Intestinal flora imbalance is closely related to the pathogenesis of rheumatoid arthritis (RA). The existing studies have explored the monomer components such as tripterygium glycosides, total glycosides of Chaenomeles speciosa, and triterpenoid saponins of Clematis, Chinese materia medica such as Tripterygium wilfordii, Caulis Sinomenii, Radix Paeoniae Alba, Fructus Gardeniae, Fructus Chebulae, Radix Ginseng, Radix et Rhizoma Rhei, Rhizoma Atractylodis Macrocephalae, Pterostilbene, and Ginger, as well as the mechanisms of Danggui Sini Decoction, Danggui Niantong Decoction, Duhuo Jisheng Decoction, Yunpi Jiedu Tongluo Qushi Decoction, Qingre Huoxue Decoction, Compound Fengshining, Qingre Yangyin Chushi Decoction, Aconitum Decoction, Zhijing Powder, Jinwu Jiangu Capsule, and Fermented Chinese Medicine Qushi Chubi Decoction in intervening RA by regulating intestinal flora, suggesting that Chinese materia medica can restore intestinal homeostasis, reduce joint inflammation and play a role in the prevention and treatment of RA by regulating immune response, improving intestinal mucosal barrier and regulating intestinal metabolites.

In order to investigate the role of sRNA OxyS in the pathogenicity of Salmonella typhi-murium infection,the OxyS gene deletion strain ATCC25241 △OxyS and the back-complemented strain ATCC25241 △OxyS/OxyS of Salmonella typhimurium ATCC25241 were constructed by using λRed homologous recombination technique.We investigated the effect of OxyS deletion on the biological characteristics and pathogenicity of Salmonella typhimurium ATCC25241.The re-sults showed that the deletion of OxyS did not affect the growth rate,the ability of biofilm forma-tion,and the ability of adhesion,invasion and intracellular survival of Salmonella typhimurium,but significantly reduced the motility of Salmonella typhimurium as well as its ability to survive in alkaline and oxidative environments.The results of mouse infection test showed that OxyS dele-tion caused a significant decrease in the virulence of Salmonella typhimurium in mice,and toxicity is reduced obviously.The qPCR results also showed that OxyS deletion could lead to changes in the transcript levels of a number of virulence-related genes of Salmonella typhimurium such as pipB,orf245,csgA,invH,tatA,sipA,sipB,and so on.The above results indicate that OxyS gene affects the biological characteristics and pathogenicity of Salmonella typhimurium and is an important virulence regulator of Salmonella typhimurium.

In order to establish a serological method for the detection of bovine respiratory syncytial virus,the prokaryotic expression of four proteins of BRSV,G,F,P,and M was carried out,and the most suitable coating antigen was screened to establish an indirect ELISA detection method.The results showed that the four recombinant proteins of BRSV,rG,rF,rP and rM were successfully expressed.The results of checkerboard screening showed that the P/N value of rG protein was the largest,which was determined to be the best coating antigen established by indirect ELISA meth-od.The optimal reaction conditions for indirect ELISA were as follows:the mass concentration of rG protein coating was 1 mg/L,37℃ for 2 h;3％BSA 37℃ block for 1 h;Serum was diluted 1∶50 and incubated at 37℃ for 1h;Secondary antibody 1∶5 000 dilution,37℃ for 30min;The color development conditions of the substrate were 37℃ for 15 min;Thirty negative sera were selected,and the cut-off value was determined to be 0.63 by the established indirect ELISA method.The re-sults of the specificity test showed that the indirect ELISA method established in this test only recognized BRSV-positive serum,and did not react with IBRV,BCoV,and BPIV3-positive serum.The results of repeatability test showed that the method had good repeatability,and the coefficient of variation within and between batches was less than 10％.The results of the sensitivity test showed that the BRSV-positive serum was still positive when diluted to 1∶8 192.The indirect ELISA method established in this experiment was used to detect 100 clinical serum samples at the same time,and the total coincidence rate of the two reached 90.48％,the positive coincidence rate was 93.42％,and the negative coincidence rate was 82.75％.The indirect ELISA established in this test can be used for the detection of bovine respiratory syncytial virus in clinical practice.

