Objective To explore the role of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in hyperoxia-induced lung injury in preterm rats. Methods At the 2 nd postnatal day Sprague-Dawley preterm rats were randomly assigned to air group and hyperoxia group (exposed to about 85% of O 2). At 3,7,14 and 21 days after exposure, six rats of each group were used to assess lung histologic changes and expression of MMP-2, MMP-9, TIMP-1 and TIMP-2 in lungs by immunohistochemistry. At 3,7 and 14 days after exposure, gelatinase activity in bronchoalveolar lavage fluid (BALF) of another six rats in each group by gelatin zymography was examed. Results Except 3 d after exposure, hyperoxia group showed lung injury characterized by subacute alveolitis and inhibition of lung development. Expression of MMP-2, MMP-9, TIMP-1 and TIMP-2 in hyperoxia group was stronger than that in air group at every time (P

Objective To investigate the efficacy and safety of aminophylline,caffeine citrate and aminophylline combined with naloxone in prevention of apnea of prematurity(AOP).Methods Ninety-four infants with a birth weight ＜ 1 500 g and gestational age ＜ 34 weeks admitted to Department of Pediatrics,Tongji Hospital Affiliated to Tongji Medical College,Huazhong University of Science and Technology between Jan.2010 and Jan.2012 were randomly divided into 3 groups.(1) Aminophylline group (n =30):30 infants received a loading dose of 4-5 mg/kg of aminophylline and then maintained by a dose of 2 mg/kg,with intravenous drip q12 h.(2) Caffeine citrate group(n =32):a loading dose of 20 mg/kg of caffeine citrate was followed by a daily maintained dose of 5 mg/kg,with intravenous drip per day.(3) Aminophylline combined naloxone group (observation group,n =32):32 infants were treated with Aminophylline combined with naloxone.After 6 hours of the first dose of aminophylline,a dose of 0.1 mg/kg naloxone was injected,q12 h.Then the two drugs were used alternately.The mortality and incidence of AOP,bronchopulmonary dysplasia(BPD),retinopathy of prematurity (ROP) and brain injury were evaluated,and drug-related side effects were recorded.Results 1.There was no significant difference in gender,gestational age,birth weight,maternal antenatal glucocorticoid application,pregnancy (including multiple pregnancy) and delivery,5 min Apgar score,oxygen therapy,and the application of positive airway pressure as well as pulmonary surfactant among the 3 groups(all P ＞0.05).2.Compared with aminophylline group,the incidence of apnea of caffeine group and observation group were significantly lower (F =6.704,P ＜ 0.05),but there was no significant difference between caffeine group and observation group (P ＞0.05).3.There was no statistically significant difference in mortality,duration of oxygen therapy,the incidence of ROP,brain injury and hearing loss,postmenstrual age,body weight at discharge,the duration and cost of hospitalization among the 3 groups(all P ＞0.05).4.The BPD incidence in caffeine group[9.4％ (3/32 cases)] and observation group [12.5％ (4/32 cases)] were lower than that in Aminophylline group [20.0％ (6/30 cases)],but there was no statistical significance among the 3 groups(P ＞ 0.05).5.No drug-related side effects were recorded in the 3 groups.Conclusions It is safe and effective to use aminophylline combined with naloxone in prevention of AOP,and its efficiency is similar to caffeine citrate.

Objective To investigate the diagnosis,treatment and prognosis of neonates with severe acute respiratory distress syndrome (ARDS) according to Berlin definition.Methods A retrospective study was carried to analyze the clinical features about diagnosis,treatment,chest X-ray findings,mortality,complications and ventilator parameters in 86 neonates with severe ARDS admitted in the NICU from January 2005 to December 2013.Results (1)Among the 86 cases,55 were cured,and 31 died with 36.0％ mortality.(2) Chest X-ray showed there was decreased lucency of bilateral lungs with ground-glass appearance,lung texture with thick chaos or dot flakes or patchy shadows in 36 neonates; diffuse infiltrates and extensive confluent consolidation shadows in bilateral lungs along with peripheral air brornchograms in 26 cases; heart shadow and diaphragmatic surface disappeared like a white lung change in 24 cases.(3) Persistent pulmonary hypertension of newborn as a complication occurred in 68 cases with 79.1％ incidence.(4) Eighty-six cases were categorized into survival group and death group.The results showed compared with the survival group,the neonates in death group required higher FiO2,and PaO2,and lower PaO2/FiO2 before mechanical ventilation (P ＜ 0.01),but needed higher initial PIP of mechanical ventilation (P ＜ 0.01).Conclusions Neonatal ARDS is still a kind of critical condition with high mortality and lack of evidence-based diagnostic criteria so far.The therapeutic strategy for neonatal ARDS should be a comprehensive measures in addition to appropriate respiratory support.

