Evolutionary conservation of VSX2 super-enhancer modules in retinal development.

Super-enhancers (SEs) are expansive regions of genomic DNA that regulate the expression of genes involved in cell identity and cell fate. We recently identified developmental stage- and cell type-specific modules within the murine Vsx2 SE. Here, we show that the human VSX2 SE modules have similar developmental stage- and cell type-specific activity in reporter gene assays. By inserting the human sequence of one VSX2 SE module into a mouse with microphthalmia, eye size was rescued. To understand the function of these SE modules during human retinal development, we deleted individual modules in human embryonic stem cells and generated retinal organoids. Deleting one module results in small organoids, recapitulating the small-eyed phenotype of mice with microphthalmia, while deletion of the other module led to disruptions in bipolar neuron development. This prototypical SE serves as a model for understanding developmental stage- and cell type-specific effects of neurogenic transcription factors with complex expression patterns. Moreover, by elucidating the gene regulatory mechanisms, we can begin to examine how dysregulation of these mechanisms contributes to phenotypic diversity and disease.

[18F]FNDP PET neuroimaging test-retest repeatability and whole-body dosimetry in humans.

PURPOSE: Soluble epoxide hydrolase (sEH) is an enzyme that shapes immune signaling through its role in maintaining the homeostasis of polyunsaturated fatty acids and their related byproducts. [18F]FNDP is a radiotracer developed for use with positron emission tomography (PET) to image sEH, which has been applied to imaging sEH in the brains of healthy individuals. Here, we report the test-retest repeatability of [18F]FNDP brain PET binding and [18F]FNDP whole-body dosimetry in healthy individuals. METHODS: Seven healthy adults (4 men, 3 women, ages 40.1 ± 4.6 years) completed [18F]FNDP brain PET on two occasions within a period of 14 days in a test-retest study design. [18F]FNDP regional total distribution volume (VT) values were derived from modeling time-activity data with a metabolite-corrected arterial input function. Test-retest variability, mean absolute deviation, and intraclass correlation coefficient (ICC) were investigated. Six other healthy adults (3 men, 3 women, ages 46.0 ± 7.0 years) underwent [18F]FNDP PET/CT for whole-body dosimetry, which was acquired over 4.5 h, starting immediately after radiotracer administration. Organ-absorbed doses and the effective dose were then estimated. RESULTS: The mean test-retest difference in regional VT (ΔVT) was 0.82 ± 5.17%. The mean absolute difference in regional VT was 4.01 ± 3.33%. The ICC across different brain regions ranged from 0.92 to 0.99. The organs with the greatest radiation-absorbed doses included the gallbladder (0.081 ± 0.024 mSv/MBq), followed by liver (0.077 ± 0.018 mSv/MBq) and kidneys (0.063 ± 0.006 mSv/MBq). The effective dose was 0.020 ± 0.003 mSv/MBq. CONCLUSION: These data support a favorable test-retest repeatability of [18F]FNDP brain PET regional VT. The radiation dose to humans from each [18F]FNDP PET scan is similar to that of other 18F-based PET radiotracers.

Partisan Polarization of Childhood Vaccination Policies, 1995‒2020.

Objectives. To examine trends in partisan polarization of childhood vaccine bills and the impact of polarization on bill passage in the United States. Methods. We performed content analysis on 1497 US state bills (1995-2020) and obtained voting returns for 228 legislative votes (2011‒2020). We performed descriptive and statistical analyses using 2 measures of polarization. Results. Vote polarization rose more rapidly for immunization than abortion or veterans' affairs bills. Bills in 2019-2020 were more than 7 times more likely to be polarized than in 1995-1996 (odds ratio [OR] = 7.04; 95% confidence interval [CI] = 3.54, 13.99). Bills related to public health emergencies were more polarized (OR = 1.76; 95% CI = 1.13, 2.75). Sponsor polarization was associated with 34% lower odds of passage (OR = 0.66; 95% CI = 0.42, 1.03). Conclusions. State lawmakers were more divided on vaccine policy, but partisan bills were less likely to pass. Bill characteristics associated with lower polarization could signal opportunities for future bipartisanship. Public Health Implications. Increasing partisan polarization could alter state-level vaccine policies in ways that jeopardize childhood immunization rates or weaken responsiveness during public health emergencies. Authorities should look for areas of bipartisan agreement on how to maintain vaccination rates. (Am J Public Health. 2022;112(10):1471-1479. https://doi.org/10.2105/AJPH.2022.306964).

