著者
Takuya Matsumoto Satoshi Kodera Hiroki Shinohara Hirotaka Ieki Toshihiro Yamaguchi Yasutomi Higashikuni Arihiro Kiyosue Kaoru Ito Jiro Ando Eiki Takimoto Hiroshi Akazawa Hiroyuki Morita Issei Komuro
出版者
International Heart Journal Association
雑誌
International Heart Journal (ISSN:13492365)
巻号頁・発行日
vol.61, no.4, pp.781-786, 2020-07-30 (Released:2020-07-30)
参考文献数
13
被引用文献数
23

The development of deep learning technology has enabled machines to achieve high-level accuracy in interpreting medical images. While many previous studies have examined the detection of pulmonary nodules in chest X-rays using deep learning, the application of this technology to heart failure remains rare. In this paper, we investigated the performance of a deep learning algorithm in terms of diagnosing heart failure using images obtained from chest X-rays. We used 952 chest X-ray images from a labeled database published by the National Institutes of Health. Two cardiologists verified and relabeled a total of 260 "normal" and 378 "heart failure" images, with the remainder being discarded because they had been incorrectly labeled. Data augmentation and transfer learning were used to obtain an accuracy of 82% in diagnosing heart failure using the chest X-ray images. Furthermore, heatmap imaging allowed us to visualize decisions made by the machine. Deep learning can thus help support the diagnosis of heart failure using chest X-ray images.
著者
Asako Takamasa Katsuhiko Suzuki Yusuke Fukami Tsuyoshi Iizuka Maria Luisa G. Tejada Wataru Fujisaki Yuji Orihashi Takuya Matsumoto
出版者
GEOCHEMICAL SOCIETY OF JAPAN
雑誌
GEOCHEMICAL JOURNAL (ISSN:00167002)
巻号頁・発行日
vol.54, no.3, pp.117-127, 2020 (Released:2020-06-22)
参考文献数
33
被引用文献数
1 5

The extinct, relatively short-lived nuclide 182Hf produced 182W as a decay product. Fractionation of Hf-W in the very early Earth led to variations in the 182W/184W ratios of terrestrial rocks; however, because these variations are very small, quantifying 182W/184W ratios requires an extremely precise method. Here, we propose an improved method for highly precise and accurate method for measuring the 182W/184W ratios of terrestrial rocks. Samples were extracted with 4-methyl-2-pentanone and purified by cation and anion exchange chromatography prior to determination of the W isotope ratio by multiple collector inductively-coupled plasma mass spectrometry (MC-ICP-MS) system coupled with a desolvating nebulizer. Sample preparation removed matrix elements (e.g., Hf, Ta, Os, and dimers of Nb and Mo) with masses similar to those of W isotopes, resulting in these elements having a negligible influence on the measured 182W/184W ratios. A W standard solution processed by ion exchange chromatography and/or solvent extraction showed a 183W deficiency, even after mass fractionation correction of the measured isotope data. As reported previously, mass-independent fractionation increases the 182W/184W ratio if the 183W/184W ratio is used to correct for mass fractionation to for better precision in natural samples. However, accurate 182W/184W ratios for a basalt reference material (JB-2) were obtained, even if 183W was used for mass fractionation correction. Our results show that it is also possible to correct for the effects of mass-independent fractionation on the 183W/184W ratio by sample-standard bracketing using a W standard solution subjected to the same preparation procedure used for the samples. A major advantage of the newly developed method is that it requires a smaller amount of sample (0.2–0.3 g; 50–80 ng W for JB-2) compared with that needed for other reported methods (typically 0.7–15 g; 500–1000 ng W). This decrease in sample amount was possible by removing matrix elements from the sample solutions, and cleaning the membrane of the desolvating nebulizer between analyses also contribute to enhancing the W ion beam intensity and to high precision. Analysis of different basalts from the Loihi, Kilauea islands and Ontong Java Plateau with various W isotopic compositions consistent with the previous studies demonstrated the reliability of the method.
著者
Takuo Emoto Naoto Sasaki Tomoya Yamashita Kazuyuki Kasahara Keiko Yodoi Yoshihiro Sasaki Takuya Matsumoto Taiji Mizoguchi Ken-ichi Hirata
出版者
日本循環器学会
雑誌
Circulation Journal (ISSN:13469843)
巻号頁・発行日
vol.78, no.12, pp.2935-2941, 2014-11-25 (Released:2014-11-25)
参考文献数
22
被引用文献数
9 40

