Objective To investigate the effect and mechanisms of celecoxib on right heart function in mice with acute high-altitude hypoxia exposure.Methods Male C57BL/6J mice(7 weeks old)were housed in a hypobaric chamber simulating an altitude of 5 800 m for 2 d to establish an animal model of acute hypobaric hypoxia.①Eighteen mice were randomly assigned to plain+saline(P+S),high-altitude hypoxia exposure+saline(H+S),and high-altitude hypoxia exposure+celecoxib(H+Cel).Body weight and routine blood indicators were measured,and cardiac ultrasound examination were performed for heart rate(HR),pulmonary artery acceleration time to ejection time ratio(AT/ET),tricuspid annular plane systolic excursion(TAPSE),tricuspid annular systolic velocity(S'),and left ventricular ejection fraction(LVEF)and fractional shortening(FS).Targeted metabolomic profiling was applied to detect the cardiac arachidonic acid(AA)metabolite levels.The contents of 12,13-dihydroxy-9Z-octadecenoic acid(12,13-diHOME)in the heart,liver,brown adipose tissue,and plasma were quantified by ELISA.② Eighteen mice were randomly assigned into plain+saline(P+S),high-altitude hypoxia exposure+saline(H+S)and high-altitude hypoxia exposure+12,13-diHOME(H+di)groups.Body weight,routine blood tests,and echocardiography were performed as above.③ Thirty-two mice were randomly divided into high-altitude hypoxia exposure+saline(H+S),high-altitude hypoxia exposure+celecoxib(H+Cel),high-altitude hypoxia exposure+soluble epoxide hydrolase inhibitor(sEHI)(H+sEHI),and high-altitude hypoxia exposure+sEHI+celecoxib(H+sEHI+Cel)groups.Body weight,routine blood tests,and echocardiography were performed as above.Cardiac and plasma contents of 12,13-diHOME and epoxyeicosatrienoic acids(EETs)were measured by ELISA.Results ① Compared to the P+S group,the H+S group exhibited significantly reduction of cardiac 12,13-diHOME level(P<0.001),increased counts of white blood cells(WBC)and neutrophils(P<0.01)and decreased TAPSE,S'and AT/ET both at resting state and under stress(P<0.01,P<0.001).Compared to the H+S group,the H+Cel group exhibited significantly increase of cardiac 12,13-diHOME level(P<0.05),reduced WBC and lymphocyte counts(P<0.01,P<0.05)and improved TAPSE and S'levels at resting state and under stress(P<0.01,P<0.001).② Compared to the H+S group,the H+di group demonstrated significantly improvement of TAPSE at basal and under stress(P<0.001)and a trend towards improved TAPSE at resting state(P=0.0532),but no obvious differences was observed in WBC and neutrophil counts between the H+di group and the H+S group.③ Compared to the H+Cel group,both the H+sEHI and H+sEHI+Cel groups exhibited significantly reduction of cardiac 12,13-diHOME level(P<0.01,P<0.05)though no statistical changes in cardiac function indicators.Compared to the H+S group,WBC counts and lymphocyte were decreased,and serum EETs level was incrased in the H+Cel group,H+sEHI group and H+sEHI+Cel group(P<0.01,P<0.001).Conclusion Celecoxib can elevate cardiac level of 12,13-diHOME and improves right heart function in mice after acute high-altitude hypoxia exposure through the CYP450-sEH metabolic pathway.

Objective:To investigate the isolation characteristics and the antibiotic resistance of Streptococcus pneumoniae in hospitalized children from the Bao′an District of Shenzhen for many consecutive years, and to provide evidence for the assessment as well as clinical prevention and treatment of Streptococcus pneumoniae infection. Methods:The isolation rate and sample source of Streptococcus pneumoniae isolates as well as age composition of hospitalized children in Bao′an Maternal and Child Health Hospital of Shenzhen city from January 2012 to December 2018 were retrospectively analyzed.The susceptibility of the isolates to antibiotics was tested by disk diffusion method and E-test method. Results:(1) From 2012 to 2018, a total of 90 807 specimens were retrospectively summarized, 9 193 strains of Streptococcus pneumoniae were isolated, with an isolation rate of 10.1%, which was the first pathogen; 98.68% (9 072/9 193 cases) from respiratory tract samples and 97.20% from sputum samples.Among 107 strains isolated from aseptic body fluid specimens, 97 strains were blood specimens. Streptococcus pneumoniae was the most common bacteria with positive culture in aseptic body fluids.(2) The isolation rate of Streptococcus pneumoniae was 10.7% in children under 2 years old, 10.2% in children between 2 and 5 years old and 4.1% in children over 5 years old.About 97% of Streptococcus pneumoniae isolates came from children under 5 years old.(3) According to breakpoints of non-meningitis strains, the sensitivity rate of parenteral Penicillin was 93.18%, the mediation rate was 6.79%, the resistance rate was only 0.03%, the lowest drug concentration to inhibit the growth of 50% bacteria(MIC 50) value was 0.50 and the lowest drug concentration to inhibit the growth of 90% bacteria(MIC 90) value was 2.00; the sensitivity rate of Ceftria-xone was 76.55%, the mediation rate was 20.18%, the resistance rate was 3.26%, the MIC 50 value was 1.00 and the MIC 90 value was 2.00; when interpreted by the breakpoint of meningitis strains, the resistance rate of extra-gastrointestinal Penicillin reached 77.22%, and the mediation rate of Ceftriaxone increased to 30.48% and the drug resistance rate reached 18.45%.The drug resistance rates of Erythromycin, Clindamycin, Tetracycline and Compound neomycin were all over 85.00%.The resistance rates against Levofloxacin and Chloramphenicol were 0.16% and 7.85% respectively.No Vancomycin-resistant Streptococcus pneumoniae was found. Conclusions:Streptococcus pneumoniae is the first bacterial pathogen causing respiratory tract and invasive infection in hospitalized children under 5 years old in this area.Penicillin is still the preferred drug for non-meningitis pneumococcal infection, but the drug resistance rate is high in meningitis patients.