Mitochondria transplantation alleviates cardiomyocytes apoptosis through inhibiting AMPKα-mTOR mediated excessive autophagy.

The disruption of mitochondria homeostasis can impair the contractile function of cardiomyocytes, leading to cardiac dysfunction and an increased risk of heart failure. This study introduces a pioneering therapeutic strategy employing mitochondria derived from human umbilical cord mesenchymal stem cells (hu-MSC) (MSC-Mito) for heart failure treatment. Initially, we isolated MSC-Mito, confirming their functionality. Subsequently, we monitored the process of single mitochondria transplantation into recipient cells and observed a time-dependent uptake of mitochondria in vivo. Evidence of human-specific mitochondrial DNA (mtDNA) in murine cardiomyocytes was observed after MSC-Mito transplantation. Employing a doxorubicin (DOX)-induced heart failure model, we demonstrated that MSC-Mito transplantation could safeguard cardiac function and avert cardiomyocyte apoptosis, indicating metabolic compatibility between hu-MSC-derived mitochondria and recipient mitochondria. Finally, through RNA sequencing and validation experiments, we discovered that MSC-Mito transplantation potentially exerted cardioprotection by reinstating ATP production and curtailing AMPKα-mTOR-mediated excessive autophagy.

Evaluation of 4D Flow MRI-Derived Relative Residence Time as a Marker for Cirrhosis Associated Portal Vein Thrombosis.

BACKGROUND: Portal vein thrombosis (PVT) is thought to arise from stagnant blood flow, yet conclusive evidence is lacking. Relative residence time (RRT) assessed using 4D Flow MRI may offer insight into portal flow stagnation. PURPOSE: To explore the relationship between RRT values and the presence of PVT in cirrhotic participants. STUDY TYPE: Prospective. POPULATION: Forty-eight participants with liver cirrhosis (27 males, median age 67 years [IQR: 57-73]) and 20 healthy control participants (12 males, median age 45 years [IQR: 40-54]). FIELD STRENGTH/SEQUENCE: 3 T/4D Flow MRI. ASSESSMENT: Laboratory (liver and kidney function test results and platelet count) and clinical data (presence of tumors and other imaging findings), and portal hemodynamics derived from 4D Flow MRI (spatiotemporally averaged RRT [RRT-mean], flow velocity, and flow rate) were analyzed. STATISTICAL TESTS: We used multivariable logistic regression, adjusted by selected covariates through the Lasso method, to explore whether RRT-mean is an independent risk factor for PVT. The area under the ROC curve (AUC) was also calculated to assess the model's discriminative ability. P < 0.05 indicated statistical significance. RESULTS: The liver cirrhosis group consisted of 16 participants with PVT and 32 without PVT. Higher RRT-mean values (odds ratio [OR] 11.4 [95% CI: 2.19, 118]) and lower platelet count (OR 0.98 per 1000 µL [95% CI: 0.96, 0.99]) were independent risk factors for PVT. The incorporation of RRT-mean (AUC, 0.77) alongside platelet count (AUC, 0.75) resulted in an AUC of 0.84. When including healthy control participants, RRT-mean had an adjusted OR of 12.4 and the AUC of the combined model (RRT-mean and platelet count) was 0.90. DATA CONCLUSION: Prolonged RRT values and low platelet count were significantly associated with the presence of PVT in cirrhotic participants. RRT values derived from 4D Flow MRI may have potential clinical relevance in the management of PVT. EVIDENCE LEVEL: 2 TECHNICAL EFFICACY: Stage 2.

Highly accelerated free-breathing real-time 2D flow imaging using compressed sensing and shared velocity encoding.

OBJECTIVES: 2D real-time (RT) phase-contrast (PC) MRI is a promising alternative to conventional PC MRI, which overcomes problems due to irregular heartbeats or poor respiratory control. This study aims to evaluate a prototype compressed sensing (CS)-accelerated 2D RT-PC MRI technique with shared velocity encoding (SVE) for accurate beat-to-beat flow measurements. METHODS: The CS RT-PC technique was implemented using a single-shot fast RF-spoiled gradient echo with SVE by symmetric velocity encoding, and acquired with a temporal resolution of 51-56.5 ms in 1-5 heartbeats. Both aortic dissection phantom (n = 8) and volunteer (n = 7) studies were conducted using the prototype CS RT (CS, R = 8), the conventional (GRAPPA, R = 2), and the fully sampled PC sequences on a 3T clinical system. Flow parameters including peak velocity, peak flow rate, net flow rate, and maximum velocity were calculated to compare the performance between different methods using linear regression, intraclass correlation (ICC), and Bland-Altman analyses. RESULTS: Comparisons of the flow measurements at all locations in the phantoms demonstrated an excellent correlation (all R2 ≥ 0.93) and agreement (all ICC ≥ 0.97) with negligible means of differences. In healthy volunteers, a similarly good correlation (all R2 ≥ 0.80) and agreement (all ICC ≥ 0.90) were observed; however, CS RT slightly underestimated the maximum velocities and flow rates (~ 12%). CONCLUSION: The highly accelerated CS RT-PC technique is feasible for the evaluation of flow patterns without requiring breath-holding, and it allows for rapid flow assessment in patients with arrhythmia or poor breath-hold capacity. CLINICAL RELEVANCE STATEMENT: The free-breathing real-time flow MRI technique offers improved spatial and temporal resolutions, as well as the ability to image individual cardiac cycles, resulting in superior image quality compared to the conventional PC technique when imaging patients with arrhythmias, especially those with atrial fibrillation. KEY POINTS: • The highly accelerated prototype CS RT-PC MRI technique with improved temporal resolution by the concept of SVE is feasible for beat-to-beat flow evaluation without requiring breath-holding. • The results of the phantom and in vivo quantitative flow evaluation show the ability of the prototype CS RT-PC technique to obtain reliable flow measurements similarly to the conventional PC MRI. • With less than 12% underestimation, excellent agreements between the two techniques were shown for the measurements of peak velocities and flow rates.

