Objective To improve the national standardized method for determining biphenyl in workplace air, which was based on activated carbon tube sampling, carbon disulfide desorption, and gas chromatography, by developing a method using GDX-502 tubes for sampling, toluene for desorption, and gas chromatography. Methods Workplace air samples were collected using GDX-502 sampling tubes and desorbed with toluene, followed by determination with gas chromatography. Results The improved method demonstrated good linearity for biphenyl concentrations ranging from 0.33 to 330.00 mg/L, with a correlation coefficient of 0.999 9. The detection limit and lower limit of quantification were 0.06 and 0.21 mg/L, and the minimum detection concentration and minimum quantification concentration were 0.04 and 0.14 mg/m³ (based on 1.5 L air sample volume), respectively. The average desorption efficiency ranged from 96.6% to 101.1%. The within-run and between-run relative standard deviations were 0.6%-1.4% and 1.4%-3.3%, respectively, with 100.0% sampling efficiency. Samples remained stable for at least 14 days at room temperature. Conclusion The improved method for biphenyl detection demonstrates rapid and accurate performance, with the advantages of low detection limits and high sampling and desorption efficiency.

Objective:To construct the over-expressed lentivirus vector of PRDM5 gene and establish the Neuro-2a cells stably transfected PRDM5,and to provide the basis evidence for exploring the effect of PRDM5 in pathogenesis of ischemic stroke(IS).Methods:The sequence of PRDM5 was searched and designed based on NCBI.The PRDM5 gene was amplified by PCR and ligated with the lentiviral vector GV492 digested by BamH Ⅰ and Age Ⅰ restriction enzymes to form the GV492-PRDM5 over-expression recombinant plasmid.The positive clones with similar length and size to the target gene fragment were screened by PCR and sent to Shenggong Bioengineering(Shanghai)Co.Ltd.for identification.The correctly-sequenced GV492-control plasmid and GV492-PRDM5 over-expression recombinant plasmid were transfected into the HEK293T cells,respectively.After 48 h of transfection,the lentiviruses were collected by centrifugation,and they were GV492-control lentivirus and GV492-PRDMS over-expression lentivirus;the titers of these two lentiviruses were determined by lentiviral titer assay.The Neuro-2a cells were divided into GV492-control group and GV492-PRDM5 group,and then infected with GV492-control lentivirus and GV492-PRDM5 over-expression lentivirus,respectively,with a lentivirus multiplicity of infection(MOI)of 100.The Neuro-2a cells successfully infected with GV492-control lentivirus and GV492-PRDM5 over-expression lentivirus were screened with puromycin(10 mng-L-1)after 72 h of infection.The growth status and the expression of green fluorescence protein of Neuro-2a cells in GV492-control group and GV492-PRDM5 group were observed by fluorescence microscope.The expression levels of PRDM5 mRNA and PRDM5 protein in the Neuro-2a cells in two groups were detected by real-time fluorescence quantitative RCR(RT-qPCR)and Western blotting methods.Results:The PCR results showed that the length of the positive transformant of GV492-PRDM5 recombinant plasmid was about 684 bp,and the gene sequence of GV492-PRDM5 over-expression recombinant plasmid was consistent with the designed and synthesized PRDM5 over-expression sequence.The titers of GV492-control lentivirus and GV492-PRDM5 over-expression lentivirus were both 2.5×108TU·mL-1 The Neuro-2a cells in GV492-control group and GV492-PRDM5 group grew well,and the expressions of green fluorescence protein were found under fluorescence microscope.The RT-qPCR results showed that the expression level of PRDM5 mRNA in the Neuro-2a cells in GV492-PRDM5 group was significantly increased compared with GV492-control group(P＜0.01).The Western blotting results showed that the specific bands appeared in the Neuro-2a cells in GV492-control group and GV492-PRDM5 group with a relative molecular weight of 75 000;compared with GV492-control group,the expression level of PRDM5 protein in the Neuro-2a cells in GV492-PRDM5 group was increased(P＜0.01).Conclusion:The over-expression lentivirus vector of PRDM5 gene is successfully constructed,and the stably transfected GV492-PRDM5-Neuro-2a cells are established.

