Background and Aims:Intrahepatic cholangiocarcinoma(ICC)is a highly malignant liver tumor,with an increasing incidence worldwide,particularly in Asia.Although radical surgical resection is currently the only potentially curative treatment,the high recurrence rate and low postoperative overall survival(OS)rate of ICC remain major clinical challenges.Adjuvant therapy(AT)and neoadjuvant therapy(NAT)are important strategies to reduce postoperative recurrence and prolong OS.Several studies have shown certain efficacy of these treatments.However,the specific efficacy and safety of combined NAT and AT in ICC treatment require further validation.This study was conducted to evaluate the value of combining NAT and AT in improving the therapeutic outcomes of ICC patients through a multicenter retrospective analysis,so as to provide scientific evidence for optimizing treatment strategies.Methods:The clinicopathologic data of 576 patients with ICC who underwent radical resection and were pathologically confirmed from 13 hospitals in China between December 2011 and December 2017 were retrospectively collected.Patients were grouped based on their treatment modality:NAT+AT group,AT group,and non-NAT/AT group.The three patient groups were matched pairwise in a 1∶1 ratio using propensity score matching(PSM)to balance baseline data.The Kaplan-Meier method was used to analyze OS and disease-free survival(DFS),and subgroup analyses were conducted according to the 8th edition of the AJCC TNM staging system.Results:A total of 395 ICC patients were included in the final analysis,with 42 patients(10.6%)in the NAT+AT group,62 patients(15.7%)in the AT group,and 291 patients(73.7%)in the non-NAT/AT group.Before PSM,significant differences were observed between groups in terms of CA19-9,liver function Child-Pugh classification,intraoperative blood loss,surgical margin,differentiation grade,vascular invasion,ECOG score,and lymph node dissection ratio(all P<0.05).After PSM,there were no significant differences in baseline characteristics between the groups(all P>0.05).After matching,the median OS and DFS in the NAT+AT group were significantly better than in the AT and non-NAT/AT groups(both P<0.05),while there were no significant differences in OS and DFS between the AT and non-NAT/AT groups(both P>0.05).Subgroup analysis showed that in TNM stage I patients,DFS in the NAT+AT group was significantly better than in the non-NAT/AT group(P<0.05),but OS was not significantly different(P>0.05).In TNM stage Ⅱ and Ⅲ patients,both OS and DFS in the NAT+AT and AT groups were significantly better than in the non-NAT/AT group(both P<0.05),and DFS in the NAT+AT group was significantly better than in the AT group in TNM stage Ⅲ patients(P<0.05).Conclusion:NAT combined with AT provides better survival benefits for patients with locally advanced ICC,but its benefit for early-stage ICC patients is limited.However,the retrospective design and sample size limitations of this study may affect the stability of the results,and future large-sample,multicenter,prospective studies are needed for further validation.

Objective:To obtain a prevalent respiratory syncytial virus (RSV) clinical isolate in Beijing and analyze the genotype and biological characteristics of the strain.Methods:A nasopharyngeal secretion specimen was collected from a child with RSV infection in Beijing in 2023 and used for viral isolation. Viral nucleic acid was amplified using qRT-PCR. The isolated virus was identified by transmission electron microscopy, indirect immunofluorescence assay, and plaque formation assay. A phylogenetic analysis was conducted based on the whole-genome sequencing results. Virus titers were determined, and replication characteristics were analyzed. The efficacy of the isolated strain for in vitro screening of antiviral drugs was validated. Results:A clinical RSV isolate, named hRSV/C-Tan/BJ 202301, was successfully isolated, which could form syncytia in Hep-2 cells. Spherical, filamentous, and irregular virus particles were observed by electron microscopy. Immunofluorescence detection showed green fluorescence in Hep-2 cells, and plaque assay showed round plaques, which were similar to the Long strain in morphology. Genomic sequence analysis showed that it belonged to ON1 genotype. It exhibited similar cell growth kinetics characteristics with the Long strain and could be used for antiviral drug screening in vitro. Conclusions:In this study, one RSV strain is successfully isolated and identified. The biological characteristics and the phylogenetic relationship of this strain reflect the characteristics of the circulating strains in Beijing, which provides experimental material for RSV vaccine development and antiviral drug screening in China.