Regulation of the CB1R/AMPK/PGC-1α signaling pathway in mitochondria of mouse hearts and cardiomyocytes with chronic intermittent hypoxia.

PURPOSE: This study evaluated the effects of chronic intermittent hypoxia (CIH) at different times on the mitochondria of mouse hearts and H9C2 cardiomyocytes to determine the role of the cannabinoid receptor 1 (CB1R)/adenosine 5'-monophosphate-activated protein kinase (AMPK)/peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) signaling pathway. METHODS: Animal and cellular CIH models were prepared in an intermittent hypoxia chamber at different times. The cardiac function of mice was determined, and heart tissue and ultrastructural changes were observed. Apoptosis, reactive oxygen species (ROS), and mitochondrial membrane potential were detected, and MitoTracker™ staining was performed to observe cardiomyocyte mitochondria. Western blot, immunohistochemistry, and cellular immunofluorescence were also performed. RESULTS: In the short-term CIH group, increases in mouse ejection fraction (EF) and heart rate (HR); mitochondrial division; ROS and mitochondrial membrane potential; and the expression levels of CB1R, AMPK, and PGC-1α were observed in vivo and in vitro. In the long-term CIH group, the EF and HR increased, the myocardial injury and mitochondrial damage were more severe, mitochondrial synthesis decreased, the apoptosis percentage and ROS increased, mitochondrial fragmentation increased, membrane potential decreased, CB1R expression increased, and AMPK and PGC-1α expression levels decreased. Targeted blocking of CB1R can increase AMPK and PGC-1α, reduce damage attributed to long-term CIH in mouse hearts and H9C2 cells, and promote mitochondrial synthesis. CONCLUSION: Short-term CIH can directly activate the AMPK/PGC-1α pathway, promote mitochondrial synthesis in cardiomyocytes, and protect cardiac structure and function. Long-term CIH can increase CB1R expression and inhibit the AMPK/PGC-1α pathway, resulting in structural damage, the disturbance of myocardial mitochondria synthesis, and further alterations in the cardiac structure. After targeted blocking of CB1R, levels of AMPK and PGC-1α increased, alleviating damage to the heart and cardiomyocytes caused by long-term CIH.

Human umbilical cord mesenchymal stem cells protect against ferroptosis in acute liver failure through the IGF1-hepcidin-FPN1 axis and inhibiting iron loading.

Acute liver failure (ALF) is a significant global issue with elevated morbidity and mortality rates. There is an urgent and pressing need for secure and effective treatments. Ferroptosis, a novel iron-dependent regulation of cell death, plays a significant role in multiple pathological processes associated with liver diseases, including ALF. Several studies have demonstrated that mesenchymal stem cells (MSCs) have promising therapeutic potential in the treatment of ALF. This study aims to investigate the positive effects of MSCs against ferroptosis in an ALF model and explore the underlying molecular mechanisms of their therapeutic function. Our results show that intravenously injected MSCs protect against ferroptosis in ALF mouse models. MSCs decrease iron deposition in the liver of ALF mice by downregulating hepcidin level and upregulating FPN1 level. MSCs labelled with Dil are mainly observed in the hepatic sinusoid and exhibit colocalization with the macrophage marker CD11b fluorescence. ELISA demonstrates a high level of IGF1 in the CCL 4+MSC group. Suppressing the IGF1 effect by the PPP blocks the therapeutic effect of MSCs against ferroptosis in ALF mice. Furthermore, disruption of IGF1 function results in iron deposition in the liver tissue due to impaired inhibitory effects of MSCs on hepcidin level. Our findings suggest that MSCs alleviate ferroptosis induced by disorders of iron metabolism in ALF mice by elevating IGF1 level. Moreover, MSCs are identified as a promising cell source for ferroptosis treatment in ALF mice.