Background:The protective function of regulatory T cells (Treg) has been identified in experimental atherosclerosis, but the contribution of Tregto the pathogenesis of human coronary artery disease (CAD) remains poorly understood. We investigated Tregand regulatory T-cell/effector T-cell (Treg/Teff) ratio in peripheral blood samples from CAD patients using a new strategy for precise identification of Treg.Methods and Results:Peripheral blood samples were collected from 73 stable CAD patients (55 middle-aged CAD patients and 18 old CAD patients) and 64 controls (47 middle-aged controls and 17 young controls). CD3+CD4+FoxP3+T cells were divided into 3 fractions: CD45RA+FoxP3lowresting Treg(Fr1), CD45RA–FoxP3highactivated Treg(Fr2), and CD45RA–FoxP3lownon-Treg(Fr3). CAD patients had lower percentages of Fr1 and Fr2 and higher percentages of Fr3 and CD45RA–Foxp3–Teff(Fr4+5) within the CD3+CD4+T-cell population compared to age-matched controls. Treg/Teffratio (Fr1+2/Fr3+4+5) in CAD patients was also markedly lower than in controls (middle-aged control, 0.17±0.09 vs. middle-aged CAD, 0.10±0.05; P<0.001). The percentage of CD4+CD28nullT cells within the CD4+T-cell population was negatively correlated with Treg/Teffratio, excluding CD4+CD28nullT cells <0.3% (r=–0.27, P<0.05). High-sensitivity C-reactive protein was also negatively correlated with Treg/Teffratio (r=–0.22, P<0.05).Conclusions:CAD patients had reduced Tregand Treg/Teffratio compared to healthy controls. The present findings may be helpful when developing immunotherapy for the prevention of CAD. (Circ J 2014; 78: 2935–2941)
著者
Masahiro OKADA Daisuke HIRAMATSU Takumi OKIHARA Takuya MATSUMOTO
出版者
The Japanese Society for Dental Materials and Devices
雑誌
Dental Materials Journal (ISSN:02874547)
巻号頁・発行日
vol.35, no.4, pp.651-658, 2016-07-29 (Released:2016-07-30)
参考文献数
48
被引用文献数
3 5

Application of hydroxyapatite (HAp) nanoparticles to repair damaged enamel has attracted recent attention. In this study, HAp nanoparticles with various morphologies (spherical, short-rod, long-rod and fiber morphologies) were synthesized via chemical precipitation methods without the addition of template molecules, and the adsorption/desorption behaviors of a cationic antibacterial agent, cetylpyridinium chloride (CPC), on the HAp nanoparticles were evaluated. The adsorption of CPC on each HAp nanoparticle showed Langmuir-type adsorption, and the short-rod/long-rod HAp nanoparticles showed thermodynamically more stable adsorption of CPC than that with the spherical/fiber HAp nanoparticles. The desorption rate of CPC from the short-rod/long-rod HAp nanoparticles was slower than that of the spherical/fiber HAp nanoparticles. The HAp nanoparticles with different CPC release profiles presented here have potential applications as nanoparticulate enamel repair agents with antibacterial properties.
著者
Bui Kamihoriuchi Yoichi Otsuka Aya Takeuchi Futoshi Iwata Takuya Matsumoto
出版者
The Mass Spectrometry Society of Japan
雑誌
Mass Spectrometry (ISSN:2187137X)
巻号頁・発行日
vol.7, no.2, pp.S0078, 2019-03-06 (Released:2019-03-07)
参考文献数
22
被引用文献数
1 7

