Disease-associated inosine misincorporation into RNA hinders translation.

Failure to prevent accumulation of the non-canonical nucleotide inosine triphosphate (ITP) by inosine triphosphate pyrophosphatase (ITPase) during nucleotide synthesis results in misincorporation of inosine into RNA and can cause severe and fatal developmental anomalies in humans. While the biochemical activity of ITPase is well understood, the pathogenic basis of ITPase deficiency and the molecular and cellular consequences of ITP misincorporation into RNA remain cryptic. Here, we demonstrate that excess ITP in the nucleotide pool during in vitro transcription results in T7 polymerase-mediated inosine misincorporation in luciferase RNA. In vitro translation of inosine-containing luciferase RNA reduces resulting luciferase activity, which is only partly explained by reduced abundance of the luciferase protein produced. Using Oxford Nanopore Direct RNA sequencing, we reveal inosine misincorporation to be stochastic but biased largely towards misincorporation in place of guanosine, with evidence for misincorporation also in place of cytidine, adenosine and uridine. Inosine misincorporation into RNA is also detected in Itpa-null mouse embryonic heart tissue as an increase in relative variants compared with the wild type using Illumina RNA sequencing. By generating CRISPR/Cas9 rat H9c2 Itpa-null cardiomyoblast cells, we validate a translation defect in cells that accumulate inosine within endogenous RNA. Furthermore, we observe hindered cellular translation of transfected luciferase RNA containing misincorporated inosine in both wild-type and Itpa-null cells. We therefore conclude that inosine misincorporation into RNA perturbs translation, thus providing mechanistic insight linking ITPase deficiency, inosine accumulation and pathogenesis.

Health Insurance Status as a Predictor of Mode of Colon Cancer Detection but Not Stage at Diagnosis: Implications for Early Detection.

OBJECTIVE: For colon cancer patients, one goal of health insurance is to improve access to screening that leads to early detection, early-stage diagnosis, and polyp removal, all of which results in easier treatment and better outcomes. We examined associations among health insurance status, mode of detection (screen detection vs symptomatic presentation), and stage at diagnosis (early vs late) in a diverse sample of patients recently diagnosed with colon cancer from the Chicago metropolitan area. METHODS: Data came from the Colon Cancer Patterns of Care in Chicago study of racial and socioeconomic disparities in colon cancer screening, diagnosis, and care. We collected data from the medical records of non-Hispanic Black and non-Hispanic White patients aged ≥50 and diagnosed with colon cancer from October 2010 through January 2014 (N = 348). We used logistic regression with marginal standardization to model associations between health insurance status and study outcomes. RESULTS: After adjusting for age, race, sex, and socioeconomic status, being continuously insured 5 years before diagnosis and through diagnosis was associated with a 20 (95% CI, 8-33) percentage-point increase in prevalence of screen detection. Screen detection in turn was associated with a 15 (95% CI, 3-27) percentage-point increase in early-stage diagnosis; however, nearly half (47%; n = 54) of the 114 screen-detected patients were still diagnosed at late stage (stage 3 or 4). Health insurance status was not associated with earlier stage at diagnosis. CONCLUSIONS: For health insurance to effectively shift stage at diagnosis, stronger associations are needed between health insurance and screening-related detection; between screening-related detection and early stage at diagnosis; or both. Findings also highlight the need to better understand factors contributing to late-stage colon cancer diagnosis despite screen detection.

Challenges, Facilitators, and Recommendations for Implementation of Home Dialysis in the Veterans Health Administration: Patient, Caregiver, and Clinician Perceptions.

Background: Home dialysis confers similar survival and greater quality of life than in-center hemodialysis for adults with ESKD but remains underutilized. We examined challenges and facilitators to implementation of home dialysis and identified stakeholder-centered strategies for improving it. Methods: We conducted a qualitative, cross-sectional, multisite evaluation that included five geographically dispersed Veterans Health Administration (VHA) home dialysis programs. Participants included patients with ESKD receiving home dialysis, their informal caregivers, and home dialysis staff. Semistructured telephone interviews were conducted and audio-recorded from 2017 through 2018, to assess perceived barriers and facilitators to patient home dialysis use in VHA. Transcribed interviews were analyzed thematically by each participant group. Results: Participants included 22 patients receiving home dialysis (18 on peritoneal dialysis [PD] and four hemodialysis [HD]); 20 informal caregivers, and 19 home dialysis program staff. Ten themes emerged as challenges to implementing home dialysis, of which six (60%) spanned all groups: need for sterility, burden of home dialysis tasks, lack of suitable home environment, physical side effects of home dialysis, negative psychosocial effects of home dialysis, and loss of freedom. Four themes (40%), identified only by staff, were insufficient self-efficacy, diminished peer socialization, geographic barriers, and challenging health status. Twelve themes emerged as facilitators to implementing home dialysis, of which seven (58%) spanned all groups: convenience, freedom, avoidance of in-center HD, preservation of autonomy, adequate support, favorable disposition, and perceptions of improved health. Two themes (17%) common among patients and staff were adequate training and resources, and physical and cognitive skills for home dialysis. Recommendations to promote implementation of home dialysis common to all participant groups entailed incorporating mental health care services, offering peer-to-peer coaching, increasing home visits, providing health data feedback, and reducing patient burden. Conclusions: Stakeholder-centered challenges were rigorously identified. Facilitators and recommendations can inform efforts to support home dialysis implementation.

