BACKGROUND:In clinical application,simple interspinous fixation without additional interbody fusion has similar fixation effects to pedicle screw and rod fusion internal fixation,and can effectively reduce the range of motion of the responsible segment and the stress of the articular process.However,after simple placement of the new interspinous fusion fixation device BacFuse,the stress at the root of the spinous process is relatively concentrated,and the spinous fracture is prone to occur.If an intervertebral fusion cage is inserted in conjunction with interspinous fixation,Von Mises stress can theoretically be dispersed to reduce the risk of spinous fracture.However,there are few studies on biomechanics and finite element analysis. OBJECTIVE:To observe the biomechanical stability of interspinous fixation-assisted endoscopic interbody fusion in the treatment of severe lumbar spinal stenosis. METHODS:The normal finite element model M0 of the L4-L5 segment of the lumbar spine was established by Mimics,Geomagic,Solidworks,and ANSYS software based on the lumbar CT images of a 26-year-old adult male volunteer excluding spinal diseases.On the basis of M0,the immediate model M1 after endoscopic decompression combined with interbody fusion,the interspinous fixation device(BacFuse)model M2 after endoscopic decompression,and the interspinous fixation(BacFuse)model M3 after endoscopic-assisted interbody fusion were established.The same stress was applied to the upper surface of the L4 vertebral body in the four groups,and the lower surface of the L5 vertebral body was fixed and supported.The range of motion and the extreme Von Mises stress of the endplate bone and the posterior ligament complex of the vertebral body were analyzed under six working conditions of flexion,extension,left/right bending,and left/right rotation. RESULTS AND CONCLUSION:(1)Compared with model M0,the range of motion value of model M1 increased significantly under six working conditions.Model M2 and model M3 had a significant reduction in range of motion.(2)Compared with model M0,the maximum stress of the vertebral body in model M1 did not change significantly under the six working conditions.The maximum stress at the rear of the M2 vertebral body increased significantly.(3)Compared with model M1,the maximum stress of model M3 did not change significantly under the six working conditions.Compared with model M2,the maximum stress of model M3 decreased significantly.(4)Compared with the model M0,the extreme Von Mises stress of the L4 and L5 endplates of the model M1 was significantly increased.The extreme Von Mises stress in L4 and L5 endplates of models M2 and M3 decreased slightly.Compared with model M1,the Von Mises stress of the bone under the L4 and L5 endplate of models M2 and M3 was significantly reduced.(5)It is concluded that the implantation of BacFuse can effectively reduce the bone stress under the endplate during simple interbody fusion,decrease the risk of cage subsidence,diminish the risk of facet joint fracture on the decompression side,and provide a good stable environment for interbody fusion.The placement of an intervertebral fusion cage can reduce the stress of the root of the spinous process,which is beneficial to decrease the risk of fracture of the root of the spinous process.

Objective To explore the effect and possible mechanism of aerobic exercise and empagliflozin(EMPA)on isoproterenol(ISO)-induced pathological cardiac remodeling.Methods Mice were divided randomly into control(Con),ISO,exercise(EX)+ISO,EMPA+ISO,and EX+EMPA+ISO groups.Mice in the EX groups were trained continuously for 6 weeks,mice in the EMPA groups were gavaged continuously for 4 weeks,and mice in the ISO groups were injected subcutaneously with ISO for 7 days before dissection.After euthanasia,the whole heart mass index,left heart mass index,heart mass to tibial length ratio,and left heart mass to tibial length ratio were calculated by weighing and measuring.Pathological changes,collagen fiber deposition,and myocardial cell cross-sectional area in the hearts were detected by hematoxylin and eosin,Sirius red,and wheat germ agglutinin staining.The expression levels of genes and proteins related to cardiac fibrosis and hypertrophy,macrophage infiltration,ferroptosis,and the phosphoinositide 3-kinase(PI3K)/AKT pathway were examined by quantitative reverse transcription-polymerase chain reaction,Western Blot,and immunofluorescence staining.Results(1)The whole heart mass index,left heart mass index,heart mass to tibial length ratio,and left heart mass to tibial length ratio showed downward trends in the EX+ISO group compared with the ISO group.The whole heart mass index and left heart mass index were significantly decreased in the EMPA+ISO group(P＜0.01,P＜0.05),and the heart mass to tibial length ratio and left heart mass to tibial length ratio were both down regulated.Mice in the EX+EMPA+ISO group had a significant decrease in whole heart mass index(P＜0.05),and the other three indicators were all down-regulated.(2)Myocardial cells were more orderly in the three intervention groups compared with the ISO group,with significant reductions in inflammatory cell infiltration(P＜0.01),the area of cardiac fibrosis,and the cross-sectional area of myocardial cells(P＜0.001).(3)The mRNA and protein expression levels of Col 1 and Anp were significantly reduced in the three intervention groups compared with the ISO group(P＜0.05,P＜0.01,P＜0.001).Col 3 mRNA expression significantly reduced in the EMPA+ISO and EX+EMPA+ISO groups(P＜0.05),and showed a downward trend in the EX+ISO group.(4)Macrophage infiltration and IL-6 mRNA levels were significantly reduced in the three intervention groups compared with the ISO group(P＜0.05,P＜0.01,P＜0.001).(5)Nrf2 and Gpx4 mRNA levels were upregulated in the three intervention groups compared with the ISO group,with a significant increase in GPX4 protein expression(P＜0.01,P＜0.001)and a significant decrease in HO-1 protein expression(P＜0.01,P＜0.001).(6)Pi3k mRNA levels were significantly increased in the EX+ISO group compared with the ISO group(P＜0.05),and Pi3k mRNA was upregulated in the EMPA+ISO and EX+EMPA+ISO groups.Akt mRNA levels showed an upward trend in the three intervention groups.PI3K and phospho-AKT protein levels were significantly increased in the EX+ISO group(P＜0.01,P＜0.05),and showed an increasing trend in the EMPA+ISO and EX+EMPA+ISO groups.Conclusions Moderate intensity aerobic exercise,the novel hypoglycemic drug EMPA,and their combination can alleviate ISO-induced pathological cardiac remodeling,possibly via a mechanism related to activation of the PI3K/AKT signaling pathway and inhibition of cardiac ferroptosis.

