Adrenocortical steroids in small-for-gestational-age term infants during the early neonatal period

We evaluated adrenocortical steroid concentrations at birth and during postnatal adaptation (2 h until 7 days) in 10 vaginally delivered term small-for-gestational-age (SGA) infants and 12 term appropriate-for-gestational age infants. Plasma aldosterone, 11-deoxycorticosterone, corticosterone, progesterone, 17-hydroxyprogesterone, 11-deoxycortisol, cortisol, and cortisone were longitudinally measured by specific RIA after Sephadex LH-20 chromatography. Mean aldosterone was significantly higher in SGA than in appropriate-for-gestational-age infants (2 h to 7 days; p less than 0.001). In SGA infants, cortisone and cortisol levels were significantly lower in umbilical artery (p less than 0.05), and all glucocorticoid levels were significantly lower 12 h after birth (p less than 0.05). Thereafter (24 h to 7 days), only 11-deoxycortisol levels remained significantly lower in SGA; corticosterone and cortisol levels were even higher (p less than 0.05) in SGA 24 h after birth. The data suggest that SGA infants maintain high aldosterone levels throughout the 1st wk of life. Low cortisol and cortisone levels in umbilical artery as well as low glucocorticoid levels at 2 h and/or 12 h compared to term appropriate-for-gestational-age infants may reflect either a less stressful postnatal adaptation or, more likely, a reduced adrenocortical synthesis in term SGA infants.     

Spontaneous labor increases nitric oxide synthesis during the early neonatal period

BACKGROUND: This paper aimed to assess the influence of spontaneous labor upon endogenous nitric oxide (NO) and endothelin 1 (ET-1) during transition to extrauterine life. METHODS: The serum levels of NO metabolites (the sum of nitrites and nitrates (NOx)) and the plasma level of ET-1 were determined in 53 healthy full-term infants (spontaneous labor group; n=40, cesarean delivery group; n=13). In both groups, blood samples were obtained from a cord vein at birth and from a peripheral vein at 5 days of age. RESULTS: The differences in serum NOx concentrations between the spontaneous labor group and the elective cesarean group were not significant at birth. By the age of 5 days, serum NOx concentrations had risen significantly in the spontaneous labor group to become significantly higher in the elective cesarean group. CONCLUSION: It is speculated that spontaneous labor might enhance endogenous NO synthesis at 5 days of age.     

小于胎龄儿生后早期肾脏功能初探

目的对小于胎龄儿(SGA)生后早期肾脏功能进行回顾性对照研究,以探寻SGA儿早期肾功能损害的诊断方法。方法选择早产SGA儿40例、足月SGA儿33例作为研究组,并以早产适于胎龄儿(AGA)80例、足月儿AGA 33例作为对照组。比较各组入院48 h内血清尿素氮(BUN)、血清肌酐(SCr)、估算肾小球滤过率(eGFR)、血压、单位体重尿量以及蛋白尿的发生情况。结果早产儿SGA组的BUN低于AGA组(P0.05),两组间SCr、eGFR、血压的差异无统计学意义(P0.05)。与足月儿AGA组比较,SGA组的SCr较高、eGFR较低,差异均有统计学意义(P0.05);两组间BUN、血压的差异无统计学意义(P0.05)。早产儿或足月儿AGA与SGA之间单位体重尿量的差异无统计学意义(P0.05)。早产儿AGA与SGA之间蛋白尿发生率的差异无统计学意义(P0.05),足月儿AGA与SGA组均无蛋白尿发生。结论 SCr、eGFR对评估SGA早期肾脏损害较为敏感。足月儿SGA较AGA肾脏功能减低。     

一氧化氮对脑室周围白质软化早产儿神经发育的影响

目的探讨一氧化氮(NO)在合并脑室周围白质软化(PVL)的早产儿神经发育中的作用。方法采用随机、对照实验,对合并PVL的106例早产儿,在出生后24h内随机分成吸入NO组(第1天10×10-6,以后改为5×10-6继续用6d)和对照组(吸入氧气7d),在纠正胎龄18个月时采用贝利发育量表评估其神经发育。结果吸入NO组贝利评分明显高于对照组(P<0.05),贝利评分低于70分的发生率明显低于对照组(P<0.05)。结论合并脑室周围白质软化早产儿采用吸入NO治疗,有利于促进其神经发育。     

