Dermacentor abaensis(D.abaensis)is a tick species distributed only in Qinghai,Gansu,and other provinces of China.It is more harmful because it can carry pathogens such as Borrelia burgdorferi and Piroplasm.However,morphological descriptions and image data for this tick spe-cies are still insufficiently detailed,and data related to molecular markers such as COX 1 and ITS2 are still missing.The ticks were collected from the body surface of yaks in Diebu County,Gannan Tibetan Autonomous Prefecture,Gansu Province.The morphological characteristics of various parts of the ticks were carefully observed using a stereomicroscope ultra-depth-of-field system.At the same time,the total DNA of the tick body wall was extracted,then the primers for COX 1 and ITS2 genes were designed,and PCR amplification was performed before sequencing.The sequen-cing results were compared with related sequences in GenBank for homology analysis,and the phy-logenetic tree was constructed to provide a basis for accurate identification of this tick species.The results showed that the female ticks were subrounded.The basic capituli were rectangular in shape.The porose area was ovoid in shape,cornua short and blunt,palps thick and short,with a slightly pointed front end.A slightly rounded scutum,and the enamel color was slightly lighter towards the back.The cervial groove was short,and in deeply concave.The festoon was obvious.The peritreme was in comma-shaped.The trailing edge was slightly curved.The genital opening had a ala.The anus was located in the posterior quarter of the middle of the abdomen,and there is a semicircular anal groove surrounded.Male ticks were slightly elongated ovoid,with no porose area.The entire surface was covered with enamel color except the cornua.The genital opening was opposite to the coxall,and there is no ala.The anal groove was deeper,and the external spur of the coxa Ⅳ was narrower and longer.All other body characteristics are similar to those of female ticks.Based on the comparative analysis of COX 1 and ITS2 gene sequences and the construction of phylogenetic tree,it was found that D.abaensis is more closely related to Dermacentor nuttalli and Dermacentor marginatus than other Dermacentor spp.The results suggested that D.abaensis have unique mor-phological and molecular marker characteristics,and the combination of the two characteristics will make it easier to rapidly and accurately identify this tick species.

Dermacentor abaensis(D.abaensis)is a tick species distributed only in Qinghai,Gansu,and other provinces of China.It is more harmful because it can carry pathogens such as Borrelia burgdorferi and Piroplasm.However,morphological descriptions and image data for this tick spe-cies are still insufficiently detailed,and data related to molecular markers such as COX 1 and ITS2 are still missing.The ticks were collected from the body surface of yaks in Diebu County,Gannan Tibetan Autonomous Prefecture,Gansu Province.The morphological characteristics of various parts of the ticks were carefully observed using a stereomicroscope ultra-depth-of-field system.At the same time,the total DNA of the tick body wall was extracted,then the primers for COX 1 and ITS2 genes were designed,and PCR amplification was performed before sequencing.The sequen-cing results were compared with related sequences in GenBank for homology analysis,and the phy-logenetic tree was constructed to provide a basis for accurate identification of this tick species.The results showed that the female ticks were subrounded.The basic capituli were rectangular in shape.The porose area was ovoid in shape,cornua short and blunt,palps thick and short,with a slightly pointed front end.A slightly rounded scutum,and the enamel color was slightly lighter towards the back.The cervial groove was short,and in deeply concave.The festoon was obvious.The peritreme was in comma-shaped.The trailing edge was slightly curved.The genital opening had a ala.The anus was located in the posterior quarter of the middle of the abdomen,and there is a semicircular anal groove surrounded.Male ticks were slightly elongated ovoid,with no porose area.The entire surface was covered with enamel color except the cornua.The genital opening was opposite to the coxall,and there is no ala.The anal groove was deeper,and the external spur of the coxa Ⅳ was narrower and longer.All other body characteristics are similar to those of female ticks.Based on the comparative analysis of COX 1 and ITS2 gene sequences and the construction of phylogenetic tree,it was found that D.abaensis is more closely related to Dermacentor nuttalli and Dermacentor marginatus than other Dermacentor spp.The results suggested that D.abaensis have unique mor-phological and molecular marker characteristics,and the combination of the two characteristics will make it easier to rapidly and accurately identify this tick species.

