Isolation and Genetic Evolution of Dengue Virus from the 2019 Outbreak in Xishuangbanna, Yunnan Province, China.

Background: Dengue virus (DENV) can be divided into four serotypes-DENV-1, DENV-2, DENV-3, and DENV-4. In humans, infection leads to dengue fever (DF), dengue hemorrhagic fever, and dengue shock syndrome, both widely prevalent in tropical and subtropical regions. In 2019, a severe outbreak of DF occurred in Xishuangbanna, Yunnan province. Objective: To investigate the etiology and genotype of the causative agents of this severe dengue outbreak in Xishuangbanna. Methods: Between October and November 2019, the sera of patients clinically diagnosed with DF were collected in the first People's Hospital of Xishuangbanna. RNA was extracted from the sera and amplified by RT-PCR with flavivirus primers. Flavivirus-positive sera were then used to inoculate Aedes albopictus cells (C6/36); viral RNA was extracted from these cells, amplified, and sequenced with DENV E gene-specific primers. Sequence splicing and nucleotide homology genetic evolution analysis were carried out by biological software (DNAStar). Unique mutations in the E genes of isolated DENV were analyzed by SWISS-MODEL and PyMOL. Results: Of the 60 samples collected from DF patients, 39 tested positively with flavivirus primers. The DENV was isolated from 25 of the 39 positive seras, of which 20 showed cytopathic effects (CPE) and 5 were no CPE. In these 25 isolated nucleic acids, 21 strains of DENV-1, 3 strains of DENV-2, and 1 strain of DENV-3 were identified according to the sequence of E protein. In the four unique mutations (D52, Y149, L312, T386), D52 and Y149 in the E protein of DENV-1 were predicted to be exposed on the surface of the prefusion conformation. Conclusion: The 2019 outbreak of DF in Xishuangbanna area of Yunnan Province consists of at least three serotypes of DENV-1, DENV-2, and DENV-3, and the sources of these virus strains are of mixed and complicated origin.

Intraoperative method based on tricuspid annular circumference in patients with mild or no tricuspid regurgitation during left-sided cardiac valve surgery for the prophylactic tricuspid annuloplasty.

BACKGROUND: During left-sided cardiac valve surgery in patients with mild or no tricuspid regurgitation (TR), the tricuspid valve exploration plays a vital role in the decision-making of concomitant tricuspid annuloplasty. Currently lack of an appropriate standard to define tricuspid annular dilatation is a challenge. The aim of this study is to introduce and evaluate an alternative intraoperative method for Tricuspid Valve annuloplasty based on annular circumference that could trace the extent of annular dilatation and predict TR-progression, which can also guide the surgeons to intraoperative decision. METHODS: From January 2011 to December 2011, 131 patients (73 females, 58 males, and mean age 54±10.8) were selected for the study underwent left-sided cardiac valve surgery at Anzhen Hospital, all the subjects preoperatively diagnosed with non-significant TR. The enrolled subjects were followed-up over 5years for TR-progression. Tricuspid annular circumference (TAC) measurement was performed via special sizer for each patient, and the obtained values divided on the subject's body surface area (BSA) to achieve the tricuspid annular circumference index (TACI). The endpoint was set as the TR-progression by more than two grades, or a final TR grade ≥3+. RESULTS: The mean follow up period was 68±3.8 months (range, 60-77 months). In univariate, multivariate and logistic regression analysis three variables were noticed to be associated with TR progression, female gender (P<0.002), body mass index (BMI) (P<0.021), and intraoperatively measured TACI (P<0.001). But in multiple regression the TACI (OR 0.812; 95% CI: 0.748-0.883; P<0.001) was the single parameter which significantly related to TR-progression. Based on the receiver-operator curve (ROC), it was likely to derive an optimal cut-off 80.2 mm/m2 which could predict the postoperative development of TR with acceptable sensitivity and specificity 69%, 89%. CONCLUSIONS: Patients with mild or no TR undergoing left-sided valve surgery, intraoperative measurement of the TAC proved to be an ideal method to judge the tricuspid-annulus, it is capable to predict TR-progression. For prophylactic tricuspid repair a presumed TACI of 80.2 mm/m2 is recommended as an indicative threshold.

A predictor for mitral valve repair in patient with rheumatic heart disease: the bending angle of anterior mitral leaflet.

