Updated on 2025/07/26

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写真a

 
Naotoshi Nakamura
 
Organization
Graduate School of Data Science Department of Data Science Professor
School of Data Science Department of Data Science
Title
Professor
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「細胞の不均一性」「個体の不均一性」をキーワードとして、生命科学・医学のさまざまな階層にわたる現象の解明、およびそのための手法開発に取り組んでいます。機械学習をはじめとするデータ駆動型解析の強力さに日々感心させられていますが、現代数学の知見や生物学・医学のドメイン知識をそこにうまく取り込むことで研究が飛躍的に進展すると考えており、そのような研究を目指しています。

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Research History

  • Yokohama City University   School of Data Science   Professor

    2025.4

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Papers

  • Modeling lesion transition dynamics to clinically characterize patients with clade I mpox in the Democratic Republic of the Congo. International journal

    Takara Nishiyama, Fuminari Miura, Yong Dam Jeong, Naotoshi Nakamura, Hyeongki Park, Masahiro Ishikane, Shotaro Yamamoto, Noriko Iwamoto, Michiyo Suzuki, Ayana Sakurai, Kazuyuki Aihara, Koichi Watashi, William S Hart, Robin N Thompson, Yasuhiro Yasutomi, Norio Ohmagari, Placide Mbala Kingebeni, John W Huggins, Shingo Iwami, Phillip R Pittman

    Science translational medicine   17 ( 805 )   eads4773   2025.7

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    Coinciding with the global outbreak of clade IIb mpox virus (MPXV), the Democratic Republic of the Congo (DRC) recently experienced a rapid surge in mpox cases with clade I MPXV. On 14 August 2024, the World Health Organization declared the continued cross-border spread of this clade in Africa a public health emergency of international concern (PHEIC). Clade I MPXV is known to be more fatal than clade IIb, but its clinical characteristics and prognosis differ between patients. Here, we used mathematical modeling to quantify temporal changes in total lesion counts during clade I MPXV infections, using data from a large cohort of patients with mpox in the DRC from 2007 to 2011. We further analyzed individuals' clinical data to explore predictive biomarkers of high lesion counts. Our analysis indicates that patients with clade I mpox can be stratified into two groups according to lesion severity and that viral load in peripheral blood at symptom onset may serve as a predictor for this classification [area under the curve (AUC) = 0.70]. Our estimates also suggest substantial individual heterogeneity in the time period during which patients have lesions, ranging from 20 to 65 days. Understanding the severity and duration of lesions in different patients, as characterized by our approach, may contribute to more tailored treatment strategies and control measures in ongoing clade I mpox outbreaks.

    DOI: 10.1126/scitranslmed.ads4773

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  • Stratifying and predicting progression to acute liver failure during the early phase of acute liver injury. International journal

    Raiki Yoshimura, Masatake Tanaka, Miho Kurokawa, Naotoshi Nakamura, Takeshi Goya, Koji Imoto, Motoyuki Kohjima, Katsuhito Fujiu, Shingo Iwami, Yoshihiro Ogawa

    PNAS nexus   4 ( 2 )   pgaf004   2025.2

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    Acute liver failure (ALF) is a serious disease that progresses from acute liver injury (ALI) and that often leads to multiorgan failure and ultimately death. Currently, effective treatment strategies for ALF, aside from transplantation, remain elusive, partly because ALI is highly heterogeneous. Furthermore, clinicians lack a quantitative indicator that they can use to predict which patients hospitalized with ALI will progress to ALF and the need for liver transplantation. In our study, we retrospectively analyzed data from 319 patients admitted to the hospital with ALI. By applying a machine-learning approach and by using the SHapley Additive exPlanations (SHAP) algorithm to analyze time-course blood test data, we identified prothrombin time activity percentage (PT%) as a biomarker reflecting individual ALI status. Unlike previous studies predicting the need for liver transplantation in patients with ALF, our study focused on PT% dynamics. Use of this variable allowed us to stratify the patients with highly heterogeneous ALI into six groups with distinct clinical courses and prognoses, i.e. self-limited, intensive care-responsive, or intensive care-refractory patterns. Notably, these groups were well predicted by clinical data collected at the time of admission. Additionally, utilizing mathematical modeling and machine learning, we assessed the predictability of individual PT% dynamics during the early phase of ALI. Our findings may allow for optimizing medical resource allocation and early introduction of tailored individualized treatment, which may result in improving ALF prognosis.

    DOI: 10.1093/pnasnexus/pgaf004

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  • Prediction of cccDNA dynamics in hepatitis B patients by a combination of serum surrogate markers. International journal

    Kwang Su Kim, Masashi Iwamoto, Kosaku Kitagawa, Hyeongki Park, Sanae Hayashi, Senko Tsukuda, Takeshi Matsui, Masanori Atsukawa, Kentaro Matsuura, Natthaya Chuaypen, Pisit Tangkijvanich, Lena Allweiss, Takara Nishiyama, Naotoshi Nakamura, Yasuhisa Fujita, Eiryo Kawakami, Shinji Nakaoka, Masamichi Muramatsu, Kazuyuki Aihara, Takaji Wakita, Alan S Perelson, Maura Dandri, Koichi Watashi, Shingo Iwami, Yasuhito Tanaka

