Therapist Anxious Distress and Avoidance of Implementing Time-Out.

Therapist anxious distress when delivering child mental health treatment has been understudied as a factor that contributes to the underuse of some evidence-based interventions (EBIs), such as time-out for children with disruptive behaviors. This study investigated therapist anxious avoidance of time-out using a three-part, vignette-based survey design. Therapists (n = 198) read a vignette of an in-session time-out and reported on their personal anxious distress and likelihood of discontinuing the implementation of time-out. Therapists also provided open-ended descriptions of challenges to delivering time-out. Therapists reported moderate anxious distress at time points 1 and 2 and lower anxious distress at time 3 when the time-out had resolved. Most therapists endorsed some avoidance of time-out. Binomial logistic regression analyses indicated that increased anxious distress corresponded with an increased probability of avoiding time-out delivery in the future. Qualitative reports expanded on challenges to implementing time-out. Findings suggest the importance of addressing therapist anxious distress when implementing children's mental health treatments.

Landscape of brain myeloid cell transcriptome along the spatiotemporal progression of Alzheimer's disease reveals distinct sequential responses to Aß and tau.

Human microglia are critically involved in Alzheimer's disease (AD) progression, as shown by genetic and molecular studies. However, their role in tau pathology progression in human brain has not been well described. Here, we characterized 32 human donors along progression of AD pathology, both in time-from early to late pathology-and in space-from entorhinal cortex (EC), inferior temporal gyrus (ITG), prefrontal cortex (PFC) to visual cortex (V2 and V1)-with biochemistry, immunohistochemistry, and single nuclei-RNA-sequencing, profiling a total of 337,512 brain myeloid cells, including microglia. While the majority of microglia are similar across brain regions, we identified a specific subset unique to EC which may contribute to the early tau pathology present in this region. We calculated conversion of microglia subtypes to diseased states and compared conversion patterns to those from AD animal models. Targeting genes implicated in this conversion, or their upstream/downstream pathways, could halt gene programs initiated by early tau progression. We used expression patterns of early tau progression to identify genes whose expression is reversed along spreading of spatial tau pathology (EC > ITG > PFC > V2 > V1) and identified their potential involvement in microglia subtype conversion to a diseased state. This study provides a data resource that builds on our knowledge of myeloid cell contribution to AD by defining the heterogeneity of microglia and brain macrophages during both temporal and regional pathology aspects of AD progression at an unprecedented resolution.

7-Dehydrocholesterol is an endogenous suppressor of ferroptosis.

Ferroptosis is a form of cell death that has received considerable attention not only as a means to eradicate defined tumour entities but also because it provides unforeseen insights into the metabolic adaptation that tumours exploit to counteract phospholipid oxidation1,2. Here, we identify proferroptotic activity of 7-dehydrocholesterol reductase (DHCR7) and an unexpected prosurvival function of its substrate, 7-dehydrocholesterol (7-DHC). Although previous studies suggested that high concentrations of 7-DHC are cytotoxic to developing neurons by favouring lipid peroxidation3, we now show that 7-DHC accumulation confers a robust prosurvival function in cancer cells. Because of its far superior reactivity towards peroxyl radicals, 7-DHC effectively shields (phospho)lipids from autoxidation and subsequent fragmentation. We provide validation in neuroblastoma and Burkitt's lymphoma xenografts where we demonstrate that the accumulation of 7-DHC is capable of inducing a shift towards a ferroptosis-resistant state in these tumours ultimately resulting in a more aggressive phenotype. Conclusively, our findings provide compelling evidence of a yet-unrecognized antiferroptotic activity of 7-DHC as a cell-intrinsic mechanism that could be exploited by cancer cells to escape ferroptosis.

Adapting to Unprecedented Times: Community Clinician Modifications to Parent-Child Interaction Therapy during COVID-19.

