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Objective:To discuss the essentials of anesthesia management and treatment strategies for emergency transcatheter aortic valve replacement (TAVR), and to provide standardized recommendations for the development of emergency TAVR technology in China.Methods:This study retrospectively analyzed the relevant data of patients undergoing emergency TAVR surgery in the Second Affiliated Hospital of Zhejiang University School of Medicine from March 2019 to February 2021, including baseline patient characteristics, perioperative echocardiography data, prognosis and 30-day follow-up. Post-operative data were compared with pre-operative data using paired-sample test.Results:Thirteen patients, aged (75.62±9.63) years, underwent emergency TAVR surgery, and 6 of them were male. Eleven patients were New York Heart Association class Ⅳ. The preoperative Society of Thoracic Surgeons score was (20.31±15.15)%. The trans-aortic valve differential pressure was significantly reduced after surgery [(68.92±30.66)mmHg vs. (2.70±2.36)mmHg, P<0.01]. Two patients died within 30 days after surgery, one patient developed a new third degree atrioventricular block, one patient had a stroke, and 4 patients developed pulmonary infection. Conclusions:Emergency TAVR surgery is a feasible and effective rescue strategy for patients with aortic stenosis in critical condition. The establishment of anesthesia standard operation procedure process for TAVR surgery helps ensure homogenized medical behavior and good teamwork.
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Objective:To evaluate the effectiveness and prognosis of emergent transcatheter aortic valve replacement (TAVR) and to provide standardized procedural suggestion for the development of emergent TAVR in China.Methods:From January 2020 to April 2021, 12 patients who underwent emergent or salvage TAVR in the Second Affiliated Hospital Zhejiang University School of Medicine were retrospectively enrolled from the TORCH registry (Transcatheter Aortic Valve Replacement Single Center Registry in Chinese Population, a prospective cohort study; NCT02803294). Baseline, periprocedural and 30-day follow up data were collected. Post-operative data were compared with pre-operative data using Paired-Samples test.Results:Patients’ median Society of Thoracic Surgeons score (STS score) was 15.432%. There was a significant decrease of mean gradient after emergent TAVR procedure (1.69 m/s vs. 4.90 m/s, P<0.01). During the 30-day follow up, there were 1 patient (8.3%) died and 2 patients received permanent pacemaker implantation. No disabling stroke, acute kidney injury, major vascular complication occurred during the first month after emergent TAVR. Among the survival patients, there was a significant releasing of heart failure symptoms to New York Heart Association function stage Ⅰ/Ⅱ in 81.8% patients at 30-day follow up. Left ventricular ejection fraction also improved significantly from (47.4±9.5)% to 58.8±8.0% ( P= 0.026). The mean gradient were (1.57±0.30) cm 2 and no patients had a moderate or severe paravalvular leakage. Besides, a significant decrease of pro-B-type natriuretic peptide (1 089.9 pg/mL vs. 12 215.5 pg/mL , P=0.001) and troponin T (0.020 ng/mL vs. 0.337 ng/mL, P=0.003) were found at 30 days after emergent TAVR. Conclusions:For patients with severe aortic stenosis and acute cardiac decompensated, emergent TAVR is a safe and effective rescue treatment.
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Objective To study the effects of different root control attachment on root control and periodontal ligament （PDL） stress during canine distal translation in plastic aligner-based orthodontic treatment. Methods Through three-dimensional (3D) finite element technology, 11 models composed of 4 attachments and 3 kinds of loading were established. Namely, attachment A: no attachments; attachment B: traditional vertical rectangular attachment; attachment C: 1/4 spherical double optimized attachment; attachment D: double optimized door arch attachment; load a: 0.15 mm distal translation of the canine; b: load a+ application of 30 N·mm counterclockwise torque to stress surface of the attachment; load c: load a+ application of 30 N·mm counterclockwise torque to the entire crown. The root control effect of distal translation of the right maxillary canine was simulated with plastic aligner under different loads. Results Displacement modes of all models were distally tipped translation. The double optimized door arch attachment showed the optimal root control effect during canine distal translation. The root control effect for two groups of double optimized attachment was better than that of traditional rectangular attachment. The effect of adding attachments on root control of the canine was better than that of applying only counterclockwise couple. The PDL stress mainly appeared in distal alveolar ridge and root apex without attachment, while the PDL stress mainly appeared in distal alveolar ridge with attachment. Conclusions The most suitable measure to improve the effect of root control during canine distal translation is to use the double optimized door arch attachment in clinic.
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Objective:To explore the value of transesophageal echocardiography(TEE) guidance for transcatheter DragonFly? system edge-to-edge tricuspid regurgitation (TR) repair.Methods:Five cases who were chosen in the Second Affiliated Hospital, Zhejiang University School of Medicine from December 2020 to January 2021 with surgical high-risk and severe functional TR underwent transcatheter DragonFly edge-to-edge repair with the guidance of TEE. Preoperative TEE was used to evaluate the tricuspid valve anatomy and the origin and etiology of regurgitation in detail; intra-procedure guidance of TEE was performed during the DragonFly system for tricuspid valve edge-to-edge repair intervention and after release of the DragonFly clip, the effect of surgery was assessed immediately and compared with pre-procedure TEE.Results:A total of 10 DragonFly clips were implanted in 5 patients (3 in each of patients, 2 in 1 patient, and 1 in each of patients). One of the 3 clips in 1 patient fell off unilaterally from the septal valve after release, and the other 9 clips were well positioned and fixed. Immediately post-operation assessment by TEE depicted the TR in 3 patients declined to mild and 2 to moderate. The vena contracta area by using three-dimensional color blood flow quantitative assessment was reduced[(0.93±0.26)cm 2 vs (0.20±0.11)cm 2]. No complications such as serious tricuspid valve injury, pericardial tamponade, thromboembolism occurred in the 5 patients. Conclusions:TEE plays an important role in guiding and monitoring transcatheter DragonFly system edge-to-edge TR repair during the entire procedure.
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Fatty acid synthase (FAS) catalyses the reaction between acetyl-CoA and malonyl-CoA to produce fatty acids. It is one of the most important enzyme in lipid biosynthesis. FAS of the oleaginous yeast Rhodosporidium toruloides has two acyl carrier protein (ACP) domains and a distinct subunit composition compared with FASs of other species. As ACP is a protein cofactor crucial for fatty acid chain elongation, more ACPs in the FAS may facilitate the reaction. To study the biochemical and structural properties of this novel FAS from R. toruloides, plasmids were constructed and transformed into Escherichia coli BL21 (DE3). The strain ZWE06 harboring plasmids pET22b-FAS1 and pET24b-FAS2 could co-overexpress the two subunits. The recombinant FAS was purified by sequentially using ammonium sulphate precipitation, sucrose density gradient centrifugation and anion exchange chromatography. The specific activity of the recombinant FAS was 548 mU/mg. The purified complex would be used to study enzyme kinetics and protein structure of FAS, and heterogeneous expression and purification will facilitate revealing the mechanism of this novel FAS with double ACPs.