    PLoS computational biology   21 ( 1 )   e1012615   2025.1

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    Quantification of intrahepatic covalently closed circular DNA (cccDNA) is a key for evaluating an elimination of hepatitis B virus (HBV) in infected patients. However, quantifying cccDNA requires invasive methods such as a liver biopsy, which makes it impractical to access the dynamics of cccDNA in patients. Although HBV RNA and HBV core-related antigens (HBcrAg) have been proposed as surrogate markers for evaluating cccDNA activity, they do not necessarily estimate the amount of cccDNA. Here, we employed a recently developed multiscale mathematical model describing intra- and intercellular viral propagation and applied it in HBV-infected patients under treatment. We developed a model that can predict intracellular HBV dynamics by use of extracellular viral markers, including HBsAg, HBV DNA, and HBcrAg in peripheral blood. Importantly, the model prediction of the amount of cccDNA in patients over time was confirmed to be well correlated with the data for quantified cccDNA by paired liver biopsy. Thus, our method combining classic and emerging surrogate markers enables us to predict the decay dynamics of cccDNA in patients undergoing treatment.

    DOI: 10.1371/journal.pcbi.1012615

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  • Gravitational change-induced alteration of the vestibular function and gene expression in the vestibular ganglion of mice.

    Murat Bazek, Motoya Sawa, Kazuhiro Horii, Naotoshi Nakamura, Shingo Iwami, Chia-Hsien Wu, Tsuyoshi Inoue, Fumiaki Nin, Chikara Abe

    The journal of physiological sciences : JPS   74 ( 1 )   44 - 44   2024.9

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    Gravity has profoundly influenced life on Earth, yet how organisms adapt to changes in gravity remains largely unknown. This study examines vestibular plasticity, specifically how the vestibular system responds to altered gravity. We subjected male C57BL/6J mice to hypergravity (2 G) followed by normal gravity (1 G) to analyze changes in vestibular function and gene expression. Mice showed significant vestibular dysfunction, assessed by righting reflex tests, which persisted for days but reversed at 1 G after exposure to 2 G. Gene expression analysis in the vestibular ganglion identified significant changes in 212 genes out of 49,585 due to gravitational changes. Specifically, 25 genes were upregulated under 2 G and recovered at 1 G after 2 G exposure, while one gene showed the opposite trend. Key neural function genes like Shisa3, Slc25a37, Ntn4, and Snca were involved. Our results reveal that hypergravity-induced vestibular dysfunction is reversible and highlight genes critical for adaptation.

    DOI: 10.1186/s12576-024-00939-y

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  • Modeling and predicting individual variation in COVID-19 vaccine-elicited antibody response in the general population. International journal

    Naotoshi Nakamura, Yurie Kobashi, Kwang Su Kim, Hyeongki Park, Yuta Tani, Yuzo Shimazu, Tianchen Zhao, Yoshitaka Nishikawa, Fumiya Omata, Moe Kawashima, Makoto Yoshida, Toshiki Abe, Yoshika Saito, Yuki Senoo, Saori Nonaka, Morihito Takita, Chika Yamamoto, Takeshi Kawamura, Akira Sugiyama, Aya Nakayama, Yudai Kaneko, Yong Dam Jeong, Daiki Tatematsu, Marwa Akao, Yoshitaka Sato, Shoya Iwanami, Yasuhisa Fujita, Masatoshi Wakui, Kazuyuki Aihara, Tatsuhiko Kodama, Kenji Shibuya, Shingo Iwami, Masaharu Tsubokura

    PLOS digital health   3 ( 5 )   e0000497   2024.5

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    As we learned during the COVID-19 pandemic, vaccines are one of the most important tools in infectious disease control. To date, an unprecedentedly large volume of high-quality data on COVID-19 vaccinations have been accumulated. For preparedness in future pandemics beyond COVID-19, these valuable datasets should be analyzed to best shape an effective vaccination strategy. We are collecting longitudinal data from a community-based cohort in Fukushima, Japan, that consists of 2,407 individuals who underwent serum sampling two or three times after a two-dose vaccination with either BNT162b2 or mRNA-1273. Using the individually reconstructed time courses of the vaccine-elicited antibody response based on mathematical modeling, we first identified basic demographic and health information that contributed to the main features of the antibody dynamics, i.e., the peak, the duration, and the area under the curve. We showed that these three features of antibody dynamics were partially explained by underlying medical conditions, adverse reactions to vaccinations, and medications, consistent with the findings of previous studies. We then applied to these factors a recently proposed computational method to optimally fit an "antibody score", which resulted in an integer-based score that can be used as a basis for identifying individuals with higher or lower antibody titers from basic demographic and health information. The score can be easily calculated by individuals themselves or by medical practitioners. Although the sensitivity of this score is currently not very high, in the future, as more data become available, it has the potential to identify vulnerable populations and encourage them to get booster vaccinations. Our mathematical model can be extended to any kind of vaccination and therefore can form a basis for policy decisions regarding the distribution of booster vaccines to strengthen immunity in future pandemics.