ObjectiveTo investigate the expression level of lysophosphatidyllecithin acyltransferase 4 （LPCAT4） in pancreatic cancer and its effect on the proliferation of pancreatic cancer cells. MethodsIn this study， the differentially expressed genes of patients with KRAS mutant and wild-type pancreatic cancer were analyzed by online database LinkedOmics. The LPCAT4 expression in pancreatic cancer tissues was analyzed online by the University of Alabama at Birmingham Cancer Data Analysis （UALCAN）， Sangerbox and gene expression profile interaction analysis 2 （GEPIA2）. Kaplan-Meier Plotter database was used to explore the correlation between LPCAT4 and the prognosis of patients with pancreatic cancer. The expression of LPCAT4 in human pancreatic cancer cells were detected by quantitative real-time PCR and Western blot analysis. LPCAT4 was knocked down in the high-expressing SW1990 cell line and overexpressed in the low-expressing MIA PaCa-2 cell line. The effects of LPCAT4 expression on cell proliferation were assessed using CCK-8 and EdU assays. STRING and GEPIA2 databases were used to obtain LPCAT4 binding and coexpressed genes in tumors， which were then analyzed by GO and KEGG. ResultsAnalysis of the LinkedOmics online database revealed a significant upregulation of LPCAT4 in patients with KRAS mutant pancreatic cancer compared to patients with KRAS wild-type pancreatic cancer. The online analysis of GEPIA2， UALCAN and Sangerbox 3.0 showed that the expression of LPCAT4 was higher in pancreatic cancer than in normal tissues. Analysis of the Kaplan-Meier Plotter database revealed that high LPCAT4 expression was associated with poorer prognosis in pancreatic cancer patients.Western blot and qPCR results showed that expression of LPCAT4 in pancreatic cancer cell lines was significantly higher than in normal pancreatic ductal epithelial cells. Knockdown of LPCAT4 in SW1990 cells inhibited proliferation， while overexpression in MIA PaCa-2 cells promoted proliferation. Enrichment analysis indicated that LPCAT4 was closely related to sulfur metabolism. ConclusionsLPCAT4 is highly expressed in pancreatic cancer and is associated with poor prognosis of patients. It plays a significant regulatory role in the proliferation of pancreatic cancer cells， with its expression level closely correlated with cell proliferation capacity. These findings reveal the critical role of LPCAT4 in the malignant progression of pancreatic cancer and provide important evidence for its potential as a therapeutic target.

Objective To establish a method for simultaneous determination of four high-molecular-weight thiol derivatives (TDs) in workplace air by gas chromatography. Methods The four kinds of vapor-phase macromolecular TDs (1-pentanethiol, 1-hexanethiol, 1-benzyl mercaptan, and n-octanethiol) in the workplace air were collected using the GDH-1 air sampling tubes, desorbed with anhydrous ethanol, separated on a DB-FFAP capillary column, and determined by flame ionization detector. Results The quantitation range of the four TDs was 0.30-207.37 mg/L, with the correlation coefficients greater than 0.999 00. The minimum detection mass concentrations and minimum quantitation mass concentrations were 0.18-0.32 and 0.60-1.05 mg/m³, respectively (both calculated based on the 1.5 L sample and 3.0 mL desorption solvent). The mean desorption efficiencies ranged from 87.07% to 103.59%. The within-run and between-run relative standard deviations were 1.92%-8.22% and 1.89%-8.45%, respectively. The samples can be stored at room temperature or 4 ℃ for three days and up to 7 days at -18 ℃. Conclusion This method is suitable for the simultaneous determination of four vapor-phase TDs in workplace air.

