Violet-light suppression of thermogenesis by opsin 5 hypothalamic neurons.

The opsin family of G-protein-coupled receptors are used as light detectors in animals. Opsin 5 (also known as neuropsin or OPN5) is a highly conserved opsin that is sensitive to visible violet light1,2. In mice, OPN5 is a known photoreceptor in the retina3 and skin4 but is also expressed in the hypothalamic preoptic area (POA)5. Here we describe a light-sensing pathway in which POA neurons that express Opn5 regulate thermogenesis in brown adipose tissue (BAT). We show that Opn5 is expressed in glutamatergic warm-sensing POA neurons that receive synaptic input from several thermoregulatory nuclei. We further show that Opn5 POA neurons project to BAT and decrease its activity under chemogenetic stimulation. Opn5-null mice show overactive BAT, increased body temperature, and exaggerated thermogenesis when cold-challenged. Moreover, violet photostimulation during cold exposure acutely suppresses BAT temperature in wild-type mice but not in Opn5-null mice. Direct measurements of intracellular cAMP ex vivo show that Opn5 POA neurons increase cAMP when stimulated with violet light. This analysis thus identifies a violet light-sensitive deep brain photoreceptor that normally suppresses BAT thermogenesis.

Modeling single cell trajectory using forward-backward stochastic differential equations.

Recent advances in single-cell sequencing technology have provided opportunities for mathematical modeling of dynamic developmental processes at the single-cell level, such as inferring developmental trajectories. Optimal transport has emerged as a promising theoretical framework for this task by computing pairings between cells from different time points. However, optimal transport methods have limitations in capturing nonlinear trajectories, as they are static and can only infer linear paths between endpoints. In contrast, stochastic differential equations (SDEs) offer a dynamic and flexible approach that can model non-linear trajectories, including the shape of the path. Nevertheless, existing SDE methods often rely on numerical approximations that can lead to inaccurate inferences, deviating from true trajectories. To address this challenge, we propose a novel approach combining forward-backward stochastic differential equations (FBSDE) with a refined approximation procedure. Our FBSDE model integrates the forward and backward movements of two SDEs in time, aiming to capture the underlying dynamics of single-cell developmental trajectories. Through comprehensive benchmarking on multiple scRNA-seq datasets, we demonstrate the superior performance of FBSDE compared to other methods, highlighting its efficacy in accurately inferring developmental trajectories.

mTOR Inhibition Restores Amino Acid Balance in Cells Dependent on Catabolism of Extracellular Protein.

Scavenging of extracellular protein via macropinocytosis is an alternative to monomeric amino acid uptake. In pancreatic cancer, macropinocytosis is driven by oncogenic Ras signaling and contributes substantially to amino acid supply. While Ras signaling promotes scavenging, mTOR signaling suppresses it. Here, we present an integrated experimental-computational method that enables quantitative comparison of protein scavenging rates across cell lines and conditions. Using it, we find that, independently of mTORC1, amino acid scarcity induces protein scavenging and that under such conditions the impact of mTOR signaling on protein scavenging rate is minimal. Nevertheless, mTOR inhibition promotes growth of cells reliant on eating extracellular protein. This growth enhancement depends on mTORC1's canonical function in controlling translation rate: mTOR inhibition slows translation, thereby matching protein synthesis to the limited amino acid supply. Thus, paradoxically, in amino acid-poor conditions the pro-anabolic effects of mTORC1 are functionally opposed to growth.

Deep generative priors for biomolecular 3D heterogeneous reconstruction from cryo-EM projections.

Cryo-electron microscopy has become a powerful tool to determine three-dimensional (3D) structures of rigid biological macromolecules from noisy micrographs with single-particle reconstruction. Recently, deep neural networks, e.g., CryoDRGN, have demonstrated conformational and compositional heterogeneity of complexes. However, the lack of ground-truth conformations poses a challenge to assess the performance of heterogeneity analysis methods. In this work, variational autoencoders (VAE) with three types of deep generative priors were learned for latent variable inference and heterogeneous 3D reconstruction via Bayesian inference. More specifically, VAEs with "Variational Mixture of Posteriors" priors (VampPrior-SPR), non-parametric exemplar-based priors (ExemplarPrior-SPR) and priors from latent score-based generative models (LSGM-SPR) were quantitatively compared with CryoDRGN. We built four simulated datasets composed of hypothetical continuous conformation or discrete states of the hERG K + channel. Empirical and quantitative comparisons of inferred latent representations were performed with affine-transformation-based metrics. These models with more informative priors gave better regularized, interpretable factorized latent representations with better conserved pairwise distances, less deformed latent distributions and lower within-cluster variances. They were also tested on experimental datasets to resolve compositional and conformational heterogeneity (50S ribosome assembly, cowpea chlorotic mottle virus, and pre-catalytic spliceosome) with comparable high resolution. Codes and data are available: https://github.com/benjamin3344/DGP-SPR.