Objective:To explore the clinical and pathological features and survival outcomes of patients with early-onset intrahepatic cholangiocarcinoma (EOICC).Methods:This is a multicenter, retrospective cohort study. Data of 1 160 intrahepatic cholangiocarcinoma patients undergoing radical resection in 14 tertiary Grade A hospitals in China from January 2010 to November 2021 were retrospectively collected. The cohort included 632 males and 528 females, aged( M (IQR)) 61 (14) years (range: 22 to 93 years). ICC aged ≤50 years at the time of diagnosis was defined as EOICC and >50 years as late-onset intrahepatic cholangiocarcinoma (LOICC). Of these, there were 247 cases in the EOICC group and 913 cases in the LOICC. The clinical and pathological characteristics of both groups were analyzed and compared using the independent sample t-test, Mann-Whitney U test or Kaplan-Meier method. Univariate and multivariate Cox regression models for patient outcomes were constructed and forest graphed. Results:Compared with the patients in the LOICC group, patients in the EOICC group had lower carcinoembryonic antigen levels (2.5(4.0) μg/L vs. 3.1(5.2)μg/L, U=124 899, P=0.009) and CA19-9 level (63.4(524.7)U/ml vs. 77.9(611.3)U/ml, U=120 320, P=0.013), higher levels of ALT (29(35)U/L vs. 24(26)U/L, U=101 214, P=0.013), a lower score of the Eastern US Cooperative Oncology Group (0 score patients: 54.7% vs. 44.1%, χ2=12.472, P=0.014), higher TNM stage ( χ2=11.807, P=0.038), and proportion of lymph node dissection (62.3% vs. 54.1%, χ2=5.355, P=0.021). Patients in the two groups in sex, first diagnosis symptoms, intrahepatic bile duct stone history, nail protein, albumin, total bilirubin, transaminase, liver function Child-Pugh grade, T stage, stage, N stage, preoperative laparoscopic exploration proportion, tumor diameter, vascular invasion proportion, differentiation, margin, intraoperative bleeding, postoperative complications, postoperative hospital days were no statistical significance (all P>0.05). Patients in the EOICC group had better outcomes than the LOICC group (median survival time: 29.7 months vs. 25.0 months, 3-year overall survival: 45.1% vs. 37.8%, P=0.027). Conclusion:EOICC patients are better than LOICC patients in carcinoembryonic antigen, CA19-9, ALT, physical strength status and TNM stage, and the long-term prognosis is also better than LOICC patients.

Objective:To obtain a prevalent respiratory syncytial virus (RSV) clinical isolate in Beijing and analyze the genotype and biological characteristics of the strain.Methods:A nasopharyngeal secretion specimen was collected from a child with RSV infection in Beijing in 2023 and used for viral isolation. Viral nucleic acid was amplified using qRT-PCR. The isolated virus was identified by transmission electron microscopy, indirect immunofluorescence assay, and plaque formation assay. A phylogenetic analysis was conducted based on the whole-genome sequencing results. Virus titers were determined, and replication characteristics were analyzed. The efficacy of the isolated strain for in vitro screening of antiviral drugs was validated. Results:A clinical RSV isolate, named hRSV/C-Tan/BJ 202301, was successfully isolated, which could form syncytia in Hep-2 cells. Spherical, filamentous, and irregular virus particles were observed by electron microscopy. Immunofluorescence detection showed green fluorescence in Hep-2 cells, and plaque assay showed round plaques, which were similar to the Long strain in morphology. Genomic sequence analysis showed that it belonged to ON1 genotype. It exhibited similar cell growth kinetics characteristics with the Long strain and could be used for antiviral drug screening in vitro. Conclusions:In this study, one RSV strain is successfully isolated and identified. The biological characteristics and the phylogenetic relationship of this strain reflect the characteristics of the circulating strains in Beijing, which provides experimental material for RSV vaccine development and antiviral drug screening in China.