Gender- and Race-Based Differences in Barriers and Facilitators to Early Detection of Colon Cancer.

Background: Early detection of colon cancer is essential to successful treatment and survival, yet most patients are diagnosed only after onset of symptoms. Previous studies suggest differences in colon cancer screening and presentation by gender and race, but reasons for this are not understood. The purpose of this study was to identify barriers and facilitators to early detection of colon cancer and to compare by gender and race. Materials and Methods: In the Colon Cancer Patterns of Care in Chicago study, non-Hispanic Black and White (NHB, NHW) patients aged 30-79 newly diagnosed with colon cancer between 2010 and 2014 (n = 249) underwent in-depth semistructured interviews regarding the pathway to colon cancer diagnosis. Mixed qualitative and quantitative methods were used to analyze patient narratives and to compare response patterns by gender and race within prespecified domains: health care access factors, provider-related factors, patient-related factors, and diagnostic workup factors. Results: Women reported more barriers than facilitators to early detection than men (barrier: facilitator ratio of 0.60 vs. 0.48). Thematic differences were seen, with women reporting more barriers related to health care access, scheduling of follow-ups, symptom recognition, and inappropriate or inconclusive diagnostic tests. Fewer women than men reported facilitators related to provider factors such as ease of scheduling follow-ups and receiving referrals for screening or a specialist. NHBs and NHWs reported similar ratios of barriers to facilitators (0.55 vs. 0.53), but more NHBs than NHWs reported barriers related to health care access, scheduling follow-ups, and clinical delays, and fewer NHBs reported facilitators related to health care accessibility (existing relationship with provider, ease of scheduling follow-ups). Conclusions: In this diverse population of patients recently diagnosed with colon cancer, we identified substantive gender- and race-based differences in the types and burden of barriers and facilitators to early detection experienced in the path to diagnosis. These differences should be explored further as they may contribute to disparities in the diagnosis and prognosis of colon cancer.

Impact of Patient-Centered Medical Home Implementation on Diabetes Control in the Veterans Health Administration.

BACKGROUND: Given its widespread dissemination across primary care, the Veterans Health Administration (VA) is an ideal setting to examine the impact of the patient-centered medical home (PCMH) on diabetes outcomes. OBJECTIVE: To assess the impact of PCMH implementation on diabetes outcomes among patients receiving care in the Veterans Health Administration. DESIGN: Retrospective cohort analysis and multilevel logistic regression. PATIENTS: Twenty thousand eight hundred fifty-eight patients in one Midwest VA network who had a diabetes diagnosis in both 2009 and 2012 and who received primary care between October 1, 2008 and September 30, 2009. MAIN MEASURES: Glycemic and lipid control using VA quality indicators [hemoglobin (Hb) A1c < 9%, low-density lipoprotein cholesterol (LDL-C) < 100 mg/dL]. KEY RESULTS: Odds of glycemic control were lower in 2012 than 2009 (OR = 0.72, 95% CI = 0.67-0.77, p < 0.001), and this change in control over time varied by race (OR of the interaction between time and race = 1.18, 95% CI = 1.02-1.36, p = 0.028). While the disparity in glycemic control between white and black patients persisted post-PCMH, the magnitude of the disparity was smaller in 2012 compared to 2009 (2012: OR = 1.32, 95% CI = 1.18-1.47, p < 0.0001 and 2009: OR = 1.59, 95% CI = 1.39-1.82, p < 0.0001). Odds of lipid control did not significantly change between 2009 and 2012 and change did not vary by race and/or gender. CONCLUSIONS: Although there were no significant improvements in odds of lipid control, and odds of glycemic control decreased following PCMH implementation, there was evidence of reduced racial disparities in glycemic control post-PCMH implementation.