BACKGROUND:At present,the pathogenesis of osteoarthritis is still unclear,and there is a lack of effective means to control the disease.Research on osteoarthritis is mostly concentrated in the field of immunity,and there are few studies in the field of oxidative stress. OBJECTIVE:To explore the roles of oxidative stress and immune infiltration in osteoarthritis and to predict related miRNAs and therapeutic agents. METHODS:The GSE55235 dataset(10 samples of osteoarthritis and 10 healthy control samples)and the GSE55457 dataset(10 samples of osteoarthritis and 10 healthy control samples)were obtained from the GEO database for merging to obtain their differentially expressed genes that were combined with oxidative stress genes to get the differentially expressed genes of oxidative stress.The differentially expressed genes of oxidative stress were analyzed for KEGG and GO enrichment,and the osteoarthritis pathways and biological processes were evaluated using GSEA enrichment analysis.The protein-protein interaction network was constructed using the STRING online website and Cytoscape software,and the Degree algorithm was run to get the key genes.The GSE1919 dataset was obtained from the GEO database as a validation dataset,and the key genes were analyzed by variance analysis and receiver operating characteristic curve analysis to get the core genes.In addition,immune infiltration was evaluated by CIBERSORT and the correlation between core genes and immune cells was explored.miRNA prediction of core genes was performed using TargetScan and target drugs were predicted using the DSigDB database. RESULTS AND CONCLUSION:Sixty-five differentially expressed genes and five core genes(IL1B,CXCL8,MYC,NFKBIA,JUN)associated with oxidative stress were identified.Enrichment analysis showed that differentially expressed genes associated with oxidative stress were concentrated in the pathways of oxidative stress,interleukin-17,osteoclast differentiation,fluid shear stress and atherosclerosis.The area under the receiver operating characteristic curve for the five core genes exceeded 0.85,indicating their excellent specificity and sensitivity in diagnosing bone and joint conditions,as well as their close association with immune cells.The predicted miRNA was has-miR-3937,and the therapeutic small-molecule drugs were metformin,ionomycin and celecoxib.To conclude,oxidative stress and immune infiltration exist in osteoarthritis,and immune infiltration is involved in activating oxidative stress.The core genes and predicted miRNAs can be used as novel markers for the diagnosis of osteoarthritis,and small molecule drugs are predicted to treat osteoarthritis.

Objective:To investigate the mechanism of ursolic acid (UA) in inhibiting the growth and metastasis of breast cancer MDA-MB-231 (“231”) cells by downregulating ANXA6.Methods:This study conducted relevant in vitro cytology and molecular biology experiments in the Department of Clinical Laboratory and Central Laboratory of Putuo Hospital, Shanghai University of Traditional Chinese Medicine from February 2023 to August 2024. Human breast cancer 231 cells were cultured in vitro, and the effects of different concentrations of UA on the proliferation and invasion and metastasis of 231 cells were detected by CCK-8 and Transwell assays. Western Blot was used to detect the effect of UA on the expression of ANXA6 and invasion and metastasis-related proteins MMP9, β-catenin and N-cadherin in 231 cells. The 231 cells