Association of Race and Ethnicity With High Longevity Deceased Donor Kidney Transplantation Under the US Kidney Allocation System.

RATIONALE & OBJECTIVE: The US Kidney Allocation System (KAS) prioritizes candidates with a≤20% estimated posttransplant survival (EPTS) to receive high-longevity kidneys defined by a≤20% Kidney Donor Profile Index (KDPI). Use of EPTS in the KAS deprioritizes candidates with older age, diabetes, and longer dialysis durations. We assessed whether this use also disadvantages race and ethnicity minority candidates, who are younger but more likely to have diabetes and longer durations of kidney failure requiring dialysis. STUDY DESIGN: Observational cohort study. SETTING & PARTICIPANTS: Adult candidates for and recipients of kidney transplantation represented in the Scientific Registry of Transplant Recipients from January 2015 through December 2020. EXPOSURE: Race and ethnicity. OUTCOME: Age-adjusted assignment to≤20% EPTS, transplantation of a≤20% KDPI kidney, and posttransplant survival in longevity-matched recipients by race and ethnicity. ANALYTIC APPROACH: Multivariable logistic regression, Fine-Gray competing risks survival analysis, and Kaplan-Meier and Cox proportional hazards methods. RESULTS: The cohort included 199,444 candidates (7% Asian, 29% Black, 19% Hispanic or Latino, and 43% White) listed for deceased donor kidney transplantation. Non-White candidates had significantly higher rates of diabetes, longer dialysis duration, and were younger than White candidates. Adjusted for age, Asian, Black, and Hispanic or Latino candidates had significantly lower odds of having a ETPS score of≤20% (odds ratio, 0.86 [95% CI, 0.81-0.91], 0.52 [95% CI, 0.50-0.54], and 0.49 [95% CI, 0.47-0.51]), and were less likely to receive a≤20% KDPI kidney (sub-hazard ratio, 0.70 [0.66-0.75], 0.89 [0.87-0.92], and 0.73 [0.71-0.76]) compared with White candidates. Among recipients with≤20% EPTS scores transplanted with a≤20% KDPI deceased donor kidney, Asian and Hispanic recipients had lower posttransplant mortality (HR, 0.45 [0.27-0.77] and 0.63 [0.47-0.86], respectively) and Black recipients had higher but not statistically significant posttransplant mortality (HR, 1.22 [0.99-1.52]) compared with White recipients. LIMITATIONS: Provider reported race and ethnicity data and 5-year post transplant follow-up period. CONCLUSIONS: The US kidney allocation system is less likely to identify race and ethnicity minority candidates as having a≤20% EPTS score, which triggers allocation of high-longevity deceased donor kidneys. These findings should inform the Organ Procurement and Transplant Network about how to remedy the race and ethnicity disparities introduced through KAS's current approach of allocating allografts with longer predicted longevity to recipients with longer estimated posttransplant survival. PLAIN-LANGUAGE SUMMARY: The US Kidney Allocation System prioritizes giving high-longevity, high-quality kidneys to patients on the waiting list who have a high estimated posttransplant survival (EPTS) score. EPTS is calculated based on the patient's age, whether the patient has diabetes, whether the patient has a history of organ transplantation, and the number of years spent on dialysis. Our analyses show that Asian, Black or African American, and Hispanic or Latino patients were less likely to receive high-longevity kidneys compared with White patients, despite having similar or better posttransplant survival outcomes.

Reducing Disparities: Regional Anesthesia Blocks for Mastectomy with Reconstruction Within Standardized Regional Anesthesia Pathways.

