Near-atomic-resolution structure of J-aggregated helical light-harvesting nanotubes

Cryo-electron microscopy has delivered a resolution revolution for biological self-assemblies, yet only a handful of structures have been solved for synthetic supramolecular materials. Particularly for chromophore supramolecular aggregates, high-resolution structures are necessary for understanding and modulating the long-range excitonic coupling. Here, we present a 3.3 Å structure of prototypical biomimetic light-harvesting nanotubes derived from an amphiphilic cyanine dye (C8S3-Cl). Helical 3D reconstruction directly visualizes the chromophore packing that controls the excitonic properties. Our structure clearly shows a brick layer arrangement, revising the previously hypothesized herringbone arrangement. Furthermore, we identify a new non-biological supramolecular motif-interlocking sulfonates-that may be responsible for the slip-stacked packing and J-aggregate nature of the light-harvesting nanotubes. This work shows how independently obtained native-state structures complement photophysical measurements and will enable accurate understanding of (excitonic) structure-function properties, informing materials design for light-harvesting chromophore aggregates.

Mouse model of Graves' orbitopathy induced by the immunization with TSHR A and IGF-1R α subunit gene

PURPOSE

The study aimed to establish a mouse model of Graves' disease (GD) with Graves' orbitopathy (GO; GD + GO) that can represent the clinical disease characteristics.

METHODS

A eukaryotic expression plasmid of insulin-like growth factor 1 receptor (IGF-1R) α subunit (pcDNA3.1/IGF-1Rα) and a thyrotropin receptor (TSHR) A subunit plasmid (pcDNA3.1/TSHR-289) were injected in female BALB/c mice followed by immediate electroporation to induce a GD + GO model. Grouping was performed according to the frequency of injection (2- to 4-week intervals) and type of injected plasmids: T: pcDNA3.1/TSHR-289( +), I: pcDNA3.1/IGF-1Rα( +), or co-injection T + I: pcDNA3.1/TSHR-289( +) and pcDNA3.1/IGF-1Rα( +). Serum TSH, T4, TSAb, TSBAb, body weight, and blood glucose levels were evaluated. Thyroid 99mTcO4- imaging and retrobulbar magnetic resonance imaging (MRI) were performed, and bilateral eye muscle volumes were measured. Immunohistochemistry and hematoxylin-eosin staining were performed on the relevant tissues, and semi-quantitative analysis was performed.

RESULTS

A total of 60% of mice (3/5, one mouse died) in the T group developed GD + GO. In the T + I group, 83.3% of mice (5/6) developed GD + GO. Mice in the I group did not develop GD. Compared with the control group, serum T4, TSAb, and TSBAb of the mice in the GD + GO model groups were increased to varying degrees (P < 0.05), and serum TSH and body weight were significantly lower compared to the control group (P < 0.05). The thyroid uptake capacity of 99mTcO4- and the volume of eye muscle of mice in the GD + GO group were significantly higher compared to the control group (P < 0.05). The thyroid and retrobulbar muscles of these mice showed varying inflammatory infiltration and interstitial muscle edema. The severity of GD + GO in the co-injection group was not related to injection frequency; however, GD and ocular signs in co-injection mice were more severe compared to the T group.

CONCLUSIONS

We successfully induced a GD + GO mouse model by a repeated co-injection of pcDNA3.1/IGF-1Rα and pcDNA3.1/TSHR-289 plasmids. Injection of pcDNA3.1/IGF-1Rα alone failed to induce GD. Co-injection of two plasmids induced more severe GD + GO than pcDNA3.1/TSHR-289( +) alone.

Aetiology and predictors of major bleeding events in patients with heart failure with reduced ejection fraction undergoing percutaneous coronary intervention

OBJECTIVES

We sought to determine the relationship between the degree of left ventricular ejection fraction (LVEF) impairment and the frequency and type of bleeding events after percutaneous coronary intervention (PCI).

DESIGN

This was an observational retrospective cohort analysis. Patients who underwent PCI from 2009 to 2017 were identified from our institutional National Cardiovascular Disease Registry (NCDR) CathPCI database. Patients were stratified by pre-PCI LVEF: preserved (≥50%), mildly reduced (41%-49%) and reduced (≤40%) LVEF.

PRIMARY OUTCOME MEASURES

The outcome was major bleeding, defined by NCDR criteria. Events were classified based on bleeding aetiology and analysed by multivariable logistic regression.

RESULTS

Among 13 537 PCIs, there were 817 bleeding events (6%). The rate of bleeding due to any cause, blood transfusion, gastrointestinal bleeding and coronary artery perforation or tamponade each increased in a stepwise fashion comparing preserved, mildly reduced and reduced LVEF reduction (p<0.05 for all comparisons). However, there were no differences in bleeding due to asymptomatic drops in haemoglobin, access site haematoma or retroperitoneal bleeding. After multivariable adjustment, mildly reduced and reduced LVEF remained independent predictors of bleeding events (OR 1.36, 95% CI 1.06 to 1.74, p<0.05 and OR 1.73, 95% CI 1.45 to 2.06, p<0.0001).

CONCLUSIONS

The degree of LV dysfunction is an independent predictor of post-PCI major bleeding events. Patients with mildly reduced or reduced LVEF are at greatest risk of post-PCI bleeding, driven by an increased need for blood transfusion, major GI bleeding events and coronary artery perforation or tamponade. Pre-PCI LV dysfunction does not predict asymptomatic declines in haemoglobin, access site haematoma or retroperitoneal bleeding.

Tight-packing of large pilin subunits provides distinct structural and mechanical properties for the Myxococcus xanthus type IVa pilus

Type IVa pili (T4aP) are ubiquitous cell surface filaments important for surface motility, adhesion to surfaces, DNA uptake, biofilm formation, and virulence. T4aP are built from thousands of copies of the major pilin subunit and tipped by a complex composed of minor pilins and in some systems also the PilY1 adhesin. While major pilins of structurally characterized T4aP have lengths of <165 residues, the major pilin PilA of Myxococcus xanthus is unusually large with 208 residues. All major pilins have a conserved N-terminal domain and a variable C-terminal domain, and the additional residues of PilA are due to a larger C-terminal domain. We solved the structure of the M. xanthus T4aP (T4aPMx) at a resolution of 3.0 Å using cryo-EM. The T4aPMx follows the structural blueprint of other T4aP with the pilus core comprised of the interacting N-terminal α1-helices, while the globular domains decorate the T4aP surface. The atomic model of PilA built into this map shows that the large C-terminal domain has more extensive intersubunit contacts than major pilins in other T4aP. As expected from these greater contacts, the bending and axial stiffness of the T4aPMx is significantly higher than that of other T4aP and supports T4aP-dependent motility on surfaces of different stiffnesses. Notably, T4aPMx variants with interrupted intersubunit interfaces had decreased bending stiffness, pilus length, and strongly reduced motility. These observations support an evolutionary scenario whereby the large major pilin enables the formation of a rigid T4aP that expands the environmental conditions in which the T4aP system functions.

