Therapeutic Activity of Resolvin D1 (RvD1) in Murine MASH

Background and Aims

Recent studies have highlighted the beneficial effect of resolvin D1 (RvD1), a DHA-derived specialized pro-resolving mediator, on metabolic dysfunction-associated steatohepatitis (MASH), but the underlying mechanisms are not well understood. Our study aims to determine the mechanism by which RvD1 protects against MASH progression.

Methods

RvD1 was administered to mice with experimental MASH, followed by bulk and single-cell RNA sequencing analysis. Primary cells including bone marrow-derived macrophages (BMDMs), Kupffer cells, T cells, and primary hepatocytes were isolated to elucidate the effect of RvD1 on inflammation, cell death, and fibrosis regression genes.

Results

Hepatic tissue levels of RvD1 were decreased in murine and human MASH, likely due to an expansion of pro-inflammatory M1-like macrophages with diminished ability to produce RvD1. Administering RvD1 reduced inflammation, cell death, and liver fibrosis. Mechanistically, RvD1 reduced inflammation by suppressing the Stat1-Cxcl10 signaling pathway in macrophages and prevented hepatocyte death by alleviating ER stress-mediated apoptosis. Moreover, RvD1 induced Mmp2 and decreased Acta2 expression in hepatic stellate cells (HSCs), and promoted Mmp9 and Mmp12 expression in macrophages, leading to fibrosis regression in MASH.

Conclusions

RvD1 reduces Stat1-mediated inflammation, mitigates ER stress-induced apoptosis, and promotes MMP-mediated fibrosis regression in MASH. This study highlights the therapeutic potential of RvD1 to treat MASH.

Impact and implications

Metabolic dysfunction-associated steatohepatitis (MASH) is an increasing healthcare burden worldwide. Current treatments for MASH and its sequelae are very limited. Recent studies highlighted the therapeutic benefit of specialized pro-resolving mediators (SPMs), including resolvin D1 (RvD1), in liver diseases. However, the mechanisms underlying these beneficial effects are not well understood. Based on unbiased transcriptomic analyses using bulk and single-cell RNA sequencing in RvD1-treated MASH livers, we show that RvD1 suppresses Stat1-mediated inflammatory responses and ER stress-induced apoptosis, and induces gene expression related to fibrosis regression. Our study provides new mechanistic insight into the role of RvD1 in MASH and highlights its therapeutic potential to treat MASH.

Highlights

Liver RvD1 levels are decreased in MASH patients and MASH miceRvD1 administration suppresses Stat1-mediated inflammatory responseRvD1 administration alleviates ER stress-induced apoptosisRvD1 administration induces fibrosis regression gene expression.

Retinal atrophy, inflammation, phagocytic and metabolic disruptions develop in the MerTK-cleavage-resistant mouse model

In the eye, cells from the retinal pigment epithelium (RPE) facing the neurosensory retina exert several functions that are all crucial for long-term survival of photoreceptors (PRs) and vision. Among those, RPE cells phagocytose under a circadian rhythm photoreceptor outer segment (POS) tips that are constantly subjected to light rays and oxidative attacks. The MerTK tyrosine kinase receptor is a key element of this phagocytic machinery required for POS internalization. Recently, we showed that MerTK is subjected to the cleavage of its extracellular domain to finely control its function. In addition, monocytes in retinal blood vessels can migrate inside the inner retina and differentiate into macrophages expressing MerTK, but their role in this context has not been studied yet. We thus investigated the ocular phenotype of MerTK cleavage-resistant (MerTKCR) mice to understand the relevance of this characteristic on retinal homeostasis at the RPE and macrophage levels. MerTKCR retinae appear to develop and function normally, as observed in retinal sections, by electroretinogram recordings and optokinetic behavioral tests. Monitoring of MerTKCR and control mice between the ages of 3 and 18  months showed the development of large degenerative areas in the central retina as early as 4 months when followed monthly by optical coherence tomography (OCT) plus fundus photography (FP)/autofluorescence (AF) detection but not by OCT alone. The degenerative areas were associated with AF, which seems to be due to infiltrated macrophages, as observed by OCT and histology. MerTKCR RPE primary cultures phagocytosed less POS in vitro, while in vivo, the circadian rhythm of POS phagocytosis was deregulated. Mitochondrial function and energy production were reduced in freshly dissected RPE/choroid tissues at all ages, thus showing a metabolic impairment not present in macrophages. RPE anomalies were detected by electron microscopy, including phagosomes retained in the apical area and vacuoles. Altogether, this new mouse model displays a novel phenotype that could prove useful to understanding the interplay between RPE and PRs in inflammatory retinal degenerations and highlights new roles for MerTK in the regulation of the energetic metabolism and the maintenance of the immune privilege in the retina.

ZFP281 controls transcriptional and epigenetic changes promoting mouse pluripotent state transitions via DNMT3 and TET1

The progression from naive through formative to primed in vitro pluripotent stem cell states recapitulates epiblast development in vivo during the peri-implantation period of mouse embryo development. Activation of the de novo DNA methyltransferases and reorganization of transcriptional and epigenetic landscapes are key events that occur during these pluripotent state transitions. However, the upstream regulators that coordinate these events are relatively underexplored. Here, using Zfp281 knockout mouse and degron knockin cell models, we identify the direct transcriptional activation of Dnmt3a/3b by ZFP281 in pluripotent stem cells. Chromatin co-occupancy of ZFP281 and DNA hydroxylase TET1, which is dependent on the formation of R-loops in ZFP281-targeted gene promoters, undergoes a "high-low-high" bimodal pattern regulating dynamic DNA methylation and gene expression during the naive-formative-primed transitions. ZFP281 also safeguards DNA methylation in maintaining primed pluripotency. Our study demonstrates a previously unappreciated role for ZFP281 in coordinating DNMT3A/3B and TET1 functions to promote pluripotent state transitions.

[Thoughts and suggestions on digital services to enhance the level of vaccination management]

With the development of information technology and the increasing demand for vaccination services among the people, it is a definite trend to enhance the quality of vaccination services through digitization. This article starts with a clear concept of digital services for vaccination, introduces the current development status in China and abroad, analyzes the advantages and disadvantages of existing models in leading regions, takes a glean from the summation, and proposes targeted solutions. This study suggests establishing a departmental coordination mechanism for data interconnection and sharing, formulating data standards and functional specifications, enhancing the functionalities of the immunization planning information system, strengthening data collection and analytical usage, and intensifying appointment management and science and health education to provide expert guidance for the construction of digital vaccination services across the country in the future.

Roles of Activin A and Gpnmb in Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD)

Metabolic dysfunction-associated steatotic liver disease (MASLD, formerly known as nonalcoholic fatty liver disease [NAFLD]) and metabolic dysfunction-associated steatohepatitis (MASH, formerly known as nonalcoholic steatohepatitis [NASH]) are leading chronic liver diseases, driving cirrhosis, hepatocellular carcinoma, and mortality. MASLD/MASH is associated with increased senescence proteins, including Activin A, and senolytics have been proposed as a therapeutic approach. To test the role of Activin A, we induced hepatic expression of Activin A in a murine MASLD/MASH model. Surprisingly, overexpression of hepatic Activin A dramatically mitigated MASLD, reducing liver steatosis and inflammation as well as systemic fat accumulation, while improving insulin sensitivity. Further studies identified a dramatic decrease in the lipid-associated macrophages marker glycoprotein NMB (Gpnmb) by Activin A, and Gpnmb knockdown in the same model produced similar benefits and transcriptional changes to Activin A expression. These studies reveal a surprising protective role for Activin A in MASLD and the potential for SASP proteins to have context-specific beneficial effects. Moreover, they implicate both Activin A and Gpnmb as potential therapeutic targets for this condition.

ARTICLE HIGHLIGHTS

Effect of methoxymine on prevention and treatment of myocardial injury and cardiac function in elderly patients with hypotension during intraspinal anesthesia

OBJECTIVE

We aimed to investigate the effects of methoxamine to prevent hypotension in the elderly with intraspinal anesthesia (IA) on myocardial injury and cardiac function.

