RESUMO
@#Abstract：Objective To improve the replication level of varicella⁃zoster virus（VZV）in human diploid cell line MRC⁃5 and increase the yield of VZV vaccine by reducing the expression of interferon（IFN）related genes via optimizing the cell line MRC⁃5. Methods Interferon receptor 1（IFNAR1）silenced MRC⁃5 cell line（MRC⁃5IFNAR1⁃）was constructed by CRISPR／Cas9 gene editing technology，which was determined for the relative expression of IFNAR1 mRNA，and for those of mRNA of IFN related genes IFNβ and OAS1 after VZV infection by qRT⁃PCR to evaluate the effect of gene silencing. Gene mutation sequences were further identified by sequencing of the silenced sites. The replication of VZV in MRC⁃5 and MRC⁃5IFNAR1⁃ cell lines was compared 168 h after VZV infection by using qRT⁃PCR and plaque formation unit（PFU）assay， to evaluate the effect of MRC⁃5IFNAR1⁃cell line on VZV replication. Results The growth status of MRC⁃5IFNAR1⁃ cell line wasconsistent with that of MRC ⁃ 5 cells，and the relative expression of IFNAR1 mRNA decreased by 73%；The relative expressions of IFNβ and OAS1 mRNA in MRC⁃5IFNAR1⁃ cell line were 61% and 90% lower than those in MRC⁃ 5 cells respectively after VZV infection；In addition，168 h after VZV infection，the level of DNA replication and the titer of VZV increased by 5. 7 folds and 4 folds respectively. Conclusion The successful establishment of MRC⁃5IFNAR1⁃ cell line may be a potential scheme to increase the yield of vaccines based on human diploid cells，and provided a reference for expanding production of VZV vaccine.
RESUMO
In the present paper, we have successfully synthesized silver nancomparticles by reducing of silver nitrate in alkaline solution via 60 degrees C water bath for 20 minutes with the use of tyrosine, a nontoxic and green macromolecule, as a reducing and stabilizing agent. The formation of silver nanoparticles was observed visually by color change of the solutions (from faint yellow to brown yellow). The morphologies of the Ag NPs were characterized by UV-Vis absorption spectroscopy and transmission electron microscopy (TEM). The UV-Vis absorption peak of silver nanoparticles located at 412 nm. The TEM image of silver nanoparticles indicated that the diameters of nanospheres are mainly in the range 15-25 nm. In order to evaluate the SERS activity of the silver nancomparticles, crystal violet and folic acid were used as the Raman probe molecule. The experimental results indicated that there are two ascendancies, firstly, the approach is convenient and the reaction condition is facile, secondly, tyrosine is a water-soluble, nontoxic and biodegradable macromolecule, which makes this approach provide a green strategy to prepare Ag NPs. Significantly, the synthesized Ag NPs exhibits good surface enhanced Raman scattering (SERS) activity as SERS substrates to detect crystal violet and folic acid in aqueous solution.
RESUMO
The ability of combining serum surface-enhanced Raman spectroscopy (SERS) with support vector machine (SVM) for improving classification esophageal cancer patients from normal volunteers is investigated. Two groups of serum SERS spectra based on silver nanoparticles (AgNPs) are obtained: one group from patients with pathologically confirmed esophageal cancer (n=30) and the other group from healthy volunteers (n=31). Principal components analysis (PCA), conventional SVM (C-SVM) and conventional SVM combination with PCA (PCA-SVM) methods are implemented to classify the same spectral dataset. Results show that a diagnostic accuracy of 77.0% is acquired for PCA technique, while diagnostic accuracies of 83.6% and 85.2% are obtained for C-SVM and PCA-SVM methods based on radial basis functions (RBF) models. The results prove that RBF SVM models are superior to PCA algorithm in classification serum SERS spectra. The study demonstrates that serum SERS in combination with SVM technique has great potential to provide an effective and accurate diagnostic schema for noninvasive detection of esophageal cancer.
