ABSTRACT
Objective To study the effects of cystic fibrosis transmembrane conductance regulator (CFTR) on neonatal rats with bronchopulmonary dysplasia (BPD).Method The hyperoxia (FiO2＞ 90％)-induced neonatal BPD rat models were established and assigned into three groups:the model group,the agonist group and the antagonist group.Room air (FiO2 21％) was inhaled by the rats in the control group.50 μl of phosphate buffered saline (PBS),genistein (50 mg/kg),arachidonic acid (500 mg/kg) and PBS were injected intraperitoneally respectively in the model group,the agonist group,the antagonist group and the control group at 24,48 and 72 h after birth.The survival rates of the neonatal rats were calculated,the survival curves were drawn,the pathological changes of the lung tissues were examined (the control group and the model group:3,14 and 21 d after birth;the agonist group and antagonist group:14 and 21 d after birth),and the expression of CFTR were studied using western blot method.The acute lung injury scores of the model group,the agonist group and the antagonist group were compared and the gray value was analyzed using Graphpad software.Result (1) The survival rates in the control group,the model group,the agonist group and the antagonist group were 96.8％,93.3％,100％ and 34.5％ respectively.The antagonist group had significantly lower survival rate than the other three groups (P＜0.001).(2)The alveoli developed gradually with age in the control group.The pulmonary pathology of the model group showed:alveolar congestion,hemorrhage,infiltration or aggregation of neutrophils in airspace or vessel wall,thickness of alveolar wall,with some enlarged alveolar spaces and reduced alveolar cavities.As the inflammation gradually decreased,some alveolar spaces significantly enlarged and the numbers of alveolar cavities significantly reduced.No significant differences existed of the acute lung injury scores among the agonist group,the antagonist group and the model group at 14 and 21 d after birth (P＞0.05).(3) The expressions of CFTR in the lungs were lower in the model group than the control group 3 d after birth (P＜0.01).No significant differences existed of the CFTR expression between the model group and the control group 14 d after birth(P＞0.05).The CFTR expression was much higher in the agonist group than the model group (P＜0.01) and also higher in the antagonist group than the model group (P＜0.05) 14 d after birth.The CFTR expression was lower in the model group than the control group,and higher in the agonist group than the model group 21 d after birth (P＜ 0.05).No significant differences existed of CFTR expression between the antagonist group and the model group 21 d after birth (P＞0.05).Conclusion CFTR may play a protective role in the pathogenesis of BPD.
ABSTRACT
Objective To explore the effect of fortified human milk feeding on growth,metabolism and complications of premature infants during hospital stay.Methods Totally,148 premature infants of gestational age ≤36 weeks and birth weight ≤1800 g,admitted to NICU of Peking Union Medical College Hospital between January 1st,2009 and December 31st,2012,were retrospectively enrolled and divided into two groups.Infants fed predominantly (＞50％) with human breast milk,combined with human milk fortification (HMF) formula when breast milk was insufficient during hospital stay,were named HMF group (n =73),and those fed exclusively with premature formula were called premature formula feeding group (PF group,n =75).Data of infants on growth,metabolism and incidence of various complications were compared between the two groups.Clinical data were expressed with mean± standard deviation or median and quartiles [M(P25,P75)].Statistical analysis was performed with t-test,x2 test or non-parameter test.Results Among the 148 infants included,there was no significant difference in gestational age,birth weight,head circumference,length at birth,time for regaining birth weight,SGA at birth,neonatal respiratory distress symdrome,intraventricular hemorrhage (over grade Ⅲ) and asphyxia rate between HMF and PF group(all P＞0.05).Infants of the HMF group showed shorter duration of parenteral nutrition [18 d(14 d,25 d) vs 24 d (18 d,31 d),Z=-2.950,P=0.003],smaller age to achieve 120 ml/(kg · d) through enteral feeding [16 d(12 d,23 d) vs 22 d (16 d,30 d),Z=-2.895,P=0.004],smaller age to achieve total energy intake of 120 kcal/(kg · d) [11 d(8 d,15 d) vs 14 d (10 d,18 d),Z=-2.392,P=0.017] than those of the PF group.Medical cost during hospital stay in the HMF group was significantly less than in the PF group [RMB:47 078 yuan(30 802 yuan,67 039 yuan) vs 58 400 yuan (38 166 yuan,82 737 yuan),Z=-1.970,P=0.049].The time for initial feeding,rate of feeding intolerance,daily weight gain after regaining birth weight,weekly increase of body length and head circumference,weight,body length and head circumference at discharge,proportion of small for gestational age infants at discharge,z scores of both birth weight and weight at discharge showed no significant difference (all P＞ 0.05).The level of blood alkaline phosphates before discharge in HMF group was significantly higher than that of the PF group [(347.7±149.4) U/L vs (288.6±108.8) U/L,t=2.570,P=0.011].None of the other biochemical indicator showed any statistical difference.The incidence of sepsis in the HMF group was slightly lower than that in the PF group [11.0％ (8/73) vs 20.0％ (15/75)] without significant difference (x2 =2.30,P＞ 0.05),neither the morbidity of retinopathy of premature,chronic lung disease,necrotizing enterocditis of newborns (all P＞0.05).Conclusions HMF for premature infants may ensure the same growth pattern as those fed by premature formula,and it also can accelerate the enteral feeding process,reduce the incidence of sepsis and decrease the medical cost during hospital stay.