Objective:To evaluate the identification rate of separating gel or HB&L pretreatment methods of MALDI-TOF-MS, thereby to provide a new idea for the rapid and accurate identification of pathogens of bloodstream infections in daily clinic practice.Methods:A total of 149 alarmed positive blood culture samples of single bacterial infection by routine laboratory methods were collected between January to December 2020 from the Sixth Medical Center, Chinese PLA General Hospital. Samples were pretreated with the separation gel accelerating tube method or the HB&L microbial culture system, followed by direct MALDI-TOF MS bacterial identification, the identification rates of the two pretreatment methods were compared and results from the traditional method were used as the standard control.Results:Among the 149 positive blood culture samples, 47.0% (70/149) were gram-negative (G -) bacteria and 53.0% (79/149) were gram-positive (G +) bacteria. Identification rate of G -strain level was 78.6% (55/70) by serum separation gel coagulation tube method and 91.4% (64/70) by HB&L microbial culture system, the difference was statistically significant ( P=0.033). Identification rate of G +strain levels was 73.4% (58/79) by serum separation gel coagulation tube method and 87.3% (69/79) by HB&L microbial culture system, the difference was statistically significant ( P=0.028). For G -bacteria in the range of 3.000-2.300, the identification rate was 22.9% (16/70) by serum separation gel accelerating tube method and 38.6% (27/70) by the HB&L microbial culture system, the difference was statistically significant ( P=0.044). For G +bacteria in the range of 3.000-2.300, the identification rate was 19.0% (15/79) by serum separation gel accelerating tube method and 34.2% (27/79) by the HB&L microbial culture system, the difference was statistically significant ( P=0.031). Conclusion:The identification rate of HB&L microbial culture system is higher than that of serum separation gel coagulation tube method. Direct MALDI-TOF MS identification of pathogenic bacteria in positive blood culture samples after pretreatment is feasible in daily clinical practice.

