Recent advances in c-Met-based dual inhibitors in the treatment of cancers

The cellular-mesenchymal epithelial transition factor (c-Met) is a receptor tyrosine kinase (RTK) located on the 7q31 locus encoding the Met proto-oncogene and plays a critical role in regulating cell proliferation, metastasis, differentiation, and apoptosis through various signaling pathways. However, its aberrant activation and overexpression have been implicated in many human cancers. Therefore, c-Met is a promising target for cancer treatment. However, the anticancer effect of selective single-targeted drugs is limited due to the complexity of the signaling system and the involvement of different proteins and enzymes. After inhibiting one pathway, signal molecules can be transmitted through other pathways, resulting in poor efficacy of single-targeted drug therapy. Dual inhibitors that simultaneously block c-Met and another factor can significantly improve efficacy and overcome some of the shortcomings of single-target inhibitors, including drug resistance. In this review, We introduced c-Met kinase and the synergism between c-Met and other anti-tumor targets, then dual-target inhibitors based on c-Met for the treatment of cancers were summarized and their design concepts and structure-activity relationships (SARs) were discussed elaborately, providing a valuable insight for the further development of novel c-Met-based dual inhibitors.

Construction of SnO2 buffer layer and analysis of its interface modification for Li and Li1.5Al0.5Ge1.5(PO4)3 in solid-state batteries

SnO2 layer between Li1.5Al0.5Ge1.5(PO4)3 (LAGP) and lithium anode was prepared through simple scratch-coating process to improve interface properties. The physical phase, morphology, and electrochemical properties of Li/SnO2/LAGP structure were characterized by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, and electrochemical analytical methods. It was found that SnO2 layer effectively improved the interface stability of LAGP and lithium anode. The prepared Li/SnO2/LAGP/SnO2/Li symmetric cell exhibited a large critical current density of 1.8 mA cm-2 and demonstrated excellent cycling characteristics. The polarization voltages of symmetric cell were 0.1 V and 0.8 V after 1000 h of cycling at current densities of 0.04 mA cm-2 and 0.5 mA cm-2, respectively. Li/SnO2@LAGP/LiFePO4 solid-state full cells were also assembled, exhibiting a discharge specific capacity of 150 mAh g-1 after 200 cycles at 0.1C with capacity retention rate of 96 %. The good interface properties of Li/SnO2/LAGP structure are attributed to the transformation of SnO2 layer into a buffer layer containing Li2O, Sn0, and LixSny alloy during cycling process, which effectively inhibits the reduction reaction between LAGP and lithium anode.

Treponema pallidum protein Tp47 induced prostaglandin E2 to inhibit the phagocytosis in human macrophages

BACKGROUND

During Treponema pallidum (T. pallidum) infection, the host's immune system actively engages in pursuit and elimination of T. pallidum, while T. pallidum skillfully employs various mechanisms to evade immune recognition. Macrophages exhibit incomplete clearance of T. pallidum in vitro and the underlying mechanism of how T. pallidum resists the attack of macrophage remains unclear.

OBJECTIVES

To investigate the effect of T. pallidum membrane protein Tp47 on the phagocytosis of macrophages.

METHODS

THP-1-derived macrophages were used to investigate the role of Tp47 in the secretion of Prostaglandin E2 (PGE2) in macrophages and the mechanism by which Tp47 induced the production of PGE2, as well as the impact of PGE2 on the macrophage's phagocytosis.

RESULTS

Tp47 (1-10 μg/mL) significantly inhibited the phagocytosis of latex beads and T. pallidum in macrophages (p ≤ 0.05). PGE2 production by macrophages could be induced by Tp47, and the phagocytic function of macrophages could be restored using PGE2 antibody. Tp47 produced PGE2 by activating the PERK/NF-κB/COX-2 pathway in macrophages. Inhibitors targeting PERK, NF-κB and COX-2, respectively, reduced the level of PGE2 and restored the phagocytic function of macrophages.

CONCLUSION

Tp47-induced PGE2 production via the PERK/NF-κB/COX-2 pathway contributed to macrophage phagocytosis inhibition, which potentially contributes to immune evasion during the T. pallidum infection.

Treponema pallidum-induced prostaglandin E2 secretion in skin fibroblasts leads to neuronal hyperpolarization: A cause of painless ulcers

BACKGROUND

Primary syphilis is characterized by painless ulcerative lesions in the genitalia, the aetiology of painless remains elusive.

OBJECTIVES

To investigate the role of Treponema pallidum in painless ulcer of primary syphilis, and the mechanisms underlying painless ulcers caused by T. pallidum.

METHODS

An experimental rabbit model of primary syphilis was established to investigate its effects on peripheral nerve tissues. Human skin fibroblasts were used to examine the role of T. pallidum in modulating neurotransmitters associated with pain and to explore the signalling pathways related to neurotransmitter secretion by T. pallidum in vitro.

RESULTS

Treponema pallidum infection did not directly lead to neuronal damage or interfere with the neuronal resting potential. Instead, it facilitated the secretion of prostaglandin E2 (PGE2) through endoplasmic reticulum stress in both rabbit and human skin fibroblasts, and upregulation of PGE2 induced the hyperpolarization of neurones. Moreover, the IRE1α/COX-2 signalling pathway was identified as the underlying mechanism by which T. pallidum induced the production of PGE2 in human skin fibroblasts.

CONCLUSION

Treponema pallidum promotes PGE2 secretion in skin fibroblasts, leading to the excitation of neuronal hyperpolarization and potentially contributing to the pathogenesis of painless ulcers in syphilis.

Association of serum 25-hydroxyvitamin D with cardiovascular mortality and kidney outcome in patients with early stages of CKD

PURPOSE

While serum 25-hydroxyvitamin D (25[OH]D) deficiency is prevalent in chronic kidney disease (CKD), the effects of 25(OH)D deficiency on cardiovascular mortality and kidney outcomes in patients with early-stage CKD remain incompletely understood.

METHODS

This multicenter retrospective cohort study included adult patients with stages 1-3 CKD from 19 medical centers across China between January 2000 and May 2021. The primary outcome was cardiovascular mortality. The secondary study outcome included CKD progression (defined as a sustained > 40% eGFR decrease from baseline or progress to end-stage kidney disease), and annual percentage change of eGFR.

RESULTS

Of 9229 adults with stages 1-3 CKD, 27.0% and 38.9% had severe (< 10 ng/mL) and moderate (10 to < 20 ng/mL) serum 25(OH)D deficiency, respectively. Compared with patients having 25(OH)D ≥ 20 ng/mL, a significantly higher risk of cardiovascular mortality (hazard ratio [HR] 1.90, 95% CI 1.37-2.63), CKD progression (HR 2.20, 95% CI 1.68-2.88), and a steeper annual decline in eGFR (estimate - 7.87%; 95% CI - 10.24% to - 5.51% per year) was found in those with serum 25(OH)D < 10 ng/mL. Similar results were obtained in subgroups and by sensitivity analyses.

CONCLUSIONS

25(OH)D deficiency is associated with increased risks of cardiovascular mortality and CKD progression in patients with early-stage CKD. Studies are needed to determine whether early intervention for 25(OH)D deficiency could improve the prognosis of patients with early-stage CKD.

Optimized 3D brachial plexus MR neurography using deep learning reconstruction

OBJECTIVE

To evaluate whether 'fast,' unilateral, brachial plexus, 3D magnetic resonance neurography (MRN) acquisitions with deep learning reconstruction (DLR) provide similar image quality to longer, 'standard' scans without DLR.

MATERIALS AND METHODS

An IRB-approved prospective cohort of 30 subjects (13F; mean age = 50.3 ± 17.8y) underwent clinical brachial plexus 3.0 T MRN with 3D oblique-coronal STIR-T2-weighted-FSE. 'Standard' and 'fast' scans (time reduction = 23-48%, mean = 33%) were reconstructed without and with DLR. Evaluation of signal-to-noise ratio (SNR) and edge sharpness was performed for 4 image stacks: 'standard non-DLR,' 'standard DLR,' 'fast non-DLR,' and 'fast DLR.' Three raters qualitatively evaluated 'standard non-DLR' and 'fast DLR' for i) bulk motion (4-point scale), ii) nerve conspicuity of proximal and distal suprascapular and axillary nerves (5-point scale), and iii) nerve signal intensity, size, architecture, and presence of a mass (binary). ANOVA or Wilcoxon signed rank test compared differences. Gwet's agreement coefficient (AC2) assessed inter-rater agreement.

RESULTS

Quantitative SNR and edge sharpness were superior for DLR versus non-DLR (SNR by + 4.57 to + 6.56 [p < 0.001] for 'standard' and + 4.26 to + 4.37 [p < 0.001] for 'fast;' sharpness by + 0.23 to + 0.52/pixel for 'standard' [p < 0.018] and + 0.21 to + 0.25/pixel for 'fast' [p < 0.003]) and similar between 'standard non-DLR' and 'fast DLR' (SNR: p = 0.436-1, sharpness: p = 0.067-1). Qualitatively, 'standard non-DLR' and 'fast DLR' had similar motion artifact, as well as nerve conspicuity, signal intensity, size and morphology, with high inter-rater agreement (AC2: 'standard' = 0.70-0.98, 'fast DLR' = 0.69-0.97).

CONCLUSION

DLR applied to faster, 3D MRN acquisitions provides similar image quality to standard scans. A faster, DL-enabled protocol may replace currently optimized non-DL protocols.