Development of an alcoholic liver disease model for drug evaluation from human induced pluripotent stem cell-derived liver organoids.

Alcoholic liver disease (ALD) poses a significant health challenge, so comprehensive research efforts to improve our understanding and treatment strategies are needed. However, the development of effective treatments is hindered by the limitation of existing liver disease models. Liver organoids, characterized by their cellular complexity and three-dimensional (3D) tissue structure closely resembling the human liver, hold promise as ideal models for liver disease research. In this study, we use a meticulously designed protocol involving the differentiation of human induced pluripotent stem cells (hiPSCs) into liver organoids. This process incorporates a precise combination of cytokines and small molecule compounds within a 3D culture system to guide the differentiation process. Subsequently, these differentiated liver organoids are subject to ethanol treatment to induce ALD, thus establishing a disease model. A rigorous assessment through a series of experiments reveals that this model partially recapitulates key pathological features observed in clinical ALD, including cellular mitochondrial damage, elevated cellular reactive oxygen species (ROS) levels, fatty liver, and hepatocyte necrosis. In addition, this model offers potential use in screening drugs for ALD treatment. Overall, the liver organoid model of ALD, which is derived from hiPSC differentiation, has emerged as an invaluable platform for advancing our understanding and management of ALD in clinical settings.

Physiological responses of coriander (Coriandrum sativum L.) to exogenous 2,4-epibrassinolide at different concentrations.

BACKGROUND: Brassinolide, known as the seventh plant hormone, can improve the photosynthetic capacity of plants, promote plant growth and development, promote the formation of horticultural crop yield, improve the quality of horticultural crops, and also improve the ability of plants to resist biological and abiotic stresses. RESULTS: The effects of different concentrations of exogenously sprayed 2,4-epibrassinolide (EBR) on growth, physiological and photosynthetic characteristics of 'All-round large leaf coriander' were studied in substrate culture. The results showed that 0.05, 0.1, and 0.5 mg.L- 1 EBR promoted the growth of coriander and increased the aboveground fresh and dry weights, with 0.5 mg.L- 1 EBR having the most significant effect. Spraying 0.1 mg.L- 1 EBR increased the content of soluble sugars and protein of coriander leaves. Spraying 0.1 and 0.5 mg.L- 1 EBR significantly increased the chlorophyll content and photosynthetic parameters of coriander leaves, and 0.5 mg.L- 1 EBR also significantly increased the chlorophyll fluorescence parameters of coriander leaves. Spraying 0.5 mg.L- 1 EBR upregulated the expression of CsRbcS, CsFBPase, and CsAld. Correlation analysis showed that aboveground fresh weight under exogenous EBR treatment was significantly positively correlated with aboveground dry weight, plant height, Pn, Gs, Ci, and CsAld (P < 0.05), and soluble sugar content was significantly positively correlated with the number of leaves, Y(II), qP, and CsRbcS. The results of the principal component analysis (PCA) showed that there was a significant separation between the treatment and the control groups. Spraying 0.5 mg.L- 1 EBR can promote the growth of coriander, improve the quality of coriander leaves, and strengthen coriander leaf photosynthetic capacity. This study provides new insights into the promotion of coriander growth and development following the application of exogenous EBR. CONCLUSION: Exogenous EBR treatment increased coriander plant height, leaf growth and aboveground dry weight, and enhanced photosynthesis. Exogenous spraying of 0.5 mg.L- 1 EBR had the most significant effect.

Four-dimensional Flow MRI Assessment of Portal Hemodynamics and Hepatic Regeneration after Portal Vein Embolization.

Background Percutaneous transhepatic portal vein (PV) embolization (PVE) is a standard preoperative procedure for advanced biliary cancer when the future liver remnant (FLR) is insufficient, yet the effect of this procedure on portal hemodynamics is still unclear. Purpose To assess whether four-dimensional (4D) MRI flowmetry can be used to estimate FLR volume and to identify the optimal time for this measurement. Materials and Methods This prospective single-center study enrolled consecutive adult patients with biliary cancer who underwent percutaneous transhepatic PVE for the right liver between June 2020 and November 2022. Portal hemodynamics were assessed using 4D flow MRI before PVE and within 1 day (0-day group) or 3-4 days (3-day group) after PVE. FLR volume was measured using CT before PVE and after PVE but before surgery. Blood flow changes were analyzed with the Wilcoxon signed rank test, and correlations with Spearman rank correlation. Results The 0-day group included 24 participants (median age, 72 years [IQR, 69-77 years]; 17 male participants), and the 3-day group included 13 participants (median age, 71 years [IQR, 68-78 years]; eight male participants). Both groups showed increased left PV (LPV) flow rate after PVE (0-day group: from median 3.72 mL/sec [IQR, 2.83-4.55 mL/sec] to 9.48 mL/sec [IQR, 8.12-10.7 mL/sec], P < .001; 3-day group: from median 3.65 mL/sec [IQR, 2.14-3.79 mL/sec] to 8.16 mL/sec [IQR, 6.82-8.98 mL/sec], P < .001). LPV flow change correlated with FLR volume change relative to the number of days from PVE to presurgery CT only in the 3-day group (ρ = 0.62, P = .02; 0-day group, P = .11). The output of the regression equation for estimating presurgery FLR volume correlated with CT-measured volume (ρ = 0.78; P = .002). Conclusion Four-dimensional flow MRI demonstrated increased blood flow in residual portal branches 3-4 days after PVE, offering insights for estimating presurgery FLR volume. Published under a CC BY 4.0 license. Supplemental material is available for this article. See also the editorial by Roldán-Alzate and Oechtering in this issue.

