OBJECTIVE T o understand the resistance capability of berberine combined with levofloxacin in vitro to methicillin-resistant Staphylococcus aureus(MRSA).METHODS Totally 100 strains of MRSA were isolated from Shanghai Eighth People's Hospital from Jul.2023 to Jun.2024,the minimum inhibitory concentrations(MICs)of berberine and levofloxacin against the strains were determined by microbroth dilution method.The anti-bacterial effect of the combined use of the two drugs on MRSA was observed.The effects of the single and com-bined use of berberine and levofloxacin on sterilization of MRSA standard strain USA 300-LAC and their influence on cellular morphology were observed.The influence of berberine on mRNA levels of drug resistance genes and ef-flux pump-related genes in the standard strain USA 300-LAC and clinical strains was determined by means of real-time fluorescent quantitative PCR.RESULTS Among the 100 clinical isolates of MRSA,most of them were isola-ted from respiratory tract specimens of respiratory medicine department and geriatrics department,and 75.00％of the strains were resistant to levofloxacin.The MICs of both berberine and levofloxacin against the standard strain USA300-LAC were 128 μg/ml;the MICs against the clinical MRSA isolates were 64 to 1024 μg/ml and 0.125 to 256 μg/ml,respectively.Berberine combined with levofloxacin showed additive effect on 17(44.74％)strains of MRSA.The combined use of the two drugs showed the most remarkable in vitro antibacterial effect.The cellular structures of the strains were unclear and the contents of bacterial bodies increased when berberine and levofloxacin were used in combination.Berberine showed various degree of inhibitory effect on gyrA,gyrB,grlA and nor A genes.CONCLUSIONS Berberine is capable of resisting the MRSA and shows synergistic or additive effect with levofloxacin.The combined use of the two drugs may reduce the MIC against levofloxacin,destroy the morpholog-ical structure,and inhibit the expression of gyrA,gyrB,grlA and nor A genes.

OBJECTIVE To explore the effect and potential mechanisms of berberine on formation of biofilms of clinical methicillin-resistant Staphylococcus aureus(MRSA)isolates.METHODS Totally 95 clinical MRSA iso-lates were collected from Shanghai Eighth People's Hospital from Jan.2023 to Dec.2023.The 14 biofilm forma-tion-related genes in the strains were detected by polymerase chain reaction(PCR)and multiplex PCR,the mini-mum inhibitory concentration(MIC)of berberine was determined by microbroth dilution method,the effect of berberine on resistance of biofilm formation was evaluated by crustal violet staining,fluorescence microscope,Congo red agar plate and extracelluar DNA(eDNA).The transcription levels of 9 biofilm formation-related genes were detected by real-time fluorescent quantitative reverse transcription PCR.RESULTS All of the 95 strains of MRSA carried eno,clfA,clfB and icaA genes,the most widespread gene profile was bbp-eno-ebpS-fnbA-fib-clfA-clfB-icaA-sasG,and 29 strains had the phenotypes with strong capability of biofilm formation.The MIC score of berberine ranged between 64 and 1 024 μg/ml.Berberine with the concentration of 1/2 MIC could inhibit the biofilm formation of MRSA(P＜0.001),and the inhibiting rate of biofilm formation of the MIC ≥512 μg/ml group was higher than that of the MIC≤128 μg/ml group and the MIC 256 μg/ml group(all P＜0.05).The re-sult under the fluorescence microscope showed that the fluorescence intensity of biofilms decreased with the rise of berberine concentration.Berberine could reduce the formation of amyloid fibrils and the release of eDNA,down-regulating the transcription levels of ica A,sasG,ebpS,fib,eno,clfA,clfB,bbp and fnbA genes(P＜0.05).CONCLUSION Berberine may inhibit the biofilm formation of MRSA by downregulating expression levels of related genes,interfering the formation of amyloid fibrils and blocking the release of eDNA,which may provide experimental bases for development of drugs resisting to MRSA biofilms.