PATIENTS AND METHODS

A retrospective study was conducted by enrolling sixty elderly patients who underwent femoral head replacement (FHR) under IA in our hospital from August 2019 to August 2020. The patients were divided into two groups according to the random number table method. In the control group (CG) (30 patients), 5 mg of ephedrine was administered sedately when patients developed hypotension (20% below basal blood pressure). In the research group (RG) (30 cases), 2 μg/(kg·h) of methoxamine hydrochloride was given as a constant-rate pump before anesthesia, and 1 mg of methoxamine hydrochloride was administered intraoperatively if hypotension occurred. The hemodynamic [systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR)], myocardial injury indexes [cardiac troponin I (cTnI), creatine kinase isoenzyme MB (CK-MB), fatty acid binding protein (FABP), plasma amino-terminal brain natriuretic peptide precursor (NT-proBNP)], cardiac function indexes [systemic vascular resistance (SVR), stroke volume (SV), net percentage ejection time (ET)] were observed before anesthesia (T1), at the end of surgery (T2), and 6 h after surgery (T3) in both groups. The Bruggemann Comfort Score (BCS) and Visual Analog Scale (VAS) scores at T3, 12 h postoperatively (T4) and 24 h postoperatively (T5) in both groups were observed, and the incidence of adverse reactions to intralesional anesthesia in both groups was counted.

RESULTS

SBP, DBP and HR at T2 were lower than those at T1 in both groups, and SBP, DBP and HR at T3 were higher than those at T2, and SBP, DBP and HR at T2 and T3 in the RG were higher than those in the CG (p<0.05). In both groups, cTnⅠ, CK-MB and FABP were higher at T2 and T3 than at T1, higher at T3 than at T2, and NT-proBNP was higher at T2 than at T1 and T3, and lower in the RG than in the CG (p<0.05). In both groups, SVR and SV at time point T2 were lower than at time point T1 and ET was higher than at time point T1, SVR and SV at time point T3 were higher than at time point T2 and ET was lower than at time point T2, SVR and SV in the RG were higher than in the CG and ET was lower than in the CG (p<0.05). VAS scores were higher in both groups at T4 and T5 than at T3, and lower in the RG than in the CG (p<0.05).

CONCLUSIONS

Methoxamine can effectively reduce the risk of hypotension in geriatric endotracheal anesthesia, which can reduce myocardial injury and stabilize cardiac function in patients.

Predictive Factors for Response to Adaptive Therapy in Thoracic Stereotactic Ablative Radiotherapy

PURPOSE/OBJECTIVE(S)

Online adaptive radiotherapy (ART) has been increasingly adopted for clinical use. However, ART for thoracic malignancies has lagged beyond its implementation for other primary cancers. Efforts are needed to identify optimal patients for ART by finding trends for changes in tumor position, shape, or proximity to OARs are needed. We hypothesized tumor size, histology, pre-RT SUV value, and intrathoracic location could influence how tumors change during cone beam computed tomography (CBCT)-based ART Stereotactic Ablative Radiotherapy (SAbR) for thoracic disease.

MATERIALS/METHODS

Data was collected from a prospective registry of patients who received CBCT-ART and SAbR for primary and secondary lung tumors. Dosimetry data was obtained from the simulation planning and the daily adaptive workflow. Central lung tumors were defined as those located within 2 cm of the bronchial tree. Plans were either delivered as per simulation or through the online adaptive workflow delivery (AD). Change in planning tumor volumes (PTV) were calculated between initial and final fractions (ΔPTV).

RESULTS

A total of 42 patients with a median age of 67 (range 17-90) and median 8.3 months follow up, treated between June 2021 and December 2022 were included. Most patients had NSCLC or presumed NSCLC (73.85%, 31/42), and most lesions were peripheral (61.9%, 26/42) versus central (31%, 13/42) or apical (7.1%, 3/42). Mean dose and median fractions were 52.5 Gy (SD 8.07) and 5 (range 3-5) while median initial (i) PTV was 31.75 cm3 (IQR 42.3 cm3). On average, ΔPTV decreased by 4.9% (SD 21) and volume shrunk by 5 cm3 (SD 14.5). AD improved per fraction PTV coverage and conformality while esophageal, cardiac, and spinal cord dose were significantly decreased (all p < 0.05), and most fractions were delivered with AD (73.4%, 138/188). AD was aborted most often for small iPTVs. ΔPTV grew >10% for two lesions though their iPTV were < 10 cm3. 12/42 ΔPTV were >10% smaller by the end of RT and corresponded to larger iPTVs. Age, lung primary, metastatic disease, smoking status, and tumor location were not predictive for >10% decrease in ΔPTV. Among 24 biopsy-proven NSCLC ΔPTV was >10% smaller in 6/12 patients (50%) with adenocarcinoma and only in 2/12 (16.7%) with SCC, although this was not significant on χ2 testing (p = 0.08). There were no differences in local, regional, distant failure or death comparing those with a ΔPTV of >10% vs <10% (all p > 0.1). Comparing pre-treatment PET SUV and tumor response, lower SUVs appear to be associated with more PTV shrinkage, with no significant PTV change plateauing at SUV 20. However, this analysis was limited by the number of patients with high SUV values.

CONCLUSION

CBCT-ART SAbR is associated with improved PTV coverage, target conformality, and reduced OAR dose. Large iPTV and adenocarcinomas were more likely to decrease >10%. High metabolic activity appeared predictive for a lack of significant ΔPTV. Further clinical and radiographic features should be explored to predict response to ART.

Towards Biology-Guided Radiotherapy Planning and Delivery on a Novel O-Ring PET-Linac Platform: Extended Beyond Bone and Lung Lesions

PURPOSE/OBJECTIVE(S)

Biology-guided radiotherapy (BgRT) with FDG signal collected via an on-board positron emission tomography (PET) system integrated in an O-ring gantry Linac was recently cleared by the FDA for lung and bone lesions. This study aims to determine if BgRT plans, guided via PET signal, are clinically acceptable for FDG-avid lesions in disease sites beyond bone and lung.

MATERIALS/METHODS

Ten patients previously treated for lesions in the liver, head and neck (HN), pancreas, renal and pelvic-abdominal lymph nodes were identified. Diagnostic PET/CT images of these treatment sites were first collected and processed/converted to mimic PET images that are acquired on PET-Linac and would be used to guide the delivery. For BgRT planning, the PTV was generated with 5 mm margin from GTV and a Biology Tracking Zone was generated including the anticipated full range of target motion. BgRT plans, guided by the emulated PET signal, were generated with 46Gy in 3 fractions for liver and 40Gy in 5 fractions for all other sites. BgRT plan deliverability was first assessed by evaluating the Activity Concentration (AC) and Normalized Target Signals (NTS) on converted PET images with the goal to meet NTS >2 (hard constraint) and AC >5kBq/ml (goal). BgRT plan quality was then evaluated with institutional guidelines on PTV coverage, OAR doses, conformity index (CI) and Heterogeneity index (HI).

RESULTS

BgRT plans were successfully generated for 11 target lesions among ten patients. The average diagnostic PET SUV, derived NTS and AC on converted PET images were 12.62, 9.33 and 12.10 kBq/ml, respectively. All images met the NTS constraints, and 8/11 plans met the AC goal for deliverability. All plans met the OAR hard constraints such as max dose on duodenum, small bowel, large bowel and spinal cord. Five of 11 plans had a limiting GI structure that resulted in an expected reduction in PTV coverage with an average PTV V100% = 77.9%, CI of 1.4, HI of 1.36 and max dose of 133.8%. The other 6 of 11 cases met the PTV V100% = 95%, had an average CI of 1.1, HI of 1.28 and Dmax of 127.67%. The estimated average time for BgRT delivery was 17 mins 25 secs. Although these plan parameters are deemed to be clinically acceptable, heterogeneity was detected inside the target region and suboptimal dose fall off was observed in some cases that may be caused by current implementation.

