Immobilized enzyme-based enzyme electrode biosensors, characterized by high sensitivity and efficiency, strong specificity, and compact size, demonstrate broad application prospects in life science research, disease diagnosis and monitoring, etc. Immobilization of enzyme is a critical step in determining the performance (stability, sensitivity, and reproducibility) of the biosensors. Random immobilization (physical adsorption, covalent cross-linking, etc.) can easily bring about problems, such as decreased enzyme activity and relatively unstable immobilization. Whereas, directional immobilization utilizing amino acid residue mutation, affinity peptide fusion, or nucleotide-specific binding to restrict the orientation of the enzymes provides new possibilities to solve the problems caused by random immobilization. In this paper, the principles, advantages and disadvantages and the application progress of enzyme electrode biosensors of different directional immobilization strategies for enzyme molecular sensing elements by specific amino acids (lysine, histidine, cysteine, unnatural amino acid) with functional groups introduced based on site-specific mutation, affinity peptides (gold binding peptides, carbon binding peptides, carbohydrate binding domains) fused through genetic engineering, and specific binding between nucleotides and target enzymes (proteins) were reviewed, and the application fields, advantages and limitations of various immobilized enzyme interface characterization techniques were discussed, hoping to provide theoretical and technical guidance for the creation of high-performance enzyme sensing elements and the manufacture of enzyme electrode sensors.

With the widespread use of antibiotics, drug-resistant bacterial infections have become a significant threat to human health. Finding new antibacterial strategies that can effectively control drug-resistant bacterial infections has become an urgent task. Unlike small molecule drugs that target bacterial proteins, antisense oligonucleotide (ASO) can target genes related to bacterial resistance, pathogenesis, growth, reproduction and biofilm formation. By regulating the expression of these genes, ASO can inhibit or kill bacteria, providing a novel approach for the development of antibacterial drugs. To overcome the challenge of delivering antisense oligonucleotide into bacterial cells, various drug delivery systems have been applied in this field, including cell-penetrating peptides, lipid nanoparticles and inorganic nanoparticles, which have injected new momentum into the development of antisense oligonucleotide in the antibacterial realm. This review summarizes the current development of small nucleic acid drugs, the antibacterial mechanisms, targets, sequences and delivery vectors of antisense oligonucleotide, providing a reference for the research and development of antisense oligonucleotide in the treatment of bacterial infections.

Objective To investigate the high-frequency ultrasonic anatomical features of the adjacent C7 transverse process and its clinical value in stellate ganglion block(SGB).Methods High-frequency ultrasound was applied to obtain ultrasonographic anatomical sonogram features in the plane of bilateral C7 transverse processes in 52 cases(104 sides in total)of healthy adults and then stored for the operator to learn and correctly label each tissue structure.Fifty patients who underwent ultrasound-guided SGB were selected and divided into the BC7 group(25 cases before study)and AC7 group(25 cases after study).The operation time,SGB success rate,number of adjusted needle tips,dosage of anaesthetic and adverse reaction of patients in both group were recorded.Results The main muscles observed in the C7 plane were the longissimus and anterior scalene muscles,the ultrasonographic anatomical relationships of the vagus nerve located in the carotid sheath,the pleura located posterior to the subclavian artery,and the recurrent laryngeal nerve located in the vicinity of the branches of the inferior thyroid artery are described,and the stellate ganglion was illustrated as a flattened hypoechogenic structure visible on the deep surface of the prevertebral fascia in the region of the external cervical longissimus muscle,vertebral artery and vein,and the medial aspect of the anterior oblique muscle,and emanated the sonographic features of several hypoechoic nerve bundles.Ultrasound guided SGB was completed uneventfully in patients of both groups,and all patients developed Horner syndrome,with the SGB success rate of 100%.The operation time[(5.36±1.11)minutes]of patients in the BC7 group was longer than that in the AC7 group[(3.08±0.86)minutes],the number of adjusted needle tips[(4.20±1.00)times]of patients in the BC7 group was more than that in the AC7 group[(2.24±0.87)times],and the dosage of anaesthetic[(1.82±0.28)mL]of patients in the BC7 group was more than that in the AC7 group[(1.64±0.22)mL],all the differences were statistically significant(P<0.05).There was no significant difference in the incidence of adverse reaction between the two groups(P>0.05).Conclusion After ultrasonic learning of adjacent structures through C7 transverse process,SGB is safe and easy to perform.

