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.

Objective: To investigate the effect of neurite outgrowth inhibitor extracellular peptide residues 1-40 (NEP1-40) combined with poly (lactic-co-glycolic acid) (PLGA) and gelatin electrospun fiber membrane on facial nerve repair in rats. Methods: According to the principle of random grouping, 108 male SD rats were divided into four groups (n = 27 in each group, approved by the ethics committee), namely, the sham group, control group, PLGA group, and NEP1-40 + PLGA group. A facial nerve fracture model was established for all of the groups except for the sham group. The control group received no further treatment, the PLGA group and the NEP1-40+PLGA group were supported by PLGA membrane, and the NEP1-40+PLGA group received one immediate local injection of NEP1-40 (5 μg/μL) at a dose of 10 μL. Facial nerve function analysis, electrophysiological examination, transmission electron microscope observation, HE staining, and immunohistochemical staining of myelin marker S100β and axonal marker β3-tubulin were used to evaluate the recovery of injured facial nerves of rats at 2, 4 and 8 weeks. Results : At 8 weeks, the facial nerve function score of the NEP1-40+PLGA group was better than that of the control group and PLGA group (P < 0.001), and facial nerve function was significantly restored. Electrophysiological examination of nerve action potentials at the injured facial nerve showed that the amplitude in the NEP1-40+PLGA group was higher than that of the control group and PLGA group (P < 0.001), but there was no significant difference in latency and conduction velocity results between the groups (P > 0.05). At 2, 4, and 8 weeks, transmission electron microscopy showed that the number of myelinated nerve fibers and myelin sheath thickness in the cross-section of the injured facial nerve in the NEP1-40+PLGA group were greater than those in the other groups (P < 0.05). At 8 weeks, HE staining showed that the facial nerves in the control group had partially recovered, but the overall cell distribution was uneven and the boundary with surrounding tissues was slightly blurred. In contrast, the NEP1-40+PLGA group had a relatively uniform cell distribution and a clearer boundary with surrounding tissues. At 2, 4, and 8 weeks, the immunohistochemical results showed that in the cross-section of the injuried facial nerve, NEP1-40 increased the expression of neural markers S100 β and β3-tubulin, especially β3-tubulin, which was close to normal levels (P > 0.05) Conclusion NEP1-40 is beneficial for the generation of new myelin sheaths and axons at the site of injury, and it can promote the repair and regeneration of injured facial nerves to a certain extent, thus accelerating the recovery of injured nerve function.

Aim To establish a reliable in vitro evaluation sys-tem to assess human liver UGTs activities and the inhibitory effect of drugs on human liver UGTs and validate its accuracy and stability.Methods Six probe substrate of the six major subtypes of human liver microsomal UGT enzymes were select-ed.The activity of human liver microsomal UGT enzymes was determined under optimized incubation conditions using a metab-olite generation method.The concentrations of metabolites were determined using a validated liquid chromatography-tandem mass spectrometry(LC-MS/MS)method.Known inhibitors were used to verify the established incubation system.Results The estab-lished LC-MS/MS analysis method complied with the require-ments of bioanalysis.In the incubation system of this experi-ment,known UGT inhibitors exhibited significant inhibitory effects.Conclusions This study successfully establishes an ac-curate and reliable in vitro evaluation system,which can be used to assess the in vitro inhibition of drugs on UGT enzymes,provi-ding important guidance for drug development and rational clini-cal medication.

Objective To investigate the efficacy of antibiotic cement column combined with iliac bone graft in the treat-ment of open fracture with bone defect of distal femur.Methods From October 2014 to March 2021,16 patients of open frac-ture bone defect of distal femur were treated with antibiotic bone cement column and iliac bone graft,including 12 males and 4 females.The age ranged from 28 to 68 years old.There were 11 cases of traffic accident injury,5 cases of falling injury,3 cases as Gustilo type Ⅰ,5 cases as type Ⅱ and 8 cases as type Ⅲ A.AO classification was used:9 cases of C2 type and 7 cases of C3 type.The time from injury to final bone grafting ranged from 4 to 119 days.The length of bone defect ranged from 2 tol0 cm.Fractures healing time,complications and knee function Merchan score were recorded.Results All the 16 patients were fol-lowed up from 9 to 29 months.The incisions of 16 patients healed in one stage without postoperative infection,plate fracture,limb shortening and valgus and varus deformity.The healing time randed from 4 to 10 months.Knee joint function according to the Merchant scoring standard,showed that 8 cases were excellent,4 cases were good,3 cases were fair,and 1 case was poor.Conclusion The use of antibiotic bone cement column combined with iliac bone graft in the treatment of open and complex bone defects of distal femur is an effective surgical method to prevent infection,assist fracture reduction,increase fixation strength and significantly reduce the amount of bone grafting.

