GraphCpG: imputation of single-cell methylomes based on locus-aware neighboring subgraphs.

MOTIVATION: Single-cell DNA methylation sequencing can assay DNA methylation at single-cell resolution. However, incomplete coverage compromises related downstream analyses, outlining the importance of imputation techniques. With a rising number of cell samples in recent large datasets, scalable and efficient imputation models are critical to addressing the sparsity for genome-wide analyses. RESULTS: We proposed a novel graph-based deep learning approach to impute methylation matrices based on locus-aware neighboring subgraphs with locus-aware encoding orienting on one cell type. Merely using the CpGs methylation matrix, the obtained GraphCpG outperforms previous methods on datasets containing more than hundreds of cells and achieves competitive performance on smaller datasets, with subgraphs of predicted sites visualized by retrievable bipartite graphs. Besides better imputation performance with increasing cell number, it significantly reduces computation time and demonstrates improvement in downstream analysis. AVAILABILITY AND IMPLEMENTATION: The source code is freely available at https://github.com/yuzhong-deng/graphcpg.git.

Use the right kidney contour as a landmark in adrenal vein sampling.

Adrenal Vein Sampling (AVS) is the gold standard for categorizing primary aldosteronism (PA). However, catheterization of the right adrenal vein (RAV) is challenging due the small size and variable location. This study aims to explore the relationship between the RAV orifice and the right kidney contour (RKC) on fluoroscopy, thus evaluating the potential of use the RKC as an anatomic marker for localizing RAV. Imaging data of 107 PA patients with successful bilateral AVS were retrospectively analyzed. Based on the body mass index (BMI), all patients were divided into the Normal Group (BMI < 24 kg/m2), Overweight Group (24 kg/m2 ≤ BMI < 28 kg/m2) and Obese Group (BMI ≥ 28 kg/m2). At the anterior view, the height level of RAV orifice was determined relative to vertebral bodies and disks. The distance from the RAV orifice to the upper edge of RKC was measured manually. The RAV orifice height level was mainly distributed from vertebral T11 to T12 (90.6%), and tended to be higher in patients with a larger BMI. The mean distance from the RAV orifice to the upper edge of RKC was 13.9±7.8mm, and had no difference among Normal group (n = 53, 14.1±8.2mm), Overweight group (n = 39, 13.7±8.0mm), and Obese group (n = 15, 13.9±5.5mm) (p = 0.981). Based on these findings, the RKC might be used as a landmark for localizing RAV on fluoroscopy, which is conductive to narrow down the exploration range and increase the success rate of RAV catheterization.

The benefits of sacubitril-valsartan in patients with acute myocardial infarction: a systematic review and meta-analysis.

AIMS: We aimed to investigate whether sacubitril-valsartan could further improve the prognosis, cardiac function, and left ventricular (LV) remodelling in patients following acute myocardial infarction (AMI). METHODS AND RESULTS: We searched the PubMed, Embase, Cochrane Library, and China National Knowledge Infrastructure (CNKI) from inception to 10 May 2021 to identify potential articles. Randomized controlled trials (RCTs) meeting the inclusion criteria were included and analysed. Thirteen RCTs, covering 1358 patients, were analysed. Compared with angiotensin-converting enzyme inhibitors (ACEI)/angiotensin receptor blockers (ARB), sacubitril-valsartan did not significantly reduced the cardiovascular mortality [risk ratio (RR) 0.65, 95% confidence interval (CI) 0.22 to 1.93, P = 0.434] and the rate of myocardial reinfarction (RR 0.65, 95% CI 0.29 to 1.46, P = 0.295) of patients following AMI, but the rate of hospitalization for heart failure (HF) (RR 0.48, 95% CI 0.35 to 0.66, P < 0.001) and the change of LV ejection fraction (LVEF) [weighted mean difference (WMD) 5.49, 95% CI 3.62 to 7.36, P < 0.001] were obviously improved. The N-terminal pro-brain natriuretic peptide (NT-ProBNP) level (WMD -310.23, 95% CI -385.89 to -234.57, P < 0.001) and the LV end-diastolic dimension (LVEDD) (WMD -3.16, 95% CI -4.59 to -1.73, P < 0.001) were also significantly lower in sacubitril-valsartan group than in ACEI/ARB group. Regarding safety, sacubitril-valsartan did not increase the risk of hypotension, hyperkalaemia, angioedema, and cough. CONCLUSIONS: This meta-analysis suggests that early administration of sacubitril-valsartan may be superior to conventional ACEI/ARB to decrease the risk of hospitalization for HF, improve the cardiac function, and reverse the LV remodelling in patients following AMI.