Objective This study aimed to investigate the antimicrobial resistance profiles of bacterial strains isolated from pediatric intensive care units(PICU)in China for better antimicrobial therapy.Methods Clinical isolates were collected from 17 institutions,including tertiary care children's hospitals and pediatric department of tertiary general hospitals in China from January 1,2020 to December 31,2022.Antimicrobial susceptibility testing was carried out according to a unified protocol using Kirby-Bauer method or automated systems.Results were interpreted according to the breakpoints released by the Clinical and Laboratory Standards Institute(CLSI)in 2020.Results A total of 10 688 isolates were collected,including gram-positive organisms(39.2％)and gram-negative organisms(60.8％).The top three organisms were S.aureus(13.6％,1 453/10 688),A.baumannii(10.0％,1 067/10 688),and coagulase-negative Staphylococcus(9.9％,1 058/10 688).Multi-drug resistant organisms(MDROs)were very common in children.The prevalence of methicillin-resistant Staphylococcus aureus(MRSA),carbapenem-resistant Enterobacterales(CRE),carbapenem-resistant E.coli,carbapenem-resistant K.pneumoniae(CRKP),carbapenem-resistant A.baumannii(CRAB),and carbapenem-resistant P.aeruginosa(CRPA)was 41.1％,19.4％,8.8％,30.9％,67.4％,and 28.8％,respectively.Overall,more than 50％of Enterobacteriales isolates were resistant to cephalosporins,while nearly 25％of Enterobacteriales isolates were resistant to carbapenems.MDROs were highly resistant to commonly used antibiotics.More than 80％of CRE and CRAB strains were resistant to all beta-lactam antibiotics.CRE and CRAB showed low resistance rates to tigecycline and polymyxin.CRPA showed lower resistance rates to piperacillin,beta-lactamase inhibitor combinations than the resistance rates to third and fourth generation cephalosporins.All of the Staphylococcus and Enterococcus isolates were susceptible to vancomycin and tigecycline.None of PRSP strains isolated from meningitis and nonmeningitis samples were resistant to rifampicin,vancomycin,or linezolid.The prevalence of β-lactamase-negative ampicillin-resistant(BLNAR)strains was 43.3％in Haemophilus influenzae.Conclusions MDROs were prevalent in PICU.It is necessary to establish an effective multidisciplinary team(MDT)to control the antimicrobial resistance.

To investigate the expression level of costimulatory molecule B7-H3 in the tumor tissues and the level of soluble costimulatory molecule B7-H3 (sB7-H3) in the serum of patients with colorectal cancer (CRC), so as to evaluate the clinical value of sB7-H3 in auxiliary diagnosis of CRC. A cross-sectional study design was adopted. A total of 232 CRC patients, 87 patients with benign colorectal diseases, and 59 healthy subjects who were treated in Shanghai Eighth People′s Hospital from January 2020 to December 2022 were selected. The levels of sB7-H3, CEA, CA199, CA724 and CA50 in the serum were detected. The receiver operating characteristic (ROC) curve was used to analyze the diagnostic value of sB7-H3 and the above-mentioned tumor markers for colorectal cancer (CRC). The expression levels of B7-H3 in CRC tissues and benign colorectal disease tissues were detected by immunohistochemistry. The relationship between the levels of sB7-H3 and clinicopathological features was analyzed statistically. The results showed that compared with the benign disease group or the healthy control respectively, the serum levels of sB7-H3, CEA, CA199, CA724 and CA50 in the CRC group were significantly increased, and the differences were statistically significant ( P<0.05). In the CRC group, the serum levels of sB7-H3 showed a weak positive correlation with CA50, CEA and CA724 (the r values were 0.220, 0.217 and 0.182 respectively; the P values were 0.005,<0.001 and 0.024 respectively), and there was no significant correlation with CA199 (the r value was 0.162; the P value were 0.051). The areas under the curve (AUC) of sB7-H3, CEA, CA199, CA724 and CA50 for diagnosing CRC were 0.862, 0.774, 0.646, 0.677 and 0.644 respectively, and the cut-off values were 20.67 ng/ml, 10.74 U/ml, 3.17 ng/ml, 3.16 U/ml, and 22.55 U/ml, respectively. Taking 20.67 ng/ml as the cut-off value, the positive rate of sB7-H3 in CRC was 62.9%, which was significantly higher than that in patients with benign colorectal diseases (35.6%) and the healthy control group (10%) ( χ2=81.995, P<0.001; χ2=103.56, P<0.001). The positive rates of sB7-H3 and CEA in patients with pathological stages Ⅲ and Ⅳ were significantly higher than those in patients with stages Ⅰ and Ⅱ ( χ2=82.876, P<0.001; χ2=22.617, P<0.001). The positive rate of sB7-H3 in patients with pathological stages Ⅰ and Ⅱ was 56.2%, which was significantly higher than that of CEA (38%) ( χ2=50.378, P<0.001). Immunohistochemistry showed that B7-H3 positive staining was mainly distributed in the cytoplasm. The positive expression rate of B7-H3 in CRC (75.8%) was significantly higher than that in benign colorectal diseases (15.4%) ( χ2=16.133, P<0.001). The serum level of sB7-H3 in CRC patients was positively correlated with the expression level of B7-H3 in tumor tissues ( r=0.766, P<0.001). The serum level of sB7-H3 was significantly correlated with distant metastasis and pathological stage of CRC ( W=899, P=0.002; H=10.465, P=0.015). In conclusion, serum level of sB7-H3 may have certain clinical value in the auxiliary diagnosis of CRC.