[Application value of laparoscopic double stapler firings and double stapling technique combined with rectal eversion and total extra-abdominal resection in the sphincter-preserving resection of low rectal cancer]

Objectives: To investigate the application value of laparoscopic double stapler firings and double stapling technique combined with rectal eversion and total extra-abdominal resection (LDER) in the anal preservation treatment of low rectal cancer. Methods: Inclusion criteria: (1) age was 18-70; (2) the distance of the lower tumor edge from the anal verge was 4-5 cm; (3) primary tumor with a diameter ≤3 cm; (4) preoperative staging of T1~2N1~2M0; (5) "difficult pelvis", defined as ischial tuberosity diameter<10 cm or body mass index>25 kg/m2; (6) patients with strong intention for sphincter preservation; (7) no preoperative treatment (e.g., chemotherapy, radiotherapy, molecular targeted therapy, or immunotherapy); (8) no lateral lymph node enlargement; (9) no previous anorectal surgery; (10) patients with good basic condition who could tolerate surgery. Exclusion criteria: (1) previously suffered from malignant tumors of the digestive tract or currently suffering from malignant tumors out of the digestive tract; (2) patients with preoperative anal dysfunction (Wexner score ≥ 10), or fecal incontinence. The specific surgical steps are as follows: the distal end of the rectum was dissected to the level of the interspace between internal and external sphincters of anal canal. Five centimeters proximal to the tumor, the mesorectum was ligated, and a liner stapler was used to transect the rectum. The distal rectum with the tumor were then everted and extracted through the anus. The rectum was transected 0.5-1.0 cm distal to the tumor with a linear stapler. Full thickness suture was used to reinforce the stump of the rectum, which was then brought back into the pelvic cavity. Finally, an end-to-end anastomosis between the colon and the rectum was performed. A retrospective descriptive study was performed of the clinical and pathological data of 12 patients with T1-T2 stage low rectal cancer treated with LDER at Henan Provincial People's Hospital from January 2020 to December 2022. Results: All 12 patients successfully completed LDER with sphincter preservation, without conversion to open surgery or changes in surgical approach. The median surgical time was 272 (155-320) minutes, with a median bleeding volume of 100 (50-200) mL. No protective stoma was performed, and all patients received R0 resection. The average hospital stay was 9 (7-15) days. There were no postoperative anastomotic leakage or perioperative deaths. All 12 patients received postoperative follow-up, with a median follow-up of 12 months (6-36 months) and a Wexner score of 8 (5-14) at 6 months postoperatively. There was no tumor recurrence or metastasis during the follow-up period. Conclusions: LDER is safe and effective for the treatment of low rectal cancer.

Identification and validation of a novel cuproptosis signature for stratifying different prognostic, immune, metabolic, and therapeutic landscapes in pancreatic adenocarcinoma

OBJECTIVE

Pancreatic adenocarcinoma (PAAD) is a highly malignant cancer that urgently needs more effective therapeutic strategies. The discovery of cuproptosis brings great inspiration for the treatment and clinical assessment of cancers.

MATERIALS AND METHODS

A novel cuproptosis-related (CR) risk signature was constructed using the Lasso regression analysis. Its prognostic value was assessed via a series of survival analyses and validated in four GEO cohorts. The effects of CR risk signature on tumor immune microenvironment (TIM) were explored through CIBERSORT, ESTIMATE, and ssGSEA algorithms. Using GESA, we investigated its associations with various patterns of programmed cell death (PCD) and the metabolism process. The somatic mutation features of each CR-risk group were also probed using 'maftools' R package and cBioPortal database. The potential linkages between CR risk score and the efficacy of multiple therapeutic approaches were elucidated using tumor mutation burden, the expressions of immune checkpoints, the TIDE score, and the GDSC database. Finally, we ascertained the biofunctions of LIPT1 (Lipoyltransferase 1) in pancreatic cancer (PC) cells through immunohistochemistry, qPCR (quantitative polymerase chain reaction), colony formation, and Transwell assays.

RESULTS

LIPT1, LIAS (lipoyl synthase), PDP1 (Pyruvate dehydrogenase phosphatase1), and GCSH (Glycine cleavage system H protein) constituted the CR risk signature. The CR risk signature possessed a high prognostic value and could improve the traditional prognostic model. Moreover, the CR risk score was indicative of the changes in infiltration levels of CD8+T cells and macrophages, whereas it was not associated with the enrichment of various PCD patterns and multiple metabolic processes. As for therapeutic correlation, CR risk score was a potential biomarker for predicting the efficacy of ICBs but failed in targeted drugs and chemotherapeutic agents. Through qPCR and immunohistochemistry detection in clinical samples, we confirmed that LIPT1 was significantly downregulated in pancreatic adenocarcinoma (PAAD) samples. Experiments in vitro revealed that silencing LIPT1 promoted the proliferation, migration, and invasion of PANC-1 and SW1990 cells.

CONCLUSIONS

The novel CR risk signature contributed to the risk stratification of PAAD patients. Cuproptosis regulatory genes, well represented by LIPT1, provided new insights into PAAD treatment and assessment.

Defining metabolic flexibility in hair follicle stem cell induced squamous cell carcinoma

Among the numerous changes associated with the transformation to cancer, cellular metabolism is one of the first discovered and most prominent[1, 2]. However, despite the knowledge that nearly every cancer is associated with the strong upregulation of various metabolic pathways, there has yet to be much clinical progress on the treatment of cancer by targeting a single metabolic enzyme directly[3-6]. We previously showed that inhibition of glycolysis through lactate dehydrogenase (LDHA) deletion in cancer cells of origin had no effect on the initiation or progression of cutaneous squamous cell carcinoma[7], suggesting that these cancers are metabolically flexible enough to produce the necessary metabolites required for sustained growth in the absence of glycolysis. Here we focused on glutaminolysis, another metabolic pathway frequently implicated as important for tumorigenesis in correlative studies. We genetically blocked glutaminolysis through glutaminase (GLS) deletion in cancer cells of origin, and found that this had little effect on tumorigenesis, similar to what we previously showed for blocking glycolysis. Tumors with genetic deletion of glutaminolysis instead upregulated lactate consumption and utilization for the TCA cycle, providing further evidence of metabolic flexibility. We also found that the metabolic flexibility observed upon inhibition of glycolysis or glutaminolysis is due to post-transcriptional changes in the levels of plasma membrane lactate and glutamine transporters. To define the limits of metabolic flexibility in cancer initiating hair follicle stem cells, we genetically blocked both glycolysis and glutaminolysis simultaneously and found that frank carcinoma was not compatible with abrogation of both of these carbon utilization pathways. These data point towards metabolic flexibility mediated by regulation of nutrient consumption, and suggest that treatment of cancer through metabolic manipulation will require multiple interventions on distinct pathways.

m6A Reader YTHDC1 Inhibits Ferroptosis and Radiosensitivity by Promoting SREBF1 mRNA Nuclear Export in Nasopharyngeal Carcinoma

PURPOSE/OBJECTIVE(S)

Radioresistance is the main reason for nasopharyngeal carcinoma (NPC) recurrence leading to treatment failure, and inducing ferroptosis has gradually been a new way to enhance radiosensitivity. N6-methyladenosine (m6A) is involved in regulation of numerous biological processes. However, whether m6A affects ferroptosis in NPC is still unclear. In this study, we conducted a siRNA library screening to identify m6A reader YTHDC1 as an essential oncogene that suppressed ferroptosis and radiosensitivity by promoting SREBF1 mRNA nuclear export in nasopharyngeal carcinoma.

MATERIALS/METHODS

The expression and function of YTHDC1 were assessed via CCK8 cell viability assay, immunostaining, real-time PCR, western blot, radiation clonogenic assay and fluorescence in situ hybridization assay. Ferroptosis was determined by detecting cell viability, lipid peroxidation, abnormal mitochondrial and cell death rate. The in vivo effects of YTHDC1 were examined with RSL3 treatment or lentivirus modification of YTHDC1 expression in radiated mouse models.

RESULTS

Based on RSL3-induced ferroptotic cell death model and a siRNA library about m6A modification associated gene screening, we identified m6A reader YTHDC1 could inhibit ferroptosis as well as radiosensitivity of NPC, both in vivo and in vitro. Mechanistically, YTHDC1 protein could recognize m6A sites in the CDS region and 3' untranslated region (3'UTR) of SREBF1 mRNA and promote SREBF1 mRNA nuclear export, which finally resulted in transcriptional upregulation of genes key to ferroptosis such as SCD and FASN. Furthermore, the high expression of YTHDC1 was negatively regulated by ZNF598 via ubiquitination and associated with unfavorable survival in NPC patients due to radioresistance.

