Objective To investigate ABCA3 gene polymorphism and its relationship with neonatal respiratory distress syndrome (NRDS) in the Guangxi Zhuang Autonomous Region of China by genotyping and haplotype analysis.Methods Using a tagging single nucleotide polymorphism (tSNP) strategy and TaqMan (r) real-time PCR,we genotyped 4 tSNPs (rs4787273,rs 1 50929,rs 11867129,and rs 17135889) and one additional coding SNP(rs13332514) of the ABCA3 gene in preterm infants with NRDS(NRDS group,n =45) and without NRDS (non-NRDS group,n =45) and subsequently predicted the haplotypes.The minor allele frequency and the haplotype 'distribution were compared between the two groups.Results The minor allele A(0.14 vs.0.05,P =0.046) and genotype AG (0.289 vs.0.111,P =0.035) frequency of SNP rs17135889 in NRDS group were significantly higher than those in non-NRDS group.Totally 6 haplotypes occurred at a frequency ≥0.01,among which,the haplotype TGGAG,depended on rs17135889,was significantly higher in NRDS group than that in non-NRDS group (0.061 vs.0.000,P =0.014).Conclusion The results suggested that SNP rs17135889 of ABCA3 gene might be related to NRDS in preterm population of the Guangxi Zhuang Autonomous Region.Allele A contributes to NRDS susceptibility in preterm infants.

Objective To observe effect of using ambroxol to humidify of airway during mechanical ventilation to treat severe pneumonia in infants,and to explore dynamic changes of respiratory mechanics.Methods Sixty-five infants with severe pneumonia need ventilator treatment according the diagnosis criterion were divided into 2 groups by random digits table method:experimental group (33 cases) and control group (32 cases).Experimental group was used ambroxol and control group was used 0.9％ sodium chloride,each 2 ml intratracheal instillation,and then took the balloon pressurized oxygen 30 s,followed by ventilator,after 24 h.Changes of respiratory mechanics indexes were observed before and after treatment,including:mean airway resistance,lung dynamic compliance,work of breathing,airway plateau pressure.Respiratory mechanics values were recorded before and after treatment.Results After treatment for 24 h,the index in experimental group were better than those in control group.Mean airway resistance were (0.68 ± 0.04) cmH2O/ (L·s) and (0.57 ± 0.05) cmH2O/ (L·s),1 cmH2O =0.098 kPa,lung dynamic compliance were (3.17 ± 0.81) ml/kPa and (2.56 ± 0.69) ml/kPa,work of breathing were (0.54 ± 0.08) J/L and(0.41 ± 0.06) J/L,airway plateau pressure were (2.23 ± 0.58) cmH2O and (2.12 ± 0.63) cmH2O.There were significant differences (P ＜ 0.05).The mechanical ventilation time in experimental group was significantly shorter than that in control group [(64.08 ± 13.92) h vs.(79.57 ± 19.64) h] (P ＜0.05).Conclusion Airway humidification using ambroxol can better treat severe pneumonia,reduce airway resistance and improve alveolar ventilation,shorten time on the machine.