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.

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.

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 dynamically observe the changes in hypoxia-inducible factor 1α(HIF-1α)and Bcl-2/adenovirus E1B19kDa-interacting protein 3(BNIP3)in children with traumatic brain injury(TBI)and evaluate their clinical value in predicting the severity and prognosis of pediatric TBI.Methods A prospective study included 47 children with moderate to severe TBI from January 2021 to July 2023,categorized into moderate(scores 9-12)and severe(scores 3-8)subgroups based on the Glasgow Coma Scale.A control group consisted of 30 children diagnosed and treated for inguinal hernia during the same period,with no underlying diseases.The levels of HIF-1α,BNIP3,autophagy-related protein Beclin-1,and S100B were compared among groups.The predictive value of HIF-1α,BNIP3,Beclin-1,and S100B for the severity and prognosis of TBI was assessed using receiver operating characteristic(ROC)curves.Results Serum levels of HIF-1α,BNIP3,Beclin-1,and S100B in the TBI group were higher than those in the control group(P＜0.05).Among the TBI patients,the severe subgroup had higher levels of HIF-1α,BNIP3,Beclin-1,and S100B than the moderate subgroup(P＜0.05).Correlation analysis showed that the serum levels of HIF-lα,BNIP3,Beclin-1,and S100B were negatively correlated with the Glasgow Coma Scale scores(P＜0.05).After 7 days of treatment,serum levels of HIF-1α,BNIP3,Beclin-1,and S100B in both non-surgical and surgical TBI patients decreased compared to before treatment(P＜0.05).ROC curve analysis indicated that the areas under the curve for predicting severe TBI based on serum levels of HIF-1α,BN1P3,Beclin-1,and S100B were 0.782,0.835,0.872,and 0.880,respectively(P＜0.05),and for predicting poor prognosis of TBI were 0.749,0.775,0.814,and 0.751,respectively(P＜0.05).Conclusions Serum levels of HIF-1α,BNIP3,and Beclin-1 are significantly elevated in children with TBI,and their measurement can aid in the clinical assessment of the severity and prognosis of pediatric TBI.IChinese Journal of Contemporary Pediatrics,2024,26(4):378-384]

Objective To investigate the impact of silymarin(SM)on the malignant growth of glioma cells and the regulatory mechanism on the miR-124-3p/WEE1 axis.Methods Glioma U87 cells were grouped into control,SM low,medium,and high concentration groups,and SM high concentration + miR-124-3p inhibitor group(SM high + miR-124-3p inhibitor group).CCK-8 was used to measure the proli-feration rate of cells;Transwell? assay was applied to assay the migration and invasion of cells;cell cycle progression was detected by flow cytometry;Western blotting was applied to measure the expression of cyclin D1 and apoptosis-related proteins;the levels of miR-124-3p and WEE1 mRNA were determined by qRT-PCR;and a luciferase activity test was applied to verify the targeting relationship between miR-124-3p and WEE1;in addition,the establishment,administration,and analysis of a NOD/SCID mouse model of intracranial trans-planted tumor were conducted.Results Compared with the control group,the cell proliferation,the numbers of migrating and invading cells,the expression of cyclin D1,and the level of WEE1 mRNA in the various SM treatment groups decreased,the number of cells in G0/G1 phase,the expression of cleaved caspase-8,cleaved caspase-9,cleaved caspase-3 and miR-124-3p increased(P＜0.05);furthermore,transfection of miR-124-3p inhibitor reversed the inhibitory effect of SM on the malignant behavior of glioma cells.In vivo experiments with mice showed that the weights and volumes of tumors in the SM treatment group were lower than those in the model group(P＜0.05),and there was no discernible change in the weight of the mice(P＞0.05).Conclusion SM can inhibit the malignant growth of glioma cells by upregulating miR-124-3p and downregulating WEE1.

Objective To compare the effects of 20 mg qd and 10 mg bidadministration of iprrazole enteric-coated tablets on the control of gastric acid in healthy subjects.Methods A randomized,single-center,parallel controlled trial was designed to include 8 healthy subjects.Randomly divided into 2 groups,20 mg qd administration group:20 mg enteric-coated tablets of iprrazole in the morning;10 mg bid administration group:10 mg enteric-coated tablets of iprrazole in the morning and 10 mg in the evening.The pH values in the stomach of the subjects before and 24 h after administration were monitored by pH meter.The plasma concentration of iprazole after administration was determined by HPLC-MS/MS.The main pharmacokinetic parameters were calculated by Phoenix WinNonlin(V8.0)software.Results The PK parameters of iprrazole enteric-coated tablets and reference preparations in fasting group were as follows:The Cmax of 20 mg qd group and 10 mg bid group were(595.75±131.15)and(283.50±96.98)ng·mL-1;AUC0-t were(5 531.94±784.35)and(4 686.67±898.23)h·ng·mL-1;AUC0-∞ were(6 003.19±538.59)and(7 361.48±1 816.77)h·ng·mL-1,respectively.The mean time percentage of gastric pH＞3 after 20 mg qd and 10 mg bid were 82.64％and 61.92％,and the median gastric pH within 24 h were 6.25±1.49 and 3.53±2.05,respectively.The mean gastric pH values within 24 h were 5.71±1.36 and 4.23±1.45,respectively.The correlation analysis of pharmacokinetic/pharmacodynamics showed that there was no significant correlation between the peak concentration of drug in plasma and the inhibitory effect of acid.Conclusion Compared with the 20 mg qd group and the 10 mg bid group,the acid inhibition effect is better,the administration times are less,and the safety of the two administration regimes is good.