Effective Facilitator Strategies for Supporting Primary Care Practice Change: A Mixed Methods Study.

PURPOSE: Practice facilitation is an evidence-informed implementation strategy to support quality improvement (QI) and aid practices in aligning with best evidence. Few studies, particularly of this size and scope, identify strategies that contribute to facilitator effectiveness. METHODS: We conducted a sequential mixed methods study, analyzing data from EvidenceNOW, a large-scale QI initiative. Seven regional cooperatives employed 162 facilitators to work with 1,630 small or medium-sized primary care practices. Main analyses were based on facilitators who worked with at least 4 practices. Facilitators were defined as more effective if at least 75% of their practices improved on at least 1 outcome measure-aspirin use, blood pressure control, smoking cessation counseling (ABS), or practice change capacity, measured using Change Process Capability Questionnaire-from baseline to follow-up. Facilitators were defined as less effective if less than 50% of their practices improved on these outcomes. Using an immersion crystallization and comparative approach, we analyzed observational and interview data to identify strategies associated with more effective facilitators. RESULTS: Practices working with more effective facilitators had a 3.6% greater change in the mean percentage of patients meeting the composite ABS measure compared with practices working with less effective facilitators (P <.001). More effective facilitators cultivated motivation by tailoring QI work and addressing resistance, guided practices to think critically, and provided accountability to support change, using these strategies in combination. They were able to describe their work in detail. In contrast, less effective facilitators seldom used these strategies and described their work in general terms. Facilitator background, experience, and work on documentation did not differentiate between more and less effective facilitators. CONCLUSIONS: Facilitation strategies that differentiate more and less effective facilitators have implications for enhancing facilitator development and training, and can assist all facilitators to more effectively support practice changes.

Novel Strategy for Untargeted Chiral Metabolomics using Liquid Chromatography-High Resolution Tandem Mass Spectrometry.

Stereospecific recognition of metabolites plays a significant role in the detection of potential disease biomarkers thereby providing new insights in diagnosis and prognosis. D-Hdroxy/amino acids are recognized as potential biomarkers in several metabolic disorders. Despite continuous advances in metabolomics technologies, the simultaneous measurement of different classes of enantiomeric metabolites in a single analytical run remains challenging. Here, we develop a novel strategy for untargeted chiral metabolomics of hydroxy/amine groups (-OH/-NH2) containing metabolites, including all hydroxy acids (HAs) and amino acids (AAs), by chiral derivatization coupled with liquid chromatography-high resolution tandem mass spectrometry (LC-HR-MS/MS). Diacetyl-tartaric anhydride (DATAN) was used for the simultaneous derivatization of-OH/-NH2 containing metabolites as well as the resulting diastereomers, and all the derivatized metabolites were resolved in a single analytical run. Data independent MS/MS acquisition (DIA) was applied to positively identify DATAN-labeled metabolites based on reagent specific diagnostic fragment ions. We discriminated chiral from achiral metabolites based on the reversal of elution order of D and L isomers derivatized with the enantiomeric pair (±) of DATAN in an untargeted manner. Using the developed strategy, a library of 301 standards that consisted of 214 chiral and 87 achiral metabolites were separated and detected in a single analytical run. This approach was then applied to investigate the enantioselective metabolic profile of the bone marrow (BM) and peripheral blood (PB) plasma samples from patients with acute myeloid leukemia (AML) at diagnosis and following completion of the induction phase of chemotherapeutic treatment. The sensitivity and selectivity of the developed method enabled the detection of trace levels of the D-enantiomer of HAs and AAs in primary plasma patient samples. Several of these metabolites were significantly altered in response to chemotherapy. The developed LC-HR-MS method entails a valuable step forward in chiral metabolomics.