OBJECTIVE: To review the research progress on the lower limb biomechanical characteristics of patients with discoid lateral meniscus (DLM) injury after surgery. METHODS: By searching relevant domestic and international research literature on DLM, the postoperative characteristics of knee joint movement biomechanics, tibiofemoral joint stress distribution, lower extremity force line, and patellofemoral joint changes in patients with DLM injury were summarized. RESULTS: Surgical treatment can lead to varying degrees of changes in the lower limb biomechanical characteristics of patients with DLM injury. Specifically, the kinematic biomechanics of the knee joint can significantly improve, but there are still problems such as extension deficits in the affected knee joint. The peak stress of the tibiofemoral joint decreases with the increase of the residual meniscus volume, and the degree of change is closely related to the residual meniscus volume. Preserving a larger volume of the meniscus, especially the anterior horn volume, helps to reduce stress concentration. The lower extremity force line will deviate outward after surgery, and the more meniscus is removed during surgery, the greater the change in the lower extremity force line after surgery. There are conditions such as cartilage degeneration, position and angle changes in the patellofemoral joint after surgery. CONCLUSION The changes in the lower limb biomechanical characteristics after DLM injury are closely related to the choice of surgical methods and rehabilitation programs. However, the mechanisms of biomechanical changes in multiple lower limb joints and individual differences still need to be further studied and clarified.
Humans ; Biomechanical Phenomena ; Tibial Meniscus Injuries/physiopathology* ; Menisci, Tibial/physiopathology* ; Knee Joint/surgery* ; Lower Extremity/physiopathology* ; Patellofemoral Joint/physiopathology* ; Range of Motion, Articular ; Knee Injuries/physiopathology*

Objective To obtain the recombinant Argonaute protein(TtAgo)from Thermus thermophilus using gene cloning and pro-tein purification techniques and detect its endonuclease activity against the KRAS 12D mutation in vitro,thereby to provide experimental evidence for its subsequent application in the detection of gene mutations.Methods The TtAgo gene sequence was amplified from the genome of Thermus thermophilus by the PCR technology.Then,the amplified sequence was inserted into the prokaryotic expression vec-tor pET-28a to construct the recombinant vector pET-28a-TtAgo.After the recombinant TtAgo protein was induced to be expressed,it was purified sequentially by the nickel ion affinity chromatography(Ni-NTA),heparin affinity chromatography,and size-exclusion chromatography.The high-specificity nuclease activity of the recombinant TtAgo protein mediated by a short DNA guide strand(gDNA)was verified in vitro.Results The prokaryotic expression vector pET-28a-TtAgo was successfully constructed by the gene cloning tech-nique,and the soluble expression of the recombinant TtAgo protein was achieved.With the help of protein purification technology,the high-purity recombinant TtAgo protein was obtained.Under the mediation of gDNA,the recombinant TtAgo protein could specifically cleave wild-type single-stranded DNA(ssDNA),double-stranded DNA(dsDNA),and RNA molecules,while had no cleavage activi-ty for tumor KRAS 12D mutant molecules.Conclusion The high-purity recombinant TtAgo protein with nuclease activity is successful-ly obtained,and its targeted cleavage activity towards the KRAS 12D mutation site is detected in vitro.