BACKGROUND: Recent data suggest disparities in receipt of regional anesthesia prior to breast reconstruction. We aimed to understand factors associated with block receipt for mastectomy with immediate tissue expander (TE) reconstruction in a high-volume ambulatory surgery practice with standardized regional anesthesia pathways. PATIENTS AND METHODS: Patients who underwent mastectomy with immediate TE reconstruction from 2017 to 2022 were included. All patients were considered eligible for and were offered preoperative nerve blocks as part of routine anesthesia care. Interpreters were used for non-English speaking patients. Patients who declined a block were compared with those who opted for the procedure. RESULTS: Of 4213 patients who underwent mastectomy with immediate TE reconstruction, 91% accepted and 9% declined a nerve block. On univariate analyses, patients with the lowest rate of block refusal were white, non-Hispanic, English speakers, patients with commercial insurance, and patients undergoing bilateral reconstruction. The rate of block refusal went down from 12 in 2017 to 6% in 2022. Multivariable logistic regression demonstrated that older age (p = 0.011), Hispanic ethnicity (versus non-Hispanic; p = 0.049), Medicaid status (versus commercial insurance; p < 0.001), unilateral surgery (versus bilateral; p = 0.045), and reconstruction in earlier study years (versus 2022; 2017, p < 0.001; 2018, p < 0.001; 2019, p = 0.001; 2020, p = 0.006) were associated with block refusal. CONCLUSIONS: An established preoperative regional anesthesia program with blocks offered to all patients undergoing mastectomy with TE reconstruction can result in decreased racial disparities. However, continued differences in age, ethnicity, and insurance status justify future efforts to enhance preoperative educational efforts that address patient hesitancies in these subpopulations.

Combined PD-1 and CTLA-4 Blockade in an International Cohort of Patients with Acral Lentiginous Melanoma.

BACKGROUND: Combination immune checkpoint blockade targeting PD-1 and CTLA-4 leads to high response rates and improved survival in advanced cutaneous melanoma (CM). Less is known about the efficacy of this combination in acral lentiginous melanoma (ALM). OBJECTIVES: To determine the efficacy of combination immune checkpoint blockade targeting PD-1 and CTLA-4 in a real-world, diverse population of ALM. METHODS: This multi-institutional retrospective study analyzed patients with histologically confirmed ALM treated with the combination of PD-1 and CTLA-4 inhibitors between 2010-2022. The primary objective of the study was objective response rate (ORR) per RECIST criteria. The secondary objectives were progression-free survival (PFS) and overall survival (OS). RESULTS: In total, 109 patients with advanced ALM treated with combined PD-1 and CTLA-4 blockade in any line of treatment were included. The majority of patients had stage IV disease (n=81, 74.2%). The ORR for the entire cohort was 18.3% (95% CI 11.6-26.9%), with 9 (8.3%) complete responses (CR) and 11 (10.1%) partial responses (PR). An additional 22 patients (20.2%) had stable disease (SD), and the disease control rate (DCR) was 38.5%. The median PFS was 4.2 months [95% CI 3.25-5.62], while the median OS was 17 months [95% CI 12.4%-23.1%]. A total of 95 patients (87.2%) had a treatment-related adverse event, with 40.4% (n=44/109) experiencing at least one grade 3 or 4 toxicity. Elevated LDH (p=.04), 2+ lines of prior therapy (p=.03), and Asian race/ethnicity (p=.04) were associated with worse OS, while Hispanic/Latino race/ethnicity was associated with better OS (p=.02). CONCLUSIONS: Combination of PD-1 and CTLA-4 blockade is less effective for ALM, as compared to CM, despite similar toxicity. Asian patients, in particular, appear to derive lower benefit from this regimen. Novel treatment approaches are needed for this rare melanoma subtype.

Evaluation of COVID-19 vaccination strategies with a delayed second dose.

Two of the Coronavirus Disease 2019 (COVID-19) vaccines currently approved in the United States require 2 doses, administered 3 to 4 weeks apart. Constraints in vaccine supply and distribution capacity, together with a deadly wave of COVID-19 from November 2020 to January 2021 and the emergence of highly contagious Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) variants, sparked a policy debate on whether to vaccinate more individuals with the first dose of available vaccines and delay the second dose or to continue with the recommended 2-dose series as tested in clinical trials. We developed an agent-based model of COVID-19 transmission to compare the impact of these 2 vaccination strategies, while varying the temporal waning of vaccine efficacy following the first dose and the level of preexisting immunity in the population. Our results show that for Moderna vaccines, a delay of at least 9 weeks could maximize vaccination program effectiveness and avert at least an additional 17.3 (95% credible interval [CrI]: 7.8-29.7) infections, 0.69 (95% CrI: 0.52-0.97) hospitalizations, and 0.34 (95% CrI: 0.25-0.44) deaths per 10,000 population compared to the recommended 4-week interval between the 2 doses. Pfizer-BioNTech vaccines also averted an additional 0.60 (95% CrI: 0.37-0.89) hospitalizations and 0.32 (95% CrI: 0.23-0.45) deaths per 10,000 population in a 9-week delayed second dose (DSD) strategy compared to the 3-week recommended schedule between doses. However, there was no clear advantage of delaying the second dose with Pfizer-BioNTech vaccines in reducing infections, unless the efficacy of the first dose did not wane over time. Our findings underscore the importance of quantifying the characteristics and durability of vaccine-induced protection after the first dose in order to determine the optimal time interval between the 2 doses.

