Association of Private Equity Firm Acquisition of Ophthalmology Practices with Medicare Spending and Use of Ophthalmology Services.

PURPOSE: Private equity (PE) firms increasingly are acquiring ophthalmology practices; little is known of their influence on care use and spending. We studied changes in use and Medicare spending after PE acquisition. DESIGN: Retrospective cohort study. PARTICIPANTS: Seven hundred sixty-two clinicians in 123 practices acquired by PE between 2017 and 2018 and 34 807 clinicians in 20 549 never-acquired practices. METHODS: We analyzed Medicare fee-for-service claims (2012-2019) combined with a novel national database of PE acquisitions of ophthalmology practices using a difference-in-differences method within an event study framework to compare changes after a practice was acquired with changes in practices that were not acquired. MAIN OUTCOME MEASURES: Numbers of beneficiaries seen; intravitreal injections and medications used for injections; and spending on ophthalmologist and optometrist services, ancillary services, and intravitreal injections. RESULTS: Comparing PE-acquired with nonacquired practices showed a 23.92% increase (n = 4.20 beneficiaries; 95% confidence interval [CI], 1.73-6.67) in beneficiaries seen per PE optometrist per quarter and no change for ophthalmologists, while spending per beneficiary increased 5.06% ($9.66; 95% CI, -2.82 to 22.14). Spending on clinician services decreased 1.62% (-$2.37; 95% CI, -5.78 to 1.04), with ophthalmologist services increasing 5.46% ($17.70; 95% CI, -2.73 to 38.15) and optometrists decreasing 4.60% (-$5.76; 95% CI, -9.17 to -2.34) per beneficiary per quarter. Ancillary services decreased 7.56% (-$2.19; 95% CI, 4.19 to -0.22). Intravitreal injection costs increased 25.0% ($20.02; 95% CI, -1.38 to 41.41) with the number increasing 5.10% (1.83; 95% CI, -0.1 to 3.80). There was a 74.09% increase (8.38 injections; 95% CI, 0.01-16.74) in ranibizumab and a 12.91% decrease (-3.40 injections; 95% CI, -6.86 to 0.07) in bevacizumab after acquisition. The event study showed consistent and often statistically significant increases in ranibizumab injections and decreases in bevacizumab injections after acquisition. CONCLUSIONS: Although not all results reached statistical significance, this study suggested that PE acquisition of practices showed little or no overall effect on use or total spending, but increased the number of unique patients seen per optometrist and the use of expensive intravitreal injections. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Changes in Diagnoses and Site of Care for Patients Receiving Hospice Care From Agencies Acquired by Private Equity Firms and Publicly Traded Companies.

Importance: Private equity firms and publicly traded companies have been acquiring US hospice agencies; an estimated 16% of US hospice agencies are owned by private equity (PE) firms or publicly traded companies (PTC). Objective: To examine the association of PE and PTC acquisitions of hospices with Medicare patients' site of care and clinical diagnoses. Design, Setting, and Participants: This cohort study of US hospice agencies used a novel national database of acquisitions merged with the Medicare Post-Acute Care and Hospice Public Use File for 2013 to 2020. Changes in sites of care and patient characteristics for hospice agencies acquired by PE or PTCs were compared with changes for patients in nonacquired for-profit hospice agencies. Exposure: Private equity and publicly traded company acquisitions. Main Outcomes and Measures: This study used a difference-in-differences approach within an event-study framework to examine the association of PE and PTC acquisitions of hospice agencies with changes in patient diagnoses and sites of care. Dependent variables were annual hospice-level measures of the Hierarchical Condition Category (HCC) score and proportion of patients diagnosed with cancer or dementia. Sites of care included the proportion of patients receiving hospice care in their personal home, nursing home, or assisted living facility. Results: A total of 158 hospice agencies acquired by PEs, 250 acquired by PTCs, and 1559 other for-profit hospice agencies were included. Preacquisition, hospice agencies that would later be acquired by PE or PTC served a mean (IQR) 30.1% (12.0%-44.0%) and 29.4% (13.0%-43.0%) of their patients in nursing homes respectively, a greater proportion compared with the 27.1% (8.0%-43.8%) served by for-profit hospices that were never acquired. Agencies acquired by PE between 2014 and 2019 saw a significant relative increase of 5.98% in dementia patients (1.38 percentage points; 95% CI, 0.35-2.40 percentage points; P = .008). In PTC-owned hospices, the proportion of patients receiving care at home increased by 5.26% (2.98 percentage points; 95% CI, 1.46-4.51 percentage points; P < .001), the proportion of dementia patients rose by 13.49% (3.11 percentage points; 95% CI, 2.14-4.09 percentage points; P < .001), and the HCC score decreased by 1.37% (-3.19 percentage points; 95% CI, -5.92 to -0.47 percentage points; P = .02). Conclusions and Relevance: These findings suggest that PE and PTCs select patients and sites of care to maximize profits.