CONCLUSION

This preliminary study showed that BgRT plans were generated successfully with emulated PET images on 11 treatment sites covering HN, abdominal and pelvic regions. All plans met NTS constraints and 8 out of 11 met AC goals for deliverability. The plan quality of all BgRT plans were clinically acceptable based on institutional constraints. Further investigations are required to test more patients/sites for BgRT plan feasibility. Dosimetric benefit from margin reduction of BgRT target should also be investigated in future study.

Dosimetric Analysis of CBCT-Based Weekly Online Adaptive Radiotherapy for Locally Advanced Non-Small Cell Lung Cancer

PURPOSE/OBJECTIVE(S)

Anatomic and geometric changes are common during a radiotherapy course amongst patients receiving conventional fractionated radiotherapy for locally advanced non-small cell lung cancer (LA-NSCLC). These changes may cause significant deviation from initial reference plan resulting in over-treatment of normal tissue or under-coverage of the target. Cone-beam computed tomography (CBCT)-based online adaptive radiotherapy (ART) platforms allow for response to these changes and is being increasingly used in the clinic though less so for intrathoracic disease. We hypothesized weekly CBCT-ART would improve target coverage and decrease dose to organs at risk (OAR) in patients with LA-NSCLC.

MATERIALS/METHODS

Data was collected from a prospective registry of 23 LA-NSCLC patients treated to 60 Gy in 30 fractions with CBCT-ART between June 2021 and December 2022. For weekly ART (Wk-ART), online plan adaptation started on week two. The adapted plan was then used to treat patients with image guidance until the next ART. For comparison, doses were recalculated with the initial reference plan on the SCT with updated contours to derive non-adapted (non-ART) dosimetry for each week. The final dosimetric parameters were obtained by averaging weekly coverage (ITV, PTV) and critical OAR (Lung, esophagus, heart, spinal cord) doses for non-ART and weekly ART treatments respectively for each patient. Paired student t-test was performed to compare the dosimetric parameters between non-ART and Wk-ART.

RESULTS

We observed an average 29% ± 19% (median: 26%) reduction in ITV volume through the radiotherapy course, with 48% (11/23) of patients showing >30% reduction. Most significant volume reductions (16%) were observed between the third and fourth adaptation. Weekly ART showed significant (p<1×10-3) improvements in ITV and PTV coverage, and showed improved clinically relevant lung, esophageal, cardiac, and lung dosimetry (Table 1), especially in the later stages of treatment when the tumor showed significant shrinkage. The average time from contour review to quality assurance completed is 8.5±1.2 min.

CONCLUSION

CBCT-ART provides robust ART plan quality and efficient workflow. There are significant improvements in target coverage and OAR sparing in LA-NSCLC treated with weekly CBCT-ART and these are driven by the significant volume reduction of the ITV throughout treatment course.

Predicted Cardiac Toxicity in Daily Cone-Beam CT-Based Online Adaptive Stereotactic Partial Breast Irradiation with Decreased PTV Margins

PURPOSE/OBJECTIVE(S)

Partial breast irradiation (PBI) targets a smaller volume over less time compared to whole breast radiation, but the organ-at-risk (OAR) sparing allowed by its large (up to 1 cm) PTV can be improved. The heart is sensitive to low doses with conventional fractionation and NTCP models have been created for heart substructures. We hypothesized that daily online adaptive stereotactic PBI (A-SPBI) IMRT with 3-mm PTV improves dosimetry and predicted cardiac toxicity risk.

MATERIALS/METHODS

Patients treated with daily CBCT-based online A-SPBI IMRT were excluded if the minimum heart dose was <1 Gy. IMRT radiation plans with 3-mm PTV margins were recreated with 1-cm margins per the Florence APBI IMRT trial planning guideline. Dose statistics were converted to the equivalent doses in 2-Gy fractions (EQD2) using α/β = 3 for use in NTCP models and for comparison using paired t tests, with differences considered significant if p≤0.05.

RESULTS

The table details heart, left anterior descending artery (LAD), and left (LV) and right ventricle (RV) EQD2 statistics for 4 left-sided and 4 right-sided 3-mm PTV plans and their 1-cm PTV replans. For 2 patients with non-zero LV V5, 9-year excess cumulative risk of acute coronary event was <0.001% for both margin sizes. No plan reached thresholds for increased risk of non-cardiac death, major adverse cardiac event, or >10% decrease in LV ejection fraction.

CONCLUSION

Given the established relationship between low MHD and cardiac events, the significant decrease in MHD revealed in comparisons of 3-mm and 1-cm PTV A-SPBI plans of our first 8 patients is promising; we expect the forthcoming larger sample size to show significant differences in substructure doses. NTCP models created for non-IMRT breast plans and targets with higher heart exposure did not predict clinically-relevant differences in cardiac risk. NTCP model development for the low heart dose achieved with A-SPBI would define expected benefit in these patients; in their absence, daily adaptation should be considered in patients with unfavorable anatomy or cardiac risk factors.

Observed and Predicted Toxicity in Daily Cone-Beam CT-Based Online Adaptive Stereotactic Partial Breast Irradiation with Decreased PTV Margins

PURPOSE/OBJECTIVE(S)

Accelerated partial breast irradiation (APBI) delivers smaller radiation volumes over less time compared to whole breast irradiation (WBI), but the organ-at-risk (OAR) sparing allowed by its large (up to 1 cm) planning target volume (PTV) can be improved. PTV can be decreased with daily online adaptive planning, which we hypothesized yields low rates of adverse events observed and predicted by normal tissue complication probability (NTCP) models.

MATERIALS/METHODS

Intensity-modulated (IMRT) cone-beam CT (CBCT)-based daily online adaptive stereotactic PBI (A-SPBI) plans with 3-mm PTV from 8 patients were recreated with 1-cm PTV per the Florence APBI IMRT trial planning guideline. Dose statistics with evidence for association with toxicity were compared. Documented toxicities were collected for patients treated with A-SPBI with a minimum follow-up of 3.5 months and Common Terminology Criteria for Adverse Events (CTCAE) v.5.0 grade was assigned. Using α/β = 3 for breast and lung, dose statistics were converted to equivalent doses in 2-Gy fractions (EQD2) for use in NTCP models and for comparison using paired t tests, with differences considered significant if p≤0.05.

RESULTS

The table details EQD2 dose statistics for breast, lung, and cosmetic toxicity for A-SPBI plans with 3-mm PTV and their 1-cm PTV re-plans in 8 patients. PTV volume, mean lung dose (MLD), and lung V5, V20, and V30 were significantly lower in 1-cm plans. Acute, subacute (3-6 months), and late toxicities were collected for 30 patients followed for a median of 8 months (range 4-13 months). Radiation dermatitis was the most common acute toxicity (n = 16, 53%), followed by hyperpigmentation (n = 12, 40%), fibrosis (n = 9, 30%), and fatigue (n = 9, 30%). One grade 3 radiation dermatitis was the only grade ≥3 toxicity. Six patients (20%) acutely developed breast or axillary edema: 4 (13.3%) resolved, and 2 (6.7%) developed acutely and persist at last follow-up, >6 months after RT. No patient had a lung V20, V30, or MLD meeting thresholds for radiation-induced lung injury, radiation pneumonitis, or symptomatic or imaging-based pneumonitis models, respectively. The breast V55 model predicted a median risk of unfavorable cosmesis of 33% (range 26-44%) for A-SBPI plans and 35% (range 28-51) for 1-cm PTV plans (p = 0.28).

CONCLUSION

Observed acute toxicities are tolerable and rarely persist in patients treated with A-SPBI with 3-mm PTV margins with daily CBCT-based online adaptation. NTCP modeling predicts similar cosmetic outcome to 1-cm margins. The significant reduction in ipsilateral lung dose with a 3-mm PTV in our first 8 patients especially supports daily adaptation in low-risk breast cancer patients with smoking history and/or lung comorbidity.

Analysis of the Measured FDG Uptake from the First-in-Human Clinical Trial of Biology-Guided Radiotherapy

PURPOSE/OBJECTIVE(S)

The RefleXion X1 system is a novel linear accelerator equipped with dual 90° PET arcs incorporated into its architecture to capture emissions from tumors and designed to respond by directing the radiation beam towards target. This study reports on the measured FDG uptake from the first in human multi-institutional clinical trial (BIOGUIDE-X) evaluating the performance and safety of the RefleXion X1 PET-LINAC.