Downregulating the P2X3 receptor in the carotid body to reduce blood pressure via acoustic gene delivery in canines.

The purinergic P2X3 receptor in the carotid body (CB) is considered a new target for treating hypertension, although approaches for targeted regulating P2X3 receptor expression are lacking. Here, we explored the feasibility of targeted P2X3 receptor down-regulation in CBs by localized low-intensity focused ultrasound (LIFU)-mediated gene delivery to reduce the blood pressure. Thirty-two Kunming canines were randomly assigned to the treatment group (n = 14), negative control group (n = 10), LIFU + cationic microbubbles group (n = 4), and LIFU-only group (n = 4). Plasmid-loaded cationic microbubbles were injected and bilateral CBs were irradiated with a LIFU-based transducer. Flow cytometry showed that 33.15% of transfected cells expressed the green fluorescent protein reporter gene. T7 endonuclease I assays showed an insertion-deletion rate of 8.30%. The P2X3 receptor mRNA- and protein-expression levels in CBs decreased by 56.31% and 45.10%, respectively, in the treatment group. Mean systolic (152.5 ± 3.0 vs 138.0 ± 2.9 mm Hg, P = 0.003) and diastolic (97.8 ± 1.5 vs 87.2 ± 2.3 mm Hg, P= 0.002) blood pressures reduced on day 14 in the treatment group, compared with the baseline values, whereas no effects were observed with LIFU treatment or cationic microbubbles injection alone. Canines treated with this strategy exhibited no local or systemic adverse events. Thus, LIFU-mediated gene delivery to CBs successfully modulated CB function and reduced blood pressure in a canine model, suggesting a new possibility for treating hypertension and further clinical translation.

Carotid body enlargement in hypertension and other comorbidities evaluated by ultrasonography.

BACKGROUND: Carotid body hyperactivity is important for sympathetic-related diseases and carotid body volume may partly reflect carotid bodies' activity. Our objective was to identify the association between carotid body volume and hypertension or other sympathetic-related diseases. METHODS: Consecutive individuals, undergoing carotid ultrasonography, who were eligible for the inclusion criteria were included. The bilateral carotid bodies were detected and volumetric parameters were measured by carotid ultrasonography in clinical. Clinical data of included participants were collected and analysed. RESULTS: A total of 1226 consecutive individuals underwent carotid ultrasonography. Carotid bodies were detected as solid, pebble-shaped, hypoechoic structures and the overall carotid body detection rate was 78.7% (965/1226). Univariate and multivariate regression analyses indicated that hypertension, chronic heart failure (CHF), chronic lung disease, smoking and high BMI were positively associated with carotid body enlargement. Compared with controls (2.63 µl), carotid body volume was significantly elevated in simple hypertensive (3.11 µl, P < 0.001), simple CHF (3.27 µl, P = 0.004) and simple smoking (3.47 µl, P < 0.001) groups. Moreover, the individuals with three comorbidities (4.05 µl) had significantly larger carotid bodies than those with one (3.23 µl, P < 0.001) or two comorbidities (3.46 µl, P = 0.017), suggesting that there existed a cumulative effect of comorbidities on carotid body volume. CONCLUSION: Carotid body enlargement is strongly associated with hypertension and other sympathetic-related diseases or risk factors, and carotid body volume evaluated by carotid ultrasonography may be further explored as a promising screening and evaluation predictor for carotid body modulation therapy in patients with hypertension and other sympathetic-related diseases.

Cardiac Denervation for Arrhythmia Treatment with Transesophageal Ultrasonic Strategy in Canine Models.

