preserving procedures (SPPs) for surgical treatment of low-lying rectal tumors have advanced considerably. However, their oncological safety for locally advanced low rectal cancer compared with abdominoperineal resection (APR) is contentious. We retrospectively analyzed cohort data of 1500 consecutive patients who underwent elective resection for stage II-III rectal cancer between 2010 and 2011. Patients with tumors 2-5 cm from the anal verge and clinical stage T3-4 were eligible. Primary outcome was 3-year local recurrence rate, and confounding effects were minimized by propensity score matching. The study involved 794 patients (456 SPPs and 338 APR). Before matching, candidates for APR were more likely to have lower and advanced lesions, whereas SPPs were carried out more often following preoperative treatment, by laparoscopic approach, and at institutions with higher case volume. After matching, 398 patients (199 each for SPPs and APR) were included in the analysis sample. Postoperative morbidity was similar between the SPPs and APR groups (38% vs 39%; RR 0.98, 95% CI 0.77-1.27). Margin involvement was present in eight patients in the SPPs group (one and seven at the distal and radial margins, respectively) and in 12 patients in the APR group. No difference in 3-year local recurrence rate was noted between the two groups (11% vs 14%; HR 0.77, 95% CI 0.42-1.41). In this observational study, comparability was ensured by adjusting for possible confounding factors. Our results suggest that SPPs and APR for locally advanced low rectal cancer have demonstrably equivalent oncological local control.

    DOI: 10.1002/ags3.12032

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  • A Unified Approach to Functional Principal Component Analysis and Functional Multiple-Set Canonical Correlation 査読

    Ji Yeh Choi, Heungsun Hwang, Michio Yamamoto, Kwanghee Jung, Todd S. Woodward

    PSYCHOMETRIKA   82 ( 2 )   427 - 441   2017年6月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:SPRINGER  

    Functional principal component analysis (FPCA) and functional multiple-set canonical correlation analysis (FMCCA) are data reduction techniques for functional data that are collected in the form of smooth curves or functions over a continuum such as time or space. In FPCA, low-dimensional components are extracted from a single functional dataset such that they explain the most variance of the dataset, whereas in FMCCA, low-dimensional components are obtained from each of multiple functional datasets in such a way that the associations among the components are maximized across the different sets. In this paper, we propose a unified approach to FPCA and FMCCA. The proposed approach subsumes both techniques as special cases. Furthermore, it permits a compromise between the techniques, such that components are obtained from each set of functional data to maximize their associations across different datasets, while accounting for the variance of the data well. We propose a single optimization criterion for the proposed approach, and develop an alternating regularized least squares algorithm to minimize the criterion in combination with basis function approximations to functions. We conduct a simulation study to investigate the performance of the proposed approach based on synthetic data. We also apply the approach for the analysis of multiple-subject functional magnetic resonance imaging data to obtain low-dimensional components of blood-oxygen level-dependent signal changes of the brain over time, which are highly correlated across the subjects as well as representative of the data. The extracted components are used to identify networks of neural activity that are commonly activated across the subjects while carrying out a working memory task.

    DOI: 10.1007/s11336-015-9478-5

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  • Altered expression of major immune regulatory molecules in peripheral blood immune cells associated with breast cancer 査読

    Kosuke Kawaguchi, Eiji Suzuki, Ayane Yamaguchi, Michio Yamamoto, Satoshi Morita, Masakazu Toi

    BREAST CANCER   24 ( 1 )   111 - 120   2017年1月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:SPRINGER JAPAN KK  

