【Objective】 To analyze the correlation between the distribution interval of minipool nucleic acid testing(NAT) positive CT value and the resolution rate, so as to improve the retest model and reduce residual risk of blood transfusion. 【Methods】 The resolution testing results by Cobas S201 system of our blood center from January 2017 to December 2021 were retrospective analyzed, and the retest model was developed based on the distribution interval of CT values. For minipool NAT HBV positive samples from March 2022 to March 2023, synchronous detection was conducted by Cobas S201 and Panther detection system, and the detection results were statistically analyzed. 【Results】 From 2017 to 2021, 474 were minipool NAT positive, among which 324 were HBV positive, accounting for 68.35%. From 2017 to 2020, the proportion of HBV positive per year was significantly higher than that of HCV and HIV(P<0.05). In resolution testing, 167 were HBV repeatable positive and 157 were HBV non-repeatable positive, accounting for 51.54% and 48.46% of HBV minipool NAT positive. HBV repeatable positive samples were with three intervals: CT value≤36, 3640, with the resolution rate at 95.8%, 56.5% and 14.8% respectively(P<0.05). The proportion of 3640, 36

The ATP-binding cassette(ABC)transporter superfamily comprises membrane proteins that efflux various substrates across extra-and intracellular membranes.Among them,ABCB1,ABCG2,and ABCC1 are directly linked to tumor multidrug resistance(MDR).This review provides an overview of the current understanding on the novel mechanisms and functions of ABCB1,ABCG2,and ABCC1 transporters in tumor MDR,discusses the latest strategies to target these transporters,and explores further opportunities to overcome MDR.

Objective:To compare the prevalence of frailty and related factors in middle-aged and elderly people aged ≥45 years in island and mountainous areas of Taizhou, Zhejiang Province.Methods:Based on cross-sectional design, stratified cluster sampling and quota sampling methods were adopted. One administrative district was randomly selected from each of six coastal and three inland administrative districts in Taizhou during July to August, representing two different geographical terrains. In the island area (Jiaojiang District), all residents aged ≥45 years were included by cluster sampling. In the mountainous area (Xianju County), participants were selected through quota sampling, with same gender and age distributions. Data about their demographic characteristics, lifestyle and health-related factors were collected through questionnaire surveys and laboratory examinations. The prevalence of frailty was assessed using the Fried frailty phenotype scale. Hierarchical analysis and multivariate logistic regression analysis were used to compare the influencing factors of frailty.Results:A total of 1 011 local residents were studied, in whom island and mountainous residents accounted for 48.1% (486/1 011) and 51.9% (525/1 011) respectively; men and women accounted for 45.9% (464/1 011) and 54.1% (547/1 011) respectively. Middle-aged (45-49 years), younger elderly (60-74 years), and older elderly (≥75 years) residents accounted for 38.6% (390/1 011), 44.6% (451/1 011), and 16.8% (170/1 011) respectively. The overall prevalence rate of frailty was 3.6% (36/1 011), the prevalence rate was 3.7% (17/464) in men and 3.5% (19/547) in women. The prevalence rates in age groups 45-59,60-74 years and ≥75 years were 0.3% (1/390), 2.2% (10/451), and 14.7% (25/170), respectively. The prevalence rates of frailty and pre-frailty in island area were 6.0% (29/486) and 39.1% (190/486), respectively, which was higher than those in mountainous area (1.3%, 7/525) and (30.9%, 162/525). After adjusting for potential confounding factors, the risk for frailty in island residents was significantly higher than that in mountainous residents (a OR=1.55,95% CI: 1.07-2.25, P=0.019). In island area, older age (60-74 years:a OR=2.52,95% CI: 1.56-4.13; ≥75 years:a OR=11.65,95% CI:5.38-26.70), being women (a