Comprehensive Neonatal Cardiac, Feed and Wrap, Non-contrast, Non-sedated, Free-breathing Compressed Sensing 4D Flow MRI Assessment.

BACKGROUND: Cardiac MRI is an important imaging tool in congenital cardiac disease, but its use has been limited in the neonatal population as general anesthesia has been needed for breath-holding. Technological advances in four-dimensional (4D) flow MRI have now made nonsedated free-breathing acquisition protocols a viable clinical option, but the method requires prospective validation in neonates. PURPOSE: To test the feasibility of compressed sensing (CS) 4D flow MRI in the neonatal population and to compare with standard previously validated two-dimensional (2D) phase-contrast (PC) flow MRI. STUDY TYPE: Prospective, cohort, image quality. POPULATION: A total of 14 healthy neonates (median [range] age: 2.5 [0-80] days; 8 male). FIELD STRENGTH AND SEQUENCE: Noncontrast 2D cine gradient echo sequence with through-plane velocity encoding (PC) sequence and compressed sensing (CS) three-dimensional (3D), time-resolved, cine phase-contrast MRI with 3D velocity-encoding (4D flow MRI) at 3 T. ASSESSMENT: Aortic 2D PC, and aortic, pulmonary trunk and superior vena cava CS 4D flow MRI were acquired using the feed and wrap technique (nonsedated) and quantified using commercially available software. Aortic flow and peak velocity were compared between methods. Internal consistency of 4D flow MRI was determined by comparing mean forward flow of the main pulmonary artery (MPA) vs. the sum of left and right pulmonary artery flows (LPA and RPA) and by comparing mean ascending aorta forward flow (AAo) vs. the sum of superior vena cava (SVC) and descending aorta flows (DAo). STATISTICAL TESTS: Flow and peak-velocity comparisons were assessed using paired t-tests, with P < 0.05 considered significant, and Bland-Altman analysis. Interobserver and intraobserver agreement and internal consistency were analyzed by intraclass correlation co-efficient (ICC). RESULTS: There was no statistically significant difference between ascending aortic forward flow between 2D PC and CS 4D Flow MRI (P = 0.26) with a bias of 0.11 mL (-0.59 to 0.82 mL) nor peak velocity (P = 0.11), with a bias of -5 cm/sec and (-26 to 16 cm/sec). There was excellent interobserver and intraobserver agreement for each vessel (interobserver ICC: AAo 1.00; DAo 0.94, SVC 0.90, MPA 0.99, RPA 0.98, LPA 0.96; intraobserver ICC: AAo 1.00; DAo 0.99, SVC 0.98, MPA 1.00, RPA 1.00, LPA 0.99). Internal consistency measures showed excellent agreement for both mean forward flow of main pulmonary artery vs. the sum of left and right pulmonary arteries (ICC: 0.95) and mean ascending aorta forward flow vs. the sum of superior vena cava and descending aorta flows (ICC: 1.00). CONCLUSION: Sedation-free neonatal feed and wrap MRI is well tolerated and feasible. CS 4D flow MRI quantification is similar to validated 2D PC free-breathing imaging with excellent interobserver and intraobserver agreement. EVIDENCE LEVEL: 1 TECHNICAL EFFICACY: Stage 2.

Highly Accelerated Compressed-Sensing 4D Flow for Intracardiac Flow Assessment.

