ObjectiveTo investigate the effects of intravenous (iv) remifentanil infusion on myocardial oxidative stress in rats.MethodsOne hundred and eighty male SD rats weighing 250-300 g were randomly divided into 15 groups (n =12 each):group control (group C); group ischemic preconditioning (group IPC); group remifentanil preconditioning ( group RPC ) ; while ia iv remifentanil infusion groups,iv remifentanil was infused at 4 different rates ( 1,5,10,20μg· kg- 1 · min- 1 ) and each rate was maintained for 15,60 and 120 min respectively.Myocardial ischemia was induced by occlusion of left coronary artery anterior descending branch for 30 min followed by 120 min reperfusion in 6 rats in each group.In group IPC myocardial ischemia was preceded by 3 cycles of 5min ischemia-5min reperfusion;whilein group RPC3cycles of 5min remifentanil infusion at 5 μg· kg-1 · min-1 were applied at 5 min interval before ischemia.Six rats in which I/R was produced were sacrificed in each group,myocardial infarct size (IS) and the area at risk (AAR) were measured and IS/AAR was calculated.The left 6 rats in each group were sacrificed at the corresponding time point (the end of each treatment)and superoxide radical expression and MDA and nitrotyrosine contents in myocardium were determined.Results IS/AAR was significantly decreased in groups IPC,RPC,1 μg·kg-1 ·min-1 × 120 min,5 μg·kg-1 ·min-1 × 60or 120 min and 10 μg· kg- 1 · min- 1 × 60 min as compared with group C.Compared with group C,the myocardial superoxide radical expression was significantly up-regulated in groups 1 μg· kg-1· min-1 × 120 min, 5 μg·kg-1 ·min-1 ×60 or 120 min,10μg·kg-1 ·min-1 ×60 or 120 min and 20 μg·kg-1 ·min-1 × 15,60 or 120min,and myocardial MDA and nitrotyrosine contents were significantly increased in group 20 μg· kg-1 · min-1 ×15,60 or 120 min.ConclusionLonger duration of high rate remifentanil infusion can induce myocardial oxidative stress in rats.

Objective To study changes of humoral immunity of the premature infants in different pathological conditions and detect the reason of the deficiency of humoral immunity in premature infants .Methods Two hundred and forty-six prematur were enrolled and 30 healthy neonates were selected as control group .The percentages of IgG ,IgA ,IgM and comp lement C3 ,C4 were detected by full automatic biochemical analyzer .Results The results showed that IgG ,IgM ,IgA ,C3 and C4 in the premature in-fants were lower than those in the normal term infants and there was a highly significant difference with the decrease of fetal age . IgG ,IgM ,IgA ,C3 and C4 of the group of the premature infants ranging from 32 to 36 weeks had reduced in different degree ,rela-tive to the groups of BW <2 000 g ,hypertension during pregnancy ,cesarean section(P<0 .05) .Conclusion The results showed that function of humoral immunity in the premature infants was depressed and low gestational age ,low birth weight ,cesarean sec-tion and hypertension during pregnancy may be the leading cause of the deficiency of humoral immunity .

AIM: To detect the effect of conjunction matrigel with mammary fad pat(MFP)implantation on the tumorigenesis, proliferation, apoptosis and metastasis of Her2 positive and negative breast cancer model. METHODS: The Her2 positive BT 474 and Her2 negative MDA-MB 231 breast cancer cells were injected into MFP of nude mice with or without matrigel to establish breast cancer model. The tumor volume was measured every 3 d. Followed up for 30 d after implantation, the nude mice were killed and the tumors and associated organs were dissected for pathological sectioning and staining with hematoxylin and eosin. The time of tumor formation and the tumorigenesis were determined after implantation. The tumor volume and metastasis rate were calculated and compared with each other. The proliferation and apoptosis of Her2 positive and negative tumors were also determined. RESULTS: Matrigel and MFP implantation technology shortened the time of tumorigenesis significantly(P<0.01). The tumorigenesis rate of BT 474 and MDA-MB 231 breast cancer cells did not show any different(P>0.05). The metastasis rate of MDA-MB 231 breast cancer cells were improved from 25.0% to 37.5%(P<0.05). CONCLUSION: Matrigel and MFP implantation can be combined to shorten the time of tumor formation by two kinds of breast cancer cells, and improve the metastasis of Her2 negative MDA-MB 231 cells. Using matrigel does not show any effect of proliferation and apoptosis on Her2 positive and negative breast cancer cells.

To explore the relationship between paediatric early warning score (PEWS) and the occurrence of mechanical ventilation complications in children with acute respiratory distress syndrome (ARDS).
 Methods: A total of 110 children with ARDS diagnosed in First Affiliated Hospital of Hebei North University, who underwent mechanical ventilation, were selected. The baseline data, blood gas analysis index, laboratory test index, ventilator parameters, pediatric critical illness score (PCIS) and PEWS in the children were recorded. With reference to ventilatory treatment results, the children with ventilator-associated complications were included in the trial group (n=20), while the patients with good cohort status were included in the control group (n=40) according to the nested case-control study. Independent sample t-test and multivariate logistic regression analysis were used to analyze the factors affecting the occurrence of complications after ventilatory treatment.
 Results: There were statistically significant differences in multiple organ dysfunction syndrome (MODS), partial pressure of oxygen/fraction of inspired oxygen (PaO2/FiO2), partial pressure of carbon dioxide (PaCO2), serum creatinine (SCr), albumin (ALB), blood urea nitrogen (BUN), mechanical ventilation time, mean article pressure (MAP), tidal volume (VT), positive end-expiratory pressure (PEEP), PCIS, PEWS between the control group and the experimental group (all P<0.05). Multivariate logistic regression analysis showed that MODS, PaO2/FiO2, PaCO2, VT, PEEP and PEWS had influence on complications after mechanical ventilation in children with ARDS (all P<0.05).
 Conclusion: The MODS, PaO2/FiO2, PaCO2, VT, PEEP, and PEWS exert effects on complications after mechanical ventilation in children with ARDS. PEWS combined with other indicators can assess the risk of complications in children with ARDS after mechanical ventilation.
Case-Control Studies ; Child ; Humans ; Positive-Pressure Respiration ; Respiration, Artificial ; Respiratory Distress Syndrome, Adult ; Tidal Volume