OR=1.94,95% CI: 1.20-3.17), suffering from depression (a OR=1.09,95% CI:1.02-1.17) were associated with frailty symptoms. In mountainous area, older age was also associated with an increased risk of frailty symptoms, but the OR value was lower than those in island area (60-74 years: a OR=1.74,95% CI:1.04-2.94;≥75 years: a OR=4.78,95% CI:2.45-9.50). Polydrug use (a OR=2.08,95% CI: 1.14-3.80) and suffering from depression (a OR=1.10,95% CI: 1.02-1.18) had significant positive association with frailty symptoms. Higher education level had significant negative association with frailty symptoms (junior high school: a OR=0.40,95% CI: 0.21-0.75; senior high school and technical secondary school: a OR=0.29,95% CI: 0.15-0.53; college or above:a OR=0.22,95% CI: 0.11-0.42). Conclusions:The prevalence of frailty in middle-aged and elderly community residents was significantly higher in island area than in mountainous area in Taizhou. The frailty-related factors varied with area. The elderly people (≥75 years) and women in island area had higher risk for frailty. Older age and suffering from depression were the independent risk factors for frailty. It is necessary to pay attention to the health risk factors and special environment in island area, and take comprehensive intervention measures to delay the process of debilitation and improve the quality of life of middle-aged and elderly people.

Objective:To explore the optimal regimen of standardized mite allergen immunotherapy for airway allergic diseases in children, and to observe the clinical efficacy, safety and compliance.Method:Use a retrospective real-world study, clinical data from 156 children aged 5-16 years who received subcutaneous immunotherapy (SCIT) with double mite allergen preparation in the pediatrics department of the Third Affiliated Hospital of Sun Yat sen University from June 2019 to September 2020 were selected for allergic rhinitis (AR) and/or allergic asthma (bronchial asthma, BA), including gender, age, total VAS(visual analogue scale) score and CSMS(combined symptom and medication scores) score at different time points (before treatment, 4-6 months, 1 year, and 2 years after initiation of desensitization), peripheral blood eosinophil counts (EOS), serum total IgE (tIgE), specific IgE (tIgE), and serum IgE (tIgE), specific IgE (sIgE), tIgG4, and incidence of local and systemic adverse reactions. All patients had a consistent regimen during the initial treatment phase (dose-escalation phase), which was performed as directed. Among them, 81 cases (observation group) continued to continue subcutaneous injection of 1 ml of vial No. 3 every 4-6 weeks during the dose maintenance phase, while 75 cases (control group) followed the old traditional regimen during the maintenance phase (i.e., change to a new vial to halve the amount of vial No. 3 by 0.5 ml, and then 0.75 ml after 1-2 weeks, and 1 ml in a further interval of 1-2 weeks). The clinical efficacy, safety and adherence to the treatment were compared between the two groups.Results:A total of 81 cases of 156 children were included in the observation group, of which 58 children with AR, 15 children with BA, and 8 children with AR combined with BA; 75 cases were included in the conventional control group, of which 52 children with AR, 16 children with BA, and 7 children with AR combined with BA. In terms of safety, the difference in the incidence of local and systemic adverse reactions between the two groups was not statistically significant ( χ2=1.541 for local adverse reactions in the control group, χ2=0.718 for the observation group; χ2=0.483 for systemic adverse reactions in the control group, χ2=0.179 for the observation group, P value >0.05 for all of these), and there were no grade Ⅱ or higher systemic adverse reactions in any of them. In the control group, there were 15 cases of dropout at 2 years of follow-up, with a dropout rate of 20.0%; in the observation group, there were 7 cases of dropout at 2 years of follow-up, with a dropout rate of 8.6%, and there was a