Substance Use and Mental Health Screening Within an Emergency Department-Based HIV Screening Program: Outcomes From 1 Year of Implementation.

INTRODUCTION: The emergency department (ED) may be an optimal setting to screen for substance use disorders (SUDs) and co-occurring psychiatric disorders (CODs). We report on the frequency of problematic substance use and comorbid elevated mental health symptoms detected during a 1-year implementation period of an ED-based SUD/COD screening approach within an established ED HIV screening program. METHODS: Patients (N = 1,924) were approached by dedicated HIV screening staff in an urban, Midwestern ED. Patients first completed measures assessing problematic alcohol (Alcohol Use Disorder Identification Test-Concise [AUDIT-C]) and substance use across 10 categories of substances (National Institute on Drug Abuse-Modified Alcohol, Smoking, and Substance Involvement Screening Test [NIDA-Modified ASSIST]). Patients with positive alcohol and/or substance use screens completed measures assessing symptoms of depression (Patient Health Questionnaire-9 [PHQ-9]), anxiety (Generalized Anxiety Disorder-7 [GAD-7]), and post-traumatic stress disorder (PTSD) (PTSD Checklist-Civilian [PCL-C]). RESULTS: Patients were predominantly male (60.3%) with a mean age of 38.1 years (SD = 13.0); most identified as White (50.8%) or Black (44.8%). A majority (58.5%) had a positive screen for problematic alcohol and/or other substance use. Of those with a positive substance use screen (n = 1,126), 47.0% had a positive screen on one or more of the mental health measures with 32.1% endorsing elevated depressive symptoms, 29.6% endorsing elevated PTSD-related symptoms, and 28.5% endorsing elevated anxiety symptoms. CONCLUSIONS: Among those receiving ED HIV screening, a majority endorsed problematic alcohol and/or other substance use and co-occurring elevated mental health symptoms. Substance use and mental health screening programs that can be integrated within other ED preventive services may enhance the identification of individuals in need of further assessment, referral, or linkage to substance use treatment services.

Association of Physician Management Companies and Private Equity Investment With Commercial Health Care Prices Paid to Anesthesia Practitioners.

