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Background: Stroke often results in significant respiratory dysfunction in patients. Respiratory muscle training (RMT) has been proposed as a rehabilitative intervention to address these challenges, but its effectiveness compared to routine training remains debated. This systematic review and meta-analysis aim to evaluate the effects of RMT on exercise tolerance, muscle strength, and pulmonary function in post-stroke patients., Aim: To systematically assess the efficacy of RMT in improving exercise tolerance, respiratory muscle strength, and pulmonary function in patients recovering from a stroke, and to evaluate whether RMT offers a significant advantage over routine training modalities in enhancing these critical health outcomes in the post-stroke population., Methods: Following the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines, a comprehensive search across PubMed, Embase, Web of Science, and the Cochrane Library was conducted on October 19, 2023, without temporal restrictions. Studies were selected based on the predefined inclusion and exclusion criteria focusing on various forms of RMT, control groups, and outcome measures [including forced expiratory volume in the first second (FEV1), forced vital capacity (FVC), maximal voluntary ventilation (MVV), peak expiratory flow (PEF), maximal inspiratory pressure (MIP), maximal expiratory pressure (MEP), and 6-min walking test (6MWT)]. Only randomized controlled trials (RCTs) were included. Data extraction and quality assessment were conducted independently by two reviewers using the Cochrane Collaboration's risk of bias tool. Statistical analyses, including those using the fixed-effect and random-effects models, sensitivity analysis, and publication bias assessment, were performed using Review Manager software., Results: A total of 15 RCTs were included. Results indicated significant improvements in MIP (12.51 cmH 2 O increase), MEP (6.24 cmH 2 O increase), and various pulmonary function parameters (including FEV1, FVC, MVV, and PEF). A substantial increase in 6MWT distance (22.26 meters) was also noted. However, the heterogeneity among studies was variable, and no significant publication bias was detected., Conclusion: RMT significantly enhances walking ability, respiratory muscle strength (MIP and MEP), and key pulmonary function parameters (FEV1, FVC, MVV, and PEF) in post-stroke patients. These findings support the incorporation of RMT into post-stroke rehabilitative protocols., Competing Interests: Conflict-of-interest statement: All the authors report no relevant conflicts of interest for this article., (©The Author(s) 2024. Published by Baishideng Publishing Group Inc. All rights reserved.)

Aim: Immune escape mutations of HBV often occur in the dominant epitope, the second-loop of the a determinant of hepatitis B surface antigen (HBsAg). To let the hosts respond to the subdominant epitopes in HBsAg may be an effective way to decrease the prevalence of immune escape mutants. For this reason, a man-made clone of HBV S gene with the second-loop deletion was constructed. Its antigenicity was evaluated by yeast expression analysis and DNA immunization in mice., Methods: HBV S gene with deleted second-loop, amino acids from 139 to 145, was generated using splicing by overlap extension. HBV deleted S gene was then cloned into the yeast expression vector pPIC9 and the mammalian expression vector pcDNA3 to generate pHB-SDY and pHB-SD, respectively. The complete S gene was cloned into the same vectors as controls. The deleted recombinant HBsAg expressed in yeasts was detected using Abbott IMx HBsAg test kits, enzyme-linked immunoadsorbent assay (ELISA) and immune dot blotting to evaluate its antigenicity in vitro. The anti-HBs responses to DNA immunization in BALB/c mice were detected using Abbott IMx AUSAB test kits to evaluate the antigenicity of that recombinant protein in vivo., Results: Both deleted and complete HBsAg were successfully expressed in yeasts. They were intracellular expressions. The deleted HBsAg could not be detected by ELISA, in which the monoclonal anti-HBs against the alpha determinant was used, but could be detected by Abbott IMx and immune dot blotting, in which multiple monoclonal anti-HBs and polyclonal anti-HBs were used, respectively. The activity of the deleted HBsAg detected by Abbott IMx was much lower than that of complete HBsAg (the ratio of sample value/cut off value, 106+/-26.7 vs 1 814.4+/-776.3, P<0.01, t = 5.02). The anti-HBs response of pHB-SD to DNA immunization was lower than that of complete HBV S gene vector pHB (the positive rate 2/10 vs 6/10, 4.56+/-3.52 mIU/mL vs 27.60+/-17.3 mIU/mL, P = 0.02, t = 2.7)., Conclusions: HBsAg with deleted second-loop of the alpha determinant still has antigenicity, and can also raise weak anti-HBs response in mice to DNA immunization, suggesting that it is possible to develop a subdominant vaccine for preventing infections of immune escape mutants of HBV.

Aim: To design and construct an exogenous multiple epitope of helper T lymphocytes (HTL), and to evaluate its effect on anti-HBs response through DNA immunization., Methods: Artificial HTL epitope, PADRE and four other HTL epitopes from different proteins were linked together using splicing by overlap extension to generate exogenous multiple epitopes of HTL, MTE5. pcMTE5 and pcHB were generated by cloning MTE5 and fragments of HBV pre-S2/S gene into mammalian expression plasmid pcDNA3. Four chimeric plasmids were constructed by cloning MTE5 into the region of pre-S2 gene (Bam HI), 5' terminal of S gene (HincII, Xba I) and 3' terminal of S gene (Acc I) of pcHB respectively. BALB/c mice were used in DNA immunization of the recombinant plasmids. Anti-HBs was detected using Abbott IMx AUSAB test kits., Results: The sequences of MTE5 and the 6 constructs of recombinant plasmids were confirmed to be correct by DNA sequencing. The anti-HBs response of the co-inoculation of pcHB and pcMTE5 was much higher than that of the inoculation of pcHB only (136.7+/-69.1 mIU/mL vs 27.6+/-17.3 mIU/mL, P<0.01, t = -6.56). Among the 4 chimeric plasmids, only the plasmid in which MTE5 was inserted into the pre-S2 region had good anti-HBs response (57.54+/-7.68 mIU/mL), and had no significant difference compared with those of pcHB and the co-inoculation of pcHB and pcMTE5., Conclusion: Exogenous multiple epitopes of HTL had immune enhancement when they were co-inoculated with pre-S2/S gene or inoculated in the chimeric form at a proper site of pre-S2/S gene of HBV. It might suggest that it was possible to improve hepatitis B vaccine using exogenous multiple epitopes of HTL. The antibody responses were very low using DNA immunization in the study. Thus, the immune enhancement effect of exogenous multiple epitopes of HTL has to be confirmed and the effect on overcoming the drawback of the polymorphism of HLA II antigens should also be evaluated after these chimeric plasmids are expressed in mammalian cell lines.