Single-cell sensor analyses reveal signaling programs enabling Ras-G12C drug resistance.

Clinical resistance to rat sarcoma virus (Ras)-G12C inhibitors is a challenge. A subpopulation of cancer cells has been shown to undergo genomic and transcriptional alterations to facilitate drug resistance but the immediate adaptive effects on Ras signaling in response to these drugs at the single-cell level is not well understood. Here, we used Ras biosensors to profile the activity and signaling environment of endogenous Ras at the single-cell level. We found that a subpopulation of KRas-G12C cells treated with Ras-G12C-guanosine-diphosphate inhibitors underwent adaptive signaling and metabolic changes driven by wild-type Ras at the Golgi and mutant KRas at the mitochondria, respectively. Our Ras biosensors identified major vault protein as a mediator of Ras activation through its scaffolding of Ras signaling pathway components and metabolite channels. Overall, methods including ours that facilitate direct analysis on the single-cell level can report the adaptations that subpopulations of cells adopt in response to cancer therapies, thus providing insight into drug resistance.

The substantial burden of iatrogenic vascular injury on the vascular surgery workforce at an academic medical center.

OBJECTIVE: Vascular surgeons are often called upon to provide emergent surgical assistance to other specialties for iatrogenic complications, both intraoperatively and in the inpatient setting. The management of iatrogenic vascular injury remains a critical role of the vascular surgeon, especially in the context of the increasing adoption of percutaneous procedures by other specialties. This study aims to characterize consultation timing, management, and outcomes for iatrogenic vascular injuries. METHODS: This study identified patients for whom vascular surgery was consulted for iatrogenic vascular complications from February 1, 2022, to May 12, 2023. Patient information, including demographic information, injury details, and details of any operative intervention, was retrospectively collected from February 1, 2022, to October 13, 2022, and prospectively collected for the remainder of the study period. Analyses were performed with R (version 2022.02.03). RESULTS: There were 87 patients with consultations related to iatrogenic vascular injury. Of these, 42 (46%) were female and the mean age was 59 years (±18 years). The most common consulting services were cardiology (32%), cardiothoracic surgery (26%), general surgery (8%), and neurointerventional radiology (10%). Reasons for consultation included hemorrhage (36%), limb ischemia (36%), and treatment of pseudoaneurysm (23%). A total of 24% of consults were intraoperative, 20% of consults related to extracorporeal membrane oxygenation cannulation, and 16% of consults related to ventricular assist devices including left ventricular assist device and intra-aortic balloon pump. The majority of these consult requests (60%) occurred during evening and night hours (5 PM to 7 AM). Emergent intervention was required in 62% of cases and consisted of primary open surgical repair of arterial injury (54%), endovascular intervention (21%), and open thromboembolectomy (15%). Overall, in-hospital mortality for the patient cohort was 20% and the reintervention rate was 23%, reflecting the underlying complexity of the illness and nature of the vascular injury in this patient group. CONCLUSIONS: Vascular surgeons play an essential role in managing emergent life-threatening hemorrhagic and ischemic iatrogenic vascular complications in the hospitalized setting. The complications require immediate bedside or intraoperative consult and often emergent open surgical or endovascular intervention. Furthermore, many of these require urgent management in the evening or overnight hours, and therefore the high frequency of these events represents a potential significant resource utilization and workforce issue to the vascular surgery workforce.

ASSOCIATION OF METFORMIN USE WITH RISK OF NEWLY ONSET NEOVASCULAR AGE-RELATED MACULAR DEGENERATION DEVELOPMENT.

PURPOSE: To investigate if metformin use reduces the odds of developing new neovascular AMD (nAMD). METHODS: This is a case-control study of 86,930 subjects with new diagnoses of nAMD and 86,918 matched control subjects using the Merative Marketscan Research Databases. Subjects were analyzed using multivariable conditional logistic regression to identify the risks of various exposures on developing nAMD. A subgroup analysis of 22,117 diabetic cases and 21,616 diabetic control subjects was also performed. RESULTS: Metformin use was associated with reduced odds ratio of developing nAMD (odds ratio 0.95, 95% confidence interval 0.91-0.98) in full sample and diabetic cohort particularly in patients without any diabetic retinopathy-an effect that persisted after Bonferroni correction. In the diabetic cohort without diabetic retinopathy, reduced odds ratio was observed at 24-month cumulative doses of 1 to 300 g, 301 to 630 g, and 631 to 1,080 g. CONCLUSION: Metformin use was associated with reduced odds ratio of nAMD, particularly in patients without diabetic retinopathy. The protective effect was noted for 24-month cumulative doses below 1,080 g. Metformin may be a novel preventive strategy for nAMD.