Aim To explore the impact of ablation termination on the maintenance of sinus rhythm in long-stand-ing persistent atrial fibrillation(LSPAF)by"Stepwise"ablation strategy.Methods This study involved 260 LSPAF patients who underwent"Stepwise"ablation strategy and clinical characteristics were collected.According to the ablation procedure,the patients were divided into ablation termination group and cardioversion group.The prognostic value of con-version to atrial flutter(AFL)and ablation termination was analyzed using subgroup analysis,followed up for 1 year to ex-plore their impact on prognosis.Results Overall,103(39.6％)cases of LSPAF were terminated by ablation.Compared to the cardioversion group,the courses of atrial fibrillation and left atrial diameter were lower in the ablation ter-mination group(all P＜0.05).At 1 year of follow-up,45(17.3％)patients had experienced recurrence,with no statis-tical difference in the proportion of recurrence between the two groups(all P＞0.05).Compared to preoperative,left atri-al diameter was significantly lower after 1 year regardless of recurrence.In subgroup analysis,conversion to AFL and ab-lation termination was associated with the maintenance of long-term sinus rhythm(all P＜0.05).On multivariable Cox re-gression,the courses of atrial fibrillation,body mass index,left atrial diameter and fasting blood glucose were independent risk factors for recurrence.Conclusions 39.6％of LSPAF recovered sinus rhythm during the"Stepwise"ablation process,but there was no correlation with long-term sinus rhythm maintenance.Termination of ablation after conversion to AFL during ablation has a predictive effect on the maintenance of long-term sinus rhythm.

Objective:To optimize the preparation process of Qinggan Liangxue Granules.Methods:The L 9 (3 4) orthogonal experimental design was used to investigate the effects of water addition, extraction time and extraction times on the extraction process of Qinggan Liangxue Granules by taking the transfer rate of astilbin and paeoniflorin as the indexes, so as to screen the optimal extraction process. The evaluation indexes of granule molding rate, water content, solubility and fluidity were used to compare the effect of finished products under different ratios of excipients and granulation conditions. Results:The optimal extraction process was to add 10 times the amount of water reflux extraction twice, each time 1.5 h; using wet granulation, the ratio of dry paste powder to base material was 4:1 ( m/ m), and the wetting agent was 95% ethanol. Conclusion:The preparation process of Qinggan Liangxue Granules is stable and feasible, which lays a foundation for further research and development and quality control.

Background::Oral anti-coagulants (OAC) are the intervention for the prevention of stroke, which consistently improve clinical outcomes and survival among patients with atrial fibrillation (AF). The main purpose of this study is to identify problems in OAC utilization among hospitalized patients with AF in China.Methods::Using data from the Improving Care for Cardiovascular Disease in China-Atrial Fibrillation (CCC-AF) registry, guideline-recommended OAC use in eligible patients was assessed.Results::A total of 52,530 patients with non-valvular AF were enrolled from February 2015 to December 2019, of whom 38,203 were at a high risk of stroke, 9717 were at a moderate risk, and 4610 were at a low risk. On admission, only 20.0% (6075/30,420) of patients with a diagnosed AF and a high risk of stroke were taking OAC. The use of pre-hospital OAC on admission was associated with a lower risk of new-onset ischemic stroke/transient ischemic attack among the diagnosed AF population (adjusted odds ratio: 0.54, 95% confidence interval: 0.43–0.68; P <0.001). At discharge, the prescription rate of OAC was 45.2% (16,757/37,087) in eligible patients with high stroke risk and 60.7% (2778/4578) in eligible patients with low stroke risk. OAC utilization in patients with high stroke risk on admission or at discharge both increased largely over time (all P <0.001). Multivariate analysis showed that OAC utilization at discharge was positively associated with in-hospital rhythm control strategies, including catheter ablation (adjusted odds ratio [OR] 11.63, 95% confidence interval [CI] 10.04–13.47; P <0.001), electronic cardioversion (adjusted OR 2.41, 95% CI 1.65–3.51; P <0.001), and anti-arrhythmic drug use (adjusted OR 1.45, 95% CI 1.38–1.53; P <0.001). Conclusions::In hospitals participated in the CCC-AF project, >70% of AF patients were at a high risk of stroke. Although poor performance on guideline-recommended OAC use was found in this study, over time the CCC-AF project has made progress in stroke prevention in the Chinese AF population.Registration::ClinicalTrials.gov, NCT02309398.

