The mechanisms of milder clinical symptoms of COVID-19 in children compared to adults.

In stark contrast to adult patients, children who contract Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) typically manifest milder symptoms or remain asymptomatic. However, the precise underlying mechanisms of this pathogenesis remain elusive. In this review, we primarily retrospect the clinical characteristics of SARS-CoV-2 infection in children, and explore the factors that may contribute to the typically milder clinical presentation in pediatric Coronavirus Disease 2019 (COVID-19) patients compare with adults patients with COVID-19. The pathophysiological mechanisms that mitigate lung injury in children are as follows: the expression level of ACE2 receptor in children is lower; the binding affinity between ACE2 receptors and viral spike proteins in children was weaker; children have strong pre-activated innate immune response and appropriate adaptive immune response; children have more natural lymphocytes; children with COVID-19 can produce higher levels of IgM, IgG and interferon; children infected with SARS-CoV-2 can produce lower levels of IL-6 and IL-10; children have fewer underlying diseases and the lower risk of worsening COVID-19; children are usually exposed to other respiratory viruses and have an enhanced cross-reactive immunity. Comprehending the relative contributions of these processes to the protective phenotype in the developing lungs can help in the diagnosis, treatment and research pertaining to children with COVID-19.

Comparison of strategies for catheter ablation of left posterior fascicular ventricular tachycardia.

AIMS: Traditional ablation strategies including targeting the earliest Purkinje potential (PP) during left posterior fascicular (LPF) ventricular tachycardia (VT) or linear ablation at the middle segment of LPF during sinus rhythm are commonly used for the treatment of LPF-VT. Catheter ablation for LPF-VT targeting fragmented antegrade Purkinje (FAP) potential during sinus rhythm is a novel approach. We aimed to compare safety and efficacy of different ablation strategies (FAP ablation vs. traditional ablation) for the treatment of LPF-VT. METHODS AND RESULTS: Consecutive patients with electrocardiographically documented LPF-VT referred for catheter ablation received either FAP ablation approach or traditional ablation approach. Electrophysiological characteristics, procedural complications, and long-term clinical outcome were assessed. A total of 189 consecutive patients who underwent catheter ablation for LPF-VT were included. Fragmented antegrade Purkinje ablation was attempted in 95 patients, and traditional ablation was attempted in 94 patients. Acute ablation success with elimination of LPF-VT was achieved in all patients. Left posterior fascicular block occurred in 11 of 95 (11.6%) patients in the FAP group compared with 75 of 94 (79.8%) patients in the traditional group (P < 0.001). Fragmented antegrade Purkinje ablation was associated with significant shorter procedure time (94 ± 26 vs. 117 ± 23 min, P = 0.03) and fewer radiofrequency energy applications (4.1 ± 2.4 vs. 6.3 ± 3.5, P = 0.003) compared with the traditional group. One complete atrioventricular block and one left bundle branch block were seen in the traditional group. Over mean follow-up of 65 months, 89 (93.7%) patients in the FAP group and 81 (86.2%) patients in the traditional group remained free of recurrent VT off antiarrhythmic drugs (P = 0.157). CONCLUSION: Left posterior fascicular-ventricular tachycardia ablation utilizing FAP and traditional ablation approaches resulted in similar acute and long-term procedural outcomes. Serious His-Purkinje injury did occur infrequently during traditional ablation. The use of FAP ablation approach was associated with shorter procedure time and fewer radiofrequency energy applications, especially for non-inducible patients.

PD-1 inhibitors-associated myocarditis in non-small cell lung cancer patients.