    DOI: 10.1371/journal.pdig.0000497

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  • Genetic intratumour heterogeneity and clonal evolution in extramammary Paget's disease. International journal

    Kenichiro Tanaka, Ikko Kajihara, Kazuro Shimokawa, Naotoshi Nakamura, Yudo Kusaba, Ryoko Sakamoto, Saki Maeda-Otsuka, Saori Yamada-Kanazawa, Soichiro Sawamura, Hisashi Kanemaru, Katsunari Makino, Jun Aoi, Shinichi Masuguchi, Takashi Suzuki, Satoshi Fukushima

    European journal of dermatology : EJD   34 ( 2 )   182 - 192   2024.4

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    All tumour cells in a patient have shared and non-shared genetic alterations, and the diversity of mutations is described as intratumoural heterogeneity (ITH). Multiregion sequencing is a genome sequencing analytical technique used for multiple, spatially-separated biopsy tissues that may further our understanding of ITH and tumour evolution. Although genetic mutations in extramammary Paget's disease (EMPD) have recently been detected by next-generation sequencing analysis, there have been no reports of ITH based on multiregion sequencing in EMPD. Thus, we clarified the landscape of ITH and tumour evolution in EMPD. We performed whole-exome sequencing on 35 tissues (30 tumour tissues and five normal skin samples as a paired control), collected from five patients with EMPD. The rate of private mutations was significantly higher than that of ubiquitous and shared mutations. Ubiquitous mutations were not present in driver genes, and most driver genes exhibited private and shared mutations. The most frequent base substitution was C>T in almost all lesions, and most mutational signatures corresponded to signature 1, 2, 3, and 8. The types of proposed aetiology in most lesions were based on age and AID/APOBEC family and BRCA1/BRCA2 mutations. Evolutionary trees were characterized by short trunks and long branches due to the extremely high ratio of private mutations. In contrast, pathogenic factors, such as base substitutions, mutational signatures, and proposed aetiology, were shared. Tumour evolution in EMPD appears to be characterized by a high level of genetic ITH with shared background factors.

    DOI: 10.1684/ejd.2024.4609

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  • Multiscale modeling of HBV infection integrating intra- and intercellular viral propagation to analyze extracellular viral markers. International journal

    Kosaku Kitagawa, Kwang Su Kim, Masashi Iwamoto, Sanae Hayashi, Hyeongki Park, Takara Nishiyama, Naotoshi Nakamura, Yasuhisa Fujita, Shinji Nakaoka, Kazuyuki Aihara, Alan S Perelson, Lena Allweiss, Maura Dandri, Koichi Watashi, Yasuhito Tanaka, Shingo Iwami

    PLoS computational biology   20 ( 3 )   e1011238   2024.3

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    Chronic infection with hepatitis B virus (HBV) is caused by the persistence of closed circular DNA (cccDNA) in the nucleus of infected hepatocytes. Despite available therapeutic anti-HBV agents, eliminating the cccDNA remains challenging. Thus, quantifying and understanding the dynamics of cccDNA are essential for developing effective treatment strategies and new drugs. However, such study requires repeated liver biopsy to measure the intrahepatic cccDNA, which is basically not accepted because liver biopsy is potentially morbid and not common during hepatitis B treatment. We here aimed to develop a noninvasive method for quantifying cccDNA in the liver using surrogate markers in peripheral blood. We constructed a multiscale mathematical model that explicitly incorporates both intracellular and intercellular HBV infection processes. The model, based on age-structured partial differential equations, integrates experimental data from in vitro and in vivo investigations. By applying this model, we roughly predicted the amount and dynamics of intrahepatic cccDNA within a certain range using specific viral markers in serum samples, including HBV DNA, HBsAg, HBeAg, and HBcrAg. Our study represents a significant step towards advancing the understanding of chronic HBV infection. The noninvasive quantification of cccDNA using our proposed method holds promise for improving clinical analyses and treatment strategies. By comprehensively describing the interactions of all components involved in HBV infection, our multiscale mathematical model provides a valuable framework for further research and the development of targeted interventions.

    DOI: 10.1371/journal.pcbi.1011238

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  • Infectious virus shedding duration reflects secretory IgA antibody response latency after SARS-CoV-2 infection. International journal

    Sho Miyamoto, Takara Nishiyama, Akira Ueno, Hyeongki Park, Takayuki Kanno, Naotoshi Nakamura, Seiya Ozono, Kazuyuki Aihara, Kenichiro Takahashi, Yuuki Tsuchihashi, Masahiro Ishikane, Takeshi Arashiro, Shinji Saito, Akira Ainai, Yuichiro Hirata, Shun Iida, Harutaka Katano, Minoru Tobiume, Kenzo Tokunaga, Tsuguto Fujimoto, Michiyo Suzuki, Maki Nagashima, Hidenori Nakagawa, Masashi Narita, Yasuyuki Kato, Hidetoshi Igari, Kaori Fujita, Tatsuo Kato, Kazutoshi Hiyama, Keisuke Shindou, Takuya Adachi, Kazuaki Fukushima, Fukumi Nakamura-Uchiyama, Ryota Hase, Yukihiro Yoshimura, Masaya Yamato, Yasuhiro Nozaki, Norio Ohmagari, Motoi Suzuki, Tomoya Saito, Shingo Iwami, Tadaki Suzuki

    Proceedings of the National Academy of Sciences of the United States of America   120 ( 52 )   e2314808120   2023.12

