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A ten-year follow-up study of stroke among residents 40 years and older in a rural community located on Shikoku Island, Japan, was completed in 1977. The response rate for the initial examinations was 85% of 920 males and 90% of 1,012 females. Seven hundred and seventy-two males and 901 females who were initially free of stroke were followed from July 1967 through June 1977. The incidence of all strokes was 10.47 per thousand person-years for males and 6.41 per thousand person-years for females. The statistically significant risk factors for stroke were age, male sex, elevated blood pressure, ECG abnormalities, and funduscopic abnormalities. Elevated blood pressure was the strongest risk factor and mean arterial pressure was the best predictive measure. Twice as high a proportion of strokes were subclassified as cerebral hemorrhage (26%) in this study as have been reported in comparable studies in the United States (12-15%). An inverse relationship between serum cholesterol levels and cerebral hemorrhage incidence, but not cerebral infarct, was observed. High alcohol intake was a risk factor for cerebral hemorrhage but not for cerebral infarct. No relationship between stroke and weight was observed despite the relationship of stroke to blood pressure and of weight to blood pressure.

SUMMARY A stroke registry was established in Shibata City, Nilgata Prefecture, Japan (population 75,000) in 1976. WHO recommendations for criteria were followed. This paper reports stroke incidence for die initial 3 years of the registry: 1976 dirough 1978. All liring padents were examined clinically by a staff physician. Only patients with a diagnosis of first stroke were included in die study. Sensitivity of the referral system was estimated at 85 + %, comparable to that in American studies.Arerage annual incidence per 1,000 in residents ^20 years was 2.61 for all strokes (3.42 for males; 1.88 for females), 0.20 for subarachnoid hemorrhage, 0.61 for cerebral hemorrhage, 1.51 for cerebral infarctionrates similar to those reported 10-20 years previously for the United States.The male-female ratio STROKE has been the leading cause of death in Japan since 1951.1 -* According to international comparisons, Japan has the highest mortality rate from stroke of any developed country.'"* Because mortality rates can be affected by factors such as access to medical care and survival, incidence is a more reliable measure of frequency. There have been few reports, however, on the incidence of stroke in Japan. Incidence rates would be helpful for studying the natural history of the disease and for developing appropriate health care facilities. To meet this need, a stroke registry was developed in Shibata, Niigata Prefecture, Japan, beginning in 1976. This paper presents data from the stroke registry during the initial 3-year period and compares the incidence rate in Shibata with incidence rates recorded from other areas of Japan and from the United States. Methods Study PopulationShibata was selected as the city in which to develop a registry because Niigata Prefecture has one of the highest age-adjusted death rates from stroke in Japan." The city of Shibata covers an area of 434 square kilometers and is located in the northern part of the prefecture ( fig. 1). Shibata includes a central From the Department of Public Health, Osaka City University Medical School, 1-4-54 Asahi-Machi Abeno-Ku, Osaka 545, Japan (Drs. Tanaka, Ueda, Yamashita, Owada, Messers Date, Baba, Hayashi, and Shoji). Niigata-Ken Medical Association, Niigata, 961 Japan (Dr. K-I Baba). Shibata-Shi, Toyosaka-Shi, KitaKambara-Gun Medical Association, Shibata, 957 Japan (Dr. Shibuya). The Department of Public Health, City of Shibata, Shibata, 957 Japan (Dr. Kon). Division of Epidemiology, School of Public Health, University of California, Los Angeles, CA 90024 (Dr. Detels).Reprints: Dr. Tanaka, Dept. Public Health, Osaka City University Medical School, 1-4-54 Asahi-Machi Abcno-ku, Osaka, 545 Japan.

Objectives To investigate the prevalence of non-alcoholic fatty liver disease (NAFLD) in children and its relationship to metabolic syndrome, insulin resistance, and waist circumference (WC). Methods This was a population-based cross-sectional, case-control study. Cases were selected among students of a primary and junior high school, respectively, and ageand sex-matched control subjects were selected randomly (ratio of cases to control subject was 37:113). Results Of the 846 students, aged between 6 and 15 years, enrolled in the study and screened by ultrasonography, 37 children were diagnosed as having NAFLD (score C 1). There was a significant sex difference in the prevalence of NAFLD(P = 0.003). The trend test revealed a strong doseresponse relationship (P \ 0.001) between pediatric NA-FLD and the number of the proposed components of pediatric metabolic syndrome in Japan (MetS-JC), such as a clustering of the components of MetS-JC. Additionally, the linear trend of the odds ratios (ORs) with increasing percentile of the homeostasis model assessmentinsulin resistance (HOMA-IR) was statistically significant (P \ 0.001). However, when WC was added to the logistic model, the ORs were no longer significant, whereas WC turned out to be an independent risk factor for NAFLD regardless of the HOMA-IR index. Conclusion The prevalence of NAFLD in children and adolescents is closely related to metabolic syndrome, insulin resistance, and WC.

For maternally transmitted microbes, a female-biased host sex ratio is of reproductive advantage. Here we found a strong female bias in a field population of the green lacewing, Mallada desjardinsi (Insecta; Neuroptera). This bias was attributed to the predominance of individuals harboring a maternally inherited male-killing bacterium that was phylogenetically closely related to the plant-pathogenic Spiroplasma phoeniceum and Spiroplasma kunkelii. Among 35 laboratory-reared broods produced by wild-caught females, 21 broods (60%)—all infected with Spiroplasma—consisted of only females (940 individuals). Among 14 broods consisting of both males and females (516 and 635 individuals, respectively), 4 broods were doubly infected with Spiroplasma and Rickettsia, 6 broods were singly infected with Rickettsia, and 3 broods were uninfected (remaining one brood was unknown). Mortality during embryonic and larval development was prominent in all-female broods but not in normal sex ratio broods. Following antibiotic treatment on all-female broods, mortality was significantly reduced and the sex ratio was restored to 1:1. Strong expression and high prevalence of this male-killer is remarkable considering its low density (~10−5–10−4 cells per host mitochondrial gene copy based on quantitative PCR). In addition, a bacterium closely related to Rickettsia bellii was present in 25 of 34 broods (73.5%), irrespective of the sex ratio, with the infection density comparable to other cases of endosymbiosis (~10−2–10−1 cells per mitochondrial gene copy). Higher density of Rickettsia than Spiroplasma was also demonstrated by electron microscopy which visualized both Spiroplasma-like cells and Rickettsia-like cells inside and outside the ovarian cells.