IMPORTANCE: Physician management companies (PMCs), often backed by private equity (PE), are increasingly providing staffing and management services to health care facilities, yet little is known of their influence on prices. OBJECTIVE: To study changes in prices paid to practitioners (anesthesiologists and certified registered nurse anesthetists) before and after an outpatient facility contracted with a PMC. DESIGN, SETTING, AND PARTICIPANTS: This retrospective cohort study used difference-in-differences methods to compare price changes before and after a facility contracted with a PMC with facilities that did not and to compare differences between PMCs with and without PE investment. Commercial claims data (2012-2017) from 3 large national insurers in the Health Care Cost Institute database were combined with a novel data set of PMC facility contracts to identify prices paid to anesthesia practitioners in hospital outpatient departments and ambulatory surgery centers. The cohort included 2992 facilities that never contracted with a PMC and 672 facilities that contracted with a PMC between 2012 and 2017, collectively representing 2 255 933 anesthesia claims. EXPOSURES: Temporal variation in facility-level exposure to PMC contracts for anesthesia services. MAIN OUTCOMES AND MEASURES: Main outcomes were (1) allowed amounts and the unit price (allowed amounts standardized per unit of service) paid to anesthesia practitioners; and (2) the probability that a practitioner was out of network. RESULTS: From before to after the PMC contract period, allowed amounts increased by 16.5% (+$116.39; 95% CI, $76.11 to $156.67; P < .001), and the unit price increased by 18.7% (+$18.79; 95% CI, $12.73 to $24.84; P < .001) in PMC facilities relative to non-PMC facilities. Results did not show evidence that anesthesia practitioners were moved out of network (+2.25; 95% CI, -2.56 to 7.06; P < .36). In subsample analyses, PMCs without PE investment increased allowed amounts by 12.9% (+$89.88; 95% CI, $42.07 to $137.69; P < .001), while PE-backed PMCs (representing half of the PMCs in the sample) increased allowed amounts by 26.0% ($187.06; 95% CI, $133.59 to $240.52; P < .001). Similar price increases were observed for unit prices. CONCLUSIONS AND RELEVANCE: In this cohort study, prices paid to anesthesia practitioners increased after hospital outpatient departments and ambulatory surgery centers contracted with a PMC and were substantially higher if the PMC received PE investment. This research provides insights into the role of corporate ownership in health care relevant to policy makers, payers, practitioners, and patients.

Emergency department screening for latent tuberculosis infection.

OBJECTIVE: Approximately 12.4 million people in the U.S. have latent tuberculosis infection (LTBI), 73% of whom are non-U.S. born. Identification and treatment of LTBI are essential for tuberculosis eradication. We evaluated an emergency department (ED) - based LTBI screening and linkage to care program. METHODS: We queried electronic records of a clinical prevention program located in a Midwestern, urban, academic ED that serves as the region's safety-net hospital. Program staff approached non-U.S. born ED patients from TB endemic areas. Patients received QuantiFERON-TB Gold Plus (QFT) blood testing and, if positive, were referred to treatment. The primary outcome was the proportion of tested patients newly diagnosed with LTBI. We secondarily report the number of patients linked to care who initiated LTBI treatment. RESULTS: The program approached 33 patients, of whom 24 (72.7%) were eligible, and 23 (95.8%) were tested. The majority were male (13, 56.5%), median age was 33 years (IQR 27-45), and 13 (56.5%) were from Latin America. Three patients (13.0%, 95% CI 0.03-0.35) were newly diagnosed with LTBI and linked to care; two (66.7%) started LTBI treatment. CONCLUSIONS: In this first report of an ED-based LTBI screening program implemented in a region with low TB prevalence, over 10% of high-risk ED patients tested positive for LTBI and were linked to treatment. Screening populations at risk for LTBI in EDs and linking them to public health treatment services should be prioritized in order to achieve TB elimination in the U.S.

Association of Surprise-Billing Legislation with Prices Paid to In-Network and Out-of-Network Anesthesiologists in California, Florida, and New York: An Economic Analysis.