Objective:To explore the role of mechanical hemodynamic support (MHS) in mapping and catheter ablation of patients with hemodynamically unstable ventricular tachycardia (VT), report single-center experience in a cohort of consecutive patients receiving VT ablation during MHS therapy, and provide evidence-based medical evidence for clinical practice.Methods:This was a retrospective cohort study. Patients with hemodynamically unstable VT who underwent catheter ablation with MHS at Beijing Anzhen Hospital, Capital Medical University between August 2021 and December 2023 were included. Patients were divided into rescue group and preventive group according to the purpose of treatment. Their demographic data, periprocedural details, and clinical outcomes were collected and analyzed.Results:A total of 15 patients with hemodynamically unstable VT were included (8 patients in the rescue group and 7 patients in the preventive group). The acute procedure was successful in all patients. One patient in the rescue group had surgical left ventricular assist device (LVAD) implantation, remaining 14 patients received extracorporeal membrane oxygenation (ECMO) for circulation support. ECMO decannulation was performed in 12 patients due to clinical and hemodynamic stability, of which 6 patients were decannulation immediately after surgery and the remaining patients were decannulation at 2.0 (2.5) d after surgery. Two patients in the rescue group died during the index admission due to refractory heart failure and cerebral hemorrhage. During a median follow-up of 30 d (1 d to 12 months), one patient with LVAD had one episode of ventricular fibrillation at 6 months after discharge, and no further episodes of ventricular fibrillation and/or VT occurred after treatment with antiarrhythmic drugs. No malignant ventricular arrhythmia occurred in the remaining 12 patients who were followed up.Conclusions:MHS contributes to the successful completion of mapping and catheter ablation in patients with hemodynamically unstable VT, providing desirable hemodynamic status for emergency and elective conditions.

Objective::The long QT syndrome type 2 is caused by the loss-of-function mutations in the KCNH2 gene, which encodes hERG1, the voltage-gated potassium channel. The hERG1 channels conduct rapid delayed rectifier K + currents ( IKr) in the human cardiac tissue. KCNH2 encodes 2 main isoforms—hERG1a and hERG1b, which assemble to form the homomeric or heteromeric hERG1 channels. However, the functional characteristics of the heteromeric hERG1 channels in long QT syndrome type 2 are not clear. In this study, a novel mutation in the N-terminus of hERG1a (F129I) was identified in a proband of long QT syndrome type 2. The purpose of this study was to identify the electrophysiological change of homomeric and heteromeric hERG1 channels with the F129I-hERG1a. Methods::Candidate genes were screened by direct sequencing. F129I-hERG1a was cloned in the pcDNA3.1 vector by site-directed mutagenesis. Then, the wild-type (WT) hERG1a and/or F129I-hERG1a were transiently expressed in the HEK293 cells with or without hERG1b co-expression. The expression levels of the transgenes, cellular distribution of hERG1a and hERG1b, and the electrophysiological features of the homomeric and the heteromeric hERG1 channels with the WT-hERG1a or F129I-hERG1a were analyzed using whole-cell patch-clamp electrophysiology, western blotting, and immunofluorescence techniques.Results::The proband was clinically diagnosed with long QT syndrome type 2 and carried a heterozygous mutation c.385T>A (F129I) in the KCNH2 gene. Electrophysiology study proved that the F129I substitution in hERG1a significantly decreased IKr in both the homomeric and heteromeric hERG1channels by 86% and 70%, respectively (WT-hERG1a (54.88 ± 18.74) pA/pF vs. F129I-hERG1a (7.34 ± 1.90) pA/pF, P < 0.001; WT-hERG1a/hERG1b (89.92 ± 24.51) pA/pF vs. F129I-hERG1a/hERG1b (26.54 ± 9.83) pA/pF, P < 0.001). The voltage dependence of I Kr activation (V ? and k) was not affected by the mutation in both the homomeric and heteromeric hERG1 channels. The peak current densities and the kinetic characteristics of I Kr were comparable for both WT/F129I-hERG1a and WT-hERG1a. The channel inactivation and deactivation analysis showed that F129I substitution did not affect deactivation of the homomeric hERG1a channel, but significantly accelerated the deactivation and recovery from inactivation of the heteromeric hERG1a/hERG1b channel based on the time constants of fast and slow recovery from deactivation F129I-hERG1a/hERG1b vs. WT-hERG1a/hERG1b ( P < 0.05). Western blotting and immunofluorescence labeling experiments showed that maturation and intracellular trafficking of the F129I-hERG1a protein was impaired and potentially increased the ratio of hERG1b to hERG1a in the F129I-hERG1a/hERG1b tetramer channel, thereby resulting in electrophysiological changes characteristic of the long QT syndrome type 2 pathology. Conclusions::IKr was significantly reduced in the homomeric and heteromeric hERG1 channels with F129I-hERG1a. The F129I mutation significantly accelerated the deactivation and recovery from inactivation of the heteromeric F129I-hERG1a/hERG1b channel. F129I-hERG1a exhibited impaired maturation and intracellular trafficking, thereby potentially increasing the ratio of the hERG1b to hERG1a stoichiometry in the hERG1 tetrameric channel. These changes demonstrated the importance of the heteromeric hERG1 channel in long QT syndrome type 2 pathophysiology.

