Natural products are important sources of drug discovery. However, the traditional methods of extraction and isolation, as well as chemical synthesis for obtaining natural products are associated with issues such as operational complexity, high costs, low efficiency, and environmental pollution. Constructing microbial cell factories through synthetic biology methods to produce medicinal natural products has the advantages of high efficiency, low cost, and environmental protection. Nevertheless, the scope and yield improvement of the products are limited by the limitations of enzymes in microbial cell factories. Protein engineering is considered one of the most effective approaches to overcome these limitations. This article introduces commonly used methods of protein engineering technology and summarizes its specific applications in improving enzyme performance, modifying the enzymatic environment, and promoting the development of synthetic biology tools in the field of pharmaceutical natural product synthesis. Furthermore, it analyzes the current bottlenecks and challenges in protein engineering and looks forward to its future application prospects, offering insights for the development and practical use of protein engineering technology.

The conventional oral drug delivery frequently results in the drug elimination before its complete release due to rapid gastric emptying and short gastrointestinal transport time, thus reducing the bioavailability of drug. In order to maintain an effective concentration of drug in the body and maximize its optimal efficacy, the frequency of administrations often needs to be increased. By contrast, gastric retention drug delivery system (GRDDS), as an innovative method of drug delivery, prolongs the retention time of the drug in the stomach and reduces irritation to the gastrointestinal tract. Consequently, it enhances the bioavailability of drug, reduces dosing frequency for patients and improves treatment adherence. In recent years, domestic and foreign studies have been conducted on gastric retention drug delivery systems. Here, we provide a comprehensive overview of the relevant literature published in recent years, examining their current marketing status, various types, as well as in vivo and in vitro evaluation methods.

Objective To investigate the effects of Erhuang Quzhi Granules combined with Silibinin Capsules on fatty liver index,inflammatory factors and autophagy-related gene levels in patients with nonalcoholic fatty liver disease(NAFLD).Methods A total of 126 patients with NAFLD of phlegm blended with blood stasis type were randomly divided into control group and observation group,with 63 cases in each group.The control group was treated with oral use of Silibinin Capsules,and the observation group was treated with oral use of Erhuang Quzhi Granules on the basis of treatment for the control group.The course of treatment lasted for 3 months.Before and after treatment,the two groups were observed in the changes of fatty liver index,and the levels of inflammatory factors of interleukin 6(IL-6)and tumor necrosis factor alpha(TNF-α),liver function and blood lipid indicators of alanine aminotransferase(ALT),aspartate aminotransferase(AST),γ-glutamyl transpeptidase(GGT),total cholesterol(TC),triglyceride(TG),high-density lipoprotein cholesterol(HDL-C)and low-density lipoprotein cholesterol(LDL-C),and autophagy-related genes of autophagy-related gene 7(ATG7)and myosin-like BCL2 binding protein(Beclin 1).After treatment,the clinical efficacy and safety of the two groups were evaluated.Results(1)After 3 months of treatment,the total effective rate of the observation group was 90.48％(57/63),and that of the control group was 71.43％(45/63).The intergroup comparison(tested by chi-square test)showed that the efficacy of the observation group was significantly superior to that of the control group(P＜0.01).(2)After treatment,the fatty liver index of the two groups was significantly decreased compared with that before treatment(P＜0.05),and the decrease of fatty liver index in the observation group was significantly superior to that in the control group(P＜0.01).(3)After treatment,the serum levels of inflammatory factors of IL-6 and TNF-α in the two groups were significantly lower than those before treatment(P＜0.05),and the decrease of serum IL-6 and TNF-α levels in the observation group was significantly superior to that in the control group(P＜0.05).(4)AAfter treatment,the serum levels of liver function indicators of ALT,AST and GGT in the two groups were significantly lower than those before treatment(P＜0.05),and the decrease of serum ALT,AST and GGT levels in the observation group was significantly superior to that in the control group(P＜0.05).(5)After treatment,the serum levels of blood lipids of TG,TC and LDL-C in the two groups were significantly lower than those before treatment(P＜0.05),and the serum HDL-C level was significantly higher than that before treatment(P＜0.05).The decrease of serum TG,TC and LDL-C levels and the increase of serum HDL-C level in the observation group were significantly superior to those in the control group(P＜0.05).(6)After treatment,the serum levels of autophagy-related genes of ATG7 and Beclin 1 in the two groups were significantly higher than those before treatment(P＜0.05),and the increase of serum ATG7 and Beclin 1 levels in the observation group was significantly superior to that in the control group(P＜0.05).(7)During the medication,no liver or kidney function damage or serious adverse reactions were found in the two groups.Conclusion Erhuang Quzhi Granules combined with Silibinin Capsules are effective for the treatment of NAFLD patients with phlegm blended with blood stasis type,which is helpful to relieve the symptoms of fatty liver,reduce the levels of inflammatory factors,improve liver function and blood lipid levels,and regulate the expression of autophagy-related genes.

