Molecular architecture of coronavirus double-membrane vesicle pore complex

Coronaviruses remodel the intracellular host membranes during replication, forming double-membrane vesicles (DMVs) to accommodate viral RNA synthesis and modifications1,2. SARS-CoV-2 non-structural protein 3 (nsp3) and nsp4 are the minimal viral components required to induce DMV formation and to form a double-membrane-spanning pore, essential for the transport of newly synthesized viral RNAs3-5. The mechanism of DMV pore complex formation remains unknown. Here we describe the molecular architecture of the SARS-CoV-2 nsp3-nsp4 pore complex, as resolved by cryogenic electron tomography and subtomogram averaging in isolated DMVs. The structures uncover an unexpected stoichiometry and topology of the nsp3-nsp4 pore complex comprising 12 copies each of nsp3 and nsp4, organized in 4 concentric stacking hexamer rings, mimicking a miniature nuclear pore complex. The transmembrane domains are interdigitated to create a high local curvature at the double-membrane junction, coupling double-membrane reorganization with pore formation. The ectodomains form extensive contacts in a pseudo-12-fold symmetry, belting the pore complex from the intermembrane space. A central positively charged ring of arginine residues coordinates the putative RNA translocation, essential for virus replication. Our work establishes a framework for understanding DMV pore formation and RNA translocation, providing a structural basis for the development of new antiviral strategies to combat coronavirus infection.

Cu1.4Mn1.6O4 as a bifunctional transducer for potentiometric Cu2+ solid-contact ion-selective electrode

Current potentiometric Cu2+ sensors mostly rely on polymer-membrane-based solid-contact ion-selective electrodes (SC-ISEs) that constitute ion-selective membranes (ISM) and solid contact (SC) for respective ion recognition and ion-to-electron transduction. Herein, we report an ISM-free Cu2+-SC-ISE based on Cu-Mn oxide (Cu1.4Mn1.6O4) as a bifunctional SC layer. The starting point is simplifying complex multi-interfaces for Cu2+-SC-ISEs. Specifically, ion recognition and signal transduction have been achieved synchronously by an ion-coupled-electron transfer of crystal ion transport and electron transfer of Mn4+/3+ in Cu1.4Mn1.6O4. The proposed Cu1.4Mn1.6O4 electrode discloses comparable sensitivity, response time, high selectivity and stability compared with present ISM-based potentiometric Cu2+ sensors. In addition, the Cu1.4Mn1.6O4 electrode also exhibits near Nernstian responses toward Cu2+ in natural water background. This work emphasizes an ISM-free concept and presents a scheme for the development of potentiometric Cu2+ sensors.

Graphene Oxide-Poly(vinyl alcohol) Hydrogel-Coated Solid-Contact Ion-Selective Electrodes for Wearable Sweat Potassium Ion Sensing

Solid-contact ion-selective electrodes (SC-ISEs) with ionophore-based polymer-sensitive membranes have been the major devices in wearable sweat sensors toward electrolyte analysis. However, the toxicity of ionophores in ion-selective membranes (ISMs), for example, valinomycin (K+ ion carrier), is a significant challenge, since the ISM directly contacts the skin during the tests. Herein, we report coating a hydrogel of graphene oxide-poly(vinyl alcohol) (GO-PVA) on the ISM to fabricate hydrogel-based SC-ISEs. The hydrogen bond interaction between GO sheets and PVA chains could enhance the mechanical strength through the formation of a cross-linking network. Comprehensive electrochemical tests have demonstrated that hydrogel-coated K+-SC-ISE maintains Nernstian response sensitivity, high selectivity, and anti-interference ability compared with uncoated K+-SC-ISE. A flexible hydrogel-based K+ sensing device was further fabricated with the integration of a solid-contact reference electrode, which has realized the monitoring of sweat K+ in real time. This work highlights the possibility of hydrogel coating for fabricating biocompatible wearable potentiometric sweat electrolyte sensors.

Associating Knee Osteoarthritis Progression with Temporal-Regional Graph Convolutional Network Analysis on MR Images

BACKGROUND

Artificial intelligence shows promise in assessing knee osteoarthritis (OA) progression on MR images, but faces challenges in accuracy and interpretability.

PURPOSE

To introduce a temporal-regional graph convolutional network (TRGCN) on MR images to study the association between knee OA progression status and network outcome.

STUDY TYPE

Retrospective.

POPULATION

194 OA progressors (mean age, 62 ± 9 years) and 406 controls (mean age, 61 ± 9 years) from the OA Initiative were randomly divided into training (80%) and testing (20%) cohorts.

FIELD STRENGTH/SEQUENCE

Sagittal 2D IW-TSE-FS (IW) and 3D-DESS-WE (DESS) at 3T.

ASSESSMENT

Anatomical subregions of cartilage, subchondral bone, meniscus, and the infrapatellar fat pad at baseline, 12-month, and 24-month were automatically segmented and served as inputs to form compartment-based graphs for a TRGCN model, which containing both regional and temporal information. The performance of models based on (i) clinical variables alone, (ii) radiologist score alone, (iii) combined features (containing i and ii), (iv) composite TRGCN (combining TRGCN, i and ii), (v) radiomics features, (vi) convolutional neural network based on Densenet-169 were compared.

