Distinct Mesenchymal Lineages and Niches Promote Epithelial Self-Renewal and Myofibrogenesis in the Lung.

The lung is an architecturally complex organ comprising a heterogeneous mixture of various epithelial and mesenchymal lineages. We use single-cell RNA sequencing and signaling lineage reporters to generate a spatial and transcriptional map of the lung mesenchyme. We find that each mesenchymal lineage has a distinct spatial address and transcriptional profile leading to unique niche regulatory functions. The mesenchymal alveolar niche cell is Wnt responsive, expresses Pdgfrα, and is critical for alveolar epithelial cell growth and self-renewal. In contrast, the Axin2+ myofibrogenic progenitor cell preferentially generates pathologically deleterious myofibroblasts after injury. Analysis of the secretome and receptome of the alveolar niche reveals functional pathways that mediate growth and self-renewal of alveolar type 2 progenitor cells, including IL-6/Stat3, Bmp, and Fgf signaling. These studies define the cellular and molecular framework of lung mesenchymal niches and reveal the functional importance of developmental pathways in promoting self-renewal versus a pathological response to tissue injury.

Fennoscandian tree-ring anatomy shows a warmer modern than medieval climate.

Earth system models and various climate proxy sources indicate global warming is unprecedented during at least the Common Era1. However, tree-ring proxies often estimate temperatures during the Medieval Climate Anomaly (950-1250 CE) that are similar to, or exceed, those recorded for the past century2,3, in contrast to simulation experiments at regional scales4. This not only calls into question the reliability of models and proxies but also contributes to uncertainty in future climate projections5. Here we show that the current climate of the Fennoscandian Peninsula is substantially warmer than that of the medieval period. This highlights the dominant role of anthropogenic forcing in climate warming even at the regional scale, thereby reconciling inconsistencies between reconstructions and model simulations. We used an annually resolved 1,170-year-long tree-ring record that relies exclusively on tracheid anatomical measurements from Pinus sylvestris trees, providing high-fidelity measurements of instrumental temperature variability during the warm season. We therefore call for the construction of more such millennia-long records to further improve our understanding and reduce uncertainties around historical and future climate change at inter-regional and eventually global scales.

Dynamic Hippo pathway activity underlies mesenchymal differentiation during lung alveolar morphogenesis.

Alveologenesis, the final stage in lung development, substantially remodels the distal lung, expanding the alveolar surface area for efficient gas exchange. Secondary crest myofibroblasts (SCMF) exist transiently in the neonatal distal lung and are crucial for alveologenesis. However, the pathways that regulate SCMF function, proliferation and temporal identity remain poorly understood. To address this, we purified SCMFs from reporter mice, performed bulk RNA-seq and found dynamic changes in Hippo-signaling components during alveologenesis. We deleted the Hippo effectors Yap/Taz from Acta2-expressing cells at the onset of alveologenesis, causing a significant arrest in alveolar development. Using single cell RNA-seq, we identified a distinct cluster of cells in mutant lungs with altered expression of marker genes associated with proximal mesenchymal cell types, airway smooth muscle and alveolar duct myofibroblasts. In vitro studies confirmed that Yap/Taz regulates myofibroblast-associated gene signature and contractility. Together, our findings show that Yap/Taz is essential for maintaining functional myofibroblast identity during postnatal alveologenesis.

Retraction Note: Fatty acids and cancer-amplified ZDHHC19 promote STAT3 activation through S-palmitoylation.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

CXCL12 defines lung endothelial heterogeneity and promotes distal vascular growth.

There is a growing amount of data uncovering the cellular diversity of the pulmonary circulation and mechanisms governing vascular repair after injury. However, the molecular and cellular mechanisms contributing to the morphogenesis and growth of the pulmonary vasculature during embryonic development are less clear. Importantly, deficits in vascular development lead to significant pediatric lung diseases, indicating a need to uncover fetal programs promoting vascular growth. To address this, we used a transgenic mouse reporter for expression of Cxcl12, an arterial endothelial hallmark gene, and performed single-cell RNA sequencing on isolated Cxcl12-DsRed+ endothelium to assess cellular heterogeneity within pulmonary endothelium. Combining cell annotation with gene ontology and histological analysis allowed us to segregate the developing artery endothelium into functionally and spatially distinct subpopulations. Expression of Cxcl12 is highest in the distal arterial endothelial subpopulation, a compartment enriched in genes for vascular development. Accordingly, disruption of CXCL12 signaling led to, not only abnormal branching, but also distal vascular hypoplasia. These data provide evidence for arterial endothelial functional heterogeneity and reveal conserved signaling mechanisms essential for pulmonary vascular development.