In order to establish a serological method for the detection of bovine respiratory syncytial virus,the prokaryotic expression of four proteins of BRSV,G,F,P,and M was carried out,and the most suitable coating antigen was screened to establish an indirect ELISA detection method.The results showed that the four recombinant proteins of BRSV,rG,rF,rP and rM were successfully expressed.The results of checkerboard screening showed that the P/N value of rG protein was the largest,which was determined to be the best coating antigen established by indirect ELISA meth-od.The optimal reaction conditions for indirect ELISA were as follows:the mass concentration of rG protein coating was 1 mg/L,37℃ for 2 h;3％BSA 37℃ block for 1 h;Serum was diluted 1∶50 and incubated at 37℃ for 1h;Secondary antibody 1∶5 000 dilution,37℃ for 30min;The color development conditions of the substrate were 37℃ for 15 min;Thirty negative sera were selected,and the cut-off value was determined to be 0.63 by the established indirect ELISA method.The re-sults of the specificity test showed that the indirect ELISA method established in this test only recognized BRSV-positive serum,and did not react with IBRV,BCoV,and BPIV3-positive serum.The results of repeatability test showed that the method had good repeatability,and the coefficient of variation within and between batches was less than 10％.The results of the sensitivity test showed that the BRSV-positive serum was still positive when diluted to 1∶8 192.The indirect ELISA method established in this experiment was used to detect 100 clinical serum samples at the same time,and the total coincidence rate of the two reached 90.48％,the positive coincidence rate was 93.42％,and the negative coincidence rate was 82.75％.The indirect ELISA established in this test can be used for the detection of bovine respiratory syncytial virus in clinical practice.

In order to establish a serological method for the detection of bovine parainfluenza virus type 3(BPIV3),the prokaryotic expression and purification of BPIV3 HN,NP,F,and P proteins were carried out,and the optimal protein-coated antigen was screened,and an indirect ELISA de-tection method was established.The results showed that the four recombinant proteins of BPIV3,rHN,rNP,rF,and rP were expressed,and the checkerboard titration results showed that rHN pro-tein had the highest P/N value as the coating protein,so it was used for the subsequent method es-tablishment.The optimal reaction conditions for indirect ELISA were found to be:the mass con-centration of the antigen coating was 0.5 mg/L,37 ℃ 1.5 h,5％skim milk,overnight blocking at 4 ℃,serum dilution at 1∶50,incubation at 37 ℃ 1 h,secondary antibody dilution at 1∶10 000 and incubation at 37℃ 0.5 h,substrate reaction conditions were 37℃ for 12 min.The results of speci-ficity experiments showed that the established method could specifically identify BPIV3 antibody-positive serum with a sensitivity of 1∶800,and the coefficient of variation in the detection of intra-and inter-assay repeatability was less than 10％,and the overall coincidence rate of the same batch of samples detected with the SVANOVIR kit was 92.22％.This method was used to detect 192 se-rum samples in Hebei Province,and the positive rate of BPIV3 antibody in serum was 66.15％.The indirect ELISA detection method of BP1V3 antibody constructed in this study is suitable for large-scale clinical serological investigations,and provides valuable data support for the research and de-velopment of BPIV3 antigen and antibody detection kits in China.

In order to establish a serological method for the detection of bovine parainfluenza virus type 3(BPIV3),the prokaryotic expression and purification of BPIV3 HN,NP,F,and P proteins were carried out,and the optimal protein-coated antigen was screened,and an indirect ELISA de-tection method was established.The results showed that the four recombinant proteins of BPIV3,rHN,rNP,rF,and rP were expressed,and the checkerboard titration results showed that rHN pro-tein had the highest P/N value as the coating protein,so it was used for the subsequent method es-tablishment.The optimal reaction conditions for indirect ELISA were found to be:the mass con-centration of the antigen coating was 0.5 mg/L,37 ℃ 1.5 h,5％skim milk,overnight blocking at 4 ℃,serum dilution at 1∶50,incubation at 37 ℃ 1 h,secondary antibody dilution at 1∶10 000 and incubation at 37℃ 0.5 h,substrate reaction conditions were 37℃ for 12 min.The results of speci-ficity experiments showed that the established method could specifically identify BPIV3 antibody-positive serum with a sensitivity of 1∶800,and the coefficient of variation in the detection of intra-and inter-assay repeatability was less than 10％,and the overall coincidence rate of the same batch of samples detected with the SVANOVIR kit was 92.22％.This method was used to detect 192 se-rum samples in Hebei Province,and the positive rate of BPIV3 antibody in serum was 66.15％.The indirect ELISA detection method of BP1V3 antibody constructed in this study is suitable for large-scale clinical serological investigations,and provides valuable data support for the research and de-velopment of BPIV3 antigen and antibody detection kits in China.

In order to investigate the role of sRNA OxyS in the pathogenicity of Salmonella typhi-murium infection,the OxyS gene deletion strain ATCC25241 △OxyS and the back-complemented strain ATCC25241 △OxyS/OxyS of Salmonella typhimurium ATCC25241 were constructed by using λRed homologous recombination technique.We investigated the effect of OxyS deletion on the biological characteristics and pathogenicity of Salmonella typhimurium ATCC25241.The re-sults showed that the deletion of OxyS did not affect the growth rate,the ability of biofilm forma-tion,and the ability of adhesion,invasion and intracellular survival of Salmonella typhimurium,but significantly reduced the motility of Salmonella typhimurium as well as its ability to survive in alkaline and oxidative environments.The results of mouse infection test showed that OxyS dele-tion caused a significant decrease in the virulence of Salmonella typhimurium in mice,and toxicity is reduced obviously.The qPCR results also showed that OxyS deletion could lead to changes in the transcript levels of a number of virulence-related genes of Salmonella typhimurium such as pipB,orf245,csgA,invH,tatA,sipA,sipB,and so on.The above results indicate that OxyS gene affects the biological characteristics and pathogenicity of Salmonella typhimurium and is an important virulence regulator of Salmonella typhimurium.