    The purpose of this study was to clarify the alterations of major immune regulators in peripheral blood mononuclear cells (PBMCs) of cancer patients and to analyze the association with the disease progression in breast cancer patients.
    The study included 6 healthy volunteers (HVs), 12 primary breast cancer (PBC) patients, and 30 metastatic breast cancer (MBC) patients. The expression of immune regulators such as, CCR6, CD4, CD8, CD14, CD40, CD56, CD80, CTLA4, CXCR4, FOXP3, IDO-1, IDO-2, NKG2D, NRP-1, PD-1, and PD-L1 mRNA in PBMCs was measured by quantitative RT-PCR. Analysis of variance with contrasts was performed to find expression patterns of the three groups (HVs, PBC, MBC).
    We clarified the alterations of mRNA of major immune regulators PD-L1, FOXP3, CD80, CD40, and CD14 in PBMCs of cancer patients and the association of these alternations with disease progression. Furthermore, PD-L1 expression was correlated with serum interferon-gamma production.
    Our data suggested that mRNA expressions of PD-L1, FOXP3, CD80, CD40 and CD14 in PBMCs are affected by disease progression. Understanding the roles of these various interactions will be of importance to future studies aiming to uncover biomarkers for predicting response to immune therapy.

    DOI: 10.1007/s12282-016-0682-7

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  • Prognostic impact of salvage treatment on hearing recovery in patients with sudden sensorineural hearing loss refractory to systemic corticosteroids: A retrospective observational study 査読

    Takayuki Nakagawa, Michio Yamamoto, Kozo Kumakawa, Shin-ichi Usami, Naohito Hato, Keiji Tabuchi, Mariko Takahashi, Keizo Fujiwara, Akira Sasaki, Shizuo Komune, Norio Yamamoto, Harukazu Hiraumi, Tatsunori Sakamoto, Akira Shimizu, Juichi Ito

    AURIS NASUS LARYNX   43 ( 5 )   489 - 494   2016年10月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCI LTD  

    Objective: To determine the prognostic factors for hearing recovery in patients with sudden sensorineural hearing loss (SSHL) refractory to systemic corticosteroids following salvage treatment.
    Methods: This is a retrospective observational study at nine tertiary referral hospitals. A total of 120 patients with sudden deafness refractory to systemic corticosteroids were enrolled. The patients were randomly assigned to receive topical application of recombinant human IGF-1 or intratympanic injection of dexamethasone as salvage treatment. Multiple regression analysis was performed to identify determinants of hearing recovery using pure tone audiometry results at 8 weeks after treatment. Clinical predictors that were evaluated included age, sex, pretreatment hearing level, presence of vertiginous symptoms, days to study entry from symptom onset and salvage treatment assignment (IGF-1 vs. dexamethasone).
    Results: The linear regression model identified age (P = 0.001), pretreatment hearing level (P < 0.001), days to study entry from symptom onset (P = 0.011) and treatment assignment (P = 0.033) at 8 weeks after treatment as significant variables influencing the recovery of pure tone audiometry average thresholds. Younger age (<60 years), early initiation of salvage treatment and treatment with topical IGF-1 therapy had significant effects on hearing recovery.
    Conclusion: The results indicate that early initiation and choice of treatment modalities for salvage treatment may be important for the prognosis of patients with refractory SSHL. The positive effect of topical IGF-1 therapy on hearing recovery indicates its utility as salvage treatment. (C) 2015 Elsevier Ireland Ltd. All rights reserved.

    DOI: 10.1016/j.anl.2015.12.004

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  • A pilot study of regenerative therapy using controlled release of recombinant human fibroblast growth factor for patients with pre-collapse osteonecrosis of the femoral head 査読

    Yutaka Kuroda, Ryuta Asada, Kazutaka So, Atsushi Yonezawa, Manabu Nankaku, Kumi Mukai, Toshiko Ito-Ihara, Harue Tada, Michio Yamamoto, Toshinori Murayama, Satoshi Morita, Yasuhiko Tabata, Masayuki Yokode, Akira Shimizu, Shuichi Matsuda, Haruhiko Akiyama

    INTERNATIONAL ORTHOPAEDICS   40 ( 8 )   1747 - 1754   2016年8月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:SPRINGER  

