Magnesium sulfate is a supplementary therapy strategy in pediatric asthma,its mechanisms includes inhibiting calcium ion from inflowing into respiratory muscle,reducing the release of the neurotransmitter in nerve-muscle junction and the depolarization of acetylcholine in the motor endplates,etc.Nebulised magnesium sulfate not only can improve the pulmonary function of the children with asthma,but also be safe and effetive.With the application of magnesium sulfate in adults,especially acute severe ones,its mechanisms,dosage,safety and efficiency of magnesium sulfate in pediatric asthma draw more attention.

Objective To investigate the association between the single nucleotide polymorphism (SNP) of leukotriene C4 synthase(LTC4S) rs730012 in the childhood asthma.Methods Sequence specific primers-polymerase chain reaction was used to assess the genetic polymorphism of LTC4S rs730012 in 105 asthma children with different order of severity and 128 non-asthma children in our hospital in the northeast of China to analyse the association between the SNP of LTC4S rs730012 and susceptibility,clinical phenotype in asthma children.Results (1) In case group,genotype frequencies of A/C,A/A and C/C were 71.4％ 、25.7％ 、2.9％,allele frequencies for A,C were 84.3％,15.7％.In control group,the genotype frequencies of A/A,A/C,C/C,were 70.3％,28.9％,0.8％,allele frequencies for A,C were 84.8％,15.2％.No significant difference was found in AA genotype and C allele frequencies between case and control grouP(x2 =0.035、0.020,P both ＞0.05).(2) C/C genotype or C allele frequencies in moderate-severe asthma group were significantly higher than the mild asthma group(x2 =5.859、5.641,P both ＜ 0.05);(3) SaO2 of A/A group was significantly higher than A/C and C/C group (t =2.976,Pboth ＜ 0.05),and FeNO and obstructive ventilatory disorder incidence rate in A/C,C/C group were higher than A/A group,the differences were statistically significant (t =2.946、x2 =5.564,P both ＜ 0.05).Conclusion The SNP of LTC4S rs730012 is associated with the order of severity,SaO2,FeNO,pulmonary function in asthma children of northeast China.However,the rs730012 is not associated with the susceptibility for asthma.

Objective:To investigate the correlation between single nucleotide polymorphism of corticosteroids receptor gene(NR3C1)and children with asthma and to analyze the efficacy of inhaled corticosteroid(ICS)treatment.Methods:The study included a control group(100 healthy children)who participated in the physical examination and an asthma group(101 children with bronchial asthma)who were hospitalized in the General Hospital of the Northern Theater Command from October 2018 to October 2020.Genomic DNA was extracted from peripheral blood samples of all enrolled subjects and then the polymorphism of the glucocorticoid receptor gene locus of NR3C1 was analyzed using SNaPshot SNP gene detection technology.The comparisons of allele frequency in rs41423247、rs7701443 between two groups were performed and the treatment effects of ICS in the asthma group were evaluated at the 12th week of treatment.Results:The frequencies of GG, GC, and CC genotypes of rs41423247 locus of NR3C1 were 75.2%, 21.8%, and 3.0% in the asthma group and 72.0%, 24.0%, and 4.0% in the control group, respectively, and there were no statistically significant differences between the two groups( χ2=0.333, P>0.05). The frequencies of GG, GA, and AA genotypes of rs7701443 locus of NR3C1 were 45.5%, 39.6%, and 14.9% in the asthma group and 56.0%, 31.0%, and 13.0% in the control group, respectively, and there were no statistically significant differences between the two groups( χ2=2.259, P>0.05). After ICS treatment, the C-ACT/ACT scores were not significantly improved in children with CC genotypes at rs41423247 locus( P>0.05), while children with GG and GC genotypes were obviously improved( P<0.05). The scores of C-ACT/ACT showed obvious differences among three genotypes of rs41423247 locus after treatment with ICS( P<0.05). The C-ACT/ACT scores of all were significantly improved in children with GG, GA, or AA genotypes at rs7701443 locus after treatment with ICS( P<0.05), while there was no significant difference among those three genotypes( P>0.05). Significantly improved pulmonary function following ICS treatment in children with asthma was observed in GG and GC genotypes of rs41423247 locus of NR3C1( P<0.05), while only MMEF was improved in CC genotype( P<0.05). Meanwhile, those pulmonary function indexes were improved in all genotypes of rs7701443 after treatment with ICS( P<0.05). Conclusion:Both rs41423247 and rs7701443 locus at NR3C1 gene have polymorphisms.But there were no significant differences in the polymorphism of rs41423247 and rs7701443 locus of NR3C1 between the asthma group and the control group.Different genotype frequencies of rs41423247 and rs7701443 at NR3C1 locus in children with asthma have different effects on ICS treatment.