STATISTICAL TESTS

DeLong test was performed to compare the areas under the ROC curve (AUC) of all models. Additionally, interpretability analysis was done to evaluate the contributions of individual regions. A P value <0.05 was considered significant.

RESULTS

The composite TRGCN outperformed all other models with AUCs of 0.841 (DESS) and 0.856 (IW) in the testing cohort (all P < 0.05). Interpretability analysis highlighted cartilage's importance over other structures (42%-45%), tibiofemoral joint's (TFJ) dominance over patellofemoral joint (PFJ) (58%-67% vs. 12%-37%), and importance scores changes in compartments over time (TFJ vs. PFJ: baseline: 44% vs. 43%, 12-month: 52% vs. 39%, 24-month: 31% vs. 48%).

DATA CONCLUSION

The composite TRGCN, capturing temporal and regional information, demonstrated superior discriminative ability compared with other methods, providing interpretable insights for identifying knee OA progression.

LEVEL OF EVIDENCE: 4

TECHNICAL EFFICACY

Stage 2.

IL-36 Regulates Neutrophil Chemotaxis and Bone Loss at the Oral Barrier

Tissue-specific mechanisms regulate neutrophil immunity at the oral barrier, which plays a key role in periodontitis. Although it has been proposed that fibroblasts emit a powerful neutrophil chemotactic signal, how this chemotactic signal is driven has not been clear. The objective of this study was to investigate the site-specific regulatory mechanisms by which fibroblasts drive powerful neutrophil chemotactic signals within the oral barrier, with particular emphasis on the role of the IL-36 family. The present study found that IL-36γ, agonist of IL-36R, could promote neutrophil chemotaxis via fibroblast. Single-cell RNA sequencing data disclosed that IL36G is primarily expressed in human and mouse gingival epithelial cells and mouse neutrophils. Notably, there was a substantial increase in IL-36γ levels during periodontitis. In vitro experiments demonstrated that IL-36γ specifically activates gingival fibroblasts, leading to chemotaxis of neutrophils. In vivo experiments revealed that IL-36Ra inhibited the infiltration of neutrophils and bone resorption, while IL-36γ promoted their progression in the ligature-induced periodontitis mouse model. In summary, these data elucidate the function of the site-enriched IL-36γ in regulating neutrophil immunity and bone resorption at the oral barrier. These findings provide new insights into the tissue-specific pathophysiology of periodontitis and offer a promising avenue for prevention and treatment through targeted intervention of the IL-36 family.

Carbon fiber-based multichannel solid-contact potentiometric ion sensors for real-time sweat electrolyte monitoring

Solid-contact ion-selective electrodes (SC-ISEs) feature miniaturization and integration that have gained extensive attention in non-invasive wearable sweat electrolyte sensors. The state-of-the-art wearable SC-ISEs mainly use polyethylene terephthalate, gold and carbon nanotube fibers as flexible substrates but suffer from uncomfortableness, high cost and biotoxicity. Herein, we report carbon fiber-based SC-ISEs to construct a four-channel wearable potentiometric sensor for sweat electrolytes monitoring (Na+/K+/pH/Cl-). The carbon fibers were extracted from commercial cloth, of which the starting point is addressing the cost and reproducibility issues for flexible SC-ISEs. The bare carbon fiber electrodes exhibited reversible voltammetric and stable impedance performances. Further fabricated SC-ISEs based on corresponding ion-selective membranes disclosed Nernstian sensitivity and anti-interface ability toward both ions and organic species in sweat. Significantly, these carbon fiber-based SC-ISEs revealed high reproducibility of standard potentials between normal and bending states. Finally, a textile-based sensor was integrated with a solid-contact reference electrode, which realized on-body sweat electrolytes analysis. The results displayed high accuracy compared with ex-situ tests by ion chromatography. This work highlights carbon fiber-based multichannel wearable potentiometric ion sensors with low cost, biocompatibility and reproducibility.

Pneumonitis After Concurrent Chemoradiation and Immune Checkpoint Inhibition in Patients with Locally Advanced Non-small Cell Lung Cancer

AIMS

Pneumonitis is a common and potentially deadly complication of combined chemoradiation and immune checkpoint inhibition (CRT-ICI) in patients with locally advanced non-small cell lung cancer (LA-NSCLC). In this study we sought to identify the risk factors for pneumonitis with CRT-ICI therapy in LA-NSCLC cases and determine its impact on survival.

MATERIALS AND METHODS

We conducted a retrospective chart review of 140 patients with LA-NSCLC who underwent curative-intent CRT-ICI with durvalumab between 2018 and 2021. Pneumonitis was diagnosed by a multidisciplinary team of clinical experts. We used multivariable cause-specific hazard models to identify risk factors associated with grade ≥2 pneumonitis. We constructed multivariable Cox proportional hazard models to investigate the impact of pneumonitis on all-cause mortality.

