母血-脐血及母乳中维生素E含量及其相关性的探讨

目的：考察胎盘、乳腺对维生素E的运转状况。方法：配对测定了12名健康孕产妇血中、母乳中及新生儿脐血中的维生素E浓度,比较其水平并进行相关性分析。结果：母血中维生素E浓度为16.23 mg/L,脐血和母乳分别为2.72 mg/L和9.12 mg/L,其维生素E水平高低依次为母血>母乳>脐血。母血—脐血间维生素E浓度的相关性分析为r=0.30,P>0.5,两者间无相关性;母血—母乳间维生素E浓度的分析提示：r=0.44,P<0.2,两者间存在弱相关性。结论：胎盘对维生素E的转运能力低下;而乳腺对维生素E具有较强的转运能力,围产期保持孕产妇良好的维生素E营养水平有利于提高母乳中维生素E含量,对改善新生儿维生素E营养状况有重要意义。     

A controlled study on the effect of injected water-miscible retinyl palmitate on plasma concentrations of retinol and retinol-binding protein in children with measles in northern Nigeria

Post-measles corneal ulceration resembling keratomalacia is frequently seen in young children in northern Nigeria. The concentration of retinol in plasma has been found to be depressed more by measles than by malnutrition. In order to determine whether this could be due to a specific influence of measles on the uptake, storage and release of retinol by the liver or its subsequent transport in the plasma, retinyl ester was administered parenterally to assess its effect on the concentration of circulating holo retinol-binding protein. A water-miscible preparation of retinyl palmitate was administered by intramuscular injection to well- and malnourished children with and without acute measles. In all cases, the concentration of both retinol and retinol-binding protein rose appreciably with 24 h of administration of the vitamin preparation. Thus the failure of post-measles corneal lesions to respond to orally or parenterally administered vitamin A would not appear to be due to the inability of such vitamin A to increase the level of circulating retinal in the plasma of children with measles.     

Reference values of cord blood transferrin, ceruloplasmin, alpha-1 antitrypsin, prealbumin, and alpha-2 macroglobulin concentrations in healthy term newborns

Acute phase proteins are sensitive markers of tissue necrosis and inflammatory process. These markers may be especially useful in the neonatal period, in which mortality and morbidity rates are high, because fetus and baby are subjected to numerous metabolic, genetic, physiologic and environmental injuries such as neonatal asphyxia and septicemia. The purpose of the present study was to establish normal cord blood levels of some acute phase proteins in healthy term neonates. Umbilical cord blood was obtained at the time of vaginal delivery in 60 newborn infants (30 girls, 30 boys). Specific protein concentrations were measured by nephelometric assay. Transferrin, ceruloplasmin, alpha-1 antitrypsin, prealbumin, and alpha-2 macroglobulin concentrations [arithmetic mean (+/- SD)] were found to be 199.7 (+/- 34.6) mg/dl, 14.6 (+/- 4.0) mg/dl, 160.2 (+/- 23.6) mg/dl, 11.9 (+/- 2.2) mg/dl, and 284.6 (+/- 44.4) mg/dl, respectively. Prealbumin levels for girls [12.9 (+/- 2.2)] were found to be significantly higher than those of boys [10.9 (+/- 1.8)] (p < 0.001), while there were no significant differences between the other proteins. We conclude that these results may be used as reference values for the diagnosis of pathological conditions in newborns.     

围生期补充维生素E对母乳维生素E浓度的影响

目的：探讨乳腺对维生素E（VE）的分泌能力。方法：将78例健康孕妇随机分为三组，围生期VE补充组口服两种剂量的VE，对照组为同期孕产妇。产后d3采集母乳，高效液相色谱法测定母乳VE浓度。结果：1．VE补充组妇女母乳VE浓度明显高于对照组（P＜0．01）；2．每天口服50mgVEW者较每天口服100mgVE的妇女相比，母乳VE水平无显著差异（P＞0．05）。结论：人乳腺具有较强的VE分泌能力，维持围生期孕妇良好的VE营养水平，对改善新生儿VE营养状况有积极意义。     

Selenium and vitamin E in cord blood from preterm and full term infants.

Selenium was determined in erythrocytes and serum, and vitamin E and beta-lipoprotein in serum from cord blood samples of 31 full term and 20 preterm infants. Venous samples from 21 mothers at birth and 15 normal adult women were also analyzed. No difference for either selenium or vitamin E was found between the preterm and full term infants. The selenium concentration in red blood cells was the same for newborn, mothers at birth, and normal adult women. The serum concentration of selenium was, however, significantly lower in the newborn, the mean level in the children being 64% of that in the mothers. The level in the mothers did not differ from that in non-pregnant women. The vitamin E concentration was found to correlate very well with the beta-lipoprotein concentration. This indicates that differences in the transport capacity account for the large difference in the serum tocopherol levels of mothers at birth and newborn.     

