The seminal receptacle of Paragonimus ohirai contains not only mature spermatozoa, but also atypical and degenerate ones, suggesting that abnormal spermatozoa are retained in this organ. The spermatozoon is of a parallel biflagellar type with cortical microtubules, consisting of the anterior region, first mitochondrial region, intermediate (amitochondrial) region, second mitochondrial region, posterior nuclear region (PNR) and tail region (TR). The first third of the spermatozoon exhibits typical undulatory movement, while the middle part shows vibratory movement. At the area between head and midsections (H-M area) the peripheral doublets of axonemes are interrupted, and the external ornamentation is distributed widely around this portion. Throughout the immotile PNR and TR, the axonemes lack the dynein arms of their peripheral doublets. H-M, PNR, and TR ultrastructural characteristics are specific in P. ohirai spermatozoon and seem to be closely related to its pattern of movement.

The localization of catecholamines was documented in the cercaria of Schistosoma mansoni and S. japonicum by a fluorescent histochemical method using glyoxylic acid (GA). Cell bodies and nerve fibres were spatially visualized in whole-mount preparations, and the fluorescent traces were investigated. The nervous system was bilaterally symmetrical, showing a similar formation in both species. A pair of cerebral ganglia with a transverse commissure showed a complex network of fluorophores, and each radiated two sets of anterior and posterior longitudinal nerve cords. A third pair of longitudinal nerve cords was observed in the most dorsal area. A posterior transverse commissure was seen to connect the posterior longitudinal cords, and the posterior terminals of the postero-ventral cords communicated with the tail cords. The glyoxylic acid-induced fluorescence (GAIF) method was demonstrated to be quite suitable for neuroanatomical and neurophysiological investigations of larval forms.

The ultrastructure of the ovary of Paragonimus ohirai was investigated in different developmental stages of experimental infection in rats, from the metacercarial stage to the adult stage. The female reproductive cells were observed in order to understand the development of the ovary. During its development in the definitive host, the ovarian primordium and the ovary increased in size and cell number and underwent morphological changes. The blind end of the female genitalia was an undifferentiated primordium at the metacercarial stage, but became the bud of an ovary on day 3. Germ cells and supporting cells were observed on day 5. Oogonia were identified in the 15-day-old ovary, followed by the appearance of young oocytes at 17 days. Large oocytes were found on day 19, but the 21-day-old ovary contained degenerated oocytes. Mature ovaries were observed in the 26-day-old worms and egg formation was seen to arise on day 28. The development of the ovary and female reproductive cells was discussed in relation to the physiology of P. ohirai.

To investigate whether blood pressure differs by taking preferred alcoholic beverage among habitual drinkers, systolic and diastolic blood pressure (SBP, DBP) were compared among groups with different beverage types in 563 middle-aged Japanese males using data from a cross-sectional health survey conducted from February, 1989 through March, 1991 in five areas of Japan. Mean values of SBP and DBP, adjusted for residence, age and body mass index (BMI), were significantly greater in 'exclusively sake' drinkers (adjusted SBP: 127.2 mmHg, adjusted DBP: 83.0 mmHg) and in 'exclusively shochu' drinkers (adjusted SBP: 127.5 mmHg, adjusted DBP: 84.2 mmHg) than in non-drinkers (adjusted SBP: 120.9 mmHg, adjusted DBP: 77.3 mmHg). Adjusted SBP and DBP of 'exclusively beer' drinkers (adjusted SBP: 121.9 mmHg, adjusted DBP: 79.1 mmHg) were significantly (for SBP: p = 0.016, for DBP: p = 0.008) lower than those of 'exclusively sake' drinkers. Similar patterns of blood pressure differences between five beverage types of habitual drinkers were found especially in the group with less than 150 g of weekly ethyl-alcohol consumption. Even after adding ethyl-alcohol consumption as a covariate among 479 habitual drinkers, the significant differences in adjusted SBP and DBP between 'exclusively beer' drinkers and 'exclusively sake' drinkers (for SBP: p = 0.032, for DBP: p = 0.044) were noted. These results may suggest that the effects of drinking on blood pressure differ by beverage type in middle-aged Japanese males.

To clarify how and why blood pressure differs between occupations, the proportions of hypertensives, and the measures of blood pressure, body mass index (BMI) and alcohol consumption among the individuals not taking antihypertensive drugs were compared between the eight occupational categories using the data from a health check-up for 589 middle-aged Japanese males, mostly randomly selected from five areas in Japan.After adjusting for age, the relationships of occupation to the proportion of hypertensives and the mean systolic and diastolic blood pressure substantially differed among the five areas. However, after further adjustment for residence, these blood pressure levels (the proportion of hypertensives, and the mean systolic and diastolic blood pressure) were found to be higher for the "Personnel in transport and communications", the "Clerical personnel", the "Managerial and civil personnel" and the "Professional and technical personnel", whereas these values were consistently lowest in the "Service personnel". Age and residence-adjusted mean BMI was also higher for the four occupational categories with the increased blood pressure levels.According to a weighted multiple regression analysis across the eight occupations, the age and residence-adjusted mean BMI was a significant predictor of the age and residence-adjusted mean systolic and diastolic blood pressure (p=0.068 and 0.018, respectively). These results suggest that the occupation-related changes in BMI may largely contribute to the occupationrelated changes in blood pressure.J Epidemiol, 1998 ; 8 : 216-226.blood pressure, occupation, body mass index, alcohol drinkingThe relations of occupation to blood pressure and cardiovascular diseases has been one of the important topics in the field of epidemiology. Furthermore, according to the modem concept of occupational health, hypertension is recognized as one of the "work-related diseases" 1.2). However, although many studies illustrated the association between occupation and blood pressure 3-8), there have not been any reports clarifying the reason why blood pressure varies by occupation. Since body mass index (BMI) and alcohol intake are major determinants of blood pressure 9-12), these life style-related factors may be key elements that can explain the relationship between occupation and blood pressure, if BMI and alcohol consumption are closely related to occupational life. The aim of this study was, first, to investigate how blood pressure levels differ by different categories of occupation among middle-aged Japanese men mostly randomly selected from different five areas in Japan. Second objective was to analyze the relation of occupation-specific blood pressure to occupation-specific BMI and alcohol consumption levels using a multiple linear regression analysis in order to clarify how and to what extent blood pressure differences between occupational categories can be explained by the differences in BMI and alcohol consumption.