ABSTRACT
Objective:To study the expression of micro RNA-155(miR-155) and IFN-γ in lung tissue in a neonatal rat model of acute respiratory distress syndrome(ARDS)lung injury by intraperitoneal injection of lipopolysaccharide(LPS).Methods:Eighty neonatal SD rats on the 7th day after birth were assigned to the experimental group(LPS group)and control group(isotonic NaCl group), with 40 rats in each group.LPS solution(4 mg/kg)was injected into the abdominal cavity of neonatal SD rats in the experimental group to establish an animal model of neonatal acute respiratory distress syndrome(NARDS). The control group was established by isotonic NaCl solution(4 ml/kg)in the same way.The lung tissue samples were taken at 3 h, 6 h, 12 h and 24 h after drug administration to observe the surface changes.Then the lung sections were stained with HE to observe the pathological changes and score the lung tissue injury.Finally, the expression levels of miR-155 and IFN-γ in the lung tissue were tested by RT-PCR and ELISA techniques, respectively.Results:(1)At the beginning of the experiment, the neonatal rats in the experimental group gradually showed the clinical manifestations of ARDS, and the macroscopic observation, pathological changes and lung tissue injury scores of the lung tissues suggested the appearance of NARDS lung injury, indicating that the model was successful.(2)The expression levels of miR-155(1.33±0.12 vs 0.95±0.02、1.77±0.17 vs 0.96±0.01、2.18±0.09 vs 0.96±0.02 and 2.43±0.06 vs 0.96±0.02)and IFN-γ(370.79±13.89 vs 273.03±11.44、424.24±10.11vs270.70±13.05、466.63±6.57 vs 268.11±7.88 and 519.13±7.09 vs 272.97±12.54)ng/L in the lung tissue of rats between the experimental group and the control group were significantly different( P<0.01), and the difference was statistically significant among the groups in the experimental group( F values were 165.983 and 408.574, P<0.01). The expression levels of miR-155 and IFN-γ in the lung tissue of the experimental group increased gradually over time and showed an increasing trend. Conclusion:After the successful establishment of NARDS animal model, the expression levels of miR-155 and IFN-γ in the lung tissue of NARDS rats have significantly increased and showed a sequential pattern.MiR-155 is expected to become an early biomarker for the diagnosis of NARDS.
ABSTRACT
High frequency oscillatory ventilation(HFOV) in the treatment of acute respiratory distress syndrome(ARDS), there are significant differences in clinical research status and evidence level among different participants.HFOV for adult ARDS: current clinical evidence suggests that HFOV is not recommended for routine mechanical ventilation in adults with ARDS.HFOV for pediatric ARDS: there is no sufficient evidence to show that HFOV is superior to conventional mechanical ventilation.Nor does it prove that HFOV is harmful.The current recommendation is: HFOV could be considered as an alternative ventilatory mode in patients with moderate-to-severe pediatric ARDS, whom with conventional mechanical ventilation plateau airway pressures exceed 28 cmH 2O(1 cmH 2O=0.098 kPa) in the absence of clinical evidence of reduced chest wall compliance.HFOV for neonatal ARDS: the existing research evidence shows that HFOV can moderately reduce the incidence of chronic lung disease in the premature infants with neonatal ARDS.It has certain advantages in improving oxygenation and alleviating ventilator induced lung injury in acute phase.It also has certain advantages for improving pulmonary function and neurodevelopmental in the long term.