Résumé
Objective Some children with congenital heart defect would get serious acute respiratory distress syndrome in ICU postoperatively,which is a tough problem.We summarized the clinical effects of synchronized intermittent mandatory ventilation (SIMV)with expiratory high frequency ventilation (HFV) for these patients in our center.Methods A total of 13 pediatric patients,with(8.15 ±4.34)months old and (8.23 ±4.01 )kg weight,used SIMV with expiratory HFV from Jan 2012 to Aug 2013.Keeping the original SIMV conditions unchanged,the expiratory oscillation amplitude were 25 to 35 Ann(A)and the oscillation frequency of 7 to 9 hertz(Hz).All patients were divided into two groups to oxygenation index(OI)30 min before HFV,high OI group(OI≤20,n ﹦5)and low OI group(OI 〈20,n ﹦8).OI ﹦MAP ×FiO2 /PaO2 .The values of OI,PaO2 /FiO2 and PaCO2 of two groups were monitored before and at 2,6,24,48 h after HFV re-spectively.Results The values of OI of all 13 patients were 19.31 ±4.42 before HFV,and then decreased to 18.77 ±5.18,16.00 ±5.22,14.77 ±6.56,and 13.92 ±6.53 respectively at 2,6,24 and 48 hours later (P 〈0.01 ).But there was no significant difference of OI in high OI group in different time points.The val-ues of PaCO2 of all 13 patients were(43.46 ±5.67)mmHg(1 mmHg ﹦0.133 kPa)before HFV,and de-creased to(38.31 ±4.21)mmHg,(37.61 ±3.36)mmHg,(34.77 ±3.81 )mmHg,and(35.92 ±2.39)mmHg respectively at 2,6,24,and 48 hours after HFV(P 〈0.01 ).Three dead patients were all in high OI group. Conclusion The mortality rate of serious acute respiratory distress syndrome with congenital heart diseases postoperatively is high.SIMV with expiratory HFV can improve oxygenation and reduce carbon dioxide,and the effect is better when OI 〈20.
Résumé
The antimicrobial peptide magainin II is expressed in the skin of the African clawed frog, Xenopus laevis, and exhibits a broad spectrum of antimicrobial activity as well as tumoricidal properties at low concentrations. In addition, magaininII plays a synergistic role during antimicrobial and tumoricidal processes with another antimicrobial peptide PGLa that is also expressed in Xenopus laevis. The optimized cDNA sequence of magainin II and magainin II-PGLa hybrid peptide according to E. coli or Pichia pastoris codon usage frequency were synthesized and sub-cloned into prokaryotic expression vector pGEX and Pichia pastoris secreted expression vector pPIC9k. The resulting recombinant plasmids were named as pGEX-magainin II and pPIC9k-magainin II-PGLa. The GST-magainin II fusion protein was highly expressed in E. coli. Furthermore, magainin II was successfully purified by digestion with PreScission Protease to cleave the GST tag. Additionally, our data obtained from the ELISA revealed that magainin II -PGLa hybrid peptide was successfully expressed in Pichia pastoris. These experiments establish a useful system for further studies of these antimicrobial peptides.