Objective: To constructCSF1R+/-mice and to analyze their genotypes, so as to provide animal model basis for disease pathological mechanism and drug target. Methods : A linearized targeting vector was designed according to Cre/Loxp system. A Loxp site was inserted upstream of the 5th exon of theCSF1Rgene, and a neomycin resistance box with Loxp sites on both sides was inserted downstream of the 5th exon. The linearized targeting vector was electroporated into embryonic stem cells. The correctly targeted embryonic stem cells were injected into the blastocysts of C57BL/6J mice to obtain chimeric mice, which were bred with Zp3-Cre mice. The newborn mice were numbered 9-14 days after birth and their tails were cut. The DNA of the mice was extracted, and the genotype of the mice was identified by polymerase chain reaction and agarose gel electrophoresis. The expression of CSF1R in mouse macrophages was detected by flow cytometry. The expression of CSF1R in mouse tissues was detected by Western blot. Results: The results of agarose gel electrophoresis showed that 453 bp bands were amplified in wild type mice, and 453 bp and 650 bp bands were amplified in heterozygous mice. The results of flow cytometry showed that the expression of CSF1R in peritoneal macrophages and bone marrow-derived macrophages of CSF1R heterozygous mice was lower than that of WT group(P<0.05). The results of Western blot showed that the expression of CSF1R in spleen, kidney and brain tissue of CSF1R heterozygous group was lower than that of WT group(P<0.05). Conclusion CSF1R+/-mice are successfully constructed, reproduced and identified, which provides an animal model basis for further revealing the potential mechanism of CSF1R in immune regulation.

Objective To construct myeloid-specific Spi1 gene knockout mice and analyze their genotypes,so as to provide animal model basis for the study of pathological mechanism of diseases and drug targets.Methods Ac-cording to the principle of CRISPR/Cas9 technology and Cre/LoxP system,sgRNA and Donor vectors were de-signed and constructed.The transcript of Exon 2(Exon 2)was used as the knockout region,and Loxp elements were placed on both sides of Exon 2.Cas9 protein,sgRNA and Donor vector were mixed and microinjected into the fertilized eggs of C57BL/6J mice,the fertilized eggs were transplanted into the uterus of C57BL/6J pregnant female mice,and F0 generation was obtained after 19～20 days.Positive F0 mice were mated with C57BL/6J mice to ob-tain stable F1 Spi1flox/+mice.Spi1flox/+mice of F1 generation were selfed to obtain Spi1flox/flox mice.Spi1flox/flox mated with Lyz2-Cre+mice to obtain Spi1flox/+/Lyz2-Cre+mice,and then mated with Spi1flox/flox,the Spi1flox/flox/Lyz2-Cre+mice were myeloid-specific Spi1 gene knockout(KO)mice.Spi1flox/flox/Lyz2-cre-mice were used as wild-type(WT)mice.DNA of WT and KO mice was extracted,and the genotypes were identified by agarose gel electro-phoresis after PCR amplification.Western blot was used to detect the expression of spleen focus forming virus provi-ral integration oncogene,Spi-1/purine rich box-1(PU.1)in immune cells of WT and KO mice.Results The results of PCR identification showed that the genotype of mice with only 220 bp amplified by flox primer was Spi1flox/flox homozygote,and the genotype of mice with 700 bp amplified by Lyz2-Cre primer was Lyz2-Cre+.Western blot showed that compared with WT group,the protein PU.1 was not expressed in bone marrow-derived macropha-ges(BMDMs)and peritoneal macrophages(PM)in KO group(P<0.01).There was no significant difference of statistics in the expression level of PU.1 in T cells between KO mice and WT mice.The results of PCR and West-ern blot showed that myeloid-specific Spi1 KO mice were successfully constructed.Conclusion The myeloid-spe-cific Spi1 gene KO mice are successfully constructed and identified,which provides animal model basis for further revealing the potential mechanism of PU.1 inimmune regulation.