BACKGROUND: Four-dimensional (4D) flow MRI allows for the quantification of complex flow patterns; however, its clinical use is limited by its inherently long acquisition time. Compressed sensing (CS) is an acceleration technique that provides substantial reduction in acquisition time. PURPOSE: To compare intracardiac flow measurements between conventional and CS-based highly accelerated 4D flow acquisitions. STUDY TYPE: Prospective. SUBJECTS: Fifty healthy volunteers (28.0 ± 7.1 years, 24 males). FIELD STRENGTH/SEQUENCE: Whole heart time-resolved 3D gradient echo with three-directional velocity encoding (4D flow) with conventional parallel imaging (factor 3) as well as CS (factor 7.7) acceleration at 3 T. ASSESSMENT: 4D flow MRI data were postprocessed by applying a valve tracking algorithm. Acquisition times, flow volumes (mL/cycle) and diastolic function parameters (ratio of early to late diastolic left ventricular peak velocities [E/A] and ratio of early mitral inflow velocity to mitral annular early diastolic velocity [E/e']) were quantified by two readers. STATISTICAL TESTS: Paired-samples t-test and Wilcoxon rank sum test to compare measurements. Pearson correlation coefficient (r), Bland-Altman-analysis (BA) and intraclass correlation coefficient (ICC) to evaluate agreement between techniques and readers. A P value < 0.05 was considered statistically significant. RESULTS: A significant improvement in acquisition time was observed using CS vs. conventional accelerated acquisition (6.7 ± 1.3 vs. 12.0 ± 1.3 min). Net forward flow measurements for all valves showed good correlation (r > 0.81) and agreement (ICCs > 0.89) between conventional and CS acceleration, with 3.3%-8.3% underestimation by the CS technique. Evaluation of diastolic function showed 3.2%-17.6% error: E/A 2.2 [1.9-2.4] (conventional) vs. 2.3 [2.0-2.6] (CS), BA bias 0.08 [-0.81-0.96], ICC 0.82; and E/e' 4.6 [3.9-5.4] (conventional) vs. 3.8 [3.4-4.3] (CS), BA bias -0.90 [-2.31-0.50], ICC 0.89. DATA CONCLUSION: Analysis of intracardiac flow patterns and evaluation of diastolic function using a highly accelerated 4D flow sequence prototype is feasible, but it shows underestimation of flow measurements by approximately 10%. EVIDENCE LEVEL: 2 TECHNICAL EFFICACY: Stage 1.

Hemodynamic Evaluation of Type B Aortic Dissection Using Compressed Sensing Accelerated 4D Flow MRI.

BACKGROUND: 4D Flow MRI is a quantitative imaging technique to evaluate blood flow patterns; however, it is unclear how compressed sensing (CS) acceleration would impact aortic hemodynamic quantification in type B aortic dissection (TBAD). PURPOSE: To investigate CS-accelerated 4D Flow MRI performance compared to GRAPP-accelerated 4D Flow MRI (GRAPPA) to evaluate aortic hemodynamics in TBAD. STUDY TYPE: Prospective. POPULATION: Twelve TBAD patients, two volunteers. FIELD STRENGTH/SEQUENCE: 1.5T, 3D time-resolved cine phase-contrast gradient echo sequence. ASSESSMENT: GRAPPA (acceleration factor [R] = 2) and two CS-accelerated (R = 7.7 [CS7.7] and 10.2 [CS10.2]) 4D Flow MRI scans were acquired twice for interscan reproducibility assessment. Voxelwise kinetic energy (KE), peak velocity (PV), forward flow (FF), reverse flow (RF), and stasis were calculated. Plane-based mid-lumen flows were quantified. Imaging times were recorded. TESTS: Repeated measures analysis of variance, Pearson correlation coefficients (r), intraclass correlation coefficients (ICC). P < 0.05 indicated statistical significance. RESULTS: The KE and FF in true lumen (TL) and PV in false lumen (FL) did not show difference among three acquisition types (P = 0.818, 0.065, 0.284 respectively). The PV and stasis in TL were higher, KE, FF, and RF in FL were lower, and stasis was higher in GRAPPA compared to CS7.7 and CS10.2. The RF was lower in GRAPPA compared to CS10.2. The correlation coefficients were strong in TL (r = [0.781-0.986]), and low to strong in FL (r = [0.347-0.948]). The ICC levels demonstrated moderate to excellent interscan reproducibility (0.732-0.989). The FF and net flow in mid-descending aorta TL were significantly different between CS7.7 and CS10.2. CONCLUSION: CS-accelerated 4D Flow MRI has potential for clinical utilization with shorter scan times in TBAD. Our results suggest similar hemodynamic trends between acceleration types, but CS-acceleration impacts KE, FF, RF, and stasis more in FL. EVIDENCE LEVEL: 1 Technical Efficacy: Stage 2.

Repeatability and reproducibility of various 4D Flow MRI postprocessing software programs in a multi-software and multi-vendor cross-over comparison study.

