Objective : To investigate the regulatory effect of artemisinin derivative dihydroartemisinin ( DHA) on anti-tumor immune function of CD8 + T cells induced by non-small cell lung cancer ( NSCLC) cells . Methods: NSCLC A549 cells were divided into DMSO control group and DHA treatment group . A549 cells were treated with DMSO and DHA at different concentrations (25 , 50 and 100 μmol/L) , and the optimal concentration of DHA was selected to treat A549 cells for 0 , 24 , 48 and 72 h according to half maximal inhibitory concentrate (IC50 ) . CCK 8 method and colony formation test were used to detect the effect of DHA on the proliferation and colony formation ability of A549 cells . Peripheral blood mononuclear cells (PBMCs ) of healthy individuals were isolated by density gradient centrifugation . After monocytes were removed by adhesion method , A549 cells pretreated with mitomycin C were co cultured with PBMCs at 10:1 ratio . After 2 weeks , flow cytometry was used to detect the proportion of CD8 + T cells and the expression levels of perforin and granzyme B . Results : Compared with the control group , the proliferation inhibition rates of A549 cells increased after treatment with 25 , 50 and 100 μmol/L DHA for 24 h (P < 0.01) . The IC50 of DHA on A549 cells was 46.26 μmol/L. According to IC50 concentration analysis , the inhibi tion rates of A549 cells treated with 50 μmol/L DHA for 0 , 24 , 48 and 72h were 1 53% , 53.50% , 63.84% and 69.91% , and the cells inhibition rates of A548 cells increased compared with the previous ob servation time point , namely 0 , 24 and 48 h (P < 0.01) . The colony formation assay showed that the colony formation number of A549 cells in DHA treated group decreased compared with the control group (P < 0.01) . Flow cytometry results showed that compared with the control group , the proportion of CD8 + T cells induced by A549 cells in the co-culture system and the proportion of CD8 + T cells expressing perforin and granzyme B were higher in DHA pretreatment group(P < 0.01) . Conclusion DHA inhibits the growth of NSCLC cells and promotes anti tumor immune response of CD8 + T cells induced by NSCLC cells .

Objective:To analyze the risk factors of bronchopulmonary dysplasia(BPD)in very preterm infants(VPI), and to provide scientific basis for the prevention and treatment of BPD in VPI.Methods:A prospective multicenter study was designed to collect the clinical data of VPI in department of neonatology of 28 hospitals in 7 regions from September 2019 to December 2020.According to the continuous oxygen dependence at 28 days after birth, VPI were divided into non BPD group and BPD group, and the risk factors of BPD in VPI were analyzed.Results:A total of 2 514 cases of VPI including 1 364 cases without BPD and 1 150 cases with BPD were enrolled.The incidence of BPD was 45.7%.The smaller the gestational age and weight, the higher the incidence of BPD( P<0.001). Compared with non BPD group, the average birth age, weight and cesarean section rate in BPD group were lower, and the incidence of male infants, small for gestational age and 5-minute apgar score≤7 were higher( P<0.01). In BPD group, the incidences of neonatal respiratory distress syndrome(NRDS), hemodynamically significant patent ductus arteriosus, retinopathy of prematurity, feeding intolerance, extrauterine growth restriction, grade Ⅲ~Ⅳ intracranial hemorrhage, anemia, early-onset and late-onset sepsis, nosocomial infection, parenteral nutrition-associated cholestasis were higher( P<0.05), the use of pulmonary surfactant(PS), postnatal hormone exposure, anemia and blood transfusion were also higher, and the time of invasive and non-invasive mechanical ventilation, oxygen use and total hospital stay were longer( P<0.001). The time of starting enteral nutrition, cumulative fasting days, days of reaching total enteral nutrition, days of continuous parenteral nutrition, days of reaching 110 kcal/(kg·d) total calorie, days of reaching 110 kcal/(kg·d) oral calorie were longer and the breastfeeding rate was lower in BPD group than those in non BPD group( P<0.001). The cumulative doses of amino acid and fat emulsion during the first week of hospitalization were higher in BPD group( P<0.001). Multivariate Logistic regression analysis showed that NRDS, invasive mechanical ventilation, age of reaching total enteral nutrition, anemia and blood transfusion were the independent risk factors for BPD in VPI, and older gestational age was the protective factor for BPD. Conclusion:Strengthening perinatal management, avoiding premature delivery and severe NRDS, shortening the time of invasive mechanical ventilation, paying attention to enteral nutrition management, reaching whole intestinal feeding as soon as possible, and strictly mastering the indications of blood transfusion are very important to reduce the incidence of BPD in VPI.