that interfered with and overexpressed ANXA6 were constructed by lentivirus transfection to generate stable ANXA6 interfering and overexpressing 231 cells, which were divided into 231/KD-ANXA6 group, 231/KD-NC group, 231/OE-ANXA6 group, and 231/OE-NC group. CCK-8 assay and Transwell assay were used to detect the proliferation activity, invasion and metastasis ability of 231 cells after interference and overexpression of ANXA6 and the effect of UA on the proliferation ability of 231 cells after interference and overexpression of ANXA6. Western Blot and RT-PCR assays were used to detect the expression of invasion and migration biomarkers such as MMP9, β-catenin, and N-cadherin in 231 cells after interference and overexpression of ANXA6. Immunohistochemistry was used to detect the expression level of ANXA6 in breast cancer tissues, and the relationship between ANXA6 expression and clinicopathological features and prognosis of breast cancer was analyzed.Results:The CCK-8 assay results showed that compared with the control group (0 μmol/L UA, 100.00%±7.37%), the proliferative activity of 231 cells at UA concentrations of 2.5, 5, 10, 20 and 40 μmol/L (90.23%±1.76%, t=2.24, P<0.05; 85.19%±4.23%, t=3.02, P<0.05; 65.45%±0.35%, t=8.11, P<0.01; 37.79%±0.98%, t=14.50, P<0.001; 18.18%±0.15%, t=19.23, P<0.001) were significantly decreased. Furthermore, UA (10, 15, 20 μmol/L) inhibited the invasion and metastasis ability of 231 cells; Western Blot assay showed that compared with the control group (0 μmol/L UA), the protein expressions of MMP9 (1.07±0.03 vs 0.99±0.11, t=1.27, P>0.05), β-catenin (1.21±0.01 vs 0.99±0.07, t=5.47, P<0.05), N-cadherin (1.05±0.09 vs 0.90±0.03, t=2.65, P>0.05) at UA of 10 μmol/L; MMP9 (1.07±0.03 vs 0.79±0.09, t=5.26, P<0.001), β-catenin (1.21±0.01 vs 0.89±0.05, t=10.55, P<0.001), and N-cadherin (1.04±0.09 vs 0.68±0.10, t=4.59, P<0.05) at UA of 15 μmol/L; MMP9 (1.07±0.03 vs 0.52±0.07, t=12.50, P<0.001), β-catenin (1.21±0.01 vs 0.83±0.02, t=24.01, P<0.000 1) and N-cadherin (1.04±0.09 vs 0.49±0.11, t=6.70, P<0.01) at UA of 20 μmol/L. Interfering with ANXA6 inhibits the proliferation, invasion and migration of 231 cells, and overexpression of ANXA6 promotes the proliferation, invasion and migration of 231 cells. Western Blot assay showed that compared with the control group (KD-NC group), the protein expressions of MMP9 (1.07±0.01 vs 0.62±0.16, t=4.86, P<0.01), β-catenin (1.02±0.14 vs 0.64±0.15, t=3.20, P<0.05), N-cadherin (0.98±0.14 vs 0.67±0.12, t=2.85, P<0.05) were decreased expression; Compared with the control group (OE-NC group), the protein expressions of MMP9 (0.54±0.22 vs 1.06±0.08, t=3.90, P<0.05), β-catenin (0.92±0.07 vs 1.06±0.04, t=3.06, P<0.05) and N-cadherin (0.90±0.07 vs 1.06±0.01, t=3.75, P<0.05) were significantly increased. Interference with ANXA6 promoted the inhibitory effect of UA on the proliferation ability of 231 cells ( P<0.05). Overexpression of ANXA6 weakened the inhibitory effect of UA on the proliferation of 231 cells ( P<0.05).The results of immunohistochemistry assay showed that the expression level of ANXA6 in breast cancer tissue was significantly increased, and the expression of ANXA6 was related to tumor size ( P<0.05), but not to age, T stage, N stage, pathological grade, AJCC stage, ER, PR and E-cad. Conclusion:The expression level of ANXA6 in breast cancer tissues is increased, and UA can inhibit the growth, invasion and metastasis of 231 cells by down-regulating the expression of ANXA6.