Circulating concentrations of chemokines in cord blood, neonates, and adults

Chemokines are critical for the movement of leukocytes. Chemotaxis is deficient in neonates, particularly those delivered prematurely, and this likely contributes to their increased vulnerability to sepsis. The concentrations of circulating chemokines in neonates have not been reported, nor is it known whether low chemokine concentrations contribute to their defective chemotaxis. We hypothesized that serum concentrations of chemokines 1) would be lower in preterm than term neonates, and 2) would be lower in preterm and term neonates than adults. Samples were obtained from preterm and term neonates with normal neutrophil and eosinophil counts, umbilical cord blood samples from pregnancies without clinical evidence of intra-amniotic infection, and healthy adult volunteers. The concentrations of epithelial neutrophil activating peptide-78, growth-related oncogene-alpha, eotaxin, RANTES (regulated upon activation, normal T cell expressed and secreted), and macrophage inflammatory protein-1 alpha were measured using specific ELISA. Serum concentrations from preterm infants were either similar to or higher than those measured in term neonates and adults. We conclude that the chemotactic defect observed in premature neonates is not the result of diminished circulating concentrations of any of the specific chemokines we measured.     

The effects of antenatal betamethasone administration on fetal heart rate and behaviour depend on gestational age

OBJECTIVE: We previously reported decreases in fetal heart rate (FHR) variability and body and breathing movements after maternal betamethasone administration. We now test the hypothesis that fetal responsiveness to betamethasone depends on the gestational age at which glucocorticoid therapy is started. DESIGN OF THE STUDY: 1-h recordings of FHR (n=350) and fetal movements (n=310) made during a 5-day period (days 0-4) were available for analysis. The recordings had been obtained from 63 pregnant women at high risk for preterm delivery who received betamethasone (two doses of 12 mg 24 h apart) between 26 and 34 weeks' gestational age (wGA). The response to betamethasone, i.e. the direction and magnitude of change in FHR and movement parameters compared with baseline (day 0), was studied in relation to gestational age at drug administration. RESULTS: Fetuses exposed to betamethasone at 29-34 wGA showed a decrease in FHR on day 1 (indicative of baroreceptor reflex), and reduced breathing activity and prolonged episodes of quiescence with a concomitant decrease in body movements on days 1 and 2. However, these changes were not observed if betamethasone administration occurred at 26-28 wGA. Betamethasone-induced reductions in FHR variability were similar in young and older fetuses. CONCLUSIONS: Age-related differential responsiveness to betamethasone was found for all studied fetal processes (body and breathing movements, FHR, and quiescence), except FHR variability. Our results suggest ontogenic changes in the mechanisms presumed to underlie these processes (glucocorticoid receptor (GR) maturation, cardiovascular and neuro-endocrine development).     

The effect of glucocorticosteroids on serum, liver, and lung vitamin A and retinyl ester concentrations.

Vitamin A and its active metabolites are important factors in promoting normal respiratory epithelial differentiation and growth. Glucocorticoids, often used to treat chronic lung diseases in infancy and childhood, are known to increase serum retinol concentrations. To determine the effects of exogenous steroids on serum retinol and retinol-binding protein concentrations (as well as on liver and lung total vitamin A, retinol, and retinyl ester concentrations), 32 weanling Sprague-Dawley rats were divided into four equal experimental groups. Eight animals were vitamin A sufficient and received 7 days of intraperitoneal dexamethasone at 0.5 mg/kg/day (group SD), 8 were vitamin A sufficient and received placebo (group SP), 8 were made vitamin A deficient and subsequently received dexamethasone (group DD), and 8 were vitamin A deficient and received placebo (group DP). Dexamethasone increased serum retinol concentrations in the SD group (2.27 +/- 0.20 mumol/L) when compared with control (SP, 1.64 +/- 0.46 mumol/L, p less than 0.001) as well as with pretreatment baseline values (1.21 +/- 0.23 mumol/L, p less than 0.001). Lung total vitamin A, retinol, and individual retinyl esters were depleted by 56 +/- 19% in the SD group, whereas liver values were depleted by 36 +/- 23%. In the vitamin A-sufficient groups the relative percentages of four major retinyl esters (palmitate, stearate, oleate, and linoleate) did not change in either tissue after steroid exposure. The vitamin A-deficient groups had no detectable tissue vitamin A, and dexamethasone did not increase serum retinol concentrations in the DD group. Serum retinol-binding protein concentrations were significantly higher in both steroid-treated groups when compared with control.(ABSTRACT TRUNCATED AT 250 WORDS)     

