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 explore the mediating role of activities of daily living (ADL) in pain and depressive symptoms in the elderly in China. Methods Utilizing the data from 2020 China Health and Retirement Longitudinal Study, 4403 Chinese elderly individuals aged ≥ 60 years old were selected as the research subjects. Depression Scale (CES-D 10) of the Center for Epidemiological Survey and ADL scale were used in the study. The PROCESS4.1 macro was used to test the mediating effect of daily living activities between pain and depressive symptoms, and the Bootstrap method was applied for verification of the mediating variables. Results A total of 2368 cases of depressive symptoms were detected in the elderly in China, with a detection rate of 53.78%. Pain was positively correlated with depressive symptoms (r=0.27, P<0.01), and activities of daily living were negatively correlated with pain and depressive symptoms (r=-0.27, -0.337, P<0.01). The results showed that the total effect value of pain on depressive symptoms was 0.33, the direct effect value was 0.24, and the mediating effect value of daily living activities was 0.09, accounting for 27.27%. Conclusion Pain and activities of daily living are important factors influencing depressive symptoms in the elderly, and activities of daily living play a partial mediating role in the relationship between pain and depressive symptoms in the elderly.

Sepsis is a condition characterized by organ dysfunction resulting from the systemic inflammatory response triggered by an infection. Excessive inflammation and immunosuppression are intertwined, and severe cases may even develop into multiple organ failure. Studies have shown that indoleamine 2,3-dioxygenase 1-mediated tryptophan metabolism is involved in the occurrence and development of sepsis, and elevated plasma kynurenine levels and Kyn/Trp ratios are early indicators of sepsis development. In this paper, we provide a comprehensive summary of the role of IDO1 in the acute inflammatory phase of sepsis, late immunosuppression, and organ damage. This includes its regulation of inflammatory state, immune cell function, blood pressure, and other aspects. Additionally, we analyze preclinical studies on targeted IDO1 drugs. An in-depth understanding and study of IDO may help to understand the pathogenesis and clinical significance of sepsis and multiple organ damage from a new perspective and provide new research ideas for exploring its prevention and treatment methods.

Objective To explore the mediating effect of health-promoting lifestyle on the relationship between health literacy and stigma among middle-aged and elderly patients with type 2 diabetes mellitus (T2DM). Methods A stratified random sampling method was used to select 415 patients with T2DM from three general hospitals in Weifang to conduct a questionnaire survey using the Disease Stigma Assessment Scale for Type 2 Diabetes Mellitus (DSAS-2), the Health Literacy Scale, and the Type 2 Diabetes Health Promotion Scale (T2DHPS). Results Sickness stigma was negatively correlated with health literacy (r=-0.547, P<0.01) and negatively correlated with health promotion (r=-0.505, P<0.01), while health promotion was positively correlated with health literacy (r=0.398, P<0.01). Health-promoting lifestyle mediated the association between health literacy and stigma (β=0.0383, P<0.01), with the mediating effect accounting for 16.00% of the total effect. Conclusion Health literacy can influence the stigma of patients with type 2 diabetes mellitus through health promotion lifestyle, suggesting that the stigma of patients with diabetes can be improved through health promotion lifestyle intervention.