B cell-reactive triad of B cells, follicular helper and regulatory T cells at homeostasis

Autoreactive B cells are silenced through receptor editing, clonal deletion and anergy induction. Additional autoreactive B cells are ignorant because of physical segregation from their cognate autoantigen. Unexpectedly, we find that follicular B cell-derived autoantigen, including cell surface molecules such as FcγRIIB, is a class of homeostatic autoantigen that can induce spontaneous germinal centers (GCs) and B cell-reactive autoantibodies in non-autoimmune animals with intact T and B cell repertoires. These B cell-reactive B cells form GCs in a manner dependent on spontaneous follicular helper T (TFH) cells, which preferentially recognize B cell-derived autoantigen, and in a manner constrained by spontaneous follicular regulatory T (TFR) cells, which also carry specificities for B cell-derived autoantigen. B cell-reactive GC cells are continuously generated and, following immunization or infection, become intermixed with foreign antigen-induced GCs. Production of plasma cells and antibodies derived from B cell-reactive GC cells are markedly enhanced by viral infection, potentially increasing the chance for autoimmunity. Consequently, immune homeostasis in healthy animals not only involves classical tolerance of silencing and ignoring autoreactive B cells but also entails a reactive equilibrium attained by a spontaneous B cell-reactive triad of B cells, TFH cells and TFR cells.

Growth, not digestibility, in chickens receiving reduced-protein diets is independent of non-specific amino-nitrogen sources when the essential-to-total-nitrogen ratio is constant and lower than 50

1. A 21 d experiment was conducted to investigate whether growth performance and coefficients of amino acids digestibility (cAID) in broilers receiving reduced-protein diets supplemented with different non-essential amino acids (NEAA) were dependent on supplemented NEAA in diets with the same essential-to-total N (eN-to-tN) ratio kept at <50%.2. The experiment used 240 male broiler chicks, allocated to eight treatments with six replicate pens per treatment, and five chicks per replicate. The diets were either adequate in protein diet (PC), reduced protein (NC) diet or the NC diet supplemented with Gly, Gln, Ser, Ala, Gly + Ser or Ala + Ser. Digesta from the distal half of the ileum were collected on d 21. Tissue samples were collected for analysis for gene expression of protein synthesis and degradation (pectoralis major and liver) and peptide and AA transporters (jejunum).3. The treatments had no effects on growth performance. Generally, cAID was greater (P < 0.05) in NC compared to the PC diet. Individual supplementation of the NC diet with Gly, Gln, Ser, Ala or Ala+Ser increased (P < 0.01) cAID of Cys compared to the PC diet. There were no treatment effects on mRNA levels for the AA or peptide transporters in the jejunum. Supplementation of the NC diet with Gln, Ser, Ala, or Gly + Ser produced an upward expression (P < 0.05) of S6 kinase in the liver compared to PC and NC. In addition, there was greater (P < 0.05) expression of TRIM36 in the pectoralis major of broiler chickens receiving the NC diet supplemented with Gly.4. When reduced-protein diets have an eN-to-tN ratio of <50% and the ratio is kept constant in all the diets, growth performance response was independent of the source of non-specific amino-N, but the treatments may influence ileal digestibility of individual AA.

Notch signaling regulates Th17 cells differentiation through PI3K/AKT/mTORC1 pathway and involves in the thyroid injury of autoimmune thyroiditis

PURPOSE

Autoimmune Thyroiditis (AIT) is the most common thyroid disease; however, there were no measures to prevent the progression of the disease. The present study attempts to identify that Notch signaling regulates the differentiation of T helper 17 (Th17) cells by activating downstream Phosphatidylinositol-3 kinase/protein kinase/mechanistic target of rapamycin complex 1 (PI3K/AKT/mTORC1) pathway participating in the thyroid injury of the experimental autoimmune thyroiditis (EAT).

METHODS

In vivo experiments, mice were randomly divided into 4 groups: a control group, an EAT group, and two groups with LY294002 treatment (pTg plus 25 mg/kg or 50 mg/kg LY294002, respectively). The degrees of thyroiditis were evaluated, and the percentage of Th17 cells, expression of interleukin-17A (IL-17A), and the main components of the Notch-PI3K signaling pathway were detected in different groups. In vitro experiments, two different dosages of LY294002 (25 and 50 μM) were used to intervene splenic mononuclear cells (SMCs) from EAT mice to further evaluate the regulatory effect of Notch-PI3K pathway on Th17 cells.

RESULTS

Our data demonstrate that the infiltration of Th17 cells and the expressions of IL-17A, Notch, hairy and split 1 (Hes1), p‑AKT (Ser473), p‑AKT (Thr308), p‑mTOR (Ser2448), S6K1, and S6K2 increased remarkably in EAT mice. After PI3K pathway was blocked, the degrees of thyroiditis were significantly alleviated, and the proportion of Th17 cells, the expression of IL-17A, and the above Notch-PI3K pathway-related molecules decreased in a dose-dependent manner. Additionally, the proportion of Th17 cells was positively correlated with the concentration of serum thyroglobulin antibody (TgAb), IL-17A, and Notch-PI3K pathway-related molecules mRNA levels.

CONCLUSIONS

Notch signal promotes the secretion of IL-17A from Th17 cells by regulating the downstream PI3K/AKT/mTORC1 pathway through Hes-Phosphatase and tensin homolog (PTEN) and participates in thyroid autoimmune damage, and the PI3K pathway inhibitor may play important effects on AIT by affecting Th17 cells differentiation.

ZnSe/SnSe Heterostructure Incorporated with Selenium/Nitrogen Co-Doped Carbon Nanofiber Skeleton for Sodium-Ion Batteries

Effective strategies toward building exquisite nanostructures with enhanced structural integrity and improved reaction kinetics will carry forward the practical application of alloy-based materials as anodes in batteries. Herein, a free-standing 3D carbon nanofiber (CNF) skeleton incorporated with heterostructured binary metal selenides (ZnSe/SnSe) nanoboxes is developed for Na-ion storage anodes, which can facilitate Na+ ion migration, improve structure integrity, and enhance the electrochemical reaction kinetics. During the carbonization and selenization process, selenium/nitrogen (Se/N) is co-doped into the 3D CNF skeleton, which can improve the conductivity and wettability of the CNF matrices. More importantly, the ZnSe/SnSe heterostructures and the Se/N co-doping CNFs can have a synergistic interfacial coupling effect and built-in electric field in the heterogeneous interfaces of ZnSe/SnSe hetero-boundaries as well as the interfaces between the CNF matrix and the selenide heterostructures, which can enable fast ion/electron transport and accelerate surface/internal reaction kinetics for Na-ion storage. The ZnSe/SnSe@Se,N-CNFs exhibit superior Na-ion storage performance than the comparative ZnSe/SnSe, ZnSe and SnSe powders, which deliver an excellent rate performance (882.0, 773.6, 695.7, 634.2, and 559.0 mAh g-1 at current rates of 0.1, 0.2, 0.5, 1, and 2 A g-1 ) and long-life cycling stability of 587.5 mAh g-1 for 3500 cycles at 2 A g-1 .

Dietary supplementation of proteases on growth performance, nutrient digestibility, blood characteristics and gut microbiota of growing pigs fed sorghum-based diets

Low-tannin sorghum is an excellent energy source in pig diets. However, sorghum contains several anti-nutritional factors that may have negative effects on nutrient digestibility. The impacts of proteases on growth performance, nutrient digestibility, blood parameters, and gut microbiota of growing pigs fed sorghum-based diets were studied in this study. Ninety-six pigs (20.66 ± 0.65 kg BW) were allocated into three groups (eight pens/group, four pigs/pen): (1) CON (control diet, sorghum-based diet included 66.98% sorghum), (2) PRO1 (CON + 200 mg/kg proteases), (3) PRO2 (CON + 400 mg/kg proteases) for 28 d. No differences were observed in growth performance and apparent total tract digestibility (ATTD) of nutrients between CON and PRO1 groups. Pigs fed PRO2 diet had increased (P < 0.05) BW on d 21 and 28, and increased (P < 0.05) average daily gain during d 14-21 and the overall period compared with pigs fed CON diet. In addition, pigs fed PRO2 diet had improved (P < 0.05) ATTD of gross energy, CP, and DM compared with pigs fed CON and PRO1 diets. Pigs fed PRO2 diet had lower (P < 0.05) plasma globulin (GLB) level and higher (P < 0.05) plasma glucose, albumin (ALB) and immunoglobulin G levels, and ALB/GLB ratio than pigs fed CON and PRO1 diets. Furthermore, pigs fed PRO2 diet had decreased (P < 0.05) the relative abundance of Acidobacteriota at the phylum level and increased (P < 0.05) the relative abundance of Prevotella_9 at the genus level. The linear discriminant analysis effect size analysis also showed that pigs fed PRO2 diet had significantly enriched short-chain fatty acid-producing bacteria, such as Subdoligranulum and Parabacteroides. In conclusion, protease supplementation at 400 mg/kg improved the growth performance of growing pigs fed sorghum-based diets, which may be attributed to the improvement of nutrient digestibility, host metabolism, immune status and associated with the altered gut microbiota profiles.