Improving Smoking and Blood Pressure Outcomes: The Interplay Between Operational Changes and Local Context.

PURPOSE: We undertook a study to identify conditions and operational changes linked to improvements in smoking and blood pressure (BP) outcomes in primary care. METHODS: We purposively sampled and interviewed practice staff (eg, office managers, clinicians) from a subset of 104 practices participating in EvidenceNOW-a multisite cardiovascular disease prevention initiative. We calculated Clinical Quality Measure improvements, with targets of 10-point or greater absolute improvements in the proportion of patients with smoking screening and, if relevant, counseling and in the proportion of hypertensive patients with adequately controlled BP. We analyzed interview data to identify operational changes, transforming these into numeric data. We used Configurational Comparative Methods to assess the joint effects of multiple factors on outcomes. RESULTS: In clinician-owned practices, implementing a workflow to routinely screen, counsel, and connect patients to smoking cessation resources, or implementing a documentation change or a referral to a resource alone led to an improvement of at least 10 points in the smoking outcome with a moderate level of facilitation support. These patterns did not manifest in health- or hospital system-owned practices or in Federally Qualified Health Centers, however. The BP outcome improved by at least 10 points among solo practices after medical assistants were trained to take an accurate BP. Among larger, clinician-owned practices, BP outcomes improved when practices implemented a second BP measurement when the first was elevated, and when staff learned where to document this information in the electronic health record. With 50 hours or more of facilitation, BP outcomes improved among larger and health- and hospital system-owned practices that implemented these operational changes. CONCLUSIONS: There was no magic bullet for improving smoking or BP outcomes. Multiple combinations of operational changes led to improvements, but only in specific contexts of practice size and ownership, or dose of external facilitation.

Medication Beliefs, HIV-Related Stigmatization, and Adherence to Antiretroviral Therapy: An Examination of Alternative Models.

HIV-related stigma and beliefs about medication necessity and concerns have separately demonstrated significant associations with antiretroviral adherence in people with HIV. However, no work has examined both of these associations in the same model. Based on the necessity-concerns framework, this study examined four alternative models of relationships among HIV-related stigma, medication beliefs, and adherence. Cross-sectional analyses were used to test the four alternative models to best depict associations among HIV-related stigma, medication beliefs, and medication adherence. Models tested included two indirect effects models, an interaction model, and a simple predictors model with no interaction or indirect effects. The outcome variable was HIV medication adherence, and model fit was determined by variance accounted for, Akaike information criterion (AIC), and Bayesian information criterion (BIC) values. An interaction model between internalized stigma and medication concerns accounted for the most variance in adherence. There was also a significant indirect effect of internalized stigma on adherence via medication concerns. Medication concerns are a promising target for interventions focusing on increasing adherence among people with HIV.

Identification of a synergistic combination of dimethylaminoparthenolide and shikonin alters metabolism and inhibits proliferation of pediatric precursor-B cell acute lymphoblastic leukemia.

Exploiting metabolic vulnerabilities of cancer cells with nontoxic, plant derived compounds constitutes a novel strategy for both chemoprevention and treatment. A high-throughput screening approach was used to evaluate a library of natural products to determine the most synergistic combination in precursor-B cell acute lymphoblast leukemia. Dimethylaminoparthenolide and shikonin effectively inhibited proliferation resulting in cell death in primary and immortalized leukemia cells, while having negligible effects on normal cells. Dimethylaminoparthenolide and shikonin have been shown separately to inhibit cell survival and proliferative signaling and activate tumor suppressors and proapoptotic pathways. Untargeted metabolomics and metabolic flux analysis with stable isotopically labeled glucose and glutamine exhibited a global shift in metabolism following treatment. Pathway analysis indicated significant differences in amino acid, antioxidant, tricarboxylic acid cycle, and nucleotide metabolism. Together, dimethylaminoparthenolide and shikonin reduced the shunting of glycolytic intermediates into the pentose phosphate pathway for biosynthetic purposes. Similarly, the incorporation of glutamine and glutamine-derived metabolites into purine and pyrimidine synthesis was inhibited by the combination of dimethylaminoparthenolide and shikonin, effectively impeding biosynthetic pathways critical for leukemia cell survival. This approach demonstrates that a synergistic pair of compounds with malignant cell specificity can effectively target metabolic pathways crucial to leukemia cell proliferation and induce apoptosis.