MATERIALS/METHODS

A total of nine patients treated with stereotactic body radiotherapy (SBRT) for lung (5) and bone (4) tumors were enrolled in the Cohort II of this study after screening their pre-study diagnostic PET/CT, acquired up to 60 days prior to enrollment, to ensure their tumor size between 2 to 5 cm and SUVmax >6. After CT simulation, the tumor and OARs were delineated, and patients had a 4-pass Imaging-only (BgRT Modeling) PET/CT acquisition on the X1 system to generate biology-guided radiotherapy (BgRT) plans. Before the patients' first and last SBRT fractions, they were injected with FDG, and short PET pre-scan (1-pass) was performed on the X1 followed by a long-PET acquisition (4-pass) to emulate the expected BgRT dose distribution without firing beam. Patients were also imaged on a third-party diagnostic PET/CT scanner after the last-fraction X1 scan. This study compares the SUVmax from the screening PET/CT, X1 Imaging-only scan, X1 PET pre-scan and long scan before the first and last-fractions, and final diagnostic PET/CT.

RESULTS

The median time from injection to PET imaging was 84 ± 15.4 mins for X1 Imaging-only (used for generating BgRT plans), 77 ± 21.6 mins for X1 pre-scan (safety check before treatment start), 108+/- 22 mins for X1 long-PET (used to emulate treatment delivery), and 161 ± 23 mins for final diagnostic PET. For a nominal 10 mCi injection, the mean SUVmax for screening imaging performed on the diagnostic PET/CT was 10.8 ± 4.3. For a 15 mCi nominal injection, the mean SUVmax calculated on the X1 was 5.3 ± 2.6, 5.4 ± 2.0, 5.5 ± 2.6, 5.2 ± 1.8 and 5.4 ± 2.2 for the Imaging-only, first-fraction PET pre-scan, first-fraction long PET scan, last-fraction PET pre-scan, and last-fraction long PET scan, respectively. The overall median SUVmax for all patients across all timepoints and scans with X1 was calculated to be 4.8 with a range of 2.4 to 9.8. The median SUVmax for the diagnostic PET/CT scan after the last fraction X1 scan was 15.8 with a range of 8.5 to 27.7.

CONCLUSION

The dual PET arcs and limited axial extent of the X1 PET subsystem results in lower system sensitivity in comparison to diagnostic PET scanners equipped with full ring and larger axial extent, as expected. With the same FDG injection, the RefleXion X1 produced SUVmax values that were 30.4 % of the diagnostic PET/CT scanners' values. Nevertheless, the X1 collected sufficient emission data to enable successful completion of emulated BgRT deliveries that met dose accuracy criteria in a clinical setting.

Imaging Performance of the PET Scan on a Novel Ring Gantry-Based PET/CT Linear Accelerator System in the First-in-Human Study of Biology-Guided Radiotherapy

PURPOSE/OBJECTIVE(S)

Biology-guided radiotherapy (BgRT) is a novel tracked dose delivery modality using real-time positron emission tomography (PET) to guide radiotherapy beamlets. The present study was performed with sequential cohorts of participants to evaluate the performance and safety of BgRT. Primary endpoints were previously reported. We hereby report on one of the secondary endpoints assessing a novel treatment planning machine with integrated dual kVCT/PET imaging ("novel device") performance in comparison to a third-party diagnostic PET/CT scan.

MATERIALS/METHODS

This single-arm, open-label, prospective study included participants with at least 1 FDG-avid targetable primary or metastatic tumor (≥2cm and ≤5cm) in the lung or bone. PET imaging data were collected on the novel device and on a third-party diagnostic PET/CT performed in sequence once at the planning timepoint in Cohort I, and immediately before the last fraction among patients undergoing stereotactic radiotherapy in Cohort II. Three central read radiation oncologists (CRRO) provided an interpretation of the novel device PET scans which were compared to an agreement standard based on 3 central radiologists' review of the paired diagnostic PET/CT scan. Positive percent agreement for localization of the target tumor within the biology-tracking zone (BTZ) was the key metric because it reflects whether advancing patients to subsequent steps in the BgRT workflow based on the novel device's imaging was ultimately appropriate.

RESULTS

In Cohort 1, 6 image comparisons were performed. The positive (%) agreement for the aggregate radiation oncologist review was 100% (5/5), reflecting that in all 5 cases where the aggregate radiation oncologists deemed the tumor to fall within the BTZ based upon the novel device PET images, the central radiologists came to the same conclusion upon review of the paired diagnostic PET/CT images. The overall (%) agreement for the aggregate radiation oncologist review was 83.3% (5/6): localization was not established on the novel device in 1 case, even though it was established on the diagnostic PET/CT. This would not pose risk in real world practice as BgRT candidacy would be aborted for tumors not visible on the novel device. In Cohort II, among the 7 image comparisons, there was 100% positive percent agreement between the aggregate CRRO and the agreement standard as the localization criteria was met in both scans for all 7 patients. This was concordant with a 100% overall percent agreement.

CONCLUSION

This investigation demonstrated a 100% positive percent agreement between central review of this novel device images by radiation oncologists and central review of the accompanying third-party PET/CT images by radiologists. There were no cases where a positive localization by the aggregate CRRO was not confirmed by the third-party PET/CT standard, providing evidence against the likelihood of falsely positive localizations on the novel device that would inappropriately advance patients in the workflow.

Dosimetric Comparison of Adaptive Radiotherapy Modalities for Stereotactic Partial Breast Irradiation

PURPOSE/OBJECTIVE(S)

An increase in the availability of adaptive radiotherapy (ART) platforms have proven to be effective in the treatment of a variety of sites. In this study, we aim to evaluate the effectiveness of non-adaptive RT and 3 different ART platforms: (1) CBCT-based, (2) CT-based, and (3) MRI-based for stereotactic partial breast irradiation (SPBI).

MATERIALS/METHODS

Data were collected from 32 patients (16 left and 16 right breast) treated at a single institution. 16 patients (8 left and 8 right) treated using the non-ART platform were re-planned onto two different ART platforms, CBCT- and MRI-based. The remaining 16 patients treated using CT-based adaptive platform were not re-planned due to the prone patient treatment position (others systems supine). All cases were planned to 30 Gy in 5 fractions. Plan quality was evaluated based on pre-defined planning goals to the OARS: ipsilateral and contralateral lungs (Dmean, Dmax, V20 Gy, V9 Gy), ipsilateral (V15 Gy, V30 Gy) and contralateral breasts (Dmax), heart (Dmean, Dmax, V3 Gy, V1.5 Gy), skin (Dmax, V36.5 Gy), and rib (Dmax, V30 Gy). Target goals were defined by Dmax, Dmin, gradient index, and paddock conformality index. Re-planned cases were compared within the cohort using a paired t-test and a 2-sided t-test was used comparing to the CT-based platform.

RESULTS

Comparing the left and right breast cohort across all platforms, the CT-based ART system showed a signification dose reduction in Dmean (p<0.001 for all platforms), Dmax (p<0.001 for left breast, p<0.03 for right breast) and V9 Gy (p<0.004 for left breast, p<0.001 for right breast) to the ipsilateral lung, V15 Gy (p<0.004 for left breast cohort) to the ipsilateral breast, and Dmax to the contralateral breast (p<0.001) and ribs (p = 0.01, p<0.001, p = 0.01 for CBCT-ART, MRI-ART, and non-ART for left breast cohort only). On average, the MR-Linac platform showed the least degree of OAR sparing across nearly all dosimetric parameters evaluated when compared to all modalities, especially for contralateral lung Dmean and Dmax (p<0.05 for all dosimetric parameters for all platforms) and contralateral breast Dmax (p<0.003 for all platforms). The CBCT-based platform showed superior dose reduction in contralateral lung mean (p<0.03 for all platforms) and heart Dmean (p = 0.065, p<0.001, p = 0.045 for non-adaptive, MRI-ART, and CT-ART for left breast and p<0.008 for right breast). PTV coverage was comparable across all platforms, averaging at approximately 95%. The CT-based ART platform showed a significantly reduced gradient index relative to the CBCT- and MRI-based platforms (p<0.001).

