Differential degradation of petroleum hydrocarbons by Shewanella putrefaciens under aerobic and anaerobic conditions

The complexity of crude oil composition, combined with the fluctuating oxygen level in contaminated environments, poses challenges for the bioremediation of oil pollutants, because of compound-specific microbial degradation of petroleum hydrocarbons under certain conditions. As a result, facultative bacteria capable of breaking down petroleum hydrocarbons under both aerobic and anaerobic conditions are presumably effective, however, this hypothesis has not been directly tested. In the current investigation, Shewanella putrefaciens CN32, a facultative anaerobic bacterium, was used to degrade petroleum hydrocarbons aerobically (using O2 as an electron acceptor) and anaerobically (using Fe(III) as an electron acceptor). Under aerobic conditions, CN32 degraded more saturates (65.65 ± 0.01%) than aromatics (43.86 ± 0.03%), with the following order of degradation: dibenzofurans > n-alkanes > biphenyls > fluorenes > naphthalenes > alkylcyclohexanes > dibenzothiophenes > phenanthrenes. In contrast, under anaerobic conditions, CN32 exhibited a higher degradation of aromatics (53.94 ± 0.02%) than saturates (23.36 ± 0.01%), with the following order of degradation: dibenzofurans > fluorenes > biphenyls > naphthalenes > dibenzothiophenes > phenanthrenes > n-alkanes > alkylcyclohexanes. The upregulation of 4-hydroxy-3-polyprenylbenzoate decarboxylase (ubiD), which plays a crucial role in breaking down resistant aromatic compounds, was correlated with the anaerobic degradation of aromatics. At the molecular level, CN32 exhibited a higher efficiency in degrading n-alkanes with low and high carbon numbers relative to those with medium carbon chain lengths. In addition, the degradation of polycyclic aromatic hydrocarbons (PAHs) under both aerobic and anaerobic conditions became increasingly difficult with increased numbers of benzene rings and methyl groups. This study offers a potential solution for the development of targeted remediation of pollutants under oscillating redox conditions.

Dose-related effects of early-life intake of sn-2 palmitate, a specific positionally distributed human milk fatty acid, on the composition and metabolism of the intestinal microbiota

sn2 Palmitate in human milk plays an important role in the physiological health of infants by reducing mineral loss, improving stool hardness, and relieving constipation. Also, sn-2 palmitate modulates intestinal microbiota. However, it remains unclear whether the effects of sn-2 palmitate on infant gut microbiota are dose-dependent. In this study, we investigated the effects of low, medium, and high doses (600, 1,800, and 5,400 mg/kg body weight, respectively) of sn-2 palmitate on the structure, composition, and metabolic function of intestinal microbes in mice. Our results showed that high doses of sn-2 palmitate significantly modulated α- and β-diversity of the intestinal microbiota. The relative abundance of Lachnospiraceae_NK4A136_group decreased with increasing doses of sn-2 palmitate. In contrast, the abundances of Bacteroidetes phylum, Bacteroides, uncultured_Lachnospiraceae, and uncultured_Muribaculaceae were positively correlated with sn-2 palmitate doses. The number of genes predicted encoding autophagy-yeast, phospholipase D signaling pathway, and pentose and glucuronate interconversion metabolic functions of intestinal microbiota increased with increasing doses of sn-2 palmitate. In addition, low and medium doses of sn-2 palmitate significantly upregulated the arginine and proline metabolic pathways, and high doses of sn-2 palmitate significantly increased purine metabolism. Our results revealed that the effects of sn-2 palmitate intake early in life on the composition and metabolism of the intestinal microbiota of mice showed dose-related differences. The study is expected to provide a scientific basis for the development of infant formulas.

Deep Learning-Based Multi-Modality Segmentation of Primary Gross Tumor Volume in CT and MRI for Nasopharyngeal Carcinoma

PURPOSE/OBJECTIVE(S)

The delineation of primary gross tumor volume (GTV) of nasopharyngeal carcinoma (NPC) is an essential step for radiotherapy planning. In clinical practice, radiation oncologists manually delineate the GTV in planning CT with the help of diagnostic MRI. This is because NPC tumors are closely adjacent to many important anatomic structures, and CT and MRI provide complementary strength to accurately determine the tumor extension boundary. Manual delineation is time-consuming with the potential registration errors between MRI and CT decreasing the delineation accuracy. In this study, we propose a fully automated GTV segmentation method based on CT and MRI by first aligning MRI to CT, and then, segmenting the GTV using a multi-modality deep learning model.

MATERIALS/METHODS

We collected 104 nasopharyngeal carcinoma patients with both planning CT and diagnostic MRI scans (T1 & T2 phases). An experienced radiation oncologists manually delineated the GTV, which was further examined by another senior radiation oncologist. Then, a coarse to fine cross-modality registration from MRI to CT was conducted as follows: (1) A rigid transformation was performed on MRI to roughly align MRI to CT with similar anatomic position. (2) Then, the region of interest (RoI) on both CT and rigid-transformed MRI were cropped. (3) A leading cross-modality deformable registration algorithm, named DEEDS, was applied on the cropped MRI and CT RoIs to find an accurate local alignment. Next, using CT and registered MRI as the combined input, a multi-modality deep segmentation network based on nnUNet was trained to generate the GTV prediction. 20% patients were randomly selected as the unseen testing set to quantitatively evaluate the performance.

RESULTS

The quantitative NPC GTV segmentation performance is summarized in Table 1. The deep segmentation model using CT alone achieved reasonable high performance with 76.6% Dice score and 1.34mm average surface distance (ASD). When both CT and registered MRI were used, the segmentation model further improved the performance by 0.9% Dice score increase and 11% relative ASD error reduction, demonstrating the complementary strength of CT and MRI in determining NPC GTV. Notably, the achieved 77.5% Dice score and 1.19mm ASD by the multimodality model is among the top performing results reported in recent automatic NPC GTV segmentation using either CT or MRI modality.

CONCLUSION

We developed a fully automated multi-modal deep-learning model for NPC GTV segmentation. The developed model can segment the NPC GTV in high accuracy. With further optimization and validation, this automated model has potential to standardize the NPC GTV segmentation and significantly decrease the workload of radiation oncologists in clinical practice.

Deep Learning for Automatic Prediction of Lymph Node Station Metastasis in Esophageal Cancer Patients from Contrast-Enhanced CT

PURPOSE/OBJECTIVE(S)

The diagnosis of lymph node (LN) metastasis in computed tomography (CT) is an essential yet challenging task in esophageal cancer staging and treatment planning. Although criteria (e.g., RECIST, morphological/texture features) are proposed to predict LN metastasis, the diagnostic accuracy remains low with sensitivity <50% and specificity <75%, as reported in previous studies. Deep learning (DL) has the potential to address this issue by learning from large-scale labeled data. However, due to the practical surgery procedure in lymph node dissection, it is difficult to pair the metastasis of individual LN reported in the pathology report to the LN instance found in the CT image. Hence, in this study, we first use pathology reports to determine the LNS metastasis, then develop a multiple instance deep learning (MIDL) model to predict lymph node station (LNS) metastasis.

MATERIALS/METHODS

We collected 1200 esophageal cancer patients with preoperative contrast-enhanced CT before surgery. A recently developed automatic mediastinal LNS segmentation model was first applied to segment LNS of 1 to 8 based on the IASLC protocol. For each LNS, the local CT region of interest (ROI) was cropped to generate a station-wise CT patch, where the LNS was labeled as metastatic if at least one metastatic LN was indicated in the pathology report. Using the station-wise CT patch and LNS label, we train a 3D MIDL model, MobileNetV3, to predict LNS metastasis. To better provide the LN position priors in MIDL, LN instances (with a short axis >4mm) were also segmented using an automatic LN detection algorithm and were added to the MIDL model as an auxiliary input. Five-fold cross-validation was conducted to evaluate the MIDL performance.