Background: Immune checkpoint inhibitors (ICIs)-associated myocarditis remains a rare but fatal adverse event. The authors sought to provide a comprehensive clinical description of ICI-associated myocarditis by analyzing symptoms, laboratory indicators, imaging features, and management of ICI-associated myocarditis in patients with non-small cell lung cancer (NSCLC). Methods: A retrospective study was conducted to analyze 14 ICI-associated myocarditis cases and 45 control patients to clarify clinical features of ICI-associated myocarditis. Detailed laboratory tests and imaging examinations were performed in 14 cases, and the rescue process and follow-up after the onset of myocarditis were recorded. Results: A total of 14 (2.08%) NSCLC patients developed ICI-related myocarditis, with a median time of onset of 34 days (interquartile range, 12 to 146 days) after ICI initiation. The most common concurrent adverse events in cases were myositis (P<0.001) and peripheral neuritis (P<0.001). Among cases, cardiac troponin I (cTnI) levels were abnormally elevated in 92% of patients, and electrocardiogram (ECG) showed abnormal in all cases. Steroid therapy was used in 92.9% of patients with ICI-associated myocarditis, of which the response rate to steroids was 76.9% and the mortality rate was 7.1%. A dose of 1 g/d of glucocorticoid supplemented by immunoglobulin was observed to be effective for severe myocarditis. Conclusions: Early identification and treatment are essential for managing myocarditis caused by ICI. Routine monitoring of cTnI level and ECG is most sensitive for the early diagnosis of ICI-related myocarditis. High-dose of glucocorticoids can effectively relieve the symptoms of ICI-associated myocarditis and stabilize the condition, especially for fulminant myocarditis.

Towards transcervical ultrasound image guidance for transoral robotic surgery.

PURPOSE: Trans-oral robotic surgery (TORS) using the da Vinci surgical robot is a new minimally-invasive surgery method to treat oropharyngeal tumors, but it is a challenging operation. Augmented reality (AR) based on intra-operative ultrasound (US) has the potential to enhance the visualization of the anatomy and cancerous tumors to provide additional tools for decision-making in surgery. METHODS: We propose a US-guided AR system for TORS, with the transducer placed on the neck for a transcervical view. Firstly, we perform a novel MRI-to-transcervical 3D US registration study, comprising (i) preoperative MRI to preoperative US registration, and (ii) preoperative to intraoperative US registration to account for tissue deformation due to retraction. Secondly, we develop a US-robot calibration method with an optical tracker and demonstrate its use in an AR system that displays anatomy models in the surgeon's console in real-time. RESULTS: Our AR system achieves a projection error from the US to the stereo cameras of 27.14 and 26.03 pixels (image is 540[Formula: see text]960) in a water bath experiment. The average target registration error (TRE) for MRI to 3D US is 8.90 mm for the 3D US transducer and 5.85 mm for freehand 3D US, and the TRE for pre-intra operative US registration is 7.90 mm. CONCLUSION: We demonstrate the feasibility of each component of the first complete pipeline for MRI-US-robot-patient registration for a proof-of-concept transcervical US-guided AR system for TORS. Our results show that trans-cervical 3D US is a promising technique for TORS image guidance.

A comprehensive review of protein-based carriers with simple structures for the co-encapsulation of bioactive agents.

The rational design and fabrication of edible codelivery carriers are important to develop functional foods fortified with a plurality of bioactive agents, which may produce synergistic effects in increasing bioactivity and functionality to target specific health benefits. Food proteins possess considerable functional attributes that make them suitable for the delivery of a single bioactive agent in a wide range of platforms. Among the different types of protein-based carriers, protein-ligand nanocomplexes, micro/nanoparticles, and oil-in-water (O/W) emulsions have increasingly attracted attention in the codelivery of multiple bioactive agents, due to the simple and convenient preparation procedure, high stability, matrix compatibility, and dosage flexibility. However, the successful codelivery of bioactive agents with diverse physicochemical properties by using these simple-structure carriers is a daunting task. In this review, some effective strategies such as combined functional properties of proteins, self-assembly, composite, layer-by-layer, and interfacial engineering are introduced to redesign the carrier structure and explore the encapsulation of multiple bioactive agents. It then highlights success stories and challenges in the co-encapsulation of multiple bioactive agents within protein-based carriers with a simple structure. The partition, protection, and release of bioactive agents in these protein-based codelivery carriers are considered and discussed. Finally, safety and application as well as challenges of co-encapsulated bioactive agents in the food industry are also discussed. This work provides a state-of-the-art overview of protein-based particles and O/W emulsions in co-encapsulating bioactive agents, which is essential for the design and development of novel functional foods containing multiple bioactive agents.

Synthesis, characterization, and anticancer activity of protamine sulfate stabilized selenium nanoparticles.

