Guiding ablation strategies for ventricular tachycardia in patients with structural heart disease by analyzing links and conversion patterns of traceable abnormal late potential zone.

BACKGROUND: Substrate-based ablation can treat uninducible or hemodynamically instability scar-related ventricular tachycardia (VT). However, whether a correlation exists between the critical VT isthmus and late activation zone (LAZ) during sinus rhythm (SR) is unknown. OBJECTIVE: To demonstrate the structural and functional properties of abnormal substrates and analyze the link between the VT circuit and abnormal activity during SR. METHODS: Thirty-six patients with scar-related VT (age, 50.0 ± 13.7 years and 86.1% men) who underwent VT ablation were reviewed. The automatic rhythmia ultrahigh resolution mapping system was used for electroanatomic substrate mapping. The clinical characteristics and mapping findings, particularly the LAZ characteristics during SR and VT, were analyzed. To determine the association between the LAZ during the SR and VT circuits, the LAZ was defined as five activation patterns: entrance, exit, core, blind alley, and conduction barrier. RESULTS: Forty-five VTs were induced in 36 patients, 91.1% of which were monomorphic. The LAZ of all patients was mapped during the SR and VT circuits, and the consistency of the anatomical locations of the LAZ and VT circuits was analyzed. Using the ultrahigh resolution mapping system, interconversion patterns, including the bridge, T, puzzle, maze, and multilayer types, were identified. VT ablation enabled precise ablation of abnormal late potential conduction channels. CONCLUSION: Five interconversion patterns of the LAZ during the SR and VT circuits were summarized. These findings may help formulate more precise substrate-based ablation strategies for scar-related VT and shorter procedure times.

Amine oxidase copper-containing 3 aggravates cardiac remodelling by generating hydrogen peroxide after myocardial infarction.

Amine oxidase copper-containing 3 (AOC3) is a member of the semicarbazide-sensitive amine oxidase enzyme family. It acts as an ectoenzyme catalysing the oxidative deamination of primary amines and generating hydrogen peroxide (H2 O2 ). While AOC3 is implicated in cardiovascular diseases such as atherosclerosis, its role in cardiac remodelling after myocardial infarction (MI) is unclear. In this study, we first confirmed a long-term upregulation of AOC3 in both cardiac myofibroblasts after MI in vivo and angiotensin II (ANGII)-treated cardiac fibroblasts in vitro. AOC3 knockdown not only inhibited the activation of cardiac fibroblasts induced by ANGII but also alleviated cardiac fibrosis in mice after MI. Using sh-AOC3 lentiviruses, exogenous recombinant AOC3 (r-AOC3), semicarbazide (an AOC3 inhibitor), and catalase (a hydrogen peroxide scavenger) treatments, we also demonstrated that AOC3 promoted H2 O2 generation, increased oxidative stress, and enhanced ERK1/2 activation, which were responsible for the activation of cardiac fibroblasts. In particular, AOC3 knockdown also improved cardiac function and hypertrophy after MI. Through a coculture system, we confirmed that AOC3 expressed on cardiac myofibroblasts was able to enhance oxidative stress and induce hypertrophy of cardiomyocytes by promoting H2 O2 generation. Similarly, r-AOC3 promoted H2 O2 generation and resulted in oxidative stress and hypertrophy of cardiomyocytes, which were almost inhibited by both semicarbazide and catalase. In conclusion, AOC3 plays a critical role in cardiac fibrosis and hypertrophy after MI by promoting the generation of H2 O2 . AOC3 is a promising therapeutic target against cardiac remodelling. © 2023 The Pathological Society of Great Britain and Ireland.

Relationships between physical activity, body image, BMI, depression and anxiety in Chinese college students during the COVID-19 pandemic.