CONCLUSION

For SPBI treatments, the CT-based ART platforms displayed a higher degree of OAR sparing for many of the dosimetric parameters recorded relative to the other ART and non-ART platforms presented. The MRI-based system typically showed less reduced OAR sparing; however, the advantage of the system is shown if soft tissue contrast is needed. PTV coverage remained comparable across all platforms.

Workflow Considerations for Biology-Guided Radiotherapy (BgRT) Implementation

PURPOSE/OBJECTIVE(S)

Biology-guided radiotherapy (BgRT) is a novel platform that combines real-time PET imaging with a 6MV Linac to target tumors. The performance and safety of BgRT was assessed in the BIOGUIDE-X clinical trial. This study aims to report on the BgRT workflow steps and assess the time required for each step of the BgRT process during this trial.

MATERIALS/METHODS

A total of nine patients were enrolled in the second Cohort of the BIOGUIDE-X study which included patients treated with stereotactic body radiotherapy (SBRT) for lung tumors (5) and bone tumors (4). The pre-treatment BgRT workflow includes CT simulation, contouring, imaging-only (BgRT Modeling) PET acquisition, BgRT planning, patient specific QA and plan approval. The imaging-only PET acquisition on the X1 collects a representative PET volumetric 3D image and is an input to develop the BgRT treatment plan. The steps during the BgRT delivery session are kVCT localization, PET pre-scan, PET evaluation and BgRT delivery. The PET PreScan is a 1-pass short-duration PET acquisition that is used to confirm that the PET biodistribution on the day of treatment is consistent with that of the imaging-only PET. During BIOGUIDE-X, the BgRT delivery step was replaced by a 4-pass long-PET acquisition that was used to emulate the expected BgRT dose distribution without turning the beam on. To assess BgRT workflow, times from 18F-FDG injection to image-only PET acquisition, 18F-FDG injection to PET pre-scan, Pre-scan to PET evaluation, and PET evaluation to BgRT delivery (long PET acquisition) were recorded.

RESULTS

Time between the 18F-FDG injection and the X1 imaging-only PET scan was 84 ± 19 minutes which includes time for 18F-FDG update. Average time to perform imaging-only PET scan was 26 ± 4 minutes. During the BgRT 'delivery' session, the mean time between the kVCT acquisition and PET pre-scan acquisition was 7 ± 3 minutes. The mean time to acquire a 1-pass PET pre-scan was 6 ± 1 then followed by 6 ± 1 minutes for the PET pre-scan dose calculation to estimate the BgRT doses that it would have delivered for this fraction. On average, the PET reconstruction, the PET signal localization verification and the evaluation of safety metrics took 11 ± 4 minutes. The mean time for BgRT 'delivery' was 27 ± 5 minutes based on the 4-pass long PET acquisition. Time from the start of the BgRT session to the end of the BgRT 'delivery' with this version of the investigative product release was 65 ± 9 minutes.

CONCLUSION

The new processes introduced by the BgRT technology were evaluated and found clinically feasible. Improvements are being undertaken to shorten the time required for each step and to increase patient comfort ahead of BgRT clinical implementation.

Hepatocyte SREBP signaling mediates clock communication within the liver

Rhythmic intraorgan communication coordinates environmental signals and the cell-intrinsic clock to maintain organ homeostasis. Hepatocyte-specific KO of core components of the molecular clock Rev-erbα and -β (Reverb-hDKO) alters cholesterol and lipid metabolism in hepatocytes as well as rhythmic gene expression in nonparenchymal cells (NPCs) of the liver. Here, we report that in fatty liver caused by diet-induced obesity (DIO), hepatocyte SREBP cleavage-activating protein (SCAP) was required for Reverb-hDKO-induced diurnal rhythmic remodeling and epigenomic reprogramming in liver macrophages (LMs). Integrative analyses of isolated hepatocytes and LMs revealed that SCAP-dependent lipidomic changes in REV-ERB-depleted hepatocytes led to the enhancement of LM metabolic rhythms. Hepatocytic loss of REV-ERBα and β (REV-ERBs) also attenuated LM rhythms via SCAP-independent polypeptide secretion. These results shed light on the signaling mechanisms by which hepatocytes regulate diurnal rhythms in NPCs in fatty liver disease caused by DIO.

A205 EVALUATING THE ASSOCIATION BETWEEN PERIPHERAL BLOOD EOSINOPHILS AND DRUG RESPONSE IN CROHN'S DISEASE: CONTINUING ANALYSIS

Background

Th2 cytokines, IL-5 and IL-13 enhance peripheral and mucosal eosinophil survival, recruitment and degranulation, facilitating inflammation in Crohn's Disease. In a preliminary analysis, peripheral eosinophilia (PBE) is seen to have an association with rates of steroid response and anti-TNF response in CD patients. Participants with high PBE (> 200 cells/μL) appear to be more steroid-responsive but less responsive to Th1-targeting anti-TNF therapies. We hypothesize the pattern of PBE at CD diagnosis can help identify distinct subsets within a larger CD population and correlate with response to treatments such as prednisone or anti-TNFs.

Purpose

We aim to evaluate the pattern of PBE of CD patients at time of diagnosis (prior to drug exposure) and with each subsequent treatment; and if baseline PBE or any changes seen with drug exposures are predictive of treatment response.

Method

A retrospective cohort study is ongoing with CD patients exposed to glucocorticoids and an anti-TNF seen at 3 hospitals affiliated with University of Western Ontario. Patients were identified using administrative databases and reviewed for biochemical data (complete blood count) and disease activity (Harvey Bradshaw Index) at baseline, before and after each drug exposure. Participants were classified as having high PBE (eosinophils>200 cells/μL) versus low PBE (eosinophils <200 cells/μL). To date, 350 patients have been screened. Subgroup analyses of PBE > 300 cells/μL, and differences between female and male patients will be carried out.

Result(s)

46 of 200 CD patients are included in the continuing analysis with a mean age of 45 years. 26 had PBE >200 cells/μL at baseline and 20 did not. The median number therapies used was 4 (IQR=0.75). All received glucocorticoids followed by an anti-TNF. There was no difference in the occurrence of hospitalization or surgery between the two groups. Overall 50% participants with high PBE >200 and >300 cells/μL had clinical response to glucocorticoid exposure, seen as a 3-point decrease in HBI compared to 45%, 47% in the low PBE cohort (n=13/26 vs. n=9/20 p=0.77; n=6/12 vs. n=16/34 p=1.0 respectively). With subsequent anti-TNF exposure, PBE rebounded in 7 participants. 36% patients in the high PBE group required anti-TNF dose escalation versus 24% in the low PBE group (n=9/25 vs. n=5/21, p=0.52). The proportion of patients with anti-TNF discontinuation was similar in both groups (high PBE 19.2%, n=5/26 vs. low PBE 15%, n=3/20, p=1.0). Men had higher steroid response rates compared to women in both high and low PBE groups (n=6/8 vs. n=8/18 p=0.21; n=4/9 vs. 4/11 p=1.0 respectively).

Conclusion(s)

Peripheral eosinophilia is seen in varying degrees in CD patients. Participants with high PBE are more steroid-responsive. High PBE patients overall were less responsive to anti-TNF therapies, requiring more dose-escalation and discontinued anti-TNF treatment. Completion of this study will help clarify the association between PBE in CD and treatment response.

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Disclosure of Interest

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PPARγ (Peroxisome Proliferator-Activated Receptor γ) Deacetylation Suppresses Aging-Associated Atherosclerosis and Hypercholesterolemia

BACKGROUND

Atherosclerosis is a medical urgency manifesting at the onset of hypercholesterolemia and is associated with aging. Activation of PPARγ (peroxisome proliferator-activated receptor γ) counteracts metabolic dysfunction influenced by aging, and its deacetylation displays an atheroprotective property. Despite the marked increase of PPARγ acetylation during aging, it is unknown whether PPARγ acetylation is a pathogenic contributor to aging-associated atherosclerosis.