To investigate role of Notch1 - 3 in hyperoxia-induced lung injury in newborn rat exposed to 85% O2, SD rat litters born on the 22th day were randomly divided into two groups: room air group and hyperoxia group. The animals were sacrificed 1, 4, 7, 10, 14 and 21 days after continued exposure to oxygen (n = 40, oxygen > 0.85) or room air (n = 40). 6 rats each group were used to assess lung histological changes by HE staining and expression of Notch in lungs by immunohistochemistry. Total RNA was extracted by Trizol reagent from frozen lung tissues. Notch mRNA were measured by reverse transcription polymerase chain reaction (RT-PCR). Our results showed that 7, 14 and 21 days after O2 exposure, hyperoxia group showed lung injury characterized by pulmonary edema, hemorrhage and lung development arrest. Positive staining for Notch1, Notch 2 in hyperoxia group was much lower than those in room air group at all time points (P < 0. 01, P < 0.05), but compared with the controls, the hyperoxia group showed higher expression of Notch3 (P > 0.05). Immunostained cells were typically airways epithelia, alveolar epithelial and inflammatory cells, and fibroblasts in hyperoxia group (P < 0.01). Notch mRNA levels showed similar change as protein level (P < 0.01). It is concluded that the prolonged exposure to 85% O2 resulted in abnormal expression of Notch receptors, which might contribute to the pathogenesis of hyperoxia-induced lung injury in newborn rats. The decreased inhibition of Notch1 might be one of the protective reaction and major mechanisms for proliferation/differentiation of type II alveolar epithelial cells. The up-regulation of Notch3 activity might result in the lung development arrest of the newborn rats.
Aerobiosis ; Animals, Newborn ; Lung/*pathology ; Lung Diseases/etiology ; Lung Diseases/*metabolism ; Lung Diseases/pathology ; RNA, Messenger/biosynthesis ; RNA, Messenger/genetics ; Random Allocation ; Rats, Sprague-Dawley ; Receptors, Notch/*biosynthesis ; Receptors, Notch/genetics

This study examined the effects of retinoic acid (RA), PD98059, SP600125 and SB203580 on the hyperoxia-induced expression and regulation of matrix metalloproteinase-2 (MMP-2) and metalloproteinase-2 (TIMP-2) in premature rat lung fibroblasts (LFs). LFs were exposed to hyperoxia or room air for 12 h in the presence of RA and the kinase inhibitors PD98059 (ERK1/2), SP600125 (JNK1/2) and SB203580 (p38) respectively. The expression levels of MMP-2 and TIMP-2 mRNA were detected by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR). MMP-2 activity was measured by zymography. The amount of p-ERK1/2, REK1/2, p-JNK1/2, JNK1/2, p-p38 and p38 was determined by Western blotting. The results showed that: (1) PD98059, SP600125 and SB203580 significantly inhibited p-ERK1/2, p-JNK1/2 and p-p38 respectively in LFs; (2) The expression of MMP-2 mRNA in LFs exposed to hyperoxia was decreased after treatment with RA, SP600125 and SB203580 respectively (P<0.01 or 0.05), but did not change after treatment with PD98059 (P>0.05). Meanwhile, RA, PD98059, SP600125 and SB203580 had no effect on the expression of TIMP-2 mRNA in LFs exposed to room air or hyperoxia (P>0.05); (3) The expression of pro- and active MMP-2 experienced no change after treatment with RA or SP600125 in LFs exposed to room air (P>0.05), but decreased remarkably after hyperoxia (P<0.01 or 0.05). SB203580 inhibited the expression of pro- and active MMP-2 either in room air or under hyperoxia (P<0.01). PD98059 exerted no effect on the expression of pro- and active MMP-2 (P<0.05). It was suggested that RA had a protective effect on hyperoxia-induced lung injury by down-regulating the expression of MMP-2 through decreasing the JNK and p38 activation in hyperoxia.