CONCLUSION

Our findings reveal the critical role of YTHDC1 specifically in inhibiting ferroptosis and radiosensitivity via m6A-dependent mechanism and provide an exploitable target and therapeutic strategy for overcoming radioresistance in NPC.

Influence of off-hours admission on outcomes of ischemic stroke: a systematic review and meta-analysis of contemporary studies

OBJECTIVE

The aim of this study was to document pooled evidence on the association between admission during off-hours and/or weekends and the risk of mortality and poor functional outcome in patients with ischemic stroke, as compared to admission during regular working hours and/or weekdays.

MATERIALS AND METHODS

We conducted a systematic search using PubMed, EMBASE, and Scopus databases. Observational studies published between 2013 and 2023 that investigated the association between weekend/off-hours admission and outcomes (mortality and functional outcomes) of ischemic stroke were considered for inclusion. A random effects model was used to conduct the analysis, and effect sizes were reported as pooled odds ratio (OR) or hazards ratio (HR) with corresponding 95% confidence intervals.

RESULTS

The analysis consisted of 31 studies and found that patients admitted during weekend/off-hours had a higher risk of in-hospital (OR 1.12, 95% CI: 1.06, 1.18), and 1-month post-admittance mortality (OR 1.13, 95% CI: 1.06, 1.20). However, the risk of mortality after 3, 6, and 12 months was not statistically different between the two patient groups. Patients admitted during weekends/off-hours had a slightly higher risk of poor functional outcomes (modified Rankin Scale score of ≥3) at 1-month post-admittance (OR 1.06, 95% CI: 1.00, 1.11). However, after 3, 6, and 12 months, the risk of poor functional outcomes was similar in both patient groups. Egger's test did not suggest the presence of publication bias for any of the outcomes.

CONCLUSIONS

Individuals who suffer from ischemic stroke and present outside of regular working hours or on weekends have a higher likelihood of experiencing short-term mortality and unfavorable functional outcomes.

Large pilin subunits provide distinct structural and mechanical properties for the Myxococcus xanthus type IV pilus

Type IV pili (T4P) are ubiquitous bacterial cell surface filaments important for surface motility, adhesion to biotic and abiotic surfaces, DNA uptake, biofilm formation, and virulence. T4P are built from thousands of copies of the major pilin subunit and tipped by a complex composed of minor pilins and in some systems also the PilY1 adhesin. While the major pilins of structurally characterized T4P have lengths of up to 161 residues, the major pilin PilA of Myxococcus xanthus is unusually large with 208 residues. All major pilins have a highly conserved N-terminal domain and a highly variable C-terminal domain, and the additional residues in the M. xanthus PilA are due to a larger C-terminal domain. We solved the structure of the M. xanthus T4P (T4P Mx ) at a resolution of 3.0 Å using cryo-electron microscopy (cryo-EM). The T4P Mx follows the structural blueprint observed in other T4P with the pilus core comprised of the extensively interacting N-terminal α1-helices while the globular domains decorate the T4P surface. The atomic model of PilA built into this map shows that the large C-terminal domain has much more extensive intersubunit contacts than major pilins in other T4P. As expected from these greater contacts, the bending and axial stiffness of the T4P Mx is significantly higher than that of other T4P and supports T4P-dependent motility on surfaces of different stiffnesses. Notably, T4P Mx variants with interrupted intersubunit interfaces had decreased bending stiffness and strongly reduced motility on all surfaces. These observations support an evolutionary scenario whereby the large major pilin enables the formation of a rigid T4P that expands the environmental conditions in which the T4P system functions.

[The effects of high risk of ovarian hyperstimulation syndrome and duration of embryo cryopreservation on perinatal outcomes of single live births in the first frozen embryo transfer cycle after whole embryo cryopreservation]

Objective: To investigate the effects of high risk of ovarian hyperstimulation syndrome (OHSS) and duration of embryo cryopreservation on perinatal outcomes of the first frozen-thawed cycle after whole embryo cryopreservation. Methods: The clinical data of 1 804 patients who underwent the first frozen-thawed cycle after whole embryo cryopreservation and achieved singleton live births in the Reproductive Center of the Third Affiliated Hospital of Zhengzhou University from January 2016 to June 2021 were retrospectively analyzed. According to whether there was high risk of OHSS in the oocyte retrieval cycle, the patients were divided into high-risk group (n=790) and non-high-risk group (n=1 014). The baseline data and perinatal outcomes were compared between the two groups. Multivariate linear regression was applied to analyze the relative factors affecting neonatal weight. And the high-risk group was divided into three subgroups according to different cryopreservation time: the embryos of 96 cycles with a cryopreservation time less than 60 days were defined as group A; the embryos of 587 cycles with a cryopreservation time around 60 to 120 days were defined as group B; the embryos of 107 cycles with a cryopreservation time more than 120 days were defined as group C. The perinatal outcomes were compared among the three groups. The measurement data in this study were represented by［M（Q₁，Q₃）］. Results: The female age in the high-risk group was 30.0 (27.0, 32.0) years old, which was lower than that in the non-high-risk group 31.0 (29.0, 34.0) (P<0.001). The male age in high-risk group was 30.0 (28.0, 33.0), lower than that in non-high-risk group 32.0 (29.0, 35.0) (P<0.001). The birth weight of high-risk group [3 500.0 (3 200.0,3 800.0) g] was higher than that of control group [3 400.0 (3 150.0,3 800.0) g](P=0.045). Multivariate linear regression analysis showed that female BMI was correlated with neonatal weight, β (95%CI) was 15.37(8.33, 22.41) (P<0.001), and the high risk of OHSS was not correlated with neonatal weight, β (95%CI) was 19.40 (-38.07, 76.87) (P=0.508). There was significant difference in the incidence of low birth weight and very low birth weight among groups A, B and C (all P values<0.05), and the incidence of low birth weight and very low birth weight in group C was higher than that in group B (all P values<0.017). Conclusions: The risk of adverse perinatal outcomes in high-risk OHSS patients who underwent the first frozen-thawed cycle after whole embryo cryopreservation was not increased. However, prolonged cryopreservation of embryos may lead to increased risk of low birth weight and very low birth weight.

[The relationship between genetic polymorphism of CYP2C19 and the efficacy of Helicobacter pylori eradication therapy in children]

Objective: To investigate the relationship between genetic polymorphisms of cytochrome P450 2C19 (CYP2C19) and the efficacy of Helicobacter pylori (Hp) eradication therapy in children. Methods: The retrospective cohort study was conducted on 125 children with gastroscopy and positive rapid urease test (RUT) from September 2016 to December 2018 who presented to the Children's Hospital of Zhejiang University School of Medicine due to gastrointestinal symptoms including nausea, vomiting, abdominal pain, bloating, acid reflux, heartburn, chest pain, vomiting blood and melena. Hp culture and drug susceptibility test were carried out with gastric antrum mucosa before treatment. All the patients completed 2 weeks of standardized Hp eradication therapy and had ¹³C urea breath test 1 month after that, which was used to evaluate the curative effect. The DNA of gastric mucosa after RUT was analyzed and CYP2C19 gene polymorphism was detected. Children were grouped according to metabolic type. Combined with the results of Hp culture and drug susceptibility, the relationship between CYP2C19 gene polymorphism and the efficacy of Hp eradicative treatment was analyzed in children. Chi square test was used for row and column variables, and Fisher exact test was used for comparison between groups. Results: One hundred and twenty five children were enrolled in the study, of whom 76 were males and 49 females. The genetic polymorphism of CYP2C19 in these children found poor metabolizer (PM) of 30.4% (38/125), intermediate metabolizer (IM) of 20.8% (26/125), normal metabolizer (NM) of 47.2% (59/125), rapid metabolizer (RM) of 1.6% (2/125), and ultrarapid metabolizer (UM) of 0. There were statistically significant in positive rate of Hp culture among these groups (χ²=124.00, P<0.001). In addition, the successful rates of Hp eradication in PM, IM, NM and RM genotypes were 84.2% (32/38), 53.8% (14/26), 67.8% (40/59), and 0, respectively, with significant differences (χ²=11.35, P=0.010); those in IM genotype was significantly lower than that in PM genotype (P=0.011). With the same standard triple Hp eradicative regimen, the successful rate of Hp eradication for IM type was 8/19, which was lower than that of PM (80.0%, 24/30) and NM type (77.3%, 34/44) (P=0.007 and 0.007, respectively). There was a significant difference in the efficacy of Hp eradication treatment among different genotypes (χ²=9.72, P=0.008). According to the clarithromycin susceptibility result, the successful rate of Hp eradication treatment for IM genotype was 4/15 in the sensitive group and 4/4 in the drug-resistant group (χ²=6.97, P=0.018). Conclusions: The genetic polymorphism of CYP2C19 in children is closely related to the efficacy of Hp eradication treatment. PM has a higher successful rate of eradication treatment than the other genotypes.

