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.

BACKGROUND:Degenerative scoliosis is defined as a condition that occurs in adulthood with a coronal cobb angle of the spine>10° accompanied by sagittal deformity and rotational subluxation,which often produces symptoms of spinal cord and nerve compression,such as lumbar pain,lower limb pain,numbness,weakness,and neurogenic claudication.The finite element method is a mechanical analysis technique for computer modelling,which can be used for spinal mechanics research by building digital models that can realistically restore the human spine model and design modifications. OBJECTIVE:To review the application of finite element method in the etiology and treatment of degenerative scoliosis. METHODS:The literature databases CNKI,PubMed,and Web of Science were searched for articles on the application of finite element method in degenerative scoliosis published before October 2023.Search terms were"finite element analysis,biomechanics,stress analysis,degenerative scoliosis,adult spinal deformity"in Chinese and English.Fifty-four papers were finally included. RESULTS AND CONCLUSION:(1)The biomechanical findings from the degenerative scoliosis model constructed using the finite element method were identical to those from the in vivo experimental studies,which proves that the finite element method has a high practical value in degenerative scoliosis.(2)The study of the etiology and treatment of degenerative scoliosis by the finite element method is conducive to the prevention of the occurrence of the scoliosis,slowing down the progress of the scoliosis,the development of a more appropriate treatment plan,the reduction of complications,and the promotion of the patients'surgical operation.(3)The finite element method has gradually evolved from a single bony structure to the inclusion of soft tissues such as muscle ligaments,and the small sample content is increasingly unable to meet the research needs.(4)The finite element method has much room for exploration in degenerative scoliosis.

Aim To investigate the regulatory role and mechanism of resveratrol in inhibiting autophagy and promoting apoptosis in choroidal melanoma cells. Methods Choroidal melanoma cells (MUM2B) were divided into control and experimental groups, and treated with different concentrations of resveratrol (0, 10, 20,40,60,80 μmol ·L

OBJECTIVE: To compare the effectiveness of O-arm navigation and C-arm navigation for guiding percutaneous long sacroiliac screws in treatment of Denis type Ⅱ sacral fractures. METHODS: A retrospective study was conducted on clinical data of the 46 patients with Denis type Ⅱ sacral fractures between April 2021 and October 2022. Among them, 19 patients underwent O-arm navigation assisted percutaneous long sacroiliac screw fixation (O-arm navigation group), and 27 patients underwent C-arm navigation assisted percutaneous long sacroiliac screw fixation (C-arm navigation group). There was no significant difference in gender, age, causes of injuries, Tile classification of pelvic fractures, combined injury, the interval from injury to operation between the two groups ( P>0.05). The intraoperative preparation time, the placement time of each screw, the fluoroscopy time of each screw during placement, screw position accuracy, the quality of fracture reduction, and fracture healing time were recorded and compared, postoperative complications were observed. Pelvic function was evaluated by Majeed score at last follow-up. RESULTS: All operations were completed successfully, and all incisions healed by first intention. Compared to the C-arm navigation group, the O-arm navigation group had shorter intraoperative preparation time, placement time of each screw, and fluoroscopy time, with significant differences ( P<0.05). There was no significant difference in screw position accuracy and the quality of fracture reduction ( P>0.05). There was no nerve or vascular injury during screw placed in the two groups. All patients in both groups were followed up, with the follow-up time of 6-21 months (mean, 12.0 months). Imaging re-examination showed that both groups achieved bony healing, and there was no significant difference in fracture healing time between the two groups ( P>0.05). During follow-up, there was no postoperative complications, such as screw loosening and breaking or loss of fracture reduction. At last follow-up, there was no significant difference in pelvic function between the two groups ( P>0.05). CONCLUSION Compared with the C-arm navigation, the O-arm navigation assisted percutaneous long sacroiliac screws for the treatment of Denis typeⅡsacral fractures can significantly shorten the intraoperative preparation time, screw placement time, and fluoroscopy time, improve the accuracy of screw placement, and obtain clearer navigation images.
Humans ; Fracture Fixation, Internal/methods* ; Retrospective Studies ; Imaging, Three-Dimensional ; Bone Screws ; Surgery, Computer-Assisted ; Tomography, X-Ray Computed ; Spinal Fractures/surgery* ; Fractures, Bone/surgery* ; Pelvic Bones/injuries* ; Postoperative Complications ; Neck Injuries