METHODS

Mice with constitutive deacetylation-mimetic PPARγ mutations on lysine residues K268 and K293 (2KR) in an LDL (low-density lipoprotein)-receptor knockout (Ldlr-/-) background (2KR:Ldlr-/-) were aged for 18 months on a standard laboratory diet to examine the cardiometabolic phenotype, which was confirmed in Western-type diet-fed 2KR:Ldlr+/- mice. Whole-liver RNA-sequencing and in vitro studies in bone marrow-derived macrophages were conducted to decipher the mechanism.

RESULTS

In contrast to severe atherosclerosis in WT:Ldlr-/- mice, aged 2KR:Ldlr-/- mice developed little to no plaque, which was underlain by a significantly improved plasma lipid profile, with particular reductions in circulating LDL. The protection from hypercholesterolemia was recapitulated in Western-type diet-fed 2KR:Ldlr+/- mice. Liver RNA-sequencing analysis revealed suppression of liver inflammation rather than changes in cholesterol metabolism. This anti-inflammatory effect of 2KR was attributed to polarized M2 activation of macrophages. Additionally, the upregulation of core circadian component Bmal1 (brain and muscle ARNT-like 1), perceived to be involved in anti-inflammatory immunity, was observed in the liver and bone marrow-derived macrophages.

CONCLUSIONS

PPARγ deacetylation in mice prevents the development of aging-associated atherosclerosis and hypercholesterolemia, in association with the anti-inflammatory phenotype of 2KR macrophages.

The interplay between nonalcoholic fatty liver disease and atherosclerotic cardiovascular disease

Therapeutic approaches that lower circulating low-density lipoprotein (LDL)-cholesterol significantly reduced the burden of cardiovascular disease over the last decades. However, the persistent rise in the obesity epidemic is beginning to reverse this decline. Alongside obesity, the incidence of nonalcoholic fatty liver disease (NAFLD) has substantially increased in the last three decades. Currently, approximately one third of world population is affected by NAFLD. Notably, the presence of NAFLD and particularly its more severe form, nonalcoholic steatohepatitis (NASH), serves as an independent risk factor for atherosclerotic cardiovascular disease (ASCVD), thus, raising interest in the relationship between these two diseases. Importantly, ASCVD is the major cause of death in patients with NASH independent of traditional risk factors. Nevertheless, the pathophysiology linking NAFLD/NASH with ASCVD remains poorly understood. While dyslipidemia is a common risk factor underlying both diseases, therapies that lower circulating LDL-cholesterol are largely ineffective against NASH. While there are no approved pharmacological therapies for NASH, some of the most advanced drug candidates exacerbate atherogenic dyslipidemia, raising concerns regarding their adverse cardiovascular consequences. In this review, we address current gaps in our understanding of the mechanisms linking NAFLD/NASH and ASCVD, explore strategies to simultaneously model these diseases, evaluate emerging biomarkers that may be useful to diagnose the presence of both diseases, and discuss investigational approaches and ongoing clinical trials that potentially target both diseases.

[Clinical features, risk factors and prognosis of idiopathic dilated cardiomyopathy complicated by ischemic stroke]

Objective: To analyze the clinical features, risk factors and prognosis of idiopathic dilated cardiomyopathy (DCM) complicated with ischemic stroke (IS) (DCM-IS). Methods: The clinical data of patients with idiopathic DCM (n=613) in Beijing Anzhen Hospital, Liangxiang Hospital and Fuxing Hospital from January 2016 to December 2020 were retrospectively collected, and among them, 123 cases were DCM-IS. Clinical features of patients with DCM-IS were summarized and multivariate logistic regression model was utilized to analyze the independent risk factors of DCM-IS. Furthermore, 1-year follow-up was conducted and Kaplan-Meier curve was adopted to analyze the prognosis of DCM, using all-cause death and heart transplantation as adverse outcomes. Results: Among the 70 patients with DCM-IS, 6 patients (8.6%, 6/70) were in accordance with the subtype of large artery atherosclerosis, and 47 patients (67.1%, 47/70) were in line with the subtype of cardiogenic embolism, and small artery occlusion subtype (ie, lacunar infarction) were detected in 17 cases (24.3%, 17/70). Hypertension [odds ratio (OR)=1.617, 95% confidence interval (CI): 1.049-2.491, P=0.029], hyperlipidemia (OR=1.918, 95%CI: 1.198-3.073, P=0.007), atrial fibrillation (AF) (OR=1.617, 95%CI: 1.016-2.572, P=0.043), lower estimated glomerular filtration rate (eGFR) (OR=0.986, 95%CI: 0.977-0.996, P=0.005) and a higher incidence of intracardiac thrombus (OR=6.127, 95%CI: 3.174-11.827, P<0.001) were risk factors for DCM-IS. The overall 1-year survival rate was lower in DCM-IS patients (70.7%) than DCM patients without stroke (83.6%, P=0.004), and the main causes of death included obstinate heart failure (3 cases of DCM-IS, and 5 cases of non-DCM-IS) and malignant arrhythmia (DCM-IS) (22 cases of DCM-IS, and 18 cases of non-DCM-IS). Conclusions: Among IS patients with idiopathic DCM, cardioembolism is the most common, followed by lacunar infarction, and the large-artery atherosclerotic subtype is the least common.Hypertension, hyperlipidemia, AF, lower eGFR value and higher incidence of intracardiac thrombus are risk factors for DCM-IS. DCM patients complicated with IS have poor short-term prognosis, and obstinate heart failure and malignant arrhythmia are their main causes of death.

CD47-SIRPα axis blockade in NASH promotes necroptotic hepatocyte clearance by liver macrophages and decreases hepatic fibrosis

Necroptosis contributes to hepatocyte death in nonalcoholic steatohepatitis (NASH), but the fate and roles of necroptotic hepatocytes (necHCs) in NASH remain unknown. We show here that the accumulation of necHCs in human and mouse NASH liver is associated with an up-regulation of the "don't-eat-me" ligand CD47 on necHCs, but not on apoptotic hepatocytes, and an increase in the CD47 receptor SIRPα on liver macrophages, consistent with impaired macrophage-mediated clearance of necHCs. In vitro, necHC clearance by primary liver macrophages was enhanced by treatment with either anti-CD47 or anti-SIRPα. In a proof-of-concept mouse model of inducible hepatocyte necroptosis, anti-CD47 antibody treatment increased necHC uptake by liver macrophages and inhibited markers of hepatic stellate cell (HSC) activation, which is responsible for liver fibrogenesis. Treatment of two mouse models of diet-induced NASH with anti-CD47, anti-SIRPα, or AAV8-H1-shCD47 to silence CD47 in hepatocytes increased the uptake of necHC by liver macrophages and decreased markers of HSC activation and liver fibrosis. Anti-SIRPα treatment avoided the adverse effect of anemia found in anti-CD47-treated mice. These findings provide evidence that impaired clearance of necHCs by liver macrophages due to CD47-SIRPα up-regulation contributes to fibrotic NASH, and suggest therapeutic blockade of the CD47-SIRPα axis as a strategy to decrease the accumulation of necHCs in NASH liver and dampen the progression of hepatic fibrosis.

Macrophages use apoptotic cell-derived methionine and DNMT3A during efferocytosis to promote tissue resolution

Efferocytosis, the clearance of apoptotic cells (ACs) by macrophages, is critical for tissue resolution, with defects driving many diseases. Mechanisms of efferocytosis-mediated resolution are incompletely understood. Here, we show that AC-derived methionine regulates resolution through epigenetic repression of the extracellular signal-regulated kinase 1/2 (ERK1/2) phosphatase Dusp4. We focus on two key efferocytosis-induced pro-resolving mediators, prostaglandin E2 (PGE2) and transforming growth factor beta 1 (TGF-β1), and show that efferocytosis induces prostaglandin-endoperoxide synthase 2/cyclooxygenase 2 (Ptgs2/COX2), leading to PGE2 synthesis and PGE2-mediated induction of TGF-β1. ERK1/2 phosphorylation/activation by AC-activated CD36 is necessary for Ptgs2 induction, but this is insufficient owing to an ERK-DUSP4 negative feedback pathway that lowers phospho-ERK. However, subsequent AC engulfment and phagolysosomal degradation lead to Dusp4 repression, enabling enhanced p-ERK and induction of the Ptgs2-PGE2-TGF-β1 pathway. Mechanistically, AC-derived methionine is converted to S-adenosylmethionine, which is used by DNA methyltransferase-3A (DNMT3A) to methylate Dusp4. Bone-marrow DNMT3A deletion in mice blocks COX2/PGE2, TGF-β1, and resolution in sterile peritonitis, apoptosis-induced thymus injury and atherosclerosis. Knowledge of how macrophages use AC-cargo and epigenetics to induce resolution provides mechanistic insight and therapeutic options for diseases driven by impaired resolution.