[Correlation analysis of dynamic enhanced energy spectrum CT parameters with Ki-67 high expression in hepatocellular carcinoma]

Objective: To investigate the correlation between dynamic enhanced energy spectral CT parameters and Ki-67 high expression in hepatocellular carcinoma (HCC). Methods: A cross-sectional study. This retrospective case-control study analyzed the clinical data of 101 patients with pathologically confirmed HCC in Xiamen Hospital of Traditional Chinese Medicine and Zhongshan Hospital of Xiamen University from December 2017 to March 2023. These 101 patients included 84 males and 17 females, and the age[M(Q1, Q3)] was 59.0(49.0,66.0)years. These patients were divided into two groups according to the immunohistochemical Ki-67 expression levels in tumor tissues: the high expression group (Ki-67%>20%, n=59) and the low expression group (Ki-67%≤20%, n=42).CT values on 70 keV and 140 keV monochromatic energy images (HU70 keV-a, HU140 keV-a, HU70 keV-p, HU140 keV-p) and water density (Dwater-a, Dwater-p) were measured in arterial phase and portal vein phase, and the difference of HU70 keV, HU140 keV, Dwater values between portal vein and arterial phase (ΔHU70 keV, ΔHU140 keV, ΔDwater), as well as ratio of HU70 keV, HU140 keV, Dwatervalues between portal vein and arterial phase (HU70 keVratio, HU140 keVratio, Dwaterratio) were calculated. Spearman correlation analysis was used to analyze the correlation between the CT spectral parameters and Ki-67%. Multivariate logistic regression model was used to determine the factors associated with high expression of Ki-67. The receiver operating characteristics (ROC) curves were used to indicate the efficacy of dynamic enhanced spectral CT in evaluating Ki-67 high expression in HCC. Results: The high Ki-67 expression group revealed higher alpha fetal protein levels, larger tumor diameter and more irregular tumor shape compared with the low Ki-67 expression group,and the differences were statistically significant (all P<0.05). Spearman correlation analysis showed that the HU140 keV-p, Dwater-p, HU70 keV ratio, HU140 keV ratio, Dwater ratio, ΔHU70 keV, ΔHU140 keV, ΔDwater were positively correlated with Ki-67 positivity rate (r:0.31-0.50, all P<0.05). The spectral CT parameters (HU70 keV-p, HU140 keV-p, Dwater-p, HU70 keV ratio, HU140 keV ratio, Dwater ratio, ΔHU70 keV, ΔHU140 keV, ΔDwater) in high Ki-67 expression group were significantly higher than those in low Ki-67 expression group (all P<0.05). Multivariate logistic regression model shows that Dwater-p(OR=1.16, 95%CI: 1.05-1.29, P=0.005), ΔHU140 keV(OR=1.39, 95%CI: 1.20-1.62, P<0.001) and irregular tumor morphology (OR=5.25, 95%CI: 1.61-17.12, P=0.006) were correlative factors for high Ki-67 expression. The HU140 keV ratio and ΔHU140 keV alone evaluated the highest AUC of high Ki-67 high expression in HCC, which were 0.82 (95%CI: 0.74-0.90), the sensitivity were 61.0%, and the specificity were 88.1% and 85.7%. The combined analysis of Dwater-p, ΔHU140 keV and irregular tumor morphology had an increased AUC of 0.88 (95%CI: 0.81-0.95) in assessment high Ki-67 expression, with the sensitivity of 84.7% and the specificity of 78.6%. Conclusions: Dynamic enhanced spectral CT parameters were positively correlated with the Ki-67 expression in HCC. Spectral CT provides a non-invasive method to evaluate the proliferation status of HCC cells, and the efficiency could be improved by multi-parameter analysis combining spectral CT parameters and morphologic features.

[Overview of design and construction of hypertensive disorders of a pregnancy-cohort in Shenzhen]

Hypertensive disorder of pregnancy (HDP) involves two major public health issues: mother-infant safety and prevention and controlling major chronic disease. HDP poses a serious threat to maternal and neonatal safety, and it is one of the leading causes of maternal and perinatal morbidity and mortality worldwide, as well as an important risk factor for long-term cardiovascular disease (CVD). In order to explore effective strategies to prevent and control the source of CVD and reduce its risk, we have established a cohort of HDPs in Shenzhen for the primordial prevention of CVD. The construction of the HDP cohort has already achieved preliminary progress till now. A total of 2 239 HDP women have been recruited in the HDP cohort. We have established a cohort data management platform and Biobank. The follow-up and assessment of postpartum cardiovascular metabolic risk in this cohort has also been launched. Our efforts will help explore the pathophysiological mechanism of HDP, especially the pathogenesis and precision phenotyping, prediction, and prevention of pre-eclampsia, which, therefore, may reduce the risk of adverse pregnancy outcomes, and provide a bridge to linking HDP and maternal-neonatal cardiovascular, metabolic risk to promote the cardiovascular health of mothers and their infants.

Global cardiothoracic surgery: A survey of trainees' interests and barriers

Background

More than 5 billion people lack access to surgical care, disproportionately in low- and middle-income countries. The emerging literature demonstrates high interest in global surgery across specialties; however, participation in global cardiothoracic surgical care remains low. To date, there has been no research quantifying the attitudes of cardiothoracic surgeons about global surgery. Our study aimed to acquire a broader understanding of cardiothoracic surgical trainees' interest in global surgery to address barriers and promote cardiac healthcare worldwide.

Methods

An online survey was sent to all North American cardiothoracic surgical residents via the Thoracic Surgery Residents Association email listserv. The survey was designed in the REDCap database and administered twice, in 2021 and 2022. Data were analyzed by descriptive and chi-square analysis using Stata.

Results

Seventy-three cardiothoracic surgical trainees responded to our survey, of whom 95.3% considered increasing cardiothoracic surgical access to be important, and 67.2% identified this as a future career priority. Most respondents (82.8%) would participate in global surgery if opportunities were available through their home institution. Lack of opportunities (70.0%) and finances (66.7%) were the primary barriers to participation. Respondents identified funding (85%) and institutional support (83.3%) as the most significant incentives to increase involvement.

Conclusions

There is strong interest in global surgery among cardiothoracic trainees; however, involvement remains low. A consensus among the North American cardiothoracic surgical community is needed to address barriers to global volunteerism within surgical residency and improve access to cardiac surgery worldwide.

Circulating monocytes expressing senescence-associated features are enriched in COVID-19 patients with severe disease

Accurate biomarkers for predicting COVID-19 severity have remained an unmet need due to an incomplete understanding of virus pathogenesis and heterogeneity among patients. Cellular senescence and its pro-inflammatory phenotype are suggested to be a consequence of SARS-CoV-2 infection and potentially drive infection-dependent pathological sequelae. Senescence-associated markers in infected individuals have been identified primarily in the lower respiratory tract, while little is known about their presence in more easily accessible bio-specimens. Here, we measured the abundance of senescence-associated signatures in whole blood, plasma and peripheral blood mononuclear cells (PBMCs) of COVID-19 patients and patients without an infection. Bulk transcriptomic and targeted proteomic assays revealed that the level of senescence-associated markers, including the senescence-associated secretory phenotype (SASP), is predictive of SARS-CoV-2 infection. Single-cell RNA-sequencing data demonstrated that a senescence signature is particularly enriched in monocytes of COVID-19 patients, partially correlating with disease severity. Our findings suggest that monocytes are prematurely induced to senescence by SARS-CoV-2 infection, might contribute to exacerbating a SASP-like inflammatory response and can serve as markers and predictors for COVID-19 and its sequelae.

Genomic epidemiological investigation of an outbreak of Serratia marcescens neurosurgical site infections associated with contaminated haircutting toolkits in a hospital barber shop

BACKGROUND

Nine surgical site infections caused by Serratia marcescens were diagnosed in neurosurgical patients in a 3500-bed hospital between 2nd February and 6th April 2022.

OBJECTIVE

To trace the source of infections caused by S. marcescens to expedite termination of the outbreak and prevent future epidemics.

METHODS

A review of all surgical procedures and cultures yielding S. marcescens since February 2022 was conducted. Samples were collected from patients and environmental sources. S. marcescens isolates were characterized by antibiotic susceptibility testing. Whole-genome sequencing (WGS) was used to investigate genetic relationships. Resistance genes, virulence genes and plasmid replicons were identified.

RESULTS

S. marcescens was isolated from patients' puncture fluid, cerebrospinal fluid and other secretions, and was also cultured from the barbers' haircutting tools, including leather knives, slicker scrapers and razors. In total, 15 isolates were obtained from patients and eight isolates were obtained from haircutting tools. All isolates exhibited identical antibiotic resistance patterns. WGS revealed close clustering among the 23 isolates which differed significantly from previous strains. Three resistance genes and nine virulence-associated genes were detected in all isolates, and 19 of 23 isolates harboured an MOBP-type plasmid. The results confirmed an outbreak of S. marcescens, which was traced to contaminated haircutting tools in the hospital barber shop. The outbreak ended after extensive reinforcement of infection control procedures and re-education of the barbers.

CONCLUSIONS

These results highlight the risk of postoperative infections related to pre-operative skin preparation, and demonstrate the value of next-generation sequencing tools to expedite outbreak investigations.

Sophora tonkinensis: response and adaptation of physiological characteristics, functional traits, and secondary metabolites to drought stress

The medicinal plant Sophora tonkinensis is a characteristic Chinese shrub of karst areas. The arid climate in karst areas produces high-quality S. tonkinensis; however, the mechanisms of drought tolerance are not clear, which restricts sustainable plantings of S. tonkinensis. This study involved a 20-day drought stress experiment with potted S. tonkinensis and threee soil water regimes: control (CK), mild drought (MDT), and severe drought (SDT). Plant morphology, biomass, physiological indicators, alkaloid content, and other changes under drought stress were monitored. The content of soluble sugars and proteins, and activity of antioxidant enzymes in leaves and roots were higher under drought than CK, indicating that S. tonkinensis is tolerant to osmotic stress in early drought stages. Content of matrine and oxymatrine increased gradually with increasing drought duration in the short term. The epidermis of S. tonkinensis leaves have characteristics of desert plants, including upper epidermal waxy layer, lower epidermal villi, and relatively sunken stomata, suggesting that S. tonkinensis has strong drought tolerance. In conclusion, drought stress changed the cell structure of S. tonkinensis, induced antioxidant enzyme activity and increased its resistance to drought.