Objective To analyze the high risk factors of obstetric brachial plexus palsy(OBPP),and to explore how to evaluate the relationship between fault medical behavior and OBPP in the process of medical damage forensic identification.Methods A retrospective analysis was carried out on 25 cases of medical damage liability disputes related to OBPP from 2017 to 2021 in Beijing Fayuan Judicial Science Evidence Appraisal Center.The shortcomings of hospitals in birth weight assessment,delivery mode selection,labor process observation and shoulder dystocia management,and the causal relation-ship between them and the damage consequences of the children were summarized.Results Fault medi-cal behavior was assessed as the primary cause in 2 cases,equal cause in 10 cases,secondary cause in 8 cases,minor cause in 1 case,no causal relationship in 1 case,and unclear causal force in 3 cases.Conclusion In the process of forensic identification of OBPP,whether medical behaviors fulfill diagno-sis and treatment obligations should be objectively analyzed from the aspects of prenatal evaluation,de-livery mode notification,standardized use of oxytocin,standard operation of shoulder dystocia,etc.Meanwhile,it is necessary to fully consider the objective risk of different risk factors and the diffi-culty of injury prevention,and comprehensively evaluate the causal force of fault medical behavior in the damage consequences.

Objective To study the correlation between traditional Chinese medicine(TCM)constitution and pathogenic factors in patients with ankylosing spondylitis(AS).Methods One hundred patients of AS and their family members who had medical consultation in the Fifth Hospital of Xi'an(i.e.,Shaanxi Hospital of Integrated Traditional Chinese and Western Medicine)in August 2019 and September 2020 were selected as the study subjects.The guidelines of Classification and Determination of Traditional Chinese Medicine Constitution issued by the China Association of Chinese Medicine were adopted to determine the traditional Chinese medicine(TCM)constitution types of the study subjects.The sociodemographic information,living habits,clinical symptoms,and TCM constitution types of the AS patients and their family members were collected by means of questionnaires and clinical investigations,and then the pathogenic factors of the patients with AS were investigated.The binomial Logistic regression model was used to analyze the correlation between TCM constitution types and pathogenic factors in patients with AS.Results(1)Among the 100 AS patients,the majority of them had the biased constitutions,and the biased constitutions with the occurrence frequency in descending order were yang deficiency constitution,qi deficiency constitution,and damp-heat constitution,which accounted for 33.00%,14.00%,and 18.00%,respectively.(2)The prevalence rates of AS in the first-,second-,and third-degree relatives of AS patients were 56.25%,40.00%and 25.00%,respectively.For the positive rates of human leukocyte antigen B27(HLA-B27)in AS patients and their family members,HLA-B27 in AS patients was all positive,while the positive rates of HLA-B27 in the first-,second-,and third-degree relatives of AS patients were 44.31%,30.67%and 15.63%,respectively.(3)The results of regression analysis showed that the disease duration of AS patients was significantly correlated with qi deficiency constitution,the grading of sacroiliac arthritis was correlated with qi stagnation constitution,and age was correlated with blood stasis constitution(P＜0.05 or P＜0.01).The results indicated that disease duration and age were the important factors affecting the constitution types of AS patients,and disease duration was closely related to qi deficiency while age was closely related to blood stasis.Conclusion AS is a highly hereditary autoimmune disease,and its onset is associated with HLA-B27.Yang deficiency is the basic constitution type of AS,and damp-heat constitution is the main constitution type in the progression of AS(especially in the active stage of the disease).The prolongation of the disease will exacerbate the illness condition of AS and then the manifestations of qi deficiency will be more obvious.

Objective To establish a stable and reliable method for the determination of ethylene oxide residue,and to analyze ethylene oxide residue in multi components made of different materials involved in some medical devices,so as to provide references for sample selection and ethylene oxide residue detection of multi-component medical device kits.Methods A method for the determination of ethylene oxide residue of multi-component medical devices was developed using headspace-gas chromatography and DB-WAX column under the conditions of headspace extraction with equilibration at 80℃ for 20 min,and the weighing mass,linearity,limit of detection,limit of quantification,precision and recovery of the method were determined.Trials of the method were carried out on the items undergoing ethylene oxide sterilization,including disposable perineal care kit,disposable gynecological examination kit,disposable suture dressing kit,disposable debridement kit and the components contacting human body in the disposable dialysis kit,and the abilities of different materials of the components were analyzed in absorbing,retaining and releasing ethylene oxide.Results The method showed high linearity(r=0.999 8)in the range of ethylene oxide mass concentration from 0.4 to 16.0 μg/mL with a weighing mass of 1.00 g,which had the limit of detection being 0.11 μg/mL,the limit of quantification being 0.37 μg/mL and the relative standard deviations(RSDs)for the precision from 0.35％to 1.52％.The average recoveries of different spiked amounts of ethylene oxide in the three blank matrices ranged from 92.68％to 101.42％with the relative standard deviations(RSDs)from 2.46％to 7.59％,which all satisfied the detection requirements.The components made of rubber and acrylonitrile-butadiene-styrene copolymer(ABS)in multi-component medical device kits had the highest ethylene oxide residues,followed by the components made of wood,degreased cotton,polypropylene and polystyrene.Conclusion The method proposed gains advantages in easy operation and high specificity,quantification and reproducibility,which can be used for the determination of ethylene oxide residue in the multi-component medical device kit undergoing ethylene oxide sterilization.References are provided for sample selection of multi-component medical devices.[Chinese Medical Equipment Journal,2024,45(1):56-61]