Prostate cancer risk assessment and avoidance of prostate biopsies using fully automatic deep learning in prostate MRI: comparison to PI-RADS and integration with clinical data in nomograms.

OBJECTIVES: Risk calculators (RCs) improve patient selection for prostate biopsy with clinical/demographic information, recently with prostate MRI using the prostate imaging reporting and data system (PI-RADS). Fully-automated deep learning (DL) analyzes MRI data independently, and has been shown to be on par with clinical radiologists, but has yet to be incorporated into RCs. The goal of this study is to re-assess the diagnostic quality of RCs, the impact of replacing PI-RADS with DL predictions, and potential performance gains by adding DL besides PI-RADS. MATERIAL AND METHODS: One thousand six hundred twenty-seven consecutive examinations from 2014 to 2021 were included in this retrospective single-center study, including 517 exams withheld for RC testing. Board-certified radiologists assessed PI-RADS during clinical routine, then systematic and MRI/Ultrasound-fusion biopsies provided histopathological ground truth for significant prostate cancer (sPC). nnUNet-based DL ensembles were trained on biparametric MRI predicting the presence of sPC lesions (UNet-probability) and a PI-RADS-analogous five-point scale (UNet-Likert). Previously published RCs were validated as is; with PI-RADS substituted by UNet-Likert (UNet-Likert-substituted RC); and with both UNet-probability and PI-RADS (UNet-probability-extended RC). Together with a newly fitted RC using clinical data, PI-RADS and UNet-probability, existing RCs were compared by receiver-operating characteristics, calibration, and decision-curve analysis. RESULTS: Diagnostic performance remained stable for UNet-Likert-substituted RCs. DL contained complementary diagnostic information to PI-RADS. The newly-fitted RC spared 49% [252/517] of biopsies while maintaining the negative predictive value (94%), compared to PI-RADS ≥ 4 cut-off which spared 37% [190/517] (p < 0.001). CONCLUSIONS: Incorporating DL as an independent diagnostic marker for RCs can improve patient stratification before biopsy, as there is complementary information in DL features and clinical PI-RADS assessment. CLINICAL RELEVANCE STATEMENT: For patients with positive prostate screening results, a comprehensive diagnostic workup, including prostate MRI, DL analysis, and individual classification using nomograms can identify patients with minimal prostate cancer risk, as they benefit less from the more invasive biopsy procedure. KEY POINTS: The current MRI-based nomograms result in many negative prostate biopsies. The addition of DL to nomograms with clinical data and PI-RADS improves patient stratification before biopsy. Fully automatic DL can be substituted for PI-RADS without sacrificing the quality of nomogram predictions. Prostate nomograms show cancer detection ability comparable to previous validation studies while being suitable for the addition of DL analysis.

Methods in regression analysis in surgical oncology research-best practice guidelines.

BACKGROUND: Using real working examples, we provide strategies and address challenges in linear and logistic regression to demonstrate best practice guidelines and pitfalls of regression modeling in surgical oncology research. METHODS: To demonstrate our best practices, we reviewed patients who underwent tissue expander breast reconstruction between 2019 and 2021. We assessed predictive factors that affect BREAST-Q Physical Well-Being of the Chest (PWB-C) scores at 2 weeks with linear regression modeling and overall complications and malrotation with logistic regression modeling. Model fit and performance were assessed. RESULTS: The 1986 patients were included in the analysis. In linear regression, age [ß = 0.18 (95% CI: 0.09, 0.28); p < 0.001], single marital status [ß = 2.6 (0.31, 5.0); p = 0.026], and prepectoral pocket dissection [ß = 4.6 (2.7, 6.5); p < 0.001] were significantly associated with PWB-C at 2 weeks. For logistic regression, BMI [OR = 1.06 (95% CI: 1.04, 1.08); p < 0.001], age [OR = 1.02 (1.01, 1.03); p = 0.002], bilateral reconstruction [OR = 1.39 (1.09, 1.79); p = 0.009], and prepectoral dissection [OR = 1.53 (1.21, 1.94); p < 0.001] were associated with increased likelihood of a complication. CONCLUSION: We provide focused directives for successful application of regression techniques in surgical oncology research. We encourage researchers to select variables with clinical judgment, confirm appropriate model fitting, and consider clinical plausibility for interpretation when utilizing regression models in their research.

