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.

The Masquelet technique, also known as the induced membrane technique, is a surgical technique for repairing large bone defects based on the use of a membrane generated by a foreign body reaction for bone grafting. This technique is not only simple to perform, with few complications and quick recovery, but also has excellent clinical results. To better understand the mechanisms by which this technique promotes bone defect repair and the factors that require special attention in practice, we examined and summarized the relevant research advances in this technique by searching, reading, and analysing the literature. Literature show that the Masquelet technique may promote the repair of bone defects through the physical septum and molecular barrier, vascular network, enrichment of mesenchymal stem cells, and high expression of bone-related growth factors, and the repair process is affected by the properties of spacers, the timing of bone graft, mechanical environment, intramembrane filling materials, artificial membrane, and pharmaceutical/biological agents/physical stimulation.
Humans ; Bone Transplantation/methods* ; Membranes, Artificial ; Bone Regeneration ; Animals

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]

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 propose an effective method for the determination of 2-chloroethanol(ethylene chlorohydrin,ECH)and ethylene glycol(EG)residues in disposable infusion sets sterilized by ethylene oxide(EO).Methods Extraction with the ratio of the mass of the disposable infusion set to the volume of the medium being 0.4 g/mL was carried out with the 8890B gas chromatograph with liquid injection,DB-WAX column and ethanol extraction medium,and quantitative determination of ECH and EG in disposable infusion sets were implemented after extraction at 37℃for 10 h.Results The method proposely was highly specific,and showed high linearity in the range of 1.25-100.00 μg/mL for both ECH and EG.The limits of detection were 0.31 and 0.11 μg/mL for ECH and EG,respectively,and the relative standard deviations(RSD)of the precision of ECH was in the range of 0.24％-2.03％and those of EG was in the range of 0.16％-0.87％.The average recoveries were 95.02％-100.58％for ECH and 99.15％-99.98％for EG.Conclusion The method proposed for the determination of ECH and EG residues gains advantages in easy operation,specificity,detection accuracy and reproducibility,and meets the requirements for the determination of ECH and EG residues in EO-sterilized disposable infusion sets.[Chinese Medical Equipment Journal,2024,45(10):31-36]

Objective:To evaluate inflammation early in the infarct zone and its dynamic changes after acute myocardial infarction (AMI) using 18F-FDG PET imaging, and analyze its relationship with left ventricular remodeling progression (LVRP). Methods:Sixteen Bama miniature pigs (4-6 months old, 8 females) were selected. AMI models were established by balloon occlusion of the left anterior descending artery. 18F-FDG PET imaging was performed before AMI and at days 1, 5, 8, and 14 post-AMI to evaluate the regional inflammation response. 18F-FDG SUV ratio (SUVR) and the percentage of uptake area of left ventricle (F-extent) in the infarct zone, and the SUVRs of the spleen and bone marrow, were measured. Echocardiography and 99Tc m-methoxyisobutylisonitrile(MIBI) SPECT myocardial perfusion imaging (MPI) were performed at the above time points and on day 28 post-AMI to assess left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV), left ventricular ejection fraction (LVEF), and myocardial perfusion defect extent. The degree of LVRP at day 28 post-AMI was defined as ΔLVESV(%)=(LVESV AMI 28 d-LVESV AMI 1 d)/LVESV AMI 1 d×100%. Data were analyzed using repeated measures analysis of variance, Kruskal-Wallis rank sum test and Pearson correlation analysis. Results:Twelve pigs were successfully modeled and completed the study. Inflammation in the infarct zone persisted until day 14 post-AMI. The SUVR of the infarct zone pre-AMI and at days 1, 5, 8, and 14 post-AMI were 1.03±0.08, 3.49±1.06, 2.93±0.90, 2.38±0.76, and 1.63±0.62, respectively ( F=49.31, P<0.001). The F-extent values in the infarct zone pre-AMI and at days 1, 5, 8, and 14 post-AMI were 0, (40.08±12.46)%, (40.00±12.76)%, (31.08±12.82)%, and 16.50%(7.25%, 22.00%), respectively ( H=37.61, P=0.001). There were no significant differences in the SUVRs of bone marrow and spleen before and after AMI ( F values: 0.69 and 0.77, both P>0.05). At day 1 post-AMI, both SUVR and F-extent in the infarct zone were significantly correlated with LVRP ( r values: 0.82 and 0.70, P values: 0.001 and 0.035). Conclusions:18F-FDG PET imaging can be used to evaluate inflammation in the infarct area and its dynamic changes after AMI. Inflammation in the infarct area is severe at day 1, and then gradually decreases. The extent and severity of inflammation visible on 18F-FDG PET imaging 1 d after AMI are closely related to LVRP.