Ambient sampling and ionization techniques based on direct liquid extraction and electrospray ionization are of great value for rapid analysis and mass spectrometry imaging. Scanning probe electrospray ionization (SPESI) enables the sampling and ionization of analyte molecules in a solid material using a liquid bridge and electrospray, respectively, from a single capillary probe. To further improve SPESI, it is essential to understand the dynamic behavior of nanoliter volumes of liquids during sampling and ionization. In this study, the dynamic formation and breakage of the liquid bridge and the subsequent electrospray ionization were investigated by measuring the displacement of the capillary probe using a new optical technique. Measurements revealed that both the time from the formation of the liquid bridge to its breakage and the time from the breakage of the liquid bridge to the detection of analyte ions were correlated with the physical properties of the solvent. It was also found that both of these times were positively correlated with the flow rate. These results will not only lead to the improvement of sampling and ionization efficiencies but also afford a greater understanding of the physicochemical properties of charged nanoliter volumes of liquids.
著者
Tomoya Yamashita Kazuyuki Kasahara Takuo Emoto Takuya Matsumoto Taiji Mizoguchi Naoki Kitano Naoto Sasaki Ken-ichi Hirata
出版者
日本循環器学会
雑誌
Circulation Journal (ISSN:13469843)
巻号頁・発行日
vol.79, no.9, pp.1882-1890, 2015-08-25 (Released:2015-08-25)
参考文献数
48
被引用文献数
4 49

Atherosclerosis is considered a chronic inflammatory disease and an intervention targeting the inflammatory process could be a new therapeutic strategy for preventing atherosclerotic cardiovascular diseases (CVD). We hypothesized that the intestine, which is considered the biggest immune organ in the human body, could be a therapeutic target for preventing CVD. We demonstrated that oral administration of anti-CD3 antibody or an active form of vitamin D3reduced atherosclerosis in mice via induction of regulatory T cells and tolerogenic dendritic cells in the gut-associated lymphoid tissues. Similar to regulatory immune responses achieved by oral tolerance, our method had systemic effects that ultimately contributed towards atherosclerosis reduction. Recently, we have been interested in the gut microbiota, which have been reported as highly associated with intestinal immunity and systemic metabolic disorders, including obesity and diabetes. Notably, the guts of obese individuals are predominantly colonized byFirmicutesoverBacteroidetes. The association between atherosclerosis and microbiota has been attracting increased attention, and gut microbiota have been shown to participate in the metabolism of a proatherogenic compound called trimethylamine-N-oxide (TMAO) and aggravate CVD. Our investigation of the relationship between susceptibility to CVD and the gut microbiota revealed a characteristic flora type. Here, we discuss the evidence for the relationship between the gut microbiota and cardiometabolic diseases, and consider the gut microbiota as new potential therapeutic targets for treating CVD. (Circ J 2015; 79: 1882–1890)
著者
Takuo Emoto Naoto Sasaki Tomoya Yamashita Kazuyuki Kasahara Keiko Yodoi Yoshihiro Sasaki Takuya Matsumoto Taiji Mizoguchi Ken-ichi Hirata
出版者
日本循環器学会
雑誌
Circulation Journal (ISSN:13469843)
巻号頁・発行日
pp.CJ-14-0644, (Released:2014-10-18)
参考文献数
22
被引用文献数
9 40

Background:The protective function of regulatory T cells (Treg) has been identified in experimental atherosclerosis, but the contribution of Tregto the pathogenesis of human coronary artery disease (CAD) remains poorly understood. We investigated Tregand regulatory T-cell/effector T-cell (Treg/Teff) ratio in peripheral blood samples from CAD patients using a new strategy for precise identification of Treg.Methods and Results:Peripheral blood samples were collected from 73 stable CAD patients (55 middle-aged CAD patients and 18 old CAD patients) and 64 controls (47 middle-aged controls and 17 young controls). CD3+CD4+FoxP3+T cells were divided into 3 fractions: CD45RA+FoxP3lowresting Treg(Fr1), CD45RA–FoxP3highactivated Treg(Fr2), and CD45RA–FoxP3lownon-Treg(Fr3). CAD patients had lower percentages of Fr1 and Fr2 and higher percentages of Fr3 and CD45RA–Foxp3–Teff(Fr4+5) within the CD3+CD4+T-cell population compared to age-matched controls. Treg/Teffratio (Fr1+2/Fr3+4+5) in CAD patients was also markedly lower than in controls (middle-aged control, 0.17±0.09 vs. middle-aged CAD, 0.10±0.05; P<0.001). The percentage of CD4+CD28nullT cells within the CD4+T-cell population was negatively correlated with Treg/Teffratio, excluding CD4+CD28nullT cells <0.3% (r=–0.27, P<0.05). High-sensitivity C-reactive protein was also negatively correlated with Treg/Teffratio (r=–0.22, P<0.05).Conclusions:CAD patients had reduced Tregand Treg/Teffratio compared to healthy controls. The present findings may be helpful when developing immunotherapy for the prevention of CAD.