Objective:To discuss the regulatory effect of physiological tensile stress on the differentiation of chondrocytes,and to clarify the associated signaling pathway mechanism.Methods:The ATDC5 chondrocytes were cultured in vitro and subjected to physiological tensile stress by four-point bending cell mechanical loading device.Initially,the cells were divided into control group and tensile stress group(2 000 μstrain/2 h group),and further divided into different stress magnitudes(1 000,2 000,and 3 000 μstrain)for 2 h,and 2 000 μstrain for different duration time(1,2,and 4 h)groups;the cells without tensile stress were used as control group.Real-time fluorescence quantitative PCR(RT-qPCR)method was used to detect the expression levels of type Ⅱ collagen(Col-Ⅱ),type Ⅹ collagen(Col-Ⅹ),aggregated proteoglycom(Aggrecan),sex-determining region Y-box protein 9(SOX9),vascular endothelial growth factor(VEGF),proliferating cell nuclear antigen(PCNA),Nel-like molecule tyep 1(Nell-1),Runt-related transcription factor 2(Runx2),Indian hedgehog(Ihh),patched homolog 1(Ptch-1),GLI family zinc finger protein 1(Gli-1),and hedgehog interacting protein 1(Hhip-1)mRNA in the cells in various groups;Western blotting method was used to detect the expression levels of Nell-1,Runx2,and Ihh proteins in the cells in various groups.The ATDC5 cells were divided into control group,cyclopamine group,tensile stress group,and cyclopamine + tensile stress group.RT-qPCR method was used to detect the expression levels of Nell-1,Ihh,Ptch-1,Gli-1,and Hhip-1 mRNA in the cells in various groups;Western blotting method was used to detect the expression levels of Nell-1 and Ihh proteins in the cells in various groups.Results:Compared with control group,the expression levels of Col-Ⅱ,Col-Ⅹ,Aggrecan,SOX9,VEGF,and PCNA mRNA in the cells in 2 000 μstrain/2 h group were significantly increased(P<0.01);after treated with 2 000 μstrain tensile stress for different duration time(1,2,and 4 h)or different tensile stresses(1 000,2 000,and 3 000 μstrain)for 2 h,compared with control group,the expression levels of Runx2 mRNA in the cells in other groups were increased with the prolongation of time or the increasing of tensile stress(P<0.01),and the expression levels of Nell-1,Ihh,Ptch-1,Gli-1,and Hhip-1 mRNA were gradually increased(P<0.01),the expression levels reached the peaking at 2 000 μstrain/2 h,and then decreased but remained significantly higher than that in control group(P<0.01).The Western blotting results showed that the expression levels of Nell-1,Runx2,and Ihh proteins in the cells were consistent with the change trend of mRNA expression levels.After pre-treated with cyclopamine,compared with control group,the expression levels of Ihh,Ptch-1,Gli-1,and Hhip-1 mRNA in the cells in cyclopamine group were significantly decreased(P<0.01),and the expression levels of Ihh,Ptch-1,Gli-1,and Hhip-1 mRNA in the cells in tensile stress and cyclopamine+tensile stress groups were significantly increased(P<0.01);compared with cyclopamine group,the expression levels of Nell-1,Ihh,Ptch-1,Gli-1,and Hhip-1 mRNA in the cells in cyclopamine+tensile stress group were significantly increased(P<0.01);compared with tensile stress group,the expression levels of Ihh,Ptch-1,Gli-1,and Hhip-1 mRNA in the cells in cyclopamine + tensile stress group were significantly decreased(P<0.01).Compared with control group,the expression level of Ihh protein in the cells in cyclopamine group was significantly decreased(P<0.01),but there was no significant difference in expression level of Nell-1 protein in the cells between control group and cyclopamine group(P>0.05),while the expression levels of Nell-1 and Ihh proteins in the cells in tensile stress group and cyclopamine + tensile stress group were significantly increased(P<0.01);compared with cyclopamine group,the expression levels of Nell-1 and Ihh proteins in the cells in tensile stress group and cyclopamine + tensile stress group were significantly increased(P<0.01);compared with tensile stress group,in the expression levels of Nell-1 and Ihh proteins in the cells in cyclopamine + tensile stress group had no significant differences(P>0.05).Conclusion:After stimulated with physiological tensile stress,Nell-1 can activate the Ihh signaling pathway upstream,and regulate the differentiation of the ATDC5 chondrocytes.

BACKGROUND:Multiple sclerosis is a chronic inflammatory demyelinating disease of the central nervous system mediated by T cells.The Toll-like receptors(TLRs)/myeloid differentiation factor 88(MyD88)/nuclear factor kappa-B(NF-κB)signaling pathway plays an important role in the development of the disease.Exploring the specific mechanism of the signaling pathway is essential for further treatment of the disease and improving the prognosis of patients. OBJECTIVE:To review the TLRs/MyD88/NF-κB signaling pathway and its role in multiple sclerosis/experimental autoimmune encephalomyelitis models,which provides new ideas and strategies for the treatment of multiple sclerosis by inhibiting the TLRs/MyD88/NF-κB signaling pathway. METHODS:The literature related to the topic from January 2002 to December 2022 was searched in CNKI,WanFang and PubMed databases.A total of 61 articles were finally included for analysis. RESULTS AND CONCLUSION:The TLRs/MyD88/NF-κB signaling pathway is an important pathway that triggers a pro-inflammatory immune response.The TLRs/MyD88/NF-κB signaling pathway plays an important role in the development of multiple sclerosis by regulating the antigen presentation of dendritic cells,destroying the integrity of the blood-brain barrier,and promoting the activation of T cells,B cells and microglia.By targeting TLRs,MyD88 and NF-κB molecules,inhibiting the activation or signal transduction of TLRs,MyD88 and NF-κB,and reducing the secretion of pro-inflammatory factors,multiple sclerosis can be treated.Animal studies have shown that active ingredients of traditional Chinese medicines,such as flavonoids and glycosides,and traditional Chinese medicine compound formulas,such as Buyang Huanwu Tang,can also treat experimental autoimmune encephalomyelitis by regulating the TLRs/MyD88/NF-κB signaling pathway,which points to the direction of searching for medicines targeting the TLRs/MyD88/NF-κB signaling pathway for the treatment of multiple sclerosis.

