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Biomedical subjects

Takayuki Matsuto

Publications and source records attributed to Takayuki Matsuto.

4 recordsLinked to original sources
PubMed2004

A new method of measuring the antioxidant activity of polyphenols using cumene hydroperoxide.

BACKGROUND: It is well known that polyphenols lower the risk of chronic diseases such as heart disease and cancer. We describe a new method using cumene hydroperoxide (CHP) to determine the antioxidant activity of polyphenols. CHP is considered to be a model reactive lipid peroxidation product. METHODS: The method was based on two reactions: the reduction of a known concentration of CHP by polyphenols and the reaction of the remaining CHP with a methylene blue derivative (10-N-methylcarbamoyl-3,7 dimethylamino-10H-phenothiazine) in the presence of haemoglobin. Methylene blue was formed as a result of the two reactions and then measured by absorbance at 675 nm. We named this assay the 'cumene hydroperoxide/haemoglobin.methylene blue (CHP/Hb.MB) method'. We examined 13 polyphenols and nine compounds known to be antioxidants. RESULTS: Among the 13 polyphenols, milicetin, with the largest number of hydroxyl groups, had the highest antioxidant activity, followed by cyanidin, pelargonidin and quercetin. It is suggested that the increase in the number of hydroxyl groups induced a higher antioxidant activity. Within-run coefficients of variation were 3.6% and 3.5% at the mean antioxidant activity of 50 micromol/L and 151 micromol/L, respectively. CONCLUSION: We conclude that this CHP/Hb.MB assay is capable of measuring the antioxidant activity of polyphenols.

Antioxidants↗
PubMed2003

An integrated medical image database and retrieval system using a web application server.

We developed an Integrated Medical Image Database and Retrieval System (INIS) for easy access by medical staff. The INIS mainly consisted of four parts: specific servers to save medical images from multi-vendor modalities of CT, MRI, CR, ECG and endoscopy; an integrated image database (DB) server to save various kinds of images in a DICOM format; a Web application server to connect clients to the integrated image DB and the Web browser terminals connected to an HIS system. The INIS provided a common screen design to retrieve CT, MRI, CR, endoscopic and ECG images, and radiological reports, which would allow doctors to retrieve radiological images and corresponding reports, or ECG images of a patient simultaneously on a screen. Doctors working in internal medicine on average accessed information 492 times a month. Doctors working in cardiological and gastroenterological accessed information 308 times a month. Using the INIS, medical staff could browse all or parts of a patient's medical images and reports.

Databases, Factual↗
PubMed2003

[Antioxidant activities of green and black teas determined by the cumene hydroperoxide/hemoglobin.methylene blue method].

Antioxidant activity in tea was measured by the new cumene hydroperoxide/hemoglobin.methylene blue(CHP/Hb.MB) method developed in our laboratory. Using the CHP/Hb.MB method, we investigated the activities of polyphenols(11 varieties) in order to determine their reactivity on CHP. According to the CHP/Hb.MB method, an increase in the number of hydroxyl groups in polyphenols induced high antioxidant activity. We found that this method was capable of measuring the antioxidant activity of polyphenols. Consequently, we were able to measure the antioxidant activities of heated, green, powdered and black teas by this method. The average of antioxidant activities of heated green tea was 207 nmol/ml, while that of green tea was 280 nmol/ml, powdered green tea was 481 nmol/ml and black tea was 215 nmol/ml respectively.

Antioxidants↗