The natural history of celiac artery aneurysms.

OBJECTIVES: The goal of this study was to document the natural history of celiac artery aneurysms (CAAs). BACKGROUND: Celiac artery aneurysms are rare. Existing literature is skewed towards outcomes after intervention of large, symptomatic aneurysms but the behavior of untreated CAAs is poorly understood. METHODS: This is a single institution, retrospective analysis of patients with CAA diagnosed by CT imaging (2015-2019) identified through an institutional radiology database. Radiologic, demographic, and follow-up data were analyzed. The primary endpoint was the mean growth rate of CAAs. RESULTS: Of the 76 patients included, 86.8% were men with a mean age at presentation of 69.8 years. The mean CAA diameter on index imaging was 15.4 +/- 3.8 mm (range, 7-30 mm). All were classified as true aneurysms and 76.3% were saccular. All patients had clinical follow-up with mean follow-up 31.2 months +/- 21.6 months. No patient developed symptoms or rupture. The mean radiological follow-up among 45 patients was 25.2 +/- 16.8 months. Over this period, 16 CAAs (35.6%) enlarged, while 29 (64.4%) remained stable. One patient (1.3%) underwent intervention for increasing size in the setting of a chronic dissection. On multivariate analysis, age <70 was significantly associated with increased risk of aneurysm growth. CONCLUSIONS: In this institutional review of patients with CAAs, the majority of aneurysms remained stable in size, with no patients developing symptoms or rupture over clinical follow-up. Given the observed benign behavior of these aneurysms, guidelines that suggest conservative management of CAAs less than 2 cm seems appropriate.

Association of metformin use with risk of newly onset neovascular age-related macular degeneration development.

PURPOSE: To investigate if metformin use reduces the odds of developing new neovascular AMD (nAMD). METHODS: This is a case-control study of 86,930 subjects with new diagnoses of nAMD and 86,918 matched controls using the Merative™ Marketscan® Research Databases. Subjects were analyzed using multivariable conditional logistic regression to identify the risks of various exposures on developing nAMD. A subgroup analysis of 22,117 diabetic cases and 21,616 diabetic controls was also performed. RESULTS: Metformin use was associated with reduced odds ratio (OR) of developing nAMD (OR 0.95, 95% confidence interval 0.91-0.98) in full sample and diabetic cohort particularly in patients without any diabetic retinopathy (DR) -an effect that persisted after Bonferroni correction. In the diabetic cohort without DR, reduced OR was observed at 24-month cumulative doses of 1 to 300g, 301 to 630g, and 631 to 1080g. CONCLUSIONS: Metformin use was associated with reduced OR of nAMD, particularly in patients without DR. The protective effect was noted for 24-month cumulative doses below 1080g. Metformin may be a novel preventive strategy for nAMD.

The impact of high-order features on performance of radiomics studies in CT non-small cell lung cancer.

High-order radiomic features have been shown to produce high performance models in a variety of scenarios. However, models trained without high-order features have shown similar performance, raising the question of whether high-order features are worth including given their increased computational burden. This comparative study investigates the impact of high-order features on model performance in CT-based Non-Small Cell Lung Cancer (NSCLC) and the potential uncertainty regarding their application in machine learning. Three categories of features were retrospectively retrieved from CT images of 347 NSCLC patients: first- and second-order statistical features, morphological features and transform (high-order) features. From these, three datasets were constructed: a "low-order" dataset (Lo) which included the first-order, second-order, and morphological features, a high-order dataset (Hi), and a combined dataset (Combo). A diverse selection of datasets, feature selection methods, and predictive models were included for the uncertainty analysis, with two-year survival as the study endpoint. AUC values were calculated for comparisons and Kruskal-Wallis testing was performed to determine significant differences. The Hi (AUC: 0.41-0.62) and Combo (AUC: 0.41-0.62) datasets generate significantly (P < 0.01) higher model performance than the Lo dataset (AUC: 0.42-0.58). High-order features are selected more often than low-order features for model training, comprising 87 % of selected features in the Combo dataset. High-order features are a source of data that can improve machine learning model performance. However, its impact strongly depends on various factors that may lead to inconsistent results. A clear approach to incorporate high-order features in radiomic studies requires further investigation.

