An isolate of rice stripe virus (designated as RSV-YL) was purified. The particles showed to be pleomorphisms under electron microscope, mainly branched filaments of about 80-250 nm in length and about 8 nm in width. There are also some open circular filaments of 3 nm and 8 nm in width, and some filaments of 13 nm in width and 130-190 nm in length. The basic morphism of RSV particles should be filaments of 3 nm in width and various length. By SDS-PAGE analysis, the molecular weight of disease-specific protein (SP) encoded by vRNA4 was 19.9 kDa and that of coat protein (CP) encoded by vcRNA3 was 33.6 kDa. When nucleic acid extracted from the purified RSV was electrophoresed under nondenaturing condition, the size of four dsRNAs (designated as dsRNA1-4 in order of decreasing size) was 4.9×106,2.7×106,2.0×106 and 1.7×106 Da, respectively, and that of four ssRNAs (designated as ssRNA1-4 in order of decreasing size) was 3.0×106,1.2×106,0.9×106 and 0.8×106 Da, respectively. A fifth segment with a size of 0.58×106 Da identified as ssRNA5 associated with the purified virus sometimes. The antiserum against the coat protein further purified by preparative electrophoresis was raised and used to investigate the serological relationships between RSV-CP and RSV-SP, CP and SP of rice grassy stunt virus (RGSV) which is also a member of Tenuivirus. The results showed that RSV-CP had no serological reaction with SP of RSV and PGSV, but could weakly react with antiserum of RGSV-CP, which confirmed that there is distantly evolutionary relationship between RGSV and RSV.

Background::High-dose dual therapy (HDDT) with proton pump inhibitors (PPIs) and amoxicillin has attracted widespread attention due to its favorable efficacy in eradicating Helicobacter pylori ( H. pylori). This study aimed to compare the efficacy and safety of high-dose PPI–amoxicillin dual therapy and bismuth-containing quadruple therapy for H. pylori rescue treatment. Methods::This was a prospective, randomized, multicenter, non-inferiority trial. Patients recruited from eight centers who had failed previous treatment were randomly (1:1) allocated to two eradication groups: HDDT (esomeprazole 40 mg and amoxicillin 1000 mg three times daily; the HDDT group) and bismuth-containing quadruple therapy (esomeprazole 40 mg, bismuth potassium citrate 220 mg, and furazolidone 100 mg twice daily, combined with tetracycline 500 mg three times daily; the tetracycline, furazolidone, esomeprazole, and bismuth [TFEB] group) for 14 days. The primary endpoint was the H. pylori eradication rate. The secondary endpoints were adverse effects, symptom improvement rates, and patient compliance. Results::A total of 658 patients who met the criteria were enrolled in this study. The HDDT group achieved eradication rates of 75.4% (248/329), 81.0% (248/306), and 81.3% (248/305) asdetermined by the intention-to-treat (ITT), modified intention-to-treat (MITT), and per-protocol (PP) analyses, respectively. The eradication rates were similar to those in the TFEB group: 78.1% (257/329), 84.2% (257/305), and 85.1% (257/302). The lower 95% confidence interval boundary (–9.19% in the ITT analysis, –9.21% in the MITT analysis, and –9.73% in the PP analysis) was greater than the predefined non-inferiority margin of –10%, establishing a non-inferiority of the HDDT group vs. the TFEB group. The incidence of adverse events in the HDDT group was significantly lower than that in the TFEB group (11.1% vs. 26.8%, P < 0.001). Symptom improvement rates and patients’ compliance were similar between the two groups. Conclusions::Fourteen-day HDDT is non-inferior to bismuth-containing quadruple therapy, with fewer adverse effects and good treatment compliance, suggesting HDDT as an alternative for H. pylori rescue treatment in the local region. Trial registration::Clinicaltrials.gov, NCT04678492.