Efficacy and safety of segmental radiofrequency ablation for isolation of the superior vena cava in patients with atrial fibrillation / 中华心血管病杂志

Objective: To analyze the three-dimensional distribution of functional sinus node, right phrenic nerve and superior vena cava(SVC)-right atrial muscle sleeves by three-dimensional electrophysiological technique in patients with atrial fibrillation (AF), and to investigate the efficacy and safety of segmental radiofrequency catheter ablation (RFCA) for isolation of superior vena cava in these patients . Methods: In this retrospective study, we enrolled 136 AF patients who underwent first RFCA in the First Affiliated Hospital of Zhengzhou University from July 2018 to June 2019 and all patients underwent SVC isolation under sinus rhythm. Baseline clinical data of patients were collected. The functional sinus node was defined by activation mapping, pacing was guided by three-dimensional mapping (Carto) system, localization of the right phrenic nerve was defined by pacing map, the superior vena cava-right atrial muscle sleeves was determined according to the change of potential during SVC isolation, segmental RFCA was performed for SVC isolation, the three-dimensional distribution of functional sinus node, right phrenic nerve and superior vena cava(SVC)-right atrial muscle sleeves was determined by three-dimensional electrophysiological technique. Immediate SVC isolation was achieved in all patients. Patients were evaluated immediately after RFCA and patients were followed at 3, 6, 9, and 12 months after RFCA. Holter monitoring was performed every 3 months, the chest radiograph and the SVC ultrasonic examination were performed every 6 months after RFCA. Postoperative complications were assessed. Results: The mean age of the 136 patients with AF was (51.6±14.2) years, 86 (63.2%) were male, 98 cases (72.1%) were paroxysmal AF and 38 cases (27.9%) were persistent AF. Right atrium activation mapping revealed that 17 (12.5%) functional sinus node were located in the SVC, 78 (57.4%) were located at the SVC-right atrium junctions, 41 (30.1%) were located below the junction level. From the head to foot view, 83 (61.0%) functional sinus node were located at the anterior lateral segment of the SVC-right atrium three-dimensional reconstruction model, 34 (25.0%) located at the posterior lateral segment, 15 (11.0%) located at the anterior wall, 4 (2.9%) located at posterior wall or anterior septum. A total of 294 SVC muscle sleeves were detected among all patients, 94 (32.0%) SVC muscle sleeves were located at the anterior septum of the SVC-right atrium three-dimensional reconstruction model, 76 (25.9%) were located at the posterior septum, 21(7.1%) were located at the posterior free wall, 11 (3.7%) were located at the posterior lateral, 27 (9.2%) were located at anterior lateral wall and 65 (22.1%) were located at the anterior free wall. Right phrenic nerve positioned relatively fix, 133 (97.8%) were located at the lateral segment of the SVC-right atrium three-dimensional reconstruction model, 3 (2.2%) were located at the anterior free wall. Sinus rhythm and SVC isolation were successfully restored immediately after RFCA, no significant SVC stenosis, right phrenic nerve palsy and functional sinus node injury occurred immediately post procedure. All patients were followed up for (11.2±3.6) months and none had postoperative complication. Conclusions: Three-dimensional electrophysiological can determine the spatial location of functional sinus node, right phrenic nerve and SVC-right atrial sleeves. On this basis, segmental RFCA is a safe and effective method to achieve complete isolation of SVC.

Electrophysiological characteristics and therapeutic efficacy of radiofrequency ablation of focal atrial tachycardia originating from the right atrial appendage during pregnancy / 中华心血管病杂志

