Browsing by Author "Liu, Yun"

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    Characterization of intratumor microbiome in cancer immunotherapy
    (Elsevier, 2023-07-12) Zhang, Zhao; Gao, Qian; Ren, Xiangmei; Luo, Mei; Liu, Yuan; Liu, Peilin; Liu, Yun; Ye, Youqiong; Che, Xiang; Liu, Hong; Han, Leng; Biostatistics and Health Data Science, School of Medicine
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    Epigenome-wide meta-analysis of blood DNA methylation and its association with subcortical volumes: findings from the ENIGMA Epigenetics Working Group
    (Springer Nature, 2021) Jia, Tianye; Chu, Congying; Liu, Yun; Van Dongen, Jenny; Papastergios, Evangelos; Armstrong, Nicola J.; Bastin, Mark E.; Carrillo-Roa, Tania; den Braber, Anouk; Harris, Mathew; Jansen, Rick; Liu, Jingyu; Luciano, Michelle; Ori, Anil P.S.; Santiañez, Roberto Roiz; Ruggeri, Barbara; Sarkisyan, Daniil; Shin, Jean; Sungeun, Kim; Tordesillas Gutiérrez, Diana; van't Ent, Dennis; Ames, David; Artiges, Eric; Bakalkin, Georgy; Banaschewski, Tobias; Bokde, Arun L.W.; Brodaty, Henry; Bromberg, Uli; Brouwer, Rachel; Büchel, Christian; Burke Quinlan, Erin; Cahn, Wiepke; de Zubicaray, Greig I.; Ehrlich, Stefan; Ekström, Tomas J.; Flor, Herta; Fröhner, Juliane H.; Frouin, Vincent; Garavan, Hugh; Gowland, Penny; Heinz, Andreas; Hoare, Jacqueline; Ittermann, Bernd; Jahanshad, Neda; Jiang, Jiyang; Kwok, John B.; Martin, Nicholas G.; Martinot, Jean-Luc; Mather, Karen A.; McMahon, Katie L.; McRae, Allan F.; Nees, Frauke; Orfanos, Dimitri Papadopoulos; Paus, Tomáš; Poustka, Luise; Sämann, Philipp G.; Schofield, Peter R.; Smolka, Michael N.; Stein, Dan J.; Strike, Lachlan T.; Teeuw, Jalmar; Thalamuthu, Anbupalam; Trollor, Julian; Walter, Henrik; Wardlaw, Joanna M.; Wen, Wei; Whelan, Robert; Apostolova, Liana G.; Binder, Elisabeth B.; Boomsma, Dorret I.; Calhoun, Vince; Crespo-Facorro, Benedicto; Deary, Ian J.; Hulshoff Pol, Hilleke; Ophoff, Roel A.; Pausova, Zdenka; Sachdev, Perminder S.; Saykin, Andrew; Wright, Margaret J.; Thompson, Paul M.; Schumann, Gunter; Desrivières, Sylvane; Radiology and Imaging Sciences, School of Medicine
    DNA methylation, which is modulated by both genetic factors and environmental exposures, may offer a unique opportunity to discover novel biomarkers of disease-related brain phenotypes, even when measured in other tissues than brain, such as blood. A few studies of small sample sizes have revealed associations between blood DNA methylation and neuropsychopathology, however, large-scale epigenome-wide association studies (EWAS) are needed to investigate the utility of DNA methylation profiling as a peripheral marker for the brain. Here, in an analysis of eleven international cohorts, totalling 3337 individuals, we report epigenome-wide meta-analyses of blood DNA methylation with volumes of the hippocampus, thalamus and nucleus accumbens (NAcc)—three subcortical regions selected for their associations with disease and heritability and volumetric variability. Analyses of individual CpGs revealed genome-wide significant associations with hippocampal volume at two loci. No significant associations were found for analyses of thalamus and nucleus accumbens volumes. Cluster-based analyses revealed additional differentially methylated regions (DMRs) associated with hippocampal volume. DNA methylation at these loci affected expression of proximal genes involved in learning and memory, stem cell maintenance and differentiation, fatty acid metabolism and type-2 diabetes. These DNA methylation marks, their interaction with genetic variants and their impact on gene expression offer new insights into the relationship between epigenetic variation and brain structure and may provide the basis for biomarker discovery in neurodegeneration and neuropsychiatric conditions.
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    Fluoride Content in Foods and Beverages From Mexico City Markets and Supermarkets
    (Sage, 2019-12) Cantoral, Alejandra; Luna-Villa, Lynda Cristina; Mantilla-Rodriguez, Andres A.; Mercado, Adriana; Lippert, Frank; Liu, Yun; Peterson, Karen E.; Hu, Howard; Téllez-Rojo, Martha M.; Martinez-Mier, Esperanza A.; Cariology, Operative Dentistry and Dental Public Health, School of Dentistry
    Background: Sources of fluoride exposure for Mexicans include foods, beverages, fluoridated salt, and naturally fluoridated water. There are no available data describing fluoride content of foods and beverages consumed in Mexico. Objective: To measure the content of fluoride in foods and beverages typically consumed and to compare their content to that of those from the United States and the United Kingdom. Methods: Foods and beverages reported as part of the Mexican Health and Nutrition Survey (n = 182) were purchased in the largest supermarket chains and local markets in Mexico City. Samples were analyzed for fluoride, at least in duplicate, using a modification of the hexamethyldisiloxane microdiffusion method. Value contents were compared to those from the US Department of Agriculture and UK fluoride content tables. Results: The food groups with the lowest and highest fluoride content were eggs (2.32 µg/100 g) and seafood (371 µg/100 g), respectively. When estimating the amount of fluoride per portion size, the lowest content corresponded to eggs and the highest to fast foods. Meats and sausages, cereals, fast food, sweets and cakes, fruits, dairy products, legumes, and seafood from Mexico presented higher fluoride contents than similar foods from the United States or the United Kingdom. Drinks and eggs from the United States exhibited the highest contents, while this was the case for pasta, soups, and vegetables from the United Kingdom. Conclusion: The majority of items analyzed contained higher fluoride contents than their US and UK counterparts. Data generated provide the first and largest table on fluoride content, which will be useful for future comparisons and estimations.