Antidepressant Dispensing to US Adolescents and Young Adults: 2016-2022.

BACKGROUND: Mental health worsened in adolescents and young adults after the coronavirus disease 2019 (COVID-19) outbreak in March 2020, but whether antidepressant dispensing to this population changed is unknown. METHODS: We identified antidepressant prescriptions dispensed to US individuals aged 12 to 25 years from 2016 to 2022 using the IQVIA Longitudinal Prescription Database, an all-payer national database. The outcome was the monthly antidepressant dispensing rate, defined as the monthly number of individuals with ≥1 dispensed antidepressant prescription per 100 000 people. We fitted linear segmented regression models assessing for level or slope changes during March 2020 and conducted subgroup analyses by sex and age group. RESULTS: Between January 2016 and December 2022, the monthly antidepressant dispensing rate increased 66.3%, from 2575.9 to 4284.8. Before March 2020, this rate increased by 17.0 per month (95% confidence interval: 15.2 to 18.8). The COVID-19 outbreak was not associated with a level change but was associated with a slope increase of 10.8 per month (95% confidence interval: 4.9 to 16.7). The monthly antidepressant dispensing rate increased 63.5% faster from March 2020 onwards compared with beforehand. In subgroup analyses, this rate increased 129.6% and 56.5% faster from March 2020 onwards compared with beforehand among females aged 12 to 17 years and 18 to 25 years, respectively. In contrast, the outbreak was associated with a level decrease among males aged 12 to 17 years and was not associated with a level or slope change among males aged 18 to 25 years. CONCLUSIONS: Antidepressant dispensing to adolescents and young adults was rising before the COVID-19 outbreak and rose 63.5% faster afterward. This change was driven by increased antidepressant dispensing to females and occurred despite decreased dispensing to male adolescents.

Strategies for improving the performance of prediction models for response to immune checkpoint blockade therapy in cancer.

Immune checkpoint blockade (ICB) therapy holds promise for bringing long-lasting clinical gains for the treatment of cancer. However, studies show that only a fraction of patients respond to the treatment. In this regard, it is valuable to develop gene expression signatures based on RNA sequencing (RNAseq) data and machine learning methods to predict a patient's response to the ICB therapy, which contributes to more personalized treatment strategy and better management of cancer patients. However, due to the limited sample size of ICB trials with RNAseq data available and the vast number of candidate gene expression features, it is challenging to develop well-performed gene expression signatures. In this study, we used several published melanoma datasets and investigated approaches that can improve the construction of gene expression-based prediction models. We found that merging datasets from multiple studies and incorporating prior biological knowledge yielded prediction models with higher predictive accuracies. Our finding suggests that these two strategies are of high value to identify ICB response biomarkers in future studies.

Thoracic Intervertebral Disc Herniation Associated With Chronic Anabolic Androgenic Steroid Use: A Case Report.

Anabolic androgenic steroids (AAS) are relatively cheap and accessible medications, commonly used by athletes and bodybuilders for performance enhancement and muscle growth stimulation. AAS usage has been associated with musculoskeletal injuries, such as tendon and ligament ruptures, and numerous other detrimental health effects. Despite these risks, individuals continue to self-administer these drugs in supraphysiologic doses. Here, we present a case of a male bodybuilder with chronic AAS use who developed a spinal thoracic intervertebral disc herniation requiring decompression and fusion. We use this case to highlight a severe potential risk associated with chronic AAS abuse and review the current literature on the biochemical, physical, and physiologic mechanisms linking chronic AAS use, weight-bearing exercise, and the risk of musculoskeletal injuries such as intervertebral disc herniations.

