With the development of medical technology，more and more extremely preterm infants（EPIs）with gestational age less than 28 weeks can be treated.However，due to the immature development of tissues and organs，the prognosis of EPIs survivors after active treatment is still not optimistic.In order to fundamentally reduce the morbidity and mortality of EPIs，the traditional treatment mode should be converted.Artificial womb（AW）simulates the maternal environment in utero through the extra-corporeal life support to maintain the protective development of fetal vital organs，which provides a new hope for improving the prognosis of EPIs.This article reviews the advantages and key technologies of AW in the protective development of fetal lung.

Objective:To explore the effects of the γ-aminobutyric acid(GABA) neurons and melanin-concentrating hormone (MCH) neurons of the nucleus accumbens (NAc)-lateral hypothalamic area (LHA) neural pathway on the rewarding feeding(palatable food sweat condensed milk) in the obesity rats.Methods:Total 142 male Wistar rats of SPF grade were divided into normal diet (ND) group ( n=68) and high-fat diet induced obesity (DIO) group ( n=74) according to the principle of body mass matching. The rats in the two groups were given normal diet and high-fat diet for 8 weeks. Eight weeks later, 6 DIO rats were randomly selected to observe the nerve projection from GABA neurons in NAc to MCH neurons in LHA by fluorogold retrograde tracing combined fluorescence immunohistochemistry. And the expressions of c-Fos and MCH in LHA after ingestion of sweet condensed milk(rewarding feeding) were observed by fluorescence immunohistochemistry (6 rats in each group). GABA receptor agonist Musimol or GABA receptor antagonist Bicuculine was microinjected into the nucleus of LHA to observe the effect of GABA on rewarding food intake in ND and DIO rats ( n=8 in each group), and the changes of rewarding food intake after blocking MCH signal ( n=8 in each group). SPSS 17.0 was used for statistical analysis, two-way ANOVA and post hoc Bonferroni test were used for comparison among multiple groups, and t-test was used for comparison between two groups. Results:After 8 weeks of high-fat diet modeling, the intake of delicious food in DIO rats was significantly higher than that in ND rats((12.52±2.29) mL, (7.45±1.23) mL, t=4.778, P<0.01) after satiety.The results of fluorogold retrograde tracing combined with fluorescence immunohistochemistry showed that GABA neurons in NAc projected nerve fibers to neurons in LHA, and GABA A receptors in some neurons in LHA coexisted with MCH.The results of NAc-LHA pathway on delicious food intake showed that the interaction between rat group and drug intervention was significant( F=9.869, P<0.01). Simple effect analysis showed that the intake of delicious food after microinjection of Musimol into LHA nucleus of ND rats was significantly lower than that of microinjection normal saline ((4.25±1.38) mL, (7.29±1.49) mL, P<0.01), while the intake of delicious food after injection of Bicuculine was significantly higher than that of microinjection normal saline((10.72±2.11) mL, (7.29±1.49) mL, P<0.05). The intake of delicious food after microinjection of Musimol into LHA nucleus in DIO group was significantly lower than that of microinjection normal saline((3.51±1.77)mL, (13.68±2.95) mL, P<0.01), but there was no significant difference between microinjection Bicuculine and microinjection normal saline ((14.83±3.44) mL, (13.68±2.95) mL, P>0.05). The results of blocking MCH signal on delicious food intake showed that the interaction effect between SNAP-94847 and Bicuculine intervention was not significant ( F=1.468, P>0.05). The main effect of SNAP-94847 intervention was significant ( F=15.880, P<0.01)and the main effect of Bicuculine intervention was significant ( F=6.930, P<0.05). After intracerebroventricular injection of MCH receptor blocker SNAP-94847, the delicious food intake of ND rats was significantly less than that of injection normal saline((4.78±1.72) mL, (7.63±2.77) mL, P<0.05), and it was not affected by pre injection of Bicuculine in LHA ((6.24±2.18) mL, (4.78±1.72) mL, P>0.05). In the DIO rats, the interaction effect between SNAP-94847 and Bicuculine intervention was not significant( F=0.006, P>0.05). The main effect of SNAP-94847 intervention was significant ( F=18.46, P<0.01) and the main effect of Bicuculine intervention was not significant ( F=2.059, P>0.05). After intracerebroventricular injection of MCH receptor blocker SNAP-94847, the delicious food intake of DIO rats was significantly lower than that of injection normal saline((6.89±2.11) mL, (12.19±4.36) mL, P<0.05), and it was not affected by pre injection of Bicuculine in LHA ((8.72±2.26) mL, (6.89±2.11) mL, P>0.05). Conclusion:GABAergic signal in NAc can regulate the expression of MCH in neurons of LHA. In the DIO rats, the sensitivity of MCH neurons in LHA to satiety signal decreases and the hedonic feeding increases.