BACKGROUND: Different software programs are available for the evaluation of 4D Flow cardiovascular magnetic resonance (CMR). A good agreement of the results between programs is a prerequisite for the acceptance of the method. Therefore, the goal was to compare quantitative results from a cross-over comparison in individuals examined on two scanners of different vendors analyzed with four postprocessing software packages. METHODS: Eight healthy subjects (27 ± 3 years, 3 women) were each examined on two 3T CMR systems (Ingenia, Philips Healthcare; MAGNETOM Skyra, Siemens Healthineers) with a standardized 4D Flow CMR sequence. Six manually placed aortic contours were evaluated with Caas (Pie Medical Imaging, SW-A), cvi42 (Circle Cardiovascular Imaging, SW-B), GTFlow (GyroTools, SW-C), and MevisFlow (Fraunhofer Institute MEVIS, SW-D) to analyze seven clinically used parameters including stroke volume, peak flow, peak velocity, and area as well as typically scientifically used wall shear stress values. Statistical analysis of inter- and intrareader variability, inter-software and inter-scanner comparison included calculation of absolute and relative error (ER), intraclass correlation coefficient (ICC), Bland-Altman analysis, and equivalence testing based on the assumption that inter-software differences needed to be within 80% of the range of intrareader differences. RESULTS: SW-A and SW-C were the only software programs showing agreement for stroke volume (ICC = 0.96; ER = 3 ± 8%), peak flow (ICC: 0.97; ER = -1 ± 7%), and area (ICC = 0.81; ER = 2 ± 22%). Results from SW-A/D and SW-C/D were equivalent only for area and peak flow. Other software pairs did not yield equivalent results for routinely used clinical parameters. Especially peak maximum velocity yielded poor agreement (ICC ≤ 0.4) between all software packages except SW-A/D that showed good agreement (ICC = 0.80). Inter- and intrareader consistency for clinically used parameters was best for SW-A and SW-D (ICC = 0.56-97) and worst for SW-B (ICC = -0.01-0.71). Of note, inter-scanner differences per individual tended to be smaller than inter-software differences. CONCLUSIONS: Of all tested software programs, only SW-A and SW-C can be used equivalently for determination of stroke volume, peak flow, and vessel area. Irrespective of the applied software and scanner, high intra- and interreader variability for all parameters have to be taken into account before introducing 4D Flow CMR in clinical routine. Especially in multicenter clinical trials a single image evaluation software should be applied.

Isolation and characterization of a novel parvovirus from a red-crowned crane, China, 2021.

BACKGROUND: Parvoviruses are icosahedral, nonenveloped viruses with single-stranded DNA genomes of approximately 5 kb in length. In recent years, parvoviruses have frequently mutated and expanded their host range to cause disease in many wild animals by altering their tissue tropism. Animal infection mainly results in acute enteritis and inflammation of other organs. In this study, we used a viral metagenomic method to detect a novel parvovirus species in a red-crowned crane that died due to severe diarrhea in China. RESULTS: The presence of the viral genome in the kidney, lung, heart, liver, and intestine were confirmed by PCR. Histopathological examination of the intestine showed a large number of infiltrated inflammatory cells. The JL21/10 strain of the red-crowned crane parvovirus was first isolated from the intestine. Whole-genome sequence analysis showed that JL21/10 shared high identity with the red-crowned crane Parvovirinae strains yc-8 at the nucleotide level (96.61%). Phylogenetic analysis of the complete genome and NS1 gene revealed that the JL21/10 strain clustered with strains in chicken and revealed a close genetic relationship with the red-crowned crane parvovirus strains.The complete of VP2 gene analysis showed that JL21/10 shared identity with the red-crowned crane yc-8 strains (97.7%), chicken (55.4%),ducks(31.0%) and geese(30.1%) at the amino acid level. The result showed that red-crowned crane parvovirus may be cross-species transmission to chicken. However, There is little possibility of transmission to ducks and geese. CONCLUSION: This is the first isolation and identification of a parvovirus in red-crowned crane that was associated with severe diarrhea.

Segmentation of the aorta in systolic phase from 4D flow MRI: multi-atlas vs. deep learning.

OBJECTIVE: In the management of the aortic aneurysm, 4D flow magnetic resonance Imaging provides valuable information for the computation of new biomarkers using computational fluid dynamics (CFD). However, accurate segmentation of the aorta is required. Thus, our objective is to evaluate the performance of two automatic segmentation methods on the calculation of aortic wall pressure. METHODS: Automatic segmentation of the aorta was performed with methods based on deep learning and multi-atlas using the systolic phase in the 4D flow MRI magnitude image of 36 patients. Using mesh morphing, isotopological meshes were generated, and CFD was performed to calculate the aortic wall pressure. Node-to-node comparisons of the pressure results were made to identify the most robust automatic method respect to the pressures obtained with a manually segmented model. RESULTS: Deep learning approach presented the best segmentation performance with a mean Dice similarity coefficient and a mean Hausdorff distance (HD) equal to 0.92+/- 0.02 and 21.02+/- 24.20 mm, respectively. At the global level HD is affected by the performance in the abdominal aorta. Locally, this distance decreases to 9.41+/- 3.45 and 5.82+/- 6.23 for the ascending and descending thoracic aorta, respectively. Moreover, with respect to the pressures from the manual segmentations, the differences in the pressures computed from deep learning were lower than those computed from multi-atlas method. CONCLUSION: To reduce biases in the calculation of aortic wall pressure, accurate segmentation is needed, particularly in regions with high blood flow velocities. Thus, the deep learning segmen-tation method should be preferred.