Stellate ganglion (SG) modification has been investigated for arrhythmia treatment. In this study, transesophageal SG imaging and intervention were explored using a homemade 30F integrated focused ultrasonic catheter in healthy mongrel canines in vivo. Anatomic details of SGs were ultrasonically imaged and evaluated. SG had a heterogeneous echoic structure and characteristic profiles sketched by hyper-echoic outlines in an ultrasonogram. Left SGs in the experimental group were successfully ablated through the esophagus under ultrasonic guidance provided by the catheter itself. Two weeks after the ablation, the QT and QTc of the experimental group decreased compared with those of the sham group and at baseline (both p values < 0.001). Histologic examination revealed that left SGs were destroyed. No major complications were observed. This approach may be further explored as a method for ganglia remodeling evaluation and as a strategy of ganglia modification for arrhythmia and for other diseases.

Anatomy and neural remodeling of the renal sympathetic nerve in a canine model and patients with hypertension.

BACKGROUND: The role of renal sympathetic nerve (RSN) in hypertension should be better understood. We aimed to three-dimensionally reconstruct the renal nerves, and explore its anatomical and histochemical characteristics in hypertensive canine model and patients. METHODS: Renal arteries with surrounding tissue were collected from canines and cadavers with or without hypertension. Serial renal artery hematoxylin-eosin sections were used for three-dimensional reconstruction, and morphological parameters were collected and analyzed. RESULTS: In hypertensive canines, the mean renal nerve number was 26.71 ±â€Š5.68 versus 19.84 ±â€Š5.68 in controls (P = 0.02), and the middle renal nerve volume was 5.31 ±â€Š2.13 versus 2.60 ±â€Š1.00 µl in controls (P = 0.01). Renal tissue norepinephrine concentrations, tyrosine hydroxylase and substance P immunoreactivity in RSN, and growth-associated protein 43 immunoreactivity in renal ganglion were significantly increased in hypertensive canines. In humans, the renal nerve was evenly distributed along the renal artery in a network pattern. The renal ganglion volume was 72.75 ±â€Š33.43 in hypertensive patients versus 37.04 ±â€Š23.95 µl in controls (P = 0.029) and the mean neuronal size in renal ganglion was 1187.3 ±â€Š219.9 µm in patients versus 714.8 ±â€Š142.7 µm in controls (P = 0.002). Tyrosine hydroxylase immunoreactivity in the RSN was 0.153 ±â€Š0.014 in patients versus 0.104 ±â€Š0.019 in controls (P = 0.013). Growth-associated protein 43 immunoreactivity in the renal ganglion was 86 612.8 ±â€Š14 642.0 in patients versus 33 469.8 ±â€Š15 666.8 µm/mm in controls (P < 0.001). CONCLUSION: Our study suggests that RSN and renal ganglion histological remodeling occurs in individuals with hypertension and the distal segment or branches of renal artery might be a promising therapeutic target for RSN modulation therapy.

Effect of Allopurinol on Myocardial Energy Metabolism in Chronic Heart Failure Rats After Myocardial Infarct.

To determine the effect of the xanthine oxidase (XO) inhibitor allopurinol on myocardial energy metabolism in a chronic heart failure rat model after myocardial infarct.An AMI model was established in 6-week-old rats via the ligation of the anterior descending coronary artery. Thirty-five rats were randomly divided into the following 3 groups: an ALLO group, an AMI group, and a Sham group. Heart failure was successfully diagnosed via echocardiography and blood tests. Xanthine oxidase (XO), malondialdehyde (MDA), PGC-1α, CPT-1, and GLUT4 were monitored in the myocardium.The TEM results demonstrated that myofilament lysis and mitochondrial swelling were alleviated in the ALLO group compared with the AMI group (without ALLO). The results also demonstrated that cardiac function was significantly improved in the ALLO group compared with the AMI group. Compared with the AMI group, the ALLO group exhibited increased respiratory-chain enzyme activity, as well as increased PGC-1α and CPT-1 mRNA and protein expression, decreased MDA content, and decreased XO and GLUT4 mRNA and protein expression.ALLO improves myocardial energy metabolism in rats with chronic heart failure, which may result from the regulation of PGC-1α in the setting of glycolipid metabolism, enhancing the production of ATP.

Effect of inhibiting malonyl-CoA decarboxylase on cardiac remodeling after myocardial infarction in rats.