statistically significant difference in the dropout rates of the patients in the two groups ( χ2=4.147, P<0.05). Comparison of serological indexes and efficacy (compared with baseline at 3 different time points after treatment, i.e., 4-6 months, 1 year and 2 years after treatment), CSMS scores of the observation group and the conventional control group at 4-6 months, 1 year and 2 years after treatment were significantly decreased compared with the baseline status ( t-values of the conventional group were 13.783, 20.086 and 20.384, respectively, all P-values <0.001, and t-values of the observation group were 15.480, 27.087, 28.938, all P-values <0.001), and VAS scores also decreased significantly from baseline status in both groups at 4-6 months, 1 year, and 2 years of treatment ( t-values of 14.008, 17.963, and 27.512 in the conventional control group, respectively, with all P-values <0.001, and t-values of 9.436, 13.184, and 22.377 in the observation group, respectively; all P-values <0.001). Intergroup comparisons showed no statistically significant differences in CSMS at baseline status, 4-6 months, 1 year and 2 years ( t-values 0.621, 0.473, 1.825, and 0.342, respectively, and P-values 0.536, 0.637, 0.070, and 0.733, respectively), and VAS was no statistically significant difference in comparison between groups at different time points ( t-values of 1.663, 0.095, 0.305, 0.951, P-values of 0.099, 0.925, 0.761, 0.343, respectively); suggesting that the treatment regimens of the observation group and the conventional control group were clinically effective, and that the two regimens were comparable in terms of efficacy. The peripheral blood eosinophil counts of the observation group and the conventional control group decreased significantly from the baseline status at 4-6 months, 1 year and 2 years of treatment ( t-values of the conventional group were 3.453, 5.469, 6.273, P-values <0.05, and the t-values of the observation group were 2.900, 4.575, 5.988, P-values <0.05, respectively). 4-6 months, 1 year and 2 years compared with the baseline status tIgE showed a trend of increasing and then decreasing ( t-value in the conventional group was -5.328, -4.254, -0.690, P-value was 0.000, 0.000, 0.492, respectively, and t-value in the observation group was -6.087, -5.087, -0.324, P-value was 0.000, 0.000, 0.745, respectively). However, the results of intergroup comparisons showed no statistically significant differences in serological indices and efficacy between the two groups in terms of peripheral blood eosinophil counts at baseline status, 4-6 months, 1 year and 2 years ( t-values of 0.723, 1.553, 0.766, and 0.234, respectively; P-values of 0.471, 0.122, 0.445, and 0.815, respectively), tIgE ( t-values of 0.170, -0.166, -0.449, 0.839, P-values 0.865, 0.868, 0.654, 0.403, respectively), tIgG4 ( t-values 1.507, 1.467, -0.337, 0.804, P-values 0.134, 0.145, 0.737, 0.422, respectively). Conclusion:Both immunotherapy regimens for airway allergic diseases with double mite allergen subcutaneous immunotherapy have significant clinical efficacy, low incidence of adverse reactions, and the observation group has better patient compliance than the control group.

Objective:To assess the value of serum tumor specific protein 70 (SP70) for prognostic stratification in acute myeloid leukemia (AML).Methods:A cohort study design was adopted. 129 newly diagnosed AML patients from September 2022 to January 2024 at the Hematology Department of the First Affiliated Hospital of Nanjing Medical University were included, as well as a control group consisted of 120 healthy individuals and 7 cases with benign hematologic diseases during the same period (total 127 cases). Clinical data were collected from Electronic Medical Records. According to the 2023 edition of the Chinese Leukemia Diagnosis and Treatment Guidelines, AML patients with good or moderate prognosis were categorized as low-to-intermediate risk, while those with poor prognosis were high-risk group. Univariate and multivariate logistic regression