Parent-Child Interaction Therapy (PCIT) is an evidence-based practice that effectively prevents and treats child disruptive behaviors and child physical maltreatment and reduces parenting stress. PCIT was adapted for telehealth delivery, internet-delivered PCIT (iPCIT), before the COVID-19 pandemic but was not widely implemented until the rapid transition to telehealth during stay-at-home orders. To understand how clinicians adapted PCIT during COVID-19, we followed up on a previous study investigating community clinician adaptations of PCIT pre-COVID-19 using the Lau et al. (2017) Augmenting and Reducing Framework. Clinicians (N = 179) who responded to the follow-up survey and reported delivering PCIT remotely completed a quantitative measure of adaptations at both time points (Fall 2019; Summer 2020) to assess how adaptations to PCIT changed following lockdown measures. Clinicians (n = 135) also provided qualitative descriptions of adaptations made early in the COVID-19 pandemic. Clinicians in the full sample were 74.3% Non-Hispanic White and 14% Latinx. Most clinicians had a master's degree (66.5%), were licensed (80.4%), and were PCIT-certified (70.4%). Paired samples t-tests showed that clinicians reported similar levels of augmenting t(179) = -0.09, p=.926) and reducing adaptations t(179) = -0.77, p=.442) at both time points. Unlike quantitative findings, qualitative findings indicated that clinicians described engaging in many types of adaptations in response to the pandemic. Clinicians discussed engaging in augmenting adaptations by extending treatment length and integrating other practices into treatment. Clinicians also discussed engaging in reducing adaptations. Implications and future directions will be discussed.

A Mixed-Methods Study of Clinician Adaptations to Parent-Child Interaction Therapy - What about Culture?

Parent-Child Interaction Therapy (PCIT) is an evidence-based practice (EBP) for young children with challenging behaviors. PCIT has been adapted to treat varying presentations and culturally diverse families. Although efforts have been made to disseminate PCIT into community settings, which often serve clinically complex, socio-culturally diverse, and marginalized communities, barriers to disseminating adapted models remain. An alternative strategy to understanding how to increase access to appropriately adapted PCIT is to learn from community clinicians' practice-based adaptations to meet their clients' diverse needs related to clinical presentation, culture, and language. This mixed-method study investigated community clinician adaptations of PCIT. Clinicians (N = 314) were recruited via PCIT listservs to complete a survey collecting background information, and adaptations to PCIT. Most clinicians had a master's degree (72.1%), were licensed (74.2%), and were PCIT-certified (70.7%). Qualitative interviews were conducted with a purposeful sample of 23 community clinicians, who were 39% Spanish-speaking, were 30% Latinx, and 30% reported serving a ≥50% Latinx clientele. Clinicians reported engaging in adaptations aimed at augmenting PCIT more extensively than adaptations involving removing core components. Themes from qualitative interviews converged with quantitative findings, with clinicians most frequently describing augmenting adaptations, and highlighted reasons for adapting PCIT. Clinicians primarily augmented treatment to address clients' clinical presentations. Clinicians rarely adapted treatment specifically for culture, but when mentioned, clinicians discussed tailoring idioms and phrases to match clients' culture for Spanish-speaking clients. Implications for training PCIT clinicians in intervention adaptations will be discussed.

How do Lay Health Worker Engage Caregivers? A Qualitative Study to Enhance Equity in Evidence-Based Parenting Programs.

Engaging caregivers in their children's mental health treatment is critical for delivering high quality, evidence-based care, particularly for young children with externalizing behaviors. Lay health workers (LHWs), including peer providers and promotoras de salud, have been identified as important workforces in addressing structural and stigma-related barriers to engagement in mental health services. Importantly, research has suggested that LHWs may be integral in efforts to address engagement disparities in evidence-based behavioral parent training programs (BPTs) for Latinx caregivers. The purpose of the study was to understand how different LHW workforces engage caregivers within their usual services, in order to inform strategies that improve access to and engagement in BPTs. Qualitative interviews were conducted with two different LHW workforces: volunteer LHWs (i.e., promotoras de salud) (n = 14), who were part of a community-embedded network, and paid LHWs (i.e., parent support partners, home visitors) (n = 9) embedded within children's mental health agencies. Participants were predominately Latinx (79%) and female (96%). Qualitative analyses revealed three primary themes related to engagement strategies used by LHWs to address barriers to care: 1.) Building Trust, 2.) Empowerment, 3.) Increasing Access. Although the majority of themes and sub-themes were consistent across the two LHW workforces, agency-embedded LHWs often discussed having the means to provide resources through their organizations, whereas community-embedded LHWs discussed acting as a bridge to services by providing information and conducting outreach. Findings have implications for partnering with different workforces of LHWs to increase equity in access to BPTs.

