Epidemiological studies in the last 40 years suggest that omega-3 fatty acids derived from fish and fish oil decrease the risk of coronary heart disease, hypertension and stroke, and their complications. The beneficial effects of omega-3 fatty acids include effects on lipids, blood pressure, cardiac and vascular function, eicosanoids, coagulation, and immunological responses. However, not all population studies have shown that omega-3 fatty acids are associated with reduced rates of coronary mortality. Such studies suffer either from small numbers of subjects or the population already had a high intake of fish. When comparing the highest intake of fish to that of the lowest fish intake, the beneficial effects of omega-3 fatty acids have been shown. In population-based case-control studies, the patients consuming modest amounts of fish, the equivalent of one fatty fish meal per week, had a significant lower risk of primary cardiac arrest compared with those who did not eat fish at all. In case-control studies, the intake of eicosapentaenoic acid and docosahexaenoic acid as reflected in adipose tissue content is inversely associated with risk of myocardial infarction.

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The signaling pathways leading to cellular protection or cell death following exposure to heavy metals have not been fully clarified. Mitogen-activated protein kinases (MAPKs), i.e., extracellular signal-regulated protein kinase (ERK), c-Jun NH₂-terminal kinase (JNK) and p38 MAPK transmit extracellular signals into the nucleus, and have been shown to participate in a diverse array of cellular functions such as cell growth, differentiation and apoptosis. Treatment with cadmium, inorganic mercury or tributyltin can activate ERK, JNK and p38 MAPK, and induces the expression of c-fos and c-jun genes prior to the development of apoptosis. However, the members of the MAPK family appear to be differentially activated depending on the heavy metal and the cell type exposed. Consequently, various cellular responses may be caused by the distinct pattern of MAPKs activation. MAPKs may be one of the important cellular signal transduction pathways affected by various environmental pollutants, including heavy metals.

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Effects of environmental (cold) stress and aging on cells in monocyte/macrophage lineage were investigated. We demonstrated that immune suppressive states seen in acute cold-stressed mice (8-10 weeks of age) is attributable to FcγRII^bright suppressor macrophages. Serum corticosterone levels were markedly increased in acute cold-stressed mice. In addition, expression of glucocorticoids (GC) receptor mRNA was observed in FcγRII^bright cells from these mice. The increase of FcγRII^bright cells in peritoneal exudate cells caused by acute cold stress was inhibited by adrenalectomy or administration of a saturating amount of the GC antagonist RU 38486 (mifepristone). On the contrary, administration of the GC agonist, dexamethasone, markedly increased the proportion of FcγRII^bright cells in peritoneal exudate cells of control mice. These results suggest that the generation of FcγRII^bright suppressor cells of monocyte/macrophage lineage by acute cold stress was mediated by action of GC through the GC receptor. We likewise found that the proportion of FcγRII^bright suppressor macrophages is increased in aged mice (22-24 months of age). Meanwhile, activated macrophages which function as antigen presenting cells were decreased in aged rats. Both the basal corticosterone concentrations in serum and the expression of mRNA for GC receptor in peritoneal macrophages increased significantly in aged animals, suggesting that these populational and functional changes of macrophages in aged animals were mediated, in part, by the increased basal levels of GC. This is probably being responsible for immunosenescence.

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To detect the type of contact dermatitis caused due to the handling of Alstroemeria wilhelmina, 1% α-methylene-γ-butyrolactone (α-MBL) dissolved in physiological saline and a five-fold diluted saline solution of original extracts of flowers, leaves and stems of the flower were applied to guinea-pigs for induction treatment, and 0.1% α-MBL physiological saline and a ten-fold diluted solution of the original extracts were applied to the animals as the challenge treatment in compliance with the guinea-pig maximization test (GMT). As a consequence, not only primary irritant dermatitis was observed, but also delayed type allergic contact dermatitis due to Alstroemeria wilhelmina was observed. α-MBL determined in the extracts using high-performance liquid chromatography (HPLC) was found to be the biochemical material cause of the contact dermatitis. The flower region contained α-MBL in the highest concentrations compared with those of the leaves and stems. Therefore, the quantification of α-MBL in the extracts was concluded as being a useful evaluating method for contact dermatitis due to the handling of Alstroemeria.