    Purpose We evaluated the safety and clinical outcomes of a single local administration of gelatin hydrogel impregnated with recombinant human fibroblast growth factor (rhFGF)-2 for the treatment of the precollapse stage of osteonecrosis of the femoral head (ONFH).
    Methods Patients with ONFH (precollapse stage a parts per thousand currency sign2) received a single local administration of 800 mu g of rhFGF-2-impregnated gelatin hydrogel and were followed up for one year. The surgery was performed using a minimally invasive technique involving a 1-cm skin incision, and walking was allowed from day one postoperatively. The primary outcomes included occurrence of adverse events and complications. The secondary outcomes included changes in the Harris hip scores, visual analog scale for pain scores, University of California, Los Angeles (UCLA) activity scores, and radiological images.
    Results We included ten patients, of which five experienced 14 adverse events, including one complication from spinal anesthesia. However, patients completely recovered from all adverse events. The mean clinical scores significantly improved by one year postoperatively compared with the pre-operative scores (before vs. after: visual analog score for pain, 21.2 vs. 5.3 mm; UCLA activity score, 5.5 vs. 6.6; Harris hip score, 81.0 vs. 96.9 points). There was only one case of femoral head collapse; however, this occurred in a hip with extensive necrosis. Stage progression and collapse did not occur in the other nine cases. Computed tomography confirmed bone regeneration in the femoral heads.
    Conclusions Clinical application of rhFGF-2-impregnated gelatin hydrogel for patients with precollapse ONFH was feasible and safe.

    DOI: 10.1007/s00264-015-3083-1

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  • Prognostic model for survival based on readily available pretreatment factors in patients with advanced pancreatic cancer receiving palliative chemotherapy 査読

    Tadayuki Kou, Masashi Kanai, Michio Yamamoto, Peng Xue, Yukiko Mori, Yasushi Kudo, Akira Kurita, Norimitsu Uza, Yuzo Kodama, Masanori Asada, Michiya Kawaguchi, Toshihiko Masui, Masaki Mizumoto, Shujiro Yazumi, Shigemi Matsumoto, Kyoichi Takaori, Satoshi Morita, Manabu Muto, Shinji Uemoto, Tsutomu Chiba

    INTERNATIONAL JOURNAL OF CLINICAL ONCOLOGY   21 ( 1 )   118 - 125   2016年2月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:SPRINGER JAPAN KK  

    We aimed to construct a prognostic model to predict survival in patients with advanced pancreatic cancer (APC) receiving palliative chemotherapy using readily available pretreatment factors.
    The model was constructed using data from 306 consecutive patients with APC who received palliative chemotherapy between January 2006 and March 2013. The predictive accuracy of the model was assessed using a concordance index (c-index) and calibration curves.
    Among the 12 potential prognostic factors investigated, multivariate analysis identified the following six independent negative prognostic factors-performance status (PS), the presence of distant metastatic disease, the status of initially unresectable disease, carcinoembryonic antigen (CEA) level, carbohydrate antigen 19-9 (CA19-9) level, and neutrophil-lymphocyte ratio (NLR). A prognostic index (PI) based on the coefficients of these factors was constructed as follows-PI = 2 (if PS 2-3) + 1 (if distant metastatic disease) + 1 (if initially unresectable disease) + 1 (if CEA level a parts per thousand yen5.0 ng/ml) + 1 (if CA 19-9 level a parts per thousand yen1,000 U/ml) + 2 (if NLR a parts per thousand yen5). The patients were classified into three prognostic groups-favorable (PI 0-1, n = 73), intermediate (PI 2-3, n = 145), and poor (PI 4-8, n = 88). The median overall survival times for each prognostic group were 16.5, 12.3, and 6.2 months, respectively (P < 0.001). Bootstrapping verified the good fitness of this model for predicting 1-year survival, and the c-index was 0.658.
    This simple prognostic model could help clinicians to estimate survival in patients with APC who receive palliative chemotherapy.