OBJECTIVETo observe the effect of intrapartum and postpartum factors on abnormal neurological findings in the extremely preterm infants.

METHODClinical data of 62 premature infants (33 of male, 29 of female) were retrospectively analyzed. None of the premature infants had birth defect; their gestational ages were all less than 28 weeks (23(+ 6)-27(+ 6) weeks). They were hospitalized within 12 hours after birth in the neonatal intensive care unit (NICU) of BAYI Children's Hospital from November 2010 to June 2013. The blood gas, birth condition, complications, the mechanical ventilation and the ultrasonic encephalography were recorded. The 62 cases were divided into 2 groups, alive group and died group. Meanwhile, all cases of survial were divided into brain injuries group and normal brain group. Data were analyzed with t-test, Chi square test and Spearman correlation analysis.

RESULTFifty-six cases were alive, and 6 cases died (3 were during the treatment and 3 were after parents gave up). The average birth weight of brain injuries group was (954 ± 182) g; and that of the normal brain group was (1 071 ± 136) g. There were significant differences between the two groups in gender (χ(2) = 4.314, P = 0.038), gestational age (χ(2) = 11.622, P = 0.001), birth weight (t = 2.728, P = 0.009), which had significant correlation with neurological outcomes. The Spearman correlative coefficients were -0.278, 0.456 and 0.364 respectively. And P values were 0.038, 0.000 and 0.006. The rates of multiple pregnancy, lung hemorrhage and surgical operation in brain injuries group were 45%(9/20), 55%(11/20), 40%(8/20), which were significantly higher than those in normal brain group, 3%(1/36), 17%(6/36), 11%(4/36)(χ(2) = 12.800, 8.936, 4.773, P all < 0.05). These three factors were the high risk factors for adverse neurological outcomes, the odds ratios were 28.64, 6.11 and 5.33 respectively. There was no significant difference in delivery mode, amniotic fluid, maternal infection, asphyxia, necrotizing enterocolitis, patent ductus arteriosus, sepsis, mechanical ventilation, inhaled nitric oxide therapy, blood glucose, blood gas analysis, doses of dopamine between brain injuries group and normal brain group. The birth weight in alive group was (1 029 ± 163) g, which was significantly higher than those in died group (870 ± 144)g (r=0.29, P=0.022). There was no significant difference in other factors between alive group and died group(P all>0.05).

CONCLUSIONGender, gestational age and birth weight may have relation with the neurological outcomes of extremely preterm infants. Multiple pregnancy, pulmonary hemorrhage and surgical operation are the risk factors of brain injuries. Birth weight is related to the survival of extremely preterm infants.

Birth Weight ; Brain Injuries ; physiopathology ; Female ; Gestational Age ; Humans ; Infant, Extremely Premature ; Infant, Newborn ; Infant, Premature, Diseases ; Lung ; pathology ; Male ; Pregnancy ; Pregnancy, Multiple ; Retrospective Studies ; Risk Factors

Objective To discuss the feasibility of preoperative diet by measuring gastric emptying time of carbohydrate and protein nutrient solutions in healthy volunteers.Methods A total of 20 healthy volunteers were collected from August 2013 to May 2014.On the morning of the trial,baseline gastric residual volume of each volunteer was measured with magnetic resonance imaging at 8 a.m.,then each of the 20 healthy volunteers took 12.5％ carbohydrate solution 400 ml (containing 40 g of maltodextrin and 10 g of sucrose) or 12.5％ whey protein solution (containing 50 g whey protein) in 5 minutes.Magnetic resonance imaging was conducted to measure the gastric residual volume every 25 minutes.The volunteers were shifted to the other nutrient solution after a 1-week interval.The gastric emptying time of both nutrient solutions was calculated to generate the curves illustrating the process of gastric emptying.Results The baseline gastric residual volume of the volunteers was (14.90 ± 9.39) ml.The total gastric emptying time of carbohydrate solution was (104.90 ± 27.98) min (95 ％ CI 98.64-111.16 min),while that of whey protein solution was (199.6 ± 34.17) min (95％ CI 184.47-214.73 min).There was a significant difference between these two types of nutrient solution in terms of gastric emptying time (P ＜ 0.000 1).Conclusions The induction of anesthesia could be performed 2 hours after carbohydrate administration,and at least 4 hours after whey protein administration.