Effects of zero-valent iron added in the flooding or drainage process on cadmium immobilization in an acid paddy soil

Zero-valent iron (ZVI) is a promising material for the remediation of Cd-contaminated paddy soils. However, the effects of ZVI added during flooding or drainage processes on cadmium (Cd) retention remain unclear. Herein, Cd-contaminated paddy soil was incubated for 40 days of flooding and then for 15 days of drainage, and the underlying mechanisms of Cd immobilization coupled with Fe/S/N redox processes were investigated. The addition of ZVI to the flooding process was more conducive to Cd immobilization. Less potential available Cd was detected by adding ZVI before flooding, which may be due to the increase in paddy soil pH and newly formed secondary Fe minerals. Moreover, the reductive dissolution of Fe minerals promoted the release of soil colloids, thereby increasing significantly the surface sites and causing Cd immobilization. Additionally, the addition of ZVI before flooding played a vital role in Cd retention after soil drainage. In contrast, the addition of ZVI in the drainage phase was not conducive to Cd retention, which might be due to the rapid decrease in soil pH that inhibited Cd adsorption and further immobilization on soil surfaces. The findings of this study demonstrated that Cd availability in paddy soil was largely reduced by adding ZVI during the flooding period and provide a novel insight into the mechanisms of ZVI remediation in Cd-contaminated paddy soils.

FLRT3 and TGF-β/SMAD4 signalling: Impacts on apoptosis, autophagy and ion channels in supraventricular tachycardia

To explore the underlying molecular mechanisms of supraventricular tachycardia (SVT), this study aimed to analyse the complex relationship between FLRT3 and TGF-β/SMAD4 signalling pathway, which affects Na+ and K+ channels in cardiomyocytes. Bioinformatics analysis was performed on 85 SVT samples and 15 healthy controls to screen overlapping genes from the key module and differentially expressed genes (DEGs). Expression profiling of overlapping genes, coupled with Receiver Operating Characteristic (ROC) curve analyses, identified FLRT3 as a hub gene. In vitro studies utilizing Ang II-stimulated H9C2 cardiomyocytes were undertaken to elucidate the consequences of FLRT3 silencing on cardiomyocyte apoptosis and autophagic processes. Utilizing a combination of techniques such as quantitative reverse-transcription polymerase chain reaction (qRT-PCR), western blotting (WB), flow cytometry, dual-luciferase reporter assays and chromatin immunoprecipitation polymerase chain reaction (ChIP-PCR) assays were conducted to decipher the intricate interactions between FLRT3, the TGF-β/SMAD4 signalling cascade and ion channel gene expression. Six genes (AADAC, DSC3, FLRT3, SYT4, PRR9 and SERTM1) demonstrated reduced expression in SVT samples, each possessing significant clinical diagnostic potential. In H9C2 cardiomyocytes, FLRT3 silencing mitigated Ang II-induced apoptosis and modulated autophagy. With increasing TGF-β concentration, there was a dose-responsive decline in FLRT3 and SCN5A expression, while both KCNIP2 and KCND2 expressions were augmented. Moreover, a direct interaction between FLRT3 and SMAD4 was observed, and inhibition of SMAD4 expression resulted in increased FLRT3 expression. Our results demonstrated that the TGF-β/SMAD4 signalling pathway plays a critical role by regulating FLRT3 expression, with potential implications for ion channel function in SVT.

Transformation and migration of Hg in a polluted alkaline paddy soil during flooding and drainage processes

Mercury (Hg) contamination in paddy soils poses a health risk to rice consumers and the environmental behavior of Hg determines its toxicity. Thus, the variations of Hg speciation are worthy of exploring. In this study, microcosm and pot experiments were conducted to elucidate Hg transformation, methylation, bioaccumulation, and risk coupled with biogeochemical cycling of key elements in a Hg-polluted alkaline paddy soil. In microcosm and pot experiments, organic- and sulfide-bound and residual Hg accounted for more than 98% of total Hg, and total contents of dissolved, exchangeable, specifically adsorbed, and fulvic acid-bound Hg were less than 2% of total Hg, indicating a low mobility and environmental risk of Hg. The decrease of pH aroused from Fe(III), SO42-, and NO3- reduction promoted Hg mobility, whereas the increase of pH caused by Fe(II), S2-, and NH4+ oxidation reduced available Hg contents. Moreover, Fe-bearing minerals reduction and organic matter consumption promoted Hg mobility, whereas the produced HgS and Fe(II) oxidation increased Hg stability. During flooding, a fraction of inorganic Hg (IHg) could be transported into methylmercury (MeHg), and during drainage, MeHg would be converted back into IHg. After planting rice in an alkaline paddy soil, available Hg was below 0.3 mg kg-1. During rice growth, a portion of available Hg transport from paddy soil to rice, promoting Hg accumulation in rice grains. After rice ripening, IHg levels in rice tissues followed the trend: root > leaf > stem > grain, and IHg content in rice grain exceed 0.02 mg kg-1, but MeHg content in rice grain meets daily intake limit (37.45 μg kg-1). These results provide a basis for assessing the environmental risks and developing remediation strategies for Hg-contaminated redox-changing paddy fields as well as guaranteeing the safe production of rice grains.

[Application of optical genome mapping technology for the detection of chromosomal structural variations]

OBJECTIVE

To assess the value of optical genome mapping (OGM) for the detection of chromosomal structural abnormalities including ring chromosomes, balanced translocations, and insertional translocations.

METHODS

Clinical data of four patients who underwent pre-implantation genetic testing concurrently with OGM and chromosomal microarray analysis at the Center of Reproductive Medicine of the Sixth Affiliated Hospital of Sun Yat-sen University from January to October 2022 due to chromosomal structural abnormalities were selected as the study subjects. Some of the results were verified by multi-color fluorescence in situ hybridization.

RESULTS

The OGM has successfully detected a balanced translocation and fine mapped the breakpoints in a patient. Among two patients with insertional translocations, OGM has provided more refined breakpoint locations than karyotyping analysis in a patient who had chromosome 3 inserted into chromosome 6 and determined the direction of the inserted fragment. However, OGM has failed to detect the chromosomal abnormality in a patient with chromosome 8 inserted into the Y chromosome. It has also failed to detect circular signals in a patient with ring chromosome mosaicism.

CONCLUSION

OGM has successfully detected chromosomal structural variations in the four patients and provided assistance for their diagnosis.

Biogeochemical cycling in paddy soils controls antimony transformation: Roles of iron (oxyhydr)oxides, organic matter and sulfate

In paddy fields, periodic flooding and drainage phases can significantly affect the availability of antimony (Sb), but the underlying mechanisms remain unclear. In this study, Sb-contaminated paddy soil was incubated under anaerobic (40 day) and subsequently aerobic (40-55 day) conditions. The Sb fractions was investigated and a kinetic model was established to quantitatively evaluate the main processes controlling Sb transformation. Under anaerobic conditions, the reductive dissolution of iron (Fe) (oxyhydr)oxides, the release of soil colloids, and dissolved organic carbon (DOC) could facilitate the release of Sb(V), while newly released Sb(V) were synchronously reduced to Sb(III) that could be incorporated into the solid phase (34.1%, 40 day) or precipitated as Sb2S3 (9.7%, 40 day). After soil aeration, a significant increase in dissolved and extracted Sb(V) (34.7%, 45 day) was observed due to the Sb(III) oxidization by the reactive oxygen species (ROS) generated from Fe(II) oxidization. The dissolved and extracted Sb(V) were simultaneously incorporated into the solid phase as the re-aggregation of soil colloids and DOC, and only contributed to 17.1% of the total Sb content at the end of aerobic phase (55 day). Our results elucidated the mechanisms about how biogeochemical Fe/S/C cycling jointly controlled Sb transformation in paddy systems.