Fatty acids and cancer-amplified ZDHHC19 promote STAT3 activation through S-palmitoylation.

Signal transducer and activator of transcription 3 (STAT3) has a critical role in regulating cell fate, inflammation and immunity1,2. Cytokines and growth factors activate STAT3 through kinase-mediated tyrosine phosphorylation and dimerization3,4. It remains unknown whether other factors promote STAT3 activation through different mechanisms. Here we show that STAT3 is post-translationally S-palmitoylated at the SRC homology 2 (SH2) domain, which promotes the dimerization and transcriptional activation of STAT3. Fatty acids can directly activate STAT3 by enhancing its palmitoylation, in synergy with cytokine stimulation. We further identified ZDHHC19 as a palmitoyl acyltransferase that regulates STAT3. Cytokine stimulation increases STAT3 palmitoylation by promoting the association between ZDHHC19 and STAT3, which is mediated by the SH3 domain of GRB2. Silencing ZDHHC19 blocks STAT3 palmitoylation and dimerization, and impairs the cytokine- and fatty-acid-induced activation of STAT3. ZDHHC19 is frequently amplified in multiple human cancers, including in 39% of lung squamous cell carcinomas. High levels of ZDHHC19 correlate with high levels of nuclear STAT3 in patient samples. In addition, knockout of ZDHHC19 in lung squamous cell carcinoma cells significantly blocks STAT3 activity, and inhibits the fatty-acid-induced formation of tumour spheres as well as tumorigenesis induced by high-fat diets in an in vivo mouse model. Our studies reveal that fatty-acid- and ZDHHC19-mediated palmitoylation are signals that regulate STAT3, which provides evidence linking the deregulation of palmitoylation to inflammation and cancer.

Regeneration of the lung alveolus by an evolutionarily conserved epithelial progenitor.

Functional tissue regeneration is required for the restoration of normal organ homeostasis after severe injury. Some organs, such as the intestine, harbour active stem cells throughout homeostasis and regeneration; more quiescent organs, such as the lung, often contain facultative progenitor cells that are recruited after injury to participate in regeneration. Here we show that a Wnt-responsive alveolar epithelial progenitor (AEP) lineage within the alveolar type 2 cell population acts as a major facultative progenitor cell in the distal lung. AEPs are a stable lineage during alveolar homeostasis but expand rapidly to regenerate a large proportion of the alveolar epithelium after acute lung injury. AEPs exhibit a distinct transcriptome, epigenome and functional phenotype and respond specifically to Wnt and Fgf signalling. In contrast to other proposed lung progenitor cells, human AEPs can be directly isolated by expression of the conserved cell surface marker TM4SF1, and act as functional human alveolar epithelial progenitor cells in 3D organoids. Our results identify the AEP lineage as an evolutionarily conserved alveolar progenitor that represents a new target for human lung regeneration strategies.

Single Cell Multiomics Identifies Cells and Genetic Networks Underlying Alveolar Capillary Dysplasia.

