The neuronal nucleus houses a meticulously organized genome. Within this structure, genetic material is not simply compacted but arranged into a precise and functional 3D chromatin landscape essential for cellular regulation. This mini-review highlights the importance of this chromatin landscape in healthy neurodevelopment, as well as the diseases that occur with aberrant chromatin architecture. We discuss insights into the fundamental mechanistic relationship between histone modifications, DNA methylation, and genome organization. We then discuss findings that reveal how these epigenetic features change throughout normal neurodevelopment. Finally, we highlight single-gene neurodevelopmental disorders that illustrate the interdependence of epigenetic features, showing how disruptions in DNA methylation or genome architecture can ripple across the entire epigenome. As such, we emphasize the importance of measuring multiple chromatin architectural aspects, as the disruption of one mechanism can likely impact others in the intricate epigenetic network. This mini-review underscores the vast gaps in our understanding of chromatin structure in neurodevelopmental diseases and the substantial research needed to understand the interplay between chromatin features and neurodevelopment.

Two decades into the era of Electronic Health Records (EHRs), the promise of streamlining clinical care, reducing burden, and improving patient outcomes has yet to be realized. A cross-sectional family physician census conducted by the American Board of Family Medicine in 2022 and 2023 included self-reported physician EHR satisfaction. Of the nearly 10,000 responding family physicians, only one-in-four (26.2%) report being very satisfied and one-in-three (33.8%) were not satisfied. These low levels of satisfaction point to the need for greater transparency in the marketplace and pressure to increase user-centric EHR design.

Single maintenance and reliever therapy (SMART) is an asthma treatment approach that utilizes combined inhaled corticosteroids and long-acting β-agonists for maintenance and quick relief therapy. Despite the evidence for its benefits in asthma treatment and its adoption into American and international asthma guidelines and recommendations, SMART remains a practice of some debate. This article reviews the available evidence for SMART and offers guidance for its integration into comprehensive asthma management. Overall, short-acting β-agonist-only asthma therapy regimens should be avoided, regardless of condition severity (SOR A Recommendation). Family medicine clinicians should start SMART for patients requiring either GINA Step 3 or 4 therapy, especially if they have signs of poor adherence (SOR B Recommendation). Finally, use budesonide-formoterol over other inhaled corticosteroid/long-acting β-agonist combinations when implementing SMART (SOR B Recommendation).

Introduction:

High-quality primary care can reduce avoidable emergency department visits and emergency hospitalizations. The availability of electronic medical record (EMR) data and capacities for data storage and processing have created opportunities for predictive analytics. This systematic review examines studies which predict emergency department visits, hospitalizations, and mortality using EMR data from primary care.

Artificial Intelligence (AI) is poised to revolutionize family medicine, offering a transformative approach to achieving the Quintuple Aim. This article examines the imperative for family medicine to adapt to the rapidly evolving field of AI, with an emphasis on its integration in clinical practice. AI's recent advancements have the potential to significantly transform health care. We argue for the proactive engagement of family medicine in directing AI technologies toward enhancing the "Quintuple Aim."

The article highlights potential benefits of AI, such as improved patient outcomes through enhanced diagnostic tools, clinician well-being through reduced administrative burdens, and the promotion of health equity by analyzing diverse data sets. However, we also acknowledge the risks associated with AI, including the potential for automation to diverge from patient-centered care and exacerbate health care disparities. Our recommendations stress the need for family medicine education to incorporate AI literacy, the development of a collaborative for AI integration, and the establishment of guidelines and standards through interdisciplinary cooperation. We conclude that although AI poses challenges, its responsible and ethical implementation can revolutionize family medicine, optimizing patient care and enhancing the role of clinicians in a technology-driven future.

Artificial intelligence (AI) is certainly going to have a large, potentially huge, impact on the practice of family medicine. The specialty is fortunate to have leading experts in the field to guide us along the way. One such team of forward thinkers provides insights into where AI can take the specialty. Another article reports on how well AI performed on the American Board of Family Medicine In-Training Examination. In addition to AI, we have 3 articles that investigate the intersection of social needs and the practice of medicine. Four clinical review articles cover nonalcoholic fatty liver disease, headache treatments, single maintenance and reliever therapy for asthma, and the use of cannabis in the setting of chronic pain. The clinical research articles cover point-of-care hemoglobin A1c testing, continuous glucose monitoring, and screening for HIV. Another group of articles examines the profession of family medicine, covering topics ranging from how women family physicians negotiate their first jobs to the words we use to define primary care.

BACKGROUND:Beneficial effects of breathing at FIO2 < 0.21 on disease outcomes have been reported in previous preclinical and clinical studies. However, the safety and intra-hospital feasibility of breathing hypoxic gas for 5 d have not been established. In this study, we examined the physiologic effects of breathing a gas mixture with FIO2 as low as 0.11 in 5 healthy volunteers.METHODS:All 5 subjects completed the study, spending 5 consecutive days in a hypoxic tent, where the ambient oxygen level was lowered in a stepwise manner over 5 d, from FIO2 of 0.16 on the first day to FIO2 of 0.11 on the fifth day of the study. All the subjects returned to an environment at room air on the sixth day. The subjects' SpO2, heart rate, and breathing frequency were continuously recorded, along with daily blood sampling, neurologic evaluations, transthoracic echocardiography, and mental status assessments.RESULTS:Breathing hypoxia concentration dependently caused profound physiologic changes, including decreased SpO2 and increased heart rate. At FIO2 of 0.14, the mean SpO2 was 92%; at FIO2 of 0.13, the mean SpO2 was 93%; at FIO2 of 0.12, the mean SpO2 was 88%; at FIO2 of 0.11, the mean SpO2 was 85%; and, finally, at an FIO2 of 0.21, the mean SpO2 was 98%. These changes were accompanied by increased erythropoietin levels and reticulocyte counts in blood. All 5 subjects concluded the study with no adverse events. No subjects exhibited signs of mental status changes or pulmonary hypertension.CONCLUSIONS:Results of the current physiologic study suggests that, within a hospital setting, delivering FIO2 as low as 0.11 is feasible and safe in healthy subjects, and provides the foundation for future studies in which therapeutic effects of hypoxia breathing are tested.

BACKGROUND:Pulmonary function tests (PFTs) have historically used race-specific prediction equations. The recent American Thoracic Society guidelines recommend the use of a race-neutral approach in prediction equations. There are limited studies centering the opinions of practicing pulmonologists on the use of race in spirometry. Provider opinion will impact adoption of the new guideline. The aim of this study was to ascertain the beliefs of academic pulmonary and critical care providers regarding the use of race as a variable in spirometry prediction equations.METHODS:We report data from 151 open-ended responses from a voluntary, nationwide survey (distributed by the Association of Pulmonary Critical Care Medicine Program Directors) of academic pulmonary and critical care providers regarding the use of race in PFT prediction equations. Responses were coded using inductive and deductive methods, and a thematic content analysis was conducted.RESULTS:There was a balanced distribution of opinions among respondents supporting, opposing, or being unsure about the incorporation of race in spirometry prediction equations. Responses demonstrated a wide array of understanding related to the concept and definition of race and its relationship to physiology.CONCLUSIONS:There was no consensus among providers regarding the use of race in spirometry prediction equations. Concepts of race having biologic implications persist among pulmonary providers and will likely affect the uptake of the Global Lung Function Initiative per the American Thoracic Society guidelines.