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    Infectious virus shedding from individuals infected with severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) is used to estimate human-to-human transmission risk. Control of SARS-CoV-2 transmission requires identifying the immune correlates that protect infectious virus shedding. Mucosal immunity prevents infection by SARS-CoV-2, which replicates in the respiratory epithelium and spreads rapidly to other hosts. However, whether mucosal immunity prevents the shedding of the infectious virus in SARS-CoV-2-infected individuals is unknown. We examined the relationship between viral RNA shedding dynamics, duration of infectious virus shedding, and mucosal antibody responses during SARS-CoV-2 infection. Anti-spike secretory IgA antibodies (S-IgA) reduced viral RNA load and infectivity more than anti-spike IgG/IgA antibodies in infected nasopharyngeal samples. Compared with the IgG/IgA response, the anti-spike S-IgA post-infection responses affected the viral RNA shedding dynamics and predicted the duration of infectious virus shedding regardless of the immune history. These findings highlight the importance of anti-spike S-IgA responses in individuals infected with SARS-CoV-2 for preventing infectious virus shedding and SARS-CoV-2 transmission. Developing medical countermeasures to shorten S-IgA response time may help control human-to-human transmission of SARS-CoV-2 infection and prevent future respiratory virus pandemics.

    DOI: 10.1073/pnas.2314808120

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  • Modeling COVID-19 vaccine booster-elicited antibody response and impact of infection history. International journal

    Takara Nishiyama, Yuichiro Miyamatsu, Hyeongki Park, Naotoshi Nakamura, Risa Yokokawa Shibata, Shingo Iwami, Yoji Nagasaki

    Vaccine   41 ( 52 )   7655 - 7662   2023.12

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    The 3-dose COVID-19 vaccine (booster vaccination) has been offered worldwide. As booster vaccinations continue, it is important to understand the antibody dynamics elicited by booster vaccination in order to evaluate and develop vaccination needs and strategies. Here, we investigated longitudinal data by monitoring IgG antibodies against the receptor binding domain (RBD) in health care workers. We extended our previously developed mathematical model to booster vaccines and successfully fitted antibody titers over time in the absence and presence of past SARS-CoV-2 infection. Quantitative analysis using our mathematical model indicated that anti-RBD IgG titers increase to a comparable extent after booster vaccination, regardless of the presence or absence of infection, but infection history extends the duration of antibody response by 1.28 times. Such a mathematical modeling approach can be used to inform future vaccination strategies on the basis of an individual's immune history. Our simple quantitative approach can be extended to any kind of vaccination and therefore can form a basis for policy decisions regarding the distribution of booster vaccines to strengthen immunity in future pandemics.

    DOI: 10.1016/j.vaccine.2023.11.040

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  • Antibody Profiling of Microbial Antigens in the Blood of COVID-19 mRNA Vaccine Recipients Using Microbial Protein Microarrays. International journal

    Hiroaki Saito, Hiroki Yoshimura, Makoto Yoshida, Yuta Tani, Moe Kawashima, Taiga Uchiyama, Tianchen Zhao, Chika Yamamoto, Yurie Kobashi, Toyoaki Sawano, Seiya Imoto, Hyeongki Park, Naotoshi Nakamura, Shingo Iwami, Yudai Kaneko, Aya Nakayama, Tatsuhiko Kodama, Masatoshi Wakui, Takeshi Kawamura, Masaharu Tsubokura

    Vaccines   11 ( 11 )   2023.11

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    Although studies have demonstrated that infections with various viruses, bacteria, and parasites can modulate the immune system, no study has investigated changes in antibodies against microbial antigens after the COVID-19 mRNA vaccination. IgG antibodies against microbial antigens in the blood of vaccinees were comprehensively analyzed using microbial protein microarrays that carried approximately 5000 microbe-derived proteins. Changes in antibodies against microbial antigens were scrutinized in healthy participants enrolled in the Fukushima Vaccination Community Survey conducted in Fukushima Prefecture, Japan, after their second and third COVID-19 mRNA vaccinations. Antibody profiling of six groups stratified by antibody titer and the remaining neutralizing antibodies was also performed to study the dynamics of neutralizing antibodies against SARS-CoV-2 and the changes in antibodies against microbial antigens. The results showed that changes in antibodies against microbial antigens other than SARS-CoV-2 antigens were extremely limited after COVID-19 vaccination. In addition, antibodies against a staphylococcal complement inhibitor have been identified as microbial antigens that are associated with increased levels of neutralizing antibodies against SARS-CoV-2. These antibodies may be a predictor of the maintenance of neutralizing antibodies following the administration of a COVID-19 mRNA vaccine.

    DOI: 10.3390/vaccines11111694

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  • Hematopoietic cell-derived IL-15 supports NK cell development in scattered and clustered localization within the bone marrow. International journal

    Shinya Abe, Takuma Asahi, Takahiro Hara, Guangwei Cui, Akihiro Shimba, Shizue Tani-Ichi, Kohei Yamada, Kazuko Miyazaki, Hitoshi Miyachi, Satsuki Kitano, Naotoshi Nakamura, Junichi Kikuta, Alexis Vandenbon, Masaki Miyazaki, Ryo Yamada, Toshiaki Ohteki, Masaru Ishii, Veronika Sexl, Takashi Nagasawa, Koichi Ikuta

    Cell reports   42 ( 9 )   113127 - 113127   2023.9

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    Natural killer (NK) cells are innate immune cells critical for protective immune responses against infection and cancer. Although NK cells differentiate in the bone marrow (BM) in an interleukin-15 (IL-15)-dependent manner, the cellular source of IL-15 remains elusive. Using NK cell reporter mice, we show that NK cells are localized in the BM in scattered and clustered manners. NK cell clusters overlap with monocyte and dendritic cell accumulations, whereas scattered NK cells require CXCR4 signaling. Using cell-specific IL-15-deficient mice, we show that hematopoietic cells, but not stromal cells, support NK cell development in the BM through IL-15. In particular, IL-15 produced by monocytes and dendritic cells appears to contribute to NK cell development. These results demonstrate that hematopoietic cells are the IL-15 niche for NK cell development in the BM and that BM NK cells are present in scattered and clustered compartments by different mechanisms, suggesting their distinct functions in the immune response.

