Biomedical subjects

Shaw Watanabe

Publications and source records attributed to Shaw Watanabe.

21 records · Page 2Linked to original sources

PubMed2002

Measurement of bisphenol A in human urine using liquid chromatography with multi-channel coulometric electrochemical detection.

Environmental exposure levels of bisphenol A (BPA) in human were investigated by measuring BPA glucuronide (BPA-G) in urine. After enzymatic hydrolysis of glucuronide substances in urine, BPA was extracted with diethyl ether. The extract was analyzed using a column-switching HPLC system employing a C(8) and a C(18) column with multi-channel coulometric electrochemical detection (ECD). The sensitivity and selectivity provided with redox mode of ECD allowed measurement of low level BPA in hydrolyzed urine. The quantification limit of BPA-G in urine was 0.2 ng/ml. RSDs of the intraassay precision were less than 3% and recoveries of the method were over 96% when analyzing BPA spiked urine samples (1.0 and 10 ng/ml). In a group of 48 women students, the level of BPA-G in urine ranged from 0.2 to 19.1 ng/ml with a median concentration of 1.2 ng/ml. Normalized against urinary creatinine, BPA-G ranged from 0.1 to 11.9 ng/mg creatinine with a median of 0.77 ng/mg creatinine.

Benzhydryl Compounds↗

PubMed2002

Isoflavones for prevention of cancer, cardiovascular diseases, gynecological problems and possible immune potentiation.

Japanese women show low incidence of and mortality from breast cancer, cardiovascular disease and climacteric symptoms compared to Caucasians. High soy bean intake is considered to attribute to that, but it is not clear whether soy protein itself or isoflavones (IFs) mixed in the soy protein has such effects. Presence of IFs in soy beans was varied by site, so we made IF-rich tablets from daidzein-rich soy germ (hypocotyl) for intervention studies. Our intervention study on young women by using the IF-rich tablet (20 and 40 mg/day) showed slight elongation of the menstrual cycle, but no adverse effects occurred. Intervention study on climacteric women showed improvement of bone density, hypertension and climacteric symptoms. Health effects of IFs on cancer occurrence, cardiovascular diseases, gynecological problems and possible immune potentiation are reviewed from functional aspects.

Adjuvants, Immunologic↗

PubMedDate not supplied

UV exposure of elementary school children in five Japanese cities.

A 1 week UV-exposure measurement and outdoor-activity pattern survey was conducted for elementary school children for four seasons at five sites in Japan, i.e. Sapporo (43 degrees 05' N, altitude 40 m), Tsukuba (36 degrees 05' N, 20 m), Tokyo (35 degrees 40' N, 45 m), Miyazaki (31 degrees 60' N, 40 m) and Naha (26 degrees 10' N, 5 m), and UV exposure was measured directly and estimated using outdoor-activity records. The study site with largest UV exposure was Miyazaki, a southern rural area. Comparing the results for boys and girls, UV exposure was larger in boys. UV exposure was large in spring and summer and small in winter. The total amount of UV exposure in spring and summer contributed 57.7-73.4% of total exposure for the year. As a whole, 8.1% and 1.8% of the schoolchildren were exposed to more than 1 minimum erythemal dose (MED) and 2 MED of solar UV in a day, respectively. The estimated yearly UV exposure ranged from 49 207 J/m2 in Miyazaki to 31 520 J/m2 in Tsukuba. The actual UV exposure correlated to potential UV exposure, estimated using outdoor-activity records and ambient UV irradiance, but the ratio differed by season and site. The yearly average of percent UV exposure to ambient UV on a horizontal plane ranged from 9.9% in Tokyo to 4.0% in Naha. In the questionnaire survey on outdoor-activity pattern, a short question "How long did you spend time outdoors between 0900 and 1500 h?" gives the best estimates of UV exposure.

Child↗