Objective: To compare the predictive efficacy of the two thrombosis risk assessment scores (Padua and IMPEDE scores) in venous thromboembolism (VTE) within 6 months in patients with newly diagnosed multiple myeloma (NDMM) in China. Methods: This study reviewed the clinical data of 421 patients with NDMM hospitalized in Beijing Jishuitan Hospital from April 2014 to February 2022. The sensitivity, specificity, accuracy, and Youden index of the two scores were calculated to quantify the thrombus risk assessment of VTE by the Padua and IMPEDE scores. The receiver operating characteristics curves of the two evaluation scores were drawn. Results: The incidence of VTE was 14.73%. The sensitivity, specificity, accuracy, and Youden index of the Padua score were 100%, 0%, 14.7%, and 0% and that of the IMPEDE score was 79%, 44%, 49.2%, and 23%, respectively. The areas under the curve of Padua and IMPEDE risk assessment scores were 0.591 and 0.722, respectively. Conclusion: IMPEDE score is suitable for predicting VTE within 6 months in patients with NDMM.
Humans ; Venous Thromboembolism/etiology* ; Multiple Myeloma/diagnosis* ; Risk Assessment ; Risk Factors ; ROC Curve ; Retrospective Studies

Objective: This study aimed to investigate the association between epicardial fat volume (EFV) and obstructive coronary artery disease (CAD) with myocardial ischemia, and evaluate the incremental value of EFV on top of traditional risk factors and coronary artery calcium (CAC) in predicting obstructive CAD with myocardial ischemia. Methods: This study was a retrospective cross-sectional study. Patients with suspected CAD who underwent coronary angiography (CAG) and single photon emission computerized tomography-myocardial perfusion imaging (SPECT-MPI) at the Third Affiliated Hospital of Soochow University from March 2018 to November 2019 were consecutively enrolled. EFV and CAC were measured by non-contrast chest computed tomography (CT) scan. Obstructive CAD was defined as coronary artery stenosis≥50% in at least one of the major epicardial coronary arteries, and myocardial ischemia was defined as reversible perfusion defects in stress and rest MPI. Obstructive CAD with myocardial ischemia was defined in patients with coronary stenosis severity≥50% and reversible perfusion defects in the corresponding areas of SPECT-MPI. Patients with myocardial ischemia bot without obstructive CAD were defined as none-obstructive CAD with myocardial ischemia group. We collected and compared the general clinical data, CAC and EFV between the two groups. Multivariable logistic regression analysis was performed to identify the relationship between EFV and obstructive CAD with myocardial ischemia. ROC curves were performed to determine whether addition of EFV improved predictive value beyond traditional risk factors and CAC for obstructive CAD with myocardial ischemia. Results: Among the 164 patients with suspected CAD, 111 patients were males, and average age was (61.4±9.9) years old. 62 (37.8%) patients were included into the obstructive CAD with myocardial ischemia group. 102 (62.2%) patients were included into the none-obstructive CAD with myocardial ischemia group. EFV was significantly higher in obstructive CAD with myocardial ischemia group than in none-obstructive CAD with myocardial ischemia group ((135.63±33.29)cm³ and (105.18±31.16)cm³, P<0.01). Univariate regression analysis showed the risk of obstructive CAD with myocardial ischemia increased by 1.96 times for each SD increase in EFV(OR 2.96; 95%CI, 1.89-4.62; P<0.01). After adjustment for traditional risk factors and CAC, EFV remained as an independent predictor for obstructive CAD with myocardial ischemia (OR, 4.48, 95%CI, 2.17-9.23; P<0.01). Addition of EFV to CAC and traditional risk factors was related to larger AUC for predicting obstructive CAD with myocardial ischemia (0.90 vs. 0.85, P=0.04, 95%CI: 0.85-0.95) and the global chi-square increased by 21.81 (P<0.05). Conclusions: EFV is an independent predictor for obstructive CAD with myocardial ischemia. Addition of EFV to traditional risk factors and CAC has incremental value for predicting obstructive CAD with myocardial ischemia in this patient cohort.
Male ; Humans ; Middle Aged ; Aged ; Female ; Coronary Artery Disease/diagnostic imaging* ; Cross-Sectional Studies ; Retrospective Studies ; Myocardial Ischemia/diagnostic imaging* ; Coronary Stenosis ; Calcium

ObjectiveTo understand the composition of related characteristics of HIV/AIDS cases in Lanzhou and analyze the influencing factors of AIDS-related deaths. MethodsThe information of HIV/AIDS cases reported in Lanzhou from 2011 to 2019 was collected， the method of survival was used analysis and Bayesian Cox Proportional Hazard Regression Model was constructed to analyze the related factors of death. ResultsA total of 2 312 HIV/AIDS patients were selected in this study， including 45 AIDS-related deaths. The results of multivariate regression showed that the older the patients were， the higher the risk of death was； the risk of death of AIDS patients at the time of diagnosis was 13.91 times higher than that of HIV-infected patients； Patients who received CD4 testing had a lower risk of death than those who did not； The risk of death was 0.22 times higher among those who received antiretroviral therapy than those who did not receive antiretroviral therapy. ConclusionsAge at diagnosis， course of disease， antiviral therapy were the influencing factors of AIDS-related death in HIV/AIDS patients in Lanzhou. Therefore， it is necessary to strengthen health education for AIDS-related groups， advocate early detection， early diagnosis， and early treatment， expand the coverage of AIDS testing and treatment， prolong the survival time of AIDS patients.