Purpose: Electrical impedance tomography (EIT) is a technique for reconstructing the conductivity distribution by injecting currents at the boundary of a subject and measuring the resulting changes in voltage. Image reconstruction for EIT is a nonlinear problem. A generalized inverse operator is usually ill-posed and ill-conditioned. Therefore, the solutions for EIT are not unique and highly sensitive to the measurement noise. Design/methodology/approach: This paper develops a novel image reconstruction algorithm for EIT based on patch-based sparse representation. The sparsifying dictionary optimization and image reconstruction are performed alternately. Two patch-based sparsity, namely, square-patch sparsity and column-patch sparsity, are discussed and compared with the global sparsity. Findings: Both simulation and experimental results indicate that the patch based sparsity method can improve the quality of image reconstruction and tolerate a relatively high level of noise in the measured voltages. Originality/value: EIT image is reconstructed based on patch-based sparse representation. Square-patch sparsity and column-patch sparsity are proposed and compared. Sparse dictionary optimization and image reconstruction are performed alternately. The new method tolerates a relatively high level of noise in measured voltages.

BACKGROUND:Impaired heart function induced by myocardial infarction is a leading cause of chronic heart failure (HF). This study aimed to investigate the effects and mechanism of noninvasive positive-pressure ventilation (NIPPV) in a rat model of HF due to myocardial infarction. MATERIAL AND METHODS:To explore the therapeutic effect and mechanism of NIPPV on acute myocardial infarction-induced HF, we established a rat model of HF by ligating the anterior descending branch of the left coronary artery and confirmed by ultrasonic cardiography and brain natriuretic peptide 45 detection. RESULTS:The levels of heat-shock protein (HSP)-70 increased and matrix metalloproteinase (MMP)-2, MMP-9, and tumor necrosis factor (TNF)-alpha decreased in the group that received NIPPV treatment compared with the control group. In addition, the histopathologic results showed less severe inflammatory infiltration and a smaller area of myocardial fibrosis in the NIPPV treatment group. CONCLUSIONS:In a rat model of HF due to myocardial infarction, NIPPV resulted in increased levels of HSP70 and reduced expression of MMP2, MMP9, and TNF-alpha and reduced myocardial neutrophil infiltration and fibrosis. Taken together, we showed that NIPPV is an effective treatment for HF induced by myocardial infarction by inhibiting the release of inflammatory factors and preventing microvascular embolism.

Type A aortic dissection (TAAD) is a vascular disease with high mortality; however, the role of gene methylation in its pathogenesis has received little attention. This study aimed to identify candidate markers of TAAD by integrating methylation and transcriptome sequencing analyses. Aortic tissue samples from five TAAD cases and five controls were sequenced on Illumina Hiseq sequencing platform and Infinium Methylation EPIC BeadChip microarray. A series of bioinformatics analyses and machine learning algorithms were used to identify key methylated genes from the differentially expressed genes and differentially methylated sites between TAAD and controls. An overexpression vector of ZC3H12A was constructed, and human vascular smooth muscle cells (HVSMCs) were transfected with the vector to explore the effects of key methylated genes on cell proliferation, migration, and phenotypic switch. Differential analysis and integration of gene expression and methylation levels between TAAD and control samples suggested 239 differentially methylated genes, mainly involved in nicotinamide nucleotide biosynthetic and metabolic processes. By applying protein-to-protein network and machine learning algorithms, we finally identified three methylated genes, including ZC3H12A, IRAK2, and CCL5, which could be used as potential markers of TAAD. Both correlation analysis and experimental validation results indicated that expression levels of these genes were significantly negatively regulated by their methylation levels. Among them, ZC3H12A was confirmed to significantly promote the proliferation and migration in HVSMCs in vitro, while inhibiting their phenotypic transformation. Three methylated genes were identified as potential diagnostic markers for TAAD. Among them, ZC3H12A might contribute to disease progression.

Background: Stroke is one of the severe complications following surgery in patients with acute type A aortic dissection (ATAAD). This study investigates the relationship between the preoperative serum uric acid to serum creatinine ratio (SUA/Scr) and postoperative stroke in patients undergoing total arch replacement with elephant trunk implantation for aortic dissection. Methods: We included ATAAD patients who were hospitalized and underwent surgery between June 1, 2015 and June 1, 2023, with complete clinical information. Preoperative SUA and Scr levels were collected to calculate SUA/Scr. The association between SUA/Scr and postoperative stroke was analyzed using univariate and multivariate logistic regression, as well as subgroup analysis. The optimal cut-off value of SUA/Scr was determined by receiver operating characteristic (ROC) curve analysis. Results: A total of 332 patients were included in the study. Patients who developed postoperative stroke had lower SUA/Scr compared to those who did not (P=0.03). Univariate logistic regression indicated that higher SUA/Scr was associated with a reduced risk of postoperative stroke [odds ratio (OR) =0.80; 95% confidence interval (CI): 0.65–0.98; P=0.03]. This association remained significant after adjusting for confounding factors (OR =0.66; 95% CI: 0.45–0.97; P=0.04). Subgroup analysis revealed that the association between higher SUA/Scr and reduced risk of postoperative stroke was significant only in male patients (OR =0.81; 95% CI: 0.65–1.01; P=0.046) and those younger than 65 years (OR =0.82; 95% CI: 0.66–1.02; P=0.048), and was observed only in patients who underwent non-axillary artery cannulation (OR =0.65; 95% CI: 0.50–0.84; P=0.001), left femoral artery cannulation (OR =0.74; 95% CI: 0.58–0.96; P=0.02), and bilateral cerebral perfusion (OR =0.51; 95% CI: 0.32–0.81; P=0.004). The ROC curve analysis identified 3.36 as the optimal cut-off value for SUA/Scr. Conclusions: A higher SUA/Scr is associated with a reduced risk of postoperative stroke in patients with aortic dissection undergoing total arch replacement with stented elephant trunk implantation and may serve as a potential predictor of postoperative stroke.

Perioperative coronary artery spasm (CAS) following coronary artery bypass grafting (CABG) is a severe or lethal condition that is rarely reported. In addition, rare cases with CAS following CABG in the non-manipulated coronary artery are angiographically documented in the perioperative period. We aimed to report our experiences on the diagnosis and treatment of a case with CAS following off-pump CABG in the non-manipulated coronary artery. A 57-year old male with coronary heart disease and unstable angina willing to undergo CABG was admitted to our department. CABG was recommended as he showed 90% stenosis in distal left anterior descending artery, 90% stenosis in intermediate branch, 90% stenosis in left circumflex coronary artery, as well as 50% stenosis in proximal right coronary artery (RCA). After CABG, the patient showed Adams–Stokes syndrome and ST-segment elevation. Then CPR was conducted and coronary angiography indicated perioperative CAS in the non-manipulated posterior descending artery. For the treatment, the patient received nitroglycerin injection into the coronary artery by catheter and pumping of diltiazem. Finally, the patient was discharged on day 7 after surgery. A comprehensive literature search was conducted to summarize the studies focused on the diagnosis and treatment of such condition, which indicated that all of the CAS cases occurred in the manipulated vessels, except one study showing CAS in the untouched native coronary artery which was similar with our case. Perioperative CAS in the non-manipulated coronary artery following CABG is a severe or lethal condition that is rarely reported, which deserves close attention by the clinicians in clinical practice.