    DOI: 10.1007/s10147-015-0864-x

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  • Clustering of multivariate binary data with dimension reduction via L-1-regularized likelihood maximization 査読

    Michio Yamamoto, Kenichi Hayashi

    PATTERN RECOGNITION   48 ( 12 )   3959 - 3968   2015年12月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCI LTD  

    Clustering methods with dimension reduction have been receiving considerable wide interest in statistics lately and a lot of methods to simultaneously perform clustering and dimension reduction have been proposed. This work presents a novel procedure for simultaneously determining the optimal cluster structure for multivariate binary data and the subspace to represent that cluster structure. The method is based on a finite mixture model of multivariate Bernoulli distributions, and each component is assumed to have a low-dimensional representation of the cluster structure. This method can be considered as an extension of the traditional latent class analysis. Sparsity is introduced to the loading values, which produces the low-dimensional subspace, for enhanced interpretability and more stable extraction of the subspace. An EM-based algorithm is developed to efficiently solve the proposed optimization problem. We demonstrate the effectiveness of the proposed method by applying it to a simulation study and real datasets. (C) 2015 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.patcog.2015.05.026

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  • Sparse estimation via nonconcave penalized likelihood in factor analysis model 査読

    Kei Hirose, Michio Yamamoto

    STATISTICS AND COMPUTING   25 ( 5 )   863 - 875   2015年9月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:SPRINGER  

    We consider the problem of sparse estimation in a factor analysis model. A traditional estimation procedure in use is the following two-step approach: the model is estimated by maximum likelihood method and then a rotation technique is utilized to find sparse factor loadings. However, the maximum likelihood estimates cannot be obtained when the number of variables is much larger than the number of observations. Furthermore, even if the maximum likelihood estimates are available, the rotation technique does not often produce a sufficiently sparse solution. In order to handle these problems, this paper introduces a penalized likelihood procedure that imposes a nonconvex penalty on the factor loadings. We show that the penalized likelihood procedure can be viewed as a generalization of the traditional two-step approach, and the proposed methodology can produce sparser solutions than the rotation technique. A new algorithm via the EM algorithm along with coordinate descent is introduced to compute the entire solution path, which permits the application to a wide variety of convex and nonconvex penalties. Monte Carlo simulations are conducted to investigate the performance of our modeling strategy. A real data example is also given to illustrate our procedure.

    DOI: 10.1007/s11222-014-9458-0

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  • Effect of Violation of the Normal Assumption on MI and ML Estimators in the Analysis of Incomplete Data 査読

    Shintaro Hojo, Michio Yamamoto, Yutaka Kano

    COMMUNICATIONS IN STATISTICS-THEORY AND METHODS   44 ( 15 )   3234 - 3250   2015年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:TAYLOR & FRANCIS INC  

    Asymptotic distributions of normal-theory-based ML/MI estimators are studied in a simple regression model under general distributions with MAR missing data. The asymptotic variance of the ML/MI estimator of residuals' variance is explicitly derived, from which it follows that the kurtosis of the error distribution primarily affects the asymptotic variance. Results of numerical simulations conducted to study finite sample properties of the estimators, conformed largely to the asymptotic results, and they also indicated interesting findings particularly for small samples, which do not follow from the asymptotic property. It is concluded that the ML estimators perform best in the situation studied here.

    DOI: 10.1080/03610926.2013.819920

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  • 臨床研究の妥当性 招待

    山本倫生, 森田智視

    呼吸   34   384 - 390   2015年

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)  

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  • 臨床研究のデザイン法 招待

    山本倫生, 森田智視

    呼吸   34   479 - 484   2015年

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    記述言語:日本語   掲載種別:研究論文(学術雑誌)  

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  • Multicentre, randomised, placebo-controlled trial of extract of Japanese herbal medicine Daikenchuto to prevent bowel dysfunction after adult liver transplantation (DKB 14 Study) 査読

    Toshimi Kaido, Tsuyoshi Shimamura, Yasuhiko Sugawara, Hiroshi Sadamori, Ken Shirabe, Michio Yamamoto, Shinji Uemoto