analyses were used to identify variables significantly associated with AML prognostic risk. ROC analysis was used to evaluate diagnostic performance. A nomogram for predicting patient prognostic risk was constructed by R 4.0.2 software, and the internal validation was performed using bootstrapping.Results:Among 129 AML patients, there were 71 males (55.0%) and 58 females (45.0%), with 42 (32.6%) classified as high-risk and 87 (67.4%) as low-intermediate risk. The high-risk group had a significantly higher median age [62 (48, 67) years] compared to the low-intermediate risk group [50 (35, 63) years, Z=-2.381, P=0.017], and a significantly higher proportion of males (30 patients, 71.4%) compared to the low-intermediate risk group (41 patients, 47.1%, χ 2=6.760, P=0.009). Multivariate logistic regression analysis indicated that serum SP70 ( OR=2.54, 95% CI: 1.68-3.84, P<0.001), hemoglobin (HB) ( OR=0.96, 95% CI: 0.93-0.99, P<0.05), and bone marrow blast (BM blast) ( OR=1.07, 95% CI: 1.02-1.13, P<0.05) were independent risk factors for high-risk prognosis in AML patients. ROC analysis showed that the area under the curve (AUC) for SP70 predicting high-risk patients was 0.908 (cut-off value of 5.74 ng/ml, 95% CI: 0.845-0.952, sensitivity 90.5%, specificity 82.8%). The combined model of serum SP70, HB, and BM blasts had an AUC of 0.931 (95% CI: 0.890-0.973); C-index=0.925 (95% CI: 0.876-0.963),with no statistically significant difference compared to serum SP70 alone ( Z=1.693, P>0.05). Conclusion:Serum SP70 may be a promising non-invasive molecular biomarker for prognostic stratification in AML.

Objective:To construct and test the reliability and validity of an assessment scale for self-management of patients with dry eye, so as to help patients establish dry eye related health behaviors.Methods:Based on the knowledge attitude and practice theory, the initial scale was constructed on the basis of literature review and qualitative interview, and revised through Delphi expert consultation and expert argumentation. After the preliminary investigation, 211 dry eye patients treated in the dry eye nursing outpatient department of Beijing Tongren Hospital from August 2023 to January 2024 were selected by convenience sampling method for questionnaire investigation to test the reliability and validity of the scale.Results:Among 211 dry eye patients, there were 58 males and 153 females, aged (39.31 ± 12.81) years old. The scale of self-management of patients with dry eye included 27 items in 3 dimensions: knowledge, attitude and behavior. The authority coefficient of the two rounds of expert consultation was 0.86, and the Kendall coordination index increased from 0.175 to 0.223 (both P < 0.01). The cumulative variance contribution rates of the three dimensions were 41.843%, 54.219% and 44.273%, respectively. The Cronbach α coefficient of the scale was 0.787, and the Spearman-Brown coefficient was 0.641. Conclusions:The scale of self-management of patients with dry eye has good reliability and validity and can be used in the assessment of dry eye patients to provide a reference basis for targeted guidance and intervention.

Objective:To analyze the influencing factors of genotypic drug resistance mutations in people living with human immunodeficiency virus and acquired immunodeficiency syndrome(PLWHA) who failed anti-retroviral therapy (ART) in Henan Province, in order to provide a basis for adjusting ART regimens and reducing drug resistance.Methods:PLWHA with virological failure (human immunodeficiency virus (HIV) RNA≥500 copies/mL) after receiving ART for more than 24 weeks were included in Henan Province from January 2018 to December 2022. Baseline CD4 + T lymphocyte counts, ART regimens and other clinical data were collected. HIV-1 gene subtypes and their drug resistance sequence mutations were detected in the Sixth People′s Hospital of Zhengzhou, and the sequences were submitted to the HIV Drug Resistance Interpretation System of Stanford University for comparison of test results. Genotypic