Objective To investigate the diagnostic value of dynamic level of TNF ?、IL 8、IL 1? and IL 6 in lung lavage fluid obtained from preterm infants with chronic lung disease (CLD). Methods Lung lavage were serially collected from 29 ventilated infants hospitalized in NICU from December 1999 to November 2002. Total cell counts, neutrophilic granulocyte counts, malondialdehyde, protein, TNF ?、IL 8、IL 1? and IL 6 in lung lavage fluid were examined. Among the 29 cases, 10 developed pneumonia, 6 HMD, 7 CLD and 6 without lung disease as control. Results Total cell counts(7.9?10 9/L), neutrophilic granulocyte counts(6.4?10 9/L), TNF ?(13.88 pmol/L)、IL 8(376.92 mg/L)、IL 1?(2.96 ?g/L)and IL 6(1.72 ?g/L) in lung lavage fluid in infants who developed CLD were higher than the others on day 5( P

Objective To determine the dynamic changes in adenosine monophosphate-activated protein kinase (AMPK) in neurons of neonatal rats suffering from hypoxic ischemic brain injury.Methods Twenty-four-hour old and seven-day old neonatal rats were used in this study.A classic primary cortical neuron oxygen glucose deprivation (OGD) model and neonatal rat hypoxic ischemic encephalopathy (HIE) model were employed.Lactic dehydrogenase (LDH) and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) were used to evaluate neuron viability and damage.The expression of phosphorylated adenosine monophosphate-activated protein kinase (P-AMPK),phosphorylated activated protein kinase (P-Akt) and Cleaved Caspase-3 in neurons and brain tissue was measured by Western blot at different time points after OGD or HIE.The Student-t test was used for statistical analysis.Results (1) Compared with the control group,LDH levels at 2,4,8 and 24 h after OGD were higher (all P＜0.05) and optical absorption levels of MTT were lower (all P＜0.05).(2) Levels of P-AMPK in the OGD group were higher than those in the control group,and showed a time-dependent increase at 30 min and 2,4,8 and 24 h (all P＜0.05).The expression levels of P-AMPK in the HIE group were higher than those in the control group (0.345 ± 0.038,0.387 ± 0.112 and 0.618 ± 0.075 at 1,3 and 7 days after HIE,and 0.132±0.032 in the control group,all P＜0.05).(3) The levels of P-Akt increased above the control levels at 30 min (0.991 ±0.134 vs 0.304±0.050),reached a maximum level at 2 h (1.183± 0.107),and then gradually declined,whereas the levels of Cleaved Caspase-3 started to increase at 30 min,and remained elevated at 24 h (all P＜0.05).Conclusion Following hypoxic ischemic brain damage,the expression of P-AMPK is significantly increased in both in vivo and in vitro studies in a time-dependent manner.

To investigate the protective effect of retinoic acid (RA) on hyperoxic lung injury and the role of RA as a modulator on mitogen-activated protein kinases (MAPKs), gastation 21 d Sprague-Dawley (SD) fetuses (term = 22 d) were delivered by hysterotomy. Within 12-24 h of birth, premature rat pups were randomly divided into 4 groups (n=12 each): air-exposed control group (group I); hyperoxia-exposed group (group II), air-exposed plus RA group (group III), hyperoxia-exposed plus RA group (group IV). Group I, III were kept in room air, and group II, IV were placed in 85 % oxygen. The pups in groups III and IV were intraperitoneally injected with RA (500 microg/kg every day). All lung tissues of premature rat pups were collected at the 4th day after birth. Terminal transferase d-UTP nick end labeling (TUNEL) staining was used for the detection of cell apoptosis. The expression of PCNA was immunohistochemically detected. Western blot analysis was employed for the determination of phosphorylated and total nonphosphorylated ERKs, JNKs or p38. Our results showed that lungs from the pups exposed to hyperoxia for 4 d exhibited TUNEL-positive nuclei increased markedly throughout the parenchyma (P<0.01), and decreased significantly after RA treatment (P<0.01). The index of PCNA-positive cells was significantly decreased (P<0.01), and was significantly increased by RA treatment (P<0.01). The air-space size was significantly enlarged, secondary crests were markedly decreased in hyperoxia-exposed animals. RA treatment improved lung air spaces and secondary crests in air-exposed pups, but had no effect on hyperoxia-exposure pups. Western blotting showed that the amounts of JNK, p38 and ERK proteins in hyperoxia-exposure or RA-treated lung tissues were same as those in untreated lung tissues (P>0.05), whereas activation of these MAPKs was markedly altered by hyperoxia and RA. After hyperoxia exposure, p-ERK1/2, p-JNK1/2 and p-p38 were dramatically increased (P<0.01), whereas p-JNK1/2 and p-p38 were markedly declined and p-ERK1/2 was further elevated by RA treatment (P<0.01). It is concluded that RA could decrease cell apoptosis and stimulate cell proliferation under hyperoxic condition. The protection of RA on hyperoxia-induced lung injury was related to the regulation of MAP kinase activation.