RESULTS

The MIDL model's performance is summarized in Table 1. The MIDL model incorporating an additional LN instance mask demonstrated a superior overall AUC of 0.7539, surpassing the model without the LN mask input by 2.93%. The specificity was evaluated at a threshold resulting in a recall of 0.7, and the best model outperformed the CT input model in terms of specificity by 2.11%. This highlights the value of including the LN position prior to the MIDL model. Notably, when a threshold was set to result in a specificity of 75%, the best MIDL model demonstrated a significantly higher recall compared to the previously reported clinical diagnostic recall (39.7% vs. 63.21%).

CONCLUSION

We developed a MIDL classification model to predict LNS metastasis using CT scans of 1200 patients. Our findings suggest that the MIDL model can substantially improve LNS metastasis prediction and has the potential to play an essential role in cancer staging, treatment planning, and prognostic analysis.

Mineral-Bound Trace Metals as Cofactors for Anaerobic Biological Nitrogen Fixation

Nitrogenase is the only known biological enzyme capable of reducing N₂ to bioavailable NH₃. Most nitrogenases use Mo as a metallocofactor, while alternative cofactors V and Fe are also viable. Both geological and bioinformatic evidence suggest an ancient origin of Mo-based nitrogenase in the Archean, despite the low concentration of dissolved Mo in the Archean oceans. This apparent paradox would be resolvable if mineral-bound Mo were bioavailable for nitrogen fixation by ancient diazotrophs. In this study, the bioavailability of mineral-bound Mo, V, and Fe was determined by incubating an obligately anaerobic diazotroph Clostridium kluyveri with Mo-, V-, and Fe-bearing minerals (molybdenite, cavansite, and ferrihydrite, respectively) and basalt under diazotrophic conditions. The results showed that C. kluyveri utilized mineral-associated metals to express nitrogenase genes and fix nitrogen, as measured by the reverse transcription quantitative polymerase chain reaction and acetylene reduction assay, respectively. C. kluyveri secreted chelating molecules to extract metals from the minerals. As a result of microbial weathering, mineral surface chemistry significantly changed, likely due to surface coating by microbial exudates for metal extraction. These results provide important support for the ancient origin of Mo-based nitrogenase, with profound implications for coevolution of the biosphere and geosphere.

Comparison of higher-order aberrations between implantable collamer lens V4c implantation and simulated spectacle correction in patients with high myopia

PURPOSE

To investigate the differences in higher-order aberrations between non-toric or toric implantable collamer lens (ICL or TICL) V4c implantation and simulated spectacle correction.

METHODS

Patients with high myopia who underwent ICL/TICL V4c implantation were enrolled. The "total no defocus" pattern of iTrace aberrometry to simulate the condition of spectacle correction was measured before ICL/TICL implantation, and higher-order aberrations in this condition were compared to those 3 months after surgery. Related factors with changes in coma were comprehensively analyzed.

RESULTS

A total of 89 right eyes of 89 patients were included. Compared to simulated spectacle correction, total-eye coma (P<0.0001 ICL, P<0.0001 TICL) and internal coma (P<0.0001 ICL, P<0.001 TICL) decreased in the ICL- and TICL-treated groups after surgery. Total-eye secondary astigmatism (P<0.0001 ICL, P=0.007 TICL) and internal secondary astigmatism (P<0.0001 ICL, P=0.009 TICL) were also decreased in both groups postoperatively. Spherical error showed positive correlations with variation in total-eye coma (r=0.37, P=0.004 ICL; r=0.56, P=0.001 TICL) and internal coma (r=0.30, P=0.02 ICL and r=0.45, P=0.01 TICL). Axial length revealed negative correlations with changes in total-eye coma (r=-0.45, P<0.001 ICL; r=-0.39, P=0.03 TICL) and internal coma (r=-0.28, P=0.03 ICL and r=-0.42, P=0.02 TICL).

CONCLUSIONS

Both ICL- and TICL-treated groups demonstrated a decrease in coma and secondary astigmatism after 3 months, postoperatively. ICL/TICL may confer a compensatory effect on coma aberration and secondary astigmatism. Patients with a higher myopia achieved a greater improvement in coma and may benefit more from ICL/TICL implantation than from spectacle correction implantation than from spectacle correction.

Inhibition of Extracellular Enzyme Activity by Reactive Oxygen Species upon Oxygenation of Reduced Iron-Bearing Minerals

The dual roles of minerals in inhibiting and prolonging extracellular enzyme activity in soils and sediments are governed by enzyme adsorption to mineral surfaces. Oxygenation of mineral-bound Fe(II) generates reactive oxygen species (ROS), yet it is unknown whether and how this process alters the activity and functional lifespan of extracellular enzymes. Here, the effect of mineral-bound Fe(II) oxidation on the hydrolytic activity of a cellulose-degrading enzyme β-glucosidase (BG) was studied using two pre-reduced Fe-bearing clay minerals (nontronite and montmorillonite) and one pre-reduced iron oxide (magnetite) at pH 5 and 7. Under anoxic conditions, BG adsorption to mineral surfaces decreased its activity but prolonged its lifespan. Under oxic conditions, ROS was produced, with the amount of •OH, the most abundant ROS, being positively correlated with the extent of structural Fe(II) oxidation in reduced minerals. •OH decreased BG activity and shortened its lifespan via conformational change and structural decomposition of BG. These results suggest that under oxic conditions, the ROS-induced inhibitory role of Fe(II)-bearing minerals outweighed their adsorption-induced protective role in controlling enzyme activity. These results disclose a previously unknown mechanism of extracellular enzyme inactivation, which have pivotal implications for predicting the active enzyme pool in redox-oscillating environments.

Facile fabrication of flexible AuNPs@CDA SERS substrate for enrichment and detection of thiram pesticide in water

Pesticide residues in water is one of the most serious problems in developing countries. Surface enhanced Raman spectroscopy (SERS) is widely used in the detection and monitoring of pesticide and other trace compounds because of its low limits of detection (LODs). However, different SERS substrate synthesis methods have different economic benefits and environmental impacts. In this paper, a flexible AuNPs@CDA SERS substrate was fabricated by the gold nanoparticles (AuNPs) and the biomass-based cellulose diacetate (CDA), which had stable test performance and considerable LODs. The substrates were economically viable and environment friendly. The characterization analysis of the substrate allows us to flexibly select different test methods (drop-test or enrichment-test) as coping strategy in different situation. The results showed that the LODs of thiram pesticide in water by enrichment-test could reach 10^-7 g/mL, and had a good linear relationship in the concentration range of 10^-7-10^-6 g/mL. This strategy can realize the rapid and effective detection and monitoring of thiram pesticide in water.

Cr(VI) Reduction by Siderophore Alone and in Combination with Reduced Clay Minerals

Siderophores and iron-containing clays are known to influence the transformation of chromium in the environment. The role of clays in hexavalent chromium [Cr(VI)] reduction has been reported extensively. However, the mechanisms of Cr(VI) reduction by siderophores and their combination with iron-bearing clays are poorly known. Herein, we report the kinetics and products of Cr(VI) reduction by a siderophore alone or in combination with reduced clays. Results showed that Cr(VI) reduction by a tri-hydroxamate siderophore─desferrioxamine B (DFOB)─at a pH of 6 was achieved by one-electron transfer via the formation of Cr(V) intermediate. The formed Cr(V) was further reduced to organically complexed Cr(III). The Cr(VI) reduction rate and extent in the presence of both DFOB and reduced clays unexpectedly decreased relative to that with reduced clays alone, despite both serving as Cr(VI) reductants. The interaction between DFOB and clays (e.g., adsorption/intercalation, dissolution, and/or oxidation) was primarily responsible for Cr(VI) reduction inhibition. The extent of inhibition increased at higher DFOB concentrations in the presence of iron-rich nontronite but decreased in the presence of iron-poor montmorillonite, which may be related to their different Cr(VI) reduction mechanisms. This study highlights the importance of siderophores in chromium transformation and its impact on the reactivity of iron-bearing clays toward heavy metal reduction in the environment.

