O-GlcNAcylation promotes topoisomerase IIα catalytic activity in breast cancer chemoresistance.

DNA topoisomerase IIα (TOP2A) plays a vital role in replication and cell division by catalytically altering DNA topology. It is a prominent target for anticancer drugs, but clinical efficacy is often compromised due to chemoresistance. In this study, we investigate the role of TOP2A O-GlcNAcylation in breast cancer cells and patient tumor tissues. Our results demonstrate that elevated TOP2A, especially its O-GlcNAcylation, promotes breast cancer malignant progression and resistance to adriamycin (Adm). O-GlcNAcylation at Ser1469 enhances TOP2A chromatin DNA binding and catalytic activity, leading to resistance to Adm in breast cancer cells and xenograft models. Mechanistically, O-GlcNAcylation-modulated interactions between TOP2A and cell cycle regulators influence downstream gene expression and contribute to breast cancer drug resistance. These results reveal a previously unrecognized mechanistic role for TOP2A O-GlcNAcylation in breast cancer chemotherapy resistance and provide support for targeting TOP2A O-GlcNAcylation in cancer therapy.

Comprehensive Glycomic and Glycoproteomic Analyses of Human Programmed Cell Death Protein 1 Extracellular Domain.

Human programmed cell death protein 1 (hPD-1) is an essential receptor in the immune checkpoint pathway. It has played an important role in cancer therapy. However, not all patients respond positively to the PD-1 antibody treatment, and the underlying mechanism remains unknown. PD-1 is a transmembrane glycoprotein, and its extracellular domain (ECD) is reported to be responsible for interactions and signal transduction. This domain contains 4 N-glycosylation sites and 25 potential O-glycosylation sites, which implicates the importance of glycosylation. The structure of hPD-1 has been intensively studied, but the glycosylation of this protein, especially the glycan on each glycosylation site, has not been comprehensively illustrated. In this study, hPD-1 ECD expressed by human embryonic kidney 293 (HEK 293) and Chinese hamster ovary (CHO) cells was analyzed; not only N- and O-glycosylation sites but also the glycans on these sites were comprehensively analyzed using mass spectrometry. In addition, hPD-1 ECD binding to different anti-hPD-1 antibodies was tested, and N-glycans were found functioned differently. All of this glycan information will be beneficial for future PD-1 studies.

Breast Cancer Screening During the COVID-19 Pandemic in the United States: Results From Real-World Health Records Data.

PURPOSE: The COVID-19 pandemic abruptly interrupted breast cancer screening, an essential preventive service in primary care. We aimed to evaluate the pandemic's impact on overall and follow-up breast cancer screening using real-world health records data. METHODS: We retrospectively analyzed a cohort of women eligible for breast cancer screening through the study period from January 1, 2017 to February 28, 2022 using TriNetX Research Network data. We examined the temporal trend of monthly screening volume throughout the study period and compared the rate of adherence to follow-up screening within 24 months after the previous screening when the follow-up screening was due in the pre-COVID period vs the COVID period. To account for multiple screenings in the longitudinal data, we applied a logistic regression model using generalized estimating equations with adjustment for individual-level covariates. RESULTS: Among 1,186,669 screening-eligible women, the monthly screening volume temporarily decreased by 80.6% from February to April 2020 and then rebounded to close to pre-COVID levels by June 2020. Yet, the follow-up screening rate decreased from 78.9% (95% CI, 78.8%-79.0%) in the pre-COVID period to 77.7% (95% CI, 77.6%-77.8%) in the COVID period. Multivariate regression analysis also showed a lower adherence to follow-up screening during the COVID period (odds ratio = 0.86; 0.86-0.87) and a greater pandemic impact among women aged 65 years and older and women of non-Hispanic "other" race (Asian, American Indian or Alaska Native, and Native Hawaiian or Other Pacific Islander). CONCLUSIONS: The COVID-19 pandemic had a transient negative effect on breast cancer screening overall and a prolonged negative effect on follow-up screening. It also exacerbated gaps in adherence to follow-up screening, especially among certain vulnerable groups, requiring innovative strategies to address potential health disparities in primary care.

Design, synthesis, and biological evaluation of novel 8-substituted quercetin derivatives targeting the ß­catenin/B-cell lymphoma 9 interaction.