Clinical, functional, and patient-reported outcomes of radial forearm versus anterolateral thigh free tissue transfer for reconstruction of glossectomy defects.

BACKGROUND: There is a lack of literature of health-related quality of life endpoints for radial forearm (RF) versus anterolateral thigh (ALT) free flap reconstruction for glossectomy defects. Our goal was to perform a comprehensive evaluation of clinical, functional, and quality of life outcomes after glossectomy reconstruction using a RF or ALT flap. METHODS: A retrospective review was performed on patients who underwent glossectomy and immediate reconstruction with RF or ALT flaps between 2016 and 2021. Outcomes of interest included readmission and reoperation rates, functional assessments, tracheostomy and gastrostomy tube status, and FACE-Q Head and Neck Cancer scores. RESULTS: Seventy-eight patients consisting of 54 RF and 24 ALT free flaps were included. ALT patients had a larger median flap size (72 vs. 48 cm2 , p = 0.021) and underwent mandibulotomy (50% vs. 7.4%, p < 0.0001) and base of tongue resection (58.3% vs. 24.1%, p = 0.005) at higher rates. No significant differences were found with respect to other outcomes. CONCLUSION: The RF and ALT flaps are suitable for glossectomy reconstruction, with minimal differences seen in postoperative outcomes. Our study suggests that ALT can be used in patients with base of tongue and larger defect sizes, while providing similar functional and clinical outcomes to RF reconstruction.

A preliminary analysis of patient reported outcomes following posterolateral mandible reconstruction: The role of flap type.

BACKGROUND: The choice of tissue type for free flap reconstruction of posterolateral mandible resections is dependent on patient and defect characteristics. We compared clinical and patient-reported outcomes following reconstruction of these defects with a soft tissue or bony free flap. METHODS: A retrospective review was performed on patients who underwent posterolateral segmental mandibulectomy with immediate free flap reconstruction at MSKCC from 2006 to 2021. Outcomes of interest were patient-reported outcome measures (PROMs) assessed by FACE-Q surveys and complications at the flap recipient site. RESULTS: Ninety patients received a bony flap and 24 patients received a soft tissue flap. Patients reconstructed with soft tissue flaps had greater rates of composite soft tissue defects (p < 0.0001), condyle resection (p = 0.001), and peripheral vascular disease (p = 0.035). Complication rates were similar between the cohorts (p > 0.05). Bony flaps scored higher on multiple FACE-Q scales: Facial Appearance (p = 0.023) Eating/Drinking (p = 0.029), Smiling (p = 0.012), Speaking (p < 0.001), Swallowing (p = 0.012), Smiling Distress (p = 0.037), and Speaking Distress (p = 0.001). CONCLUSION: Reconstruction of posterolateral mandibular defects has a similar complication profile when utilizing a bony or soft tissue free flap. Bony flaps may perform better with respect to PROMs. Reconstructive surgeons should consider using bony flap reconstruction to achieve higher patient satisfaction and quality of life.

Microfluidic Surgery in Single Cells and Multicellular Systems.

Microscale surgery on single cells and small organisms has enabled major advances in fundamental biology and in engineering biological systems. Examples of applications range from wound healing and regeneration studies to the generation of hybridoma to produce monoclonal antibodies. Even today, these surgical operations are often performed manually, but they are labor intensive and lack reproducibility. Microfluidics has emerged as a powerful technology to control and manipulate cells and multicellular systems at the micro- and nanoscale with high precision. Here, we review the physical and chemical mechanisms of microscale surgery and the corresponding design principles, applications, and implementations in microfluidic systems. We consider four types of surgical operations: (1) sectioning, which splits a biological entity into multiple parts, (2) ablation, which destroys part of an entity, (3) biopsy, which extracts materials from within a living cell, and (4) fusion, which joins multiple entities into one. For each type of surgery, we summarize the motivating applications and the microfluidic devices developed. Throughout this review, we highlight existing challenges and opportunities. We hope that this review will inspire scientists and engineers to continue to explore and improve microfluidic surgical methods.