A 5' UTR Language Model for Decoding Untranslated Regions of mRNA and Function Predictions.

The 5' UTR, a regulatory region at the beginning of an mRNA molecule, plays a crucial role in regulating the translation process and impacts the protein expression level. Language models have showcased their effectiveness in decoding the functions of protein and genome sequences. Here, we introduced a language model for 5' UTR, which we refer to as the UTR-LM. The UTR-LM is pre-trained on endogenous 5' UTRs from multiple species and is further augmented with supervised information including secondary structure and minimum free energy. We fine-tuned the UTR-LM in a variety of downstream tasks. The model outperformed the best known benchmark by up to 5% for predicting the Mean Ribosome Loading, and by up to 8% for predicting the Translation Efficiency and the mRNA Expression Level. The model also applies to identifying unannotated Internal Ribosome Entry Sites within the untranslated region and improves the AUPR from 0.37 to 0.52 compared to the best baseline. Further, we designed a library of 211 novel 5' UTRs with high predicted values of translation efficiency and evaluated them via a wet-lab assay. Experiment results confirmed that our top designs achieved a 32.5% increase in protein production level relative to well-established 5' UTR optimized for therapeutics.

Computationally designed sensors detect endogenous Ras activity and signaling effectors at subcellular resolution.

The utility of genetically encoded biosensors for sensing the activity of signaling proteins has been hampered by a lack of strategies for matching sensor sensitivity to the physiological concentration range of the target. Here we used computational protein design to generate intracellular sensors of Ras activity (LOCKR-based Sensor for Ras activity (Ras-LOCKR-S)) and proximity labelers of the Ras signaling environment (LOCKR-based, Ras activity-dependent Proximity Labeler (Ras-LOCKR-PL)). These tools allow the detection of endogenous Ras activity and labeling of the surrounding environment at subcellular resolution. Using these sensors in human cancer cell lines, we identified Ras-interacting proteins in oncogenic EML4-Alk granules and found that Src-Associated in Mitosis 68-kDa (SAM68) protein specifically enhances Ras activity in the granules. The ability to subcellularly localize endogenous Ras activity should deepen our understanding of Ras function in health and disease and may suggest potential therapeutic strategies.

Association of Contrast Sensitivity With Eye Disease and Vision-Related Quality of Life.

PURPOSE: To investigate contrast sensitivity (CS) as a screening tool to detect eye disease and assess its association with both eye disease and vision-related quality of life. DESIGN: Cross-sectional study. METHODS: Setting and population: Adults receiving care from a free clinic and a Federally Qualified Health Center in Michigan. MAIN OUTCOME MEASURES: Screening positive for eye disease and Visual Function Questionnaire (VFQ) score. OBSERVATION: Participants received a vision exam reviewed via telemedicine for disease, completed a demographic survey, and the 9-item VFQ. The ability of CS to predict eye disease was explored and area under the curve (AUC) is reported. Logistic and linear regression were used to investigate the continuous effect of CS on the probability of screening positive for eye disease and VFQ score, respectively, adjusting for age and visual acuity. RESULTS: 1159 included participants were, on average, 54.9 ± 14.5 years old, 62% identified as female, 34% as White, 54% as Black, 10% as Hispanic/Latino, and reported mean VFQ score of 79.7 ± 15.3. CS ranged from 0.00 to 1.95 log units (mean = 1.54 ± 0.24), 21% of eyes had glaucoma, 19% cataract, 6% DR, and 2% AMD. AUCs were 0.53 to 0.73. A 0.3 log unit decrease in better eye CS was associated with increased odds of glaucoma (odds ratio [OR] = 1.35, confidence interval [CI] = 1.09-1.67), cataract (OR = 1.35, CI = 1.05-1.72), DR (OR = 2.05, CI = 1.51-2.77), and AMD (OR = 2.08, CI = 1.10-3.91). A 0.3 log unit increase in better eye CS was associated with a 5.9 unit increase in VFQ. CONCLUSION: While CS alone is not sufficient to identify people with eye disease, it is an important measure of visual function that can add value to comprehensive eye screening.