[Clinical features and risk factors of left ventricular hypertrophy in children with primary hypertension]

Objective: To assess the clinical features and relative factors of left ventricular hypertrophy (LVH) in children with primary hypertension. Methods: In this retrospective cohort study, 430 children diagnosed with primary hypertension in Children's Hospital, Capital Institute of Pediatrics from January 2019 to September 2022 were enrolled. Their clinical data was analyzed and LVH was assessed by echocardiography. According to left ventricular geometry, these children were assigned to the LVH group and normal geometry group. General conditions, laboratory indicators and ambulatory blood pressure parameters between two groups were compared by independent sample t-test or Mann-Whitney U test. Spearman correlation coefficient was used to analyze the correlation between LVH and clinical indicators including blood pressure, biochemical and metabolic indicators. The independent risk factors of LVH were analyzed by multivariable logistic regression. The receiver operating characteristic (ROC) curve was used to explore the value of risk factors in the diagnosis of LVH. Results: Among the 430 children with primary hypertension, 342 (79.5%) were males and 88 (20.5%) females. Their age was (12.6±2.3) years, and 123 children (28.6%) of them had LVH. Body mass index (BMI) ((30.0±5.2) vs. (26.2±4.3) kg/m2), ratio of stage 2 hypertension (75.6% (93/123) vs. 59.6% (183/307)), 24-hour systolic blood pressure (24 h SBP)((131±10) vs. (128±10) mmHg,1 mmHg=0.133 kPa), daytime systolic blood pressure (SBP) ((135±11) vs. (131±11) mmHg), nighttime SBP ((128±11) vs. (123±10) mmHg), cholesterol level ((4.0±0.7) vs. (3.9±0.7) mmol/L), serum uric acid level ((447±81) vs. (426±91) μmol/L) and incidence of hyperinsulinemia (69.9% (86/123) vs.59.0% (181/307)) were significantly elevated in the LVH group compared with those in the normal geometry group (all P<0.05). There were more patients with a disease course over 5 years in the LVH group than in the normal geometry group, with a statistically significant difference (χ2=8.90,P=0.031). Spearman correlation analysis showed that BMI, 24 h SBP, daytime SBP, nighttime SBP, triglyceride, uric acid, and serum sodium level were positively correlated with LVMI (r=0.43, 0.20, 0.18, 0.18, 0.18, 0.16, and 0.12, all P<0.05). BMI, hyperinsulinemia, and cholesterol level were positively correlated with relative wall thickness (RWT) (r=0.22, 0.12, and 0.16, all P<0.05). The multivariate logistic regression analysis showed that BMI (OR=1.17, 95%CI 1.10-1.25) and 24 h SBP (OR=1.04, 95%CI 1.01-1.08) were the independent risk factors for LVH (both P<0.05). The area under the receiver operator characteristic curve, combined with BMI and 24 h SBP, was 0.72 (95%CI 0.67-0.77, P<0.05), with a sensitivity and specificity of 71.5% and 64.8%, respectively. Conclusions: BMI and 24 h SBP are the independent risk factors for LVH in children with primary hypertension, and the combination of BMI and 24 h SBP has an acceptable diagnostic value for LVH. Early monitoring of these indexes is necessary to predict preclinical cardiac damage.

Expression of ICAM-1 and E-selectin in different metabolic obesity phenotypes: discrepancy for endothelial dysfunction

OBJECTIVES

Endothelial dysfunction, the earliest vascular alteration, is a consequence of metabolic disorders associated with obesity. However, it is still unclear whether a proportion of obese individuals without metabolic alterations associated with obesity, defined as "metabolically healthy obesity (MHO)", exhibit better endothelial function. We therefore aimed to investigate the association of different metabolic obesity phenotypes with endothelial dysfunction.

METHODS

The obese participants without clinical cardiovascular disease from the MESA (Multi-Ethnic Study of Atherosclerosis) were allocated to the different metabolic obesity phenotypes based on their metabolic status, including MHO and metabolically unhealthy obesity (MUO). Associations of metabolic obesity phenotypes with the biomarkers of endothelial dysfunction, including soluble intercellular adhesion molecule-1 (sICAM-1) and soluble E-selectin (sE-selectin), were evaluated using multiple linear regression models.

RESULTS

Plasma levels of sICAM-1 and sE-selectin were respectively measured in 2371 and 968 participants. Compared to the non-obese participants, those with MUO were associated with higher concentrations of sICAM-1 (β 22.04, 95% CI 14.33-29.75, P < 0.001) and sE-selectin (β 9.87, 95% CI 6.00-13.75, P < 0.001) after adjusting for confounders. However, no differences were found for the concentrations of sICAM-1 (β 0.70, 95% CI - 8.91 to 10.32, P = 0.886) and sE-selectin (β 3.69, 95% CI - 1.13 to 8.51, P = 0.133) in the participants with MHO compared to the non-obese participants.

CONCLUSIONS

Individuals with MUO were associated with elevated biomarkers of endothelial dysfunction, but the association with endothelial dysfunction was not found in those with MHO, indicating that the individuals with MHO might exhibit better endothelial function.

Effects of dietary methionine supplementation from different sources on growth performance and meat quality of barrows and gilts

Methionine is indispensable for growth and meat formation in pigs. However, it is still unclear that increasing dietary sulphur-containing amino acid (SAA) levels using different methionine sources affects the growth performance and meat quality of barrows and gilts. To investigate this, 144 pigs (half barrows and half gilts) were fed the control (100% SAA, CON), DL-Methionine (125% SAA, DL-Met)-supplemented, or OH-Methionine (125% SAA, OH-Met)-supplemented diets during the 11-110 kg period. The results showed that plasma methionine levels varied among treatments during the experimental phase, with increased plasma methionine levels observed following increased SAA consumption during the 25-45 kg period. In contrast, pigs fed the DL-Met diet had lower plasma methionine levels than those fed the CON diet (95-110 kg). Additionally, gilts fed the DL-Met or OH-Met diets showed decreased drip loss in longissimus lumborum muscle (LM) compared to CON-fed gilts. OH-Met-fed gilts had higher pH45min values than those fed the CON or DL-Met diets, whereas OH-Met-fed barrows had higher L45min values than those fed the CON or DL-Met diets. Moreover, increased consumption of SAA, regardless of the methionine source, tended to decrease the shear force of the LM in pigs. In conclusion, this study indicates that increasing dietary levels of SAA (+25%) appeared to improve the meat quality of gilts by decreasing drip loss and increasing meat tenderness.

[Clinical analysis of adult oculomoclonus-myoclonus syndrome with vertigo]

The clinical manifestation, physical and laboratory examination, electrophysiological, and imaging data of 2 female adult OMS patients with vertigo were analyzed at the Department of Neurology of the First Medical Center of Chinese PLA General Hospital from February 2021 to March 2022. The treatment strategy and clinical outcome were followed up. The two female patients were aged 42 and 66 years. Anti-NMDA receptor antibody and anti-GABAB receptor antibody were detected in serological screening, respectively. The two patients met the diagnostic criteria for OMS, and one was screened for breast tumor. The clinical symptoms of the two patients were relieved after immunomodulation therapy. OMS is a group of rare clinical syndromes; its clinical evaluation process should be standardized and the etiology should be actively searched for.

[A follow-up study of the severe occlusal surface wear of implant-supported full-arch prostheses]

Objective: To evaluate the severe occlusal surface wear of implant-supported full-arch prostheses, and to explore the risk factors affecting the severe occlusal surface wear of implant-supported full-arch prostheses. Methods: Five hundred and thirty-five patients who received implant-supported fixed complete dental prostheses or implant-overdentures and completed at least one follow-up 3 months after the delivery of definitive prostheses were enrolled from October 1994 to October 2021 in this retrospective cohort study. The information on demographics, implants, definitive prostheses, and related outcomes was collected. Cox proportional hazard regression model was adopted to analyze the risk factors of the severe wear of occlusal surfaces in implant-supported full-arch prostheses. Univariate analysis was performed on the factors that may affect the severe wear of occlusal surfaces, and the parameters of P<0.10 in univariate analysis were included in multivariate analysis to explore the risk factors affecting the severe wear of occlusal surfaces in implant-supported full-arch prostheses. Results: Severe wear of the posterior occlusal surfaces was detected in 114 prostheses with a duration of 61.4 (33.3, 89.4) months. 13 cases occurred≤2 years after the delivery of definitive prostheses, 44 cases>2 years and≤5 years, 44 cases>5 years and≤10 years, and the other 13 cases>10 years. There was no significant difference in the average time of severe occlusal surface wear between implant-supported fixed complete dental prostheses and implant-overdentures in the maxilla (Z=-1.03, P=0.303). However, in the mandible, it was 48.2 (31.2, 80.2) and 79.2 (51.3, 119.1) months respectively, which was statistically significant (Z=-2.93, P=0.003). Cox proportional hazard regression model showed opposed fixed dentition, bruxism, and posterior resin occlusal surfaces were risk factors (P<0.05) affecting the severe wear of the occlusal surfaces. Conclusions: Severe occlusal surface wear was clinically common with the prolonged application of implant-supported full-arch prostheses. Prostheses opposed to fixed dentition, in patients with bruxism, and made of posterior resin materials were at higher risk of severe occlusal surface wear on the posterior artificial teeth. Regular follow-up, patients' behavior guidance, and clinicians' appropriate intervention were necessary to manage this complication.