Importance: Several states have passed surprise-billing legislation to protect patients from unanticipated out-of-network medical bills, yet little is known about how state laws influence out-of-network prices and whether spillovers exist to in-network prices. Objective: To identify any changes in prices paid to out-of-network anesthesiologists at in-network facilities and to in-network anesthesiologists before and after states passed surprise-billing legislation. Design, Setting, and Participants: This retrospective economic analysis used difference-in-differences methods to compare price changes before and after the passage of legislation in California, Florida, and New York, which passed comprehensive surprise-billing legislation between January 1, 2014, and December 31, 2017, to 45 states that did not. Commercial claims data from the Health Care Cost Institute were used to identify prices paid to anesthesiologists in hospital outpatient departments and ambulatory surgery centers. The final analytic sample comprised 2 713 913 anesthesia claims across the 3 treated states and the 45 control states. Exposures: Temporal and state-level variation in exposure to surprise-billing legislation. Main Outcomes and Measures: The unit price (allowed amounts standardized per unit of service) paid to out-of-network anesthesiologists at in-network facilities and to in-network anesthesiologists. Results: This retrospective economic analysis of 2 713 913 anesthesia claims found that after surprise-billing laws were passed in 3 states, the unit price paid to out-of-network anesthesiologists at in-network facilities decreased significantly in 2 of them: California, -$12.71 (95% CI, -$25.70 to -$0.27; P = .05) and Florida, -$35.67 (95% CI, -$46.27 to -$25.07; P < .001). In New York, a decline in the overall out-of-network price was not statistically significant (-$7.91; 95% CI, -$17.48 to -$1.68; P = .10); however, by the fourth quarter of 2017, the decline was -$41.28 (95% CI, -$70.24 to -$12.33; P = .01). In-network prices decreased in California by -$10.68 (95% CI, -$12.70 to -$8.66; P < .001); in Florida, -$3.18 (95% CI, -$5.17 to -$1.19; P = .002); and in New York, -$8.05 (95% CI, -$11.46 to -$4.64; P < .001). Conclusions and Relevance: This retrospective study found that prices paid to in-network and out-of-network anesthesiologists in hospital outpatient departments and ambulatory surgery centers decreased after the introduction of surprise-billing legislation, providing early insights into how prices may change under the federal No Surprises Act and in states that have recently passed their own legislation.

Missed HIV diagnoses when screening only emergency department patients who have blood samples obtained for other clinical purposes.

OBJECTIVE: Emergency departments (EDs) are highly valued settings for HIV screening. Most large-volume ED HIV screening programs have attenuated operational barriers by screening only ED patients who already have a blood sample available for other clinical reasons. Our objective was to estimate the proportion of HIV positive patients who are missed when an ED excludes patients for whom HIV screening would be the only indication to obtain a blood sample. METHODS: This cross-sectional analysis used existing electronic records of patients seen between 2017 and 2019 by an urban, academic ED and its HIV screening program, which includes patients regardless of whether they receive other ED blood testing. The primary outcome was the proportion of patients tested by the screening program who were newly diagnosed with HIV (Sample 1) for whom HIV screening would be the only indication for venipuncture. We secondarily 1) estimate the proportion of ED patients who received venipuncture using a representative sample of consecutively approached participants which prospectively recorded whether patients had blood obtained or intravenous catheter placement during usual ED care (Sample 2) and 2) report patient characteristics including HIV risk factors for those with and without ED venipuncture for both groups. RESULTS: Of 41 persons newly diagnosed with HIV by the ED screening program (Sample 1), 13 (31.7%, 95%CI 18.6-48.2) did not undergo venipuncture for any reason other than their HIV test. The proportion of ED visits without a venipuncture (Sample 2) was 44.2% (95% CI 41.9-46.6). Patient characteristics were similar for both groups. CONCLUSIONS: Screening only those patients with a blood sample already available or easily obtainable due to usual ED care, misses many opportunities for earlier HIV diagnosis. Innovation in research, policy, and practice is needed to overcome still unaddressed barriers to ED HIV screening when HIV screening is the only indication for collection of a biological sample.

HIV detection by an emergency department HIV screening program during a regional outbreak among people who inject drugs.

OBJECTIVE: Multiple HIV outbreaks among persons who inject drugs (PWID) have occurred in the US since 2015. Emergency departments (EDs), recognized as essential venues for HIV screening, may play a unique role in identifying undiagnosed HIV among PWID, who frequently present for complications of injection drug use (IDU). Our objective was to describe changes in HIV diagnoses among PWID detected by an ED HIV screening program and estimate the program's contribution to HIV diagnoses among PWID county-wide during the emergence of a regional HIV outbreak. METHODS: This was a retrospective study of electronically queried clinical records from an urban, safety-net ED's HIV screening program and publicly available HIV surveillance data for its surrounding county, Hamilton County, Ohio. Outcomes included the change in number of HIV diagnoses and the ED's contribution to case identification county-wide, overall and for PWID during 2014-2018. RESULTS: During 2014-2018, the annual number of HIV diagnoses made by the ED program increased from 20 to 42 overall, and from 1 to 18 for PWID. We estimated that the ED contributed 18% of HIV diagnoses in the county and 22% of diagnoses among PWID. CONCLUSIONS: The ED program contributed 1 in 5 new HIV diagnoses among PWID county-wide, further illustrating the importance of ED HIV screening programs in identifying undiagnosed HIV infections. In areas experiencing increasing IDU, HIV screening in EDs can provide an early indication of increasing HIV diagnoses among PWID and can substantially contribute to case-finding during an HIV outbreak.

