Hirotsugu Miyake

Prevalence of prostatism in Japanese men in a community-based study with comparison to a similar American study.

PURPOSE We estimate the prevalence of urinary symptoms in Japanese men. MATERIALS AND METHODS A total of 289 eligible residents 40 to 79 years old completed a questionnaire with questions worded similarly to those of the international prostate symptom score (response rate 42%). RESULTS The ratio of moderate-to-severe symptoms was 41%, 29%, 31% and 56% for each age decade from ages 40 to 79 years, respectively, after adjusting for nonresponse. Within each age decade the median international prostatic symptom score was higher for Japanese men than for United States men with little difference in rates of increase with participant age or bother. CONCLUSION Lower urinary tract symptoms were common in Japanese men, with age-related increases similar to those of United States men.

Effects of the mass screening of neuroblastoma in sapporo city

One hundred sixty‐seven cases of neuroblastoma in the Registry of Childhood Malignancies in Hokaido Prefecture from 1969 to 1984 were studied, using the age at diagnosis, the clinical stage at diagnosis, and the survival rate to assess the influence of the mass screening of neuroblastoma performed in Sapporo City since 1981. In Sapporo City, the capital of Hokkaido Prefecture, the condition of the three parameters improved significantly after the institution of mass screening had not yet been performed, no significant change was observed in any of the three parameters (48‐month survival rate changed only from 21.1% to 28.1%). Consequently, the improvement in Sapporo City was thought to be attributed to the effects of the mass screening.

JAPANESE MEN HAVE SMALLER PROSTATE VOLUMES BUT COMPARABLE URINARY FLOW RATES RELATIVE TO AMERICAN MEN: RESULTS OF COMMUNITY BASED STUDIES IN 2 COUNTRIES

PURPOSE We compared prostate volume and peak urinary flow rate in Japanese and American men 40 to 79 years old. MATERIALS AND METHODS Prostate volume and peak urinary flow rate were measured in eligible Japanese men and results were compared to those of a randomly selected American cohort. RESULTS Mean prostate volume plus or minus standard deviation averaged 20.3 +/- 10.6 ml. in Japanese and 29.6 +/- 13.4 ml. in American men, while predicted cross-sectional increases with age decade were 1.5 and 5.5 ml., respectively. Peak urinary flow rate was higher but the decrease with increasing age was greater in Japanese men. CONCLUSIONS Prostate volume is larger and the increase with age is more pronounced in American than in Japanese men. However, Japanese men may have a higher peak urinary flow rate and greater cross-sectional decrease with age.

Neurobehavioural effects and pharmacokinetics of toluene in rats and their relevance to man.

The present study was designed to determine the critical concentrations in blood and brain associated with specific behavioural changes during and after exposure to toluene. The effects of a single four hour exposure to toluene on signalled bar press shock avoidance in rats were tested. Rats exposed to 125, 250, and 500 ppm toluene showed a decline in conditioned avoidance responses at 20 minutes exposure compared with the pre-exposure baseline, although they recovered to almost the same level of performance as that before exposure. Exposure to 1000 ppm toluene for about four hours and 2000 ppm for two hours produced a concentration related increase in incorrect responses, acceleration of the reaction time, and decreases in the effective avoidance response rate. Beginning at 4000 ppm toluene exposure, the response rate increased; thereafter, it gradually decreased and finally slight ataxia was observed. After 4000 ppm exposure, all rats showed signs of excitation such as a pronounced increase in response rate. From analysis of the temporal courses of the blood and brain toluene concentrations during and after each exposure, excitative performance decrements were noticed in rats with blood and brain concentrations about 27 micrograms/ml blood and 32 micrograms/g respectively. Anaesthetic performance decrements were seen when the blood toluene concentration increased to 120 micrograms/ml and that of the brain reached about 160 micrograms/g. According to our results, the effects on the central nervous system are considered to be a function of both the exposure concentration and its duration, which are closely related to the increase of brain and blood toluene concentration.

Impaired colour discrimination among workers exposed to styrene : relevance of a urinary metabolite

OBJECTIVES--To survey the loss of colour vision among Japanese workers who have been exposed to styrene concentrations currently considered low (about 20 ppm). Also to assess the effects of styrene by examination of the nature of the relation between disorder of colour vision and age, alcohol consumption, and other variables. METHODS--Colour discrimination was examined in 64 male workers exposed to styrene (mean age; 38.0, mean exposed years; 7.0) and in 69 controls (mean age; 38.0). A standardised questionnaire was adopted to collect work history, occupational or non-occupational solvent exposure, alcohol consumption, and drug use. Colour vision was evaluated by the Lanthony desaturated panel D-15 test. The results of the test were expressed as the colour confusion index (CCI). RESULTS--The mean atmospheric styrene concentration was about 20 ppm. The mean urinary concentration of mandelic acid was 0.22 g/l. There was a significant difference in CCI between exposed workers and age matched controls. Colour vision of workers whose concentration of urinary mandelic acid was > or = 0.42 g/l was significantly impaired when compared with workers whose concentration was < 0.42 g/l. Multiple linear regression analysis that controlled confounding variables such as age, alcohol consumption, smoking, and educational attainment showed that the CCI was significantly related to the concentration of urinary mandelic acid. In both exposed workers and controls, the types of defects were mostly blue-yellow loss, although a few subjects showed complex loss. No one showed only red-green loss. CONCLUSIONS--These findings suggest that exposure to moderate styrene concentrations can lead to impairment of colour vision, and that there is a significant correlation with the urinary metabolite of styrene.