    BMJ OPEN   5 ( 9 )   e008356   2015年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:BMJ PUBLISHING GROUP  

    Introduction: This multicentre randomised controlled clinical trial will aim to determine the ability of an extract (TJ-100) of Daikenchuto (traditional Japanese herbal medicine; Kampo) to prevent bowel dysfunction in at least 110 patients after liver transplantation (LT).
    Methods and analysis: The following co-primary end points will be evaluated on postoperative day 7: total oral and enteral caloric intake, abdominal distension and abdominal pain. The secondary end points will comprise sequential changes of total oral and enteral caloric intake after LT, sequential changes in numeric rating scales for abdominal distension and pain, elapsed time to the first postoperative passage of stool, quality of life assessment using the Gastrointestinal Symptom Rating Scale score (Japanese version), postoperative liver function, liver regeneration rate, incidence of bacteraemia and bacterial strain, trough level of immunosuppressants, occurrence of acute cellular rejection, discharge or not within 2 months after LT, sequential changes of portal venous flow to the graft and ascites discharge. The two arms of the study will comprise 55 patients per arm.
    Ethics and dissemination: The study has been conducted according to the CONSORT statement. All participants signed a written consent form, and the study has been approved by the institutional review board of each participating institute and conducted in accordance with the Declaration of Helsinki of 1996. The findings will be disseminated through scientific and professional conferences, and in peer-reviewed journals.

    DOI: 10.1136/bmjopen-2015-008356

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  • 検査データの解析 招待

    山本倫生, 森田智視

    呼吸   34   1090 - 1095   2015年

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    記述言語:日本語  

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  • 傾向スコアによる調整解析 招待

    山本倫生, 森田智視

    呼吸   34   1187 - 1193   2015年

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    記述言語:日本語  

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  • Functional factorial K-means analysis 査読

    Michio Yamamoto, Yoshikazu Terada

    COMPUTATIONAL STATISTICS & DATA ANALYSIS   79   133 - 148   2014年11月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCIENCE BV  

    A new procedure for simultaneously finding the optimal cluster structure of multivariate functional objects and finding the subspace to represent the cluster structure is presented. The method is based on the k-means criterion for projected functional objects on a subspace in which a cluster structure exists. An efficient alternating least-squares algorithm is described, and the proposed method is extended to a regularized method for smoothness of weight functions. To deal with the negative effect of the correlation of the coefficient matrix of the basis function expansion in the proposed algorithm, a two-step approach to the proposed method is also described. Analyses of artificial and real data demonstrate that the proposed method gives correct and interpretable results compared with existing methods, the functional principal component k-means (FPCK) method and tandem clustering approach. It is also shown that the proposed method can be considered complementary to FPCK. (C) 2014 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.csda.2014.05.010

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  • A randomized controlled clinical trial of topical insulin-like growth factor-1 therapy for sudden deafness refractory to systemic corticosteroid treatment 査読

    Takayuki Nakagawa, Kozo Kumakawa, Shin-ichi Usami, Naohito Hato, Keiji Tabuchi, Mariko Takahashi, Keizo Fujiwara, Akira Sasaki, Shizuo Komune, Tatsunori Sakamoto, Harukazu Hiraumi, Norio Yamamoto, Shiro Tanaka, Harue Tada, Michio Yamamoto, Atsushi Yonezawa, Toshiko Ito-Ihara, Takafumi Ikeda, Akira Shimizu, Yasuhiko Tabata, Juichi Ito

    BMC MEDICINE   12 ( 219 )   2014年11月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:BIOMED CENTRAL LTD  