Objective To investigate the effect and mechanism of naringin on acute lung injury(ALI)in septic mice.Methods The acute lung injury mouse model of sepsis was established by intraperitoneal injection of 10 mg·kg-1 lipopolysaccharide.The mice were randomly divided into control group(injected with equal amounts of saline and phosphate buffer),model group(mouse model of sepsis acute lung injury),naringin group(50 mg·kg-1 naringin injected intraperitoneally 1 hour prior to lipopolysaccharide modeling)and BzATP group(50 mg·kg-1 naringin+5 mg·kg-1 BzATP injected intraperitoneally 1 hour prior to lipopolysaccharide modeling).After modeling,lung tissues were taken 24 h later,lung coefficients were calculated;lung tissue interleukin(-ILβ-1 β),interleukin-10(IL-10)and tumor necrosis factor-α(TNF-α)levels were detected by enzyme-linked immunosorbent assay;the expression of purinergic 2X7 receptor(P2X7R),nucleotide-binding oligomerization structural domain-like receptor protein 3(NLRP3)and nuclear factor-κB(NF-κB)proteins were detected by Western blotting.Results The lung coefficients in the control,model,naringin and BzATP groups were(6.26±0.31),(9.09±1.02),(7.02±0.45)and(8.79±0.55)mg·g-1;the contents of TNF-α were(56.41±0.35),(174.68±1.58),(85.23±1.68)and(162.97±3.42)pg·mL-1;the contents of IL-1β were(44.18±7.37),(119.91±17.16),(85.41±2.14)and(104.57±3.39)pg·mL-1;the contents of IL-10 were(50.82±2.89),(28.31±1.86),(42.82±1.98)and(25.19±1.69)pg·mL-1;P2X7 protein expression levels were 0.45±0.16,1.33±0.10,0.64±0.09 and 1.05±0.18;NF-κB protein expression levels were 0.38±0.19,1.29±0.09,0.57±0.11 and 0.92±0.07;NLRP3 protein expression levels were 0.72±0.14,1.28±0.23,0.75±0.09 and 1.27±0.23.Compared with the model group in the control group and naringin group,compared with the naringin group in the BzATP group,the differences of the above indexes were statistically significant(P＜0.01,P＜0.05).Conclusion Naringin attenuates acute lung injury in septic mice by inhibiting the P2X7 receptor-mediated NF-κB/NLRP3 signaling pathway.

Micro vesicles(MVs)are the membrane structures produced by the direct outgrowth of the cell membrane,which can be involved in the pathogenesis of many diseases;MVs can also be used in the diagnosis of diseases and the prediction of prognosis.In recent years,there are more and more researches related to MVs in the field of sepsis,and the mechanism of MVs in sepsis is now reviewed.

Objective This study aimed to compare the current Essen rabies post-exposure immunization schedule(0-3-7-14-28)in China and the simple 4-dose schedule(0-3-7-14)newly recommended by the World Health Organization in terms of their safety,efficacy,and protection. Methods Mice were vaccinated according to different immunization schedules,and blood was collected for detection of rabies virus neutralizing antibodies(RVNAs)on days 14,21,28,35,and 120 after the first immunization.Additionally,different groups of mice were injected with lethal doses of the CVS-11 virus on day 0,subjected to different rabies immunization schedules,and assessed for morbidity and death status.In a clinical trial,185 rabies-exposed individuals were selected for post-exposure vaccination according to the Essen schedule,and blood was collected for RVNAs detection on days 28 and 42 after the first immunization. Results A statistically significant difference in RVNAs between mice in the Essen and 0-3-7-14 schedule groups was observed on the 35th day(P<0.05).The groups 0-3-7-14,0-3-7-21,and 0-3-7-28 showed no statistically significant difference(P>0.05)in RVNAs levels at any time point.The post-exposure immune protective test showed that the survival rate of mice in the control group was 20%,whereas that in the immunization groups was 40%.In the clinical trial,the RVNAs positive conversion rates on days 28(14 days after 4 doses)and 42(14 days after 5 doses)were both 100%,and no significant difference in RVNAs levels was observed(P>0.05). Conclusion The simple 4-dose schedule can produce sufficient RVNAs levels,with no significant effect of a delayed fourth vaccine dose(14-28 d)on the immunization potential.

Objective Recombinase-aided polymerase chain reaction(RAP)is a sensitive,single-tube,two-stage nucleic acid amplification method.This study aimed to develop an assay that can be used for the early diagnosis of three types of bacteremia caused by Staphylococcus aureus(SA),Pseudomonas aeruginosa(PA),and Acinetobacter baumannii(AB)in the bloodstream based on recombinant human mannan-binding lectin protein(M1 protein)-conjugated magnetic bead(M1 bead)enrichment of pathogens combined with RAP. Methods Recombinant plasmids were used to evaluate the assay sensitivity.Common blood influenza bacteria were used for the specific detection.Simulated and clinical plasma samples were enriched with M1 beads and then subjected to multiple recombinase-aided PCR(M-RAP)and quantitative PCR(qPCR)assays.Kappa analysis was used to evaluate the consistency between the two assays. Results The M-RAP method had sensitivity rates of 1,10,and 1 copies/μL for the detection of SA,PA,and AB plasmids,respectively,without cross-reaction to other bacterial species.The M-RAP assay obtained results for<10 CFU/mL pathogens in the blood within 4 h,with higher sensitivity than qPCR.M-RAP and qPCR for SA,PA,and AB yielded Kappa values of 0.839,0.815,and 0.856,respectively(P<0.05). Conclusion An M-RAP assay for SA,PA,and AB in blood samples utilizing M1 bead enrichment has been developed and can be potentially used for the early detection of bacteremia.