The impact of a multidisciplinary intervention to reduce severe retinopathy of prematurity in Kampala, Uganda.

BACKGROUND: To address the threat of retinopathy of prematurity (ROP) in Sub-Saharan Africa (SSA), the Stop Infant Blindness in Africa (SIBA) project introduced a comprehensive program, including subspecialty training and oxygen management equipment. METHODS: A before-and-after retrospective cohort study compared preterm infants < 1750 g or < 34 weeks' gestation before (2022) and after (2023) program implementation. Outcomes included: the proportion with severe ROP, the proportion with Zone III vascularization on first examination, and factors associated with severe ROP. RESULTS: Overall, 140 infants were screened before and 122 after program implementation. The proportion with Zone III vascularization increased from 16.1% (N = 11) pre-intervention to 44.9% (N = 32) post-intervention (p = 0.001). The proportion with severe ROP decreased from 27.8% (N = 19) to 12.8% (N = 9, p = 0.03). Factors predicting severe ROP on adjusted analyses were gestational age and blood transfusion. CONCLUSION: In SSA, introduction of a comprehensive program to prevent and treat ROP can decrease the risk of severe ROP.

Computational design of non-porous pH-responsive antibody nanoparticles.

Programming protein nanomaterials to respond to changes in environmental conditions is a current challenge for protein design and is important for targeted delivery of biologics. Here we describe the design of octahedral non-porous nanoparticles with a targeting antibody on the two-fold symmetry axis, a designed trimer programmed to disassemble below a tunable pH transition point on the three-fold axis, and a designed tetramer on the four-fold symmetry axis. Designed non-covalent interfaces guide cooperative nanoparticle assembly from independently purified components, and a cryo-EM density map closely matches the computational design model. The designed nanoparticles can package protein and nucleic acid payloads, are endocytosed following antibody-mediated targeting of cell surface receptors, and undergo tunable pH-dependent disassembly at pH values ranging between 5.9 and 6.7. The ability to incorporate almost any antibody into a non-porous pH-dependent nanoparticle opens up new routes to antibody-directed targeted delivery.

Oral Metformin Inhibits Choroidal Neovascularization by Modulating the Gut-Retina Axis.

Purpose: Emerging data indicate that metformin may prevent the development of age-related macular degeneration (AMD). Whereas the underlying mechanisms of metformin's anti-aging properties remain undetermined, one proposed avenue is the gut microbiome. Using the laser-induced choroidal neovascularization (CNV) model, we investigate the effects of oral metformin on CNV, retinal pigment epithelium (RPE)/choroid transcriptome, and gut microbiota. Methods: Specific pathogen free (SPF) male mice were treated via daily oral gavage of metformin 300 mg/kg or vehicle. Male mice were selected to minimize sex-specific differences to laser induction and response to metformin. Laser-induced CNV size and macrophage/microglial infiltration were assessed by isolectin and Iba1 immunostaining. High-throughput RNA-seq of the RPE/choroid was performed using Illumina. Fecal pellets were analyzed for gut microbiota composition/pathways with 16S rRNA sequencing/shotgun metagenomics, as well as microbial-derived metabolites, including small-chain fatty acids and bile acids. Investigation was repeated in metformin-treated germ-free (GF) mice and antibiotic-treated/GF mice receiving fecal microbiota transplantation (FMT) from metformin-treated SPF mice. Results: Metformin treatment reduced CNV size (P < 0.01) and decreased Iba1+ macrophage/microglial infiltration (P < 0.005). One hundred forty-five differentially expressed genes were identified in the metformin-treated group (P < 0.05) with a downregulation in pro-angiogenic genes Tie1, Pgf, and Gata2. Furthermore, metformin altered the gut microbiome in favor of Bifidobacterium and Akkermansia, with a significant increase in fecal levels of butyrate, succinate, and cholic acid. Metformin did not suppress CNV in GF mice but colonization of microbiome-depleted mice with metformin-derived FMT suppressed CNV. Conclusions: These data suggest that oral metformin suppresses CNV, the hallmark lesion of advanced neovascular AMD, via gut microbiome modulation.