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Biomedical subjects

Y Sekita

Publications and source records attributed to Y Sekita.

6 recordsLinked to original sources
PubMed1990

Cerebral circulation and oxygen metabolism associated with subclinical periventricular hyperintensity as shown by magnetic resonance imaging.

A combined magnetic resonance imaging and positron emission tomography study was performed on 21 patients with cerebrovascular risk factors but without neurological abnormalities. Our purpose was to investigate the hypothesis that periventricular hyperintensity (PVH) reflects ischemia. Periventricular hyperintensity was evaluated with a method we devised, and cerebral circulation and oxygen metabolism were evaluated with the oxygen-15 steady-state technique. We concluded that the brain with severe periventricular hyperintensity had abnormal circulation, although oxygen metabolism was not measurably affected. The role of a compensation mechanism under conditions of decreased oxygen supply was considered.

Aged↗
PubMed1990

Disturbance in daily sleep/wake patterns in patients with cognitive impairment and decreased daily activity.

The sleep/wake patterns of 121 chronically ill, mentally and physically handicapped patients were visually monitored hourly for 14 consecutive days. Four types of sleep/wake patterns were found. In order to investigate how cognitive and physical functions correlated with sleep disorders, patients were classified based on a scale of mental function and the grading of daily activity. The percent of total sleep hours and the sleep rating, showing disturbances in sleep/wake pattern, were evaluated. We found a high degree of individuality in sleep/wake patterns. Sleep disturbance was associated with daily activity as well as with cognitive impairment. This monitoring system provides medical personnel with valuable information for clinical management.

Activities of Daily Living↗
PubMed1987

A statistical approach to the prediction of the possible presence of pollutant chemicals in the environment.

In the present study, trials were performed to examine the applicability of Hayashi's theory of quantification (second type) to prediction of the possible presence (i.e., detection) or absence (nondetection) of a given chemical in the environment. The dependent variables employed were the results of a nationwide environmental monitoring on pollutant chemicals conducted by the Environment Agency of Japan. When 102 chemicals were analyzed utilizing five factors as independent variables--annual production, use pattern, n-octanol/water partition coefficient (Po/w), water solubility, and biodegradability--it was found that production, use pattern, and Po/w are the major contributing factors in the prediction. Further studies with 186 chemicals utilizing these three factors as the independent variables showed that, through the combined evaluation of the results of analyses with three pairs out of the three variables, the absence of a chemical in the environment at an analytically meaningful level can be predicted with a success rate of 94.4%. The rate for the presence was 76.4%.

Chemical Phenomena↗