This study aimed to investigate the inhibitory effect of tubuloside B (Tub B) on amyloid β-protein (Aβ), and analyse the potential mechanism. A model of amyloid fibril was established by incubation of Aβ_1-42 in vitro. Thioflavin-T (ThT), Congo red (CR), 8-anilino-1-naphthene sulfonic acid (ANS) staining and transmission electron microscopy (TEM) were applied to detect the suppression of Tub B on the formation of Aβ_1-42 fibril. Circular dichroism (CD) was used to analyse the regulatory effect of Tub B on the secondary structure of Aβ_1-42. 3-(4,5-Dimethyl-2-thiazole) -2,5-diphenyltetrazolium bromide (MTT) and red blood cell hemolysis experiments were used to investigate the attenuation of Tub B on Aβ_1-42 induced cytotoxicity. 2',7'-Dichlorofluorescin diacetate (DCFH-DA) staining was used to assess the expression of intracellular reactive oxygen species (ROS) induced by Aβ_1-42. And molecular docking experiment was used to explore the interaction between Tub B and Aβ_1-42. The results indicated that Tub B could inhibit Aβ_1-42 fibrillization in a certain extent, which retarded the structural transition of α-helix to β-sheet of Aβ_1-42, hampered the exposure of hydrophobic regions, and attenuated amyloid-induced cytotoxicity and hemolysis. In summary, Tub B can prevent the formation of Aβ_1-42 amyloid fibril, which may be related to its antioxidant activity and hydrogen bonding and hydrophobic interactions with protein molecules. All animal experiments were approved by the Experimental Animal Research Center of Air Force Medical University (No. 20190051).

Tropane alkaloids (TAs) are a class of anticholinergic drugs widely used in clinical practice and mainly extracted from plant, among which Atopa belladonna is the main commercial drug source. It is of great industrial value to obtain TAs in large quantities by plant metabolic engineering. In TAs pathway, cytochrome oxidase CYP82M3 catalyze the synthesis of tropinone and then tropinone reductase I (TRI) compete with TRII for tropinone to form tropine leading to the TAs synthesis (drainage). In this study, based on the "increasing flow and drainage" metabolic engineering strategy, two genes, namely HnCYP82M3 and DsTRI from Hyoscyamus niger and Datura stramonium, respectively, were overexpressed in the hair roots of A. belladonna, with a view to promote the TAs accumulation. The HnCYP82M3 gene was cloned from the root of H. niger, and it encoded amino acid with 91.7% sequence identity with AbCYP82M3 from A. belladonna. Overexpression of HnCYP82M3 alone did not affect the content of TAs in hair roots of A. belladonna, indicating that CYP82M3 was not a key enzyme in TAs biosynthesis. Simultaneous overexpression of HnCYP82M3 and DsTRI greatly promoted the accumulation of the three TAs, and the contents of hyoscyamine, anisodamine and scopolamine were 4.97 times, 2.83 times and 2.19 times that of the control, respectively, and the increase amplitude was greater than that of single overexpression of DsTRI. This study showed that the "increasing flow and drainage" strategy of enzyme genes co-expression at branch points was a promising metabolic engineering method to effectively improve the biosynthesis of TAs in A. belladonna, and laid a theoretical and technical foundation for the large-scale industrial acquisition of TAs.

