This study was aimed at investigating the effectiveness of various host nucleic acid removal and non-specific amplifica-tion techniques in animal tissue samples,to increase the accuracy of pathogen identification in tissue samples.Simulated samples were prepared with a mixture of mouse lung tissue homogenates and Klebsiella pneumoniae fluids,and processed with six host nucleic acid removal kits and three non-specific amplification techniques.The effectiveness of each method in removing host DNA and enriching nucleic acids of pathogenic microorganisms was evaluated through real-time fluorescence quantitative PCR and high-throughput se-quencing.For host nucleic acid removal techniques,the method of selective cleavage and quantitative degradation of host DNA(Com-plete5 kit)effectively decreased the host nucleic acid content in tissue samples and increased the relative abundance of pathogen nucleic acids.In contrast,the magnetic bead method for host DNA removal(Next microbiome DNA enrichment Kit kit)was less effec-tive.At lower pathogen concentrations(77 CFU/mL),the Vazyme kit was more effective than the other kits in removing host nucleic acids.Non-specific amplification techniques(MALBAC whole genome amplification,MDA isothermal amplification,and random primer amplification)were not applicable to tissue samples and were not effective in increasing the relative abundance of pathogen nucleic acids.Selective lysis and quantitative degradation of host DNA were suitable for processing tissue samples with high host back-ground and low pathogenic microorganism levels,whereas non-specific amplification methods were not applicable to tissue samples for pre-processing of macro-genome high-throughput sequencing.

Objective To detect the expression of lactate dehydrogenase A(LDHA),FoxP3,and CD4 in hepatocellular carcinoma(HCC)and to analyze the effect of bufalin on LDHA as well as on the differentiation and function of regulatory T(Treg)cells in the tumor microenvironment of HCC mice.Methods Immunohistochemical staining was performed to detect the difference in the expression of LDHA,FoxP3(Treg cell marker),and CD4 between the tumor and adjacent tissues from 91 HCC patients.Hepl-6 subcutaneous tumor-bearing mouse model was established.The mice were randomly divided into control,bufalin+pyruvic acid,oxalate,and bufalin groups(n=5 each group).The mass and volume of subcutaneous tumors were compared.Immunohistochemical staining was performed to detect the expression of LDHA,FoxP3,and CD4 in tumors of mice in each group.ELISA was used to detect the levels of transforming growth factor β(TGF-β)and interleukin-10(IL-10)in the serum of mice in each group to evaluate the immune function of Treg cells.Results Compared with adjacent tissues,HCC tissues exhibited significantly higher LDHA and FoxP3 expression and lower CD4 expression(P＜0.001).The results of the correlation analysis showed that LDHA was positively correlated with FoxP3 expression and negatively correlated with CD4 expression(P＜0.05).The experimental results of Hep1-6 subcutaneous tumor-bearing mice showed that the tumor volume was significantly smaller in the bufalin and oxalate groups than in the control group and was significantly larger in the bufalin+pyruvic acid group than in the bufalin group(P＜0.001).The results of immunohistochemical staining showed that the expression levels of LDHA and the percentage of FoxP3+cells in the bufalin and oxalate groups were significantly lower than those in the control group,and the percentage of CD4+cells in the bufalin group was significantly higher than that in the control group(P＜0.001).The expres-sion level of LDHA and the percentage of FoxP3+cells in the bufalin+pyruvic acid group were significantly higher than those in the bufalin group,while the percentage of CD4+cells was significantly lower than that in the bufalin group(P＜0.001).The results of ELISA showed that the levels of TGF-β and IL-10 in the bufalin and oxalate groups were significantly lower than those in the control group(P＜0.001).Conclusion Bufalin inhibits cell growth,downregulates LDHA expression,and suppresses the differentiation and proliferation of Treg cells in HCC mice.

