Objective　To explore the development of endogenous CO and its mechanisms in asthma.Methods　50 guinea pigs were equally separated 5 groups.After the models of asthmatic guinea pigs were established in 4 groups,3 groups of them were treated with dexamethasone,the specific stimulator(hemin)and inhibitor(Sn-PP)of HO-1 respectively.The rest of groups were asthmatic one and normal control one(NCG).From all tested animals,the COHb in blood and lung HO-1 activity were examined,the lung tissues were pathologically observed and immunohistochemically stained.Results　In asthmatic and hemin stimulated groups,the levels of COHb with enhanced expression of lung HO-1 and their activity were significantly increased compared with NCG(t=4.43～9.97,P＜0.01).For example,the lung HO-1 activities in asthmatic group were (881±361)pmol/(mg*pro*h),COHb (4.94±2.15)% respectively.In dexamethason prevented and Sn-PP inhibited groups,however,all determined levels were markedly reduced compared with asthmatic group(P＜0.01).Conclusion　The increased HO-1 had resulted in the growth of endogenous CO in asthma.

The key mechanism of severe infection (sepsis) is systemic inflammatory reaction syndrome. Continuous blood purification (CBP) is helpful for treatment of sepsis through removing medium and large molecular weight inflammatory mediators. Clinical application and lab researches have confirmed that CBP can stabilize cardiopulmonary function in patients with severe sepsis. Continuous veno-venous hemodiafiltration, continuous plasma filtration absorption and high volume hemofiltration can play a role in lowering inflammatory mediators in plasma and tissue. CBP has revealed a good prospect in the treatment of severe sepsis in children.

Neonatal jaundice is one of the common diseases in preterm neonates. But there are still some problems to be determined,for example,the clinical diagnosis criteria for neonatal jaundice,the prediction,diagnosis and therapies for hyperbilirubinemia,and diagnosis for bilirubin encephalopathy in early-stage and prevention from bilirubin encephalopathy sequelae.

As a kind of effective treatment,continuous blood purification (CBP),still left some risk factors in critically ill children.The risk factors include catheter-related complications such as bleeding and mispractice at the acute phase,long-term complications such as catheter infections,tube jam;complications occurred in the process of CBP such as low blood pressure,hypothermia and abnormal coagulation;metabolic complications such as lost syndrome and imbalance syndrome.CBP should be implemented safely and effectively in pediatric field by mastering the skill proficiently,continuously monitoring vital signs,tackling complications and accidental episodes.

Objective To study common Gram negative bacterial pathogens and their drug resistant pattern in sputum isolates from patients in pediatric intensive care unit (PICU) of Chengdu children' s hospital. Methods Comparing to the period of 2004-2006 with 2007-2009, we retrospectively reviewed eligible sputum isolates of common Gram negative bacilli and their drug resistance pattern. All specimens were processed according to standard microbiological methods for both quantitative and qualitative cultures. Pathogen was the single predominant growth after two consecutive cultures. Strict quality control was used in all test agents and paper disk for drug resistance analysis. Results Total of 598 Gram negative bacterial isolates were identified in patients over 6 years. The first 5 bacteria respectively were Escherichia coli 167 samples(27.93%), Klebsiella pneumoniae 109 samples ( 18.23% ), Enterobacter cloacae 93 samples ( 15.55% ),Acinetobacter baumannii 64 samples ( 10. 7% ), Pseudomonas aeroginosa 43 samples (7. 19% ). They were mostly sensitive to Imipenam, Amikacin, Piperacillin/Tazobactam. Most drug resistance rate was found in Amoxicillin, Ampicillin, Cephalosporin. Apart from Pseudomonas aeroginosa and Acinetobacter Baumannii,no Gram negative bacteria was found to be resistant to Imipenam. Klebsiella pneumoniae and ESBL secreting Escherichia coli isolates were obviously increasing when compared to 3 years ago. Conclusion Comparing the period of 2004-2006, the Gram negative bacterial isolates were increasing in our PICU patients during 2007 to 2009. Close monitoring of drug resistance pattern changes in PICU would guide rational use of antibiotics in these critically ill children.