Objective To breed and identify the T lymphocyte-conditional Spi1 knockout mice for the further in-vestgation of the specific role of Spi1-encoded protein PU.1.Methods The Lck-Cre mice were mated with Spi1flox/flox mice to obtain Lck-Cre×Spi1flox/flox mice(T lymphocyte-specific Spi1 knockout mice),and the genotype was determined by polymerase chain reaction(PCR)and agarose gel electrophoresis.Magnetic beads were used to sort out the splenic T lymphocytes,and the knockdown efficiency of PU.1 in T cells was detected by Western blot,quantitative real-time PCR(qPCR)and flow cytometry.Results The Lck-Cre×Spi1flox/flox mouse genotype was stably inherited.Compared with Spi1flox/flox mice,the expression level of PU.1 was significantly reduced in splenic T cells of Lck-Cre×Spi1flox/flox mice.Conclusion In this study,the T lymphocyte-specific Spi1 knockout mice was successfully constructed by applying Cre/LoxP system and CRISPR/Cas9 technology,which provided a reliable an-imal model for the subsequent experiments of the specific role of PU.1 in T cell-related diseases.

Objective To investigate the feasibility of granzyme B(GB)promoter-controlled ferritin heavy chain(FTH1)reporter gene expression for monitoring the activation status of chimeric antigen receptor T cells(CAR-T)by magnetic resonance imaging(MRI).Methods Cytotoxic T lymphocytes(CTLs)were screened by Ficoll density gradient centrifugation and flow sorting.The GB promoter and FTH1 gene were ligated together with disialoganglioside 2(GD2)CAR,and lentiviral vectors were transfected into CTLs to construct GD2-CAR-T/pGB-FTH1 cells.GD2-CAR-T/pCMV-FTH1,GD2-CAR-T,and T cells served as control cells.CytoTox96@non-radioactive cytotoxicity was used to detect the killing effect of each group of cells after co-culture with human neuroblastoma cells(SK-N-SH).ELISA was employed to detect the coincubation factor as well as the amount of GB secretion.Western blotting,Prussian blue staining and cellular MRI were applied to detect the expression of the FTH1 gene after co-culture.Results CTLs were successfully obtained,and then GD2-CAR-T/pGB-FTH1,GD2-CAR-T/pCMV-FTH1 and GD2-CAR-T cells were constructed.The killing effect,co-incubation factor and GB secretion of the above 3 groups of cells were significantly higher than those of the T cells,and the level of GB expression was highest at day 1,and then decreased in order at day 3 and day 7 after co-culturing with SK-N-SH cells.The relative expression of FTH1 and iron content of the GD2-CAR-T/pGB-FTH1 cells showed the same trend as GB expression,and the MRI signals were gradually increased.There were no significant differences in the relative expression of FTH1,iron content and MRI signals in the GD2-CAR-T/pCMV-FTH1 cells at all time points.No FTH1 expression or iron aggregation was observed in the GD2-CAR-T and T cells groups.Conclusion MRI based on the FTH1 reporter gene driven by the granzyme B promoter can reflect the GB expression level and tumor killing effect of CAR-T cells,which provides a potential real-time visual means to monitor the cell activation status for CAR-T therapy.

Objective To construct Csf1r-CreERT2 R26REYFP reporter gene mice and assess the efficacy of Csf1r-CreERT2-mediated enhancement of CSF1R in CD45+cells labeled with yellow fluorescein protein EYFP.Methods Csf1r-CreERT2 mice were crossbred with R26REYFP homozygous mice,and Csf1r-CreERT2R26REYFP mice were identified through PCR and Western Blot analyses.Flow cytometry was employed to evaluate CSF1R tag-efficiency in CD45+cells across different mouse tissues following tamoxifen induction.Results Csf1r-CreERT2 R26REYFP reporter gene mice were acquired.In addition,it was found that Csf1r-CreERT2-mediated EYFP could effectively mark CSF1R in various tissues of mice and CD45+cells in different locations.Compared to the R26REYF P group,the highest labeling efficiency was observed in the brain tissue(P＜0.001),the lowest in the thymus tissue(P＜0.05),and no sig-nificant difference was observed in the spleen tissue.Conclusion Adult Csf1r-CreERT2 mice and R26REYFP mice are effective ways to obtain Csf1r-CreERT2 R26REYFP induced conditional fluorescence mice.Csf1r-CreERT2 can mediate EYFP to effectively trace CSF1R in CD45+cells in different parts of mice.