This study was aimed at investigating the effect of lymphocyte activation gene-3(LAG3)on liver B lymphocyte subsets and their functions in WT and LAG3-KO mice infected with Echinococcus multilocularis(E.multilocularis).In a mouse model of E.multilocularis infection,the expression and localization of CD19 and α-SMA in liver were detected by immu nohistochemistry.CD80,CD86 and MHC-Ⅱ molecules expressed on B cells and their subsets in mice liver were detected by flow cytometry.After 12 weeks of infection,the area and percentage of CD19 in LAG3-KO group was slightly higher than that in WT group,but the difference was not statistically(t=-1.241、-1.237,P＞0.05).The area and percentage of a-SMA in LAG3-KO group was higher than that in WT group(t=-3.224、-3.227,P＜0.05).The proportion of CD80 and MHC-Ⅱ molecules expressed on liver B cells in LAG3-KO group was up-regulated(t=-2.379,-3.321,P＜0.05).The percentage of liver B2 cells in LAG3-KO group was higher than that in WT group(t=-2.695,P＜0.05).The expression of CD80 on Blb cells in LAG3-KO group was significantly up-regulated(t=-5.315,P＜0.001).The proportion of CD80 of B2 cells in LAG3-KO group was lower than that in WT group(t=2.806,P＜0.05).The expression of MHC-Ⅱ molecule in B2 cells in LAG3-KO group was up-regulated(t=-4.227,P＜0.01).It is suggested that LAG3 molecules affected the B cell subsets and func-tion of mouse liver in the middle stage of E.multilocularis infection,especially B2 lymphocytes.LAG3 molecule exerted an in-hibitory effect on the activation of B cells and the expression of MHC-class Ⅱ molecules,suggesting that it may be involved in B cell exhaustion caused by E.multilocularis.

Oligoasthenozoospermia(OAS)is one of the most common types of male infertility,which,however,still lacks ef-fective treatment.An increasing number of studies have shown the potential therapeutic value of omega-3 polyunsaturated fatty acid(ω-3 PUFA)in the treatment of OAS.This article presents an overview of the studies on the effects of ω-3 PUFA on fatty acid composition and metabolism,inflammatory response,and oxidative stress in OAS,hoping to provide some new ideas for the treatment of the dis-ease.

Objective:To investigate the effects of Xiongcan Yishen Formula(XYF)on ferroptosis in mouse TM3 Leydig cells after oxidative stress injury(OSI)induced by H2O2.Methods:An oxidative stress injury model was established in mouse TM3 Leydig cells using H2O2 induction.The modeled TM3 cells were randomly divided into OSI group,XYF group,the ferroptosis inhibitor Ferrostatin-1(F-1)group,and F-1+XYF group,which were respectively intervened with blank serum,20%drug-containing serum,2μmol/L F-1,and2μmol/L F-1+20%drug-containing serum.A control group(normal TM3 cells+blank serum)was also set up.The morphology of cells in each group was observed,and the levels of testosterone,superoxide dismutase(SOD),reactive oxygen spe-cies(ROS),malondialdehyde(MDA),ferritin heavy chain 1(FTH1),solute carrier family 7 member 11(SLC7A11),glutathione(GSH),glutathione peroxidase 4(GPX4),fatty acid CoA ligase 4(FACL4),total iron ions,and ferrous ions were detected.Re-sults:Compared with the model group,the control group showed significantly decreased expression of ROS,MDA,FACL4,total iron,and ferrous ions(P<0.05),and significantly increased levels of testosterone,SOD,GSH,FTH1,SLC7A11,and GPX4(P<0.05).The male silkworm kidney-tonifying formula group significantly promoted testosterone secretion by TM3 cells and upregulated the expression of FTH1,SLC7A11,GPX4,GSH,and SOD in TM3 cells(P<0.05),while significantly downregulating ROS,MDA,FACL4,total iron ions,and ferrous ions(P<0.05).Conclusion:Following H2O2 exposure,oxidative stress can induce ferroptosis in mouse TM3 Leydig cells.XYF can antagonize OSI and ferroptosis in TM3 cells by activating the SLC7A11/GSH/GPX4 axis,which may underlie the mechanism of XYF in the treatment of male late-onset hypogonadism.

AIM To study the chemical constituents form the leaves of Castanopsis orthacantha Fance and their α-glucosidase inhibitory activities.METHODS The methanol extract form the leaves of C.orthacanth was isolated and purified by various column chromatography methods,such as MCI gel CHP 20P,Sephadex LH-20,Diaion HP20SS,then the structures of obtained compounds were identified by physicochemical properties and spectral data.The α-glucosidase inhibitory activities were determined by PNPG method.RESULTS Eighteen compounds were isolated and identified as protocatechuic acid(1),gallic acid(2),3-O-α-L-arabininopyranosyl-4-hydroxybenzoic acid(3),3-O-galloyl shikimic acid(4),methyl 4-epi-shikimate-3-O-gallate(5),5-O-galloyl shikimic acid(6),5-O-caffeoylshikimic acid(7),6-O-galloyl-glucoside(8),1,6-di-O-galloyl-β-D-pyranogluloside(9),1,3-di-O-galloyl-α-D-glucoside(10),2,3-di-O-galloyl-D-glucoside(11),β-O-methylgluco-2,3-digalloyl esters(12),(3R,1'S)-[1'-(6"-O-galloyl-β-D-gluco-pyranosyl)oxyethyl]-3-hydroxy-dihydrofuran-2(3H)-one(13),4-O-D-(6'-O-galloyl)glucopyranyl-(E)-p-coumaryl acid(14),chestanin(15),1-desgalloyl eugeniin(16),picrorhiza acid(17),11-methyl chebulate(18).The IC50 values of compounds 2 and 16 were(0.12±0.059),(0.00089±0.00025)mmol/L,respectively.CONCLUSION All compounds are isolated from the leaves of C.orthacantha for the first time.Compounds 2 and 16 have strong α-glucosidase inhibitory activities.

