Biomedical subjects

Keiichi Hirano

Publications and source records attributed to Keiichi Hirano.

5 recordsLinked to original sources

PubMed2006

[Angina pectoris presenting with unusual form of coronary spasm: a case report].

A 46-year-old male with asthma bronchiale and eosinophilia was admitted to our hospital because of continuous severe chest pain. Electrocardiography showed ST segment elevation in leads II, III and aVF during chest pain. Emergency coronary angiography showed a series of coronary arterial narrowings in segments 1 and 2. After injection of nitroglycerin 0.1 mg and nicorandil 2 mg into the right coronary artery, the coronary arterial narrowing was gradually relieved. The artery became completely normal after 10 min. Left coronary arterial angiography showed no abnormalities. The diagnosis was spontaneous coronary arterial spasm based on the coronary angiographic findings. The spasm occurred as multiple short narrow arterial segments. Normalization of the coronary artery took a long time. In a case like this, thrombus is easily formed that may cause acute myocardial infarction and unnecessary coronary angioplasty may be performed.

Angina Pectoris↗

PubMed2004

alpha-Aminoallylation of aldehydes in aqueous ammonia.

alpha-Aminoallylation of aldehydes in aqueous ammonia has been developed; commercial aqueous ammonia was successfully used, and this method does not require anhydrous conditions thus leading to easy and practical operations.

Journal Article↗

PubMed2004

alpha-Aminoallylation of aldehydes with ammonia: stereoselective synthesis of homoallylic primary amines.

Three-component reactions of aldehydes, ammonia, and allylboronates were found to provide homoallylic primary amines in high yields with high chemo- and stereoselectivities. A two-step, one-pot, stereoselective synthesis of an uncommon alpha-amino acid, alloisoleucine, was achieved utilizing this reaction.

Aldehydes↗

PubMed2002

Large-area phase-contrast X-ray imaging using a two-crystal X-ray interferometer.

Large-area (25 x 20 mm) phase-contrast X-ray imaging was attained by using a skew-symmetric two-crystal X-ray interferometer. The sub-nrad angular control required to operate the X-ray interferometer was achieved with a sleeve bearing and a feedback-positioning system. As a demonstration, measurements of a phase map of a rat's liver and a phase-contrast tomographic three-dimensional image of a piece of a rabbit's liver were performed at the Photon Factory using 0.07 nm synchrotron radiation X-rays.

Animals↗

PubMed2002

[Phase-contrast x-ray imaging with x-ray interferometer for medical applications].

Phase-contrast x-ray imaging with x-ray interferometer can depict the minute difference within the biological object, and its sensitivity is about 1000 times higher than that of absorption-contrast method. For biomedical use of this technique, a large monolithic x-ray interferometer and 2 crystal interferometer having a field of view with 25 mm x 25 mm is being developed. Phase-contrast x-ray CT could reveal detail structures within tumor and surrounded tissue, and the vessel imaging of rat liver is also possible using physiological saline at 17.7 keV x-ray energy. Recently, human breast tissues were imaged at 35 keV and the contrast of image was much better than usual absorption contrast x-ray image obtained at 17.7 keV energy.

Animals↗