Dual green hemostatic sponges constructed by collagen fibers disintegrated from Halocynthia roretzi by a shortcut method

Recently, biomacromolecules have received considerable attention in hemostatic materials. Collagen, an ideal candidate for hemostatic sponges due to its involvement in the clotting process, has been facing challenges in extraction from raw materials, which is time-consuming, expensive, and limited by cultural and religious restrictions associated with traditional livestock and poultry sources. To address these issues, this study explored a new shortcut method that using wild Halocynthia roretzi (HR), a marine fouling organism, as a raw material for developing HR collagen fiber sponge (HRCFs), which employed urea to disrupt hydrogen bonds between collagen fiber aggregates. This method simplifies traditional complex manufacturing processes while utilized marine waste, thus achieving dual green in terms of raw materials and manufacturing processes. FTIR results confirmed that the natural triple-helical structure of collagen was preserved. HRCFs exhibit a blood absorption ratio of 2000-3500 %, attributed to their microporous structure, as demonstrated by kinetic studies following a capillary model. Remarkably, the cytotoxicity and hemolysis ratio of HRCFs are negligible. Furthermore, during in vivo hemostasis tests using rabbit ear and kidney models, HRCFs significantly reduce blood loss and shorten hemostasis time compared to commercial gelatin sponge and gauze, benefiting from the capillary effect and collagen's coagulation activity. This study provides new insights into the design of collagen-based hemostatic biomaterials, especially in terms of both raw material and green manufacturing processes.

Fe(II) Oxidation Shaped Functional Genes and Bacteria Involved in Denitrification and Dissimilatory Nitrate Reduction to Ammonium from Different Paddy Soils

Microbial nitrate reduction can drive Fe(II) oxidation in anoxic environments, affecting the nitrous oxide emission and ammonium availability. The nitrate-reducing Fe(II) oxidation usually causes severe cell encrustation via chemodenitrification and potentially inhibits bacterial activity due to the blocking effect of secondary minerals. However, it remains unclear how Fe(II) oxidation and subsequent cell encrustation affect the functional genes and bacteria for denitrification and dissimilatory nitrate reduction to ammonium (DNRA). Here, bacteria were enriched from different paddy soils with and without Fe(II) under nitrate-reducing conditions. Fe(II) addition decelerated nitrate reduction and increased NO2- accumulation, due to the rapid Fe(II) oxidation and cell encrustation in the periplasm and on the cell surface. The N2O accumulation was lower in the treatment with Fe(II) and nitrate than that in the treatment with nitrate only, although the proportions of N2O and NH4+ to the reduced NO3- were low (3.25% ∼ 6.51%) at the end of incubation regardless of Fe(II) addition. The dominant bacteria varied from soils under nitrate-reducing conditions, while Fe(II) addition shaped a similar microbial community, including Dechloromonas, Azospira, and Pseudomonas. Fe(II) addition increased the relative abundance of napAB, nirS, norBC, nosZ, and nirBD genes but decreased that of narG and nrfA, suggesting that Fe(II) oxidation favored denitrification in the periplasm and NO2--to-NH4+ reduction in the cytoplasm. Dechloromonas dominated the NO2--to-N2O reduction, while Thauera mediated the periplasmic nitrate reduction and cytoplasmic NO2--to-NH4+ during Fe(II) oxidation. However, Thauera showed much lower abundance than the dominant genera, resulting in slow nitrate reduction and limited NH4+ production. These findings provide new insights into the response of denitrification and DNRA bacteria to Fe(II) oxidation and cell encrustation in anoxic environments.

The Influence of Pulmonary Veins' Anatomic Features and Catheter Coaxiality on Cryoballoon Ablation Results for Paroxysmal Atrial Fibrillation

A total of 172 consecutive patients with sympathetic paroxysmal atrial fibrillation who received cryoballoon (CB) ablation from 2020 to 2021 were retrospectively analyzed in this study. Catheter coaxiality and anatomic features of pulmonary veins (PVs) on computed tomography images were explored by several parameters and their influence on the cryoablation results was then analyzed. The rate of incomplete CB occlusion was significantly higher for inferior than superior PVs. A multivariate analysis revealed that a short distance (<6.3 mm) from PV ostium to first branch (D-PVB) and a small angle (<32.5°) of first branch were independent predict factors for an incomplete CB occlusion in right inferior PVs (RIPVs). A combination of D-PVB and angle of first branch could elevate the predictor value for an incomplete balloon occlusion with a sensitivity of 0.85 and specificity of 1.0 for RIPVs. For PVs with a perfect balloon occlusion, the best catheter coaxiality was observed in right superior PV while the worst catheter coaxiality was observed in RIPV. A more aggressive catheter manipulation with a "7" or "reverse-U" shape of long sheath could obtain a better catheter coaxiality compared with conventional manipulation strategy for RIPVs. In Conclusion, a short D-PVB and a small angle of first branch were independent predict factors for an incomplete CB occlusion in RIPVs. A more aggressive catheter manipulation strategy was recommended to achieve a complete balloon occlusion and a better catheter coaxiality for RIPVs.

[A rational analysis of the commonly used renal tumor scoring systems in predicting surgical outcomes of cystic renal masses]

Objective: To explore the predictive effect of the renal tumor scoring system on the surgical outcomes of cystic renal masses (CRM). Methods: A retrospective analysis was performed on the data of 234 patients who received robotic-assisted partial nephrectomy (RAPN) treatment in the First Affiliated Hospital of Xi'an Jiaotong University from January 2018 to June 2020. And 31 cases had CRM and 203 cases had solid renal masses (SRM). The propensity score of patients was calculated by logistic regression model, and 1∶2 matching was performed by the nearest neighbor method. The changes in perioperative indexes and long-term estimated glomerular filtration rate (eGFR) in CRM group and SRM group were compared. The CRM group and SRM group were stratified according to the complexity grading of R.E.N.A.L. score and PADUA score, respectively, to compare the difference in the achievement rate of ideal surgical outcome between the two groups, and analyze the predictive factors affected. The CRM diameter was stratified with 4 cm as the cut-off value (CRM1 group with a diameter<4 cm, CRM2 group with a diameter≥4 cm), and the surgical results were compared with the matched SRM1 group and SRM2 group. Results: In the matching cohort, the CRM group comprised 29 patients with a mean age of (48.7±10.8) years, of which 22 (75.9%) were males. The SRM group included 58 patients with a mean age of (50.4±10.2) years, of which 41 (70.7%) were males, with no statistically significant difference (all P>0.05). The warm ischemia time (WIT) [M (Q1,Q3)] in the CRM group was longer than that in the SRM group [23(18, 25) vs 19(17, 25) min, P=0.040]. The operation time (OT) [M (Q1,Q3)] in the CRM group was also longer than that of the SRM group [130(100, 150) vs 108(86, 120) min, P=0.006]. The change in serum creatinine before and after the operation [M (Q1,Q3)] was higher in the CRM group than in the SRM group [15(10, 23) vs 12(6, 17) μmol/L, P=0.030]. The ideal surgical outcomes were achieved in 7 patients (24.1%) in the CRM group and 36 patients (62.1%) in the SRM group. The number of patients achieving ideal surgical outcomes in R.E.N.A.L. intermediate complex surgery and PADUA advanced complex surgery in the SRM group were 24 (58.5%) and 15 (51.7%), respectively, which were higher than those in the CRM group 6 (27.3%) and 1 (5.9%) respectively (P<0.05). Preoperative eGFR (OR=0.758, 95%CI: 0.719-0.799) and the nature of the tumor (CRM as reference, OR=4.883, 95%CI: 1.550-15.378) were influencing factors for achieving the ideal surgical outcome. Subgroup analysis showed that eGFR changes before and after surgery and the estimated blood loss (EBL) in the CRM2 group were higher than those in the SRM2 group, and WIT and OT were longer than those in the SRM2 group (all P<0.05). The EBL and WIT of the CRM1 group were shorter than those of the CRM2 group (P<0.05). Conclusion: The surgical risk of RAPN in complex CRMs with a maximum diameter of≥4 cm is higher than the risk of RAPN in SRM with equivalent R.E.N.A.L. and PADUA scores.

Role of PPAR-related genes in chronic heart failure: evidence from large populations

BACKGROUND

The role of PPAR signaling and its associated genes in the pathogenesis and progression of chronic heart failure (CHF) remains elusive.