Resistance to mesenchymal reprogramming sustains clonal propagation in metastatic breast cancer.

The acquisition of mesenchymal traits is considered a hallmark of breast cancer progression. However, the functional relevance of epithelial-to-mesenchymal transition (EMT) remains controversial and context dependent. Here, we isolate epithelial and mesenchymal populations from human breast cancer metastatic biopsies and assess their functional potential in vivo. Strikingly, progressively decreasing epithelial cell adhesion molecule (EPCAM) levels correlate with declining disease propagation. Mechanistically, we find that persistent EPCAM expression marks epithelial clones that resist EMT induction and propagate competitively. In contrast, loss of EPCAM defines clones arrested in a mesenchymal state, with concomitant suppression of tumorigenicity and metastatic potential. This dichotomy results from distinct clonal trajectories impacting global epigenetic programs that are determined by the interplay between human ZEB1 and its target GRHL2. Collectively, our results indicate that susceptibility to irreversible EMT restrains clonal propagation, whereas resistance to mesenchymal reprogramming sustains disease spread in multiple models of human metastatic breast cancer, including patient-derived cells in vivo.

Dual truncation of tau by caspase-2 accelerates its CHIP-mediated degradation.

Intraneuronal aggregates of the microtubule binding protein Tau are a hallmark of different neurodegenerative diseases including Alzheimer's disease (AD). In these aggregates, Tau is modified by posttranslational modifications such as phosphorylation as well as by proteolytic cleavage. Here we identify a novel Tau cleavage site at aspartate 65 (D65) that is specific for caspase-2. In addition, we show that the previously described cleavage site at D421 is also efficiently processed by caspase-2, and both sites are cleaved in human brain samples. Caspase-2-generated Tau fragments show increased aggregation potential in vitro, but do not accumulate in vivo after AAV-mediated overexpression in mouse hippocampus. Interestingly, we observe that steady-state protein levels of caspase-2 generated Tau fragments are low in our in vivo model despite strong RNA expression, suggesting efficient clearance. Consistent with this hypothesis, we find that caspase-2 cleavage significantly improves the recognition of Tau by the ubiquitin E3 ligase CHIP, leading to increased ubiquitination and faster degradation of Tau fragments. Taken together our data thus suggest that CHIP-induced ubiquitination is of particular importance for the clearance of caspase-2 generated Tau fragments in vitro and in vivo.

Intervention and Implementation Characteristics to Enhance Father Engagement: A Systematic Review of Parenting Interventions.

In recent years, the prevalence rates of children's mental health disorders have increased with current estimates identifying that as many as 15-20% of children meet criteria for a mental health disorder. Unfortunately, the same robust parenting interventions which have long targeted some of the most common and the most treatable child concerns (e.g., externalizing, disruptive behavior, and aggression) have also shown consistently low rates of father engagement. This persistent issue of engagement comes in the wake of an increasingly large body of literature which highlights the unique positive contributions fathers make to children and families when they are engaged in parenting interventions. As the role fathers play in families shifts to become more inclusive of childcare responsibilities and less narrowly defined by financial contributions, it becomes increasingly important to understand how best to engage fathers in interventions that aim to enhance parenting efficacy and family outcomes such as coparenting. The current review examined intervention (e.g., format and setting) and implementation characteristics (e.g., training and agency-level changes) associated with father engagement. Particular attention is paid to studies which described father-specific engagement strategies (e.g., inviting fathers directly, father-only groups, and adapting intervention to incorporate father preferences). A total of 26 articles met inclusion criteria after screening and full-text review. Results indicate that father engagement (i.e., initiating treatment) remains low with 58% of studies either not reporting father engagement or having engagement rates below 50%. More than two-thirds of studies did not include specific father engagement strategies. Those that did focused on changes to treatment format (e.g., including recreational activities), physical treatment setting (e.g., in-home and school), and reducing the number of sessions required for father participation as the most common father-specific engagement strategies. Some studies reported efforts to target racially and ethnically diverse fathers, but review results indicated most participants identified as Non-Hispanic White. Interventions were largely standard behavioral parent training programs (e.g., PCIT and PMT) with few exceptions (e.g., COACHES and cultural adaptations), and very few agencies or programs are systematically making adjustments (e.g., extended clinic hours and changes to treatment format) to engage fathers. Recommendations for future directions of research are discussed including the impact of differential motivation on initial father engagement in treatment, the importance of continuing to support diverse groups of fathers, and the potential for telehealth to address barriers to father engagement.