BACKGROUND:Post–COVID-19 syndrome has affected millions of people, with rehabilitation being at the center of non-pharmacologic care. However, numerous published studies show conflicting results due to, among other factors, considerable variation in subject characteristics. Currently, the effects of age, sex, time of implementation, and prior disease severity on the outcomes of a supervised rehabilitation program after COVID-19 remain unknown.METHODS:This was a non-randomized case-control study. Subjects with post–COVID-19 sequelae were enrolled. Among study participants, those who could attend an 8-week, supervised rehabilitation program composed the intervention group, whereas those who couldn’t the control group. Measurements were collected at baseline and 8 weeks thereafter.RESULTS:Study groups (N = 119) had similar baseline measurements. Participation in rehabilitation (n = 47) was associated with clinically important improvements in the 6-min walk test (6MWT) distance, adjusted (for potential confounders) odds ratio (AOR) 4.56 (95% CI 1.95–10.66); 1-min sit-to-stand test, AOR 4.64 (1.88-11.48); Short Physical Performance Battery, AOR 7.93 (2.82–22.26); health-related quality of life (HRQOL) 5-level EuroQol-5D (Visual Analog Scale), AOR 3.12 (1.37–7.08); Montreal Cognitive Assessment, AOR 6.25 (2.16–18.04); International Physical Activity Questionnaire, AOR 3.63 (1.53–8.59); Fatigue Severity Scale, AOR 4.07 (1.51–10.98); Chalder Fatigue Scale (bimodal score), AOR 3.33 (1.45–7.67); Modified Medical Research Council dyspnea scale (mMRC), AOR 4.43 (1.83–10.74); Post–COVID-19 Functional Scale (PCFS), AOR 3.46 (1.51–7.95); and COPD Assessment Test, AOR 7.40 (2.92–18.75). Time from disease onset was marginally associated only with 6MWT distance, AOR 0.99 (0.99–1.00). Prior hospitalization was associated with clinically important improvements in the mMRC dyspnea scale, AOR 3.50 (1.06–11.51); and PCFS, AOR 3.42 (1.16–10.06). Age, sex, and ICU admission were not associated with the results of any of the aforementioned tests/grading scales.CONCLUSIONS:In this non-randomized, case-control study, post–COVID-19 rehabilitation was associated with improvements in physical function, activity, HRQOL, respiratory symptoms, fatigue, and cognitive impairment. These associations were observed independently of timing of rehabilitation, age, sex, prior hospitalization, and ICU admission.

The Coalition for Epidemic Preparedness Innovations (CEPI) has developed a robust CMC (Chemistry, Manufacturing, and Controls) Framework to enhance the likelihood of successful vaccine development. This Framework serves as a comprehensive guide, aiding developers in building effective strategies to overcome the challenges posed by the different phases of vaccine development, including the ones often referred to as the "valleys of death". The Framework lists stage-appropriate deliverables, categorized and refined, spanning five key areas: manufacturing process, formulation and stability, analytics, supply chain, and compliance. By emphasizing the critical aspects of CMC development, CEPI's objective is to expedite the progression of vaccine candidates from research to deployment, reducing delays, mitigating risks, and optimizing the overall development process, all while upholding uncompromising quality standards, ultimately increasing the probability of success.

The pursuit of harnessing data for knowledge creation has been an enduring quest, with the advent of machine learning (ML) and artificial intelligence (AI) marking significant milestones in this journey. ML, a subset of AI, emerged as the practice of employing mathematical models to enable computers to learn and improve autonomously based on their experiences. In the pharmaceutical and biopharmaceutical sectors, a significant portion of manufacturing data remains untapped or insufficient for practical use. Recognizing the potential advantages of leveraging the available data for process design and optimization, manufacturers face the daunting challenge of data utilization. Diverse proprietary data formats and parallel data generation systems compound the complexity. The transition to Pharma 4.0 necessitates a paradigm shift in data capture, storage, and accessibility for manufacturing and process operations. This paper highlights the pivotal role of AI in converting process data into actionable knowledge to support critical functions throughout the whole product life cycle. Furthermore, it underscores the importance of maintaining compliance with data integrity guidelines, as mandated by regulatory bodies globally. Embracing AI-driven transformations is a crucial step toward shaping the future of the pharmaceutical industry, ensuring its competitiveness and resilience in an evolving landscape.

For clean-room technologies such as isolators and restricted access barrier systems (RABS), decontamination using hydrogen peroxide (H₂O₂) is increasingly attractive to fulfill regulatory requirements. Several approaches are currently used, ranging from manual wipe disinfection to vapor phase hydrogen peroxide (VPHP) or automated nebulization sanitization. Although the residual airborne H₂O₂ concentration can be easily monitored, detection of trace H₂O₂ residues in filled products is rather challenging. To simulate the filling process in a specific clean room, technical runs with water for injection (WfI) are popular. Thus, the ability to detect traces of H₂O₂ in water is an important prerequisite to ensure a safe and reliable use of H₂O₂ for isolator or clean room decontamination. The objective of this study was to provide a validated quantitative, fluorometric Amplex UltraRed assay, which satisfies the analytical target profile of quantifying H₂O₂ in WfI at low nanomolar to low micromolar concentrations (ppb range) with high accuracy and high precision. The Amplex UltraRed technology provides a solid basis for this purpose; however, no commercial assay kit that fulfills these requirements is available. Therefore, a customized Amplex UltraRed assay was developed, optimized, and validated. This approach resulted in an assay that is capable of quantifying H₂O₂ in WfI selectively, sensitively, accurately, precisely, and robustly. This assay is used in process development and qualification approaches using WfI in H₂O₂-decontaminated clean rooms and isolators.

Obidoxime chloride is an antidote for nerve gas intoxication. As an emergency medicine, it is being stored by the Israel Defense Forces (IDF) scattered throughout Israel in depots without a controlled environment (field conditions), thus being exposed to high and fluctuating temperatures. These conditions do not meet the manufacturer’s requirements. In addition, due to possible supply shortages, the utilization of expired batches was suggested. The current work investigated these matters. Long-term (15 years) storage under different conditions was initiated. Chemical stability and toxicity in rats were assessed. No difference was found between field conditions vs the controlled environment. The obidoxime assay remained >95% for 5 years and >90% for 7 years. The pH remained above the lower specification limit for 7–8 years. The major degradation product, 4-pyridinealdoxime, surpassed the allowed limit at 5 years. The content of total unknown impurities reached its maximum allowed by the IDF limit at 4–5 years. Threefold higher than clinically utilized doses of valid-to-date Toxogonin batches administered to rats did not cause any abnormality. However, expired batches produced significant toxic effects. Although no difference was found between storage of obidoxime ampoules when adhering to manufacturer’s recommendations vs field conditions, accumulation of degradants over the limit allowed by the IDF at 4–5 years of storage and the toxicity of the expired batches observed in rats led the IDF to a decision to shorten the shelf-life of this product from 5 to 4 years when stored in an uncontrolled environment of the Mediterranean climate.