METHODS

We accessed the gene expression profile and relevant baseline information of CHF samples from the Gene Expression Omnibus (GEO) database, specifically from the GSE57338 project.

RESULTS

From GSE57338 project, we derived the expression value of 126 PPAR-related genes. A protein-protein interaction network was then established to illustrate potential protein interactions. ClueGO analysis results revealed that these genes predominantly participate in functions such as export across plasma membrane, regulation of lipid metabolic process, fatty acid metabolism, circulatory system vascular processes, alcohol metabolism, triglyceride metabolism and regulation of lipid localization and response to nutrient. Using the cytohubba plug-in in Cytoscape, we pinpointed ACADM, PPARG and CPT2 as potential central molecules in HF pathogenesis and progression. Subsequent Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis delved into the potential biological role of these three genes in CHF. Immune infiltration analysis suggested that the infiltration level of neutrophils and M2 macrophages might be notably influenced by these genes, thereby playing a role in the CHF mechanism.

CONCLUSIONS

Our research provides a comprehensive insight into the significance of PPAR associated genes in CHF development. Notably, the genes ACADM, PPARG and CPT2 emerged as potential targets for clinical interventions.

Radiation Therapy Knowledge and Health Literacy among Culturally Diverse Patients with Prostate Cancer Treated at a Safety-Net Hospital

PURPOSE/OBJECTIVE(S)

Shared decision making is integral to the physician-patient relationship for radiotherapy (RT) patients. It is implicit that patients both comprehend and retain information explained during consultation. However, quality and quantity of patient knowledge following this visit is unknown. The purpose of this study was to evaluate post-consultation RT knowledge and health literacy among a diverse group of patients.

MATERIALS/METHODS

Participants were patients ≥18 years old who received consultation for definitive or salvage RT to the prostate gland/fossa between April 2021 and January 2023 at an urban safety-net hospital. Following consultation, patients completed the Radiation Oncology Knowledge Assessment Survey (ROKAS), designed to measure patient understanding of proposed RT treatment (e.g., treatment frequency, length, safety) and possible short- and long-term side effects (SE). Additional measures included patients' health literacy, health numeracy (numerical medical concepts), acculturation (assimilation to the dominant culture), and socioeconomic factors. ROKAS was administered in both English and Spanish with Spanish-speaking patients offered medical translation if desired. Bivariate Pearson correlations were conducted to examine the relationships between independent variables and post-consultation RT knowledge. Two-sided t-tests were conducted to examine differences in patients' knowledge by language.

RESULTS

Overall, 39 ROKAS were completed by 24 English-speaking and 15 Spanish-speaking patients (mean age 64.4 [SD 6.8], range 52-79). The majority (93%) of patients 'agreed' or 'strongly agreed' that they understood all the RT information presented. However, only 70% of the RT questions were answered correctly with 26% of patients answering all RT questions correctly. Similarly, 95% of patients 'agreed' or 'strongly agreed' with knowing the side effects of their proposed treatment, but only 71% and 74% of short- and long-term SE questions, respectively, were answered correctly. Higher health literacy (p = 0.04) and health numeracy (p = 0.001) were significantly correlated with better understanding of short-term SE, but not with RT knowledge or long-term SE. Spanish-speaking patients had significantly lower scores of health literacy (p = 0.001) and understanding of long-term (p = 0.01), but not short-term SE.

CONCLUSION

There is a significant gap between perceived and measured knowledge of RT treatment and SE in patients who receive consultation for RT to the prostate gland/fossa. Health literacy was significantly associated with improved knowledge of RT and short-term SE. Spanish-speaking patients had poorer understanding of long-term SE than English-speaking patients. Efforts to identify gaps in patient health literacy are needed to target those at risk and ensure that culturally diverse patient populations can engage in shared decision making with their providers.

Contouring Analysis on Synthetic Contrast-Enhanced MR from GRMM-GAN and Implications on MR-Guide Radiation Therapy

PURPOSE/OBJECTIVE(S)

MR-guided linear accelerators have been commercialized making MR-only planning and adaptation an appealing alternative circumventing MR-CT registration. However, obtaining daily contrast-enhanced MR images can be prohibitive due to the increased risk of side effects from repeated contrast injections. In this work, we evaluate the quality of contrast-enhanced multi-modal MR image synthesis network GRMM-GAN (gradient regularized multi-modal multi-discrimination sparse-attention fusion generative adversarial network) for MR-guided radiation therapy.

MATERIALS/METHODS

With IRB approval, we trained the GRMM-GAN based on 165 abdominal MR studies from 65 patients. Each study included T2, T1 pre-contrast (T1pre), and T1 contrast enhanced (T1ce) images. The two pre-contrast MR modalities, T2 and T1pre images were adopted as inputs for GRMM-GAN, and the T1ce image at the portal venous phase was used as an output. Ten MR scans containing 21 liver tumors were selected for contouring analysis. A Turing test was first given to six radiation oncologists, in which 100 real T1ce and synthetic T1ce image slices are randomly given to the radiation oncologists to determine the authenticity of the synthesis. We then invited two radiation oncologists (RadOnc 1 and RadOnc2) to manually contour the 21 liver tumors independently on the real T1ce images. RadOnc2 then performed contouring on the respective synthetic T1ce MRs. DICE coefficient (defined as the intersection over the average of two volumes) and Hausdorff distance (HD, measuring how far two volumes are from each other) were used as analysis metrics. The DICE coefficients were calculated from the two radiation oncologists' contours on the real T1ce MR for each tumor. The DICE coefficients were also calculated from RadOnc 2's contours on real and synthetic MRs. Besides, tumor center shifts were extracted. The tumor center of mass coordinates was extracted from real and synthetic volumes. The difference in the coordinates indicated the shifts in the superior-inferior (SI), right-left (RL), and anterior-posterior (AP) directions between real and synthetic tumor volumes.

RESULTS

An average of 52.3% test score was achieved from the six radiation oncologists, which is close to random guessing. RadOnc 1 and RadOnc 2, who had participated in the contouring analysis, achieved an average DICE of 0.91±0.02 from tumor volumes drawn on the real T1ce MRs. This result sets the inter-operator uncertainty baseline in the real clinical setting. RadOnc 2 achieved an average DICE (real vs. synth) of 0.90±0.04 and HD of 4.76±1.82 mm. Only sub-millimeter (SI: 0.67 mm, RL: 0.41 mm, AP: 0.39 mm) tumor center shifts were observed in all three directions.

CONCLUSION

The GRMM-GAN method has the potential for MR-guided liver radiation when contrast agents cannot be administered daily and provide synthetic contrast-enhanced MR for better tumor targeting. The network can produce synthetic MR images with satisfactory contour agreement and geometric integrity.

Automation of Dosimetric Data Collection Using C# ESAPI for Intracavitary and Hybrid Intracavitary/Interstitial Brachytherapy Plans

PURPOSE/OBJECTIVE(S)

Dosimetric data extraction for complex brachytherapy plans can be a time-consuming and error-prone process. The Eclipse Scripting API (ESAPI) Microsoft .NET framework and its ability to access the ARIA treatment planning database makes it a powerful tool for researchers to incorporate automation into data collection. This automation allows for more efficient and error-free collection of dosimetric data, and the program can be iterated over multiple patients at one time. The main objectives of this study were (i) to develop a C# ESAPI script capable of automated data collection for multiple brachytherapy plans and (ii) to apply the script and examine dosimetric characteristics of a patient cohort with locally advanced cervical cancer treated using tandem and ovoid (T/O) applicators or hybrid tandem and ovoid applicators with needles (T/O + N).

MATERIALS/METHODS

We developed a ESAPI script capable of receiving a list of patient IDs and creating a CSV dataset of dosimetric data of the requested patients. Eclipse commands were accessed to create a CSV dataset consisting of baseline demographic data, average V100, V125, D100, D90 as well as D0.1cc, D1cc, D2cc of organs at risk (bladder, rectum, sigmoid colon, small bowel) per fraction. We applied the ESAPI script to our single-institution retrospective cohort which included patients who underwent brachytherapy as part of definitive radiation treatment for cervical cancer between May 2017 and November 2022. Patients either received T/O or T/O + N brachytherapy boost. Statistical analysis was performed using two-sided t-tests to examine differences in descriptive dose metrics between the two techniques.