Dietary vitamin A intake and serum retinol concentrations of preschool children from different socio-economical levels in Izmir, Turkey

Aim: Vitamin A deficiency (VAD), especially in its subclinical form, is a world health problem in young children. The aim of this study was to determine the prevalence of VAD among preschool children in various socio‐economic groups in ?zmir, Turkey. Methods: One hundred and one children aged 24–59 months were selected for the study with cluster sampling method. A questionnaire was completed by the parents, and the dietary pattern was assessed by using a 3‐day dietary record method. Results: Mean serum retinol concentration of the children was 28.3 ± 10.2 μg/dL. Serum vitamin A concentration of two children (2%) was below 10 μg/dL (VAD), whereas 18 (18%) children had vitamin A concentrations between 10 and 20 μg/dL (subclinical deficiency). We did not find any relationship between mean serum retinol concentrations and the independent variables such as socio‐economical levels, age groups, birth weight and gestational age. However, there was a statistically significant positive correlation between serum retinol concentrations and weight‐for‐age and weight‐for‐height Z scores of the children (p < 0.05). Conclusion: Because one‐fifth of the children under 5 years have VAD in ?zmir, Turkey, nutrition education must be given to the families during well‐child care visits, and routine vitamin supplementation should be considered especially in children with malnutrition.     

The effect of maternal and infant factors on cord blood yield

Umbilical cord blood (CB) can be used as an alternative hematopoietic stem cell source for transplantation in hematological malignancy and blood disorders. The success of transplantation is highly related to the levels of total nucleated cell and CD34⁺ cell counts. The evaluation of optimal conditions can decrease the rate of graft rejection due to low cell count and increases the quality of CB units (CBUs) in the blood bank and the success rate of engraftment. To this end, we review the maternal and infant parameters affecting the quality and quantity of CBUs.     

The effect of betamethasone on neonatal neutrophil chemotaxis

Antenatal maternal glucocorticoid administration has been widely used to accelerate fetal lung maturation. Glucocorticoids have also been used postnatally in selected neonates as antiinflammatory agents. Numerous studies have shown that glucocorticoids inhibit multiple components of the immune system including neutrophil (PMN) function in children and adults. Since PMNs are of critical importance in host defense against bacterial infection, impaired PMN function in newborn infants is thought to be an important cause of their increased morbidity and mortality from bacterial infection. Further compromise of neonatal PMN function by exogenous factors such as glucocorticoids may therefore be of significant clinical importance. A micropore filter chemotactic assay was used to determine the in vitro effect of betamethasone on the random migration and directed migration (chemotaxis) of PMNs from 18 neonates. The addition of a concentration of betamethasone (0.01 microgram/ml) similar to that found in cord blood following a standard dose administered to the mother resulted in a significant (p less than 0.01) inhibition in mean neonatal PMN random migration (-15.0 +/- 0.8%) and chemotaxis (-23.5 +/- 3.0%). A similar inhibition was not found when PMNs from 14 adults were exposed to the same concentrations of betamethasone. Betamethasone administration to pregnant women or their newborn infants may further impair PMN motility and lead to an increased morbidity and mortality from bacterial infection in neonates.     

Nitrofen interferes with trophoblastic expression of retinol-binding protein and transthyretin during lung morphogenesis in the nitrofen-induced congenital diaphragmatic hernia model

Background  

Retinoids play a key role in lung development. Retinoid signaling pathway has been shown to be disrupted in the nitrofen model of congenital diaphragmatic hernia (CDH) but the exact mechanism is not clearly understood. Retinol-binding protein (RBP) and transthyretin (TTR) are transport proteins for delivery of retinol to the tissues via circulation. Previous studies have shown that pulmonary retinol levels are decreased during lung morphogenesis in the nitrofen CDH model. In human newborns with CDH, both retinol and RBP levels are decreased. It has been reported that maternal RBP does not cross the placenta and the fetus produces its own RBP by trophoblast. RBP and TTR synthesized in the fetus are essential for retinol transport to the developing organs including lung morphogenesis. We hypothesized that nitrofen interferes with the trophoblastic expression of RBP and TTR during lung morphogenesis and designed this study to examine the trophoblastic expression of RBP and TTR, and the total level of RBP and TTR in the lung in the nitrofen model of CDH.     