[Enhance the management of cardiac arrest and improve the prognosis of the patients]

Cardiac arrest is one of the major public health problems with sudden onset, high mortality and high disability rate. The prevalence of cardiovascular disease continues to rise and the burden of cardiac arrest is increasing in China. It is of great significance to explore more effective prevention and treatment measures to improve the prognosis of patients with cardiac arrest. This article discusses the relevant progress on the treatment ability of emergency and critical cardiovascular diseases, medicines and technologies for cardiac arrest care, and registry studies of cardiac arrest, to further promote the effective improvement of key capacities at various stages of the prevention and treatment of cardiac arrest in China.

[Drug resistance and genomic characteristics of Salmonella enterica serovar London from clinical and food sources in Hangzhou City from 2017 to 2021]

Objective: To analyze the drug resistance and genomic characteristics of Salmonella enterica serovar London isolated from clinical and food sources in Hangzhou City from 2017 to 2021. Methods: A total of 91 Salmonella enterica serovar London strains isolated from Hangzhou City from 2017 to 2021 were analyzed for drug susceptibility, pulsed field gel electrophoresis (PFGE) typing and whole genome sequencing. Multilocus sequence typing (MLST), core genome multilocus sequence typing (cgMLST) and detection of drug resistance genes were performed by using the sequencing data. Phylogenetic analysis was conducted to compare the 91 genomes from Hangzhou City with 347 genomes from public databases. Results: No significant difference in the drug resistance rate was observed between clinical strains and food strains to 18 drugs in Hangzhou City(all P>0.05), and the multidrug resistance (MDR) rate was 75.8% (69/91). Most strains were resistant to 7 drug classes simultaneously. One strain was resistant to Polymyxin E as well as positive for mcr-1.1, and 50.5% (46/91) of the strains were resistant to Azithromycin and were positive for mph(A). All 91 Salmonella enterica serovar London strains were ST155, which were subdivided into 44 molecular types by PFGE and 82 types by cgMLST. Phylogenetic analysis showed that most strains from Hangzhou City (83/91) were clustered together, and a small number of human isolates from Europe, North America and pork isolates from Hubei and Shenzhen were mixed in the cluster. Other strains from Hangzhou City (8/91) were closely related to strains from Europe, America and Southeast Asia. Strains isolated from pork were the most closely related to clinical strains. Conclusion: The epidemic of Salmonella enterica serovar London in Hangzhou City is mainly caused by the spread of ST155 strains, which is mainly transmitted locally. At the same time, cross-region transmission to Europe, North America, Southeast Asia, and other provinces and cities in China may also occur. There is no significant difference in the drug resistance rate between clinical strains and food strains, and a high level of MDR is found in the strains. Clinical infection of Salmonella enterica serovar London may be closely related to pork consumption in Hangzhou City.

Analysis of SOD1 Variants in Chinese Patients with Familial Amyotrophic Lateral Sclerosis

BACKGROUND

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease, and genetic contributors exert a significant role in the complicated pathogenesis. Identification of the genetic causes in ALS families could be valuable for early diagnosis and management. The development of potential drugs for patients with genetic defects will shed new light on ALS therapy.

AIM

To identify causative variants in three Chinese families with familial ALS (FALS), reveal the pathogenic mechanism, and look for the targeted drug for ALS.

DESIGN AND METHODS

Whole-exome sequencing and bioinformatics were used to perform genetic analysis of the ALS families. Functional analysis was performed to study the variants' function and search for potential drug targets.

RESULTS

Three heterozygous missense variants of the SOD1 gene were identified in families with FALS. The clinical manifestations of these patients include spinal onset, predominant lower motor neurons presentation, and absence of cognitive involvement. Functional analysis showed that all three SOD1 variants led to increased reactive oxygen species (ROS) levels, reduced cell viability, and formation of cytoplasmic aggregates. Remarkably, the decreased cell viability induced by variants was rescued after treatment with the ROS inhibitor N-acetylcysteine.

CONCLUSIONS

This study identified three SOD1 variants in three families with FALS. The variant SOD1 toxicity was associated with oxidative damage and aggregation, and N-acetylcysteine could rescue the decreased cell viability induced by these variants. Our findings support a pathogenic role for ROS in SOD1 deficiencies, and provide a potential drug N-acetylcysteine for ALS therapy, especially in SOD1-patients with limb onset.

[The effect of Helicobacter pylori infection on duodenal bulbar microbiota in children with duodenal ulcer]

Objective: To investigate the characteristics of duodenal bulbar microbiota in children with duodenal ulcer and Helicobacter pylori (Hp) infection. Methods: This prospective cohort study enrolled 23 children with duodenal ulcers diagnosed by gastroscopy who were admitted to the Children's Hospital of Zhejiang University School of Medicine due to abdominal pain, abdominal distension, and vomiting from January 2018 to August 2018. They were divided into Hp-positive and Hp-negative groups according to the presence or absence of Hp infection. Duodenal bulbar mucosa was sampled to detect the bacterial DNA by high-throughput sequencing. The statistical difference in α diversity and β diversity, and the relative abundance in taxonomic level between the two groups were compared. Microbial functions were predicted using the software PICRUSt. T-test, Rank sum test or χ² test were used for comparison between the two groups. Results: A total of 23 children diagnosed with duodenal ulcer were enrolled in this study, including 15 cases with Hp infection ((11.2±3.3) years of age, 11 males and 4 females) and 8 cases without Hp infection ((10.1±4.4) years of age, 6 males and 2 females). Compared with Hp-negative group, the Hp-positive group had higher Helicobacter abundance (0.551% (0.258%, 5.368%) vs. 0.143% (0.039%, 0.762%), Z=2.00, P=0.045) and lower abundance of Fusobacterium, Streptococcus and unclassified- Comamonadaceae (0.010% (0.001%, 0.031%) vs. 0.049% (0.011%, 0.310%), Z=-2.24, P=0.025; 0.031% (0.015%, 0.092%) vs. 0.118% (0.046%, 0.410%), Z=-2.10, P=0.036; 0.046% (0.036%, 0.062%) vs. 0.110% (0.045%, 0.176%), Z=-2.01, P=0.045). Linear discriminant analysis (LDA) effect sized showed that at the genus level, only Helicobacter was significantly enriched in Hp-positive group (LDA=4.89, P=0.045), while Streptococcus and Fusobacterium significantly enriched in Hp-negative group (LDA=3.28, 3.11;P=0.036,0.025, respectively). PICRUSt microbial function prediction showed that the expression of oxidative phosphorylation and disease-related pathways (pathways in cancer, renal cell carcinoma, amoebiasis, type 1 diabetes mellitus) in Hp-positive group were significantly higher than that in Hp-negative group (all P<0.05), while the expression of pathways such as energy metabolism and phosphotransferase system pathways were significantly lower than that in Hp-negative group (all P<0.05). Conclusion: In children with Hp-infected duodenal ulcers, the mucosal microbiota of the duodenal bulb is altered, characterized by an increased abundance of Helicobacter and a decreased abundance of Clostridium and Streptococcus, and possibly alters the biological function of the commensal microbiota through specific metabolic pathways.