Assessment of hepatic arterial hemodynamics with 4D flow MRI: in vitro analysis of motion and spatial resolution related error and in vivo feasibility study in 20 volunteers.

OBJECTIVES: To assess the ability of four-dimensional (4D) flow MRI to measure hepatic arterial hemodynamics by determining the effects of spatial resolution and respiratory motion suppression in vitro and its applicability in vivo with comparison to two-dimensional (2D) phase-contrast MRI. METHODS: A dynamic hepatic artery phantom and 20 consecutive volunteers were scanned. The accuracies of Cartesian 4D flow sequences with k-space reordering and navigator gating at four spatial resolutions (0.5- to 1-mm isotropic) and navigator acceptance windows (± 8 to ± 2 mm) and one 2D phase-contrast sequence (0.5-mm in -plane) were assessed in vitro at 3 T. Two sequences centered on gastroduodenal and hepatic artery branches were assessed in vivo for intra - and interobserver agreement and compared to 2D phase-contrast. RESULTS: In vitro, higher spatial resolution led to a greater decrease in error than narrower navigator window (30.5 to -4.67% vs -6.64 to -4.67% for flow). In vivo, hepatic and gastroduodenal arteries were more often visualized with the higher resolution sequence (90 vs 71%). Despite similar interobserver agreement (κ = 0.660 and 0.704), the higher resolution sequence had lower variability for area (CV = 20.04 vs 30.67%), flow (CV = 34.92 vs 51.99%), and average velocity (CV = 26.47 vs 44.76%). 4D flow had lower differences between inflow and outflow at the hepatic artery bifurcation (11.03 ± 5.05% and 15.69 ± 6.14%) than 2D phase-contrast (28.77 ± 21.01%). CONCLUSION: High-resolution 4D flow can assess hepatic artery anatomy and hemodynamics with improved accuracy, greater vessel visibility, better interobserver reliability, and internal consistency. KEY POINTS: • Motion-suppressed Cartesian four-dimensional (4D) flow MRI with higher spatial resolution provides more accurate measurements even when accepted respiratory motion exceeds voxel size. • 4D flow MRI with higher spatial resolution provides substantial interobserver agreement for visualization of hepatic artery branches. • Lower peak and average velocities and a trend toward better internal consistency were observed with 4D flow MRI as compared to 2D phase-contrast.

Immunogenicity and protective efficacy of a DNA vaccine inducing optimal expression of the SARS-CoV-2 S gene in hACE2 mice.

The wide spread of coronavirus disease 2019 (COVID-19) has significantly threatened public health. Human herd immunity induced by vaccination is essential to fight the epidemic. Therefore, highly immunogenic and safe vaccines are necessary to control SARS-CoV-2, whose S protein is the antigenic determinant responsible for eliciting antibodies that prevent viral entry and fusion. In this study, we developed a SARS-CoV-2 DNA vaccine expressing the S protein, named pVAX-S-OP, which was optimized according to the human-origin codon preference and using polyinosinic-polycytidylic acid as an adjuvant. pVAX-S-OP induced specific antibodies and neutralizing antibodies in BALB/c and hACE2 transgenic mice. Furthermore, we observed 1.43-fold higher antibody titers in mice receiving pVAX-S-OP plus adjuvant than in those receiving pVAX-S-OP alone. Interferon gamma production in the pVAX-S-OP-immunized group was 1.58 times (CD3+CD4+IFN-gamma+) and 2.29 times (CD3+CD8+IFN-gamma+) lower than that in the pVAX-S-OP plus adjuvant group but higher than that in the control group. The pVAX-S-OP vaccine was also observed to stimulate a Th1-type immune response. When, hACE2 transgenic mice were challenged with SARS-CoV-2, qPCR detection of N and E genes showed that the viral RNA loads in pVAX-S-OP-immunized mice lung tissues were 104 times and 106 times lower than those of the PBS control group, which shows that the vaccine could reduce the amount of live virus in the lungs of hACE2 mice. In addition, pathological sections showed less lung damage in the pVAX-S-OP-immunized group. Taken together, our results demonstrated that pVAX-S-OP has significant immunogenicity, which provides support for developing SARS-CoV-2 DNA candidate vaccines.

Ferroptosis in viral infection: the unexplored possibility.

Virus-induced cell death has long been thought of as a double-edged sword in the inhibition or exacerbation of viral infections. The vital role of iron, an essential element for various enzymes in the maintenance of cellular physiology and efficient viral replication, places it at the crossroads and makes it a micronutrient of competition between the viruses and the host. Viruses can interrupt iron uptake and the antioxidant response system, while others can utilize iron transporter proteins as receptors. Interestingly, the unavailability of iron facilitates certain viral infections and causes cell death characterized by lipid peroxide accumulation and malfunction of the antioxidant system. In this review, we discuss how iron uptake, regulation and metabolism, including the redistribution of iron in the host defense system during viral infection, can induce ferroptosis. Fenton reactions, a central characteristic of ferroptosis, are caused by the increased iron content in the cell. Therefore, viral infections that increase cellular iron content or intestinal iron absorption are likely to cause ferroptosis. In addition, we discuss the hijacking of the iron regulatoy pathway and the antioxidant response, both of which are typical in viral infections. Understanding the potential signaling mechanisms of ferroptosis in viral infections will aid in the development of new therapeutic agents.

