0.05). However, the MDA level in the experimental group was higher than that of the control on day 3 [(55.92?5.53)nmol/mg prot vs (22.52?4.36)nmol/mg prot, P

Objective To evaluate the effects of supine and prone position on ventilation function in neonates in the initial six-hour period after weaning. Methods Sixty-four neonates weaned from mechanical ventilation and with normal body temperature hospitalized from Sep. 2004 to Apr. 2006 in our NICU were randomly divided into prone group and supine group. All of them were oxygen administrated through head net, oxygen flow rate was adjusted continously to keep SpO2 at normal level by monitoring SpO2 and RR. FiO2、RR were recorded at 15 minutes,1 h,2 h,3 h,4 h,5 h,6 h after weaning. Arterial blood gas was meas-ured at 1 h ,6 h after weaning and A-aDO2, RI, OI were calculated. Results (1) At 1～6 h after weaning the values of FiO2 in prone group were significantly lower than those in the supine group(P<0.01). (2) After weaning there was a decreasing tendency of RR in the prone group and the significant decrease was found at 4 h ,5 h ,6 h compared with supine group (P<0.01). (3) At 1h and 6h after weaning, the value of PaO2 and OI were significantly higher and the value of A-aDO2, RI were lower in the prone group than in the supine group(P<0.05,P<0.01). (4) At 6 h the PaCO2 in prone group were obviously higher than that in supine group (P<0.05). Conclusion At first 6h after weaning prone position can improve ventilation functions.

Objective To investigate the changes of epithelial sodium channel(ENaC) expression and sodium and water transport function in the neonatal rat pulmonary edema induced by hyperoxia.Methods The neonatal rats were randomly divided into the hyperoxia group and the control group.After 1,3,5 and 7 d hyperoxia exposure,the lung tissues were collected to measure the wet-to-dry weight ratio and the expression of α-,β-and γ-ENaC subunits were detected by western blot analysis.Alveolar fluid clearance (AFC) and amiloride-sensitive AFC were measured after 5 d to reveal the effect of hyperoxia on the activity of ENaC.Results The lung water contents significantly increased in the hyperoxia group indicating that pulmonary edemahappened(3 d:(6.37 ±0.64) vs (5.56±0.15),t=3.46,P＜0.01;5 d:(5.86 +0.52) vs (5.11±0.21),t=-3.82,P ＜0.01;7 d:(5.56±0.45) vs (4.80±0.09),t =-4.72,P ＜0.01).AFC increased significantly,but no significant difference was found in amiloride-insensitive AFC between the two groups which indicate that amiloride-sensitive AFC increased significantly (AFC:(20.32 ± 3.33) ％ vs (12.97 ± 2.46) ％,t =-6.16,P ＜ 0.01 ; amiloride-insensitive AFC:(10.42 ± 3.44) ％ vs (8.67 ± 3.13) ％,t =-1.30 P =0.21).The expression of α-,β-and γ-ENaC did not reduced after hyperoxia exposure compared with the control group.Conclusion Although bronchopulmonary dysplasia of early pulmonary edema induced by hyperoxia,dysfunctional transport of Na + may not be a key factor involved in pulmonary edema at the early stage of bronchopulmonary dysplasia.

Objective To explore the incidence rate and high-risk factors for bronchopulmonary dysplasia(BPD) in premature infants of mechanical ventilation.Methods From Jan 2008 to Dec 2009,196 very low birth weight infants with gestational age less than 32 weeks in our NICU were enrolled in the study.61 cases had the histories of mechanical ventilation.The clinical materials of 21 cases with BPD were compared to 41 cases without BPD in retrospective analysis.Results The total incidence of BPD in the very low birth weight infants with gestational age less than 32 weeks was 10.7%,and 34.4% in those infants with mechanical ventilation.The gestational age and birth weight of BPD group were lower than those without BPD,and the rates of premature rupture of fetal membrane and complicated neonatal respiratory distress syndrome (NRDS),postnatal infection,with long time intravenous nutrition in BPD group were higher than those without BPO control (P<0.05).Gender,asphyxia history,the use of pulmonary surfactant (PS),positive end-expiratory pressure,and mean airway pressure were not different significantly between two groups (P>0.05).Peak inspiratory pressure (PIP),the time of mechanical ventilation and oxygen administration were different significantly between two groups (P<0.05).NRDS,postnatal infection,the duration of ventilation,and hyperoxia were the risk factors for BPD,and the regression coefficient were 3.683,1.541,1.188 and 1.647.Conclusion Preventing premature,low birth weight,NRDS,shortening the duration of high peak inspiratory pressure and hyperoxia with mechanical ventilation and the use of the parenteral nutrition,managing the infection of the prenatal and postnatal are the key points of preventing BPD.