Introduce a rotational robust optimization framework for spot-scanning proton arc (SPArc) therapy

Objective. Proton dosimetric uncertainties resulting from the patient's daily setup errors in rotational directions exist even with advanced image-guided radiotherapy techniques. Thus, we developed a new rotational robust optimization SPArc algorithm (SPArc_rot) to mitigate the dosimetric impact of the rotational setup error in Raystation ver. 6.02 (RaySearch Laboratory AB, Stockholm, Sweden).Approach.The initial planning CT was rotated ±5° simulating the worst-case setup error in the roll direction. The SPArc_rotuses a multi-CT robust optimization framework by taking into account of such rotational setup errors. Five cases representing different disease sites were evaluated. Both SPArc_originaland SPArc_rotplans were generated using the same translational robust optimized parameters. To quantitatively investigate the mitigation effect from the rotational setup errors, all plans were recalculated using a series of pseudo-CT with rotational setup error (±1°/±2°/±3°/±5°). Dosimetric metrics such as D98% of CTV, and 3D gamma analysis were used to assess the dose distribution changes in the target and OARs.Main results.The magnitudes of dosimetric changes in the targets due to rotational setup error were significantly reduced by the SPArc_rotcompared to SPArc in all cases. The uncertainties of the max dose to the OARs, such as brainstem, spinal cord and esophagus were significantly reduced using SPArc_rot. The uncertainties of the mean dose to the OARs such as liver and oral cavity, parotid were comparable between the two planning techniques. The gamma passing rate (3%/3 mm) was significantly improved for CTV of all tumor sites through SPArc_rot.Significance.Rotational setup error is one of the major issues which could lead to significant dose perturbations. SPArc_rotplanning approach can consider such rotational error from patient setup or gantry rotation error by effectively mitigating the dose uncertainties to the target and in the adjunct series OARs.

[The value of CMR high-risk attributes in predicting ventricular remodeling in ST-segment-elevation myocardial infarction patients with mildly reduced or preserved ejection fraction]

Objective: To evaluate the predictive value of a multiparametric cardiac magnetic resonance (CMR) approach for ventricular remodeling in ST-segment-elevation myocardial infarction (STEMI) patients with mildly reduced or preserved left ventricular ejection fraction (LVEF). Methods: This study is a prospective cohort study. STEMI patients with acute LVEF>40% after primary percutaneous coronary intervention (PCI) in Beijing Anzhen Hospital from October 2019 to September 2021 were enrolled. All patients received acute (3-7 days) and follow-up (3 months) CMR post-PCI. According to absence or presence of ventricular remodeling, patients were divided into ventricular remodeling group and non-ventricular remodeling group. Basic clinical characteristics and CMR indicators were analyzed and compared between the two groups. Logistic regression and receiver operating characteristic (ROC) curves were used to explore the predictive performance of CMR high-risk attributes for ventricular remodeling in STEMI patients with mildly reduced or preserved LVEF. The predictive value of combining multiple high-risk characteristics of CMR for ventricular remodeling was analyzed and compared with the traditional clinical risk factor model. Results: A total of 123 STEMI patients were enrolled (aged (57.1±11.1) years, 102 (82.9%) males). There were 97 cases (78.9%) patients in the non-ventricular remodeling group and 26 cases (21.1%) in the ventricular remodeling group. After adjustment for clinical risk factors, stroke volume<51.6 ml, global circumferential strain>-13.7%, infarct size>39.2%, microvascular obstruction>0.5%, and myocardial salvage index<43.9 were independently associated with ventricular remodeling in STEMI patients with mildly reduced or preserved LVEF. The incidence of ventricular remodeling increased with the increasing number of CMR high-risk attributes (P<0.01). The number of CMR high-risk attributes ≥3 was an independent predictor of adverse remodeling (adjusted OR=5.95, 95 CI%: 2.25-15.72, P<0.01) in STEMI patients with mildly reduced or preserved LVEF. Furthermore, the number of CMR high-risk attributes had incremental predictive value over baseline clinical risk factors (area under curve: 0.843 vs. 0.696, P<0.01). Conclusions: In STEMI patients with mild reduced or preserved LVEF, 5 CMR characteristics are associated with ventricular remodeling. The combination of ≥3 CMR high-risk characteristics is an independent predictor of ventricular remodeling, which has incremental predictive value beyond traditional risk factors in this patient cohort.

Convergent evolution in the supercoiling of prokaryotic flagellar filaments

The supercoiling of bacterial and archaeal flagellar filaments is required for motility. Archaeal flagellar filaments have no homology to their bacterial counterparts and are instead homologs of bacterial type IV pili. How these prokaryotic flagellar filaments, each composed of thousands of copies of identical subunits, can form stable supercoils under torsional stress is a fascinating puzzle for which structural insights have been elusive. Advances in cryoelectron microscopy (cryo-EM) make it now possible to directly visualize the basis for supercoiling, and here, we show the atomic structures of supercoiled bacterial and archaeal flagellar filaments. For the bacterial flagellar filament, we identify 11 distinct protofilament conformations with three broad classes of inter-protomer interface. For the archaeal flagellar filament, 10 protofilaments form a supercoil geometry supported by 10 distinct conformations, with one inter-protomer discontinuity creating a seam inside of the curve. Our results suggest that convergent evolution has yielded stable superhelical geometries that enable microbial locomotion.

Development of Risk Prediction Model for Muscular Calf Vein Thrombosis with Acute Exacerbation of Chronic Obstructive Pulmonary Disease

Purpose

This study aims to establish a risk prediction model for muscular calf vein thrombosis (MCVT) in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD).

Methods

The research sample consisted of 248 patients with AECOPD and all of them underwent vascular ultrasounds of both lower limbs in this retrospective study. Univariate analysis and multivariate logistic regression analysis were conducted on factors with significant group differences to screen for the independent risk factors of MCVT. A nomogram to predict the risk of MCVT was constructed and validated with bootstrap resampling.

Results

According to the exclusion criteria, 240 patients were included for analysis, divided into the MCVT group (n = 81) and the non-MCVT group (n = 159). Multivariate logistic regression analyses showed that hypertension, elevated MPV, reduced albumin (ALB), elevated D-dimer and bed rest ≥3 days were independent risk factors for MCVT in AECOPD. A nomogram model for predicting AECOPD with MCVT was established based on them. The area under the curve (AUC) of receiver operating characteristic (ROC) curve for the prediction model and the simplified Wells score was 0.784 (95% CI: 0.722–0.847) and 0.659 (95% CI: 0.583–0.735), respectively. The cut-off value and Youden index of prediction model were 0.248 and 0.454, respectively. At the same time, the sensitivity, specificity, positive predictive value, and negative predictive value of the prediction model were 85.9%, 59.5%, 84.6%, and 77.4%, respectively. The sensitivity and specificity of the simplified Wells score were 67.9% and 56.3%, respectively. Validation by the use of bootstrap resampling revealed optimal discrimination and calibration, and the decision analysis curve (DAC) suggested that this prediction model involved high clinical practicability.

Conclusion

We developed a nomogram that can predict the risk of MCVT for AECOPD patients. This model has the potential to assist clinicians in making treatment recommendations and formulating corresponding prevention measures.

Susceptibility weighted MRI pinpoints spontaneous intracerebral hemorrhage in stroke-prone spontaneously hypertensive rats

PURPOSE

To find magnetic resonance imaging (MRI) precursors of spontaneous intracerebral hemorrhage in stroke-prone spontaneously hypertensive rats (SHRSP).