Rationale: Alveolar capillary dysplasia with misalignment of pulmonary veins (ACDMPV) is a lethal developmental disorder of lung morphogenesis caused by insufficiency of FOXF1 (forkhead box F1) transcription factor function. The cellular and transcriptional mechanisms by which FOXF1 deficiency disrupts human lung formation are unknown. Objectives: To identify cell types, gene networks, and cell-cell interactions underlying the pathogenesis of ACDMPV. Methods: We used single-nucleus RNA and assay for transposase-accessible chromatin sequencing, immunofluorescence confocal microscopy, and RNA in situ hybridization to identify cell types and molecular networks influenced by FOXF1 in ACDMPV lungs. Measurements and Main Results: Pathogenic single-nucleotide variants and copy-number variant deletions involving the FOXF1 gene locus in all subjects with ACDMPV (n = 6) were accompanied by marked changes in lung structure, including deficient alveolar development and a paucity of pulmonary microvasculature. Single-nucleus RNA and assay for transposase-accessible chromatin sequencing identified alterations in cell number and gene expression in endothelial cells (ECs), pericytes, fibroblasts, and epithelial cells in ACDMPV lungs. Distinct cell-autonomous roles for FOXF1 in capillary ECs and pericytes were identified. Pathogenic variants involving the FOXF1 gene locus disrupt gene expression in EC progenitors, inhibiting the differentiation or survival of capillary 2 ECs and cell-cell interactions necessary for both pulmonary vasculogenesis and alveolar type 1 cell differentiation. Loss of the pulmonary microvasculature was associated with increased VEGFA (vascular endothelial growth factor A) signaling and marked expansion of systemic bronchial ECs expressing COL15A1 (collagen type XV α 1 chain). Conclusions: Distinct FOXF1 gene regulatory networks were identified in subsets of pulmonary endothelial and fibroblast progenitors, providing both cellular and molecular targets for the development of therapies for ACDMPV and other diffuse lung diseases of infancy.

A longitudinal investigation of breastfeeding planning, initiation, and duration among individuals with pre-pregnancy overweight or obesity.

Individuals with a body mass index (BMI)≥25 kg/m2 are less likely to initiate and continue breastfeeding than are those with BMIs<25. Given the intergenerational health benefits of breastfeeding, it is important to understand breastfeeding behaviors and their correlates among individuals with BMIs≥25. Thus, in an observational cohort with BMI≥25 (N = 237), we aimed to characterize longitudinal relationships among breastfeeding planning, initiation, and duration and their sociodemographic/clinical correlates and determine if pre-pregnancy BMI predicts breastfeeding planning, initiation, and duration. Breastfeeding behaviors, weight/BMI, and sociodemographic/clinical characteristics were assessed in early, mid, and late pregnancy, and at six-months postpartum. Most participants planned to (84%) and initiated (81%) breastfeeding, of which 37% breastfed for ≥6 months. Participants who were married, first-time parents, higher in education/income, and had never smoked tobacco were more likely to plan, initiate, and achieve ≥6 months of breastfeeding. Higher pre-pregnancy BMI was not associated with breastfeeding planning or initiation but was associated with lower adjusted odds of breastfeeding for ≥6 months relative to <6 months. Findings suggest that support aimed at extending breastfeeding among those with elevated pre-pregnancy BMI may be warranted. Future interventions should also address sociodemographic and clinical inequities in breastfeeding.

Disparities in Guideline-Recommended Statin Use for Prevention of Atherosclerotic Cardiovascular Disease by Race, Ethnicity, and Gender : A Nationally Representative Cross-Sectional Analysis of Adults in the United States.