RESULTS

The developed ESAPI script automatically generated a CSV file of baseline demographic data as well as dosimetric data for patients who underwent T/O or T/O + N brachytherapy boost. We demonstrated that the ESAPI script could acquire and analyze the data quickly (<5 s per test case) compared to time required to generate data via manual review (5 min per test case). This is a 98% reduction in time required to review and collect data per patient. The analyzed cohort included 72 patients with cervical cancer: 40 with T/O technique and 32 with T/O + N technique. Larger clinical target volumes (CTV) were seen in the group that received treatment with T/O + N technique versus T/O alone (37.4 cc vs 25.2 cc, p < 0.0007). Dose metrics including V100, V125, D100, D90 of the high-risk CTV as well as D0.1cc, D1cc, D2cc of the bladder, rectum, small bowel were not significantly different between techniques. However, the D0.1cc, D1cc, D2cc of the sigmoid colon were higher for patients who received T/O + N technique by 95, 74, and 64 cGy respectively (p < 0.005, p < 0.003 and p < 0.007).

CONCLUSION

This study highlights the use of a newly developed ESAPI script specific to brachytherapy plans which allows for iteration over multiple patients at one time. We were able to quickly compare multiple dose metrics for two patient groups treated at our institution.

Impact of FAPI-PET/CT on Target Volume Definition in Radiation Therapy of Locally Advanced Biliary Tract Cancer: Compared with MRI/CT

PURPOSE/OBJECTIVE(S)

A new radioactive positron emission tomography (PET) tracer uses inhibitors of fibroblast activation protein (FAPI) to visualize FAP-expressing cancer associated fibroblasts. Significant FAPI-uptake has recently been demonstrated in biliary tract cancer (BTC) patients. Target volume delineation for radiation therapy still relies on often less precise conventional magnetic resonance imaging (MRI) registered with computed tomography (CT) imaging, especially in locally advanced BTC patients. The need for improvement in precise tumor detection and delineation led us to innovatively use the novel FAPI-PET/CT for radiation treatment planning.

MATERIALS/METHODS

Gross tumor volumes (GTVs) of five locally advanced BTC cases were contoured under FAPI-PET/CT method. MRI/CT was used to delineate tumors additionally. The differentiation in target definition was analyzed between FAPI-PET/CT-based GTVs and the manually MRI/CT-based GTVs.

RESULTS

Target definition differed significantly between different imaging methods with mean dice similarity coefficients of 0.5527, mean Jaccard similarity coefficients of 0.4296 and mean volumetric overlap difference of 0.5704, while the mean volumes and standard deviations of GTVs were 18.12±15.10 cm3 and 38.44±24.72 cm3, based on FAPI-PET/CT and MRI/CT respectively (P = 0.102). There was a discordance and difference between the volumes of FAPI-GTVs-based GTVs and the manually contoured GTVs based on MRI/CT.

CONCLUSION

Due to its high tumor to background contrast, FAPI-PET/CT seems to be a superior imaging modality compared to the current gold standard MRI/CT in BTC. For the first time, we demonstrate how FAPI-PET/CT could facilitate target definition and increases accuracy in radiation oncology in BTC. Limited to the sample size, we still need more large-scale data to support this view.

Universal DNA methylation age across mammalian tissues

Aging, often considered a result of random cellular damage, can be accurately estimated using DNA methylation profiles, the foundation of pan-tissue epigenetic clocks. Here, we demonstrate the development of universal pan-mammalian clocks, using 11,754 methylation arrays from our Mammalian Methylation Consortium, which encompass 59 tissue types across 185 mammalian species. These predictive models estimate mammalian tissue age with high accuracy (r > 0.96). Age deviations correlate with human mortality risk, mouse somatotropic axis mutations and caloric restriction. We identified specific cytosines with methylation levels that change with age across numerous species. These sites, highly enriched in polycomb repressive complex 2-binding locations, are near genes implicated in mammalian development, cancer, obesity and longevity. Our findings offer new evidence suggesting that aging is evolutionarily conserved and intertwined with developmental processes across all mammals.

Novel Insight into Microbially Mediated Nitrate-Reducing Fe(II) Oxidation by Acidovorax sp. Strain BoFeN1 Using Dual N-O Isotope Fractionation

Microbially mediated nitrate reduction coupled with Fe(II) oxidation (NRFO) plays an important role in the Fe/N interactions in pH-neutral anoxic environments. However, the relative contributions of the chemical and microbial processes to NRFO are still unclear. In this study, N-O isotope fractionation during NRFO was investigated. The ratios of O and N isotope enrichment factors (18ε:15ε)-NO3- indicated that the main nitrate reductase functioning in Acidovorax sp. strain BoFeN1 was membrane-bound dissimilatory nitrate reductase (Nar). N-O isotope fractionation during chemodenitrification [Fe(II) + NO2-], microbial nitrite reduction (cells + NO2-), and the coupled process [cells + NO2- + Fe(II)] was explored. The ratios of (18ε:15ε)-NO2- were 0.58 ± 0.05 during chemodenitrification and -0.41 ± 0.11 during microbial nitrite reduction, indicating that N-O isotopes can be used to distinguish chemical from biological reactions. The (18ε:15ε)-NO2- of 0.70 ± 0.05 during the coupled process was close to that obtained for chemodenitrification, indicating that chemodenitrification played a more important role than biological reactions during the coupled process. The results of kinetic modeling showed that the relative contribution of chemodenitrification was 99.3% during the coupled process, which was consistent with that of isotope fractionation. This study provides a better understanding of chemical and biological mechanisms of NRFO using N-O isotopes and kinetic modeling.

A small extent of seawater intrusion significantly enhanced Cd uptake by rice in coastal paddy fields

Paddy fields located around estuaries suffer from seawater intrusion, and how and to what extent salinity levels influence Cd accumulation in rice grains is still unclear. Pot experiments were carried out by cultivating rice under alternating flooding and drainage conditions with different salinity levels (0.2‰, 0.6‰ and 1.8‰). The Cd availability was greatly enhanced at 1.8‰ salinity due to the competition for binding sites by cations and the formation of Cd complexation with anions, which also contributed to Cd uptake by rice roots. The soil Cd fractions were investigated and found that the Cd availability significantly decreased during flooding stage, while it rapidly increased after soil drainage. During drainage stage, Cd availability was greatly enhanced at 1.8‰ salinity mainly attributed to the formation of CdCl_n^2-n. The kinetic model was established to quantitatively evaluate Cd transformation, and it found that the release of Cd from organic matter and Fe-Mn oxides was greatly enhanced at 1.8‰ salinity. The results of pot experiments showed that there was a significant increase in Cd content in rice roots and grains in the treatment of 1.8‰ salinity, because the increasing salinity induced an increase in Cd availability and upregulation of key genes regulating Cd uptake in rice roots. Our findings elucidated the key mechanisms by which high salinity enhanced Cd accumulation in rice grains, and more attention should be given to the food safety of rice cultivated around estuaries.

Governing the aggregation of type I collagen mediated through β-cyclodextrin

The effect of carbohydrates on collagen self-assembly behavior has been widely investigated because of their regulation on collagen fibrogenesis in vivo. In this paper, β-cyclodextrin (β-CD) was selected as an external disturbance to explore its intrinsic regulating mechanism on collagen self-assembly. The results of fibrogenesis kinetics indicated that β-CD had a bilateral regulation on collagen self-aggregation process, which was closely related to the content of β-CD: collagen protofibrils with low β-CD content were less aggregated compared to collagen protofibrils with high β-CD content. However, typical periodic stripes of ~67 nm on collagen fibrils were observed from transmission electron microscope (TEM), indicating that β-CD did not disturb the lateral arrangement of collagen molecules to form a 1/4 staggered structure. Correspondingly, the degree of aggregation of collagen self-assembled fibrils was closely correlated with the addition of β-CD content, as confirmed by field emission scanning electron microscopy (FESEM) and atomic force microscope (AFM). In addition, collagen/β-CD fibrillar hydrogel had good thermal stability and cytocompatibility. These results provide a better understanding of how to construct a structurally reliable collagen/β-CD fibrillar hydrogel as a biomedical material in a β-CD-regulated environment.