Macular Volume Scan as a Marker of Angiographic Uveitic Retinal Vasculitis: A Retrospective Longitudinal Study.

PURPOSE: To determine whether optical coherence tomography (OCT) thickness values from macular volume scans can be used to detect uveitic retinal vasculitis. METHODS: Retrospective study of patients with noninfectious retinal vasculitis. Fluorescein angiogram (FA) and 61-line OCT macular volume scans with an overlying Early Treatment Diabetic Retinopathy study (ETDRS) grid were obtained. Correlation between 1mm and 6mm ETDRS ring values and posterior pole vasculitis was analyzed. A linear longitudinal model was used to assess the relationship between global retinal vasculitis scores and OCT macular thickness parameters. RESULTS: Ninety-nine eyes of 54 patients were included. A total of 460 OCT and fluorescein angiogram pairs were analyzed. Central (1mm) macular thickness was weakly correlated with posterior pole vasculitis (correlation coefficient [rho]=0.09, p=0.06). Both the mean 6mm ring (rho=0.11, p=0.018) and the average of the superior and inferior (S/I) 6mm ring values (rho=0.13, p=0.006) were strongly correlated with posterior pole leakage. The longitudinal model showed that S/I 6mm ring values are associated with vasculitis in the posterior pole, mid and far periphery (p<0.0001). CONCLUSIONS: OCT-based macular volume thickness can detect uveitic retinal vasculitis and aid in monitoring disease activity.

Development and Validation of a Risk Score Predicting Death Without Transplant in Adult Heart Transplant Candidates.

Importance: The US heart allocation system prioritizes medically urgent candidates with a high risk of dying without transplant. The current therapy-based 6-status system is susceptible to manipulation and has limited rank ordering ability. Objective: To develop and validate a candidate risk score that incorporates current clinical, laboratory, and hemodynamic data. Design, Setting, and Participants: A registry-based observational study of adult heart transplant candidates (aged ≥18 years) from the US heart allocation system listed between January 1, 2019, and December 31, 2022, split by center into training (70%) and test (30%) datasets. Adult candidates were listed between January 1, 2019, and December 31, 2022. Main Outcomes and Measures: A US candidate risk score (US-CRS) model was developed by adding a predefined set of predictors to the current French Candidate Risk Score (French-CRS) model. Sensitivity analyses were performed, which included intra-aortic balloon pumps (IABP) and percutaneous ventricular assist devices (VAD) in the definition of short-term mechanical circulatory support (MCS) for the US-CRS. Performance of the US-CRS model, French-CRS model, and 6-status model in the test dataset was evaluated by time-dependent area under the receiver operating characteristic curve (AUC) for death without transplant within 6 weeks and overall survival concordance (c-index) with integrated AUC. Results: A total of 16 905 adult heart transplant candidates were listed (mean [SD] age, 53 [13] years; 73% male; 58% White); 796 patients (4.7%) died without a transplant. The final US-CRS contained time-varying short-term MCS (ventricular assist-extracorporeal membrane oxygenation or temporary surgical VAD), the log of bilirubin, estimated glomerular filtration rate, the log of B-type natriuretic peptide, albumin, sodium, and durable left ventricular assist device. In the test dataset, the AUC for death within 6 weeks of listing for the US-CRS model was 0.79 (95% CI, 0.75-0.83), for the French-CRS model was 0.72 (95% CI, 0.67-0.76), and 6-status model was 0.68 (95% CI, 0.62-0.73). Overall c-index for the US-CRS model was 0.76 (95% CI, 0.73-0.80), for the French-CRS model was 0.69 (95% CI, 0.65-0.73), and 6-status model was 0.67 (95% CI, 0.63-0.71). Classifying IABP and percutaneous VAD as short-term MCS reduced the effect size by 54%. Conclusions and Relevance: In this registry-based study of US heart transplant candidates, a continuous multivariable allocation score outperformed the 6-status system in rank ordering heart transplant candidates by medical urgency and may be useful for the medical urgency component of heart allocation.

Quality of Life Outcomes after Free Fibula Flap Reconstruction of Mandibular Defects: A Longitudinal Examination.