    DOI: 10.1016/j.celrep.2023.113127

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  • Blood flow kinetic energy is a novel marker for right ventricular global systolic function in patients with left ventricular assist device therapy Reviewed International journal

    Koichi Akiyama, Paolo C. Colombo, Eric J. Stöhr, Ruiping Ji, Isaac Y. Wu, Keiichi Itatani, Shohei Miyazaki, Teruyasu Nishino, Naotoshi Nakamura, Yasufumi Nakajima, Barry J McDonnell, Koji Takeda, Melana Yuzefpolskaya, Hiroo Takayama

    Frontier's in Cardiovascular Medicine   10   1093576 - 1093576   2023.5

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    OBJECTIVES: Right ventricular (RV) failure remains a major concern in heart failure (HF) patients undergoing left ventricular assist device (LVAD) implantation. We aimed to measure the kinetic energy of blood in the RV outflow tract (KE-RVOT) - a new marker of RV global systolic function. We also aimed to assess the relationship of KE-RVOT to other echocardiographic parameters in all subjects and assess the relationship of KE-RVOT to hemodynamic parameters of RV performance in HF patients. METHODS: Fifty-one subjects were prospectively enrolled into 4 groups (healthy controls, NYHA Class II, NYHA Class IV, LVAD patients) as follows: 11 healthy controls, 32 HF patients (8 NYHA Class II and 24 Class IV), and 8 patients with preexisting LVADs. The 24 Class IV HF patients included 21 pre-LVAD and 3 pre-transplant patients. Echocardiographic parameters of RV function (TAPSE, St', Et', IVA, MPI) and RV outflow color-Doppler images were recorded in all patients. Invasive hemodynamic parameters of RV function were collected in all Class IV HF patients. KE-RVOT was derived from color-Doppler imaging using a vector flow mapping proprietary software. Kruskal-Wallis test was performed for comparison of KE-RVOT in each group. Correlation between KE-RVOT and echocardiographic/hemodynamic parameters was assessed by linear regression analysis. Receiver operating characteristic curves for the ability of KE-RVOT to predict early phase RV failure were generated. RESULTS: KE-RVOT (median ± IQR) was higher in healthy controls (55.10 [39.70 to 76.43] mW/m) than in the Class II HF group (22.23 [15.41 to 35.58] mW/m, p < 0.005). KE-RVOT was further reduced in the Class IV HF group (9.02 [5.33 to 11.94] mW/m, p < 0.05). KE-RVOT was lower in the LVAD group (25.03 [9.88 to 38.98] mW/m) than the healthy controls group (p < 0.005). KE-RVOT had significant correlation with all echocardiographic parameters and no correlation with invasive hemodynamic parameters. RV failure occurred in 12 patients who underwent LVAD implantation in the Class IV HF group (1 patient was not eligible due to death immediately after the LVAD implantation). KE-RVOT cut-off value for prediction of RV failure was 9.15 mW/m (sensitivity: 0.67, specificity: 0.75, AUC: 0.66). CONCLUSIONS: KE-RVOT, a novel noninvasive measure of RV function, strongly correlates with well-established echocardiographic markers of RV performance. KE-RVOT is the energy generated by RV wall contraction. Therefore, KE-RVOT may reflect global RV function. The utility of KE-RVOT in prediction of RV failure post LVAD implantation requires further study.

    DOI: 10.3389/fcvm.2023.1093576

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  • Lifestyle changes during the coronavirus disease 2019 pandemic impact metabolic dysfunction-associated fatty liver disease. International journal

    Hideki Fujii, Naotoshi Nakamura, Shinya Fukumoto, Tatsuo Kimura, Akemi Nakano, Yuji Nadatani, Yukie Tauchi, Yuuko Nishii, Shingo Takashima, Yoshihiro Kamada, Toshio Watanabe, Norifumi Kawada

    Liver international : official journal of the International Association for the Study of the Liver   42 ( 5 )   995 - 1004   2022.5

