[Protective effect of N-acetylcysteine on hyperoxic lung injury and its relation with p38 mitogen-activated protein kinase signaling pathway].

Objective: To investigate the expression of p38 mitogen-activated protein kinase (MAPK) in hyperoxic lung injury (HLI), and explore the protective effect of N-acetylcysteine (NAC) on HLI and its mechanism.

Methods: Thirty Wistar rats aged 3 weeks old were divided into five groups with 6 rats in each group according to random digits table: room-air group (A), hyperoxia injury group (B), hyperoxia+NAC group (C), hyperoxia+p38 MAPK inhibitor (SB203580) group (D), hyperoxia+NAC+SB203580 group (E). Rats in NAC groups were injected with NAC (200 mg/kg) intraperitoneally, and they received an intravenous injection of SB203580 (0.

N-acetylcysteine protects alveolar epithelial cells from hydrogen peroxide-induced apoptosis through scavenging reactive oxygen species and suppressing c-Jun N-terminal kinase.

The production of reactive oxygen species (ROS) during hyperoxia contribute to alveolar epithelial apoptosis. In the present study, the molecular mechanisms of oxidative stress-induced alveolar epithelial cell apoptosis were investigated. The cytoprotective effects of N-acetylcysteine (NAC) were evaluated.

[The proliferation-promoting effects of calcitonin gene-related peptide on type II alveolar epithelial cell exposed to hyperoxia mediated by protein kinase C alpha pathway].

Objective: To explore the effects of calcitonin gene-related peptide (CGRP) on type II alveolar epithelial cell (AECII) exposed to hyperoxia, and to determine whether the mechanism is mediated by protein kinase C alpha/nuclear factor-KappaB (PKC alpha/NF-KappaB) signal pathway.

Methods: AECII were isolated from the lung of 21 days fetal rat and cultured for 15 hours to coalesce. Then AECII were randomly assigned into four groups: air, hyperoxia, O(2)/CGRP, and O(2)/CGRP8-37 (a receptor antagonist against CGRP).

[Expression and role of p38 mitogen-activated protein kinase in hyperoxia-induced lung injury juvenile rat model].

Objective: Some research has shown that p38 mitogen-activated protein kinase (p38MAPK) plays important roles in lung injuries induced by various factors. Its expression and role in hyperoxia-induced lung injury remains unknown. This study investigated the expression and role of p38MAPK in hyperoxia-induced lung injury juvenile rat model.

[Changes of aquaporin expression during lung development in rats].

Objective: Many studies have shown that tissue development is closely correlated with fluid transport. Aquaporins (AQPs) are a group of cell membrane proteins that actively and selectively transport water. This study aimed to investigate the changes of AQPs expression during lung development in rats in order to elucidate the role of AQPs in the rat lung development.

[Oxidative stress induced the expression of Bax and p53 during the apoptosis of alveolar type II epithelial cell].

Objective: To investigate the effects of oxidative stress on the survival and apoptosis of alveolar epithelial type II (ATII) cells, as well as the mechanisms of apoptosis.

Methods: 500 mumol/L H(2)O(2) was added into primary ATII cells at different times and cell viability, apoptotic ratio and the expression of Bax and p53 were measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, flow cytometry (FCM) and Western blotting analysis, respectively. The change in mitochondrial membrane potential (MMP) was detected by fluorescence microscopy and FCM.

[Apoptosis of alveolar type II epithelial cells regulated by extracellular signal-regulated kinase under oxidative stress].

Objective: To investigate survival and apoptotic responses of alveolar type II epithelial cells (AT II cells) under oxidative stress and the regulation mechanism mediated by extracellular signal-regulated kinase (ERK).

Methods: Primary passage of cultured rat AT II cells were challenged with hydrogen peroxide (H(2)O(2)), and the cells were pretreated with specific inhibitor of ERK (PD 98059) in another group. Cell viability, apoptotic rate and the expression of phosphorylated ERK1/2 (p-ERK1/2)were measured by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay, flow cytometry and Western blotting analysis, respectively.

[Expression and modulation of aquaporin 5 in hyperoxia induced lung injury].

Objective: To explore the expression and the modulation of aquaporin 5(AQP5) in hyperoxia induced lung injury.

Methods: Sixty four Wistar rats of 2 weeks old, were randomly assigned to following groups (n=8): air group, hyperoxia 3, 7, 14 days groups, air + dexamethasone (Dex), hyperoxia 3, 7, 14 days + Dex groups. The rats were kept in oxygen chamber at normal pressure (O(2)> or =95%) in hyperoxia groups, and in normal pressure air (O(2)=21%) in room-air group, and the rats in Dex groups were injected with Dex (5 mg.

[Study on the relationship between cytosolic phospholipase A2-gamma activation and myocardial cell injury during cardiopulmonary bypass].

Objective: To investigate the relationship between cytosolic phospholipase A(2)-gamma(cPLA(2)-gamma) activation and alteration of myocardial ultrastructure during cardiopulmonary bypass (CPB) in the operation of ventricular septal defect.

Methods: Myocardial tissues from the right atria of 12 patients undergone ventricular septal defect were collected before and after CPB, cPLA(2)-gamma gene expression was detected by reverse transcription-polymerase chain reaction (RT-PCR) and analysis was carried out using gel image analysis software. Meanwhile, alteration of myocardial ultrastructure was observed under electron microscopy.

[Clinical study on respiratory mechanics of synchronized intermittent mandatory ventilation in premature infants with respiratory failure].

Objective: To evaluate the clinical significance of synchronized intermittent mandatory ventilation (SIMV) in prematures infants necessitating assistant ventilation.

Methods: Forty-two premature infants were studied in whom SIMV was used in 24 and intermittent mandatory ventilation (IMV) was used in 18. The parameters of fractional concentration of inspired oxygen (FiO(2)), peak inspiratory pressure (PIP), expiratory tidal volume (V(Texp)), oxygen index (OI), compliance of the respiratory system (Crs) and airway resistance (Raw) were compared.

[Study on effect of dexamethasone on the expression of matrix metalloproteinase and its tissue inhibitors in hyperoxia-induced lung injury].

Objective: To observe the effect of dexamethasone on the mRNA expression of matrix metalloproteinase (MMPs) and tissue inhibitor of metalloproteinase (TIMPs) in the lung tissue and to explore the protective mechanism of dexamethasone in hyperoxia-induced lung injury.

Methods: Thirty-two two-week old Wistar rats were randomly divided into atmospheric-air group (n=16) and hyperoxia group (n=16). After 7 days of continuous exposure to high concentration O (2)(>95%), the lung wet/dry(W/D) ratio, the protein content in bronchoalveolar lavage fluid(BALF) and histopathological changes of the lung were measured in 16 rats(8 in each group).

[Evaluation of antibacterial activity of amoxycillin sodium and clavulanate potassium and the pharmacoeconomics in the therapy of acute respiratory infection].

Objective: To explore the antibacterial activity of amoxycillin sodium and clavulanate potassium (trade name: Anqi) in vitro and the pharmacoeconomics in the therapy of acute respiratory infection.

Methods: Minimal inhibition concentration (MIC), minimal bactericidal concentration (MBC) and bactericidal curve of amoxycillin sodium and clavulanate potassium against common pathogens were determined and compared with some other same kind of antibiotics without beta-Lactamase inhibitor. Eighty cases diagnosed as respiratory infection were randomly divided into 4 groups: group 1 was treated with i.