Objective:To study the course and mechanism of the immune response to SARS virus. Methods:The recombinant SARS virus S1 subunit was expressed in E. Coli according to the results of bioinformatics analysis. After purification, the recombinant S1 protein was identified by 6 serum samples of recovered SARS patients and 6 serum samples of health donors, which were collected before out-break of SARS. Results:Sequencing analysis confirmed that the recombinant protein has the same sequence of natural SARS virus S1 subunit. The recombinant S1 protein could react with all the samples from recovered SARS patients but not the control samples from healthy donors according to the results of Western blot. Conclusion:The recombinant SARS virus S1 subunit may provide a good tool for the research of immune response to SARS virus and the producing of recombinant vaccine to prevent people from SARS.

Objective:To optimize the injection protocol of contrast medium for contrast-enhanced MRA (CEMRA) of pulmonary artery and to evaluate the diagnostic value of CEMRA and pulmonary perfusion imaging (PPI) in an experimental model of acute pulmonary embolism. Methods:CEMRA and PPI were performed in 6 normal pigs with different doses of gadolinium contrast agent (5ml, 10ml, 15ml, 20ml and 25ml) at an injection rate of 3ml/s, and 3 pulmonary embolism models were injected with 20 ml contrast agent at 3 ml/s. DSA was also performed for comparison. Results:The signal intensities and the signal to noise ratios of the pulmonary arteries kept increasing with the dose increase of the contrast agent, but the best angio-pulmonary contrast dose was 10-15ml (0.25-0.375mmol/kg), while the optimal dose for PPI was 15-20ml (0.375-0.5mmol/kg). Although CEMRA demonstrated less obstructed pulmonary arteries than DSA (5/10 vs 8/10)did, it detected all obstructions when combined with PPI. The pulmonary infarction zones showed wedge-shaped perfusion defects on the PPI images, with the signal intensities lower than those of the normal areas (137.86±45.32 vs 330.14±46.52, P<0.001). Conclusion:It is suggested that the optimal dose of the contrast agent is 0.25mmol/kg to 0.375mmol/kg for CEMRA, and 0.375mmol/kg to 0.5mmol/kg for lung perfusion. CEMRA combined with PPI may be better than DSA in demonstrating pulmonary embolism.

Objective To identify the electrophysiological charateristics and cause of ridge gap related reentry after MI ablation in atrial ifbrillation patients. Methods Activation and entrainment mapping was performed in 82 redo cases for OAT recurrence in whom MI was ablated during the index produre. Once ridge gap related reentry was conifrmed, detailed mapping was performed in MI and ridge region. In addition, in 36 cases undergoing MI ablation and fulfilling criterion for bidirectional block, differential pacing was repeated at the ridge to identify a ridge gap. Results Out of 82 redo cases for OAT recurrence in whom MI was ablated during the index produre, 7 (8.5%) was found to be ridge gap related reentry. TCL was (247.9±19.2) ms, and the left atrial endocardial activation time was (145.4±17.7) ms, accounting for (58.5±3.2)%of TCL. However, wide double potential was recorded along the previous ablated MI line where PPI was (34.3±6.6) ms longer than TCL, while PPI was signiifcantly shorter at the ridge[PPI-TCL (11.4±3.9) ms, P<0.001]. Tachycardia was terminated at the ridge in 6 cases and at the corresponding site in coronary sinus in 1 case. No recurrence was found during follow-up for (11.1±4.5) months. In addition, in 36 patients undergoing MI ablation in whom criterion of bi-directional block was fuliflled, conduction gap located at the ridge was found in 5 (13.9%) cases. Conclusions MI ridge gap related reentry is a distinctive OAT, in which the ridge was used as the critical isthmus, whereas the previous ablated MI line is not part of the reentry. MI pseudo-block due to the ridge gap may lead to this type of recurrent tachycardia.

Objective The recurrence of perimitral atrial tachycardia is common after initial ablation of persistent atrial fibrillation (AF). The aim of the study is to explore a preferable ablation approach for perimitral atrial tachycardia in the redo ablation of persistent AF. Methods Seventy-four patients with perimitral atrial tachycardia after initial ablation for persistent AF were included in our study. Patients were distinguished into either the group of having ablation during tachycardia (Group A) or the group having ablation after cardioversion to sinus rhythm (Group B) according to the different ablation strategies. The procedural endpoints were pulmonary vein isolation and bidirectional conduction block of all the ablated lines. The primary endpoint of the study was freedom from atrial tachyarrhythmia recurrence during the follow-up period. Results There were statistical differences in baseline clinical data between the 2 groups. During the redo procedure, conduction recovery rate across the mitral isthmus (MI),cavotricuspid isthmus and left atial roofline were 100％, 40.5％ and 48.6％ respectively. The procedural time, fluoroscopy time, mapping time were longer in the patients of group A. During a mean follow-up of (16.9±6.3) months, 31 (72.1％) patients in group A and 21(67.7％) patients in group B maintained in sinus rhythm in the absence of antiarrhythmic durgs (P =0.771) . Conclusion In patients with perimitral atrial tachycardia after initial ablation for persistent AF,ablation in sinus rhythm is a more simplified method and as effective as ablation during tachycardia.