During B-cell development, cells progress through multiple developmental stages, with the pro-B-cell stage defining commitment to the B-cell lineage. YY1 is a ubiquitous transcription factor that is capable of both activation and repression functions. We found here that knockout of YY1 at the pro-B-cell stage eliminates B lineage commitment. YY1 knockout pro-B cells can generate T lineage cells in vitro using the OP9-DL4 feeder system and in vivo after injection into sublethally irradiated Rag1^–/– mice. These T lineage-like cells lose their B lineage transcript profile and gain a T-cell lineage profile. Single-cell RNA-seq experiments showed that as YY1 knockout pro-B cells transition into T lineage cells in vitro, various cell clusters adopt transcript profiles representing a multiplicity of hematopoietic lineages, indicating unusual lineage plasticity. In addition, YY1 KO pro-B cells in vivo can give rise to other hematopoietic lineages in vivo. Evaluation of RNA-seq, scRNA-seq, ChIP-seq, and scATAC-seq data indicates that YY1 controls numerous chromatin-modifying proteins leading to increased accessibility of alternative lineage genes in YY1 knockout pro-B cells. Given the ubiquitous nature of YY1 and its dual activation and repression functions, YY1 may regulate commitment in multiple cell lineages.

Animal germline development and fertility rely on paralogs of general transcription factors that recruit RNA polymerase II to ensure cell type-specific gene expression. It remains unclear whether gene expression processes downstream from such paralog-based transcription is distinct from that of canonical RNA polymerase II genes. In Drosophila, the testis-specific TBP-associated factors (tTAFs) activate over a thousand spermatocyte-specific gene promoters to enable meiosis and germ cell differentiation. Here, we show that efficient termination of tTAF-activated transcription relies on testis-specific paralogs of canonical polymerase-associated factor 1 complex (PAF1C) proteins, which form a testis-specific PAF1C (tPAF). Consequently, tPAF mutants show aberrant expression of hundreds of downstream genes due to read-in transcription. Furthermore, tPAF facilitates expression of Y-linked male fertility factor genes and thus serves to maintain spermatocyte-specific gene expression. Consistently, tPAF is required for the segregation of meiotic chromosomes and male fertility. Supported by comparative in vivo protein interaction assays, we provide a mechanistic model for the functional divergence of tPAF and the PAF1C and identify transcription termination as a developmentally regulated process required for germline-specific gene expression.

Massively parallel reporter assays (MPRAs) are powerful tools for quantifying the impacts of sequence variation on gene expression. Reading out molecular phenotypes with sequencing enables interrogating the impact of sequence variation beyond genome scale. Machine learning models integrate and codify information learned from MPRAs and enable generalization by predicting sequences outside the training data set. Models can provide a quantitative understanding of cis-regulatory codes controlling gene expression, enable variant stratification, and guide the design of synthetic regulatory elements for applications from synthetic biology to mRNA and gene therapy. This review focuses on cis-regulatory MPRAs, particularly those that interrogate cotranscriptional and post-transcriptional processes: alternative splicing, cleavage and polyadenylation, translation, and mRNA decay.

Cellular plasticity in adult multicellular organisms is a protective mechanism that allows certain tissues to regenerate in response to injury. Considering that aging involves exposure to repeated injuries over a lifetime, it is conceivable that cell identity itself is more malleable—and potentially erroneous—with age. In this review, we summarize and critically discuss the available evidence that cells undergo age-related shifts in identity, with an emphasis on those that contribute to age-associated pathologies, including neurodegeneration and cancer. Specifically, we focus on reported instances of programs associated with dedifferentiation, biased differentiation, acquisition of features from alternative lineages, and entry into a preneoplastic state. As some of the most promising approaches to rejuvenate cells reportedly also elicit transient changes to cell identity, we further discuss whether cell state change and rejuvenation can be uncoupled to yield more tractable therapeutic strategies.

The brain's capacity to predict and anticipate changes in internal and external environments is fundamental to initiating efficient adaptive responses, behaviors, and reflexes that minimize disruptions to physiology. In the context of feeding control, the brain predicts and anticipates responses to the consumption of dietary substances, thus driving adaptive behaviors in the form of food choices, physiological preparation for meals, and engagement of defensive mechanisms. Here, we provide an integrative perspective on the multisensory computation between exteroceptive and interoceptive cues that guides feeding strategy and may result in food-related disorders.

The study of biological mechanisms, while crucial, cannot fully explain complex phenomena like the instinct to eat. The mind–body connection, as exemplified by the concept of "voodoo death," highlights the profound influence of belief and cultural context on physiology. Indigenous knowledge systems further emphasize the interconnectedness of humans with their environment. Recent discoveries in gut–brain communication reveal the intricate neural circuits that drive our visceral desires, but a holistic approach that integrates both physiological mechanisms and the subjective experience of life, informed by diverse cultural perspectives, will be essential to truly understand what it means to be alive.

Binding of arbitrary information into distinct memory representations that can be used to guide behavior is a hallmark of relational memory. What is and is not bound into a memory representation and how those things influence the organization of that representation remain topics of interest. While some information is intentionally and effortfully bound—often the information that is consistent with task goals or expectations about what information may be required later—other information appears to be bound automatically. The present set of experiments sought to investigate whether spatial memory would be systematically influenced by the presence and absence of distinct categories of stimuli on a spatial reconstruction task. In this task, participants must learn multiple item-location bindings and place each item back in its studied location after a short delay. Across three experiments, participants made significantly more within-category errors (i.e., misassigning one item to the location of a different item from the same category) than between-category errors (i.e., misassigning one item to the location of an item from a different category) when categories were perceptually or semantically distinct. These data reveal that category information contributed to the organization of the memory representation and influenced spatial reconstruction performance. Together, these results suggest that categorical information can influence memory organization, and not always to the benefit of overall task performance.

Internal ribosomal entry sites (IRESs) recruit the ribosome to promote translation, typically in an m7G cap-independent manner. Although IRESs are well-documented in viral genomes, they have also been reported in mammalian transcriptomes, where they have been proposed to mediate cap-independent translation of mRNAs. However, subsequent studies have challenged the idea of these "cellular" IRESs. Current methods for screening and discovering IRES activity rely on a bicistronic reporter assay, which is prone to producing false positive signals if the putative IRES sequence has a cryptic promoter or cryptic splicing sites. Here, we report an assay for screening IRES activity using a genetically encoded circular RNA comprising a split nanoluciferase (nLuc) reporter. The circular split nLuc reporter is less susceptible to the various sources of false positives that adversely affect the bicistronic IRES reporter assay and provides a streamlined method for screening IRES activity. Using the circular split nLuc reporter, we find that nine reported cellular IRESs have minimal IRES activity. Overall, the circular split nLuc reporter offers a simplified approach for identifying and validating IRESs and exhibits reduced propensity for producing the types of false positives that can occur with the bicistronic reporter assay.