The ß-catenin/B-cell lymphoma 9 (BCL9) protein-protein interaction (PPI) is a potential target for aberrantly active Wnt/ß-catenin signaling which actively participates in initiating and progressing of many cancers. Herein, we discovered novel 8-substituted quercetin derivatives with potential inhibitory activities targeting ß-catenin/BCL9 PPI. Among all the derivatives, compound B4 displayed the most promising PPI inhibitory activity with an IC50 value of 2.25 µM in a competitive fluorescence polarization assay and a KD value of 1.44 µM for the ß-catenin protein. Furthermore, B4 selectively inhibited the growth of colorectal cancer (CRC) cells, suppressed the transactivation of Wnt signaling, and downregulated the expression of oncogenic Wnt target gene. Especially, B4 showed potent anti-CRC activity in vivo with the tumor growth inhibition (TGI) of 75.99 % and regulated the tumor immune microenvironment.

Role of electroanatomical mapping-guided superior vena cava isolation in paroxysmal atrial fibrillation patients without provoked superior vena cava triggers: a randomized controlled study.

AIMS: Data about whether empirical superior vena cava (SVC) isolation (SVCI) improves the success rate of paroxysmal atrial fibrillation (PAF) are conflicting. This study sought to first investigate the characteristics of SVC-triggered atrial fibrillation and secondly investigate the impact of electroanatomical mapping-guided SVCI, in addition to circumferential pulmonary vein isolation (CPVI), on the outcome of PAF ablation in the absence of provoked SVC triggers. METHODS AND RESULTS: A total of 130 patients undergoing PAF ablation underwent electrophysiological studies before ablation. In patients for whom SVC triggers were identified, SVCI was performed in addition to CPVI. Patients without provoked SVC triggers were randomized in a 1:1 ratio to CPVI plus SVCI or CPVI only. The primary endpoint was freedom from any documented atrial tachyarrhythmias lasting over 30 s after a 3-month blanking period without anti-arrhythmic drugs at 12 months after ablation. Superior vena cava triggers were identified in 30 (23.1%) patients with PAF. At 12 months, 93.3% of those with provoked SVC triggers who underwent CPVI plus SVCI were free from atrial tachyarrhythmias. In patients without provoked SVC triggers, SVCI, in addition to CPVI, did not increase freedom from atrial tachyarrhythmias (87.9 vs. 79.6%, log-rank P = 0.28). CONCLUSION: Electroanatomical mapping-guided SVCI, in addition to CPVI, did not increase the success rate of PAF ablation in patients who had no identifiable SVC triggers. REGISTRATION: ChineseClinicalTrials.gov: ChiCTR2000034532.

Catheter ablation versus antiarrhythmic drug therapy for sustained ventricular tachycardia in patients with hypertrophic cardiomyopathy.

BACKGROUND: Ventricular tachycardia (VT) is the primary cause of sudden cardiac death in patients with hypertrophic cardiomyopathy (HCM). However, the strategy for VT treatment in HCM patients remains unclear. This study is aimed to compare the effectiveness of catheter ablation versus antiarrhythmic drug (AAD) therapy for sustained VT in patients with HCM. METHODS: A total of 28 HCM patients with sustained VT at 4 different centers between December 2012 and December 2021 were enrolled. Twelve underwent catheter ablation (ablation group) and sixteen received AAD therapy (AAD group). The primary outcome was VT recurrence during follow-up. RESULTS: Baseline characteristics were comparable between two groups. After a mean follow-up of 31.4 ± 17.5 months, the primary outcome occurred in 35.7% of the ablation group and 90.6% of the AAD group (hazard ratio [HR], 0.29 [95%CI, 0.10-0.89]; P = 0.021). No differences in hospital admission due to cardiovascular cause (25.0% vs. 71.0%; P = 0.138) and cardiovascular cause-related mortality/heart transplantation (9.1% vs. 50.6%; P = 0.551) were observed. However, there was a significant reduction in the composite endpoint of VT recurrence, hospital admission due to cardiovascular cause, cardiovascular cause-related mortality, or heart transplantation in ablation group as compared to that of AAD group (42.9% vs. 93.7%; HR, 0.34 [95% CI, 0.12-0.95]; P = 0.029). CONCLUSIONS: In HCM patients with sustained VT, catheter ablation reduced the VT recurrence, and the composite endpoint of VT recurrence, hospital admission due to cardiovascular cause, cardiovascular cause-related mortality, or heart transplantation as compared to AAD.