A critical review of mineral-microbe interaction and coevolution: mechanisms and applications

The mineral-microbe interactions play important roles in environmental change, biogeochemical cycling of elements, and formation of ore deposits. Minerals provide both beneficial (physical and chemical protection, nutrients, and energy) and detrimental (toxic substances and oxidative pressure) effects to microbes, resulting in mineral-specific microbial colonization. Microbes impact dissolution, transformation, and precipitation of minerals through their activity, resulting in either genetically-controlled or metabolism-induced biomineralization. Through these interactions minerals and microbes coevolve through Earth history. The mineral-microbe interactions typically occur at microscopic scale but the effect is often manifested at global scale. Despite advances achieved through decades of research, major questions remain. Four areas are identified for future research: integrating mineral and microbial ecology, establishing mineral biosignatures, linking laboratory mechanistic investigation to field observation, and manipulating mineral-microbe interactions for the benefit of humankind.

DOCK4 regulates ghrelin production in gastric X/A-like cells

PURPOSE

Ghrelin, a gastric hormone, provides a hunger signal to the central nervous system to stimulate food intake. Ghrelin also modulates neuroinflammatory and apoptotic processes. Dedicator of cytokinesis 4 (DOCK4), a guanine nucleotide exchange factor (GEF), is involved in the regulation of neuronal polarization and axon regeneration. However, the effect of DOCK4 on ghrelin production has not been explored.

METHODS

The expression of DOCK4 in human and mouse stomach was examined by immunohistochemical staining. The synthesis and secretion of ghrelin in Dock4 null mice were evaluated by real-time quantitative PCR, Western blot and ELISA. The effects of DOCK4 on ghrelin production in mHypoE-42 cells were measured by real-time quantitative PCR and Western blot.

RESULTS

We showed that DOCK4 was expressed in both human and mouse gastric ghrelin cells. The mRNA and protein levels of gastric ghrelin, as well as ghrelin secretion, were remarkably diminished in Dock4 null mice. Furthermore, we showed that overexpression of Dock4 significantly stimulated ghrelin expression, while siRNA knockdown of endogenous Dock4 resulted in a marked decrease of ghrelin in mHypoE-N42 cells.

CONCLUSIONS

Our results identify DOCK4 as a critical regulator for ghrelin production in gastric X/A-like cells.

Rheumatoid arthritis and the risk of major cardiometabolic diseases: a Mendelian randomization study

OBJECTIVE

Rheumatoid arthritis (RA) is suggested to be implicated in the development of cardiometabolic diseases. We conducted a Mendelian randomization (MR) study to assess potential causality for associations of RA with the risk of cardiometabolic diseases, including type 2 diabetes (T2D), coronary artery disease (CAD), and ischaemic stroke.

METHOD

Seventy independent single-nucleotide polymorphisms (SNPs) associated with RA were identified as instrumental variables from a genome-wide association study (GWAS) of 58 284 European subjects. Summary-level data for the associations of the 70 genetic variants with T2D, CAD, and ischaemic stroke were taken from three GWASs with a total of 1 529 131 participants. Inverse-variance weighted (IVW) MR was used in the main analyses.

RESULTS

The main IVW MR analysis showed that genetically determined RA was associated with higher risks of T2D [odds ratio (OR): 1.04, 95% confidence interval (CI) 1.02-1.05; p < 0.001] and CAD (OR: 1.02, 95% CI 1.00-1.03; p = 0.012), but not ischaemic stroke (OR: 1.00, 95% CI 0.99-1.02; p = 0.961). Sensitivity analyses with multiple MR methods confirmed these associations. MR-Egger regression showed no evidence of pleiotropy in the association between genetically determined RA and the risk of T2D, CAD, and ischaemic stroke. Leave-one-out sensitivity analysis showed that the association between genetically determined RA and the risk of T2D, CAD, and ischaemic stroke was not driven by any individual SNP.

CONCLUSION

Genetically determined RA was associated with increased risks of T2D and CAD, suggesting that RA plays a crucial role in the pathogenesis of T2D and CAD.

Cold Spray: Over 30 Years of Development Toward a Hot Future

Cold Spray (CS) is a deposition process, part of the thermal spray family. In this method, powder particles are accelerated at supersonic speed within a nozzle; impacts against a substrate material triggers a complex process, ultimately leading to consolidation and bonding. CS, in its modern form, has been around for approximately 30 years and has undergone through exciting and unprecedented developmental steps. In this article, we have summarized the key inventions and sub-inventions which pioneered the innovation aspect to the process that is known today, and the key breakthroughs related to the processing of materials CS is currently mastering. CS has not followed a liner path since its invention, but an evolution more similar to a hype cycle: high initial growth of expectations, followed by a decrease in interest and a renewed thrust pushed by a number of demonstrated industrial applications. The process interest is expected to continue (gently) to grow, alongside with further development of equipment and feedstock materials specific for CS processing. A number of current applications have been identified the areas that the process is likely to be the most disruptive in the medium-long term future have been laid down.

A bibliometric analysis of primary ovarian insufficiency from 2010 to 2020

OBJECTIVE

This study aimed to carry out a bibliometric analysis of primary ovarian insufficiency (POI) from 2010 to 2020 and to reveal the research status and hotspots in the future.

METHOD

A total of 3087 articles and reviews related to POI published from 2010 to 2020 retrieved from the Web of Science Core Collection were used for bibliometric analysis. CiteSpace and VOSviewer were adopted to analyze countries and regions, organizations, authors, journals, keywords and co-cited references.

RESULTS

The number of publications about POI increased year by year. The USA produced the largest number of publications and the most influence in this field. The main research directions of POI can be roughly divided into four aspects according to the analysis of keywords and co-cited references: genetic research of POI; stem cell therapy for patients with POI; prediction of ovarian function; and fertility preservation of cancer patients. Genetic research and stem cell therapy may become research hotspots in the future.

CONCLUSION

This study might be the first bibliometric study to analyze publications of POI from multiple indicators, in order to provide new opinions for the research trends and possible hotspots of POI.

Combined Effects of Fe(III)-Bearing Nontronite and Organic Ligands on Biogenic U(IV) Oxidation

Bioreduction of soluble U(VI) to sparingly soluble U(IV) solids was proposed as a remediation method for uranium contamination. Therefore, the stability and longevity of biogenic U(IV) are critical to the success of uranium remediation. However, co-occurrence of clay minerals and organic ligands could potentially reoxidize U(IV) to U(VI). Herein, we report a combined effect of Fe(III)-rich nontronite (NAu-2) and environmentally prevalent organic ligands on reoxidation of biogenic U(IV) at circumneutral pH. After 30 days of incubation, structural Fe(III) in NAu-2 oxidized 45.50% U(IV) with an initial rate of 2.7 × 10^-3 mol m^-2 d^-1. Addition of citrate and ethylenediaminetetraacetic acid (EDTA) greatly promoted the oxidative dissolution of U(IV) by structural Fe(III) in NAu-2, primarily through the formation of aqueous ligand-U(IV) complexes. In contrast, a model siderophore, desferrioxamine B (DFOB), partially inhibited U(IV) oxidation due to the formation of stable DFOB-Fe³⁺ complexes. The resulting U(VI) species intercalated into an NAu-2 interlayer or adsorbed onto an NAu-2 surface. Our results highlight the importance of organic ligands in oxidative dissolution of U(IV) minerals by Fe(III)-bearing clay minerals and have important implications for the design of nuclear waste storage and remediation strategies, especially in clay- and organic-rich environments.