Deletion of the neural tube defect-associated gene Mthfd1l disrupts one-carbon and central energy metabolism in mouse embryos.

One-carbon (1C) metabolism is a universal folate-dependent pathway essential for de novo purine and thymidylate synthesis, amino acid interconversion, universal methyl-donor production, and regeneration of redox cofactors. Homozygous deletion of the 1C pathway gene Mthfd1l encoding methylenetetrahydrofolate dehydrogenase (NADP+-dependent) 1-like, which catalyzes mitochondrial formate production from 10-formyltetrahydrofolate, results in 100% penetrant embryonic neural tube defects (NTDs), underscoring the central role of mitochondrially derived formate in embryonic development and providing a mechanistic link between folate and NTDs. However, the specific metabolic processes that are perturbed by Mthfd1l deletion are not known. Here, we performed untargeted metabolomics on whole Mthfd1l-null and wildtype mouse embryos in combination with isotope tracer analysis in mouse embryonic fibroblast (MEF) cell lines to identify Mthfd1l deletion-induced disruptions in 1C metabolism, glycolysis, and the TCA cycle. We found that maternal formate supplementation largely corrects these disruptions in Mthfd1l-null embryos. Serine tracer experiments revealed that Mthfd1l-null MEFs have altered methionine synthesis, indicating that Mthfd1l deletion impairs the methyl cycle. Supplementation of Mthfd1l-null MEFs with formate, hypoxanthine, or combined hypoxanthine and thymidine restored their growth to wildtype levels. Thymidine addition alone was ineffective, suggesting a purine synthesis defect in Mthfd1l-null MEFs. Tracer experiments also revealed lower proportions of labeled hypoxanthine and inosine monophosphate in Mthfd1l-null than in wildtype MEFs, suggesting that Mthfd1l deletion results in increased reliance on the purine salvage pathway. These results indicate that disruptions of mitochondrial 1C metabolism have wide-ranging consequences for many metabolic processes, including those that may not directly interact with 1C metabolism.

Association of Depressive Symptoms with Lapses in Antiretroviral Medication Adherence Among People Living with HIV: A Test of an Indirect Pathway.

Viral suppression, a critical component of HIV care, is more likely when individuals initiate antiretroviral therapy (ART) early in disease progression and maintain optimal levels of adherence to ART regimens. Although several studies have documented the negative association of depressive symptoms with ART adherence, less is known about how depressed mood relates to intentional versus unintentional lapses in adherence as well as the mechanisms underlying this association. The purpose of the current study was to examine the association of depressive symptoms with ART adherence, assessed as a multidimensional construct. Secondarily, this study conducted preliminary indirect path models to determine if medication self-efficacy could explain the depressed mood-adherence relationship. Depressive symptoms were not associated with 95% ART taken, self-reported viral load, deliberate adjustments to ART regimens or skipped ART doses. However, the indirect association of depressive symptoms via decrements in medication self-efficacy was significant for 95% ART taken, self-reported viral load and skipped ART doses, but not deliberate changes to ART regimens. In this sample of HIV-positive outpatients, there is evidence to support medication self-efficacy as a potential mechanism underlying the association between depressive symptoms and ART adherence. Additional longitudinal studies are needed to formally examine medication taking self-efficacy as a mediator.

Correction to: Association of Depressive Symptoms with Lapses in Antiretroviral Medication Adherence Among People Living with HIV: A Test of an Indirect Pathway.

The original version of this article unfortunately contained a mistake in Fig. 1. The figure was incorrectly presented with the results of an additional path model for forgotten antiretroviral therapy (ART) doses that was dropped from the primary analyses.