L-精氨酸对胎儿宫内发育迟缓患者母血及脐血一氧化氮水平的影响(英文)

目的　有研究表明一氧化氮 (NO)减少可能在胎儿宫内发育迟缓 (IUGR)的发生发展中起重要作用 ,该文探讨L 精氨酸 (L Arg)对IUGR孕妇外周血及新生儿脐血中NO水平的影响。 方法　选择IUGR孕妇 6 6例 ,其中常规治疗组 36例 ,予以常规治疗 ;L Arg组 30例 ,在常规治疗的基础上加用L Arg治疗。选择正常初产妇30例作为正常对照组。监测治疗前后孕妇血清NO水平变化及脐静脉血清NO水平。结果　治疗后 ,L Arg组孕妇血清NO水平显著高于常规治疗组 (5 8.4 2± 2 3.1 2 μmol/Lvs4 3.4 9± 2 0 .2 7μmol/L) (P <0 .0 1 ) ;L Arg组胎儿脐静脉血清NO水平显著高于常规治疗组 (2 5 .2 3± 1 2 .0 5 μmol/Lvs1 6 .95± 1 1 .1 9μmol/L) (P <0 .0 1 )。结论　L Arg能显著提高IUGR孕妇外周血及脐血中NO水平     

Endothelium-derived relaxing and contracting factors during the early neonatal period

Abstract The interaction and relative potency of nitric oxide, an endothelium-derived relaxing factor, and endothelin-1, an endothelium-derived contracting factor, may be important in the transition from fetal to extrauterine life. The change in level of nitric oxide during the early neonatal period has not been measured. Accordingly, the serum levels of nitric oxide metabolites (the sum of nitrite and nitrate) and plasma endothelin-1 were determined in 20 healthy neonates at birth, at 12 and 24 h postnatally, and at the age of 5 d. The lowest serum concentration of nitric oxide metabolites was observed at birth (26.2 ± 9.1 µmol 1^-1, mean ± SD) and increased with age, whereas the highest plasma concentration of endothelin-1 was observed at birth (14.0 ± 6.7 pg ml^-1) and decreased with age. These changes suggest that nitric oxide and endothelin-1 play roles in the circulatory adaptation of the neonate to extrauterine life.     

