Objective Currently, there is no commercially available quantitative detection kit for the main Felis domestic allergen (Fel d 1) in China. To establish a rapid detection method for Fel d 1, this study aims to prepare monoclonal antibodies against Fel d 1 protein. Methods The codon preference of Escherichia coli was utilized to optimize and synthesize the Fel d 1 gene. The prokaryotic expression plasmid pET-28a-Fel d 1 was constructed and used to express and purify the recombinant Fel d 1 protein. Subsequently, the recombinant protein was immunized into BALB/c mice and monoclonal antibodies (mAbs) were prepared by the hybridoma technique. An indirect ELISA was established using the recombinant Fel d 1 as the coating antigen, and hybridoma cell lines were screened for positive clones. The specificity and antigenic epitopes of the mAbs were confirmed by Western blot analysis. Finally, the selected hybridoma cells were injected into the peritoneal cavities of BALB/c mice for large-scale monoclonal antibody production. Results The recombinant plasmid pET-28a-Fel d 1 was successfully constructed, and soluble Fel d 1 protein was obtained after optimizing the expression conditions. Western blot and antibody titer assays confirmed the successful isolation of two hybridoma cell lines, 7D11 and 5H4, which stably secreted mAbs specific to Fel d 1. Antibody characterization revealed that the 5H4 mAb was of the IgG2a subtype and could recognize the amino acid region 105-163 of Fel d 1, while the 7D11 mAb was the IgG1 subtype and could recognize the amino acid region 1-59. Conclusion The high-purity recombinant Fel d 1 protein produced in this study provides a promising alternative for clinical immunotherapy of cat allergies. Furthermore, the monoclonal antibody prepared in this experiment lays a material foundation for the in-depth study of the biological function of Fel d 1 and the development of ELISA detection.
Animals ; Antibodies, Monoclonal/biosynthesis* ; Mice, Inbred BALB C ; Cats ; Mice ; Allergens/genetics* ; Glycoproteins/genetics* ; Enzyme-Linked Immunosorbent Assay ; Hybridomas/immunology* ; Recombinant Proteins/genetics* ; Female ; Antibody Specificity

Objective To investigate the correlation of vascular senescence indicators,brachial-ankle pulse wave velocity(baPWV),cardio-ankle vascular index(CAVI),ankle-brachial index(ABI)with total burden of MRI in patients with cerebral small vessel disease(CSVD).Methods A total of 200 CSVD patients admitted to our hospital from November 2023 to October 2024 were retrospectively recruited,and based on their total MRI burden,they were divided into a low-burden group(score:0-1,103 cases)and a high-burden group(score:2-4,97 cases).A athero-sclerosis monitoring device(VS-1500A)was used to detect baPWV,CAVI,and ABI values.The relationships of the three indicators with total MRI burden score and their predictive values for the burden score were analyzed.Results The high-burden group had significantly higher BMI,el-evated homocysteine and uric acid levels,and increased baPWV and CAVI,but lower ABI than the low-burden group(P＜0.01).Multivariate logistic analysis showed that baPWV,CAVI and ABI were independent influencing factors for high MRI burden of CSVD patients.Spearman correlation analysis showed that baPWV and CAVI values were positively correlated(r=0.589,P=0.000;r=0.458,P=0.000),and ABI was negatively correlated with the total MRI burden score of CSVD patients(r=-0.352,P=0.000).ROC curve analysis showed that baPWV(AUC=0.816,P=0.000),CAVI(AUC=0.725,P=0.000)and ABI(AUC=0.676,P=0.000)were all predic-tors for high MRI burden score in CSVD patients.Conclusion baPWV and CAVI are positively,and ABI is negatively correlated with the total MRI burden score of CSVD patients.baPWV,CAVI and ABI show higher predictive value for the high burden score,with baPWV most significant.