    Background: To date, no therapeutic option has been established for sudden deafness refractory to systemic corticosteroids. This study aimed to examine the efficacy and safety of topical insulin-like growth factor-1 (IGF-1) therapy in comparison to intratympanic corticosteroid therapy.
    Methods: We randomly assigned patients with sudden deafness refractory to systemic corticosteroids to receive either gelatin hydrogels impregnated with IGF-1 in the middle ear (62 patients) or four intratympanic injections with dexamethasone (Dex; 58 patients). The primary outcome was the proportion of patients showing hearing improvement (10 decibels or greater in pure-tone average hearing thresholds) 8 weeks after treatment. The secondary outcomes included the change in pure-tone average hearing thresholds over time and the incidence of adverse events.
    Results: In the IGF-1 group, 66.7% (95% confidence interval [CI], 52.9-78.6%) of the patients showed hearing improvement compared to 53.6% (95% CI, 39.7-67.0%) of the patients in the Dex group (P = 0.109). The difference in changes in pure-tone average hearing thresholds over time between the two treatments was statistically significant (P = 0.003). No serious adverse events were observed in either treatment group. Tympanic membrane perforation did not persist in any patient in the IGF-1 group, but did persist in 15.5% (95% CI, 7.3-27.4%) of the patients in the Dex group (P = 0.001).
    Conclusions: The positive effect of topical IGF-1 application on hearing levels and its favorable safety profile suggest utility for topical IGF-1 therapy in patients with sudden deafness.

    DOI: 10.1186/s12916-014-0219-x

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  • Estimation of an oblique structure via penalized likelihood factor analysis 査読

    Kei Hirose, Michio Yamamoto

    COMPUTATIONAL STATISTICS & DATA ANALYSIS   79   120 - 132   2014年11月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:ELSEVIER SCIENCE BV  

    The problem of sparse estimation via a lasso-type penalized likelihood procedure in a factor analysis model is considered. Typically, model estimation assumes that the common factors are orthogonal (i.e., uncorrelated). However, if the common factors are correlated, the lasso-type penalization method based on the orthogonal model frequently estimates an erroneous model. To overcome this problem, factor correlations are incorporated into the model. Together with parameters in the orthogonal model, these correlations are estimated by a maximum penalized likelihood procedure. Entire solutions are computed by the EM algorithm with a coordinate descent, enabling the application of a wide variety of convex and nonconvex penalties. The proposed method is applicable even when the number of variables exceeds that of observations. The effectiveness of the proposed strategy is evaluated by Monte Carlo simulations, and its utility is demonstrated through real data analysis. (C) 2014 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.csda.2014.05.011

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  • A general formulation of cluster analysis with dimension reduction and subspace separation 査読

    Yamamoto, M, Hwang, H

    Behaviormetrika   41   115 - 129   2014年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

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  • A cluster-based factor rotation 査読

    Michio Yamamoto, Robert I. Jennrich

    BRITISH JOURNAL OF MATHEMATICAL & STATISTICAL PSYCHOLOGY   66 ( 3 )   487 - 502   2013年11月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:WILEY-BLACKWELL  

    A new oblique factor rotation method is proposed, the aim of which is to identify a simple and well-clustered structure in a factor loading matrix. A criterion consisting of the complexity of a factor loading matrix and a between-cluster dissimilarity is optimized using the gradient projection algorithm and the k-means algorithm. It is shown that if there is an oblique rotation of an initial loading matrix that has a perfect simple structure, then the proposed method with Kaiser's normalization will produce the perfect simple structure. Although many rotation methods can also recover a perfect simple structure, they perform poorly when a perfect simple structure is not possible. In this case, the new method tends to perform better because it clusters the loadings without requiring the clusters to be perfect. Artificial and real data analyses demonstrate that the proposed method can give a simple structure, which the other methods cannot produce, and provides a more interpretable result than those of widely known rotation techniques.

    DOI: 10.1111/bmsp.12007

    Web of Science

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  • Clustering of functional data in a low-dimensional subspace 査読

    Michio Yamamoto

    ADVANCES IN DATA ANALYSIS AND CLASSIFICATION   6 ( 3 )   219 - 247   2012年10月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:SPRINGER HEIDELBERG  

    To find optimal clusters of functional objects in a lower-dimensional subspace of data, a sequential method called tandem analysis, is often used, though such a method is problematic. A new procedure is developed to find optimal clusters of functional objects and also find an optimal subspace for clustering, simultaneously. The method is based on the k-means criterion for functional data and seeks the subspace that is maximally informative about the clustering structure in the data. An efficient alternating least-squares algorithm is described, and the proposed method is extended to a regularized method. Analyses of artificial and real data examples demonstrate that the proposed method gives correct and interpretable results.

