Fecal calprotectin: A novel predictor of ulcerated esophageal injury after atrial fibrillation catheter ablation.

BACKGROUND: Atrial esophageal fistula (AEF) is a lethal complication that can occur post atrial fibrillation (AF) ablation. Esophageal injury (EI) is likely to be the initial lesion leading to AEF. Endoscopic examination is the gold standard for a diagnosis of EI but extensive endoscopic screening is invasive and costly. This study was conducted to determine whether fecal calprotectin (Fcal), a marker of inflammation throughout the intestinal tract, may be associated with the existence of esophageal injury. METHODS: This diagnostic study was conducted in a cohort of 166 patients with symptomatic AF undergoing radiofrequency catheter ablation from May 2020 to June 2021. Fcal tests were performed 1-7 days after ablation. All patients underwent endoscopic ultrasonography 1 or 2 days after ablation. RESULTS: The levels of Fcal were significantly different between the EI and non-EI groups (404.9 µg/g (IQR 129.6-723.6) vs. 40.4 µg/g (IQR 15.0-246.2), p < .001). Analysis of ROC curves revealed that a Fcal level of 125 µg/g might be the optimal cut-off value for a diagnosis of EI, giving a 78.8% sensitivity and a 65.4% specificity. The negative predictive value of Fcal was 100% for ulcerated EI. CONCLUSIONS: The level of Fcal is associated with EI post AF catheter ablation. 125 µg/g might be the optimal cut-off value for a diagnosis of EI. Negative Fcal could predict the absence of ulcerated EI, which could be considered a precursor to AEF.

Comparison of physiological and transcriptome responses of corals to strong light and high temperature.

Coral reefs are essential for marine ecology and biodiversity. Global climate change has resulted in severe coral reef degradation, partly via coral bleaching, which is caused by rising sea temperatures and solar light intensity. In this study, we examined the impact of strong light (300 µmol.m-2.s-1) and high temperature (33°C) on the growth, immunity, and gene expression of Galaxea fascicularis. Strong light caused coral bleaching in the absence of high sea temperatures, while no obvious bleaching was observed under high temperature alone. The effect of strong light on calcification rate of G. fascicularis is significantly weaker than that of high temperature. Both strong light and high temperatures significantly affected the immune enzyme activity of G. fascicularis symbionts, with the former having a strong effect on their photosystem. Temperature affected the digestive system, replication and repair, and cell growth and death of coral hosts, as indicated by transcriptomics analysis. These results provide a valuable for strategies to mitigate coral bleaching. TEASER: We explored the effects of strong light exposure and high temperature on coral reefs and their symbiont algae.

Satellite observations reveal anthropogenic pressure significantly affects the suspended particulate matter concentrations in coastal waters of Hainan Island.

Suspended particulate matter (SPM) plays a crucial role in assessing the health status of coastal ecosystems. Satellite remote sensing offers an effective approach to investigate the variations and distribution patterns of SPM, with the performance of various satellite retrieval models exhibiting significant spatial heterogeneity. However, there is still limited information on precise remote sensing retrieval algorithms specifically designed for estimating SPM in tropical areas, hindering our ability to monitor the health status of valuable tropical ecological resources. A relatively accurate empirical algorithm (root mean square error = 2.241 mg L-1, mean absolute percentage error = 42.527%) was first developed for the coastal SPM of Hainan Island based on MODIS images and over a decade of field SPM data, which conducted comprehensive comparisons among empirical models, semi-analytical models, and machine learning models. Long-term monitoring from 2003 to 2022 revealed that the average SPM concentration along the coastal wetlands of Hainan Island was 6.848 mg L-1, which displayed a decreasing trend due to government environmental protection regulations (average rate of change of -0.009 mg L-1/year). The seasonal variations in coastal SPM were primarily influenced by sea surface temperature (SST). Spatially, the concentrations of SPM along the southwest coast of Hainan Island were higher in comparison to other waters, which was attributable to sediment types and ocean currents. Further, anthropogenic pressure (e.g., agricultural waste input, vegetation cover) was the main influence on the long-term changes of coastal SPM in Hainan Island, particularly evident in typical tropical ecosystems affected by aquaculture, coastal engineering, and changes in coastal green vegetation. Compared to other typical ecosystems around the globe, the overall health status of SPM along the coast wetlands of Hainan is considered satisfactory. These findings not only establish a robust remote sensing model for long-term SPM monitoring along the coast of Hainan Island, but also provide comprehensive insights into SPM dynamics, thereby contributing to the formulation of future coastal zone management policies.