Retained functional normal and preleukemic HSCs at diagnosis are associated with good prognosis in DNMT3AmutNPM1mut AMLs.

Acute myeloid leukemia (AML) is a heterogeneous disease characterized by high rate of relapse and mortality. Current chemotherapies whilst successful in eradicating blasts, are less effective in eliminating relapse-causing leukemic stem cells (LSCs). Although LSCs are usually identified as CD34+CD38- cells, there is significant heterogeneity in surface marker expression, and CD34- LSCs exist particularly in NPM1mut AMLs. By analyzing diagnostic primary DNMT3AmutNPM1mut AML samples, we suggest a novel flow cytometry sorting strategy particularly useful for CD34neg AML subtypes. To enrich for LSCs independently of CD34 status, positive selection for GPR56 and negative selection for NKG2D ligands are used. We show that the functional reconstitution capacity of CD34- and CD34+ LSCs as well as their transcriptomes are very similar which support phenotypic plasticity. Furthermore, we show that although CD34+ subpopulations can contain next to LSCs also normal and/or preleukemic hematopoietic stem cells (HSCs), this is not the case in CD34-GPR56+NKG2DL- enriched LSCs which thus can be isolated with high purity. Finally, we show that patients with AML, who retain at the time of diagnosis a reserve of normal and/or preleukemic HSCs in their bone marrow able to reconstitute immunocompromised mice, have significantly longer relapse-free and overall survival than patients with AML in whom functional HSCs are no longer detectable.

Clinician Maladaptive Anxious Avoidance in the Context of Implementation of Evidence-Based Interventions: A Commentary.

This paper posits that a clinician's own anxious reaction to delivering specific evidence-based interventions (EBIs) should be better accounted for within implementation science frameworks. A key next step for implementation science is to delineate the causal processes most likely to influence successful implementation of evidence-based interventions (EBIs). This is critical for being able to develop tailored implementation strategies that specifically target mechanisms by which implementation succeeds or fails. First, we review the literature on specific EBIs that may act as negatively valenced stimuli for clinicians, leading to a process of clinician maladaptive anxious avoidance that can negatively impact EBI delivery. In the following sections, we argue that there are certain EBIs that can cause emotional distress or discomfort in a clinician, related to either: (1) a clinicians' fear of the real or predicted short-term distress the EBI can cause patients, or (2) fears that the clinician will inadvertently cause the patient harm and/or face liability. This distress experienced by the clinician can perpetuate a cycle of maladaptive anxious avoidance by the clinician, contributing to lack of or suboptimal EBI implementation. We illustrate how this cycle of maladaptive anxious avoidance can influence implementation by providing several examples from leading EBIs in the psychosocial literature. To conclude, we discuss how leveraging decades of treatment literature aimed at mitigating maladaptive anxious avoidance can inform the design of more tailored and effective implementation strategies for EBIs that are negatively valenced.

Antigen presentation safeguards the integrity of the hematopoietic stem cell pool.