Single-stage computer-assisted approach for tumour resection and functional restoration of Brown class III maxillary defects-titanium mesh and zygomatic implants combined with vascularized anterolateral thigh flap

The functional restoration of Brown class III maxillary defects is a challenging endeavour in oral and maxillofacial surgery. Conventional reconstruction techniques with osseous free flaps have certain limitations, such as the need for multiple operations and greater patient morbidity. This study introduces a single-stage computer-assisted approach for tumour resection and functional restoration of these defects using titanium mesh, zygomatic implants, and a vascularized anterolateral thigh flap (ALTF). Virtual surgical planning was used to simulate tumour resection, titanium mesh placement, and zygomatic implant insertion. Surgery was performed under the guidance of mixed reality and surgical navigation. The tumour was resected by total hemimaxillectomy, and the reconstruction was performed using a pre-bent patient-specific titanium mesh for the orbital floor and two zygomatic implants placed and exposed through tunnels in an ALTF. The ALTF survived without any perioperative complications. A fixed prosthesis with built-in titanium frame was delivered 4 months postoperatively. At the 1-year follow-up, there was no tumour recurrence, the implants were osseointegrated, and aesthetics and masticatory function were satisfactory. An occlusal force of 155 N was attained on the reconstructed side, compared to 127 N on the non-surgical side.

Effects of various wet environments on the characteristics of the dust cake deposited on the surface of filter media

The effect of wet environments on the dust cake of filter media was studied. The collapse angles of dust particles and the collapse angles between dust particles and filter media increase with increasing dust moisture content, relative humidity, and spray rate. The smallest growth rate of collapse was observed under dust moisture content, while the largest growth rate occurred under the spray rate condition. The collapse angles between dust particles and filter media of coated filter media were smaller compared to those of mechanical filter media under different wet environments. The dust cake drag coefficients of both filter media initially increase and then decrease with an increase in the dust moisture content, decrease with the acceleration of the relative humidity, and show a pattern of first decreasing and then increasing as the spray rate increases. The dust loading capacity of both filter media follows an opposite trend to that of the dust cake drag coefficients.

Towards Clinical Proton Minibeam Radiation Therapy (pMBRT): Development of Clinical pMBRT System Prototype and pMBRT-Specific Treatment Planning Method

PURPOSE/OBJECTIVE(S)

Proton minibeam radiation therapy (pMBRT) is an emerging spatially fractionated RT (SFRT) modality that can provide very high therapeutic index compared to conventional radiotherapy methods and clinically-available SFRT methods (GRID and LATTICE). The biological data collected thus far encourage the preparation of clinical trials in pMBRT. This work is to facilitate the clinical translation of pMBRT by developing (1) the first clinical pMBRT system prototype worldwide, readily available for both small-animal biology studies and large-animal pMBRT trials; (2) pMBRT-specific treatment planning method with peak-valley dose ratio (PVDR) optimization capability for large animal and patient pMBRT trials, which is currently unavailable.

MATERIALS/METHODS

The pMBRT system is based on clinically-used pencil-beam-scanning proton machine equipped with large-field clinical-size pMBRT collimator, pMBRT-dedicated treatment planning system, and KV/CBCT imaging guidance. The multi-slit brass collimator has 10 × 10 cm field size, 0.4mm width per slit and 4 mm center-to-center distance. The divergence of slits is tailed to the divergence of the proton beam. A unique universal collimator design is implemented, so that we can keep the outer fitting to the snout and conveniently inter-change collimators as needed. The pMBRT-specific treatment planning method jointly optimizes PVDR and dose objectives, to meet a minimal PVDR threshold and maximize PVDR, to avoid the situations where meeting dose objectives can compromise PVDR when PVDR were not optimized. In addition, the survival fraction for organs at risk is also optimized. The dose calculation engine is based on the Monte Carlo method using TOPAS. The optimization algorithm utilizes total variation and L1 sparsity regularization to maximize PVDR and iterative convex relaxation method to solve the optimization problem.

RESULTS

Monte Carlo simulations via TOPAS were performed to design this large-field multi-slit collimator, using the beam structure and the beam data specific to our proton system, with mean dose rate of 8 Gy/min under clinical condition with the collimator in place. The feasibility of using this pMBRT system for small-animal studies has been demonstrated, with customized 3D printed holder for immobilizing small animals, on-board KV imaging system for accurate small-animal positioning, and the GAFchromic film for verifying radiation dose and PVDR. On the other hand, the efficacy of pMBRT-specific treatment planning method (with PVDR optimization capability) to improve PVDR has been demonstrated using retrospective patient planning studies in comparison with standard proton treatment planning method (without PVDR optimization capability).

CONCLUSION

The initial development of a clinical pMBRT system prototype and pMBRT-specific treatment planning method of PVDR optimization capability has been completed with ongoing efforts to make this system ready for large-animal pMBRT studies.

Consolidative Radiotherapy for Residual PET-Avid Disease on Day +30 Post CAR T-Cell Therapy in Non-Hodgkin Lymphoma

PURPOSE/OBJECTIVE(S)

Up to30% of non-Hodgkin lymphoma (NHL) patients achieve a partial response (PR) to anti-CD19 Chimeric Antigen Receptor T-cell Therapy (CART) on day +30. Most PR patients relapse and only 30% achieve spontaneous complete response (CR) without additional therapies. This study is the first to report on the role of consolidative radiotherapy (cRT) for PR PET-avid disease on day +30 post-CART in NHL.

MATERIALS/METHODS

Aretrospective review across 3 institutions from 2018 to 2022 identified 60 patients with B-cell NHL who received CART and achieved PR (Deauville 4-5) with <5 PET-avid disease sites on day +30. Progression-free survival (PFS) was defined from CART infusion to any disease progression. Overall survival (OS) was defined from CART infusion to death. Local relapse-free survival (LRFS), calculated based on the total number of PR sites, was defined from CART infusion to local relapse (LR) in the PR site identified on day +30. cRT was defined as comprehensive (compRT) - treated all PR PET-avid sites - or focal (focRT).

RESULTS

Followingday +30 PET scan, 45 PR patients were observed and 15 received cRT. Only one patient received consolidative systemic therapy and belonged to the cRT group. Prior to CART, bridging RT was given to 13 patients (9 in observation group and 4 in cRT group). There were no significant differences in the pre-CART and day +30 baseline characteristics, including the median size and SUVmax of the PR sites, between the two groups. However, the median number of PR sites on day +30 was higher in the cRT group (2 [range 1-3] vs 1 [range 1-3], p = 0.003). The median equivalent 2 Gy dose was 39.1 (Interquartile range 36.8-41) Gy, and the most common cRT regimen was 37.5 Gy in 15 fractions. The median follow-up was 21 months. Among the observed patients, 15 (33%) achieved spontaneous CR, and 27 (60%) experienced disease progression with all relapses involving the initial PR sites. Among patients who received cRT, 10 (67%) achieved CR, and 3 (20%) had disease progression with no relapses in the radiated PR sites. None of the 10 cRT patients achieving CR relapsed or required subsequent therapies. The 2-year PFS was 80% and 37% (p = 0.012) and the 2-year OS was 78% and 43% (p = 0.12) in the cRT and observation groups, respectively. Patients consolidated with compRT (n = 12) had superior 2-year PFS (92% vs 37%, p = 0.003) and 2-year OS (86% vs 43%, p = 0.048) compared to observed or focRT patients (n = 48). There were no grade 3+ RT-related toxicities. A total of 90 PR sites were identified; 64 were observed and 26 received cRT. Fourteen (22%) observed PR sites achieved spontaneous sustained CR and 42 (66%) experienced LR. Twenty-four (92%) PR sites consolidated with cRT achieved sustained CR and none experienced LR. The 2-year LRFS was 100% in the cRT sites and 31% in the observed sites (p<0.001).

CONCLUSION

NHL patients who achieve PR by PET to CART are at high risk of local progression. cRT for residual PET-avid disease on day +30 post-CART appears to alter the pattern of relapse and improve LRFS and PFS.

Proton LET Optimization Via Iterative Convex Relaxation Method

PURPOSE/OBJECTIVE(S)

If not optimized, the LET distribution can greatly impact normal tissue toxicity near tumor targets, because the LET often peaks at the distal edge of Bragg peak. LET optimization can account for biological effectiveness of protons during treatment planning, for minimizing biological proton dose and hot spots to normal tissues. However, the LET optimization is nonlinear and nonconvex to solve, which poses a great challenge in optimization. This work will develop an effective LET optimization method via iterative convex relaxation (ICR).

MATERIALS/METHODS

In contrast to the generic nonlinear optimization method, such as Quasi-Newton (QN) method, that does not account for specific characteristics of LET optimization, ICR is tailored to LET modeling and optimization in order to effectively and efficiently solve the LET problem. Specifically, nonlinear dose-averaged LET term is iteratively linearized and becomes convex during ICR, while nonconvex dose-volume constraint and minimum-monitor-unit constraint are also handled by ICR, so that the solution for LET optimization is obtained by solving a sequence of convex and linearized convex subproblems. Since the high LET mostly occurs near the target, a 1cm normal-tissue expansion of clinical target volume (CTV) (excluding CTV), i.e., CTV1cm, is defined to as an auxiliary structure during treatment planning, where LET is minimized.

RESULTS

ICR was validated in comparison with QN for abdomen, lung, and head-and-neck (HN) cases. ICR was effective for LET optimization, as ICR substantially reduced the LET and biological dose in CTV1cm the ring, with preserved dose conformality to CTV. Compared to QN, ICR had smaller LET, physical and biological dose in CTV1cm, and higher conformity index values; ICR was also computationally more efficient, which was about 3 times faster than QN. A lung case is presented in the table, where the quantities from top to bottom are computational time T (unit: second); total objective F, dose objective Fd and LET objective FL (unit: 10-3); conformity index for physical dose CId and biological dose CIb; mean LET L (unit: keV/μm), mean physical dose d and mean biological dose b (in ratio to prescription dose) for CTV1cm; mean LET L (unit: keV/μm), mean physical dose d and mean biological dose b (in ratio to prescription dose; unit: 10-1) for the heart.