Objective To study the pharmacokinetics and bioequivalence of two formulations of rasagiline mesylate tablets in healthy subjects under fasting and fed conditions.Methods The two-period,two-sequence,crossover study design was adopted in the fasting study.Thirty-six subjects were enrolled and given either test preparation or reference preparation 1 mg respectively in two periods.After collecting plasma samples,the plasma concentration of rasagiline was determined by liquid chromatography-tandem mass spectrometry(LC-MS/MS)and the bioequivalence was evaluated using the average bioequivalence(ABE)method.The four-period,two-sequence,fully replicate crossover study design was adopted in the fed study.Forty-eight subjects were enrolled and given the test preparation or the reference preparation at a dose of 1 mg twice respectively in four periods.According to the degree of intra-individual variation of Cmax,AUC0-t and AUC0-∞,the equivalence was evaluated using the reference-scaled average bioequivalence and ABE method,respectively.Results In the fasting study,the pharmacokinetic parameters of rasagiline of the test and reference preparation were as follow:Cmax were(9.70±3.14)and(9.62±3.85)ng·mL-1,AUC0-t were(6.03±1.47)and(6.02±1.95)ng·h·mL-1,AUC0-∞ were(6.13±1.51)and(6.12±1.97)ng·h·mL-1.The 90％confidence interval(CI)of the geometric mean ratio(GMR)were 94.11％-118.06％,99.22％-107.74％and 99.16％-107.44％for Cmax,AUC0-t and AUC0-∞,respectively,which were within the acceptance criteria of 80.00％-125.00％.In the fed study,the pharmacokinetic parameters of rasagiline of the test and reference preparation were as follow:Cmax were(3.00±1.92)and(3.52±1.77)ng·mL-1,AUC0_t were(5.02±1.20)and(5.06±1.20)ng·h·mL-1,AUC0-∞ were(5.11±1.23)and(5.14±1.22)ng·h·mL-1.The 90％CI of GMR were 96.99％-101.19％and 97.17％-101.41％for AUC0-t and AUC0-∞,which were within the acceptance criteria of 80.00％-125.00％.The 95％upper confidence bound of Cmax for were less than"0",and the point estimate of GMR were within the acceptance criteria of 80.00％-125.00％.The incidence of adverse events in fasting and fed studies was 22.86％and 22.92％,respectively,and all adverse events were moderate to mild.Conclusion The two rasagiline mesylate tablets were bioequivalent,and both the formulations were well tolerated.

Purpose To demonstrate the advantages of non-contrast-enhanced whole-heart coronary magnetic resonance angiography(NCE-CMRA)in evaluating coronary arteries by comparing ultrasonography(US),and to explore the clinical value of NCE-CMRA in the diagnosis of coronary artery lesions of Kawasaki disease(KD)in children.Materials and Methods NCE-CMRA and US imaging data of 41 children with KD from June 2017 to June 2021 who were diagnosed clinically in Lanzhou University Second Hospital were analyzed retrospectively.The display ability of US and NCE-CMRA in coronary arteries were compared.At the same time,the imaging characteristics of NCE-CMRA were analyzed,and the imaging characteristics such as the range and degree of coronary artery lesions displayed by NCE-CMRA were summarized.Results The overall segment display rate of NCE-CMRA in 41 children with KD was 75.6%;the overall segment display rate of US was 46.3%,with statistical difference between the two techniques(χ2=59.04,P<0.001).Regarding the display of the middle and distal segments of coronary arteries,NCE-CMRA had a clear imaging advantage over US(χ2=57.98 and 161.47,P<0.001).In all cases,25 patients(200 segments)had coronary artery lesions,and 94 segments of coronary artery showed different degrees of dilatation,including 8 segments(8.6%)of giant coronary artery aneurysm,35 segments(37.2%)of medium coronary artery aneurysm,and 51 segments(54.2%)of small coronary artery aneurysm or coronary artery dilation.Conclusion NCE-CMRA technology can objectively and accurately display coronary artery in children,and it can specifically evaluate the degree of damage caused by KD.It has important clinical significance in the diagnosis and evaluation of coronary artery lesions in children with KD.