Objective::The long QT syndrome type 2 is caused by the loss-of-function mutations in the KCNH2 gene, which encodes hERG1, the voltage-gated potassium channel. The hERG1 channels conduct rapid delayed rectifier K + currents ( IKr) in the human cardiac tissue. KCNH2 encodes 2 main isoforms—hERG1a and hERG1b, which assemble to form the homomeric or heteromeric hERG1 channels. However, the functional characteristics of the heteromeric hERG1 channels in long QT syndrome type 2 are not clear. In this study, a novel mutation in the N-terminus of hERG1a (F129I) was identified in a proband of long QT syndrome type 2. The purpose of this study was to identify the electrophysiological change of homomeric and heteromeric hERG1 channels with the F129I-hERG1a. Methods::Candidate genes were screened by direct sequencing. F129I-hERG1a was cloned in the pcDNA3.1 vector by site-directed mutagenesis. Then, the wild-type (WT) hERG1a and/or F129I-hERG1a were transiently expressed in the HEK293 cells with or without hERG1b co-expression. The expression levels of the transgenes, cellular distribution of hERG1a and hERG1b, and the electrophysiological features of the homomeric and the heteromeric hERG1 channels with the WT-hERG1a or F129I-hERG1a were analyzed using whole-cell patch-clamp electrophysiology, western blotting, and immunofluorescence techniques.Results::The proband was clinically diagnosed with long QT syndrome type 2 and carried a heterozygous mutation c.385T>A (F129I) in the KCNH2 gene. Electrophysiology study proved that the F129I substitution in hERG1a significantly decreased IKr in both the homomeric and heteromeric hERG1channels by 86% and 70%, respectively (WT-hERG1a (54.88 ± 18.74) pA/pF vs. F129I-hERG1a (7.34 ± 1.90) pA/pF, P < 0.001; WT-hERG1a/hERG1b (89.92 ± 24.51) pA/pF vs. F129I-hERG1a/hERG1b (26.54 ± 9.83) pA/pF, P < 0.001). The voltage dependence of I Kr activation (V ? and k) was not affected by the mutation in both the homomeric and heteromeric hERG1 channels. The peak current densities and the kinetic characteristics of I Kr were comparable for both WT/F129I-hERG1a and WT-hERG1a. The channel inactivation and deactivation analysis showed that F129I substitution did not affect deactivation of the homomeric hERG1a channel, but significantly accelerated the deactivation and recovery from inactivation of the heteromeric hERG1a/hERG1b channel based on the time constants of fast and slow recovery from deactivation F129I-hERG1a/hERG1b vs. WT-hERG1a/hERG1b ( P < 0.05). Western blotting and immunofluorescence labeling experiments showed that maturation and intracellular trafficking of the F129I-hERG1a protein was impaired and potentially increased the ratio of hERG1b to hERG1a in the F129I-hERG1a/hERG1b tetramer channel, thereby resulting in electrophysiological changes characteristic of the long QT syndrome type 2 pathology. Conclusions::IKr was significantly reduced in the homomeric and heteromeric hERG1 channels with F129I-hERG1a. The F129I mutation significantly accelerated the deactivation and recovery from inactivation of the heteromeric F129I-hERG1a/hERG1b channel. F129I-hERG1a exhibited impaired maturation and intracellular trafficking, thereby potentially increasing the ratio of the hERG1b to hERG1a stoichiometry in the hERG1 tetrameric channel. These changes demonstrated the importance of the heteromeric hERG1 channel in long QT syndrome type 2 pathophysiology.