Background and Aims:Intrahepatic cholangiocarcinoma(ICC)is a highly malignant liver tumor,with an increasing incidence worldwide,particularly in Asia.Although radical surgical resection is currently the only potentially curative treatment,the high recurrence rate and low postoperative overall survival(OS)rate of ICC remain major clinical challenges.Adjuvant therapy(AT)and neoadjuvant therapy(NAT)are important strategies to reduce postoperative recurrence and prolong OS.Several studies have shown certain efficacy of these treatments.However,the specific efficacy and safety of combined NAT and AT in ICC treatment require further validation.This study was conducted to evaluate the value of combining NAT and AT in improving the therapeutic outcomes of ICC patients through a multicenter retrospective analysis,so as to provide scientific evidence for optimizing treatment strategies.Methods:The clinicopathologic data of 576 patients with ICC who underwent radical resection and were pathologically confirmed from 13 hospitals in China between December 2011 and December 2017 were retrospectively collected.Patients were grouped based on their treatment modality:NAT+AT group,AT group,and non-NAT/AT group.The three patient groups were matched pairwise in a 1∶1 ratio using propensity score matching(PSM)to balance baseline data.The Kaplan-Meier method was used to analyze OS and disease-free survival(DFS),and subgroup analyses were conducted according to the 8th edition of the AJCC TNM staging system.Results:A total of 395 ICC patients were included in the final analysis,with 42 patients(10.6%)in the NAT+AT group,62 patients(15.7%)in the AT group,and 291 patients(73.7%)in the non-NAT/AT group.Before PSM,significant differences were observed between groups in terms of CA19-9,liver function Child-Pugh classification,intraoperative blood loss,surgical margin,differentiation grade,vascular invasion,ECOG score,and lymph node dissection ratio(all P<0.05).After PSM,there were no significant differences in baseline characteristics between the groups(all P>0.05).After matching,the median OS and DFS in the NAT+AT group were significantly better than in the AT and non-NAT/AT groups(both P<0.05),while there were no significant differences in OS and DFS between the AT and non-NAT/AT groups(both P>0.05).Subgroup analysis showed that in TNM stage I patients,DFS in the NAT+AT group was significantly better than in the non-NAT/AT group(P<0.05),but OS was not significantly different(P>0.05).In TNM stage Ⅱ and Ⅲ patients,both OS and DFS in the NAT+AT and AT groups were significantly better than in the non-NAT/AT group(both P<0.05),and DFS in the NAT+AT group was significantly better than in the AT group in TNM stage Ⅲ patients(P<0.05).Conclusion:NAT combined with AT provides better survival benefits for patients with locally advanced ICC,but its benefit for early-stage ICC patients is limited.However,the retrospective design and sample size limitations of this study may affect the stability of the results,and future large-sample,multicenter,prospective studies are needed for further validation.

Objective:To explore the clinical and pathological features and survival outcomes of patients with early-onset intrahepatic cholangiocarcinoma (EOICC).Methods:This is a multicenter, retrospective cohort study. Data of 1 160 intrahepatic cholangiocarcinoma patients undergoing radical resection in 14 tertiary Grade A hospitals in China from January 2010 to November 2021 were retrospectively collected. The cohort included 632 males and 528 females, aged( M (IQR)) 61 (14) years (range: 22 to 93 years). ICC aged ≤50 years at the time of diagnosis was defined as EOICC and >50 years as late-onset intrahepatic cholangiocarcinoma (LOICC). Of these, there were 247 cases in the EOICC group and 913 cases in the LOICC. The clinical and pathological characteristics of both groups were analyzed and compared using the independent sample t-test, Mann-Whitney U test or Kaplan-Meier method. Univariate and multivariate Cox regression models for patient outcomes were constructed and forest graphed. Results:Compared with the patients in the LOICC group, patients in the EOICC group had lower carcinoembryonic antigen levels (2.5(4.0) μg/L vs. 3.1(5.2)μg/L, U=124 899, P=0.009) and CA19-9 level (63.4(524.7)U/ml vs. 77.9(611.3)U/ml, U=120 320, P=0.013), higher levels of ALT (29(35)U/L vs. 24(26)U/L, U=101 214, P=0.013), a lower score of the Eastern US Cooperative Oncology Group (0 score patients: 54.7% vs. 44.1%, χ2=12.472, P=0.014), higher TNM stage ( χ2=11.807, P=0.038), and proportion of lymph node dissection (62.3% vs. 54.1%, χ2=5.355, P=0.021). Patients in the two groups in sex, first diagnosis symptoms, intrahepatic bile duct stone history, nail protein, albumin, total bilirubin, transaminase, liver function Child-Pugh grade, T stage, stage, N stage, preoperative laparoscopic exploration proportion, tumor diameter, vascular invasion proportion, differentiation, margin, intraoperative bleeding, postoperative complications, postoperative hospital days were no statistical significance (all P>0.05). Patients in the EOICC group had better outcomes than the LOICC group (median survival time: 29.7 months vs. 25.0 months, 3-year overall survival: 45.1% vs. 37.8%, P=0.027). Conclusion:EOICC patients are better than LOICC patients in carcinoembryonic antigen, CA19-9, ALT, physical strength status and TNM stage, and the long-term prognosis is also better than LOICC patients.