Objective To observe the efficacy of self-made Wenshen Jianpi Formula in the treatment of polycystic ovary syndrome(PCOS)with deficiency of spleen and kidney type,and to explore its mechanism of regulating glucose-lipid metabolism and intestinal flora.Methods A total of 105 PCOS patients with deficiency of spleen and kidney type who attended the clinic at Kunshan Hospital of Chinese Medicine from October 2020 to October 2023 were selected as the study object.According to the treatment methods,the patients were divided into the observation group(53 cases)and the control group(52 cases).The control group was treated with metformin and ethinylestradiol and cyproterone,while the observation group was treated with self-made Wenshen Jianpi Formula on the basis of treatment for the control group,and the course of treatment lasted three months.The changes of traditional Chinese medicine(TCM)syndrome scores,number of follicles,ovarian volume,glucose-lipid metabolism indicators and intestinal flora in the two groups before and after treatment were observed.After treatment,the clinical efficacy and the total incidence of adverse reactions of the patients in the two groups were compared.Results(1)After three months of treatment,the total effective rate of the observation group was 96.23%(51/53),while that of the control group was 76.92%(40/52),and the intergroup comparison(by chi-square test)showed that the clinical efficacy of the observation group was significantly superior to that of the control group(P＜0.01).(2)After treatment,the scores of TCM symptoms such as soreness and weakness in the waist and knee,physical intolerance of cold,vertigo and dizziness,lassitude and weakness in the two groups were decreased when compared with those before treatment(P＜0.05),and the decrease of the scores in the observation group was significantly superior to that in the control group(P＜0.01).(3)After treatment,the number of follicles in the two groups was reduced(P＜0.05)and the volume of the left and right ovaries were reduced when compared with those before treatment(P＜0.05),and the reduction of follicles number as well as the bilateral ovarian volume in the observation group was significantly superior to that in the control group(P＜0.01).(4)After treatment,the levels of total cholesterol(TC),triglycerides(TG),fasting plasma glucose(FPG),2-hour postprandial glucose(2hPG),and glycosylated hemoglobin(HbA1c)in the two groups were decreased when compared with those before treatment(P＜0.05),and the decrease of the above glucose-lipid metabolism indicators in the observation group was significantly superior to that in the control group(P＜0.01).(5)After treatment,the levels of Bifidobacteria and Lactobacilli in both groups were higher(P＜0.05)and the levels of Enterococci and Enterobacteria were lower than those before treatment(P＜0.05),and the observation group had higher levels of Bifidobacteria and Lactobacilli and lower levels of Enterococci and Enterobacteria than the control group after treatment,the differences being statistically significant(P＜0.01).(6)The total incidence of adverse reactions in the observation group was 5.66%(3/53)and that in the control group was 7.69%(4/52),and the intergroup comparison showed that the difference was not statistically significant(P＞0.05).Conclusion Self-made Wenshen Jianpi Formula can significantly enhance the clinical efficacy of PCOS patients with deficiency of spleen and kidney type,reduce the volume of ovaries,decrease the number of follicles,and regulate the imbalance of glucose-lipid metabolism and gut microflora homeostasis effectively,without serious adverse reactions,which is safe and effective.

Objective To describe the changing trend and related factors of prevalence rates of healthcare-associa-ted infection(HAI)in a tertiary hospital in the past 10 years,and analyze the influencing factors for HAI.Methods A cross-sectional survey on HAI was conducted for 10 consecutive years from 2013 to 2022(one day was selected as the survey day each year),data were collected.The distribution and related factors of prevalence rates of HAI were analyzed by trend-x2 test and Pearson correlation coefficient.Multivariate logistic regression and multilayer percep-tron(MLP)models were constructed to analyze the independent effect and significance of factors.Results From 2013 to 2022,the prevalence rates of HAI ranged from 4.66％to 8.07％in this hospital,showing a linear upward trend.The proportions of ICU patients and utilization rate of central venous catheters within 2 days before the sur-vey showed linear upward trends,while the proportion of patients with urinary catheters within 2 days before the survey and proportion of patients undergoing surgery within 30 days before the survey decreased.The MLP model revealed that the top 3 important factors for HAI were length of hospital stay＞10 days,admission in ICU,and in-dwelling central venous catheters within 2 days before the survey.Multivariate logistic regression model indicated that length of hospital stay＞10 days,indwelling central venous catheters or urinary catheters within 2 days before the survey,surgery within 30 days before the survey,and admission in ICU were independent influencing factors for HAI.Conclusion The incidence of HAI in this hospital presents a linear increase in recent 10 years,the causes should be further analyzed and the direction of intervention should be determined through targeted surveillance.Adopting trend test statistical analysis method,logistic regression,MLP multi-factor model can further explore the data value of HAI prevalence survey.