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 changing distribution and antibiotic resistance profiles of clinical isolates of Staphylococcus in hospitals across China from 2015 to 2021.Methods Antimicrobial susceptibility testing was conducted for the clinical isolates of Staphylococcus according to the unified protocol of CHINET(China Antimicrobial Surveillance Network)using disk diffusion method and commercial automated systems.The CHINET antimicrobial resistance surveillance data from 2015 to 2021 were interpreted according to the 2021 CLSI breakpoints and analyzed using WHONET 5.6.Results During the period from 2015 to 2021,a total of 204,771 nonduplicate strains of Staphylococcus were isolated,including 136,731(66.8％)strains of Staphylococcus aureus and 68,040(33.2％)strains of coagulase-negative Staphylococcus(CNS).The proportions of S.aureus isolates and CNS isolates did not show significant change.S.aureus strains were mainly isolated from respiratory specimens(38.9±5.1)％,wound,pus and secretions(33.6±4.2)％,and blood(11.9±1.5)％.The CNS strains were predominantly isolated from blood(73.6±4.2)％,cerebrospinal fluid(12.1±2.5)％,and pleural effusion and ascites(8.4±2.1)％.S.aureus strains were mainly isolated from the patients in ICU(17.0±7.3)％,outpatient and emergency(11.6±1.7)％,and department of surgery(11.2±0.9)％,whereas CNS strains were primarily isolated from the patients in ICU(32.2±9.7)％,outpatient and emergency(12.8±4.7)％,and department of internal medicine(11.2±1.9)％.The prevalence of methicillin-resistant strains was 32.9％in S.aureus(MRSA)and 74.1％in CNS(MRCNS).Over the 7-year period,the prevalence of MRSA decreased from 42.1％to 29.2％,and the prevalence of MRCNS decreased from 82.1％to 68.2％.MRSA showed higher resistance rates to all the antimicrobial agents tested except trimethoprim-sulfamethoxazole than methicillin-susceptible S.aureus(MSSA).Over the 7-year period,MRSA strains showed decreasing resistance rates to gentamicin,rifampicin,and levofloxacin,MRCNS showed decreasing resistance rates to gentamicin,erythromycin,rifampicin,and trimethoprim-sulfamethoxazole,but increasing resistance rate to levofloxacin.No vancomycin-resistant strains were detected.The prevalence of linezolid-resistant MRCNS increased from 0.2％to 2.3％over the 7-year period.Conclusions Staphylococcus remains the major pathogen among gram-positive bacteria.MRSA and MRCNS were still the principal antibiotic-resistant gram-positive bacteria.No S.aureus isolates were found resistant to vancomycin or linezolid,but linezolid-resistant strains have been detected in MRCNS isolates,which is an issue of concern.

Objective:To explore the plasma metabolomic characteristics of children with transfusion-dependent thalassemia(TDT),and reveal the changes of metabolic pattern in children with TDT.Methods:23 children with TDT who received regular blood transfusion in Ganzhou Women and Children's Health Care Hospital in 2021 were selected,and 11 healthy children who underwent physical examination during the same period were selected as the control group.The routine indexes between children with TDT and the control group were compared,and then the metabolic composition of plasma samples from children with TDT and the control group was detected by liquid chromatography-mass spectrometry.An OPLS-DA model was established to perform differential analysis on the detected metabolites,and the differential metabolic pathways between the two groups were analyzed based on the differential metabolites.Results:The results of routine testing showed that the indexes of ferritin,bilirubin,total bile acid,glucose and triglycerides in children with TDT were significantly higher than those in healthy controls,while hemoglobin and total cholesterol were significantly lower(all P＜0.05).However there was no significant difference in lactate dehydrogenase between the two groups(P＞0.05).Compared with the control group,190 differential metabolites(VIP＞1)were identified in TDT children.Among them,168 compounds such as arginine,proline and glycocholic acid were significantly increased,while the other 22 compounds such as myristic acid,eleostearic acid,palmitic acid and linoleic acid were significantly decreased.The metabolic pathway analysis showed that the metabolic impact of TDT on children mainly focused on the upregulation of amino acid metabolism and downregulation of lipid metabolism.Conclusion:The amino acid and lipid metabolism in children with TDT were significantly changed compared with the healthy control group.This finding is helpful to optimize the treatment choice for children with TDT,and provides a new idea for clinical treatment.

AIM To study endophytic fungi from Scutellaria baicalensis Georgi.and the enzyme inhibitory activities of their secondary metabolites.METHODS Six different media were used to isolate and purify endophytic fungi from S.baicalensis by tissue homogenate method.The activities of secondary metabolites were evaluated by targeting different enzymes.The highly active strains were identified by molecular biology combined with morphology,and the highly active chemical components were tracked and separated by modern chromatographic separation technology.RESULTS Sixty-four endophytic fungal strains were isolated from S.baicalensis,and one hundred and twenty-eight secondary metabolites were obtained by fermentation.The samples with certain inhibitory activities against adenosine deaminase(ADA),β-lactamase and tyrosinase(TYR)accounted for 14.06%,3.91%and 18.75%,respectively.Strain HTS-23-2 showed high TYR inhibitory activity,and 99%homology with Aspergillus flavus by molecular identification.One compound was isolated from the fermentation samples and identified as kojic acid.CONCLUSION S.baicalensis harbors a rich diversity of endophytic fungi,which serve as a valuable resource for active substances.