Objective:To study the therapeutic effect of cardiac rehabilitation in patients with acute myocardial infarction(AMI)after percutaneous coronary intervention(PCI)and its effect on inflammatory factors.Methods:A total of 94 AMI patients after PCI admitted in Hospital of China University of Geosciences(Wuhan)between June 2020 and August 2021 were selected and randomly divided into control group(n=47,routine therapy)and study group(n=47,individualized cardiac rehabilitation therapy based on routine therapy).Cardiopulmonary exercise indexes,blood lipid indexes,inflamma-tory factors and cardiac function indexes were compared between two groups before and 3 months after treatment.Results:Compared with control group after treatment,participants in study group had significant higher anaerobic threshold[(15.46±3.07)ml·min-1·kg-1 vs.(19.37±3.27)ml·min 1·kg-1],maximal oxygen uptake[(21.26±4.05)ml·min-1·kg-1 vs.(25.31±4.10)ml·min-1·kg-1],left ventricular ejection fraction(LVEF)[(52.20±5.75)％vs.(57.91±5.17)％],6min walking distance(6MWD)[(430.58±43.87)m vs.(481.52±44.57)m]and levels of high density lipoprotein cholesterol(HDL-C)[(1.30±0.32)mmol/L vs.(1.49±0.35)mmol/L]and interleukin(IL)-10[(5.45±0.55)pg/ml vs.(6.19±0.59)pg/ml](P＜0.01 all),and significant lower levels of triglyceride(TG)[(1.88±0.65)mmol/L vs.(1.54±0.63)mmol/L],total cholesterol(TC)[(3.49±0.54)mmol/L vs.(3.13±0.47)mmol/L],low density lipoprotein cholesterol(LDL-C)[(2.12±0.59)mmol/L vs.(1.57±0.52)mmol/L],tumor necrosis factor-α(TNF-α)[(128.34±14.5)pg/ml vs.(99.28±8.51)pg/ml],leptin(LEP)[(623.49±61.27)pg/ml vs.(483.57±47.61)pg/ml]and N terminal pro B-type natriuretic peptide(NT-proBNP)[(396.59±18.12)pg/ml vs.(302.96±17.56)pg/ml](P＜0.05 or＜0.01).Conclusion:Cardiac rehabilitation therapy can significantly im-prove the blood lipid levels,cardiac function and exercise endurance,and effectively reduce the levels of inflammatory fac-tors in AMI patients after PCI,which is an important component of secondary prevention in these patients.

Objective To investigate the biomechanical effects of the backside design of tibial trays on the bone-prosthesis fixation interfaces in unicompartmental knee arthroplasty(UKA).Methods Finite element models of medial knee arthroplasty were constructed using a fixed UKA prosthesis.The knee joint load and joint motion under walking motion were considered as boundary conditions,and the differences in tibial von Mises stress,contact stress,and micromotion of the bone-prosthesis fixation interface of the UKA tibial trays with big keel,small keel,two-peg with fin,three-oblique peg,and three-upright peg types were compared.Results At the maximum medical knee force moment,compared to the two-peg with fin type,the tibial von Mises stress,contact stress,and micromotion of the bone-prosthesis fixation interface decreased by 8%and 15.9%and increased by 9.9%for the big keel type;decreased by 12.3%and increased by 7.5%and 0.9%for the small keel type;decreased by 10%,10.5%,and increased by 1.2%for the three-oblique peg type;and decreased by 7.7%,14.7%,and 1.6%for the three-upright peg type,respectively.However,the maximum micromotion of the bone-prosthesis fixation interface occurred at 21%of the gait cycle.Compared to the two-peg with fin type,the micromotion of the bone-prosthesis fixation interface increased by 11.6%for the big keel type,increased by 1.6%for the small keel type,decreased by 0.4%for the three-oblique peg type,and decreased by 2.3%for the three-upright peg type.Conclusions To improve the long-term fixation effects of tibial prostheses,it is recommended to focus on a two-upright peg with fin or small keel designs when UKA tibial trays are designed,which can effectively balance the stress transfer and interface micromotion,thereby ensuring prosthesis stability and reducing the risk of aseptic loosening.