BACKGROUND: Mobility and flexibility of anterior mitral leaflet (AML) are considered to be the important factor for mitral valve (MV) repair in rheumatic population, we try to use the bending angle of AML to quantify its' mobility and flexibility and investigate whether it can predict the success of rheumatic MV repair or not. METHODS: Total 54 patients underwent rheumatic MV surgeries with mild lesions of subvalvular apparatus from August, 2017 to November, 2017 at the author institution, we divided the patients into MV repair and MV replacement groups which included directly MV replacement and repair attempt but failed repairing transfer to replacement intraoperatively. Patients' MV structure was carefully evaluated on transthoracic echocardiography (TTE) and scored by the Wilkins score (WS) preoperatively. The bending angle of AML was measured during systole and diastole at different level before surgery. RESULTS: The differences of patients' demographic characteristics between repair group and replacement group were not statistically significant (P value >0.05) and the differences among B-angle, T-angle, Bs-angle, C-angle of AML between repair group and replacement groups were not statistically significant (P value >0.05). Only BT-angle in repair group was significantly larger than that of replacement group (21.56°±3.84°, 10.29°±6.02°, respectively, P<0.001), therefore the BT-angle was tested as a predictor of reparability by observing the receiver operating characteristic (ROC) curve (ROC area: 0.944, standard error: 0.06, 95% CI: 0.826-1), BT-angle of AML on preoperative transthoracic echo of 15.5° or more predicts feasibility of rheumatic MV repair with 100% sensitivity and 85.7% specificity in patients with mild lesions of subvalvular apparatus. Logistic regression for a single area of calcification (diameter <0.8 cm) at commissure were shown that: ß: 0.08, Exp (ß): 1.083, P: 0.777>0.05, the minor single calcified area at commissure had no effect on reparability of rheumatic MV disease. The differences of total WS and each component score between repair group and replacement group were not statistically significant (P value >0.05). By observing the ROC curve for total WS (ROC area: 0.508), the WS cannot be a predictor for the rheumatic MV repair. CONCLUSIONS: The bending angle of AML which was considered as quantification of mobility and flexibility of AML can be a predictor for MV repair in patients with rheumatic heart disease (RHD). The small single area of commissural calcification had no effect on reparability of rheumatic MV disease. WS cannot appropriately predict the outcome of rheumatic MV repair.

A meta-analysis of late outcomes of mitral valve repair in patients with rheumatic heart disease.

BACKGROUND: Rheumatic heart disease (RHD) is a predominant health concern in developing countries. The aim of this meta-analysis was to evaluate the outcomes of mitral valve (MV) repair in patients with RHD, and identify predictors that may postoperatively affect treatment outcome. METHODS: A meta-analysis of eligible studies assessing patients undergoing MV repair with RHD and reporting the outcomes of MV repair, including 30-day mortality and long-term follow-up survival, MV reoperation rate and postoperative adverse events. Relevant English articles were searched up to 1 March, 2017 in Web of Science, PubMed, Google Scholar, Cochrane Library, EmBase, Elsevier, and Science Direct. Selected studies should meet all inclusion criteria, and underwent data extraction. RESULTS: A total of ten studies with 2,770 patients met all inclusion criteria, and were selected for assessment. Pooled analysis showed that 30-day mortality in patients with rheumatic MV disease after MV repair surgery was 1.9%, 95% confidence interval (CI) (0.8-2.9%); long-term survival was 97.3%, 95% CI (95.9-98.6%), and a freedom from reoperation rate of 93.6%, 95% CI (91.4-95.9%) was obtained; freedom from adverse events was 97.5%, 95% CI (95.2-99.8%). CONCLUSIONS: The outcome of rheumatic MV repair is outstanding in terms of low early mortality, high long-term survival and freedom from valve-related complications, which may be very common in patients after rheumatic MV replacement; meanwhile, MV reoperation rate after initial surgery is acceptable. Surgeons may try to repair MV in RHD when it is feasible.

Neuroprotective effects of gypenosides in experimental autoimmune optic neuritis.

