Browsing by Author "Weiss, David"

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    Characterizing chronological accumulation of comorbidities in healthy veterans: a computational approach.
    (Scientific reports, 2021-04-14) Hong, Julian C; Hauser, Elizabeth R; Redding, Thomas S; Sims, Kellie J; Gellad, Ziad F; O'Leary, Meghan C; Hyslop, Terry; Madison, Ashton N; Qin, Xuejun; Weiss, David; Bullard, A Jasmine; Williams, Christina D; Sullivan, Brian A; Lieberman, David; Provenzale, Dawn
    Understanding patient accumulation of comorbidities can facilitate healthcare strategy and personalized preventative care. We applied a directed network graph to electronic health record (EHR) data and characterized comorbidities in a cohort of healthy veterans undergoing screening colonoscopy. The Veterans Affairs Cooperative Studies Program #380 was a prospective longitudinal study of screening and surveillance colonoscopy. We identified initial instances of three-digit ICD-9 diagnoses for participants with at least 5 years of linked EHR history (October 1999 to December 2015). For diagnoses affecting at least 10% of patients, we calculated pairwise chronological relative risk (RR). iGraph was used to produce directed graphs of comorbidities with RR > 1, as well as summary statistics, key diseases, and communities. A directed graph based on 2210 patients visualized longitudinal development of comorbidities. Top hub (preceding) diseases included ischemic heart disease, inflammatory and toxic neuropathy, and diabetes. Top authority (subsequent) diagnoses were acute kidney failure and hypertensive chronic kidney failure. Four communities of correlated comorbidities were identified. Close analysis of top hub and authority diagnoses demonstrated known relationships, correlated sequelae, and novel hypotheses. Directed network graphs portray chronologic comorbidity relationships. We identified relationships between comorbid diagnoses in this aging veteran cohort. This may direct healthcare prioritization and personalized care.
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    Whole genome re-sequencing to identify suppressor mutations of mutant and foreign Escherichia coli FtsZ.
    (PLoS One, 2017) Gardner, Kiani AJ Arkus; Osawa, Masaki; Erickson, Harold P
    FtsZ is an essential protein for bacterial cell division, where it forms the cytoskeletal scaffold and may generate the constriction force. We have found previously that some mutant and foreign FtsZ that do not complement an ftsZ null can function for cell division in E. coli upon acquisition of a suppressor mutation somewhere in the genome. We have now identified, via whole genome re-sequencing, single nucleotide polymorphisms in 11 different suppressor strains. Most of the mutations are in genes of various metabolic pathways, which may modulate cell division indirectly. Mutations in three genes, ispA, accD and nlpI, may be more directly involved in cell division. In addition to the genomic suppressor mutations, we identified intragenic suppressors of three FtsZ point mutants (R174A, E250K and L272V).