[Safety and efficacy of the early administration of levosimendan in patients with acute non-ST-segment elevation myocardial infarction and elevated NT-proBNP levels: An Early Management Strategy of Acute Heart Failure (EMS-AHF)]

Objectives: To investigated the safety and efficacy of treating patients with acute non-ST-segment elevation myocardial infarction (NSTEMI) and elevated levels of N-terminal pro-hormone B-type natriuretic peptide (NT-proBNP) with levosimendan within 24 hours of first medical contact (FMC). Methods: This multicenter, open-label, block-randomized controlled trial (NCT03189901) investigated the safety and efficacy of levosimendan as an early management strategy of acute heart failure (EMS-AHF) for patients with NSTEMI and high NT-proBNP levels. This study included 255 patients with NSTEMI and elevated NT-proBNP levels, including 142 males and 113 females with a median age of 65 (58-70) years, and were admitted in the emergency or outpatient departments at 14 medical centers in China between October 2017 and October 2021. The patients were randomly divided into a levosimendan group (n=129) and a control group (n=126). The primary outcome measure was NT-proBNP levels on day 3 of treatment and changes in the NT-proBNP levels from baseline on day 5 after randomization. The secondary outcome measures included the proportion of patients with more than 30% reduction in NT-proBNP levels from baseline, major adverse cardiovascular events (MACE) during hospitalization and at 6 months after hospitalization, safety during the treatment, and health economics indices. The measurement data parameters between groups were compared using the t-test or the non-parametric test. The count data parameters were compared between groups using the χ² test. Results: On day 3, the NT-proBNP levels in the levosimendan group were lower than the control group but were statistically insignificant [866 (455, 1 960) vs. 1 118 (459, 2 417) ng/L, Z=-1.25,P=0.21]. However, on day 5, changes in the NT-proBNP levels from baseline in the levosimendan group were significantly higher than the control group [67.6% (33.8%,82.5%)vs.54.8% (7.3%,77.9%), Z=-2.14, P=0.03]. There were no significant differences in the proportion of patients with more than 30% reduction in the NT-proBNP levels on day 5 between the levosimendan and the control groups [77.5% (100/129) vs. 69.0% (87/126), χ²=2.34, P=0.13]. Furthermore, incidences of MACE did not show any significant differences between the two groups during hospitalization [4.7% (6/129) vs. 7.1% (9/126), χ²=0.72, P=0.40] and at 6 months [14.7% (19/129) vs. 12.7% (16/126), χ²=0.22, P=0.64]. Four cardiac deaths were reported in the control group during hospitalization [0 (0/129) vs. 3.2% (4/126), P=0.06]. However, 6-month survival rates were comparable between the two groups (log-rank test, P=0.18). Moreover, adverse events or serious adverse events such as shock, ventricular fibrillation, and ventricular tachycardia were not reported in both the groups during levosimendan treatment (days 0-1). The total cost of hospitalization [34 591.00(15 527.46,59 324.80) vs. 37 144.65(16 066.90,63 919.00)yuan, Z=-0.26, P=0.80] and the total length of hospitalization [9 (8, 12) vs. 10 (7, 13) days, Z=0.72, P=0.72] were lower for patients in the levosimendan group compared to those in the control group, but did not show statistically significant differences. Conclusions: Early administration of levosimendan reduced NT-proBNP levels in NSTEMI patients with elevated NT-proBNP and did not increase the total cost and length of hospitalization, but did not significantly improve MACE during hospitalization or at 6 months.

Cryoballoon ablation for atrial fibrillation in patients with heart failure with mildly reduced and preserved ejection fraction

AIMS

Limited data are available on the outcomes of cryoballoon ablation (CBA)-based pulmonary vein isolation (PVI) for atrial fibrillation (AF) in patients with heart failure (HF) with preserved ejection fraction (HFpEF) and mildly reduced ejection fraction (HFmrEF). The present study aimed to evaluate the safety and effectiveness of CBA in such patients.

METHODS AND RESULTS

Consecutive patients with AF referred for CBA-based PVI from two highly experienced electrophysiology centres were included in this retrospective study. Of 651 patients undergoing CBA, 471 cases were divided into four groups: No HF (n = 255), HFpEF (n = 101), HFmrEF (n = 78), and HF with reduced ejection fraction (n = 37). Similar early recurrence of atrial arrhythmia was found among groups (16.2% vs. 15.4% vs. 14.9% vs. 12.2%, P = 0.798), and no significant difference of long-term sinus rhythm (SR) maintenance was identified among the HFmrEF, HFpEF, and No HF groups (71.8% vs. 75.2% vs. 79.6%, P = 0.334). CBA is safe for patients with HFmrEF and HFpEF with similar complications compared with the No HF group (3.8% vs. 4.0% vs. 3.1%, P = 0.814). The reassessment of cardiac function after CBA showed that patients with HF indicated beneficial outcomes. Left atrial diameter (LAD) and left ventricular ejection fraction were significantly improved in the HFmrEF group. There were 41.6% of patients in the HFpEF group who were completely relieved from HF. LAD and New York Heart Association (NYHA) were associated with recurrence in the HFpEF and HFmrEF groups, and the maintenance of SR was an independent predictor of NYHA improvement for all HF groups.

CONCLUSIONS

Patients with HFmrEF and HFpEF could benefit from CBA with high SR maintenance and significant HF improvement.

Hematite-promoted nitrate-reducing Fe(II) oxidation by Acidovorax sp. strain BoFeN1: Roles of mineral catalysis and cell encrustation

Although nitrate-reducing Fe(II) oxidizing (NRFO) bacteria can grow sustainably in natural environments, numerous laboratory studies suggested that cell encrustation-induced metabolism limitations and cell death occurred more seriously in the absence of natural minerals. Hence, a study on how natural minerals could affect NRFO is warranted. This study examined the impact of hematite on NRFO by Acidovorax sp. BoFeN1 with different electron donors (acetate and Fe(II), acetate alone, and Fe(II) alone) and with nitrate as an electron acceptor. When acetate and Fe(II) were used as the electron donors, the amount of Fe(II) oxidation and nitrate reduction was enhanced in the presence of hematite, whereas no promotion was observed when only acetate was added as an electron donor. Under the conditions with only Fe(II) added as an electron donor, the level of Fe(II) oxidation was increased from 3.07 ± 0.06 to 3.92 ± 0.02 mM in the presence of hematite and nitrate reduction was enhanced. This suggests that hematite promotes microbial nitrate reduction by accelerating the biological oxidation of Fe(II). The main secondary minerals were goethite and lepidocrocite. After adding hematite, the assemblage of iron minerals on the cell surface decreased, and the cell crusts became thinner, indicating that hematite effectively mitigated cell encrustation. Furthermore, hematite accelerated the chemical oxidation of Fe(II) by nitrite. Hence, hematite can promote the NRFO of Acidovorax sp. BoFeN1 via two possible pathways: (i) hematite acts as nucleation sites to mitigate cell encrustation; (ii) hematite catalyzes the biological and chemical oxidation of Fe(II) through the mineral catalysis effects. This study highlights the importance of existing iron minerals on NRFO and sheds light on the survival strategy of NRFO bacteria in anoxic subsurface environments.

Can a simple echocardiographic Doppler VTI based flow comparison between the RVOT and LVOT assist in identifying patients with a significant atrial septal defect?

Background

Detection of haemodynamically significant shunting from atrial septal defect (ASD) can be identified by using the pulmonary-systemic flow ratio (Qp/Qs). However, calculation of Qp/Qs by echocardiography relies on geometric assumptions that outflow tracts are circular, suffers from squared linear measures, and accurate measurement of right ventricular outflow tract (RVOT) diameter is challenging. Whilst adults with ASD should have overt right ventricular dilatation, RV sizing on echocardiography is often subjective and underappreciated. We evaluated whether a dimensionless index of flow (VTI) differences between the RVOT and left ventricular outflow tract (LVOT) could assist in identifying patients with ASD, and compared it with relative atrial index (RAI), a parameter previously assessed in identifying atrial shunting.