Objective To compare the clinical efficacy of 3% hypertonic saline with 20% mannitol in the treatment of acute brain edema in children.Methods Twenty children with acute brain edema were randomly divided into hypertonic saline(HS) group and mannitol group.HS group and mannitol group were given 3% HS solution or 20% mannitol respectively.Main outcome measurements included intracranial pressure(ICP),mean arterial pressure(MAP),central venous pressure(CVP),cerebral perfusion pressure (CPP),serum electrolytes,plasma osmolality,renal function and urine volume.Results Both 3% HS and 20% mannitol were effective in reducing ICP(P ＜0.05).Therapeutic effect lasted(4.5±1.2) h in HS group and(3.2±1.5) h in mannitoi group.3% HS had a longer duration of action than marmitol(P＜0.05).At the time point of 2 hours after treatment,MAP and CPP of HS group increased more than those of mannitol group(P＜0.05).Conclusion Both 3% HS and 20% mannitol could rapidly decrease ICP.3% HS has a longer duration of action in reducing ICP than 20% mannitol.3% HS is more effective in stabilizing circulation and improving CPP than 20% mannitol.

Objective To investigate the role of CT three-dimensional reconstruction (3D-CT) in the diagnosis of bronchial foreign body.Methods Thirty-seven suspected pediatric cases of bronchial foreign bodies underwent CT scanning and 3D-CT reconstruction,whose accuracy was defined by bronchoscopical or surgical findings.Results For all the 37 cases,chest X-ray showed 8 cases (group A) had bronchial foreign body,while 29 cases(group B) were negative.In group A,CT findings suggested lung infection in 5 cases,congenital pulmonary dysplasia-lung lobe absence in 2 cases and tracheo-esophageal fistula in 1 case.In group B (29 patients),25 cases with bronchial foreign bodies were suspected by CT scanning and further bronchoscopical examination confirmed the existence of 24 cases of vegetable foreign body,one case of the tracheal tumor.For the four cases with negative result of bronchial foreign bodies after CT scanning,lung infection and laryngitis were confirmed in two cases respectively.Among the 24 surgically-confirmed cases of vegetable foreign bodies,CT scanning showed tracheobronchial foreign body in fourteen positive results,irregular tracheal stenosis in six cases and obstructive atelectasis,emphysema,pneumonia in seven each.Tracheobronchial foreign body and irregular tracheal stenosis were direct signs,accounting for 74%(20/27).Obstructive atelectasis,emphysema and pneumonia were indirect signs,accounting for 26%(7/27).Conclusion 3D-CT plays an important role in diagnosis and differential diagnosis of bronchial foreign body.

ObjectiveTo assess the effects of dopamine,dobutamine and norepinephrine on the P(g-a)CO2 and superior mesenteric blood flow in septic shock.MethodsRabbit septic shock model was established by challenging with intravenous injection of lipopolysaccharides from Escherichia coil(2 mg/kg).The rabbits with septic shock were randomly assigned to 3 groups-dopamine group(n = 8),dobutamine group(n = 8) and norepinephrine group(n = 8).Apart from volume resuscitation with normal saline solution [20 ml/(kg· h)]，dopamine[5μg/(kg·min)],dobutamine[(5μg/(kg·min)]and norepinephrine [(1μg/(kg·min)]were infused in dopamine group,dobutamine group and norepinephrine group respeclively.Cardiac index(CI) and superior mesenteric blood flow index(SMBFI) were continuously monitored by doppler flowrneter.Gastric mucosal PCO2 was evaluated by gas tonometry every 10 min.Arterial and venous blood gas analyses and lactate levels were measured every 1 h.ResultsMAP,CI,and SMBFI significandy decreased and P(g-a) CO2 increased after lipopolysaccharides infusion in three groups.After 2-hour treatment,MAP in norepinephrine group[(70 +3) mm Hg]was higher than that of dopamine group[(66±4) mm Hg]and dobutamine group[(65±4) mm Hg](P ＜0.05).SMBFI in norepinephrine group [(18.7±2.9) ml/(kg·min)]was higher than that of dopamine group[(16.2±1.6) ml/(kg·min)]and dobutamine group[(15.8±1.9) ml/(kg·min)](P＜0.05).P(g-a) CO2 in norepinephrine group [(30±6) mm Hg]was lower than that of dobutamine group[(23±5)mm Hg](P＜0.05).Condnsion As an adjuvant therapy of volume resuscitation,norepinephrine is more effective than low dose dopamine and dobutamine in improving splanchnic perfusion.