Caenorhabditis elegans is an important model organism for human health and disease, with foundational contributions to the understanding of gene expression and tissue patterning in animals. An invaluable tool in modern gene expression research is the presence of a high-resolution ribosome structure, though no such structure exists for C. elegans. Here, we present a high-resolution single-particle cryogenic electron microscopy (cryo-EM) reconstruction and molecular model of a C. elegans ribosome, revealing a significantly streamlined animal ribosome. Many facets of ribosome structure are conserved in C. elegans, including overall ribosomal architecture and the mechanism of cycloheximide, whereas other facets, such as expansion segments and eL28, are rapidly evolving. We identify uL5 and uL23 as two instances of tissue-specific ribosomal protein paralog expression conserved in Caenorhabditis, suggesting that C. elegans ribosomes vary across tissues. The C. elegans ribosome structure will provide a basis for future structural, biochemical, and genetic studies of translation in this important animal system.

Vault RNAs (vtRNAs) are evolutionarily conserved small noncoding RNAs transcribed by RNA polymerase III. Vault RNAs were initially described as components of the vault particle, but have since been assigned multiple vault-independent functions, including regulation of PKR activity, apoptosis, autophagy, lysosome biogenesis, and viral particle trafficking. The full-length transcript has also been described as a noncanonical source of miRNAs, which are processed in a DICER-dependent manner. As central molecules in vault-dependent and independent processes, vtRNAs have been attributed numerous biological roles, including regulation of cell proliferation and survival, response to viral infections, drug resistance, and animal development. Yet, their impact to mammalian physiology remains largely unexplored. To study vault RNAs in vivo, we generated a mouse line with a conditional Vaultrc5 loss-of-function allele. Because Vaultrc5 is the sole murine vtRNA, this allele enables the characterization of the physiological requirements of this conserved class of small regulatory RNAs in mammals. Using this strain, we show that mice constitutively null for Vaultrc5 are viable and histologically normal but have a slight reduction in platelet counts, pointing to a potential role for vtRNAs in hematopoiesis. This work paves the way for further in vivo characterizations of this abundant but mysterious RNA molecule. Specifically, it enables the study of the biological consequences of constitutive or lineage-specific Vaultrc5 deletion and of the physiological requirements for an intact Vaultrc5 during normal hematopoiesis or in response to cellular stresses such as oncogene expression, viral infection, or drug treatment.

Hepatocyte nuclear factor 4 alpha antisense 1 (HNF4A-AS1) is a long noncoding RNA (lncRNA) gene physically located next to the transcription factor HNF4A gene in the human genome. Its transcription products have been reported to inhibit the progression of hepatocellular carcinoma (HCC) and negatively regulate the expression of cytochrome P450s (CYPs), including CYP1A2, 2B6, 2C9, 2C19, 2E1, and 3A4. By altering CYP expression, lncRNA HNF4A-AS1 also contributes to the susceptibility of drug-induced liver injury. Thus, HNF4A-AS1 lncRNA is a promising target for controlling HCC and modulating drug metabolism. However, HNF4A-AS1 has four annotated alternative transcripts in the human genome browsers, and it is unclear which transcripts the small interfering RNAs or small hairpin RNAs used in the previous studies are silenced and which transcripts should be used as the target. In this study, four annotated and two newly identified transcripts were confirmed. These six transcripts showed different expression levels in different liver disease conditions, including metabolic dysfunction-associated steatotic liver disease, alcohol-associated liver disease, and obesity. The expression patterns of all HNF4A-AS1 transcripts were further investigated in liver cell growth from human embryonic stem cells to matured hepatocyte-like cells, HepaRG differentiation, and exposure to rifampicin treatment. Several HNF4A-AS1 transcripts highly displayed correlations with these situations. In addition, some of the HNF4A-AS1 transcripts also showed a strong correlation with CYP3A4 during HepaRG maturation and rifampicin exposure. Our findings provide valuable insights into the specific roles of HNF4A-AS1 transcripts, paving the way for more targeted therapeutic strategies for liver diseases and drug metabolism.

Antifolates are important for chemotherapy in non–small cell lung cancer (NSCLC). They mainly rely on reduced folate carrier (RFC) and proton-coupled folate transporter (PCFT) to enter cells. PCFT is supposed to be the dominant transporter of the two in tumors, as it operates optimally at acidic pH and has limited transport activity at physiological pH, whereas RFC operates optimally at neutral pH. In this study, we found RFC showed a slightly pH-dependent uptake of antifolates, with similar affinity values at pH 7.4 and 6.5. PCFT showed a highly pH-dependent uptake of antifolates, with an optimum pH of 6.0 for pemetrexed and 5.5 for methotrexate. The Michaelis-Menten constant (K_m) value of PCFT for pemetrexed at pH 7.4 was more than 10 times higher than that at pH 6.5. Interestingly, we found that antifolate accumulations mediated by PCFT at acidic pH were significantly affected by the efflux transporter, breast cancer resistance protein (BCRP). The highest pemetrexed concentration was observed at pH 7.0–7.4 after a 60-minute accumulation in PCFT-expressing cells, which was further evidenced by the cytotoxicity of pemetrexed, with the IC₅₀ value of pemetrexed at pH 7.4 being one-third of that at pH 6.5. In addition, the in vivo study indicated that increasing PCFT and RFC expression significantly enhanced the antitumor efficacy of pemetrexed despite the high expression of BCRP. These results suggest that both RFC and PCFT are important for antifolates accumulation in NSCLC, although there is an acidic microenvironment and high BCRP expression in tumors.

Human organic anion transporting polypeptide (OATP) 1B1 and 1B3 are two highly homologous liver-specific uptake transporters. However, 2’,7’-dichlorofluorescein (DCF) is preferably transported by OATP1B1. In the present study, the molecular mechanisms for the selective transport of DCF by OATP1B1 were investigated by constructing and characterizing an array of OATP1B1/1B3 chimeras and site-directed mutagenesis. Our results show that transmembrane domain (TM) 10 is crucial for the surface expression and function of OATP1B1, in which Q541 and L545 play the most important roles in DCF transport. Replacement of TM10 in OATP1B1 with its OATP1B3 counterpart led to OATP1B1’s complete intracellular retention. Q541 and L545 may interact with DCF directly via hydrogen bonding and hydrophobic interactions. The decrease of DCF uptake by Q541A and L545S was due to their reduced binding affinity for DCF as compared with OATP1B1. In addition, Q541 and L545 are also crucial for the transport of estradiol-17β-glucuronide (E17βG) but not for the transport of estrone-3-sulfate (E3S), indicating different interaction modes between DCF/E17βG and E3S in OATP1B1. Taken together, Q541 and L545 in TM10 are critical for OATP1B1-mediated DCF uptake, but their effect is substrate-dependent.