Methods

Data from 64 consecutive patients who underwent ASD closure and had no concomitant lesions, were compared with 63 normal controls. RVOT VTI, LVOT VTI, LVOT diameter, and atrial areas were measured.

Results

Between controls and ASD patients, there was no difference in LVOT VTI or forward stroke volume, but ASD patients had significantly higher RVOT VTI. The RVOT-LVOT VTI ratio was 1:1 in controls and 1.5:1 in ASD patients. Area under the ROC curve analysis of RVOT-LVOT VTI ratio was 0.83, and a ratio of 1.1:1 predicted patients with ASD with 86% sensitivity and 73% specificity. In comparison, the area under the ROC curve analysis of RAI was 0.70, and an RAI of 1.05:1 predicted patients with ASD with 77% sensitivity and 44% specificity.

Conclusion

Calculation of the dimensionless RVOT-LVOT VTI ratio is simple, and may be a useful additional semi-quantitative tool to assist cardiologists and sonographers in detecting atrial shunting, particularly in patients with borderline or overt right heart dilatation, and identify who patients should undergo further evaluation.

Funding Acknowledgement

Type of funding sources: None.

Estimation of the Frequency and Time of Human Exposure to Arsenic by Single Hair Analysis

Arsenic (As) and its compounds are widely used in many applications. Long-term exposure to As can cause acute and chronic poisoning. In severe cases, it can lead to adverse effects, such as gene mutation, cell cancer and fetal malformation. The objective of this study was to accurately estimate As exposure frequency and time. Quantitative analysis of As in single hairs obtained from APL (acute promyelocytic leukemia) patients treated with As₂O₃ was performed by LA-ICP-MS. An informative As concentration distribution profile of single hair was applied to estimate the As exposure frequency and time. As exposure frequency was estimated according to the number of As concentration peaks. As exposure time was estimated according to the hair growth length in combination with the hair growth rate. The validation results demonstrate that this method was more efficient than the traditional method; compared with the traditional method, which provides estimates in months, our model shortened the As exposure time estimate to the range of a few days, which considerably improved the inference accuracy. Therefore, these results can be used for forensic toxicology studies, environmental exposure monitoring, etc.

Moricizine prevents atrial fibrillation by late sodium current inhibition in atrial myocytes

Background

Enhanced late sodium current (INaL) is reportedly related to an increased risk of atrial fibrillation (AF). Moricizine, as a widely used anti-arrhythmia drug for suppressing ventricular tachycardia, has also been shown to prevent paroxysmal AF. However, the mechanism of its therapeutic effect remains poorly understood.

Methods

Angiotensin II (Ang II) was induced in C57Bl/6 mice (male wild-type) for 4 weeks to increase the susceptibility of AF, and acetylcholine-calcium chloride was used to induce AF. The whole-cell patch-clamp technique was used to detect INaL from isolated atrial myocytes. The expression of proteins in atrial of mice and HL-1 cells were examined by Western-blot.

Results

The results showed that moricizine significantly inhibited Ang II-mediated atrial enlargement and reduced AF vulnerability. We found that the densities of INaL were enhanced in Ang II-treated left and right atrial cardiomyocytes. Simultaneously, the Ang II-induced increase in INaL currents density was alleviated by the administration of moricizine, and no alteration in Nav1.5 expression was observed. In normal isolated atrial myocytes, moricizine significantly reduced Sea anemone toxin II (ATX II)-enhanced INaL density with a reduction of peak sodium currents. In addition, moricizine reduced the Ang II-induced upregulation of phosphorylated calcium/calmodulin-dependent protein kinase-II (p-CaMKII) in both the left and right atria. In HL-1 cells, moricizine also reduced the upregulation of p-CaMKII with Ang II and ATX II intervention, respectively.

Conclusions

Our results indicate that Ang II enhances the INaL via activation of CaMKII. Moricizine inhibits INaL and reduces CaMKII activation, which may be one of the mechanisms of moricizine suppression of AF.

Human pulmonary artery smooth muscle cell dysfunction is regulated by miR-509-5p in hypoxic environment

Reportedly, dysfunction of human pulmonary arterial smooth muscle cells (PASMCs) is associated with the pathogenesis of pulmonary arterial hypertension (PAH). Herein, the role of miR-509-5p in hypoxia-induced PASMCs and the underlying mechanism were explored. PASMCs were cultured under both normoxia and hypoxia conditions. Quantitative real-time polymerase-chain reaction (qPCR) was employed for quantifying the expressions of miR-509-5p and DNMT1 mRNA in the serum of PAH patients and PASMCs. MiR-509-5p mimics and inhibitors were then, respectively, transfected into PAMSCs, and CCK-8 and Transwell assays were utilized to detect PASMCs' proliferation and migration. Flow cytometry was executed for evaluating PASMCs' apoptosis. Interrelation between miR-509-5p and DNMT1 was determined utilizing bioinformatics analysis and dual-luciferase reporter assay. Western blot assay was used to detect the expression of DNMT1 or SOD2. MiR-509-5p in serum samples of patients with PAH as well as hypoxia-induced PASMCs was significantly down-regulated, whereas DNMT1 was markedly up-regulated. MiR-509-5p mimics reduces the proliferation and migration of PASMCs, but promotes the apoptosis; conversely, miR-509-5p inhibitors exerted opposite effects. DNMT1 was identified as a target gene of miR-509-5p, and overexpression of DNMT1 reversed the biological functions of miR-509-5p in regulating the phenotypes of PAMSCs. MiR-509-5p up-regulated the expression of SOD2 by down-regulating DNMT1. MiR-509-5p regulates the proliferation, migration and apoptosis of PASMCs, and restoration of miR-509-5p may be a promising strategy to treat PAH.

[Expression and diagnostic value of NKX3.1 and NKX2.2 in mesenchymal chondrosarcoma]

Objective: To investigate the immunohistochemical expression of NKX3.1 and NKX2.2 in mesenchymal chondrosarcoma (MC), and to explore the differential diagnostic value of NKX3.1 and NKX2.2 in MC and other types of small round cell malignant tumors. Methods: A total of 12 cases of MC and 97 other small round cell malignant tumors diagnosed in Jinling Hospital, Nanjing University School of Medicine from 2001 to 2020 were collected for NKX3.1 and NKX2.2 immunohistochemical detection. Among them, two kinds of NKX3.1 antibodies [rabbit polyclonal antibody and rabbit monoclonal antibody (EP356)] were used for detection in 12 cases of MC, and one NKX3.1 antibody (rabbit polyclonal antibody) was detected in 97 cases of other small round cell malignant tumors, and the relevant literature was reviewed. Results: The 12 MC patients included 7 females and 5 males, with a mean age of 33 years (14-54 years). Nine cases were from bone and three from soft tissue. Among the 12 MC patients, 8 patients had postoperative recurrence or metastasis, and 3 of them died of tumor recurrence or metastasis. Histologically, 12 cases of MC showed typical bidirectional differentiation.The positive rate of both NKX3.1 antibodies in MC was 12/12, NKX3.1 was focal weakly positive in only one of 12 chondrosarcomas (grade 3), 5 alveolar rhabdomyosarcomas, 5 embryonal rhabdomyosarcomas, and 5 solitary fibrous tumors, respectively. The remaining 70 cases of other small round cell malignant tumors were negative. The positive rates of NKX2.2 in MC, Ewing sarcoma and olfactory neuroblastoma were 12/12, 15/15 and 4/5, respectively. In 12 cases of chondrosarcoma (grade 3), 5 cases of poorly differentiated synovial sarcoma, 5 cases of alveolar rhabdomyosarcoma, and 5 cases of solitary fibrous tumor, NKX2.2 was focally and weakly positive in only one case, respectively, and all the remaining 50 cases of other small round cell malignant tumors were negative. Conclusions: The expression of NKX3.1 and NKX2.2 proteins are significant indicators in the diagnosis of MC, and the combined detection of NKX3.1 and NKX2.2 can help distinguish MC from most other small round cell malignant tumors.