BACKGROUND: Both depression and anxiety are worldwide burden that is not being abated with our current knowledge and treatment of the condition. Numerous clinical trials have supported that physical activity (PA) can reduce the depression and anxiety in adolescents, but little is known about its mechanism of action. Therefore, the study objectives were to explore the potential relationship between physical activity and depression and anxiety from the perspective of body image and body mass index (BMI), and to provide an important reference for future self-esteem education and health promotion intervention. METHODS: The participants in this study were 251 Chinese college students between 17 and 22 years old. Participants completed the International Physical Activity Questionnaire-Short Form (IPAQ-SF), the Body Image Questionnaire (BIQ), the Self-rating Depression Scale (SDS) and the Self-rating Anxiety Scale (SAS). A descriptive and correlational approach was used, using the PROCESS macro for Statistical Package for the Social Sciences (SPSS). RESULTS: (1) Physical activity was significantly negatively correlated with both depression and anxiety (t = -0.216, p < 0.001; t = -0.184, p < 0.01). (2) Body image had a significant moderating effect on the relationship between physical activity and anxiety among college students, but there was no moderating effect between depression and physical activity. BMI has no moderating effect on the two interrelationships. CONCLUSION: There is only body image that moderates the relationship between anxiety and physical activity.

Elabela ameliorates doxorubicin-induced cardiotoxicity by promoting autophagic flux through TFEB pathway.

Doxorubicin (DOX) is a widely used and effective antineoplastic drug; however, its clinical application is limited by cardiotoxicity. A safe and effective strategy to prevent from doxorubicin-induced cardiotoxicity (DIC) is still beyond reach. Elabela (ELA), a new APJ ligand, has exerted cardioprotective effect against multiple cardiovascular diseases. Here, we asked whether ELA alleviates DIC. Mice were injected with DOX to established acute DIC. In vivo studies were assessed with echocardiography, serum cTnT and CK-MB, HW/BW ratio and WGA staining. Cell death and atrophy were measured by AM/PI staining and phalloidin staining respectively in vitro. Autophagic flux was monitored with Transmission electron microscopy in vivo, as well as LysoSensor and mRFP-GFP-LC3 puncta in vitro. Our results showed that ELA improved cardiac dysfunction in DIC mice. ELA administration also attenuated cell death and atrophy in DOX-challenged neonatal rat cardiomyocytes (NRCs). Additionally, we found that ELA restored DOX-induced autophagic flux blockage, which was evidenced by the reverse of p62 and LC3II, improvement of lysosome function and accelerated degradation of accumulated autolysosomes. Chloroquine, a classical autophagic flux inhibitor, blunted the improvement of ELA on cardiac dysfunction. At last, we revealed that ELA reversed DOX-induced downregulation of transcription factor EB (TFEB), and silencing TFEB by siRNA abrogated the effects of ELA on autophagic flux as well as cell death and atrophy in NRCs. In conclusion, this study indicated that ELA ameliorated DIC through enhancing autophagic flux via activating TFEB. ELA may become a potential target against DIC.

Mechanisms underpinning the onset of seed coat impermeability and dormancy-break in Astragalus adsurgens.

Impermeable seed coats, i.e. physical dormancy (PY) influence the germination ecology of plants from 18 angiosperm families. Astragalus adsurgens (Fabaceae; Papilinoidaae) is a perennial plant widespread in temperate regions that is thought to produce both permeable and impermeable seeds. Why seeds vary in the permeability of their coat, in addition to the mechanisms by which impermeable seeds break dormancy, are not completely understood. However, seeds are often consumed by herbivores; a phenomenon that might facilitate the germination of impermeable seeds. Here, we tested whether: (1) moisture content plays a significant role in the onset of seed coat impermeability (and therefore PY) at similar ranges reported for species from tropical ecosystems; and (2) the presence of impermeable coats offer any benefits for seed survival when consumed by animals. We tested these hypotheses using A. adsurgens seeds collected from Inner Mongolia, China. Freshly collected seeds with a moisture content of 9.7% were permeable to water and therefore not physically dormant. However, seeds became impermeable when dried below a threshold of 6.5% moisture content. Treating impermeable seeds with hydrochloric acid effectively broke dormancy. Scanning electron microscope (SEM) revealed that HCl treated seeds had a narrow opening in the hilum and extra-hilar regions, through which water entered. Seeds with impermeable coats survived significantly better than permeable seeds when consumed by cows. Irrespective of coat permeability, most seeds were egested between 12 and 24 h. In seeds that maintained dormancy after gut passage, this was broken by additional acid scarification. Overall results suggest that: (1) seed coat impermeability is induced by reduced moisture content; (2) imbibition primarily occurs at the hilum and extra-hilar region; and (3) impermeable seeds may benefit from endozoochory.