BACKGROUND: The age, biomarkers, and clinical history (ABC)-atrial fibrillation (AF)-Stroke score have been proposed to refine stroke risk stratification, beyond what clinical risk scores such as the CHA2DS2-VASc score can offer. This study aimed to identify risk factors associated with thromboembolism and evaluate the performance of the ABC-AF-Stroke score in predicting thromboembolism in non-anticoagulated AF patients following successful ablations. METHODS: A total of 2692 patients who underwent successful ablations with discontinued anticoagulation after a 3-month blanking period in the Chinese Atrial Fibrillation Registry (CAFR) between 2013 and 2019 were included. Cox regression analysis was conducted to present the association of risk factors with thromboembolism risk. The ABC-AF-Stroke score was evaluated in terms of discrimination, including concordance index (C-index), net reclassification improvement (NRI) and integrated discrimination improvement (IDI), clinical utilization by decision curve analysis (DCA), and calibration by comparing the predicted risk with the observed annualized event rate. RESULTS: After a median follow-up of 3.5 years, 64 patients experienced thromboembolism events. Age, prior history of stroke/transient ischemic attack (TIA), high-sensitivity cardiac troponin T (cTnT-hs), and N-terminal pro-B-type natriuretic peptide (NT-proBNP) were independently associated with thromboembolism risk. The ABC-AF-Stroke score performed statistically significantly better than the CHA2DS2-VASc score in terms of C-index (0.67, 95% confidence interval [CI]: 0.59-0.74 vs. 0.60, 95% CI: 0.52-0.67, P = 0.030) and reclassification capacity. The DCA implied that the ABC-AF-Stroke score could identify more thromboembolism events without increasing the false positive rate compared to the CHA2DS2-VASc score. The calibration curve showed that the ABC-AF-Stroke score was well calibrated in this population. CONCLUSIONS In this real-world study enrolling non-anticoagulated AF patients following successful ablations, age, prior history of stroke/TIA, level of NT-proBNP, and cTnT-hs were independently associated with an increased risk of thromboembolism. The ABC-AF-Stroke score was well-calibrated and statistically significantly outperformed the CHA2DS2-VASc score in predicting thromboembolism risk.
Humans ; Anticoagulants/therapeutic use* ; Atrial Fibrillation/complications* ; East Asian People ; Ischemic Attack, Transient ; Registries ; Risk Assessment ; Risk Factors ; Stroke/etiology* ; Thromboembolism/etiology* ; Troponin T

Objective:To investigate the long-term safety of digoxin in patients with coronary artery disease (CAD) and atrial fibrillation (AF).Methods:This was a prospective study, in which 25 512 AF patients were enrolled from China Atrial Fibrillation Registry Study. After exclusion of patients receiving ablation therapy at the enrollment, 1 810 CAD patients [age: (71.5±9.3)years] with AF were included. The subjects were grouped into the digoxin group and non-digoxin group, and were followed up for a period of 80 months. Long-term outcomes were compared between the groups and an adjusted Cox regression analysis was applied to evaluate the risk of digoxin on the long-term outcomes. The primary endpoint was all-cause mortality.Results:The patients were followed up for a median period of 3.05 years. After multivariable adjustment, the Cox regression analysis showed that digoxin significantly increased the risk of all-cause mortality ( HR=1.28, 95% CI 1.01-1.61, P=0.038), cardiovascular mortality ( HR=1.48,95% CI 1.10-2.00, P=0.010), cardiovascular hospitalization ( HR=1.67,95% CI 1.35-2.07, P=0.008) and the composite endpoints ( HR=2.02,95% CI 1.71-2.38, P<0.001). In the subgroup of patients with heart failure (HF), digoxin was not associated with the risk of all-cause mortality, but was still associated with the increased risk of cardiovascular mortality ( HR=1.44,95% CI 1.05-1.98, P=0.025), cardiovascular hospitalization ( HR=1.44,95% CI 1.09-1.90, P=0.010) and the composite endpoints ( HR=1.37, 95% CI 1.01-1.70, P=0.004). However, in the subgroup of patients without HF, digoxin was only associated with all-cause mortality ( HR=2.56,95% CI 1.44-4.54, P=0.001). Conclusion:Digoxin significantly increased the risk of all-cause mortality in CAD patients with AF, especially in patients without HF.