[Succinate dehydrogenase-deficient renal cell carcinoma:a clinicopathological, ultrastructural and molecular analysis]

Objective: To investigate the clinicopathological features, immunophenotype, ultrastructure, genetic alterations and prognosis of succinate dehydrogenase-deficient renal cell carcinoma (SDH RCC). Methods: A total of 11 SDH RCCs, diagnosed from 2010 to 2019, were selected from the Department of Pathology of Nanjing Jingling Hospital, Nanjing University School of Medicine for clinicopathologic, immunohistochemical (IHC), ultrastructural investigation and follow-up. The molecular features of seven cases were analyzed by the panel-targeted DNA next generation sequencing (NGS). Results: There were seven males and four females, with ages ranging from 24 to 62 years (mean 41.4 years, median 41 years). Microscopically, SDH RCC was mainly composed of solid and tubular structures with local cystic change. Four cases showed nested or trabecular structure distributed in a loose hypocellular connective tissue or around scar, similar to oncocytoma. The neoplastic cells demonstrated flocculent eosinophilic cytoplasm with typical intracytoplasmic vacuoles. Immunohistochemically, eight cases were negative for SDHB; three cases showed focal and weak expression, whereas normal renal tubular and vascular endothelial cells demonstrated strong cytoplasmic staining. NGS of DNA targeted-panel detected pathogenic mutations of SDHB gene in seven cases (including three cases with equivocal IHC expression of SDHB), without any mutations in other SDH related genes. There were four cases of SDHB missense mutation, one case of frameshift mutation, one case of splicing mutation, and one case of acquired stop codon mutation. Conclusions: SDH RCC is a distinct variant of RCCs with genetic tendency or with hereditary cancer syndrome. NGS is recommended to detect the related gene mutations for a definitive diagnosis. The patients should be closely followed up.

Exosomes and Exosomal Non-coding RNAs Are Novel Promises for the Mechanism-Based Diagnosis and Treatments of Atrial Fibrillation

Atrial fibrillation (AF) is the most common arrhythmia worldwide and has a significant impact on human health and substantial costs. Currently, there is a lack of accurate biomarkers for the diagnosis and prognosis of AF. Moreover, the long-term efficacy of the catheter ablation in the AF is unsatisfactory. Therefore, it is necessary to explore new biomarkers and treatment strategies for the mechanism-based AF. Exosomes are nano-sized biovesicles released by nearly all types of cells. Since the AF would be linked to the changes of the atrial cells and their microenvironment, and the AF would strictly influence the exosomal non-coding RNAs (exo-ncRNAs) expression, which makes them as attractive diagnostic and prognostic biomarkers for the AF. Simultaneously, the exo-ncRNAs have been found to play an important role in the mechanisms of the AF and have potential therapeutic prospects. Although the role of the exo-ncRNAs in the AF is being actively investigated, the evidence is still limited. Furthermore, there is a lack of consensus regarding the most appropriate approach for exosome isolation and characterization. In this article, we reviewed the new methodologies available for exosomes biogenesis, isolation, and characterization, and then discussed the mechanism of the AF and various levels and types of exosomes relevant to the AF, with the special emphasis on the exo-ncRNAs in the diagnosis, prognosis, and treatment of the mechanism-based AF.

Inflammasome-mediated neurodegeneration following heart disease

Background

Myocardial infarction (MI) has been suggested as a critical predisposing factor for Alzheimer’s disease (AD); however, the underlying mechanisms remain unknown. PYD domains-containing protein 3 (NLRP3) is a key factor to mediate inflammasome formation. Previous studies have shown that NLRP3 activation in brain microglia is required for AD; however, its possible role in MI-induced future development of neurodegeneration is not yet understood. These questions were addressed in the current study.

Methods

We generated microglia-specific NLRP3 mutation mice in the AD-prone APP/PS1 background (APP/PS1/NLRP3^MKO), and studied the neurodegeneration in these mice after MI compared to the control wild-type C57/BL6J or APP/PS1 mice. NLRP3, IL-1β and caspase-1 levels were determined by Enzyme-linked immunoassay (ELISA). The heart function was determined by the slope of end systolic pressure-volume relationship, left ventricular end diastolic pressure, the positive maximal pressure derivative as well as the degree of fibrosis by Masson’s trichrome staining. Mouse behavior measurement includes Morris water-maze test and motor assessment.

Results

We found that compared with the control wild-type C57/BL6J or APP/PS1 mice, the effects of MI on the subsequent development of defected spatial reference memory and motor activity were all attenuated in APP/PS1/NLRP3^MKO mice, likely resulting from the reduced formation of amyloid-beta peptide aggregates (Aβ) plaques.

Conclusions

NLRP3 may play a non-redundant role in the MI-induced future development of AD.

Long term prognostic utility of exercise capacity in renal transplant candidates

Background

Pharmacological stress testing is commonly performed for cardiovascular risk stratification in potential renal transplant candidates due to a perceived inability for these patients to exercise. We have previously reported that exercise stress testing is feasible in renal transplant candidates but the prognostic utility of exercise capacity in this patient group is not known.

Purpose

This study prospectively evaluated the effect of exercise capacity on the risk of major adverse cardiovascular events (MACE), defined as a composite of cardiac death, non-fatal myocardial infarction, and stroke, in renal transplant candidates undergoing exercise stress echocardiography (ESE) for pre-transplant cardiovascular assessment.

Methods

We evaluated 898 consecutive patients with chronic kidney disease stage 4/5 who underwent symptom-limited treadmill ESE over 5-year mean follow-up. Exercise capacity was measured by age and sex predicted metabolic equivalents (METs). The primary outcome was achievement of predicted METs with first MACE. Cox proportional hazard multivariable modelling was used to determine MACE predictors with transplantation treated as a time-varying covariate. We also performed secondary analysis using a 7 MET threshold.

Results

There were 106 MACE with an annual cumulative risk of 2.4%. During follow-up, 525 (58%) received transplantation. Achievement of predicted METs (48%) (hazard ratio (HR) 0.49, 95% confidence interval (CI) 0.29–0.82, p=0.007) and transplantation (HR 0.52, 95% CI 0.30–0.91, p=0.02) were independently associated with reduced MACE. Similar results were observed using a 7 MET threshold achieved by 734 (82%) patients. Patients achieving predicted METs had no difference in MACE regardless of subsequent transplantation (HR 0.78, 95% CI 0.32–1.92, p=0.59). Patients who achieved predicted METs and did not receive transplantation had similar outcomes to those that did not achieve predicted METs and received transplantation (HR 0.97, 95% CI 0.42–2.25, p=0.95).

Conclusions

Exercise capacity is associated with reduced long-term MACE in renal transplant candidates undergoing ESE for pre-transplant cardiovascular assessment. Achievement of age and sex predicted METs confers excellent prognosis independent of subsequent transplantation.

Funding Acknowledgement

Type of funding sources: None.

Pulmonary artery pressure is associated with mid-term major adverse cardiovascular events and postprocedure pericardial effusion in atrial fibrillation patients undergoing left atrial appendage occlusion

Background

Patients with nonvalvular atrial fibrillation (NVAF) undergoing left atrial appendage occlusion (LAAO) are at high risk of stroke or bleeding. However, risk factors for their adverse cardiovascular events remain largely unknown. Pulmonary hypertension has been shown to be related to poor prognosis in many heart diseases. In this study, we determined whether elevated pulmonary artery systolic pressure (PASP) is associated with postprocedure adverse events and major adverse cardiovascular events (MACE) in these patients.

Methods

From June 2017 and December 2019, 530 consecutive patients with NAVF at high risk of stroke or bleeding who undergone LAAO were retrospectively enrolled in our study. The preprocecure PASP was obtained by transthoracic echocardiography using the simplified Bernoulli's equation. Patients were followed-up through clinic visits or over the phone at discharge at 1-3 months, 6 months, and annually thereafter. The median follow-up time was 12 months, and clinical data were analyzed. MACE was defined as myocardial infarction, definite heart failure, stroke, or all-cause death. The outcome of postprocedure pericardial effusion included in-hospital pericardial effusion and pericardial effusion detected after discharge.