drug resistance to nucleotide reverse transcriptase inhibitors (NRTI), non-nucleoside reverse transcriptase inhibitors (NNRTI), protease inhibitors (PI) and integrase inhibitors (INSTI) was determined. Multivariate logistic regression was used to analyze the influencing factors of drug resistance in patients with ART failure. Results:Among 982 PLWHA, the sequences of 899 cases were successfully amplified, and drug resistance was detected in 737 cases, with the drug resistance rate of 81.98%(737/899). The rates of resistance to NRTIs, NNRTIs, PIs and INSTIs were 71.97%(647/899), 79.31%(713/899), 5.23%(47/899) and 2.72%(20/734), respectively.The largest number of those who developed concomitant resistance to two classes of drugs was 588 cases (79.78%), mainly NRTI and NNRTI concomitant resistance in 583 cases (79.10%). There were 99 cases (13.43%) who developed resistance to only one class of drugs, and those who developed concurrent resistance to three classes of drugs were 48 cases (6.51%), and two cases (0.27%) were found to be resistant to all four classes of drugs mentioned above. A total of 10 HIV genotypes were detected, among which subtype B accounted for the most (59.73%(537/899)), followed by circulating recombinant form (CRF)01_AE subtype (21.91%(197/899)) and CRF07_BC subtype (9.45%(85/899)). The risk factors affecting the development of drug resistance were baseline CD4 + T lymphocyte counts, ART regimens and HIV-1 genotypes. The risk of drug resistance in patients with baseline CD4 + T lymphocyte counts <100/μL was 4.55 times (95% confidence interval ( CI) 2.69 to 7.70) higher than patients with CD4 + T lymphocyte counts≥250/μL, the risk of drug resistance in patients using 2NRTIs+ NNRTI regimen was 4.51 times (95% CI 1.75 to 11.63) higer than those using 2NRTIs+ INSTI regimen, and patients infected with B and CRF01_AE subtype was 2.18 times (95% CI 1.10 to 4.29) and 2.70 times (95% CI 1.26 to 5.78) higer than those with CRF07_BC subtype, respectively. Conclusions:The incidence of genotypic drug resistance in PLWHA with ART failure in Henan Province is high. Low baseline CD4 + T lymphocyte counts, 2NRTIs+ NNRTI regimens, and genotype B and CRF01_AE are risk factors for drug resistance in PLWHA.

Objective:To explore the optimal regimen of standardized mite allergen immunotherapy for airway allergic diseases in children, and to observe the clinical efficacy, safety and compliance.Method:Use a retrospective real-world study, clinical data from 156 children aged 5-16 years who received subcutaneous immunotherapy (SCIT) with double mite allergen preparation in the pediatrics department of the Third Affiliated Hospital of Sun Yat sen University from June 2019 to September 2020 were selected for allergic rhinitis (AR) and/or allergic asthma (bronchial asthma, BA), including gender, age, total VAS(visual analogue scale) score and CSMS(combined symptom and medication scores) score at different time points (before treatment, 4-6 months, 1 year, and 2 years after initiation of desensitization), peripheral blood eosinophil counts (EOS), serum total IgE (tIgE), specific IgE (tIgE), and serum IgE (tIgE), specific IgE (sIgE), tIgG4, and incidence of local and systemic adverse reactions. All patients had a consistent regimen during the initial treatment phase (dose-escalation phase), which was performed as directed. Among them, 81 cases (observation group) continued to continue subcutaneous injection of 1 ml of vial No. 3 every 4-6 weeks during the dose maintenance phase, while 75 cases (control group) followed the old traditional regimen during the maintenance phase (i.e., change to a new vial to halve the amount of vial No. 3 by 0.5 ml, and then 0.75 ml after 1-2 weeks, and 1 ml in a further interval of 1-2 weeks). The clinical efficacy, safety and adherence to the treatment were compared between the two groups.Results:A total of 81 cases of 156 children were included in the observation group, of which 58 children with AR, 15 children with BA, and 8 children with AR combined