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    BACKGROUND AND AIMS: The coronavirus disease 2019 (COVID-19) pandemic precipitated lifestyle changes. We aimed to clarify whether COVID-19-induced lifestyle changes affected the development of metabolic dysfunction-associated fatty liver disease (MAFLD). METHODS: This retrospective longitudinal study included 973 participants who underwent health check-ups between 2018 and 2020. We used data from the MedCity21 health examination registry. Participants' clinical characteristics and lifestyle habits were investigated. Independent lifestyle predictors of MAFLD development before the pandemic (2018-2019) and during the pandemic (2019-2020) were identified using logistic regression analysis. RESULTS: In 2018, 261 (27%) patients were diagnosed with MAFLD. Before the pandemic, 22 patients developed new MAFLD. During this time, routine late-night meals were identified as an independent lifestyle predictor of MAFLD development (hazard ratio [HR] 2.54, 95% confidence interval [CI] 1.02-6.36, P = .046). In contrast, 44 patients developed new MAFLD during the pandemic. During this time, higher daily alcohol intake was identified as an independent lifestyle predictor of MAFLD development (HR 1.03, 95% CI 1.01-1.05, P = .008). In participants aged <60 years, daily alcohol intake and the proportion of participants who ate 2 times/day were significantly higher in patients who developed MAFLD during the pandemic than in those who did not. In participants aged ≥60 years, no lifestyle habits were associated with MAFLD development before or during the pandemic. CONCLUSIONS: New MAFLD diagnoses increased during the COVID-19 pandemic. Changes in lifestyle factors, particularly in those aged <60 years, must be monitored and addressed as the pandemic continues.

    DOI: 10.1111/liv.15158

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  • Preoperative Left Ventricular Energy Loss in the Operating Theater Reflects Subjective Symptoms in Chronic Aortic Regurgitation Reviewed International journal

    Atsushi Kainuma, Keiichi Itatani, Koichi Akiyama, Yoshifumi Naito, Maki Ishii, Masaru Shimizu, Junya Ohara, Naotoshi Nakamura, Yasufumi Nakajima, Satoshi Numata, Hitoshi Yaku, Teiji Sawa

    Frontiers in Surgery   9   739743 - 739743   2022.2

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    Background

    There is currently no subjective, definitive evaluation method for therapeutic indication other than symptoms in aortic regurgitation. Energy loss, a novel parameter of cardiac workload, can be visualized and quantified using echocardiography vector flow mapping. The purpose of the present study was to evaluate whether energy loss in patients with chronic aortic regurgitation can quantify their subjective symptoms more clearly than other conventional metrics.

    Methods

    We studied 15 patients undergoing elective aortic valve surgery for aortic regurgitation. We divided the patients into symptomatic and asymptomatic groups using their admission records. We analyzed the mean energy loss in one cardiac cycle using transesophageal echocardiography during the preoperative period. The relationships between symptoms, energy loss, and other conventional metrics were statistically analyzed.

    Results

    There were seven and eight patients in the symptomatic and asymptomatic groups, respectively. The mean energy loss of one cardiac cycle was higher in the symptomatic group (121 mW/m [96–184]) than in the asymptomatic group (87 mW/m [80–103]) (p = 0.040), whereas the diastolic diameter was higher in the asymptomatic group (65 mm [59–78]) than in the symptomatic group (57 mm [51–57]) (p = 0.040). There was no significant difference between the symptomatic and asymptomatic groups in terms of other conventional metrics.

    Conclusions

    An energy loss can quantify patients' subjective symptoms more clearly than other conventional metrics. The small sample size is the primary limitation of our study, further studies assessing larger cohort of patients are warranted to validate our findings.

    DOI: 10.3389/fsurg.2022.739743

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  • Expression of Cancer Stem Cell Markers EpCAM and CD90 Is Correlated with Anti- and Pro-Oncogenic EphA2 Signaling in Hepatocellular Carcinoma. International journal

    Nobuhiko Asakura, Naotoshi Nakamura, Atsushi Muroi, Yosui Nojima, Taro Yamashita, Shuichi Kaneko, Kazuki Ikeda, Naohiko Koshikawa, Takashi Suzuki

    International journal of molecular sciences   22 ( 16 )   2021.8

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    Hepatocellular carcinoma (HCC) is the third leading cause of cancer death worldwide. Additionally, the efficacy of targeted molecular therapies with multiple tyrosine kinase inhibitors is limited. In this study, we focused on the cellular signaling pathways common to diverse HCC cells and used quantitative reverse phase protein array (RPPA) and statistical analyses to elucidate the molecular mechanisms determining its malignancy. We examined the heterogeneity of 17 liver cancer cell lines by performing cluster analysis of their expression of CD90 and EpCAM cancer stem cell markers. Gaussian mixture model clustering identified three dominant clusters: CD90-positive and EpCAM-negative (CD90+), EpCAM-positive and CD90-negative (EpCAM+) and EpCAM-negative and CD90-negative (Neutral). A multivariate analysis by partial least squares revealed that the former two cell populations showed distinct patterns of protein expression and phosphorylation in the EGFR and EphA2 signaling pathways. The CD90+ cells exhibited higher abundance of AKT, EphA2 and its phosphorylated form at Ser897, whereas the EpCAM+ cells exhibited higher abundance of ERK, RSK and its phosphorylated form. This demonstrates that pro-oncogenic, ligand-independent EphA2 signaling plays a dominant role in CD90+ cells with higher motility and metastatic activity than EpCAM+ cells. We also showed that an AKT inhibitor reduced the proliferation and survival of CD90+ cells but did not affect those of EpCAM+ cells. Taken together, our results suggest that AKT activation may be a key pro-oncogenic regulator in HCC.