Knowledge and trust of mothers regarding childhood vaccination in Rwanda.

INTRODUCTION: Knowledge and trust are some of the contributing factors to vaccine acceptance(VA) and Vaccine hesitancy (VH) is one of the top threats to global health. A significant drop in childhood vaccination has been observed in recent years. One important reason that influences mothers' choice to either postpone or avoid children's vaccinations is knowledge and trust in childhood vaccines. This study aimed to assess mothers' knowledge and trust on vaccination of their children, and to examine the association between vaccination knowledge and selected socio-demographic factors. METHODS: A cross-sectional survey was conducted from January 2022 to March 2022 to assess the knowledge and trust of mothers regarding childhood vaccination. Data was collected with self-administered questionnaires. Multivariable logistic regression analysis was employed to assess factors associated with childhood vaccine knowledge and trust. RESULTS: Of the 2,126 Rwandan parents who participated in the study, the proportions with good knowledge of - and good trust in childhood vaccination were 95.5% and 91.4%, respectively. The popular sources of information about childhood vaccination were health care professionals (91.8%) and mass media (28.9%). Multinomial logistic regression analysis showed that good knowledge of - and trust in childhood vaccination were associated with the relationship with child(ren), education, occupation, and monthly income. The Multinomial logistic regression also revealed that the determinants of good knowledge of - and trust in childhood vaccination were; caregiver (p = 4.0 × 10-4, adjusted Odds Ratio (aOR); 1.7, 95%C.I; 1.3 - 2.3), no formal educational status (p = 3.3 × 10-2, aOR; 1.7, 95%C.I; 1.0 - 3.0), the unemployed occupational status (p = 2.4 × 10-2, aOR; 1.2, 95%C.I; 1.0 - 1.4), and persons on more than $401 per month (p = 2.0 × 10-4, aOR; 3.5, 95%C.I; 1.8 - 6.8). CONCLUSION: The majority of parents in Rwanda had both good knowledge of-and good trust regarding childhood vaccination. Public health strategies to promote vaccination, education programmes as well as improved communication tools between health care professionals/traditional leaders/religious leaders and parents need to be considered to achieve favourable vaccination attitudes and practices for all parents in Rwanda.

Care settings of transient ischemic attack in the United States: A cohort study from the TriNetX health research network.

BACKGROUND: Evaluation and hospitalization rates after a transient ischemic attack (TIA)-like presentation vary widely in clinical practice. This study aimed to examine variations in care settings at initial TIA diagnosis in the United States. METHODS: We retrospectively analyzed an adult cohort with a first TIA principal diagnosis between January 1, 2015, and December 31, 2019, from TriNetX Diamond Network. Care settings at TIA diagnosis were defined as hospital care (including inpatient services and observation unit care without admission) and outpatient care (including any outpatient or emergency department visits). We estimated the distribution of care settings at TIA diagnosis and examined the associations of the hospital care setting with baseline age, sex, race, ethnicity, region, and stroke history. RESULTS: Among the 554,315 included patients, 38.8% received hospital care at their initial TIA diagnosis. A higher percentage of hospital care was observed in the age group of 50-64 years (40.3%), Black (46.0%), Hispanic (41.2%), South (40.9%), and Midwest (43.0%) Regions, and with a history of stroke (39.6%). Multivariable logistic regression consistently showed patients who were aged 50-64 years (Odds Ratio=1.09, 95% CI: [1.07, 1.11]), Black (1.28, [1.24, 1.32]), Hispanic (1.13, [1.09, 1.18]), from South (1.20, [1.18, 1.22]) and Midwest Region (1.33, [1.30, 1.35]), and had a history of stroke (1.02, [1.00, 1.04]) to more likely receive hospital care. CONCLUSIONS: Although there are TIA care disparities based on demographics, most patients with initial TIA received acute care in outpatient settings. It is imperative to ensure primary providers can risk-stratify TIA patients and provide rapid and proper management.

Delay from Screening to Diagnosis in Autism Spectrum Disorder: Results from a Large National Health Research Network.