Exercise significantly alters human physiological functions, such as increasing cardiac output and muscle blood flow and decreasing glomerular filtration rate (GFR) and liver blood flow, thereby altering the absorption, distribution, metabolism, and excretion of drugs. In this study, we aimed to establish a database of human physiological parameters during exercise and to construct equations for the relationship between changes in each physiological parameter and exercise intensity, including cardiac output, organ blood flow (e.g., muscle blood flow and kidney blood flow), oxygen uptake, plasma pH and GFR, etc. The polynomial equation P = a_iHRⁱ was used for illustrating the relationship between the physiological parameters (P) and heart rate (HR), which served as an index of exercise intensity. The pharmacokinetics of midazolam, quinidine, digoxin, and lidocaine during exercise were predicted by a whole-body physiologically based pharmacokinetic (WB-PBPK) model and the developed database of physiological parameters following administration to 100 virtual subjects. The WB-PBPK model simulation results showed that most of the observed plasma drug concentrations fell within the 5^th–95^th percentiles of the simulations, and the estimated peak concentrations (C_max) and area under the curve (AUC) of drugs were also within 0.5–2.0 folds of observations. Sensitivity analysis showed that exercise intensity, exercise duration, medication time, and alterations in physiological parameters significantly affected drug pharmacokinetics and the net effect depending on drug characteristics and exercise conditions. In conclusion, the pharmacokinetics of drugs during exercise could be quantitatively predicted using the developed WB-PBPK model and database of physiological parameters.

The CYP3A7 enzyme accounts for ~50% of the total cytochrome P450 (P450) content in fetal and neonatal livers and is the predominant P450 involved in neonatal xenobiotic metabolism. Additionally, it is a key player in healthy birth outcomes through the oxidation of dehydroepiandrosterone (DHEA) and DHEA-sulfate. The amount of the other hepatic CYP3A isoforms, CYP3A4 and CYP3A5, expressed in neonates is low but highly variable, and therefore the activity of individual CYP3A isoforms is difficult to differentiate due to their functional similarities. Consequently, a better understanding of the contribution of CYP3A7 to drug metabolism is essential to identify the risk that drugs may pose to neonates and developing infants. To distinguish CYP3A7 activity from CYP3A4/5, we sought to further characterize the selectivity of the specific CYP3A inhibitors CYP3cide, clobetasol, and azamulin. We used three substrate probes, dibenzylfluorescein, luciferin-PPXE, and midazolam, to determine the IC₅₀ and metabolism-dependent inhibition (MDI) properties of the CYP3A inhibitors. Probe selection had a significant effect on the IC₅₀ values and P450 inactivation across all inhibitory compounds and enzymes. CYP3cide and azamulin were both identified as MDIs and were most specific for CYP3A4. Contrary to previous reports, we found that clobetasol propionate (CP) was not an MDI of CYP3A5 but was more selective for CYP3A5 over CYP3A4/7. We further investigated CYP3cide and CP’s ability to differentiate CYP3A7 activity in an equal mixture of recombinant CYP3A4, CYP3A5, and CYP3A7, and our results provide confidence of CYP3cide’s and CP’s ability to distinguish CYP3A7 activity in the presence of the other CYP3A isoforms.

Early detection of drug-drug interactions (DDIs) can facilitate timely drug development decisions, prevent unnecessary restrictions on patient enrollment, resulting in clinical study populations that are not representative of the indicated study population, and allow for appropriate dose adjustments to ensure safety in clinical trials. All of these factors contribute to a streamlined drug approval process and enhanced patient safety. Here we describe a new approach for early prediction of the magnitude of change in exposure for cytochrome P450 (P450) CYP3A4-related DDIs of small-molecule anticancer drugs based on the model-based extrapolation of human-CYP3A4-transgenic mice pharmacokinetics to humans. Victim drugs brigatinib and lorlatinib were evaluated with the new approach in combination with the perpetrator drugs itraconazole and rifampicin. Predictions of the magnitude of change in exposure deviated at most 0.99- to 1.31-fold from clinical trial results for inhibition with itraconazole, whereas exposure predictions for the induction with rifampicin were less accurate, with deviations of 0.22- to 0.48-fold. Results for the early prediction of DDIs and their clinical impact appear promising for CYP3A4 inhibition, but validation with more victim and perpetrator drugs is essential to evaluate the performance of the new method.

The regulation of drug-metabolizing enzymes and transporters by cytokines has been extensively studied in vitro and in clinic. Cytokine-mediated suppression of cytochrome P450 (CYP) or drug transporters may increase or decrease the systemic clearance of drug substrates that are primarily cleared via these pathways; neutralization of cytokines by therapeutic proteins may thereby alter systemic exposures of such drug substrates. The Food and Drug Administration recommends evaluating such clinical drug interactions during clinical development and has provided labeling recommendations for therapeutic proteins. To determine the clinical relevance of these drug interactions to dose adjustments, trends in steady-state exposures of CYP-sensitive substrates coadministered with cytokine modulators as reported in the University of Washington Drug Interaction Database were extracted and examined for each of the CYPs. Coadministration of cytochrome P450 family 3 subfamily A (CYP3A) (midazolam/simvastatin), cytochrome P450 subfamily 2C19 (omeprazole), or cytochrome P450 subfamily 1A2 (caffeine/tizanidine) substrates with anti-interleukin-6 and with anti-interleukin-23 therapeutics led to changes in systemic exposures of CYP substrates ranging from ~ –58% to ~35%; no significant trends were observed for cytochrome P450 subfamily 2D6 (dextromethorphan) and cytochrome P450 subfamily 2C9 (warfarin) substrates. Although none of these changes in systemic exposures have been reported as clinically meaningful, dose adjustment of midazolam for optimal sedation in acute care settings has been reported. Simulated concentration-time profiles of midazolam under conditions of elevated cytokine levels when coadministered with tocilizumab, suggest a ~six- to sevenfold increase in midazolam clearance, suggesting potential implications of cytokine–CYP drug interactions on dose adjustments of sensitive CYP3A substrates in acute care settings. Additionally, this article also provides a brief overview of nonclinical and clinical assessments of cytokine–CYP drug interactions in drug discovery and development.

Pregnane X receptor (PXR) belongs to the nuclear receptor superfamily that plays a crucial role in hepatic physiologic and pathologic conditions. Phase separation is a process in which biomacromolecules aggregate and condense into a dense phase as liquid condensates and coexist with a dilute phase, contributing to various cellular and biologic functions. Until now, whether PXR could undergo phase separation remains unclear. This study aimed to investigate whether PXR undergoes phase separation. Analysis of the intrinsically disordered regions (IDRs) using algorithm tools indicated a low propensity of PXR to undergo phase separation. Experimental assays such as hyperosmotic stress, agonist treatment, and optoDroplets assay demonstrated the absence of phase separation for PXR. OptoDroplets assay revealed the inability of the fusion protein of Cry2 with PXR to form condensates upon blue light stimulation. Moreover, phase separation of PXR did not occur even though the mRNA and protein expression levels of PXR target, cytochrome P450 3A4, changed after sorbitol treatment. In conclusion, for the first time, these findings suggested that exogenous PXR does not undergo phase separation following activation or under hyperosmotic stress in nucleus of cells.