[The effects of robotic-assisted versus laparoscopic-assisted radical right hemicolectomy on short-term outcome and long-term prognosis based on propensity score matching]

Objective: To compare the short-term and long-term outcomes between robotic-assisted and laparoscopic-assisted radical right hemicolectomy in patients with adenocarcinoma of the right colon. Methods: Retrospective review of a prospectively collected database identified 288 right colon cancer patients who underwent either robotic-assisted (n=57) or laparoscopic-assisted right hemicolectomy (n=231) between October 2014 and October 2020 at Department of Gastrointestinal Surgery, the Affiliated Hospital of Qingdao University. There were 161 males and 127 females, aging (60.3±12.8) years (range: 17 to 86 years). After propensity score matching as 1∶4 between robotic-assisted and laparoscopic-assisted right hemicolectomy, there were 56 cases in robotic group and 176 cases in laparoscipic group. Perioperative outcomes and overall survival were compared between the two groups using t test, Wilcoxon rank sum test, χ² test, Fisher exact test, Kaplan-Meier method and Log-rank test, respectively. Results: The total operative time was similar between the robotic and laparoscopic group ((206.9±60.7) minutes vs. (219.9±56.3) minutes, t=-1.477, P=0.141). Intraoperative bleeding was less in the robotic group (50 (20) ml vs. 50 (50) ml, Z=-4.591, P<0.01), while the number of lymph nodes retrieved was significantly higher (36.0±10.0 vs. 29.0±10.1, t=4.491, P<0.01). Patients in robotic group experienced significantly shorter hospital stay, shorter time to first flatus, and defecation (t: -2.888, -2.946, -2.328, all P<0.05). Moreover, the overall peri-operative complication rate was similar between robotic and laparoscopic group (17.9% vs. 22.7%, χ²=0.596,P=0.465). The 3-year overall survival were 92.9% and 87.9% respectively and the 3-year disease-free survival rates were 83.1% and 82.6% with no statistical significance between the robotic and laparoscopic group (P>0.05). Conclusions: Compared to laparoscopic-assisted right hemicolectomy, robot-assisted right hemicolectomy could improve some short-term clinical outcomes. The two procedures are both achieving comparable survival.

[Regulatory effect of small nuclear ribonucleoprotein-associated protein B on proliferation and metastasis of liver cancer cells]

Objective: To study the expression and effect of small nuclear ribonucleoprotein-associated protein B (SNRPB) on proliferation and metastasis of liver cancer tissues and cells. Methods: The bioinformatics database starBase v3.0 and GEPIA were used to analyze the expression of SNRPB in liver cancer tissue and normal liver tissue, as well as the survival and prognosis of liver cancer patients. The expression of SNRPB mRNA and protein in liver cancer cell lines were analyzed by qRT-PCR and Western blot. RNA interference technique (siRNA) was used to determine SNRPB protein expression down-regulation. The proliferation effect on hepatocellular carcinoma cells was observed by MTT assay. Transwell invasion and migration assay was used to detect the changes in the metastatic ability of liver cancer cells after SNRPB down-regulation. Western blot was used to detect the changes of epithelial mesenchymal transition (EMT) markers in liver cancer cells after down-regulation of SNRPB expression. Data were compared between two groups and multiple groups using t-test and analysis of variance. Results: The expression of SNRPB was significantly higher in liver cancer tissue than normal liver tissue, and its expression level was correlated with the prognosis of liver cancer patients. Compared with the immortalized hepatocyte LO(2), the expression of SNRPB was significantly increased in the liver cancer cells (P < 0.01). siRNA-SNRPB had significantly inhibited the expression of SNRPB mRNA and protein in liver cancer cells. MTT results showed that the absorbance value was lower in SNRPB knockdown group than negative control group, and the difference at 96 h after transfection was most significant (P < 0.01). Transwell assay results showed that compared with the negative control group, the SNRPB knockdown group (MHCC-97H: 121.27 ± 8.12 vs. 46.38 ± 7.54; Huh7: 126.50 ± 6.98 vs. 41.10 ± 8.01) invasion and migration (MHCC-97H: 125.20 ± 4.77 vs. 43.18 ± 7.32; Huh7: 132.22 ± 8.21 vs. 38.00 ± 6.78) ability was significantly reduced (P < 0.01) in liver cancer cells. Western blot showed that the expression level of epithelial phenotype marker E-cadherin was decreased after down-regulation of SNRPB, while the expression levels of mesenchymal phenotype markers N-cadherin and vimentin was increased, suggesting that down-regulation of SNRPB inhibited EMT in liver cancer cells. Conclusion: SNRPB expression is significantly increased in liver cancer tissues and cells, and it is involved in regulating the proliferation, metastasis and EMT of liver cancer cells.

The Association between Dietary Magnesium Intake and Telomere Length in Adults with Hypertension

BACKGROUND

Dietary micronutrients are significantly associated with telomere length, as shown in multiple studies. However, no study has investigated the association between magnesium intake and telomere length in adults with hypertension.

METHODS

Participants were included from the National Health and Nutrition Examination Survey (NHANES) in 1999-2000 and 2001-2002. Dietary magnesium intake was assessed using the 24 - hour recall method and the telomere length of leukocytes was measured using polymerase chain reaction (PCR). A multivariate regression model was then used to assess the association between dietary magnesium intake and telomere length in adults with hypertension.

RESULTS

Our final analysis included 2199 hypertensive adults (46.79% males) with a mean dietary magnesium intake of 254.82±133.47 mg/day. Linear regression, adjusted for race, sex, age, smoking, uric acid, and other variables, showed that every 1 mg increase in dietary magnesium intake was associated with a 0.20 (95% CI: 0.01, 0.39, p = 0.043) longer telomere length in all participants. In the ≥45 years age group, there was a statistically significant association between the telomere length and dietary magnesium (95% CI: 0.16, 0.63, p <0.001).

CONCLUSIONS

This study suggests that increased magnesium intake is associated with a longer telomere length in hypertensive adults, especially in those ≥45 years of age. However, further research is needed to determine a causal relationship.

[Effect of perioperative accelerated rehabilitation management program for children with congenital spinal deformity]

Objective: To explore the perioperative therapeutic effect of enhanced recovery after surgery (ERAS) in children with congenital spinal deformity and summarize the clinical experience. Methods: Fifty-nine pediatric patients with congenital spinal deformities admitted to Beijing Children's Hospital from May 2020 to January 2021 were included in this study, and all patients underwent posterior spinal osteotomy orthopedic implant fusion with internal fixation. There were 22 males and 37 females, aged (7.4±4.1) years. Patients were divided into ERAS group (n=29) and control group (n=30) according to the management model. Patients in the ERAS group were managed with an accelerated recovery management model during the perioperative period, which mainly included: high protein diet, shortened fasting time, optimized anesthesia protocol, and multimodal analgesia. Patients in the control group received the traditional perioperative management model. The indexes of surgery, diet, pain score and laboratory tests were compared between the two groups. Results: All patients completed the surgery successfully. The mean temperature and pain scores of patients in the ERAS group were lower than those in the control group at 3 days postoperatively (P<0.05). The time to exhaustion and defecation in the ERAS group was (1.0±0.8) d and (2.5±0.9) d postoperatively, both significantly earlier than those in the control group ((3.4±0.8) d and (4.0±1.1) d) (both P<0.05). C-reactive protein was 38(8,46) mg/L in patients of the ERAS group on the day 3 postoperatively, which was significantly lower than that in the control group 47(22,93) mg/L (P=0.023). The hemoglobin level on postoperative day 3 was (110.7±9.6) g/L in the ERAS group, which was significantly higher than that in the control group ((104.5±11.4) g/L) (P=0.029). Postoperative complications occurred in 8(27.6%) and 9(30.0%) patients in the ERAS and control groups, respectively (P=1.000), with mild abdominal pain and bloating being the most common complications in both groups, most of which were not treated specifically. Conclusion: ERAS is a safe and effective perioperative management mode for children with congenital spinal deformity. Compared with the traditional method, it can significantly improve the treatment efficiency and deserve clinical application.