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    Prenatal Fluoride Exposure and Cognitive Outcomes in Children at 4 and 6–12 Years of Age in Mexico
    (2017) Bashash, Morteza; Thomas, Deena; Hu, Howard; Martinez-Mier, E. Angeles; Sanchez, Brisa N.; Basu, Niladri; Peterson, Karen E.; Ettinger, Adrienne S.; Wright, Robert; Zhang, Zhenzhen; Liu, Yun; Schnaas, Lourdes; Mercado-García, Adriana; Téllez-Rojo, Martha María; Hernández-Avila, Mauricio; Cariology, Operative Dentistry and Dental Public Health, School of Dentistry
    BACKGROUND: Some evidence suggests that fluoride may be neurotoxic to children. Few of the epidemiologic studies have been longitudinal, had individual measures of fluoride exposure, addressed the impact of prenatal exposures or involved more than 100 participants. OBJECTIVE: Our aim was to estimate the association of prenatal exposure to fluoride with offspring neurocognitive development. METHODS: We studied participants from the Early Life Exposures in Mexico to Environmental Toxicants (ELEMENT) project. An ion-selective electrode technique was used to measure fluoride in archived urine samples taken from mothers during pregnancy and from their children when 6–12 y old, adjusted for urinary creatinine and specific gravity, respectively. Child intelligence was measured by the General Cognitive Index (GCI) of the McCarthy Scales of Children’s Abilities at age 4 and full scale intelligence quotient (IQ) from the Wechsler Abbreviated Scale of Intelligence (WASI) at age 6–12. RESULTS: We had complete data on 299 mother–child pairs, of whom 287 and 211 had data for the GCI and IQ analyses, respectively. Mean (SD) values for urinary fluoride in all of the mothers (n=299) and children with available urine samples (n=211) were 0.90 (0.35) mg/L and 0.82 (0.38) mg/L, respectively. In multivariate models we found that an increase in maternal urine fluoride of 0.5mg/L (approximately the IQR) predicted 3.15 (95% CI: −5.42, −0.87) and 2.50 (95% CI −4.12, −0.59) lower offspring GCI and IQ scores, respectively. CONCLUSIONS: In this study, higher prenatal fluoride exposure, in the general range of exposures reported for other general population samples of pregnant women and nonpregnant adults, was associated with lower scores on tests of cognitive function in the offspring at age 4 and 6–12 y.
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    Urinary and Plasma Fluoride Levels in Pregnant Women from Mexico City
    (Elsevier, 2016-10) Thomas, Deena B.; Basu, Niladri; Martinez-Mier, E. Angeles; Sánchez, Brisa N.; Zhang, Zhenzhen; Liu, Yun; Parajuli, Rajendra; Peterson, Karen; Mercado-Garcia, Adriana; Bashash, Morteza; Hernández-Avila, Mauricio; Hu, Howard; Téllez-Rojo, Martha Maria; Department of Cariology, Operative Dentistry and Dental Public Health, School of Dentistry
    Background There is need to assess the developmental neurotoxicity of fluoride. Our knowledge of prenatal fluoride exposure is challenged as few population-based studies have been conducted and these generally date back several decades, provide incomplete data on sociodemographic variables, and have methodological limitations. Objective To measure urinary and plasma fluoride levels across three time points in pregnant mothers who were enrolled in the Early Life Exposures in Mexico to Environmental Toxicants (ELEMENT) birth cohort study. Methods Fluoride levels were characterized in archived urine and plasma from 872 pregnant mothers sampled from the ELEMENT cohort. Various statistical methods were used to analyze the fluoride data with particular consideration for changes across three stages of pregnancy and against sociodemographic variables. Results All samples had detectable levels of fluoride. The mean urinary and plasma fluoride levels were 0.91 and 0.0221 mg/L respectively, and these were not statistically different across three stages of pregnancy. Fluoride levels correlated across the stages of pregnancy studied, with stronger correlations between neighboring stages. Urinary fluoride changed as pregnancy progressed with levels increasing until ~23 weeks and then decreasing until the end of pregnancy. For plasma fluoride, there was a decreasing trend but this was not of statistical significance. Creatinine-adjusted urinary fluoride levels did not associate consistently with any of the sociodemographic variables studied. Conclusions This study provides the most extensive characterization to date of fluoride exposure throughout pregnancy. These results provide the foundation to explore exposure-related health outcomes in the ELEMENT cohort and other studies.