Objective To analyze the antimicrobial susceptibility,molecular types,serotypes,virulence factors and resistance mechanisms of Streptococcus agalactiae(S.agalactiae)isolated from pregnant women with ad-vanced maternal age in Tangshan City,and provide basic data for the treatment,prevention and control of S.aga-lactiae infection.Methods 42 strains of S.agalactiae isolated from pregnant women with advanced maternal age in North China University of Science and Technology Affiliated Hospital as well as Tangshan Maternal and Child Health Hospital were collected.Detection of antimicrobial susceptibility and whole genome sequencing of 13 antimi-crobial agents were performed.Results The percentage of tetracycline,erythromycin,levofloxacin,and chloram-phenicol concurrently resistant strains was 7.1％,35.7％of the strains presented multidrug resistance to erythro-mycin,clindamycin,and levofloxacin.The carriage rates of resistance genes ermB and tetM were 66.7％and 47.6％,respectively.29 strains(69.0％)exhibited mutations in both gyrA and parC fluoroquinolone resistance determi-nants.42 strains of S.agalactiae belonged to 4 serotypes,namely ⅠB(35.7％),Ⅲ(33.3％),Ⅴ(26.2％),andⅠA(4.8％);and 11 sequence types(STs),with the highest proportion being ST10(35.7％)and ST19(31.0％);as well as 6 clonal complexes(CCs),among which CC19(42.9％)and CC12(35.7％)had the highest proportion.All S.agalactiae carried virulence factor-encoding genes of cfb,cylE,and pavA.Conclusion The molecular types and serotypes of S.agalactiae carried by pregnant women with advanced maternal age in Tangshan City pre-sent polymorphism,with obvious multidrug resistance,and carry multiple types of drug resistance genes and viru-lence genes.

Objective To monitor the susceptibility of clinical isolates to antimicrobial agents in tertiary hospitals in major regions of China in 2022.Methods Clinical isolates from 58 hospitals in China were tested for antimicrobial susceptibility using a unified protocol based on disc diffusion method or automated testing systems.Results were interpreted using the 2022 Clinical &Laboratory Standards Institute(CLSI)breakpoints.Results A total of 318 013 clinical isolates were collected from January 1,2022 to December 31,2022,of which 29.5％were gram-positive and 70.5％were gram-negative.The prevalence of methicillin-resistant strains in Staphylococcus aureus,Staphylococcus epidermidis and other coagulase-negative Staphylococcus species(excluding Staphylococcus pseudintermedius and Staphylococcus schleiferi)was 28.3％,76.7％and 77.9％,respectively.Overall,94.0％of MRSA strains were susceptible to trimethoprim-sulfamethoxazole and 90.8％of MRSE strains were susceptible to rifampicin.No vancomycin-resistant strains were found.Enterococcus faecalis showed significantly lower resistance rates to most antimicrobial agents tested than Enterococcus faecium.A few vancomycin-resistant strains were identified in both E.faecalis and E.faecium.The prevalence of penicillin-susceptible Streptococcus pneumoniae was 94.2％in the isolates from children and 95.7％in the isolates from adults.The resistance rate to carbapenems was lower than 13.1％in most Enterobacterales species except for Klebsiella,21.7％-23.1％of which were resistant to carbapenems.Most Enterobacterales isolates were highly susceptible to tigecycline,colistin and polymyxin B,with resistance rates ranging from 0.1％to 13.3％.The prevalence of meropenem-resistant strains decreased from 23.5％in 2019 to 18.0％in 2022 in Pseudomonas aeruginosa,and decreased from 79.0％in 2019 to 72.5％in 2022 in Acinetobacter baumannii.Conclusions The resistance of clinical isolates to the commonly used antimicrobial agents is still increasing in tertiary hospitals.However,the prevalence of important carbapenem-resistant organisms such as carbapenem-resistant K.pneumoniae,P.aeruginosa,and A.baumannii showed a downward trend in recent years.This finding suggests that the strategy of combining antimicrobial resistance surveillance with multidisciplinary concerted action works well in curbing the spread of resistant bacteria.