Respiratory control minimizes diaphragmatic contraction and dry cough during pulsed-field ablation of atrial fibrillation.

AIMS: Pulsed-field ablation (PFA) is a promising new ablation modality to treat atrial fibrillation. However, PFA can cause varying degrees of diaphragmatic contraction and dry cough, especially under conscious sedation. This prospective study presents a method to minimize the impact of PFA on diaphragmatic contraction and dry cough during the procedure. METHODS AND RESULTS: Twenty-eight patients underwent PFA for pulmonary vein (PV) and superior vena cava isolation under conscious sedation. Each patient received two groups of ablations in each vein: the control group allowed PFA application during any phase of respiratory cycle, while the test group used respiratory control, delivering PFA energy only at the end of expiration. A rating score system was developed to assess diaphragmatic contraction and dry cough. A total of 1401 control ablations and 4317 test ablations were performed. The test group had significantly lower scores for diaphragmatic contraction (P < 0.01) and dry cough (P < 0.001) in all PVs compared to the control group. The average relative reductions in scores for all PVs were 33-47% for diaphragmatic contraction and 67-83% for dry cough. The percentage of ablations with scores ≧2 for diaphragmatic contraction decreased significantly from 18.5-28.0% in the control group to 0.4-2.6% in the test group (P < 0.001). For dry cough, the percentage decreased from 11.9-43.7% in the control group to 0.7-2.1% in the test group. CONCLUSION: Pulsed-field ablation application at the end of expiration can reduce the severity of diaphragmatic contraction and eliminate moderate and severe dry cough during PV isolation performed under conscious sedation.

Selective anatomical catheter ablation of left atrial ganglionated plexus for vasovagal syncope: Left superior and right anterior ganglionated plexus ablation.

BACKGROUND: Vasovagal syncope (VVS) is one of the most common causes of syncope. Traditional treatment has not achieved satisfactory results. The purpose of this study was to assess the feasibility and efficacy of selective anatomical catheter ablation of left atrial ganglionated plexus (GP) as a therapeutic strategy for the patients of symptomatic VVS. METHODS: A total of 70 patients with at least once recurrent syncopal episode of VVS with a positive head-up tilt test were enrolled. They were divided into GP ablation group and control group. Patients in GP ablation group received anatomical catheter ablation of left superior ganglionated plexus (LSGP) and right anterior ganglionated plexus (RAGP). Patients in the control group were guideline-directed conventional therapy. The primary endpoint was VVS recurrences. The secondary endpoint was the recurrence of syncope and prodrome events. RESULTS: There were no statistical differences in clinical characteristics between the ablation group (n = 35) and the control group (n = 35). Over a follow-up of 12 months, the ablation group had significantly lower syncope recurrence compared with the control group (5.7% vs. 25.7%, p = .02), and the ablation group had significantly lower syncope and prodrome recurrence compared with the control group (11.4% vs. 51.4%, p < .001). In GP ablation, 88.6% of the patients showed significant vagal response during LSGP ablation, and 88.6% of the patients showed significantly increased heart rate during RAGP ablation. CONCLUSIONS: For patients with recurrent VVS, selective anatomical catheter ablation of LSGP and RAGP is superior to conventional therapy in reducing syncope recurrence.

Intracardiac echocardiography is a safe and effective alternative to transesophageal echocardiography for left atrial appendage thrombus evaluation at the time of atrial fibrillation ablation: The ICE-TEE study.