    DOI: 10.1007/s11634-012-0113-3

    Web of Science

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MISC

  • Prognostic impact of salvage treatment on hearing recovery in patients with sudden sensorineural hearing loss refractory to systemic corticosteroids : A retrospective observational study

    Takayuki Nakagawa, Michio Yamamoto, Kozo Kumakawa, Shin-Ichi Usami, Naohito Hato, Keiji Tabuchi, Mariko Takahashi, Keizo Fujiwara, Akira Sasaki, Shizuo Komune, Norio Yamamoto, Harukazu Hiraumi, Tatsunori Sakamoto, Akira Shimizu, Juichi Ito

    Journal of Otolaryngology of Japan   120 ( 3 )   274 - 275   2017年

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    記述言語:日本語   掲載種別:速報,短報,研究ノート等(学術雑誌)   出版者・発行元:Oto-Rhino-Laryngological Society of Japan Inc.  

    DOI: 10.3950/jibiinkoka.120.274

    Scopus

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  • 予測的クラスタリングによる認知機能障害のサブタイプ分類

    山本 倫生

    「行列分解に基づく大規模複雑データ解析法に関する研究」研究会   2016年3月

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    記述言語:日本語  

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  • 低次元成分モデルに基づく予測可能なクラスター構造の推定

    山本 倫生

    「行列分解型多変量データ解析法に関する研究」研究会   2016年2月

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    記述言語:日本語  

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  • Canonical correlation analysis for multivariate functional data 招待

    Yamamoto, M, Terada, Y

    8th International Conference of the ERCIM WG on Computational and Methodological Statistics (CMStatistics)   2015年12月

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    記述言語:英語  

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  • Outcome-guided clustering using supervised dimension reduction approach

    Yamamoto, M, Kawaguchi, A, Hwang, H

    2015 International Workshop for JSCS 30th Anniversary   2015年10月

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    記述言語:英語  

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  • An extension of factor rotation via the penalized maximum likelihood estimation 招待

    Hirose, K, Yamamoto, M

    2015年度統計関連学会連合大会   2015年9月

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    記述言語:英語  

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  • 次元縮約とクラスタリングの同時分析法とその問題点 招待

    山本 倫生

    日本行動計量学会第43回大会   2015年9月

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    記述言語:日本語  

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  • DROC: An outcome-guided clustering using a component-based approach 招待

    Yamamoto, M

    日本行動計量学会 岡山地域部会第56回研究会   2015年7月

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  • A simultaneous analysis of dimension reduction and clustering with correlated error variables 招待

    山本 倫生

    The 2015 conference of the International Federation of Classification Societies (IFCS 2015)   2015年7月

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  • A component-based approach to find outcome-related clusters 査読

    Yamamoto, M, Kawaguchi, A

    The 80th Annual meeting of the Psychometric Society (IMPS 2015)   2015年7月

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  • 成分分析モデルに基づく予後因子を用いたアウトカム変数に関連するクラスターの推定

    山本 倫生

    2015年度日本計量生物学会年会   2015年3月

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  • 次元縮約を伴う教師ありクラスタリング法の提案

    山本 倫生

    第30回大規模データ科学研究会   2015年2月

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  • 非凸ペナルティに基づく正則化最小二乗法による結果変数に関連したクラスターの推定

    山本 倫生

    平成26年度複雑データの解析法に関する研究会   2015年2月

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  • 医師主導型の介入および侵襲を伴う臨床研究のデータの質保証体制の構築に向けた京大病院での取り組み