Objective:To determine the evaluation indexes of national standard strains of genotypes 1, 3 and 5 of Japanese encephalitis virus (JEV) and evaluate the national standard JEV strains.Methods:According to the national standard strain evaluation technical standards of pathogenic microbial bacteria (virus) species, based on the application of Japanese encephalitis virus research, and according to the morphological characteristics, biological characteristics, molecular biological characteristics and other research data to identify the characteristics of G1, G3 and G5 genotypes of JEV.Results:Spherical virus particles with a diameter of about 60 nm were visible under electron microscope of the three Japanese encephalitis virus strains. The cytopathic effect was mainly characterized by cell shrinkage and exfoliation in BHK-21 and Vero cell lines, cell fusion and exfoliation were shown after infection with C6/36 cell line; the virus titer was 10 5-10 7 PFU/ml, and the plaque size was different by genotype. The median lethal dose of intrabitoneal challenge in G1, G3 and G5 JEV in three weeks-old mice was 50.51 PFU, 6.98 PFU, and 8.13 PFU, and the median lethal dose of intracranial challenge in five weeks mice was 3 PFU, 0.3 PFU, 1.35 PFU. The whole genome length of G1, G3 and G5 JEV was 10 967 bp, 10 976 bp and 10 983 bp, respectively. Conclusions:Three genotypic national standard strains of JE V were identified and evaluated by electron microscopy, cell, animal and genome laboratory indexes, which provided reference for the identification and evaluation of other national standard strains of JEV.

Objective:To establish and optimize the in vitro enrichment method for human coronavirus NL63 reference strain (HCoV-NL63-NC_005831).Methods:HCoV-NL63 was cultured in rhesus monkey kidney cell line (LLC-MK2). Then at 135 000× g, the virus culture supernatant was centrifuged for 4 h, 6 h, 8 h, 10 h and 12 h to enrich the virus, and compared with the enrichment method of commercial PEG Precipitation Kit. Real time reverse transcription polymerase chain reaction (qRT-PCR), TCID 50 assay and plaque assay were used to quantitatively detect the viral nucleic acid and viral biological activity of the original virus solution and the enriched virus solution respectively. The virus morphology before and after enrichment was observed after negative staining under a transmission electron microscope. Results:After 100∶1 volume enrichment by ultracentrifugation and PEG precipitation, both of the concentration of virus nucleic acid and live virus were higher than that of the original virus solution ( P < 0.001), and before and after the enrichment of the two method, the normal negative staining morphology of virus particles can be observed under the electron microscope. After 4 h, 6 h, 8 h, 10 h and 12 h ultracentrifugation, the concentration of live virus was (7.35±1.62) times, (13.98±1.71) times, (36.36±10.41) times, (48.16±9.38) times, (48.16±9.38) times and (54.26±7.02) times that of the original virus solution, respectively; the concentration of live virus after PEG precipitation was (3.39±0.16) times that of the original virus solution, and the nucleic acid concentration and live virus concentration of concentrated virus solution obtained by ultracentrifugation were significantly higher than those obtained by PEG precipitation ( P < 0.05). After 8 h, 10 h or 12 h ultracentrifugation, the virus concentration was significantly higher than that of 4 h or 6 h ( P < 0.05). However, there was no significant difference in virus content between 8 h, 10 h and 12 h ( P >0.05). Conclusions:Compared with commercial PEG precipitation method, ultracentrifugation method can enrich HCoV-NL63 virus more effectively; when the relative centrifugal force is 135 000× g, the better enrichment effect in vitro can be obtained by selecting the super separation time of 8 h.

Objective:To construct 2019 novel coronavirus (2019-nCoV) 614D and 614G pseudovirus by HIV lentivirus packaging system and explore their biological specificity.Methods:The recombinant expression plasmids pCDNA3.1-614D and pCDNA3.1-614G were transiently cotransfected with psPAX2 and pLenti CMV Puro LUC into 293T cells respectively. After 72 hours, the supernatant was collected and ultracentrifuged with 20% sucrose cushion. The titer, morphology, protein expression and neutralizing activity of pseudovirus were determined.Results:S protein specific fluorescence was detected by indirect immunofluorescence test, Western blot analysis showed S protein was expressed, and the spike of pseudovirus was observed under transmission electron microscope. The titers of pseudovirus 614D and 614G were 1.12×10 4 and 2.52×10 4 TCID 50/ml, respectively. The pseudovirus 614D and 614G could be neutralized by S rabbit polyclonal antibody, indicating that the pseudovirus has high specificity. Conclusions:In this study, 2019-nCoV 614D and 614G pseudovirus was successfully constructed, which laid the foundation for the establishment of in vitro neutralizing antibody detection platform based on pseudovirus.