Selenium nanoparticles (SeNPs) have attracted much recent interest as nutraceuticals, while they face great challenges, such as poor stability and low cellular uptake efficiency. This study introduced a facile approach to synthesizing protamine sulfate (PS) functionalized selenium nanoparticles (PS-SeNPs) by using PS as a surface decorator. The monodisperse spherical PS-SeNPs with a particle size of 130 nm and a ζ-potential of +31 mV were ligated with PS through Se-N, Se-O bonds, and physical adsorption, which exhibits excellent physical stability against pH, temperature, and storage time. The positive surface charge of PS-SeNPs contributed to the enhancement of cellular uptake efficiency by endocytosis, which was 3-times higher than bare SeNPs. Compared to SeNPs (IC50 = 17.675 µg/mL), PS-SeNPs could dramatically inhibit the proliferation of HepG2 cells with an IC50 value of 5.507 µg/mL, as reflected by the induction of apoptosis, S phase arresting, overproduction of intracellular ROS, and depolarization of mitochondria membrane. Overall, these results demonstrated the great potential of PS-SeNPs that can be applied as a functional ingredient in foods and nutraceuticals.

Progress in the Surface Functionalization of Selenium Nanoparticles and Their Potential Application in Cancer Therapy.

As an essential micronutrient, selenium participates in numerous life processes and plays a key role in human health. In the past decade, selenium nanoparticles (SeNPs) have attracted great attention due to their excellent functionality for potential applications in pharmaceuticals. However, the utilization of SeNPs has been restricted by their instability and low targeting ability. Since the existing reviews mainly focused on the applications of SeNPs, this review highlights the synthesis of SeNPs and the strategies to improve their stability and targeting ability through surface functionalization. In addition, the utilization of functionalized SeNPs for the single and co-delivery of drugs or genes to achieve the combination of therapy are also presented, with the emphasis on the potential mechanism. The current challenges and prospects of functionalized SeNPs are also summarized. This review may provide valuable information for the design of novel functionalized SeNPs and promote their future application in cancer therapy.

Hybrid ablation procedure for the treatment of nonparoxysmal atrial fibrillation: A systematic review and meta-analysis.

BACKGROUND: Hybrid ablation combines the advantages of surgical and catheter ablation. Many studies have explored the efficiency and safety of hybrid ablation in patients with nonparoxysmal AF. METHODS: We systematically searched for prospective controlled trials that compared hybrid ablation with catheter/surgical ablation in PubMed, Web of Science, Wiley Library, and CNKI. Our main assessment indicators included maintenance of sinus rhythm (SR) without antiarrhythmic drugs for more than 12 months, major adverse events (MAEs), procedure time and fluoroscopy time. RESULTS: Of 1214 identified studies, five were eligible and were included in our analysis (N = 451 participants). The pooled results showed that hybrid ablation was more effective in maintaining SR than a single procedure (surgical ablation or catheter ablation) (OR = 2.52, 95% confidence interval [CI]: 1.63-3.89, p < .001). Little significant heterogeneity was revealed (p = .32 for heterogeneity, I2  = 14%). More MAEs occurred in the hybrid group than in the single procedure group (OR = 7.47, 95% CI: 1.90-29.41, p = .004; I2  = 0%). Two trials reported the procedure and fluoroscopy times, and the procedure time for hybrid ablation was significantly longer than that of a single procedure (mean difference = 107.42, 95% CI: 88.62 to 126.22, p < .001; I2  = 82%). There was no significant difference in fluoroscopy time between the 2 groups (mean difference = -1.00, 95% CI: -5.37 to 3.36, p = .65; I2  = 12%). CONCLUSIONS: Hybrid ablation was more effective than catheter ablation and was as effective as surgical ablation in patients with nonparoxysmal AF. Meanwhile, hybrid ablation, especially concomitant hybrid ablation, increases the incidence of MAEs and prolongs the procedure time.

Synthesis, characterization, and biological evaluation of novel selenium-containing chitosan derivatives.

Though great efforts have been made to develop selenium polysaccharides with unique properties using HNO3-Na2SeO3 methods, the Se content is still low due to the poor esterification efficiency of H2SeO3. Herein, selenodiacetic acid (SA) was introduced into chitosan (CS) to synthesize O-selenodiacetyl chitosan (OSAC) and chitosan-ammonium selenodiacetate (CASA) by covalent and non-covalent interaction, respectively. The obtained CS derivatives were characterized by UV-vis, FTIR, 1H NMR, XPS, TGA, and XRD spectra, and the OSAC and CASA showed high Se content up to 15,720 ± 475 and 26,363 ± 698 µg/g. The OSAC and CASA demonstrated increased antioxidant activities compared to the CS in DPPH and ABTS free radical scavenging assays. Moreover, they exhibited a potent anticancer effect on HepG2 cells with the IC50 values of 0.918 and 1.459 µg/mL. Taken together, this study provides a promising strategy for the design of novel selenium polysaccharides with high Se content and greater biological activity.