极低出生体重儿院内生长发育状态多中心回顾性研究

目的 研究极低出生体重儿(VLBWI)住院期间的生长发育状态及相关影响因素.方法 回顾性调查广东省珠江三角洲地区9个城市的9家医院新生儿科于2010年7月1日至2011年6月30日,出院的VLBWI的住院资料,根据出生体重,分为宫内生长发育迟缓[IUGR组(n=63)]和非IUGR组(n=120),非IUGR组又根据其出院时是否发展为宫外生长发育迟缓(EUGR)而分为EUGR组(n=71)和非EUGR组(n=49),对比性研究IUGR组和非IUGR组住院期间的日均体重增长速度和出院时EUGR的发生率,及各组的院内营养摄入情况、生长速度和相关疾病因素的影响.结果 (1)出生时IUGR和出院时EUGR的发生率分别为34.4％和72.1％,IUGR组的日均体重增长速度高于非IUGR组[(12.5 ±2.7) g/kg vs (11.3±2.5) g/kg,t=3.068,P=0.002],但IUGR组发展为EUGR的比例明显高于非IUGR组(96.8％vs 59.2％,x2=29.145,P =0.000).(2) IUGR组在生后1、2、4周、达完全经口喂养前和住院期间的日均热卡摄入[62(51,69) kcal/kg vs 56(45,64) kcal/kg、83 (71,94) kcal/kg vs 76(66,88) kcal/kg、107(94,120) kcal/kg vs 95(85,108) kcal/kg; 103(96,110) kcal/kg vs 97(89,106) kcal/kg、121(111,131) kcal/kg vs 111 (101,119) kcal/kg](1 kcal=4.1840 kJ).蛋白质摄入[1.7(1.3,2.0) g/kgvs 1.6(1.2,1.8) g/kg、2.6(2.1,2.9) g/kg vs 2.3(1.9,2.7) g/kg、3.3(2.7,3.6) g/kgvs2.7(2.4,3.2) g/kg、3.1(2.6,3.4) g/kgvs 2.8(2.4,3.3) g/kg、3.4(3.1,3.8) g/kgvs3.1(2.8,3.5) g/kg]均高于非IUGR组(P＜0.05).热卡累积损失[407(360,483)kcal/kg vs 448(393,527) kcal/kg、534(369,689) kcal/kg vs 612(453,758) kcal/kg、367(12,724) kcal/kg vs 718(330,996) kcal/kg、381 (231,609) kcal/kg vs 656(394,959) kcal/kg、0(0,350) kcal/kg vs 387(85,826) kcal/kg].蛋白质累积损失[12.3(10.2,15.5) g/kg vs 13.7(11.7,16.4) g/kg、12.8(7.8,19.4) g/kg vs 17.5(11.9,22.7) g/kg、6.2(0,22.6)g/kg vs 21.7 (7.3,30.3)g/kg、6.6(1.8,23.0)g/kg vs22.1(7.2,32.5) g/kg、1.9(0,16.7)g/kg vs 20.1 (0,32.6) g/kg]则相应低于非IUGR组(P＜0.05).(3)非EUGR组的日均体重增长速度高于EUGR组[(12.7±2.2)g/kgvs (10.3±2.1) g/kg,t=6.137,P=0.000];开始喂养时间[1.0(1.0,3.0)dvs 3.0(2.0,5.0)d]、禁食时间[3.0(1.0,5.5)d vs 4.0(3.0,9.0)d]、最低体重出现时间[4.0(3.0,6.0) dvs6.0(5.0,8.0)d]、恢复出生体重时间[11.0(9.0,14.0) dvs 13.0(10.0,17.0)d]均短于非EUGR组(P＜0.05);需机械通气治疗者比例(70.4％ vs 51.0％)低于非EUGR组(P＜0.05).(4)非EUGR组在生后2周的日均热卡摄入[81(70,91) kcal/kg vs 73(63,85) kcal/kg]和生后1周[1.6(1.4,2.0) g/kgvs 1.4(1.1,1.8) g/kg]、生后2周[2.4(2.1,2.7) g/kg vs 2.1(1.8,2.6) g/kg]、达完全经口喂养前[3.0(2.5,3.4) g/kg vs 2.7(2.3,3.1)g/kg]的蛋白质摄入高于EUGR组(P＜0.05),而生后2周的热卡累积损失[546(403,707) kcal/kg vs 655(494,795) kcal/kg]和生后1周[13.1(10.9,15.1) g/kg vs 14.8(12.0,16.6) g/kg]、生后2周[15.5(11.4,19.8) g/kg vs 20.0(12.1,24.0) g/kg]的蛋白质累积损失低于EUGR组(P＜0.05),在其余各阶段的日均热卡、蛋白质摄入量及累积损失量比较差异无统计学意义(P＞0.05).(5)IUGR组新生儿呼吸窘迫综合征发生率低于非IUGR组(34.9％ vs 56.7％),孕母妊娠期高血压疾病、胎儿窘迫发生率则高于非IUGR组(54.0％ vs 24.2％、25.4％ vs 7.5％),新生儿窒息、坏死性小肠结肠炎、败血症、支气管肺发育不良、缺氧缺血性脑病/颅内出血、胆汁淤积症和孕母胎膜早破、胎盘早剥/前置胎盘的发生率组间比较差异无统计学意义(P＞0.05).(6) EUGR组新生儿败血症发生率(11.3％ vs0％)和孕母妊娠期高血压疾病发生率(31.0％ vs 14.3％)高于非EUGR组(P＜0.05),但新生儿呼吸窘迫综合征、窒息、坏死性小肠结肠炎、支气管肺发育不良、缺氧缺血性脑病/颅内出血、胆汁淤积症和孕母胎膜早破、胎盘早剥/前置胎盘、胎儿宫内窘迫的发生率组间比较差异无统计学意义(P＞0.05).结论 IUGR早产儿发生EUGR的风险远高于非IUGR者;导致非IUGR早产儿发生EUGR的危险因素包括:日均体重增长速度、最低体重出现时间、恢复出生体重时间、开始喂养时间、禁食时间、机械通气治疗、营养摄入与累积损失、疾病等因素.     