Objective To investigate the mechanism of epidermal growth factor receptor-forkhead transcription factor A2 (EGFR-FOXA2) pathway-involved high secretion of mucus in human bronchial epitheli-um (HBE) cells after respiratory syncytial virus (RSV) infection and to evaluate the effects of intervention using agonist ( rosiglitazone ) and antagonist ( GW9662 ) of peroxidase proliferation activated receptor γ( PPARγ) and EGFR inhibitor ( AG1478 ) . Methods HBE cells were randomly divided into six groups: A group ( AG1478+RSV) , B group ( rosiglitazone+RSV) , C group ( GW9662+RSV) , D group ( RSV) , E group (0. 1％ dimethyl sulfoxide DMSO) and F group (HBE cell control group). Two hours before RSV infection, A, B and C groups were respectively treated with 10 μmol/L of AG1478, rosiglitazone and GW9662. Expression of EGFR, PPARγ and FOXA2 at mRNA level in each group was detected by real-time fluorescence quantitative RT-PCR 12 h, 24 h and 48 h after HBE cells were infected with or without RSV. Expression of phosphorylated-EGFR ( p-EGFR) and EGFR at protein level was detected by Western blot. ELISA was performed to measure the expression of mucin-5AC (MUC5AC). Results Compared with F group, EGFR expression at mRNA lev-el, p-EGFR/EGFR protein ratio and MUC5AC expression at protein level were increased in a time-dependent manner in A, B, C and D groups at 12 h, 24 h and 48 h. Compared with group F, the expression of PPARγat mRNA level in A, B, and D groups increased at each time point. Moreover, PPARγ expression gradually in-creased over time in A and B groups, reaching the peaks at 48 h, but was in decline in D group. Expression of FOXA2 at mRNA level in RSV-infected HBE cells was declined at each time point compared with that in group F, especially in D group. Compared with group D, A and B groups showed significantly decreased EGFR ex-pression at mRNA level, p-EGFR/EGFR protein ratio and MUC5AC expression at protein level, but markedly increased FOXA2 expression at mRNA level. Conclusions RSV infection increased the expression of MUC5AC at protein level in HBE cells. PPARγand EGFR-FOXA2 signaling pathways were involved in the hypersecretion of airway mucus during RSV infection.

Objective: To investigate the effects and mechanism of Holothurian Glycosaminoglycan (hGAG) alone in combination with cisplatin (DDP) on apoptosis of pulmonary adenocarcinoma cell A549. Methods: A549 cells were separately treated with blank, hGAG, DDP and hGAG combined with DDP (hGAG + DDP). The cell morphology in 4 groups was observed using light microscope. CCK8 assay was used to determine the cell viability. Flow cytometry by Hoechst 33258 and AnnexinV-FITC/PI staining was applied to detect cell apoptosis. Western blot was then used to detect the protein expression of Bax, Bcl-2, survivin and caspase-3. Results: After treatment for 24 h, the inhibitory rates of A549 cells in control, hGAG, DDP and hGAG + DDP groups were 0, (19.74±5.39)%, (42.01±2.57)% and (53.89±4.58)%, respectively. Moreover, after treatment for 48 h and 72 h, the inhibitory rates in each group were 0, (23.17±4.78)% and (29.17±4.21 )%, (54.00±7.64)% and (59.35±7.31)%, as well as (77.58±4.26)% and (79.94±4.58)%, respectively. The cell viability was significantly lower in drug treatment groups compared with those in control group at the same time point (P<0.05). Hochest 33258 staining showed that no obvious apoptotic cells were detected in the control group, while apoptotic cells were visible in hGAG, cisplatin and combination groups. Flow cytometry showed that cell apoptotic rates were (2.38±0.59)%, (12.59±4.22)%, (16.36±3.63)% and (44.60±5.45)% in the control, hGAG, DDP and hGAG + DDP groups, respectively. The cell apoptosis was significantly lower in drug treatment groups compared with those in control group at the same time point (P<0.05). Furthermore, western blot results showed that the expression of Bax and caspase-3 protein was increased (P<0.05), whereas Bcl-2 and survivin was decreased (P<0.05) in the hGAG+ DDP group compared with cisplatin alone (P<0.05). Conclusions HGAG can inhibit the proliferation and promote the apoptosis of human lung adenocarcinoma A549 cells. Meanwhile, it can strengthen the chemosensitivity of A549 cells to DDP via up-regulation of Bax, caspase-3 and down-regulation of Bcl-2 and survivin.

Objective: To analyze the correlation between serum HBV DNA level and HBsAg titer in hepatitis B e antigen positive pregnant women without antiviral therapy, and investigate the impact of genomic variability of preS/S regions on their correlations. Methods: Prenatal serum samples from 882 pregnant women with chronic HBV infection who were positive for HBsAg, HBeAg and HBV DNA and were not on antiviral therapy were included in the analysis. The Abbott i2000 and m2000 systems were used to qualitatively or quantitatively detect HBsAg, HBeAg and HBV DNA levels, respectively. HBV genotyping was performed using a type-specific primer nested polymerase chain reaction (nPCR). In addition, serum samples of pregnant women with HBV DNA levels correlated with HBsAg titer and HBV DNA levels higher than HBsAg titers were used to perform preS/S region amplification by nPCR method. PCR products were directly sequenced and mutation sites were analyzed by MEGA6.0 stasticial software. Mann-Whitney U test was used for the measurement data, and 2-test test for count data. Correlations between variables were analyzed using Spearman’s rank correlation. Results: Serum HBsAg titer of HBeAg-positive pregnant women was positively correlated with HBV DNA level (r = 0.754, P < 0.01). Compared with the control group, mutation sites A60V (100% vs. 15.38%, χ² = 7.61, P < 0.01), V90A (100% vs. 30.77%, χ² = 4.43, P < 0.05) and I161T of HBV preS/S region (80.00% vs. 0, χ² = 9.14, P < 0.01) showed a significant decrease in HBsAg titer. Conclusion Serum HBV DNA levels were positively correlated with HBsAg titer in HBeAg-positive pregnant women. Therefore, serum HBsAg titer may be used as a surrogate marker of serum HBV DNA. Single or multiple amino acid mutations sites A60V, V90A, and I161T in preS/S region may be one of the reasons that lead to a significant drop in HBsAg titer and affect its correlation with HBV DNA levels.