with BA; 75 cases were included in the conventional control group, of which 52 children with AR, 16 children with BA, and 7 children with AR combined with BA. In terms of safety, the difference in the incidence of local and systemic adverse reactions between the two groups was not statistically significant ( χ2=1.541 for local adverse reactions in the control group, χ2=0.718 for the observation group; χ2=0.483 for systemic adverse reactions in the control group, χ2=0.179 for the observation group, P value >0.05 for all of these), and there were no grade Ⅱ or higher systemic adverse reactions in any of them. In the control group, there were 15 cases of dropout at 2 years of follow-up, with a dropout rate of 20.0%; in the observation group, there were 7 cases of dropout at 2 years of follow-up, with a dropout rate of 8.6%, and there was a statistically significant difference in the dropout rates of the patients in the two groups ( χ2=4.147, P<0.05). Comparison of serological indexes and efficacy (compared with baseline at 3 different time points after treatment, i.e., 4-6 months, 1 year and 2 years after treatment), CSMS scores of the observation group and the conventional control group at 4-6 months, 1 year and 2 years after treatment were significantly decreased compared with the baseline status ( t-values of the conventional group were 13.783, 20.086 and 20.384, respectively, all P-values <0.001, and t-values of the observation group were 15.480, 27.087, 28.938, all P-values <0.001), and VAS scores also decreased significantly from baseline status in both groups at 4-6 months, 1 year, and 2 years of treatment ( t-values of 14.008, 17.963, and 27.512 in the conventional control group, respectively, with all P-values <0.001, and t-values of 9.436, 13.184, and 22.377 in the observation group, respectively; all P-values <0.001). Intergroup comparisons showed no statistically significant differences in CSMS at baseline status, 4-6 months, 1 year and 2 years ( t-values 0.621, 0.473, 1.825, and 0.342, respectively, and P-values 0.536, 0.637, 0.070, and 0.733, respectively), and VAS was no statistically significant difference in comparison between groups at different time points ( t-values of 1.663, 0.095, 0.305, 0.951, P-values of 0.099, 0.925, 0.761, 0.343, respectively); suggesting that the treatment regimens of the observation group and the conventional control group were clinically effective, and that the two regimens were comparable in terms of efficacy. The peripheral blood eosinophil counts of the observation group and the conventional control group decreased significantly from the baseline status at 4-6 months, 1 year and 2 years of treatment ( t-values of the conventional group were 3.453, 5.469, 6.273, P-values <0.05, and the t-values of the observation group were 2.900, 4.575, 5.988, P-values <0.05, respectively). 4-6 months, 1 year and 2 years compared with the baseline status tIgE showed a trend of increasing and then decreasing ( t-value in the conventional group was -5.328, -4.254, -0.690, P-value was 0.000, 0.000, 0.492, respectively, and t-value in the observation group was -6.087, -5.087, -0.324, P-value was 0.000, 0.000, 0.745, respectively). However, the results of intergroup comparisons showed no statistically significant differences in serological indices and efficacy between the two groups in terms of peripheral blood eosinophil counts at baseline status, 4-6 months, 1 year and 2 years ( t-values of 0.723, 1.553, 0.766, and 0.234, respectively; P-values of 0.471, 0.122, 0.445, and 0.815, respectively), tIgE ( t-values of 0.170, -0.166, -0.449, 0.839, P-values 0.865, 0.868, 0.654, 0.403, respectively), tIgG4 ( t-values 1.507, 1.467, -0.337, 0.804, P-values 0.134, 0.145, 0.737, 0.422, respectively). Conclusion:Both immunotherapy regimens for airway allergic diseases with double mite allergen subcutaneous immunotherapy have significant clinical efficacy, low incidence of adverse reactions, and the observation group has better patient compliance than the control group.