To examine delay from developmental screening to autism diagnosis, we used real-world health care data from a national research network to estimate the time between these events. We found an average delay of longer than 2 years from first screening to diagnosis, with no significant differences observed by sex, race, or ethnicity.

Disability-Adjusted Life-Years for Drug Overdose Crisis and COVID-19 Are Comparable During the Two Years of Pandemic in the United States.

OBJECTIVES: The drug overdose crisis with shifting patterns from primarily opioid to polysubstance uses and COVID-19 infections are 2 concurrent public health crises in the United States, affecting the population of sizes in different magnitudes (approximately < 10 million for substance use disorder [SUD] and drug overdoses vs 80 million for COVID-19 within 2 years of the pandemic). Our objective is to compare the relative scale of disease burden for the 2 crises within a common framework, which could help inform policy makers with resource allocation and prioritization strategies. METHODS: We calculated disability-adjusted life-years (DALYs) for SUD (including opioids and stimulants) and COVID-19 infections, respectively. We collected estimates for SUD prevalence, overdose deaths, COVID-19 cases and deaths, disability weights, and life expectancy from multiple publicly available sources. We then compared age distributions of estimated DALYs. RESULTS: We estimated a total burden of 13.83 million DALYs for SUD and drug overdoses and 15.03 million DALYs for COVID-19 in 2 years since March 2020. COVID-19 burden was dominated by the fatal burden (> 95% of total DALYs), whereas SUD burden was attributed to both fatal (53%) and nonfatal burdens (47%). The highest disease burden was among individuals aged 30 to 39 years for SUD (27%) and 50 to 64 years for COVID-19 (31%). CONCLUSIONS: Despite the smaller size of the affected population, SUD and drug overdoses resulted in comparable disease burden with the COVID-19 pandemic. Additional resources supporting evidence-based interventions in prevention and treatment may be warranted to ameliorate SUD and drug overdoses during both the pandemic and postpandemic recovery.

A scoping review of the opioid epidemic among U.S. Immigrants: Implications for treatment practices.

The purpose of this review was to identify knowledge gaps within the literature regarding the impact of opioid use disorder, specific to immigrants in the United States, by addressing the following questions: 1) What is presented in the literature about the impact of opioid use disorder (OUD) and the opioid epidemic on immigrants in the United States?; and 2) What role does culture play in the opioid use disorder experiences of immigrants in the United States? Nineteen research articles were uncovered that addressed immigrants in the U.S. and opioid use disorder. The following themes prevailed: 1) OUD comparisons, 2) OUD comorbidities, 3) disparate OUD treatment engagement, and 4) the role of country of origin. Limited review findings support the need for future research on the topic of opioid misuse among immigrants in the United States. The authors elaborated on additional issues that influence OUD rates and warrant further exploration. Matters related to the potential positive roles of religion and faith leaders, cultural perceptions and expectations about gender roles, immigration status, ethnically diverse needs among sub-groups of immigrants, the role of geographic location within the U.S., and the implications of COVID-19 on OUD among immigrants need to be addressed to alleviate the deleterious impact of opioid misuse among immigrants.

ppGalNAc-T4-catalyzed O-Glycosylation of TGF-ß type â ¡ receptor regulates breast cancer cells metastasis potential.

GalNAc-type O-glycosylation, initially catalyzed by polypeptide N-acetylgalactosaminyltransferases (ppGalNAc-Ts), is one of the most abundant and complex posttranslational modifications of proteins. Emerging evidence has proven that aberrant ppGalNAc-Ts are involved in malignant tumor transformation. However, the exact molecular functions of ppGalNAc-Ts are still unclear. Here, the role of one isoform, ppGalNAc-T4, in breast cancer cell lines was investigated. The expression of ppGalNAc-T4 was found to be negatively associated with migration of breast cancer cells. Loss-of-function studies revealed that ppGalNAc-T4 attenuated the migration and invasion of breast cancer cells by inhibiting the epithelial-mesenchymal transition (EMT) process. Correspondingly, transforming growth factor beta (TGF-ß) signaling, which is the upstream pathway of EMT, was impaired by ppGalNAc-T4 expression. ppGalNAc-T4 knockout decreased O-GalNAc modification of TGF-ß type Ⅰ and Ⅱ receptor (TßR Ⅰ and Ⅱ) and led to the elevation of TGF-ß receptor dimerization and activity. Importantly, a peptide from TßR Ⅱ was identified as a naked peptide substrate of ppGalNAc-T4 with a higher affinity than ppGalNAc-T2. Further, Ser31, corresponding to the extracellular domain of TßR Ⅱ, was identified as the O-GalNAcylation site upon in vitro glycosylation by ppGalNAc-T4. The O-GalNAc-deficient S31 A mutation enhanced TGF-ß signaling activity and EMT in breast cancer cells. Together, these results identified a novel mechanism of ppGalNAc-T4-catalyzed TGF-ß receptors O-GalNAcylation that suppresses breast cancer cell migration and invasion via the EMT process. Targeting ppGalNAc-T4 may be a potential therapeutic strategy for breast cancer treatment.