Objective To investigate the expression and the significance of AQP2 in the kidneys of septic rats. Methods Sixty-four Wistar rats of 6 weeks were randomly divided into two groups: sham group and the septic model group. Septic models were made by cecum ligation perforation (CLP). Fach group was divided into 3-hour,6-hour,12-hour and 24-hour subgroups,with 8 rats in each. The urine,blood and kidney sampies were collected. The urine volume ,urine osmotic pressure and renal function were observed. The expressions of AQP2 protein in rats' kidneys were determined by using immunohistochemical method and the expressions of AQP2 mRNA with real-time PCR. The pathological changes of the kidneys were observed under light microscopy. Results After CLP,urea volume of Wistar rats in septic model group decreased and urine osmotic pressure increased at 3 hours; urea volume gradually increased and urine osmotic pressure decreased at 6 hours; Serum Cr and urea nitrogen began to increase at 6 hours and reached the peak at 24 hours. The longer the time lasted after CLP,the more serious the injury of kidney became,which was mainly manifested as that the space between the epithelial cells of the tubular wall disappeared,nucleus disappeared,glomerular loops fused,and cell structure was unclear. Renal mesenchymal was infiltrated with inflammatory cells. AQP2 mRNA expression increased at 3 hours,decreased at 12 hours and 24 hours ,AQP2 protein expression decreased at 12 hours,with the lowest at 24 hours,which were significantly different from those of the sham groups(P<0.05). Conclusion AQP2 may regulate the water metabolism of septic rats' kidney. The decreased AQP2 protein expression is one of the main pathological mechanisms that results in dysfunction of urine concentration in sepsis.

Objective To establish a method of isolation, purification and identification of type Ⅱ alveolar epithelial cells (AEC- K ) from neonate piglet lungs of 1 ～ 3 days old and to investigate effects of proinflammatory cytokines on expression of growth factors (GFs). The yield, viability and purity of AEC- Ⅱ obtained using different enzyme digestion and purifying methods were compared. Methods After the first 24-hour culture of AEC- Ⅱ ,the media containing interleukin (IL)-1β,IL-6 and IGF-Ⅰ at different concentrations were used to culture AEC-Ⅱ for another 48 hours. And then the cells were counted and the expressions of insulin-like growth factor (IGF-Ⅰ ), platelet-derived growth factor ( PDGF), surfactant proteins (SP) -A and SP-B mRNA were determined by real time PCR. Results A significantly higher yield of AEC-Ⅱ was achieved by digesting the lung with 30 unit/ml elastase and 0.1 % trypsin at 37 t for 20 min, the yield was (5.33 ±0.54) × 106 after adjusted by the weight of lung and heart (P <0.01). The number of purified AEC-II obtained by immune adherence method was (38.0 ±28.0) × 106 perpiglet which was higher than by the method of percoll. The optimal phenotype maintenance time of AEC- Ⅱ was the first 24～96 hours in the primary culture. With increasing concentrations of IL-1 β and IL-6, there were decreased proliferation and expression of SP-A and IGF-Ⅰ mRNA in the cultured AEC- Ⅱ ,but SP-B mRNA expression was not affected. Both AEC-Ⅱ proliferation and expression of SP-A, SP-B mRNA decreased significantly after cultured with anti-IGF-Ⅰ. Conclusion In a new model of cultured AEC-Ⅱ from neonate piglets, IL-1β and IL-6 inhibited AEC- Ⅱ proliferation and SP-A mRNA expression through IGF-Ⅰ -dependent mechanisms.