Hematopoietic stem and progenitor cells (HSPCs) are responsible for the production of blood and immune cells. Throughout life, HSPCs acquire oncogenic aberrations that can cause hematological cancers. Although molecular programs maintaining stem cell integrity have been identified, safety mechanisms eliminating malignant HSPCs from the stem cell pool remain poorly characterized. Here, we show that HSPCs constitutively present antigens via major histocompatibility complex class II. The presentation of immunogenic antigens, as occurring during malignant transformation, triggers bidirectional interactions between HSPCs and antigen-specific CD4+ T cells, causing stem cell proliferation, differentiation, and specific exhaustion of aberrant HSPCs. This immunosurveillance mechanism effectively eliminates transformed HSPCs from the hematopoietic system, thereby preventing leukemia onset. Together, our data reveal a bidirectional interaction between HSPCs and CD4+ T cells, demonstrating that HSPCs are not only passive receivers of immunological signals but also actively engage in adaptive immune responses to safeguard the integrity of the stem cell pool.

MYCN mediates cysteine addiction and sensitizes neuroblastoma to ferroptosis.

Aberrant expression of MYC transcription factor family members predicts poor clinical outcome in many human cancers. Oncogenic MYC profoundly alters metabolism and mediates an antioxidant response to maintain redox balance. Here we show that MYCN induces massive lipid peroxidation on depletion of cysteine, the rate-limiting amino acid for glutathione (GSH) biosynthesis, and sensitizes cells to ferroptosis, an oxidative, non-apoptotic and iron-dependent type of cell death. The high cysteine demand of MYCN-amplified childhood neuroblastoma is met by uptake and transsulfuration. When uptake is limited, cysteine usage for protein synthesis is maintained at the expense of GSH triggering ferroptosis and potentially contributing to spontaneous tumor regression in low-risk neuroblastomas. Pharmacological inhibition of both cystine uptake and transsulfuration combined with GPX4 inactivation resulted in tumor remission in an orthotopic MYCN-amplified neuroblastoma model. These findings provide a proof of concept of combining multiple ferroptosis targets as a promising therapeutic strategy for aggressive MYCN-amplified tumors.

Tau in the brain interstitial fluid is fragmented and seeding-competent.

In Alzheimer disease, Tau pathology is thought to propagate from cell to cell throughout interconnected brain areas. However, the forms of Tau released into the brain interstitial fluid (ISF) in vivo during the development of Tauopathy and their pathological relevance remain unclear. Combining in vivo microdialysis and biochemical analysis, we find that in Tau transgenic mice, human Tau (hTau) present in brain ISF is truncated and comprises at least 10 distinct fragments spanning the entire Tau protein. The fragmentation pattern is similar across different Tau transgenic models, pathological stages and brain areas. ISF hTau concentration decreases during Tauopathy progression, while its phosphorylation increases. ISF from mice with established Tauopathy induces Tau aggregation in HEK293-Tau biosensor cells. Notably, immunodepletion of ISF phosphorylated Tau, but not Tau fragments, significantly reduces its ability to seed Tau aggregation and only a fraction of Tau, separated by ultracentrifugation, is seeding-competent. These results indicate that ISF seeding competence is driven by a small subset of Tau, which potentially contribute to the propagation of Tau pathology.

Improving the Quality of Children's Mental Health Care with Progress Measures: A Mixed-Methods Study of PCIT Therapist Attitudes.

Progress measures are an evidence-based technique for improving the quality of mental health care, however, clinicians rarely incorporate them into treatment. Research into how measure type impacts clinician preference has been recommended to help improve measure implementation. Parent-Child Interaction Therapy (PCIT) is an assessment-driven treatment that serves as an ideal intervention through which to investigate measure preferences given its routine use of two types of assessments, a behavioral observation (the Dyadic Parent-Child Interaction Coding System) and a parent-report measure (the Eyberg Child Behavior Inventory). This study investigated PCIT therapist attitudes towards progress measures used within PCIT and children's mental health treatment generally. A mixed-method (QUAN + QUAL) study design examined PCIT therapist attitudes towards two types of progress measures and measures used in two contexts (PCIT and general practice). Multi-level modeling of a survey distributed to 324 PCIT therapists identified predictors of therapist attitudes towards measures, while qualitative interviews with 23 therapists expanded and clarified the rationale for differing perceptions. PCIT therapists reported more positive attitudes towards a behavioral observation measure, the DPICS, than a parent-report measure, the ECBI, and towards measures used in PCIT than in general practice. Clinician race/ethnicity was significantly related to measure-specific attitudes. Qualitative interviews highlighted how perceptions of measure reliability, type of data offered, ease of use, utility in guiding sessions and motivating clients, and embeddedness in treatment protocol impact therapist preferences. Efforts to implement progress monitoring should consider preferences for particular types of measures, as well as how therapists are trained to embed measures in treatment.