CONCLUSION

A LET-specific optimization method based on ICR has been developed for solving proton LET optimization, which has been shown to be more computationally efficient than generic nonlinear optimizer via QN, with better plan quality in terms of LET, biological and physical dose conformality.

Virtual-Collimator Based Spatial Dose Modulation for Proton GRID Therapy

PURPOSE/OBJECTIVE(S)

Compared to conventional proton therapy, the proton GRID therapy can substantially improve normal tissue protection (with the delivery of spatially-modulated peak-valley dose pattern to normal tissues) while maintaining the tumor control efficacy (with the delivery of uniform dose pattern to tumor targets). The realization of proton GRID often relies on the use of physical collimators to shape the spatial dose distribution. However, the physical collimator may increase neutron dose, decrease delivery efficiency, and limit the freedom for patient positioning. Here we propose a virtual-collimator (VC) method for proton GRID. This new approach can generate peak-to-valley pattern with high peak-to-valley dose ratio (PVDR), without using a physical collimator.

MATERIALS/METHODS

The principle behind the VC method to modulate the spatial dose distribution consists of two major steps: (1) the primary beam is essentially halved, i.e., the beamlets are interleaved, so that the organ-at-risk (OAR) plane has the peak-valley dose pattern, while the target plane also has the valley dose; (2) the complementary beam is added with half complementary beamlets to fill in the previously valley-dose positions at the target plane, so that the target dose is uniform, while on the other hand, the complementary beam is angled slightly from the primary beam, so that the OAR still has the peak-valley dose pattern. Moreover, on top of VC, we also utilize sparsity regularization method using total variation and L1 sparsity (TVL1) to further jointly optimize PVDR and dose objectives, namely VC-TVL1.

RESULTS

VC and VC-TVL1 were validated in comparison with conventional proton GRID treatment planning method via IMPT ("CONV") and TVL1-based proton GRID treatment planning method without VC ("TVL1"), for a prostate case with single-beam (270° only) or two-beam (90° and 270°) scenarios. As shown in the table, the results show that VC can indeed modulate spatial dose with higher PVDR than CONV or even TVL1. VC had higher spatial modulation frequency with smaller peak-to-peak distance than TVL1. Moreover, VC+TVL1, as the synergy of VC and TVL1, further improved PVDR from VC or TVL1 alone.

CONCLUSION

A new way to deliver proton GRID therapy without a physical collimator is developed using the VC method. The VC method can be synergized with TVL1 optimization algorithm to further jointly optimize PVDR and dose objectives.

The Incidence and Prognosis Value of Perineural Invasion in Rectal Carcinoma: From Meta-Analyses and Real-World Clinical Pathological Features

AIMS

Perineural invasion (PNI) is a special type of metastasis of several cancers and has been reported as being a factor for poor prognosis in colorectal carcinoma. However, investigations of PNI in only rectal cancer and a comprehensive analysis combining meta-analyses with real-world case studies remain lacking.

MATERIALS AND METHODS

First, articles from 2000 to 2020 concerning the relationship between PNI and rectal cancer prognoses and clinical features were meta-analysed. Subsequently, we carried out a retrospective analysis of 312 rectal cancer cases that underwent radical surgery in the real world. The incidence of PNI and the relationship between PNI and prognosis, as well as clinicopathological factors, were investigated.

RESULTS

The incidence of PNI was 23.09% and 33.01% in the meta-analysis and clinical cases, respectively. PNI occurred as early as stage I (2.94%). Moreover, neoadjuvant therapy significantly reduced the PNI-positive rate (20.34% versus 26.54%). Both meta-analysis and real-world clinical case studies suggested that PNI-positive patients had poorer prognoses than PNI-negative patients. We established an effective risk model consisting of T stage, differentiation and lymphovascular invasion to predict PNI in rectal cancer.

CONCLUSION

PNI is a poor prognostic factor for rectal cancer and could occur even in stage I. Additionally, neoadjuvant therapy could sufficiently reduce the PNI-positive rate. T stage, lymphovascular invasion and differentiation grade were independent risk factors for PNI and the risk model that included these factors could predict the probability of PNI.

A New Treatment Planning Method for Efficient Proton ARC Therapy with Direct Minimization of Number of Energy Jumps

PURPOSE/OBJECTIVE(S)

The optimization of energy layer distributions is crucial for efficient proton ARC therapy: on one hand, a sufficient number of energy layers is needed to ensure the plan quality; on the other hand, an excess number of energy jumps can substantially slow down the treatment delivery. This work will develop a new treatment plan optimization method with direct minimization of number of energy jumps (NEJ), which will be shown to outperform state-of-the-art methods in both plan quality and delivery efficiency.

MATERIALS/METHODS

The proposed method jointly optimizes the plan quality and minimizes the NEJ. To minimize NEJ, (1) the proton spots x is summed per energy layer to form the energy vector y; (2) y is binarized via sigmoid transform into y1; (3) y1 is multiplied with a predefined energy order vector via dot product into y2; (4) y2 is filtered through the finite-differencing kernel into y3 in order to identify NEJ; (5) only the NEJ of y3 is penalized, while x is optimized for plan quality. The solution algorithm to this new method is based on iterative convex relaxation.

RESULTS

The new method is validated in comparison with state-of-the-art methods called energy sequencing (ES) method and energy matrix (EM) method. In terms of delivery efficiency, the new method had fewer NEJ, less energy switching time, and generally less total delivery time. In terms of plan quality, the new method had smaller optimization objective values, lower normal tissue dose, and generally better target coverage. A head-and-neck case is provided in the table with the following dosimetric parameters: planning objective value F; conformity index CI; homogeneity index HI; mean dose of larynx DOAR; mean body dose Dbody; the unit of dose is Gy.

CONCLUSION

We have developed a new treatment plan optimization method with direct minimization of NEJ, and demonstrated that this new method outperformed state-of-the-art methods (ES and EM) in both plan quality and delivery efficiency.

Vertex Position Optimization for LATTICE Therapy

PURPOSE/OBJECTIVE(S)

LATTICE radiation therapy (RT) aims to deliver 3D heterogenous dose of high peak-to-valley dose ratio (PVDR) to the tumor target, with peak dose at lattice vertices inside the target and valley dose for the rest of the target. In current clinical practice the lattice vertex positions are constant during treatment planning. This work proposes a new LATTICE plan optimization method that can optimize lattice vertex positions as plan variables, which is the first lattice vertex position optimization study to the best of our knowledge.

MATERIALS/METHODS

The new LATTICE treatment planning method optimizes lattice vertex positions as well as other plan variables (e.g., photon fluences or proton spot weights), with optimization objectives for target PVDR and organs-at-risk (OAR) sparing. To satisfy mathematical differentiability, the lattice vertices are approximated in sigmoid functions. For geometric feasibility, proper geometry constraints are enforced onto the lattice vertex positions. The lattice vertex position optimization problem is solved by iterative convex relaxation method, where lattice vertex positions and photon/proton plan variables are jointly updated via the Quasi-Newton method.

RESULTS

Both photon and proton LATTICE RT were considered, and the optimal lattice vertex positions in terms of plan objectives were found by solving all possible combinations on given discrete positions via heuristic searching based on standard IMRT/IMPT, which served as the ground truth for validating the new LATTICE method ("NEW"). That is, the plan with the smallest optimization objective ("BEST"), the plan with the median optimization objective ("MID"), and the plan with the largest optimization objective ("WORST") were selected as the reference plans to be compared with NEW. The table was for an abdomen case with the large bowel as the OAR, where the parameters are total optimization objective f, the mean valley dose of target Dvalley, the mean peak dose of target Dpeak, PVDR = Dpeak/Dvalley, and the mean dose of large bowel Dbowel. The unit of doses is Gy. The results in the table show that the new method indeed provided the optimal lattice vertex positions with the smallest optimization objective, the largest target PVDR, and the best OAR sparing.

CONCLUSION

A new LATTICE treatment planning method is proposed and validated that can optimize lattice vertex positions as well as other photon or proton plan variables for improving target PVDR and OAR sparing.

Development and validation of a diagnostic model for AFP-negative hepatocellular carcinoma

PURPOSE

AFP appears to be negative in about 30% of overall hepatocellular carcinoma (HCC). Our study aimed to develop a nomogram model to diagnose AFP-negative HCC (AFPN-HCC).

PATIENTS AND METHODS

The training set included 294 AFPN-HCC patients, 159 healthy objects, 63 patients with chronic hepatitis B(CHB), and 64 patients with liver cirrhosis (LC). And the validation set enrolled 137 healthy controls objects, 47 CHB patients and 45 patients with LC. LASSO, univariate, and multivariable logistic regression analysis were performed to construct the model and then transformed into a visualized nomogram. The receiver operating characteristic (ROC) curves, the calibration curve, decision curve analysis (DCA), and clinical impact curve (CIC) were further used for validation.

RESULTS

Four variables including age, PIVKA-II, platelet (PLT) counts, and prothrombin time (PT) were selected to establish the nomogram. The area under the curve (AUC) of the ROC to distinguish AFPN-HCC patients was 0.937(95% CI 0.892-0.938) in training set and 0.942(95% CI 0.921-0.963) in validation set. We also found that the model had high diagnostic value for small-size HCC (tumor size < 5 cm) (AUC = 0.886) and HBV surface antigen-positive AFPN-HCC (AUC = 0.883).