The orexigenic gut peptide ghrelin is an endogenous ligand for the growth hormone secretagogue receptor type 1a (GHSR1a). Systemic ghrelin administration has previously been shown to increase gastric motility and emptying. While these effects are known to be mediated by the vagus nerve, the cellular mechanism underlying these effects remains unclear. Therefore, the purpose of the present study was to investigate the signaling mechanism by which GHSR1a inhibits voltage-gated Ca²⁺ channels in isolated rat gastric vagal afferent neurons using whole-cell patch-clamp electrophysiology. The ghrelin pharmacological profile indicated that Ca²⁺ currents were inhibited with a log (Ic₅₀) = –2.10 ± 0.44 and a maximal inhibition of 42.8 ± 5.0%. Exposure to the GHSR1a receptor antagonist (D-Lys3)-GHRP-6 reduced ghrelin-mediated Ca²⁺ channel inhibition (29.4 ± 16.7% vs. 1.9 ± 2.5%, n = 6, P = 0.0064). Interestingly, we observed that activation of GHSR1a inhibited Ca²⁺ currents through both voltage-dependent and voltage-independent pathways. We also treated the gastric neurons with either pertussis toxin (PTX) or YM-254890 to examine whether the Ca²⁺ current inhibition was mediated by the Gα_i/o or Gα_q/11 family of subunits. Treatment with both PTX (Ca²⁺ current inhibition = 15.7 ± 10.6%, n = 8, P = 0.0327) and YM-254890 (15.2 ± 11.9%, n = 8, P = 0.0269) blocked ghrelin’s effects on Ca²⁺ currents, as compared with control neurons (34.3 ± 18.9%, n = 8). These results indicate GHSR1a can couple to both Gα_i/o and Gα_q/11 in gastric vagal afferent neurons. Overall, our findings suggest GHSR1a-mediated inhibition of Ca²⁺ currents occurs through two distinct pathways, offering necessary insights into the cellular mechanisms underlying ghrelin’s regulation of gastric vagal afferents.

ABSTRACTDespite global consensus on the importance of male involvement in family planning, disparities persist in low- and middle-income countries, where women continue to bear the responsibility for these initiatives. The Philippines, with a high fertility rate and unmet family planning needs, exemplifies this challenge. We present the experiences and lessons learned from implementing the no-scalpel vasectomy (NSV) program in Davao City, showcasing its potential for increasing male engagement in family planning decisions. Launched in 2008, the program aimed to address gender disparity by promoting NSV as a safe and effective contraceptive alternative to female-centric methods. Through the use of culturally sensitive information campaigns and couple-focused counseling, the program challenged traditional notions of masculinity and encouraged shared decision-making. Strong local government commitment and public-private partnerships played key roles in driving the program’s success. Results showed an average annual increase of 80% in NSV clients over the past 3 years compared to before the COVID-19 pandemic, underscoring its effectiveness. The program presents a compelling intervention model for similar initiatives, highlighting how overcoming cultural barriers, infrastructure limitations, and budgetary constraints through policy advocacy, strategic partnerships, and tailored approaches can significantly boost male involvement in family planning and improve reproductive health outcomes within communities.

ABSTRACTWe document the effort over the last 30 years to respond to the call by women advocates at the International Conference on Population and Development for more woman-initiated single or dual-purpose contraceptive methods by developing the Caya contoured diaphragm, an innovative diaphragm designed to meet the needs of women and their partners and expand options for nonhormonal barrier contraception. We describe the complex and interrelated set of activities undertaken to develop the product using a human-centered design process and how we are working to create a corollary sustainable market. This review includes the evidence generated around improved acceptability among couples in low- and middle-income countries and depicts challenges and practical actions on how to dispel misconceptions about diaphragm use. Importantly, we share programmatic lessons learned on increasing universal access to this new sexual and reproductive health technology. Following our new model for increasing access to new and underutilized methods, Caya is now registered and being marketed in nearly 40 countries worldwide.

ABSTRACTIntroduction:Emergency contraceptive pills (ECPs) are effective and can be used safely at any age repeatedly within the same cycle. They are often favored by youth yet are underutilized. Private facilities can increase ECP access but present barriers including cost. Identifying effective public-sector ECP distribution models can help ensure equitable access. The Malawi Ministry of Health developed a strategy to improve ECP access in 2020. We documented ECP provision through select public, youth-serving channels recommended by the strategy: general and youth-specific outreach, paid and unpaid community health workers (CHWs), and youth clubs.Methods:We conducted this mixed methods study from November 2022–March 2023 in 2 rural districts (Mchinji and Phalombe) implementing the strategy. We conducted qualitative interviews with 10 national stakeholders, 46 providers, and 24 clients aged 15–24 years about ECP service delivery. Additionally, 25 providers collected quantitative tally data about clients seeking ECPs. We analyzed qualitative data using grounded theory and quantitative data descriptively.Results:Stakeholders and providers reported ECP uptake increased in geographies where the strategy was implemented, especially among youth. Providers documented 3,988 client visits for ECPs over 3 months. Of these visits, 26% were from male clients, 36% were from clients aged younger than 20 years, and 64% received ECPs for the first time. Across channels, youth club leaders and unpaid CHWs reported the most client visits per provider and served the youngest clients. However, no ECPs were dispensed during 29% of visits due to stock-outs. While many providers were supportive of youth accessing ECPs, most held unfavorable attitudes toward repeat use.Conclusion:ECP access should be expanded through provision in the studied channels, especially youth clubs and CHWs. However, to meet demand, the supply chain must be strengthened. We recommend addressing providers’ attitudes about repeat use to ensure informed method choice.

ABSTRACTTraining health workers is one of the biggest challenges and cost drivers when introducing a new contraceptive method or service delivery innovation. PATH developed a digital training curriculum for family planning providers who are learning to offer subcutaneous DMPA (DMPA-SC), including through self-injection, as an option among a range of contraceptive methods. The DMPA-SC eLearning course for health workers includes 10 lessons with an emphasis on informed choice counseling and training clients to self-inject. In partnership with Ministries of Health in Senegal and Uganda, the course was rolled out in select areas in 2019–2020, including during the COVID-19 pandemic when physical distancing requirements restricted in-person training. We conducted evaluations in both countries to assess the practical application of this digital training approach for contraceptive introduction. The evaluation consisted of a post-training survey, an observational assessment conducted during post-training supportive supervision, and an estimation of training costs.In both countries, a majority (88.6% in Uganda and 64.3% in Senegal) scored above 80% on a DMPA-SC knowledge test following the training. In Senegal, where there was a comparison group of providers trained in person, those providers scored similar on the post-test to eLearners. Providers in both groups and in both countries felt more prepared to administer DMPA-SC or offer self-injection to clients after receiving a supervision visit (93%–98% of eLearners felt very prepared after supervision as compared to 45%–72% prior). The evaluation results suggest that digital approaches offer a number of benefits, can be cost-effective, and are most optimal when blended with in-person training and/or supportive supervision.

