Sam Oh
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Researcher at University of California, San Francisco, Department of Medicine
Background: Exposure to environmental pollutants has been shown to be associated with asthma, but few studies have evaluated the effect of wood smoke on asthma and disease severity in a developing country, where use of stoves powered by solid fuels is a common practice. Objective: In a population in Olancho, Honduras, we evaluated the association between cooking fuel, stove type and asthma. We also evaluated the effects of these factors on asthma symptoms, lung function, and atopy. Methods: Participants with physician-diagnosed asthma (n = 597) and controls without asthma (n = 429) were recruited from the Olancho province in Honduras. Participants were interviewed using a questionnaire and their baseline pulmonary function was measured using spirometry. Results: The prevalence of use of wood as a cooking fuel was 66.9% in the study population, of which 42.1% of participants used wood as their only fuel. Use of wood as a cooking fuel was more prevalent among households with lower income, lower maternal education, and less urbanization. The prevalence of use of an open wood stove as the primary cooking stove among participants with asthma was 6.2% higher (95% CI 0.8 - 11.7%, p = .02) than among healthy controls. In a multiple logistic regression model, we identified a significant association between use of an open wood stove and asthma (OR = 1.80, 95% CI = 1.17 - 2.78, p = 0.007), compared to the referent (electric) stove category. Among participants with asthma, we identified a significant association between use of wood as cooking fuel and increased daytime respiratory symptoms (OR = 1.46, CI: 1.01 - 2.58, p = 0.046) and nocturnal symptoms (OR = 2.51, CI: 1.04 - 2.62, p = 0.04), though not with pulmonary function. Among control participants without asthma, use of wood as cooking fuel was associated with atopy (OR = 1.94, CI = 1.14 - 3.33, p = 0.015) and cough (OR = 2.22, CI = 1.09 - 4.88, p = 0.04). Conclusions: Use of an open wood stove for cooking in a developing country appears to be a significant risk factor for asthma and respiratory symptoms. Exposure to wood smoke may play a role in atopic sensitization and respiratory symptoms, leading to the development of obstructive lung disease in susceptible individuals.
Epigenetics & Chromatin, 2017-01-03
Genetic data are known to harbor information about human demographics, and genotyping data are commonly used for capturing ancestry information by leveraging genome-wide differences between populations. In contrast, it is not clear to what extent population structure is captured by whole-genome DNA methylation data. We demonstrate, using three large cohort 450K methylation array data sets, that ancestry information signal is mirrored in genome-wide DNA methylation data, and that it can be further isolated more effectively by leveraging the correlation structure of CpGs with cis-located SNPs. Based on these insights, we propose a method, EPISTRUCTURE, for the inference of ancestry from methylation data, without the need for genotype data. EPISTRUCTURE can be used to infer ancestry information of individuals based on their methylation data in the absence of corresponding genetic data. Although genetic data are often collected in epigenetic studies of large cohorts, these are typically not made publicly available, making the application of EPISTRUCTURE especially useful for anyone working on public data. Implementation of EPISTRUCTURE is available in GLINT, our recently released toolset for DNA methylation analysis at: http://glint-epigenetics.readthedocs.io.
American Journal of Respiratory and Critical Care Medicine, 2018-06-15
Asthma is the most common chronic disease of children, with significant racial/ethnic differences in prevalence, morbidity, mortality and therapeutic response. Albuterol, a bronchodilator medication, is the first-line therapy for asthma treatment worldwide. We performed the largest whole genome sequencing (WGS) pharmacogenetics study to date using data from 1,441 minority children with asthma who had extremely high or low bronchodilator drug response (BDR). We identified population-specific and shared pharmacogenetic variants associated with BDR, including genome-wide significant (p < 3.53 x 10-7) and suggestive (p < 7.06 x 10-6) loci near genes previously associated with lung capacity (DNAH5), immunity (NFKB1 and PLCB1), and β-adrenergic signaling pathways (ADAMTS3 and COX18). Functional analyses centered on NFKB1 revealed potential regulatory function of our BDR-associated SNPs in bronchial smooth muscle cells. Specifically, these variants are in linkage disequilibrium with SNPs in a functionally active enhancer, and are also expression quantitative trait loci (eQTL) for a neighboring gene, SLC39A8. Given the lack of other asthma study populations with WGS data on minority children, replication of our rare variant associations is infeasible. We attempted to replicate our common variant findings in five independent studies with GWAS data. The age-specific associations previously found in asthma and asthma-related traits suggest that the over-representation of adults in our replication populations may have contributed to our lack of statistical replication, despite the functional relevance of the NFKB1 variants demonstrated by our functional assays. Our study expands the understanding of pharmacogenetic analyses in racially/ethnically diverse populations and advances the foundation for precision medicine in at-risk and understudied minority populations.
Objective: To evaluate if pharmacy students participation in personal pharmacogenetic (Pgx) testing enhances their knowledge and attitude towards precision medicine (PM). Methods: First-year pharmacy students were offered personalized pharmacogenetic testing as a supplement to a required curricular pharmacogenomics course. Ninety-eight of 122 (80%) students completed pre- and post-course surveys assessing knowledge and attitudes regarding PM; 73 students also volunteered for personal pharmacogenetic testing of the following drug metabolizing enzymes (CYP2C19, CYP2D6, UGT1A1) and pharmacodynamics-relevant proteins (interleukin (IL)-28B & human lymphocyte antigen HLAB*5701). Results: Among the 122 students, we found that incorporating pharmacogenetic testing improved mean knowledge and attitude by 1.0 and 0.3 Likert points, respectively. We observed statistically significant improvements in 100% of knowledge and 70% of attitude-related statements for students who decided to undergo personal pharmacogenetic testing. Students who were enrolled in the course but did not partake in personalized pharmacogenetic testing had similar gains in knowledge and attitude. Conclusion: This study demonstrates the feasibility and importance of educating future pharmacists by incorporating pharmacogenetic testing into professional school curricula. Students who opt not to participate in genotyping may still benefit by learning vicariously through the shared learning environment created by genotyped students.
PLOS Medicine, 2015-12-15
Summary Points Health disparities persist across race/ethnicity for the majority of Healthy People 2010 health indicators. Most physicians and scientists are informed by research extrapolated from a largely homogenous population, usually White and male. A growing proportion of Americans are not fully benefiting from clinical and biomedical advances since racial and ethnic minorities make up nearly 40% of the U.S. population. Ignoring the racial/ethnic diversity of the U.S. population is a missed scientific opportunity to fully understand the factors that lead to disease or health. U.S. biomedical research and study populations must better reflect the country's changing demographics. Adequate representation of diverse populations in scientific research is imperative as a matter of social justice, economics, and science.