Private Equity In Dermatology: Effect On Price, Utilization, And Spending.

Private equity firms have increasingly acquired physician practices, and particularly dermatology practices. Analyzing commercial claims from the Health Care Cost Institute (2012-17), we used a difference-in-differences design within an event study framework to estimate the prevalence of private equity acquisitions and their impact on dermatologist prices, spending, utilization, and volume of patients. By 2017 one in eleven dermatologists practiced in a private equity-owned practice, and private equity-owned practices employed four advanced practitioners for every ten dermatologists compared with three for non-private equity practices. Private equity firms targeted their acquisitions at larger practices that saw more commercially insured patients compared with practices that were never acquired by private equity firms. The volume of patients per private equity dermatologist ranged from 4.7 percent to 17.0 percent higher than the volume per non-private equity dermatologist up to nine quarters after acquisition. At 1.5 years after acquisition, prices paid to private equity dermatologists for routine medical visits were 3-5 percent higher than those paid to non-private equity dermatologists. There was no significant consistent impact on dermatology spending or use of biopsies, lesion destruction, or Mohs surgery. Policy makers and dermatology practice leaders may want to track the rapidly evolving phenomenon of private equity acquisitions.

Application of Next Generation Sequencing (NGS) in Phage Displayed Peptide Selection to Support the Identification of Arsenic-Binding Motifs.

Next generation sequencing (NGS) in combination with phage surface display (PSD) are powerful tools in the newly equipped molecular biology toolbox for the identification of specific target binding biomolecules. Application of PSD led to the discovery of manifold ligands in clinical and material research. However, limitations of traditional phage display hinder the identification process. Growth-based library biases and target-unrelated peptides often result in the dominance of parasitic sequences and the collapse of library diversity. This study describes the effective enrichment of specific peptide motifs potentially binding to arsenic as proof-of-concept using the combination of PSD and NGS. Arsenic is an environmental toxin, which is applied in various semiconductors as gallium arsenide and selective recovery of this element is crucial for recycling and remediation. The development of biomolecules as specific arsenic-binding sorbents is a new approach for its recovery. Usage of NGS for all biopanning fractions allowed for evaluation of motif enrichment, in-depth insight into the selection process and the discrimination of biopanning artefacts, e.g., the amplification-induced library-wide reduction in hydrophobic amino acid proportion. Application of bioinformatics tools led to the identification of an SxHS and a carboxy-terminal QxQ motif, which are potentially involved in the binding of arsenic. To the best of our knowledge, this is the first report of PSD combined with NGS of all relevant biopanning fractions.

ADAD1 and ADAD2, testis-specific adenosine deaminase domain-containing proteins, are required for male fertility.

Adenosine-to-inosine RNA editing, a fundamental RNA modification, is regulated by adenosine deaminase (AD) domain containing proteins. Within the testis, RNA editing is catalyzed by ADARB1 and is regulated in a cell-type dependent manner. This study examined the role of two testis-specific AD domain proteins, ADAD1 and ADAD2, on testis RNA editing and male germ cell differentiation. ADAD1, previously shown to localize to round spermatids, and ADAD2 had distinct localization patterns with ADAD2 expressed predominantly in mid- to late-pachytene spermatocytes suggesting a role for both in meiotic and post-meiotic germ cell RNA editing. AD domain analysis showed the AD domain of both ADADs was likely catalytically inactive, similar to known negative regulators of RNA editing. To assess the impact of Adad mutation on male germ cell RNA editing, CRISPR-induced alleles of each were generated in mouse. Mutation of either Adad resulted in complete male sterility with Adad1 mutants displaying severe teratospermia and Adad2 mutant germ cells unable to progress beyond round spermatid. However, mutation of neither Adad1 nor Adad2 impacted RNA editing efficiency or site selection. Taken together, these results demonstrate ADAD1 and ADAD2 are essential regulators of male germ cell differentiation with molecular functions unrelated to A-to-I RNA editing.

