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.

This consensus will introduce the characteristics of fillers used in the surgical cavities of domestic nasal surgery patients based on relevant literature and expert opinions. It will also provide recommendations for the selection of cavity fillers for different nasal diseases, with chronic sinusitis as a representative example.
Humans ; Nasal Cavity/surgery* ; Nasal Surgical Procedures ; China ; Consensus ; Sinusitis/surgery* ; Dermal Fillers

This article elucidates therapeutic approaches for KRAS G12C-mutant advanced non-small cell lung cancer, with focus on global advancements in inhibitor research. It also summarizes clinical evidence on the efficacy of targeted agents in monotherapy and combination therapies, analyzes their clinical advantages and challenges, and explores future directions for novel treatment modalities.

As a new generation of time-of-flight mass spectrometry,multiple-reflection time-of-flight mass spectrometry(MR-TOF-MS)has been increasingly applied in the fields such as nuclear physics,chemistry,and biology due to its ultra-high resolution and rapid analysis capabilities.However,the analytical performance of MR-TOF-MS largely depends on the ion bunch state entering the mass analyzer.In this study,a rectangular ion trap(RIT)was developed,designed and processed using printed circuit board technology,as an ion accumulating and focusing device for MR-TOF mass analyzer.Compared to traditional ion traps composed of two sets of planar electrodes,this RIT had higher voltage utilization efficiency,resulting in more efficient ion collection and focusing.The ions were cooled to a sufficiently small bunch for precise mass measurement with MR-TOF-MS mass spectrometry in only 1 ms of cooling time in the RIT,then orthogonally ejected to the MR-TOF mass spectrometer for mass analysis.Experimental results indicated that the working cycle,ion flux,and ion focusing state of the RIT fully met the requirements of the MR-TOF mass analyzer.When coupled with the MR-TOF mass analyzer,the RIT enabled MR-TOF-MS to achieve a mass resolution of 1.5×105.

The occurrence of benign prostate hyperplasia(BPH)was related to disrupted sex steroid hormones,and metformin(Met)had a clinical response to sex steroid hormone-related gynaecological disease.How-ever,whether Met exerts an antiproliferative effect on BPH via sex steroid hormones remains unclear.Here,our clinical study showed that along with prostatic epithelial cell(PEC)proliferation,sex steroid hormones were dysregulated in the serum and prostate of BPH patients.As the major contributor to dysregulated sex steroid hormones,elevated dihydrotestosterone(DHT)had a significant positive rela-tionship with the clinical characteristics of BPH patients.Activation of adenosine 5'-monophosphate(AMP)-activated protein kinase(AMPK)by Met restored dysregulated sex steroid hormone homeostasis and exerted antiproliferative effects against DHT-induced proliferation by inhibiting the formation of androgen receptor(AR)-mediated Yes-associated protein(YAP1)-TEA domain transcription factor(TEAD4)heterodimers.Met's anti-proliferative effects were blocked by AMPK inhibitor or YAP1 over-expression in DHT-cultured BPH-1 cells.Our findings indicated that Met would be a promising clinical therapeutic approach for BPH by inhibiting dysregulated steroid hormone-induced PEC proliferation.

The incidence of intrahepatic cholangiocarcinoma (ICC) continues to rise, and there are no effective drugs to treat it. The immune microenvironment plays an important role in the development of ICC and is currently a research hotspot. Icaritin (ICA) is an innovative traditional Chinese medicine for the treatment of advanced hepatocellular carcinoma. It is considered to have potential immunoregulatory and anti-tumor effects, which is potentially consistent with the understanding of "Fuzheng" in the treatment of tumor in traditional Chinese medicine. However, whether ICA can be used to treat ICC has not been reported. Therefore, in this study, sgp19/kRas, an in situ ICC mouse model with intact immune system, was selected to evaluate the efficacy of ICA in the treatment of ICC in vivo for the first time, and the effects of ICA on the tumor immune microenvironment of ICC mice were analyzed by flow cytometry. This experiment was approved by the Experimental Animal Ethics Committee of Capital Medical University (approval number: AEEI-2023-138). In this study, sgp19/kRas ICC mouse model was treated with oral gavage of 100 mg·kg^-1 ICA. We found that ICA significantly inhibited tumor growth and tumor cell proliferation in the sgp19/kRas ICC mouse model after 3 weeks of treatment. Flow cytometry analysis indicated that ICA treatment markedly reduced the proportion of M2 macrophages and increased the number of CD3⁺CD4⁺ T cells. In vitro experiments demonstrated that ICA promoted macrophage polarization towards the M1 phenotype while inhibiting polarization towards the M2 phenotype. Furthermore, transcriptomic analysis suggested that ICA enhanced Toll-like receptor 9 (TLR9) expression, influencing macrophage nitric oxide metabolism synthesis pathways and receptor-related activities, thereby regulating macrophage polarization. In summary, this study demonstrates that ICA treatment significantly delays tumor progression in sgp19/kRas ICC mouse models. Mechanistically, ICA may achieve its anti-ICC effects by upregulating TLR9 receptor expression levels, promoting macrophage polarization towards the M1 phenotype, and altering the tumor immune microenvironment.