Depressive Symptoms and Condomless Sex Among Men Who Have Sex with Men Living with HIV: A Curvilinear Association.

Depressive symptoms are highly prevalent among HIV-positive men who have sex with men (MSM) and may contribute to risky health behaviors. However, research linking depressed mood to condomless sex in HIV-positive MSM has yielded mixed findings and has focused primarily on testing for a linear association. In the current study, we tested both linear and curvilinear models to assess the association of depressive symptoms to condomless anal sex for the most recent sexual episode in a sample of MSM living with HIV (N = 96, M age = 44, 57% Caucasian). Participants completed the Center for Epidemiological Studies-Depression Scale and self-reported on their sexual behaviors. Findings confirmed a curvilinear association of depressive symptoms with condomless anal sex for encounters involving non-primary partner: MSM with moderate levels of depressed mood were more likely to report non-condom use compared to those with low and high levels of depressive symptoms. Future research should test whether treatment for depression can serve to enhance the impact of sexual health promotion interventions for MSM.

The Association of HIV-Related Stigma to HIV Medication Adherence: A Systematic Review and Synthesis of the Literature.

This paper provides a review of the quantitative literature on HIV-related stigma and medication adherence, including: (1) synthesis of the empirical evidence linking stigma to adherence, (2) examination of proposed causal mechanisms of the stigma and adherence relationship, and (3) methodological critique and guidance for future research. We reviewed 38 studies reporting either cross-sectional or prospective analyses of the association of HIV-related stigma to medication adherence since the introduction of antiretroviral therapies (ART). Although there is substantial empirical evidence linking stigma to adherence difficulties, few studies provided data on psychosocial mechanisms that may account for this relationship. Proposed mechanisms include: (a) enhanced vulnerability to mental health difficulties, (b) reduction in self-efficacy, and (c) concerns about inadvertent disclosure of HIV status. Future research should strive to assess the multiple domains of stigma, use standardized measures of adherence, and include prospective analyses to test mediating variables.

A Follow-Up Community Survey of Knowledge and Beliefs About Cancer and Genetics.

The purpose of this study is to assess changes since the launch of the US Surgeon General's campaign in the public's beliefs about the role of genetics in the etiology of cancer, as well as changes in recording family health history. We conducted a survey of 480 Western New York adults, assessing: (1) experiences with cancer, (2) beliefs about cancer and genetics, and (3) practices of recording family health history. Most respondents were aware of the importance of family history. The sample also showed increased knowledge about cancer and genetics compared with a previous survey. However, only 7 % kept written records that included medical conditions, which was not different from a previous survey. Time constraints, apathy, and reluctance to find out negative health information were the most reported barriers. Results suggest a need for continued education of the public, with increased emphasis on written family health records.

Depressive Symptoms Mediate the Effect of HIV-Related Stigmatization on Medication Adherence Among HIV-Infected Men Who Have Sex with Men.

This study tested the hypothesis that depressive symptoms would mediate the association of HIV-related stigma to medication adherence. We recruited HIV-infected men who have sex with men (MSM; N = 66; 66 % White, 23 % African-American) from an outpatient infectious disease clinic, and asked them to complete self-report measures. Mediational analyses showed that depressive symptoms fully mediated the association between HIV-related stigma and adherence. That is, stigma-related experiences were positively associated with depressive symptoms and negatively associated with adherence, and, in the final model, depressive symptoms remained a significant correlate of adherence while stigma did not. A test of the indirect effect of stigma on adherence through depressive symptoms was also significant (unstandardized b = -0.19; bootstrap 95 % CI -0.45 to -0.01). These results highlight the importance of treating depressive symptoms in interventions aiming to improve medication adherence among HIV-infected MSM.

Spinal Cord Injury Community Personal Opinions and Perspectives on Spinal Cord Stimulation.