ABSTRACTBackground: This analysis aimed to evaluate the effectiveness of eliciting sexual partners from HIV-positive clients using the elicitation box model (where an HIV-positive index can report sexual contacts on paper and insert in a box for a health care provider to contact at a later time) compared to the conventional model (in which a health care provider elicits sexual contacts directly from clients) in Akwa Ibom, Southern Nigeria.Methods: Between March 2021 and April 2022, data were collected from index testing registers at 4 health facilities with a high volume of HIV clients currently on treatment in 4 local government areas in Akwa Ibom State. Primary outcome analyzed was the elicitation ratio (number of partners elicited per HIV-index offered index testing services). Secondary outcomes were the index testing acceptance (index HIV-positive clients accepted index testing service), testing coverage (partners tested for HIV from a list of partners elicited from HIV-index accepted index testing services), testing yield (index partners identified HIV positive from index partners HIV-tested), and linkage rate (index partners identified HIV positive and linked to antiretroviral therapy).Results: Of the total 2,705 index clients offered index testing services, 91.9% accepted, with 2,043 and 439 indexes opting for conventional elicitation and elicitation box models, respectively. A total of 3,796 sexual contacts were elicited: 2,546 using the conventional model (elicitation ratio=1:1) and 1,250 using the elicitation box model (elicitation ratio=1:3). Testing coverage was significantly higher in the conventional compared to the elicitation box model (P<.001). However, there was no significant difference in the testing yield (P=.81) and linkage rate using the conventional compared to elicitation box models (P=.13).Conclusion: The implementation of the elicitation box model resulted in an increase in partner elicitation compared to the conventional model. Increasing the testing coverage by implementing the elicitation box model should be considered.

ABSTRACTIntroduction:Postpartum hemorrhage (PPH) remains the leading cause of maternal mortality. A new clinical intervention (E-MOTIVE) holds the potential to improve early PPH detection and management. We aimed to develop and pilot implementation strategies to support uptake of this intervention in Kenya, Nigeria, South Africa, and Tanzania.Methods:Implementation strategy development: We triangulated findings from qualitative interviews, surveys and a qualitative evidence synthesis to identify current PPH care practices and influences on future intervention implementation. We mapped influences using implementation science frameworks to identify candidate implementation strategies before presenting these at stakeholder consultation and design workshops to discuss feasibility, acceptability, and local adaptations. Piloting: The intervention and implementation strategies were piloted in 12 health facilities (3 per country) over 3 months. Interviews (n=58), case report forms (n=1,269), and direct observations (18 vaginal births, 7 PPHs) were used to assess feasibility, acceptability, and fidelity.Results:Implementation strategy development: Key influences included shortages of drugs, supplies, and staff, limited in-service training, and perceived benefits of the intervention (e.g., more accurate PPH detection and reduced PPH mortality). Proposed implementation strategies included a PPH trolley, on-site simulation-based training, champions, and audit and feedback. Country-specific adaptations included merging the E-MOTIVE intervention with national maternal health trainings, adapting local PPH protocols, and PPH trollies depending on staff needs. Piloting: Intervention and implementation strategy fidelity differed within and across countries. Calibrated drapes resulted in earlier and more accurate PPH detection but were not consistently used at the start. Implementation strategies were feasible to deliver; however, some instances of limited use were observed (e.g., PPH trolley and skills practice after training).Conclusion:Systematic intervention development, piloting, and process evaluation helped identify initial challenges related to intervention fidelity, which were addressed ahead of a larger-scale effectiveness evaluation. This has helped maximize the internal validity of the trial.

ABSTRACTPolitics is one of the critical factors that influence health policy agendas. However, scholarly efforts, especially in low- and middle-income countries, rarely focus on how politics influence health policy agenda-setting. We conducted a qualitative document review to examine the factors that led to developing the free primary health care policy for maternal health in Papua New Guinea. We also discuss mechanisms through which national politics, as an overriding factor, influenced the development of the policy. The review draws on Kingdon’s multiple-stream model for agenda-setting and incorporates theoretical insights from Fox and Reich’s framework for analyzing the politics of health reform for universal health coverage in low- and middle-income countries.

Mitochondrial dysfunction is a hallmark of many genetic neurodegenerative diseases, but therapeutic options to reverse mitochondrial dysfunction are limited. While recent studies support the possibility of improving mitochondrial fusion/fission dynamics and motility to correct mitochondrial dysfunction and resulting neurodegeneration in Charcot-Marie-Tooth disease (CMT) and other neuropathies, the clinical utility of reported compounds and relevance of preclinical models are uncertain. Here, we describe motor and sensory neuron dysfunction characteristic of clinical CMT type 2 A in a CRISPR/Casp-engineered Mfn2 Thr105Met (T105M) mutant knock-in mouse. We further demonstrate that daily oral treatment with a novel mitofusin activator derived from the natural product piperine can reverse these neurologic phenotypes. Piperine derivative 8015 promoted mitochondrial fusion and motility in Mfn2-deficient cells in a mitofusin-dependent manner and reversed mitochondrial dysfunction in cultured fibroblasts and reprogrammed motor neurons from a human CMT2A patient carrying the MFN2 T105M mutation. Like previous mitofusin activators, 8015 exhibited stereospecific functionality, but the more active stereoisomer, 8015-P2, is unique in that it has subnanomolar potency and undergoes entero-hepatic recirculation which extends its in vivo half-life. Daily administration of 8015-P2 to Mfn2 T105M knock-in mice for 6 weeks normalized neuromuscular and sensory dysfunction and corrected histological/ultrastructural neurodegeneration and neurogenic myoatrophy. These studies describe a more clinically relevant mouse model of CMT2A and an improved mitofusin activator derived from piperine. We posit that 8015-P2 and other piperine derivatives may benefit CMT2A or other neurodegenerative conditions wherein mitochondrial dysdynamism plays a contributory role.

Glioblastoma (GBM) is a disease of the whole brain, with infiltrative tumor cells protected by an intact blood-brain barrier (BBB). GBM has a poor prognosis despite aggressive treatment, in part due to the lack of adequate drug permeability at the BBB. Standard of care GBM therapies include radiation and cytotoxic chemotherapy that lead to DNA damage. Subsequent activation of DNA damage response (DDR) pathways can induce resistance. Various DDR inhibitors, targeting the key regulators of these pathways such as ataxia telangiectasia mutated and Rad3-related (ATR), are being explored as radio- and chemosensitizers. Elimusertib, a novel ATR kinase inhibitor, can prevent repair of damaged DNA, increasing efficacy of DNA-damaging cytotoxic therapies. Robust synergy was observed in vitro when elimusertib was combined with the DNA-damaging agent temozolomide; however, we did not observe improvement with this combination in in vivo efficacy studies in GBM orthotopic tumor-bearing mice. This in vitro–in vivo disconnect was explored to understand factors influencing central nervous system (CNS) distribution of elimusertib and reasons for lack of efficacy. We observed that elimusertib is rapidly cleared from systemic circulation in mice and would not maintain adequate exposure in the CNS for efficacious combination therapy with temozolomide. CNS distribution of elimusertib is partially limited by P-glycoprotein efflux at the BBB, and high binding to CNS tissues leads to low levels of pharmacologically active (unbound) drug in the brain. Acknowledging the potential for interspecies differences in pharmacokinetics, these data suggest that clinical translation of elimusertib in combination with temozolomide for treatment of GBM may be limited.