BACKGROUND: Intracardiac echocardiography (ICE) technology has been increasingly accepted as an integral part of atrial fibrillation (AF) ablation procedures. It is still unknown whether ICE can routinely replace transesophageal echocardiography (TEE) for routine thrombus screening in non-selective AF patients. OBJECTIVE: To assess whether ICE can routinely replace TEE in screening for left atrial (LA)/left atrial appendage (LAA) thrombus in general patients undergoing catheter ablation for AF. METHODS: A total of 2003 consecutive patients undergoing AF ablation were included. 1155 patients (ICE group) received intra-procedural ICE examination for LA/LAA thrombus screening, while 848 patients (TEE group) received pre-procedure TEE examination. The incidence of thrombus, peri-procedure complications, and hospital efficiency were assessed. RESULTS: The LA and LAA were adequately visualized in all patients. Five patients in the ICE group and 15 patients in the TEE group were found to have LAA thrombus. The incidence of major periprocedural thrombo-embolic events was comparable between two groups (0.2% vs. 0.1%, p = .76), none were due to undetected LA/LAA thrombus. Other major periprocedural complications occurred at similar rates in both groups, while post-procedure fever was less common in the ICE group (12.7% vs. 17.4%, p < .001). Procedure times and hospital length of stay were both shorter in the ICE group (142 min [87-197 min] vs. 150 min [95-205 min], and 3[2-4] day vs. 4[3-5] day, respectively, both p < .001). CONCLUSIONS: ICE can replace TEE for atrial thrombus screening in AF patients undergoing ablation without increased complications. An "ICE replacing TEE" workflow can also reduce the incidence of postoperative fever and improve hospital efficiency.

Chinese expert consensus on the construction of the fluoroless cardiac electrophysiology laboratory and related techniques.

Transcatheter radiofrequency ablation has been widely introduced for the treatment of tachyarrhythmias. The demand for catheter ablation continues to grow rapidly as the level of recommendation for catheter ablation. Traditional catheter ablation is performed under the guidance of X-rays. X-rays can help display the heart contour and catheter position, but the radiobiological effects caused by ionizing radiation and the occupational injuries worn caused by medical staff wearing heavy protective equipment cannot be ignored. Three-dimensional mapping system and intracardiac echocardiography can provide detailed anatomical and electrical information during cardiac electrophysiological study and ablation procedure, and can also greatly reduce or avoid the use of X-rays. In recent years, fluoroless catheter ablation technique has been well demonstrated for most arrhythmic diseases. Several centers have reported performing procedures in a purposefully designed fluoroless electrophysiology catheterization laboratory (EP Lab) without fixed digital subtraction angiography equipment. In view of the lack of relevant standardized configurations and operating procedures, this expert task force has written this consensus statement in combination with relevant research and experience from China and abroad, with the aim of providing guidance for hospitals (institutions) and physicians intending to build a fluoroless cardiac EP Lab, implement relevant technologies, promote the standardized construction of the fluoroless cardiac EP Lab.

Catheter ablation for persistent atrial fibrillation with left ventricular systolic dysfunction: Who is the best candidate?

BACKGROUND: Tachycardia-induced cardiomyopathy is poorly recognized pre-ablation. It remains unclear of better patient selection and timing for catheter ablation in persistent atrial fibrillation (PerAF) with heart failure (HF). METHODS: Consecutive patients with PerAF and left ventricular ejection fraction (LVEF) <50% referred for AF ablation were retrospectively included. The impact of LV size, heart rate (HR), and LVEF pre-ablation were analyzed for assessing LV systolic function recovery, defined as LVEF increase of ≥20% or to a value ≥55% after ablation. RESULTS: A total of 120 patients (2017-2020) were included. After 19 ±14 months post ablation, LVEF improvement was similar in patients with normal or dilated LV (18.3 ± 9.4% vs. 16.1 ± 10.8%, P = .25), rapid or controlled HR (19.5 ± 10% vs. 16.1 ± 10%, P = .09), but higher in HFrEF (HF with reduced EF) than HFmrEF (HF with midrange EF) (21.6 ± 10.3% vs. 14.9 ± 9.3%, P < .01). There was more LV systolic function recovery in those with normal to moderate LV dilation (80%, odds ratio [OR] 15.22, P < .01), HR ≥80 bpm (79%, OR 5.38, P < .01) and HFmrEF (80%, OR 4.03, P < .01). The overall AF freedom was similar between normal and dilated LV (59% vs. 62%, P = .95), rapid and controlled HR (67% vs. 56%, P = .18), and HFmrEF and HFrEF (65% vs. 50%, P = .19). CONCLUSION: Catheter ablation is effective independent of LV dilation, rate control or HFrEF. Patients with normal to moderate LV dilation, resting HR ≥80 bpm and HFmrEF may be candidates for early PerAF ablation to achieve LVEF normalization.

Comparison of synchronization between left bundle branch and his bundle pacing in atrial fibrillation patients: An intra-patient-controlled study.

