著者

Junichi Kaneshiro Yasushi Okada Tomohiro Shima Mika Tsujii Katsumi Imada Taro Ichimura Tomonobu M. Watanabe

出版者

The Biophysical Society of Japan

雑誌

Biophysics and Physicobiology (ISSN:21894779)

巻号頁・発行日

vol.16, pp.147-157, 2019 (Released:2019-09-20)

参考文献数

41

被引用文献数

2 5

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Cryo-electron microscopy and X-ray crystallography have been the major tools of protein structure analysis for decades and will certainly continue to be essential in the future. Moreover, nuclear magnetic resonance or Förster resonance energy transfer can measure structural dynamics. Here, we propose to add optical second-harmonic generation (SHG), which is a nonlinear optical scattering process sensitive to molecular structures in illuminated materials, to the tool-kit of structural analysis methodologies. SHG can be expected to probe the structural changes of proteins in the physiological condition, and thus link protein structure and biological function. We demonstrate that a conformational change as well as its dynamics in protein macromolecular assemblies can be detected by means of SHG polarization measurement. To prove the capability of SHG polarization measurement with regard to protein structure analysis, we developed an SHG polarization microscope to analyze microtubules in solution. The difference in conformation between microtubules with different binding molecules was successfully observed as polarization dependence of SHG intensity. We also succeeded in capturing the temporal variation of structure in a photo-switchable protein crystal in both activation and inactivation processes. These results illustrate the potential of this method for protein structure analysis in physiological solutions at room temperature without any labeling.

著者

Akihiko Ishijima Yasushi Okada

出版者

The Biophysical Society of Japan

雑誌

Biophysics and Physicobiology (ISSN:21894779)

巻号頁・発行日

pp.bppb-v18.029, (Released:2021-10-21)

著者

Yohei Mima Yuhei Sangatsuda Masahiro Yasaka Yoshiyuki Wakugawa Shinji Nagata Yasushi Okada

出版者

The Japanese Society of Internal Medicine

雑誌

Internal Medicine (ISSN:09182918)

巻号頁・発行日

vol.53, no.21, pp.2523-2527, 2014 (Released:2014-11-01)

参考文献数

10

被引用文献数

10 13

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A 75-year-old man with paroxysmal atrial fibrillation developed a traumatic intracranial hemorrhage during warfarin treatment. The administration of warfarin was stopped and rivaroxaban therapy, a novel oral anticoagulant (NOAC), was started. Immediately, his platelet count decreased to 3.7×104 /μL. The platelet count recovered rapidly after cessation of rivaroxaban administration. Development of thrombocytopenia and its rapid recovery was observed again after another administration, and subsequent cessation, of the drug. A diagnosis of rivaroxaban-induced thrombocytopenia was made. The incidence of thrombocytopenia due to NOACs is rare. Careful attention to thrombocytopenia, which is associated with a higher risk for life-threatening bleeding, is therefore necessary during treatment with NOACs.

著者

Shinichiro Uchiyama Takao Hoshino Hugo Charles Kenji Kamiyama Taizen Nakase Kazuo Kitagawa Kazuo Minematsu Kenichi Todo Yasushi Okada Jyoji Nakagawara Ken Nagata Hiroshi Yamagami Takenori Yamaguchi Pierre Amarenco

出版者

Japan Atherosclerosis Society

雑誌

Journal of Atherosclerosis and Thrombosis (ISSN:13403478)

巻号頁・発行日

pp.58552, (Released:2020-09-17)

