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 As one of the key populations in the prevention and treatment of iodine deficiency disorders, it is important to continuously monitor the iodine nutritional level of school-age children. The current reference interval for thyroid volume in China is based on age only, without taking into account differences in individual developmental levels, and the distribution of thyroid volume may vary regionally due to economic, demographic, and environmental factors. The current reference cut-off points for thyroid volume proposed by the World Health Organization are not based on the Chinese population. Objective To understand the iodine nutritional status and distribution of thyroid volume (Tvol) among children aged 8-10 years in Huangpu District, Shanghai, China, to identify impact factors of Tvol, and to propose a reference range upper limit for local thyroid health surveillance, so as to provide a basis for goiter control and prevention. Methods Six hundred children aged 8-10 years in Huangpu District were recruited in 2017, 2020, and 2023, and body height, weight, thyroid volume, urinary iodine, and iodine content of household edible salt were determined. A multilevel model was constructed using population density and area as regional variables, and age, body surface area (BSA), and body mass index (BMI) as potential impact factors for at the individual level, to assess their effects on thyroid volume. Quantile regression of thyroid volume was performed, and the 98th percentile (P₉₈) of thyroid volume was predicted based on age and BSA. Results The iodized salt coverage in the households of surveyed children in 2017, 2020, and 2023 was 72.0%, 57.0%, and 48.0%, respectively, and the iodized salt coverage decreased by year (χ²=24.31, P<0.001). The urinary iodine level of children in 2017 was higher than that in 2020 and 2023 (χ²=18.77, P<0.001). The Tvol medians of children in 2017, 2020, and 2023 were 2.29, 2.49, and 2.97 mL, respectively, and the Tvol increased by year (χ²=60.04, P<0.001). The proportion of goiter was higher in children in 2023 than in 2017 and 2020 (χ²=6.57, P<0.05). Sex differences were not statistically significant for urinary iodine levels, thyroid volume, and goiter. The median Tvol was 2.26, 2.58, and 2.76 mL in children of 8, 9, and 10 years old respectively, and the Tvol increased with age (χ²=49.02, P <0.001). Tvol was positively correlated with age, BSA, and BMI with correlation coefficients of 0.2846, 0.3723, and 0.2950, respectively. The final quantile regression model showed that the strongest effect of BSA was associated with the 98th percentile of Tvol. Multilevel models considering population density or area as regional variables failed to achieve convergence. Conclusion To establish the upper limit of the reference interval for thyroid volume of healthy children in Huangpu District, the effects of age and BSA should be considered at the individual level, and the upper limit of the normal interval for goiter screening is suggested to be the 98th percentile value of BSA at the same age. In addition, the adaptability of population density and regional area as indicators of regional aggregation of thyroid volume distribution still needs to be further explored.

Background::Clinical opportunistic screening is a cost-effective cancer screening modality. This study aimed to establish an easy-to-use diagnostic model serving as a risk stratification tool for identification of individuals with malignant gastric lesions for opportunistic screening.Methods::We developed a questionnaire-based diagnostic model using a joint dataset including two clinical cohorts from northern and southern China. The cohorts consisted of 17,360 outpatients who had undergone upper gastrointestinal endoscopic examination in endoscopic clinics. The final model was derived based on unconditional logistic regression, and predictors were selected according to the Akaike information criterion. External validation was carried out with 32,614 participants from a community-based randomized controlled trial.Results::This questionnaire-based diagnostic model for malignant gastric lesions had eight predictors, including advanced age, male gender, family history of gastric cancer, low body mass index, unexplained weight loss, consumption of leftover food, consumption of preserved food, and epigastric pain. This model showed high discriminative power in the development set with an area under the receiver operating characteristic curve (AUC) of 0.791 (95% confidence interval [CI]: 0.750–0.831). External validation of the model in the general population generated an AUC of 0.696 (95% CI: 0.570–0.822). This model showed an ideal ability for enriching prevalent malignant gastric lesions when applied to various scenarios.Conclusion::This easy-to-use questionnaire-based model for diagnosis of prevalent malignant gastric lesions may serve as an effective prescreening tool in clinical opportunistic screening for gastric cancer.

Transcatheter aortic valve replacement(TAVR)has emerged as a promising therapeutic alternative for addressing aortic valve-related pathologies.However,the occurrence of rapid arrhythmias linked to TAVR procedures is progressively drawing scrutiny.Presently,pharmacologic interventions constitute the mainstay of managing atrial arrhythmias related to TAVR,while the potential of ablation as a viable treatment modality remains undefined.Notably,in cases where the arrhythmia's genesis is presumed to be intricately linked to the prosthetic valve,the practicality and safety of ablation procedures remain unverified.Our institution has successfully ventured into radiofrequency ablation for a distinctive patient presenting with this intricate condition,thereby tentatively affirming the efficacy and safety of catheter ablation administered on the surface of prosthetic valves.