Airway nitric oxide in infants with acute wheezy bronchitis

Concentrations of nitric oxide (NO) in exhaled air are increased in children and adults with asthma, and NO measurements are used as a non-invasive marker to monitor airway inflammation in these patients. To define the role of NO in infants with acute wheezy bronchitis, we measured nasal and end-tidal NO concentrations in 17 infants with acute virus-associated wheezy bronchitis, in 22 term infants without respiratory disease, and in nine premature infants. Nasal NO measurements were performed with an olive placed in the infant's nose; end-tidal NO concentrations were assessed during tidal breathing through a snugly fitting face mask. Both end-tidal NO concentrations and nasal NO concentrations were reduced in infants with acute wheezy bronchitis. There were no differences in NO concentrations between term infants and premature infants. Measurements by both techniques were highly reproducible, as assessed by repeated measurements three times daily on three consecutive days in eight premature infants. Reduced airway NO concentrations in infants with virus-associated acute wheezy bronchitis are in contrast to findings in adults where both upper and lower airway NO levels are increased in patients with asthma. Whether this reflects a different inflammatory reaction to upper airway infections in acutely wheezy infants or pathophysiologic differences in airway response remains to be determined.     

高危早产儿宫外生长迟缓的危险因素分析

目的探讨我院高危早产儿宫外生长迟缓(EUGR)的发生率和相关危险因素。方法回顾性调查2011年1月至2012年12月我院收治并存活至出院的高危早产儿(出生体重<1500 g或出生胎龄<33周)及其母亲的住院资料。根据"中国15城市不同胎龄新生儿出生体重值",出生体重位于同胎龄儿第10百分位以下定义为宫内生长受限(IUGR)早产儿,出院体重位于校正胎龄儿第10百分位以下定义为EUGR早产儿。并根据此表计算出生体重的Z值(Z1)、出院体重的Z值(Z2),比较Z值的变化。比较EUGR组及非EUGR组围产期及出生后危险因素的差异,根据Logistic回归分析得出EUGR的高危因素。结果共194例早产儿纳入本研究,IUGR发生率为29.9%(58/194),EUGR发生率为51.5%(100/194)。出院时Z2(-1.27±0.83)较出生时Z1(-0.83±0.78)显著下降(P<0.001)。IUGR早产儿发生EUGR比例明显高于非IUGR早产儿(93.1%比33.8%,P<0.001),但Z值下降幅度却小于非IUGR早产儿[(-0.31±0.58)比(-0.50±0.53),P=0.039]。根据Logistic回归分析,高危早产儿发生EUGR的高危因素为出生体重<1500 g、IUGR、住院天数超过6周及CRP升高。结论 EUGR是极低出生体重儿及小胎龄早产儿的重要并发症,针对相关的围产因素进行积极的营养管理,有可能减少其发生率,改善早产儿的结局。     