Antibacterial Mechanisms of Reduced Iron-Containing Smectite-Illite Clay Minerals

Reduced nontronite has been demonstrated to be antibacterial through the production of hydroxyl radical (^•OH) from the oxidation of structural Fe(II). Herein, we investigated the antibacterial activity of more common smectite-illite (S-I) clays toward Escherichia coli cells, including montmorillonite SWy-3, illite IMt-2, 50-50 S-I rectorite RAr-1, 30-70 S-I ISCz-1, and nontronite NAu-2. Under an oxic condition, reduced clays (with a prefix r before mineral names) produced reactive oxygen species (ROS), and the antibacterial activity followed the order of rRAr-1 > rSWy-3 ≥ rNAu-2 ≫ rIMt-2 ≥ rISCz-1. The strongest antibacterial activity of rRAr-1 was contributed by a combination of ^•OH and Fe(IV) generated from structural Fe(II)/adsorbed Fe²⁺ and soluble Fe²⁺, respectively. Higher levels of lipid and protein oxidation, intracellular ROS accumulation, and membrane disruption were consistent with this antibacterial mechanism of rRAr-1. The antibacterial activity of other S-I clays depended on layer expandability, which determined the reactivity of structural Fe(II) and the production of ^•OH, with the expandable smectite being the most antibacterial and nonexpandable illite the least. Our results provide new insights into the antibacterial mechanisms of clay minerals.

Single-cell transcriptome analysis yields new insights into the pathogenic mechanisms and possible genetic etiology of cardiomyopathies

Background

Inherited cardiomyopathies (CM) represent a clinically heterogeneous group of primary cardiac muscle disorders with a strong genetic underpinning. Recent rapid genomic advances have led to the identification of numerous disease-causing genes for both non-syndromic (nsCM) and syndromic (sCM) cardiomyopathies. This has greatly facilitated molecular genetic testing, thus enabling accurate disease diagnosis needed for the practice of precision medicine and the optimization of patient outcome. However, many cardiomyopathies remain unexplained with the known genes and dominant genetic model of disease.

Purpose

To reassess the genetic features of known CM genes as a strategy to recover novel candidate CM genes.

Methods

Known hypertrophic CM (HCM), dilated CM (DCM) and pediatric CM genes were curated from the literature and from 23 commercial CM diagnostic panels. They were classified as non-syndromic and syndromic, and further annotated using two constraint metrics, the missense Z score and pLI score obtained from the GnomAD database. Publicly available mouse (n=6) and human (n=3) single-cell RNA (scRNA) datasets were downloaded and cardiomyocyte specific differentially expressed genes (DEGs) (fold change &gt;0.1; adjusted P&lt;0.0001) were recovered. Genes identified as DEGs in at least 4 mouse or 3 human scRNA datasets were recovered as nsCM candidate genes.

Results

Analyses of 9 scRNA datasets showed the majority of known nsCM genes are cardiomyocyte specific (Fig. 1a-b). nsCM and sCM genes have distinct expression and genetic profile. nsCM genes are associated with higher heart expression and lower loss intolerance (Fig. 1c). In contrast, syndromic CM genes mostly showed lower expression with high loss intolerance, consistent with their higher clinical impact. However, interestingly some of the nsCM genes (MYLK2, TMPO and KLF10) show low or even no detectable expression in mouse and human cardiac cells. Using the scRNA data, we assessed cellular expression of genes in the 23 commercial CM diagnostic panels. This analysis showed some of the CM genes with high cardiomyocytes expression have low coverage on the current commercial CM panels (Fig. 1d). Using human and mouse scRNA data, we recovered 224 mouse and 157 human nsCM candidate genes. MTUS2 (microtubule-associated tumor suppressor candidate 2) was identified as a strong nsCM candidate gene supported by evidence from both mouse and human studies (Fig. 1e-f).

Conclusions

Our analysis showed many of the nsCM genes have differential cardiomyocyte expression with low loss intolerance, while the reverse was observed for many sCM genes. We propose increasing commercial panel coverage of cardiomyocytes-specific expressed genes may help increase disease diagnostic yield. Additionally, novel candidate genes uncovered trained on cardiomyocyte expression profile may help accelerate elucidation of unsolved cardiomyopathy cases.

Funding Acknowledgement

Type of funding sources: None.

P–501 Deep in the Maze: The psychosocial trajectory and decision making of Women with recurrent implantation failure of IVF

Study question

To understand the psychosocial trajectory of Chinese women who have experienced recurrent implantation failure (RIF) of IVF and their decision making accordingly.

Summary answer

Chinese women experience despair, doubt, and disorientation along with the cumulative failure cycles of IVF, and stick to IVF as the ultimate option.

What is known already

Recurrent implantation failure, the absence of implantation after repeated embryo transfers is a stressful event for people undergoing treatment for infertility. Numerous researches have focused on the psychological wellness of women undertaking IVF, but pay less attention to the subgroup who have undergone repeated failures. Current studies have shown that women after repeated unsuccessful IVF might endure anxiety, depression, and other psychosocial distress; however, the feelings brought by the different times of failure are unlike, and these experiences will affect their treatment decisions accordingly, which is rarely studied.

Study design, size, duration

Semi-structured interview was adopted with sixteen Chinese women from March 2020 to July 2020. The interview lasted 90 minutes. A follow-up survey was conducted three months after the interview. Driven by grounded theory, data is analyzed by thematic analysis.

Participants/materials, setting, methods

Convenience sampling was used to recruit female participants who have failed to achieve clinical pregnancy after two consecutive cycles of fresh or frozen IVF embryo transfers with a cumulative number of transferred embryos of four or more cleavage-stage embryos or two or more blastocysts. Chinese-speaking women who were undertaking IVF treatment in the reproductive center of hospital in Shenzhen City were recruited by pamphlets and doctors’ referral.

Main results and the role of chance

Chinese women with recurrent implantation failures experience the following psychosocial trajectory during the cumulative failure cycles of IVF: despair, doubt, and disorientation. Despair usually comes after the first failure: the high expectation for success rates makes the initial failure exceptionally shocking and desperate. Huge distress brings two kinds of decisions: start a new IVF cycle quickly to welcome the positive results in the imagination, or wait for a period of time to avoid the pain of failure again. Doubt usually appears after the second failure. In addition to doubting the health function of their body, recurrent failure makes the patients particularly doubt the efficacy of IVF and doctors’ clinical judgment. Some patients would do ‘hospital shopping’ and consider change clinics. Disorientation can be seen in patients who have experienced more than three cycles of failure. Past experience and meaning cannot help them understand and solve the current dilemma. The inherent concept of fertility continues to strengthen their belief of having a baby as ultimate goal. The follow-up survey found that most women still choose to continue IVF treatment after repeated failure. They are like being in the maze of fertility, wandering for a long time but unable to get out.

Limitations, reasons for caution

Several limitations are identified: self-selection bias due to convenience sampling; narrow sampling approach may limits the generalizability; the exclusion of men may ignore the marital interdependence during the infertility treatment.

Wider implications of the findings: Patients who have experienced recurrent implantation failure demand promising intervention during and after infertility treatment. The findings demonstrate the need for both supportive and implication counseling to facilitate them cope with the psychosocial distress, and make value-based decision making, so as to enhance their self-agency.

Trial registration number

Not applicable

Nylon membranes modified by gold nanoparticles as surface-enhanced Raman spectroscopy substrates for several pesticides detection

Surface enhanced Raman spectroscopy (SERS) is an attractive means for trace compound detection because of its high sensitivity, however, the poor reproducibility is a major challenge. Herein, we propose a facile SERS strategy employing the several developed test processes to improve the repeatability of the SERS analysis based on regular nylon membranes as substrates to detect trace compounds. Various methods, including in situ reduction, immersion adsorption, and filtration, were first compared to prepare composite substrates using nylon membranes and gold nanoparticles. The substrates prepared by filtration showed the best test parallelism (RSD = 7.85%). Its limit of detection (LOD) could reach 10^-8 g mL^-1 with a good linear relationship in the range 10^-8 to 10^-7 g mL^-1. Finally, three pesticide solutions were tested to verify the substrate applicability. A superior LOD of 10^-8 g mL^-1 was observed for thiram, whereas the LODs of both phorate and benthiocarb could reach 10^-6 g mL^-1. Overall, modifying nylon membrane substrates with gold nanoparticles improves the repeatability and economic viability of SERS and favors its wider commercial application for detecting trace compounds.