    DOI: 10.3390/ijms22168652

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  • Publisher Correction: Genome-wide association study of individual differences of human lymphocyte profiles using large-scale cytometry data. International journal

    Daigo Okada, Naotoshi Nakamura, Kazuya Setoh, Takahisa Kawaguchi, Koichiro Higasa, Yasuharu Tabara, Fumihiko Matsuda, Ryo Yamada

    Journal of human genetics   66 ( 6 )   643 - 643   2021.6

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  • 細胞生物学の数理(1) 概論とMichaelis-Menten式

    中村直俊

    応用数理   31 ( 1 )   32 - 37   2021

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  • Mathematical Cell Biology (4): Dealing with Uncertainty Invited Reviewed

    Naotoshi Nakamura

    31 ( 4 )   28 - 33   2021

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    Authorship:Lead author   Language:Japanese   Publishing type:Research paper (scientific journal)  

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  • Mathematical Cell Biology (3): Moving Cells Invited Reviewed

    Naotoshi Nakamura

    31 ( 3 )   28 - 33   2021

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    Authorship:Lead author   Language:Japanese   Publishing type:Research paper (scientific journal)  

    DOI: 10.11540/bjsiam.31.3_28

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  • Distance-Matrix-Based Extraction of Motility Features from Functionally Heterogeneous Cell Populations

    Naotoshi Nakamura, Ryo Yamada

    Springer Proceedings in Mathematics and Statistics   370   283 - 293   2021

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    Language:English   Publishing type:Research paper (international conference proceedings)   Publisher:Springer  

    DOI: 10.1007/978-981-16-4866-3_21

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  • 細胞生物学の数理(2):細胞間不均一性

    中村直俊

    応用数理   31 ( 2 )   74 - 79   2021

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  • Effectiveness of dispatcher instructions-dependent or independent bystander cardiopulmonary resuscitation on neurological survival among patients with out-of-hospital cardiac arrest Reviewed International journal

    Toshihiro Hatakeyama, Takeyuki Kiguchi, Daisuke Kobayashi, Naotoshi Nakamura, Chika Nishiyama, Sumito Hayashida, Kosuke Kiyohara, Tetsuhisa Kitamura, Takashi Kawamura, Taku Iwami

    Journal of Cardiology   75 ( 3 )   315 - 322   2020.3

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    BACKGROUND: We evaluated the association between survival and bystandercardiopulmonary resuscitation (CPR) with or without dispatcher instructions (DI) considering the time from emergency call receipt by the dispatch center to emergency medical services (EMS) personnel's contact with the patient (i.e. time to EMS arrival). METHODS: This prospective study conducted in Osaka City, Japan, from 2009 to 2015 included patients with medical cause-related out-of-hospital cardiac arrest who were ≥18 years old. The primary outcome was one-month favorable neurological survival. Using multiple logistic regression models, the adjusted odds ratios (AOR) of independent and DI-dependent CPR for the primary outcome were compared with no CPR. Adjustments were made for patients' age, sex, activities of daily living before the cardiac arrest, year of cardiac arrest, location, presence or absence of witnesses, etiology of cardiac arrest, and the time from EMS contact with the patient to patient's arrival at the hospital. The effective estimated "time to EMS arrival" was also calculated. RESULTS: For analyses 10,925 individuals were eligible. Independent CPR had a significantly higher one-month favorable neurological survival than no CPR whereas there was no significant difference between DI-dependent CPR and no CPR (AOR, 1.90 [1.47-2.46] and 1.16 [0.91-1.47], respectively). The estimated "time to EMS arrival" for a one-month favorable neurological survival after independent CPR was ≤13min. CONCLUSIONS: Bystander CPR that did not need DI was associated with significantly higher one-month favorable neurological survival than no CPR, with an effective estimated "time to EMS arrival" of ≤13min.

    DOI: 10.1016/j.jjcc.2019.08.007

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  • Extension of Sinkhorn Method: Optimal Movement Estimation of Agents Moving at Constant Velocity Reviewed

    Daigo Okada, Naotoshi Nakamura, Takuya Wada, Ayako Iwasaki, Ryo Yamada

    Transactions of the Japanese Society for Artificial Intelligence   34 ( 5 )   D - J13_1   2019.9

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    Publishing type:Research paper (scientific journal)   Publisher:Japanese Society for Artificial Intelligence  

    DOI: 10.1527/tjsai.d-j13

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  • LAVENDER: latent axes discovery from multiple cytometry samples with non-parametric divergence estimation and multidimensional scaling reconstruction Reviewed

    Naotoshi Nakamura, Daigo Okada, Kazuya Setoh, Takahisa Kawaguchi, Koichiro Higasa, Yasuharu Tabara, Fumihiko Matsuda, Ryo Yamada

    bioRxiv   673434   2019.6

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    Language:English   Publisher:Cold Spring Harbor Laboratory  

    <title>Abstract</title>Computational cytometry methods are now frequently used in flow and mass cytometric data analyses. However, systematic bias-free methodologies to assess inter-sample variability have been lacking, thereby hampering efficient data mining from a large set of samples. Here, we devised a computational method termed LAVENDER (<italic>l</italic>atent <italic>a</italic>xes disco<italic>ve</italic>ry from multiple cytometry samples with <italic>n</italic>onparametric <italic>d</italic>ivergence <italic>e</italic>stimation and multidimensional scaling <italic>r</italic>econstruction). It measures the Jensen-Shannon distances between samples using the <italic>k</italic>-nearest neighbor density estimation and reconstructs samples in a new coordinate space, called the LAVENDER space. The axes of this space can then be compared against other omics measurements to obtain biological information. Application of LAVENDER to multidimensional flow cytometry datasets of 301 Japanese individuals immunized with a seasonal influenza vaccine revealed an axis related to baseline immunological characteristics of each individual. This axis correlated with the proportion of plasma cells and the neutrophil-to-lymphocyte ratio, a clinical marker of the systemic inflammatory response. The same method was also applicable to mass cytometry data with more molecular markers. These results demonstrate that LAVENDER is a useful tool for identifying critical heterogeneity among similar, yet different, single-cell datasets.

