A qualitative analysis was developed to identify different ingredients from three Ginkgo biloba preparations(including Yinxingye Diwan, extract of Ginkgo biloba leaves tablets and Yinxingtongzhi Diwan)based on high resolution mass spectrometry and metabolomics technology. An XSELECT HSS T3(4. 6 mm×150 mm, 3. 5 μm)column was used for separation, with the mobile phases consisting of acetonitrile and water containing 0. 1% formic acid. The column temperature was set at 40 °C. Negative ion mode was used for mass spectrometric data acquisition. Through partial least squares projection to latent structure-discriminant analysis(PLS-DA), we firstly found the different compounds among different Ginkgo biloba preparations. Subsequently, the compounds displaying different abundance levels via database searching and literature matching were identified. Finally, we identified 21 different compounds between the extract of Ginkgo biloba leaves tablets and Yinxingye Diwan, which mostly belong to the organic acids and flavonols families. Quantitative analysis showed that the ingredients which had higher abundance in extract of Ginkgo biloba leaves tablets were mainly organic acids, whereas those exhibiting higher levels in Yinxingye Diwan are flavonols. We also identified 12 different ingredients between the Yinxingye Diwan and Yinxingtongzhi Diwan, which were flavonols, sciadopitysin and organic acids. The results of this study are useful for studying different chemical constituents from distinct Ginkgo biloba preparations.

MALDI-MS is an emerging technique that enables rapid profiling of endogenous substances in a high throughput. Nevertheless, its application to metabolite analysis is often hindered by the presence of massive matrix background peaks using conventional matrices. Herein rhein was introduced as a novel matrix for MALDI-MS analysis of cation metabolites. Several strong and weak basic metabolites were measured using rhein. Compared to the previously reported ionless matrix NSA and conventional matrix CHCA, clean MALDI-MS spectra were obtained devoid of matrix signals. Subsequently, we applied this matrix to profile a biologically complex sample, mice intestinal contents. In addition, we have validated the applicability of rhein to MALDI-MS imaging, which allows for simultaneous mapping of hundreds of metabolites from single mouse ileum section. In summary, the discovery of rhein as a novel MALDI matrix enables efficient and reliable profiling and imaging of endogenous metabolites from biological samples with no matrix interferences, which will greatly promote the utility of MALDI-MS-based platform for metabolome studies.

Porcine reproductive and respiratory syndrome (PRRS) is a highly contagious disease caused by porcine reproductive and respiratory syndrome virus (PRRSV), which causes great economic losses. At the moment, no effective neutralizing antibody is available for scientific research and treatment. Therefore, developing a method for screening the neutralizing monoclonal antibodies is of great significance for the prevention and treatment of PRRSV and the screening of antigen sites. Monoclonal antibodies have been widely used in the treatment and diagnosis of many human and animal diseases. Therefore, screening effective neutralizing antibodies for different pathogens is an urgent task. Among the methods for monoclonal antibody screening, B cell immortalization is an effective method to obtain neutralizing monoclonal antibody. Specifically, in this study, the bcl-6 and bcl-xl genes were connected by f2a and then the yielded product was ligated to a vector for retrovirus packaging. The swine lymphocytes immunized with PRRSV were infected the yielded mature viruses and cultured in the complete medium containing CD40L and IL21 cytokines. Then, CD21 was used as the marker to screen B cells with the magnetic bead method. Finally, monoclonal B cells were obtained and the secretion of antibodies was tested. The results showed that the plasmid, either being transfected alone or with the packaged plasmids, could be expressed, and that the packaged retrovirus could infect the cells. Moreover, the infected lymphocytes secreted antibodies, so did the screened B cells. Therefore, the method for screening monoclonal antibody against PRRSV was successfully established.
Animals ; Antibodies, Monoclonal ; Antibodies, Neutralizing ; Antibodies, Viral ; Humans ; Porcine Reproductive and Respiratory Syndrome/prevention & control* ; Porcine respiratory and reproductive syndrome virus/genetics* ; Swine