Duration and cost-effectiveness of hepatocellular carcinoma surveillance in hepatitis C patients after viral eradication.

BACKGROUND & AIMS: Successful treatment of chronic hepatitis C with oral direct-acting antivirals (DAAs) leads to virological cure, however, the subsequent risk of hepatocellular carcinoma (HCC) persists. Our objective was to evaluate the cost-effectiveness of biannual surveillance for HCC in patients cured of hepatitis C and the optimal age to stop surveillance. METHODS: We developed a microsimulation model of the natural history of HCC in individuals with hepatitis C and advanced fibrosis or cirrhosis who achieved virological cure with oral DAAs. We used published data on HCC incidence, tumor progression, real-world HCC surveillance adherence, and costs and utilities of different health states. We compared biannual HCC surveillance using ultrasound and alpha-fetoprotein for varying durations of surveillance (from 5 years to lifetime) vs. no surveillance. RESULTS: In virologically cured patients with cirrhosis, the incremental cost-effectiveness ratio (ICER) of biannual surveillance remained below $150,000 per additional quality-adjusted life year (QALY) (range: $79,500-$94,800) when surveillance was stopped at age 70, irrespective of the starting age (40-65). Compared with no surveillance, surveillance detected 130 additional HCCs in 'very early'/early stage and yielded 51 additional QALYs per 1,000 patients with cirrhosis. In virologically cured patients with advanced fibrosis, the ICER of biannual surveillance remained below $150,000/QALY (range: $124,600-$129,800) when surveillance was stopped at age 60, irrespective of the starting age (40-50). Compared with no surveillance, surveillance detected 24 additional HCCs in 'very early'/early stage and yielded 12 additional QALYs per 1,000 patients with advanced fibrosis. CONCLUSION: Biannual surveillance for HCC in patients cured of hepatitis C is cost-effective until the age of 70 for patients with cirrhosis, and until the age of 60 for patients with stable advanced fibrosis. LAY SUMMARY: Individuals who are cured of hepatitis C using oral antiviral drugs remain at risk of developing liver cancer. The value of lifelong screening for liver cancer in these individuals is not known. By simulating the life course of hepatitis C cured individuals, we found that ultrasound-based biannual screening for liver cancer is cost-effective up to age 70 in those with cirrhosis and up to age 60 in those with stable advanced fibrosis.

Conceptualizing and Measuring Abatement from the Opioid Epidemic: A Case Study from Pennsylvania.

Policy Points In 2021, four major pharmaceutical manufacturers and distributors reached a proposed settlement agreement with 46 state Attorneys General of $26 billion to address their liabilities in fueling the US opioid epidemic. It raises important questions about abatement conceptualization and measurement for allocating settlement funds among substate entities. We outline the political economy tensions undergirding the settlement and allocation, introduce an abatement conceptual framework, describe how an abatement formula was developed for Pennsylvania to allocate settlement funds, and summarize considerations for future settlement allocation efforts. Documenting the challenges and experiences of this task is essential to inform future efforts.

CRISPR/Cas9 gene editing for the creation of an MGAT1-deficient CHO cell line to control HIV-1 vaccine glycosylation.