Objective:To investigate the changes in thyroid hormone levels and inflammatory markers in critically ill children，analyze their correlation with disease severity，and explore their potential impact on prognosis,providing references for clinical management and prognosis assessment in critical illness.Methods:A retrospective cohort study was conducted involving 394 pediatric patients admitted to the ICU of the Capital Pediatric Institute Affiliated Children's Hospital from 2019 to 2023.Based on the pediatric critical illness score,patients were divided into three groups:the extremely critical group (score ≤ 70, n=81),the critical group (score 71–80, n=150),and the non-critical group (score>80, n=163).Data collected included thyroid function indicators，inflammatory markers[C-reactive protein（CRP)，procalcitonin(PCT),tumor necrosis factor(TNF)-α，interleukin (IL)，etc.]，clinical information，and outcomes.The correlation between thyroid function indicators and inflammatory markers were analyzed.The predictive value of thyroid function indicators and inflammatory markers for prognosis in critically ill pediatric patients was assessed. Results:Of the 394 children,non-thyroidal disease syndrome occurred in 321 cases,with an overall incidence of 81.5%,which increased with disease severity.Thyroid hormone [total triiodothyronine (TT3),free triiodothyronine (FT3),and total tetraiodothyronine (TT4)] levels were significantly lower in the extremely critical group than in the other groups ( P<0.05).Inflammatory markers such as CRP,PCT,TNF-α,IL-6,IL-8,and IL-10 were significantly higher in the extremely critical group than in the other groups ( P<0.05).Thyroid hormones were negatively correlated with inflammatory markers,and the receivor operating characteristic curves analysis indicated that TT3,FT3,IL-6 and IL-8 levels,could effectively differentiate disease prognosis.Univariate regression model showed significant associations between TT3,FT3,TT4,PCT,IL-8,and IL-10 and disease prognosis.The multivariate Logistic regression model showed IL-6 and IL-8 were independent predictors of disease prognosis. Conclusion:Significant reductions in thyroid hormone levels are closely related to disease severity and poor prognosis.Changes in inflammatory markers reflect the inflammatory state and severity of the disease and impact prognosis.Monitoring thyroid function and inflammatory status is important in clinical management，which provids new insights into prognosis assessment and treatment strategies for critically ill children.

Objective·To investigate the changes in transcriptome and chromatin accessibility during the differentiation of human embryonic stem cells(hESCs)into neural progenitor cells(NPCs)using in vitro differentiation models and high-throughput multi-omics sequencing technologies.Methods·hESCs were first induced to differentiate into NPCs in vitro using the embryoid body formation method,and cells at both stages were collected.The cell phenotypes were identified by reverse transcription-quantitative real-time PCR(RT-qPCR)and immunofluorescence(IF)staining.Transcriptome sequencing(RNA-seq)was conducted to detect and analyze the differentially expressed genes(DEGs)between hESCs and NPCs.The assay for transposase-accessible chromatin with high-throughput sequencing(ATAC-seq)was employed to assess chromatin accessibility changes between hESCs and NPCs.Motif enrichment analysis was performed on differentially accessible chromatin regions to discover potential regulatory transcription factors.Finally,an integrated analysis of RNA-seq and ATAC-seq data and the protein-protein interaction(PPI)network were performed to identify key genes and regulatory pathways involved in the early stages of neural differentiation in vitro.Results·Both RT-qPCR and IF results indicated that the expression levels of pluripotency markers(NANOG and POU5F1)were high at the hESC stage but significantly decreased at the NPC stage,while early neural differentiation markers(PAX6,SOX1,and NES)were minimally expressed at the hESC stage but markedly upregulated at the NPC stage.RNA-seq analysis revealed that compared to the hESC stage,there were 5 597 genes upregulated and 3 654 genes downregulated at the NPC stage.Gene function enrichment analysis showed that the upregulated genes at the NPC stage were enriched in the functions related to neural development.ATAC-seq analysis demonstrated a total of 27 491 genomic regions had significant changes in chromatin accessibility during the differentiation from hESC to NPC,with 12 381 regions showing increased accessibility and 15 110 regions showing decreased accessibility.Motif enrichment analysis revealed that transcription factor genes such as DLX1 and LHX2 might play an important role in the differentiation process from hESCs into NPCs.Integrated analysis of RNA-seq and ATAC-seq data revealed that overlapping genes with high expression at the NPC stage were mainly enriched in axon guidance,forebrain development,and neuron migration.After neural differentiation,the expression levels of CTNND2 and LHX2 genes increased,and the chromatin accessibility of related genomic regions also increased.PPI network analysis indentified candidate downstream genes including PRKACA,CDH2,and ERBB4.Conclusion·The in vitro differentiation model of hESCs combined with high-throughput multi-omics sequencing technologies can be used to depict the changes in transcriptome and chromatin accessibility during the differentiation of hESCs into NPCs.In this process,the expression levels of genes related to axon guidance,forebrain development,and neuronal migration pathways increase and related chromatin accessibility is enhanced.