Objective To investigate the effects of exosomes derived from hypoxia-treated mesenchymal stem cells on chondrocyte injury.Methods After mesenchymal stem cells were subjected to hypoxic treatment,the secreted exosomes were collected and co-cultured with IL-1β-stimulated chondrocytes.Cell viability was assessed using the CCK-8 assay,while apoptosis was evaluated by flow cytometry and the measurement of Caspase-3 and PARP activities.Intracellular levels of ROS,Fe2+,and MDA were quantified using commercial assay kits.The expression of GPX4,SLC7A11,and ACSL4 was analyzed at both mRNA and protein levels via qRT-PCR and Western blot,respectively.Additionally,the secretion of COL2A1,MMP13,ADAMTS5,TNF-α,IL-6,and PGE2 was determined by ELISA.Results Chondrocyte viability was significantly enhanced following the uptake of exosomes derived from hypoxia-treated mesenchymal stem cells(H-Exo)(P<0.05).IL-1β treatment reduced chondrocyte viability,increased Caspase-3 and PARP activities,and promoted apoptosis(P<0.05);however,H-Exo effectively reversed IL-1 β-induced apoptotic effects.Furthermore,IL-1 β markedly down-regulated the expression of GPX4 and SLC7A11,up-regulated ACSL4 expression,and elevated intracellular levels of ROS,Fe2+,and MDA(P<0.05),indicating the induction of ferroptosis.Both the ferroptosis inhibitor and H-Exo significantly attenuated IL-1β-triggered ferroptosis,and H-Exo counteracted the detrimental effects of IL-1β as well as those induced by a ferroptosis inducer.Additionally,IL-1β suppressed the expression of the chondrogenic marker COL2A1,up-regulated the catabolic enzymes MMP13 and ADAMTS5,and enhanced the secretion of pro-inflammatory cyto-kines TNF-α,IL-6,and PGE2(P<0.05).Notably,H-Exo alleviated IL-1β-mediated inflammation and restored the balance between chondrogenic anabolism and catabolism.Conclusions Exosomes secreted by mesenchymal stem cells under hypoxic conditions can effectively inhibit chondrocyte apoptosis and ferroptosis,thereby alleviating cellular injury.These findings suggest that such exosomes exert a protective effect on chondrocytes and hold prom-ise as a novel therapeutic strategy for cartilage repair.

Objective To develop a solvent desorption-gas chromatography method for quantifying malononitrile in workplace air. Methods Malononitrile in workplace air was collected using a silica gel tube and desorbed with methanol. Separation was performed using DB-FFAP capillary column, and detection was performed by hydrogen flame ionization detector. Results The linear ranges of malononitrile were 4.00-600.00 mg/L, with the correlation coefficient of 0.999 92. The detection limit was 0.54 mg/L. The minimum detection concentration was 0.36 mg/m³ (based on a collected air volume of 1.5 L). The average desorption efficiency was 95.0%-101.0%. The within-run and between-run relative standard deviations were 0.9%-5.3% and 1.0%-6.8%, respectively. The sampling efficiency was 100.0%. The samples were stable at 4 ℃ for at least 14 days. Conclusion The solvent desorption-gas chromatography method established in this study for the determination of malononitrile in workplace air is simple to use, with high accuracy and good precision, and is suitable for the determination of malononitrile in workplace air.

Objective:To explore the clinical characteristics of biliary system diseases complicated by severe acute pancreatitis(SAP) and the risk factors.Methods:This is a retrospective cohort study. A retrospective analysis was conducted on the clinical data of 159 SAP patients admitted to the Department of Pancreatic and Biliary Surgery,the First Affiliated Hospital of Harbin Medical University from January 2019 to October 2024. There were 105 male cases, 54 female cases;aged (42.3±10.8)years (range:20 to 71 years). Grouping was performed according to the presence or absence of concurrent acute acalculous cholecystitis (AAC) and biliary stricture. There were 58 cases in the AAC group,including 40 males and 18 females;aged (43.8±10.6) years (range:28 to 71 years);101 cases in the non-AAC group,including 64 males and 37 females;aged (41.5±10.8) years (range:20 to 64 years);there were statistically significant differences between the two groups in terms of admission total bilirubin,Balthazar-CTSI score,fasting time,and the proportions of concurrent shock and sepsis (all P<0.05);the time from onset of SAP to diagnosis of AAC( M (IQR)) was 10.5 (13.3) days (range: 3 to 34 days). There were 15 cases in the biliary stricture group,including 13 males and 2 females;age (46.5±10.0) years (range:33 to 63 years);141 cases in the non-biliary stricture group,including 89 males