Background: Spinal cord stimulation (SCS) clinical trials are evaluating its efficacy and safety for motor, sensory, and autonomic recovery following spinal cord injury (SCI). The perspectives of people living with SCI are not well known and can inform the planning, delivery, and translation of SCS. Objectives: To obtain input from people living with SCI on the top priorities for recovery, expected meaningful benefits, risk tolerance, clinical trial design, and overall interest in SCS. Methods: Data were collected anonymously from an online survey between February and May 2020. Results: A total of 223 respondents living with SCI completed the survey. The majority of respondents identified their gender as male (64%), were 10+ years post SCI (63%), and had a mean age of 50.8 years. Most individuals had a traumatic SCI (81%), and 45% classified themselves as having tetraplegia. Priorities for improved outcome for those with complete or incomplete tetraplegia included fine motor skills and upper body function, whereas priorities for complete or incomplete paraplegia included standing and walking, and bowel function. The meaningful benefits that are important to achieve are bowel and bladder care, less reliance on caregivers, and maintaining physical health. Perceived potential risks include further loss of function, neuropathic pain, and complications. Barriers to participation in clinical trials include inability to relocate, out-of-pocket expenses, and awareness of therapy. Respondents were more interested in transcutaneous SCS than epidural SCS (80% and 61%, respectively). Conclusion: SCS clinical trial design, participant recruitment, and translation of the technology can be improved by better reflecting the priorities and preferences of those living with SCI identified from this study.

How does facilitation in healthcare work? Using mechanism mapping to illuminate the black box of a meta-implementation strategy.

BACKGROUND: Healthcare facilitation, an implementation strategy designed to improve the uptake of effective clinical innovations in routine practice, has produced promising yet mixed results in randomized implementation trials and has not been fully researched across different contexts. OBJECTIVE: Using mechanism mapping, which applies directed acyclic graphs that decompose an effect of interest into hypothesized causal steps and mechanisms, we propose a more concrete description of how healthcare facilitation works to inform its further study as a meta-implementation strategy. METHODS: Using a modified Delphi consensus process, co-authors developed the mechanistic map based on a three-step process. First, they developed an initial logic model by collectively reviewing the literature and identifying the most relevant studies of healthcare facilitation components and mechanisms to date. Second, they applied the logic model to write vignettes describing how facilitation worked (or did not) based on recent empirical trials that were selected via consensus for inclusion and diversity in contextual settings (US, international sites). Finally, the mechanistic map was created based on the collective findings from the vignettes. FINDINGS: Theory-based healthcare facilitation components informing the mechanistic map included staff engagement, role clarification, coalition-building through peer experiences and identifying champions, capacity-building through problem solving barriers, and organizational ownership of the implementation process. Across the vignettes, engagement of leaders and practitioners led to increased socialization of the facilitator's role in the organization. This in turn led to clarifying of roles and responsibilities among practitioners and identifying peer experiences led to increased coherence and sense-making of the value of adopting effective innovations. Increased trust develops across leadership and practitioners through expanded capacity in adoption of the effective innovation by identifying opportunities that mitigated barriers to practice change. Finally, these mechanisms led to eventual normalization and ownership of the effective innovation and healthcare facilitation process. IMPACT: Mapping methodology provides a novel perspective of mechanisms of healthcare facilitation, notably how sensemaking, trust, and normalization contribute to quality improvement. This method may also enable more efficient and impactful hypothesis-testing and application of complex implementation strategies, with high relevance for lower-resourced settings, to inform effective innovation uptake.

Identification of Evolutionarily Conserved VSX2 Enhancers in Retinal Development.