Elezanumab, a clinical stage human monoclonal antibody that selectively targets repulsive guidance molecule A to promote neuroregeneration and neuroprotection in neuronal injury and demyelination models.

Repulsive guidance molecule A (RGMa) is a potent inhibitor of axonal growth and a regulator of neuronal cell death. It is up-regulated following neuronal injury and accumulates in chronic neurodegenerative diseases. Neutralizing RGMa has the potential to promote neuroregeneration and neuroprotection. Previously we reported that a rat anti-N terminal RGMa (N-RGMa) antibody r5F9 and its humanized version h5F9 (ABT-207) promote neuroprotection and neuroregeneration in preclinical neurodegenerative disease models. However, due to its cross-reactivity to RGMc/hemojuvelin, ABT-207 causes iron accumulation in vivo, which could present a safety liability. Here we report the generation and characterization of a novel RGMa-selective anti-N-RGMa antibody elezanumab, which is currently under Phase 2 clinical evaluation in multiple disease indications. Elezanumab, a human monoclonal antibody generated by in vitro PROfusion mRNA display technology, competes with ABT-207 in binding to N-RGMa but lacks RGMc cross-reactivity with no impact on iron metabolism. It neutralizes repulsive activity of soluble RGMa in vitro and blocks membrane RGMa mediated BMP signaling. In the optic nerve crush and optic neuritis models, elezanumab promotes axonal regeneration and prevents retinal nerve fiber layer degeneration. In the spinal targeted experimental autoimmune encephalomyelitis (EAE) model, elezanumab promotes axonal regeneration and remyelination, decreases inflammatory lesion area and improves functional recovery. Finally, in the mouse cuprizone model, elezanumab reduces demyelination, which is consistent with its inhibitory effect on BMP signaling. Taken together, these preclinical data demonstrate that elezanumab has neuroregenerative and neuroprotective activities without impact on iron metabolism, thus providing a compelling rationale for its clinical development in neurodegenerative diseases.

Aggressive PDACs Show Hypomethylation of Repetitive Elements and the Execution of an Intrinsic IFN Program Linked to a Ductal Cell of Origin.

Pancreatic ductal adenocarcinoma (PDAC) is characterized by extensive desmoplasia, which challenges the molecular analyses of bulk tumor samples. Here we FACS-purified epithelial cells from human PDAC and normal pancreas and derived their genome-wide transcriptome and DNA methylome landscapes. Clustering based on DNA methylation revealed two distinct PDAC groups displaying different methylation patterns at regions encoding repeat elements. Methylationlow tumors are characterized by higher expression of endogenous retroviral transcripts and double-stranded RNA sensors, which lead to a cell-intrinsic activation of an interferon signature (IFNsign). This results in a protumorigenic microenvironment and poor patient outcome. Methylationlow/IFNsignhigh and Methylationhigh/IFNsignlow PDAC cells preserve lineage traits, respective of normal ductal or acinar pancreatic cells. Moreover, ductal-derived Kras G12D/Trp53 -/- mouse PDACs show higher expression of IFNsign compared with acinar-derived counterparts. Collectively, our data point to two different origins and etiologies of human PDACs, with the aggressive Methylationlow/IFNsignhigh subtype potentially targetable by agents blocking intrinsic IFN signaling. SIGNIFICANCE: The mutational landscapes of PDAC alone cannot explain the observed interpatient heterogeneity. We identified two PDAC subtypes characterized by differential DNA methylation, preserving traits from normal ductal/acinar cells associated with IFN signaling. Our work suggests that epigenetic traits and the cell of origin contribute to PDAC heterogeneity.This article is highlighted in the In This Issue feature, p. 521.

The proteomic landscape of small urinary extracellular vesicles during kidney transplantation.