Mitral valve prolapse is one of the common causes of mitral regurgitation.Mitral valve prolapse complicated with leaflet cleft is rare in clinical practice,which most often undergo surgical mitral valve repair or mitral valve replacement.We report a case of mitral valve prolapse with posterior leaflet cleft treated by transcatheter edge-to-edge mitral valve repair,in order to provide a model for similar cases.

Objective:To analyze the clinical phenotype and gene mutation of a genetic coagulation factor Ⅻ(FⅫ)deficiency pedigree and explore the molecular pathogenesis.Methods:The activated partial thromboplastin time(APTT)and FⅫ activity(FⅫ:C)were detected by clotting method.The FⅫ antigen(FⅫ:Ag)was tested with ELISA.All exons and flanks of F12 gene were determined by Sanger sequencing.ClustalX-2.1-win,PROVEAN and Swiss-Pdb Viewer software were used to analyze the conservatism of amino acids at the mutant site,forecast whether the mutant amino acids were harmful and confirm the influence of the mutation on protein structure.Results:The APTT of the proband prolonged to 71.3 s.The FⅫ:C and FⅫ;Ag were decreased to 5％and 6％,respectively.There were two heterozygous missense mutations c.580G＞T and c.1681G＞A detected in exon 7 and exon 14 of F12 gene,resultingin p.Gly175Cys and p.Gly542Ser,severally.Proband's father carried the p.Gly175Cys heterozygous mutation,while mother,brother and daughter had the p.Gly542Ser heterozygous mutation.Software analysis showed that both Gly175 and Gly542 were conserved,the two mutations were harmful and when mutations had occurred,the corresponding sites affected the protein local structure.Conclusion:The p.Gly175Cys and p.Gly542Ser compound heterozygous mutations are the molecular pathogenesis of the hereditary coagulation FⅫ deficiency pedigree.The p.Gly175Cys mutation has been detected for the first time in the world.

Objective:To examine the factors that contribute to memory impairment in elderly stroke patients and develop a predictive model.Methods:One hundred stroke patients from the First People's Hospital of Changzhou were selected to assess the incidence of memory impairment using the Montreal cognitive assessment memory index score(MoCA-MIS).Univariate analysis and multivariate Logistic regression were performed to determine the factors influencing memory impairment in these patients.Additionally, the correlation among relevant scale scores was examined, and a prediction model was developed.Results:In the study, 49 patients(49.0%)did not exhibit memory impairment.Patients with memory impairment were found to have higher proportions of individuals over 75 years old, elevated levels of triglyceride(TG), total cholesterol(TC), low-density lipoproteins cholesterol(LDL-C), and National Institute of Health Stroke Scale(NIHSS)scores compared to those without memory impairment.Conversely, patients without memory impairment had higher proportions of individuals with more than 9 years of education, higher levels of high-density lipoprotein cholesterol(HDL-C), mini-mental state examination(MMSE)scores, Rivermead behavioural memory test-Ⅱ(RBMT-Ⅱ)scores, and picture-based memory impairment screen(PMIS)scores(all P<0.05).Furthermore, Montreal cognitive assessment-memory index(MoCA-MIS)scores in stroke patients with memory impairment showed negative correlations with NIHSS scores, TG, and LDL-C, while showing positive correlations with HDL-C, MMSE scores, RBMT-Ⅱ scores, and PMIS scores(all P<0.05).Multifactorial Logistic regression analysis indicated that years of education, TG, HDL-C, NIHSS score, MMSE score, RBMT-Ⅱ score, PMIS score, and the location of the lesion in the cortex or temporal lobe were significant factors influencing memory impairment in stroke patients(all P<0.05).The receiver operating characteristic curve(ROC)analysis revealed an area under curve(AUC)of 0.955(95% CI: 0.921-0.977)for the prediction model of memory impairment in stroke patients, with a Yoden index of 0.841. Conclusions:The risk of memory impairment in stroke patients is associated with education years and blood lipid levels.Factors such as high education level, active cognitive function, and memory training serve as protective factors against memory impairment.The prediction model developed using these influencing factors demonstrates high predictive accuracy for post-stroke memory impairment.