BACKGROUND: Although statins are a class I recommendation for prevention of atherosclerotic cardiovascular disease and its complications, their use is suboptimal. Differential underuse may mediate disparities in cardiovascular health for systematically marginalized persons. OBJECTIVE: To estimate disparities in statin use by race-ethnicity-gender and to determine whether these potential disparities are explained by medical appropriateness of therapy and structural factors. DESIGN: Cross-sectional analysis. SETTING: National Health and Nutrition Examination Survey from 2015 to 2020. PARTICIPANTS: Persons eligible for statin therapy based on 2013 and 2018 American College of Cardiology/American Heart Association blood cholesterol guidelines. MEASUREMENTS: The independent variable was race-ethnicity-gender. The outcome of interest was use of a statin. Using the Institute of Medicine framework for examining unequal treatment, we calculated adjusted prevalence ratios (aPRs) to estimate disparities in statin use adjusted for age, disease severity, access to health care, and socioeconomic status relative to non-Hispanic White men. RESULTS: For primary prevention, we identified a lower prevalence of statin use that was not explained by measurable differences in disease severity or structural factors among non-Hispanic Black men (aPR, 0.73 [95% CI, 0.59 to 0.88]) and non-Mexican Hispanic women (aPR, 0.74 [CI, 0.53 to 0.95]). For secondary prevention, we identified a lower prevalence of statin use that was not explained by measurable differences in disease severity or structural factors for non-Hispanic Black men (aPR, 0.81 [CI, 0.64 to 0.97]), other/multiracial men (aPR, 0.58 [CI, 0.20 to 0.97]), Mexican American women (aPR, 0.36 [CI, 0.10 to 0.61]), non-Mexican Hispanic women (aPR, 0.57 [CI, 0.33 to 0.82), non-Hispanic White women (aPR, 0.69 [CI, 0.56 to 0.83]), and non-Hispanic Black women (aPR, 0.75 [CI, 0.57 to 0.92]). LIMITATION: Cross-sectional data; lack of geographic, language, or statin-dose data. CONCLUSION: Statin use disparities for several race-ethnicity-gender groups are not explained by measurable differences in medical appropriateness of therapy, access to health care, and socioeconomic status. These residual disparities may be partially mediated by unobserved processes that contribute to health inequity, including bias, stereotyping, and mistrust. PRIMARY FUNDING SOURCE: National Institutes of Health.

IL-6 enhances CD4 cell motility by sustaining mitochondrial Ca2+ through the noncanonical STAT3 pathway.

Interleukin 6 (IL-6) is known to regulate the CD4 T cell function by inducing gene expression of a number of cytokines through activation of Stat3 transcription factor. Here, we reveal that IL-6 strengthens the mechanics of CD4 T cells. The presence of IL-6 during activation of mouse and human CD4 T cells enhances their motility (random walk and exploratory spread), resulting in an increase in travel distance and higher velocity. This is an intrinsic effect of IL-6 on CD4 T-cell fitness that involves an increase in mitochondrial Ca2+ Although Stat3 transcriptional activity is dispensable for this process, IL-6 uses mitochondrial Stat3 to enhance mitochondrial Ca2+-mediated motility of CD4 T cells. Thus, through a noncanonical pathway, IL-6 can improve competitive fitness of CD4 T cells by facilitating cell motility. These results could lead to alternative therapeutic strategies for inflammatory diseases in which IL-6 plays a pathogenic role.

Come back when you're infected: pharmacy access to sterile syringes in an Arizona Secret Shopper Study, 2023.

BACKGROUND: Pharmacies are critical healthcare partners in community efforts to eliminate bloodborne illnesses. Pharmacy sale of sterile syringes is central to this effort. METHODS: A mixed methods "secret shopper" syringe purchase study was conducted in the fall of 2022 with 38 community pharmacies in Maricopa and Pima Counties, Arizona. Pharmacies were geomapped to within 2 miles of areas identified as having a potentially high volume of illicit drug commerce. Daytime venue sampling was used whereby separate investigators with lived/living drug use experience attempted to purchase syringes without a prescription. Investigator response when prompted for purchase rationale was "to protect myself from HIV and hepatitis C." A 24-item instrument measured sales outcome, pharmacy staff interaction (hostile/neutral/friendly), and the buyer's subjective experience. RESULTS: Only 24.6% (n = 28) of 114 purchase attempts across the 38 pharmacies resulted in syringe sale. Less than one quarter (21.1%) of pharmacies always sold, while 44.7% never sold. Independent and food store pharmacies tended not to sell syringes. There emerged distinct pharmacy staff interactions characterized by body language, customer query, normalization or othering response, response to purchase request and closure. Pharmacy discretion and pharmacy policy not to sell syringes without a prescription limited sterile syringe access. Investigators reported frequent and adverse emotional impact due to pharmacy staff negative and stigmatizing interactions. CONCLUSIONS: Pharmacies miss opportunities to advance efforts to eliminate bloodborne infections by stringent no-sale policy and discretion about syringe sale. State regulatory policy facilitating pharmacy syringe sales, limiting pharmacist discretion for syringe sales, and targeting pharmacy-staff level education may help advance the achievement of public health goals to eliminate bloodborne infections in Arizona.