Objective To obtain the recombinant Argonaute protein(TtAgo)from Thermus thermophilus using gene cloning and pro-tein purification techniques and detect its endonuclease activity against the KRAS 12D mutation in vitro,thereby to provide experimental evidence for its subsequent application in the detection of gene mutations.Methods The TtAgo gene sequence was amplified from the genome of Thermus thermophilus by the PCR technology.Then,the amplified sequence was inserted into the prokaryotic expression vec-tor pET-28a to construct the recombinant vector pET-28a-TtAgo.After the recombinant TtAgo protein was induced to be expressed,it was purified sequentially by the nickel ion affinity chromatography(Ni-NTA),heparin affinity chromatography,and size-exclusion chromatography.The high-specificity nuclease activity of the recombinant TtAgo protein mediated by a short DNA guide strand(gDNA)was verified in vitro.Results The prokaryotic expression vector pET-28a-TtAgo was successfully constructed by the gene cloning tech-nique,and the soluble expression of the recombinant TtAgo protein was achieved.With the help of protein purification technology,the high-purity recombinant TtAgo protein was obtained.Under the mediation of gDNA,the recombinant TtAgo protein could specifically cleave wild-type single-stranded DNA(ssDNA),double-stranded DNA(dsDNA),and RNA molecules,while had no cleavage activi-ty for tumor KRAS 12D mutant molecules.Conclusion The high-purity recombinant TtAgo protein with nuclease activity is successful-ly obtained,and its targeted cleavage activity towards the KRAS 12D mutation site is detected in vitro.

To investigate the expression level of costimulatory molecule B7-H3 in the tumor tissues and the level of soluble costimulatory molecule B7-H3 (sB7-H3) in the serum of patients with colorectal cancer (CRC), so as to evaluate the clinical value of sB7-H3 in auxiliary diagnosis of CRC. A cross-sectional study design was adopted. A total of 232 CRC patients, 87 patients with benign colorectal diseases, and 59 healthy subjects who were treated in Shanghai Eighth People′s Hospital from January 2020 to December 2022 were selected. The levels of sB7-H3, CEA, CA199, CA724 and CA50 in the serum were detected. The receiver operating characteristic (ROC) curve was used to analyze the diagnostic value of sB7-H3 and the above-mentioned tumor markers for colorectal cancer (CRC). The expression levels of B7-H3 in CRC tissues and benign colorectal disease tissues were detected by immunohistochemistry. The relationship between the levels of sB7-H3 and clinicopathological features was analyzed statistically. The results showed that compared with the benign disease group or the healthy control respectively, the serum levels of sB7-H3, CEA, CA199, CA724 and CA50 in the CRC group were significantly increased, and the differences were statistically significant ( P<0.05). In the CRC group, the serum levels of sB7-H3 showed a weak positive correlation with CA50, CEA and CA724 (the r values were 0.220, 0.217 and 0.182 respectively; the P values were 0.005,<0.001 and 0.024 respectively), and there was no significant correlation with CA199 (the r value was 0.162; the P value were 0.051). The areas under the curve (AUC) of sB7-H3, CEA, CA199, CA724 and CA50 for diagnosing CRC were 0.862, 0.774, 0.646, 0.677 and 0.644 respectively, and the cut-off values were 20.67 ng/ml, 10.74 U/ml, 3.17 ng/ml, 3.16 U/ml, and 22.55 U/ml, respectively. Taking 20.67 ng/ml as the cut-off value, the positive rate of sB7-H3 in CRC was 62.9%, which was significantly higher than that in patients with benign colorectal diseases (35.6%) and the healthy control group (10%) ( χ2=81.995, P<0.001; χ2=103.56, P<0.001). The positive rates of sB7-H3 and CEA in patients with pathological stages Ⅲ and Ⅳ were significantly higher than those in patients with stages Ⅰ and Ⅱ ( χ2=82.876, P<0.001; χ2=22.617, P<0.001). The positive rate of sB7-H3 in patients with pathological stages Ⅰ and Ⅱ was 56.2%, which was significantly higher than that of CEA (38%) ( χ2=50.378, P<0.001). Immunohistochemistry showed that B7-H3 positive staining was mainly distributed in the cytoplasm. The positive expression rate of B7-H3 in CRC (75.8%) was significantly higher than that in benign colorectal diseases (15.4%) ( χ2=16.133, P<0.001). The serum level of sB7-H3 in CRC patients was positively correlated with the expression level of B7-H3 in tumor tissues ( r=0.766, P<0.001). The serum level of sB7-H3 was significantly correlated with distant metastasis and pathological stage of CRC ( W=899, P=0.002; H=10.465, P=0.015). In conclusion, serum level of sB7-H3 may have certain clinical value in the auxiliary diagnosis of CRC.