Fractional exhaled nitric oxide in infants during cow's milk food challenge

Cow's milk allergy (CMA) is the most common food allergy in early childhood. The golden standard for the diagnosis of CMA is a food challenge after a period of elimination. Increased levels of fractional exhaled nitric oxide (FE_NO) have been shown after bronchial allergen provocation. We evaluated whether FE_NO may also be a predictor of a positive reaction during cow's milk challenge in infants. Forty-four infants [mean age (range): 4.2 (3.7–4.6) months] suspected of CMA underwent an open food challenge with cow's milk formula administered in ascending quantities, starting with 2 ml and then 6, 20, 60 and 200 ml until a clinical reaction occurred. Off-line FE_NO samples were obtained during tidal breathing by means of a facemask covering infants' nose and mouth. FE_NO was measured twice before the challenge (baseline), immediately before each new dose of milk and after a positive reaction or after the last dose of milk. Eleven children showed immediate positive clinical responses to cow's milk, whereas 13 infants presented only a late-type reaction. FE_NO values before or after a positive reaction (either immediate or late) were not different from FE_NO values at baseline. Baseline FE_NO in infants with a positive reaction did not differ from FE_NO in infants without a reaction at any time point. We conclude that FE_NO values are not predictive and not related to the occurrence of a positive reaction during a cow's milk challenge in infants, suggesting that a positive reaction may not result from eosinophilic activation.     

Lipoproteins in preterm and small-for-gestational-age infants during the first week of life

Plasma lipoprotein levels and composition have been determined in preterm and small-for-gestational-age (SGA) infants, and compared to full-term infants, during the first week of life. Significantly lower levels of HDL and higher levels of VLDL were found in both preterm and SGA infants in comparison to full-term healthy infants. These results suggest a low capacity to metabolize VLDL. Preterm infants showed a behaviour similar to full-term infants with regard to the changes in lipoprotein composition. Small-for-gestational-age infants showed a higher lipoprotein lipid content than preterm infants. A low ratio of cholesteryl ester to free cholesterol (CE/FC) was found in both preterm and SGA infants suggesting a reduced lecithin: cholesterol acyl transferase (LCAT) activity. In preterm infants we observed no changes in the CE/FC ratio during the first week of life, whereas in SGA infants this ratio increased after birth.     

骨定量超声技术在早产儿骨发育评价中应用和影响早产儿骨发育因素的研究

目的探讨定量超声(QUS)技术评价早产儿骨发育的作用及早产儿骨发育的影响因素。方法选取2009年2～7月本院NICU住院的早产儿为观察组,按2∶1比例随机选择同期出生的足月儿为对照组,用定量超声仪测量生后2d之内胫骨声波速度(SOS),同时检测出生24h内血钙、镁、磷和碱性磷酸酶,分析不同胎龄、体重、性别、母妊娠期高血压疾病及生化指标等因素对SOS值的影响,对有意义的因素进行多元回归分析。结果(1)胫骨SOS值早产儿低于足月儿;胎龄≤30周早产儿低于胎龄34～36周早产儿和足月儿,胎龄31～33周早产儿低于胎龄34～36周早产儿和足月儿;出生体重<1500g新生儿低于1500～2500g和>2500g的新生儿,P均<0.05;不同性别之间SOS值差异无统计学意义(P>0.05);早产适于胎龄儿低于早产小于胎龄儿,P<0.001;母妊娠期高血压疾病组早产儿高于非妊娠期高血压疾病组,P<0.05。(2)SOS值与胎龄(r=0.347,P<0.001)、母妊娠期高血压疾病(r=0.215,P=0.016)、宫内发育迟缓(r=0.367,P<0.001)、血钙(r=0.259,P=0.004)和血镁(r=0.234,...     

Endogenous nitric oxide in the upper airways of premature and term infants

Concentrations of endogenous nitric oxide (NO) were measured in premature ( n = 18) and term infants ( n = 7). Nasal gas was aspirated continuously and after timed occlusions, 15 s and 60 s, by a fast-response chemiluminescence analyser. The sampling flow rate was 20 ml min^-1. Typical NO recordings consisted of plateaux and postocclusive peaks. In term infants peak NO concentrations (60 s occlusion) were 2. 71 ± 0. 44 parts per million (ppm) within lOmin after birth, increasing ( p < 0. 05) to 3. 81 ± 0. 25 ppm at 4–7 d postnatally. Peak NO values (15 s occlusion) averaged 1. 22 ± 0. 16 ppm in premature infants (postconcep-tional age 25–37 weeks, body weight 623–2844 g) and the NO concentrations increased significantly with postconceptional age ( p < 0. 05). Nasal excretion rate, estimated from plateau NO concentrations and sampling flow rate, was 0. 10 ± 0. 01 nmol min^-1 kg^-1 in both groups. We conclude that premature and term newborn infants excrete considerable amounts of NO in the upper airways, with hitherto not fully known functions.     