ObjectiveTo explore host factors interacting with influenza virus nucleoprotein （NP） and study their effects on influenza virus replication， as well as the mechanism of gardenia jasminoides iridoid glycoside （IGE） in inhibiting influenza virus. MethodA yeast two-hybrid system was utilized to screen host factors that interacted with influenza virus NP. Heterogeneous nuclear ribonucleoprotein D0 （HNRNPD）， glucosamine-6-phosphate deaminase 1 （GNPDA1）， poly（rC）-binding protein 1 （PCBP1）， and protein inhibitor of activated signal transducer and activator of transcription （STAT） protein 1 （PIAS1） were validated by immunoprecipitation assay. The effects of PIAS1 and HNRNPD on influenza virus replication were compared by a dual luciferase assay， and the effects of IGE on influenza virus replication were examined in the presence of transfected ribonucleoprotein （RNP） and knockdown of PIAS1. ICR mice were randomly divided into a normal group， model group， oseltamivir phosphate group， and high， medium， and low dose IGE groups， with 10 mice in each group. In addition to the normal group， each group was infected with the influenza A virus FM1 strain by nasal drip to establish a viral pneumonia model. The high， medium， and low dose IGE groups were given drugs of 50， 25， and 12.5 mg∙kg^-1 by gavage， and the oseltamivir phosphate group was given the drug of 27.5 mg∙kg^-1 by gavage. Equal amounts of distilled water were instilled in the normal and model groups for four consecutive days. Later， protein expression of PIAS1， NP， phosphorylated （p）-STAT3， STAT3， p-STAT1， and STAT1 were detected in the lung tissue by Western blot. ResultIn yeast two-hybrid assays， 16 potential host targets interacting with influenza virus NP were identified. Immunoprecipitation experiments revealed that HNRNPD and PIAS1 could interact with influenza virus NP. The dual luciferase reporter assays found that both PIAS1 knockdown and overexpression significantly affected IAV RNP activity （P<0.05， P<0.01）， and the effect of HNRNPD on IAV RNP was not significant. Both high and low dose IGE groups reduced influenza virus replication （P<0.05） and reversed the increase in influenza virus replication caused by the knockdown of PIAS1（P<0.05， P<0.01）. The expressions of PIAS1， NP， p-STAT3， p-STAT1， and STAT1 in the lung tissue of infected mice were reduced to different degrees in each IGE group （P<0.05， P<0.01）. ConclusionPIAS1 interacts with influenza virus NP and is able to inhibit influenza virus replication. IGE may exert antiviral effects by inhibiting the activity of IAV RNP through the PIAS1/STAT1 pathway.