RESULTS

The median age of the cohort was 67 years; most patients were current or former smokers (86%). The cumulative incidence of grade ≥2 pneumonitis was 23%. Among survivors, 25/28 patients had persistent parenchymal scarring. In multivariable analyses, the mean lung dose (hazard ratio 1.14 per Gy, 95% confidence interval 1.03-1.25) and interstitial lung disease (hazard ratio 3.8, 95% confidence interval 1.3-11.0) increased the risk for pneumonitis. In adjusted models, grade ≥2 pneumonitis (hazard ratio 2.5, 95% confidence interval 1.0-6.2, P = 0.049) and high-grade (≥3) pneumonitis (hazard ratio 8.3, 95% confidence interval 3.0-23.0, P < 0.001) were associated with higher all-cause mortality.

CONCLUSIONS

Risk factors for pneumonitis in LA-NSCLC patients undergoing CRT-ICI include the mean radiation dose to the lung and pre-treatment interstitial lung disease. Although most cases are not fatal, pneumonitis in this setting is associated with markedly increased mortality.

DeepKOA: a deep-learning model for predicting progression in knee osteoarthritis using multimodal magnetic resonance images from the osteoarthritis initiative

Background

No investigations have thoroughly explored the feasibility of combining magnetic resonance (MR) images and deep-learning methods for predicting the progression of knee osteoarthritis (KOA). We thus aimed to develop a potential deep-learning model for predicting OA progression based on MR images for the clinical setting.

Methods

A longitudinal case-control study was performed using data from the Foundation for the National Institutes of Health (FNIH), composed of progressive cases [182 osteoarthritis (OA) knees with both radiographic and pain progression for 24-48 months] and matched controls (182 OA knees not meeting the case definition). DeepKOA was developed through 3-dimensional (3D) DenseNet169 to predict KOA progression over 24-48 months based on sagittal intermediate-weighted turbo-spin echo sequences with fat-suppression (SAG-IW-TSE-FS), sagittal 3D dual-echo steady-state water excitation (SAG-3D-DESS-WE) and its axial and coronal multiplanar reformation, and their combined MR images with patient-level labels at baseline, 12, and 24 months to eventually determine the probability of progression. The classification performance of the DeepKOA was evaluated using 5-fold cross-validation. An X-ray-based model and traditional models that used clinical variables via multilayer perceptron were built. Combined models were also constructed, which integrated clinical variables with DeepKOA. The area under the curve (AUC) was used as the evaluation metric.

Results

The performance of SAG-IW-TSE-FS in predicting OA progression was similar or higher to that of other single and combined sequences. The DeepKOA based on SAG-IW-TSE-FS achieved an AUC of 0.664 (95% CI: 0.585-0.743) at baseline, 0.739 (95% CI: 0.703-0.775) at 12 months, and 0.775 (95% CI: 0.686-0.865) at 24 months. The X-ray-based model achieved an AUC ranging from 0.573 to 0.613 at 3 time points. However, adding clinical variables to DeepKOA did not improve performance (P>0.05). Initial visualizations from gradient-weighted class activation mapping (Grad-CAM) indicated that the frequency with which the patellofemoral joint was highlighted increased as time progressed, which contrasted the trend observed in the tibiofemoral joint. The meniscus, the infrapatellar fat pad, and muscles posterior to the knee were highlighted to varying degrees.

Conclusions

This study initially demonstrated the feasibility of DeepKOA in the prediction of KOA progression and identified the potential responsible structures which may enlighten the future development of more clinically practical methods.

[Expression changes of NaV channel subunits correlate with developmental maturation of electrophysiological characteristics of rat cerebellar Purkinje neurons]

OBJECTIVE

To investigate the variations in the expression of voltage-gated sodium (Na_v) channel subunits during development of rat cerebellar Purkinje neurons and their correlation with maturation of electrophysiological characteristics of the neurons.

METHODS

We observed the changes in the expression levels of Na_V1.1, 1.2, 1.3 and 1.6 during the development of Purkinje neurons using immunohistochemistry in neonatal (5-7 days after birth), juvenile (12-14 days), adolescent (21-24 days), and adult (42-60 days) SD rats. Using whole-cell patch-clamp technique, we recorded the spontaneous electrical activity of the neurons in ex vivo brain slices of rats of different ages to analyze the changes of electrophysiological characteristics of these neurons during development.

RESULTS

The expression of Na_V subunits in rat cerebellar Purkinje neurons showed significant variations during development. Na_V1.1 subunit was highly expressed throughout the developmental stages and increased progressively with age (P < 0.05). Na_V1.2 expression was not detected in the neurons in any of the developmental stages (P > 0.05). The expression level of Na_V1.3 decreased with development and became undetectable after adolescence (P < 0.05). Na_V1.6 expression was not detected during infancy, but increased with further development (P < 0.05). Na_V1.1 and Na_V1.3 were mainly expressed in the early stages of development. With the maturation of the rats, Na_V1.3 expression disappeared and Na_V1.6 expression increased in the neurons. Na_V1.1 and Na_V1.6 were mainly expressed after adolescence. The total Na_V protein level increased gradually with development (P < 0.05) and tended to stabilize after adolescence. The spontaneous frequency and excitability of the Purkinje neurons increased gradually with development and reached the mature levels in adolescence. The developmental expression of Na_V subunits was positively correlated with discharge frequency (r=0.9942, P < 0.05) and negatively correlated with the excitatory threshold of the neurons (r=0.9891, P < 0.05).

