Using the results of principle component analysis of data from 47 prefectures, we classified selected prefectures into 4 groups according to similarity of geographical feature, traffic conditions, and degree of urbanization. We analyzed the relationships between incidence rates of traffic accidents and factors thought to affect the incidence rates. The results of the study are as follows: 1) Falling into the first classification were areas where there is very little traffic. Yamanashi, Nagano, Tottori, Tokushima, Kagawa, and Kochi Prefectures were included in this classification. The incidence rates for accidents on major roads in these areas were high, and the death rates were also high. It was thought that factors influencing these high rates might be the bad road conditions, lax traffic control, lack of safety policy, and lack of adequate medical facilities. 2) A second classification was the Tokyo Metropolitan Area. Tokyo, Saitama, Chiba and Kanagawa Prefectures fell into this classification area. The total incidence rate of traffic accidents, the death rate, and other traffic accident indices were low. Factors influencing these low rates were thought to be the existence of adequate medical facilities, the continuing improvement of the transportation network, strict traffic control, and satisfactory safety policy. 3) A third classification was a highway classification. Tochigi, Shizuoka, Kyoto, Hiroshima, and Fukuoka Prefectures were included in this classification. For areas in this classification, the total incidence rate was high, as was the injury rate, and the rate of hit and run accidents. It was thought that road improvement, traffic control, safety policy, and regulation of traffic offenses had not kept up with the rapid urbanization in these areas, thus contributing to these high rates. 4. The last classification was of remote areas. Iwate, Akita, Toyama, Gifu, Shimane, Nagasaki, and Miyazaki Prefectures were classified here. In these remote areas, the fatality rates for traffic accidents were very high. The contributing factor seemed to be lack of emergency medical facilities and ambulances.
Analysis was made to ascertain the social relations in Iheya Island, the northern end of Okinawa Prefecture, based on the applications for registration of marriage during the twenty-four-year period, 1957-80. As a result, author has obtained following findings. 1) It had been endogamous at the first five year period in which the inter-island marriage accounted for 80.4%. However, it had changed to exogamous in the period of 1966-71, in which the marriage within the island had decreased to 43.2% and to the contrary, marriage with those both from the other parts of Okinawa and from the Japan mainland had increased. 2) There was a marked tendency of exogamous especially among female since the reversion of the administrative authority in Okinawa to Japan from the United States in 1972. The young seldom return to the island, once they left for higher education or finding employment in the Okinawa Island or the mainland Japan. 3) Although the noticeable change from endogamous to exogamous had observed, moving in the island of those registered in the Japan mainland was negligible . And therefore it may fairly be presumed that the tendency of endogamous among those living in the island has been maintained. 4) The findings suggest that the traditional ways of life and value systems in the island are succeeding from generation to generation, and the island is rather socially isolated.
Superoxide dismutase (SOD) activities of peripheral blood lymphocytes (PBL) in inhabitants of a mountain village were measured in order to determine a range of the SOD activity. The validity of SOD assay was based on the ability of SOD to inhibit the interception of •O2- generated enzymatically through the xanthine-xanthine oxidase system with nitro blue tetrazolium (NBT). The results were as follows: 1) The distribution of levels in logalistic converted SOD of PBL in 142 subjects showed a normal distribution. The geometric means of total, male, and female were respectively 33.1, 3 and 33.9 units/mg protein. No significant difference between the SOD activities of male and female was found. 2) In the subjects of the village aged 20-82, the SOD activities of PBL did not demonstrate any significant defferences in age. 3) The SOD activities of the subjects with atopy tended to be higher than those with non-atopy. However, there were not significant influences of smoking and drinking on the SOD activities.
The A -mode ultrasonic skin thickness device newly developed has been tested for practical uses since 1982. In order to approve both sensibility and specificity of ultrasonic measurement, the target waves reflected from interface between subcutaneous fat layer and muscles were identified in comparison with X-ray CT scan picture at thigh in the former report. Through the trial it has become clear that the ultrasonic device is able to measure skin thickness precisely even at thigh where skinfold calipers are unable to fold skin. In this report, the ultrasonic device has been checked also regarding to stability of measurement among inspectors who are 7 medical students in comparison with EIKEN's caliper. The experiment was conducted as follows: 1) Seven students measured each other, so that every students assessed six students except for himself and was measured 6 times by his colleagues with ultrasonic device and EIKEN's skinfold caliper respectively. 2) Their measurement were conducted at first by a student with ultrasonic device successively. Then another student in turn measured his colleagues and this turn of inspector continued until all students finished. 3) When all students had measured their colleagues using ultrasonics, they repeated then measurement with EIKEN's caliper in the same way of turning. 4) Measuring point was keeping marked by black magic ink on upper-arm posterior during the experiment. Results were as follows: 1) Standard deviation of measured values were much smaller in ultrasonic measurement than in EIKEN's measurement, i.e., standard deviations were 0.29mm at minimum and 0.70mm at maxium in ultrasonics and 0.94mm at minimum and 3.20mm at maximum in EIKEN's caliper. 2) As well as sensitivity and specificity in the former report, reproducibility of inter-inspectors was also confirmed here, so that ultrasonic device became much more available for practical uses. 3) As the students were new-comers for the ultrasonic measurement, accuracy of the measurement will be more improved through the intensive training and the establishment of measuring manual in future.