    森田智視, 多田春江, 渡邊美恵子, 山本倫生, 上山華栄, 柏木直子, 川口淳, 町田優子, 榎本佳代子

    日本臨床試験学会第6回学術集会総会   2015年2月

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  • Prognostic model for survival in patients with advanced pancreatic cancer receiving palliative chemotherapy. 査読

    Yu Uneno, Tadayuki Kou, Masashi Kanai, Michio Yamamoto, Peng Xue, Yukiko Mori, Yasushi Kudo, Akira Kurita, Norimitsu Uza, Yuzo Kodama, Masanori Asada, Toshihiko Masui, Shujiro Yazumi, Shigemi Matsumoto, Kyoichi Takaori, Satoshi Morita, Manabu Muto, Tsutomu Chiba

    JOURNAL OF CLINICAL ONCOLOGY   33 ( 3 )   2015年1月

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    記述言語:英語   掲載種別:研究発表ペーパー・要旨(国際会議)   出版者・発行元:AMER SOC CLINICAL ONCOLOGY  

    Web of Science

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  • Penalized likelihood factor analysis and estimation of oblique structure

    Hirose, K, Yamamoto, M

    Workshop on Statistical Methods for Large Complex Data, D509 Institute of Natural Sciences   2014年11月

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  • 因子間相関を仮定した因子分析モデルの正則化スパース推定

    廣瀬慧, 山本倫生

    日本計算機統計学会第28回シンポジウム   2014年11月

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  • Extension of rotation technique via penalization in factor analysis model 査読

    Hirose, K, Yamamoto, M

    International Conference of Advances in Interdisciplinary Statistics and Combinatorics (AISC) 2014   2014年10月

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  • 医師主導型介入臨床試験のデータの質保証体制の構築に向けた京大病院での取り組み

    渡邊美惠子, 多田春江, 山本倫生, 上山華栄, 川口淳, 町田優子, 榎本佳代子, 森田智視

    ARO協議会第2回学術集会   2014年9月

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  • 多変量カテゴリカルデータに対する低次元空間上でのクラスター構造の探索

    山本倫生, 林賢一

    日本行動計量学会第42回大会   2014年9月

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  • 一般化関数正準相関分析とその性質について

    山本 倫生

    2014年度統計関連学会連合大会   2014年9月

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  • 正則化スパース因子分析は因子回転に取って代わるか? 招待

    廣瀬慧, 山本倫生

    2014年度統計関連学会連合大会   2014年9月

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  • Functional multiple-set canonical correlation analysis for square integrable stochastic processes 査読

    Yamamoto, M

    The 21st International Conference on Computational Statistics (COMPSTAT 2014)   2014年8月

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  • 多施設型医師主導治験の体制構築と実施ー食道癌化学放射線療法(CRT)後の救済光線力学療法(PDT)の開発ー

    笠井宏委, 伊藤達也, 大橋真也, 猪原登志子, 山本倫生, 多田春江, 矢野友規, 武藤学

    第12回日本臨床腫瘍学会学術集会   2014年7月

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  • Lasso-type penalized maximum likelihood factor analysis via nonconvex penalties 査読

    Hirose, K, Yamamoto, M

    The 3rd Institute of Mathematical Statistics Asia Pacific Rim Meeting (IMS-APRM 2014)   2014年7月

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  • Simultaneous analysis of clustering and dimension reduction for binary variables with application to biomedical data 査読

    Yamamoto, M, Hayashi, K

    The 27th International Biometric Conference   2014年7月

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  • 次元縮約を伴うカテゴリカルデータのクラスタリング

    山本倫生, 林賢一

    平成25年度統計数理研究所共同研究「複雑データの解析法に関する研究会」   2014年2月

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  • 部分空間分離による多変量関数データの低次元部分空間におけるクラスター構造の推定

    山本 倫生

    第26回大規模データ科学に関する研究会   2014年1月

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担当授業科目

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  • 計算統計学I (2021年度) 3・4学期  - 火3~4

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