BACKGROUND: His bundle pacing (HBP) is a physiological pacing strategy to preserve the electrical synchrony of ventricular conduction and left ventricular (LV) function. Left bundle branch pacing (LBBP) has emerged as an alternative physiological pacing technique. OBJECTIVE: To evaluate cardiac electrical and mechanical synchrony comparing LBBP and HBP in patients with permanent atrial fibrillation (AF). METHODS: Consecutive patients with symptomatic bradycardia and AF were enrolled from January to June of 2019. The cardiac electrical and mechanical synchrony in different pacing mode were evaluated at baseline and after implantation. RESULTS: Both HBP and LBBP were performed in 20 patients. LBBP significantly widened the QRS duration compared with the intrinsic conduction (113.2 ± 14.5  vs. 96.5 ± 16.2 ms; p = .01), while HBP did not (104.5 ± 22.3  vs. 96.5 ± 16.2 ms; p = .12). Both LBBP and HBP patients had similar LV myocardial strain measurements for the mechanical synchrony evaluation without significant change compared with baseline. There was no significant difference in right ventricular synchrony measurement between LBBP and HBP. Compared to HBP, LBBP had less interventricular synchrony (IMVD, 14.7 ± 9.2  vs. 3.1 ± 12.7 ms, p < .01; Ts-LV-RV, 37.9 ± 10.7  vs. 18.5 ± 10.8 ms, p < .001). CONCLUSIONS: Although LBBP's a physiological pacing mode can achieve a similar cardiac electrical and mechanical synchronization when compared to HBP, LBBP results in modest delay in RV activation, and the clinical implication remains to be studied.

Solvothermal Synthesis of Multiple Dihydropyrimidinones at a Time as Inhibitors of Eg5.

Solvothermal synthesis of multiple dihydropyrimidinones at a time has been developed in inexpensive and green bio-based solvent lactic acid without any additional catalysts or additives. By this method, thirty new dihydropyrimidinone derivatives were synthesized in two batches and characterized. All of the compounds were screened by Eg5 motor protein ATPase assay, and the positive compounds were tested against the Caco-2 cell line, HeLa cell line, L929 cell line and T24 cell line in vitro. Among them, compound C9 exhibited the best inhibitory activity against motor protein ATPase with an IC50 value of 30.25 µM and significant cytotoxic activity in the micromolar range against the cells above. The Lineweaver-Burk plot revealed that compound C9 was a mixed-type Eg5 inhibitor. A molecular modeling study using the Discovery Studio program was performed, where compound C9 exhibited good binding interaction with Eg5 motor protein ATPase, and this was consistent with the attained experimental results.

Adjunctive percutaneous ablation targeting epicardial arrhythmogenic structures in patients of atrial fibrillation with recurrence after multiple procedures.

INTRODUCTION: Repeat ablation strategy for atrial fibrillation (AF) recurrence after multiple ablation procedures is known to be challenging. This study evaluated the insights of adjunctive ablation for epicardial arrhythmogenic substrates in those patients via a percutaneous epicardial approach. METHODS AND RESULTS: Thirty-five consecutive patients with AF/atrial tachycardia (AT) recurrence, who had two or more prior ablation procedures, were enrolled from September 2016 to December 2018. In addition to a standard endocardial approach, epicardial mapping and ablation were performed via a percutaneous subxiphoid access in the electrophysiology lab. Adjunctive epicardial ablations for left lateral ridge (LLR) were performed in 31 of 35 patients (88.6%) for efficient transmural lesions with pacing capture loss. Marshall Bundle (MB) potentials were documented on epicardial LLR in three patients and abolished by direct epicardial ablation. Bachmann's bundle (BB) was ablated as an epicardial conduction gap in four patients with a refractory anterior wall line. Two epicardial AT/AF triggers were detected followed by successful termination with epicardial ablation. No periprocedural complications occurred. About 23 of 35 patients (65.7%) remained free from AF/AT after 23.2 ± 9 months of the procedure. CONCLUSIONS: Patients with multiple failed prior AF procedures refractory to antiarrhythmic therapy might warrant a percutaneous epicardial mapping and ablation strategy, with adjunctive therapy for targeting LLR/MB, BB, and underlying epicardial triggers in addition to a standard endocardial approach.

Intraprocedural endpoints to predict durable pulmonary vein isolation: a randomized trial of four post-ablation techniques.

