Acute effects of NO2 on hospitalization risk of children with respiratory diseases in Foshan City / 公共卫生与预防医学

Objective To explore the acute effects of NO2 on children's respiratory hospitalization risk in Foshan City. Methods The daily average concentrations of six air pollutants such as NO2 and fine particulate matter, and meteorological data including average temperature and relative humidity in Foshan were collected from 2016 to 2019. Data on the daily number of children newly hospitalized for respiratory diseases (ECRH) in Foshan Women and Children Hospital were retrieved. Time series analysis was used to quantitatively evaluate the effect of daily NO2 concentration on the hospitalization risk of children with respiratory diseases. Results From 2016 to 2019, the average ECRH in the hospital was 10. The daily average concentrations of air pollutants NO2, PM2.5, PM10, and SO2 were 42.0 μg/m3, 35.3 μg/m3, 58.1 μg/m3, and 11.4 μg/m3, respectively. The air pressure, daily average temperature and relative humidity of atmosphere were 1008.4 Pa, 23.7℃ and 73.3%, respectively. ECRH was significantly correlated with the daily average concentration of NO2 (r=0.079, P3 increase of NO2 concentration in the single pollutant model, the excess risk of ECHR in the hospital increased by 1.22% (95% CI: 0.06%, 2.40%) and 1.37% (95% CI: 0.23%, 2.53%) in lag0 and Lag1 day, respectively. The strongest effect appeared in lag0:7 with the excess risk increasing by 1.70% (95% CI:0.12%, 3.31%). In the NO2 + SO2 + CO + O3_8h + PM2.5 and NO2 + SO2 + CO + O3_8h + PM10 multi-pollutant models, significance correlation still existed between the daily average NO2 concentration and ECHR in lag0, lag1 and lag0:1 to lag0:7. The strongest effect appeared in lag0:1, and the excess risks were 4.06% (95% CI: 1.83%, 6.34%) and 3.95% (95% CI: 1.85%, 6.09%), respectively. Dose-response relationship analysis showed a linear relationship between the daily average NO2 concentration and ECHR, and the excess risk of new hospitalization gradually increased with the increase of daily average NO2 concentration. Conclusion There was a significant correlation between NO2 concentration and hospitalization risk of children with respiratory diseases in Foshan City, which suggests that the government should further strengthen the prevention and control of air pollution.

Effects of antibiotic stewardship on neonatal bloodstream infections / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To investigate the effects of antibiotic stewardship on the pathogen and clinical outcome of neonatal bloodstream infections (BSIs).</p><p><b>METHODS</b>A retrospective study was performed on neonates with BSIs who were admitted to the neonatal ward in the years of 2010 (pre-stewardship) and 2013 (post-stewardship) for pathogens, antibiotic resistance, antibiotic use, and clinical outcomes.</p><p><b>RESULTS</b>The admission rate of BSIs (6.47% vs 2.78%) and the incidence of nosocomial BSIs (0.70% vs 0.30%) in 2013 were significantly higher than in 2010 (P<0.01). However, there were no signicant differences in the clinical outcomes between the years of 2010 and 2013 (P>0.05). The four most common pathogens isolated from blood cultures, Staphylococcus haemolyticus, Staphylococcus epidermidis, Klebsiella pneumoniae ssp pneumoniae and E.coli, were similar between the two years. There were no significant differences in the detection rates of extended spectrum β-lactamase-positve Klebsiella pneumoniae ssp pneumoniae or E.coli between the two years. The detection rates of methicillin-resistant Staphylococcus/β-lactamase-positive Staphylococcus haemolyticus and Staphylococcus epidermidis were similar between the two years (P>0.05).</p><p><b>CONCLUSIONS</b>Since the implementation of antibiotic stewardship, there has been no marked variation in the common pathogens and their antibacterial resistance in neonatal BSIs. The antibiotic stewardship could promote the recovery of patients with BSIs.</p>

Construction and expression of ricin A chain and green fluorescent protein fusion gene in E. coli / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To study the expression and purification of a fusion protein of ricin A chain (RTA) and green fluorescent protein (GFP).</p><p><b>METHODS</b>The DNA sequence encoding ricin A chain was inserted into pEGFPC1 first to make the template sequence of the fusion protein. The fusion gene was amplified from the plasmid pEGFP-RTA by PCR, and directly subcloned into T vector. The fusion gene then was cloned into expression vector pET-28a(+), and the sequence was confirmed by sequencing. Expression was induced by IPTG in E. coli BL21(DE3). The fusion protein was purified by metal chelated affinity chromatography. The cytotoxicity of fusion protein was analyzed by the MTT assay in HepG2 and Hela cells.</p><p><b>RESULTS</b>The fusion protein of ricin A chain and GFP could be produced in E. coli transformed with the expression plasmid of pET-28a(+)-GFP-RTA. The molecular weight of the recombinant protein was measured by SDS-PAGE. The fusion protein showed a green fluorescence and had a similar cytotoxicity of RTA.</p><p><b>CONCLUSION</b>A recombinant fusion protein of RTA and GFP expressed in E. coli is possessed of similar biological activity of individual GFP and RTA, which could be used in study of the intracellular trafficking and translocation of RTA.</p>