Gamma-H2AX upregulation caused by Wip1 deficiency increases depression-related cellular senescence in hippocampus.

The PP2C family member Wild-type p53-induced phosphatase 1 (Wip1) critically regulates DNA damage response (DDR) under stressful situations. In the present study, we investigated whether Wip1 expression was involved in the regulation of DDR-induced and depression-related cellular senescence in mouse hippocampus. We found that Wip1 gene knockout (KO) mice showed aberrant elevation of hippocampal cellular senescence and of γ-H2AX activity, which is known as a biomarker of DDR and cellular senescence, indicating that the lack of Wip1-mediated γ-H2AX dephosphorylation facilitates cellular senescence in hippocampus. Administration of the antidepressant fluoxetine had no significant effects on the increased depression-like behaviors, enriched cellular senescence, and aberrantly upregulated hippocampal γ-H2AX activity in Wip1 KO mice. After wildtype C57BL/6 mice were exposed to the procedure of chronic unpredictable mild stress (CUMS), cellular senescence and γ-H2AX activity in hippocampus were also elevated, accompanied by the suppression of Wip1 expression in hippocampus when compared to the control group without CUMS experience. These CUMS-induced symptoms were effectively prevented following fluoxetine administration in wildtype C57BL/6 mice, with the normalization of depression-like behaviors. Our data demonstrate that Wip1-mediated γ-H2AX dephosphorylation may play an important role in the occurrence of depression-related cellular senescence.

Effectiveness of transcutaneous electrical acupoint stimulation for improving depressive mood status among nursing home elders in Taiwan: a pilot study.

The purpose of this study was to test the effectiveness of transcutaneous electrical acupoint stimulation (TEAS) to improve depressive mood status among elders in a nursing home in Taiwan. This was an experimental, pre- and posttest study with 2 groups. Nine subjects in the experimental group received TEAS for 15 minutes, 5 times a week for 1 month. Seven subjects in the control group received social visits for 15 minutes, 5 times a week for 1 month. Results indicated that the posttest depression scores significantly differed between the 2 groups. Subjects in the experimental group showed a statistically significant improvement in depressive mood status, but changes in the depressive mood status of subjects in the comparison group were not statistically significant. In conclusion, TEAS can be a safe, easy, and noninvasive technique for nursing home staff to improve the depressive mood status of elders.

The effects of a web-based supplementary program for facilitating nursing students' basic nursing skills.

This study examined the effects of an asynchronous Web-based supplementary learning program on the performance of nursing students' basic nursing skills. A posttest quasi-experimental design was used. Students in the intervention group (n = 62) were given login information to access the online program, while the control group (n = 99) was not. Data from both groups were collected before and 4 weeks after the intervention. An objective assessment of basic nursing skills was used to evaluate the level of skill demonstrated by the participants. Results indicate that the Web-based supplementary learning program is effective at strengthening students' basic nursing skills (P = .002). The findings also reveal that students in the intervention group showed higher-than-average satisfaction with the supplementary program (mean, 3.80 [SD, 0.81]). Thus, this Web-based program offers a learning opportunity for nursing students to enhance their skills beyond their formal lectures.

The effectiveness of a health promotion programme for women in southern Taiwan.

The purpose of this study was to assess the effectiveness of an 8 week aerobic exercise class for women on changes in their physical activity behaviour. This was a descriptive, retrospective and comparison study. Because the data were collected after an 8 week aerobic exercise class, there were two groups of subjects. Subjects in the exercise group had attended exercise classes, but subjects in the control group had not. Results showed statistically significant differences between the two groups in the frequency/week of moderately intense exercise-related activities, caloric expenditure/week in all exercise-related activities and caloric expenditure/week in moderately intense exercise-related activities. However, there was no statistically significant difference in the frequency/week of all exercise-related activities. The result that women in the exercise group practised physical activities more than women in the control group might be related to their high exercise self-efficacy expectations.