Leisure Time Physical Activity as a Determinant of Self-Perceived Health and Fitness in Middle-Aged Male Employees

Leisure Time Physical Activity as a Determinant of Self‐Perceived Health and Fitness in Middle‐Aged Male Employees: Goroh Okano, et al. Division of Exercise Science, School of Medicine, Sapporo Medical University—Self‐perceived health and fitness are epidemiological predictors of subsequent mortality and/or functional limitation. The present study was designed to analyze which lifestyle factors contribute to good status of self‐perceived health and fitness in middle‐aged male employees. Participants (n=401) aged 50–59 were assessed as to the status of self‐perceived health and fitness, and various lifestyle factors including nutrition, smoking, drinking, physical activity, psychological stress, sleeping and relaxation. Logistic regression analysis revealed that among the lifestyle factors surveyed in the present study, doing exercise/sports at a medium level (either ≥4.5METs/1–2 times per week or <4.5METs/≥3–4 times per week) of physical activity index (PAI) was the only predictor of good self‐perceived health. Similarly, doing exercise/sports at or above the medium level of PAI was identified as the only independent predictor of good self‐perceived fitness. In addition, maintaining the habit of doing exercise/sports at or above the medium level of PAI throughout the year, and having this habit through the 4 th and 5th decades of life or starting to have it from the age of 50 through 59 were important to obtain a good status of self‐perceived health and fitness. These findings suggest that leisure time physical activity level is a determinant of good health and fitness in the middle‐aged male employees in the present study.

Regional distribution of lead, zinc, iron and copper in suckling and adult rat brains

The flameless atomic absorption method was applied to reveal regional differences in heavy metals between suckling and adult rat brains. The lead concentrations in the suckling brains were considerably different from those in the adult rats. The levels of lead concentration in the cerebrum and cerebellum of the normal suckling rats were 3-4 times higher than those of adult rats. Iron concentrations in the cerebrum of the suckling brains were approximately half those in the adult brains. Zinc and copper concentrations in medulla from the suckling rats were higher than those in the same region from the adult rats.

Dietary and Other Risk Factors of Ovarian Cancer among Elderly Women

The age‐specific mortality rate of ovarian cancer is increasing among women over 50 years of age, but remaining at a stable level among women under 50. This case‐control study of ovarian cancer was undertaken to assess the environmental factors which may increase the mortality of the disease in the elderly. Fifty‐six women with primary epithelial ovarian cancer whose ages were 50 years old or over were compared with two age‐matched control groups. The results of the Mantel‐Haenszel analysis were as follows. More cases were found to have never married than controls (P<0.05), a larger proportion of cases were nulliparous (P<0.05), a smaller proportion of cases had experienced an induced abortion (P< 0.05) or had undergone permanent sterilization by tubal ligation (P<0.05), the occurrence of breast or uterine cancer was more common in the mother or sisters of cases (P<0.01), a larger percentage of cases used to eat meat daily (P< 0.01) or used to eat fish daily (P< 0.05), and a larger proportion of cases weighed under 40 kg (P<0.05). Daily meat consumption was significantly associated with the occurrence of ovarian cancer even after adjusting for reproductive and other risk factors by conditional logistic regression analysis. The attributable risk for ovarian cancer in the elderly was 19.2% for daily meat consumption. The recent change in dietary habits might in part explain the rise of the mortality rate among the Japanese elderly.

Mass screening for neuroblastoma and mortality in birth cohorts

Mortality resulting from neuroblastoma in birth cohorts in both Sapporo City and the whole of Japan was investigated to evaluate the effects of a high‐performance liquid chromatography (HPLC) mass screening program, targeting on 6 month‐old infants. In Sapporo City, the non‐HPLC screened cohort showed no reduction in mortality at 4 years of age compared with the pre‐screening cohort. However, the HPLC screened cohort showed a reduction of 69% in mortality compared with the pre‐screening cohort. On a nation‐wide scale, there was a significant decline in mortality for the non‐HPLC screened cohort compared with the pre‐screening cohort; for the HPLC screened cohort for 1989‐1991, there was also a reduction in mortality for children younger than 2 years of age. The incidence of neuroblastoma at 1‐4 years of age in the HPLC cohort in Sapporo City was about half that in the pre‐screening cohort, along with and probably because of an increasing incidence among infants in the same cohort. Our findings suggest that HPLC screening may detect some poor‐prognosis neuroblastoma cases at early stages, thus providing for more favorable therapy. Int. J. Cancer 71:552‐555, 1997.

Mass screening of neuroblastoma in Sapporo City, Japan.

In Sapporo City a mass screening program for neuroblastoma aiming at 6-month-old infants has been performed since April 1981. By March 1990, 136,001 infants were screened; 26 true-positive cases of neuroblastoma and six false-negative cases were detected. The sensitivity of the mass screening method was about 80% throughout the 9 years. During the 9-year period, a total of nine children with neuroblastoma who were not screened were also identified. Clinical stage, age at diagnosis, and survival rate for the 32 patients who were screened (26 true positives and six false negatives) were much more favorable than those for the nine patients who were not screened. A remarkable decrease in the incidence of cases of neuroblastoma with advanced clinical stages over 1 year of age, especially among children 1-4 years of age, was noted after the start of the mass screening. The mortality from this tumor in children up to 4 years of age significantly decreased after the start of the urinary screening program. Rescreening at 14 months of age was begun in April, 1991 in Sapporo City. Performing two screening examinations decreases the probability of overlooking a patient. Thus, it is expected that tumors missed on the first screening would be detected by the second screening.