The antimicrobial drug pyrimethamine inhibits STAT3 transcriptional activity by targeting the enzyme dihydrofolate reductase.

Cancer is often characterized by aberrant gene expression patterns caused by the inappropriate activation of transcription factors. Signal transducer and activator of transcription 3 (STAT3) is a key transcriptional regulator of many protumorigenic processes and is persistently activated in many types of human cancer. However, like many transcription factors, STAT3 has proven difficult to target clinically. To address this unmet clinical need, we previously developed a cell-based assay of STAT3 transcriptional activity and performed an unbiased and high-throughput screen of small molecules known to be biologically active in humans. We identified the antimicrobial drug pyrimethamine as a novel and specific inhibitor of STAT3 transcriptional activity. Here, we show that pyrimethamine does not significantly affect STAT3 phosphorylation, nuclear translocation, or DNA binding at concentrations sufficient to inhibit STAT3 transcriptional activity, suggesting a potentially novel mechanism of inhibition. To identify the direct molecular target of pyrimethamine and further elucidate the mechanism of action, we used a new quantitative proteome profiling approach called proteome integral solubility alteration coupled with a metabolomic analysis. We identified human dihydrofolate reductase as a target of pyrimethamine and demonstrated that the STAT3-inhibitory effects of pyrimethamine are the result of a deficiency in reduced folate downstream of dihydrofolate reductase inhibition, implicating folate metabolism in the regulation of STAT3 transcriptional activity. This study reveals a previously unknown regulatory node of the STAT3 pathway that may be important for the development of novel strategies to treat STAT3-driven cancers.

Prolactin levels and breast cancer risk by tumor expression of prolactin-related markers.

BACKGROUND: Higher circulating prolactin has been associated with increased breast cancer risk. Prolactin binding to the prolactin receptor (PRLR) can activate the transcription factor STAT5, thus, we examined the association between plasma prolactin and breast cancer risk by tumor expression of PRLR, STAT5, and the upstream kinase JAK2. METHODS: Using data from 745 cases and 2454 matched controls in the Nurses' Health Study, we conducted polytomous logistic regression to examine the association between prolactin (> 11 ng/mL vs. ≤ 11 ng/mL) measured within 10 years of diagnosis and breast cancer risk by PRLR (nuclear [N], cytoplasmic [C]), phosphorylated STAT5 (pSTAT5; N, C), and phosphorylated JAK2 (pJAK2; C) tumor expression. Analyses were conducted separately in premenopausal (n = 168 cases, 765 controls) and postmenopausal women (n = 577 cases, 1689 controls). RESULTS: In premenopausal women, prolactin levels > 11 ng/mL were positively associated with risk of tumors positive for pSTAT5-N (OR 2.30, 95% CI 1.02-5.22) and pSTAT5-C (OR 1.64, 95% CI 1.01-2.65), but not tumors that were negative for these markers (OR 0.98, 95% CI 0.65-1.46 and OR 0.73, 95% CI 0.43-1.25; p-heterogeneity = 0.06 and 0.02, respectively). This was stronger when tumors were positive for both pSTAT5-N and pSTAT5-C (OR 2.88, 95% CI 1.14-7.25). No association was observed for PRLR or pJAK2 (positive or negative) and breast cancer risk among premenopausal women. Among postmenopausal women, plasma prolactin levels were positively associated with breast cancer risk irrespective of PRLR, pSTAT5, or pJAK2 expression (all p-heterogeneity ≥ 0.21). CONCLUSION: We did not observe clear differences in the association between plasma prolactin and breast cancer risk by tumor expression of PRLR or pJAK2, although associations for premenopausal women were observed for pSTAT5 positive tumors only. While additional studies are needed, this suggests that prolactin may act on human breast tumor development through alternative pathways.

Quantitative Measures of Right Ventricular Size and Function by Echocardiogram Correlate with Cardiac Catheterization Hemodynamics in Congenital Diaphragmatic Hernia.