Construction of Polygonatum sibiricum Polysaccharide Functionalized Selenium Nanoparticles for the Enhancement of Stability and Antioxidant Activity.

Although selenium nanoparticles (SeNPs) have attracted great attention due to their potential antioxidant activity and low toxicity, the application of SeNPs is still restricted by their poor stability. A combination of polysaccharides and SeNPs is an effective strategy to overcome the limitations. In this study, Polygonatum sibiricum polysaccharide (PSP) was used as a stabilizer to fabricate SeNPs under a simple redox system. Dynamic light scattering, transmission electron microscopy, energy dispersive X-ray, ultraviolet-visible spectroscopy, Fourier transform infrared, and X-ray photoelectron spectrometer were applied to characterize the synthesized PSP-SeNPs. The stability and the antioxidant activity of PSP-SeNPs were also investigated. The results revealed that the zero-valent and well-dispersed spherical PSP-SeNPs with an average size of 105 nm and a negative ζ-potential of -34.9 mV were successfully synthesized using 0.1 mg/mL PSP as a stabilizer. The prepared PSP-SeNPs were stable for 30 days at 4 °C. The decoration of the nanoparticle surface with PSP significantly improved the free radical scavenging ability of SeNPs. Compared to the H2O2-induced oxidative stress model group, the viability of PC-12 cells pretreated with 20 µg/mL PSP-SeNPs increased from 56% to 98%. Moreover, PSP-SeNPs exhibited a higher protective effect on the H2O2-induced oxidative damage on PC-12 cells and lower cytotoxicity than sodium selenite and SeNPs. In summary, these results suggest the great potential of PSP-SeNPs as a novel antioxidant agent in the food or nutraceuticals area.

Changes in left atrial appendage orifice following percutaneous left atrial appendage closure using three-dimensional echocardiography.

Percutaneous left atrial appendage (LAA) occlusion is increasingly performed in patients with atrial fibrillation and long-term contraindications for anticoagulation. Our aim was to evaluate the effects of LAA occlusion with the Watchman device on the geometry of the LAA orifice and assess its impact on the adjacent left upper pulmonary vein (LUPV) hemodynamics. We included 50 patients who underwent percutaneous LAA occlusion with the Watchman device and had acceptable three-dimensional transesophageal echocardiography images of LAA pre- and post-device placement. We measured offline the LAA orifice diameters in the long axis, and the minimum and maximum diameters, circumference, and area in the short axis view. Eccentricity index was calculated as maximum/minimum diameter ratio. The LUPV peak S and D velocities pre- and post-procedure were also measured. Patients were elderly (mean age 76 ± 8 years), 30 (60%) were men. There was a significant increase of all LAA orifice dimensions following LAA occlusion: diameter 1 (pre-device 18.1 ± 3.2 vs. post-device 21.5 ± 3.4 mm, p < 0.001), diameter 2 (20.6 ± 3.9 vs. 22.1 ± 3.6 mm, p < 0.001), minimum diameter (17.6 ± 3.1 vs. 21.3 ± 3.4 mm, p < 0.001), maximum diameter (21.5 ± 3.9 vs. 22.4 ± 3.6 mm, p = 0.022), circumference (63.6 ± 10.7 vs. 69.6 ± 10.5 mm, p < 0.001), and area (3.1 ± 1.1 vs. 3.9 ± 1.2 cm2, p < 0.001). Eccentricity index decreased after procedure (1.23 ± 0.16 vs. 1.06 ± 0.06, p < 0.001). LUPV peak S and D velocities did not show a significant difference (0.29 ± 0.15 vs. 0.30 ± 0.14 cm/s, p = 0.637; and 0.47 ± 0.19 vs. 0.48 ± 0.20 cm/s, p = 0.549; respectively). LAA orifice stretches significantly and it becomes more circular following LAA occlusion without causing a significant impact on the LUPV hemodynamics.