Objective:To investigate the association of urinary cadmium level with body mass index (BMI) and body circumferences among the older adults over 65 years old in 9 longevity areas of China.Methods:Subjects were older adults over 65 years old from the Healthy Aging and Biomarkers Cohort Study (HABCS) between 2017 and 2018 conducted in 9 longevity areas in China. A total of 1 968 older adults were included in this study. Information including socio-demographic characteristics, lifestyles, diet intake, and health status was collected by using questionnaires and physical examinations. Urine samples were collected to detect urinary cadmium and creatinine levels. Body circumferences included waist circumference, hip circumference and calf circumference. Subjects were divided into three groups (low:<0.77 μg/g·creatinine, middle:0.77-1.69 μg/g·creatinine, high:≥1.69 μg/g·creatinine) by tertiles of creatinine-adjusted urinary cadmium concentration. Multiple linear regression models were used to analyze the association of creatinine-adjusted urinary cadmium level with BMI and body circumferences. The dose-response relationship of creatinine-adjusted urinary cadmium concentration with BMI and body circumferences was analyzed by using restrictive cubic splines fitting multiple linear regression model.Results:The mean age of subjects was (83.34±11.14) years old. The median (Q1, Q3) concentration of creatinine-adjusted urinary cadmium was 1.13 (0.63, 2.09) μg/g·creatinine, and the BMI was (22.70±3.82) kg/m 2. The mean values of waist circumference, hip circumference, and calf circumference were (85.42±10.68) cm, (92.67±8.90) cm, and (31.08±4.76) cm, respectively. After controlling confounding factors, the results of the multiple linear regression model showed that for each increment of 1 μg/g·creatinine in creatinine-adjusted urinary cadmium, the change of BMI, waist circumference, hip circumference, and calf circumference in the high-level group was -0.28 (-0.37, -0.19) kg/m 2, -0.74 (-0.96, -0.52) cm, -0.78 (-0.96, -0.61) cm, and -0.20 (-0.30, -0.11) cm, respectively. The restrictive cubic splines curve showed a negative nonlinear association of creatinine-adjusted urinary cadmium with BMI ( Pnonlinear<0.001) and negative linear associations of creatinine-adjusted urinary cadmium with waist circumference ( Plinear<0.001), hip circumference ( Plinear<0.001), and calf circumference ( Plinear<0.001). Conclusion:Urinary cadmium level is significantly associated with decreased BMI, waist circumference, hip circumference and calf circumference among older adults over 65 years old in 9 longevity areas of China.

Objective:To investigate the association of urinary cadmium level with body mass index (BMI) and body circumferences among the older adults over 65 years old in 9 longevity areas of China.Methods:Subjects were older adults over 65 years old from the Healthy Aging and Biomarkers Cohort Study (HABCS) between 2017 and 2018 conducted in 9 longevity areas in China. A total of 1 968 older adults were included in this study. Information including socio-demographic characteristics, lifestyles, diet intake, and health status was collected by using questionnaires and physical examinations. Urine samples were collected to detect urinary cadmium and creatinine levels. Body circumferences included waist circumference, hip circumference and calf circumference. Subjects were divided into three groups (low:<0.77 μg/g·creatinine, middle:0.77-1.69 μg/g·creatinine, high:≥1.69 μg/g·creatinine) by tertiles of creatinine-adjusted urinary cadmium concentration. Multiple linear regression models were used to analyze the association of creatinine-adjusted urinary cadmium level with BMI and body circumferences. The dose-response relationship of creatinine-adjusted urinary cadmium concentration with BMI and body circumferences was analyzed by using restrictive cubic splines fitting multiple linear regression model.Results:The mean age of subjects was (83.34±11.14) years old. The median (Q1, Q3) concentration of creatinine-adjusted urinary cadmium was 1.13 (0.63, 2.09) μg/g·creatinine, and the BMI was (22.70±3.82) kg/m 2. The mean values of waist circumference, hip circumference, and calf circumference were (85.42±10.68) cm, (92.67±8.90) cm, and (31.08±4.76) cm, respectively. After controlling confounding factors, the results of the multiple linear regression model showed that for each increment of 1 μg/g·creatinine in creatinine-adjusted urinary cadmium, the change of BMI, waist circumference, hip circumference, and calf circumference in the high-level group was -0.28 (-0.37, -0.19) kg/m 2, -0.74 (-0.96, -0.52) cm, -0.78 (-0.96, -0.61) cm, and -0.20 (-0.30, -0.11) cm, respectively. The restrictive cubic splines curve showed a negative nonlinear association of creatinine-adjusted urinary cadmium with BMI ( Pnonlinear<0.001) and negative linear associations of creatinine-adjusted urinary cadmium with waist circumference ( Plinear<0.001), hip circumference ( Plinear<0.001), and calf circumference ( Plinear<0.001). Conclusion:Urinary cadmium level is significantly associated with decreased BMI, waist circumference, hip circumference and calf circumference among older adults over 65 years old in 9 longevity areas of China.