Expert statement on the construction criteria of critical care department in municipal and district designated hospitals under the pandemic prevention and control / 中华危重病急救医学

The global coronavirus disease 2019 epidemic is still in a pandemic state. Aging population with underlying diseases is prone to become severe, and have a higher mortality. The treatment capacity of the critical care department directly determines the treatment success rate of critical illness. At present, there is still a certain gap between domestic and foreign countries in intensive care unit (ICU), which is not only in the allocation of medical staff, but also in the beds and settings. The current medical model cannot fully meet the needs of development. The experience and lessons of many major public health emergencies suggested that " dual track of peace and war" approach in discipline construction of critical care is the best medical model. Following the concept of "combination of peace and war", strengthening the discipline construction of critical care department in municipal and district designated hospitals, allocating reasonable standard ICU, step-down ICU and combat readiness ICU, establishing rapid response team, and strengthening regular training and scientific management may be the key measures to deal with the epidemic.

Mechanism of nuclear translocation of hypoxia-inducible factor-1α in influenza A (H1N1) virus infected-alveolar epithelial cells / 中华危重病急救医学

Objective:To investigate the molecule mechanism of nuclear translocation of hypoxia-inducible factor-1α (HIF-1α) in influenza A (H1N1) virus infected-alveolar epithelial cells.Methods:Human lung adenocarcinoma epithelial cells (A549 cells) were cultured in vitro, and cells in logarithmic growth phase were selected for experiments. ① Experiment 1: the A549 cell model with H1N1 virus infection was established by using H1N1 virus infected cells with multiplicity of infection (MOI) 1.0 for 24 hours (H1N1 virus infection group), and the blank control group was set up. Importin 4 and Importin 7 protein expressions were detected by Western Blot to investigate whether HIF-1α nuclear translocation depended on Importin 4 or Importin 7. ② Experiment 2: the A549 cells were infected with H1N1 virus under different MOI (0, 0.1, 0.5, 1.0, 2.0, 4.0) for 24 hours. Then the A549 cells were infected with H1N1 virus (MOI 1.0) for different time (0, 3, 6, 12, 18, 24, 36 hours). The septin 9 isoform 1 (SEPT9_i1) mRNA expression was detected by real-time fluorescence quantitative reverse transcription-polymerase chain reaction (RT-PCR) to investigate the effect of different MOI and infection time on the expression of SEPT9_i1. ③ Experiment 3: a cell model with SEPT9_i1 silencing was established by transfection of small interfering RNA (siRNA) for 24 hours (siRNA-SEPT9_i1 group), and the blank control group and blank vector control group (siControl group) were set up. Then the cells in the three groups were infected with H1N1 virus (MOI 1.0) for 24 hours after 24-hour transfection, and the SEPT9_i1 mRNA expression was detected by real-time fluorescence quantitative RT-PCR to investigate the interference efficiency of siRNA-SEPT9_i1. ④ Experiment 4: the cells were divided into siControl group and siRNA-SEPT9_i1 group. The transfection methods of two groups was as the same as experiment 3, and then the cells were infected with H1N1 virus (MOI 1.0) after 24-hour transfection. The distribution of HIF-1α was detected by immunofluorescence at 24 hours after infection. The M gene expression of virus was detected by real-time fluorescence quantitative RT-PCR at 6, 12, 24, 36, 48 hours after infection. The effects of SEPT9_i1 on HIF-1α translocation and virus