Objective:To study effects of different pretreatment methods on the detection of pesticide residues in Angelicae Sinensis Radix,ChrysanthemI Flos,Lych Fructus,Astragali Radix and Lonicerae Japonicae Flos.Methods:The samples were treated with QuEChERS method and high-speed homogenization combined with hydro-phile-lipophile balance(HLB)solid-phase extraction method,and the residual amounts of carbofuran,3-carboxyl-carbofuran,phorate,phorate sulfone,phorate sulfoxide,and methyl isoflurophos were simultaneously determined using UHPLC-MS/MS.With a gradient elutionof 0.1％formic acid solution containing 5 mmol·L-1 ammonium formate and t 0.1％formic acid solution containing 5 mmol·L-1 ammonium formate-acetonitrile(volume ratio of 5:95),Ultra-performance liquid chromatography column Agilent Poroshell 120 SB-C18(2.1 mm × 100 mm,2.7μm)was used at 35 ℃ and the electrospray ion source was scanned in the positive ion mode and detected in the multiple reaction monitoring mode in mass spectrometry.Results:The deviation of the results measured by QuECh-ERS method and HLB solid-phase extraction method was between 9.09％-55.56％.Conclusion:In the selection of the pretreatment method for the detection of pesticide residues in traditional Chinese medicine,it is recommen-ded to take the measurement data of positive samples as the evaluation index and basis,and choose the method with higher measurement value and high extraction efficiency.

This study was performed to explore the differential genes and functions of double-negative T cells in peripheral blood of patients with colorectal cancer.Two colorectal cancer patients and two healthy physical examiners were selected,and peripheral blood double-negative T cells were firstly sorted by flow cytometry,and then sequencing data were obtained using single cell full-length transcriptome(SMART-seq2)sequencing technology to screen differentially expressed genes.The screened differentially expressed genes were subjected to Gene Ontology Enrichment(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway enrichment analysis.The STRING database was used to construct the protein interaction network and identify key genes by Cytoscape software;RT-qPCR was used to verify the differential expression genes in DNT cells.Compared with healthy subjects,there were 1 276 peripheral blood double-negative T-cell differential genes in colorectal cancer patients,including 141 up-regulated genes and 1 135 down-regulated genes.GO analysis showed that the differential genes were mainly involved in biological functions such as methylation,metabolic processes and transferase activity;KEGG pathway analysis showed that the differential genes were mainly involved in signaling pathways such as autophagy,P53 signaling pathway and phosphatidylinositol metabolism.The protein interaction network contains 1 154 nodes and 1 022 edges,in addition,10 hub genes were identified:PIK3C3,WIPI1,ATG101,PIK3R4,DDX10,RBM28,SDAD1,ATG16L1,UVRAG,ATG7.RT-qPCR validated 10 differentially expressed genes,of which 7 differentially expressed genes showed trends consistent with sequencing results,and 3 genes showed expression inconsistent with sequencing results.DNT cells may be involved in the development of colorectal cancer through methylation,P53 signaling pathway and autophagy,and at the same time,DNT cells may inhibit the development of colorectal cancer through the regulation of genes.This study provides a theoretical basis for further investigation of the function of DNT cells in malignant tumors.