Objective To investigate the distribution and antimicrobial resistance profiles of the common pathogens isolated from urine from 2015 to 2021 in the CHINET Antimicrobial Resistance Surveillance Program.Methods The bacterial strains were isolated from urine and identified routinely in 51 hospitals across China in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Antimicrobial susceptibility was determined by Kirby-Bauer method,automatic microbiological analysis system and E-test according to the unified protocol.Results A total of 261 893 nonduplicate strains were isolated from urine specimen from 2015 to 2021,of which gram-positive bacteria accounted for 23.8％(62 219/261 893),and gram-negative bacteria 76.2％(199 674/261 893).The most common species were E.coli(46.7％),E.faecium(10.4％),K.pneumoniae(9.8％),E.faecalis(8.7％),P.mirabilis(3.5％),P.aeruginosa(3.4％),SS.agalactiae(2.6％),and E.cloacae(2.1％).The strains were more frequently isolated from inpatients versus outpatients and emergency patients,from females versus males,and from adults versus children.The prevalence of ESBLs-producing strains in E.coli,K.pneumoniae and P.mirabilis was 53.2％,52.8％and 37.0％,respectively.The prevalence of carbapenem-resistant strains in E.coli,K.pneumoniae,P.aeruginosa and A.baumannii was 1.7％,18.5％,16.4％,and 40.3％,respectively.Lower than 10％of the E.faecalis isolates were resistant to ampicillin,nitrofurantoin,linezolid,vancomycin,teicoplanin and fosfomycin.More than 90％of the E.faecium isolates were ressitant to ampicillin,levofloxacin and erythromycin.The percentage of strains resistant to vancomycin,linezolid or teicoplanin was＜2％.The E.coli,K.pneumoniae,P.aeruginosa and A.baumannii strains isolated from ICU inpatients showed significantly higher resistance rates than the corresponding strains isolated from outpatients and non-ICU inpatients.Conclusions E.coli,Enterococcus and K.pneumoniae are the most common pathogens in urinary tract infection.The bacterial species and antimicrobial resistance of urinary isolates vary with different populations.More attention should be paid to antimicrobial resistance surveillance and reduce the irrational use of antimicrobial agents.

Objective To understand the distribution and changing resistance profiles of clinical isolates of Enterococcus in hospitals across China from 2015 to 2021.Methods Antimicrobial susceptibility testing was conducted for the clinical isolates of Enterococcus according to the unified protocol of CHINET program by automated systems,Kirby-Bauer method,or E-test strip.The results were interpreted according to the Clinical & Laboratory Standards Institute(CLSI)breakpoints in 2021.WHONET 5.6 software was used for statistical analysis.Results A total of 124 565 strains of Enterococcus were isolated during the 7-year period,mainly including Enterococcus faecalis(50.7％)and Enterococcus faecalis(41.5％).The strains were mainly isolated from urinary tract specimens(46.9％±2.6％),and primarily from the patients in the department of internal medicine,surgery and ICU.E.faecium and E.faecalis strains showed low level resistance rate to vancomycin,teicoplanin and linezolid(≤3.6％).The prevalence of vancomycin-resistant E.faecalis and E.faecium was 0.1％and 1.3％,respectively.The prevalence of linezolid-resistant E.faecalis increased from 0.7％in 2015 to 3.4％in 2021,while the prevalence of linezolid-resistant E.faecium was 0.3％.Conclusions The clinical isolates of Enterococcus were still highly susceptible to vancomycin,teicoplanin,and linezolid,evidenced by a low resistance rate.However,the prevalence of linezolid-resistant E.faecalis was increasing during the 7-year period.It is necessary to strengthen antimicrobial resistance surveillance to effectively identify the emergence of antibiotic-resistant bacteria and curb the spread of resistant pathogens.