Objective To investigate the risk factors for early neurological deterioration(END)following intravenous thrombolysis with recombinant tissue plasminogen activator(rt-PA)acute mild ischemic stroke(AMIS)patients.Methods Eighty-six patients with AMIS who underwent intravenous thrombolysis with rt-PA in the Department of Neurology,Civil Aviation General Hospital between January 2019 and October 2022 were retrospectively analyzed.Patients were categorized into END group(n=8)and non-END group(n=78)based on the presence of END within 24 hours after thrombolysis(NIHSS score increased by≥2 points within 24 hours after intravenous thrombolysis).Baseline characteristics,including age,gender,past medical history(hypertension,diabetes,hyperlipidemia,etc.),smoking history,pre-thrombolysis NIHSS score,homocysteine level,fibrinogen level,and post-thrombolysis bleeding transformation were documented for each patient.A multivariate logistic regression analysis was conducted to access the risk factors associated with END following intravenous thrombolysis in AMIS.Results There were significant differences in homocysteine and fibrinogen levels,as well as bleeding transformation after thrombolysis between the two groups(P<0.05).In contrast,other factors such as age,gender,past medical history,pre-thrombolysis NIHSS score,and other imaging features were not statistically significant(P>0.05).Multivariate logistic regression analysis revealed that elevated homocysteine level was independently linked to risk of END after intravenous thrombolysis in AMIS,with an odds ratio of 1.074(95%CI 1.011-1.142,P=0.021).Conclusions Hyperhomocysteinemia emerges as an independent risk factor for END following intravenous thrombolysis in patients with AMIS.

Objective To investigate the relationship between single nucleotide polymorphisms(SNPs)in the eNOS gene and genetic susceptibility to systemic lupus erythematosus(SLE)in Hainan.Methods Blood samples were collected from SLE patients(SLE group,n=214)and healthy controls(control group,n=214)from January 2020 to December 2022 at the First Affiliated Hospital of Hainan Medical College and Hainan Provincial People's Hospital.The bases of eNOS gene rs3918188,rs1799983 and rs1007311 loci in each group were detected by SNaPshot sequencing technology.Logistic regression was used to analyze the correlation between genotypes,alleles and gene models(dominant model,recessive model,and overdominant model)of the above 3 target loci of the eNOS gene and genetic susceptibility to SLE.Haplotype analysis was conducted using HaploView 4.2 software to investigate the relationship between haploid and genetic susceptibility to SLE at each site.Results The results of logistic regression analysis revealed that the CC genotype and the C allele at rs3918188 locus were risk factors for genetic susceptibility to SLE(CC vs.AA:OR=2.449,P<0.05;C vs.A:OR=2.133,P<0.001).In recessive model at rs3918188 locus,CC genotype carriers had an increased risk of SLE development compared with AA+AC genotype carriers(OR=2.774,P<0.001).In contrast,in overdominant model at this locus,AC genotype carriers had a decreased risk of SLE occurrence compared with AA+CC genotype carriers(OR=0.385,P<0.001).In addition,polymorphisms of rs1799983 and rs1007311 were not associated with susceptibility to SLE in genotype,allele type and the 3 genetic models(P>0.05).Haplotype analysis revealed a strong linkage disequilibrium between the rs1007311 and rs1799983 loci of the eNOS gene,but no significant correlation was found between haplotype and genetic susceptibility to SLE(P>0.05).Conclusion The CC genotype and C allele at rs3918188 locus of eNOS gene may be risk factors for SLE in Hainan,while the risk of SLE occurrence is reduced in carriers of AC genotype under the overdominant model.

Patients with severe trauma require an extremely timely treatment and transfusion plays an irreplaceable role in the emergency treatment of such patients. An increasing number of evidence-based medicinal evidences and clinical practices suggest that patients with severe traumatic bleeding benefit from early transfusion of low-titer group O whole blood or hemostatic resuscitation with red blood cells, plasma and platelet of a balanced ratio. However, the current domestic mode of blood supply cannot fully meet the requirements of timely and effective blood transfusion for emergency treatment of patients with severe trauma in clinical practice. In order to solve the key problems in blood supply and blood transfusion strategies for emergency treatment of severe trauma, Branch of Clinical Transfusion Medicine of Chinese Medical Association, Group for Trauma Emergency Care and Multiple Injuries of Trauma Branch of Chinese Medical Association, Young Scholar Group of Disaster Medicine Branch of Chinese Medical Association organized domestic experts of blood transfusion medicine and trauma treatment to jointly formulate Chinese expert consensus on blood support mode and blood transfusion strategies for emergency treatment of severe trauma patients ( version 2024). Based on the evidence-based medical evidence and Delphi method of expert consultation and voting, 10 recommendations were put forward from two aspects of blood support mode and transfusion strategies, aiming to provide a reference for transfusion resuscitation in the emergency treatment of severe trauma and further improve the success rate of treatment of patients with severe trauma.

