RESUMO
Objective To optimize the method to elicit the facial nerve F wave and to establish its reference values and its related parameters, in order to provide an electrophysiological basis for facial nerve assessment in patients with hemifacial spasm (HFS). Methods Thirty-six healthy volunteers and 22 patients with HFS underwent this project. Compound muscle action potentials (CAMP, or M waves) and F waves were elicited by stimulating the marginal mandibular branch of the facial nerve and recorded with needle electrodes placed in the mentalis muscle. The association between F parameters and Cohen Grading of the HFS patients were analyzed. Results There were no significant differences in F parameters between men and women or between the two sides in control subjects. Minimal latency of F wave (Fmin) and mean latency of F wave (Fmean) had positive correlations with head circumference (Fmin r=0.449, P=0.013; Fmean r=0.391, P=0.033), but had no correlations with age nor height. Patients with HFS had prolonged duration of F wave (Fdura) in spasm side, compared with normal side (13.1 ms vs. 9.5 ms, P<0.01) and healthy subjects (13.1 ms vs. 9.7 ms, P<0.001), and increased ratio of F-wave amplitude and M-wave amplitude (F/M) in spasm side, compared with normal side (6.9% vs. 3.8%, P<0.001) and healthy subjects (6.9% vs. 3.7%, P<0.001). F/M exhibited a positive correlation with Cohen Grading (r=0.538, P=0.001). Conclusion A clear facial nerve F wave can be achieved by stimulating the marginal mandibular branch of the facial nerve, which provides an objective basis for evaluation of the facial nerve function in HFS patients with increased F/M and prolonged Fdura.
RESUMO
Objective:To investigate whether His-tag to change the immunogenicity of recombinant protein G1F/M2 of respiratory syncytial virus.Methods:The G1 and F/M2 gene fragments were amplified by PCR method and then ligated into the expressing vector pET-His or pET-DsbA-His.Each recombinant plasmid was transferred into E.coli BL21(DE3) and the expression was induced by IPTG.The expressed His-G1F/M2 or DsbA-His-G1F/M2 was purified by affinity chromatography.The latter was digested with thrombase and G1F/M2 was purified by affinity chromatography.His-G1F/M2 or G1F/M2 was used to immunize BALB/c mice.Anti-RSV antibody was measured by ELISA and RSV-specific CTL responses by MTT.Results:No significant difference was observed between the level of anti-RSV antibody or RSV-specific CTL response induced by G1F/M2 and that by His-G1F/M2.Conclusion:His-tag does not change the immunogenicity of recombinant protein G1F/M2 of respiratory syncytial virus.
RESUMO
Objective: To investigate the regulation of respiratory syncytial virus CTL epitope fused with G protein antigen fragment G1 to the specific immunoresponses. Methods: The recombinant plasmid pET-DsbA-G1 or pET-DsbA-G1F/M2 was transferred into E.coli BL21(DE3) and the fusion protein DsbA-G1F/M2 or DsbA-G1 was expressed.The expressing product was induced and purified by affinity chromatography. The two proteins were used to immunized BALB/c mice i.p, respectively. Serum and spleen cells were collected regularly. RSV-specific CTL responses were measured by MTT, IgG and IgG1 and IgG2a antibodies by ELISA, neutralizing antibodies by plaque reduction assay. Results: The recombinant proteins were expressed successfully and the purity was over 90% after purified by affinity chromatography. The protein DsbA-G1F/M2 induced significant RSV-specific CTL responses, while DsbA-G1 without CTL epitope did not induce detctable CTL responses. Strong IgG antibody responses were elicited,indicated by both. IgG1 and IgG2a titers induced by DsbA-G1F/M2, while only IgG1 was induced by DsbA-G1.The ratio of IgG1/IgG2a was downregulated significantly. Both antigens induced high level of neutralizing antibodies, but the latter was a little lower. Conclusion: DsbA-G1F/M2, the fusion protein of a CTL epitope and G protein fragment G1 can induce both cellular immunity and humoral immunity. The activation of CTLs downregulates the ratio of IgG1/IgG2a.The more balanced immunoresponse is advantageous for improving safety of the candidate vaccine.