Objective To explore and validate the mechanism of Prepared Radix Polygoni Multiflori in the treatment of NAFLD based on network pharmacology and animal non-alcoholic fatty liver disease(NAFLD)model experiments.Methods Consult the literature to compare the differences between Radix Polygoni Multiflori and Prepared Radix Polygoni Multiflori(PRPM).Herb database and SwissADME database were used to screen the active ingredients of Prepared Radix Polygoni Multiflori,SwissTargetPrediction database was used to predict its targets,OMIM,DISGENET and GEENCARDS databases were used to screen the NAFLD-related targets,conduct GO functional enrichment analysis and KEGG pathway enrichment analysis.The active ingredient-target-KEGG signaling pathway-NAFLD network was mapped later.The mice with NAFLD were treated with Prepared Radix Polygoni Multiflori by gavage for 8 weeks;serum triglyceride level and alanine aminotransferase(ALT)activity were measured;the liver lesions were observed by HE staining;the potential mechanism of action of Radix Polygoni Multiflori in the treatment of NAFLD was verified by Western blot.Results The differences between Radix Polygoni Multiflori and PRPM were consulted.Six pharmacological components and 32 potential action targets of Radix Polygoni Multiflori for the treatment of NAFLD were screened by network pharmacology,GO and KEGG pathways were enriched to lipid and atherosclerosis-related pathways,AMPK signaling pathway,etc.;HE staining verified that Prepared Radix Polygoni Multiflori has the function of improving NAFLD and is associated with the alteration of FASN,ACC,SCD protein of AMPK signaling pathway.Conclusion Radix Polygoni Multiflori has the potential to improve NAFLD by regulating FASN,ACC and SCD.

Objective:To study the medication rules of treating cervical spondylosis by National TCM master Liu Bailing based on data mining and network pharmacology, and explore the potential action mechanism of its core compounds.Methods:By collecting the prescriptions of National TCM master Liu Bailing treating cervical spondylosis in the past 8 years, this paper analyses the frequency, nature, flavor, meridian, hierarchical clustering and association rules of those prescriptions by RStudio to obtain the core prescription. Then, the effective components of the core prescription were collected by using TCMSP, and the network of "medicine-component-target" was constructed by using Cytoscape 3.8.0; by searching for databases like GEO, DisGeNET, TTD HPO and Genecards were retrieved to obtain the target data set of cervical spondylosis; by using STRING 11.0 platform to construct protein interaction network; by using DAVID platform to cary out gene ontology (GO) and KEGG pathway enrichment analysis; by using Auto Dock software for molecular docking.Results:In the 844 prescriptions, there are 199 Chinese medicines and the properties are mainly warm, plain and cold; the flavors were mainly sweet, pungent and bitter; mainly belong to the liver, spleen, and kidney meridians. The Association Rule shows that the core compound is made up of Salvia miltiorrhiza, Gastrodia elata, Rhizoma corydalis, Alisma rhizoma, centipede, Astragalus membranaceus and Rhizome of Pueraria. Besides, 140 effective constituents and 247 targets of the core prescription were screened, and the main constituents were quercetin, kamanol, luteolin, tanshinone ⅡA, β-sitosterol, etc. 13 core targets among the core prescription treating cervical spondylosis were obtained, which were enriched into 30 pathways including toll-like receptor signaling pathway, TNF signaling pathway and HIF-1 signaling pathway. Conclusion:National TCM master Liu Bailing treatment of cervical spondylosis mainly focuses on expelling wind and relieving pain, dredging meridians and soothing tendons, and the mechanism of action of the core prescription may focus on inhibiting inflammatory response and relieving oxidative stress, providing guidance and reference for the clinical treatment of cervical spondylosis.

Objective:To explore the influencing factors of accidental falls outside the hospital in elderly patients with accidental injury in the Emergency Department, so as to provide a basis for preventing accidental injuries.Methods:Convenience sampling was used to select 210 emergency elderly patients who visited the hospital due to accidental injuries from November 2017 to May 2020 in the Second Medical Center, People's Liberation Army General Hospital as the research object. Patients were investigated with the self-designed Out-of-hospital Accidental Injury Consultation Questionnaire. Single factor analysis and binomial Logistic regression were used to analyze the influencing factors of falls in elderly patients. A total of 210 questionnaires were distributed in this survey, and 180 valid questionnaires were returned with the valid response rate of 85.71%.Results:A total of 147 falls occurred among 180 elderly patients in the Emergency Department, and the incidence of falls was 81.7%. Binomial Logistic regression analysis showed that old age, outdoor, chronic diseases and no use of walking aids were independent risk factors for falls ( P<0.05) . Conclusions:The main types of accidental injuries in elderly patients are falls. Strengthening the nursing education of fall prevention measures, improving compliance with medications, choosing suitable walking aids or trying other new fall prevention technologies, and establishing a multi-party participation model can effectively prevent and reduce the occurrence of falls in elderly patients.