[Regulatory effects of LIM kinase 1 on the proliferation and metastasis of hepatocellular carcinoma cells]

Objective: To study LIM kinase 1 (LIMK1) expressional condition, and its regulatory effects on the proliferation and metastasis of hepatocellular carcinoma cells and tissues. Methods: The online database starBase v3.0 and GEPIA were used to analyze the LIMK1 expression in hepatocellular carcinoma cells and normal liver tissues, and then the relevant survival analysis was performed. LIMK1 expression in hepatocellular carcinoma cell line was analyzed by Western blot. Hep3B and Huh7 cells were transiently transfected after LIMK1 protein expression was down-regulated by small interfering RNA (siRNA). LIMK1 effects on the proliferation of Hep3B and Huh7 cells were observed by MTT assay and colony formation assay. Transwell assay was used to detect the change in metastatic ability of hepatocellular carcinoma cell after the down-regulation of LIMK1 expression. Western blot was used to detect the changes of related indexes in the process of epithelial mesenchymal transition after the down-regulation of LIMK1 expression. Data were analyzed by one-way ANOVA. Results: The expression level of LIMK1 in liver cancer tissues was significantly higher than that of normal liver tissues, and was related with prognosis (P ​< 0.01). Furthermore, LIMK1 expression in HCC cell lines was significantly higher than that of immortalized liver L02 cells (P < 0.05). Functional correlated experiment showed that the proliferation and metastatic ability of liver cancer cells were significantly inhibited after LIMK1 expression down-regulation (P < 0.05). Simultaneously, LIMK1 was also involved in the process of epithelial-mesenchymal transition. Conclusion: LIMK1 was overexpressed in HCC tissues and cells, and may regulate the proliferation and metastasis of HCC cells and participate in epithelial-mesenchymal transition process.

POS0417 EXOGENOUS CXCL5 RESTORES ENDOGENOUS BLOOD-TISSUE CHEMOKINE GRADIENT TO IMPROVE SURVIVAL IN MURINE LUPUS

Background:

Systemic lupus erythematosus (SLE) is a multi-organ autoimmune disease that is potentially fatal. There is an unmet need to improve current therapies. In patients with SLE, we observed that serum CXCL5 levels were significantly lower than healthy control subjects and negatively correlated with disease activity(1-9).

Objectives:

The aim of this study is to elucidate the effect of supplemental serum CXCL5 in abrogating the pathological processes of SLE.

Methods:

Ten doses of exogenous CXCL5 (3µg/kg) was administered to 16-week-old Faslpr mice weekly by intravenous injection. Mice were monitored for 10 weeks. Splenic immune profile was measured by flow cytometry. Circulating cytokine and immunoglobulin profile were detected by Luminex technology. Renal function was evaluated by urinary spot albumin creatinine ratio. In situ renal immune cell infiltration and complement 3 deposition were detected by Haematoxylin and Eosin (H&E) and immunohistochemistry staining. The molecular pathways involved were examined by RNA sequencing.

Results:

In Faslpr mice, intravenous administration of exogenous CXCL5 significantly improved mouse survival with concomitant reduction of autoantibody secretion, proteinuria, complement 3 deposition, neutrophil infiltration and lupus nephritis classes. Through evaluating the changes of immune profile, cytokine profile and molecular pathways, we found that intravenous CXCL5 reduced inflammation via an orchestral effect of regulating neutrophil trafficking and modulating helper T cell-mediated immune response. Pharmacokinetic and real-time Polymerase Chain Reaction studies further demonstrated that this orchestration was triggered by a cascade reaction - restoring vascular under-expressed CXCL5 by an exogenous stimulation, re-establishing the normal serum levels of endogenous CXCL5 and reverting the CXCL5 chemokine gradient between inflamed tissues and blood circulation.

Conclusion:

Managing the dysregulation of CXCL5 by exogenous supplement may provide a new option for SLE therapy.

References:

[1]Dufies M, Grytsai O, Ronco C, et al. New CXCR1/CXCR2 inhibitors represent an effective treatment for kidney or head and neck cancers sensitive or refractory to reference treatments. Theranostics. 2019;9(18):5332-5346. doi:10.7150/thno.34681

[2]Yildirim K, Colak E, Aktimur R, et al. Clinical Value of CXCL5 for Determining of Colorectal Cancer. Asian Pac J Cancer Prev. Sep 26 2018;19(9):2481-2484. doi:10.22034/apjcp.2018.19.9.2481

[3]Wu K, Yu S, Liu Q, Bai X, Zheng X. The clinical significance of CXCL5 in non-small cell lung cancer. Onco Targets Ther. 2017;10:5561-5573. doi:10.2147/ott.s148772

[4]Zhao J, Ou B, Han D, et al. Tumor-derived CXCL5 promotes human colorectal cancer metastasis through activation of the ERK/Elk-1/Snail and AKT/GSK3beta/beta-catenin pathways. Mol Cancer. Mar 29 2017;16(1):70. doi:10.1186/s12943-017-0629-4

[5]Han KQ, Han H, He XQ, et al. Chemokine CXCL1 may serve as a potential molecular target for hepatocellular carcinoma. Cancer Med. Oct 2016;5(10):2861-2871. doi:10.1002/cam4.843

[6]Pappa CA, Tsirakis G, Kanellou P, et al. Monitoring serum levels ELR+ CXC chemokines and the relationship between microvessel density and angiogenic growth factors in multiple myeloma. Cytokine. Dec 2011;56(3):616-20. doi:10.1016/j.cyto.2011.08.034

[7]Zhang L, Li H, Ge C, et al. CXCL3 contributes to CD133(+) CSCs maintenance and forms a positive feedback regulation loop with CD133 in HCC via Erk1/2 phosphorylation. Sci Rep. Jun 3 2016;6:27426. doi:10.1038/srep27426

[8]Matsubara J, Honda K, Ono M, et al. Reduced plasma level of CXC chemokine ligand 7 in patients with pancreatic cancer. Cancer Epidemiol Biomarkers Prev. Jan 2011;20(1):160-71. doi:10.1158/1055- 9965.epi-10-0397

[9]Ma Y, Ren Y, Dai ZJ, Wu CJ, Ji YH, Xu J. IL-6, IL-8 and TNF-alpha levels correlate with disease stage in breast cancer patients. Adv Clin Exp Med. May-Jun 2017;26(3):421-426. doi:10.17219/acem/62120

Disclosure of Interests:

None declared

Identification of a mitogen-activated protein kinase kinase (AccMKK4) from Apis cerana cerana and its involvement in various stress responses

The mitogen-activated protein kinase (MAPK) cascade pathway is a ubiquitous signal transduction pathway in eukaryotes that regulates a variety of immune responses. This study accomplished the first isolation of an AccMKK4 gene from Apis cerana cerana and explored its function. Yeast two-hybrid experiments proved that AccMKK4 can interact with Accp38b, and the silencing of AccMKK4 in honeybees downregulated the expression level of Accp38b, which suggests that AccMKK4 might participate in the oxidative stress response through the p38 MAPK pathway. Tissue-specific expression levels of AccMKK4 analysis showed that AccMKK4 in the thorax, particularly muscle tissue, was higher than that in other tissues. The qRT-PCR results from different conditions demonstrated that AccMKK4 responds to various environmental stresses. After AccMKK4 silencing, the transcription level of some antioxidant genes and the activity of antioxidant-related enzymes are reduced, which indicated that AccMKK4 plays an important role in resistance against oxidative stress caused by external stimuli. In summary, our findings indicate that AccMKK4 probably plays an indispensable role in the response of honeybees to environmental stress and might aid for further research on the role of the MAPK cascade pathway in the antioxidant defence mechanisms of insects.