Objectives:To investigate the effect of the expression of low-density lipoprotein receptor associated protein (LDLR) on the vascular abnormalities in hepatocellular carcinoma (HCC) and its mechanisms.Methods:Based on the information of Oncomine Cancer GeneChip database, we analyzed the correlation between the expression level of LDLR and the expression level of carcinoembryonic antigen (CEA) and CD31 in hepatocellular carcinoma tissues. Lentiviral transfection of short hairpin RNA target genes was used to construct LDLR-knockdown MHCC-97H and HLE hepatocellular carcinoma cells. The differential genes and their expression level changes in LDLR-knockdown hepatocellular carcinoma cells were detected by transcriptome sequencing, real-time fluorescence quantitative polymerase chain reaction, and protein immunoblotting. The gene-related signaling pathways that involve LDLR were clarified by enrichment analysis. The effect of LDLR on CEA was assessed by the detection of CEA content in conditioned medium of hepatocellular carcinoma cells. Angiogenesis assay was used to detect the effect of LDLR on the angiogenic capacity of human umbilical vein endothelial cells, as well as the role of CEA in the regulation of angiogenesis by LDLR. Immunohistochemical staining was used to detect the expression levels of LDLR in 176 hepatocellular carcinoma tissues, and CEA and CD31 in 146 hepatocellular carcinoma tissues, and analyze the correlations between the expression levels of LDLR, CEA, and CD31 in the tissues, serum CEA, and alanine transaminase (ALT).Results:Oncomine database analysis showed that the expressions of LDLR and CEA in the tissues of hepatocellular carcinoma patients with portal vein metastasis were negatively correlated ( r=-0.64, P=0.001), whereas the expressions of CEA and CD31 in these tissues were positively correlated ( r=0.46, P=0.010). The transcriptome sequencing results showed that there were a total of 1 032 differentially expressed genes in the LDLR-knockdown group and the control group of MHCC-97H cells, of which 517 genes were up-regulated and 515 genes were down-regulated. The transcript expression level of CEACAM5 was significantly up-regulated in the cells of the LDLR-knockdown group. The Gene Ontology (GO) function enrichment analysis showed that the differential genes were most obviously enriched in the angiogenesis function. The Kyoto Encyclopedia of Genes and Genomes (KEGG) signaling pathway enrichment analysis showed that the relevant pathways involved mainly included the cellular adhesion patch, the extracellular matrix receptor interactions, and the interactions with the extracellular matrix receptors. The CEA content in the conditioned medium of the LDLR-knockdown group was 43.75±8.43, which was higher than that of the control group (1.15±0.14, P＜0.001). The results of angiogenesis experiments showed that at 5 h, the number of main junctions, the number of main segments, and the total area of the lattice formed by HUVEC cells cultured with the conditioned medium of MHCC-97H cells in the LDLR-knockdown group were 295.3±26.4, 552.5±63.8, and 2 239 781.0±13 8211.9 square pixels, which were higher than those of the control group (113.3±23.5, 194.8±36.5, and 660 621.0±280 328.3 square pixels, respectively, all P＜0.01).The number of vascular major junctions, the number of major segments, and the total area of the lattice formed by HUVEC cells cultured in conditioned medium with HLE cells in the LDLR-knockdown group were 245.3±42.4, 257.5±20.4, and 2 535 754.5±249 094.2 square pixels, respectively, which were all higher than those of the control group (113.3±23.5, 114.3±12.2, and 1 565 456.5±219 259.7 square pixels, respectively, all P＜0.01). In the conditioned medium for the control group of MHCC-97H cells,the number of main junctions, the number of main segments, and the total area of the lattice formed by the addition of CEA to cultured HUVEC cells were 178.9±12.0, 286.9±12.3, and 1 966 990.0±126 249.5 spixels, which were higher than those in the control group (119.7±22.1, 202.7±33.7, and 1 421 191.0±189 837.8 square pixels, respectively). The expression of LDLR in hepatocellular carcinoma tissues was not correlated with the expression of CEA, but was negatively correlated with the expression of CD31 ( r=-0.167, P=0.044), the level of serum CEA ( r=-0.061, P=0.032), and the level of serum ALT (r=-0.147, P=0.05). The expression of CEA in hepatocellular carcinoma tissues was positively correlated with the expression of CD31 ( r=0.192, P=0.020). The level of serum CEA was positively correlated with the level of serum ALT ( r=0.164, P=0.029). Conclusion:Knocking down LDLR can promote vascular abnormalities in HCC by releasing CEA.

Currently,human health due to corona virus disease 2019(COVID-19)pandemic has been seriously threatened.The coronavirus severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)spike(S)protein plays a crucial role in virus transmission and several S-based therapeutic approaches have been approved for the treatment of COVID-19.However,the efficacy is compromised by the SARS-CoV-2 evolvement and mutation.Here we report the SARS-CoV-2 S protein receptor-binding domain(RBD)inhibitor licorice-saponin A3(A3)could widely inhibit RBD of SARS-CoV-2 variants,including Beta,Delta,and Omicron BA.1,XBB and BQ1.1.Furthermore,A3 could potently inhibit SARS-CoV-2 Omicron virus in Vero E6 cells,with EC50 of 1.016 pM.The mechanism was related to binding with Y453 of RBD deter-mined by hydrogen-deuterium exchange mass spectrometry(HDX-MS)analysis combined with quan-tum mechanics/molecular mechanics(QM/MM)simulations.Interestingly,phosphoproteomics analysis and multi fluorescent immunohistochemistry(mIHC)respectively indicated that A3 also inhibits host inflammation by directly modulating the JNK and p38 mitogen-activated protein kinase(MAPK)path-ways and rebalancing the corresponding immune dysregulation.This work supports A3 as a promising broad-spectrum small molecule drug candidate for COVID-19.