Objective To investigate the early MRI performance and the evolution of premature infants who developed into periventficular leucomalacia (PVL) eventually.Methods Twelve premature infants diagnosed as PVL by MRI in the department of neonatology in Shengjing Hospital of China Medical University from Jan 2010 to Dec 2013 were selected,all of the cases underwent conventional MRI and diffusion-weighted imaging (DWI) examination twice,the first examinations were finished in 2 to 7 days (mean 5.5 d) after birth and the second examinations were taken in 17 to 23 days(mean 20.3 d).Results The first examination showed:all cases performed high signal intensity of periventricular matter,including 6 diffuse and symmetrical,3 linear and 3 clustered high signal.However,only 5 of the 12 cases showed slightly high signal on T1 weighted image with low signal on T2 weighted image on conventional MRI,the other 7 cases showed no change;for the reexamination:foci of different numbers and sizes showed up in all cases,with the performance of low signal on T1 weighted image,high signal on T2 weighted image and low signal on DWI correspondingly.Conclusion DWI is superior to conventional MRI in finding and forecasting PVL;diffuse white matter damage have more probability to develop into PVL,severe local white matter damage such as multi-clustered and linear damage also can develop into PVL.

Objective To investigate the expression and significance of Smad4 and Smad7 in newborn rats with hyperoxia-induced chronic lung disease(CLD).Methods Sixty-four newborn Wistar rats 12 h after birth were divided into high-oxygen group (n =32) and air group (n =32,control group) by random number table method.The high-oxygen group was placed in the oxygen glass tank with continuous infusion of oxygen.And 1,3,7,14 d after experiment,tracheal separated,the chest opened to expose heart and lung,slices were Masson staining,undergo dynamic observation of the pulmonary pathological changes under light microscope.Lung fibrosis score was carried out to determine the degree of pulmonary fibrosis,and immunohistochemical technique was used to detect Smad4 and Smad7 protein expression in lung tissue.The expression levels of Smad4 and Smad7 protein in lung tissue were detected with Western blot.Results Compared with the air group,there was statistically significant difference in pulmonary fibrosis score on day 7 (2.67 ± 0.21 vs 0.58 ± 0.17) and day 14 (4.48 ± 0.24 vs 0.63 ± 0.13) in high-oxygen group (P ＜ 0.05) ; Smad4 and Smad7 was main in visible lung epithelial cells and interstitial fibroblasts.Smad4 expression in the high-oxygen group gradually enhanced,compared with the air group (P ＜ 0.05) on day 7 (122.35 ± 10.3 vs 140.08 ±7.77) and day 14(129.7 ± 7.33 vs 144.99 ± 6.49).Smad7 expression in the high-oxygen group first increased and then decreased,expression in the high-oxygen group increased on day 7 (122.35 ± 10.29 vs 130.56 ±9.8),and compared decreased with the air group(P ＜0.05) on day 14(132.16 ±4.38 vs 126.22 ±6.49).Conclusion The newborn rat exposed hyperoxia,the up-regulation of Smad4 protein expression and the down-regulation of Smad7 protein expression are imposible closely related to the happen and development of CLD pulmonary fibrosis.

Objective To investigate p16 promoter methylation in premature rats with chronic lung disease induced by hyperoxia. Methods Eighty premature Wistar rats were randomly divided into two groups: hyperoxia group (fraction of inspiratory oxygen) 0. 90 and control group (fraction of inspiratory oxygen 0. 21), 40 rats for each group. Semi-nested methylation specific polymerase chain reaction and methylation specific polymerase chain reaction were applied respectively to detect p16 promoter methylation in lung tissues. Additionally, p16 mRNA and protein expressions in lung tissue were detected by reverse transcription- polymerase chain reaction, Western blot and immunohistochemistry method. Results The methylation was not found in control group by seminested methylation specific polymerase chain reaction and methylation specific polymerase chain reaction, while was found in different aged rats of the hyperoxia group. The methylation detection rate was higher by using the semi-nested methylation-specific polymerase chain reaction (52.5%, 21/40) than that by methylation specific polymerase chain reaction (42.5%, 17/40) in the hyperoxia group,but there was no statistically significant difference between the two methods. The p16 mRNA in the hyperoxia group were significantly lower than in the control group at day 7, 14 and 21(1.73 ± 0.40 vs 2.11±0. 37,1.29±0. 19 vs 1.60±0. 27,0. 95±0.25 vs 1.72±0. 34, t=2.19, 2.95 and 10. 43,P＜0. 05). The p16 protein expressions by western blot in the hyperoxia group were significantly lower than in the control group at day 7, 14 and 21 also (88. 1±8. 7 vs 95.0±4.1,65.7±4.5 vs 83. 5±13.6 and 50.4±4.9 vs 86.7±11.9, t=2.27,3.95 and 13.40,P＜0.05). The expression of p16 mRNA (1.06±0.61) and protein (62.32±25.65) in lung tissues of rats with methylation was lower than that without methylation (1.63±0.62 and 94.93±22.21, respectively) (t=2.95, OR=0. 86;t=4.28, OR=0. 85,P＜0.01, respectively). Conclusions Exposure to hyperoxia might induce p16 promoter methylation in lung tissues in premature rats. Methylation risk increases as exposure time extends. p16 promoter methylation induced by hyperoxia might participate in the mechanism of lowering p16 mRNA and protein expression, but might not result in p16 gene silence.