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Quercetin, a flavonoid, widely distributed in many fruits and vegetables, is well known to have an anti-tumor effect despite its mutagenicity. In this study, we examined the effect of dietary quercetin on duodenum-tumorigenicity of mice induced by a chemical carcinogen, N-ethyl-N'-nitro-N-nitrosoguanidine (ENNG). Eight-week-old male C57BL/6 mice were divided into 4 groups; ENNG without quercetin (group A), ENNG with 0.2% quercetin (group B), ENNG with 2% quercetin (group C), and 2% quercetin without ENNG (group D). ENNG was given in drinking water for the first 4 weeks, and thereafter quercetin was given in a mixed diet. At week 20, the average number of duodenal tumors per mouse was significantly higher in group C (mean±SE, 7.26±1.75, p<0.05) than in group A (2.32±0.31). The size of the duodenal tumors increased significantly in group B (1.79±0.09 mm, p<0.001) compared with group A (1.43±0.09 mm). In contrast, no duodenal tumor was induced in group D. The present findings suggest that excessive intake of quercetin occasionally is a risk factor for carcinogenesis of some specific organs such as the upper intestine.

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Objectives: The reliability of surveys on smoking habits based on questionnaires was investigated, using the urinary cotinine content as an objective index.
Methods: The subjects tested were 2,849 office workers of middle age, who responded to questions concerning their smoking status, and also their urinary cotinine was measured by the HPLC method.
Results: The boundary value between smokers and non-smokers, determined by the histogram independent of the questionnaire, was 63.1 and 79.4 ng/mg of creatinine for males and females, respectively. The rate of misclassification of the non-smokers and former smokers as smokers was 1.3% for males and 1.8% for females, whereas that of current smokers as non-smokers was 6.3% and 2.1%. We also assessed the effect of smoke inhalation on the urinary cotinine value, and found a significant difference for males in the cotinine value by the presence of inhalation and also its depth.
Conclusions: The rate of misclassification in this study was considered to be comparatively low. Several studies have also assessed the reliability of the questionnaire on smoking habits, and found different misclassification rates, indicating the dependence on the race and number of subjects tested. To our knowledge, there were only a few surveys on smoking among large groups, particularly in Japan, such as this one, therefore the results obtained in this study are meaningful.

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Background: Epidemiological findings suggest that weight fluctuations are associated with unfavorable health outcomes compared with stable weight. However, the interrelationship between the weight cycling history and dieting status in a non-clinical male trial on the risk for bio-behavioral health is unclear.
Objective: The purpose of this study was to examine the relation between weight cycling history as a result of intentional weight loss and bio-behavioral health in Japanese adult males.
Method: A cross-sectional study was performed on a group of 146 Japanese working males (47.5±9.3 yr.). Each subject completed a series of self-reported questionnaires in which information about weight cycling history, current dieting practices, life-styles, and social background were assessed. Results of the physical check up were used to assess biological parameters. Self-reported weight cycling was defined as intentionally losing 10% of one's weight and regaining the lost weight.
Results: Cyclers reported a significantly greater incidence of current dieting and recent weight gain compared with non-cyclers. Taking regular meals, eating breakfast everyday, and not eating snacks between meals every day were significantly less frequent among cyclers compared with non-cyclers after controlling for BMI. The adjusted odds ratio for AST abnormality was 5.46 (95%CI: 1.08 −27.67), ALT abnormality was 3.31 (95%CI: 1.24−8.78), and γ-GTP was 3.38 (95%CI: 1.07−10.67) among cyclers, compared with non-cyclers.
Conclusion: These findings suggest that a history of weight cycling in men, regardless of current weight status, is associated with adverse bio-behavioral health. The risk for several liver enzyme abnormalities associated with weight cycling history was substantial, independent of relative body weight and lifestyle factors.