Based on the review of existed references,research methods and experiences of ethnographic studies of Chinese medicine in the UK,this article proposed several suggestions on the social scientific studies of Chinese medicine abroad under the background of the "Belt and Road":studies should be more pragmatic in order to take the role of think tank;multi-discipline studies are encouraged to take the advantages of professional subjects;multi-cultures should be respected and local conditions should be taken into consideration to achieve conversational communication and all-win interest consortium;qualitative research should be more emphasized to present more ethnographic work for analytical studies;historical studies should be paid attention to in order to get dynamic trends.

Objective To investigate the clinical distribution situation and drug resistance change of Klebsiella pneumoniae in the Navy General Hospital during 2011‐2015 in order to provide reference for rational use of antibacterial agents in clinic .Methods The clinically isolated Klebsiella pneumoniae in this hospital during 2011‐2015 were selected and performed the analysis on the de‐tection rate ,department distribution ,specimens source ,resistance of antibacterial drugs and change trend of resistance to carbapen‐em antibacterial drugs .Results The number the detected Klebsiella pneumoniae strains and isolation rate during 2011 -2015 showed an increasing trend year by year ,the specimens sources were mainly from 10 departments of intensive care units(ICU) ,hy‐perbaric oxygen department ,respiratory department ,radiation oncology department ,kidney disease department ,etc .;the submitted specimens were dominated by sputum and urine ,accounting for 59 .7% and 21 .4% of submitted specimens ;the drug resistance of Klebsiella pneumoniae during 2011‐2015 showed the increasing trend year by year .Klebsiella pneumoniae had higher resistance rates to piperacillin ,ampicillin ,ampicillin/sulbactam and cefuroxime and had lower resistance rate to amikacin ,imipenem ,meropen‐em and tobramycin ;the resistance rates to imipenem and meropenem were increased year by year ,and pan‐drug resistant Klebsiella pneumoniae showed a rapidly rising trend .Conclusion The drug resistance of Klebsiella pneumonia is serious ,especially carbapene‐ms‐resistant Klebsiella pneumoniae is significantly increased in the recent years ,therefore its drug resistance monitoring should be strengthened for guiding rational drug use in clinic .