Objective: To analyze the electrophysiological characteristics and the therapeutic efficacy of irrigated-tip catheter radiofrequency ablation(RFA) without radiation for pregnant women with focal atrial tachycardia(AT) originating from the right atrial appendage (RAA). Methods: Data from 55 women with focal AT, who underwent radiofrequency ablation (RFA) in the First Affiliated Hospital of Zhengzhou University from October 2016 to March 2019, were screened. 2 non-pregnant women with right atrial appendage tachycardia (RAAT) and 4 pregnant women with non-RAAT were excluded. The remaining 49 cases were divided into RAAT during pregnancy group (n=6, including 4 cases of tachycardia-induced cardiomyopathy) and non-pregnant and non-RAAT group (control, n=43). Under the guidance of three-dimensional mapping system, the earliest activation site was identified, RFA with the irrigated catheter without x-ray fluoroscopy was performed in RAAT patients during pregnancy, all patients in control group underwent non-zero-ray ablation. Patients were followed up at 3, 6, 12 months post procedure, and yearly follow up thereafter in outpatient clinic. Electrocardiogram or Holter monitoring was performed during follow up. AT recurrence and surgical complications were recorded during follow up. At 6 months after RFA, echocardiography examination and laboratory examination including N-terminal B-type brain natriuretic peptide measurement were performed in the pregnant patients, delivery results were also recorded in the pregnant patients. The electrophysiological characteristics of RAAT during pregnancy were analyzed, the therapeutic efficacy of RFA was compared between the two groups. Results: This study is a retrospective study. Age ((30.7±6.2)years vs. (57.2±11.7)years), left ventricular ejection fraction ((46.0±12.8)% vs. (60.1±5.9)%), proportions of organic heart disease (0% vs. 58%) were significantly lower in the RAAT patients during pregnancy group than in control group (P<0.05), while proportions of patients with persistent tachycardia (100% vs. 7%), symptoms of chest distress and palpitation (6/6 vs. 49%) and left ventricular ejection farction≤50% (4/6 vs. 9%) were significantly higher in RAAT group than in control group (P<0.05), heart rate was similar between the two groups ((163.7±11.1)beats/minutes vs. (153.7±15.2)beats/minutes, P>0.05). The characteristic P-wave morphology was observed in RAAT patients during pregnancy, i.e, P wave was mostly upright (5/6) in inferior-leads (Ⅱ, Ⅲ, aVF) and in lead I and aVL, deep and wide negative P wave was found in V1 lead (5/6), and gradually became positive from V2-V6. The mean tachycardia cycle length was (361.7±38.5) ms. Three-dimensional mapping showed that the origin points of the 6 RAAT pregnant patients were all scattered in the local region, the local region was ablated accordingly, 2 patients (2/6) received extensive ablation of local areas. Immediate successful rate was similar between the two groups (6/6 vs. 93%). During follow up ((15.3±4.0) months), no complications were observed after RFA, postoperative recurrence rate was similar (1/6 vs. 12%). Uncomplicated delivery was reported in all 6 pregnant RAAT post ablation. Normal cardiac structure and function was observed in the 4 pregnant patients with tachycardia-induced cardiomyopathy post ablation. Compared to pre-ablation phase, reduced left atrial dimension ((30.3±1.3) mm vs. (36.8±6.7) mm, P>0.05), increased left ventricular ejection fraction ((64.0±2.9)% vs. (39.8±10.7)%), reduced left ventricular end-diastolic dimension ((44.8±4.0) mm vs. (60.0±2.9) mm) and reduced N-terminal B-type natriuretic peptide value ((136.2±47.5) ng/L vs. (3 408.4±901.3) ng/L) were observed at 6 months post ablation (P<0.05). Conclusion: The electrophysiological characteristics are suggestive for focal AT originating from RAA during pregnancy. Under the guidance of 3-dimension activation mapping, no fluoroscopic RFA with irrigated-tip catheter is a safe and effective strategy for the treatment of focal RAAT during pregnancy.