Objective To detect the expression of lactate dehydrogenase A(LDHA),FoxP3,and CD4 in hepatocellular carcinoma(HCC)and to analyze the effect of bufalin on LDHA as well as on the differentiation and function of regulatory T(Treg)cells in the tumor microenvironment of HCC mice.Methods Immunohistochemical staining was performed to detect the difference in the expression of LDHA,FoxP3(Treg cell marker),and CD4 between the tumor and adjacent tissues from 91 HCC patients.Hepl-6 subcutaneous tumor-bearing mouse model was established.The mice were randomly divided into control,bufalin+pyruvic acid,oxalate,and bufalin groups(n=5 each group).The mass and volume of subcutaneous tumors were compared.Immunohistochemical staining was performed to detect the expression of LDHA,FoxP3,and CD4 in tumors of mice in each group.ELISA was used to detect the levels of transforming growth factor β(TGF-β)and interleukin-10(IL-10)in the serum of mice in each group to evaluate the immune function of Treg cells.Results Compared with adjacent tissues,HCC tissues exhibited significantly higher LDHA and FoxP3 expression and lower CD4 expression(P＜0.001).The results of the correlation analysis showed that LDHA was positively correlated with FoxP3 expression and negatively correlated with CD4 expression(P＜0.05).The experimental results of Hep1-6 subcutaneous tumor-bearing mice showed that the tumor volume was significantly smaller in the bufalin and oxalate groups than in the control group and was significantly larger in the bufalin+pyruvic acid group than in the bufalin group(P＜0.001).The results of immunohistochemical staining showed that the expression levels of LDHA and the percentage of FoxP3+cells in the bufalin and oxalate groups were significantly lower than those in the control group,and the percentage of CD4+cells in the bufalin group was significantly higher than that in the control group(P＜0.001).The expres-sion level of LDHA and the percentage of FoxP3+cells in the bufalin+pyruvic acid group were significantly higher than those in the bufalin group,while the percentage of CD4+cells was significantly lower than that in the bufalin group(P＜0.001).The results of ELISA showed that the levels of TGF-β and IL-10 in the bufalin and oxalate groups were significantly lower than those in the control group(P＜0.001).Conclusion Bufalin inhibits cell growth,downregulates LDHA expression,and suppresses the differentiation and proliferation of Treg cells in HCC mice.

Objective:To investigate the relationship between thoracic aortic calcification (TAC) and autonomic nervous system (ANS) function in patients receiving continuous ambulatory peritoneal dialysis (CAPD).Methods:It was a cross-sectional study. The CAPD patients with dialysis duration >6 months between January and December 2022 were retrospectively enrolled. The baseline clinical data, heart rate variability (HRV) data such as standard deviation of all normal to normal intervals (SDNN), root mean square of successive differences between adjacent normal-to-normal intervals (RMSSD), high frequency (HF), very low frequency (VLF), low frequency (LF), LF/HF, acceleration capacity (AC) and deceleration capacity (DC), and skin sympathetic nerve activity (SKNA) were collected. TAC was defined as TAC score (TACS) >100 AU. The patients were divided into TACS >100 AU group and TACS≤100 AU group based on whether the thoracic aorta was calcified. The differences of those data between the two groups were compared. Logistic regression model was used to analyze the related factors of TAC. Spearman correlation analysis method was used to analyze the correlation between peripheral blood neuropeptide Y, ANS parameters, average amplitude SKNA (aSKNA) and TACS.　Cox regression model was used to analyze the risk factors of all-cause mortality in patients with CAPD.Results:The study included 106 CAPD patients with 50 males (47.2%), age of (46.04±11.10) years and dialysis duration of (41.55±30.52) months. TACS>100 AU group exhibited significantly lower heart rate ( t=2.015, P=0.046), DC ( t=2.131, P=0.035), LF/HF ( Z=3.332, P<0.001) and ln(LF/HF) ( t=3.326, P=0.001), and higher AC ( t=-2.392, P=0.019) than TACS≤100 AU group. Multivariate logistic regression analysis results showed that after adjusting for age and eosinophil count, lnVLF ( OR=0.66, 95% CI 0.45-0.98, P=0.038), lnLF ( OR=0.69, 95% CI 0.49-0.97, P=0.032), DC ( OR=0.79, 95% CI 0.64-0.99, P=0.039) and AC ( OR=1.32, 95% CI 1.04-1.68, P=0.021) were independently correlated with the risk of TAC. Spearman correlation analysis showed that neuropeptide Y level in peripheral blood was correlated with aSKNA ( r=0.23, P=0.017), lnSDNN ( r=-0.20, P=0.036) and TACS ( r=0.19, P=0.048). During the follow-up period of (25.8±4.2) months, 5 patients (4.72%) died, including 1 patient in the TACS≤100 AU group and 4 patients in the TACS>100 AU group. Compared with the survival group, the death group had higher TACS ( Z=-2.262, P=0.024) and lower LF/HF ( Z=-2.750, P=0.006). Cox regression analysis results showed that increased ln(LF/HF) was an independent influencing factor for all-cause mortality in CAPD patients ( HR=0.22, 95% CI 0.05-0.83, P=0.026). Conclusions:HRV parameters (lnVLF, lnLF, AC and DC) of CAPD patients are independently associated with TAC. The dysfunction of ANS in CAPD patients (especially the decreased vagus nerve activity) may promote TAC.