OBJECTIVES: The objective of this study was to determine the effect of inhibiting malonyl-CoA decarboxylase (MCD) on cardiac remodeling following myocardial infarction (MI) in rats. We used an ultrasound (US)-mediated microbubble (MB) approach for targeted delivery of a microRNA (miRNA) interference plasmid to the myocardium to silence MCD expression. METHODS: Five pairs of RNA interference sequences were screened and ranked according to their highest inhibition rates in HEK293 cells. The plasmid with the highest inhibition rate was transfected by US into the rat myocardium after mixing with lipid MB. Twelve and 16 weeks after MI, cardiac function was measured by echocardiography, and glucose transporter-4 (GLUT-4) and high-energy phosphate levels were monitored in the myocardium before and after transfection. RESULTS: Ejection fraction (EF) decreased by 16% in the control MI group, while it decreased by 8% in the MCD inhibition group that utilized the US-mediated MB approach. Concomitant with the improved EF, high-energy phosphates were increased and lactic acid was decreased in the left ventricle (LV), with no changes in triglyceride or GLUT-4 levels. CONCLUSIONS: Inhibiting MCD by an US-mediated injection of miRNA into the rat myocardium increased energy reserves in the LV after MI, most likely by limiting lactic acidosis and improving cardiac function without increasing lipid toxicity.

Septal ablation induced by transthoracic high-intensity focused ultrasound in canines.

BACKGROUND: High-intensity focused ultrasound (HIFU) can achieve accurate and focused deep tissue ablation through an extracorporeal emission. Cardiac ablation using HIFU applied transthoracically must overcome potential interference from intervening thoracic structures. The aim of this study was to explore the efficacy and safety of septal ablation that was induced using transthoracic HIFU. METHODS: Twenty-one canines were pretreated to improve acoustic transmission. Single ablations were induced by targeting transthoracic HIFU with acoustic power of 400 W for 3 sec at the middle and basal septum in eight canines. Extended ablations were performed to create larger lesions at the basal septum in eight more canines. The three-dimensional morphology of a basal septum lesion induced by a single ablation was analyzed. The temperature at the ablative targets was measured in the other five canines. RESULTS: The cardiomyocytes in the lesions underwent necrosis with a clear boundary. The three-dimensional morphology of the lesions appeared approximately as ellipsoids with a flatter endocardial side. The peak temperature at a power of 400 W for 3 sec was 93.27 ± 2.54°C, and it remained >50°C for nearly 10 sec. No procedure-related complications were observed. CONCLUSIONS: Ultrasound-guided transthoracic HIFU has the potential to safely create small dot or large mass lesions in the septum without a thoracotomy or a catheter.

Noninvasive renal sympathetic denervation by extracorporeal high-intensity focused ultrasound in a pre-clinical canine model.

OBJECTIVES: This study investigated the feasibility of noninvasive renal sympathetic denervation (RSD) by using the novel approach of extracorporeal high-intensity focused ultrasound (HIFU). BACKGROUND: Catheter-based RSD has achieved promising clinical outcomes. METHODS: Under the guidance of Doppler flow imaging, therapeutic ablations (250 W × 2 s) were performed by using extracorporeal HIFU on the bilateral renal nerves (36.3 ± 2.8 HIFU emissions in each animal) in a mean 27.4-min procedure in 18 healthy canines of the ablation group. Similar procedures without acoustic energy treatment were conducted in 5 canines of the sham group. The animals were killed on day 6 or 28. Blood pressure (BP), plasma noradrenaline (NA) level, and renal function were determined on days 0, 6, and 28. Pathological examinations were performed on all retrieved samples. RESULTS: All of the animals survived the treatment. After ablation, BP and NA significantly decreased compared with the baseline values (BP changed -15.9/-13.6 mmHg, NA changed -55.4% [p < 0.001] 28 days after ablation]) and compared with the sham group on days 6 and 28. Ablation lesions around the renal artery adventitia were observed on day 6. A histological examination revealed the disruption of nerve fibers, necrosis of Schwann cells and neurons, and apparent denervation on day 28. No procedure-related complications were observed. CONCLUSIONS: Effective RSD was successfully achieved by using the extracorporeal HIFU method in canines. Thus, noninvasive HIFU may be further explored as an important and novel strategy for RSD.

Effects of transmyocardial jet revascularization with chitosan hydrogel on channel patency and angiogenesis in canine infarcted hearts.