OBJECTIVE: To evaluate associations between cardiac catheterization (cath) hemodynamics, quantitative measures of right ventricular (RV) function by echocardiogram, and survival in patients with congenital diaphragmatic hernia (CDH). STUDY DESIGN: This single-center retrospective cohort study enrolled patients with CDH who underwent index cath from 2003 to 2022. Tricuspid annular plane systolic excursion z score, RV fractional area change, RV free wall and global longitudinal strain, left ventricular (LV) eccentricity index, RV/LV ratio, and pulmonary artery acceleration time were measured from preprocedure echocardiograms. Associations between hemodynamic values, echocardiographic measures, and survival were evaluated by Spearman correlation and Wilcoxon rank sum test, respectively. RESULTS: Fifty-three patients (68% left-sided, 74% liver herniation, 57% extracorporeal membrane oxygenation, 93% survival) underwent cath (39 during index hospitalization, 14 later) including device closure of a patent ductus arteriosus in 5. Most patients (n = 31, 58%) were on pulmonary hypertension treatment at cath, most commonly sildenafil (n = 24, 45%) and/or intravenous treprostinil (n = 16, 30%). Overall, hemodynamics were consistent with precapillary pulmonary hypertension. Pulmonary capillary wedge pressure was >15 mm Hg in 2 patients (4%). Lower fractional area change and worse ventricular strain were associated with higher pulmonary artery pressure while higher LV eccentricity index and higher RV/LV ratio were associated with both higher pulmonary artery pressure and higher pulmonary vascular resistance. Hemodynamics did not differ based on survival status. CONCLUSIONS: Worse RV dilation and dysfunction by echocardiogram correlate with higher pulmonary artery pressure and pulmonary vascular resistance on cath in this CDH cohort. These measures may represent novel, noninvasive clinical trial targets in this population.

A JAK/STAT-mediated inflammatory signaling cascade drives oncogenesis in AF10-rearranged AML.

Leukemias bearing fusions of the AF10/MLLT10 gene are associated with poor prognosis, and therapies targeting these fusion proteins (FPs) are lacking. To understand mechanisms underlying AF10 fusion-mediated leukemogenesis, we generated inducible mouse models of acute myeloid leukemia (AML) driven by the most common AF10 FPs, PICALM/CALM-AF10 and KMT2A/MLL-AF10, and performed comprehensive characterization of the disease using transcriptomic, epigenomic, proteomic, and functional genomic approaches. Our studies provide a detailed map of gene networks and protein interactors associated with key AF10 fusions involved in leukemia. Specifically, we report that AF10 fusions activate a cascade of JAK/STAT-mediated inflammatory signaling through direct recruitment of JAK1 kinase. Inhibition of the JAK/STAT signaling by genetic Jak1 deletion or through pharmacological JAK/STAT inhibition elicited potent antioncogenic effects in mouse and human models of AF10 fusion AML. Collectively, our study identifies JAK1 as a tractable therapeutic target in AF10-rearranged leukemias.

[Successful therapy of non-cirrhotic non-malignant portal vein thrombosis (NCNMPT) by interventional therapy using transjugular lysis catheter]. / Erfolgreiche Interventionelle Therapie eines Patienten mit nichtzirrhotischer nichtmaligner Pfortaderthrombose mit lokaler Lyse.

NCNMPT is a rare condition with a prevalence of 0.3%. THERAPY: Patient (69 y) with NCNMPT and small bowel ileus received interventional therapy using transjugular local lysis into the superior mesenteric vein. OUTCOME/DISCUSSION: Successful lysis with complete remission. Improved therapeutic efficacy of interventional versus drug therapy alone.

Higher judgements of learning for emotional words: processing fluency or memory beliefs?

Previous research has shown that emotionally-valenced words are given higher judgements of learning (JOLs) than are neutral words. The current study examined potential explanations for this emotional salience effect on JOLs. Experiment 1 replicated the basic emotionality/JOL effect. In Experiments 2A and 2B, we used pre-study JOLs and assessed memory beliefs qualitatively, finding that, on average, participants believed that positive and negative words were more memorable than neutral words. Experiment 3 utilised a lexical decision task, resulting in lower reaction times (RTs) for positive words than for neutral words, but equivalent RTs for negative and neutral words, suggesting that processing fluency may partially account for higher JOLs for positive words, but not for negative words. Finally, we conducted a series of moderation analyses in Experiment 4 which assessed the relative contributions of fluency and beliefs to JOLs by measuring both factors in the same participants, showing that RTs made no significant contribution to JOLs for either positive or negative words. Our findings suggest that although positive words may be more fluently processed than neutral words, memory beliefs are the primary factor underlying higher JOLs for both positive and negative words.