This study was aimed at investigating the effectiveness of various host nucleic acid removal and non-specific amplifica-tion techniques in animal tissue samples,to increase the accuracy of pathogen identification in tissue samples.Simulated samples were prepared with a mixture of mouse lung tissue homogenates and Klebsiella pneumoniae fluids,and processed with six host nucleic acid removal kits and three non-specific amplification techniques.The effectiveness of each method in removing host DNA and enriching nucleic acids of pathogenic microorganisms was evaluated through real-time fluorescence quantitative PCR and high-throughput se-quencing.For host nucleic acid removal techniques,the method of selective cleavage and quantitative degradation of host DNA(Com-plete5 kit)effectively decreased the host nucleic acid content in tissue samples and increased the relative abundance of pathogen nucleic acids.In contrast,the magnetic bead method for host DNA removal(Next microbiome DNA enrichment Kit kit)was less effec-tive.At lower pathogen concentrations(77 CFU/mL),the Vazyme kit was more effective than the other kits in removing host nucleic acids.Non-specific amplification techniques(MALBAC whole genome amplification,MDA isothermal amplification,and random primer amplification)were not applicable to tissue samples and were not effective in increasing the relative abundance of pathogen nucleic acids.Selective lysis and quantitative degradation of host DNA were suitable for processing tissue samples with high host back-ground and low pathogenic microorganism levels,whereas non-specific amplification methods were not applicable to tissue samples for pre-processing of macro-genome high-throughput sequencing.

Objective:To investigate the relationship between thoracic aortic calcification (TAC) and autonomic nervous system (ANS) function in patients receiving continuous ambulatory peritoneal dialysis (CAPD).Methods:It was a cross-sectional study. The CAPD patients with dialysis duration >6 months between January and December 2022 were retrospectively enrolled. The baseline clinical data, heart rate variability (HRV) data such as standard deviation of all normal to normal intervals (SDNN), root mean square of successive differences between adjacent normal-to-normal intervals (RMSSD), high frequency (HF), very low frequency (VLF), low frequency (LF), LF/HF, acceleration capacity (AC) and deceleration capacity (DC), and skin sympathetic nerve activity (SKNA) were collected. TAC was defined as TAC score (TACS) >100 AU. The patients were divided into TACS >100 AU group and TACS≤100 AU group based on whether the thoracic aorta was calcified. The differences of those data between the two groups were compared. Logistic regression model was used to analyze the related factors of TAC. Spearman correlation analysis method was used to analyze the correlation between peripheral blood neuropeptide Y, ANS parameters, average amplitude SKNA (aSKNA) and TACS.　Cox regression model was used to analyze the risk factors of all-cause mortality in patients with CAPD.Results:The study included 106 CAPD patients with 50 males (47.2%), age of (46.04±11.10) years and dialysis duration of (41.55±30.52) months. TACS>100 AU group exhibited significantly lower heart rate ( t=2.015, P=0.046), DC ( t=2.131, P=0.035), LF/HF ( Z=3.332, P<0.001) and ln(LF/HF) ( t=3.326, P=0.001), and higher AC ( t=-2.392, P=0.019) than TACS≤100 AU group. Multivariate logistic regression analysis results showed that after adjusting for age and eosinophil count, lnVLF ( OR=0.66, 95% CI 0.45-0.98, P=0.038), lnLF ( OR=0.69, 95% CI 0.49-0.97, P=0.032), DC ( OR=0.79, 95% CI 0.64-0.99, P=0.039) and AC ( OR=1.32, 95% CI 1.04-1.68, P=0.021) were independently correlated with the risk of TAC. Spearman correlation analysis showed that neuropeptide Y level in peripheral blood was correlated with aSKNA ( r=0.23, P=0.017), lnSDNN ( r=-0.20, P=0.036) and TACS ( r=0.19, P=0.048). During the follow-up period of (25.8±4.2) months, 5 patients (4.72%) died, including 1 patient in the TACS≤100 AU group and 4 patients in the TACS>100 AU group. Compared with the survival group, the death group had higher TACS ( Z=-2.262, P=0.024) and lower LF/HF ( Z=-2.750, P=0.006). Cox regression analysis results showed that increased ln(LF/HF) was an independent influencing factor for all-cause mortality in CAPD patients ( HR=0.22, 95% CI 0.05-0.83, P=0.026). Conclusions:HRV parameters (lnVLF, lnLF, AC and DC) of CAPD patients are independently associated with TAC. The dysfunction of ANS in CAPD patients (especially the decreased vagus nerve activity) may promote TAC.