Methaemoglobinaemia risk factors with inhaled nitric oxide therapy in newborn infants

Background: Inhaled nitric oxide (iNO), commonly used for hypoxic neonates, may react with haemoglobin to form methaemoglobin (MetHb). MetHb monitoring during iNO therapy has been questioned since low doses of iNO are used. Aim: To evaluate the incidence of and identify risk factors associated with elevated MetHb in neonates treated with iNO. Methods: Neonates who were treated with iNO and had at least one MetHb measurement were included. Demographic characteristics and methods of iNO administration (dosage, duration) at the time of each MetHb measurement were analysed. Results: Four hundred and fifty‐two MetHb measurements from 81 premature and 82 term and near‐term infants were analysed. MetHb was above 5% in one‐term infant, and between 2.5–5% in 16 infants. A higher maximum dose of iNO (22.7 vs 17.7 p.p.m.), but not gestational age, was a significant risk factor for elevated MetHb. Significantly higher oxygen levels (75.5% vs 51.7%) were associated with higher MetHb in term infants. Preterm infants had no risk for high MetHb when iNO was kept below 8 p.p.m. These data suggest the possibility of limiting blood withdrawal when low doses iNO are used. Conclusion: High MetHb is exceptional in neonates treated with low dose iNO. Associated risk factors are related to high iNO dose and the simultaneous use of high concentrations of oxygen.     

Nitric oxide in neonatal transposition of the great arteries

Three newborn infants with transposition of the great arteries (TGA) and intact ventricular septum (IVS) developed postnatal persistent pulmonary hypertension of the newborn (PPHN) and were successfully treated with inhaled nitric oxide (iNO). Intervention with balloon atrial septostomy (BAS) was performed in two of the infants before the iNO treatment, but they continued to be severely hypoxic with metabolic acidosis. However, the iNO immediately improved oxygenation and the clinical condition. The third neonate had a moderately large atrial communication and echocardiographic signs of PPHN. He received iNO before BAS with dramatic clinical improvement, which therefore postponed BAS.

Conclusion: Early diagnosis of PPHN and treatment with iNO may improve final outcome in neonates with TGA and IVS. In the presence of moderately large atrial communication and PPHN, treatment with iNO might be considered before BAS.     

Methodological aspects of exhaled nitric oxide measurements in infants

Guidelines for the measurement of fractional exhaled nitric oxide (FE(NO)) recommend refraining from lung function tests (LFT) and certain foods and beverages before performing FE(NO) measurements, as they may lead to transiently altered FE(NO) levels. Little is known of such factors in infants. The aim of the present study was to evaluate whether forced expiratory maneuvers, sedation, nasal contamination, and breastfeeding affect FE(NO) values in infants. FE(NO) was measured off-line during tidal breathing by means of a facemask covering nose and mouth. FE(NO) measurements were performed in 45 sedated infants (mean age 12.1 months) who underwent LFT because of airway diseases and in 83 unsedated healthy infants (mean age 4.3 months). In infants with airway diseases, no difference was found in FE(NO) values before and 5 min after LFT (n = 19 infants, p = 0.7) and FE(NO) values before sedation did not differ from FE(NO) values during sedation (n = 10 infants, p = 0.2).Oral FE(NO) values were significantly lower than mixed (nasal + oral) FE(NO) (n = 42 infants, p < 0.001). FE(NO) values before and 5 min after breastfeeding were not different (n = 11 healthy infants, p = 0.57). The short-term reproducibility in healthy infants (n = 54) was satisfactory (intraclass correlation coefficient = 0.94). We conclude that, in infants with airway diseases, LFT prior to FE(NO) measurement did not influence FE(NO) values and FE(NO) values did not change after sedation. Oral FE(NO) values were significantly lower than mixed (oral + nasal) FE(NO), and breastfeeding did not influence FE(NO). Short-term reproducibility in awake healthy infants was good.     