Super-enhancers (SEs) are expansive regions of genomic DNA that regulate the expression of genes involved in cell identity and cell fate. Recently, we found that distinct modules within a murine SE regulate gene expression of master regulatory transcription factor Vsx2 in a developmental stage- and cell-type specific manner. Vsx2 is expressed in retinal progenitor cells as well as differentiated bipolar neurons and Müller glia. Mutations in VSX2 in humans and mice lead to microphthalmia due to a defect in retinal progenitor cell proliferation. Deletion of a single module within the Vsx2 SE leads to microphthalmia. Deletion of a separate module within the SE leads to a complete loss of bipolar neurons, yet the remainder of the retina develops normally. Furthermore, the Vsx2 SE is evolutionarily conserved in vertebrates, suggesting that these modules are important for retinal development across species. In the present study, we examine the ability of these modules to drive retinal development between species. By inserting the human build of one Vsx2 SE module into a mouse with microphthalmia, eye size was rescued. To understand the implications of these SE modules in a model of human development, we generated human retinal organoids. Deleting one module results in small organoids, recapitulating the small-eyed phenotype of mice with microphthalmia, while deletion of the other module leads to a complete loss of ON cone bipolar neurons. This prototypical SE serves as a model for uncoupling developmental stage- and cell-type specific effects of neurogenic transcription factors with complex expression patterns. Moreover, by elucidating the gene regulatory mechanisms, we can begin to examine how dysregulation of these mechanisms contributes to phenotypic diversity and disease.

Pilot imaging of the colony stimulating factor 1 receptor in the brains of virally-suppressed individuals with HIV.

OBJECTIVE: Neuroimmune activation is a putative driver of cognitive impairment in people with HIV (PWH), even in the age of modern antiretroviral therapy. Nevertheless, imaging of the microglial marker, the 18 kDa translocator protein (TSPO), with positron emission tomography (PET) in treated PWH has yielded inconclusive findings. One potential reason for the varied TSPO results is a lack of cell-type specificity of the TSPO target. DESIGN: [ 11 C]CPPC, 5-cyano- N -(4-(4-[ 11 C]methylpiperazin-1-yl)-2-(piperidin-1-yl)phenyl) furan-2-carboxaminde, is a radiotracer for use with PET to image the colony stimulating factor 1 receptor (CSF1R). The CSF1R is expressed on microglia and central nervous system macrophages, with little expression on other cell types. We used [ 11 C]CPPC PET in virally-suppressed- (VS)-PWH and HIV-uninfected individuals to estimate the effect sizes of higher CSF1R in the brains of VS-PWH. METHODS: Sixteen VS-PWH and 15 HIV-uninfected individuals completed [ 11 C]CPPC PET. [ 11 C]CPPC binding (V T ) in nine regions was estimated using a one-tissue compartmental model with a metabolite-corrected arterial input function, and compared between groups. RESULTS: Regional [ 11 C]CPPC V T did not significantly differ between groups after age- and sex- adjustment [unstandardized beta coefficient ( B ) = 1.84, standard error (SE) = 1.18, P  = 0.13]. The effect size was moderate [Cohen's d  = 0.56, 95% confidence interval (CI) -0.16, 1.28), with strongest trend of higher V T in VS-PWH in striatum and parietal cortex (each P  = 0.04; Cohen's d  = 0.71 and 0.72, respectively). CONCLUSIONS: A group difference in [ 11 C]CPPC V T was not observed between VS-PWH and HIV-uninfected individuals in this pilot, although the observed effect sizes suggest the study was underpowered to detect regional group differences in binding.

Glutaminase inhibition in combination with azacytidine in myelodysplastic syndromes: Clinical efficacy and correlative analyses.

Malignancies can become reliant on glutamine as an alternative energy source and as a facilitator of aberrant DNA methylation, thus implicating glutaminase (GLS) as a potential therapeutic target. We demonstrate preclinical synergy of telaglenastat (CB-839), a selective GLS inhibitor, when combined with azacytidine (AZA), in vitro and in vivo, followed by a phase Ib/II study of the combination in patients with advanced MDS. Treatment with telaglenastat/AZA led to an ORR of 70% with CR/mCRs in 53% patients and a median overall survival of 11.6 months. scRNAseq and flow cytometry demonstrated a myeloid differentiation program at the stem cell level in clinical responders. Expression of non-canonical glutamine transporter, SLC38A1, was found to be overexpressed in MDS stem cells; was associated with clinical responses to telaglenastat/AZA and predictive of worse prognosis in a large MDS cohort. These data demonstrate the safety and efficacy of a combined metabolic and epigenetic approach in MDS.