Chitosan/zein bilayer films with one-way water barrier characteristic: Physical, structural and thermal properties.

Chitosan (C) and zein (Z) were used to develop bilayer films with a characteristic one-way water barrier using a layer-by-layer (LBL) casting method. The effects of mass ratios (C:Z1:1, C:Z1:2, C:Z1:3, C:Z3:1, C:Z2:1) on the microstructure and physicochemical properties of bilayer films were investigated. Bilayer films had uniform microstructures, and C:Z = 1:3 showed a firmer structure as the Z aggregates were distributed in the continuous phase of C. The intermolecular interactions between the C and Z layers were observed using FTIR and XRD analysis. TGA demonstrated that adding Z layer enhanced the thermal stability of C films. LBL coating gave the C/Z bilayer film an increased elongation and tensile strength, as well as a decreased water vapor and oxygen permeability, especially for C:Z = 1:3 which had better properties. The results suggested that C and Z bilayer films may be a promising material for food packaging with the desired water resistance.

Synthesis, characterization, and anti-tumor properties of O-benzoylselenoglycolic chitosan.

This study introduces a facile method for synthesizing O-benzoylselenoglycolic chitosan with a high selenium concentration of 45.32 mg/g. The characterizations of the chemical structure via FTIR, 1H NMR, 13C NMR, TGA, and XRD analyses indicated that benzoylselenoglycolic acid was successfully grafted onto the C6 hydroxyl group of chitosan. The anti-cancer activity of the O-benzoylselenoglycolic chitosan was investigated in vitro using a HepG2 cell model, and the results indicated that it has excellent anticancer activity against HepG2 cancer cells with an IC50 value of 0.53 µg/mL while exhibiting non-toxicity against normal cells (L-02). Furthermore, a mechanistic study revealed that the O-benzoylselenoglycolic chitosan could induce early apoptosis, G2/M, S phase arrest, and activation of caspase-3 activity to inhibit the HepG2 cell growth. This study has led to novel organic selenium species, and the results suggest its potential to be used as an effective ingredient for cancer prevention and therapy in the food and pharmaceutical fields.

Label-free identification of human coronary atherosclerotic plaque based on a three-dimensional quantitative assessment of multiphoton microscopy images.

The rupture of coronary atherosclerotic plaque (CAP) and the resulting intracoronary thrombosis account for most acute coronary syndromes. Thus, the early identification and risk assessment of CAP is crucial for timely medical intervention. In this study, we propose a quantitative and label-free method for human CAP identification using multiphoton microscopy (MPM) and three-dimensional (3D) image analysis techniques. By detecting the intrinsic MPM signals, the microstructures of collagen and elastin fibers within normal and CAP-lesioned human coronary artery walls were imaged. Using a 3D gray level co-occurrence matrix method and 3D weighted vector summation algorithm, quantitative indicators that characterize the spatial texture and orientation features of the fibers were extracted. We demonstrate that these indicators show superior accuracy and repeatability over 2D texture features in CAP discrimination. Furthermore, by combining the 3D microstructural indicators, a support vector machine model that classifies CAP from the normal arterial wall with an accuracy of >97% was established. In conjunction with advances in multiphoton endoscopy, the proposed method shows great potential in providing a quantitative, label-free, and real-time tool for the early identification and risk assessment of CAP in the future.

Quantitative Evaluation of Mechanical Stimulation for Tissue-Engineered Blood Vessels.

Functional small-diameter tissue-engineered blood vessels (TEBVs) have been developed in silico using biodegradable polymeric scaffolds under pulsatile perfusion. Accurate simulation of physiological mechanical stimulations in vitro is a crucial factor in vascular engineering. However, little is known about the patterns of mechanical stimulation on silicone tubes. This study aimed to determine the optimal mechanical conditions required for inducing circumferential deformations in silicone tubes during in vitro vascular development under pulsatile perfusion. For this purpose, we established a data acquisition (DAQ) system with a laser micrometer and pressure transducers to evaluate changes in the diameter of silicone tubes in response to pulsatile flow and validated the results on cultured TEBVs. The established DAQ system showed satisfactory reproducibility for measuring diameter variation in the in silico model. Furthermore, the hardness and thickness of the silicone tubes affected the mechanical conditioning in the three-dimensional culture system under different working pressures, frequencies, and circumferential deformations. We demonstrated a simple and reliable approach to quantify the circumferential strain and deformations to ensure optimal mechanical stimulation of the cultured TEBVs under pulsatile perfusion. Based on the results, we were able to dynamically culture dense cellularized small-diameter TEBVs. This study highlights the importance of mechanical stimulation in vascular tissue engineering. Impact statement This study demonstrated a direct and noncontact data acquisition system for quantifying the strain on the supporting silicone medium during three-dimensional tissue-engineered blood vessel culture, which can help optimize the mechanical parameters for vascular tissue engineering.