OBJECTIVE T o understand the resistance capability of berberine combined with levofloxacin in vitro to methicillin-resistant Staphylococcus aureus(MRSA).METHODS Totally 100 strains of MRSA were isolated from Shanghai Eighth People's Hospital from Jul.2023 to Jun.2024,the minimum inhibitory concentrations(MICs)of berberine and levofloxacin against the strains were determined by microbroth dilution method.The anti-bacterial effect of the combined use of the two drugs on MRSA was observed.The effects of the single and com-bined use of berberine and levofloxacin on sterilization of MRSA standard strain USA 300-LAC and their influence on cellular morphology were observed.The influence of berberine on mRNA levels of drug resistance genes and ef-flux pump-related genes in the standard strain USA 300-LAC and clinical strains was determined by means of real-time fluorescent quantitative PCR.RESULTS Among the 100 clinical isolates of MRSA,most of them were isola-ted from respiratory tract specimens of respiratory medicine department and geriatrics department,and 75.00％of the strains were resistant to levofloxacin.The MICs of both berberine and levofloxacin against the standard strain USA300-LAC were 128 μg/ml;the MICs against the clinical MRSA isolates were 64 to 1024 μg/ml and 0.125 to 256 μg/ml,respectively.Berberine combined with levofloxacin showed additive effect on 17(44.74％)strains of MRSA.The combined use of the two drugs showed the most remarkable in vitro antibacterial effect.The cellular structures of the strains were unclear and the contents of bacterial bodies increased when berberine and levofloxacin were used in combination.Berberine showed various degree of inhibitory effect on gyrA,gyrB,grlA and nor A genes.CONCLUSIONS Berberine is capable of resisting the MRSA and shows synergistic or additive effect with levofloxacin.The combined use of the two drugs may reduce the MIC against levofloxacin,destroy the morpholog-ical structure,and inhibit the expression of gyrA,gyrB,grlA and nor A genes.

Objective This study aimed to investigate the antimicrobial resistance profiles of bacterial strains isolated from pediatric intensive care units(PICU)in China for better antimicrobial therapy.Methods Clinical isolates were collected from 17 institutions,including tertiary care children's hospitals and pediatric department of tertiary general hospitals in China from January 1,2020 to December 31,2022.Antimicrobial susceptibility testing was carried out according to a unified protocol using Kirby-Bauer method or automated systems.Results were interpreted according to the breakpoints released by the Clinical and Laboratory Standards Institute(CLSI)in 2020.Results A total of 10 688 isolates were collected,including gram-positive organisms(39.2％)and gram-negative organisms(60.8％).The top three organisms were S.aureus(13.6％,1 453/10 688),A.baumannii(10.0％,1 067/10 688),and coagulase-negative Staphylococcus(9.9％,1 058/10 688).Multi-drug resistant organisms(MDROs)were very common in children.The prevalence of methicillin-resistant Staphylococcus aureus(MRSA),carbapenem-resistant Enterobacterales(CRE),carbapenem-resistant E.coli,carbapenem-resistant K.pneumoniae(CRKP),carbapenem-resistant A.baumannii(CRAB),and carbapenem-resistant P.aeruginosa(CRPA)was 41.1％,19.4％,8.8％,30.9％,67.4％,and 28.8％,respectively.Overall,more than 50％of Enterobacteriales isolates were resistant to cephalosporins,while nearly 25％of Enterobacteriales isolates were resistant to carbapenems.MDROs were highly resistant to commonly used antibiotics.More than 80％of CRE and CRAB strains were resistant to all beta-lactam antibiotics.CRE and CRAB showed low resistance rates to tigecycline and polymyxin.CRPA showed lower resistance rates to piperacillin,beta-lactamase inhibitor combinations than the resistance rates to third and fourth generation cephalosporins.All of the Staphylococcus and Enterococcus isolates were susceptible to vancomycin and tigecycline.None of PRSP strains isolated from meningitis and nonmeningitis samples were resistant to rifampicin,vancomycin,or linezolid.The prevalence of β-lactamase-negative ampicillin-resistant(BLNAR)strains was 43.3％in Haemophilus influenzae.Conclusions MDROs were prevalent in PICU.It is necessary to establish an effective multidisciplinary team(MDT)to control the antimicrobial resistance.