地塞米松和倍他米松对大鼠胎肺骨形态发生蛋白信号转导的影响

目的：比较产前地塞米松、倍他米松给药对大鼠胎肺骨形态发生蛋白(BMP)信号转导通路的影响。方法：15只孕鼠随机分成5组：对照组、地塞米松治疗1 d组、3 d组和倍他米松治疗1 d组及3 d组。孕鼠妊娠第19天剖腹取胎鼠肺组织,通过RT-PCR、免疫组化和Western blot技术检测各组胎肺BMP4、BMP受体2（BMPR-II）、Smad1、转录活化因子2（ATF-2）基因转录及蛋白表达水平。结果：(1) BMP4 mRNA、BMPR-II mRNA、Smad1 mRNA的表达在倍他米松3 d组、1 d组及地塞米松3 d组均高于对照组(P＜0.05)。(2)免疫组化结果显示：与对照组相比,BMP4、BMPR-II、pSmad1、ATF-2在地塞米松3 d组、倍他米松1 d组及3 d组表达量显著增加(P＜0.01)。(3) Western blot检测显示与对照组相比,BMP4、BMPR-II蛋白在地塞米松3 d组及倍他米松1 d组、3 d组中表达丰富(P＜0.01)。结论：倍他米松、地塞米松可能参与调控大鼠胎肺BMP信号转导过程。对BMP信号转导分子BMP4、BMPR-II、Smad1表达的上调可能是其促胎肺成熟的重要机制之一。［中国当代儿科杂志,2010,12(11)：891-896］     

Effects of antenatal betamethasone administration on fetal heart rate and behavior in twin pregnancy

The efficacy of antenatal corticosteroid therapy in reducing the incidence of respiratory distress syndrome in twin pregnancy is controversial. The corticosteroid levels achieved with the current regimen might not be high enough to reach both siblings. In singleton fetuses, maternal betamethasone administration causes transient reductions in fetal heart rate (FHR), FHR variability, and body and breathing movements. We performed a prospective study to determine whether there are similar effects of betamethasone on FHR and behavior in preterm twin pregnancy and whether the effects occur similarly in both twin members. Eighteen women who were carrying twins received optimal corticosteroid treatment. Simultaneous recordings were made on twins before (day 0), during (days 1-2), and after (days 3-4) corticosteroid therapy using separate cardiotocography and ultrasound machines. Betamethasone administration was associated with significant transient decreases in basal FHR (day 1), FHR variability (days 2 and 3), and body and breathing movements (day 2). The overall changes in twins were similar to those previously found in singleton pregnancies. There was a high degree of association of response to betamethasone among individual members of twin pairs. The betamethasone-induced effects were unrelated to fetal sex, positioning, chorionicity, and discordance in size, but there was an effect of gestation on FHR. We conclude that the current regimen of antenatal corticosteroids used in preterm twin pregnancies results in observable physiologic and behavioral changes in twin pairs irrespective of their composition. This provides evidence that the achieved betamethasone levels are high enough to reach the compartment of either twin member.     

Blood gases and pulmonary blood flow during resuscitation of very preterm lambs treated with antenatal betamethasone and/or Curosurf: effect of positive end-expiratory pressure

Resuscitation of very premature lambs with positive end-expiratory pressure (PEEP) improves oxygenation and reduces pulmonary blood flow (PBF). However, the effects of PEEP on blood gases and PBF have not been studied in preterm lambs receiving antenatal corticosteroids or postnatal surfactant. Lambs were delivered at 125 d of gestation (term 147 d) and ventilated with a tidal volume (VT) of 5 mL/kg using different levels of PEEP. Four treatment groups were studied: (1) antenatal betamethasone 24 and 36 h before delivery; (2) postnatal Curosurf; (3) antenatal betamethasone and postnatal Curosurf; (4) untreated controls. Blood gases, PBF, and ventilator parameters were recorded during the first 2 h. Increasing PEEP improved oxygenation even after antenatal betamethasone and postnatal Curosurf, without adverse effects on arterial PCO2. Increasing PEEP reduced PBF; this effect was not altered by betamethasone and/or Curosurf. In very preterm lambs ventilated with fixed VT, increasing levels of PEEP improved oxygenation after antenatal glucocorticoids and/or postnatal surfactant. These treatments do not alter the deleterious effects of high levels of PEEP on PBF.     

