Single course of antenatal steroids did not alter cortisol in preterm infants up to 18 months

Aims: To determine whether a single course of antenatal dexamethasone alters resting cortisol at 3, 8 and 18 months corrected age in preterm infants. Methods: Preterm infants born ≤32 weeks gestational age were recruited during 2001–2004 from a single neonatal intensive care unit. Resting salivary cortisol was collected at least once at 3, 8 and 18 months corrected age in a longitudinal cohort. A mixed‐effects repeated measures analysis was used to accommodate cases with less than complete follow‐up. Results: One hundred and thirty three infants were included in the present study, contributing 266 cortisol samples. Of these, 107 infants had been exposed to a single course of antenatal dexamethasone and 26 not exposed to antenatal steroids. There was no significant main effect of antenatal steroids on resting cortisol at any age. This result was not altered after adjusting for gestational age at birth, neonatal cumulative pain, morphine exposure, mechanical ventilation days and post‐natal steroid exposure. Conclusions: No effect of a single course of dexamethasone on resting salivary cortisol, an indicator of hypothalamic‐pituitary‐adrenal axis function, was found in infancy up to 18 months corrected age in infants born very preterm.     

氧化应激在儿童过敏性紫癜发病中的作用

过敏性紫癜是儿童时期最常见的系统性血管炎,其确切病因及发病机制尚不明确.已有研究表明,氧化应激在风湿免疫性疾病及肾小球疾病发病及病理损伤过程中起重要作用,但氧化应激在儿童过敏性紫癜发病及病理损伤过程中的作用国内外关注较少.该文就机体氧化应激的产生、过敏性紫癜发病及病理损伤过程中活性氧的来源、氧化系统及抗氧化系统改变,以及氧化应激与IgA1异常糖基化之间可能存在的关系等进行综述.     

Quality of child–parent attachment moderates the impact of antenatal stress on child fearfulness

Background: Animal studies have shown that prenatal stress has persisting effects on several aspects of offspring development; more recent studies show that this effect may be eliminated by positive postnatal rearing. Human studies of prenatal anxiety/stress are now also beginning to document links between antenatal stress/anxiety and behavioural and cognitive development of the child; however, there is no human evidence as to whether the early caregiving environment moderates the effect of antenatal anxiety/stress on child outcomes. Methods: Antenatal and postnatal measures of stress were collected on 123 women who were recruited from an antenatal clinic. Laboratory‐based assessment of the children’s cognitive development and fearfulness were assessed when the children were aged 17 months. In addition, child–parent attachment quality was assessed using the Strange Situation. Results: Attachment classification moderated the link between antenatal stress and observed fearfulness. The effect of antenatal stress on fearfulness was most accentuated in children with an Insecure/Resistant attachment classification; the significant antenatal stress × attachment classification interaction held after controlling for postnatal stress and obstetric, social and demographic factors. Attachment did not moderate the effects of antenatal anxiety on cognitive development. Discussion: These findings provide the first human evidence that postnatal parenting may moderate the adverse effects of antenatal stress. These results raise developmental questions about the timing and effect of interventions to reduce the adverse effects of antenatal stress exposure.     

Oxidative stress biomarkers in the perinatal period: Diagnostic and prognostic value

Perinatal oxidative stress (OS) is involved in the physiopathology of many pregnancy-related disorders and is largely responsible for cellular, tissue and organ damage that occur in the perinatal period especially in preterm infants, leading to the so-called “free-radicals related diseases of the newborn”. Reliable biomarkers of lipid, protein, DNA oxidation and antioxidant power in the perinatal period have been demonstrated to show specificity for the disease, to have prognostic power or to correlate with disease activity. Yet potential clinical applications of oxidative stress biomarkers in neonatology are still under study. Overcoming the technical and economic difficulties that preclude the use of OS biomarkers in the clinical practice is a challenge that needs to be overcome to identify high-risk subjects and to predict their short- and long-term outcome. Cord blood, urine and saliva represent valid and ethically acceptable biological samples for investigations in the perinatal period.     

Oxygen in the neonatal period: Oxidative stress,oxygen load and epigenetic changes

Preterm infants frequently require positive pressure ventilation and oxygen supplementation in the first minutes after birth. It has been shown that the amount of oxygen provided during stabilization, the oxygen load, if excessive may cause hyperoxia, and oxidative damage to DNA. Epidemiologic studies have associated supplementation with pure oxygen in the first minutes after birth with childhood cancer. Recent studies have shown that the amount of oxygen supplemented to preterm infants after birth modifies the epigenome. Of note, the degree of DNA hyper-or hypomethylation correlates with the oxygen load provided upon stabilization. If these epigenetic modifications would persist, oxygen supplied in the first minutes after birth could have long term consequences. Further studies with a robust power calculation and long-term follow up are needed to bear out the long-term consequences of oxygen supplementation during postnatal stabilization of preterm infants.     

脓毒症线粒体损伤的氧化应激机制及靶向抗氧化剂的研究

线粒体是细胞氧化的重要部位,在脓毒症时氧化应激作为炎症反应最终的结果,可引起线粒体的改变,从而可能导致器官功能损伤。在正常情况下,抗氧化防御系统通过相互作用可以对抗氧化应激,预防对线粒体的损伤。氧化应激在器官功能损伤的过程中起着重要的作用,目前已有研究发现针对线粒体的抗氧化剂靶向治疗可能是脓毒症引起的多器官功能衰竭治疗的一种新策略。该文就氧化应激在脓毒症线粒体损伤机制及靶向抗氧化剂的研究作一综述。     

出院后喂养方式对早产低出生体重儿生后3个月生长指标增长率的影响

目的：通过研究早产儿出院后配方奶（PDF）与母乳（BM）、足月儿配方奶（TF）等不同喂养方式对早产低出生体重儿（LBWI）出院至生后3个月时的体重、身长、头围等生长指标增长率的影响,为早产LBWI出院后喂养方式的选择提供参考。方法：广东省广州市、佛山市10家医院新生儿科出院的407例早产LBWI按照出院后喂养方式的不同,分为PDF组（n=258）、BM组（n=58）、TF组（n=91）,观察各组在生后3个月时的体重、身长、头围等生长指标值,并计算和比较各生长指标较出生时的增长率。结果：PDF组在生后3个月时的体重、身长和头围分别大于BM组和TF组（P＜0.05）;体重和身长增长率分别大于BM组和TF组（P＜0.05）。结论：出院后予PDF喂养能使早产LBWI在生后3个月时的体重、身长增长率较BM、TF喂养者更大,从而具有较大的体重、身长值,但远期效果有待进一步研究。