    DOI: 10.1101/673434

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  • Erratum to: Vector flow mapping analysis of left ventricular energetic performance in healthy adult volunteers. Reviewed International journal

    Akiyama K, Maeda S, Matsuyama T, Kainuma A, Ishii M, Naito Y, Kinoshita M, Hamaoka S, Kato H, Nakajima Y, Nakamura N, Itatani K, Sawa T

    BMC cardiovascular disorders   17 ( 1 )   172 - 172   2017.6

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1186/s12872-017-0612-4

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  • Flow-dynamics assessment of mitral-valve surgery by intraoperative vector flow mapping. Reviewed International journal

    Akiyama K, Nakamura N, Itatani K, Naito Y, Kinoshita M, Shimizu M, Hamaoka S, Kato H, Yasumoto H, Nakajima Y, Mizobe T, Numata S, Yaku H, Sawa T

    Interactive cardiovascular and thoracic surgery   24 ( 6 )   869 - 875   2017.6

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    DOI: 10.1093/icvts/ivx033

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  • Vector flow mapping analysis of left ventricular energetic performance in healthy adult volunteers. Reviewed

    Akiyama K, Maeda S, Matsuyama T, Kainuma A, Ishii M, Naito Y, Kinoshita M, Hamaoka S, Kato H, Nakajima Y, Nakamura N, Itatani K, Sawa T

    BMC cardiovascular disorders   17 ( 1 )   21   2017.1

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1186/s12872-016-0444-7

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  • Secretory glands and microvascular systems imaged in aqueous solution by atmospheric scanning electron microscopy (ASEM). Reviewed International journal

    Yamazawa T, Nakamura N, Sato M, Sato C

    Microscopy research and technique   79 ( 12 )   1179 - 1187   2016.12

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1002/jemt.22773

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  • Visualization of Ca2+ Filling Mechanisms upon Synaptic Inputs in the Endoplasmic Reticulum of Cerebellar Purkinje Cells. Reviewed International journal

    Okubo Y, Suzuki J, Kanemaru K, Nakamura N, Shibata T, Iino M

    The Journal of neuroscience : the official journal of the Society for Neuroscience   35 ( 48 )   15837 - 15846   2015.12

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1523/JNEUROSCI.3487-15.2015

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  • Bifurcation analysis of a self-organizing signaling system for eukaryotic chemotaxis Reviewed

    Nakamura Naotoshi, Shibata Tatsuo

    JAPAN JOURNAL OF INDUSTRIAL AND APPLIED MATHEMATICS   32 ( 3 )   807 - 828   2015.11

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    File: Nakamura-Shibata2015_Article_BifurcationAnalysisOfASelf-org (1).pdf

    DOI: 10.1007/s13160-015-0185-5

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  • Temporal switching and cell-to-cell variability in Ca2+ release activity in mammalian cells Reviewed International journal

    Nakamura Naotoshi, Yamazawa Toshiko, Okubo Yohei, Iino Masamitsu

    MOLECULAR SYSTEMS BIOLOGY   5   247 - 247   2009.3

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1038/msb.2009.6

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Books

MISC

  • Genome-wide association study of individual differences of human lymphocyte profiles using large-scale cytometry data (vol 71, pg 613, 2021)

    Daigo Okada, Naotoshi Nakamura, Kazuya Setoh, Takahisa Kawaguchi, Koichiro Higasa, Yasuharu Tabara, Fumihiko Matsuda, Ryo Yamada

    JOURNAL OF HUMAN GENETICS   66 ( 6 )   643 - 643   2021.6

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  • 大阪市での市民救助者への口頭指導と院外心停止後の神経学的予後

    畠山稔弘, 畠山稔弘, 木口雄之, 小林大介, 中村直俊, 西山知佳, 林田純人, 清原康介, 北村哲久, 川村孝, 石見拓

    日本救急医学会雑誌   30 ( 9 (Web) )   2019

  • Bifurcation analysis of a self-organizing signaling system for eukaryotic chemotaxis (Theory of Biomathematics and Its Applications XII : Mathematical and experimental approach to clarify patterns in a transition process)

    Nakamura Naotoshi

    RIMS Kokyuroku   1994   88 - 93   2016.4

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    Language:Japanese   Publisher:Kyoto University  

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  • Mathematical Analysis of smoking population dynamics : An epidemiological model (Kyoto Winter Research Program in Mathematical Biology Next Wave)

    TAKASHINA Nao, ASAO Akihiro, NAKAMURA Naotoshi

    RIMS Kokyuroku   1706   35 - 40   2010.8

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    Language:Japanese   Publisher:Kyoto University  

    CiNii Books

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