Kidney transplantation is the preferred renal replacement therapy available. Yet, long-term transplant survival is unsatisfactory, partially due to insufficient possibilities of longitudinal monitoring and understanding of the biological processes after transplantation. Small urinary extracellular vesicles (suEVs) - as a non-invasive source of information - were collected from 22 living donors and recipients. Unbiased proteomic analysis revealed temporal patterns of suEV protein signature and cellular processes involved in both early response and longer-term graft adaptation. Complement activation was among the most dynamically regulated components. This unique atlas of the suEV proteome is provided through an online repository allowing dynamic interrogation by the user. Additionally, a correlative analysis identified putative prognostic markers of future allograft function. One of these markers - phosphoenol pyruvate carboxykinase (PCK2) - could be confirmed using targeted MS in an independent validation cohort of 22 additional patients. This study sheds light on the impact of kidney transplantation on urinary extracellular vesicle content and allows the first deduction of early molecular processes in transplant biology. Beyond that our data highlight the potential of suEVs as a source of biomarkers in this setting.

Collaborating with health economists to advance implementation science: a qualitative study.

BACKGROUND: Implementation research infrequently addresses economic factors, despite the importance of understanding the costs of implementing evidence-based practices (EBPs). Though partnerships with health economists have the potential to increase attention to economic factors within implementation science, barriers to forming these collaborations have been noted. This study investigated the experiences of health economists and implementation researchers who have partnered across disciplines to inform strategies to increase such collaborations. METHODS: A purposeful sampling approach was used to identify eight health economists and eight implementation researchers with experience participating in cross-disciplinary research. We used semi-structured interviews to gather information about participants' experiences with collaborative research. Thematic analysis was conducted to identify core themes related to facilitators and barriers to collaborations. RESULTS: Health economists and implementation researchers voiced different perspectives on collaborative research, highlighting the importance of increasing cross-disciplinary understanding. Implementation researchers described a need to measure costs in implementation studies, whereas many health economists described that they seek to collaborate on projects that extend beyond conducting cost analyses. Researchers in both disciplines articulated motivations for collaborative research and identified strategies that promote successful collaboration, with varying degrees of convergence across these themes. Shared motivations included improving methodological rigor of research and making a real-world impact. Strategies to improve collaboration included starting partnerships early in the study design period, having a shared interest, and including health economists in the larger scope of the research. CONCLUSIONS: Health economists and implementation researchers both conduct research with significant policy implications and have the potential to inform one another's work in ways that might more rapidly advance the uptake of EBPs. Collaborative research between health economists and implementation science has the potential to advance the field; however, researchers will need to work to bridge disciplinary differences. By beginning to develop strong working relationships; increasing their understanding of one another's disciplinary culture, methodology, and language; and increasing the role economists have within research design and execution, both implementation researchers and health economists can support successful collaborations and robust and informative research.

Novel Non-integrating DNA Nano-S/MAR Vectors Restore Gene Function in Isogenic Patient-Derived Pancreatic Tumor Models.

We describe herein non-integrating minimally sized nano-S/MAR DNA vectors, which can be used to genetically modify dividing cells in place of integrating vectors. They represent a unique genetic tool, which avoids vector-mediated damage. Previous work has shown that DNA vectors comprising a mammalian S/MAR element can provide persistent mitotic stability over hundreds of cell divisions, resisting epigenetic silencing and thereby allowing sustained transgene expression. The composition of the original S/MAR vectors does present some inherent limitations that can provoke cellular toxicity. Herein, we present a new system, the nano-S/MAR, which drives higher transgene expression and has improved efficiency of establishment, due to the minimal impact on cellular processes and perturbation of the endogenous transcriptome. We show that these features enable the hitherto challenging genetic modification of patient-derived cells to stably restore the tumor suppressor gene SMAD4 to a patient-derived SMAD4 knockout pancreatic cancer line. Nano-S/MAR modification does not alter the molecular or phenotypic integrity of the patient-derived cells in cell culture and xenograft mouse models. In conclusion, we show that these DNA vectors can be used to persistently modify a range of cells, providing sustained transgene expression while avoiding the risks of insertional mutagenesis and other vector-mediated toxicity.