CONCLUSION

The changes in the expression levels of Na_V subunits are correlated with the maturation of high frequency electrophysiological properties of the neurons, suggesting thatmature Na_V subunit expressions is the basis of maturation of electrophysiological characteristics of the neurons.

Context-aware deep network for coronary artery stenosis classification in coronary CT angiography

Automatic coronary artery stenosis grading plays an important role in the diagnosis of coronary artery disease. Due to the difficulty of learning the informative features from varying grades of stenosis, it is still a challenging task to identify coronary artery stenosis from coronary CT angiography (CCTA). In this paper, we propose a context-aware deep network (CADN) for coronary artery stenosis classification. The proposed method integrates 3D CNN with Transformer to improve the feature representation of coronary artery stenosis in CCTA. We evaluate the proposed method on a multicenter dataset (APOLLO study with NCT05509010). Experimental results show that our proposed method can achieve the accuracy of 0.84, 0.83, and 0.86 for stenosis diagnosis on the lesion, artery, and patient levels, respectively.

[Assessment of the diagnostic value and prognosis of different detection markers in endocervical adenocarcinoma]

Objective: To study the diagnostic value of different detection markers in histological categories of endocervical adenocarcinoma (ECA), and their assessment of patient prognosis. Methods: A retrospective study of 54 patients with ECA in the Cancer Hospital, Chinese Academy of Medical Sciences from 2005-2010 were performed. The cases of ECA were classified into two categories, namely human papillomavirus-associated adenocarcinoma (HPVA) and non-human papillomavirus-associated adenocarcinoma (NHPVA), based on the 2018 international endocervical adenocarcinoma criteria and classification (IECC). To detect HR-HPV DNA and HR-HPV E6/E7 mRNA in all patients, we used whole tissue section PCR (WTS-PCR) and HPV E6/E7 mRNA in situ hybridization (ISH) techniques, respectively. Additionally, we performed Laser microdissection PCR (LCM-PCR) on 15 randomly selected HR-HPV DNA-positive cases to confirm the accuracy of the above two assays in identifying ECA lesions. Receiver operating characteristic (ROC) curves were used to analyze the efficacy of markers to identify HPVA and NHPVA. Univariate and multifactorial Cox proportional risk model regression analyses were performed for factors influencing ECA patients' prognoses. Results: Of the 54 patients with ECA, 30 were HPVA and 24 were NHPVA. A total of 96.7% (29/30) of HPVA patients were positive for HR-HPV DNA and 63.3% (19/30) for HR-HPV E6/E7 mRNA, and 33.3% (8/24) of NHPVA patients were positive for HR-HPV DNA and HR-HPV E6/E7 mRNA was not detected (0/24), and the differences were statistically significant (P<0.001). LCM-PCR showed that five patients were positive for HR-HPV DNA in the area of glandular epithelial lesions and others were negative, which was in good agreement with the E6/E7 mRNA ISH assay (Kappa=0.842, P=0.001). Analysis of the ROC results showed that the AUC of HR-HPV DNA, HR-HPV E6/E7 mRNA, and p16 to identify HPVA and NHPVA were 0.817, 0.817, and 0.692, respectively, with sensitivities of 96.7%, 63.3%, and 80.0% and specificities of 66.7%, 100.0%, and 58.3%, respectively. HR-HPV DNA identified HPVA and NHPVA with higher AUC than p16 (P=0.044). The difference in survival rates between HR-HPV DNA (WTS-PCR assay) positive and negative patients was not statistically significant (P=0.156), while the difference in survival rates between HR-HPV E6/E7 mRNA positive and negative patients, and p16 positive and negative patients were statistically significant (both P<0.05). Multifactorial Cox regression analysis showed that International Federation of Obstetrics and Gynecology (FIGO) staging (HR=19.875, 95% CI: 1.526-258.833) and parametrial involvement (HR=14.032, 95% CI: 1.281-153.761) were independent factors influencing the prognosis of patients with ECA. Conclusions: HR-HPV E6/E7 mRNA is more reflective of HPV infection in ECA tissue. The efficacy of HR-HPV E6/E7 mRNA and HR-HPV DNA (WTS-PCR assay) in identifying HPVA and NHPVA is similar, with higher sensitivity of HR-HPV DNA and higher specificity of HR-HPV E6/E7 mRNA. HR-HPV DNA is more effective than p16 in identifying HPVA and NHPVA. HPV E6/E7 mRNA and p16 positive ECA patients have better survival rates than negative.

Safety and Efficacy of Combination SARS-CoV-2 Neutralizing Monoclonal Antibodies Amubarvimab Plus Romlusevimab in Nonhospitalized Patients With COVID-19

BACKGROUND

Development of safe and effective SARS-CoV-2 therapeutics is a high priority. Amubarvimab and romlusevimab are noncompeting anti-SARS-CoV-2 monoclonal antibodies with an extended half-life.

OBJECTIVE

To assess the safety and efficacy of amubarvimab plus romlusevimab.

DESIGN

Randomized, placebo-controlled, phase 2 and 3 platform trial. (ClinicalTrials.gov: NCT04518410).

SETTING

Nonhospitalized patients with COVID-19 in the United States, Brazil, South Africa, Mexico, Argentina, and the Philippines.

PATIENTS

Adults within 10 days onset of symptomatic SARS-CoV-2 infection who are at high risk for clinical progression.