AIMS: The optimal procedural endpoint to achieve permanent pulmonary vein isolation (PVI) during ablation of atrial fibrillation (AF) remains unknown. We aimed to compare the impact of prolonged waiting periods and adenosine triphosphate (ATP) testing after PVI on long-term freedom from AF. METHODS AND RESULTS: In total, 538 patients (median age 61 years, 62% male) undergoing first-time radiofrequency ablation for paroxysmal AF were randomized into four groups: Group 1 [PVI (no testing), n = 121], Group 2 (PVI + 30min waiting phase, n = 151), Group 3 (PVI+ATP, n = 131), and Group 4 (PVI + 30min+ATP, n = 135). The primary endpoint was freedom from AF. Repeat mapping to assess for late pulmonary vein (PV) reconnection was performed in patients who remained AF-free for >3 years (n = 46) and in those who had repeat ablation for AF recurrence (n = 82). During initial procedure, acute PV reconnection was observed in 33%, 26%, and 42% of patients in Groups 2, 3, and 4, respectively. At 36 months, no significant differences in freedom from AF recurrence were observed among all four groups (55%, 61%, 50%, and 62% for Groups 1, 2, 3, and 4, respectively; P = 0.258). Late PV reconnection was commonly observed, with a similar incidence between patients with and without AF recurrence (74% vs. 83%; P = 0.224). CONCLUSION: Although PVI remains the cornerstone for AF ablation, intraprocedural techniques to assess for PV reconnection did not improve long-term success. Patients without AF recurrence after 3 years exhibited similarly high rates of PV reconnection as those that underwent repeat ablation for AF recurrence. The therapeutic mechanisms of AF ablation may not be solely predicated upon durable PVI.

Risk of esophageal thermal injury during catheter ablation for atrial fibrillation guided by different ablation index.

BACKGROUND: During ablation for atrial fibrillation (AF), energy delivery toward the left atrial posterior wall may cause esophageal injury (EI). Ablation index (AI) was introduced to estimate ablation lesion size, however, the impact of AI technology on the risk of EI has not been explored. METHOD: From March 2019 to December 2019, 60 patients with paroxysmal AF undergoing first-time ablation were prospectively enrolled. The first 30 consecutive patients were ablated with the AI target value of 400 (AI-400 group), and the later 30 consecutive patients were ablated with the AI target value of 350 at the posterior wall (AI-350 group). Endoscopic ultrasonography was used to evaluate EI postablation. EI was classified as a category 1 (erythema or erosion) or a category 2 (hematoma or ulceration). RESULTS: Compared with the AI-400 group (59.9 ± 8.4 years; male, 60%), the AI-350 group (59.1 ± 9.9 years; male, 50%) had a lower incidence of EI (3.3% vs 26.7%, P = .03). There was no significant difference in the percentage of first-pass PVI between the AI-400 group and the AI-350 group (left PVI: 80% vs 73.4%, P = .54; right PVI: 80% vs 60%, P = .1). Neither ablation time nor fluoroscopy time was significantly different between the AI-400 group and the AI-350 group. CONCLUSIONS: AF ablation guide by AI target value of 350 may reduce esophageal thermal injury and has a similar efficiency on the acute success rate of first-pass PVI compared with an AI target value of 400 at the posterior wall.

Esophageal contraction during cryoablation: A possible protective mechanism.

BACKGROUND: Contraction of the esophagus was observed during cryoablation for paroxysmal atrial fibrillation (PAF). The purpose of this study is to investigate the mechanism of esophageal contraction and the correlation between the contraction and esophageal thermal lesions. METHODS: This prospective study enrolled 64 patients with PAF undergoing second-generation cryoballoon (CB2) ablation for pulmonary vein isolation (PVI). During PVI for the left inferior pulmonary vein, contrast esophagography was performed before and during cryoablation. The sample population was divided into two groups: A (31 patients) and B (33 patients). Group A consisted of patients in whom the distal half of the CB was in proximity to the esophagus, while for group B the esophagus was away from the distal half of the CB. Esophageal contraction was recorded as a variation in the width of the esophageal lumen during PVI. Postablation esophageal endoscopy was done on all patients. RESULTS: The reduction in the width of the esophageal lumen in group A was greater than in group B during freezing (40.12 ± 23.24% vs 8.14 ± 10.35%, P < .001). Following endoscopy, no apparent esophageal lesion was detected in all patients. CONCLUSION: The extent of esophageal contraction is correlated with the positioning of the esophagus at the distal half of the CB. The findings of this study indicate that esophageal contraction during freezing may be a self-protective mechanism.