replication were explored. ⑤ Experiment 5: the cells were divided into blank control group (complete medium), SP600125 group [100 μmol/L c-Jun N-terminal kinase (JNK) signaling pathway inhibitor SP600125 for 2 hours], H1N1 virus infection group (H1N1 virus of MOI 1.0 for 24 hours), H1N1 virus+SP600125 group (pretreated with 100 μmol/L SP600125 for 2 hours before 24-hour H1N1 virus infection). Real-time fluorescence quantitative RT-PCR was used to detect the expressions of SEPT_i1 mRNA and viral M gene to investigate the effect of JNK signaling pathway on SEPT9_i1 expression and virus replication. Results:① Experiment 1: compared with the blank control group, the protein expressions of Importin 4 and Importin 7 in the H1N1 virus infection group had no significant changes [Importin 4 protein (Importin 4/GAPDH): 1.08±0.03 vs. 1.05±0.03, Importin 7 protein (Importin 7/GAPDH): 0.87±0.11 vs. 0.78±0.03, both P > 0.05]. These indicated that the HIF-1α nuclear translocation in A549 cells might not be independent of Importin 4 and Importin 7 during H1N1 virus infection. ② Experiment 2: the SEPT9_i1 mRNA expression in A549 cells was increased with the increase in MOI and infection time of H1N1 virus, and peaked at MOI 2.0 or 18 hours after infection, and the differences were statistically significant as compared with MOI 0 or 0 hour after infection (2 -ΔΔCT: 1.39±0.05 vs. 1.00±0.00 at MOI 2.0, 1.47±0.04 vs. 1.00±0.00 at 18 hours, both P < 0.01). This indicated that the SEPT9_i1 expression in A549 cells was related to the MOI and the infection time during H1N1 virus infection. ③ Experiment 3: compared with the blank control group, the SEPT9_i1 mRNA expression in A549 cells was significantly decreased in the siRNA-SEPT9_i1 group (2 -ΔΔCT: 0.38±0.11 vs. 1.00±0.00, P < 0.01), and there was no significant difference between the siControl group and blank control group (2 -ΔΔCT: 1.03±0.16 vs. 1.00±0.00, P > 0.05). This indicated that SEPT9_i1 silence could inhibit the expression of SEPT9_i1 mRNA in H1N1 virus-infected A549 cells. ④ Experiment 4: HIF-1α nuclear translocation in the H1N1 virus-infected A549 cells in the siRNA-SEPT9_i1 group was significantly reduced as compared with the siControl group. The virus M gene expression after H1N1 virus infection in the siControl group was gradually increased, and peaked at 48 hours. The expression of virus M gene in A549 cells in the siRNA-SEPT9_i1 group was significantly down-regulated, and showed a statistically significant difference at 48 hours as compared with the siControl group (2 -ΔΔCT: 3.47±0.66 vs. 8.17±0.38, P < 0.05). This indicated that HIF-1α nuclear translocation and virus replication in H1N1 virus-infected A549 cells were inhibited after silencing SEPT9_i1. ⑤ Experiment 5: the expressions of SEPT9_i1 mRNA and virus M gene in A549 cells in the H1N1 virus infection group were significantly higher than those in the blank control group. However, the expressions of SEPT9_i1 mRNA and viral M gene in A549 cells in the H1N1 virus+SP600125 group were significantly lower than those in the H1N1 virus infection group (2 -ΔΔCT: SEPT9_i1 mRNA was 0.12±0.10 vs. 1.53±0.14, viral M gene was 2.13±0.10 vs. 4.66±0.14, both P < 0.05). There was no significant difference in above indicators between the SP600125 group and the blank control group. This indicated that the JNK signaling pathway could regulate the expression of SEPT9_i1 in A549 cells during H1N1 virus infection, and the JNK signaling pathway inhibition could down-regulate the expression of SEPT9_i1 and inhibit virus replication. Conclusion:The H1N1 virus regulates the expression of SEPT9_i1 by activating the JNK signaling pathway, thus increase HIF-1α transport efficiency and H1N1 replication.