"As safe as possible": a qualitative study of opioid withdrawal and risk behavior among people who use illegal opioids.

BACKGROUND: Opioid withdrawal is a regular occurrence among many people who use illicit opioids (PWUIO) that has also been shown to increase their willingness to engage in risk-involved behavior. The proliferation of fentanyl in the illicit opioid market may have amplified this relationship, potentially putting PWUIO at greater risk of negative health outcomes. Understanding the relationship between withdrawal and risk-involved behavior may also have important implications for the ways that problematic drug use is conceptualized, particularly in disease models of addiction, which position risk behavior as evidence of pathology that helps to justify ontological distinctions between addicts and non-addicts. Examining withdrawal, and its role in PWUIO's willingness to engage in risk, may aid in the development of alternative theories of risk involvement and create discursive spaces for de-medicalizing and de-othering people who use illegal drugs. METHODS: This article is based on 32 semi-structured interviews with PWUIO in the New York City area who also reported recent withdrawal experience. Interviews were conducted remotely between April and August 2022 and recorded for later transcription. Data were then coded and analyzed based on a combination of inductive and deductive coding strategies and informed by the literature. RESULTS: Participants described a strong relationship between withdrawal and their willingness to engage in risk-involved behavior that was exacerbated by the proliferation of fentanyl. Yet, their descriptions did not align with narratives of risk as a product of bad decisions made by individuals. Rather, data demonstrated the substantial role of social and structural context, particularly drug policies like prohibition and criminalization, in the kinds of risks that PWUIO faced and their ability to respond to them. CONCLUSIONS: Withdrawal should be taken more seriously both from an ethical perspective and as an important catalyst of risk behavior. However, theories that position activities taken to avoid withdrawal as irrational and as evidence of pathology are poorly aligned with the complexity of PWUIO's actual lives. We recommend the use of less deterministic and less medicalized theories of risk that better account for differences between how people view the world, and for the role of socio-structural forces in the production of risk.

CT-based migration analysis is more precise than radiostereometric analysis for tibial implants: a phantom study on a porcine cadaver.

BACKGROUND AND PURPOSE: Radiostereometric analysis (RSA) is the gold standard for migration analysis, but computed tomography analysis methods (CTRSA) have shown comparable results in other joints. We attempted to validate precision for CT compared with RSA for a tibial implant. MATERIAL AND METHODS: RSA and CT were performed on a porcine knee with a tibial implant. Marker-based RSA, model-based RSA (MBRSA), and CT scans from 2 different manufacturers were compared. CT analysis was performed by 2 raters for reliability evaluation. RESULTS: 21 double examinations for precision measurements for RSA and CT-based Micromotion Analysis (CTMA) were analysed. Mean (95% confidence interval) precision data for maximum total point motion (MTPM) using marker-based RSA was 0.45 (0.19-0.70) and 0.58 (0.20-0.96) using MBRSA (F-statistic 0.44 [95% CI 0.18-1.1], p = 0.07). Precision data for total translation (TT) for CTMA was 0.08 (0.03-0.12) for the GE scanner and 0.11 (0.04-0.19) for the Siemens scanner (F-statistic 0.37 [0.15-0.91], p = 0.03). When comparing the aforementioned precision for both RSA methods with both CTMA analyses, CTMA was more precise (p < 0.001). The same pattern was seen for other translations and migrations. Mean effective radiation doses were 0.005 mSv (RSA) (0.0048-0.0050) and 0.08 mSv (CT) (0.078-0.080) (p < 0.001). Intra- and interrater reliability were 0.79 (0.75-0.82) and 0.77 (0.72-0.82), respectively. CONCLUSION: CTMA is more precise than RSA for migration analysis of a tibial implant, has overall good intra- and interrater reliability but higher effective radiation doses in a porcine cadaver.