Identification of EOMES-expressing spermatogonial stem cells and their regulation by PLZF.

Long-term maintenance of spermatogenesis in mammals is supported by GDNF, an essential growth factor required for spermatogonial stem cell (SSC) self-renewal. Exploiting a transgenic GDNF overexpression model, which expands and normalizes the pool of undifferentiated spermatogonia between Plzf +/+ and Plzf lu/lu mice, we used RNAseq to identify a rare subpopulation of cells that express EOMES, a T-box transcription factor. Lineage tracing and busulfan challenge show that these are SSCs that contribute to steady state spermatogenesis as well as regeneration following chemical injury. EOMES+ SSCs have a lower proliferation index in wild-type than in Plzf lu/lu mice, suggesting that PLZF regulates their proliferative activity and that EOMES+ SSCs are lost through proliferative exhaustion in Plzf lu/lu mice. Single cell RNA sequencing of EOMES+ cells from Plzf +/+ and Plzf lu/lu mice support the conclusion that SSCs are hierarchical yet heterogeneous.

Directed Evolution and Engineering of Gallium-Binding Phage Clones-A Preliminary Study.

The phage surface display technology is a useful tool to screen and to extend the spectrum of metal-binding protein structures provided by nature. The directed evolution approach allows identifying specific peptide ligands for metals that are less abundant in the biosphere. Such peptides are attractive molecules in resource technology. For example, gallium-binding peptides could be applied to recover gallium from low concentrated industrial wastewater. In this study, we investigated the affinity and selectivity of five bacteriophage clones displaying different gallium-binding peptides towards gallium and arsenic in independent biosorption experiments. The displayed peptides were highly selective towards Ga3+ whereby long linear peptides showed a lower affinity and specificity than those with a more rigid structure. Cysteine scanning was performed to determine the relationship between secondary peptide structure and gallium sorption. By site-directed mutagenesis, the amino acids of a preselected peptide sequence are systematically replaced by cysteines. The resulting disulphide bridge considerably reduces the flexibility of linear peptides. Subsequent biosorption experiments carried out with the mutants obtained from cysteine scanning demonstrated, depending on the position of the cysteines in the peptide, either a considerable increase in the affinity of gallium compared to arsenic or an increase in the affinity for arsenic compared to gallium. This study shows the impressive effect on peptide-target interaction based on peptide structure and amino acid position and composition via the newly established systematic cysteine scanning approach.

Chromatopanning for the identification of gallium binding peptides.

This study is concerned with a chromatography-based approach (Immobilized Metal Ion Affinity Chromatography) for the recovery of gallium binding peptide sequences from a recombinant phage display library. The here described methods apply the fundamental knowledge and methods of separation science and meet thereby the key requirement of the phage display technique of precise separation of target-binding bacteriophage clones from non-interacting bacteriophage during the biopanning. During the chromatopanning called process, a total of 101 bacteriophage clones were identified of which in subsequent binding experiments, phage clones expressing the peptide sequences TMHHAAIAHPPH, SQALSTSRQDLR and HTQHIQSDDHLA were characterized to bind >10 fold better to a target that presents immobilized gallium ions than control phage, displaying no peptide sequence. The performance of biopanning experiments in chromatographic systems is particularly suitable for demanding targets such as trivalent metal ions. We found, that the selection process benefits immensely from the stable immobilization of the target metal ions during the entire biopanning process as well as the complete recovery of well interacting bacteriophage clones. Among others, this was possible due to an enhanced monitoring of process conditions and fractionation of eluates.

Peptides as biosorbents - Promising tools for resource recovery.