Objective To investigate the positive time length of nucleic acid detection in 22 confirmed cases of coronavirus disease (COVID-19) in Yangzhou and analyze the influencing factors, and to provide evidence for the prevention and control of the disease. Method A total of 22 confirmed cases were followed up for five weeks. Throat swabs were collected for nucleic acid detection. The relevant data were collected and statistical analysis was conducted on the basis of survival analysis. Results The positive rate of throat swabs was 100%, 100% and 66.67% at 1-2d, 3-4d and 5-7d, respectively, after the onset of COVID-19. The average positive time of all confirmed cases was 16.32 days, including 18.50 days for common type and 13.70 days for light type. The difference was statistically significant (χ²=4.36, P=0.037). Multivariate Cox regression analysis showed that case type (or=0.19, 95%CI:0.06-0.61) and onset visit time (or=0.70,95%CI:0.55-0.88) had an impact on the positive time length of nucleic acid detection. Conclusion The positive rate of respiratory samples is high within one week after the onset of the confirmed cases, and the positive time length of light type cases was shorter than that of common types. The positive time length of nucleic acid detection may be shortened after timely treatment with drugs.

Objectives: To explore and summarize the beneficial effects of a traditional Chinese medicine prepara-tion, Tripterygium glycosides tablets (TGT), in rheumatoid arthritis (RA) animal models of neo-vascularization, and to provide a reference for future clinical applications and research on its pharmacologic mechanism.Methods: We searched the databases PubMed, Embase, Web of Science, Chinese National Knowledge Infrastructure, VIP, Wan Fang and SinoMed (China Biomedical Document Service System) to identify studies of TGT with outcome indicators of angiogenesis-related factors that were published before April 2020. Subgroup analysis and meta-regression were performed for dosage and duration of TGT. Statistical tests and subgroup analysis were conducted using RevMan 5.3, and meta-regression and sensitivity analysis were conducted using STATA/SE 15.0. Results: Fourteen studies of TGT in RA rats were included in this analysis. Treatment with TGT signifi-cantly reduces synovial microvessel density and the expression of vascular endothelial growth factor (VEGF), VEGF receptor 2, hypoxia inducible factor α, c-Fos, c-Jun, angiopoietin-1 and angiopoietin-2 compared with control groups (P < .05). Subgroup analysis did not show a significant association of the mRNA levels of VEGF in synovium, assessed using quantitative real-time PCR, with duration or dosage of TGT. Meta-regression analysis also indicated that the effects of dosage and duration were not significantly associated with differences in VEGF mRNA levels. Sensitivity analysis on VEGF mRNA levels did not fundamentally change the results. Conclusions: TGT can reduce synovial neovascularization by decreasing synovial microvessel density and expression of VEGF, VEGF receptor 2, hypoxia-inducible factorα, c-Fos, c-Jun, Ang-1 and Ang-2, thereby suppressing pannus formation and bone destruction in rat models of RA. Additional well-designed studies are required to confirm these findings.

Objective To investigate the relationship between subclinical hypothyroidism (SCH) and diabetic retinopathy (DR) in patients with type 2 diabetes mellitus (T2DM).Methods A total of 792 patients of T2DM were enrolled in the study.There were 448 males and 344 females,with an average age of (54.13 ± 13.06)years.The average duration of diabetes was (8.03 4±6.70) years.The patients were grouped according to the degree of DR and thyroid function.Among them,483 patients (61.0％) were no DR,240 patients (30.3％) were mild DR,69 patients (8.7％) were severe DR.725 patients (91.5％) were normal thyroid function,67 patients (8.5％) were SCH.The prevalence of SCH among no DR group,mild DR group and severe DR group was compared.And the prevalence of DR between normal thyroid function group and SCH group was compared.Logistic regression analysis was used to estimate the association between SCH and DR.Results No significant differences among the three groups (no DR group,mild DR group,severe DR group) were found in the prevalence of SCH (x2=1.823,P=0.402).There were no significant differences in the incidences of DR between normal thyroid function group and SCH group (x2=1.618,P=0.239).Logistic regression analysis demonstrated that SCH was not significant associated with DR [mild DR:odds ratio (OR)=1.361,95％ confidence interval (CI)=0.773-2.399,P=0.286;severe DR:OR=1.326,95％CI=0.520-3.384,P=0.555;DR:OR=1.353,95％ CI=0.798-2.294,P=0.261).Conclusion SCH is not significant associated with DR in patients with T2DM.