The role of KCa3.1 activating NLRP3 inflammasome in paraquat treated-alveolar epithelial cells / 中华急诊医学杂志

Objective:To explore the effect of KCa3.1 activating NLRP3 inflammasome in paraquat PQ treated-alveolar epithelial cells.Methods:The A549 cells were cultured in vitro and divided into the control group, TRAM-34 (specific inhibitor of KCa3.1) group, PQ group and PQ+TRAM-34 group. The expression of KCa3.1 was detected by immunofluorescence in A549 cells. Western blot was used to detect the level of the proteins related with the NLRP3 infammasome and NEK7 protein. And the level of cell potassium was detected by cell potassium concentration kit.Results:The level of KCa3.1 was significantly increased in A549 cells after PQ treatment by immunofluorescence. The expressions of NLRP3 infammasome-related proteins (NLRP3, ASC and Caspase-1) and NEK7 protein were increased after PQ treatment, and the expressions of NLRP3 infammasome-related proteins and NEK7 protein were decreased after inhibition of KCa3.1, and the difference was statistically significant [NLRP3/β-actin (control group vs TRAM-34 group vs PQ group vs PQ+TRAM-34 group): [ (0.02±0.00) vs (0.03±0.00) vs (0.74±0.00) vs (0.32±0.01) , ASC/β-actin (control group vs TRAM-34 group vs PQ group vs PQ+TRAM-34 group): [ (0.12±0.01) vs (0.11±0.03) vs (0.46±0.02) vs (0.17±0.03) ];Caspase-1/ β-actin (control group vs TRAM-34 group vs PQ group vs PQ+TRAM-34 group): [ (0.05±0.00) vs (0.04±0.00) vs (0.34±0.03) vs (0.15±0.01) ]; NEK7/ β-actin (control group vs PQ group vs PQ+TRAM-34 group);[ (0.38±0.03) vs (0.83±0.02) vs (0.51±0.01) , P<0.01]. The potassium level was decreased after PQ treatment and the degree could be declined by the KCa3.1 inhibitor by colorimetric detection with statistically significant difference (control group vs PQ group vs PQ+TRAM-34 group:[ (1.00±0.00) vs (0.60±0.05) vs (0.86±0.02) , P<0.01]. Conclusions:The KCa3.1 could promote the outflow of intracellular potassium and up-regulate the expression of NEK7, thereby activate the NLRP3 inflammatory in PQ-induced pulmonary fibrosis.

Influences of hypoxia inducible factor-1α on the expression of inflammatory cytokines in mice with influenza A (H1N1) virus infection / 中华微生物学和免疫学杂志

Objective@#To analyze the changes in the expression of hypoxia inducible factor-1α (HIF-1α) and inflammatory cytokines and to investigate the role of HIF-1α in regulating the production of inflammatory cytokines during influenza A (H1N1) virus infection.@*Methods@#BALB/c mice were injected with H1N1 virus to establish the mouse model of H1N1 virus infection. Fifteen BALB/c mice were randomly divided into three groups: control group, H1N1 virus group and H1N1 virus+ HIF-1α inhibitor group. Inflammatory cytokines (IL-6, TNF-α, IL-1β and IL-10) in samples of serum and lung tissues were detected by Luminex and ELISA. Levels of HIF-1α in serum and lung tissue samples were detected by Western blot and ELISA, respectively.@*Results@#Compared with the control group, the levels of inflammatory cytokines in serum (IL-6, TNF-α, IL-1β and IL-10) and lung tissues (IL-6 and TNF-α) and the expression of HIF-1α in serum and lung tissues in the H1N1 virus group were significantly increased. The levels of HIF-1α, IL-6, TNF-α IL-1β and IL-10 in lung tissues in H1N1 virus+ HIF-1α inhibitor group were significantly lower than those of the H1N1 virus group.@*Conclusion@#During H1N1 virus infection, the levels of inflammatory cytokines and HIF-1α were significantly increased. The production of inflammatory cytokines was significantly reduced after inhibiting HIF-1α expression, suggesting that HIF-1α might promote the production of inflammatory cytokines.