Objective To investigate the protective effect of dexmedetomidine(Dex)pretreatment on myocardial ischemia-reperfusion mice and the effect of Nod-like receptor protein 3(NLRP3)inflammatory signaling pathway.Methods C57BL/6J mice were randomly divided into sham group(only threading without ligation),model group(recovery after ligation of left anterior descending coronary artery),positive group(modeling after intraperitoneal injection of 1 mg·kg-1 trimetazidine),Dex group(modeling after intraperitoneal injection of 20 μg·kg-1 dexmedetomidine),MCC950 group(modeling after intraperitoneal injection of 10 mg·kg-1 NLRP3 inhibitor MCC950),12 mice in each group.Cardiac function indexes were detected at 24 h after reperfusion,the expression level of related proteins in myocardial tissue was detected by Western blot,enzyme-linked immunosorbent assay(ELISA)was used to detect the expression level of serum factor,myocardial antioxidant index was detected by kit method,and apoptosis was detected by Tunel method.Results The NLRP3 protein expression levels of sham group,model group,positive group,Dex group and MCC950 group were 0.31±0.05,1.06±0.07,0.52±0.05,0.65±0.07 and 0.39±0.04,respectively;the expression levels of apoptosis-associated granuloid protein(ASC)were 0.27±0.08,0.88±0.09,0.46±0.05,0.59±0.07 and 0.34±0.04,respectively;CK-MB levels were(25.64±2.94),(102.08±7.04),(49.61±7.70),(60.86±5.24)and(63.24±5.38)U·L-1,respectively;IL-6 levels were(104.78±10.73),(231.54±15.56),(158.20±16.54),(165.10±14.77)and(141.17±14.08)pg·mL-1,respectively;Tunel positive cell rates were(4.34±0.16)％,(25.98±1.58)％,(8.74±0.93)％,(11.06±1.07)％and(9.19±0.88)％,respectively.Sham group were compared with model group;Dex group and MCC950 group were compared with model group,the above indexes were statistically significant(all P＜0.05).Conclusion Dexmedetomidine preconditioning may prevent ischemia-reperfusion myocardial injury by inhibiting NLRP3/ASC/caspase-1 inflammatory pathway,inflammatory response and myocardial cell apoptosis.

Objective To study the in vitro expression of three phenylalanine hydroxylase(PAH)mutants(p.R243Q,p.R241C,and p.Y356X)and determine their pathogenicity.Methods Bioinformatics techniques were used to predict the impact of PAH mutants on the structure and function of PAH protein.Corresponding mutant plasmids of PAH were constructed and expressed in HEK293T cells.Quantitative reverse transcription polymerase chain reaction was used to measure the mRNA expression levels of the three PAH mutants,and their protein levels were assessed using Western blot and enzyme-linked immunosorbent assay.Results Bioinformatics analysis predicted that all three mutants were pathogenic.The mRNA expression levels of the p.R243Q and p.R241C mutants in HEK293T cells were similar to the mRNA expression level of the wild-type control(P>0.05),while the mRNA expression level of the p.Y356X mutant significantly decreased(P<0.05).The PAH protein expression levels of all three mutants were significantly reduced compared to the wild-type control(P<0.05).The extracellular concentration of PAH protein was reduced in the p.R241C and p.Y356X mutants compared to the wild-type control(P<0.05),while there was no significant difference between the p.R243Q mutant and the wild type control(P>0.05).Conclusions p.R243Q,p.R241C and p.Y356X mutants lead to reduced expression levels of PAH protein in eukaryotic cells,with p.R241C and p.Y356X mutants also affecting the function of PAH protein.These three PAH mutants are to be pathogenic.[Chinese Journal of Contemporary Pediatrics,2024,26(2):188-193]

Objective To evaluate the effect of delayed cleaning on the cleaning and disinfection quality of gastro-scopes after pre-treatment with different solutions.Methods According to the factorial design table,combination of the pre-treatment cleaning solutions(factor A)(including multi-enzyme cleaning solution[A1],clean water[A2])and delayed cleaning durations(factor B)(including 0 minutes after pre-treatment[B1],30 minutes after pre-treat-ment[B2],1 hour after pre-treatment[B3],and 3 hours after pre-treatment[B4])yielded eight groups(A1B1,A1B2,A1B3,A1B4,A2B1,A2B2,A2B3,A2B4).According to the usage order of gastroscopes,96 gastroscopes used in the digestive endoscopy center of a tertiary first-class hospital from May to September,2023 were randomly assigned to each group by random number table method,with 12 gastroscopes in each group.Specimens were taken at four time points:after pre-treatment,before cleaning,after cleaning,and after disinfection.Due to instant clea-ning,no specimen before cleaning were taken from A1B1 and A2B1 groups,thus only 3 specimens were taken from these two groups each.Four specimens were taken from gastroscopes in the rest groups,resulting in 360 specimens in total.The internal condition of the biopsy cavity was observed through a cavity detector during each delayed cleaning period after pre-treatment,and specimens were taken at the subsequent reprocessing processes of the gas-troscopes.The microbial conditions of the gastroscopes after pre-treatment,before cleaning,after cleaning,and af-ter disinfection were compared.Results After pre-treatment with multi-enzyme cleaning solution and clean water,there was no statistically significant difference in microbiological detection result(P＞0.05).The biopsy cavity re-mained moist during the delayed cleaning period.There was no statistically significant difference in the microbial de-tection results of factors A and B before and after delayed cleaning as well as after disinfection(all P＞0.05).There was no interaction effect between factor A and B.The distribution of bacterial colonies and disinfection qualified rate of gastroscopes after pre-treatment with two cleaning solutions were also not statistically different(both P＞0.05).Conclusion Delayed cleaning for 30 minutes,1 hour,and 3 hours after pre-treatment does not affect the cleaning and disinfection quality of gastroscopes.When clinical demand is urgent,immediate cleaning should be carried out.However,a certain buffering time(no longer than 3 hours)before cleaning is acceptable,when cleaning and disin-fection workload is heavy and timely cleaning cannot be carried out.