AIM: To determine whether gypenosides have protective effects in experimental autoimmune optic neuritis (EAON). METHODS: Mice were randomly divided into seven groups: control group, model group, three different density gypenosides monotherapy, methylprednisolone monotherapy, combination of gypenosides and methylprednisolone group. The control group was subcutaneously injected with oil emulsion adjuvant and all other groups were subcutaneously immunized with an emulsified mixture of myelin oligodendrocyte glycoprotein (MOG) 35-55 peptide to induce EAON. Mice in the gypenosides groups were administered injections daily with three concentrations (15 mg/kg, 30 mg/kg, 45 mg/kg) of gypenosides respectively. Mice in the methylprednisolone group and the combination treatment group were injected daily with methylprednisolone (20 mg/kg) or methylprednisolone (20 mg/kg) + gypenosides (30 mg/kg), respectively. After MOG immunization, visual evoked potential (VEP), optical coherence tomography (OCT), and histopathologic examination were performed at 14, 20, 30, and 40d post-inoculation (p.i.). All results were expressed as mean±SEM. The data were evaluated by one-way ANOVA followed by Tukey or Games-Howell test. RESULTS: Compared with the control group, p2 latency was prolonged in the model group (P=0.041). Combination treatment can alleviated the change in VEP at 20d p.i. (P=0.012). Average peripapillary retinal nerve fiber layer (RNFL) thickness was reduced in the model group (P=0.000, 30d; P=0.000, 40d) and gypenosides treatment remarkably diminished the degree of RNFL degeneration at 30d and 40d p.i (P=0.000, 30d; P=0.000, 40d). The pathomorphological results showed a decrease in demye-lination (P=0.020) and inflammatory reactions in the combination group compared with the model group (20d p.i.). Gypenosides treatment also alleviated the degree of axonal loss (40d p.i.) (P=0.003). CONCLUSION: Treatment with gypenosides exerts protective effects on retinal nerve fibers and axons in EAON. When combined with gypenosides, methylprednisolone reduces demyelination in the acute stage of EAON.

Analysis of risk factors for recurrence after video-assisted pulmonary vein isolation of lone atrial fibrillation--results of 5 years of follow-up.

OBJECTIVE: The purpose of the present study was to assess the efficacy of the long-term results after video-assisted pulmonary vein isolation and left atrial appendage excision for lone atrial fibrillation (AF) and to determine the most significant risk factors for the long-term results. METHODS: From December 2006 to December 2012, 332 consecutive patients with lone AF underwent minimally invasive surgical ablation at our center. Of the 332 patients, 91, who had undergone video-assisted pulmonary vein isolation>5 years earlier, were evaluated in the present study (48 with paroxysmal AF, 21 with persistent AF, and 22 with long-standing persistent AF). The median follow-up period was 66 months. The primary endpoint was the success rate of video-assisted pulmonary vein isolation, defined as the absence of any atrial arrhythmia recurrence lasting >30 seconds at the clinical visit and on the electrocardiogram or long-term cardiac rhythm recording after discharge. RESULTS: During the follow-up period, 1 patient (1.1%) experienced a stroke and 4 (4.4%) died of noncardiac disease. At the 5-year follow-up point, 43 of 78 patients (55.1%) were in normal sinus rhythm. Of the 39 patients with paroxysmal AF and 39 with nonparoxysmal AF, 27 (69.2%) and 16 (44.1%) were in normal sinus rhythm, respectively. The results of the univariate and multivariate analyses of the preoperative risk factors for AF recurrence showed a left atrial diameter of ≥44 mm (hazard ratio, 5.56; 95% confidence interval, 1.68-18.387; P=.005) and an AF duration of ≥31.5 months (hazard ratio, 3.67; 95% confidence interval, 1.50-8.95; P=.004) were the most significant independent risk factors. CONCLUSIONS: Patients with lone AF with a large preoperative left atrial diameter and long AF duration will not be suitable for video-assisted pulmonary vein isolation alone and might need to undergo ablation of the lesions.

[Primary experience of treating 23 lone atrial fibrillation patients with a completely thoracoscopic modified Maze procedure].

OBJECTIVE: To evaluate the safety and feasibility of a completely thoracoscopic modified Maze procedure for treatment of patients with lone atrial fibrillation(AF). METHODS: From September 2010 to October 2011, completely thoracoscopic modified Maze procedure was performed in 23 patients with lone atrial fibrillation (14 paroxysmal AF and 9 persistent AF). All patients were either refractory or intolerant to antiarrhythmic drug therapy or already experienced unsuccessful catheter-based ablation. This procedure includes three 1 cm ports for thoracoscopic camera and ablation device on each side of chest wall. Bilaterally pulmonary vine isolation was made by an Atricure TM bipolar radiofrequency device. Two epicardial ablation lines were created on LAPW to connect bilaterally pulmonary vine ablation lesion using Coolrail linear pen. LAA was removed by a Johnson and Johnson EZ45G stapler. RESULTS: The procedures were successful in all the patients, 20 patients were in sinus rhythm immediately after surgery, 2 patients were still in AF rhythm and 1 patient in pacing rhythm post surgery. Three-month follow up were finished in 23 patients and there was 1 patient in AF rhythm, 95.7% patients were free of AF; 6-month follow up were finished in 22 patients, 3 patients were in AF rhythm and 2 patients in AFL rhythm, 77.3% patients were free of AF. CONCLUSION: Our results suggested that the completely thoracoscopic modified Maze procedure is a safe, feasible and effective technique for treating patients with atrial fibrillation.