This study investigated the effects of hyperoxia on dynamic changes of thioredoxin-1 (Trx1) and thioredoxin reductase-1 (TrxR1) in alveolar type II epithelial cells (AECII) of premature rats. Pregnant Sprague-Dawley rats were sacrificed on day 19 of gestation. AECII were isolated and purified from the lungs of premature rats. When cultured to 80% confluence, in vitro cells were randomly divided into air group and hyperoxia group. Cells in the hyperoxia group were continuously exposed to 95% O(2)/5% CO(2) and those in the air group to 95% air/5% CO(2). After 12, 24 and 48 h, cells in the two groups were harvested to detect their reactive oxygen species (ROS), apoptosis, TrxR1 activity and the expressions of Trx1 and TrxR1 by corresponding protocols, respectively. The results showed that AEC II exposed to hyperoxia generated excessive ROS and the apoptosis percentage in the hyperoxia group was increased significantly at each time points as compared with that in the air group (P<0.001). Moreover, TrxR1 activity was found to be markedly depressed in the hyperoxia group in comparison to that in the air group (P<0.001). RT-PCR showed the expressions of both Trx1 and TrxR1 mRNA were significantly increased in AECII exposed to hyperoxia for 12 and 24 h (P<0.01), respectively. At 48 h, the level of Trx1 mRNA as well as that of TrxR1 mRNA in the hyperoxia group was reduced and showed no significant difference from that in the air group (P>0.05). Western blotting showed the changes of Trx1 protein expressions in the hyperoxia group paralleled those of Trx1 mRNA expressions revealed by RT-PCR. It was concluded that hyperoxia can up-regulate the protective Trx1/TrxR1 expressed by AECII in a certain period, however, also cause dysfunction of the cytoplasmic thioredoxin system by decreasing TrxR1 activity, which may contribute to the progression of oxidative stress and cell apoptosis and finally result in lung injury.

Objective To investigate the role of opioid receptors in the protective effects of isoflurane-induced delayed preconditioning against myocardial ischemia-reperfusion (I/R) injury in rabbits. Methods Forty male New Zealand white rabbits weighing 2.0-2.5 kg were randomly assigned into 4 groups ( n = 10 each) : group I sham operation (S); group II I/R; group Ⅲ isoflurane + I/R (Iso) and group IV Iso + naloxone + I/R (Nal). Myocardial I/R was induced by 40 min occlusion of left anterior descending branch (LAD) of coronary artery followed by 120 min reperfusion. In group Ⅲ (Iso) 2% isoflurane in 100% O2 was inhaled for 2 h and I/R was produced 24 h later. In group IV (Nal) naloxone 6 mg/kg was given iv 10 min before 2 h of 2% isoflurane inhalation and I/R was produced 24 h later. At the end of 120 min reperfusion, infarct size (IS) and area at risk (AAR) were determined by Evan's blue and TTC staining. Myocardial ultrastructure was examined by electron microscopy. The phosphorylated p38MAPK protein expression in myocardium was determined by Western blot. Results The IS was significantly smaller in group Iso ( Ⅲ ) ( 19.7% ± 2.8%) than in I/R group ( II ) (37.8% ±1.7%) (P<0.05). The phosphorylated p38MAPK protein expression in myocardium was significantly lower in group Iso than in group I/R. Microscopic examination showed less myocardial damage in Iso group than in group I/R. The protective effects of delayed preconditioning by isoflurane was prevented by naloxone pretreatment. ConclusionOpioid receptors may be involved in the protective effects of delayed preconditioning by isoflurane against myocardial I/R injury.