METHOD

SHRSP rats were used with both a low/high salt (n = 18 or 11) Japanese diet and salty drinking water to generate spontaneous intracerebral hemorrhage (ICH). Various MRI sequences, and in particular, susceptibility weighted imaging (SWI), were used and combined with a gadolinium (Gd) contrast agent or oxygen gas to identify the rupture of the blood brain barrier (BBB) and the temporal ICH.

RESULTS

Most rats developed hypertensive ICH stroke in the high salt group during the 10-13 week period compared to only one third of rats in the low salt group during the 14-18 week period. The location of stroke for both the low/high-salt groups was highest in the striatum (58%/43%), followed by the cortex (21%/30%). The edematous enhancement on T2 weighted (T2W) imaging or Gd based T1 weighted (Gd-T1W) imaging due to the ruptured BBB preceded the striatal hemorrhages seen on SWI. The most recent bleeds were observed on temporal SWI or on oxygen-enhanced SWI. The mode of the volume of bleeds was 0.4 mm³. A positive correlation between susceptibility x volume and R2* x volume of the bleeds was observed.

CONCLUSIONS

SHRSP rats with the high salt diet effectively generated a hypertensive hemorrhagic stroke which could be monitored by various MRI sequences. The venous dilation on SWI may precede any abnormality on T2W or Gd-T1W imaging. The edematous enhancement on T2W or Gd-T1W indicated a BBB breakdown that may precede striatal ICH by several days. This suggests the need for immediate treatment to improve outcome if this finding is observed. The use of oxygen with SWI was able to help differentiate old bleeds from very recent bleeds.

miR-3934 regulates the apoptosis and secretion of inflammatory cytokines of basophils via targeting RAGE in asthma

Background

Several miRNAs are now known to have clear connections to the pathogenesis of asthma. The present study focused on the potential role of miR-3934 during asthma development.

Methods

miR-3934 was detected as a down-regulated miRNA in basophils by sequencing analysis. Next, the expression levels of miR-3934 in peripheral blood mononuclear cells of 50 asthma patients and 50 healthy volunteers were examined by RT-qPCR methods. The basophils were then treated with AGEs and transfected with miR-3934 mimics. The apoptosis levels were examined by flow cytometry assay; and the expression levels of cytokines were detected using the ELISA kits. Finally, the Western blot was performed to examined the expression of key molecules in the TGF-β/Smad signaling pathway.

Results

miR-3934 was down-regulated in the basophils of asthmatic patients. The expression of the pro-inflammatory cytokines IL-6, IL-8 and IL-33 was enhanced in basophils from asthmatic patients, and this effect was partially reversed by transfection of miR-3934 mimics. Furthermore, receiver operating characteristics analysis showed that miR-3934 levels can be used to distinguish asthma patients from healthy individuals. miR-3934 partially inhibited advanced glycation end products-induced increases in basophil apoptosis by suppressing expression of RAGE.

Conclusion

Our results indicate that miR-3934 acts to mitigate the pathogenesis of asthma by targeting RAGE and suppressing TGF-β/Smad signaling.

[Bilateral anterior lenticonus: a case report]

A patient complained of ophthalmology with poor vision in both eyes for more than 30 years and aggravation for more than 2 years. The central anterior lens capsule was found to have a conical protrusion under a slit-lamp microscope after pupil dilation in both eyes. The diagnosis was bilateral cataract and congenital anterior lenticonus. Phacoemulsification cataract extraction combined with intraocular lens implantation was performed. The visual acuity in both eyes was significantly better after surgery.

P-447 Enhancing oxygen availability in the dynamic culture of bovine ovarian cortical tissue improves the yield of secondary follicles

Study question

Does enhancing oxygen availability during dynamic in vitro culture of bovine ovarian cortical tissue (BOCT) improve follicle growth and health?

Summary answer

Enhancing oxygen availability during dynamic in vitro culture of BOCT in perifusion bioreactors (PB) does improve follicle health and yield to secondary follicles

What is known already

Oxygen availability has been demonstrated to represent a key factor in follicle health and growth during in vitro culture of bovine and human ovarian cortical tissue (HOCT) under static culture conditions. Disruption of solutes gradients and application of physiological fluid mechanical stress, through in vitro dynamic culture of HOCT in a newly designed perifusion bioreactor have been shown to further enhance follicle growth and health. As it shows striking similarities with human, bovine folliculogenesis is considered a valuable model to study follicle growth in vitro

Study design, size, duration

Bovine ovaries from animals aged 8-24 months were collected at slaughterhouse. In each experiment (n = 3), BOCT strips from the same ovary were cultured for 6 days in perifusion bioreactors (PB, dynamic culture) and conventional dishes (CD, static culture). Culture outcome in static culture was analysed and compared to two bioreactor configurations in which medium oxygenation was kept low by using a standard tube reservoir (StPB) or was enhanced by using a gas-permeable dish reservoir (PB+O2).

Participants/materials, setting, methods

Slices of BOCT 0.5mm thick were cut with a tissue slicer and chopped into 1x1mm strips. In each experiment, fresh (D0) and cultured tissue (groups of ten strips) were analyzed. Follicle stages and health were assessed by histology (hematoxylin-eosin staining). Follicle viability was estimated by labelling with live-dead far-red and propidium iodide followed by clearing before analysis at the confocal laser scanning microscope.

Main results and the role of chance

Overall, 2417 follicles were analyzed (histology, 1476; viability, 941). At day 0 most follicles were primordial (primordial, 88.7%; primary, 10.6%; secondary, 0.7%), and had good quality (grade 1-2, 92.2%; grade 3, 7.8%), and high viability (91.8%). At day 6, follicle growth and health in StPB was superior than in CD (StPB vs CD - staging: primordial, 6.8 vs 16.3, P &lt; 0.01; primary, 70.7 vs 74.1, NS; secondary, 22.5 vs 9.6%, P &lt; 0.01; grading: grade 1 + 2, 71.4 vs 44.8, P &lt; 0.01; grade 3, 28.6 vs 55.2%, P &lt; 0.01). Dynamic culture in StPB better-preserved follicle viability compared to static culture in CD (StPB vs CD: 77.75 vs 64.9%, P &lt; 0.01). Enhancing oxygen availability during dynamic culture increased follicle progression and viability (PB+O2 vs StPB - staging: primordial, 5.1 vs 6.8, NS; primary, 65.4 vs 70.7, NS; secondary, 29.5 vs 22.5%, P &lt; 0.05; viability - 92 vs 77.75, P &lt; 0.01). Overall, the obtained results demonstrate that i) disruption of stagnant layers of medium and application of shear stress to BOCT through dynamic culture improves follicle activation, growth and health; ii) enhancing oxygen availability by means of a gas-permeable medium reservoir further increases follicle progression and viability.

Limitations, reasons for caution

Although the bovine is considered a reliable model for human folliculogenesis, the study should be validated on human ovarian tissue.

Wider implications of the findings

A limiting step in the in vitro production of mature oocytes starting from primordial follicles is the low yield of secondary follicles after organ culture. The adoption of a newly designed dynamic bioreactor and modulation of oxygen availability could represent a valuable tool for multistep in vitro folliculogenesis.

Trial registration number

none

Unnecessary caesarean section delivery in rural China: exploration of relationships with full-term gestational age and early childhood development

INTRODUCTION

Gestational age at delivery is reportedly associated with cognitive and non-cognitive development in early childhood. Delivery at an earlier full-term gestational age has been associated with an increased rate of caesarean section (C-section) delivery; the high rate of C-section delivery in China implies that the rate of medically unnecessary C-section delivery is also high. This study investigated the relationships of medically unnecessary C-section delivery with full-term gestational age and early childhood development in rural China.