The development of transforming growth factor βreceptor inhibitors (TGFβRi) as new medicines has been affected by cardiac valvulopathy and arteriopathy toxicity findings in nonclinical toxicology studies. PF-06952229 (MDV6058) selected using rational drug design is a potent and selective TGFβRI inhibitor with a relatively clean off-target selectivity profile and good pharmacokinetic properties across species. PF-06952229 inhibited clinically translatable phospho-SMAD2 biomarker (≥60%) in human and cynomolgus monkey peripheral blood mononuclear cells, as well as in mouse and rat splenocytes. Using an optimized, intermittent dosing schedule (7-day on/7-day off/cycle; 5 cycles), PF-06952229 demonstrated efficacy in a 63-day syngeneic MC38 colon carcinoma mouse model. In the pivotal repeat-dose toxicity studies (rat and cynomolgus monkey), PF-06952229 on an intermittent dosing schedule (5-day on/5-day off cycle; 5 cycles, 28 doses) showed no cardiac-related adverse findings. However, new toxicity findings related to PF-06952229 included reversible hepatocellular (hepatocyte necrosis with corresponding clinically monitorable transaminase increases) and lung (hemorrhage with mixed cell inflammation) findings at ≥ targeted projected clinical efficacious exposures. Furthermore, partially reversible cartilage hypertrophy (trachea and femur in rat; femur in monkey) and partially to fully reversible, clinically monitorable decreases in serum phosphorus and urinary phosphate at ≥ projected clinically efficacious exposures were observed. Given the integral role of TGFβ in endochondral bone formation, cartilage findings in toxicity studies have been observed with other TGFβRi classes of compounds. The favorable cumulative profile of PF-06952229 in biochemical, pharmacodynamic, pharmacokinetic, and nonclinical studies allowed for its evaluation in cancer patients using the intermittent dosing schedule (7-day on/7-day off) and careful protocol-defined monitoring.

Clinical reports suggest that the most effective strategies for managing opioid use disorder comprise a comprehensive treatment program of both pharmacological and nonpharmacological approaches. However, the conditions under which these combinations are most effective are not well characterized. This study examined whether the presence of an alternative reinforcer could alter the efficacy of Food and Drug Administration–approved opioid antagonist or agonist medications, as well as the nonopioid flumazenil, in decreasing oxycodone choice self-administration in nonhuman primates. Adult squirrel monkeys (n = 7; four females) responded under concurrent second-order fixed-ratio (FR)-3(FR5:S);TO45s schedules of reinforcement for intravenous oxycodone (0.1 mg/kg) or saline on one lever and 30% sweetened condensed milk or water on the other. Doses of naltrexone (0.00032–1.0 mg/kg), nalbuphine (0.32–10 mg/kg), buprenorphine (0.0032–0.032 mg/kg), methadone (0.32–1.0 mg/kg), or flumazenil (1–3.2 mg/kg) were administered intramuscularly prior to oxycodone self-administration sessions that occurred with either milk or water as the alternative. Naltrexone, a μ-opioid receptor antagonist, was >30-fold more potent when milk was available compared with water and abolished oxycodone intake (injections/session) while concomitantly increasing milk deliveries at the highest dose tested. Pretreatment with the low-efficacy μ-agonist nalbuphine was most effective in the presence of milk compared with water, decreasing oxycodone preference to <50% of control values. The higher efficacy μ-agonists, methadone and buprenorphine, and the benzodiazepine antagonist flumazenil did not appreciably alter the reinforcing potency of oxycodone under either condition. These results suggest that antagonist medications used in combination with alternative reinforcers may be an effective strategy to curtail opioid abuse–related behaviors.

Cannabinoid and opioid receptor activities can be modulated by a variety of post-translational mechanisms including the formation of interacting complexes. This study examines the involvement of endogenous and exogenous chaperones in modulating the abundance and activity of cannabinoid CB₁ receptor (CB₁R), opioid receptor (DOR), and CB₁R-DOR interacting complexes. Focusing on endogenous protein chaperones, namely receptor transporter proteins (RTPs), we examined relative mRNA expression in the mouse spinal cord and found RTP4 to be expressed at higher levels compared with other RTPs. Next, we assessed the effect of RTP4 on receptor abundance by manipulating RTP4 expression in cell lines. Overexpression of RTP4 causes an increase and knock-down causes a decrease in the levels of CB₁R, DOR, and CB₁R-DOR interacting complexes; this is accompanied by parallel changes in signaling. The ability of small molecule lipophilic ligands to function as exogenous chaperones was examined using receptor-selective antagonists. Long-term treatment leads to increases in receptor abundance and activity with no changes in mRNA supporting a role as pharmacological chaperones. Finally, the effect of cannabidiol (CBD), a small molecule ligand and a major active component of cannabis, on receptor abundance and activity in mice was examined. We find that CBD administration leads to increases in receptor abundance and activity in mouse spinal cord. Together, these results highlight a role for chaperones (proteins and small molecules) in modulating levels and activity of CB₁R, DOR, and their interacting complexes potentially through mechanisms including receptor maturation and trafficking.

Endocannabinoids, which are present throughout the central nervous system (CNS), can activate cannabinoid receptors 1 and 2 (CB1 and CB2). CB1 and CB2 agonists exhibit broad anti-inflammatory properties, suggesting their potential to treat inflammatory diseases. However, careful evaluation of abuse potential is necessary. This study evaluated the abuse potential of lenabasum, a selective CB2 receptor agonist in participants (n = 56) endorsing recreational cannabis use. Three doses of lenabasum (20, 60, and 120 mg) were compared with placebo and nabilone (3 and 6 mg). The primary endpoint was the peak effect (E_max) on a bipolar Drug Liking visual analog scale (VAS). Secondary VAS and pharmacokinetic (PK) endpoints and adverse events were assessed. Lenabasum was safe and well tolerated. Compared with placebo, a 20-mg dose of lenabasum did not increase ratings of Drug Liking and had no distinguishable effect on other VAS endpoints. Dose-dependent increases in ratings of Drug Liking were observed with 60 and 120 mg lenabasum. Drug Liking and all other VAS outcomes were greatest for nabilone 3 mg and 6 mg, a medication currently approved by the US Food and Drug Administration (FDA). At a target therapeutic dose (20 mg), lenabasum did not elicit subjective ratings of Drug Liking. However, supratherapeutic doses of lenabasum (60 and 120 mg) did elicit subjective ratings of Drug Liking compared with placebo. Although both doses of lenabasum were associated with lower ratings of Drug Liking compared with 3 mg and 6 mg nabilone, lenabasum does have abuse potential and should be used cautiously in clinical settings.