Neuronal Glutamate Transporters Control Dopaminergic Signaling and Compulsive Behaviors.

There is an ongoing debate on the contribution of the neuronal glutamate transporter EAAC1 to the onset of compulsive behaviors. Here, we used behavioral, electrophysiological, molecular, and viral approaches in male and female mice to identify the molecular and cellular mechanisms by which EAAC1 controls the execution of repeated motor behaviors. Our findings show that, in the striatum, a brain region implicated with movement execution, EAAC1 limits group I metabotropic glutamate receptor (mGluRI) activation, facilitates D1 dopamine receptor (D1R) expression, and ensures long-term synaptic plasticity. Blocking mGluRI in slices from mice lacking EAAC1 restores D1R expression and synaptic plasticity. Conversely, activation of intracellular signaling pathways coupled to mGluRI in D1R-containing striatal neurons of mice expressing EAAC1 leads to reduced D1R protein level and increased stereotyped movement execution. These findings identify new molecular mechanisms by which EAAC1 can shape glutamatergic and dopaminergic signals and control repeated movement execution.SIGNIFICANCE STATEMENT Genetic studies implicate Slc1a1, a gene encoding the neuronal glutamate transporter EAAC1, with obsessive-compulsive disorder (OCD). EAAC1 is abundantly expressed in the striatum, a brain region that is hyperactive in OCD. What remains unknown is how EAAC1 shapes synaptic function in the striatum. Our findings show that EAAC1 limits activation of metabotropic glutamate receptors (mGluRIs) in the striatum and, by doing so, promotes D1 dopamine receptor (D1R) expression. Targeted activation of signaling cascades coupled to mGluRIs in mice expressing EAAC1 reduces D1R expression and triggers repeated motor behaviors. These findings provide new information on the molecular basis of OCD and suggest new avenues for its treatment.

Examining racial disparities in colon cancer clinical delay in the Colon Cancer Patterns of Care in Chicago study.

PURPOSE: We explored a potential racial disparity in clinical delay among non-Hispanic (nH) Black and White colon cancer patients and examined factors that might account for the observed disparity. METHODS: Patients aged 30-79 years with a newly diagnosed colon cancer from 2010 to 2014 (n = 386) were recruited from a diverse sample of nine public, private, and academic hospitals in and around Chicago. Prolonged clinical delay was defined as 60 days or more or 90 days or more between medical presentation (symptoms or a screen-detected lesion) and treatment initiation (surgery or chemotherapy). Multivariable logistic regression with model-based standardization was used to estimate the disparity as a difference in prevalence of prolonged delay by race. RESULTS: Prevalence of delay in excess of 60 days was 12 percentage points (95% confidence interval: 2%, 22%) higher among nH Blacks versus Whites after adjusting for age, facility, and county of residence. Travel burden (time and distance traveled from residence to facility) explained roughly one-third of the disparity (33%, P = .05), individual and area-level socioeconomic status measures explained roughly one-half (51%, P = .21), and socioeconomic measures together with travel burden explained roughly four-fifths (79%, P = .08). CONCLUSIONS: Low socioeconomic status and increased travel burden are barriers to care disproportionately experienced by nH Black colon cancer patients.

Comparison of segmented flow analysis and ion chromatography for the quantitative characterization of carbohydrates in tobacco products.

Segmented flow analysis (SFA) and ion chromatography with pulsed amperometric detection (IC-PAD) are widely used analytical techniques for the analysis of glucose, fructose, and sucrose in tobacco. In the work presented here, 27 cured tobacco leaves and 21 tobacco products were analyzed for sugars using SFA and IC. The results of these analyses demonstrated that both techniques identified the same trends in sugar content across tobacco leaf and tobacco product types. However, comparison of results between techniques was limited by the selectivity of the SFA method, which relies on the specificity of the reaction of p-hydroxybenzoic acid hydrazide (PAHBAH) with glucose and fructose to generate a detectable derivative. Sugar amines and chlorogenic acid, which are found in tobacco, are also known to react with PAHBAH to form a reaction product that interferes with the analysis of fructose and glucose. To mitigate this problem, solid phase extraction (SPE) was used to remove interferences such as sugar amines and chlorogenic acid from sample matrices prior to SFA. A combination of C18 and cation exchange solid phase extraction cartridges was used, and the results from SFA and IC analyses showed significant convergence in the results of both analytical methods. For example, the average difference between the results from the SFA and IC analyses for flue-cured tobacco samples dropped by 73% when the two-step C18/cation exchange resin sample cleanup was used.