Acute changes of left ventricular function during surgical revascularization by 3D speckle tracking.

BACKGROUND: Detecting early impact of coronary artery bypass grafting (CABG) on left ventricular (LV) function is important because such measures may contribute to meaningful improvement in clinical outcomes. We aimed to gain knowledge about acute changes of LV performance during surgical revascularization using three-dimensional speckle tracking echocardiography (3D STE). METHODS: Thirty-five patients scheduled for CABG surgery who underwent intraoperative transesophageal echocardiography (TEE) were enrolled (mean age 68.9 ± 7.3 years). TEE was performed before and after surgery, as well as before and after grafting. 3D LV ejection fraction (LVEF), tissue motion annular displacement (TMAD) of the mitral valves, 3D global longitudinal strain (GLS), global circumferential strain (GCS), twist, and torsion were quantified. Regional longitudinal strain (LS) was calculated based on coronary perfusion territories in a 16-segment LV model. RESULTS: Despite the absence of change in TMAD and 3D LVEF, 3D GLS (-18.6 ± 4.3% at baseline vs -16.0 ± 4.0% after surgery, P = .01) was significantly decreased, followed with no significant effect on GCS, twist, and torsion during surgery. 3D GLS correlated significantly with 3D LVEF (r between -0.34 and -0.51, P < .05 for all) under the whole operation. Territorial LS did not increase immediately after surgery. CONCLUSION: 3D speckle tracking imaging allows for detailed and direct evaluation of myocardial deformation, though impaired LV longitudinal function is still apparent immediately after surgery. GLS is more sensitive to an acute reduction in LV function than conventional parameters, which can be potentially useful for serial monitoring of functional recovery.

The characterization and biological activities of synthetic N, O-selenized chitosan derivatives.

Synthetic selenium polysaccharides with potential bioactivity have drawn great interest due to the SeO bonds existing in the structure. Herein, N, O-selenized N-(2-carboxyethyl) chitosan (sNCCS) was synthesized through carboxyethylation and selenylation. Various characterizations were performed to identify the structure of sNCCS, indicating that SeO bonds were formed both at the C-6 hydroxyl groups and the introduced C-2 carboxyethyl groups. The highest yield and selenium content of all sNCCS reached 84.5% and 1.553 mg/g, respectively. In vitro evaluation exhibited that sNCCS has excellent bile acid binding capacity, which was 1.63, 2.00, and 2.55-fold higher than that of N-(2-carboxyethyl) chitosan (NCCS). Moreover, it was found that higher selenium content could significantly enhance the antioxidant properties of sNCCS. Importantly, no obvious cytotoxic effect had been observed on Caco-2 cells. Taken together, sNCCS with desirable biological activity and non-cytotoxicity might be considered as an effective ingredient in the fields of food or medicine.

Understanding Non-P2 Mitral Regurgitation Using Real-Time Three-Dimensional Transesophageal Echocardiography: Characterization and Factors Leading to Underestimation.