METHODS

We conducted a survey of 2765 children (aged 5-24 months) who resided in 22 national designated poverty counties. Primary caregivers were interviewed to collect information regarding child and household characteristics (including the child's gestational age), each child's delivery method, and reasons for C-section delivery (if applicable). The children were assessed using the Bayley Scales of Infant Development. Developmental outcomes were compared among gestational age-groups; regression analyses were used to assess relationships among medically unnecessary C-section delivery, gestational age, and developmental outcomes.

RESULTS

Overall, 56.2% of children were born at ≤39 weeks of gestation. Among C-section deliveries, 13.1% were medically necessary and >40% could clearly be classified as medically unnecessary. Repeat C-section was the most common reason given for medically unnecessary C-section delivery. For each 1-week increase in full-term gestational age, cognition scale scores increased by 0.62 points (P<0.01), language scale scores increased by 0.84 points (P<0.01), and motor scale scores increased by 0.55 points (P<0.05). Medically unnecessary Csection delivery was significantly associated with lower full-term gestational age.

CONCLUSION

Higher full-term gestational age was significantly associated with better childhood developmental outcomes, indicating that medically unnecessary C-section delivery may negatively influence early childhood development.

POS0218 DECREASED miR-122-5p IN NEUTROPHIL-DERIVED EXOSOMES ATTENUATED IMMUNOREGULATORY FUNCTION ON MACROPHAGES BY TARGETING IRF5 EXPRESSION IN BEHCET’S DISEASE

Background

Behçet’s disease (BD) is a chronic systemic vasculitis characterized by the overactivation of neutrophils and macrophages. Exosomes are membrane-derived vesicles that mediate intercellular communications and neutrophil-derived exosomes account for the major portion of serum exosomes in BD. However, the role of neutrophil-derived exosomes in BD remains unknown.

Objectives

1) To investigate the production of exosomes by BD neutrophils; 2) To elucidate the regulation of macrophage by BD neutrophil-derived exosomes; 3) To explore the mechanism of immunoregulatory functions of BD neutrophil-derived exosomes.

Methods

BD and healthy control (HC) neutrophil-derived exosomes were extracted and quantified. Human monocyte-derived macrophages (HMDM) were stimulated with BD and HC neutrophil-derived exosomes, and TNF-α and IL-6 production were examined. Differently expressed miRNAs in BD neutrophil-derived exosomes were analyzed using miRNA sequencing. LPS-induced HMDM were treated with miRNA mimics or inhibitors, and TNF-α and IL-6 production were detected. miRNA was overexpressed in macrophages, and RNA sequencing was performed to analyze regulating pathways. Dual-luciferase assays were performed to confirm miRNA-mRNA interaction.

Results

BD neutrophils produced a significantly lower level of exosomes than HC ones. Both BD and HC neutrophil-derived exosomes suppressed TNF-α and IL-6 production by macrophages, but to a lesser extent by BD neutrophil-derived exosomes. Six downregulated miRNAs were presented in BD neutrophil-derived exosomes, including miR-122-5p. miR-122-5p mimics inhibited IL-6 and TNF-α production while miR-122-5p inhibitor promoted IL-6 and TNF-α production by HMDMs. Overexpression of miR-122-5p attenuated TLR4 and IFN-β signaling. miR-122-5p directly targeted 3’UTR of IRF5, the TF regulating TLR4 pathway and autocrine of IFN-β, and downregulated IRF5 expression confirmed by dual luciferase assay. Knocking down IRF5 dampened IL-6 and TNF-α production in HMDMs.

Figure 1.

(A) Decreased production of BD neutrophil-derived exosomes. (B) Reduced suppression of macrophage activation by BD neutrophil-derived exosomes. (C) Differentially expressed miRNAs (downregulated) in BD neutrophil-derived exosomes. (D) miR-122-5p suppressed TLR4 and JAK-STAT signaling in HMDM. (E) miR-122-5p inhibited activation of HMDM. (F) miR-122-5p inhibited IRF5 expression in HMDM.

Conclusion

Our findings suggested the reduced production and immunoregulatory function of BD neutrophil-derived exosomes, mediated by lower levels of miR-122-5p in neutrophil-derived exosomes. Impaired BD neutrophil-derived exosomes might be implicated in the overactivation of macrophages in BD.

References

[1]Kolonics, Ferenc et al. Cells vol. 9,12 2718. 18 Dec. 2020,

Disclosure of Interests

None declared

Redefine the Role of Spot-Scanning Proton Beam Therapy for the Single Brain Metastasis Stereotactic Radiosurgery

Purpose

To explore the role of using Pencil Beam Scanning (PBS) proton beam therapy in single lesion brain stereotactic radiosurgery (SRS), we developed and validated a dosimetric in silico model to assist in the selection of an optimal treatment approach among the conventional Volumetric Modulated Arc Therapy (VMAT), Intensity Modulated Proton Therapy (IMPT) and Spot-scanning Proton Arc (SPArc).

Material and Methods

A patient’s head CT data set was used as an in silico model. A series of targets (volume range from 0.3 cc to 33.03 cc) were inserted in the deep central and peripheral region, simulating targets with different sizes and locations. Three planning groups: IMPT, VMAT, and SPArc were created for dosimetric comparison purposes and a decision tree was built based on this in silico model. Nine patients with single brain metastases were retrospectively selected for validation. Multiple dosimetric metrics were analyzed to assess the plan quality, such as dose Conformity Index (CI) (ratio of the target volume to 100% prescription isodose volume); R50 (ratio of 50% prescription isodose volume to the target volume); V_12Gy (volume of brain tissue minus GTV receiving 12 Gy), and mean dose of the normal brain. Normal tissue complication probability (NTCP) of brain radionecrosis (RN) was calculated using the Lyman-Kutcher-Burman (LKB) model and total treatment delivery time was calculated. Six physicians from different institutions participated in the blind survey to evaluate the plan quality and rank their choices.

Results

The study showed that SPArc has a dosimetric advantage in the V_12Gy and R50 with target volumes > 9.00 cc compared to VMAT and IMPT. A significant clinical benefit can be found in deep centrally located lesions larger than 20.00 cc using SPArc because of the superior dose conformity and mean dose reduction in healthy brain tissue. Nine retrospective clinical cases and the blind survey showed good agreement with the in silico dosimetric model and decision tree. Additionally, SPArc significantly reduced the treatment delivery time compared to VMAT (SPArc 184.46 ± 59.51s vs. VMAT: 1574.78 ± 213.65s).

Conclusion

The study demonstrated the feasibility of using Proton beam therapy for single brain metastasis patients utilizing the SPArc technique. At the current stage of technological development, VMAT remains the current standard modality of choice for single lesion brain SRS. The in silico dosimetric model and decision tree presented here could be used as a practical clinical decision tool to assist the selection of the optimal treatment modality among VMAT, IMPT, and SPArc in centers that have both photon and proton capabilities.

Developing an accurate model of spot-scanning treatment delivery time and sequence for a compact superconducting synchrocyclotron proton therapy system

BACKGROUND

A new compact superconducting synchrocyclotron single-room proton solution delivers pulsed proton beams to each spot through several irradiation bursts calculated by an iterative layer delivery algorithm. Such a mechanism results in a new beam parameter, burst switching time (BST) in the total beam delivery time (BDT) which has never been studied before. In this study, we propose an experimental approach to build an accurate BDT and sequence prediction model for this new proton solution.

METHODS

Test fields and clinical treatment plans were used to investigate each beam delivery parameter that impacted BDT. The machine delivery log files were retrospectively analyzed to quantitatively model energy layer switching time (ELST), spot switching time (SSWT), spot spill time (SSPT), and BST. A total of 102 clinical IMPT treatment fields' log files were processed to validate the accuracy of the BDT prediction model in comparison with the result from the current commercial system. Interplay effect is also investigated as a clinical application by comparing this new delivery system model with a conventional cyclotron accelerator model.