Objective To investigate the variation in expression and the significance of markers indi-cating typeⅠalveolar epithelial cells ( AECⅠ) and type Ⅱ alveolar epithelial cells ( AECⅡ) in hyperoxia induced bronchopulmonary dysplasia( BPD) model. Methods A total of 80 term normal Wistar rats were randomly devided into model group (85% oxygen) or control group (room air) within 12 h after birth,with 40 rats in each group. On day 7,day 14,day 21 after exposure,the pathological characteristics of lung tissues were observed using HE staining, the expression and location of AECⅠ marker aquaporin 5 ( AQP5 ) and AECⅡmarker surfactant protein-C ( SP-C) were examined using immunofluorescence double staining. West-ern blot analysis was employed to examine the expressions levels of AQP5 and SP-C proteins,while real-time PCR was used to evaluate the mRNA expression of AQP5 and SP-C. Results Alveolar developmental disor-der was observed in lung tissues of the model group,including fewer,larger,simplified alveoli,thicker alveo-lar walls,and fewer alveolar secondary septa. Immunofluorescence double staining showed increased and dis-organized AQP5 and SP-C expression, with significantly higher ratio of double-stained cells/SP-C positive cells in the model group ( P<0. 001 ) . Comparing to the control group, the expression of AQP5 and SP-C protein increased from 7 d after hyperoxia exposure,which continued to 21 d. The mRNA expression levels of these two markers both significantly increased in the model group compared with the control group, with AQP5 starting from 7 d while SP-C starting from 14 d after hyperoxia exposure (P<0. 05),and the differ-ence between two groups became more significant with the exposure time extending. Conclusion The expression of AECⅠ marker AQP5 and AECⅡ marker SP-C both increase in the lung tissues of hyperoxia induced BPD newborn rats,with more AECⅡ transdifferentiated into AECⅠ. These changes of the markers indicate that there is excessive transdifferentiation of AECⅡ in the recovery process after BPD lung injury.

Objective: To evaluate the influence of acute moderate hemodilution on the dose-response and timecourse of effect of vecuronium. Method:Sixty patients. ASA grade Ⅰ,aged 17-45 years,scheduled for elective plastic surgery were included in the study,of which,thirty patients underwent hemodilution during surgery and thirty patients did not receive hemodilution as controls. General anesthesia was maintained with 60% nitrous oxide in oxygen,and further increments of thiopental 2 mg/kg or fentanyl 2?g/kg as required. After anesthesia was stable,the status of acute moderate hemodilution was developed by drainage o{ venous blood and intravenous infusion of lactated Ringer'ssolution, 6% dextran and.gelofusine,during which the level of hemoatocrit dropped from 45.7% to 26.2%. Neuromuscular function was assessed by TOF stimulation of accelerometry with the percentage depression of T_1 response used as the study parameter. The dose-response relationships of vecuronium were determined with the cumulative dose-response technique. Result:During hemodilution the dose-response curve of vecuronium was parallelly shifted to the left. Compared to the control patients,ED_(50),ED_(90) and ED_(95) of vecuronium in the hemodilution patients were decreased by 22%,18% and 17%, respectively. Following an intravenous administration of total dose of vecuronium 80?g/kg, vecuronium-induced neuromuscular block was significantly longer in the hemodilution patients than in the control patients. Conclusion:Acute moderate hemodilution could significantly enhance the neuromuscular blocking effect of vecuronium and prolong its duration of action.

Objective To investigate the correlation between brain injury and premature infants with bronchopulmonary dysplasia (BPD)and to analyze the risk factors of brain injury in premature infants with BPD based on MRI changes.Methods A total of 1 13 premature infants diagnosed with BPD were studied as case group from January 2010 to December 2014 at the neonatal ward of Shengjing Hospital of China Medical University.One hundred and sixty-two premature infants without BPD were selected as control group.There were no significant differences in gestational age and birth weight between the two groups.All cases were per-formed MRI examination in hospital.The occurrence of brain injuries(white matter injury and intracranial hemorrhage)were compared based on MRI changes between the two groups,and the risk factors of brain in-jury in case group were analyzed.Results The case group and control group were performed MRI on (33.73 ±16.00)d,(24.40 ±12.29)d after birth respectively.The ratio of brain injury,intracranial hemor-rhage,cerebral white matter damage and severe brain injury of case group was higher than those of the control group(48.7% vs.32.7%,3 1.9% vs.21.6%,31.9% vs.21.6%,16.8% vs.8.6%,respectively).The differences were significant in the ratio of brain injury and severe brain injury (P =0.008,P =0.040,respec-tively).Logistic regression analysis showed that postnatal infection was a risk factor for brain injury of the case group(OR =2.21 ,95%CI 1.04 ~4.72,P ﹤0.05).Conclusion More brain injury(including the white matter injury and intracranial hemorrhage)and severe brain injury(including grade III ~IV intraventricular hemorrhage and periventricular leukomalacia)are detected in premature infants with BPD.Postnatal infection is a risk factor of brain injury for premature infants with BPD.