Objective This study aimed to investigate the effects of P.odoratum extract on lactase activity and microflora diversity in mice with bacterial dysbacteriosis.Methods SPF male BALB/c mice were randomized into 4 groups:control,model,P.odoratum extract low dose(1.56 g·kg-1·d-1)and high dose(3.12 g·kg-1·d-1)treatment group.There were 8 mice in each group(5 in the blank group).In addition to the control group,after 7 days of intragastric administration of mixed antibiotics,the administration groups were given P.odoratum extract for 7 days,and the control group and the model group were given the same amount of sterile water.The changes of diarrhea,body weight and food intake of mice were recorded.The colon HE staining sections,ZO-1 protein,IL-6 expression,and serum LPS concentration were detected.Feces were collected for lactase activity and microbial diversity determination with 16S rRNA high-throughput sequencing technology.Results After 7 days of antibiotic intervention,compared with the control group,the mice in the model group had soft stool,weight loss,reduced food intake,and significantly reduced intestinal flora diversity.At the 14th day,in the model group,ulceration accompanied by slight interstitial congestion and edema was seen in the colon,ZO-1 expression was significantly reduced,IL-6 expression was significantly increased,serum LPS was significantly increased,lactase activity was significantly reduced,and intestinal flora diversity was still lower compared with the control group.After 7 days of administration,compared with the model group,P.odoratum reduced the diarrhea rate of mice,promoted a recovery of body weight and food intake,downregulated pathological colon tissue damage,significantly increased ZO-1 protein expression,and reduced colon factor IL-6 and serum LPS concentration.In addition,P.odoratum can significantly up-regulate lactase activity and improve the community richness and diversity of dysbacteriosis mice.It is shown that three phyla(up-regulated Firmicutes,down-regulated Proteobacteria and Bacteroidetes)and seven genera(up-regulated Rikenellaceae_RC9_gut_group,Rikenella,Colidextribacter,norank_f__Lachnospiraceae,norank_f__Oscillospiraceae,and Lachnospiraceae_NK4A136_group,down-regulated Alloprevotella),the abundance of which was significantly correlated with body weight and lactase activity,serum LPS,and colon factor IL-6.Conclusion P.odoratum can alleviate the gut barrier injury and dysfunction caused by antibiotic induced dysbiosis,and its mechanism may be achieved by regulating microflora structure.

Objective:To investigate the changes in adaptive phenotypes of Yersinia pestis ( Yp) during successive passages in macrophages. Methods:A Yp strain of 201-MI was induced by 50 successive passages of Yp 201 strain in Raw264.7 cells. Phenotypic characteristics of 201 and 201-MI strains were compared by analyzing their survival rates in macrophages, growth curves, biofilm formation abilities, acid and hydrogen peroxide-stress tolerance, and virulence to mammal cells (Raw264.7 and HeLa cells) and mice. Results:Comparing with 201 strain, 201-MI strain showed various phenotypic changes, including higher survival rate in Raw264.7 cells, faster growth in iron-deficient medium, higher tolerance to acid and hydrogen peroxide, decreased biofilm formation ability, and less damages to Raw264.7 and HeLa cells. More-over, 201-MI strain showed decreased virulence to mice in both subcutaneous and intraperitoneal challenges. Preliminary comparative genomics analysis revealed some indel and nonsense mutations in 201-MI strain, which might account for its phenotype changes.Conclusions:After successive passages in macrophages, Yp showed some phenotypic changes, which might reflect its adaptive evolution under the pressure of macrophages. Detailed multi-omics analysis would be of great help to understand the underlying genetic mechanisms of these changes, and the related Yp-macrophage interaction processes as well.