CONCLUSIONS

Our model was effective for discrimination of AFPN-HCC from patients with benign liver diseases and healthy controls, and might be helpful for the diagnosis for AFPN-HCC.

The Role of Radiotherapy in Patients with Refractory Hodgkin Lymphoma after Brentuximab Vedotin and -/or Immune Checkpoint Inhibitors

PURPOSE/OBJECTIVE(S)

Brentuximab vedotin (BV) and immune checkpoint inhibitors (ICIs) had important roles in the treatment of relapse or refractory (R/R) Hodgkin lymphoma (HL). Treatment of refractory disease after BV and -/or ICIs remains a challenge. This study was conducted to evaluate the efficacy and safety of radiotherapy for R/R HL after failure to BV or ICIs.

MATERIALS/METHODS

We retrospectively analyzed patients in two institutions with R/R HL who had failed after first-line therapy, and were refractory to BV or ICIs, and received radiotherapy (RT) thereafter. The overall response rate (ORR), duration of response (DOR), progression-free survival (PFS) and overall survival (OS) were analyzed.

RESULTS

A total of 19 patients were enrolled. First-line systemic therapy consisted of ABVD (84.2%), AVD + ICIs (10.5%) and BEACOPP (5.3%), respectively. After first-line therapy, 15 patients (78.9%) were refractory, and 4 patients (21.1%) relapsed. After diagnosis of R/R HL, 8 patients (42.1%) received BV, and 17 patients (89.5%) received ICIs. RT was delivered in all 19 patients who failed after BV or ICIs. In 16 efficacy-evaluable patients, the ORR and CR rate were 100% and 100%. The median DOR was 17.2 months (range, 7.9 to 46.7 months). 3 patients progressed at outside of the radiation field. The in-field-response rate was 100%. The 12-month PFS and OS were 84.4% and 100%, respectively. No patients were reported with sever adverse events.

CONCLUSION

This study concluded that radiotherapy was effective and safe for refractory HL after BV or ICIs. Further prospective studies were warranted.

An Effective Dose Rate Optimization Algorithm for Efficient Conventional-Dose-Rate Proton Therapy and Ultra-High-Dose-Rate FLASH Proton Therapy

PURPOSE/OBJECTIVE(S)

The treatment delivery with high dose rate is desirable for efficient conventional-dose-rate proton therapy (IMPT and proton ARC) and essential for achieving biological sparing effect to normal tissues for ultra-high-dose-rate FLASH proton therapy. The minimum-monitor-unit (MMU) problem is mathematically fundamental to these high-dose-rate proton therapy problems, since the dose rate is proportionally associated with the MMU threshold. However, the MMU problem is nonconvex and larger MMU threshold that leads to higher dose rate makes the nonconvex problem more difficult to solve, for which the conventional optimization methods (e.g., alternating direction method of multipliers (ADMM) or proximal gradient descent (PGD) usually cannot satisfactorily solve. This work will develop an effective dose rate optimization algorithm for the MMU problem.

MATERIALS/METHODS

The new method is based on orthogonal matching pursuit (OMP), and consists of two essential components. First, the iterative convex relaxation method is used to determine the active sets for dose-volume planning constraints and decouple the MMU constraint from the rest. Second, a modified OMP optimization algorithm is used to handle the MMU constraint: the non-zero spots are greedily selected via OMP to form the solution set to be optimized, and then a convex constrained subproblem is formed and can be conveniently solved to optimize the spot weights restricted to this solution set via OMP. During this iterative process, the new non-zero spots localized via OMP will be adaptively added to or removed from the optimization objective.

RESULTS

The new method via OMP is validated in comparison with conventional methods (ADMM and PGD) and a recently proposed new method (called stochastic coordinate descent (SCD) method) for high-dose-rate IMPT, ARC, and FLASH problems of large MMU thresholds, and the results suggest that OMP substantially improved the plan quality from PGD, ADMM and SCD in terms of both target dose conformality (e.g., quantified by max target dose and conformity index) and normal tissue sparing (e.g., mean and max dose). A brain case is provided in the table: compared to PGD/ADMM/SCD, OMP improved the conformity index from 0.42/0.52/0.33 to 0.65 for IMPT and 0.46/0.60/0.61 to 0.83 for ARC.

CONCLUSION

A new dose rate optimization algorithm via OMP is developed to solve the MMU problem with large MMU thresholds, and validated using examples of IMPT, ARC, and FLASH with substantially improved plan quality from conventional methods (ADMM and PGD) and a recently proposed new method SCD.

Aggregation-Induced Asymmetric Charge States of Amino Acids in Supramolecular Nanofibers

Electrostatic interactions contribute critically to the kinetic pathways and thermodynamic outcomes of peptide self-assembly involving one or more than one charged amino acids. While it is well understood in protein folding that those amino acids with acidic/basic side chains could shift their pKas when placed in a hydrophobic microenvironment, to what extent aggregation of monomeric peptide units from the bulk solution could alter their charged status and how this change in pKa values would reciprocally impact their assembly outcomes. Here, we design and analyze two solution systems containing peptide amphiphiles with hydrocarbon chains of different lengths to determine the factor of deprotonation on assembly. Our results suggest that models of supramolecular nanofibers with uniformly distributed, fully charged amino acids are oversimplified. We demonstrate, with molecular dynamics simulations, and validate with experimental results that asymmetric, different protonation states of the peptides lead to distinct nanostructures after self-assembly. The results give estimates on the electrostatic interactions in peptide amphiphiles required for their self-assembly and shed light on modeling molecular assembly systems containing charged amino acids.

How APTMS Acts as a Bridge to Enhance the Compatibility of the Interface between the Hydrophilic Poly(vinyl alcohol) Film and the Hydrophobic Stearic Acid Coating

The hydrophobic modification of poly(vinyl alcohol) (PVA) film as a biodegradable packaging material has received significant attention in recent research. Despite the use of stearic acid (SA) as a coating for the PVA film, a challenge persists due to the poor compatibility between SA and PVA. This study addressed the aforementioned issue by utilizing (3-aminopropyl)trimethoxysilane (APTMS) as a bridging agent to establish a connection between the hydrophilic PVA film and the hydrophobic SA coating through hydrogen bonding and chemical reactions. First, SEM and EDS analyses confirmed the enhanced interfacial compatibility between the SA coating and the PVA film. Subsequently, the results from 1H NMR, FTIR, and XPS experiments presented evidence of hydrogen bonding and chemical reactions among APTMS, SA, and the PVA film. Interestingly, the PVA-APTMS-SA film demonstrated a contact angle of 120.77°, a water absorption of 7.81%, and a water vapor transmission rate of 8.69 g/m2/h. Furthermore, such a composite film displayed exceptional adhesion performance, requiring detachment stresses of 9.86 ± 0.91 and 6.17 ± 0.75 MPa when tested on glass and marble surfaces, respectively. In conclusion, the PVA-APTMS-SA film exhibited significant potential in extending the freshness of fresh-cut apples, making it a promising eco-friendly packaging material for food preservation.

Deciphering a global source of non-genetic heterogeneity in cancer cells

Cell-to-cell variability within a clonal population, also known as non-genetic heterogeneity, has created significant challenges for intervening with diseases such as cancer. While non-genetic heterogeneity can arise from the variability in the expression of specific genes, it remains largely unclear whether and how clonal cells could be heterogeneous in the expression of the entire transcriptome. Here, we showed that gene transcriptional activity is globally modulated in individual cancer cells, leading to non-genetic heterogeneity in the global transcription rate. Such heterogeneity contributes to cell-to-cell variability in transcriptome size and displays both dynamic and static characteristics, with the global transcription rate temporally modulated in a cell-cycle-coupled manner and the time-averaged rate being distinct between cells and heritable across generations. Additional evidence indicated the role of ATP metabolism in this heterogeneity, and suggested its implication in intrinsic cancer drug tolerance. Collectively, our work shed light on the mode, mechanism, and implication of a global but often hidden source of non-genetic heterogeneity.

Comparison of prevalence, resistance, biofilm-forming ability and virulence between carbapenem-non-susceptible and carbepenem-susceptible Enterobacter cloacae complex in clusters

OBJECTIVES

This study aimed to explore differences in prevalence, resistance, biofilm-forming ability and virulence between carbapenem-non-susceptible and carbapenem-susceptible Enterobacter cloacae complex (ECC) in different clusters.

METHODS

Ninety-one carbapenem-non-susceptible isolates and an equal number of carbapenem-susceptible isolates and their clinical information were collected from a university teaching hospital in China. The strains were divided into different clusters based on hsp60 analysis. The agar dilution method was used to determine the minimum inhibitory concentrations of common antibiotics. The crystal violet assay was used to measure biofilm-forming ability. The Galleria mellonella infection model and polymerase chain reaction of virulence genes were used to evaluate virulence.

RESULTS

The isolates were divided into 12 clusters based on hsp60 analysis. Cluster VIII accounted for a greater proportion of carbapenem-non-susceptible isolates than the other clusters. The same clusters exhibited different resistance rates in carbapenem-non-susceptible and carbapenem-susceptible isolates. Moreover, carbapenem-non-susceptible isolates carried fewer virulence genes than carbapenem-susceptible isolates, and carbapenem-non-susceptible isolates in cluster II in did not carry the detected virulence genes. Virulence of carbapenem-non-susceptible and carbapenem-susceptible isolates differed significantly in clusters I, III, VIII and IX, as evaluated using the G. mellonella infection model. Carbapenem-non-susceptible isolates in cluster VIII showed higher prevalence, resistance, biofilm-forming ability and pathogenicity compared with the other clusters.