参考文献数

22

被引用文献数

4

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Aims: We have previously reported 5-year follow-up data on the TIAregistry.org, an international prospective cohort in patients with transient ischemic attack (TIA) or minor stroke. We conducted a Japanese subgroup analysis because outcomes and predictors might differ according to ethnicities and regions. In this study, we compared the baseline and 5-year follow-up data of Japanese and non-Japanese patients with TIA or minor stroke.Methods: Patients with TIA or minor ischemic stroke within 7 days after the onset were classified into two groups based on ethnicity, Japanese (n=345) and non-Japanese (n=3502); further, 5-year event rates were compared between the two groups. We also determined predictors of 5-year stroke for both groups. Results: Vascular death and death from any cause were identified to be less prevalent, unlike stroke and intracranial hemorrhage, which was determined to be more prevalent in Japanese than in non-Japanese patients. Five-year rate of stroke was significantly higher in Japanese patients. Cumulative stroke and major cardiovascular event rates did not decline but instead linearly increased from 1 to 5 years in both groups. Baseline risk factors for 5-year stroke were as follows: age, diabetes, history of stroke or TIA, and congestive heart failure in Japanese patients. Independent predictors of 5-year stroke were large artery atherosclerosis, congestive heart failure, diabetes, and age in Japanese patients. Conclusions: Recurrent stroke and intracranial hemorrhage were determined to be more prevalent at 5 years after TIA or minor stroke in Japanese patients than in non-Japanese patients. Strategies to mitigate the long-term risks of stroke, aside from adherence to current guidelines, should take Japanese-patient-specific residual risks into account.

著者

Sohei Yoshimura Masatoshi Koga Shoichiro Sato Kenichi Todo Hiroshi Yamagami Masaya Kumamoto Ryo Itabashi Tadashi Terasaki Kazumi Kimura Yoshiki Yagita Yoshiaki Shiokawa Kenji Kamiyama Satoshi Okuda Yasushi Okada Shunya Takizawa Yasuhiro Hasegawa Tomoaki Kameda Satoshi Shibuya Yoshinari Nagakane Yasuhiro Ito Hideki Matsuoka Kazuhiro Takamatsu Kazutoshi Nishiyama Kyohei Fujita Teppei Kamimura Daisuke Ando Toshihiro Ide Takeshi Yoshimoto Masayuki Shiozawa Soichiro Matsubara Yoshitaka Yamaguchi Naoto Kinoshita Takayuki Matsuki Junji Takasugi Keisuke Tokunaga Kyoko Higashida Kazunari Homma Kazuomi Kario Shoji Arihiro Kazunori Toyoda for the SAMURAI Study Investigators

出版者

The Japanese Circulation Society

雑誌

Circulation Journal (ISSN:13469843)

巻号頁・発行日

pp.CJ-18-0067, (Released:2018-06-01)

参考文献数

27

被引用文献数

34

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Background:We determined the 2-year long-term risk-benefit profile in patients with stroke or transient ischemic attack (TIA) receiving warfarin or direct oral anticoagulants (DOACs) for nonvalvular atrial fibrillation (NVAF) using a prospective, multicenter, observational registry in Japan.Methods and Results:NVAF patients within 7 days after onset of ischemic stroke/TIA were enrolled in 18 stroke centers. Outcome measures included ischemic and bleeding events and death in the 2-year follow-up period. We enrolled 1,116 patients taking either warfarin (650 patients) or DOACs (466 patients) at acute hospital discharge. DOAC users were younger and had lower National Institutes of Health Stroke Scale, CHADS2and discharge modified Rankin Scale scores than warfarin users (P<0.0001 each). Incidences of stroke/systemic embolism (adjusted hazard ratio, 1.07; 95% CI, 0.66–1.72), all ischemic events (1.13; 0.72–1.75), and ischemic stroke/TIA (1.58; 0.95–2.62) were similar between groups. Risks of intracranial hemorrhage (0.32; 0.09–0.97) and death (0.41; 0.26–0.63) were significantly lower for DOAC users. Infection was the leading cause of death, accounting for 40% of deaths among warfarin users.Conclusions:Stroke/TIA patients receiving DOACs for secondary prevention were younger and had lower stroke severity and risk indices than those receiving warfarin. Estimated cumulative incidences of stroke and systemic embolism within 2 years were similar between warfarin and DOACs users, but those of death and intracranial hemorrhage were significantly lower among DOAC users.