Identification of peptide mimotopes of an abroad-spectrum neutralizing epitope of highly pathogenic avian influenza hemagglutinin / 病毒学报

A monoclonal antibody (8H5), which showed strong neutralization activity against 33 strains of H5N1 viruses isolated from hosts at various regions from 2002 to 2006, was characterized in our lab recently. This result indicated the presence of highly conserved neutralizing site on hemagglutinin (HA) of various H5N1 subtypes. In the present study, the peptide phage display technique was applied to generate mimotope of the conserved neutralizing epitope recognized by 8H5 mAb. Five peptides displayed on phage were identified to specifically bind to 8H5 mAb. One of the five peptides, 123, was further displayed on the virus-like particle assembled from aa 1-149 fragment of HBcAg. The chimeric particle HBc-T123 conserved the specific binding to 8H5 mAb, and competed with H5N1 viruses for 8H5 mAb. The antiserum induced by HBc-T123 intensively stained on SF21 cells infected by recombinant baculovirus containing HA gene of YU22 virus, indicating the production of cross-reactive antibody to H5N1 HA.

Isolation of human antibodies against hepatitis E virus from phage display library by immobilized metal affinity chromatography / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To isolate human antibodies against hepatitis E virus from phage display library by a new method of panning phage antibody library based on immobilized metal affinity chromatography (IMAC).</p><p><b>METHODS</b>Phage antibody library was allowed to mix with hex-His tagged expressed HEV specific antigen, NE2, in solution for adequate binding before affinity resin for hex-His was added. The non-specific phage antibodies were removed by extensive washing and the specific bound phage antibodies could then be eluted to infect TG1 or repeat the binding process for subsequent rounds of purification. The specificity of the selected human antibodies were tested by antigen competitive ELISA, human sera blocking ELISA, scFv expression, and sequence analysis.</p><p><b>RESULTS</b>His-NE2 specific recombinant phages were successfully enriched after panning procedure. Two individual phage clones, 126 and 138, showed 50% inhibition in NE2 antigen competition ELISA and obvious blocking effect by HEV positive serum in blocking ELISA. Soluble scFv of 126, 138 bound to NE2 specifically.</p><p><b>CONCLUSION</b>Two specific human phage antibodies against hepatitis E virus (HEV) from phage display library were isolated by immobilized metal affinity chromatography. The immobilized metal affinity chromatography applied to phage antibody selection was a helpful supplement to the selection in solution.</p>

Preparation and identification of a single-chain antibody fragment against high pathogenic H5N1 avian influenza virus / 生物工程学报

Previously, an mAb 10F7 was developed against H5N1 hemagglutinin, which was highly specific to 34 different H5N1 strains and showed good neutralizing activity. In the present study, the single-chain fragment of the antibody was cloned into a prokaryotic vector and then expressed in E. coli. The activity of the scFv was tested in hemagglution inhibition and neutralization experiment. Two H5N1 virus strains were inhibited to bind erythrocyte cells by the scFv while the H9 virus was not. Also, five H5N1 virus strains were neutralized during infecting MDCK cells. These results showed an approachable method for developing therapeutic antibody to H5N1 virus.

The therapeutic effect of Smad7 and urokinase-type plasminogen activator gene co-expression on rat liver fibrosis / 中华消化杂志

Objective To investigate the therapeutic effects of Smad7 and urokinase-type plas- minogen activator(uPA)co expression on CCl_4-induced rat liver fibrosis.Methods Forty SD rats were subcutaneously injectied of 40% CCl_4 every three days for 8 weeks.The rats were then divided into model group,AdSmad7/uPA group(injected with AdSmad7/uPA via tail vein),AdSmad7 group(injec- ted with AdSmad7 via tail vein)or AdGFP group(injected with AdGFP via tail vein).Ten healthy rats were served as control.The serum levels of procollagenⅢ(PCⅢ)and laminin(LN)were determined by radioimmunoassay,and the hydroxyproline level in liver tissues were examined by alkaline hydrolysis. The expressions of Smad7 and uPA in tissue were examined by immunohistochemistry and fibrosis area was stained with Sirius red.Results The expressions of Smad7 and uPA protein were significantly higher in AdSmad7/uPA group than that in AdGFP group after 3 days.Serum levels of ALT,AST,PCⅢand LN were significantly decreased in AdSmad7/uPA group compared to Smad7 and AdGFP groups (all P value