BACKGROUND:Clinical treatment for colon cancer mainly includes fluorouracil,irinotecan and oxaliplatin-based therapy.Studies have shown that membrane transport proteins such as ATP-binding cassette transport protein of G2(ABCG2)mediate the transport of these drugs.However,when patients develop resistance to these chemotherapeutic drugs,the high expression of ABCG2 leads to a significant decrease in the therapeutic effect and raises the problem of drug resistance in colon cancer.New drugs and treatments are urgently needed to improve the efficacy.Lycium barbarum polysaccharide has a wide range of biological activities.It can be used as anti-tumor drug to overcome the damage to normal cells in the process of chemotherapy and radiotherapy in tumor patients. OBJECTIVE:To explore the reversal effect of Lycium barbarum polysaccharide in combination with oxaliplatin on colon cancer drug-resistant cells through in vitro experiments to investigate the possible molecular mechanism of Lycium barbarum polysaccharide reversal on colon cancer drug-resistant cells. METHODS:Colon cancer cell line HCT116 and oxaliplatin-resistant cell line HCT116-OXR were selected for in vitro experiments.The optimal intervention concentration and intervention time of Lycium barbarum polysaccharide and oxaliplatin were determined by CCK8 assay of cell proliferation.Samples were further divided into the HCT116 control group,HCT116-OXR blank treatment group,Lycium barbarum polysaccharide group(2.5 mg/mL Lycium barbarum polysaccharide),and oxaliplatin group(10 μmol/L oxaliplatin),and Lycium barbarum polysaccharide + oxaliplatin group(2.5 mg/mL Lycium barbarum polysaccharide +10 μmol/L oxaliplatin).Cell apoptosis was detected by flow cytometry.The protein expression levels of phosphomannose isomerase(PMI)and ABCG2 were detected by immunofluorescence and western blot assay.Phosphatidylinositol3-kinase(PI3K),protein kinase B(AKT),B-cell lymphoma 2(Bcl-2)and BCL2-Associated X(Bax)were detected by western blot assay. RESULTS AND CONCLUSION:(1)HCT116-OXR was more sensitive to Lycium barbarum polysaccharide compared to HCT116(P<0.05).(2)Compared with the HCT116-OXR blank group,Lycium barbarum polysaccharide + oxaliplatin could promote apoptosis of HCT116-OXR cells(P<0.05).The protein expression of Bcl-2 was significantly down-regulated(P<0.05);the protein expression of Bax was significantly up-regulated(P<0.05);the protein expression of ABCG2,PMI,PI3K and AKT was significantly down-regulated(P<0.05).(3)These results indicate that Lycium barbarum polysaccharide reverses drug resistance in colon cancer by inhibiting PMI/PI3K/AKT signaling pathway,which lays the foundation for studying the molecular mechanism of Lycium barbarum polysaccharide's sensitizing chemotherapeutic effects.

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.

This study used kidney metabolomics to investigate the underlying mechanisms of Guilingji (GLJ) on mild cognitive impairment (MCI) rats. The rats were randomly divided into 6 groups (n = 8), i.e., control group, model group, positive drug (Ginkgo biloba tablet, donepezil) group, GLJ group (low and high dose group). The MCI rat model was replicated using subcutaneous injection of D-galactose into the back of the neck along with a semi-high-fat diet for a total of 8 weeks, and drug was administered from the 5th week for 4 weeks. The kidney function and renal pathological changes of each group of rats were tested. And LC-MS based kidney metabolomics coupled with multivariate data analysis were conducted to explore the potential biomarkers, and corresponding metabolic pathways were then determined. After administration of GLJ, the level of urea nitrogen was decreased compared with those of the model group, and the abnormalities of morphology in kidney tissues were improved. The positive drugs (ginkgo biloba tablet and donepezil) had no significant modulating effect on renal function indexes. Ginkgo biloba tablet can lessen the pathological injury of kidney tissue, and donepezil had no improvement on renal histopathology. A total of 23 MCI related differential metabolites were identified in kidney, and 17 metabolites were signifcantly restored by GLJ compared with those of the model group. Additionally, we found that the cysteine and methionine metabolism, nicotinate and nicotinamide metabolism, taurine and hypotaurine metabolism, glycerophospholipid metabolism were significantly involved in the regulatory effect of GLJ. The results illuminate the "cong shen zhi nao" mechanism of GLJ, and also provide a research basis for the clinical use of GLJ for the treatment of MCI. The animal experiment of this study was approved by the Ethics Committee of Shanxi University (approval number: 2020DW121).