C/N-Dependent Element Bioconversion Efficiency and Antimicrobial Protein Expression in Food Waste Treatment by Black Soldier Fly Larvae.

The black soldier fly (BSF), Hermetia illucens, has emerged as a promising species for waste bioconversion and source of antimicrobial proteins (AMPs). However, there is a scarcity of research on the element transformation efficiency and molecular characterization of AMPs derived from waste management. Here, food waste treatment was performed using BSF larvae (BSFL) in a C/N ratio of 21:1−10:1, with a focus on the C/N-dependent element bioconversion, AMP antimicrobial activity, and transcriptome profiling. The C-larvae transformation rates were found to be similar among C/Ns (27.0−35.5%, p = 0.109), while the N-larvae rates were different (p = 0.001), with C/N 21:1−16:1 (63.5−75.0%) being higher than C/N 14:1−10:1 (35.0−45.7%). The C/N ratio did not alter the antimicrobial spectrum of AMPs, but did affect the activities, with C/N 21:1 being significantly lower than C/N 18:1−10:1. The lysozyme genes were found to be significantly more highly expressed than the cecropin, defensin, and attacin genes in the AMP gene family. Out of 51 lysozyme genes, C/N 18:1 and C/N 16:1 up-regulated (p < 0.05) 14 and 12 genes compared with C/N 21:1, respectively, corresponding to the higher activity of AMPs. Overall, the element bioconversion efficiency and AMP expression can be enhanced through C/N ratio manipulation, and the C/N-dependent transcriptome regulation is the driving force of the AMP difference.

Application of Exogenous Silicon for Alleviating Photosynthetic Inhibition in Tomato Seedlings under Low-Calcium Stress.

To address the low Ca-induced growth inhibition of tomato plants, the mitigation effect of exogenous Si on tomato seedlings under low-Ca stress was investigated using different application methods. We specifically analyzed the effects of root application or foliar spraying of 1 mM Si on growth conditions, leaf photosynthetic properties, stomatal status, chlorophyll content, chlorophyll fluorescence, ATP activity and content, Calvin cycle-related enzymatic activity, and gene expression in tomato seedlings under low vs. adequate calcium conditions. We found that the low-Ca environment significantly affected (reduced) these parameters, resulting in growth limitation. Surprisingly, the application of 1 mM Si significantly increased plant height, stem diameter, and biomass accumulation, protected photosynthetic pigments, improved gas exchange, promoted ATP production, enhanced the activity of Calvin cycle key enzymes and expression of related genes, and ensured efficient photosynthesis to occur in plants under low-Ca conditions. Interestingly, when the same amount of Si was applied, the beneficial effects of Si were more pronounced under low-Ca conditions that under adequate Ca. We speculate that Si might promote the absorption and transport of calcium in plants. The effects of Si also differed depending on the application method; foliar spraying was better in alleviating photosynthetic inhibition in plants under low-Ca stress, whereas root application of Si significantly promoted root growth and development. Enhancing the photosynthetic capacity by foliar Si application is an effective strategy for ameliorating the growth inhibition of plants under low-Ca stress.

Development and Comprehensive SPE-UHPLC-MS/MS Analysis Optimization, Comparison, and Evaluation of 2,4-Epibrassinolide in Different Plant Tissues.

A determination method for trace 24-epibrassinolide (EBL) in plant tissues was developed using ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The plant tissue samples were extracted using a methanol-formic acid solution, and the corresponding supernatant was purified with ODS C18 solid-phase extraction column. The extracts were separated using a Zorbax Eclipse Plus C18 (2.1 mm × 50 mm, 1.8 µm) column with methanol and 0.1% formic acid as the mobile phase. The ion source for the mass spectrometry was an electrospray ionization source with positive ion mode detection. The linear range of the target compound was 0.7~104 µg/kg, the limit of detection (LOD) was 0.11~0.37 µg/kg, the limit of quantification (LOQ) was 0.36~1.22 µg/kg, the recovery rate was 84.0~116.3%, and the relative standard deviation (RSD%) was 0.8~10.5. The samples of maize plumule, brassica rapeseed flower, and marigold leaf were detected using the external standard method. The optimization of the extraction method and detection method of EBL improved the detection sensitivity, laid a foundation for the artificial synthesis of EBL, improved the extraction rate of EBL, and provided a theoretical basis for the study of EBL in many plants.