Contrasting seasonal variations of geochemistry and microbial community in two adjacent acid mine drainage lakes in Anhui Province, China

Acid mine drainage (AMD) is generated by the bio-oxidation of sulfide minerals. To understand the AMD formation and evolution, it is necessary to determine the composition and variation of acidophilic community, and their role in AMD ecosystem. In this study, we compared seasonal variations of geochemistry and microbial composition of two adjacent AMD lakes with different formation histories in Anhui Province, China. Lake Paitu (PT) formed in 1970s near a mine dump and the pH was in the range of 3.01-3.16, with the lowest in spring and summer while the highest in winter. The main ions in PT were Al and SO₄^2-, whereas Fe concentration was relatively low. The concentrations of these ions were the lowest in summer and the highest in winter. Lake Tafang (TF) formed in around 2013 in a pit was more acidic (pH 2.43-2.75), but the seasonal variation of pH was the same as PT. Compared with Lake PT, TF had higher Fe, lower Al and SO₄^2- concentrations, and showed no significant seasonal changes. Despite salient seasonal variations of prokaryotic composition in Lake PT, Ferrovum was the major iron-oxidizing bacterium in most seasons. Furthermore, Lake PT was also rich in heterotrophic bacteria (48.6 ± 15.9%). Both prokaryotic diversity and evenness of Lake TF were lower than PT, and chemolithotrophic iron-oxidizing bacteria (71.7 ± 25.4%) were dominant in almost all samples. Besides Ferrovum, more acid tolerant iron-oxidizer Leptospirillum and Acidithiobacillus were also abundant in Lake TF. Chlamydomonas was the major eukaryote in Lake PT and it flourished repeatedly at the end of December, causing an extremely high chlorophyll a concentration (587 μg/L) at one sampling site in 2016, which provided rich nutrients for heterotrophic bacteria. The main alga in Lake TF was Chrysonebula, but its concentration was low, apparently because of the strong acidity and dark red color of lake water.

Promotion of Microbial Oxidation of Structural Fe(II) in Nontronite by Oxalate and NTA

Iron redox cycling occurs extensively in soils and sediments. Previous research has focused on microbially mediated redox cycling of aqueous Fe. At circumneutral pH, most Fe occurs in solid phase, where Fe and organic ligands interact closely. However, the role of organic ligands in microbial oxidation of solid-phase Fe(II) is not well understood. Here, we incubated reduced nontronite NAu-2 (rNAu-2) with an iron-oxidizing bacterium and in the presence of oxalate and nitrilotriacetic acid. These ligands significantly enhanced the rate and extent of microbial oxidation of structural Fe(II) in rNAu-2. Aqueous and solid-phase analyses, coupled with biogeochemical modeling, revealed a pathway for ligand-enhanced bio-oxidation of solid-phase Fe(II): (1) dissolution of rNAu-2 to form aqueous Fe(II)-ligand complex; (2) bio-oxidation to Fe(III)-ligand complex; (3) rapid reduction of Fe(III)-ligand complex to Fe(II)-ligand complex by structural Fe(II) in rNAu-2. In this process, the Fe(II)-ligand and Fe(III)-ligand complexes effectively serve as electron shuttle to expand the bioavailable pool of solid-phase Fe(II). These results have important implications for a better understanding of the bioavailability and reactivity of solid-phase Fe pool in the environment.

[Predictive value of N-terminal B-type natriuretic peptide on outcome of elderly hospitalized non-heart failure patients]

Objective: To investigate the predictive value of N-terminal type B natriuretic peptide（NT-proBNP) on the prognosis of elderly hospitalized patients without heart failure（non-heart failure). Method: Elderly patients aged 65 years or older, who were admitted to Beijing Hospital from September 2018 to February 2019, were enrolled in this study. Patients with clinical diagnosis of heart failure or left ventricular ejection fraction（LVEF)<50% were excluded. The patients were divided into 2 groups based on the serum NT-proBNP level: low NT-proBNP group （<125 ng/L) and high NT-proBNP group（≥125 ng/L). Patients were followed up at 3, 6, and 12 months after enrollment, and the major adverse events were recorded. The composite endpoint events included all-cause mortality, readmission or Emergency Department visits. Cardiovascular events include death, readmission or emergency room treatment due to cardiogenic shock, myocardial infarction, angina pectoris, arrhythmia, heart failure or stroke/transient ischemic attack. Results: A total of 600 elderly patients with non-heart failure were included in the analysis. The average age was （74.9±6.5) years, including 304（50.7%) males. The median follow-up time was 344（265, 359) days. One hundred and seventy-eight（29.7%) composite endpoint events were recorded during the follow-up, 19（3.2%) patients died, and 12（2.0%) patients were lost to follow-up. There were 286(47.7%) cases in low NT-proBNP group and 314 cases（52.3%) in high NT-proBNP group. Patients were older, prevalence of atrial fibrillation and myocardial infarction was higher; MMSE scores and ADL scores, albumin and creatinine clearance rate were lower in high NT-proBNP group than in low NT-proBNP group（all P<0.05). At 1-year follow-up, the incidence of composite endpoint events was significantly higher in high NT-proBNP group than in low NT-proBNP group（33.4%（105/314) vs. 24.8%（71/286), P = 0.02). Cardiovascular events were more common in high NT-proBNP group than in low NT-proBNP group（17.5%（55/314) vs. 8.4%（24/286), P = 0.001). Kaplan-Meier survival analysis showed both composite endpoint events（Log-rank P=0.016) and cardiovascular events（Log-rank P=0.001) were higher in high NT-proBNP group than in low NT-proBNP group. All-cause mortality was also significantly higher in highNT-proBNP group than in lowNT-proBNP group（4.8%（15/314) vs. 1.4%（4/286), P = 0.020), and Kaplan-Meier survival analysis demonstrated borderline statistical significance（Log-rank P = 0.052). Cox proportional hazard regression analysis showed that after adjusting for age, sex, creatinine clearance rate, myocardial infarction, and atrial fibrillation, NT-proBNP remained as an independent risk factor for composite endpoint events（HR=1.376，95%CI 1.049-1.806, P=0.021), and cardiovascular events（HR=1.777, 95%CI 1.185-2.664, P=0.005), but not for all-cause mortality（P=0.206). Conclusions: NT-proBNP level at admission has important predictive value on rehospitalization and cardiovascular events for hospitalized elderly non-heart failure patients. NT-proBNP examination is helpful for risk stratification in this patient cohort.

[Application of pump-controlled retrograde trial off in weaning from veno-arterial extracorporeal membrane oxygenation in adult patients]

Objective: To Summarize the experience of pump-controlled retrograde trial off (PCRTO) in the process of veno-arterial extracorporeal membrane oxygenation (VA-ECMO) withdrawal in adult patients. Methods: Adult patients who received ECMO assistance in Intensive Care Unit for Cardiac Surgery from March to July 2019 were collected. According to our strategies, PCRTO was used if the patients can wean from VA-ECMO and hemodynamic indexes were recorded during the process. The statistics data was collected, including the 48 hours survival rate, ECMO re-assistance rate, thrombus complications, Intensive Care Unit (ICU) stay time and hospital stay time after weaning from VA-ECMO. The patients who failed in the test were continued to be assisted by ECMO. Results: There were 46 patients assisted by VA-ECMO in our center. In total, 21 adults who met the offline test standard underwent 26 PCRTOs, including 10 male adults (47.6%), with an age of 65 (55, 68) years old. Eighteen adults passed the withdrawal test. No new thrombus was found in the arteriovenous ultrasound of the lower extremity after weaning from ECMO, and no pulmonary embolism was found in the chest X-ray. The success rate of weaning from ECMO was 69.23%(18/26). The D-dimer decreased [584(348,2 107)μg/L vs 1 440(631,2 916)μg/L, P=0.014] and the left ventricular ejection fraction (LVEF) increased (51.4%±8.5% vs 46.9%±10.6%, P=0.013) on the next day after weaning. There were significant differences in heart rate (HR), central venous pressure (CVP), oxygenation index and lactate (Lac) during the PCRTO in the group which involved the cases of the 8 failed experiments (all P<0.05). Compared with the failure group, there were significant differences in age, blood flow rate, CVP before the test, HR, pulse oxygen saturation(SpO(2)), CVP, Lac and oxygenation index after the test, and the variations of SpO(2), CVP and Lac. Conclusion: PCRTO is a simple, reversible, safe and effective weaning method. It can be used in the process of VA-ECMO withdrawal in adult patients.

