Trimethylamine N-oxide and risk of inflammatory bowel disease: A Mendelian randomization study.

A previous study suggested that inflammatory bowel disease (IBD) patients have low plasma levels of trimethylamine N-oxide (TMAO). In the present study, we examined this hypothesis using Mendelian randomization analysis. We used summary statistics data for single-nucleotide polymorphisms associated with plasma levels of TMAO, and the corresponding data for IBD from a genome-wide association meta-analysis of 59,957 individuals (25,042 diagnosed IBD cases, 34,915 controls). The association between genetically predicted plasma TMAO levels and IBD showed odds ratios (95% confidence interval [CI]) per 1 interquartile range increment (per 2.4 µmol/L) in TMAO levels were 0.91 (0.81-1.01, P = .084) for IBD, 0.88 (0.76-1.02, P = .089) for ulcerative colitis, 0.91 (0.79-1.05, P = .210) for Crohn disease. There was no evidence for pleiotropy based on the Mendelian randomization-Egger regression analyses (P-intercept = 0.669 for IBD). Further investigations would be needed to understand the causal relationship between TMAO and IBD.

Polyunsaturated fatty acids and risk of anorexia nervosa: A Mendelian randomization study.

PURPOSE: Observational studies have suggested that polyunsaturated fatty acids (PUFAs) decrease the risk of anorexia nervosa (AN). In the present study, we examined this hypothesis using a Mendelian randomization analysis. METHODS: We used summary statistics for single-nucleotide polymorphisms associated with plasma levels of n-6 (linoleic acid and arachidonic acid) and n-3 PUFAs (alpha-linolenic acid, eicosapentaenoic acid, docosapentaenoic acid, and docosahexaenoic acid) and the corresponding data for AN from a genome-wide association meta-analysis of 72,517 individuals (16,992 diagnosed AN cases and 55,525 controls). RESULTS: None of the genetically predicted PUFAs were significantly associated with the risk of AN; odds ratios (95 % confidence interval) per 1 standard deviation increase in PUFA levels were 1.03 (0.98, 1.08) for linoleic acid, 0.99 (0.96, 1.03) for arachidonic acid, 1.03 (0.94, 1.12) for alpha-linolenic acid, 0.98 (0.90, 1.08) for eicosapentaenoic acid, 0.96 (0.91, 1.02) for docosapentaenoic acid, and 1.01 (0.90, 1.36) for docosahexaenoic acid. LIMITATION: Only two types of fatty acids (LA and DPA) can be used for pleiotropy tests using the MR-Egger intercept test. CONCLUSION: This study does not support the hypothesis that PUFAs decrease the risk of AN.

Synthesis of Pt-Loaded Y2WO6:Eu3+ Microspheres and Their Hydrogen-Sensitive Turn-Off Luminescence.

Pt nanoparticles were loaded on Y2WO6:Eu3+ phosphor microspheres to enhance hydrogen sensitivity at low temperatures through turn-off luminescence. Mesoporous Y2WO6:Eu3+ microspheres were synthesized first by a hydrothermal method. Pt loading on the surface of the Y2WO6:Eu3+ microspheres was then carried out by a method of the self-regulated reduction of surfactants using aqueous K2PtCl4 solutions. Structural and morphological properties of unloaded and Pt-loaded Y2WO6:Eu3+ microspheres were investigated by various techniques such as X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. The relative photoluminescence intensity of the Pt-loaded Y2WO6:Eu3+ microspheres, due to 5D0 → 7F J (J = 0, 1, 2, 3, 4) electronic transitions of doped Eu3+ ions, was found to decrease as low as 22% after the microspheres were kept in the hydrogen gas atmosphere at a low temperature of 150 °C for 15 min. Meanwhile, mechanisms underlying this turn-off luminescence of the Pt/Y2WO6:Eu3+ microspheres in response to hydrogen gas are illustrated in detail.