375 research outputs found

    Diversity of Melissococcus plutonius from Honeybee Larvae in Japan and Experimental Reproduction of European Foulbrood with Cultured Atypical Isolates

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    European foulbrood (EFB) is an important infectious disease of honeybee larvae, but its pathogenic mechanisms are still poorly understood. The causative agent, Melissococcus plutonius, is a fastidious organism, and microaerophilic to anaerobic conditions and the addition of potassium phosphate to culture media are required for growth. Although M. plutonius is believed to be remarkably homologous, in addition to M. plutonius isolates with typical cultural characteristics, M. plutonius-like organisms, with characteristics seemingly different from those of typical M. plutonius, have often been isolated from diseased larvae with clinical signs of EFB in Japan. Cultural and biochemical characterization of 14 M. plutonius and 19 M. plutonius-like strain/isolates revealed that, unlike typical M. plutonius strain/isolates, M. plutonius-like isolates were not fastidious, and the addition of potassium phosphate was not required for normal growth. Moreover, only M. plutonius-like isolates, but not typical M. plutonius strain/isolates, grew anaerobically on sodium phosphate-supplemented medium and aerobically on some potassium salt-supplemented media, were positive for β-glucosidase activity, hydrolyzed esculin, and produced acid from L-arabinose, D-cellobiose, and salicin. Despite the phenotypic differences, 16S rRNA gene sequence analysis and DNA-DNA hybridization demonstrated that M. plutonius-like organisms were taxonomically identical to M. plutonius. However, by pulsed-field gel electrophoresis analysis, these typical and atypical (M. plutonius-like) isolates were separately grouped into two genetically distinct clusters. Although M. plutonius is known to lose virulence quickly when cultured artificially, experimental infection of representative isolates showed that atypical M. plutonius maintained the ability to cause EFB in honeybee larvae even after cultured in vitro in laboratory media. Because the rapid decrease of virulence in cultured M. plutonius was a major impediment to elucidation of the pathogenesis of EFB, atypical M. plutonius discovered in this study will be a breakthrough in EFB research

    Maternal Feeding Controls Fetal Biological Clock

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    BACKGROUND: It is widely accepted that circadian physiological rhythms of the fetus are affected by oscillators in the maternal brain that are coupled to the environmental light-dark (LD) cycle. METHODOLOGY/PRINCIPAL FINDINGS: To study the link between fetal and maternal biological clocks, we investigated the effects of cycles of maternal food availability on the rhythms of Per1 gene expression in the fetal suprachiasmatic nucleus (SCN) and liver using a transgenic rat model whose tissues express luciferase in vitro. Although the maternal SCN remained phase-locked to the LD cycle, maternal restricted feeding phase-advanced the fetal SCN and liver by 5 and 7 hours respectively within the 22-day pregnancy. CONCLUSIONS/SIGNIFICANCE: Our results demonstrate that maternal feeding entrains the fetal SCN and liver independently of both the maternal SCN and the LD cycle. This indicates that maternal-feeding signals can be more influential for the fetal SCN and particular organ oscillators than hormonal signals controlled by the maternal SCN, suggesting the importance of a regular maternal feeding schedule for appropriate fetal molecular clockwork during pregnancy

    Relationship of household salt intake level with long-term all-cause and cardiovascular disease mortality in Japan: NIPPON DATA80.

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    In Asian countries, a major source of salt intake is from seasoning or table salt added at home. However, little is known about the adverse effects of salt intake evaluated according to household unit. We investigated the relationship between household salt intake level and mortality from all-cause and cardiovascular diseases (CVDs). Participants included 8702 individuals (56% women) who were living with someone else and who were aged 30-79 years and enrolled in the National Nutritional Survey of Japan in 1980 with a 24-year follow-up. Household nutrient intake was evaluated using a 3-day weighing record method in which all foods and beverages consumed by any of the household members were recorded. The household salt intake level was defined as the amount of salt consumed (g) per 1000 kcal of total energy intake in each household, and its average was 6.25 (2.02) g/1000 kcal. During the follow-up, there were 2360 deaths (787 CVD, 168 coronary heart disease [CHD], and 361 stroke). Cox proportional hazard ratios (HRs) for an increment of 2 g/1000 kcal in household salt intake were calculated and adjusting for sex, age, body mass index, smoking status, alcohol consumption status, self-reported work exertion level, household potassium intake, household saturated fatty acid intake, and household long-chain n-3 polyunsaturated fatty acid intake. The HRs (95% confidence intervals) were 1.07 (1.02, 1.12) for all-cause mortality, 1.11 (1.03, 1.19) for CVD, 1.25 (1.08, 1.44) for CHD, and 1.12 (1.00, 1.25) for stroke. The household salt intake level was significantly associated with long-term risk of all-cause, CVD, CHD, and stroke mortality in a representative Japanese population

    Association between socioeconomic status and physical inactivity in a general Japanese population: NIPPON DATA2010.

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    Background:Lower socioeconomic status (SES) may be related to inactivity lifestyle; however, the association between SES and physical inactivity has not been sufficiently investigated in Japan.Methods:The study population is the participants of NIPPON DATA2010, which is a prospective cohort study of the National Health and Nutrition Survey 2010 in Japan. They were residents in 300 randomly selected areas across Japan. This study included 2,609 adults. Physical activity was assessed by physical activity index (PAI) calculated from activity intensity and time. The lowest tertile of PAI for each 10-year age class and sex was defined as physical inactivity. Multivariable logistic regression analyses were conducted to examine the association of SES (employment status, educational attainment, living status, and equivalent household expenditure (EHE)) with physical inactivity.Results:In the distribution of PAI by age classes and sex, the highest median PAI was aged 30-39 years among men (median 38.6), aged 40-49 years among women (38.0), and median PAI was decreased with increasing age. Multivariable-adjusted model shows that not working was significantly associated with physical inactivity after adjustment for age in all age groups and sexes. Not living with spouse for adult women and elderly men was significantly associated with physical inactivity compared to those who living with spouse. However, neither educational attainment nor EHE had any significant associations with physical inactivity.Conclusions:The result indicated that physical inactivity was associated with SES in a general Japanese population. SES of individuals need to be considered in order to prevent inactivity lifestyle
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