Objective To evaluate the quality of life of patients with Kaschin-Beck disease (KBD)receiving total knee arthroplasty (TKA) before and after the operation.Methods Clinical efficacy of 25 patients with KBD who underwent TKA in Department of Orthopaedics,Shaanxi Provincial People's Hospital from January 2015 to January 2017 was prospectively analyzed.A questionnaire survey on KBD quality of life (KBDQOL)was carried out to evaluate the quality of life of the patients before,6 months and 1 year after the surgery.Results The scores of physical function,activity limit,social support,mental status and total health scores of KBDQOL in 6 months after the surgery (30.60 ± 3.73,23.24 ± 2.03,15.16 ± 1.62,18.92 ± 2.89,12.80 ± 2.57) and 1 year after the surgery (32.00 ± 3.19,23.76 ± 1.59,15.60 ± 1.29,20.16 ± 2.67,17.28 ± 3.88) were significantly higher than those of before the surgery (18.84 ± 4.94,21.04 ± 2.72,12.80 ± 2.06,13.68 ± 3.42,7.92 ± 1.93,P ＜ 0.05).However,there was no significant difference in economic scores before,6 months and 1 year after the surgery (10.68 ± 2.98,10.60 ± 2.78,10.48 ± 2.80,P ＞ 0.05).Conclusions The quality of life after TKA in patients with KBD severe knee osteoarthritis is significantly better than that before the surgery.The KBDQOL questionnaire is an appropriate tool for evaluating the quality of life in KBD patients.

Objective To study the therapeutic effects of arthroscopic debridement combined with sodium hyaluronate injection in treatment of Kashin-Beck disease with ankle arthritis.Methods Using prospective study,Kashin-Beck disease patients with ankle arthritis,who had underwent arthroscopic debridement combined with sodium hyaluronate injection,were selected as study subjects.X-ray stratification was performed based on Kellgren-Lawrence grading method,grade 1,2,3 were studied,if there were fewer patients at grade 1,then merge with grade 2.Visual analogue scale (VAS),anterior and posterior ankle activity and ankle hindfoot score were used to evaluate the effects before and 3,6,12 months after the treatment.Results Totally 33 patients were collected,VAS scores (6.9 ± 0.2,2.9 ± 0.2,2.1 ± 0.1,1.9 ± 0.1),anterior and posterior ankle activities (20.9 ± 0.6,31.5 ± 0.6,32.1 ± 0.6,34.1 ± 0.4),and ankle hindfoot scores (51.3 ± 0.5,70.8 ± 1.1,76.0 ± 0.9,77.0 ± 0.9) before and 3,6,12 months after the treatment,were compared,and the differences were statistically significant (F =267.47,703.09,756.49,P ＜ 0.01).VAS scores (7.0 ± 0.2,2.8 ± 0.2,1.7 ± 0.1,1.7 ± 0.1;7.0 ± 0.3,3.2 ± 0.3,2.8 ± 0.2,2.2 ± 0.2),anterior and posterior ankle activities (22.4 ± 0.7,32.5 ± 0.6,33.1 ± 0.6,51.3 ± 0.5;18.1 ± 0.9,29.6 ± 1.0,30.2 ± 1.0,31.4 ± 0.9),and ankle hindfoot scores (51.6 ± 0.9,70.9 ± 0.5,77.7 ± 0.9,79.1 ± 1.0;50.6 ± 0.5,65.5 ± 1.8,72.8 ± 1.4,72.9 ± 1.4) in grade 1 + grade 2,and grade 3 patients before and 3,6,12 months after the treatment,were compared,and the differences were statistically significant (F =244.80,64.04;379.94,498.83;1 393.07,159.70,P ＜ 0.01).Compared with those before the treatment,VAS scores of all,grade 1 + grade 2,and grade 3 patients in 3,6,12 months after the treatment significantly decreased,anterior and posterior ankle activities and ankle hindfoot scores significantly increased (P ＜ 0.05).Conclusion Arthroscopic debridement combined with sodium hyaluronate injection is effective in the treatment of Kashin-Beck with disease ankle arthritis.