A163 EVALUATING THE ASSOCIATION BETWEEN PERIPHERAL BLOOD EOSINOPHILS AND DRUG RESPONSE IN CROHN’S DISEASE: A PRELIMINARY REPORT

Background

Th1, Th2, and Th17 immune pathways are variably activated in inflammatory bowel disease (IBD). The degree to which pathway having a more dominant role in propagating Crohn’s disease (CD) is not considered when selecting a treatment strategy. Th2 cytokines, IL-5 and IL-13 enhance eosinophil survival, recruitment and degranulation, facilitating inflammation. Mucosal eosinophilia has been documented in CD and its presence is a surrogate marker of Th2 pathway activation. Peripheral eosinophilia has an established role in asthma to help prognosticate treatment response to Th2-cytokine-specific therapies. We hypothesize the pattern of peripheral blood eosinophils (PBE) at CD diagnosis will identify distinct subsets within a larger CD population and correlate with response to treatments such as prednisone or anti-TNFs.

Aims

We aim to evaluate the pattern of PBE of CD patients at time of diagnosis (prior to drug exposure) and with each subsequent treatment; and if baseline PBE or any changes seen with drug exposures are predictive of treatment response.

Methods

A retrospective cohort study is ongoing with CD patients exposed to glucocorticoids and an anti-TNF seen at one of 3 hospitals affiliated with University of Western Ontario. Patients were identified using administrative databases and reviewed for biochemical data (complete blood count) and disease activity (Harvey Bradshaw Index) at baseline as well as before and after each drug exposure. Participants were classified as having high PBE (eosinophils >200 cells/μl) versus low PBE (eosinophils <200 cells/μl).

Results

To date,10 of 200 CD patients are included in the preliminary analyses with a mean age of 47. 8 had PBE >200 cells/μL at baseline, while 2 did not. The median number therapies used was 4 (IQR=0.75). All received glucocorticoids followed by an anti-TNF. There was no difference in the occurrence of hospitalization or surgery between the two cohorts. Overall 75% (n=6/8) participants with high PBE had clinical response to glucocorticoid exposure, seen as a 3-point decrease in HBI compared to 0% (n=0/2, p=0.5) in the low PBE cohort. With subsequent anti-TNF exposure, PBE rebounded in 6 participants. More patients in the high PBE group required anti-TNF dose escalation versus the low PBE group (63%, n=5/8 versus 50%, n=1/2, p=0.99). The proportion of patients with anti-TNF discontinuation was similar in both groups (high PBE, 50%, n=4/8 versus low PBE, 50%, n=1/2, p=1.00).

Conclusions

Peripheral eosinophilia is seen in varying degrees in CD patients. Participants with high PBE appear to be more steroid-responsive which is typical for Th2-mediated pathways. They were less responsive to Th1-targeting anti-TNF therapies, requiring more dose-escalation and discontinued anti-TNF treatment. Completion of this study will help clarify the association between PBE in CD and treatment response.

Funding Agencies

None

First Direct Detection Constraints on Planck-Scale Mass Dark Matter with Multiple-Scatter Signatures Using the DEAP-3600 Detector

Dark matter with Planck-scale mass (≃10^{19}  GeV/c^{2}) arises in well-motivated theories and could be produced by several cosmological mechanisms. A search for multiscatter signals from supermassive dark matter was performed with a blind analysis of data collected over a 813 d live time with DEAP-3600, a 3.3 t single-phase liquid argon-based detector at SNOLAB. No candidate signals were observed, leading to the first direct detection constraints on Planck-scale mass dark matter. Leading limits constrain dark matter masses between 8.3×10^{6} and 1.2×10^{19}  GeV/c^{2}, and ^{40}Ar-scattering cross sections between 1.0×10^{-23} and 2.4×10^{-18}  cm^{2}. These results are interpreted as constraints on composite dark matter models with two different nucleon-to-nuclear cross section scalings.

Pulse-shape discrimination against low-energy Ar-39 beta decays in liquid argon with 4.5 tonne-years of DEAP-3600 data

The DEAP-3600 detector searches for the scintillation signal from dark matter particles scattering on a 3.3 tonne liquid argon target. The largest background comes from 39 Ar beta decays and is suppressed using pulse-shape discrimination (PSD). We use two types of PSD estimator: the prompt-fraction, which considers the fraction of the scintillation signal in a narrow and a wide time window around the event peak, and the log-likelihood-ratio, which compares the observed photon arrival times to a signal and a background model. We furthermore use two algorithms to determine the number of photons detected at a given time: (1) simply dividing the charge of each PMT pulse by the mean single-photoelectron charge, and (2) a likelihood analysis that considers the probability to detect a certain number of photons at a given time, based on a model for the scintillation pulse shape and for afterpulsing in the light detectors. The prompt-fraction performs approximately as well as the log-likelihood-ratio PSD algorithm if the photon detection times are not biased by detector effects. We explain this result using a model for the information carried by scintillation photons as a function of the time when they are detected.

[Correlation between neck pressure pain threshold and forward head posture in patients with temporomandibular joint disorders]

Objective: To investigate the association between neck muscles pressure pain thresholds (PPT) and forward head posture (FHP) in patients with temporomandibular disorders (TMD). Methods: A total of 145 TMD patients, including 23 males and 122 females with a median age of 28 years, were enrolled in the Department of Rehabilitation Medicine, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine from December 2019 to April 2020. Informations of FHP and neck muscles PPT were collected for all participants. FHP was characterized by the craniocervical angle (CVA) between C7, the tragus of the ear and the horizontal line. Each of the participants completed a questionaire of the neck disability index (NDI). The patients with CVA≤51 ° were asigned into FHP group, otherwise the patients with CVA>51° were asigned into non-FHP group. PPT were measured at the midpoint of the upper trapezius and 1 cm aside from C5-C6 articular pillars. Nonparametric test and Spearman correlation analysis were conducted for the data analysis. Results: There were 70 patients in the FHP group and 75 patients in the non-FHP group. The trapezius PPT of the FHP group [2.82(0.86) kg] was significantly higher than that of the non-FHP group [2.46(0.80) kg] (P<0.01). No significant differences in PPT and NDI were observed between the two groups (P>0.05). Low correlation was found between trapezius PPT and FHP negatively (r=-0.273, P<0.01) and no correlation was found between C5-C6 PPT and FHP (r=-0.124, P>0.05). PPT in trapezius and C5-C6 was negatively correlated with NDI in moderate (r=-0.301, P<0.01) and low (r=-0.206, P<0.05) levels. Conclusions: The trapezius PPT was correlated with FHP negatively. The more FHP, the more pain tolerant of trapezius muscles. There was no correlation between neck function and FHP directly. The higher threshold was followed by better neck function.

P–797 A novel method for establishing human embryonic stem cells independent of feeder cells

Study question

Is there a efficient establishing method of human embryonic stem cells directly from the human blastocysts independent of feeder cells?

Summary answer

We established a novel method of generating human embryonic stem cells directly from human blastocysts independent of feeder layer cells.

What is known already

Establishing embryonic stem cells lines mainly needed to coculture ICM clumps with feeder cells (like mouse or human fibroblasts) ,this brought in potential heterogeneous pollution.Although there had be some reports about generating human ESCs independent of feeder cells,but the efficiency was low and conditioned medium were unstable and also had the biological contamination.