Anthocidins A⁻D, New 5-Hydroxyanthranilic Acid Related Metabolites from the Sea Urchin-Associated Actinobacterium, Streptomyces sp. HDa1.

Four new 5-hydroxyanthranilic acid related compounds, named anthocidins A⁻D (1⁻4), two known analogues n-lauryl 5-hydroxyanthranilate (5) and isolauryl 5-hydroxyanthranilate (6), together with benzamide (7), 3-hydroxy-4-methoxycinnamamide (8), and (3S-cis)-hexahydro-3-[(3,4-dihydroxyphenyl)methyl]pyrrolo[1,2-a]pyrazine-1,4-dione (9), were isolated from the fermentation broth of the marine-derived actinomycete, Streptomyces sp. HDa1, which was isolated from the gut of a sea urchin, Anthocidaris crassispina, collected from Hainan Island, China. The structures of these secondary metabolites were elucidated on the basis of their 1D and 2D-NMR and mass spectroscopic data, and anthocidin A was confirmed by single-crystal X-ray diffraction with Cu Kα radiation. Anthocidins A⁻D (1⁻4) feature an acetyl group substitution at the amino group and varying alkyl side chains at the carboxyl group of 5-hydroxyanthranilic acid, and compound 5 was isolated as a natural product for the first time. The cytotoxic and antibacterial activity of compounds 1⁻9 were evaluated.

Impact of Anatomically Guided Ganglionated Plexus Ablation on Electrical Firing from Isolated Pulmonary Veins.

BACKGROUND: The mechanisms underlying atrial fibrillation (AF) initiation and pulmonary vein isolation (PVI) effectiveness remain unclear. Ganglionated plexus (GPs) have been implicated in AF initiation and maintenance. In this study, we evaluated the impact of GP ablation in patients with pulmonary vein (PV) firing after PVI. METHODS: Patients with drug-refractory paroxysmal AF undergoing radiofrequency catheter ablation therapy with PVI were screened. Among 840 cases over a 3.75-year period, 12 cases were identified with persistent PV firing (left = 4 and right = 8) after PVI was achieved and left atrial sinus rhythm restored. Adjacent GP ablation was performed anatomically and followed if necessary by additional PV ablation. RESULTS: In eight patients, PV firing was terminated during GP ablation outside of the circumferential ablation line. In one patient, additional PV ablation resulted in cessation of PV firing and in the remaining three patients, firing could not be terminated by GP ablation or additional PVI. CONCLUSION: GP ablation outside of wide antral circumferential line frequently results in the cessation of rapid firing from electrically isolated PVs. These observations suggest that interactions between left atrium and PV beyond electrical conduction warrant consideration in AF mechanisms.

Alendronate prevents angiotensin II-induced collagen I production through geranylgeranylation-dependent RhoA/Rho kinase activation in cardiac fibroblasts.

Collagen I is the main component of extracellular matrix in cardiac fibrosis. Our previous studies have reported inhibition of farnesylpyrophosphate synthase prevents angiotensin II-induced cardiac fibrosis, while the exact molecular mechanism was still unclear. This paper was designed to investigate the effect of alendronate, a farnesylpyrophosphate synthase inhibitor, on regulating angiotensin II-induced collagen I expression in cultured cardiac fibroblasts and to explore the underlying mechanism. By measuring the mRNA and protein levels of collagen I, we found that alendronate prevented angiotensin II-induced collagen I production in a dose-dependent manner. The inhibitory effect on collagen I expression was reversed by geranylgeraniol, and mimicked by inhibitors of RhoA/Rho kinase pathway including C3 exoenzyme and GGTI-286. Thus we suggested geranylgeranylation-dependent RhoA/Rho kinase activation was involved in alendronate-mediated anti-collagen I synthetic effect. Furthermore, we accessed the activation status of RhoA in alendronate-, geranylgeraniol- and GGTI-286-treated cardiac fibroblasts and gave an indirect evidence for RhoA activation via geranylgeranylation. Then we came to the conclusion that in cardiac fibroblasts, alendronate could protect against angiotensin II-induced collagen I synthesis through inhibition of geranylgeranylation and inactivation of RhoA/Rho kinase signaling. Targeting geranylgeranylation and RhoA/Rho kinase signaling will hopefully serve as therapeutic strategies to reduce fibrosis in heart remodeling.

Use of intracardiac echocardiography in vein of Marshall ethanol infusion for ablation of persistent atrial fibrillation.