[Predictors for perioperative blood loss in pediatric patients with congenital scoliosis]

Objective: To identify predictors of massive blood loss after posterior hemivertebra resection for patients with congenital scoliosis. Methods: The data of 106 children with congenital scoliosis were collected from June 2017 to June 2019 in Beijing Children's Hospital. All the cases received posterior hemivertebra resection and internal fixation. The blood volume was estimated by weight and height. The visible blood loss was recorded according to medical record, and the hidden blood loss was calculated by OSTHEO formula. Perioperative information including age, gender, height, weight, Cobb and kyphosis angle, level fused, number of screws, operative time, and laboratory examinations was collected. Then multivariable linear regression was performed to determine the independent risk factors of blood loss. Results: All the surgeries were completed successfully. The mean age of the children was (7.3±2.3) years and the operative time was (162±56) min. The mean fused levels were 3 and the correction rate for deformity was 78.4%. The amount of blood loss was (568±208) ml which accounted for 42.3% of total blood volume. The visible and hidden blood loss was (334±193) ml and (234±199) ml, respectively, and which accounted for 58.8% and 41.2% of total blood loss. Multivariable linear regression analysis indicated that age, preoperative Cobb angle, the time of surgery and the number of fused levels were independent risk factors of total blood loss. Preoperative Cobb angle ≥40°, spinal fusion ≥4 levels and operative duration ≥140 min indicated more blood loss (all P<0.05). Conclusions: The perioperative blood loss of congenital scoliosis is massive with a high percentage of hidden blood loss. The patients with severe deformity, more fused levels and increased operative time brings higher risk of massive blood loss.

Hypomethylation of Notch1 DNA is associated with the occurrence of uveitis

Uveitis is a serious intra-ocular inflammatory disease that can lead to visual impairment even blindness worldwide. Notch signaling can regulate the differentiation of naive CD4⁺ T cells, influencing the development of uveitis. DNA methylation is closely related to the autoimmune diseases. In this study, we measured the Notch1 DNA methylation level, determined the Notch1 and related DNA methylases mRNA expression and evaluated the ratio of T helper type 17 regulatory T cell (Th17/T_reg ) in peripheral blood mononuclear cells (PBMCs) from uveitis patients and normal control subjects; we also tested the levels of relevant inflammatory cytokines in serum from the participants. Results indicated that compared with those in normal control individuals, the expression of ten-eleven translocation 2 (TET2) and Notch1 mRNA is elevated in uveitis patients, whereas the methylation level in Notch1 DNA promotor region [-842 ~ -646 base pairs (bp)] is down-regulated, and is unrelated to anatomical location. Moreover, the Th17/T_reg ratio is up-regulated in PBMCs from uveitis patients, accompanied by the elevated levels of proinflammatory cytokines [e.g. interleukin (IL)-2, IL-6, IL-17 and interferon (IFN)-γ] in serum from uveitis patients. These findings suggest that the over-expression of TET2 DNA demethylase may lead to hypomethylation of Notch1, activate the Notch1 signaling, induce naive CD4⁺ T cells to differentiate theTh17 subset and thus disturb the balance of the Th17/T_reg ratio in uveitis patients. Overall, hypomethylation of Notch1 DNA is closely associated with the occurrence of uveitis. Our study preliminarily reveals the underlying mechanism for the occurrence of uveitis related to the hypomethylation of Notch1 DNA, providing a novel therapeutic strategy against uveitis in clinical practice.

AB0128 CXCL5 DAMPENS INFLAMMATION IN THE PRE-CLINICAL MODEL OF SYSTEMIC LUPUS ERYTHEMATOSUS VIA THE ORCHESTRAL EFFECT OF REGULATING NEUTROPHIL TRAFFICKING AND SUPPRESSING HELPER T CELL-MEDIATED IMMUNE RESPONSE

Background:

Patients with systemic lupus erythematosus (SLE) suffer from severe morbidity and mortality1-4, either from the disease itself or from side effects of immunosuppression5. Discovery of novel effective therapies with less toxicity is an urgent need.

Objectives:

The aim of this study is to elucidate the therapeutic potential and working mechanism of cytokine CXCL5 in lupus mice.

Methods:

Treatment with CXCL5, bone marrow (BM)-MSCs, standard of care (SOC) with combination of methylprednisolone and cyclophosphamide was given to 16-week-old Faslprmice. Mice were monitored for 10 weeks. Splenic immune cell subsets were measured by flow cytometry. Circulating cytokine and immunoglobulin were detected by Luminex technology. Renal function was evaluated by urinary spot albumin creatinine ratio. In situ renal immune cell infiltration and complement 3 deposition were detected by Haematoxylin and Eosin (H&E) staining and immunohistochemistry.

Results:

CXCL5 demonstrated consistent and potent immunosuppressive capacity in suppressing SLE with reduced autoantibody secretion, lymphoproliferation and preserved kidney function. With further exploration, we proved that CXCL5 reduced the proliferation of helper T cells (TH1 and TH2) in thein vitrofunctional assay. When we administrated CXCL5 to lupus mice, it promoted the proliferation of regulatory T cells and reduced the proliferation of TH17 cells, macrophages and neutrophils. Multiple proinflammatory cytokines including IL-2, IL-6, IL-12, IL-17A, KC/CXCL1, MIP-1β/CCL4 and TNF-α were also reduced. When combined with SOC, CXCL5 boosted its therapeutic effect and reduced the relevant indices of disease activity. When we correlated the effect of four different treatment groups (CXCL5, BM-MSCs, SOC, and CXCL5 plus SOC) on mice survival and target cell changes, we found that TH17 cells were the key effector cells involved in the pathogenesis of SLE.

Conclusion:

These findings demonstrated that CXCL5 dampens inflammation in the pre-clinical model of systemic lupus erythematosus via the orchestral effect of regulating neutrophil trafficking and suppressing helper T cell-mediated immune response. Administrating exogenous CXCL5 might be an attractive option to treat patients with lupus.

References:

[1]Ji S, Guo Q, Han Y, Tan G, Luo Y, Zeng F. Mesenchymal stem cell transplantation inhibits abnormal activation of Akt/GSK3beta signaling pathway in T cells from systemic lupus erythematosus mice.Cell Physiol Biochem.2012;29(5-6):705-712.

[2]Peng SL. Altered T and B lymphocyte signaling pathways in lupus.Autoimmun Rev.2009;8(3):179-183.

[3]Ferucci ED, Johnston JM, Gaddy JR, et al. Prevalence and incidence of systemic lupus erythematosus in a population-based registry of American Indian and Alaska Native people, 2007-2009.Arthritis Rheumatol.2014;66(9):2494-2502.

[4]Jakes RW, Bae SC, Louthrenoo W, Mok CC, Navarra SV, Kwon N. Systematic review of the epidemiology of systemic lupus erythematosus in the Asia-Pacific region: prevalence, incidence, clinical features, and mortality.Arthritis Care Res (Hoboken).2012;64(2):159-168.

[5]Sattwika PD, Mustafa R, Paramaiswari A, Herningtyas EH. Stem cells for lupus nephritis: a concise review of current knowledge.Lupus.2018;27(12):1881-1897.

Acknowledgments:

The work was supported by SMART II Centre Grant (NMRC/CG/M011/2017_SGH) and SingHealth Foundation (SHF/FG638P/2016).

Disclosure of Interests:

None declared