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Objective: To examine changes in the Body Mass Index (BMI) and in the prevalence of obesity among male Japanese workers after five years.
Design: Follow-up study, based on data from annual health checkups performed at workplaces.
Subjects and Methods: We had access to the data for a total of 63,951 male workers aged 20 through 54 years in 1992 who were examined in both 1992 and 1997. In quinquennial cohorts, we compared the findings for mean BMI and the prevalence of obesity in 1992 with the findings in 1997.
Results: Between 1992 and 1997, in all cohorts the mean BMI increased significantly. For each adjacent cohort pair the mean BMI value in 1997 was significantly higher than in 1992. In 1992, 21.3% of all subjects were obese, increasing by 3.4% after five years to 24.7% in 1997. In the younger 1968—1972 and 1963—1967 cohorts the prevalence of obesity increased by 6.3% during five years. The significant increase in the obesity prevalence was observed from 1992 to 1997 for each age-adjusted cohort.
Conclusions: These results suggest a substantial increase in obesity among male Japanese workers. The notable increase in the prevalence of obesity among young male adults and the general trend toward widespread obesity during five years signal an increasing risk of lifestyle-related diseases.

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The relations between salivary variables, lifestyle and mental health status were investigated for 61 healthy female university students. The salivary secretion rates were significantly higher in the good lifestyle group compared with the poor lifestyle group. Among the 8 lifestyle items tested, “eating breakfast” and “mental stress” were significantly related to the salivary secretion rates. The present findings suggest that the acquisition of a good lifestyle is also very important from the viewpoint of the prevention of oral disease.
A highly significant correlation (r=0.97; p<0.01) between the salivary cortisol levels and the cortisol secretion rates when controlled for the salivary secretion rates was also observed. This suggests that there is a high correlation between the intact salivary cortisol levels and the total cortisol quantity per unit time. Therefore, both these values can be used as a good index for the salivary cortisol determination.

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Objective: To assess the validity of a questionnaire for evaluating the physical activity of young children as reported by parents.
Methods: Twenty-one male 1st grade elementary school children were the study subjects. The questionnaire contained 3 questions relating to the physical activity of children and was completed by their parents. These questions were: preference for physical activity: like very much, like, don't like; physical activity compared to peers: more than, the same as, less than peers; time spent on exercise activity per day: <30 min, 30—60 min, 60 min or more. We also assessed physical activity more objectively, using a small instrument for calculating total steps, energy expenditure originating from exercise, and total energy expenditure per day. The contribution of the questionnaire items to the objective indices was evaluated by linear regression analysis.
Results: Preference for physical activity was significantly associated with all the objective indices. Physical activity compared with peers had links with total energy expenditure. Time spent in activity was related to total steps and energy expenditure from exercise.
Conclusion: All the questionnaire items were valid measures for evaluating the physical activity level in young children and could be applied to a large epidemiological survey.

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Objectives: Several studies have reported that the secretory immunoglobulin A (S-IgA) concentration in saliva is an indicator of psychological stress. The aim of this study was to clarify the relationship between S-IgA and the stress from academic examinations.
Methods: S-IgA levels in 10 medical student volunteers from the second year course between May 4 and July 13, 2000 were examined using the ELISA method.
Results: There was a tendency for S-IgA in saliva to be higher on the day before academic examinations and during them, and lower on the days between these examinations.
Conclusions: It may be possible to use this measurement to monitor psychological stress in students and workers.

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The aim of this study was to clarify the worldwide residual levels of organochloride compounds, such as BHC and DDT, which were reportedly concentrated in animal tissues by biological food chains. As a part of the investigation of endocrine disrupting chemicals (EDCs), we had a chance to measure the level of these compounds in Hungarian canned foods.
Seven kinds of canned foods were purchased at a market in Budapest, Hungary, and the concentrations of eighteen organochloride compounds (α-BHC; β-BHC; γ-BHC; δ-BHC; p,p’-DDT; p,p’-DDE; p,p’-DDD; o,p’-DDT; heptachlor; heptachlor-epoxide; aldrin; dieldrin; endrin; oxychlordane; trans-chlordane; cis-chlordane; trans-nonachlor; and cis-nonachlor) were measured.
Other than DDT and its metabolites, none of the EDCs were detected (levels <0.4 ppb). DDT and its metabolites, however, were detected in fish, meat and chicken liver pate. One of the DDT metabolites was detected quite frequently: p,p’-DDE was detected at a level of 1.8 ppb in fish soup concentrate, 2.3 ppb in Hungarian luncheon meat, 0.5 ppb in special luncheon meat, and 0.6 ppb in chicken liver pate.
Of eighteen organochloride compounds examined, only DDT and its metabolites were detected in fish, animal meat, and animal liver. It is suggested that the DDT contamination in fish and meat is worldwide even after the ban of its use.

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