95 research outputs found

    A Ly-alpha Emitter with an Extremely Large Rest-frame Equivalent Width of ~900A at z=6.5: A Candidate of Population III-dominated Galaxy?

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    We have identified a very interesting Ly-alpha emitter, whose Ly-alpha emission line has an extremely large observed equivalent width of EW_0=436^{+422}_{-149}A, which corresponds to an extraordinarily large intrinsic rest-frame equivalent width of EW_0^{int}=872^{+844}_{-298}A after the average intergalactic absorption correction. The object was spectroscopically confirmed to be a real Ly-alpha emitter by its apparent asymmetric Ly-alpha line profile detected at z=6.538. The continuum emission of the object was definitely detected in our deep z'-band image; thus, its EW_0 was reliably determined. Follow-up deep near-infrared spectroscopy revealed emission lines of neither He II lambda1640 as an apparent signature of Population III, nor C IV lambda1549 as a proof of active nucleus. No detection of short-lived He II lambda1640 line is not necessarily inconsistent with the interpretation that the underlying stellar population of the object is dominated by Population III. We found that the observed extremely large EW_0 of the Ly-alpha emission and the upper limit on the EW_0 of the He II lambda1640 emission can be explained by population synthesis models favoring a very young age less than 2-4Myr and massive metal-poor (Z<10^{-5}) or even metal-free stars. The observed large EW_0 of Ly-alpha is hardly explained by Population I/II synthesis models with Z>10^{-3}. However, we cannot conclusively rule out the possibility that this object is composed of a normal stellar population with a clumpy dust distribution, which could enhance the Ly-alpha EW_0, though its significance is still unclear.Comment: 10 pages, 5 figures. Accepted for publication in Ap

    Prophylactic effects of isomaltodextrin in a Balb/c mouse model of egg allergy

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    The aim of this study was to evaluate the potential effects of isomaltodextrin (IMD), a dietary saccharide polymer derived from enzymatically produced from starch, on the ability to alter immune response (IR) bias to hen egg ovalbumin (Ova) induced allergic inflammation in mice. Groups of Balb/c mice were pre-treated with various doses of IMD in drinking water (1.0, 2.5, and 5.0% w/v) for 6 weeks and subsequently sensitized to the Ova together with continuous administration of IMD. To evaluate changes in immune response bias, immunoglobulin isotype-associated antibody activity, concentrations of type 1 and 2 cytokines and the percentage of T-regulatory cells (T-regs) in blood were measured. Clinical signs of allergy were assessed after oral challenge with Ova. Treatment with IMD did not significantly alter the frequency of clinical signs, however there was a trend in the overall reduction of clinical signs. Effect on IR bias was observed in the treatment groups as reflected by reduction in a type 1-biased phenotype as evident by decrease in isotype-specific IgE, IgG and increase in IL-12 cytokine production and a high proportion of Tregs. This study revealed that IMD could be a useful prophylactic candidate for alteration of allergic IR bias in mice and an immunestimulator for reducing egg induced allergic reactions

    Influence of Alcohol Consumption on the Development of Erosive Esophagitis in Both Sexes : A Longitudinal Study

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    The influence of changes in alcohol consumption on erosive esophagitis (EE) development in both sexes is unclear. This observational study investigated sex differences in the influence of alcohol consumption on EE development, and included 2582 patients without EE at baseline from 13,448 patients who underwent >2 health check-ups over >1 year. The rates of non-drinkers who started drinking, and drinkers who abstained from drinking, who increased, and who decreased their weekly alcohol consumption were 7.2%, 9.7%, 14.7%, and 24.1% and 7.3%, 17.8%, 12.8%, and 39.0% in men and women, respectively. In the final cohort, 211/1405 (15.0%) men and 79/1177 (6.7%) women newly developed EE. The odds ratio (OR) for drinking in EE development was 1.252 (95% confidence interval (CI), 0.907–1.726) among men and 1.078 (95% CI, 0.666–1.747) among women. Among men aged <50 years, the OR for drinking ≥70 g/week in EE development was 2.825 (95% CI, 1.427–5.592), whereas among women, the OR for drinking ≥140 g/week in EE development was 3.248 (95% CI, 1.646–6.410). Among participants aged <50 years, the OR for daily drinking in EE development was 2.692 (95% CI, 1.298–5.586) among men and 4.030 (95% CI, 1.404–11.57) among women. The influence of alcohol consumption on EE development differed between the sexes. We recommend no alcohol consumption for individuals aged <50 years to avoid EE development. Daily drinkers should be assessed for EE development

    Differences in Several Factors in the Development of Erosive Esophagitis Among Patients at Various Stages of Metabolic Syndrome : A Cross-Sectional Study

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    Background: Erosive esophagitis (EE) is strongly associated with metabolic syndrome (MS), but is not always recognized in individuals with MS and the prevalence of EE in individuals with non-MS is not low. Aim: To examine the differences in clinical factors associated with EE at various stages of MS, as well as the differences in metabolites between subjects with MS, with and without EE. Methods: A total of 7,097 persons who underwent health checkups including esophagogastroduodenoscopy were analyzed. We examined the differences in clinical factors for EE among subjects with non-MS, pre-MS, and MS and compared metabolites between 34 subjects with MS, with and without EE. Results: EE prevalence was significantly higher in the MS and pre-MS groups than in the non-MS group (p < 0.001). EE severity was higher in the MS group than in the pre-MS and non-MS groups (p < 0.001). In the non-MS group, there were significant differences between subjects with and without EE with respect to Helicobacter pylori (H. pylori) and smoking. In the pre-MS and MS groups, there were significant differences in H. pylori, hiatal hernia, and drinking in those with and without EE. The levels of glutamine, hypoxanthine, and lactic acid metabolites were significantly different between subjects with MS, with and without EE (all p < 0.05). Conclusion: Although H. pylori and lifestyle factors such as smoking and drinking are important for EE, differences in these factors should be considered at various stages of MS. Additionally, several metabolites may be involved in the development of EE in MS
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