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.

Objective To examine the changing antimicrobial resistance profile of Enterobacter spp.isolates in 53 hospitals across China from 2015 t0 2021.Methods The clinical isolates of Enterobacter spp.were collected from 53 hospitals across China during 2015-2021 and tested for antimicrobial susceptibility using Kirby-Bauer method or automated testing systems according to the CHINET unified protocol.The results were interpreted according to the breakpoints issued by the Clinical & Laboratory Standards Institute(CLSI)in 2021(M100 31st edition)and analyzed with WHONET 5.6 software.Results A total of 37 966 Enterobacter strains were isolated from 2015 to 2021.The proportion of Enterobacter isolates among all clinical isolates showed a fluctuating trend over the 7-year period,overall 2.5％in all clinical isolates amd 5.7％in Enterobacterale strains.The most frequently isolated Enterobacter species was Enterobacter cloacae,accounting for 93.7％(35 571/37 966).The strains were mainly isolated from respiratory specimens(44.4±4.6)％,followed by secretions/pus(16.4±2.3)％and urine(16.0±0.9)％.The strains from respiratory samples decreased slightly,while those from sterile body fluids increased over the 7-year period.The Enterobacter strains were mainly isolated from inpatients(92.9％),and only(7.1±0.8)％of the strains were isolated from outpatients and emergency patients.The patients in surgical wards contributed the highest number of isolates(24.4±2.9)％compared to the inpatients in any other departement.Overall,≤ 7.9％of the E.cloacae strains were resistant to amikacin,tigecycline,polymyxin B,imipenem or meropenem,while ≤5.6％of the Enterobacter asburiae strains were resistant to these antimicrobial agents.E.asburiae showed higher resistance rate to polymyxin B than E.cloacae(19.7％vs 3.9％).Overall,≤8.1％of the Enterobacter gergoviae strains were resistant to tigecycline,amikacin,meropenem,or imipenem,while 10.5％of these strains were resistant to polycolistin B.The overall prevalence of carbapenem-resistant Enterobacter was 10.0％over the 7-year period,but showing an upward trend.The resistance profiles of Enterobacter isolates varied with the department from which they were isolated and whether the patient is an adult or a child.The prevalence of carbapenem-resistant E.cloacae was the highest in the E.cloacae isolates from ICU patients.Conclusions The results of the CHINET Antimicrobial Resistance Surveillance Program indicate that the proportion of Enterobacter strains in all clinical isolates fluctuates slightly over the 7-year period from 2015 to 2021.The Enterobacter strains showed increasing resistance to multiple antimicrobial drugs,especially carbapenems over the 7-year period.

Objective To understand the changing distribution and antimicrobial resistance profiles of Proteus,Morganella and Providencia in hospitals across China from January 1,2015 to December 31,2021 in the CHINET Antimicrobial Resistance Surveillance Program.Methods Antimicrobial susceptibility testing was carried out following the unified CHINET protocol.The results were interpreted in accordance with the breakpoints in the 2021 Clinical & Laboratory Standards Institute(CLSI)M100(31 st Edition).Results A total of 32 433 Enterobacterales strains were isolated during the 7-year period,including 24 160 strains of Proteus,6 704 strains of Morganella,and 1 569 strains of Providencia.The overall number of these Enterobacterales isolates increased significantly over the 7-year period.The top 3 specimen source of these strains were urine,lower respiratory tract specimens,and wound secretions.Proteus,Morganella,and Providencia isolates showed lower resistance rates to amikacin,meropenem,cefoxitin,cefepime,cefoperazone-sulbactam,and piperacillin-tazobactam.For most of the antibiotics tested,less than 10％of the Proteus and Morganella strains were resistant,while less than 20％of the Providencia strains were resistant.The prevalence of carbapenem-resistant Enterobacterales(CRE)was 1.4％in Proteus isolates,1.9％in Morganella isolates,and 15.6％in Providencia isolates.Conclusions The overall number of clinical isolates of Proteus,Morganella and Providencia increased significantly in the 7-year period from 2015 to 2021.The prevalence of CRE strains also increased.More attention should be paid to antimicrobial resistance surveillance and rational antibiotic use so as to prevent the emergence and increase of antimicrobial resistance.