Despite many innovations, meeting both economic and ecological requirements remains challenging for conventional resource recovery technology. The development of highly selective peptides puts a new competitor on the market. We present an approach to identify peptides for resource recovery using Phage Surface Display. Here, we describe the development of peptides for binding of rare earth element terbium-containing solids and for removal and enrichment of the heavy metal ions of cobalt and nickel out of waste waters and leaching solutions. We identified phage displaying specific peptides with ∼100× enhanced affinity towards terbium-containing solids or ∼20× enhanced affinity towards nickel (∼3× cobalt).

Androgen receptor deficiency in monocytes/macrophages does not alter adiposity or glucose homeostasis in male mice.

Androgen deprivation in men leads to increased adiposity, but the mechanisms underlying androgen regulation of fat mass have not been fully defined. Androgen receptor (AR) is expressed in monocytes/macrophages, which are resident in key metabolic tissues and influence energy metabolism in surrounding cells. Male mice bearing a cell-specific knockout of the AR in monocytes/macrophages (M-ARKO) were generated to determine whether selective loss of androgen signaling in these cells would lead to altered body composition. Wild-type (WT) and M-ARKO mice (12-22 weeks of age, n = 12 per group) were maintained on a regular chow diet for 8 weeks and then switched to a high-fat diet for 8 additional weeks. At baseline and on both the regular chow and high-fat diets, no differences in lean mass or fat mass were observed between groups. Consistent with the absence of differential body weight or adiposity, no differences in food intake (3.0 ± 0.5 g per day for WT mice vs 2.8 ± 0.4 g per day for M-ARKO mice) or total energy expenditure (0.6 ± 0.1 Kcal h-1 for WT mice vs 0.5 ± 0.1 Kcal h-1 for M-ARKO mice) were evident between groups during high-fat feeding. Liver weight was greater in M-ARKO than that in WT mice (1.5 ± 0.1 g vs 1.3 ± 0.0 g, respectively, P = 0.02). Finally, M-ARKO mice did not exhibit impairments in glucose tolerance or insulin sensitivity relative to WT mice at any study time point. In aggregate, these findings suggest that AR signaling specifically in monocytes/macrophages does not contribute to the regulation of systemic energy balance, adiposity, or insulin sensitivity in male mice.

Tobacco use and health insurance literacy among vulnerable populations: implications for health reform.

BACKGROUND: Under the Affordable Care Act (ACA), millions of Americans have been enrolling in the health insurance marketplaces. Nearly 20% of them are tobacco users. As part of the ACA, tobacco users may face up to 50% higher premiums that are not eligible for tax credits. Tobacco users, along with the uninsured and racial/ethnic minorities targeted by ACA coverage expansions, are among those most likely to suffer from low health literacy - a key ingredient in the ability to understand, compare, choose, and use coverage, referred to as health insurance literacy. Whether tobacco users choose enough coverage in the marketplaces given their expected health care needs and are able to access health care services effectively is fundamentally related to understanding health insurance. However, no studies to date have examined this important relationship. METHODS: Data were collected from 631 lower-income, minority, rural residents of Virginia. Health insurance literacy was assessed by asking four factual questions about the coverage options presented to them. Adjusted associations between tobacco use and health insurance literacy were tested using multivariate linear regression, controlling for numeracy, risk-taking, discount rates, health status, experiences with the health care system, and demographics. RESULTS: Nearly one third (31%) of participants were current tobacco users, 80% were African American and 27% were uninsured. Average health insurance literacy across all participants was 2.0 (SD 1.1) out of a total possible score of 4. Current tobacco users had significantly lower HIL compared to non-users (-0.22, p < 0.05) after adjustment. Participants who were less educated, African American, and less numerate reported more difficulty understanding health insurance (p < 0.05 each.) CONCLUSIONS: Tobacco users face higher premiums for health coverage than non-users in the individual insurance marketplace. Our results suggest they may be less equipped to shop for plans that provide them with adequate out-of-pocket risk protection, thus placing greater financial burdens on them and potentially limiting access to tobacco cessation and treatment programs and other needed health services.