Objective:To investigate the relationship between rs2075748 and rs542269 single nucleotide polymorphisms of cholinergic muscarinic receptor 1 (CHRM1)gene and susceptibility of childhood asthma, as well as the differences of pulmonary function and serum acetylcholine(Ach)levels among different genotypes.Methods:A total of 156 asthmatic children who were treated in the outpatient or hospitalized in the General Hospital of the Northern Theater Command from September 2018 to September 2020 were selected as the case group, while 134 non-asthmatic children who had a healthy physical examination were selected as the control group.The SNaPshot SNP typing technique was used to analyze the genotype of the CHRM1 gene rs2075748 and rs542269 of the study subjects.Serum Ach level was detected by double antibody sandwich method, and the pulmonary function of the case group was detected.Results:After analyzing the CHRM1 gene polymorphism, it was found that the CC, CT, and TT genotype frequencies at rs2075748 were 65.4%, 28.8%, 5.8% in the case group, and 62.8%, 32.4%, 4.8% in the control group.The C and T allele frequencies were 79.8% and 20.2% in the case group, 74.3% and 25.7% in the control group.There were no significant difference in the genotype and allele frequency distribution between the two group ( χ2=2.688, 2.530, both P>0.05), and there were no significant difference in the recessive and dominant modes between the two groups ( χ2=0.338, 2.686, both P>0.05). The TT and CT genotype frequencies at rs542269 locus were 72.4% and 27.6% in the case group, 62.7% and 37.3% in the control group.The T and C allele frequency were 86.2% and 13.8% in the case group, 81.3% and 18.7% in the control group.The genotype and allele frequency distribution were not obvious different between the two group ( χ2=3.145, 2.544, both P>0.05). The risk of asthma with variant CT and TT at rs2075748 locus of CHRM1 gene were not statistically different from that of wild-type CC (both P>0.05), and the risk of asthma with variant CT at rs542269 locus was no different from that of wild-type TT ( P>0.05). The difference in FEF50% Pred and FEF75% Pred of different genotypes at rs2075748 were statistically significant( F=3.118, 4.808, both P<0.05), wild-type CC was lower than variant CT(both P<0.05). There were no statistically significant difference in pulmonary function among different genotypes at rs542269 (both P>0.05). There was significant difference in serum Ach level between different genotypes of rs2075748 ( F=4.716, P<0.05), variant CT was lower than wild-type CC ( P<0.05), variant TT was lower than wild-type CC ( P<0.05), while no significant difference was find between variant CT and TT ( P>0.05). There was no significant difference in serum Ach level between different genotypes of rs542269 ( P>0.05). Conclusion:The rs2075748 locus of CHRM1 gene is not susceptible to asthma, but it may be related to the small airway function of asthmatic children, besides there are differences in serum Ach levels with different genotypes, and the variant serum Ach level is lower.The rs542269 locus is not a susceptibility site for asthma, and there are no difference in pulmonary function and serum Ach levels in asthmatic children with different genotypes.

OBJECTIVE To explore the effects of ADRB2 gene regulatory region polymorphism on the efficacy of short-acting beta 2 receptor agonists （SABA） in the treatment of acute asthma attack in children. METHODS A total of 127 children with acute mild to moderate bronchial asthma who received SABA treatment for 7 days in the General Hospital of Northern Theater Command from October 2016 to October 2020 were selected to detect their genotype distribution and compare the improvement of pulmonary functional indicators and curative effect among different genotypes. The effect of the high-order interaction of gene polymorphism on therapeutic effect was investigated. RESULTS Among 127 children， there were 80， 44 and 3 cases of TT， TA and AA types at locus rs2895795， 93， 32 and 2 cases of CC， CG and GG types at locus rs11168070， and 41， 64 and 22 cases of GG， GA and AA types at locus rs12654778， respectively， in accordance with Hardy-Weinberg equilibrium （P＞0.05）. After treatment， the improvement rate of the peak expiratory flow in percent predicted value （PEF%pred） and the improvement rate of the forced expiratory flow at 75% vital capacity in percent predicted value （FEF75%pred） in children with TA type were significantly lower than that of TT type at locus rs2895795 （P＜0.05）； the improvement rates of PEF%pred and FEF75%pred in children with CG type were significantly lower than that of CC type at locus rs11168070 （P＜0.05）； the improvement rates of PEF%pred in children with GA and AA type were significantly lower than that of GG type at locus rs12654778 （P＜0.05）. The differences in fractional exhaled nitric oxide before and after treatment were not statistically significant among different genotypes at each locus （P＞0.05）. The proportion of remarkable improvement of children with TT type at locus rs2895795 was 2.358 times that of children with TA+ AA type （P＜0.05）， and there was no significant effect of higher-order interaction of ADRB2 polymorphism on the efficacy in children with asthma （P＞0.05）. CONCLUSIONS Polymorphisms in the regulatory region of the ADRB2 gene in children with bronchial asthma are associated with the efficacy of SABA in the treatment of acute asthma attack in children. At locus rs2895795， rs11168070 and rs12654778， the improvement of lung function of children with wild-type is more obvious， and the efficacy of SABA treatment on children with TT type is better at locus rs2895795.