The effect of antenatal vitamin A and beta-carotene supplementation on gut integrity of infants of HIV-infected South African women

BACKGROUND: Vitamin A is important for protection against diarrhea, and supplements may benefit gut function of infants of HIV-infected mothers. METHODS: We studied 238 infants of HIV-infected South African women participating in a randomized, double-blind, placebo-controlled trial of vitamin A during pregnancy (1.5 mg retinyl palmitate and 30 mg beta-carotene daily) plus 60 mg retinyl palmitate at delivery. The placebo group received identical placebo capsules at the same times. When infants were 1, 6, and 14 weeks of age, lactulose/mannitol dual sugar intestinal permeability tests were performed. RESULTS: Maternal vitamin A supplementation did not significantly affect infant gut permeability in the group as a whole at any time. By multiple regression analysis, HIV infection of the infant by 14 weeks was significantly associated with increased gut permeability at both 6 and 14 weeks. After controlling for birth weight, gestational age, current weight, feeding mode and recent morbidity, there was a trend toward an interaction between vitamin A supplementation and HIV infection (P = 0.086) at 14 weeks. Vitamin A made no difference to gut permeability of uninfected infants (lactulose/mannitol ratio for vitamin A group: 0.11, 95% confidence interval [CI] 0.08, 0.15, n = 73 and for placebo group: 0.09, 95% CI 0.06, 0.12, n = 76), but largely prevented the increase in the ratio of HIV-infected infants (vitamin A group: 0.17, 95% CI 0.13, 0.23, n = 23; placebo group: 0.50, 95% CI 0.37, 0.68, n = 20). The effects on the lactulose/mannitol ratio were related to changes in lactulose, not mannitol, excretion. Vitamin A supplementation was associated with significantly lower lactulose excretion at 1 and 14 weeks, suggesting the major effect of vitamin A was on maintaining the integrity of gut tight junctions. CONCLUSIONS: Vitamin A supplementation of HIV-infected pregnant women may prevent the deterioration in gut integrity in the subgroup of their infants who themselves become infected. Improving vitamin A status of HIV-infected infants may decrease their gastrointestinal morbidity.     

影响脐血造血干细胞移植供体品质的相关因素分析

目的探讨影响脐血产品质量的供体相关因素,建立选择脐血移植供体的最优化标准。方法脐血采集自2000年6月至2006年12月在广州市妇婴医院足月分娩的产妇,分析脐血的总有核细胞数(TNC)、CD+34细胞数和总集落数(CFUs)与脐血供体相关因素(新生儿性别和体重、产妇年龄、孕周、分娩方式、胎粪污染、采集体积)的关系。结果TNC与CD+34细胞数、总集落数三者两两间均有相关性,TNC与CD3+4细胞数相关性最好。TNC与新生儿体重、采集体积、产妇年龄有相关关系;阴道分娩、孕周(40周和女性新生儿组TNC数分别高于剖宫产、36~40孕周和男性组。CD+34细胞数和总集落数与采集体积有相关关系,与新生儿体重、产妇年龄无相关关系。CD3+4细胞数受分娩方式的影响(阴道分娩高于剖宫产),不同新生儿性别及孕周间差异无统计学意义。阴道分娩和男性组总集落数分别高于剖宫产和女性组,两组孕周间总集落数差异无统计学意义。采集体积与新生儿体重有关,与产妇年龄、分娩方式、新生儿性别、孕周无关。胎粪污染时TNC较高,CD+34细胞数、总集落数均无影响。结论孕周和新生儿体重指标增加到标准化的脐血采集前供体选择标准,将有利于获得更好的脐血采集质量、提高库存脐血的有效性。     

Reverse triiodothyronine, thyroid hormone, and thyrotrophin concentrations in placental cord blood.

Reverse triiodothyronine (rT3), triiodothyronine (T3), thyroxine (T4), thyroxine binding globulin (TBG), and thyrotrophin (TSH) were measured in sera from placental cord blood in an unselected series of 272 deliveries. In this series the concentrations of rT3 (mean 3.33 nmol/l, 95% confidence limits 1.6--7.0 nmol/l), were log normally distributed and did not overlap the adult normal range (0.11--0.44 nmol/l). There were no correlations between the cord blood concentrations of rT3, T3, T4, and TSH. The cord serum rT3 concentration was not influenced by maturity, birth-weight, or neonatal risk factors, whereas these factors did affect the concentrations of T3, T4, AND TBG. There is no arteriovenous rT3 concentration difference across the placenta, therefore the cord rT3 reflects the systemic rT3 concentration in the baby at birth. As rT3 in the neonate largely, if not entirely, derives from thyroxine from the fetal thyroid, measurement of the cord rT3 concentration may be a good immediate screening test for neonatal hypothyroidism.     

The effect of dexamethasone on neutrophil adherence in umbilical cord blood

Neutrophil adherence immediately after delivery and after incubation with saline and with two different concentrations of dexamethasone was studied in umbilical cord blood of 27 full-term neonates. Dexamethasone was not found to have any significant effect on neutrophil adherence in vitro.