Testicular adenosine to inosine RNA editing in the mouse is mediated by ADARB1.

Adenosine to inosine (A-to-I) RNA editing occurs in a wide range of tissues and cell types and can be catalyzed by one of the two adenosine deaminase acting on double-stranded RNA enzymes, ADAR and ADARB1. Editing can impact both coding and noncoding regions of RNA, and in higher organisms has been proposed to function in adaptive evolution. Neither the prevalence of A-to-I editing nor the role of either ADAR or ADARB1 has been examined in the context of germ cell development in mammals. Computational analysis of whole testis and cell-type specific RNA-sequencing data followed by molecular confirmation demonstrated that A-to-I RNA editing occurs in both the germ line and in somatic Sertoli cells in two targets, Cog3 and Rpa1. Expression analysis demonstrated both Adar and Adarb1 were expressed in both Sertoli cells and in a cell-type dependent manner during germ cell development. Conditional ablation of Adar did not impact testicular RNA editing in either germ cells or Sertoli cells. Additionally, Adar ablation in either cell type did not have gross impacts on germ cell development or male fertility. In contrast, global Adarb1 knockout animals demonstrated a complete loss of A-to-I RNA editing in spite of normal germ cell development. Taken together, these observations demonstrate ADARB1 mediates A-to-I RNA editing in the testis and these editing events are dispensable for male fertility in an inbred mouse strain in the lab.

APOBEC1 complementation factor (A1CF) is dispensable for C-to-U RNA editing in vivo.

Editing of the human and murine ApoB mRNA by APOBEC1, the catalytic enzyme of the protein complex that catalyzes C-to-U RNA editing, creates an internal stop codon within the APOB coding sequence, generating two protein isoforms. It has been long held that APOBEC1-mediated editing activity is dependent on the RNA binding protein A1CF. The function of A1CF in adult tissues has not been reported because a previously reported null allele displays embryonic lethality. This work aimed to address the function of A1CF in adult mouse tissues using a conditional A1cf allele. Unexpectedly, A1cf-null mice were viable and fertile with modest defects in hematopoietic, immune, and metabolic parameters. C-to-U RNA editing was quantified for multiple targets, including ApoB, in the small intestine and liver. In all cases, no changes in RNA editing efficiency were observed. Blood plasma analysis demonstrated a male-specific increase in solute concentration and increased cellularity in the glomeruli of male A1cf-null mice. Urine analysis showed a reduction in solute concentration, suggesting abnormal water homeostasis and possible kidney abnormalities exclusive to the male. Computational identification of kidney C-to-U editing sites from polyadenylated RNA-sequencing identified a number of editing sites exclusive to the kidney. However, molecular analysis of kidney C-to-U editing showed no changes in editing efficiency with A1CF loss. Taken together, these observations demonstrate that A1CF does not act as the APOBEC1 complementation factor in vivo under normal physiological conditions and suggests new roles for A1CF, specifically within the male adult kidney.

Genetic Architectures of Quantitative Variation in RNA Editing Pathways.

RNA editing refers to post-transcriptional processes that alter the base sequence of RNA. Recently, hundreds of new RNA editing targets have been reported. However, the mechanisms that determine the specificity and degree of editing are not well understood. We examined quantitative variation of site-specific editing in a genetically diverse multiparent population, Diversity Outbred mice, and mapped polymorphic loci that alter editing ratios globally for C-to-U editing and at specific sites for A-to-I editing. An allelic series in the C-to-U editing enzyme Apobec1 influences the editing efficiency of Apob and 58 additional C-to-U editing targets. We identified 49 A-to-I editing sites with polymorphisms in the edited transcript that alter editing efficiency. In contrast to the shared genetic control of C-to-U editing, most of the variable A-to-I editing sites were determined by local nucleotide polymorphisms in proximity to the editing site in the RNA secondary structure. Our results indicate that RNA editing is a quantitative trait subject to genetic variation and that evolutionary constraints have given rise to distinct genetic architectures in the two canonical types of RNA editing.