The purpose of this study was to investigate whether transmyocardial jet revascularization (TMJR) with chitosan scaffolds retains channel patency and enhances angiogenesis after acute myocardial infarction (AMI) in a canine model. A total of 32 canines were randomly divided into four groups: myocardial infarction (MI), normal saline (NS), chitosan hydrogel (CH), and chitosan plus growth factor (CH + GF) groups. TMJR was performed surgically using a needle-free injector from the epicardium of canines in the NS, CH, and CH + GF groups; channels were filled with NS, CH, and CH + GF, respectively. After 6 weeks, the patency of the channels and angiogenesis around the channels were assessed by hematoxylin-eosin staining, immunohistochemistry, and Masson's trichrome staining. Results suggest that the channels in the CH and CH + GF groups may retain patency with luminal endothelization. Moreover, the vessel densities of the NS, CH, and CH + GF groups were significantly higher than that of the MI group, and that of the CH + GF group was the highest (p < 0.05). This study suggests that TMJR with chitosan scaffolds may help retain transmyocardial channel patency and enhance angiogenesis after AMI in canines.

The feasibility and safety of transendocardial gene injection in canine using a multifunctional intracardiac echocardiography catheter.

BACKGROUND: Transendocardial gene delivery may expose patients to the risk of pericardial perfusion due to excessive needle injections. This study investigated the feasibility and safety of transendocardial gene injection using a newly developed multifunctional intracardiac echocardiography catheter. METHODS: This new system integrated intracardiac echocardiography, a retractable 29-G needle, and other accessories into a single catheter (10F) that could be delivered into the left ventricle via a retrograde aortic approach. In three canines, the catheter was used to inject 0.2 ml of Evan's blue; six canines received myocardial injections of plasmid containing the EGFP transgene. In addition, two canines received transendocardial injections of a pAdTrace-bFGF plasmid. All canines receiving gene delivery were sacrificed after 3 days. The hearts were harvested for gross, histological examination and gene expression assessment. RESULTS: This catheter provided visual guidance for accurate needle-tip positioning within the target myocardium; the needle position was subsequently confirmed by microbubble infusion. No animal had pericardial effusion or sustained ventricular arrhythmia. Tissue staining showed well-demarcated margins within the target myocardium. In animals injected with pEGFP-N1, confocal microscopy demonstrated successful gene expression. In zones where pAdTrace-bFGF was injected, immunohistochemistry also showed positive staining. Compared to normal tissue (0.38±0.04), RT-PCR showed high levels of bFGF expression (0.63±0.02) in the target area (P<0.01). CONCLUSIONS: Transendocardial gene injection using a multifunctional intracardiac echocardiography catheter is feasible and could improve procedure-related safety which may provide a new strategy for transgene delivery in future.

A new strategy for septal ablation with transendocardial ethanol injection using a multifunctional intracardiac echocardiography catheter: a feasibility study in canines.

OBJECTIVES: To evaluate the feasibility and safety of a novel multifunctional intracardiac echocardiography catheter for target septal ablation with transendocardial ethanol injection in canines. BACKGROUND: Percutaneous transluminal septal myocardial ablation has been the primary catheter-based strategy for the treatment of hypertrophic obstructive cardiomyopathy (HOCM). However, inherent limitations of the technique have reduced its therapeutic efficacy. METHODS: A new catheter (10 F), integrated with a nitinol needle (29 G) and a 6.5-10-MHz, 32-element, side-fire ultrasound imaging transducer, was delivered into the right ventricle in nine canines and the left ventricle in three canines. A 0.3-ml microbubble and 0.5-1.5 ml absolute ethanol were sequentially injected into the interventricular septum. Electrocardiograph recordings were obtained during the whole procedure. Three hours after this operation, the heart was harvested for gross and histological examination. RESULTS: In all canines, the catheter provided the structural support and helped guide proper needle position within the septum. The microbubble further allowed the confirmation of the needle location through focal echo-density enhancement. Different amounts of ethanol infusion produced a dose-related effect on myocardial ablation. Macroscopic examination showed that the target myocardium became pale with a distinct border between lesions and normal tissue. Hematoxylin and eosin staining further confirmed necrosis within the injection region. CONCLUSIONS: Transendocardial ethanol injection at the interventricular septum resulted in controlled myocardial infarction. In addition, the injection depth could be visually followed using this new system, which may provide a safer and more intuitive method for the treatment of HOCM or other cardiomyopathies.