To establish a TaqMan-based multiplex RT-qPCR method for the identification of Japa-nese encephalitis virus(JEV),Porcine reproductive and respiratory syndrome virus(PRRSV),and Classical swine fever virus(CSFV),this study designed and synthesized three pairs of specific primers and probes based on the conserved sequences of JEV E,PRRSV ORF6,and CSFV E2 a-vailable in the NCBI GenBank.By optimizing the reaction system and protocol,a multiplex RT-qPCR method for detecting these three viruses was developed and applied to the detection of clini-cal samples.The results showed that the established TaqMan multiplex RT-qPCR specifically am-plified the gene fragments of JEV,PRRSV,and CSFV,and did not amplify other non-target genes,indicating good specificity of the method.Intra-assay and inter-assay repeatability tests showed that the coefficient of variation(Cv)values were all below 3％,demonstrating that the method has ex-cellent repeatability.Sensitivity tests revealed that the minimum detectable amount for the recom-binant plasmids of the three viruses was 100 copies/pL.Using the established method,a total of 969 samples,including blood,aborted fetuses,semen,and deceased pigs,from 26 pig farms in Guizhou Province were tested.The detection rates were 34.3％(332/969)for JEV,28.3％(274/969)for PRRSV,and 19.8％(192/969)for CSFV.The co-infection rates were 10.1％(98/969)for JEV and PRRSV,12.1％(117/969)for JEV and CSFV,and 14.6％(141/969)for CSFV and PRRSV.Additionally,the triple co-infection rate of JEV,PRRSV,and CSFV was 7.9％(77/969).These results indicate that the TaqMan multiplex RT-qPCR method developed in this study is ef-fective for detecting these three viruses in pig farms,providing technical support for identifying vi-ral causes of reproductive disorders.

To establish a TaqMan-based multiplex RT-qPCR method for the identification of Japa-nese encephalitis virus(JEV),Porcine reproductive and respiratory syndrome virus(PRRSV),and Classical swine fever virus(CSFV),this study designed and synthesized three pairs of specific primers and probes based on the conserved sequences of JEV E,PRRSV ORF6,and CSFV E2 a-vailable in the NCBI GenBank.By optimizing the reaction system and protocol,a multiplex RT-qPCR method for detecting these three viruses was developed and applied to the detection of clini-cal samples.The results showed that the established TaqMan multiplex RT-qPCR specifically am-plified the gene fragments of JEV,PRRSV,and CSFV,and did not amplify other non-target genes,indicating good specificity of the method.Intra-assay and inter-assay repeatability tests showed that the coefficient of variation(Cv)values were all below 3％,demonstrating that the method has ex-cellent repeatability.Sensitivity tests revealed that the minimum detectable amount for the recom-binant plasmids of the three viruses was 100 copies/pL.Using the established method,a total of 969 samples,including blood,aborted fetuses,semen,and deceased pigs,from 26 pig farms in Guizhou Province were tested.The detection rates were 34.3％(332/969)for JEV,28.3％(274/969)for PRRSV,and 19.8％(192/969)for CSFV.The co-infection rates were 10.1％(98/969)for JEV and PRRSV,12.1％(117/969)for JEV and CSFV,and 14.6％(141/969)for CSFV and PRRSV.Additionally,the triple co-infection rate of JEV,PRRSV,and CSFV was 7.9％(77/969).These results indicate that the TaqMan multiplex RT-qPCR method developed in this study is ef-fective for detecting these three viruses in pig farms,providing technical support for identifying vi-ral causes of reproductive disorders.

Background: It remains controversial whether palliative primary tumor resection (PPTR) can provide survival benefits to the patients with metastatic colorectal cancer (mCRC) who have unresectable metastases. The aim of this study was to evaluate whether PPTR could improve the survival of patients with mCRC. Methods: We conducted a retrospective study on consecutive mCRC patients with unresectable metastases who were diagnosed at Sun Yat?sen University Cancer Center in Guangzhou, Guangdong, China, between January 2005 and December 2012. Overall survival (OS) and progression?free survival (PFS) after first?line chemotherapy failure were compared between the PPTR and non?PPTR patient groups. Results: A total of 387 patients were identified, including 254 who underwent PPTR and 133 who did not. The median OS of the PPTR and non?PPTR groups was 20.8 and 14.8 months (P < 0.001), respectively. The median PFS after first?line chemotherapy was 7.3 and 4.8 months (P < 0.001) in the PPTR and non?PPTR groups, respectively. A larger proportion of patients in the PPTR group (219 of 254, 86.2%) showed local progression compared with that of patients in the non?PPTR group (95 of 133, 71.4%; P < 0.001). Only patients with normal lactate dehydrogenase (LDH) levels and with carcinoembryonic antigen (CEA) levels <70 ng/mL benefited from PPTR (median OS, 22.2 months for the PPTR group and 16.2 months for the non?PPTR group; P < 0.001). Conclusions: For mCRC patients with unresectable metastases, PPTR can improve OS and PFS after first?line chemo?therapy and decrease the incidence of new organ involvement. However, PPTR should be recommended only for patients with normal LDH levels and with CEA levels <70 ng/mL.