Objective:To explore the role of peroxisome proliferator-activated receptor (PPAR) signaling pathway in the pathogenesis of acne inversa (AI) .Methods:Skin tissue samples were obtained from 8 AI patients and 4 healthy controls from Hospital of Dermatology, Chinese Academy of Medical Science and Peking Union Medical College from 2013 to 2019, and high-throughput sequencing was performed for tissue-specific mRNA expression profiling. Gene Ontology (GO) analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, and Gene Set Enrichment Analysis (GSEA) were carried out. Real-time fluorescence-based quantitative PCR (qPCR) and Western blot analysis were performed to verify the results of high-throughput sequencing.Results:Analysis of the specific expression profiles showed that 2 738 differentially expressed genes were screened out in the AI patients compared with the healthy controls, of which 1 328 genes were significantly up-regulated and 1 410 genes were significantly down-regulated. GO analysis demonstrated that the positive regulation of interferon γ secretion, T cell receptor complex and C-X-C chemokine receptor activity were significantly enriched in the AI lesions. KEGG analysis demonstrated that the signaling pathways associated with primary immuno‐deficiency, PPAR, and chemokine-chemokine receptor interaction were significantly enriched in the AI lesions. GSEA demonstrated that the PPAR signaling pathway was significantly weakened in the AI lesions. The mRNA expression levels of PPARA and PPARG were significantly lower in the AI patients (0.336 ± 0.120, 0.253 ± 0.078, respectively) than in the healthy group (1.000 ± 0.146, 1.000 ± 0.172, t = 3.50, 3.95, respectively, both P < 0.05), so were their protein levels. However, there was no significant difference in the PPARD mRNA expression level between the two groups ( t = 0.34, P = 0.750). The mRNA expression levels of nuclear hormone receptor 9-cis retinoid X receptor alpha (RXRA), RXRG and fatty acid-binding protein 4 were significantly lower in the AI patients than in the healthy controls ( t = 2.96, 2.96, 4.62, respectively, all P < 0.05) . Conclusion:The PPAR signaling pathway was restrained and lipid metabolism was disordered in AI patients.

Objective To investigate the application value of low-molecular-weight heparin calcium combined with alprostadil in the treatment of hypoparathyroidism(HP)after thyroid surgery.Methods Sixty patients with HP after thyroid surgery were randomly divided into two groups:study group(30 cases)and control group(30 cases).The study group received low-molecular-weight heparin calcium and alprostadil,along with oral calcium supplements and calcitriol or an intravenous infusion of calcium gluconate,for three consecutive days after surgery.The control group received only oral calcium supplements and calcitriol or intravenous calcium gluconate.The values and changes in parathyroid hormone(PTH),postoperative drainage volume,and postoperative complications were compared between two groups.Results There were no significant difference in PTH levels at 3 days,1 week,1 month,and 6 months after surgery between two groups(P＞0.05).The difference in PTH levels between 3 days and 1 day after surgery was(6.77±2.61)ng/L in study group and(1.29±1.12)ng/L in control group,with a significant difference(P＜0.05).The difference in PTH levels between 1 week and 1 day after surgery was(10.51±3.66)ng/L in study group and(2.65±2.17)ng/L in control group(P＜0.05).There were no significant difference in PTH levels at 1 month,6 months,and 1 day after surgery(P＞0.05).Comparison of postoperative drainage volume:The postoperative drainage volume of study group was(90.07±22.24)ml,and that of control group was(88.20±24.09)ml,with no statistical significance(P＞0.05).There was no significant difference in postoperative complications between two groups(P＞0.05).Conclusion In cases of HP after total thyroidectomy,timely use of low-molecular-weight heparin calcium and alprostadil can accelerate the recovery of PTH and reduce patient numbness,which is safe,effective,and worthy of clinical promotion.

Umbilical cord mesenchymal stem cells (UC-MSCs) have been widely used in regenerative medicine, but there is limited research on the stability of UC-MSCs formulation during production. This study aims to assess the stability of the cell stock solution and intermediate product throughout the production process, as well as the final product following reconstitution, in order to offer guidance for the manufacturing process and serve as a reference for formulation reconstitution methods. Three batches of cell formulation were produced and stored under low temperature (2-8 ℃) and room temperature (20-26 ℃) during cell stock solution and intermediate product stages. The storage time intervals for cell stock solution were 0, 2, 4, and 6 h, while for intermediate products, the intervals were 0, 1, 2, and 3 h. The evaluation items included visual inspection, viable cell concentration, cell viability, cell surface markers, lymphocyte proliferation inhibition rate, and sterility. Additionally, dilution and culture stability studies were performed after reconstitution of the cell product. The reconstitution diluents included 0.9% sodium chloride injection, 0.9% sodium chloride injection + 1% human serum albumin, and 0.9% sodium chloride injection + 2% human serum albumin, with dilution ratios of 10-fold and 40-fold. The storage time intervals after dilution were 0, 1, 2, 3, and 4 h. The reconstitution culture media included DMEM medium, DMEM + 2% platelet lysate, 0.9% sodium chloride injection, and 0.9% sodium chloride injection + 1% human serum albumin, and the culture duration was 24 h. The evaluation items were viable cell concentration and cell viability. The results showed that the cell stock solution remained stable for up to 6 h under both low temperature (2-8 ℃) and room temperature (20-26 ℃) conditions, while the intermediate product remained stable for up to 3 h under the same conditions. After formulation reconstitution, using sodium chloride injection diluted with 1% or 2% human serum albumin maintained a viability of over 80% within 4 h. It was observed that different dilution factors had an impact on cell viability. After formulation reconstitution, cultivation in medium with 2% platelet lysate resulted in a cell viability of over 80% after 24 h. In conclusion, the stability of cell stock solution within 6 h and intermediate product within 3 h meets the requirements. The addition of 1% or 2% human serum albumin in the reconstitution diluent can better protect the post-reconstitution cell viability.