INTERVENTION

Combination of monoclonal antibodies amubarvimab plus romlusevimab or placebo.

MEASUREMENTS

Nasopharyngeal and anterior nasal swabs for SARS-CoV-2, COVID-19 symptoms, safety, and progression to hospitalization or death.

RESULTS

Eight-hundred and seven participants who initiated the study intervention were included in the phase 3 analysis. Median age was 49 years (quartiles, 39 to 58); 51% were female, 18% were Black, and 50% were Hispanic or Latino. Median time from symptom onset at study entry was 6 days (quartiles, 4 to 7). Hospitalizations and/or death occurred in 9 (2.3%) participants in the amubarvimab plus romlusevimab group compared with 44 (10.7%) in the placebo group, with an estimated 79% reduction in events (P < 0.001). This reduction was similar between participants with 5 or less and more than 5 days of symptoms at study entry. Grade 3 or higher treatment-emergent adverse events through day 28 were seen less frequently among participants randomly assigned to amubarvimab plus romlusevimab (7.3%) than placebo (16.1%) (P < 0.001), with no severe infusion reactions or drug-related serious adverse events.

LIMITATION

The study population was mostly unvaccinated against COVID-19 and enrolled before the spread of Omicron variants and subvariants.

CONCLUSION

Amubarvimab plus romlusevimab was safe and significantly reduced the risk for hospitalization and/or death among nonhospitalized adults with mild to moderate SARS-CoV-2 infection at high risk for progression to severe disease.

PRIMARY FUNDING SOURCE

National Institute of Allergy and Infectious Diseases of the National Institutes of Health.

Directly Using Ti3C2Tx MXene for a Solid-Contact Potentiometric pH Sensor toward Wearable Sweat pH Monitoring

The level of hydrogen ions in sweat is one of the most important physiological indexes for the health state of the human body. As a type of two-dimensional (2D) material, MXene has the advantages of superior electrical conductivity, a large surface area, and rich functional groups on the surface. Herein, we report a type of Ti₃C₂T_x-based potentiometric pH sensor for wearable sweat pH analysis. The Ti₃C₂T_x was prepared by two etching methods, including a mild LiF/HCl mixture and HF solution, which was directly used as the pH-sensitive materials. Both etched Ti₃C₂T_x showed a typical lamellar structure and exhibited enhanced potentiometric pH responses compared with a pristine precursor of Ti₃AlC₂. The HF-Ti₃C₂T_x disclosed the sensitivities of -43.51 ± 0.53 mV pH^-1 (pH 1-11) and -42.73 ± 0.61 mV pH^-1 (pH 11-1). A series of electrochemical tests demonstrated that HF-Ti₃C₂T_x exhibited better analytical performances, including sensitivity, selectivity, and reversibility, owing to deep etching. The HF-Ti₃C₂T_x was thus further fabricated as a flexible potentiometric pH sensor by virtue of its 2D characteristic. Upon integrating with a solid-contact Ag/AgCl reference electrode, the flexible sensor realized real-time monitoring of pH level in human sweat. The result disclosed a relatively stable pH value of ~6.5 after perspiration, which was consistent with the ex situ sweat pH test. This work offers a type of MXene-based potentiometric pH sensor for wearable sweat pH monitoring.

Machine learning accurately quantifies epicardial adipose tissue from non-contrast CT images in coronary artery disease

Funding Acknowledgements

Type of funding sources: Other. Main funding source(s): Industry Alignment Fund – Pre-positioning Programme

Background

Epicardial adipose tissue (EAT) is the visceral fat deposit within the pericardium that surrounds the heart and the coronary arteries. EAT volume measured from non-contrast CT (NCCT) has been demonstrated to be significantly associated with adverse cardiovascular risk,1 particularly in patients with coronary artery disease.2 However, routine measurement of EAT volume is still challenging in clinical practice, as it is a tedious manual process and prone to human error.

Purpose

We aimed to develop a fully automated AI toolkit (i.e., AI EAT) for the quantification of EAT from routine NCCT scans and assess its performance in reference to clinical ground truth.

Methods

This is a multicenter study which performs CT scans in 5000 Asian Admixture patients (APOLLO study NCT05509010). In the current stage of this study, NCCT data analysis were conducted in 551 patients with 26,037 images. AI EAT was developed via a novel deep learning framework using an ensemble region-based UNet. The region-based UNet uses 2 component UNet models to perform segmentation of pericardium at the apex region and non-apex region (middle and basal). EAT volume was obtained by automated thresholding of the voxels (-190 to -30 Hounsfield Unit) within the pericardium (Figure 1). The network was trained in 501 patients with 23,712 NCCT images and tested in 50 patients with 2,325 NCCT images. The performance of AI EAT was evaluated with respect to clinical ground truth using Dice similarity coefficient (DSC), Pearson correlation, and Bland-Altman analysis.

Results

The AI EAT quantification process took less than 10 seconds per subject, compared with 20-30 minutes for expert readers. Compared to clinical ground truth, our AI EAT achieved a DSC of 0.96±0.01 and 0.91±0.02 for pericardium and EAT segmentations, respectively. There was strong agreement between the AI EAT and clinical ground truth in deriving the EAT volume (r=0.99, P&lt;0.001) with minimal error of 7±5%.