Objective Cryoballoon ablation of pulmonary vein (PV) ostia often induces a vagal response.This prospective study was designed to assess the effectiveness of prophylactic intravenous administration of atropine on hemodynamic impairment induced by cryoballoon ablation in patients with atrial fibrillation.Methods Twenty-five patients with paroxysmal atrial fibrillation undergoing cryoballoon ablation were prospectively enrolled and assigned to either the trial group on the control group.First twelve patients (the trial group) were administered 1 mg of atropine before deflation of the cryoballoon,while the following 13 patients (the control group) were given atropine only after the onset of the hemodynamic variation (decrease in heart rate and/or blood pressure).Treatment was considered effective when the hemodynamic variations were restored.Results In the trial group,three patients with transient hypotension did not require further supportive care throughout the procedures and one patient with hypotension required supportive management.In the control group,hypotension,bradycardia and mixed bradycardia with hypotension requiring supportive care occurred in six,three,and three patients,respectively.Overall,the rate of marked vagal responses was significantly lower when prophylactic atropine was administrated (4/12 vs.12/13 patients,P ＜ 0.01).Conclusions Atropine is effective in the prevention of all types of vasovagal responses induced by cryoballoon ablation in patients with atrial fibrillation.

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 carry out prenatal diagnosis for a fetus with Pallister-killian syndrome (PKS). METHODS: The fetus was found to have limb malformations at 23rd gestational week. With informed consent from its parents, amniotic fluid sample was taken from the fetus and subjected to chromosomal karyotyping, chromosomal microarray analysis (CMA) and fluorescence in situ hybridization (FISH) assay. RESULTS: G-banding analysis suggested the fetus has a mos47,XY,+mar[55]/46,XY[10] karyotype. CMA analysis of the cultured amniocytes with CytoScan 750K microarray revealed a segmental tetrasomy duplication of 12p13.33p11.1. FISH confirmed a 70% mosaicism of tetrasomy 12p in the metaphase amniocytes with 12pter/12qter probes. CONCLUSION Combined use of G-banding karyotyping, CMA and FISH analysis has enabled diagnosis of PKS in the fetus. Although short limb is a common feature of PKS, unequal femur length has not been reported previously, which has expanded the spectrum of PKS-associated limb abnormalities.
Chromosome Disorders/genetics* ; Chromosomes, Human, Pair 12/genetics* ; Female ; Fetus ; Humans ; In Situ Hybridization, Fluorescence ; Mosaicism ; Pregnancy ; Prenatal Diagnosis

Objectives: This study explored the relationship between weight control and atrial fibrillation (AF) recurrence after catheter ablation in overweight and obese patients. Methods: We prospectively enrolled consecutive 333 overweight and obese patients aged 28 to 87 years old, who underwent catheter ablation for AF in Beijing Anzhen Hospital between October 2015 and February 2016. Data of patients′ characteristics, laboratory examination and treatment were collected at baseline. Each patient was followed up at 3, 6 and 12 months after ablation to collect information on weight, AF recurrence, stroke, major bleeding, hospitalization for cardiovascular reasons and death, etc. Patients were divided into weight controlled group (ΔBMI<-1 kg/m²) and weight uncontrolled group (ΔBMI≥-1 kg/m²), according to the changes in the most recent exposure BMI before AF recurrence in patients with recurrence or the BMI at 12 months′ follow-up in patients without recurrence and the BMI at baseline. Multivariate logistic regression was performed to adjust other known risk factors of AF recurrence and to explore the association between weight control and AF recurrence after catheter ablation. Results: There were 54 patients in weight controlled group and 279 patients in weight uncontrolled group. There were no significant differences in age, gender, education level, left atrial size and history of hypertension between the two groups (all P>0.05). The proportion of patients using angiotensin-converting enzyme inhibitors/angiotensin receptor blockers was higher in the weight controlled group (50.0%(27/54) vs. 34.8%(97/279), P=0.034). However, there was no significant difference in the proportion of patients with obesity (33.3% (18/54) vs. 29.7% (83/279)), paroxysmal AF (59.3% (32/54) vs. 56.6% (158/279)) and AF duration less than 5 years (76.9% (40/52) vs. 65.4% (178/272)) between the weight controlled group and the uncontrolled group. During 1-year follow-up after ablation, the recurrence rate of AF was significantly lower in the weight controlled group than that in the weight uncontrolled group (14.8% (8/54) vs. 32.6%(91/279), P=0.009). Multivariable logistic regression analysis shows that weight control is independently associated with a lower postoperative AF recurrence rate (OR=0.40, 95%CI 0.18-0.90, P=0.026). Conclusion Weight control is strongly associated with a lower AF recurrence rate after catheter ablation in overweight and obese patients.