Study design, size, duration

We used ten day5/6 donated human blastocysts from our reproductive center ,most of them were genetically diseased embryos with abnormal PGT diagnosis.After establishing ESCs procedure , all the cell lines were identified with pluripotency and differentiation potential tests.The success rate of system was calculated and compared with the conventional methods.

Participants/materials, setting, methods

In brief, ICM clumps were separated mechanically by using a micromanipulation system,and then transferred to a 30ul mTESR plus culture media drop pretreated with the geltrex (1:100 dilution) matrix and oxygen concentration was 5%. When cells attached and migrated,we also used laser to destroy the remaining trophoblast cells.About 10 days,the typical ES clone can be mechanically passaged and cells can be cultured in normal oxygen concentrations after passage 2. .

Main results and the role of chance

Using this method we had successfully established nine embryonic stem cell lines from donated human blastocysts ,the success rate was 90% (9/10). Each cell lines had passed the evaluation test of embryonic stem cell. When compared with the conventional feeder cells dependent method,our novol methods not only eliminated the pollution from heterogeneous cells,but also had higher success rate (90% vs 25%).

Limitations, reasons for caution

Due to the scarcity of donated human blastocysts, this experiment was a single-center experiment with small samples.

Wider implications of the findings: We speculated that the batch differences of culture dishes, matrix and culture medium might affect the establish efficiency , and how to carry out a high level of quality control work might be the key factor to keep the system stable.

Trial registration number

basic research

P-797 A novel method for establishing human embryonic stem cells independent of feeder cells

Study question

Is there a efficient establishing method of human embryonic stem cells directly from the human blastocysts independent of feeder cells?

Summary answer

We established a novel method of generating human embryonic stem cells directly from human blastocysts independent of feeder layer cells.

What is known already

Establishing embryonic stem cells lines mainly needed to coculture ICM clumps with feeder cells (like mouse or human fibroblasts), this brought in potential heterogeneous pollution. Although there had be some reports about generating human ESCs independent of feeder cells, but the efficiency was low and conditioned medium were unstable and also had the biological contamination.

Study design, size, duration

We used ten day5/6 donated human blastocysts from our reproductive center, most of them were genetically diseased embryos with abnormal PGT diagnosis. After establishing ESCs procedure, all the cell lines were identified with pluripotency and differentiation potential tests. The success rate of system was calculated and compared with the conventional methods.

Participants/materials, setting, methods

In brief, ICM clumps were separated mechanically by using a micromanipulation system,and then transferred to a 30ul mTESR plus culture media drop pretreated with the geltrex (1:100 dilution) matrix and oxygen concentration was 5%. When cells attached and migrated,we also used laser to destroy the remaining trophoblast cells. About 10 days,the typical ES clone can be mechanically passaged and cells can be cultured in normal oxygen concentrations after passage 2..

Main results and the role of chance

Using this method we had successfully established nine embryonic stem cell lines from donated human blastocysts, the success rate was 90% (9/10). Each cell lines had passed the evaluation test of embryonic stem cell. When compared with the conventional feeder cells dependent method,our novol methods not only eliminated the pollution from heterogeneous cells,but also had higher success rate (90% vs 25%).

Limitations, reasons for caution

Due to the scarcity of donated human blastocysts, this experiment was a single-center experiment with small samples.

Wider implications of the findings

We speculated that the batch differences of culture dishes, matrix and culture medium might affect the establish efficiency, and how to carry out a high level of quality control work might be the key factor to keep the system stable.

Trial registration number

basic research

A comparison between raltitrexed plus cisplatin and docetaxel plus cisplatin in concurrent chemoradiation for non-surgical esophageal squamous cell carcinoma

PURPOSE

Chemoradiotherapy (CRT) is considered as a standard treatment for unresectable and inoperable esophageal cancer (EC) patients. However, no consensus has been reached regarding the optimal synchronous chemotherapy regimen and the best combination of radiotherapy and chemotherapy. The aim of this study was to evaluate the efficacy and toxicity of raltitrexed plus cisplatin and docetaxel plus cisplatin to find a safe and effective concurrent chemotherapy schedule.

PATIENTS AND METHODS

Our retrospective study included 151 EC patients treated with raltitrexed and cisplatin (RP) (n=90) or docetaxel and cisplatin (DP) (n=61) from 2011 till 2018. Survival outcomes and treatment related toxicity were analyzed between the two groups.

RESULTS

PFS and OS were 18 and 34 months in the RP group, while 13 and 20 months in the DP group (P=0.118 and P=0.270). The 1-, 2-, 3-year survival rates of the RP group were 71.1, 55.4 and 46.4%. For the DP group, these were 63.9, 44.3 and 37.6%, respectively. Compared with DP group, RP group received a superior CR rate (68.9% versus 52.5%, P=0.041). There was a trend that the total number of toxic reactions in RP group was lower than that in DP group (P=0.058).

CONCLUSIONS

Even RP and DP groups have the similar survival outcomes and toxicity, raltitrexed/cisplatin get a higher complete response rate. Our study suggests that raltitrexed combined with cisplatin is a safe and effective concurrent chemotherapy regimen and it might be used as an alternative for cisplatin/5-FU and cisplatin/docetaxel in CCRT for EC patients.

TAM receptors and their ligand-mediated activation: Role in atherosclerosis

TAM family tyrosine kinase receptors including Tyro3, Axl, and MerTK are the key efferocytosis receptors presenting on antigen-presenting cell that mediate the clearance of apoptotic cells. They are thought to regulate inflammatory diseases by modulating inflammatory response and efferocytosis. Recent studies have revealed novel roles of TAM receptors in the biosynthesis of specialized pro-resolving mediators (SPMs) and inflammation resolution. In this chapter, we discuss the central roles of TAM signaling in atherosclerosis focusing on their regulation in efferocytosis and inflammation resolution and highlight the unique therapeutic potential of SPMs in blocking the progression of atherosclerosis.

[Clinical effects of individualized free anterolateral thigh flap in repairing complex refractory wound]

Objective: To explore the clinical effects of individualized free anterolateral thigh flap in repairing complex refractory wound. Methods: From July 2015 to May 2019, 19 patients with complex refractory wounds were hospitalized in Yulin NO.1 People's Hospital of Guangxi Zhuang Autonomous Region, including 12 males and 7 female, aged 13-67 years. There were 5 patients with multiple tissue defects, 7 patients with large area of wounds, and 7 patients with wounds in special areas. The sizes of wounds after complete debridement were 8 cm×5 cm-23 cm×7 cm. According to the repair demand, the wounds in 5 patients were repaired with anterolateral thigh flaps and flow-through, the wounds in 7 patients were repaired with anterolateral thigh flaps chimed with lateral thigh muscle flaps, with vascular anastomosis in 2 patients, the wounds in 6 patients were repaired with unilateral anterolateral thigh lobulated flaps, and the wound in 1 patient was repaired with bilateral anterolateral thigh flap in series connection. The sizes of flaps were 10 cm×7 cm-25 cm×9 cm. The donor sites were sutured directly or repaired with thin split-thickness skin graft of head. The survival of the flaps, the appearance of the donor sites, and wounds repair after the operation and during follow-up were observed. Results: The lobulated flap in 1 patient had local necrosis after the operation and finally healed by debridement, dressing change, and transplanting medium split-thickness skin graft in groin. The flaps in 18 patients survived with good blood supply, and the lobulated flap tissue was swollen in 1 of 18 patients. The donor sites which were directly sutured in 18 patients only had linear scar, and the donor site which was repaired with thin split-thickness skin graft of head in 1 patient had flaky scar. Follow-up of 1-12 months showed that all the wounds healed well, the flap thinning operations were performed in 5 patients in 3 months post operation because the flaps were slightly bloated. The CT angiography after the operation showed that the anastomosed blood vessels were unobstructed in 7 patients with reconstructed local blood supply. Conclusions: The special forms of anterolateral thigh flap, such as lobulation, series connection, and chimerism can be designed according to the anatomical characteristics of the descending branch of the lateral femoral artery to meet individualized repair demand for complex refractory wounds, and achieve the double purposes of making full use of the donor site tissue and good repair of the recipient site.