ABSTRACT
Objective@#Quadrivalent influenza vaccines contain two lineages of type B virus, this study aimed to assess whether the result of single radial immunodiffusion (SRID) are accurate. The cross-interference of two type B hemagglutinins remains unknown.@*Methods@#We detected the vaccine samples developed by Jiangsu GDK Biological Technology Co., ltd by SRID.@*Results@#There was no significant difference between the HA content of antigen reagent, bulk sample and mixed sample of two B bulk within 10 to 40 μg/ml (P>0.05). Then each hemagglutinin B was diluted respectively by other three HA, 30 μg/ml, the other hemagglutinin B or phosphate buffer solution were measured within 10-160 μg/ml. Within 10-40 μg/ml, the HA content was proportional to the diameters of immunodiffusion (R2=0.998), while within the higher content range, a ternary linear regression equation fitted best (R2=0.999).@*Conclusions@#No cross-interference between B/Brisbane and B/Phuket was found in SRID within both detection ranges.
ABSTRACT
Objective@#To evaluate the immunogenicity of high-dose inactivated quadrivalent influenza serial vaccines (split virion) for elderly people.@*Methods@#Immunogenicity assays on mouse as research animal model with inactivated quadrivalent influenza serial vaccines (split virion) were carried out. Then rates of seroconversion and geometric mean hemagglutination inhibition titers (GMTs) at day 21 after the last vaccination among those who received high-dose (HD) A+ B influenza vaccine, were compared with those who received other vaccines by hemagglutination inhibition (HAI) test.@*Results@#The result of HAI test showed in HD serial vaccine groups, GMTs for all kinds of HA in the two HD serial vaccine groups were significantly different from that of the two SD serial vaccine groups, respectively (P<0.0001), but not the titers for A3 in one B dose first group. Further- more, GMTs for strain A in one B dose first groups were significantly higher than that of one B dose first groups in both HD and SD groups, and vice versa in the GMTs for strain B. The result of the assay of the impact of different immunization intervals of HD serial influenza vaccine on immunogenicity indicated that the immunity responses in 7 or 10 d groups were higher than that in 3 d group.@*Conclusions@#It is a new method to prevent the flu for elderly by HD A+ B serial influenza vaccine, whose HA dose per immunization was reduced into two injections, worked best when the immunization interval was 7-10 d. The protective immunity can be improved by selecting immune procedure of the serial vaccine according to the epidemic type surveillance of influenza virus A and B strains.
ABSTRACT
<p><b>OBJECTIVE</b>To investigate the effect of peroxiredoxin I (Prx I) gene silencing on the radiosensitivity of breast carcinoma MCF-7 cell xenograft in nude mice and explore the mechanism.</p><p><b>METHODS</b>MCF-7 cells were transfected with the recombinant plasmids pGPU6-PrxI and pGPU6-HK separately. The pGPU6-PrxI-transfected cells stably expressing Prx I shRNA and pGPU6-HK-transfected cells were inoculated subcutaneously into BALB/c nude mice. After exposure to ionizing radiation (IR) with 6 MV X-ray, the xenografts were harvested for measuring the tumor volume and mass, and the tumor inhibition rates were calculated. Immunohistochemistry was employed for detecting the expressions of Prx I and caspase-3 proteins. The ultrastructural changes of the tumor tissues following the exposure were observed using electron microscopy. Western blotting was used to analyze the expressions of γ-H2AX and Rad51 proteins.</p><p><b>RESULTS</b>Following IR exposure, the pGPU6-Prx I-transfected cell xenograft showed a significantly delayed growth and smaller tumor volume as compared with pGPU6-HK xnegraft, with a tumor inhibition rate reaching 79.76%, significantly higher than that in non-exposed pGPU6-Prx I group (34.92%) and pGPU6-HK+IR group (56.94%) (P<0.05). The pGPU6-Prx I-transfected xenografts showed significantly increased tumor cell apoptosis and necrosis, down-regulated the expressions of Prx I and Rad51 proteins, and up-regulated the expressions of caspase-3 and γ-H2AX proteins; these changes were even more obvious after IR exposure, which caused a decrease of Rad51 protein by 84.8% and an increase in γ-H2AX protein by 5.6 folds compared with those in pGPU6-HK group (P<0.05).</p><p><b>CONCLUSION</b>Prx I gene silencing can significantly enhance the radiosensitivity of breast carcinoma xenograft in nude mice possibly by increasing DNA damage and lowering the capacity of the cells for DNA repair. Prx I may serve as an ideal molecular target for radiosensitization of breast carcinoma.</p>