Conclusion

End-to-end deep learning system accurately quantifies epicardial adipose tissue in standard NCCT images without manual segmentation.

Prediction model for knee osteoarthritis using magnetic resonance-based radiomic features from the infrapatellar fat pad: data from the osteoarthritis initiative

Background

The infrapatellar fat pad (IPFP) plays an important role in the incidence of knee osteoarthritis (OA). Magnetic resonance (MR) signal heterogeneity of the IPFP is related to pathologic changes. In this study, we aimed to investigate whether the IPFP radiomic features have predictive value for incident radiographic knee OA (iROA) 1 year prior to iROA diagnosis.

Methods

Data used in this work were obtained from the osteoarthritis initiative (OAI). In this study, iROA was defined as a knee with a baseline Kellgren-Lawrence grade (KLG) of 0 or 1 that further progressed to KLG ≥2 during the follow-up visit. Intermediate-weighted turbo spin-echo knee MR images at the time of iROA diagnosis and 1 year prior were obtained. Five clinical characteristics-age, sex, body mass index, knee injury history, and knee surgery history-were obtained. A total of 604 knees were selected and matched (302 cases and 302 controls). A U-Net segmentation model was independently trained to automatically segment the IPFP. The prediction models were established in the training set (60%). Three main models were generated using (I) clinical characteristics; (II) radiomic features; (III) combined (clinical plus radiomic) features. Model performance was evaluated in an independent testing set (remaining 40%) using the area under the curve (AUC). Two secondary models were also generated using Hoffa-synovitis scores and clinical characteristics.

Results

The comparison between the automated and manual segmentations of the IPFP achieved a Dice coefficient of 0.900 (95% CI: 0.891-0.908), which was comparable to that of experienced radiologists. The radiomic features model and the combined model yielded superior AUCs of 0.700 (95% CI: 0.630-0.763) and 0.702 (95% CI: 0.635-0.763), respectively. The DeLong test found no statistically significant difference between the receiver operating curves of the radiomic and combined models (P=0.831); however, both models outperformed the clinical model (P=0.014 and 0.004, respectively).

Conclusions

Our results demonstrated that radiomic features of the IPFP are predictive of iROA 1 year prior to the diagnosis, suggesting that IPFP radiomic features can serve as an early quantitative prediction biomarker of iROA.

Transformer-based multilevel region and edge aggregation network for magnetic resonance image segmentation

To improve the quality of magnetic resonance (MR) image edge segmentation, some researchers applied additional edge labels to train the network to extract edge information and aggregate it with region information. They have made significant progress. However, due to the intrinsic locality of convolution operations, the convolution neural network-based region and edge aggregation has limitations in modeling long-range information. To solve this problem, we proposed a novel transformer-based multilevel region and edge aggregation network for MR image segmentation. To the best of our knowledge, this is the first literature on transformer-based region and edge aggregation. We first extract multilevel region and edge features using a dual-branch module. Then, the region and edge features at different levels are inferred and aggregated through multiple transformer-based inference modules to form multilevel complementary features. Finally, the attention feature selection module aggregates these complementary features with the corresponding level region and edge features to decode the region and edge features. We evaluated our method on a public MR dataset: Medical image computation and computer-assisted intervention atrial segmentation challenge (ASC). Meanwhile, the private MR dataset considered infrapatellar fat pad (IPFP). Our method achieved a dice score of 93.2% for ASC and 91.9% for IPFP. Compared with other 2D segmentation methods, our method improved a dice score by 0.6% for ASC and 3.0% for IPFP.

A Solid-Contact Reference Electrode Based on Silver/Silver Organic Insoluble Salt for Potentiometric Ion Sensing

Solid-contact ion-selective electrodes are a type of ion measurement devices that have been focused in wearable biotechnology based on the features of miniaturization and integration. However, the solid-contact reference electrodes (SC-REs) remain relatively less focused compared with numerous working (or indicator) electrodes. Most SC-REs in wearable sensors rely on Ag/AgCl reference electrodes with solid electrolytes, for example, the hydrophilic electrolyte salts in polymer matrix, but face the risk of electrolyte leakage. Herein, we report a type of SC-REs based on the silver/silver tetraphenylborate (Ag/AgTPB) organic insoluble electrode. The SC-RE consists of a Ag substrate, a solid contact (AgTPB), and a plasticized poly(vinyl chloride) (PVC) membrane containing the hydrophobic organic salt of tetrabutylammonium tetraphenylborate (TBATPB). The potentiometric measurements demonstrated that the SC-RE of Ag/AgTPB/PVC-TBATPB showed a reproducible standard potential in various electrolytes and disclosed high long-term stability. This SC-RE was further fabricated on a flexible substrate and integrated into all-solid-state wearable potentiometric ion sensor for sweat Cl- monitoring.

1283. Safety, Tolerability, and Pharmacokinetics of BRII-778, A Modified-Release Oral Formulation of Rilpivirine in Healthy Adult Subjects

Background

BRII-778 is a modified release (MR) formulation of rilpivirine for once-weekly (QW) oral administration. BRII-778 aims to prolong oral absorption, lower C_max, relatively, and reduce peak to trough ratio achieved with a MR formulation of rilpivirine, within the known efficacy and safety bounds established by once daily oral administration of rilpivirine. QW BRII-778 dosing may have advantages over once daily rilpirvirine in terms of patient convenience, and treatment adherence. Multiple MR formulations of rilpivirine were evaluated in healthy adult subjects in this Phase 1 study.