BACKGROUND: Few methods have been reported to demonstrate real-time effects during vein of Marshall (VOM) ethanol infusion in persistent atrial fibrillation (PeAF). OBJECTIVE: This study was to evaluate the impact of left atrial (LA) monitoring using intracardiac echocardiography (ICE) during VOM ethanol infusion. METHODS: Seventy-four consecutive patients with PeAF who underwent VOM ethanol infusion followed by radiofrequency (RF) ablation were included. Patients with findings on ICE consistent with echogenic streaming in the LA and with increased myocardial local echogenicity along the VOM area were placed into one group (group A) and those without into the other group (group B). Outcomes between the 2 groups were compared. RESULTS: Forty-six patients (62%) were placed into group A. A new ethanol-induced low-voltage area in group A was larger than that in group B (8.5 cm2 [5.5-10.2 cm2] and 4.0 cm2 (2.4-6.3 cm2]; P < .001). The RF ablation time required to achieve MI block was reduced in group A patients (263.0 seconds [196.0-351.0 seconds] vs 417.0 seconds [315.0-709.5 seconds] in group B patients; P < .001). MI block was achieved in 46 patients (100%) via an endocardial approach in group A and 27 patients (96.4%) in group B (extra coronary sinus ablation in 4 patients). One patient developed clinically significant pericardial effusions and required pericardiocentesis in group B. CONCLUSION: Presence of increased myocardial local echogenicity at the ridge and consistent echogenic streaming in the LA detected by ICE-based imaging during VOM ethanol infusion suggests increased ablated tissue in that region and lower RF ablation time during ablation for PeAF.

Mapping seagrasses on the basis of Sentinel-2 images under tidal change.

Tidal variations make the water bodies in satellite remote sensing images on different shooting dates have different inundation ranges and depths. Although the underwater substrates do not change, the spectral properties differ due to attenuation effects. These differences have an impact on the results when multi-temporal remote sensing images are used to analyze seagrasses. This paper proposes a remote sensing mapping method for seagrasses taking the tidal influence, using the seagrasses growth area in Xincun Bay, Hainan Province, China as a case study. a) The seagrasses growth area was determined from remote sensing images. The seagrasses were divided into two types: the seagrasses exposed to water surface or tidal flats (non-submerged seagrasses) and the seagrasses submerged in water (submerged seagrasses). b) The spectral features of seagrasses in Sentienl-2 image were analyzed. We found that the spectral characteristics of non-submerged seagrasses were similar to terrestrial vegetation and these seagrasses could be extracted by using NDVI. The submerged seagrasses spectral was different, forming a reflection peak at the first vegetation red edge band (i.e.705 nm) in Sentinel-2 images. This reflection peak was used to design the Submerged Seagrasses Identification Index (SSII) for extracting underwater seagrass. c) The extraction results of non-submerged seagrasses and submerged seagrasses were merged to map the seagrasses in the study area. The experimental results show that the mapping method proposed in this study can fully consider the influence of tidal changes in remote sensing images on seagrasses identification. The SSII constructed based on Sentinel-2 images extracted submerged seagrasses effectively. This study will provide references to remote sensing mapping of seagrasses and integrated ecological management in coastal zones.

A review of metal contamination in seagrasses with an emphasis on metal kinetics and detoxification.

Seagrasses are important foundation species in coastal ecosystems, and they provide food and habitat that supports high biodiversity. However, seagrasses are increasingly subjected to anthropogenic disturbances such as metal pollution, which has been implicated as a significant factor driving seagrass losses. There have been several reviews synthesizing the metal concentrations in seagrasses and evaluating their utility as biomonitors for metal pollution in the coastal environment at the local scale. However, the interpretation of metal data in seagrass biomonitors requires a more mechanistic understanding of the processes governing metal bioaccumulation and detoxification. In this review, the progress and trends in metal studies in seagrasses between 1973 and 2022 were analyzed to identify frontier topics in this field. In addition, we tried to (1) analyze and assess the current status of metal contamination in seagrasses on a global scale by incorporating more metal data from tropical and Indo-Pacific seagrasses, (2) summarize the geochemical and biological factors governing metal uptake and loss in seagrasses, and (3) provide an up-to-date understanding of metals' effects on seagrasses and their physiological responses to metal challenges. This review improves our understanding of the highly variable metal concentrations observed in the field.