Objective·To investigate the changes in transcriptome and chromatin accessibility during the differentiation of human embryonic stem cells(hESCs)into neural progenitor cells(NPCs)using in vitro differentiation models and high-throughput multi-omics sequencing technologies.Methods·hESCs were first induced to differentiate into NPCs in vitro using the embryoid body formation method,and cells at both stages were collected.The cell phenotypes were identified by reverse transcription-quantitative real-time PCR(RT-qPCR)and immunofluorescence(IF)staining.Transcriptome sequencing(RNA-seq)was conducted to detect and analyze the differentially expressed genes(DEGs)between hESCs and NPCs.The assay for transposase-accessible chromatin with high-throughput sequencing(ATAC-seq)was employed to assess chromatin accessibility changes between hESCs and NPCs.Motif enrichment analysis was performed on differentially accessible chromatin regions to discover potential regulatory transcription factors.Finally,an integrated analysis of RNA-seq and ATAC-seq data and the protein-protein interaction(PPI)network were performed to identify key genes and regulatory pathways involved in the early stages of neural differentiation in vitro.Results·Both RT-qPCR and IF results indicated that the expression levels of pluripotency markers(NANOG and POU5F1)were high at the hESC stage but significantly decreased at the NPC stage,while early neural differentiation markers(PAX6,SOX1,and NES)were minimally expressed at the hESC stage but markedly upregulated at the NPC stage.RNA-seq analysis revealed that compared to the hESC stage,there were 5 597 genes upregulated and 3 654 genes downregulated at the NPC stage.Gene function enrichment analysis showed that the upregulated genes at the NPC stage were enriched in the functions related to neural development.ATAC-seq analysis demonstrated a total of 27 491 genomic regions had significant changes in chromatin accessibility during the differentiation from hESC to NPC,with 12 381 regions showing increased accessibility and 15 110 regions showing decreased accessibility.Motif enrichment analysis revealed that transcription factor genes such as DLX1 and LHX2 might play an important role in the differentiation process from hESCs into NPCs.Integrated analysis of RNA-seq and ATAC-seq data revealed that overlapping genes with high expression at the NPC stage were mainly enriched in axon guidance,forebrain development,and neuron migration.After neural differentiation,the expression levels of CTNND2 and LHX2 genes increased,and the chromatin accessibility of related genomic regions also increased.PPI network analysis indentified candidate downstream genes including PRKACA,CDH2,and ERBB4.Conclusion·The in vitro differentiation model of hESCs combined with high-throughput multi-omics sequencing technologies can be used to depict the changes in transcriptome and chromatin accessibility during the differentiation of hESCs into NPCs.In this process,the expression levels of genes related to axon guidance,forebrain development,and neuronal migration pathways increase and related chromatin accessibility is enhanced.

OBJECTIVE To investigate the serotypes and antimicrobial resistance rate of clinically isolated Salmonel-la in a children's hospital in Suzhou,and to provide reference for the treatment of salmonellosis.METHOD Totally 177 strains of Salmonella isolated from Children's Hospital of Wujiang District from Jan.2021 to Dec.2023 were collected,and the results of serotypes and drug sensitivity of Salmonella were analyzed.RESULTS The male to fe-male isolation rate of Salmonella was 1.39∶1,with a median age of children infection at 1.3(0.8,2.3)years.The highest number of Salmonella strains were isolated in the month of Jun.,followed by Jul.,Aug.,Sep.,Oct.and May,collectively accounting for 82.49％of all isolates.Acute gastroenteritis was manifested in 142 cases(80.22％),with respiratory tract infections in 38 cases(21.47％)and septicemia in 7 cases(3.95％).The differ-ence in detection rates across the three years was not statistically significant(P=0.806).Salmonella Typhimuri-um was the predominant serotype,representing 54.24％of all isolates.The antimicrobial drug with the highest rate of resistance in Salmonella was ampicillin(71.35％,122/171),followed by sulfamethoxazole/metronidazole(43.60％,75/172),and ampicillin/sulbactam(30.23％,52/172),and no imipenem resistant strains were found.29.07％(50/172)of strains showed multidrug resistance.CONCLUSIONS Boys under three years of age are sus-ceptible to Salmonella infections in summer and fall in this region,with Salmonella Typhimurium being the pre-dominant serotype.Clinical attention should be paid to the characteristics of Salmonella infection and drug resist-ance,as well as the early diagnosis and rational use of antimicrobial drugs.