Over the last decade, multiple broadly neutralizing monoclonal antibodies (bN-mAbs) to the HIV-1 envelope protein (Env) gp120 have been described. Many of these recognize epitopes consisting of both amino acid and glycan residues. Moreover, the glycans required for binding of these bN-mAbs are early intermediates in the N-linked glycosylation pathway. This type of glycosylation substantially alters the mass and net charge of Envs compared to molecules with the same amino acid sequence but possessing mature, complex (sialic acid-containing) carbohydrates. Since cell lines suitable for biopharmaceutical production that limit N-linked glycosylation to mannose-5 (Man5) or earlier intermediates are not readily available, the production of vaccine immunogens displaying these glycan-dependent epitopes has been challenging. Here, we report the development of a stable suspension-adapted Chinese hamster ovary (CHO) cell line that limits glycosylation to Man5 and earlier intermediates. This cell line was created using the clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated protein 9 (Cas9) gene editing system and contains a mutation that inactivates the gene encoding Mannosyl (Alpha-1,3-)-Glycoprotein Beta-1,2-N-Acetylglucosaminyltransferase (MGAT1). Monomeric gp120s produced in the MGAT1- CHO cell line exhibit improved binding to prototypic glycan-dependent bN-mAbs directed to the V1/V2 domain (e.g., PG9) and the V3 stem (e.g., PGT128 and 10-1074) while preserving the structure of the important glycan-independent epitopes (e.g., VRC01). The ability of the MGAT1- CHO cell line to limit glycosylation to early intermediates in the N-linked glycosylation pathway without impairing the doubling time or ability to grow at high cell densities suggests that it will be a useful substrate for the biopharmaceutical production of HIV-1 vaccine immunogens.

Correction: Knowledge About COVID-19 Among Adults in China: Cross-sectional Online Survey.

[This corrects the article DOI: 10.2196/26940.].

Knowledge About COVID-19 Among Adults in China: Cross-sectional Online Survey.

BACKGROUND: A detailed understanding of the public's knowledge and perceptions of COVID-19 could inform governments' public health actions in response to the pandemic. OBJECTIVE: The aim of this study was to determine the knowledge and perceptions of COVID-19 among adults in China and its variation among provinces and by sociodemographic characteristics. METHODS: Between May 8 and June 8, 2020, we conducted a cross-sectional online survey among adults in China who were registered with the private survey company KuRunData. We set a target sample size of 10,000 adults, aiming to sample 300-360 adults from each province in China. Participants were asked 25 questions that tested their knowledge about COVID-19, including measures to prevent infection, common symptoms, and recommended care-seeking behavior. We disaggregated responses by age; sex; education; province; household income; rural-urban residency; and whether or not a participant had a family member, friend, or acquaintance who they know to have been infected with SARS-CoV-2. All analyses used survey sampling weights. RESULTS: There were 5079 men and 4921 women who completed the questionnaire and were included in the analysis. Out of 25 knowledge questions, participants answered a mean and median of 21.4 (95% CI 21.3-21.4) and 22 (IQR 20-23) questions correctly, respectively. A total of 83.4% (95% CI 82.7%-84.1%) of participants answered four-fifths or more of the questions correctly. For at least one of four ineffective prevention measures (using a hand dryer, regular nasal irrigation, gargling mouthwash, and taking antibiotics), 68.9% (95% CI 68.0%-69.8%) of participants answered that it was an effective method to prevent a SARS-CoV-2 infection. Although knowledge overall was similar across provinces, the percent of participants who answered the question on recommended care-seeking behavior correctly varied from 47.0% (95% CI 41.4%-52.7%) in Tibet to 87.5% (95% CI 84.1%-91.0%) in Beijing. Within provinces, participants who were male, were middle-aged, were residing in urban areas, and had higher household income tended to answer a higher proportion of the knowledge questions correctly. CONCLUSIONS: This online study of individuals across China suggests that the majority of the population has good knowledge of COVID-19. However, a substantial proportion still holds misconceptions or incorrect beliefs about prevention methods and recommended health care-seeking behaviors, especially in rural areas and some less wealthy provinces in Western China. This study can inform the development of tailored public health policies and promotion campaigns by identifying knowledge areas for which misconceptions are comparatively common and provinces that have relatively low knowledge.

Protective effects of acetylcholine on hypoxia-induced endothelial-to-mesenchymal transition in human cardiac microvascular endothelial cells.