Experimental study on formation of neutrophil extracellular traps in human peripheral blood induced by paraquat in vitro / 中华危重病急救医学

Objective To explore whether paraquat (PQ) can induce the formation of neutrophil extracellular traps (NETs) in human peripheral blood.Methods Neutrophils were isolated from healthy human peripheral blood,and the cells were identified by hematoxylin-eosin (HE) strain.The cells were treated with different concentrations of PQ [0 (as control),200,400,600,800,1 000 and 1 200 μmol/L],and the cell viability was measured by cell proliferation and CCK-8 cytotoxicity detection kit,and the median lethal concentration of PQ was selected.The cells were treated with the median lethal concentration of PQ (PQ poisoning group),and the untreated cells were served as the control.Immunofluorescence staining was adopted to evaluate NETs formation.PicoGreen dye was used to determine the quantitative content of circulating free DNA.Western Blot was used to determine the expressions of citrullinated histone 3(H3Cit) and myeloperoxidase (MPO) in the supernatant.Results The purity of neutrophils was about 95％ by HE staining.The cells were treated with different concentrations of PQ,and the result showed that the viability of cells was (58 ± 2)％ with 800 μmol/L PQ for treatment.The immunofluorescence showed that there were few expressions of H3Cit and MPO in neutrophils in the control group,and there was no NETs formation,which was composed of DNA,H3Cit and MPO.Compared with the control group,a large amount of NETs was generated from neutrophils stimulated by 800 μmol/L of PQ.Meanwhile,quantitative result showed that the content of cell free DNA in the supernatant was significantly increased in PQ poisoning group as compared with that of control group (μg/L:2 235 ± 462 vs.561 ± 87,P ＜ 0.01).The protein expressions of H3Cit and MPO in the supernatant were also significantly increased as compared with those of control group [H3Cit protein expression (gray value):0.23 ± 0.03 vs.0.11 ± 0.01,MPO protein expression (gray value):0.47 ± 0.05 vs.0.21 ± 0.04,both P ＜ 0.05].Conclusion 800 μmol/L of PQ can induce the formation of NETs in human peripheral blood.

Mechanism on the role of caspase recruitment domain-containing protein 9 in the early stage of acute pancreatitis / 中华消化杂志

Objective To investigate the mechanism of caspase recruitment domain‐containing protein 9 (CARD9) in the early stage of acute pancreatitis(AP) .Methods Peripheral blood mononuclear cells (PBMC ) of 49 AP patients (33 mild acute pancreatitis (MAP ) patients and 16 severe acute pancreatitis (SAP) patients) were collected on the Day 1st ,3rd and 5th of hospitalization .Twenty healthy volunteers were enrolled in control group .The expression level of CARD9 ,B‐cell lymphoma(Bcl)‐10 ,p38 mitogen‐activated protein kinase (MAPK ) and p65 nuclear factor Kappa B (NF‐κB ) in PBMC of AP patients were detected by Western blotting .The co‐localization ,expression and binding between CARD9 and Bcl‐10 in PBMC of control group ,SAP group and MAP group on the Day 1st hospitalization were determined by cell immune‐fluorescence staining and co‐immuno precipitation method .Single factor analysis of variance and Mann‐Whitney test were performed for data comparison between groups .Pearson method was used for correlation analysis .Results The results of Western blotting indicated that the expression of CARD9 and Bcl‐10 in PBMC of SAP group on the Day 1st ,3rd and 5th of hospitalization (1 .12 ± 0 .05 ,1 .03 ± 0 .03 and 1 .01 ± 0 .01 ;1 .74 ± 0 .08 ,1 .72 ± 0 .10 and 1 .69 ± 0 .11) were all significantly higher than those of control group (0 .33 ± 0 .10 and 1 .02 ± 0 .11) and MAP group (0 .71 ± 0 .02 ,0 .55 ± 0 .06 and 0 .25 ± 0 .07 ;1 .15 ± 0 .03 ,1 .09 ± 0 .07 and 1 .01 ± 0 .04) ,and the differences were statistically significant (F= 35 .76 and 18 .20 ,all P< 0 .05) .The expression of p38 MAPK in PBMC of SAP group on the Day lst ,3rd of hospitalization (1 .88 ± 0 .08 、1 .68 ± 0 .11) were significantly higher than those of MAP group on the Day 1st ,3rd ,5th (0 .86 ± 0 .08 ,0 .77 ± 0 .10 ,0 .73 ± 0 .20) and healthy control group (0 .58 ± 0 .24 , F= 7 .24 ,all P < 0 .01) .The expression of p65 NF‐κB in PBMC of SAP group on the Day 1st ,3rd of hospitalization (1 .64 ± 0 .02 ,1 .55 ± 0 .03) were significantly higher than those of MAP group on the Day 3rd ,5th (1 .06 ± 0 .14 ,0 .87 ± 0 .20) and healthy control group (1 .17 ± 0 .13 ,F= 4 .51 ,all P< 0 .05) .The results of immune‐fluorescence staining indicated that CARD9 and Bcl‐10 co‐localized in nucleus .The results of co‐immuno precipitation showed that the binding degree between CARD9 and Bcl‐10 of SAP group was significantly higher than that of control group and MAP group . Pearson correlative analysis suggested that the level of p65 NF‐κB and p38 MAPK in PBMC of AP patients were positive correlated with the expression of CARD9 (r= 0 .692 and 0 .834 ,both P< 0 .01) .Conclusion CARD9 is positive correlated with NF‐κB and MAPK , which indicates CARD9 induced inflammatory cytokines by activating NF‐κB and MAPK signaling pathways in AP .