Objective By detecting the variation of long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) DNA methylation in preeclampsia-like mouse models generated by different ways, to explore the roles of multifactor and multiple pathways in preeclampsia pathogenesis on molecular basis. Methods Established preeclampsia-like mouse models in different ways and divided into groups as follows: (1) Nw-nitro-L-arginine-methyl ester (L-NAME) group: wild-type pregnant mouse received subcutaneous injection of L-NAME;(2) lipopolysaccharide (LPS) group:wild-type pregnant mouse received intraperitoneal injection of LPS; (3) apolipoprotein C-Ⅲ (ApoC3) group: ApoC3 transgenic pregnant mouse with dysregulated lipid metabolism received subcutaneous injection of L-NAME;(4)β2 glycoprotein I (β-2GPI) group:wild-type pregnant mouse received subcutaneous injection ofβ-2GPI. According to the first injection time (on day 3, 11, 16 respectively), the L-NAME, LPS and ApoC3 groups were further subdivided into:pre-implantation (PI) experimental stage, early gestation (EG) experimental stage, and late gestation (LG) experimental stage.β-2GPI group was only injected before implantation. LCHAD gene methylation levels in placental were detected in different experimental stage. Normal saline control groups were set within wild-type and ApoC3 transgenic pregnant mice simultaneously. Results (1) CG sites in LCHAD DNA:45 CG sites were detected in the range of 728 bp before LCHAD gene transcription start site, the 5, 12, 13, 14, 15, 16, 19, 24, 25, 27, 28, 29, 30, 31, 32, 34, 35, 43 CG sites were complex sites which contained two or more CG sequences, others were single site which contained one CG sequence. The 3, 5, 6, 11, 13, 14, 18, 28 sites in L-NAME, LPS, ApoC3 and β-2GPI groups showed different high levels of methylation; the 16, 25, 31, 42, 44 sites showed different low levels of methylation; other 32 sites were unmethylated. (2) Comparison of LCHAD gene methylation between different groups:the methylation levels of LCAHD gene at 3, 11, 13, 14, 18 sites in L-NAME, LPS, ApoC3 andβ-2GPI groups were significantly higher than those in the normal saline control group (P<0.05); and the methylation levels of 42, 44 sites in these groups were significantly lower than those in the normal saline control group (P<0.05). (3) Methylation of LCHAD gene at the same site between different experimental stages: ① The 3, 11, 18 sites of EG experimental stage was significantly lower than PI and LG experimental stage in L-NAME group (P<0.05);the 3, 11, 18 sites of PI experimental stage was significantly lower than EG and LG experimental stage in LPS group (P<0.05);these sites of PI experimental stage was significantly higher than EG and LG experimental stages in ApoC3 group (P<0.05).②The methylation of site 5 in L-NAME and LPS groups were significantly higher than that of the normal saline control group (P<0.05), and the LG experimental stages were significantly higher than other stages, but in ApoC3 group , only PI and EG stages were significantly higher than the normal saline control group (P<0.05).③At site 6 in L-NAME group which showed high methylation level was significantly higher than the same site in other groups which showed low methylation level (P<0.05).④At 13, 14 sites, earlier preeclampsia onset caused a lower methylation level in L-NAME group, but PI experimental stage was significantly higher than EG and LG experimental stages in LPS group (P<0.05), EG experimental stage was significantly higher than PI and LG experimental stages in ApoC3 group (P<0.05). ⑤ At site 28, earlier preeclampsia onset caused a higher methylation level in L-NAME group, but PI experimental stage was significantly lower than EG and LG experimental stages in LPS group (P<0.05), EG experimental stage was significantly higher than PI and LG experimental stages in ApoC3 group (P<0.05).⑥The 16, 25, 31 sites in ApoC3 group were significantly higher than other groups (P<0.05). ⑦ At site 42 in β-2GPI group was unmethylated, but it in other groups showed low methylation level, the methylation level of site 42 inβ-2GPI group was significantly lower than that in other groups (P<0.05). Conclusions The methylation of 6 and 42 CG sites may be related to LCHAD gene expression in placenta of L-NAME and β-2GPI induced preeclampsia-like models respectively;LCHAD gene expression and DNA methylation may not have obviouscorrelation in LPS and ApoC3 induced preeclampsia-like models. Differences exist in LCHAD DNA methylation in preeclampsia-like models generated by different ways, revealed a molecular basis to expand our understanding of the multi-factorial pathogenesis of preeclampsia.

BACKGROUNDPreeclampsia (PE) is associated with abnormal fatty acid beta-oxidation (FAO), especially metabolic disorders of long-chain fatty acid oxidation. The role of FAO dysfunction in inadequate invasion is unclear. The aim of this study was to explore the influence of various lengths fatty acids oxidation on invasiveness of trophoblasts.

METHODSPrimary human trophoblast cells and HTR8/SVneo cells were treated with fatty acids of various lengths. Morphological changes, lipid deposition and ultrastructure changes of trophoblast cells were detected. Cells invasiveness was determined by transwell insert. CPT1, CPT2 and long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) protein expression were analyzed. The correlation between intracellular lipid droplets deposition and cells invasiveness was evaluated.

RESULTSCells treated with long-chain fatty acids showed significant increased lipid droplets deposition, severe mitochondrial damage, decreased CPT2 and LCHAD protein expression (P < 0.05) but no significant difference in CPT1 protein expression (P > 0.05). Invasiveness of the trophoblast cells of the LC-FFA group significantly decreased (P < 0.05). Intracellular lipid droplets deposition was negatively correlated with invasivenss (R = -0.745, P < 0.05).

CONCLUSIONTrophoblast cells after stimulation with long chain fatty acids exist fatty acid oxidation disorders, and reduce the ability of trophoblastic invasion.

Cell Line ; Cells, Cultured ; Fatty Acids, Nonesterified ; pharmacology ; Humans ; Lipid Metabolism ; Long-Chain-3-Hydroxyacyl-CoA Dehydrogenase ; metabolism ; Trophoblasts ; drug effects