Results

Univariate analyses indicated that patients who had MACE tended to have elevated PASP (P=0.005). After dividing the cohort according to the cut-off value of PASP, Kaplan-Meier curves indicated that patients with PASP ≥39.5 mmHg had a higher risk of MACE (P=0.007) and heart failure hospitalization (P=0.005) compared to patients whose PASP <39.5 mmHg. Cox regression analysis showed that PASP was a predominant risk factor of MACE (HR =2.337, 95% CI, 1.207-4.526, P=0.012) and heart failure hospitalization (HR =3.701, 95% CI, 1.118-12.251, P=0.032). Furthermore, the PASP cut-off added incremental discriminatory capacity to the MACE risk model of this cohort. In addition, logistic regression showed that PASP had as a significant association with postprocedure pericardial effusion (OR =1.061, P=0.032).

Conclusions

Elevated PASP was associated with postprocedure pericardial effusion and mid-term MACEs in patients with atrial fibrillation (AF) undergoing LAAO.

Effectiveness and safety of exercise training and rehabilitation in chronic thromboembolic pulmonary hypertension: a systematic review and meta-analysis

BACKGROUND

Patients with chronic thromboembolic pulmonary hypertension (CTEPH) still have impaired exercise training and quality of life (QoL) despite pulmonary arterial hypertension (PAH)-targeted drugs. Exercise training is considered to improve exercise capacity and QoL in patients with pulmonary hypertension (PH), but this has not been fully studied in CTEPH patients. We conducted the meta-analysis and systematic review to evaluate the effectiveness and safety of exercise training in patients with CTEPH.

METHODS

The relevant literature was retrieved for the meta-analysis using the PubMed, EMBASE, and Cochrane Library databases published before December 2020. The primary outcome was a change in six-minute walk distance (6MWD). We also assessed the effect of exercise training on peak oxygen uptake per kilogram (peak VO2/kg), mean pulmonary artery pressure (mPAP) assessed by right heart catheterization (RHC), N-terminal pro-brain-type natriuretic peptide (NT-proBNP), and QoL.

RESULTS

A total of 6 studies with 234 exercise training patients were included. In the pooled analysis, 6MWD significantly improved by 70.14 m (WMD: 58.33 to 81.95, I2=0) after 3-week exercise training. After 12 or 15-week exercise training, 6MWD and peak VO2/kg significantly improved (WMD: 106.22 m, 95% CI: 65.90 to 146.55, I2=87.4%, P<0.0001; 1.84 mL/min/kg, 95% CI: 0.72 to 2.96, P=0.001, respectively). Furthermore, the mPAP decreased by 12.17 mmHg after 12-week exercise training (95% CI: -14.53 to -9.82, P<0.001, I2=99%). The subscales of QoL such as physical function, general health perception, and mental health improved in varying degrees. NT-proBNP did not improve significantly in the pooled analysis. In addition, exercise training was well tolerated without major adverse events occurred during training, and the dropout rate was low.

DISCUSSION

Exercise training may improve exercise capacity, mPAP, and QoL, and was well tolerated among patients with CTEPH. However, more large-scale multicenter studies are needed to confirm the effectiveness and safety of exercise training in patients with CTEPH.

[Hypoxia Accelerate β-Actin Expression through Transcriptional Activation of ACTB by Nuclear Respiratory Factor-1]

Cytoskeletal protein β-actin is abundant both in the cytoplasm and the nucleus, its mRNA is commonly utilized an internal control for gene expression analysis. Recent reports demostrated that hypoxia influences the levels of β-actin in a variety of cells. The mechanism underlying this change are not yet elucidated. In this work, we show that the changes in the levels of hypoxia-induced Nuclear respiratory factor-1 (NRF-1) lead to the change in expression of β-actin. We compared the protein levels of NRF-1 and β-actin in gastric cancer and adjacent tissues and found their significantly upregulation in cancer (33% patitents). When gastric cancer cells and normal gastric cells were treated with 1% O2 for 48 h, the trends in expression levels of NRF-1 and β-actin were similar. When NRF-1 expression was modified by its overexpressing or silencing, the levels of β-actin changed accordingly. In β-actin gene (ACTB), three binding sites for NRF-1 were found. These sites are conserved in human, mouse and rat genomes. In ChIP experiments, we showed that NRF-1 directly binds to human ACTB and mouse Actb coding regions. Its seems that the transcription of β-actin encoding gene is NRF-1 dependent.

11-year follow-up outcomes of catheter ablation of para-hisian accessory pathways

Funding Acknowledgements

Type of funding sources: None.

Background

Ablation of para-hisian accessory pathways (APs) remains challenging due to anatomic characteristics and few studies have focused on the causes for recurrence of radiofrequency ablation of para-hisian APs.

Objective

This retrospective single center study was aimed to explore the risk factors for recurrence of para-hisian APs.

Methods

113 patients who had a para-hisian AP with an acute success were enrolled in the study. In the 11-year follow-up, 15 cases had a recurrent para-hisian AP. Therefore 98 patients were classified into success group while 15 patients were classified into recurrence group. Demographic and ablation characteristics were analyzed.

Results

Gender difference was similar in two groups. The median age was 36.2 years old and was younger in recurrence group. Maximum ablation power was significantly higher in success group (29 ± 7.5 vs 22.9 ± 7.8, p &lt; 0.01). Ablation time of final target sites was found to be markedly higher in success group (123.4 ± 53.1 vs 86.7 ± 58.3, p &lt; 0.05). Ablation time less than 60 seconds was detected in 12 (12.2%) cases in success group and 7 (46.7%) cases in recurrence group (p &lt; 0.01). Occurrence of junctional rhythm was significantly higher in recurrence group (25.5% vs 53.3%, p &lt; 0.05). No severe conduction block, no pacemaker implantation and no stroke were reported. Junctional rhythm during ablation (OR = 3.833, 95%CI 1.083-13.572, p = 0.037) and ablation time &lt;60s (OR = 5.487, 95%CI 1.411-21.340, p = 0.014) were independent risk factors for the recurrence of para-hisian AP.

Conclusions

Considering the long-term safety of ablation of para-hisian AP, proper extension of ablation time and increase of ablation power could be applied during operation.

The tissue transglutaminase: a potential target regulating MDR in breast cancer

OBJECTIVE

Multi-drug resistance (MDR) is the main obstacle influencing the anti-tumor effect in breast cancer. To date, no proper potential targets are found to overcome MDR. Here, tTG was explored to show whether it is a potential target to regulate MDR in breast cancer.

MATERIALS AND METHODS

tTG was silenced by small interfere siRNA. After that, the mRNA level of CD44, CD24, LRP, MRP and MDR1 were detected by RT-PCR. The Western blot analysis was used to detect the expression of LRP, P-gp and MRP. In addition, the impact of tTG on cell apoptosis, as well as cell proliferation were observed. Finally, to evaluate the role of tTG in BALB/c nude mice, the growth of tumor was performed, and the immunohistochemistry analysis was used to observe the expression of LRP, P-gp and MRP in vivo.

RESULTS

In MCF-7/ADR, Compared to MCF-7, tTG expression was highly increased. After silencing tTG, the mRNA level and the protein level of P-gp, MRP, LRP were both differently decreased. The mRNA level of CD44 and CD24 was also down-regulated after silencing tTG. In addition, the cell proliferation was significantly inhibited in the ADR + tTG siRNA+Adriamycin group (p<0.05), and the tumor growth was prevented in a time-dependent situation. Cell apoptosis was significantly strengthened in the ADR+tTG siRNA+Adriamycin group (p<0.05). In vivo, the growth of tumors was reduced after silencing tTG, and the LRP, P-gp and MRP expression were significantly down-regulated in ADR + tTG SiRNA +adriamycin group (p<0.05).

CONCLUSIONS

It is concluded that the tTG may be a potential target regulating the MDR by regulating LRP, P-gp and MRP expression as well as the expression of CD44CD24 to improve the MDR in breast cancer.