Methods

This was a Phase 1, randomized, double-blinded, placebo-controlled, study of single ascending dose (SAD) and multiple ascending dose (MAD) cohorts, evaluating the safety, tolerability, and PK of BRII-778. Three MR formulations of rilpivirine, BRII-778-A1, -A2, and -A3, were evaluated in this study. Rilpivirine PK profiles after single or multiple doses of the three BRII-778 formulations were characterized under the fed state over the dose range of 150 mg to 750 mg. Food effect was assessed after a single oral dose of BRII-778-A3 750 mg. Exploratory concentration-QTc (C-QTc) analysis was conducted using combined SAD and MAD data.

Results

BRII-778 as single dose or multiple doses was generally safe and well-tolerated when administered to healthy adult subjects. There were no Grade ≥3 AEs, SAEs or AEs leading to withdrawal in BRII-778 dosing arms. PK profiles of BRII-778 were consistent with slower oral absorption with MR formulation. The increase in exposure was less than dose proportional. Mild accumulation in plasma was observed after 3 QW BRII-778-A3 doses. BRII-778-A3 750 mg under the fed state enhanced bioavailability by improving gastric dissolution and/or subsequent absorption. Exploratory C-QTc analysis confirmed a concentration-dependent effect on the QTc interval with escalating doses of BRII-778, but the interpretations are limited by small sample size. There were no clinically significant EKG changes and no individual subject met QTc stopping criteria.

Conclusion

SAD and MAD administration of BRII-778 formulations were generally safe and well tolerated. Rilpivirine PK profiles post BRII-778 dosing supports further evaluation of BRII-778 for potential QW regimen.

Disclosures

David A. Margolis, MD MPH, Brii Biosciences: Stocks/Bonds Ji Ma, PhD, Brii Biosciences: Stocks/Bonds Michael Watkins, PharmD, Brii Biosciences: Stocks/Bonds Yujin Wang, M.Sc., Brii Biosciences: Stocks/Bonds Chetana Trivedi, B.A., Brii Biosciences: Stocks/Bonds Xuelian Wei, PhD, Brii Biosciences: Stocks/Bonds Lijie Zhong, PhD, Brii Biosciences: Stocks/Bonds Kamlesh Patel, PhD, Brii Biosciences: Stocks/Bonds Li Yan, MD PhD, Brii Biosciences: Stocks/Bonds Zhi Hong, PhD, Brii Biosciences: Ownership Interest Jean-Luc Girardet, PhD, Brii Biosciences: Stocks/Bonds Lianhong Xu, PhD, Brii Biosciences: Stocks/Bonds.

1282. Safety, Tolerability, and Pharmacokinetics of BRII-732, A Medoxomil Carbonate Prodrug of Islatravir in Healthy Adult Subjects

Background

BRII-732, a prodrug of islatravir (ISL), is a potent HIV-1 nucleotide reverse transcriptase translocation inhibitor. Following oral absorption, BRII-732 is rapidly converted to ISL, which is metabolized intracellularly to the active metabolite, ISL triphosphate (ISL-TP). Single doses of ISL as low as 0.5 mg significantly suppressed HIV-1 RNA by more than 1.0 log at day 7 in treatment-naive adults with HIV-1 infection. Current development work with BRII-732 is designed to provide optimal drug exposure to enable once weekly (QW) dosing, to be part of combination antiretroviral therapy to provide improved patient convenience and treatment adherence.

Methods

This was a Phase 1, randomized, double-blind, placebo-controlled study consisting of healthy adult subjects enrolled in five single ascending dose and two multiple ascending dose cohorts. The objectives of the study were to assess the safety, tolerability, and PK profiles of BRII-732 and ISL in plasma; ISL-DP and ISL-TP in human PBMCs. BRII-732 was orally administered in the fasted state using an oral solution formulation. Safety-related assessments included physical examinations, ECGs, vital signs, AEs, and standard clinical laboratory tests.

Results

BRII-732 as single dose or multiple doses was generally safe and well-tolerated when administered to healthy adult subjects. There were no Grade ≥ 3 AEs, SAEs, drug-related AEs leading to withdrawal or graded lymphocyte abnormalities. BRII-732 rapidly converted to ISL post BRII-732 oral administration with no detectable level (LLOQ = 1.0 ng/mL) of BRII-732 in systemic circulation at 0.5h. Dose proportional ISL exposure increases were observed over the dose range of 10 mg to 200 mg of BRII-732. No meaningful ISL accumulation in plasma was observed after 3 QW BRII-732 doses. ISL-DP and ISL-TP exposures in PBMC cells increased dose-dependently. Approximately 1.7-2.0 fold accumulation ratios for ISL-DP and ISL-TP are consistent with observed long terminal half-lives of 110-150 hours.

Conclusion

Safety, tolerability and PK profiles including ISL in plasma and ISL-TP in PBMC cells after single and multiple oral administrations of BRII-732 supports further development of BRII-732 as part of oral weekly combination antiretroviral therapy.

