著者
Michio MURAKOSHI Hiroshi WADA
出版者
The Japan Society of Mechanical Engineers
雑誌
Journal of Biomechanical Science and Engineering (ISSN:18809863)
巻号頁・発行日
vol.16, no.3, pp.21-00125, 2021 (Released:2021-09-15)
参考文献数
38

The high sensitivity of mammalian hearing is achieved by cochlear amplification. The basis of this amplification is the motility of outer hair cells (OHCs), which are sensory cells in the inner ear. This motility may be due to voltage-dependent conformational changes of the motor protein prestin, which is densely embedded in the lateral membrane of OHCs. However, the membrane structure of prestin has not yet been elucidated. Therefore, the membrane structure of prestin was herein investigated by force spectroscopy using an atomic force microscope (AFM). The gene of prestin fused with an Avi-tag at its C terminus was transfected into Chinese hamster ovary (CHO) cells and the inside-out plasma membrane was isolated. The Avi-tag was enzymatically biotinylated and attached to a streptavidin-coated AFM cantilever via biotin-streptavidin binding. Prestin was then pulled out from the plasma membrane and the relationship between the force applied to the protein and the extension distance, i.e., the force-extension (FE) curve, was assessed. The curves obtained showed saw-toothed patterns. An attempt was then made to analyze these curves using the worm-like chain model. The force caused by stretching of the intracellular C terminus and that due to the extraction of one or several transmembrane domains were identified. The present results imply that the C terminus and the subsequent transmembrane domains of prestin correspond to those of the previously reported model with 12 transmembrane domains.

2 0 0 0 OA BYZANTINE STUDIES

著者
Hiroshi WADA
出版者
The Society for Near Eastern Studies in Japan
雑誌
Orient (ISSN:04733851)
巻号頁・発行日
vol.36, pp.123-128, 2001 (Released:2008-03-24)
参考文献数
36
著者
Dilshadbek Tursunbayevich Usmanov Satoshi Ninomiya Lee Chuin Chen Subhrakanti Saha Mridul Kanti Mandal Yuji Sakai Rio Takaishi Ahsan Habib Kenzo Hiraoka Kentaro Yoshimura Sen Takeda Hiroshi Wada Hiroshi Nonami
出版者
The Mass Spectrometry Society of Japan
雑誌
Mass Spectrometry (ISSN:2187137X)
巻号頁・発行日
vol.6, no.2, pp.S0059-S0059, 2017-02-24 (Released:2017-02-24)
参考文献数
89
被引用文献数
9

In mass spectrometry, analytes must be released in the gas phase. There are two representative methods for the gasification of the condensed samples, i.e., ablation and desorption. While ablation is based on the explosion induced by the energy accumulated in the condensed matrix, desorption is a single molecular process taking place on the surface. In this paper, desorption methods for mass spectrometry developed in our laboratory: flash heating/rapid cooling, Leidenfrost phenomenon-assisted thermal desorption (LPTD), solid/solid friction, liquid/solid friction, electrospray droplet impact (EDI) ionization/desorption, and probe electrospray ionization (PESI), will be described. All the methods are concerned with the surface and interface phenomena. The concept of how to desorb less-volatility compounds from the surface will be discussed.
著者
Kenzo Hiraoka Osamu Ariyada Dilshadbek T. Usmanov Lee C. Chen Satoshi Ninomiya Kentaro Yoshimura Sen Takeda Zhang Yu Mridul K. Mandal Hiroshi Wada Stephanie Rankin-Turner Hiroshi Nonami
出版者
The Mass Spectrometry Society of Japan
雑誌
Mass Spectrometry (ISSN:2187137X)
巻号頁・発行日
vol.9, no.1, pp.A0092, 2020-12-04 (Released:2020-12-04)
参考文献数
61
被引用文献数
17

In 2007, probe electrospray ionization/mass spectrometry (PESI/MS) was developed. In this technique, the needle is moved down along a vertical axis and the tip of the needle touched to the sample. After capturing the sample at the needle tip, the needle is then moved up and a high voltage is applied to the needle at the highest position to generate electrospray. Due to the discontinuous sampling followed by the generation of spontaneous electrospray, sequential and exhaustive electrospray takes place depending on the surface activity of the analytes. As modified versions of PESI, dipping PESI (dPESI), sheath-flow PESI (sfPESI) and adjustable sfPESI (ad-sfPESI) have been developed. These methods are complementary to each other and they can be applicable to surface and bulk analysis of various biological samples. In this article, the characteristics of these methods and their applications to real samples will be reviewed.
著者
Kenichi Sakakura Yousuke Taniguchi Mitsunari Matsumoto Hiroshi Wada Shin-ichi Momomura Hideo Fujita
出版者
一般社団法人 インターナショナル・ハート・ジャーナル刊行会
雑誌
International Heart Journal (ISSN:13492365)
巻号頁・発行日
pp.15-421, (Released:2016-05-09)
被引用文献数
20

Rotational atherectomy to an angulated calcified lesion is always challenging. The risk of catastrophic complications such as a burr becoming stuck or vessel perforation is greater when the calcified lesion is angulated. We describe the case of an 83-year-old female suffering from unstable angina. Diagnostic coronary angiography revealed an angulated calcified lesion in the proximal segment of the right coronary artery. We performed rotational atherectomy to the lesion, but intentionally did not advance the rotational atherectomy burr beyond the top of the angulation. We controlled the rotational atherectomy burr and stopped it just before the top of the angulation to avoid complications. Following rotational atherectomy, balloon dilatation with a non-compliant balloon was performed, and drug-eluting stents were successfully deployed. In this manuscript, we provide a review of the literature on this topic, and discuss how rotational atherectomy to an angulated calcified lesion should be performed.
著者
Hiroaki Nakagawa Hiroshi Wada Takashi Hajiro Taishi Nagao Emiko Ogawa Atsushi Hatamochi Toshihiro Tanaka Yasutaka Nakano
出版者
一般社団法人 日本内科学会
雑誌
Internal Medicine (ISSN:09182918)
巻号頁・発行日
vol.54, no.24, pp.3181-3184, 2015 (Released:2015-12-15)
参考文献数
15
被引用文献数
16

A 17-year-old teen was hospitalized with bilateral pneumothorax. After the bilateral lungs were expanded using catheter tubes, he fully recovered and he was discharged from our hospital. He had a history of colon perforation. Ehlers-Danlos syndrome (EDS) was suspected due to the combination of colon perforation and pneumothorax, and EDS type IV was confirmed after a genetic study identified a c.1511g>a mutation in the COL3A1 gene. This is the first report of bilateral pneumothorax caused by EDS type IV. Clinicians should consider EDS type IV in the differential diagnosis for bilateral pneumothorax in conjunction with distinct previous histories and radiological findings.