广州和佛山地区早产低出生体重儿出院时宫外生长迟缓发生情况调查

目的评价早产低出生体重儿出生时宫内生长受限(IUGR)和出院时宫外生长迟缓(EUGR)的发生情况。方法广州市、佛山市10家医院新生儿科出院的早产低出生体重儿(胎龄<37周,体重<2500g),分别以出生时、出院时生长发育指标在相应宫内生长速率期望值的第10百分位水平以下定义为IUGR、EUGR,分别计算各胎龄组、各体重组IUGR、EUGR发生率及总的发生率,并计算各胎龄组、各体重组EUGR发生率比IUGR发生率增加的比例。结果共595例早产低出生体重儿,出生时以体重、身长、头围为指标的IUGR发生率分别为20.2%、16.5%和24.4%,出院时以体重、身长、头围为指标的EUGR发生率分别为42.2%、28.1%和34.3%。不同出生胎龄(<31周、31～32周、33～34周、≥35周)出院时EUGR发生率较出生时IUGR发生率变化的情况:以体重为指标,EURG发生率各组分别增加36.8%、24.8%、19.1%、18.3%;以身长为指标,EUGR发生率各组分别增加26.5%、17.4%、8.2%、6.5%;以头围为指标,各组分别增加26.5%、14.0%、8.2%、3.2%,胎龄越小,增加率越高,组间比较差异有统计学意义(P<0.05)。不同出生体重(<1500g、1500～1999g、≥2000g)出院时EUGR发生率较出生时IUGR发生率变化的情况:以体重为指标,EUGR发生率分别增加45.3%、21.2%、17.4%;以身长为指标,EUGR发生率分别增加29.7%、14.8%、4.6%;以头围为指标,EUGR发生率分别增加26.6%、12.0%、4.3%,体重越低,增加率越高,组间比较差异有统计学意义(P<0.05)。结论早产低出生体重儿IUGR发生率较高,出院时EUGR发生率较IUGR发生率增高,且出院时EUGR发生率较出生时IUGR发生率的增加随出生胎龄和出生体重的降低而升高。     

Nitric oxide metabolites in the urine of full-term and preterm infants

BACKGROUND: In newborn full-term and preterm infants the urine nitrites and nitrates (NOx) were measured, in order to investigate the effects of different pathological conditions (infection, hypoxia) on systemic nitric oxide production. METHODS: Urine nitrites and nitrates were determined by means of the Griess reaction, after reduction of nitrates to nitrites with nitrate reductase. RESULTS: The NOx level was higher in preterm (278 nmol/mL) than full-term (176 nmol/mL) infants. Low NOx (115 nmol/mL) levels accompanied generalized infections, while its high contents (650 nmol/mL) was found in cytomegalovirus and one case of Pneumocystis carinii infection. Moderate increase of NOx production was observed in infants with local pulmonary infections and encephalopathies. CONCLUSIONS: The results indicate urinary NOx level is lowered in infants with life-threatening generalized infection. A possibility of a rapid test based on newborn urinary NOx level determination is considered.     

Macromolecular absorption in small-for-gestational-age infants

Using human alpha-lactalbumin as a marker protein, macromolecular absorption was studied in 40 preterm infants, appropriate for gestational age (AGA), in 12 AGA term infants and in 18 preterm infants, small for gestational age (SGA). The absorption of alpha-lactalbumin was measured as concentration in serum after a human milk feed and expressed as micrograms alpha-lactalbumin/l serum/l human milk/kg body weight on day 7, 14, 21 and 42 after delivery. The serum concentration of alpha-lactalbumin was correlated negatively with maturity and postnatal age. In the SGA infants, the concentration of alpha-lactalbumin was significantly higher than in the AGA infants of similar gestational age. The data show that intrauterine growth retardation causes a delayed postnatal decrease in macromolecular absorption. This may indicate delayed intestinal maturation.