Endothelial-to-mesenchymal transition (EndMT) has been reported as a key factor in myocardial fibrosis. Acetylcholine (ACh), a neurotransmitter of the vagus nerve, has been confirmed to exert cardio-protective properties with unclear mechanisms. In this study, the specific markers of cell injury, EndMT, inflammation, and autophagy were measured. We found that treatment with ACh prevented hypoxia-induced cell viability reduction and apoptosis in human cardiac microvascular endothelial cells (HCMECs). Additionally, our results indicate that pre-treatment with ACh significantly suppresses hypoxia-induced EndMT and NF-κB activation in HCMECs. ACh also reduced hypoxia-inducible factor (HIF)-1ɑ protein levels under hypoxia. Knock down of HIF-1ɑ enhanced the inhibitory effect of ACh on NF-κB activation. The NF-κB-specific small molecule inhibitor BAY 11-7082, prostaglandin E2, and LY294002 prevented hypoxia-induced EndMT. Moreover, our data show that hypoxia triggers autophagy in HCMECs, and ACh significantly upregulates autophagy activity. Pre-treatment of HCMECs with 3-methyladenine or chloroquine partially reversed ACh-induced EndMT inhibition. These results suggest that ACh may confer protection against hypoxia-induced EndMT through the inhibition of NF-κB and the induction of autophagy.

Bipolar catheter ablation in ventricular myocardium.

BACKGROUND: Recurrence rates after catheter radiofrequency ablation (RFA) for arrhythmias arising from deep myocardial substrates can exceed 40%. Failure of RFA is in part due to the inability of widely used unipolar ablation (UA) to create transmural lesions capable of disrupting the critical components of the arrhythmia circuit. A radiofrequency generator was custom-made to deliver bipolar ablation (BA) to test the hypothesis that BA is more effective compared to UA in achieving transmurality and to determine the optimal configuration for ventricular BA. METHODS: Sequential UA and BA were created in porcine ventricular septal and free wall preparations using irrigated, contact-force sensing ablation catheters, orientated perpendicularly to the myocardium. Return catheters, durations of ablation, irrigating fluids, and power settings were varied to determine the optimal configuration for BA. Lesion characteristics, transmurality, and occurrence of steam pops were analyzed. RESULTS: In both ventricular septal and free wall models, BA resulted in significantly more transmural lesions while causing less steam pops (P < .01). BA lesions were deeper, narrower but larger in volume. Use of 8 mm ground catheters in the epicardium resulted in overheating during BA with temperatures exceeding 95°C, limiting power delivery. Increasing duration and powers of BA resulted in progressively larger lesions and increased transmurality (all P < .01), and 0.45% saline as the irrigation did not enhance BA. CONCLUSION: BA created larger lesions with increased chances of transmurality but at lower risks of steam pops. Use of an irrigated catheter as the return electrode and 30 W of BA delivered over 120 seconds provides the optimal balance between creating deep, transmural lesions and avoiding steam pops.

Contact- versus noncontact-guided ablation of the right ventricular outflow tract arrhythmias: A propensity score matched analysis.

BACKGROUND: There are unique advantages and disadvantages in the choice of contact mapping (CM) versus noncontact mapping (NCM) systems during ablation of right ventricular outflow tract (RVOT) arrhythmias. This study compared acute procedural success and clinical outcomes in matched patients undergoing CM- versus NCM-guided RVOT ablation. METHODS: A total of 167 consecutive patients with idiopathic RVOT ventricular arrhythmias underwent NCM- or CM-guided ablation. Propensity scoring was used to match each patient undergoing NCM-guided ablation to one control patient undergoing CM-guided ablation. RESULTS: A total of 120 patients were included in this final analysis. If initial ablation was acutely unsuccessful in either group, patients crossed over to the other group. Ablation was acutely successful in 47 of 60 (78.3 %) patients in the NCM group and 55 of 60 (91.7%) in the CM group (P = .002). Thirteen NCM patients required CM and two CM patients crossed over to utilize NCM (P = .002). Procedural duration, fluoroscopy time, and dose in NCM were greater than that in CM (P < .05, respectively). However, procedural complications were not different between two groups. During a mean follow-up of 51 ± 20.6 months, 51 of the 60 NCM patients remained free of arrhythmia, while 48 of the 60 CM patients had no recurrent arrhythmias (P = .47). CONCLUSION: Contact mapping, compared to NCM, is the superior initial technique to guide RVOT arrhythmia ablation due to a higher procedural success without the need to switch to alternative mapping techniques and shorter procedural and fluoroscopic times.