Objective:To investigate the changes in thyroid hormone levels and inflammatory markers in critically ill children，analyze their correlation with disease severity，and explore their potential impact on prognosis,providing references for clinical management and prognosis assessment in critical illness.Methods:A retrospective cohort study was conducted involving 394 pediatric patients admitted to the ICU of the Capital Pediatric Institute Affiliated Children's Hospital from 2019 to 2023.Based on the pediatric critical illness score,patients were divided into three groups:the extremely critical group (score ≤ 70, n=81),the critical group (score 71–80, n=150),and the non-critical group (score>80, n=163).Data collected included thyroid function indicators，inflammatory markers[C-reactive protein（CRP)，procalcitonin(PCT),tumor necrosis factor(TNF)-α，interleukin (IL)，etc.]，clinical information，and outcomes.The correlation between thyroid function indicators and inflammatory markers were analyzed.The predictive value of thyroid function indicators and inflammatory markers for prognosis in critically ill pediatric patients was assessed. Results:Of the 394 children,non-thyroidal disease syndrome occurred in 321 cases,with an overall incidence of 81.5%,which increased with disease severity.Thyroid hormone [total triiodothyronine (TT3),free triiodothyronine (FT3),and total tetraiodothyronine (TT4)] levels were significantly lower in the extremely critical group than in the other groups ( P<0.05).Inflammatory markers such as CRP,PCT,TNF-α,IL-6,IL-8,and IL-10 were significantly higher in the extremely critical group than in the other groups ( P<0.05).Thyroid hormones were negatively correlated with inflammatory markers,and the receivor operating characteristic curves analysis indicated that TT3,FT3,IL-6 and IL-8 levels,could effectively differentiate disease prognosis.Univariate regression model showed significant associations between TT3,FT3,TT4,PCT,IL-8,and IL-10 and disease prognosis.The multivariate Logistic regression model showed IL-6 and IL-8 were independent predictors of disease prognosis. Conclusion:Significant reductions in thyroid hormone levels are closely related to disease severity and poor prognosis.Changes in inflammatory markers reflect the inflammatory state and severity of the disease and impact prognosis.Monitoring thyroid function and inflammatory status is important in clinical management，which provids new insights into prognosis assessment and treatment strategies for critically ill children.

OBJECTIVE To investigate the serotypes and antimicrobial resistance rate of clinically isolated Salmonel-la in a children's hospital in Suzhou,and to provide reference for the treatment of salmonellosis.METHOD Totally 177 strains of Salmonella isolated from Children's Hospital of Wujiang District from Jan.2021 to Dec.2023 were collected,and the results of serotypes and drug sensitivity of Salmonella were analyzed.RESULTS The male to fe-male isolation rate of Salmonella was 1.39∶1,with a median age of children infection at 1.3(0.8,2.3)years.The highest number of Salmonella strains were isolated in the month of Jun.,followed by Jul.,Aug.,Sep.,Oct.and May,collectively accounting for 82.49％of all isolates.Acute gastroenteritis was manifested in 142 cases(80.22％),with respiratory tract infections in 38 cases(21.47％)and septicemia in 7 cases(3.95％).The differ-ence in detection rates across the three years was not statistically significant(P=0.806).Salmonella Typhimuri-um was the predominant serotype,representing 54.24％of all isolates.The antimicrobial drug with the highest rate of resistance in Salmonella was ampicillin(71.35％,122/171),followed by sulfamethoxazole/metronidazole(43.60％,75/172),and ampicillin/sulbactam(30.23％,52/172),and no imipenem resistant strains were found.29.07％(50/172)of strains showed multidrug resistance.CONCLUSIONS Boys under three years of age are sus-ceptible to Salmonella infections in summer and fall in this region,with Salmonella Typhimurium being the pre-dominant serotype.Clinical attention should be paid to the characteristics of Salmonella infection and drug resist-ance,as well as the early diagnosis and rational use of antimicrobial drugs.