Disclosures

David A. Margolis, MD MPH, Brii Biosciences: Stocks/Bonds Ji Ma, PhD, Brii Biosciences: Stocks/Bonds Michael Watkins, PharmD, Brii Biosciences: Stocks/Bonds Yujin Wang, M.Sc., Brii Biosciences: Stocks/Bonds Chetana Trivedi, B.A., Brii Biosciences: Stocks/Bonds Chi-Chi Peng, PhD, Brii Biosciences: Stocks/Bonds Xuelian Wei, PhD, Brii Biosciences: Stocks/Bonds Lijie Zhong, PhD, Brii Biosciences: Stocks/Bonds Kamlesh Patel, PhD, Brii Biosciences: Stocks/Bonds Jean-Luc Girardet, PhD, Brii Biosciences: Stocks/Bonds Michael Wang, PhD MBA, Brii Biosciences: Stocks/Bonds Annalise VonderEmbse, PhD, Brii Biosciences: Stocks/Bonds Li Yan, MD PhD, Brii Biosciences: Stocks/Bonds Zhi Hong, PhD, Brii Biosciences: Ownership Interest Lianhong Xu, PhD, Brii Biosciences: Stocks/Bonds.

[Effect of autologous hematopoietic stem cell transplantation on minimal residual disease in patients with multiple myeloma]

Objective: To evaluate the effect of autologous hematopoietic stem cell transplantation (ASCT) on minimal residual disease (MRD) in patients with multiple myeloma (MM). Method: From August 2018 to August 2021, 92 patients newly diagnosed with MM who had received either the bortezomib combined with cyclophosphamide and dexamethasone (VCD) or the bortezomib, lenalidomide and dexamethasone (VRD) induction regimens followed by sequential ASCT were assessed for overall survival (OS) and the MRD negative rate. The differences in efficacy at 100 days after transplantation were assessed according to factors, including age, risk stratification, target organ damage, and pre-transplant regimen, etc. Results: Among the 92 patients, there were 45 males and 47 females, with a median age of 57.3 (35-67) years. Fifty-seven patients received the VCD regimen, and 35 received VRD as induction regimen. Forty-three patients received busulphan combined with cyclophosphamide and etoposide (BCV), and 49 patients received high-dose melphan (HDM) regimen as pre-transplantation treatment. After transplantation, the total complete remission (CR) rate of 92 patients increased from 23.9% (22/92) to 58.7% (54/92), and the MRD negative rate increased from 4.4% (4/92) to 33.7% (31/92), and the differences were statistically significant (all P<0.05). After transplantation, the MRD negative rates of patients with PR, VGPR and ≥CR before transplantation were 17.6% (6/34), 33.3% (12/36) and 59.1% (13/22), respectively (P=0.006). The CR rates of patients with or without plasmacytoma at initial diagnosis were 36.4% (4/11) and 65.4% (53/81), respectively (P=0.029), and the MRD negative rates were 18.2% (2/11) and 39.5% (32/81), respectively (P=0.037), and the differences were statistically significant. The MRD negative rates in high-risk patients and standard-risk group were 30.5% (12/28) and 42.9% (18/59), respectively (P=0.258). For patients who achieved efficacy above VGPR before transplantation, the MRD negative rates after transplantation in VCD-induced group and VRD group were 29% (9/31) and 59.3% (16/27), respectively (P=0.033), and in BCV group and HDM group were 24% (6/25) and 57.6% (19/33), respectively (P=0.016), the differences between the groups were both statistically significant. Conclusion: ASCT can overcome the adverse factors such as high-risk cytogenetic abnormalities, and significantly improve the CR rate and MRD negative rate of MM patients. However, the benefit for patients with plasmacytoma at initial diagnosis is not as good as that of patients without.

Carbon-Based Transducers for Solid-Contact Calcium Ion-Selective Electrodes: Mesopore and Nitrogen-Doping Effects

Solid-contact ion-selective electrodes (SC-ISEs) exhibit great potential in the detection of routine and portable ions which rely on solid-contact (SC) materials for the transduction of ions to electron signals. Carbon-based materials are state-of-the-art SC transducers due to their high electrical double-layer (EDL) capacitance and hydrophobicity. However, researchers have long searched for ways to enhance the interfacial capacitance in order to improve the potential stability. Herein, three representative carbon-based SC materials including nitrogen-doped mesoporous carbon (NMC), reduced graphene oxide (RGO), and carbon nanotubes (CNT) were compared. The results disclose that the NMC has the highest EDL capacitance owing to its mesopore structure and N-doping while maintaining high hydrophobicity so that no obvious water-layer effect was observed. The Ca²⁺-SC-ISEs based on the SC of NMC exhibited high potential stability compared with RGO and CNT. This work offers a guideline for the development of carbon-material-based SC-ISEs through mesoporous and N-doping engineering to improve the interfacial capacitance. The developed NMC-based solid-contact Ca²⁺-SC-ISE exhibited a Nernstian slope of 26.3 ± 3.1 mV dec^-1 ranging from 10 μM to 0.1 M with a detection limit of 3.2 μM. Finally, a practical application using NMC-based SC-ISEs was demonstrated through Ca²⁺ ion analysis in mineral water and soil leaching solutions.