Objective:To assess the value of serum tumor specific protein 70 (SP70) for prognostic stratification in acute myeloid leukemia (AML).Methods:A cohort study design was adopted. 129 newly diagnosed AML patients from September 2022 to January 2024 at the Hematology Department of the First Affiliated Hospital of Nanjing Medical University were included, as well as a control group consisted of 120 healthy individuals and 7 cases with benign hematologic diseases during the same period (total 127 cases). Clinical data were collected from Electronic Medical Records. According to the 2023 edition of the Chinese Leukemia Diagnosis and Treatment Guidelines, AML patients with good or moderate prognosis were categorized as low-to-intermediate risk, while those with poor prognosis were high-risk group. Univariate and multivariate logistic regression analyses were used to identify variables significantly associated with AML prognostic risk. ROC analysis was used to evaluate diagnostic performance. A nomogram for predicting patient prognostic risk was constructed by R 4.0.2 software, and the internal validation was performed using bootstrapping.Results:Among 129 AML patients, there were 71 males (55.0%) and 58 females (45.0%), with 42 (32.6%) classified as high-risk and 87 (67.4%) as low-intermediate risk. The high-risk group had a significantly higher median age [62 (48, 67) years] compared to the low-intermediate risk group [50 (35, 63) years, Z=-2.381, P=0.017], and a significantly higher proportion of males (30 patients, 71.4%) compared to the low-intermediate risk group (41 patients, 47.1%, χ 2=6.760, P=0.009). Multivariate logistic regression analysis indicated that serum SP70 ( OR=2.54, 95% CI: 1.68-3.84, P<0.001), hemoglobin (HB) ( OR=0.96, 95% CI: 0.93-0.99, P<0.05), and bone marrow blast (BM blast) ( OR=1.07, 95% CI: 1.02-1.13, P<0.05) were independent risk factors for high-risk prognosis in AML patients. ROC analysis showed that the area under the curve (AUC) for SP70 predicting high-risk patients was 0.908 (cut-off value of 5.74 ng/ml, 95% CI: 0.845-0.952, sensitivity 90.5%, specificity 82.8%). The combined model of serum SP70, HB, and BM blasts had an AUC of 0.931 (95% CI: 0.890-0.973); C-index=0.925 (95% CI: 0.876-0.963),with no statistically significant difference compared to serum SP70 alone ( Z=1.693, P>0.05). Conclusion:Serum SP70 may be a promising non-invasive molecular biomarker for prognostic stratification in AML.

Objective To investigate the protective effect of metformin against PM2.5-induced functional impairment of placental trophoblasts and explore the underlying mechanism.Methods Sixteen pregnant Kunming mice were randomly assigned into two groups(n=8)for intratracheal instillation of PBS or PM2.5 suspension at 1.5,7.5,and 12.5 days of gestation.The pregnancy outcome of the mice was observed,and placental zonal structure and vascular density of the labyrinth area were examined with HE staining,followed by detection of ferroptosis-related indexes in the placenta.In cultured human trophoblasts(HTR8/SVneo cells),the effects of PM2.5 exposure and treatment with metformin on cell viability,proliferation,migration,invasion,and tube formation ability were evaluated using CCK8 assay,EDU staining,wound healing assay,Transwell experiment,and tube formation experiment;the cellular expressions of ferroptosis-related proteins were analyzed using ELISA and Western blotting.Results M2.5 exposure of the mice during pregnancy resulted in significantly decreased weight and number of the fetuses and increased fetal mortality with a reduced placental weight(all P<0.001).PM2.5 exposure also caused obvious impairment of the placental structure and trophoblast ferroptosis.In cultured HTR8/SVneo cells,PM2.5 significantly inhibited proliferation,migration,invasion,and angiogenesis of the cells by causing ferroptosis.Metformin treatment obviously attenuated PM2.5-induced inhibition of proliferation,migration,invasion,and angiogenesis of the cells,and effectively reversed PM2.5-induced ferroptosis in the trophoblasts as shown by significantly increased intracellular GSH level and SOD activity,reduced MDA and Fe2+ levels,and upregulated GPX4 and SLC7A11 protein expression(P<0.05 or 0.01).Conclusion PM2.5 exposure during pregnancy causes adverse pregnancy outcomes and ferroptosis and functional impairment of placental trophoblasts in mice,and metformin can effectively alleviate PM2.5-induced trophoblast impairment.