CONCLUSIONS

The study findings indicate the need to identify subgroups of ECC, and provide better advice and guidance for the use of carbapenems.

Developing a Surgical Simulation Curriculum for the Rwandan Context

OBJECTIVE

We report on the development and implementation of a surgical simulation curriculum for undergraduate medical students in rural Rwanda.

DESIGN

This is a narrative report on the development of scenario and procedure-based content for a junior surgical clerkship simulation curriculum by an interdisciplinary team of simulation specialists, surgeons, anesthesiologists, medical educators, and medical students.

SETTING

University of Global Health Equity, a new medical school located in Butaro, Rwanda.

PARTICIPANTS

Participants in this study consist of simulation and surgical educators, surgeons, anesthesiologists, research fellows and University of Global Health Equity medical students enrolled in the junior surgery clerkship.

RESULTS

The simulation training schedule was designed to begin with a 17-session simulation-intensive week, followed by 8 sessions spread over the 11-week clerkship. These sessions combined the use of high-fidelity mannequins with improvised, bench-top surgical simulators like the GlobalSurgBox, and low-cost gelatin-based models to effectively replace resource intensive options.

CONCLUSIONS

Emphasis on contextualized content generation, low-cost application, and interdisciplinary design of simulation curricula for low-income settings is essential. The impact of this curriculum on students' knowledge and skill acquisition is being assessed in an ongoing fashion as a substrate for iterative improvement.

Long-Term Patient-Reported Symptom Improvement and Quality of Life after Transthoracic Diaphragm Plication in Adults

BACKGROUND

Open and robotic-assisted transthoracic approaches for diaphragm plication are accepted surgical interventions for diaphragm paralysis and eventration. However, long-term patient-reported symptom improvement and quality of life (QOL) remains unclear.

STUDY DESIGN

A telephone-based survey was developed focusing on postoperative symptom improvement and QOL. Patients who underwent open or robotic-assisted transthoracic diaphragm plication (2008-2020) across three institutions were invited to participate. Patients who responded and provided consent were surveyed. Likert responses on symptom severity were dichotomized and rates before and after surgery were compared using McNemar's test.

RESULTS

Forty-one percent of patients participated (43 of 105 responded, mean age 61.0 years, 67.4% male, 37.2% robotic-assisted surgery), with an average time between surgery and survey of 4.1 ± 3.2 years. Patients reported significant improvement in dyspnea while lying flat (67.4% pre- vs 27.9% postoperative, p < 0.001), dyspnea at rest (55.8% pre- vs 11.6% postoperative, p < 0.001), dyspnea with activity (90.7% pre- vs 55.8% postoperative, p < 0.001), dyspnea while bending over (79.1% pre- vs 34.9% postoperative, p < 0.001), and fatigue (67.4% pre- vs 41.9% postoperative, p = 0.008). There was no statistical improvement in chronic cough. 86% of patients reported improved overall QOL, 79% had increased exercise capacity, and 86% would recommend surgery to a friend with a similar problem. Analysis comparing open and robotic-assisted approaches found no statistically significant differences in symptom improvement or QOL responses between the groups.

CONCLUSIONS

Patients report significantly improved dyspneic and fatigue symptoms after transthoracic diaphragm plication, regardless of open or robotic-assisted approach. The majority of patients report improved QOL and exercise capacity.

Dissecting and improving gene regulatory network inference using single-cell transcriptome data

Single-cell transcriptome data has been widely used to reconstruct gene regulatory networks (GRNs) controlling critical biological processes such as development and differentiation. Although a growing list of algorithms has been developed to infer GRNs using such data, achieving an inference accuracy consistently higher than random guessing has remained challenging. To address this, it is essential to delineate how the accuracy of regulatory inference is limited. Here, we systematically characterized factors limiting the accuracy of inferred GRNs and demonstrated that using pre-mRNA information can help improve regulatory inference compared to the typically used information (i.e., mature mRNA). Using kinetic modeling and simulated single-cell data sets, we showed that target genes' mature mRNA levels often fail to accurately report upstream regulatory activities because of gene-level and network-level factors, which can be improved by using pre-mRNA levels. We tested this finding on public single-cell RNA-seq data sets using intronic reads as proxies of pre-mRNA levels and can indeed achieve a higher inference accuracy compared to using exonic reads (corresponding to mature mRNAs). Using experimental data sets, we further validated findings from the simulated data sets and identified factors such as transcription factor activity dynamics influencing the accuracy of pre-mRNA-based inference. This work delineates the fundamental limitations of gene regulatory inference and helps improve GRN inference using single-cell RNA-seq data.

Depression, anxiety and PTSD symptoms before and during the COVID-19 pandemic in the UK

BACKGROUND

The impact of the coronavirus disease 2019 (COVID-19) pandemic on mental health is still being unravelled. It is important to identify which individuals are at greatest risk of worsening symptoms. This study aimed to examine changes in depression, anxiety and post-traumatic stress disorder (PTSD) symptoms using prospective and retrospective symptom change assessments, and to find and examine the effect of key risk factors.

METHOD

Online questionnaires were administered to 34 465 individuals (aged 16 years or above) in April/May 2020 in the UK, recruited from existing cohorts or via social media. Around one-third (n = 12 718) of included participants had prior diagnoses of depression or anxiety and had completed pre-pandemic mental health assessments (between September 2018 and February 2020), allowing prospective investigation of symptom change.

RESULTS

Prospective symptom analyses showed small decreases in depression (PHQ-9: -0.43 points) and anxiety [generalised anxiety disorder scale - 7 items (GAD)-7: -0.33 points] and increases in PTSD (PCL-6: 0.22 points). Conversely, retrospective symptom analyses demonstrated significant large increases (PHQ-9: 2.40; GAD-7 = 1.97), with 55% reported worsening mental health since the beginning of the pandemic on a global change rating. Across both prospective and retrospective measures of symptom change, worsening depression, anxiety and PTSD symptoms were associated with prior mental health diagnoses, female gender, young age and unemployed/student status.

CONCLUSIONS

We highlight the effect of prior mental health diagnoses on worsening mental health during the pandemic and confirm previously reported sociodemographic risk factors. Discrepancies between prospective and retrospective measures of changes in mental health may be related to recall bias-related underestimation of prior symptom severity.

Erratum: Global Polarization of Ξ and Ω Hyperons in Au+Au Collisions at sqrt[s_{NN}]=200 GeV [Phys. Rev. Lett. 126, 162301 (2021)]

This corrects the article DOI: 10.1103/PhysRevLett.126.162301.

Tp47-Induced Monocyte-Derived Microvesicles Promote the Adherence of THP-1 Cells to Human Umbilical Vein Endothelial Cells via an ERK1/2-NF-κB Signaling Cascade

The Treponema pallidum membrane protein Tp47 induces immunocyte adherence to vascular cells and contributes to vascular inflammation. However, it is unclear whether microvesicles are functional inflammatory mediators between vascular cells and immunocytes. Microvesicles that were isolated from Tp47-treated THP-1 cells using differential centrifugation were subjected to adherence assays to determine the adhesion-promoting effect on human umbilical vein endothelial cells (HUVECs). Intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1) levels in Tp47-induced microvesicle (Tp47-microvesicle)-treated HUVECs were measured, and the related intracellular signaling pathways of Tp47-microvesicle-induced monocyte adhesion were investigated. Tp47-microvesicles promoted THP-1 cell adhesion to HUVECs (P < 0.01) and upregulated ICAM-1 and VCAM-1 expression in HUVECs (P < 0.001). The adhesion of THP-1 cells to HUVECs was inhibited by anti-ICAM-1 and anti-VCAM-1 neutralizing antibodies. Tp47-microvesicle treatment of HUVECs activated the extracellular signal-regulated kinase 1/2 (ERK1/2) and NF-κB signaling pathways, whereas ERK1/2 and NF-κB inhibition suppressed the expression of ICAM-1 and VCAM-1 and significantly decreased the adhesion of THP-1 cells to HUVECs. IMPORTANCE Tp47-microvesicles promote the adhesion of THP-1 cells to HUVECs through the upregulation of ICAM-1 and VCAM-1 expression, which is mediated by the activation of the ERK1/2 and NF-κB pathways. These findings provide insight into the pathophysiology of syphilitic vascular inflammation.

[Application of mixture analysis methods in association between metals mixture exposure and DNA oxidative damage]

Objectives: To study the association between metals mixture exposure and DNA oxidative damage using mixture analysis methods, and to explore the most significant exposure factors that cause DNA oxidative damage. Methods: Workers from steel enterprises were recruited in Shandong Province. Urinary metals were measured by using the inductively coupled plasma mass spectrometry method. The level of urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) was determined by using the ultra-high performance liquid chromatography-mass spectrometry method. Bayesian kernel machine regression (BKMR), elastic net regression and quantile g-computation regression were used to analyze the association between urinary metals and urinary 8-OHdG. Results: A total of 768 subjects aged (36.15±7.40) years old were included in the study. BKMR, elastic net regression and quantile g-computation all revealed an overall positive association between the mixture concentration and increased urinary 8-OHdG. The quantile g-computation results showed that with a 25% increase in metal mixtures, the urinary 8-OHdG level increased by 77.60%. The elastic net regression showed that with a 25% increase in exposure risk score, the urinary 8-OHdG level increased by 26%. The BKMR summarized the contribution of individual exposures to the response, and selenium, zinc, and nickel were significant contributors to the urinary 8-OHdG elevation. Conclusion: Exposure to mixed metals causes elevated levels of DNA oxidative damage, and selenium, zinc, and nickel are significant exposure factors.