BACKGROUND: A comprehensive understanding of changes in health-related quality of life after head and neck cancer surgery is necessary for effective preoperative counseling. The goal of this study was to perform a longitudinal analysis of postoperative quality of life outcomes after fibula free flap (FFF) mandible reconstruction. METHODS: A retrospective review was performed for all patients who underwent oncologic mandible reconstruction with an FFF between 2000 and 2021. Completion of at least one postoperative FACE-Q questionnaire was necessary for inclusion. FACE-Q scores were divided into five time periods for analysis. Functional outcomes measured with speech language pathology (SLP) assessments and tracheostomy and gastrostomy tube status were analyzed at three time points. RESULTS: One hundred and nine patients were included. Of these, 68 patients also had at least one SLP assessment. All outcomes as measured by the various FACE-Q scales did not improve significantly from the immediate postoperative time point to the last evaluated time point (p > 0.05). SLP functional outcomes showed some deterioration over time, but these were not significant (p > 0.05). The percentage of patients who required a tracheostomy (18 to 2%, p = 0.002) or gastrostomy tube (25 to 11%, p = 0.035) decreased significantly from the immediate postoperative time point to the last evaluated time point. CONCLUSION: Subjective quality of life outcomes do not change significantly with time after oncologic FFF mandible reconstruction. Reconstructive surgeons can use these results to help patients establish appropriate and achievable quality of life goals after surgery. Further studies are warranted to elucidate the impact of specific relevant clinical variables on postoperative quality of life.

Lipid nanodiscs as a template for high-resolution cryo-EM structures of peripheral membrane proteins.

Peripheral membrane proteins are ubiquitous throughout cell biology and are required for a variety of cellular processes such as signal transduction, membrane trafficking, and autophagy. Transient binding to the membrane has a profound impact on protein function, serving to induce conformational changes and alter biochemical and biophysical parameters by increasing the local concentration of factors and restricting diffusion to two dimensions. Despite the centrality of the membrane in serving as a template for cell biology, there are few reported high-resolution structures of peripheral membrane proteins bound to the membrane. We analyzed the utility of lipid nanodiscs to serve as a template for cryo-EM analysis of peripheral membrane proteins. We tested a variety of nanodiscs and we report a 3.3 Å structure of the AP2 clathrin adaptor complex bound to a 17-nm nanodisc, with sufficient resolution to visualize a bound lipid head group. Our data demonstrate that lipid nanodiscs are amenable to high-resolution structure determination of peripheral membrane proteins and provide a framework for extending this analysis to other systems.

Encephalopsin (OPN3) is required for normal refractive development and the GO/GROW response to induced myopia.

Purpose: Myopia, or nearsightedness, is the most common form of refractive error and is increasing in prevalence. While significant efforts have been made to identify genetic variants that predispose individuals to myopia, these variants are believed to account for only a small portion of the myopia prevalence, leading to a feedback theory of emmetropization, which depends on the active perception of environmental visual cues. Consequently, there has been renewed interest in studying myopia in the context of light perception, beginning with the opsin family of G-protein coupled receptors (GPCRs). Refractive phenotypes have been characterized in every opsin signaling pathway studied, leaving only Opsin 3 (OPN3), the most widely expressed and blue-light sensing noncanonical opsin, to be investigated for function in the eye and refraction. Methods: Opn3 expression was assessed in various ocular tissues using an Opn3eGFP reporter. Weekly refractive development in Opn3 retinal and germline mutants from 3 to 9 weeks of age was measured using an infrared photorefractor and spectral domain optical coherence tomography (SD-OCT). Susceptibility to lens-induced myopia was then assessed using skull-mounted goggles with a -30 diopter experimental and a 0 diopter control lens. Mouse eye biometry was similarly tracked from 3 to 6 weeks. A myopia gene expression signature was assessed 24 h after lens induction for germline mutants to further assess myopia-induced changes. Results: Opn3 was found to be expressed in a subset of retinal ganglion cells and a limited number of choroidal cells. Based on an assessment of Opn3 mutants, the OPN3 germline, but not retina conditional Opn3 knockout, exhibits a refractive myopia phenotype, which manifests in decreased lens thickness, shallower aqueous compartment depth, and shorter axial length, atypical of traditional axial myopias. Despite the short axial length, Opn3 null eyes demonstrate normal axial elongation in response to myopia induction and mild changes in choroidal thinning and myopic shift, suggesting that susceptibility to lens-induced myopia is largely unchanged. Additionally, the Opn3 null retinal gene expression signature in response to induced myopia after 24 h is distinct, with opposing Ctgf, Cx43, and Egr1 polarity compared to controls. Conclusions: The data suggest that an OPN3 expression domain outside the retina can control lens shape and thus the refractive performance of the eye. Prior to this study, the role of Opn3 in the eye had not been investigated. This work adds OPN3 to the list of opsin family GPCRs that are implicated in emmetropization and myopia. Further, the work to exclude retinal OPN3 as the contributing domain in this refractive phenotype is unique and suggests a distinct mechanism when compared to other opsins.