and 52 females;age (41.9±10.8) years (range: 20 to 71 years); there were statistically significant differences between the two groups in the proportions of infected pancreatic necrosis,pancreatic head necrosis,and lower extremity venous thrombosis (all P<0.05);the time from the onset of SAP to the diagnosis of biliary stenosis in patients with biliary stenosis was 2.0 (3.0) months (range: 1 to 19 months). Univariate analysis was performed using independent sample t-test, Mann-Whitney U test, χ 2 test,or Fisher′s exact probability method,and variables with P<0.05 in univariate analysis were included in multivariate logistic regression analysis. The receiver operating characteristic (ROC) curve was used to analyze the diagnostic and predictive value of the multivariate logistic regression model for AAC and biliary stricture. Results:There were statistically significant differences in fasting time,Balthazar-CTSI score,admission total bilirubin,and the proportions of concurrent shock and sepsis between the AAC group and non-AAC group ( P<0.05). Multivariate logistic analysis showed that admission total bilirubin ( OR=1.033,95% CI: 1.010 to 1.058, P=0.004),Balthazar-CTSI score ( OR=1.276,95% CI: 1.036 to 1.572, P=0.022),fasting time ( OR=1.127,95% CI: 1.044 to 1.216, P=0.002), and sepsis ( OR=4.033, 95% CI: 1.419 to 11.462, P=0.009) were independent risk factors for AAC complicated by SAP. The area under the curve (AUC) of the ROC curve was 0.820 (95% CI: 0.752 to 0.888). There were statistically significant differences in the proportions of infected pancreatic necrosis,pancreatic head necrosis,and lower extremity venous thrombosis between the biliary stricture group and non-biliary stricture group ( P<0.05). Multivariate logistic analysis showed that infected pancreatic necrosis ( OR=7.376,95% CI:1.566 to 37.750, P=0.012) and pancreatic head necrosis ( OR=3.898,95% CI:1.180 to 12.877, P=0.026) were independent risk factors for biliary stricture complicated by SAP. The AUC of the ROC curve was 0.806 (95% CI:0.715 to 0.898). Conclusions:AAC typically occurs in the early stage of SAP,and biliary stricture usually occurs in the late stage of SAP. Admission total bilirubin,Balthazar-CTSI score,fasting duration,and concurrent sepsis are independent risk factors for AAC complicating SAP. Infected pancreatic necrosis and pancreatic head necrosis are independent risk factors for biliary stricture complicating SAP.

Objective:To investigate the clinicopathological and molecular genetic characteristics of diffuse gliomas with the features of polymorphous low-grade neuroepithelial tumor of the young (PLNTY) and their prognostic values.Methods:A retrospective analysis was performed on 14 cases of diffuse gliomas with PLNTY features diagnosed at the First Affiliated Hospital of Fujian Medical University, Fuzhou, China from June 2020 to August 2024. Their clinicopathological characteristics were examined, and their molecular genetic and epigenetic features were assessed using next-generation sequencing (NGS) and methylation analysis. Factors influencing prognosis were also analyzed.Results:Among the 14 patients, there were 8 males and 6 females, aged 3-62 years, median 29 (9, 50) years. All cases were initially diagnosed as low-grade diffuse gliomas histologically but exhibited the histological and immunohistochemical features of PLNTY. At the molecular level, all cases showed molecular abnormalities involving the mitogen-activated protein kinase pathway, including 5 cases with FGFR3-TACC3 (F3T3) fusion, 3 cases with FGFR2 fusion, 5 cases with BRAF V600E mutation, and 1 case with FGFR1 mutation. Among them, TERT promoter mutations were frequently observed in tumors with F3T3 fusion (5/5), while NCOR2 in-frame insertion mutations were prominent in tumors with non-F3T3 fusions. Clinical follow-up showed recurrence in 3 cases, all of which had F3T3 fusion and concurrent TERT promoter mutations. Prognostic analysis confirmed that F3T3 fusion with concurrent TERT promoter mutation was associated with poor prognosis.Conclusions:Diffuse gliomas with PLNTY features exhibit heterogeneity in clinicopathology and molecular genetics, with FGFR3/FGFR2 fusions and BRAF/FGFR1 mutations as the most common molecular alteration. They often have concurrent F3T3 fusion and TERT promoter mutations, which are related to poor prognosis. The possibility of molecular glioblastoma should be considered for these tumors. It is thus recommended to perform genetic testing on diffuse gliomas with PLNTY features in order to facilitate integrated diagnosis and provide molecular evidence for accurate evaluation of prognoses.