Oxidative stress and apoptosis in gut barrier dysfunction of severe acute pancreatitis / 中华急诊医学杂志

Objective By means of animal study,investigated the gut barrier function in severe acute pancreatitis ( SAP),and role of inflammatory factors releasing,gut mucosa oxidative stress,cell apoptosis in it.Methods The animal experiment was done in the animal center of first people' s hospital,shanghai jiaotong university.Twenty four BALB/c mice were randomized ( random number) divided into two groups with twelve mice each group.The SAP group,mice received six intraperitoneal injections of cerulein at 1-hour intervals, the dose was 50μg/kg, then given one intraperitoneal injection of 10 mg/kg lipopolysaccharide ( LPS from E.Coli) for the induction of severe acute pancreatitis.The control ( sham operation) group,the mice received intraperitoneal injection of 2 ml normal saline for six times at 1-hour intervals.All the animals of each group were averaged to two batches,4 h and 8h after being operated respectively,to be anesthetized and adopted blood and tissue specimen.Then we observed the pathological change of pancreas and gut,scored it.We measured the blood value of diamine oxidase ( DAO),amylase and tumor necrosis factor-α (TNF-α).We detected content of malondialdehyde (MDA),superoxide dismutase (SOD),glutathione (GSH) and activity of xanthine oxidase (XO) in gut mucosa.We detected the casepase-3 activity and cell apopotosis by means of terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) in gut mucosa,and conculated the apopotosis index (AI).Then using the PASW 18.0 software,we analyzed the data by anova and t-test,to make sure if the values were statistically different between the two groups and the mechanism of gut barrier dysfunction in panreatitis.Results At 4 h and 8 h after operation,the SAP-group-mice had significantly higher pancreas pathological score (P ＜0.01 ),blood amylase value ( P ＜ 0.05 ),gut pathological score and blood DAO and TNF-α value ( P ＜0.01 ),compared with the contral-group-mice.The gut mucosa MDA content and XO activity of mice in SAP group were significantly higher than which in control group ( P ＜ 0.01 ). The SAP-group-mice had significantly lower gut mucosa SOD content ( P ＜ 0.01 ) and GSH content ( P ＜ 0.05 ),compared with the contral-group-mice.The gut mucosa cells of mice in SAP group had significantly higher caspase-3 activity and apoptosis index than which in control group ( P ＜ 0.01 ).Conclusions In severe acute pancreatitis,inflammatory factors such as TNF-αwere waterfall-style released,induced gut mucosa suffer from ischemia-reperfusion injury,then serious oxidative stress developed in mucosa and activated caspase-3 pathway,inducing gut mucosa cells apoptose seriously,which was an important mechanism of gut barrier dysfunction.