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Biomedical subjects

Takayuki Matsuto

Publications and source records attributed to Takayuki Matsuto.

7 recordsLinked to original sources

[Report on a training course for clinical research coordinators].

Recently, nurses and pharmacists have become to play important roles in clinical trials as clinical research coordinators (CRC). However, clinical laboratory personnel have a very few chances to contribute to such tasks. CRCs have responsibility to protect the human rights, to assure the safety of volunteers during studies, and to keep quality of data. One of the authors had a chance to participate in a training course for CRC that was held in Tokyo, 2004. In this paper, we report about the training course and roles of CRC. We also discuss how laboratory personnel should contribute to clinical trials.

Biomedical Research↗

[Consultation for the prevention of atherosclerotic diseases].

We have conducted a population-based, long-term trial with the purpose of investigating risk factors for atherosclerotic diseases in a Japanese population, from 1996 (Niigata Study). Through the trial, we have learned what is going on at the initial phase of atherosclerotic diseases. This experience plays an important role in contributing to clinical decision-making. We are engaging ourselves in improving not only diagnoses but also therapies and research relating to atherosclerotic diseases. We are specialized in performing laboratory tests for lipid analysis such as the two-dimensional nondenaturing electrophoresis of lipoproteins, which is exclusively conducted in our laboratory. Three children with the oculocerebrorenal syndrome of Lowe, for example, were confirmed by these lipid analyses and also by gene analyses performed by us. Our potential goal is a regenerative or cellular therapy for patients with vascular insufficiency. We are now conducting basic research for angiogenesis.

Atherosclerosis↗

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↗

Lipid analyses for the management of vascular diseases.

Despite a long history of studies on lipid abnormalities, numerous problems in laboratory technologies and techniques remain unresolved. One of the most commonly tested molecules is low-density lipoprotein (LDL) cholesterol, and a homogenous assay technique for measurement of this molecule has recently been introduced. Although the method represents remarkable technological breakthroughs with great potential for improving lipoprotein analysis, some discrepancies exist among assay protocols. Even for direct measurement of high-density lipoprotein (HDL) cholesterol, which has widely been accepted, there are still large discrepancies among data obtained by different protocols. Oxidatively modified LDL is an independent factor that is considered to directly contribute to the pathogenesis of early atherosclerosis. Lipid peroxidation products, surface charge, and spectrophotometric patterns are all applicable to the evaluation of in vitro oxidation. Only enzyme-linked immunosorbent assays using monoclonal antibodies have a potential for clinical use, but such methods are not yet standardized. There is also increasing evidence for the presence of anti-oxidized LDL autoantibodies in human sera, but the diagnostic utility remains controversial. In addition, small dense LDL has recently attracted much attention as an independent risk factor. Although this is a potential target of oxidization, a robust and simple analytical method does not yet exist. This review presents the current state of laboratory technologies for testing lipid abnormalities.

Animals↗

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↗

[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↗