BACKGROUND: P2 prolapse is a common cause of degenerative mitral regurgitation (MR); echocardiographic characteristics of non-P2 prolapse are less known. Because of the eccentric nature of degenerative MR jets, the evaluation of MR severity is challenging. The aim of this study was to test the hypotheses that (1) the percentage of severe MR determined by transthoracic echocardiography (TTE) would be lower compared with that determined by transesophageal echocardiography (TEE) in patients with non-P2 prolapse and also in a subgroup with "horizontal MR" (a horizontal jet seen on TTE that hugs the leaflets without reaching the atrial wall, particularly found in non-P2 prolapse) and (2) the directions of MR jets between TTE and real-time (RT) three-dimensional (3D) TEE would be discordant. METHODS: One hundred eighteen patients with moderate to severe and severe degenerative MR defined by TEE were studied. The percentage of severe MR between TTE and TEE was compared in P2 and non-P2 prolapse groups and in horizontal and nonhorizontal MR groups. Additionally, differences in the directions of the MR jets between TTE and RT 3D TEE were assessed. RESULTS: Eighty-six percent of patients had severe MR according to TEE. TTE underestimated severe MR in the non-P2 group (severe MR on TTE, 57%; severe MR on TEE, 85%; P < .001) but not in the P2 group (severe MR on TTE, 79%; severe MR on TEE, 91%; P = .157). Most "horizontal" MR jets were found in the non-P2 group (85%), and this subgroup showed even more underestimation of severe MR on TTE (TTE, 22%; TEE, 89%; P < .001). There was discordance in MR jet direction between two-dimensional TTE and RT 3D TEE in 41% of patients. CONCLUSIONS: Non-P2 and "horizontal" MR are significantly underestimated on TTE compared with TEE. There is substantial discordance in the direction of the MR jet between RT 3D TEE and TTE. Therefore, TEE should be considered when these subgroups of MR are observed on TTE.

Understanding tricuspid valve remodelling in atrial fibrillation using three-dimensional echocardiography.

AIMS: Atrial fibrillation (AF) has been associated with tricuspid annulus (TA) dilation in patients with severe functional tricuspid regurgitation (TR); however, the impact of AF is less clear in patients without severe TR. Our aim was to characterize TA remodelling in patients with AF in the absence of severe TR using 3D transoesophageal echocardiography (TOE). METHODS AND RESULTS: Ninety patients underwent clinically indicated transthoracic and TOE: non-structural (NS)-AF (n = 30); AF with left heart disease (LHD) (n = 30), and controls in sinus rhythm (n = 30). Three-dimensional TOE datasets were analysed to measure TA dimensions using novel dedicated tricuspid valve software. The NS-AF group showed biatrial dilatation and normal right ventricular (RV) size with decreased longitudinal function compared to controls, whereas the LHD-AF group showed biatrial dilatation, RV enlargement, decreased biventricular function, and higher systolic pulmonary artery pressure compared with the other groups. Indexed TA area, minimum diameter, maximum diameter, and total perimeter were significantly larger in the NS-AF group than in controls (measurements in end-diastole: 6.4 ± 1.1 vs. 5.0 ± 0.6 cm2/m2, 1.8 ± 0.3 vs. 1.6 ± 0.2 cm/m2, 2.1 ± 0.3 vs. 1.9 ± 0.2 cm/m2, and 6.6 ± 0.9 vs. 5.9 ± 0.7 cm/m2, respectively, all P < 0.05). There was no significant difference in any indexed TA parameter between AF groups. TA circularity index (ratio between minimum and maximal diameters) and TA fractional area change between end-diastole and end-systole were no different among the three groups. CONCLUSION: AF is associated with right atrial and tricuspid annular remodelling independent of the presence of LHD in patients with intrinsically normal tricuspid leaflets without severe TR.

Effect of chitosan with different molecular weight on the stability, antioxidant and anticancer activities of well-dispersed selenium nanoparticles.

This study was designed to evaluate and compare the stability, antioxidant and anticancer activities of selenium nanoparticles (SeNPs) decorated with different molecular weight (MW) of chitosan (CS) (1500 Da, 48 kDa, 510 kDa). The size range of well-dispersed SeNPs was effectively controlled by I- first and then coated with CS. The morphology, size and surface charge of generated SeNPs were characterised by several technologies. Fourier transform infrared spectroscopy was used to investigate the relationship between SeNPs and CS. SeNPs decorated with CS (510 kDa) can keep stable for more than 45 days. As observed from the results of a simple photometric system, the antioxidant activities of decorated SeNPs were enhanced compared to undecorated SeNPs. SeNPs coated with higher MW of CS (510 kDa) showed the strongest antioxidant activities. Moreover, the treatments of SeNPs decorated with CS inhibited the growth of HepG2 cells in a time- and dose-dependent manner. The proposed results demonstrated the critical roles of the MW of CS on the stability, antioxidant and anticancer properties of CS-coated SeNPs, which provided an important design cue for future applications of functional foods and additives.