RESULTS

The study finds that BST depends on the amount of data to be transmitted between two sequential radiation bursts, including a machine irradiation log file of the previous burst and a command file to instruct the proton system to deliver the next burst. The 102 clinical treatment fields showed that the accuracy of each component of the BDT matches well between machine log files and BDT prediction model. More specifically, the difference of ELST, SSWT, SSPT, and BST were (- 3.1 ± 5.7)%, (5.9 ± 3.9)%, (2.6 ± 8.7)%, and (- 2.3 ± 5.3)%, respectively. The average total BDT was about (2.1 ± 3.0)% difference compared to the treatment log files, which was significantly improved from the current commercial proton system prediction (58 ± 15)%. Compared to the conventional cyclotron system, the burst technique from synchrocyclotron effectively reduced the interplay effect in mobile tumor treatment.

CONCLUSION

An accurate BDT and sequence prediction model was established for this new clinical compact superconducting synchrocyclotron single-room proton solution. Its application could help users of similar facilities better assess the interplay effect and estimate daily patient treatment throughput.

Lattice dynamics of BaFe2Se3

This paper presents a study of the lattice dynamics in BaFe₂Se₃. We combined first-principle calculations, infrared measurements and a thorough symmetry analysis. Our study confirms thatPnmacannot be the space group of BaFe₂Se₃, even at room temperature. The phonons assignment requiresPmto be the BaFe₂Se₃space group, not only in the magnetic phase, but also in the paramagnetic phase at room temperature. This is due to a strong coupling between a short-range spin-order along the ladders, and the lattice degrees of freedom associated with the Fe-Fe bond length. This coupling induces a change in the bond-length pattern from an alternated trapezoidal one (as inPnma) to an alternated small/large rectangular one. Out of the two patterns, only the latter is fully compatible with the observed block-type magnetic structure. Finally, we propose a complete symmetry analysis of the BaFe₂Se₃phase diagram in the 0-600 K range.

Assessing the Accuracy of Estimated Lipoprotein(a) Cholesterol and Lipoprotein(a)-Free Low-Density Lipoprotein Cholesterol

Background

Accurate measurement of the cholesterol within lipoprotein(a) (Lp[a]‐C) and its contribution to low‐density lipoprotein cholesterol (LDL‐C) has important implications for risk assessment, diagnosis, and treatment of atherosclerotic cardiovascular disease, as well as in familial hypercholesterolemia. A method for estimating Lp(a)‐C from particle number using fixed conversion factors has been proposed (Lp[a]‐C from particle number divided by 2.4 for Lp(a) mass, multiplied by 30% for Lp[a]‐C). The accuracy of this method, which theoretically can isolate “Lp(a)‐free LDL‐C,” has not been validated.

Methods and Results

In 177 875 patients from the VLDbL (Very Large Database of Lipids), we compared estimated Lp(a)‐C and Lp(a)‐free LDL‐C with measured values and quantified absolute and percent error. We compared findings with an analogous data set from the Mayo Clinic Laboratory. Error in estimated Lp(a)‐C and Lp(a)‐free LDL‐C increased with higher Lp(a)‐C values. Median error for estimated Lp(a)‐C <10 mg/dL was −1.9 mg/dL (interquartile range, −4.0 to 0.2); this error increased linearly, overestimating by +30.8 mg/dL (interquartile range, 26.1–36.5) for estimated Lp(a)‐C ≥50 mg/dL. This error relationship persisted after stratification by overall high‐density lipoprotein cholesterol and high‐density lipoprotein cholesterol subtypes. Similar findings were observed in the Mayo cohort. Absolute error for Lp(a)‐free LDL‐C was +2.4 (interquartile range, −0.6 to 5.3) for Lp(a)‐C<10 mg/dL and −31.8 (interquartile range, −37.8 to −26.5) mg/dL for Lp(a)‐C≥50 mg/dL.

Conclusions

Lp(a)‐C estimations using fixed conversion factors overestimated Lp(a)‐C and subsequently underestimated Lp(a)‐free LDL‐C, especially at clinically relevant Lp(a) values. Application of inaccurate Lp(a)‐C estimations to correct LDL‐C may lead to undertreatment of high‐risk patients.

A WC/WO star exploding within an expanding carbon-oxygen-neon nebula

The final fate of massive stars, and the nature of the compact remnants they leave behind (black holes and neutron stars), are open questions in astrophysics. Many massive stars are stripped of their outer hydrogen envelopes as they evolve. Such Wolf-Rayet stars¹ emit strong and rapidly expanding winds with speeds greater than 1,000 kilometres per second. A fraction of this population is also helium-depleted, with spectra dominated by highly ionized emission lines of carbon and oxygen (types WC/WO). Evidence indicates that the most commonly observed supernova explosions that lack hydrogen and helium (types Ib/Ic) cannot result from massive WC/WO stars^2,3, leading some to suggest that most such stars collapse directly into black holes without a visible supernova explosion⁴. Here we report observations of SN 2019hgp, beginning about a day after the explosion. Its short rise time and rapid decline place it among an emerging population of rapidly evolving transients^5-8. Spectroscopy reveals a rich set of emission lines indicating that the explosion occurred within a nebula composed of carbon, oxygen and neon. Narrow absorption features show that this material is expanding at high velocities (greater than 1,500 kilometres per second), requiring a compact progenitor. Our observations are consistent with an explosion of a massive WC/WO star, and suggest that massive Wolf-Rayet stars may be the progenitors of some rapidly evolving transients.

Utilizing phenotypic characteristics of metastatic brain tumors to improve the probability of detecting circulating tumor DNA from cerebrospinal fluid in non-small-cell lung cancer patients: development and validation of a prediction model in a prospective cohort study

Background

Circulating tumor DNA (ctDNA) in cerebrospinal fluid (CSF) has become a promising surrogate for genomic profiling of central nervous system tumors. However, suboptimal ctDNA detection rates from CSF limit its clinical utility. Thus precise screening of suitable patients is needed to maximize the clinical benefit.

Patients and methods

Between February 2017 and December 2020, 66 newly diagnosed non-small-cell lung cancer (NSCLC) patients with brain parenchymal metastases were prospectively enrolled as a training cohort and 30 additional patients were enrolled as an external validation cohort. CSF samples and matched primary tumor tissues were collected before treatment and subjected to next-generation sequencing (NGS). The imageological characteristics of patients’ brain tumors were evaluated by radiologists using enhanced magnetic resonance imaging images. The clinical and imageological characteristics were evaluated by complete subsets regression, Akaike information criteria, and Bayesian information criteria methods to establish the prediction model. A nomogram was then built for CSF ctDNA detection prediction.

Results

The somatic mutation detection rate of genes covered by our targeted NGS panel was significantly lower in CSF ctDNA (59.09%) than tumor tissue (91.84%). The T_size (diameter of the largest intracranial lesion) and LVD_min (minimum lesion–ventricle distance for all intracranial lesions) were significantly associated with positive CSF ctDNA detection, and thus, were selected to establish the prediction model, which achieved an area under the ROC curve (AUC) of 0.819 and an accuracy of 0.800. The model’s predictive ability was further validated in the independent external cohort (AUC of 0.772, accuracy of 0.767) and by internal cross-validation. The CSF ctDNA detection rate was significantly improved from 58.18% (32/55) to 81.81% (27/33) in patients after model selection (P = 0.022).

Conclusions

This study developed a regression model to predict the probability of detecting CSF ctDNA using the phenotypic characteristics of metastatic brain lesions in NSCLC patients, thus, maximizing the benefits of CSF liquid biopsies.

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Intracranial tumor size and distance to nearest ventricle were significantly correlated with positive CSF ctDNA detection.

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A prediction model incorporating T_size and LVD_min was developed and validated to evaluate the odds of CSF ctDNA positivity.

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The CSF ctDNA detection rate was significantly improved in patients after model selection.