Objective To investigate the correlation of vascular senescence indicators,brachial-ankle pulse wave velocity(baPWV),cardio-ankle vascular index(CAVI),ankle-brachial index(ABI)with total burden of MRI in patients with cerebral small vessel disease(CSVD).Methods A total of 200 CSVD patients admitted to our hospital from November 2023 to October 2024 were retrospectively recruited,and based on their total MRI burden,they were divided into a low-burden group(score:0-1,103 cases)and a high-burden group(score:2-4,97 cases).A athero-sclerosis monitoring device(VS-1500A)was used to detect baPWV,CAVI,and ABI values.The relationships of the three indicators with total MRI burden score and their predictive values for the burden score were analyzed.Results The high-burden group had significantly higher BMI,el-evated homocysteine and uric acid levels,and increased baPWV and CAVI,but lower ABI than the low-burden group(P＜0.01).Multivariate logistic analysis showed that baPWV,CAVI and ABI were independent influencing factors for high MRI burden of CSVD patients.Spearman correlation analysis showed that baPWV and CAVI values were positively correlated(r=0.589,P=0.000;r=0.458,P=0.000),and ABI was negatively correlated with the total MRI burden score of CSVD patients(r=-0.352,P=0.000).ROC curve analysis showed that baPWV(AUC=0.816,P=0.000),CAVI(AUC=0.725,P=0.000)and ABI(AUC=0.676,P=0.000)were all predic-tors for high MRI burden score in CSVD patients.Conclusion baPWV and CAVI are positively,and ABI is negatively correlated with the total MRI burden score of CSVD patients.baPWV,CAVI and ABI show higher predictive value for the high burden score,with baPWV most significant.

Objective·To study the relationship between evolution and the developmental process from the perspective of DNA sequence conservation,and explore their inherent principles.Methods·First,conservation rate(CR)was established by analyzing the conservation of amino acid sequences of coding genes in 100 species to quantify the evolutionary conservation of genes.The relationship between CR and developmental potential was verified by using the feature genes involved in embryonic stem cells pathways.Secondly,cell type-specific genes and their characteristics in conservation were studied by analyzing the RNA sequencing(RNA-seq)data of the three early germ layers(ectoderm,mesoderm and endoderm)and their corresponding mature organs(brain,heart,liver,etc).Then,chromatin immunoprecipitation sequencing(ChIP-seq)data of enhancer histone H3 acetylated at lysine 27(H3K27ac)from early germ layers and mature organs were collected to search for enhancer sites and identify super enhancers in various cells and tissues by using the ROSE procedure.Functional enrichment and signaling pathway analysis of genes was used to examine the identity correlation between SEs-regulated genes and the corresponding cell characteristics,to clarify whether the SEs identified in this study were consistent with the characteristics reported in previous studies.Finally,PhastCons program was used to calculate the DNA conservation score(CS)of non-coding regulatory regions to study their relationship with developmental potential.Results·In the coding region of DNA,CR was successfully established to quantify the conservation of genes.The gene expression data of early germ layers and mature organs showed that the genes with higher conservation rate were more relevant to the stemness and early developmental process,and the differences between the tissues from early and late development could be distinguished by using CR.In the non-coding regions of DNA,it was found that the conservation of regulatory regions was also correlated with development.The CS of the SE sequences in the early developmental germ layers was significantly higher than that of the SE sequences in the corresponding mature organs.However,cell-specific typical enhancers(TEs)did not show such a trend.Conclusion·During the developmental process,CR of genes expressed in the coding region decreases,and CS of super-enhancer DNA in the non-coding region decreases.