Fractionalization in Fractional Correlated Insulating States at n±1/3 Filled Twisted Bilayer Graphene.

Fractionalization without time-reversal symmetry breaking is a long-sought-after goal in the study of correlated phenomena. The earlier proposal of correlated insulating states at n±1/3 filling in twisted bilayer graphene and recent experimental observations of insulating states at those fillings strongly suggest that moiré graphene systems provide a new platform to realize time-reversal symmetric fractionalized states. However, the nature of fractional excitations and the effect of quantum fluctuation on the fractional correlated insulating states are unknown. We show that excitations of the fractional correlated insulator phases in the strong coupling limit carry fractional charges and exhibit fractonic restricted mobility. Upon introduction of quantum fluctuations, the resonance of "lemniscate" structured operators drives the system into quantum lemniscate liquid (QLL) or quantum lemniscate solid (QLS). We find an emergent U(1)×U(1) 1-form symmetry unifies distinct motions of the fractionally charged excitations in the strong coupling limit and in the QLL phase, while providing a new mechanism for fractional excitations in two dimensions. We predict emergent Luttinger liquid behavior upon dilute doping in the strong coupling limit due to restricted mobility and discuss implications at a general n±1/3 filling.

Prospective validation of tumor folate receptor expression density with the association of pafolacianine fluorescence during intraoperative molecular imaging-guided lung cancer resections.

PURPOSE: Pafolacianine, a folate receptor alpha-targeted NIR tracer, has demonstrated clear efficacy in intraoperative molecular imaging-guided (IMI) lung cancer surgery. However, the selection of patients who would benefit from IMI remains challenging given the variability of fluorescence with patient-associated and histopathologic factors. Our goal in this study was to prospectively evaluate whether preoperative FRα/FRß staining can predict pafolacianine-based fluorescence during real-time lung cancer resections. METHODS: This was a prospective study conducted between 2018 and 2022 that reviewed core biopsy and intraoperative data from patients with suspected lung cancer. A total of 196 patients were deemed eligible, of whom core biopsies were taken from 38 patients and assessed for FRα and FRß expression by immunohistochemistry (IHC). All patients underwent infusion of pafolacianine 24 h prior to surgery. Intraoperative fluorescence images were captured with the VisionSense bandpass filter-enabled camera. All histopathologic assessments were performed by a board-certified thoracic pathologist. RESULTS: Of the 38 patients, 5 (13.1%) were found to have benign lesions (necrotizing granulomatous inflammation, lymphoid aggregates) and 1 had metastatic non-lung nodule. Thirty (81.5%) had malignant lesions, with the vast majority (23, 77.4%) being lung adenocarcinoma (7 (22.5%) SCC). None of the benign tumors (0/5, 0%) exhibited in vivo fluorescence (mean TBR of 1.72), while 95% of the malignant tumors fluoresced (mean TBR of 3.11 ± 0.31) compared to squamous cell carcinoma (1.89 ± 0.29) of the lung and sarcomatous lung metastasis (2.32 ± 0.09) (p < 0.01). The TBR was significantly higher in the malignant tumors (p = 0.009). The median FRα and FRß staining intensities were both 1.5 for benign tumors, while the FRα and FRß staining intensities were 3 and 2 for malignant tumors, respectively. Increased FRα expression was significantly associated with the presence of fluorescence (p = 0.01), CONCLUSION: This prospective study sought to determine whether preoperative FRα and FRß expression on core biopsy IHC correlates with intraoperative fluorescence during pafolacianine-guided surgery. These results, although of small sample size, including limited non-adenocarcinoma cohort, suggest that performing FRα IHC on preoperative core biopsies of adenocarcinomas as compared to squamous cell carcinomas could provide low-cost, clinically useful information for optimal patient selection which should be further explored in advanced clinical trials.